Magnetic Turtle an Example of the Topic Education and science by

Magnetic Turtle by Expert Leah. | 08 Dec 2016 Abstract Need essay sample on "Magnetic Turtle" topic? We will write a custom essay sample specifically for you Proceed Earths magnetic field serves as ubiquitous source of directional and positional information for many marine animals. These animals use this information for their needs to survive like choosing correct migratory pathways, returning back home and to catch their prey to name a few. This has been confirmed by many researchers by behavioral experiments on many marine animals. Some examples are migration of Hatchling sea turtle in the North Atlantic Gyre, navigation of Spiny Lobsters and magnetic orientation behavior of Tritonia Diomedea. This paper reviews the magnetic navigation behavior of the Hatchling Sea Turtles and Spiny Lobsters and the behavioral experiments carried out to confirm the same by different researchers. Very little is known about the neural mechanisms underlying magnetic navigation behavior of different marine animals due to complexity of neural network. Therefore, researchers have chosen Tritonia Diomedea, which has relatively simple neural network and studied its magnetic orientation behavior by employing electrophysiological methods to explore the underlying neural mechanisms and try to extract the bigger picture by analyzing and correlating the data. This paper reviews the research in this direction as well and discusses important findings and finally the author concludes that besides behavioral experiments little is known at least about the basic mechanisms and processes underlying the magnetic navigation behavior of marine animals and besides the other important aspects of the issue, work needs to be done on the role played by higher order processing in circuits involving the sensory information. Sensory System and Navigation Human beings are having a set of sensory systems that fullfils their needs of survival on this planet in their habitat. The important sensory systems are the vision system, the hearing system, contact sensing system, temperature sensing system etc. Any of the sensory systems can be looked upon to be made up of receptors, signal processing systems and actuation mechanisms. These sensory systems are known to adapt to the habitat and guides our actions, reactions whatever we call it. In different organisms different sensory systems are evolved different levels of sophistication according to the needs of their habitat. Of these sensory systems, it is mainly the vision system that guides navigation behavior of most of the organisms, at least on the land mass of the Earth. The organisms that rely on their vision system identify and store various landmarks and thus make a map, in their mind, which they use to navigate to the desired destinations. Besides, they have visibly identifiable direction markers like rising and setting sun and different stars. So obsessed we are with our vision system, which is quite natural looking at the extent to which we rely on it for our own navigational and other needs, that apparently it looks as the only possible sensory system to support a sophisticated navigational behavior. However, scientific finding contradict this notion and present before us strange observations where highly sophisticated navigational behavior of many species could exists with little support from the vision system. This is observed mainly in marine animals. These animals reside in different habitat, need to migrate on different length and time scales and finally they need to return home. Not only this, they need to be reasonably accurate and precise on their pathway during the course of migration as the deviation from the proper path could prove fatal. Surprisingly they do so under seawater, where sunlight can hardly reach to shine their habitat or pathways, visibility is very poor due to turbidity and more importantly their habitat lacks features or what we say without any landmark (so obsessed we are with landmarks!). Migratory Behavior of Hatchling Sea Turtle Hatchling sea turtles go on their specific migratory track, along the North Atlantic Gyre, since generations, in their life cycle. This migratory track originates from their birthplace at the east coast of Florida, USA. Starting from their nests at the east coast of Florida, USA, they cross the beach to the sea and migrate offshore to the Gulf Stream and North Atlantic Gyre. This is a circular system encircling the Sargasso Sea (Cain et al 2005). They remain in the Gyre system for several years and cross to the eastern side of the Atlantic Ocean. After that they return to the south eastern USA i.e. their birth place, to reside in the coastal feeding grounds. The primary reason for this migratory pathway is that the North Atlantic Gyre is food-rich environment for young turtles. However, the turtles can not afford to stray beyond the extremes of the gyre as it will be fatal for them. Near Portugal, the east-flowing stream of the Gyre pides and the northern branch goes past Great Britain and temperature of the water falls rapidly. If at all the turtles are swept northwards they will soon die of cold. Similar is the situation at the southern extreme of the Gyre where failing to recognize the extremes of the Gyre will throw them in the vast sea and far away fro their home. So the question is how the young turtles with no experience of the Gyre, determine extremes of the Gyre so precisely? Do they have some kind of map built in them and some sensory system continuously sensing and telling them as where on this map they are? We will return to the answer but before, let us explore another equally important example. Navigation of Spiny Lobsters The Caribbean Spiny Lobster resides on hard bottom and coral reefs throughout the waters of Caribbean and south eastern US. They are nocturnal and spend their day protected within crevices and holes. They travel considerable distance during night and at the end comeback to either same den or another similar den nearby. Even when these lobsters are taken away and left at a location several kilometers away from their home, they come back home. Again the question is how they the direction and path to their home. Which sensory system they rely upon for such a perfect navigational capability? Navigation Based on Magnetic Sensory System These marine animals have developed a geomagnetic compass to determine direction (Lohmann et al 1995a). Behavioral experiments under replicated magnetic field conditions have stimulated similar navigational behavior in hatchling turtles and spiny lobster than that in their actual migratory path. But to return home with such an accuracy and precision requires having much more than just magnetic compass sense. They must be capable be constructing maps by detecting and combining different features of magnetic field. Several features of magnetic field like field intensity and the angle at which geomagnetic lines intersect Earths surface vary with latitude, predictably and these can be used in position finding (Lohmann 1999). Johnsen et al (2005) have reviewed physics and neurobiology of magnetorecection. They have examined the possible mechanisms of magnetoreception. The mechanisms are 1. Electromagnetic Induction, 2. Chemical Magnetoreception and 3. Magnetite sensors. The authors have evaluated the physics and / or chemistry underlying each of these mechanisms, evidence for these mechanisms and contradictions in accepting these mechanisms. Mechanism Underlying Magnetic Orientation Though, little understanding has been gained about the basic mechanisms underlying magnetoreception, based on behavioral experiments it can be said without any doubt that, there exists a fairly evolved magnetoreception and magnetic sensory system based on geomagnetism that helps them navigate so well in absence of any other sensory system to do the same. Not only the magnetoreception system, rather the entire magnetic sensory system is still a mystery to be solved. Which part of the neural system receives the magnetic signal from the environment, which part of the neural system is then takes these signals for further processing, how the signals are processed, what signals are given to which part of the neural system to generate the actuation signal. The entire circuitry and not just the circuitry but the higher order processing aspects are all very little known. The reason being the complexity of the neural network of the vertebrate, which makes it difficult to isolate the magnetic effects from other effects for deriving useful information by employing the electrophysiological studies. To overcome complexity of neural network of the vertebrates, a simple invertebrate Tritonia Diomedea was chosen for electrophysiological studies. This animal was chosen as it shows magnetic orientation under behavioral experiments and has very simple central nervous system consisting of approximately 7000 neurons in six fused ganglia and many of these neurons can be identified by their color, size and location within central ganglia. Besides, the nervous system is readily accessible for electrophysiological studies. Intracellular electrophysiological recordings show that three bilaterally symmetric pairs of identifiable neurons respond with altered electrical activity to changes in Earths magnetic field strength. Two of these pairs identified as Pd5 and Pd6 are excited by changes in direction of ambient magnetic field, while the third pair Pd7 neuron is inhibited by same magnetic stimuli that excites Pd5 and Pd6. Therefore, it can be concludes that in Tritonia Diomedea the three neuron pairs Pd5, Pd6 and pd7, are magnetically responsive cells and function in the neural circuitry underlying magnetic orientation behavior. Recent anatomical, electrophysiological and immunological analyses have provided some insight into likely roles of these neurons. Pd5 and Pd6 are large cells (~ 400 m) and produce peptide neurotransmitters and therefore, these are likely to function in generating or modulating the motor output of the magnetic orientation circuitry. The function of Pd7 is not so obvious, however some possible functionality of the same has been offered. Like Pd7 possibly controls or modulates some subtle aspects of tuning or locomotion that occurs during magnetic orientation behavior. Another possibility is that it might be suppressing the behavior that otherwise impede magnetic orientation or locomotion. Besides, neurobiological investigation of magnetic orientation in Tritonia Diomedea a few work has been done on the neural mechanisms underlying magnetic navigation behavior of vertebrates. However, not much success has been reported so far primarily due to complexity of their neural network. Also, hardly any work has been done on the role higher order signal processing associated with sensory systems. It should be noted that the original signals detected by sensors are considerably altered by the higher order signal processing and has hardly any resemblance with the original signals. Therefore, this aspect is very important and should find special focus in any serious research aiming to reveal the basic mechanisms underlying magnetic orientation behavior of different animals. References Cain S. D., Boles L. C, Wang J. H. and Lohmann K. J. (2005). Magnetic Orientation and Navigation in Marine Turtles, Lobsters, and Molluscs: Concepts and Conundrums. Integr. Comp. Biol., 45, 539-546. Johnsen Snke and Lohmann K. J. (2005). The Physics and Neurobiology of Magnetoreception. Nature Reviews (Neuroscience), 6, 703-712. Lohmann, K. J., Pentcheff N. D., Nevitt G. A., Stetten G. D., Zimmer-Faust R. K., Jarrard H. E. et al. (1995a). Magnetic Orientation of Spiny Lobsters in the Ocean: Experiments with Undersea Coil Systems, J. Exp. Biol., 198, 2041-2048. Lohmann K. J., Hester J. T. and Lohmann CMF. (1999). Long Distance Navigation in Sea Turtles, Ethol. Ecol. Evol., 11, 1-23.

buy custom Fascinating Argumentative Essay Sample on Drug-Sniffing Dogs

buy custom Fascinating Argumentative Essay Sample on Drug-Sniffing Dogs Argumentative Essay Sample on Drug-Sniffing Dogs in High School Campuses The Use of Drug-Sniffing Dogs in High School Campuses With the rising use of drugs amongst high school students, initiatives to curb these trends are developed within the various institutions that get charged with molding their character. The family institutions, schools and religious departments put their efforts to reduce the statistic of students abusing drugs. The use of marijuana, alcohol, ecstasy and commonly abused prescription drugs by students makes the control of drug abuse strenuous. The scope of drugs that can be abused is far beyond the limit of control measures put forward to prevent access to them. The high schools recently initiated a new measure to deter students from the use of drugs, which are drug-sniffing dogs. The dogs do random, periodical searches through the campuses of a given high school to fish out drugs and other related paraphernalia. This was meant to discourage students from coming to school with drugs. This move is not appropriate as it is extreme and is followed by a plethora of adverse effects.

Elision in Italian - Italian Elision

Elision in Italian - Italian Elision In Italian linguistics, elision is the omission of a unaccented final vowel before a word beginning with a vowel or the (since the letter â€Å"h† is silent). Normally, in spoken Italian, many elisions take place unconsciously, but only a portion of them are accepted forms in written Italian where they are marked with an apostrophe. A phenomenon similar to elision is called vocalic apocopation. It differs from elision, though, since an apostrophe is never used. The Spoken Elision and the Written Elision In theory, elisions are possible whenever two vowels are adjacent at the beginning or end of adjoining words- especially when those vowels are the same. In practice though, elisions have become less frequent in contemporary Italian, which is ironic since the so-called d eufonica has become increasingly common. Certain elisions seem automatic, like how â€Å"lamico - (male) friend† and â€Å"lamica - (female) friend† sound much better than â€Å"lo amico† and â€Å"la amica.† However, others may appear superfluous, like â€Å"una idea  » unidea.† And certain joined elisions result in awkward spellings with more apostrophes than necessary, like â€Å"dunaltra casa - of another home.† Here are the primary words that can be elided in Italian: Lo, la (as articles or pronouns), una and compounds, questo, questa, quello, quella Lalbero - TreeL’uomo - ManLho vista - I saw her / itUnantica via - an old streetNient’altro - Nothing elseNessunaltra- Nothing elseQuestorso - This bearQuestalunna - This student The preposition â€Å"di† and other grammatical morphemes ending in -i, like the pronouns mi, ti, si, vi Dandare - About goingDItalia - Of ItalyDell’altro - OtherD’accordo - Of agreement (e.g Sono d’accordo - I agree)D’oro - Of goldMha parlato - He talked to meMascolti? - Are you listening to me?Talzi presto? - Did you get up early?Savvià ² - He proceededSudirono - (They) were heardVilludono - They are deceiving you The preposition da is usually not elided, except in a few fixed phrases Daltronde - MoreoverD’altra parte - Somewhere elseDora in poi - From now on For ci and gli (and also as an article), there must be continuity with the usual spelling of the sounds: ci, ce, cia, cio, ciu; gli, glie, glia, glio, gliu. That is to say, ci is elided before e- or i-, while gli elides only before another i-. Accordingly cindicà ² la strada - he / she showed us the roadCà ¨ - there isc’era(no) - there was / there areCeravamo - There wasglItaliani - ItaliansGlimpedironoT’acchiappo - I catch you Some exceptions are: ci andà ² - he / she went thereci obbligarono - they forced usgli alberi - treesgli ultimi - the last The particle (particella) : se nandà ² - he / she left. Many other words such as santo, santa, senza, bello, bella, buono, buona, grande: SantAngelo - Saint AngelSantAnna - Saint AnnaSenzaltro - Certainly, definitelyBellaffare - Good businessBellamica - Good friendBuon’anima - Good soulGranduomo - Great man Others: Mezz’ora - Half hourA quattr’occhi - Face to faceArdo d’amore - I’m burning with love for you

Research into Recent Developments in Gold Prices Paper

Into Recent Developments in Gold Prices - Research Paper Example Relating the context of recession to the price changes of gold in the international market, it can be stated that the revitalization of demand for the commodity in the recovery period of 2010-2011 led to the sustained and rapid rise in gold price. With gradually stabilizing demand along with the Customer Price Index (CPI) in major economies including US and UK, the purchase rate of gold also increased which further augmented gold prices to maintain balances in its supply and demand ratios. With reference to the above presented chart, it can be apparently noted that gold price augmented rapidly during the month of August, 2011. For instance, the average gold price was recorded as USD 1572.81 per OZ for the month of July 2011 which increased to USD 1755.81 per OZ in the month of August 2011. It is in this context that gold suppliers intended to foster the reserves of the commodity encouraging production as well as recycling following the recovery of the financial market. Although, a 7% increase in the mine production was witnessed, the recycling activity made negative contribution of 3% in comparison to the previous year. On the similar context, the demand for gold was also rising steeply in the previous quarters of the year, i.e. 971.70 tons in Q1 and 919.80 tons in Q2. Therefore, in order to maintain the balance in the supply of gold having lesser growth rate than the demand, the price of the commodity increased rapidly during the month of August 2011.

Edcaution Assignment Example | Topics and Well Written Essays - 500 words

Edcaution - Assignment Example Secondly, designers of norm-referenced tests should pick the content taught in the many schools, in the country. This is especially in the case of nationwide or district-wide examinations. Essay questions, true or false tests, matching questions, definition and open-ended questions are examples of criterion-referenced tests. They measure a student’s level of competence based on a preset standard without comparing him or her with peers. The objectives of the course and the curriculum inform the setting of criterion-referenced tests. These tests are most helpful when they measure students’ ability in given areas. There exists a need to ensure high validity and reliability of these tests. Firstly, designers of these tests should ensure that they pick the content matching the objectives of the course and the standards of the curriculum (Popham, 2008). A big cluster around the high end of the grading system shows many students met the standards. Secondly, the designers of these tests should suspend their biases. Bias-free tests are fair to all students regardless of gender, ethnic background, race and socio-economic status. High-stakes tests are another group of tests besides norm-referenced tests. The outcomes of these tests serve to make important decisions in people’s lives. A licensure examination is an example of a high-stakes test. This is because the results of the examination help decide the possibility of an examinee getting a permit to practice as a professional nurse (Kubiszyn & Borich, 2007). Because the results of high-stakes tests determine whether individuals get permits to do something or not, they need high reliability and validity. Speed tests measure the rate at which individuals can perform a given task. The test measures the speed of performance only and not the knowledge of individuals. There is a possibility of misusing

Essay --

During the Meiji Restoration, Japan transformed into a strong industrialized nation by adopting the Western political, cultural, and technological ideas. Japan was the â€Å"only non-Western country to industrialize in the nineteenth century and that, moreover, she did so in an extremely short time† (Sugiyama 1). Japan’s social, political, and economic aspects were all affected by the Western technologies to transform Japan into an industrialized nation (Wittner 1). By adopting the Western ideas during the Meiji Restoration, Japan has turned into a powerful industrialized nation by becoming an â€Å"international political player in the 1880s† (Wittner 1). Prior to the Meiji Restoration, the Western powers viewed Japan as the backward nation because â€Å"in terms of military strength and economic development, Japan was indeed far behind the Western nations† (Hane and Perez 84). The Meiji government feared that Western nations would colonize Japan because they had already done it to other Asian countries by using military forces (Hane and Perez 84). The Meiji government’s fear came out to be true when the Western powers imposed unequal commercial treaties on Japan. Because of these unequal treaties Japan was â€Å"deprived of the right to regulate tariffs, and Western residents in the treaty ports were granted the privilege of extraterritoriality† (Hane and Perez 84). However, these unequal treaties were significant to the Meiji Restoration because they became the foundation of Japan’s industrial revolution by providing Japan with the access not only to Western technologies but also to political, cultural, and social ideas (Hane and Perez 82). Moreover, the treaties were important to Japan’s economic future because they increased the Japan’s econom... ...Restoration was the telephone. Iwadare Kunihiko established Nihon Denki (Nippon Electric Co., also known as NEC) by teaming up with the Western Electric (WE) of the United States (Odagiri and Goto 161). Kunihiko and NEC adopted WE’s technology and communication equipment, which helped expand the production of telephones (Odagiri and Goto 162). The telephone production was important for Japan’s industrialization because communication became easier. Many people were able to keep in touch with their friends and families who live far away by simply calling them. The telephone was also important for business because it sped up the commercial transactions. As more people are using the telephone, more private owned telephone companies were operated to raise profits. The American telephone technology brought industrialization in Japan by increasing the telephone production.

A Marriage Agreement

Marriage, as they say, takes two to work. Gender roles should not exist in marriage because it would only bring conflicts to the relationship. Couples need to become partners while still maintaining their individuality. They need to learn how to make decisions with the other person in mind. If not, the marriage will most likely turn into a divorce with the couple thinking that this is the best solution.Alix Kates Shulman, in her essay entitled A Marriage Agreement, believes that everything can be worked out if couples only knew how to work around each other. She proves this by presenting the audience with their Marriage Agreement in which both she and her husband explicitly detail each other's chores and responsibility.The author admits that the agreement was a little formal; however, it worked for their marriage (p. 181), and this is what is important. The couple decided to make an agreement after realizing that they have grown too accustomed to their everyday chores wherein the wif e did everything from taking care of the children to cleaning the house while the husband spends time away from his family to make some money.This is what most couples have become, which makes their marriage fall apart. Shulman writes how verbal agreement to delegate tasks and share duties will not work and that a written agreement will make it easier for couples to adjust to the new divisions of their responsibilities.However as good as the author’s narration of how they delegated the tasks, for overall effectiveness of convincing readers of the effectivity of such delegation the author must present proof and comparison of the advantages of such agreements. The essay simply indicates in passing the effectiveness of such delegations without further proof or solidification and therefore, becomes weak in persuading its readers.The main article starts off with introducing the current situation of marriage life in America. It starts off by imprinting an image to the readers on ho w overworked and lopsided the delegation of domestic responsibilities is towards women. It was presented in a way that is very academic stating statistics and quoting researches.This acts as a clear introduction of the featured author’s feminist view of how household responsibilities must be shared among spouses. The article then goes on saying how better it is for families that do not follow the traditional delegation of household work than those who are not willing to share the duties and responsibilities of taking care of home and family (p.179). All these up to this point were presented in a very clear manner with the intent of the author to convince her audience of how sharing responsibilities is beneficial to marriage life introduced smoothly.However, from this academic level of argumentation, the article presents an essay that is a personal account of a marriage life. This essay is supposedly the main argument of the article but for some reason, it does not provide muc h strength to the stated arguments. Rather, it simply gives a glimpse of how to spread evenly responsibilities without much proof of its effectivity. This is the main flaw of the essay as it does not strengthen the main article.