Mahmoud Darwish Narratives of Exile and Diaspora in the Poetry

Mahmoud Darwish was a Palestinian who lived between 1942 and 2008. His birth place was al- Birwa, a village in Galilee, which was occupied and eventually razed by the army from Israel. Considering that Darwish and the family had not participated in the authorized Israeli tally, they were regarded as internal refugees. For several years, Darwish resided in Paris and Beirut as an expatriate.Advertising We will write a custom essay sample on Mahmoud Darwish: Narratives of Exile and Diaspora in the Poetry specifically for you for only $16.05 $11/page Learn More Darwish wrote numerous poetry and prose books. As a result, he was an award winner to the Lenin Peace Prize, Lannan Cultural Freedom Prize (Lannan Foundation), Belles Lettres Medal (France), and Knight of Arts. This paper aims at discussing the narratives of exile and diaspora in Darwish’s poetry. There are a wide array of attitudes linked to the exile and diaspora in Darwish’s poetry. T he Palestinian literature is punctuated through the themes of diaspora and exile. In the poem â€Å"Earth Scrapes Us†, Darwish depicts the level of nostalgia he had for his motherland. He wished that they were motherland’s wheat, its mother, and that their mother would have mercy on them. Similar to the Jews, the Palestinians had a destiny of residing in diaspora. This is because they had the habit of migrating from one exile to the other. Therefore, Darwish finds himself marveling about where their consequent refugee camp would be. On the same note, he made the revelations that the bleeding wounds bore by the refugees from Palestine would develop and become masses of olive trees. In several series of poems, Darwish created a vivid picture of the wretched conditions that his people in Beirut’s exile were residing in. In addition, he scrutinized the Palestinian refugees’ massacres since they were entrapped in the Lebanese civil war. Darwish’s poetry is a narration of the entire story concerning the Palestinian misfortunes while in the Lebanese Diaspora. The Lebanese allies and Israeli army heartlessly attacked the Palestinians’ refugee camps, which were based in Lebanon. After the Palestinian Liberation Organization’s multitudes were expatriated from Lebanon in 1982, the Israeli attacked the country. During this period, defenseless refugee camps were invaded and many children and women who were disarmed were killed. This was accomplished by the Israeli in coordination with the Lebanese Christian militias. In addition to this, these militias were accountable for the Palestinian refugees’ mass killings. This happened during the Tel-Al- Z a’tar massacre while the Lebanese Civil War was ongoing.Advertising Looking for essay on literature languages? Let's see if we can help you! Get your first paper with 15% OFF Learn More Furthermore, the Palestinian refugee camps were under siege for a p eriod of more than 6 months. The Shi’ite Muslim militias and Syrian army had besieged the refugee camps. A majority of the exiled refugees starved to death. Darwish used a wide array of images in his poems. For instance, he utilized the sea image in â€Å"Brief Reflections on an Ancient and Beautiful City on the Coast of the Mediterranean Sea† to symbolize the Palestinian exile. Having been banished from their country, the refugees from Palestine had resided in the Lebanese exile from 1948. In 1982, when Lebanon was invaded by the Israeli, the Palestinian refugees were enforced to abandon their Lebanon camps and migrate to a new exile. Darwish gave a narration of how the sea evacuated the Palestinian refugees. In this case, the sea symbolized the Palestinian exile. Darwish also gave a highlight of the period that the Palestinian suffering lasted. The Palestinians’ exile took place in 1967 and 1948. This was after all the Palestinian terrains had been occupied. D uring the 3rd exodus in 1982, the Palestinian evacuees who were residing in Lebanon underwent through grave suffering. This was depicted in the statement that the sea could not hold an additional immigration since it had no more room. The survivors of the camps’ genocide were referred to by Darwish as the Massacre generation. These were doomed since they had to migrate from exile to exile. However, death was their only fate. Hence, Darwish showed the sympathy he had for the Palestinian refugees and offered apologies for the atrocities imposed upon the victim and land. In the ‘Victim Number48’, there is a description of the experiences of a Palestinian expatriate in Lebanon. Such experience is used to symbolize all the Palestinian refugees who were living in the Arabian land. It is worth noting that the expatriates were exposed to alienation, exile sufferings, and vulnerability to genocide and war. The Palestinian refugees were termed to as the victims who were de nied national passports. Ironically, the host country only gave them a travel document. There is a symbol of a poor woman in one of the poems. The poor woman symbolizes all Palestinian mothers who have no option but witness the suffering and death subjected to their children.Advertising We will write a custom essay sample on Mahmoud Darwish: Narratives of Exile and Diaspora in the Poetry specifically for you for only $16.05 $11/page Learn More The sufferings are particularly carried out by the Israeli soldiers as well as in the Arabian nations where the Palestinian refugees were regarded as aliens. In essence, Darwish made a lot of efforts in exploring the experiences in exile and diaspora. This essay on Mahmoud Darwish: Narratives of Exile and Diaspora in the Poetry was written and submitted by user Sonia Whitney to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.

Start-to-Finish Ecology Research Paper Writing Guide

Start-to-Finish Ecology Research Paper Writing Guide An ecology research paper is academic writing based on an original scientific investigation on a particular ecological topic, analysis of gathered information, and interpretation of the research findings. Ecology research papers may focus on different aspects, such as biogeochemistry and ecosystem science, evolutionary patterns and processes, community ecology, organismal biology, population biology, and chemical ecology, and commonly researched areas, such as sustainability, conservation, and environment. Questions you should ask yourself before beginning the research paper investigation and writing process include: How do I begin the ecology research paper and what ecology topic do I choose? Where do I find information and what gaps exist in various ecology topics of interest? How do I formulate the research paper’s title and thesis statements? What form of scientific investigation do I need to use in my research paper and why? This ecology research paper writing guide provides a step-by-step analysis of tips that help you respond to the above questions. Regardless of the requirements that should be followed when writing an ecology research paper, the first important element entails deciding what to research and write about. Therefore, identifying an ecology research paper topic is an important first step in the writing process. Picking a Suitable Topic for Your Ecology Research Paper Writing Topics that disinterest you and those that may not be too challenging contribute to loss of enthusiasm and diminish the efforts you may put towards researching and putting the research paper together. Therefore, choose topics that interest and challenge you to improve your attitude towards the topic and the research process. The following steps are essential when selecting research topics in ecology. Brainstorm for ideas. Generate topic ideas by exploring the strong opinions you have on current environmental issues such as sustainability, conservation, and environment. Try to remember recent topics or information acquired recently that piqued your interest in topics such as community ecology, ecosystem science, or population biology, among other ecology research areas. Other ways of brainstorming for ideas entail exploring issues that you are interested in knowing about, gaps in the literature that you can fill, and class aspects that need in-depth research and analysis. Research general background information. Scan through ecology journals, articles, and books for an overview of the research topic. Reading general information on various topics allows you to see how ideas relate and the scope of topics. Key research words can be sourced from the read articles and books. Focus on the topic. Once you have selected a probable topic, ensure it is manageable and that it is not too broad or too narrow. If it is too broad like â€Å"the environment,† limit the topic by defining a geographical area, population, time frame, culture, or a specific discipline in ecology. For instance, you can limit the topic â€Å"environment† by geography by focusing on the environmental impacts of industrial production in Quanzhou, China. Define the topic as a research question. Formulate questions about the topic to develop clear ideas on how to amend the topic by limiting or broadening the scope. For instance, if the topic idea is sustainability, the research question could be, â€Å"How has sustainability practices enhanced ecological agriculture?† A focused research question would be, â€Å"How has sustainability practices enhanced ecological agriculture in Japan?† Thus, a suitable research topic would be â€Å"The role of sustainable practices in enhancing ecological agriculture: a case analysis of Japan’s agricultural system.† Viable ecology research paper topics are as follows: Assessing the Impacts of Human Activities on Communities and the Ecosystem Function Across Spatial Scales; Predicted and Actual Effects and Ramifications of Land-Use and Climate Change on Biodiversity in Agricultural Settings; A Systematic Review of the Role of Species’ Physiological Limits in Improving the Precision of Ecological Niche Models; Analysis of The Neuroethology of Learning and Memory in Honeybees and Bumble Bees; Assess the Factors that Affect Bee Health. Developing an Appropriate Thesis Statement for Your Ecology Research Paper Your research paper should have a strong thesis statement that articulates the unifying theme of your paper. Depending on your chosen topic, the thesis statement could present an argument, provoke different thoughts, or describe ideas. The thesis should define what the research is about and guide the intended audience through your ideas to help make sense of your paper. The statement will minimize possibilities of you engaging in disconnected thoughts likely to lose the readers’ interest. When creating a thesis statement: Write in point form the topic and main ideas that should be discussed. Free write the essential thoughts you have about your paper. Make connections between the major points of your paper and highlight causes, applications, and implications of your arguments. In this case, ask yourself why you are writing the research paper. Combine the above ideas into a sentence or two to come up with a thesis statement. The thesis statement should present a point of view that readers and other writers can agree or disagree with. Moreover, it should provide reasons for choosing specific viewpoints. Additional Tips for Creating a Good Thesis Statement. Begin the process with a question. As noted above, the answers you come up with from the question can become your thesis statement. For instance: Question: What are the benefits of climate controlled storage? Answer: A major benefit of climate controlled storage is that it maintains a consistent temperature and protects artifacts from extreme temperatures. Thus, the thesis statement can be, ‘Climate controlled storage units are important because they maintain a consistent temperature and protect artifacts from extreme temperatures.’ In addition, correlate your thesis statement to the type of research paper you are writing; that is, is your research argumentative, persuasive, or informative? The Structure of an Ecology Research Paper A scholarly research paper has six main sections, but the number of segments may vary depending on the topic, the purpose of the research paper, and its length. The sections include the title, the abstract, the introduction, the body, the conclusion, and the reference section. In most cases, the body section contains other sub-divisions such as methods, results, and discussion. Title of the Research Paper Different writing conventions have diverse requirements concerning how the title page of your research paper should appear. The common elements that cut across all conventions are the name of the author, the title of the research paper, and the assignment or the publication date. Abstract The abstract is a brief section of your research paper that describes your study, states its significant and major findings, and summarizes the major points. Although the section comes before the actual paper, it is appropriate to write it last. Introduction The introduction should occupy about 10% of your entire research paper. However, the length may vary depending on the topic and the availability of segments such as problem statement, the significance of the research, and objectives. Whether the noted segments are stand-alone elements of the introduction or not, you should include information about: The objective of the research; Background information on the study topic; The significance of the research topic and the paper to the intended audience; Thesis statement, purpose statement, and an outline of the paper. The introduction of a scientific research paper should also include a brief review of the relevant literature and state the hypotheses to be tested. Body This part of the research paper focuses on the study completely. The body should: Present relevant and current research that pertains to your ecology research topic. Provide evidence that supports your arguments objectively. Avoid drawing any conclusions regarding the research. The body section can be written in prose with each paragraph presenting new ideas or theme and supporting evidence. In such a case, the outline for the body is as follows: Paragraph 1: Main idea 1 Supporting evidence 1 Supporting evidence 2 Paragraph 2: Main idea 2 Supporting evidence 1 Supporting evidence 2 The noted outline can be used for all the major themes and ideas. Other elements that should be incorporated in the body paragraphs include: A topic sentence: the topic sentence in each paragraph should organize and encapsulate the entire ideas and content of the paragraph. The sentence should appear at the beginning of the paragraph. The questions you should ask yourself when writing the topic sentence include: What will the paragraph discuss? Why did I choose to include the information I have? Why is this paragraph essential to the context of my thesis statement and arguments? What point am I trying to make? If your topic sentence requires further elaboration, add one or two sentences that explain it. An introduction to your evidence. Research papers require students to incorporate evidence to support claims highlighted in the paragraphs and the research paper as a whole. The evidence may be in the form of quotes, figures, examples, and statistics. The evidence must be well integrated into the topic sentence, as well as your claim and opinions. In this case, you should ensure that the reader can transition from your opinions to evidence that supports your viewpoints. A concluding sentence. The concluding sentence acts as an element that reasserts how your paragraph contributes to the development of your claim and the research paper. It should also help in transitioning from the paragraph to the next. As noted earlier, some research papers are more elaborate and are based on the scientific method of inquiry. If your research paper is based on a purely scientific method of inquiry, your body section needs more than just paragraphs with topic sentences and supporting evidence. These types of research papers have other subsections, such as research methodology, results/findings, analysis, and discussion of findings. Research Methodology The research methodology section should elaborate the research design used to gather data for analysis. You should describe the methods and materials employed in detail to allow the reader to understand the basis of the stand and replicate the entire study where necessary. If the ecology research is based on human participants, describe your sampling process and data collection methods and procedures. Results/Findings This section of the research should highlight the main features of the gathered data. You should not provide a complete description of the details besides presenting data in tables and figures. However, some data cannot be presented in graphical forms, which implies that you can present the results in parenthesis. Discussion Interpret and evaluate the results presented in the earlier section critically. You need to compare your findings to your expectations and evaluate whether they agree with formulated hypotheses where applicable. Moreover, compare your findings with the results from similar studies in your chosen ecology topic. Respond to the research questions and draw conclusions. Conclusion The conclusion of your research paper should address your thesis statement by synthesizing the research presented in the paper. Summarize the main points of your research paper and findings of the study, as well as their implications and significance. A good conclusion should: Restate and not simply repeat your thesis statement; Offer summarized and synthesized findings of your research; State implications and recommendations for further study based on your study findings; Make sure not to introduce new content into the conclusion. Reference Section. The reference section highlights the literature cited. The references should be well articulated and in line with the appropriate formats as dictated by various writing conventions. Post Writing Tips from Our Writers to Polish Up Your Ecology Research Paper Proofreading your research paper is the major post writing activity you should engage in. You should review: Paragraph level issues, such as the sequencing of ideas, the presentation of topic sentences, the generalizations, the summaries, the use of transitions, and the presentation of evidence for your claims; Sentence level issues, such as the word choice, the sentence structure, the spelling, and the punctuation; Consistent use of a single system of documentation, appropriate citation of borrowed primary and secondary sources, and the accuracy of the works cited list. The proofreading should be done hours or days later to promote objectivity.

Comparison between First and Last Covenants of the Old Testament Term Paper

Comparison between First and Last Covenants of the Old Testament - Term Paper Example The Old Testament views God’s commands decreed upon Adam, the father of humanity, during his stay in the Garden of Eden, as the first covenant issued by the Lord to the humankind. The covenant assured bestowing of God’s countless bounties and blessings upon man, against which it imposed only one single restriction on him i.e. not to taste the fruit of the forbidden tree (of knowledge). (Genesis, 2: 16-17) Additionally, God blessed Adam with the mandate of remaining fruitful and multiply subsequently, as the Old Testament reveals that God said to Adam to â€Å"be fruitful and multiply; fill the earth and subdue it; have dominion over the fish of the sea, over the birds of the air, and over every living thing that moves on the earth† (Gen. 1:28). Similarly, the Lord made His covenant with King David, which is stated to be the last covenant described in the Old Testament; according to which God would not only send Messiah from the line of David, but also the rulers and kings would also belong to the same line. Additionally, messiah would also rule over the entire world, and all the races would be as his subjugated ones. Hence, God would bless Davidic seed with the spiritual and materialistic domination for the future generations to come. â€Å"The Davidic king would be the one to defeat all the Satanic enemies of God and establish the kingdom of blessing all over the world (Ps. 2, 89:21-29; 110). He would be the seed of the woman who would defeat the seed of the serpent and save the world. Not only a king, he is also a priest after the order of Melchizedek (Ps. 110). It is even hinted that He would offer Himself as the sacrifice for sin (Isaiah. 52:13-53:12).† (Quoted in Smith, 2009: 8) This prophecy pointed to the futu re work of the Lord Jesus Christ. By closely examining both the covenants, it becomes crystal clear that Adam’s covenant maintains several similarities in with the Davidic one. God had blessed Adam and his children with the supremacy over every creature. On the other hand, King David was also favored with the same bounty, as he and his son king Solomon were not only granted the crown, wealth, power and prestige, but also they had domination over the djinns, ogres, humans and beast alike. King David intended to build a house for God, though the Lord refused the offer. Instead He blessed David with glorious house, power and throne, and a wise and powerful son in the person of King Solomon. â€Å"God promised to give him a son who would ultimately reign on the throne of David for ever and build a house of worship for all nations of the world.† (Quoted in the kingdom divided) Hence, God blessed a comfortable dwelling to David, according to the Covenant, as He had blessed A dam an outstanding abode in heavens. God had allowed Adam to reside in heavens and get involved into every type of activity of his own choice from dawn to dusk and dusk to dawn. Consequently, Adam and Eve led a very exuberant life in heaven. Somehow, since man has been created frail and weak, the first parents of humanity could not constrain themselves from the covenant they had made with their Creator, and thus broke their allegiance with the Lord by eating

Product and Brand Life Cycle Management Assignment

Product and Brand Life Cycle Management - Assignment Example Writing on marketing trends and PLC, Kvesic (2008) observed that the ability of a product to withstand the market over very long time is directly influenced by the extent by which the product responds to present needs of the market. The Apple iPhone 6 and most of its processor brands can thus be noted to be such products that were introduced to meet current demand of phone users. For example, most phone users are now enthused with large screen, flatter and high function operating system, all of which this phone provides (Thomas and Bradshaw, 2014). Whiles the Apple iPhone 6 is in its growth stage, the Moto X, which is a product in the same industry as the former can be said to be in its decline stages or even beyond. Even though the Moto X could be said to have dominated the market well when it was first introduced back in 2013, the same cannot be said of the product today. It is for this reason that the product is said to be at the decline stage of the PLC. This is because at the decline stage of the PLC, Kvesic (2008) noted that the demand for a brand or product begins to drop drastically. Such drop in demand automatically affects sales and the capital injection into the marketing of the product. Interestingly for the Moto X, the maturity of the brand on its lifecycle was not directly related to what was happening with Smartphone as a product. This is because even the declining performance of the brand, other brands of Smartphone that were introduced at the time experienced peaked sales. A typical example of this was the iPh one 5c (Dilger, 2013). From the observation made above where it has been stated that iPhone 5c flourished whiles Moto X declined, it can be noted that marketing mix variables have a lot of roles to play in the marketing of brands and products according to their lifecycle (Perreault Jr., Cannon & McCarthy, 2014). For

Metaphysics and Theories of Reality Essay Example | Topics and Well Written Essays - 750 words

Metaphysics and Theories of Reality - Essay Example Through these representations, philosophers able to find logic on each other's work. The find meaning and answers to each ideas; answers find its way resulting to another answer. Therefore, based on disagreements and debates from one century to another there's always a never ending process to the meaning of each statements whether it is factual or not. "The Father of all things is war"; I firmly believe that Order and Chaos co-exist with one another and without this, war will be the result. Order and Chaos should be balanced and complement each other. Order is there to make sure that everything is organize, logically formed in a presentable manner and guidelines to follow. If any of these things were not followed accordingly, chaos will be the end result. These two are like a big circle that continuously moving into one direction and is never ending that is why it is a must that each one should follow what is directed. "You can't step into the same river twice"; In my opinion this is a perfect example of what has St. Augustine has mentioned that time is both a combination of linear and progress. Progress in such a way that life is a moving process, each day that we live, we are going and moving forward to one direction. Every path that we crossed is something that we need to think about and needs some changes over time. Linear in a way like parallel to the progress that each one is undertaking daily. Everything that we do cannot whether good or bad decisions affect the linear and progress directions of our lives. It is also one way of saying that change is inevitable. "The only thing that stays the same is nothing stays the same"; Yes, it's actually true that the only permanent thing in this world is change as quoted by one of our great philosophers. It is also true that Eternity and Time has something to do with stability and change. We know that Eternity is God, our creator and the most high. Yet, he's the one who has a full control of our destiny, our path and the one who creates stability. Time is something that can be changed but hard to get back since we can't bring back what was happened in the past though we know that we can change the future or even foresee it and learn from it. The three ideas selected are of great relevance and of importance to our everyday lives. These three are basic human foundation in order for us to be able to survive, reach our goals, target specific aims and use as a guidelines in order to have a clear path and a smooth road towards gaining experience, learning from it and achieving the things that we are aiming for. Likewise, these are ruling principles wherein we could adapt in order to measure how effective are we doing in terms of relationships, goals, and decisions. Through these principles we can then say that in one way or another we can apply it to our activities of daily living. We know for a fact that whatever the religion is, we all believe that we have one supreme being who is above all creations and that through HIM that's the main reason why we are here in this planet. Every day we make our decisions and every day through mistakes we all learn from it this is where we apply that change is the only permanen

About Health Education Taught In Schools

About Health Education Taught In Schools Should health education be taught in schools? In this day and age, health problems play a pivotal role in Ss„Â ¢ ability to come to school, stay in school and make the best performance during their studies whether in primary schools, secondary schools or in universities. Developing the health of student can also be done well by the schools which lack healthcare resources. According to a survey of a 12.5 per cent of sample of schools in England and Wales (Williams, 1985), some 87 per cent of primary schools were teaching about health and a further 4 per cent planned to do so in the near future. The comparable figures for secondary schools were 85 per cent and 9 per cent respectively. Most people agree with that school should do more on health education, but others believe that there are also many drawbacks on health education in schools. What is health education? (http://www.ltscotland.org.uk/healthpromotingschools/)health promotion in schools is not just about encouraging children and young people to eat well and to exercise; it encompasses a much broader holistic approach. This approach is called the whole school approach, which includes promoting the physical, social, spiritual, mental and emotional wellbeing of all pupils and staff. This essay will identify and discuss the positive and negative sides of it. Recently, health education is gaining popularity in all kinds of schools among all kinds of students .It has many shining points. Developing the health, hygiene and nutrition of children is an important thing to school because it„Â ¢s difficult to children to learn when they are hungry or sick. But safe physical surroundings and advantageous psychosocial surroundings should be guarantee of a good school policy, and it also should avoid molestation, insulting language and discrimination; using drug, alcohol and tobacco isn„Â ¢t allowable of a good school policy and the same to violence and bullying. Students can improve their health-related knowledge, attitudes, skills, and stimulate the interest of children to concentrate their energy and improve their health, take precautions against disease and avoid health-related risk behaviors in a variety of health areas by health education. Firstly, health education is benefit to children„Â ¢s physiology via two aspects: h ealth eating and physical activities. Via health education, children can learn more knowledge of healthy food choices which can contribute the children„Â ¢s confidence, skills, knowledge and understanding. By learning the knowledge of choosing healthy food, it will increase children„Â ¢s consumption of complex carbohydrates, and decrease their consumption of saturated fat, cholesterol, sodium, and sugar, then increase their level of habitual physical activity; after it, children will generalize these changes to other family members.

Caridina japonica :: essays papers

Caridina japonica Caridina japonica, die "Amanogarnele" Yamato-numa-ebi Sà ¼ÃƒÅ¸wassergarnelen der Gattungen Atyopsis, Macrobrachium und Caridina erobern schon seit langer Zeit die Becken und Herzen derjenigen Aquarianer im Sturm, die so unvorsichtig waren, sich ernsthaft mit diesen faszinierenden Wirbellosen einzulassen. Dennoch mußten sie hinsichtlich einer breiteren Popularità ¤t meist hinter der beflossten Konkurrenz ein unverdientes Nischendasein fristen, obwohl sie doch mit Eigenschaften aufwarten kà ¶nnen, die besonders einige Vertreter zu fast idealen Aquariumbewohnern machen. Zuzutrauen wà ¤re ihnen selbstverstà ¤ndlich auch, daß sie ihren großen Auftritt auf einen Zeitpunkt verlegen wollten, der ihnen hierfà ¼r endlich einen angemessenen Rahmen bieten konnte. Opfer dieser ausgeklà ¼gelten Strategie wurde schließlich der japanische Fotograf und Pflanzenliebhaber Takashi Amano, der mit seinen phantastischen Fotobà ¤nden und der Prà ¤sentation seines Konzeptes eines "Naturaquariums" nicht nur der Aquaristik weltweit neue, interessante Impulse vermittelte, sondern auch einer kleinen Sà ¼ÃƒÅ¸wassergarnele ihr "coming out". Es ist angerichtet... verschiedene Algen unter dem Mikroskop Warum genießt nun unter zahllosen Arten der Gattung Caridina ausgerechnet C. japonica inzwischen geradezu einen "Kultstatus" ? In Pflanzenbecken mit sehr mà ¤ÃƒÅ¸igem Fischbesatz, starker Beleuchtung und entsprechend hierauf abgestimmter CO2-Zufuhr finden nicht nur Wasserpflanzen gà ¼nstige Bedingungen vor, sondern auch verschiedene Algenarten, insbesondere Fadenalgen. Gerade bei solch einem "schnellen" Becken laufen gelegentlich einmal einige Faktoren schneller aus dem Ruder, als man mit Korrekturen nachkommen kann und die Algen nutzen die Gunst der Stunde, sich nicht dankbar auf das ihnen wohlwollend eingerà ¤umte Maß zu beschrà ¤nken. Auf der Suche nach einer natà ¼rlichen Algenprophylaxe hat Takashi Amano parallel zum Einsatz von Otocinclus-Arten (fà ¼r die Scheiben *g*) mit verschiedenen einheimischen Sà ¼ÃƒÅ¸wassergarnelen experimentiert. C. japonica aus der Region Yamato soll sich dabei als die weitaus effizienteste Art erwiesen haben. Yamato-numa-ebi - charakteristischer Rà ¼ckenstreifen Nachdem ich selbst seit einiger Zeit Erfahrungen mit verschiedenen Sà ¼ÃƒÅ¸wassergarnelen sammeln konnte, vor allem mit Neocaridina denticulata und meinem persà ¶nlichen kleinem Favoriten, der Zebra- oder Rotschwanzgarnele C. serrata, stand ich den sagenumwobenen Qualità ¤ten von C. japonica als Rasenmà ¤her fà ¼r Fadenalgen mehr als skeptisch gegenà ¼ber. Kennengelernt hatte ich meine Garnelen bisher als ausgesprochene Allesfresser, bevorzugt wurde immer genau das Futterangebot, welches bei geringstem Aufwand die meiste Energie lieferte. Die Palette reicht von Tubifex à ¼ber Trockenfuttertabletten bis hin zu abgestorbenen Pflanzenteilen. Algen waren auch dabei... Irgendwann war ich vollstà ¤ndig vom "Garnelen-Bazillus" durchdrungen, und meine C. serrata stießen mit ihrer energischen Forderung nach einem eigenen Becken nur auf schwache Gegenwehr, da ich ohnehin die Einrichtung eines Pflanzenbeckens ohne jeglichen Fischbesatz plante. Schon nach kurzer Zeit bekundeten die kleinen Racker ihr Wohlgefallen am neuen Lebensraum durch monatliche Verdoppelung des Bestandes, kamen aber der ihnen zugedachten Aufgabe als Algenkontrolleure nur mehr als nachlà ¤ssig nach.

Overcoming Multimedia Addiction Essay

Some of the students nowadays are struggling to stay awake while the rest of the world is asleep just to read their friends’ posts and comments and status on Facebook. They even spend most of their time staring at the big screens of their personal computers just to play online games like DOTA and Counterstrike. Some also spend their money just to buy the latest mobile phones, mp3 players, and other techno gadgets out there. However, they must keep in mind that everything has its own limits. Otherwise, it can become a cause of concern and in extreme cases, addiction. Multimedia addiction can cause destruction and violence to students. Multimedia is simply defined as multi tasking of applications in a single device or gadget. This includes graphics, animation, pictures, videos, and other applications which can be opened simultaneously or consecutively. Smart phone, laptop, iPod, television, and mp4 player are some of many multimedia gadgets that are ‘in’ especially to students because of its amazing features. Consider the television. Whether it is a box, slim, or flat screen, it has become almost like another member of the household. It sits in the living room, in the kitchen, or even in the terrace of your house. It bombards us with all kinds of information about almost anything under the sun. It informs us on what laundry soap to use; what toothpaste to brush our teeth with, or which candidate to vote in the 2013 election. It brings us local news and news from around the world. And of course, it entertains us with sports, music, movies, telenovelas, lifestyle segments and variety programs. Cellular phones, on the other hand, are used for communication purposes. But because of technological advancements, new applications like built- in cameras are added to them. That’s why many people patronize it so much. Laptops are made for easy handling. Unlike personal computers, you can now bring it anywhere because of its small size. Almost every student today has his or her own laptops. The dependence on multimedia gadgets extend to students who became the primary beneficiaries of these gadgets. Tech- net survey said that 42 % of students are using mobile phones, 36 % are using laptop, 15 % are using play station, and 7 % are using mp3 players (â€Å"2012 Most Addicting Gadgets†, www. Technet.com). The use of multimedia gadgets can be constructive and destructive to students (Despabiladeras 15). Many of them consider the use of these gadgets constructive when they help them in their studies. Today, the internet is the major source of knowledge and information. In just one click, they can now find the answers to their assignments. They also use software like Microsoft office and the like for their project presentation. Many schools now use computer oriented techniques for teaching. The traditional way of teaching like writing too many lessons in a manila paper is already replaced by powerpoint presentations which are indeed favorable for the students. They no longer copy too many notes because there are handouts already prepared for them. Multimedia also gives information about the latest happenings and discoveries around the world. The use of social media sites like Facebook allows them to socialize with other people. Some also say that playing online games like DOTA and Counte rstrike have positive effects on them because they relieve stress from the hectic schedule of their schooling. In contrary, students say that multimedia gadgets can be destructive too. Problems begin when students became addicted to these gadgets to the point of discarding other activities which can truly affect their balance and studies (www. Gadgetforums.com). Because of these gadgets, they now prefer playing games that reading books. In most schools, use of cellular phones is banned but many of the students still carry them. They push their parents to buy them the latest mobile phone or other gizmos because their peers use it. The effect of this addiction is that they can no longer resist themselves from taking calls and accessing Facebook and other social networking sites during school hours. â€Å"The use of gadgets can be destructive when it makes your personality bad like when you become wild because of video games†, Bryan Capus said ( Despabiladeras 15). They forgot to budget their time because most of their time are consumed by these gadgets. The overuse of these also affects their health. Too much exposure to these gadgets can cause diseases like brain tumor and cancer caused by radiation (â€Å" Radiation From Gadgets†, www. Healthcare.com). They are prone to sickness because they no longer engaged in outdoor activities. It is alarming to know that 47 % of students nowadays are addicted to computers and other multimedia gadgets ( Despabiladeras 16.). Their parents have a big role in overcoming their children’s addiction. For example, most of the students are advised or told by their parents to limit their internet surfing time until 8:30 p.m. or 9:00 p.m. or but not to reach 10:00 p.m. as they have classes the next day ( Clifford 72). Some also advice their children to engage in other recreational activities like playing basketball or playing the guitar instead of watching T.V. or sitting all day in front of their PCs. One parent posted the following on gadgetforums.com: In today’s high- tech and modern world, we are all connected with each other through the miracle of working inventions and innovations like PC, tablets, smart phones, gaming, internet and so much more. And I think we feel that we won’t have a normal day without getting hooked to any one of these devices. The problem begins to rise when our children became addicted to these gadgets to the point of discarding other activities which can truly affect their balance and health. To avoid this, I try to ensure my son has balance in this area. Playing team sports has helped, that’s one thing in his like that doesn’t require gadget. Sports is one of the best ways to add moving activities to a child’s routine with the aim of creating a certain balance between studying and playing. We could not really avoid our children to get into gadgets as this is the wave of the future with the introduction of tablets which can he fully integrate with schools in the near fu ture ( www.gadgetforums.com). According to gadgetforums.com, there are eight ways to overcome gadget addiction. First, limit the amount of time you spent on any type of gadget. Second, learn to balance and manage your time. Make a time table on when to use your gadget. Third, spend most of your time in your studies. This will give you higher grades in return. Fourth, read books rather than playing games. Surfing the internet for recent news and discoveries will help too. Fifth, spend your free time with your family and friends. Go to an outing of family reunion that doesn’t require gadgets. Sixth, socialize with your true friends, not your ‘virtual’ friends. Your Facebook friends will never help you if you have a problem. Seventh, avoid buying newly released gadgets if you still have one that is still working. And the last is self discipline. It is interesting to know the opinions of students on multimedia gadget addiction; whether it is constructive or destructive for them and what their parents do in influencing their media habits. To prevent this addiction, students should analyze their gadget preferences and see what’s good of bad in it for them. They must set in mind that multimedia gadgets is there to help them, not to enslave them.

New World of Business

The article â€Å"Knowledge Management for the New World of Business† by Yogesh Malhotra discusses the importance of changes, information technologies and innovations as the main drives of business success. The author shows that attitudes towards knowledge management have been changed and nowadays knowledge management offers new ideas and concepts how to make business successful, innovative and, what is more important, socially responsible.The paper is retrieved from online database through search engines. Despite the paper is online source, the author offers well-supported, well-structured and well-organized study of world business in terms of knowledge management. Further, the paper is directly related with knowledge management filed as the author discusses the importance of knowledge, innovations, information technologies and changes which are known to be key components of knowledge management field. (Malhotra 1998)Malhotra says that today is the era of information technolo gies being associated with knowledge. The author argues that knowledge is critical source in business activity as it drives company either to success or complete failure.   New technologies as, for example, intranets, data-mining, web-casting and video-conferencing, offer new ways of meeting business challenges in knowledge era. Moreover, information technologies are encouraged by press trade. As a result, information technologies positively contribute business performance. For example, intranets and networks are effective in increasing inherent capabilities to facilitate knowledge management. (Malhotra 1998)Business is experiencing transition from the era of competitive advantage to the era of knowledge creation. Earlier business was characterized by low levels of changes and innovations. However, â€Å"the new world of knowledge-based industries is distinguished by its emphasis on precognition and adaptation in contrast to the traditional emphasis on optimization based on predi ction†. (Malhotra 1998) The author argues that knowledge-based business world is characterized by re-definition and re-evaluation of organizational objectives, goals, and missions. Simply saying, the business re-shapes the way of arranging things.Business environment is motivated by radical changes and innovations which â€Å"overwhelm the traditional organizational response of predicting and reacting based on pre-programmed heuristics†. (Malhotra 1998) Modern business world requires anticipatory response, and demands flexibility and resurfacing of old assumptions. Modern world tends not play following predictable rules – instead, it tends to change these rules and to keep changing. As result, new types of organizations have emerged: business ecosystems and virtual corporations. (Malhotra 1998)The author offers his own definition of knowledge management for a new business world and stresses that new definition should go beyond quick and predictable views of many others. Instead, definition should move executives, managers and common employees to think strategically and critically about the purpose of knowledge management. Malhotra says that knowledge managements is critical to organizational adaptation and survival as it drives and monitors environmental changes.Knowledge management â€Å"embodies organizational processes that seek synergistic combination of data and information processing capacity of information technologies, and the creative and innovative capacity of human beings†. (Malhotra 1998) Nevertheless, one problem exists as there is confusion between the terms ‘knowledge’ and ‘information’. The author claims that these notions are distinct entities as information is generated by computer systems and human interpretation of actions, whereas knowledge is of subjective nature.Malhotra recommends business managers to realize that knowledge is imbedded in them and the process of knowledge acquiring is social interactions. It is emphasized that knowledge creation depends solely on human beings as computers are only tools with information-gathering capabilities. New world of business is defined as wicked environment which requires interpretations of information and knowledge. (Malhotra 1998)One more positive moment in the article is that the author offers recommendations how to incorporate knowledge management in business activities. Firstly, it is necessary to refuse to control employees and their behaviors through setting predictable and pre-defined objectives and procedures. Instead, it would be better to create organization being capable of constructing diverse meanings. Secondly, the author recommends re-evaluating companies ideas how to arrange things and practices. Executive managers should consider dynamically changing business environment, as well as external and internal threats.   Thirdly, it is effective to invest in â€Å"multiple and diverse interpretations to ena ble constructive conflict mode of inquiry and, thus, lessen oversimplification of issues or premature decision closure†. (Malhotra 1998)Summing up, new business world offers new opportunities of success and knowledge plays crucial role in this process. New strategies are to encourage human imagination and creativity to promote internal diversity and to meet the needs and demands of the wicked environment.   Knowledge management makes companies and organizations re-think and re-evaluate their goals and practices, as well as use the power of knowledge in finding new ways of improving business performance. (Malhotra 1998)Works CitedMalhotra, Yogesh. 1998. Knowledge Management for the New World of Business. Available at http://www.brint.com/km/whatis.htm.   Accessed March 15, 2008. New World of Business The article â€Å"Knowledge Management for the New World of Business† by Yogesh Malhotra discusses the importance of changes, information technologies and innovations as the main drives of business success. The author shows that attitudes towards knowledge management have been changed and nowadays knowledge management offers new ideas and concepts how to make business successful, innovative and, what is more important, socially responsible. The paper is retrieved from online database through search engines. Despite the paper is online source, the author offers well-supported, well-structured and well-organized study of world business in terms of knowledge management. Further, the paper is directly related with knowledge management filed as the author discusses the importance of knowledge, innovations, information technologies and changes which are known to be key components of knowledge management field. (Malhotra 1998)Malhotra says that today is the era of information technol ogies being associated with knowledge. The author argues that knowledge is critical source in business activity as it drives company either to success or complete failure.   New technologies as, for example, intranets, data-mining, web-casting and video-conferencing, offer new ways of meeting business challenges in knowledge era. Moreover, information technologies are encouraged by press trade. As a result, information technologies positively contribute business performance. For example, intranets and networks are effective in increasing inherent capabilities to facilitate knowledge management. (Malhotra 1998)Business is experiencing transition from the era of competitive advantage to the era of knowledge creation. Earlier business was characterized by low levels of changes and innovations. However, â€Å"the new world of knowledge-based industries is distinguished by its emphasis on precognition and adaptation in contrast to the traditional emphasis on optimization based on pred iction†. (Malhotra 1998) The author argues that knowledge-based business world is characterized by re-definition and re-evaluation of organizational objectives, goals, and missions. Simply saying, the business re-shapes the way of arranging things.Business environment is motivated by radical changes and innovations which â€Å"overwhelm the traditional organizational response of predicting and reacting based on pre-programmed heuristics†. (Malhotra 1998) Modern business world requires anticipatory response, and demands flexibility and resurfacing of old assumptions. Modern world tends not play following predictable rules – instead, it tends to change these rules and to keep changing. As result, new types of organizations have emerged: business ecosystems and virtual corporations. (Malhotra 1998)The author offers his own definition of knowledge management for a new business world and stresses that new definition should go beyond quick and predictable views of many others. Instead, definition should move executives, managers and common employees to think strategically and critically about the purpose of knowledge management. Malhotra says that knowledge managements is critical to organizational adaptation and survival as it drives and monitors environmental changes.Knowledge management â€Å"embodies organizational processes that seek synergistic combination of data and information processing capacity of information technologies, and the creative and innovative capacity of human beings†. (Malhotra 1998) Nevertheless, one problem exists as there is confusion between the terms ‘knowledge’ and ‘information’. The author claims that these notions are distinct entities as information is generated by computer systems and human interpretation of actions, whereas knowledge is of subjective nature.Malhotra recommends business managers to realize that knowledge is imbedded in them and the process of knowledge acquiring i s social interactions. It is emphasized that knowledge creation depends solely on human beings as computers are only tools with information-gathering capabilities. New world of business is defined as wicked environment which requires interpretations of information and knowledge. (Malhotra 1998)One more positive moment in the article is that the author offers recommendations how to incorporate knowledge management in business activities. Firstly, it is necessary to refuse to control employees and their behaviors through setting predictable and pre-defined objectives and procedures. Instead, it would be better to create organization being capable of constructing diverse meanings. Secondly, the author recommends re-evaluating companies ideas how to arrange things and practices. Executive managers should consider dynamically changing business environment, as well as external and internal threats.   Thirdly, it is effective to invest in â€Å"multiple and diverse interpretations to en able constructive conflict mode of inquiry and, thus, lessen oversimplification of issues or premature decision closure†. (Malhotra 1998)Summing up, new business world offers new opportunities of success and knowledge plays crucial role in this process. New strategies are to encourage human imagination and creativity to promote internal diversity and to meet the needs and demands of the wicked environment.   Knowledge management makes companies and organizations re-think and re-evaluate their goals and practices, as well as use the power of knowledge in finding new ways of improving business performance. (Malhotra 1998)Works CitedMalhotra, Yogesh. 1998. Knowledge Management for the New World of Business. Available at http://www.brint.com/km/whatis.htm.   Accessed March 15, 2008.

Compare and Contrast Vertebrate and Invertebrate Vision Essays

Compare and Contrast Vertebrate and Invertebrate Vision Essays Compare and Contrast Vertebrate and Invertebrate Vision Paper Compare and Contrast Vertebrate and Invertebrate Vision Paper Although vertebrates and invertebrates originally evolved from a common ancestral root, both have developed very different physical utilities for vision. Both are fairly effective and have taken many millions of years to evolve. They contain many common underlying mechanisms but differ in the features used to provide them. The definition of an eye is an organ of visual perception that includes parts specialized for optical processing of light as well as well as photoreceptive neurons (Alberts). The main feature of an eye therefore, in all organisms that possess one, is the collection of photoreceptors used in converting light energy into action potentials (electrical energy). When comparing vertebrate and invertebrate vision, the two best-studied cases are the compound eye exemplified by arthropods and the simple eye used in vertebrates. The main difference between the compound and simple eye is that the compound eye uses a spatial array of lenses so that each image in a local region of visual space falls onto one or a few photoreceptors. The simple eye, however, uses a single lens to image the world onto an array of photoreceptors. Compound eyes produce mosaic images. The compound eye is made up of many optical units called ommatidiums, each of which is aimed at a different part of the visual field. Each ommatidium samples a different part of the visual field through a separate lens. In a simple eye, each receptor cell samples part of the field through a lens shared by all receptor cells. In compound eyes, each ommatidium samples an angular cone-shaped portion of the environment, taking in about 2-3i of the visual field. In contrast, each receptor of a simple eye may sample as little as 0. 2i of the visual field. In addition, the simple eye, inverts the image that falls on the retina. Since the receptive field of each ommatidium is relatively large, compound eyes have lower visual acuity than simple eyes. The mosaic image formed by a compound eye is also coarser than that of a simple eye. The simple eye in vertebrates focuses incident light in two stages. In the initial stage, incident light rays are refracted as they pass through the clear outer surface of the eye, called the cornea. They are further refracted as they pass through a second structure, the lens, and finally form an inverted image on the rear internal surface of the eye, the retina. Objects at different distance can be focussed in higher vertebrates by changing the curvature and thickness of the lens, which affects its focal length, the distance at which an image passed through the lens comes into focus. Diffraction is a property of all light and because of this, the angular resolution (resolving power) of any eye is limited by the diameter of its lens. The larger the lens diameter, the higher spatial resolution. The biggest problem for compound eyes is that the resolution is limited because the facets of the individual lens are so small. A compound eye of a given size will have a much lower resolving power than a simple eye of the same size. Optical superposition compound eyes are one way of increasing the effective lens diameter. This structure works by using several separate elements to image incident rays onto a single point, such as a single photoreceptor. This method is used in insects such as fireflies. Another way, is to use neural superposition. Simple eyes on the other hand, use a single lens, and have evolved entirely separately in the cephalopods and vertebrates. The octopus is a good example because the optical design of its eyes is remarkably similar to the vertebrate eye. The one major difference, however is that in octopus eyes, as in all fish eyes, the lens is much more powerful because it has to compensate for the loss in refractive power from the cornea, due to being underwater. Simple eyes have a much larger lens diameter which means that the spatial resolution achievable is much higher than is ever possible with a compound eye. Experiments by Kirschfeld have suggested that in order to obtain the same spatial resolution as a human eye, a compound eye would need to be about 1m across. The eye is a complex structure which has caused many arguments between evolutionary biologists and theologists. Theologists believe that the eye is so perfectly designed to harvest light, and that no intermediary design would be effective, that it must have been created by a divine designer. Biologists believe that it was created step-by-step through natural selection, and that any one step is always an improvement on the last, and thus the eye did not have to be this complex to be of benefit. This argument can be backed up by the evidence of optical diseases in which humans are handicapped in their sight, yet to them, the vision they have is better than none at all, as was a primitive form of an eye. Myopia (short-sightedness) and hypermetropia (long-sightedness) occur when the optical image of a point at infinity (i. e. he far point) falls respectively in front of or behind the retina. These errors commonly occur when the eyeball is too long, or too short, and is easily corrected with a concave or convex lens. These diseases are commonly found amongst the elderly who no longer have such deformable lens and so have difficulty varying the curvature of the lens, and thus focussing on objects at different distances effectively. This is an accommodation problem. Accommodation (discovered by Helmholz) is brought about by the ciliary body that acts on the zonular fibres that support the lens. It contains circumferential (circular) muscle fibres that allow it to act as a sphincter. The lens can be dilated by relaxing the circumferential fibres, and is said to be unaccommodated. The radial fibres of the ciliary body also act by pulling outwards on the zonular fibres that support the lens, thereby thinning it. The lens is accommodated when the circumferential fibres contract, and the lens is forced to shrink. The tension in the zonular fibres is reduced, and the lens is allowed to relax into a thicker, more curved shape, with greater refractive power. A related neuronal mechanism produces binocular convergence, in which the left and right eyes are positioned by the ocular muscles so that the images received by the two eyes fall on analogous parts of the two retinas, regardless of the distance between the object and the eyes. When an object is close, each of the two eyes must rotate towards the middle of the nose; when an object is far away, the two eyes rotate outward from the midline. Photoreceptors transduce photons of electromagnetic radiation from the visible light spectrum, into electrical signals that can be interpreted by the nervous system. The energy of the electromagnetic radiation varies inversely with its wavelength, and we perceive this variation in energy as variation in colour. The outermost layer of the vertebrate retina includes two classes of photoreceptor in vertebrates: rods and cones. There are about 100 million rods in the eye and 5 million cones. A small central area called the fovea, is densely packed with cones, but in the periphery, rods outnumber cones by 20:1. Cones function best in bright light and provide high resolution, whereas rods function best in dim light but provide much less resolution. In humans, cones mediate colour vision, and rods mediate achromatic vision. These different properties are used to expand the visual capabilities of animals living in certain conditions. For example, animals that live in flat, open environments such as rabbits, usually have horizontal regions within the retina that contain a high density of cones. This concentration of cones is called the visual streak. This region corresponds to the horizon in the visual world and is thought to confer maximal resolution in this part of the scene, allowing the animal to interpret shapes on the horizon with great precision. A receptor current exists for all sensory receptors which are usually modulated by the stimulus. In the case of vertebrate photoreceptors, the light stimulus actually reduces the circulating current, by causing the closure of ion channels. Although both invertebrates and vertebrates have eyes containing photoreceptors, they differ in their structure. Vertebrate receptor cells contain a segment with an internal structure similar to that of a cilium. This cilium connects the outer segment, which contains the photoreceptive membranes to the inner segment, which includes the nucleus and mitochondria. The photoreceptors of many invertebrates lack the ciliary structure that connects the inner and outer segments of vertebrate rods and cones and the lamellae and or stacks of disks containing visual pigment. Instead, the visual pigment is located in the microvilli formed by the plasma membrane, and these pigment-containing microvilli are organised into rhabdomeres. Visual pigments consist of 2 major components: a protein (opsin) and a light-absorbing molecule (either retinal or 3-dehydroretinal). Opsins are protein visual pigment molecules consisting of 7 transmembrane ? -helix domains. Opsins are coupled to photopigment molecules that are structurally altered by the absorption of photons, and in turn modify the opsin protein. The retinal molecule assumes two sterically distinct states in the retina. In the absence of light, the opsin and retinal are linked covalently and retinal is in an 11-cis formation. The covalent bond allows this light-absorbing molecule to act as a powerful antagonist. On capturing a photon, the retinal isomerises into the all-trans configuration, initiating a series of changes in the visual pigment, as the molecule is rendered enzymatically active. When light hits the photopigment, an intermediate metharhodopsin II forms that activates the G-protein transducin. Transducin activity closes Na+ channels and the receptor cell hyperpolarizes. Activated rhodopsin is hydrolysed spontaneously to retinal and rhodopsin which is hydrolysed spontaneously to retinal and opsin which are both used repeatedly. Studies made on the horseshoe crab, Limulus polyphemus have revealed a lot about vision. The crab has paired lateral compound eyes as well as five simple eyes: medial and lateral pairs on the dorsal surface and a single unpaired simple eye on the ventral surface. The compound eyes are typical compound eyes whereas the simple eyes are similar in structure to the simplest eye known, which consists of a shallow open pit lined with photoreceptor cells that are backed by screening pigment. Each ommatidium of a compound eye contains several photoreceptor cells. The photoreceptor cells of the Limulus compound eye are located at the base of each ommatidium. Each ommatidium lies beneath a hexagonal section of an outer transparent layer, the corneal lens. Visual transduction takes place in 12 retinular, or photoreceptor, cells. Each retinular cell has a rhabdomere, a part of the cell in which the plasma membrane is thrown into densely packed microvilli, making this the part of the cell that captures light energy. The microvilli greatly increase the surface area of the plasma membrane, which increases the probability that incident light will be captured by the rhodopsin molecules embedded in the membrane. Together, the 12 rhabdomeres of the retinular cells make up a rhabdome, which surrounds the dendrite of an afferent neuron, the eccentric cell. Depolarisations of the plasma membrane can be recorded in the retinular cells when the eye is exposed to very dim light. These quantum bumps increase in frequency as the light intensity increases (i. e. as more photons impinge on the receptors). The bumps are electrical signals generated as a result of the absorption of individual quanta of light. How can capture of a single photon lead to rapid release of so much energy? In this case, through a cascade of chemical reactions inside the cell that includes G-protein activation. Activation of the G-protein cascade occurs by diffusional contact between activated rhodopsin and molecules of G-protein, which are activated sequentially, as explained above; the activated g-protein in turn activates an effector enzyme, the PDE (phosphodiesterase); this is a 1:1 step, i. e. it has no amplification. A second stage of amplification occurs because the activated PDE is an enzyme which catalyses the destruction of cGMP. The net effect is to open ion channels, allowing cations to enter the cell. In Limulus, the receptor current through the light activated channels is carried by Na+, K+ and some Ca2+. This current causes a depolarising receptor potential. When the light goes off, the channels close again, and the membrane repolarises. The sensitivity of individual photoreceptors drops with exposure to light. This light adaptation is thought to be mediated by Ca+ ions, which enter the cells when light causes ion channels to open and which by some mechanism then reduce the current through light-activated channels. Although the Limulus eye is simple compared to that of invertebrates, the visual system is capable of generating electrical activity that parallels some of the more sophisticated features of human visual perception. The crab does however lack the degree of colour perception seen by the human eye, because it lacks the short and long wave colour pigments in its cones. It is interesting to see how two totally different mechanisms of visual perception can be so different yet interrelated in many ways, and that they have involved independently to perform the same function.

The Archival Turn to Carry Out Research Essay Example | Topics and Well Written Essays - 500 words

The Archival Turn to Carry Out Research - Essay Example Rather than basing his argument on the fact that there is only one model of science that is best carried out in a reflexive, he prefers an interdependence and coexistence of two models of science that is positive and reflective. Positive strives to separate the subject from the object while reflective mainly concentrates on dialogue as a defining principle, as well as inter-subjectivity between the participant and an observer in the field. In a nutshell, we can say that reflective science enjoins what positive separates; the participant and the observer. Reflective science employs a number of contexts, key among them intervention that acts as a catalyst to reveal the true state of the interviewee by subjecting him to space and time. The other context effect is that of the process. The interviewer cannot dictate the meaning for the interviewee because it relies on the respondent’s interpretation of the question. It is of paramount importance to note that reflective science dict ates that the observer should help the participants recall those situational experiences by moving them through space and time. This, in turn, brings about the situational knowledge which is the knowledge that is located in a specific time and space. The third context is the structuration that refers to the external filed within which the interview occurs. Reflective science thus insists on studying the world from the standpoint of its structuration by shaping the forces that surround it. The last context is reconstruction that advocates for social organizations as compared to individualism. Though it may seem difficult to carry out sampling in such a case whereby there are social institutions it is always prudent to look for ways to generalize it.

Classroom Management and Communication with Parents Assignment

Classroom Management and Communication with Parents - Assignment Example The seating arrangement of the teacher should be ensured in the instructional area. It will help the students to listen to the teachers quite transparently. On the other hand, the seats of the students should be arranged in such a way that can help the students to face the teachers or the instructors vertically (Marks, 2010). It will help to enhance face to face interaction between the teachers and the students. Computer can be considered as an important classroom resource that can enhance the digital visualization of the species. There should be one computer in the classroom. This computer should be arranged and established in the instructional area show that the teacher or the instructor can have easy access to it. Projector also can be considered as one of the important resources of this plant unit classroom. This projector will be placed at the centre ceiling of the classroom. It will be connected to the computer. A giant screen can be considered as a type of other special equipment that should utilized to visualize the samples or graphs or figures of the species that are stored in the computer. This giant screen should be placed right behind the instructional area. This arrangement or placement will help the students to face the instructor and the giant screen vertically. It can enhance the level of learning and understanding of the students. Therefore, it is clear that one instruction al table, vertically faced seating arrangement of students, one computer, one projector and one giant screen should be arranged for the classroom setting. On the other hand, five reference books, pens and papers will be used as the required non-technology resources in the classroom. This type of classroom setting will help to enhance effective both way communication between the teachers and the students. It is true that the teachers will try to teach the students