Tootsie Roll free essay sample

My hypothesis was that it will take 30-45 chews to eat a tootsie roll/frootie. My hypothesis was somewhat supported by my data that I have from lab experiment. Independent Variable: The independent variable is the type/flavor of the tootsie roll/frootie which we are eating in our lab experiment, because they represent the inputs or causes, or are tested to see if they are the cause. Dependent Variable: The dependent variable is how many chews it takes to eat a tootsie roll/frootie because it represents the output or effect, or is tested to see if it is the effect. Constant: We did not use any safety equipment in this lab, but you could’ve used safety goggles, gloves, and possibly an apron. Procedure: The first step to do this lab you need to get all of the supplies, which are listed under â€Å"Materials Used†. Then you need to make a hypothesis about anything that has to do with the main question, that which we gave you. We will write a custom essay sample on Tootsie Roll or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Then you need to make a data table that includes all of the types of tootsie rolls/frooties, and how many chews it took to chew each one (you can see mine under â€Å"Data Table†). After this you need to pick one person to eat ALL of the tootsie rolls/ frooties. This person, that you chose to chew you tootsie rolls/frooties, will unwrap one and put it in their mouth and start chewing. The person chewing will count how many times they chew the tootsie roll/frootie that they have in their mouth. The person you picked will then repeat everything to each of the eight of the tootsie rolls/frooties, and after each one you need to record how many chews it took to eat it. Data Table: Questions: #1. How could you make you results more accurate? I can make my results more accurate by making sure the person chewing is chewing on the same side of the mouth. Another thing you can do is have everybody count how many times the person chews and how fast each time and the pace you eat the tootsie roll/frootie. #2. How well did you group work together? (explain) Our group worked really well together. We picked one person to chew the tootsie rolls/frooties with no complaining from anybody else, and we all agreed on the same person. #3. What would you do differently next time? The only thing I would change would be that there would tootsie rolls/frooties for everybody so that everybody didn’t have to watch one person eat all of them.

Why the Crucible is a Tragic Comedy Essays

Why the Crucible is a Tragic Comedy Essays Why the Crucible is a Tragic Comedy Essay Why the Crucible is a Tragic Comedy Essay Essay Topic: Clueless The Crucible Why The Crucible is A Tragic Comedy Have you ever been dancing in the woods naked, while a colored foreign lady sings songs with only made up words that start and end with the letter B? If so, you are to be hanged for witch craft with no question. They were so clueless about having a problem in their town that it went way too far and they didnt really think things through all the way. People would Just run around telling the authorities that so and so is a witch. They would be taken away and hanged for no reason. There was no proof about them being witches or nobody went into further investigation. Lets take a minute and really think about how the catastrophe in Salem really started. A group of young girls blind to what they are doing by dancing around a big pot and Just so happens to get naked. No big deal right? People who hung there had no proof saying they practiced witch craft. There was really no proof what the girls had done that night or what they were doing. The men in charge were really quick to jump to conclusions. With no trial of any investigation of any sort they Just had their mind set on that they were witches. Citizens accused of witch craft by anyone else basically had no chance at all ecause, there never really would be a trial for them. The person accusing the other person of being a witch could be easily making it all up. They never asked the witness for proof of what they supposedly saw. It was always the good people that were punished and the people that actually practiced witch craft were the ones lying saying they witnessed the good people practicing witch craft. The young ladies that started the whole Salem witch trials lied, and they started to show it when few of the girls started to tell the reverends the truth, but were influenced back into the lie by the other girls again. Another reason that says the young girls were lying is they blamed the witch craft on people that hurt them, or has the man they like. Also shown they were lying when some of them took all of their parents money and ran away on a boat in the middle of the night. The conclusion of my point of view is that this whole thing was way blown out of proportion by the reverends and men in charge. People were so scared of the fact that the idea of people practicing witchcraft is in their town. Including the higher up men position were being questioned so they had to show to the public they had it under control by anging innocent accused people. These poor innocent people were lucky to be given two options: admit to practicing witch craft and be free but hung with that reputation, or die for not admitting to it. In these times people literally lived by the bible and they strongly believed that if they lied they were going to hell, so these people were not going to admit and lie so they swallowed their pride and died for no reason at all. With that being said this story sounds like a tragic comedy to me. Why the Crucible is a Tragic Comedy By warpony2730

The Why, Where, and How of Writing for the Christian Market

The Why, Where, and How of Writing for the Christian Market Writing for Christian markets may not be at the top of your write-for list. I grew up in church, so it seemed a natural place for me to begin my writing career. I was already familiar with publications and what types of stories and articles they used. As with any freelance market, you want payment for your effort, so all the publications listed here do pay, and most I have written for many times over the years, selling fillers, devotionals, articles, and stories. A serious freelancer is always on the lookout for new markets. Many Christian publications, especially Sunday school take home papers, publish weekly so the number of manuscripts they need is greater than a traditional monthly magazine. They accept a variety of pieces; fillers, fiction, nonfiction, poetry, and devotionals. The age range is diverse. There are publications for the smallest of children up to adults. Our Little Friend is for children from ages 1-5. They seek true-to-life stories one or two pages long. One story I wrote for them was about kids making fun of each other. Mature Living is for those facing retirement. Many older people feel as if they are used up. I offered encouragement and gave examples of things anyone could do to help others in a list article. Devo’Zine is a devotional market geared toward teens that Ive written for using lessons from teaching young people at church. Youth leaders are always looking for great activity ideas to use with their kids, and Insight Youth Resources has paid me for ideas our youth group did. ParentLife is a magazine that has published multiple funny saying from my kids as fillers. Do you work with women in the church? Today’s Christian Woman  needs articles that offer strength and encouragement for everyday women. Need more market ideas? An invaluable tool for finding these markets is the Christian Writer’s Market.   You can also ask friends for help. Do they attend a church that hands out take-home papers? Do they subscribe to Christian magazines? Ask to borrow copies and research to see if those publications accept freelance work. You could also Google â€Å"Christian magazines,† â€Å"Christian publications,† or â€Å"Christian writers wanted.† I have found some regular writing employment doing this. When considering topic ideas, note that many of the publications follow a theme list. Lookout and Youth Worker both do. Theme lists give basic ideas of what the editors want during certain times of the year. Once you repeatedly write for these publications, many will come to you with an urgent need, when something on their theme list hasn’t been fulfilled, and they know you are dependable. Some Christian publications just want to hear your story. I have used many of my own experiences, especially when it came to the teenage years, mine and my children’s (Guide). Guide wants true stories, and many of my teens experiences ended up on their pages. And keep in mind that not all Christian publications are overtly religious. Some of the children’s publications simply want stories with a moral lesson. But be aware of the diversity amongst denominations and their beliefs. For example, some conservative publications want women to wear dresses, if clothing happens to be mentioned in your story. Some denominations worship on the Sabbath, which is actually Saturday, not Sunday. Others won’t include anything about drinking. Here is a site with helpful information on denominations. Don’t underestimate the power of the Christian market for your writing. You can stretch yourself, get some new

Student Survival Guide Essay Example | Topics and Well Written Essays - 1000 words

Student Survival Guide - Essay Example As a result, a student must learn how to manage and find information with little time and energy spent on the search and which produces a maximum return on their efforts. To use a simple word picture, in the classroom, the information is a pool, or a small lake from which to draw. In the workplace, the river of information is always moving, and attempts to put up a dam in order to measure and quantify the amounts of water simply will not be successful. A student must learn to paddle the boat, and gather information from the moving stream all at the same time. While internet searches have become less arcane over the past few years, a student cannot expect to find everything he or she needs from a Google.com search or a stop at Wikipedeia.com. A student should find and subscribe to a few favorite online libraries and databases which will provide depth of information. Two of my favorite online libraries are www.questia.com and www.highbeam.com. These online libraries contain scholarly journals, complete book transcripts as well as newspapers and magazine articles. These web sites can often provide all the background and research materials for the successful internet enabled student. Unfortunately, with the availability of electronic versions of data, the temptation to copy and paste information, and thereby plagiarize another's work is strong. The mass amounts of data which are available, and the time crunch under which today's students must produce results create the perfect envelope in which to commit intellectual robbery, and pull someone else's ideas. In order to maintain intellectual honesty, and uphold academic standards of integrity, the student should take this mantra as his own personal guide. "If the idea is not mine, I should cite the source." By applying this standard, the student can steer his boat around the whirlpools, rocks and rapids which will quickly capsize his boat should he begin to copy others work and call it his own. Material which comes from another's published works, whether taken in summary, or repeated word for word - if the material contains an idea from another person's published work, it must be cited as such. Developing Effective Study Skills Effective study skills in the online learning environment are somewhat different from those which a student needs in the traditional classroom. In the traditional classroom, many elements co-exist as part of the learning process. These elements go beyond simply inhaling information and exhaling assignments and tests. In the traditional classroom, a learning community already exists. The learners are able to draw encouragement, inspiration, and fellowship from one another. In the traditional classroom, one person can set the pace somewhat unconsciously, a level to which other students are drawn toward as they set their own goals. In the online learning environment, the students are individualized and compartmentalized. The online community still can, and must exist in order to create an effective learning environment. However, the students must seek out that community, and become a part of electronic tools such as chat rooms, group discussions, and list serve email digests in order to form the e-learning community. If the student only reads lessons and turns in assignments, he or she will be missing

Body Language Essay Example | Topics and Well Written Essays - 500 words

Body Language - Essay Example Depending on the type of body language incorporated a certain image of you is placed on those around you especially people you have been used to like co-workers, for example, wearing a smiling face in front of co-workers communicates that something good has happened to you and you are about to share a joyous story, while a cruel face will send an opposite signal. However your personality or character as known to the co workers will add a lot to your sign language ,a person who is always a joker might be mistaken since some times seriousness in his face accompanied by a serious comment can be outdone by the previous jokes to the audience. Moreover, the occupation is a very critical consideration in determining the effect of a sign language. For instance, a nurse might say that a patient is recovering verbally but post a sign to his colleague that patient is worsening (Kennedy, 2009). To a patient, body language sends the most effective message and thus one has to be very careful when handling them. While encouraging a patient its important to avoid putting on a worried face since this might make him think that he is worse off. Due to the fact that misinterpretation of body language might affect a patient psychologically, a speaker should avoid any ambiguous sign. While answering questions it’s important to always take time and avoid any emotional reaction that could send a different signal. Understanding their body language helps also effect your communication. In any situation where the patient provides a message verbally that strongly contradicts the body movements mostly the facial expression, its advisable that one should base his response mostly on the body sign. This helps the patient feel cared for and apart from comforting him it would help him open up for better treatment. More than fifty percent of messages in any conversation are sending verbally and thus several signs have

Barrack Obama’s Campaign Speech Essay Example for Free

Barrack Obama’s Campaign Speech Essay Communication can be defined as the act/art of exchanging/transmission of thoughts or information by the means of speech, signs, written means and the behavior. It was the occasion of the America’s Presidential candidates Campaign when the Illinois Senator Barrack Hussein Obama delivered the speech announcing his will of seeking the democratic nomination for presidency in 2008. It was on Saturday evening (19. 06GMT) of February 10th 2007 on the Venue of Springfield, when the Senator Barrack Obama now the Elect president of United States of America delivered the persuasive speech used on this focus paper. In this Speech it excellently exploits the elements of speech. First, The candidate Senator Obama by that time was very prepared for the occasion against the deliverance of the amazing speech towards the audience. His introduction of the speech appreciates all the audience present and recognizes their vital role they do play for that occasion. For instances He starts by thanking all the people for their coming and gives the reasons why the occasion was very important to every individual. His introduction captures the attention of the audience giving time to deliver his message. Part of introduction was â€Å"†¦it’s humbling but in my heart I know you didn’t come here just for me, you came here because you believe in what this country can be. † Secondly there is use ‘of being yourself ’ while giving the speech. The Senator gives personal and professional examples and life history precisely, possibly helping him to gain support to emphasize his own points of the campaign. The self-example messages matches with the destined purposes of the Campaign. Thirdly, Obama stayed relaxed throughout the speech delivery session, very composed and maximal prepared for the outcome. He remained focused on passing the message. He too employed other means of speech presentation such as movement/ walking, gestures. In addition, the Senator used the Natural humor and avoided depicting/ pinpointing an individual from the Audience and he didn’t over do it thus maintaining the audience on move of the speech. The other element that I figure was the Body plans and hand positions. I keenly observed the movement and gestures of the Senator. He moved within the three positions – the right, the center and the left- and the hand position was well managed and maintained throughout the session. He didn’t hide behind the lectern and he excellently maintained the eye contact with the audience throughout the speech session. Lastly of the elements of speech, the Senator was very keen and well informed about every detailed he presented. He used the environmental reference that surrounded the Venue appropriately on his speech. He understands what is the past, currently and the future happening of the immediate ground. He keenly observes the audience to an extent of identifying some schoolmates but he didn’t mention their names. â€Å"†¦friends that I see in the audience. †. Speech Accomplishment: The speech is accomplishing the real mission of the Senator while being elected as the president of United States of America. He explains out what he will accomplish for the country when he will be in power. He gives new hope the people of America; to believe that ‘yes he can’ bring peace where there is war, bring hope where there is despair, reach what is more possible and build a more perfect union. The Senator aspires to establish convergence place where the farmers, teachers, students, businessmen, laborers, young and the aged, male and female, rich and the poor’s clamoring can be heard. The speech intends to accomplish the enlightenment of the US people the existence of presumptuousness in the present government calling for the change, in the faces of the depressed he will increase the employment opportunities in order to lift the millions out of poverty, Welcome the immigrants to the shores of America and experience justice and righteousness around the globe. The Senator contemplates the currently status of the US and around the globe and promises to accomplish missions such as to quench the anxiety of the feel of rising health care costs and the illusions of the stagnant wages, to bring the war in Iraq to an end by bringing the troops back home by march next year and give Sunni and Shia to resolve the problem and bring out peace, minimize oil dependency that is threatening America’s future, instill an ethic achievements in children by setting high standards of learning providing the resources for them to succeed, recruiting the new army of teachers and giving them the batter pay and more support for the exchange of accountability, making colleges affordable and investing in the scientific researches, to reshape the economy, strengthen the communities, to cut bureaucracy by use of technology, free America from the Tyranny Oil, solve the crisis of global warming by innovation and by capping the greenhouse gases, give incentives for the businesses, and destroying the deadliest unguarded weapons. The Speech was a persuasive, since it is persuading the people of America to elect the Senator as the President of America by voting for him in the year 2008. It was evidenced in his speech as persuasive where he says â€Å" †¦If you will join me in this improbable quest, if you feel destiny calling, and see as I see, a future of endless possibility stretching before us, if you sense as I sense, that the time is now to shake of our slumber, and slough off our fear, and make good on the debt we owe the past and the future generations, then I am ready to take up the cause, and match with you and work with you to finish the work that needs to be done. † The main aim of the speech was to persuade for votes that resulted to the delivery of the speech. But on the process he enlightens the people the critically analyze and keenly make judgment for the best next US president. I can also say it is informative to some extent that it elaborates the incidences that have been taking place and the others that are likely to take place in the United States of America. Audience’s reaction towards the speech was very applauding during the speech presentation and indeed the audience was very pleased with the amazing speech, contented that Obama can make out to be the best candidate to be elected and very disappointed with the previous disguised government. The speech disclosed the factual facts to the audience, which was the quenching of the long thirst, the beginning of the new hope and the change on which the Americans can believe in. At some points the multitude nodded their heads as a sign of concession/ agreement to what was spoken, and at some point the audience was pity as a sign of how sympathetic and pathetic the situation was in as per that time. The pattern of speech was sequential, topical and spatial. The speech was sequential since it has the introduction, the body and the conclusion as the structure of the speech. Obama welcoming the audience, he presents his speech (The body) where he factually speaks of what he should do when he will be in power, he identifies what to change and or improve, what to innovate and implement, what changes he is able to bring, what was the defects the previous government, and finally he give out his conclusion of expecting the people of America to vote for him if they want the change they can believe in. The speech was also topical since Obama Generally emphasizes on the Change that that Americans can Believe in. He bases his own speech on change and frequently mentions change throughout his speech. Despite of having other minor topics such as speaking about education, the economy, war, resources and the political history his main topic was about change. To some extent but not very, the speech was descriptive. It entails what to be done, how, when and by whom. Obama described in his speech for instance that the only source for change in America is people, the only peace in war at Iraq lies between Sunn and Shia, the only way to prosper in future is by doing the present that needs to be done. Also Obama gave the vivid description on how to solve some of the long-lasting problems in America. For instance the problem of global warming can be solved by innovations that can tap the greenhouse gases, creating more job opportunities, investments can solve the problem of poverty, practice of justice and establishment of converges to listen the clamoring of each and every one in the US. In conclusion, Communication is the transmission of information from one person to another. The occasion of the speech was during the campaign of the Presidential candidate of America on Democratic Party at Springfield. The utilized elements of speech were such as being prepared for the speech presentation, being yourself when representing speech, being composed and contented when delivering speech, body plan and hands position, gestures and movements. Accomplishment of the speech was to convince the audience to vote for Him/ Change. The type of speech was persuasive as he persuades for the votes, the reactions of the audience was a sign of relieve or being relieved if Obama was to be the president and indeed he became. Finally the pattern of the speech is Sequential, topical and somehow spatial. References: 1. Public Speaking an Audience-Centered Approach By Steven A. Beebe and Susan J. Beebe. (2008) 2. http://www. guardian. co. uk/world/2007/feb/10/barackobama. 3. http://www. ljlseminars. com/elements. htm. 4. Organization Pattern Of Speech By Osborn (2000).

Wembley Stadium pricing study Essay -- essays research papers

Ticket Pricing Strategy for the new Wembley Stadium 1  Ã‚  Ã‚  Ã‚  Ã‚  Introduction OBJECTIVE  Ã‚  Ã‚  Ã‚  Ã‚  To maximise profits from ticket sales at Wembley Stadium KEY ASSUMPTIONS  Ã‚  Ã‚  Ã‚  Ã‚  1. Wembley has a monopoly on certain types of match 2. Wembley is run by profit maximising managers selling tickets to utility maximising buyers STRATEGY  Ã‚  Ã‚  Ã‚  Ã‚  Set prices for seats as close to the willingness to pay as possible using price discrimination KEY CHOICES  Ã‚  Ã‚  Ã‚  Ã‚  What type of seating to sell and at what price? 2  Ã‚  Ã‚  Ã‚  Ã‚  Scope This strategy is limited to the following football matches: †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  England home matches – competitive and friendly †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Major cup semi-finals and final †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Lower league play-off finals Wembley has a monopoly on these matches due to Football Association (FA) policy2. Theory states that Wembley should charge as close to the willingness to pay of its customers as possible to maximise its profits1. The ability to do this depends on demand and the ability to price discriminate between market segments. 3  Ã‚  Ã‚  Ã‚  Ã‚  Absolute Demand Absolute demand for tickets will be high due to several factors: †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Football is England’s national sport †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Watching live matches is popular †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Wembley Stadium is the ‘home of football’ with a long and distinguished history There is good evidence for assuming high demand: †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  The last three competitive England home games were sold-out2 †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Attendance figures for club matches are consistently high3 †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Recent cup finals at Cardiff Millennium Stadium were sold-out4 Actual demand varies between market segments but can be found from market research, e.g. membership schemes and studying events at similar grounds. 4  Ã‚  Ã‚  Ã‚  Ã‚  Market Segmentation The table below shows the range of customers that buy tickets for football matches. Elasticity of demand is shown for each category and explained below: Market Segments   Ã‚  Ã‚  Ã‚  Ã‚  Elasticity of Demand  Ã‚  Ã‚  Ã‚  Ã‚  Reason for Elasticity 1  Ã‚  &nbs... ...y for rugby union and league †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Pop concerts – outdoor arenas are alternatives with similar capacity There are a wide range of substitutes available for these that affect willingness to pay. 11  Ã‚  Ã‚  Ã‚  Ã‚  Other Event-Related Income Stadiums contain much more than just an arena to watch sport including: †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Refreshments and merchandise †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Broadcasting rights †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Advertising †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Car parking †¢Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Other events, e.g. conferences Income for the above would be approximately proportional to the number of people in the stadium. 12  Ã‚  Ã‚  Ã‚  Ã‚  References 1.  Ã‚  Ã‚  Ã‚  Ã‚  Cabral, Luis. â€Å"Introduction to Industrial Organization†, MIT Press, 2000. 2.  Ã‚  Ã‚  Ã‚  Ã‚  www.thefa.com 3.  Ã‚  Ã‚  Ã‚  Ã‚  http://stats.football.co.uk/dom/ENG/PR/attend.html 4.  Ã‚  Ã‚  Ã‚  Ã‚  http://stats.football.co.uk/dom/ENG/trn/ENGFAC_F.html#F 5.  Ã‚  Ã‚  Ã‚  Ã‚  www.wembleystadium.com 6.  Ã‚  Ã‚  Ã‚  Ã‚  www.millenniumstadium.com

Optic Radiation In Optic Neuritis Health And Social Care Essay

ABSTRACT. Optic neuritis ( ON ) is defined as an redness of the ocular nervus and provides a utile theoretical account for analyzing the effects of inflammatory demyelination of white affair. The purpose of this survey was to measure the diffusion changes both of the ocular nervus and ocular radiation in patients with acute and chronic ON utilizing diffusion tensor MR imagination ( DT-MRI ) . Thirty-three patients with idiopathic demyelinating ocular neuritis ( IDON ) and 33 gender- and age-matched healthy controls were examined with DT-MRI, T1- and T2-weighted MRI. Compared with controls, both first episode and recurrent patients with IDON in the ague phase showed significantly increased radial diffusivity ( I »aS? ) and decreased average fractional anisotropy ( FA ) in the affected nervousnesss. Reduced FA, increased I »aS? , average diffusivity ( MD ) and axial diffusivity ( I »a ) were determined in patients with subacute IDON. We found no important difference in the direct ional diffusivity of ocular radiation in patients whose disease had lasted less than one twelvemonth compared with healthy controls. However, important alterations of FA and I »aS? of the ocular radiation were detected in patients with disease continuance more than one twelvemonth. These consequences show the great potency and capacity of DT-MRI steps as really utile biomarkers and indexs for the rating of myelin hurt in the ocular tract. Ocular nervus sheath dilation can be detected utilizing conventional T2-weighted MRI as has been reported by Hickman et Al. [ 2-3 ] . These two surveies assessed the effects of a individual inflammatory procedure and its attach toing demyelination in a cohort of patients during their first episode of acute one-sided ON, and reported a consistent form of alterations associated with demyelination lesions caused by redness in the ocular nervus. It is of great clinical importance to find prodromic alterations and the implicit in pathological mechanisms in patients with ON. However, since the hyperintensity can be a consequence of either redness, gliosis or axonal devolution, T2-weighted images fail to place the cause underlying the pathology. Diffusion tensor MR imagination ( DT-MRI ) , a widely recognized imagination technique that identifies the dominant way of H2O diffusion and the magnitude of anisotropy in vivo [ 4 ] has late gained more prominence for the probe of white affair cons truction, unity and connectivity. The demyelination harm in the ocular nervus and ocular radiation can be located with the aid of DT-MRI parametric quantities, such as average diffusivity ( MD ) and fractional anisotropy ( FA ) , axial diffusivity I »a and radial diffusivity I »aS? [ 5-6 ] . Postmortem scrutiny of MS patients suggests that the pathological mechanisms of ON may include a combination of redness, demyelination, astrocytosis and axonal devastation [ 7 ] . Surveies in mouse ocular nervus after retinal ischaemia have revealed elusive alterations of axons and medulla in the white affair and found I »a and I »aS? values to be associated with axonal pathological alterations [ 8-9 ] . These consequences suggest DTI to be superior compared to other conventional imaging techniques for the intent of researching the pathological mechanisms of ON. Particular challenges associated with DT-MRI of the ocular nervus are the little diameter and the nomadic constructions surrounded by CSF and orbital fat [ 10-11 ] . In visible radiation of this, and despite utilizing different sequences and protocols, it is rather singular that several different groups have reported similar values in healthy controls ( MD 1.0-1.3A-10-3 mm2/s and FA 0.4-0.6 ) and altered diffusion paramet ric quantities in chronic ON patients [ 12-13 ] . The different developmental phases of ON seem to be associated with different pathological mechanisms. The acute phase is characterized by redness and perchance demyelination of the ocular nervus. The chronic phase, on the other manus, typically shows axonal harm, perchance even axonal decease taking to wasting of the ocular nervus [ 14-16 ] . Increased MD and decreased FA were observed in a heterogenous cohort of patients with chronic ON [ 17 ] ; increased evident diffusion coefficient ( ADC ) values were found particularly in chronic patients [ 18-19 ] . A survey closely related to our work showed axial diffusivity I »a in the acute phase to supply of import predictive information and the radial diffusivity I »aS? in the subacute phase to stand for the best step correlated with the visus [ 20 ] . A recent survey proved tractography to be a method sensitive plenty to observe pathological abnormalcies in the ocular radiations after ON [ 21 ] . Understanding the connexion between altered diffusion parametric quantities of the ocular nervus, ocular radiation and ocular public presentation will supply insight into the implicit in pathological mechanisms and may be valuable for being able to foretell the ocular development after ON. The old surveies mentioned above, have shown different pathological mechanisms during the different phases of ON and we were interested to corroborate these findings by DT-MRI, a novel and sensitive methodological attack. We hypothesized that the pathological alterations happening during the unwellness might impact the diffusion indices otherwise and that we therefore might happen differing diffusion values in the ague and subacute phases of ON based on the concluding clinical diagnosing. Materials and methods Subjects Thirty-three patients who fulfilled the clinical standards set by the Optic Neuritis Study Group [ 22, 23 ] were recruited from May 2008 to December 2008 at the Beijing Tongren Hospital. The patient group consisted of 12 males and 21 females from 10 to 58 old ages ( average 31.1A ±12.8 old ages ) . The demographic informations assessed during the MRI survey is included in Table 1. Thirty-three gender- and age-matched healthy controls ( 12 male and 21 female, average ages 29.21A ±12.09 old ages ( run 10-60 old ages ) ) with normal neurological scrutiny and no history of neurological upsets served as control topics. Table 1. Demographic and clinical features of patients with IDON Characteristic No of patients Gender Male 12 Female 21 Age ( old ages ) Median 31.1 Range 10-58 Phase of disease ( casesi?†° Acute 33 First 26 Backsliding 7 Subacute 18 First 6 Backsliding 12 In this paper we will further mention to the single eyes of the topics as instances, wholly the survey included 51 instances in the patient group. In 33 instances with acute IDON we managed to obtain the MRI informations within 30 yearss of the oncoming of symptoms. Twenty-six of these instances were first manifestations of the acute signifier of ON, the other 7 were perennial instances. We defined the ON to be acute if a patient experience an episode of ON within 30 yearss from the oncoming of ocular symptoms [ 20, 22, 24 ] . In 18 instances with subacute IDON, the MRI-data was acquired more than 30 yearss after the eruption of the unwellness. Six instances were first episodes and 12 the consequence of a recurrent episodes. At the same clip, we selected 9 topics whose disease had lasted longer than 1 twelvemonth and 14 topics less than 1 twelvemonth to look into the secondary effects to OR. The survey was approved by the moralss commission of the Beijing Tongren Hospital and a written informed consent was obtained from each topic harmonizing to the Declaration of Helsinki. Data acquisition All measurings were performed on a 1.5-T Signa MRI system ( General Electric, Milwaukee, WI, USA ) . Head gesture was minimized by keeping foam tablets provided by the maker. Subjects were asked to shut their eyes in order to minimise any effects of deliberate oculus motion during the acquisition clip. Each topic was scanned utilizing a high declaration T2-weighted ( fluid-attenuated inversion recovery sequences ) FLAIR sequence ( TR=9000ms, TE=120ms, TI=2125ms, field of position ( FOV ) =24A-21cm2, matrix size 256A-222, 32 pieces, 4.0 millimeter piece thickness with 0.8-mm interslice spread ) in order to observe any encephalon abnormalcies. At the clip of the ocular neuritis, the patients had no important image impairment or other marks of neurologic lesions in the ocular radiation. The images of the ocular nervousnesss were obtained with an 8-channel caput spiral utilizing coronal-oblique spin-echo EPI sequence with parallel acquisition. The coronal-oblique pieces were set extraneous to the nervousnesss ( See Fig.1 ) . The covering scope was from the ocular papilla to the orbital vertex of the ocular nervus. We used the undermentioned acquisition parametric quantities for the ocular nervus: one b0 and 6 non-collinear gradient waies with b=600s/mm2, FOV= 22A-22 cm2, matrix size 128A-128, NEX= 16, 8 immediate 5.0 millimeter pieces. By concentrating entirely on the ocular nervus, the signal-noise-ratio ( SNR ) of images was set at 35-40. The diffusion acquisition parametric quantities of the ocular radiation were the undermentioned: one b0 and 15 non-collinear waies with b=1000 s/mm2, TR=6000ms, TI=71ms, FOV = 24A-24cm2, matrix size 128A-128, NEX=6, 22 immediate 4.0 millimeter pieces. In add-on a whole-brain 3D T1 SPGR sequence ( TR=10ms, TE=4.4ms, TI=600ms, FOV=2 6A-26cm2, matrix size=256A-256, NEX=1, 152 immediate 1.0-mm pieces ) was used as a beginning image for the subsequent co-registration of the ocular radiation. Figure 1. Position of the pieces viewed on an axial localizer position of the ocular nervus. There are 8 pieces from the anterior portion ( next to the ocular papilla ) to the posterior portion ( near the orbital vertex ) of the ocular nervus. Datas processing The first measure was to formalize the quality of the natural images. The images with deficient quality were rescanned until they met the SNR standards set for the analysis. Then eddy current deformations and gesture artefacts in the DT-MRI informations were corrected by using affine alliance, utilizing FMRIBs diffusion tool chest ( FSL, Oxford, UK. ) [ 25-26 ] . In order to be able to compare diffusion belongingss in patients and controls, a method to place matching anatomical parts was required. The first necessary measure was to happen a consistent spacial standardization for the two separate groups. Due to the different protocols for ocular nervus and ocular radiation we present two different methods for the processing of the several MRI-data, and depict these methods in the undermentioned subdivisions. Ocular nervus fibre Image enrollment The maps of MD, FA and eigenvector were calculated on a voxel-by-voxel footing, followed by a diagonalization of the reconstructed tensor matrix in order to obtain characteristic root of a square matrixs ( I »1, I »2, I »3 ) and eigenvectors utilizing DTIStudio ( MRI Studio Software, Johns Hopkins University, USA ) . To be able to rectify for planetary morphological differences a expansive mean b0 informations set was created from all topics. This mean image was so used as a mention relation to which each topic was positioned ( single b0 to template b0 ) with a 12-parameter affine theoretical account. The same transmutation parametric quantities were so used to co-register the MD and FA images to the templet b0. Regions of involvement ( ROI ) choice The intraorbital 4th bed of the nervus ( about 2.0cm after the ball ) was used for the undermentioned analysis ( See Fig.2 ) . The ROIs were defined manually on the b0-template ( mean non-diffusion-weighted ) dwelling of two square 2A-2 voxels ( Fig.2A ) . To avoid prejudice caused by the partial volume consequence, the ROIs were placed in the centre of the nervus. After averaging the images across the population, the b0-images contained significantly less noise than in single images. The associated color-coded maps were used for optimum ROI arrangement ( Fig.2B ) and to vouch objectiveness the process was performed by an experient radiotherapist blinded to the individuality of the topic. The ROIs of single instances were mapped from the templet b0 utilizing an reverse transmutation. These ROIs were so overlaid to the MD, FA and eigenvalue maps, where average values from the 4 voxels were obtained ( Fig.2C-D ) . Figure 2. ROI choice in the 3rd piece of the ON. ( A ) Non-diffusion-weighted b0 image, ( B ) Color-map, ( C ) FA map, and ( D ) MD map. The pointer is indicating to the ocular nervus. The ROIs were placed on the b0-averaged images and so transferred onto the FA and MD maps. Ocular radiation fibre All piece of lands in the informations were reconstructed utilizing a fiber assignment uninterrupted tracking algorithm [ 6 ] . In order to minimise the anatomical encephalon variableness between topics, a group-based Atlas model was introduced building a population specific templet. We applied the joint analysis model for group-based co-registration uniting structural and diffusion tensor MRI similar to Tao et Al. [ 27 ] , but utilized the Diffeomorphic Anatomical Registration utilizing Exponentiated Lie algebra ( DARTEL ) enrollment method [ 28 ] . As a high-dimensional diffeomorphic enrollment method, this novel technique utilizes the big distortion model parameterized by speed vector Fieldss to continue topology. The amount of square differences between the beginning and mark images are minimized at the same time to the enrollment, and the additive elastic energy of the distortions are used to falsify the mark image, which can better the realignment public presentation of little interior constructions [ 29-30 ] . Combined DTI and structural analysis grapevine Group templet maps were created utilizing statistical parametric function ( SPM8, Wellcome Department of Cognitive Neurology, Institute of Neurology, London, UK ) to find the normal inter-subject variableness of white affair tracts. We built a structural Atlas from all topics T1 images with the DARTEL tool chest. After this measure the b0 -volume of each DT-MRI information set was registered to the associated T1 image utilizing a 12-parameter affine transmutation. The corrected diffusion images of each topic were algebraically transformed to compose a structural Atlas infinite, enabling anatomical designation and comparing of the ocular radiation in the aforesaid atlas infinite. An overview of the process observing differences between the diffusion belongingss of fibre piece of lands is shown in Fig.3. Figure 3. Ocular radiation analysis grapevine jointly utilizing structural and diffusion images. Regions of involvement ( ROI ) choice After the atlas building process, we used a multiple ROI attack to work the fibre piece of land. The get downing ROI was manually placed in the sidelong geniculate organic structure on a reconstructed axial image with an AND operation. It was designed to include the ocular radiation of each side and the full environing white affair. For each piece of land, a 2nd spherical ROI with 4mm radius was placed in the occipital lobe near the midplane with an AND operation. Reconstructed fibres perforating both ROIs were considered representative of the ocular radiation ( See Fig.4 ) . These two ROIs were so overlaid on the FA maps and transferred to other directional diffusivity maps. Diffusivity in all spacial waies was obtained from every voxel along the path of the ocular radiation. Figure 4. DTI fiber tracking and extraction of ocular radiation. DTI fibre paths ( green ) were launched from a get downing part of involvement ( white box ) in a plane buttocks to the sidelong geniculate karyon. Fiber paths were filtered with a 2nd part of involvement ( two balls ) in a plane adjacent to the ocular cerebral mantle. Statistical analysis All statistical analyses were performed utilizing SPSS v13.0 ( SPSS Inc. , USA ) . In a first measure, ipsilateral differences between patients and controls were explored utilizing a mated t-test. To avoid the prejudice originating from the categorization of the bilateral involved nervousnesss of one patient being the same ON phase into the same group, we applied Generalized Estimating Equation ( GEE ) . This method, introduced by Zeger et Al. [ 31 ] , extends generalised additive theoretical accounts to suit correlated informations from topics with similar features. Consequences Directional diffusivity of ocular nervus Acute accent ON The survey consisted of 33 acute-stage instances: 26 first manifestations and 7 recurrent instances. Significant differences within the ROIs comparing the two subgroups of patients and their controls were detected in all DT-MRI measurings ( paired t trial, see Table 2, besides see Fig.5 ) . The average FA was significantly reduced ; the mean MD and I »aS? were increased in the acute-stage IDON instances compared to healthy controls. In patients with first manifestation, significantly decreased I »a values were detected ( t = 2.10, P = 0.046 ) . And increased I »a were found in recurrent patients compared to controls ( t = 0.84, P = 0.434 ) with no important difference. Since there were merely 7 instances with a perennial disease history, we decided to measure merely the first manifestation group and matched healthy group in Table 3 utilizing GEE. This survey proved the average FA from ON patients to be significantly lower compared to healthy controls ( omega = 61.053, P & lt ; 0.001 ) . Compared to healthy controls, we found drastically elevated I »aS? ( z = 19.181, P & lt ; 0.001 ) in the patients and somewhat decreased I »a , but the latter did non make statistical significance ( z = 3.414, P = 0.065 ) . ( A ) ( B ) ( C ) ( D ) Figure 5. Quantitative analysis of DT-MRI indices in ON. Relative alterations of the ( A ) FA, ( B ) MD, ( C ) I »a , ( D ) I »aS? in each ocular nervus from controls and the instances of first oncoming during acute phase ( expressed as mean A ± standard divergence ) . Paired t trial demonstrated that MD and I »aS? were significantly elevated and FA was notably reduced in affected nervousnesss. Table 2. Diffusion parametric quantities from the instances during acute stage of IDON ( first and perennial oncoming ) Indexs Acute Controls t-value p-value FA foremost 0.39A ± 0.08 0.59A ± 0.09 8.40 0.000 recurrent 0.33A ± 0.05 0.64A ± 0.11 7.46 0.000 MD foremost 1.50A ± 0.20 1.40A ± 0.30 2.22 0.036 recurrent 1.80A ± 0.28 1.20A ± 0.36 3.54 0.012 I »a foremost 2.18A ± 0.31 2.39A ± 0.45 2.10 0.046 recurrent 2.50A ± 0.31 2.27A ± 0.64 0.84 0.434 I »aS? foremost 1.10A ± 0.20 0.80A ± 0.27 5.40 0.000 recurrent 1.50A ± 0.28 0.70A ± 0.28 5.45 0.002 Thirty-three instances with IDON were of acute phase ( the continuance of the disease from scrutiny to last onset twenty-four hours was less than one month ) , of which 26 instances in 19 topics were foremost affected and seven instances in 7 topics suffered from recurrent episodes. Axial, radial, and average diffusivities ( I »a , I »aS? , MD ) are given in A µm2/ms. Fractional anisotropy is without units. All values of DTI indices are given as the mean A ± criterion divergence. IDON=idiopathic ocular neuritis. Table 3. The GEE consequences of diffusion indices from the instances of first oncoming during acute phase Indexs Parameter appraisal criterion divergence z-value p-value FA -0.201 0.026 61.053 0.000 MD 0.137 0.000 3.253 0.071 I »a -0.208 0.000 3.414 0.065 I »aS? 0.309 0.000 19.181 0.000 Twenty-six instances in 19 topics were foremost involved. The values of axial, radial, and average diffusivities ( I »a , I »aS? , MD ) are given in A µm2/ms. Fractional anisotropy is without units. All values are expressed as the natural logarithm of the ratio between controls and patients with IDON in the acute phase. IDON=idiopathic ocular neuritis. GEE=Generalized estimating equation. Subacute ON The DT-MRI information of 18 remitting instances is illustrated in Table 4. As is shown, both instances with first manifestation of IDON ( paired t trial, n = 6 ) ) and perennial IDON ( paired t trial, n = 12 ) showed a similar tendency with decreased FA values and increased MD, I »a and I »aS? when compared to controls ( see Table 4 ) . However, there was no important difference in I »a ( t = 2.46, P = 0.057 ) between subacute IDON patients with first episode and controls. We suspect that this may be due to the little sample size ( n=6 ) . Table 4. Diffusion indices from instances during the subacute stage of IDON ( first and perennial oncoming ) Indexs Acute Controls t-value p-value FA foremost 0.39A ±0.08 0.56A ±0.03 4.42 0.007 recurrent 0.35A ±0.10 0.56A ±0.05 8.01 0.000 MD foremost 1.80A ±0.28 1.40A ±0.08 3.87 0.012 recurrent 2.10A ±0.44 1.50A ±0.140 4.73 0.001 I »a foremost 2.64A ±0.36 2.34A ±0.10 2.46 0.057 recurrent 2.96A ±0.49 2.52A ±0.29 2.35 0.038 I »aS? foremost 1.40A ±0.27 0.90A ±0.09 4.25 0.008 recurrent 1.70A ±0.45 1.00A ±0.10 5.88 0.000 Eighteen instances with IDON were in the subacute phase ( the continuance of the disease from the scrutiny twenty-four hours to the last oncoming had been more than one month ) in which six instances in 5 topics had been affected for the first clip and twelve in 8 topics had been affected antecedently. Patients were defined as â€Å" recurrent † , if they had had more than two oncomings of symptoms at the clip of the MRI appraisal. Axial, radial, and average diffusivities ( I »a , I »aS? , MD ) are given in A µm2/ms. Fractional anisotropy is without units. All values of DTI indices are given as the mean A ± criterion divergence. IDON=idiopathic ocular neuritis. Directional diffusivity of ocular radiation The DT-MRI scrutiny of ocular radiation was performed on 23 patients. Nine patients, whose diseases had lasted from 1 twelvemonth to 13 old ages, and 14 patients, whose diseases had lasted from 8 yearss to 4 months, were included in this analysis. The path of the reconstructed fibres and tract-specific quantification was consistent with the known anatomy of the human ocular tract from old surveies conducted by Ciccarelli et Al. and Xie et Al. [ 21, 32 ] . These findings showed connexions from the posterior portion of the ocular radiation to ocular countries and connexions between the median portion and the karyon of the sidelong geniculate organic structure. Table 5 illustrates the average FA, MD, I »aS? and I »a within the reconstructed ocular radiation of 9 patients whose disease had lasted more than 1 twelvemonth ( mated T trial, n=9 ) . Compared to the control group, the FA values demo a statistically important lessening ( t = 3.45, P = 0.009 ) and the I »aS? value a dramat ic addition ( t = 3.92, P = 0.004 ) ( See Fig.6 ) . Compared to the controls, there is no statistically alteration in the mean FA, MD, I »aS? and I »a within the reconstructed ocular radiation of 14 patients, whose disease had lasted less than 1 twelvemonth ( mated T trial, n=14, see Table 6 ) . ( A ) ( B ) Figure 6. Relative alterations of the FA and I »aS? in each ocular nervus from controls and patients who had suffered more than one twelvemonth from ocular damage ( expressed as mean A ± standard divergence ) . Table 5. Diffusion parametric quantities in IDON patients whose disease had lasted more than 1 twelvemonth in comparing with controls Parameter ON Controls t-value p-value FA 0.46A ± 0.04 0.50A ± 0.03 3.45 0.009 MD 0.89A ± 0.05 0.84A ± 0.02 2.14 0.065 I »a 1.38A ± 0.07 1.37A ± 0.07 0.41 0.691 I »aS? 0.64A ± 0.06 0.58A ± 0.02 3.92 0.004 Nine topics are included. Axial, radial, and average diffusivities ( I »a , I »aS? , MD ) are given in A µm2/ms. Fractional anisotropy is without units. All values of DTI indices are given as the mean A ± criterion divergence. IDON=idiopathic ocular neuritis. Table 6. Diffusion parametric quantities in IDON patients whose disease had lasted less than 1 twelvemonth in comparing with controls Indexs ON Controls t-value p-value FA 0.49A ±0.04 0.48A ±0.03 0.62 0.547 MD 0.88A ±0.04 0.87A ±0.04 1.06 0.308 I »a 1.41A ±0.03 1.38A ±0.06 2.06 0.062 I »aS? 0.62A ±0.05 0.61A ±0.04 0.34 0.738 Fourteen topics are included. Axial, radial, and average diffusivities ( I »a , I »aS? , MD ) were given in A µm2/ms. Fractional anisotropy was without units. All values of DTI indices are given as the mean A ± criterion divergence. IDON=idiopathic ocular neuritis. Discussion The most common cause for IDON is believed to be an autoimmune reaction against the medulla environing the fibres in the ocular nervus which induces an inflammatory response that can ensue nerve harm. In some instances, early symptoms of ON may bespeak an eruption of MS, a disease besides caused by redness and axon harm in encephalon and the spinal cord. Therefore, a alternate biomarker is needed to uncover the implicit in pathological procedures of ON. In the current survey we used the directional diffusivities from DT-MRI to look into the abnormalcies in ocular nervousnesss and ocular radiation after ON. The diameter of the human ocular nervus is about 3-4mm. The nervus is surrounded by several beds of membranes, for illustration nervus sheath and orbital fat. Artifacts caused by eye-movement and the susceptibleness effects caused by nearby fistulas make it hard to get dependable diffusion image informations and to keep an equal SNR. Methods like spin-echo echo planar imagination ( SE-EPI ) [ 33 ] , interior volume imaging ( IVI ) or decreased field of position technique [ 34-36 ] were introduced to better image quality. In this survey, the SE-EPI protocol, a comparatively low maximal b-value with 600 s/mm2, six independent waies and a high figure of acquisitions were used to guarantee a suited a sufficiently high SNR. This method has antecedently been validated by several writers, such as Trip et al. , Kolbe et al. , Xu et Al. and many more [ 12, 17, 34, 36-37 ] . In add-on, we scanned the ocular nervus bilaterally in a coronal plane since the image deformation was greater in a sepa rate one-sided acquisition. Kolbe et Al. [ 12 ] scanned ocular nervousnesss separately in 10 coronal oblique pieces set extraneous to the nervus and analyzed the first six pieces. The group found the diffusivity values to alter drastically along the length of the ocular nervus. The FA values in the 1st and 2nd piece were well lower and the MD values well higher than in other parts. No important differences in FA or MD were found in the 3 last pieces. In the presented survey, we divided the ocular nervus into eight extraneous coronal oblique pieces. The superimposed form of DT-MRI diffusivity was confirmed in a pretest survey: the ocular nervus on pieces 6-8 was identical in most instances, and the diffusion indices were susceptible to vitreous organic structure in the pieces 1-2. In contrast, robust directional diffusivity was observed in the pieces 3-5. FA and MD values showed no important differences between the right and the left ocular nervus in healthy controls as illustrated in Table 7. Randomized discrep ancy block-analysis indicated important differences in FA but non in MD among the pieces ( see Table 8, FA: F = 17.54, P & lt ; 0.001 ; MD: F=0.500, p=0.613 ) . In add-on, the FA values in the 4th and 5th pieces were higher than in the 3rd piece ( p & lt ; 0.000 ( 3rd vs. 4th ) , p & lt ; 0.000 ( 3rd vs. 5th ) ) , but did non differ statistically from each other ( p = 0.757 ( 4th vs. 5th ) ) . We suggest that the consequence of oculus motions is smaller in the posterior portion of the ocular nervus. We assume that two factors may impact the diffusivity values: foremost, the possible mobility of the ocular nervus may be reduced in the mid-posterior portion ; 2nd, a more directional motion of H2O molecules in the well-organized and compact fibres. The fifth bed of the ocular nervus ( about 2.5 centimeters distal from the orb ) could be measured clearly in most topics, but measurings failed in five teenaged and in one 60-year-old patient due to reconstruction jobs. For that ground we had to utilize the 4th bed ( about 2 centimeter after the ball ) in this survey. DT-MRI utilizations H2O diffusion features to retrace white affair construction through diffusion way and amplitude. Altered diffusion parametric quantities were found in patients with chronic ON compared to healthy controls: MD was increased and FA decreased [ 13 ] . Harmonizing to Smith et Al. [ 38 ] , the pathophysiological mechanisms underlying the clinical symptoms in the ague ON include redness, hydrops, demyelination and loss of axons in the ocular nervus. A self-generated visus recovery a few hebdomads or even months after the hurt has been reported in some instances. Many factors like a diminishing inflammatory response, remyelination, Restoration of conductivity in demyelinated axons, as suggested by Smith et Al. [ 38 ] and cortical or subcortical malleability, as proposed for illustration by Toosy et Al. and Werring et Al. [ 14-15, 39-40 ] may take to the ocular recovery. Since the demyelination presumptively is a dynamic procedure, we hypothesized that different DTI indic es may alter at different phases of ON. Table 7. Lateral differences of FA and MD values in pieces 3-5 from 10 healthy controls in the pretest survey FA MD Right side Left side t-value p-value Right side Left side t-value p-value 3rd 0.57A ± 0.04 0.56A ± 0.06 0.297 0.774 1.57A ± 0.14 1.60A ± 0.19 -0.795 0.452 4th 0.67A ± 0.05 0.67A ± 0.05 -0.291 0.779 1.61A ± 0.23 1.58A ± 0.18 0.853 0.418 5th 0.67A ± 0.05 0.68A ± 0.05 -0.472 0.65 1.50A ± 0.20 1.52A ± 0.20 -0.628 0.548 FA and MD values showed no important differences between the right and the left ocular nervus in healthy controls Average Diffusivities ( MD ) are given in A µm2/ms. Fractional anisotropy ( FA ) is without units. Table 8. Comparison of FA and MD values in pieces 3-5 from 10 healthy controls in the pretest survey Indexs Slice Statistic 3rd ( meanA ±std ) 4th ( meanA ±std ) 5th ( meanA ±std ) F-value p-value FA 0.56A ± 0.04 0.67A ± 0.05 0.68A ± 0.05 17.54 & lt ; 0.001 MD 1.58A ± 0.15 1.60A ± 0.21 1.51A ± 0.21 0.500 0.613 Randomized discrepancy block-analysis indicated important differences in FA but non in MD among 3rd-5th pieces. In add-on, after multiple comparings by the least important difference ( LSD ) trial, we found the FA values in the 4th and 5th pieces were higher than in the 3rd piece ( F = 17.54, P & lt ; 0.001 ; P & lt ; 0.000 ( 3rd vs. 4th ) , p & lt ; 0.000 ( 3rd vs. 5th ) ) , but did non differ statistically from each other ( p = 0.757 ( 4th vs. 5th ) ) . Average Diffusivities ( MD ) are given in A µm2/ms. Fractional anisotropy ( FA ) is without units. Naismith et Al. [ 20 ] discovered the FA and I »aS? to be the first parametric quantities to alter in the acute IDON. I »a was decreased to a singular extent in the acute IDON and this step was found to correlate with the ocular result. In our survey, we found significantly increased average I »aS? and decreased FA in 33 instances with acute IDON during first episode and recurrent instances when compared to controls, and besides detected a lessening in the I »a of patients with a first episode in the acute phase by utilizing mated t trial ( t =2.10, P = 0.046 ) although that difference did non make statistical significance ( z = 3.414, P = 0.065 ) after GEE theoretical account analysis was performed. Since the pathological alterations in recurrent instances are more complex than in instances with first clip manifestation, and since the sample size of recurrent instances was little ( n=6 ) , we will merely discourse the first episode subgroup as we assume that this theoretical account likely reflects the pathological alterations in acute period more closely. In instances with white affair hurt merely affecting medulla devolution, we hypothesize that I »aS? is likely to increase, reflecting the increased freedom of H2O molecules to undergo Brownian Motion perpendicular to the axons due to the loss of myelin unity. The consequences of our survey confirm consistent pathological alterations and back up our premise. Experimental autoimmune encephalomyelitis ( EAE ) is a widely used carnal theoretical account, which can imitate many characteristics of human MS. ON is one of the phenotypes in EAE mice. The I »a and I »aS? appear to be both sensitive and specific for axonal hurt and demyelination, severally in Xu et Al. survey [ 14 ] . Wu et Al. [ 41 ] studied an EAE murine theoretical account in the ague phase utilizing in vivo diffusion-weighted imagination with diffusion sensitising gradients parallel and perpendicular to the axonal piece of lands. They detected that progressive acute axonal harm resulted in a 23 % lessening in I »a at 20 yearss after immunisation. Using a mated t-test, we found that I »a lessenings in patients with first episode in the ague IDON, a determination we ascribe to axonal hurt happening during the acute phase. However, this decision needs to be reconfirmed by more research. Trip et Al. and Kolbe et Al. [ 12, 17 ] found increased MD and reduced FA-values in patients with one-sided IDON who had suffered from ocular symptoms for a lower limit of at least one twelvemonth. The writers considered these alterations to be chiefly caused by axonal loss, with demyelination and gliosis playing a partial function. In our survey, 18 instances with IDON in the subacute phase, both of first manifestations and recurrent instances, showed significantly decreased FA and increased I »aS? , I »a and MD when compared to controls, back uping the findings of the aforesaid writers. The DT-MRI fibre paths and cleavage of ocular radiation from the sidelong geniculate karyon to the ocular cerebral mantle have already been studied by Yamamoto et Al. and Berman et Al. [ 42-43 ] . Bajraszewski et Al. [ 44 ] found significantly increased MD and reduced FA besides in the ocular radiation in patients with ocular neuritis ( symptom onset 4.0 A ± 0.4 old ages ) compared to controls and suggested the alterations to be caused by anterograde effects of the nervus harm. Our survey found no important alterations in diffusion parametric quantities in patients with ON continuance under one twelvemonth, but a significantly decreased FA and higher I »aS? if the disease continuance exceeded that period of clip. This difference indicates more serious wasting of the ocular radiation after the return of symptoms. The most likely pathogenesis of unnatural diffusion in ocular radiation would look to be secondary lesions induced by axonal devolution after ON. We besides observed an increased MD value in ocular radiation in chronic ON patients compared with control topics. However, the alteration was non important ( t = 2.14, P = 0.065 ) , perchance because of the little figure of patients. These findings support our hypothesis that unnatural diffusion in ocular radiation is an of import feature of ON. Further research is still needed to further beef up the function of DT-MRI measurings in ON rating and degree appraisal. Decisions In the current survey, we applied DT-MRI methodological analysis to look into alterations in ocular nervus and radiation. Our consequences in footings of diffusion parametric quantity alterations both during ague and remitting ON support and widen antecedently reported findings. Additionally, we found significantly decreased FA and increased I »aS? in the ocular radiation of chronic ON patients. We were able to observe dynamic alterations in the diffusion parametric quantities during the development of chronic ON, perchance bespeaking ongoing medulla harm. Based on our fresh findings we suggest directional diffusivity to possess great possible as a specific biomarker and rating step for myelin hurt. Future probes are needed to find whether these indices have practical parts to the diagnosing and forecast for patients with ON. Recognitions This work was supported by grants from NSFC ( 20670530, 60875079 ) , the 863 undertaking ( 2007AA01Z327 ) and Beijing Nova Plan ( 2007A094 ) . We would wish to thank Prof. Chunshui Yu and Dr. Wen Qin for proficient aid geting MR images, Dr. Wei Shi, MD Nora Hailla, and Dr. Siegfried Wurster for valuable expertness and counsel to this research, Prof. Xiaojun Zhang for patient enlisting and all our topics kindly holding to take portion in this survey.

Harmful Algal Blooms and Aquaculture

Harmful Algal Blooms and how they are Linked to Aquaculture Abstract Harmful algal blooms cause a wide range of negative effects on aquaculture. These effects are come from the complexity of harmful algal species; the toxins they create and morphology they have adapted. Science still lacks a full understanding of factors that are envolved in blooms formation. Aquaculture and harmful algal blooms are directly related because it is one of many anthropogenic factors that unintentionally produce the conditions that promote harmful algal blooms.The methods of production, feeds used, waste produced can lead to nutrient loading and eutrophic conditions by releasing essential nutrients into water that are necessary for algal growth. Phosphorus and nitrogen compounds are two of the main byproducts or aquaculture that are associated with bloom formation. To minimize the effects of harmful algal blooms on aquaculture you must understand the diversity and complexity of harmful algal blooms and t heir relationship with aquaculture. Abstract Harmful algal blooms cause a wide range of negative effects on aquaculture.These effects are come from the complexity of harmful algal species; the toxins they create and morphology they have adapted. Science still lacks a full understanding of factors that are envolved in blooms formation. Aquaculture and harmful algal blooms are directly related because it is one of many anthropogenic factors that unintentionally produce the conditions that promote harmful algal blooms. The methods of production, feeds used, waste produced can lead to nutrient loading and eutrophic conditions by releasing essential nutrients into water that are necessary for algal growth.Phosphorus and nitrogen compounds are two of the main byproducts or aquaculture that are associated with bloom formation. To minimize the effects of harmful algal blooms on aquaculture you must understand the diversity and complexity of harmful algal blooms and their relationship with a quaculture. Andrew Blajda Introduction Over the last several decades harmful algal blooms events or HABs are believed to be increasing in frequency and geographic range. The reported increase is a major concern because of the wide scale impact they have on he environment and human activities. The effect of HABs on aquaculture can be very damaging with reduced growth, mortalities or accumulation of toxins. If aquaculture operations take place in the open bodies of water they have little or no way of avoiding incoming blooms. Harmful algal bloom events that come in contact with aquaculture operations often have negative effects that can include student growth, weakened immunity, mortalities, and on economic losses.One of the bigger concerns today is the apparent increase in harmful bloom events. Researchers have linked this increase with anthropogenic activities, aquaculture being one of them. Aquaculture operations adds additional nutrients to the system, this lowers nutrients that l imits algal growth. A better understand of the dynamics and characters the form and make up a bloom combined with the a better understanding of nutrient loading of aquaculture could potentially help reduce the negative effects harmful algal blooms have on aquaculture.Single celled microscopic algae like phytoplankton are the most globally abundant species and one of the oceans’ most important resources. These autotrophic primary producers form the bottom of the food pyramid, acting as the primary source of food for larval finfish, crustaceans, filter feeding bivalves, and other species (Hallengraeff, 1995). In normal concentrations, these single celled algae work in balance with the ocean and its inhabitants, filling important roles in chemical and nutrient cycles. They act as primary producers, providing nutrients and food for variety of different species.These simple microscopic species are vitally important to the success of both fisheries and aquaculture, but in some situ ations they can also have detrimental effects on the marine and coastal environment and numerous terrestrial and marine species. A combination of physical, chemical, biological, hydrological, and meteorological events can generate appropriate conditions that allow these simple single celled microalgae can exhibit exponential growth and reproduction. These natural events create the opportunity for algal bloom formation with potential large scale negative effects throughout the area they cover (Graham, 2007).Algal blooms can be very diverse and differ from one another in many ways . How they form, the algal specie of causation, characteristics and dynamics of a blooms, the species they affect, and impacts they cause are some of the complex factors that are found in blooms (Zingone & Enevoldsen, 2000). The specific characteristics used to define a harmful bloom vary by sources. Hans Paerl, among others, defined harmful blooms by using several characteristics. Paerl also defined harmful blooms at their most basic level by classifying them as having nuisance conditions, meaning ecological and/or economic impacts (Paerl, 1988).As harmful algal blooms move across the ocean, the observable effects they cause go beyond the ocean and marine species it covers. These events will also have wide spread negative impacts on costal terrestrial organism and both human health and activities. Algal species produce sevral different toxins that are detrimental effects to human health, causing various illnesses and mortalities. About 10% of foodborne disease in the United States results from algal toxins; worldwide they cause more than 60,000 intoxications a year. Van Dolah, 2000) Economic losses due harmful algal blooms have been estimated in the tens of millions of dollars, from costs of beach clean ups, decreased tourism, and closing or stopping sales of commercial fisheries and aquaculture (Van Dolah et al. , 2001). Over the past several decades there has been an apparent increa se in the frequency and geographic range of harmful algal blooms. This apparent increase has been attributed to both increased observations and focus on harmful algal blooms and increased inputs from anthropogenic sources.Aquaculture is one of many anthropogenic activities that is believed to be hypernutrification and eutrophic conditions in surrounding bodies of water. This paper will attempt to gain a better understanding of diversity of harmful algal blooms and also the effect aquaculture has on the environment in adding in formation of harmful algal blooms. Algal Blooms Historically algal blooms are a naturally occurring phenomenon in earth’s oceans and have been observed throughout recorded history (Hallegraeff, 1993).These events are often beneficial to bivalves by supplying an abundant food supply to these filters feeding that relay on microalgae for their source of nutrients. Algal blooms can quickly turn into detrimental to the environment and its inhabitants are var ious ways (Leverone, 2007). Sources from human history including the bible may contain the first documented cases of algal blooms. In Exodus 7: 20-21 referring to one of the plaques on Egypt â€Å"all the waters that were in the river turned to blood, and the fish that was in the river died†.Some historians and scientist now believe this biblical reference from 1,000BC could be the first written record of an algal bloom. (Hallegraeff, 1993) Other historical sources may have unknowing recorded written evidence on algal blooms, in China around 200AD general Zhu Ge-Ling documented sicknesses and losses of military personnel after drinking from a river that was stained green. (Chorus & Bartram, 1999) Examination of fossil algal specimens and historical reference compounding evidence that these event are not a new phenomenon and have been occurring in earth’s oceans for thousands if not millions of years.Recent finding from numerous long term studies conducted around the wo rld has brought a strong belief in the scientific community that algal blooms have been increasing in their frequency and geographic distribution. Even though most scientiest support the idea of a global increase of blooms and twith strong evidence supporting this theroy there is still a major dissagreement about what is causing the increase (Pelley, 1998). The apparent increase of algal blooms, along with the global impacts on aquatic organisms, the environment, human health, and activities has increased interest and research being done on these events (Li et al. 2002; Van Dolah et al. , 2001). The exact characteristics and descriptions that define an algal bloom are fairly broad and very from source to source. I was unable to find a universal definition of algal blooms. The description and definition I came across were similar but differed in many aspects; this included sizes, formation factors, impacts, and algal species. Overall algal blooms are generally defined significant inc rease in biomass due to a rapid reproduction of a single microalgal species.The problem with this source is there can also be macroalgal blooms. Others described them as forming high density populations, with some species creating visible discoloration of the water. (Carstensen, Henriksen, & Heiskanen, 2007; Diersing, 2009) Others define blooms by impacts they cause; displacing indigenes species, destroy habitat, oxygen depletion, and alter biochemical cycles. (Hoagland et al. , 2002) A more generalized definition was given by Hallegraeff, adding that a bloom must have at least million cells per liter (Hallegraeff, 1993).The defining characteristic that differentiates a bloom from a harmful algal bloom is when they takes on a destructive roll and causes environment impacts. The term harmful is defined more specifically as causing negative impacts on the environment and adverse effects on both aquatic and terrestrial organisms. This is due to factors such as toxins they produce, spec ie specific cell physical structure causing damage to aquatic organisms or by accumulation of biomass affect naturally occurring organisms causing alterations food web dynamics and biochemical cycles (Anderson et al. 2002). Depending on the species, some algae produce toxins that can affect crustaceans, fish, shellfish, birds and mammals including humans; nontoxic species can still causes damage by blocking light from penetrating the water column, clogging or damaging gills, and creating anoxic conditions from accelerated decomposition as they die off (Silver et al. , 2006; Sellner et al. , 2003) Harmful alga can also have impacts on shoreline coastal habitats, toxins can be transported onto the shore by sea spray (Hoagland et al. , 2002).There are over 5,000 know photoplanktonic algal species that inhabit the marine waters only a small portion, about 300 species are known to have blooming capabilities and even fewer, about 40-80 species or 2-3% of all photoplantonic algal species a re known to have toxic chemicals producing capabilities; this includes members that form red tides (Hallegraeff, 1993; Smayda, 1997). Nontoxic red tides are not uncommon, today people often incorrectly or mistakenly refer to toxic algal blooms as red tides even when brown, green or colorless (Anderson, 1994).Toxic and other harmful algal species are ubiquitous throughout the marine and freshwater environment; the majority of the time they present at low population densities that cause few, if any and only minor impacts on the environment and its local inhabitants (Van Dolah, 2000). There are a variety of different phycotoxins algal species are able to synthesize; individual species will only produce one type of toxin. The evolutionary advantages of these toxins are not fully understood; they are believed to play a role in bloom formation and predator protecting (Nehring, 1993).The different phycotoxins vary from one another in terms of the impacts and degree of damage they have on m arine and terrestrial organisms, depending on the toxicity, the concentration, and the organisms. Toxicity vary among algal species Dinophysis is one example, they have the ability to produce toxins that have negative effects at densities as low as 100 cells per L-1 (Sellner et al. , 2003). The most toxic algal species are mainly found in dinoflagellets (Table 1) with some having toxicity greater than venomous snakes. Table 1.Toxicity of several phycotoxins created different organisms including algae. (Van Dolah, 2000) The taxonomic algal groups’ dinoflagellets, raphidophyetes, cynobactria, and some diatoms are known to have the capabilities of phycotoxins production; these species are often the culprit behind harmful algal blooms. Phycotoxins are toxic chemicals created biologically by photosynthetic organisms. Dinoflagellets are one of the predominate species that forms red tides; members of this group also produce toxin that lead to foodborne illness and human mortalities (Li et al. , 2002; Hallegraeff et al. 1995). Human induced illnesses are not an uncommon result from consumption of seafood. Many algal toxins are potentially dangerous and even deadly to humans. Toxins accumulate in tissues of organisms like shellfish, finfish, and crustaceans that come in contact with a toxic bloom. These species are usually far less affected by algal toxins having adaptive mechanisms that lower the effects on the organisms associated with toxic blooms. However toxins still accumulate within the tissues and detoxification can take weeks before they reach levels safe for human consumption.Algal toxins cause for concerns for humans not only because they maintain their toxicity long after the bloom but more importantly because they can withstanding heat from cooking. Algal toxin foodborne diseases are caused by various species or toxins and come from different vectors. Bivalve vectors can induce human illness that include (Table 2) paralytic shellfish poisoning (PSP) , neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), diarrhetic shellfish poisoning (DSP); other vectors can lead to various other diseases as well (Van Dolah, 2000).The popular term of red tide given to harmful algal bloom comes from compact, high densities of algal cells that containing red photosynthetic pigments, causing the water to appear red (Carstensen et al. , 2007). These toxic species can normally be found in low concentrations have no impacts on organisms and environment. The adverse effects on organism often deepened on cell concentration; in blooms toxic algae aggregate and are more dangerous (Van Dolah, 2000).Some toxic algal species have developed unique life cycles and morphological characteristics that allow them to occupy a specific niche that will be further examined. Table 2. Foodborne and environmental disease caused by harmful algal species, the toxin produced and the primary vector they inhabit. (Van Dolah, 2000) Harmful algal species ha ve many adverse impacts on bivalves’ this includes a wide range of sub-lethal and lethal effects; some algal species are more detrimental than others (Leverone, 2007). It is believed that increase frequency of blooms is partially due to the introduction of non-indigenous algal species.Non-indigenous species potentially will create a specific niche, and/or out compete native species. Indigenous naturally occurring harmful algal species are far less direct effects on bivalves; this is because they have been able to naturally adapt to their presence over time. Native algal species in most case do not have as bad direct, detrimental impacts on shellfish and are usually not associated with large scale bivalve die off. The exception to this is in cases of intense blooms (Matsuyama & Shumway, 2009; Nehring, 1993; Zingone & Enevoldsen, 2000).It’s still hard to truly say many large scale die-offs and increase sub-lethal impacts are directly due to non-indigenous algal species b ecause identification is sometimes difficult, longer term data individual algal species geographic ranges are limited combined, and the theory anthropogenic factors are causing an overall increase in blooms. In many circumstance of HAB mortalities it’s difficult to differentiate whether they resulted from the algal specie or unfavorable water quality that coincide with blooms (Anderson et al. , 2002; Leverone, 2007).Complex morphology are found in many harmful algal species that helps protect them from predation and the environment and help obtain nutrients. Diatom algae are members of the Bacillariophyceae class; they have been around for over 180 million years helping to create earth’s atmosphere and also play a major role in nutrient and chemical cycles. Over their evolutionary history diatoms have developed a variety of different exterior cellular morphology for protection from the environment and predation. They have a range of cell shapes and sizes and also form unique frustule cell walls made from silica.The frustule cell wall is made up of two over lapping overlapping silica bands forming a protective shell. The 100,000 diatom species have developed â€Å"seeming infinite variations† of cell wall micropatterns and structures; including ridges, spines and plates (Kroger & Poulsen, 2008) These cellular morphological characteristics help protect them under adverse environmental conditions and restrict or prevent predation. Some species of diatoms have developed such strong cell walls with structural properties that enable them to survive ingestion and escape after passing through the digestive system. (Merkel, et al. 2003) The benefits of these structures do have negative effects and come at the expense of motile abilities, limits growth, and makes the cell very dense; motile restorations and high cell densities make diatoms much more likely to sink out of the high nutrient water column. Bloom Formation The intricacy of bloom formatio n is due to both the abiotic(environmental and anthropogenic factors) and biotic factors; these being the algae themselves. Adaptations of life cycle, morphology, and environmental conditions enable rapid reproduction of certain algal species that have developed specific niches (Sellner et al. 2003; Zingone & Enevoldsen, 2000). Algal blooms formation driven by the complex relation between the environmental factors and algal species; although we understand the basics of formation there are still many unknowns. There are seemingly endless amounts of variables and factors that play a role in creating of a bloom. The main driving factors of when and where a bloom forms are a combination of environmental/anthropogenic factors (nutrient cycles and inputs) and algal morphology (Pinckney et al. , 1997; Sellner et al. ,2003).As simple as it sounds, there are countless variables including natural condition, anthropogenic effects, algal physiological and morphological characteristics that lead to the unpredictability and overall misunderstanding we still have on blooms. (Sellner et al. , 2003; Anderson, 1994) The belief that algal blooms are increasing in frequency and geographic range is a popular belief that is backed by numerous studies. The cause of this apparent increase has been attributed to the expanding human population (anthropogenic effects).Some still argue that the increase in blooms is due to the increase in observations from studies worldwide, a better understanding of blooms and better record keeping; but with overwhelming evidence supporting the lateral it’s hard to believe the human race is not playing a major roll. (Sellner et al. , 2003) Looking at the numer of literary reference to harmful algal bloom over 70 years(figure 1) shows a dramitic increase algal blooms from the 1920’s through late 1990’s (Hallegraeff, 1993). This also give arguments that increase research and technology contriubute to the increase ovserevd.Figure 1. Li terary references of harmful algal blooms from Aquatic Sciences and Fisheries Abstract (AFSA) publications over about 70 years. The increase can be attributed to a combination of anthropogenic factors or increased observations and present arguments for both sides. (Hallegraeff, 1993) Today we have an understanding of the natural environmental processes and factors that lead to bloom formation; but the effects humans apply to the environment alter the natural cycles making it more difficult to predict blooms (Paerl, 1988).Blooms occur under irregular conditions that promote growth and reproduction allowing some species to flourish. The conditions found in blooms broad and often species’ specific adding to the complexity and unpredictability of blooms. In general the conditions associated with blooms are abundance (eutrophic), or an imbalance of nutrients, along with favorable water conditions (temperature, DO, salinity, etc. ). Natural processes like atmospheric deposition, wa ter column turnover, upwelling, oceanic currents, storms, and anomalous weather events (El Nino) work together and fluctuate over time effecting mixing rates, water quality.Nutrients pools build up over time from organic decomposition in benthic sediment. Mixing of the sediment perelapses the nutrient pools and bring about eutrophic conditions or alter the water chemistry that enable specific species of algae to flourish (Sellner et al. , 2003; Van Dolah, 2000; Paerl, 1988). Natural mixing rates occur during regularly during temporal or seasonal with environmental fluxes or randomly from disturbances (natural anthropogenic). Sediment mixing are very important environment processes, releasing nutrients back into the water column allowing for increased primary producer growth.Seasonal and temporal sediment mixing produce lead to the specific conditions that form blooms. Eutrophication has been defined as â€Å"an increase in supply of organic matter to the ecosystem; in terms of alga l bloom this refers to an increase in nutrients that allows an increase of primary production† (Bonsdorff et al. , 1997). Three key nutrients, nitrates ammonia and phosphates are associated with eutrophication and considered the driving forces behind bloom (Sheng, Jinghong, Shiqiang, Jixi, Dingyong, & Ke, 2006). The levels found in marine waters are driven naturally based on natural events discussed above.Studies have found a correlation between anthropogenic actives leading to nitrogen and phosphorus nutrient loading and the apparent increase in frequency of algal blooms along with alteration of natural nitrogen/phosphorus ratio (Bonsdorff et al. , 1997; Paerl, 2009). There are various anthropogenic activities that have led to the both local and global increase of nutrients in fresh and marine waters. Aquaculture is just one of many of these activities. Many studies have shown that aquaculture operations have byproducts that can cause eutrophic conditions.Nutrient loading fro m aquaculture only has local effects and the amount of effects it causes is size dependent (Anderson et al. , 2002). Aquaculture and Nutrient Loading It is important to understand the relationship between aquaculture and harmful algal blooms. Additional nutrients from the feed used, effluent discharge, and waste products are some of the source that lead to nutrient loading (Tacon & Forster, 2003). The amount of additional nutrients added to a system increases based on how intensive the operation is.HABs have wide spread negative impacts on aquaculture, the hope of significantly minimizing these impacts are still years away. To minimize the effects on aquaculture you must understand characteristics and dynamics of blooms, this includes the diversity of species involved and the factors associated with bloom formation. The apparent increase frequency and geographic range of harmful algal blooms is very important to aquaculture because aquaculture plays a role in helping create the cond itions necessary for bloom formation.Aquaculture operations provided year round nutrient inputs in a local aspect, this eliminates nutrient limitations in those areas (Bonsdorff et al. , 1997). This section will discuss and review the relationship aquaculture has with nutrient loading and eutrophication of the surrounding water. Nitrogen and phosphors are to key elements that take on various forms necessary for bloom formation. Both nitrogen and phosphors in the forms of nitrates, ammonia, phosphates and other compounds are byproducts of aquaculture.Algal growth is limited by nutrient availability, mainly based on availability of nitrogen and phosphors in the environment. Nitrogen in the forms of nitrates and ammonia are water soluble and enter the system from either dissolved feeds, effluent discharge, or from waste produced by fish. Phosphates often accumulate mainly in the sediment and during mixing events are released into the water in high quantities (Karakassis, Pitta, & Krom, 2005). Nutrient loading from aquaculture that leads to eutrophic conditions come from several sources. The amount and source of the nutrients depends on the operation.Location of farm (open ocean, ponds, raceways etc. ), what is being cultured (shrimp, finfish, bivalves), what are the inputs (feeds, fertilizer, etc. ) and how intensive the operation is. The source of local nutrient loading from aquaculture can be traced back to where the operation is taking place. Open ocean farming of finfish for instance causes eutrophic conditions right around the cages. On the other hand inland facilities such as pond systems and other flow through systems release effluent discharge causing nutrient in the and around the bodies of water they run into.The species being cultured also plays a major role. Bivalves for instance play a role in limiting algal growth by filter feeding, while finfish inputs and excreting essential nutrients in their waste is a major source of nutrients (Soto & Mena, 199 1). How intensive an operation is and the actual inputs into the system are directly related. The more intensive an operation the more inputs and the more inputs the greater chance of hypernutrification and eutrophic conditions. Different operations require different inputs and these inputs have different nutrient atios. Culture of some juvenile finfish require fertilization to promote phytoplankton growth for feed this puts the essential nutrients for algal growth directly into the system. The feeds used in aquaculture vary on the nutrients they are made up of, how stable they are and whether they float or sink. These factors are all in play in nutrient loading that come directly from aquaculture (Islam, 2005). The effects of aquaculture feeds on nutrient loading depend on several factors. There are three main factors these include; 1) the amount of wasted feed.This is due to poor farming and management practice and floating Vs. sinking feeds. Poor management practices means over o r an improper feeding technique that puts more feed in the water. Floating and sinking feed choices is also important. Sinking feeds may not be eaten by finfish if they go through the bottom of a net or cage, or if they sit on the bottom. On the other hand floating feeds may be less stable or uneaten if they are transported out of a system or to a place where they are unable to be eaten. 2) The actual quality of the feed.This poor stability and high solubility of feed pellets in water mean that once they are in the water they will be broken down and release more and nutrients and in less time. The final factor is deals is loosely related to the previous two. 3) Once the feed is ingested factors such as limitations of absorption and retention of the nutrients from the feed. This factor deals mainly with poor digestibility or metabolism of the species being culture to the feed they are given. The nutrients in the feeds many not be utilized to their full potential once ingested fish wi ll excrete the excess nutrients (Soto & Mena, 1991).Feed and nutrient inputs play a major role in nutrient loading and creating the conditions that promote algal growth either directly in the form of uneaten feeds or nutrients leaching or dissolving from the feeds, or indirectly from the digestion, metabolism and waste products from the species being cultured (Tacon & Forster, 2003). The important of feeds in nutrient loading must not be overlooked one study estimated that 70% of phosphorus and 30-50% of nitrogen in feeds is not utilized by fish and is released into the environment (Soto & Mena, 1991).This only shows two of the most essential nutrients associated with bloom formation and not the various other nutrients that are also released and are important for algal growth. This also shows the significance of feeds based on the large amount of nutrients that are not utilized and instead entering the environment, promoting algal growth. Over all aquaculture farm operations lead to excessive amounts of inorganic and organic fertilizer, feeds, and wastes that are put into local water bodies with high concentrations nutrient, that lead to nutrient loading and eutrophic conditions.Discussion and Conclusions Aquaculture over the last several decades has grown globally in both its production and popularity. In the future aquaculture will continue to grow in its importance to the human population as alternative food source to agriculture and wild fisheries, as well as helping with the depleted ocean stocks. As of now it appear that we will be seeing an increase in aquaculture around the world in the years to come. Although there are many benefits to aquaculture and the potential of increased production may have we must measure the benefits against the environment impacts they cause.Nutrient loading is just one of the environmental impacts associated with aquaculture and the effects of nutrient loading go beyond promotion of algal blooms. The global increase in aqua culture coincides with the apparent increase in harmful algal. Although there are many other anthropogenic factors that are at play in global nutrient loading aquaculture is a major local point-source form. We must understand the specific conditions that are associated blooms and the role aquaculture plays along with how complex and diverse blooms can if we hope to develop mechanisms that can significantly reduce the impacts on aquaculture.I choose the topic of harmful algal blooms and aquaculture effects of nutrient loading because it fits in perfect with our class: aquaculture and the environment. The purpose of this paper was to gain a general understanding of harmful algal blooms, and also to review the factors of aquaculture that lead to nutrient loading, eutrophic conditions, and the aid in bloom formation. This topic caught my attention because of similar topics I’ve cover and work I’ve done this semester in this class and others classes.Harmful algal blooms in general are very interesting because of the diversity of blooms, the range of effects they have, how unique the species involved are, and because of the complexity and over all lack of understanding have in factors of bloom formation. The purpose of this class included reviewing the impact of aquaculture on the environment and methods of reducing or eliminating those impacts. This paper focuses on harmful algal blooms and how aquaculture creates conditions that promoted bloom formation.I focused a great deal of this paper on harmful algal blooms because if you hope to minimize the impacts they cause you must appreciate and understand their complexity and also understand the relation they have with aquaculture. The purpose of this paper was not to examine direct ways in which to minimize nutrient inputs of harmful algal blooms but the information given on harmful algal blooms and the role aquaculture plays in promoting bloom formation is useful to future studies and reviews focusing on ways to minimize the impacts of HABs on aquaculture and help reduce the factors of aquaculture that promote harmful bloom formation.Bibliography Anderson, D. M. (1994). Red Tides. Scientific American Vol. 271, No. 2, 52-58. Anderson, D. M. , Glibert, P. M. , & Burkholder, J. M. (2002). Harmful Algal Blooms and Eutrophication: Nutrient Sources, Composition, and Consequences . 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