Blood pressure Essay Example for Free

Blood pressure Essay Question One: Hypertension (in addition to a number of medical conditions) may be considered as primary or secondary. Explain these concepts giving three examples of secondary hypertension and their pathophysiology. Most of the conditions that cause secondary hypertension involve the overproduction of one of the bodys hormones. Some of the medical problems that can cause secondary hypertension include: Kidney disease. Secondary hypertension is related to damaged kidneys or to an abnormal narrowing of one or both renal arteries. The renal arteries are the major blood vessels that bring blood to each kidney. When the kidneys blood supply is reduced by a narrowing (called renal artery stenosis), the kidney produces high levels of a hormone called renin. High levels of renin trigger the production of other substances in the body that raise blood pressure, particularly a molecule called angiotensin II. Adrenal disease. The adrenal glands sit on top of the kidneys and produce several hormones that help regulate blood pressure. Sometimes, one or both adrenal glands make and secrete an excess of one of these hormones. Three different types of adrenal gland conditions cause high blood pressure: Pheochromocytoma. A tumour of the adrenal gland that overproduces the hormones epinephrine (adrenalin) and norepinephrine (noradrenalin). Hyperaldosteronism (also called Conns syndrome). Both adrenal glands can overproduce the salt-retaining hormone aldosterone or it can arise in a benign adrenal tumour. Hypercortisolism (also called Cushings syndrome). Both adrenal glands can overproduce the hormone cortisol or it can arise in a benign or malignant tumour. Hyperparathyroidism. A hormone called parathormone is made by four tiny glands in the neck called parathyroid glands. If the glands produce too much hormone, calcium levels in the blood increase. People with hyperparathyroidism are more likely to have high blood pressure. The exact reason for this association is not known. Question Two: Roger was a symptomatic and only came in for a check up. Why is it important for this silent disease to be detected and appropriately treated? As blood flows through arteries it pushes against the inside of the artery walls. The more pressure the blood exerts on the artery walls, the higher the blood pressure will be. The size of small arteries also affects the blood pressure. When the muscular walls of arteries are relaxed, or dilated, the pressure of the blood flowing through them is lower than when the artery walls narrow, or constrict. Blood pressure is highest when the heart beats to push blood out into the arteries. When the heart relaxes to fill with blood again, the pressure is at its lowest point. Blood pressure when the heart beats is called systolic pressure. Blood pressure when the heart is at rest is called diastolic pressure. When blood pressure is measured, the systolic pressure is stated first and the diastolic pressure second. Blood pressure is measured in millimeters of mercury (mm Hg). For example, if a persons systolic pressure is 120 and diastolic pressure is 80, it is written as 120/80 mm Hg. The Ameri can Heart Association has long considred blood pressure less than 140 over 90 normal for adults. However, the National Heart, Lung, and Blood Institute in Bethesda, Maryland released new clinical guidelines for blood pressure in 2003, lowering the standard normal readings. A normal reading was lowered to less than 120 over less than 80. Hypertension is a major health problem, especially because it has no symptoms. Many people have hypertension without knowing it. In the United States, about 50 million people age six and older have high blood pressure. Hypertension is more common in men than women and in people over the age of 65 than in younger persons. More than half of all Americans over the age of 65 have hypertension. It also is more common in African-Americans than in white Americans. Hypertension is serious because people with the condition have a higher risk for heart disease and other medical problems than people with normal blood pressure. Serious complications can be avoided by getting regular blood pressure checks and treating hypertension as soon as it is diagnosed. If left untreated, hypertension can lead to the following medical conditions: arteriosclerosis, also called atherosclerosis heart attack stroke enlarged heart kidney damage. Arteriosclerosis is hardening of the arteries. The walls of arteries have a layer of muscle and elastic tissue that makes them flexible and able to dilate and constrict as blood flows through them. High blood pressure can make the artery walls thicken and harden. When artery walls thicken, the inside of the blood vessel narrows. Cholesterol and fats are more likely to build up on the walls of damaged arteries, making them even narrower. Blood clots also can get trapped in narrowed arteries, blocking the flow of blood. Arteries narrowed by arteriosclerosis may not deliver enough blood to organs and other tissues. Reduced or blocked blood flow to the heart can cause a heart attack. If an artery to the brain is blocked, a stroke can result. Hypertension makes the heart work harder to pump blood through the body. The extra workload can make the heart muscle thicken and stretch. When the heart becomes too enlarged it cannot pump enough blood. If the hypertension is not treated, the heart may fail. The kidneys remove the bodys wastes from the blood. If hypertension thickens the arteries to the kidneys, less waste can be filtered from the blood. As the condition worsens, the kidneys fail and wastes build up in the blood. Dialysis or a kidney transplant are needed when the kidneys fail. About 25% of people who receive kidney dialysis have kidney failure caused by hypertension. Question Three: The renin-angiotensin system plays a central role in blood pressure regulation. Explain the renin-angiotensin system with reference to Conns syndrome. The Renin-Angiotensin-Aldosterone System is a hormone system that regulates BP and fluid balance. When blood volume is low, the juxtaglomerular cells in the kidneys secrete Renin directly into circulation. Plasma Renin converts a polypeptide called Angiotensinogen, which is secreted from Liver into Angiotensin I, which in turn is converted to Angiotensin II (or ATII) by the enzyme called ACE (Angiotensin converting enzyme) found in the lungs. It so happens that Angiotensin II is a potent vaso-active peptide that causes blood vessels to constrict, resulting in increased blood pressure. Angiotensin II also stimulates the secretion of the hormone Aldosterone from Adrenal cortex. Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water into the blood. This increases the volume of fluid in the body, which also increases blood pressure. If the renin-angiotensin-aldosterone system is too active, blood pressure will be too high. There are many drugs that interrupt different steps in this system to lower blood pressure. These drugs are one of the main ways to control HBP, heart failure, renal failure and the harmful effects of Diabetes. Angiotensin II is degraded to angiotensin III by angiotensinases located in red blood cells and the vascular beds of most tissues. Angiotensin III has 40% of the pressor action of ATII, but 100% of the aldosterone-producing activity of ATII. Angiotensin II has autocrine, paracrine and endocrine actions on different systems: Cardiovascular effects: AT II is the most powerful vasopressor known, constricting both arteries and veins. Myocyte growth is stimulated through a local tissue RAAS. The same system can be activated in the smooth muscle cells in conditions of HTN or endothelial damage thus contributing to and accelerating the process of Atherosclerosis. Neurological effects: ATII increases the thirst sensation by directly stimulating the Subfornical organ of the brain (Dipsogenic action). AT II also decreases the response of Baroreceptor reflex. ATII increases secretions of both ADH and ACTH besides stimulating postganglionic sympathetic fibers to secrete Noradrenaline. Adrenal effects: Angiotensin II acts on the Adrenal cortex causing it to release Aldosterone, a hormone that causes the kidneys to retain sodium and lose potassium.

The Effectiveness Of Heterogeneous Grouping

The Effectiveness Of Heterogeneous Grouping As EFL teachers we are concerned with two main issues in language learning. The first issue addresses the skills students should acquire in EFL classes as a result of teaching-learning experiences. Such skills are often measured by students achievement. The second issue takes account of the strategies EFL teachers use to help students acquire such skills and in turn increase their achievement. Writing is a skill which requires efforts from both the student and the teacher. It is one of the four language skills which are given emphasis in second language learning. Writing is one of the skills which need to be mastered by the learners to meet the secondary school graduation requirements (Panofsky et al 2005). They learn different genres of writing like descriptive, expository, recount and narrative based on the prescribed syllabus of their providers. Language learning involves learning the language code as well as the culture associated with the language (Becket Gonzales 2004). Students writing abilities are affected by the type of instructions teachers use within their classroom practices. It is one of the productive skills that learners are expected to achieve in order to ensure their communicative competence. While learning writing, students are supposed to get involved in many activities that enable them to produce a piece of writing at the end. They can be engaged for example in class discussions, act in role playing or get involved in peer editing (Hensen, 2002). While engaged in classroom activities students build up experience and have more practice that may finally give the chance to reach a proper product of writing. In teaching writing, teachers strive hard to find strategies to facilitate increasing students achievement. There are many methods adopted by the teachers in teaching EFL writing in the classrooms. One of the methods recommended in teaching writing is the incorporation of cooperative learning (Kagan 2002). Students can be grouped in a variety of more flexible ways so that they spend some portion of a school day in heterogeneous groups and some portion in homogeneous groups. (Grady et al 2007). Supporting students writing involves providing some form of assistance that helps them carry out one or more processes involved in writing. These procedures include structuring how students carry out a particular writing process, having peers to help one another as they compose a piece of writing , providing students with feedback on their performance, focusing students attention on specific aspects of tasks, and providing a model of what the end product should look like (Graham Perin 2007). In most EFL classes, some learners perform better beyond grade-level, others struggle with target language, while another great part of the class falls somewhere in between. In their effort to meet the needs of such a diverse students, educators tend to assign pair and group work with students of different ability levels finding ways to involve all students in the activities. These ways could include communicative and cooperative tasks to allow scaffolding of less advanced students. In such a classroom environment, advanced level learners perform as a bridge to assist the learning process and lower level classmates show a readiness to cross that bridge (Sean, 2002).   As a general rule, it seems reasonable to propose that classroom harmony might better be achieved in a group of motivated students who are allowed to take part and cooperate. Statement of the problem Teachers as well as educators seem to have struggled to find answers to questions about heterogeneous and homogeneous grouping: Are they of certain benefits for learners? Do they harm anyone? Who gets the benefit or the harm the most? And why? (Kulik 1992). The answers to such questions are not always clear-cut and often depend on whom you ask and what learning outcomes are considered important. To many educators, grouping is considered as an proper response to academic diversity. To others, the practice has harmful unintended consequences and should be abandoned (Ansalone, 2001). Statement of the purpose Consequently, this study aims to investigate the effect of homogeneous grouping versus heterogeneous grouping on EFL students achievement in writing in the hope that it may settle the argument on which is better for both high and low achievers. Homogeneous grouping can be defined as dividing students into small groups which include students of the same ability or level for example high achievers together and low achievers together. While heterogeneous grouping can be defined as dividing students into groups that include mixed or different levels, high and low achievers together. Theoretical Framework When tackling the issue of cooperative learning or grouping it is useful to draw upon the theories of social constructivism and multiple intelligences so as to view intelligence from a multi-dimensional perspective. Social constructivism emphasizes the significance of the social environment in cognitive development. Vygotsky, as reported by Seng et al. (2003), wrote: Every function in the childs cultural development environment appears twice: first, on the social level, and later on the individual level, first between people (interpsychological), and then inside the child (intrapsychological). Vygotsky (1978) supposed that intelligence starts in the social environment and directs itself inward. Other writers on constructivism elaborated on this theme. Students must interact with other students as well as materials in order to learn. The conventional ways of teaching through lecturing and recitation do not work effectively (Hillocks, 2002). Teachers must allow a learning environment i n which students search for meaning, appreciate uncertainty, and inquire responsibly (Brooks, 1993). Gardner (1993), in his work on multiple intelligences (MI), highlighted the importance of precisely understanding the profile of intelligences of the individual learner to provide a more enlightened search for remedies for difficulties. Edward (2004) stated that the problems students encounter at school are because of the fact that they have different kinds of minds and therefore remember, understand, perform, and learn in differently. Gardner identified 8 separate intelligences; two of them are linguistics and interpersonal intelligences. Armstrong (199) stressed the need to provide learning experiences which may accommodate those 8 intelligences through a variety of multi-spectrum experiences. Moreover, there are two cognitive theories that are directly applied to cooperative learning, the developmental and the elaboration theories (Slavin, 1987). The developmental theories presume that interaction among students around appropriate tasks raises their mastery of critical conceptions (Damon, 1984). When students interact with other students, they will need to explain and discuss each others perspectives, which lead to greater understanding of learning targets. Also the effort to resolve potential conflicts within collaborative activities develops higher levels of understanding (Slavin, 1990). The elaboration theory proposes that one of the most effective means of learning is to explain the material to someone else. Cooperative learning activities improve elaborative thinking and frequent giving and receiving explanations, which increases the depth of understanding, the quality of reasoning, and the accuracy of long term retention (Johnson, Johnson, Holubec, 1986). Thus, the use of cooperative learning methods should lead to the improvement of students learning and retention from both the developmental and cognitive theoretical perspectives. Cooperative learning has its roots in the theories of social interdependence, cognitive development, and behavioral learning. Some research provides remarkably strong evidence that cooperative learning results in greater effort to achieve, more positive relationships, and greater psychological health than competitive or individualistic learning efforts (Johnson, Johnson, Holubec, 1994( Cognitive growth springs from the arrangement of a variety of perspectives at the time individuals work to reach common goals. Both Piaget and Vygotsky saw cooperative learning with more able peers and instructors as resulting in cognitive development and intellectual growth (Johnson, et al., 1998). The assumption of behavioral learning theory is that students will work hard on tasks that provide a reward and that students will fail to work on tasks that provide no reward or punishment. Cooperative learning is one strategy that rewards individuals for participation in the groups effort. Slavin (1987), highlighted two main theoretical perspectives related to cooperative learning, motivational and cognitive. The motivational theories of cooperative learning stress the students motivation to accomplish academic work, whereas the cognitive theories emphasize the effects of working with others. A major element of cooperative learning is positive interdependence, as students perceive that their success or failure depends on working together as a team (Johnson, Johnson, Holubec, 1986). From the motivational theories perspective, cooperative goal structure creates such a situation in which the only way group members can achieve their goals is when the group is successful (Slavin, 1990,). As a result, for the reason of attaining certain goals, students are likely to encourage their group members to do whatever helps the group to succeed and to help one another with a group task. Review of Literature A number of studies examined the effects of cooperative learning techniques on student learning. Humphreys, Johnson, and Johnson (1982) compared cooperative, competitive, and individualistic strategies and concluded that students who were taught by cooperative methods learned and retained significantly more information than students taught by the other two methods. Sherman and Thomas (1986) reached similar findings in a study which involved high school students taught by cooperative and individualistic methods. Slavin(1983) based on a review of 46 studies related to cooperative learning found that cooperative learning resulted in significant positive effects in 63% of the studies, and only two studies reported higher achievement for the comparison group. Johnson, Maruyama, Johnson, Nelson, and Skon (1981) conducted a meta-analysis of 122 studies related to cooperative learning and concluded that there was strong evidence for the advantage of cooperative learning in promoting achievement over competitive and individualistic strategies. Johnson and Ahlgren (1976) investigated the relationships between students attitudes toward cooperation, competition, and attitudes toward education. The results of the study pointed out that student cooperativeness, rather than competitiveness, was positively related to being motivated to learn. Humphreys, Johnson, and Johnson (1982) also found that students studying in a cooperative learning treatment group rated more positively in their learning experience than did students in competitive and individualistic treatment groups. In a study involving elementary and secondary students Wodarski, et al., (1980) concluded that 95% of the elementary students enjoyed the cooperative learning activities and that they had learned a lot about the subject. Cooperative learning can result in positive effects on student achievement (Devries Slavin, 1978; Cohen, 1986; Davidson, 1989; Johnson Johnson, 1989; Okebukola, 1985; Reid, 1992; Slavin, 1990). Academic benefits include higher achievement in reading comprehension, writing (Mathes, Fuchs, Fuchs, 1997) and mathematics (Ross, 1995; Whicker, Nunnery, Bol, 1997) and improved conceptual understanding and achievement in science (Lonning, 1993; Watson, 1991). Social benefits include more on-task behaviors and helping interactions with group members (Burron, James, Ambrosio, 1993; Gillies Ashman, 1998; McManus Gettinger, 1996), higher self-esteem, more friends, more involvement in classroom activities, and improved attitudes toward learning (Lazarowitz, Baird, Bolden, 1996; Lazarowitz, Hertz-Lazarowitz, Baird, 1994). Emmer and Gerwels (2002) stated that some research on cooperative learning addressed instructional components. In a number of studies students were taught interaction skills, such as how to question or to help each other so that they did not give answers but facilitated each others thinking (Fuchs, Fuchs, Kazdan, Allen, 1999; Gillies Ashman, 1996, 1998; Nattiv, 1994; Webb, Troper, Fall, 1995). When students are taught these skills, positive outcomes like increased intrinsic motivation, self-esteem, and liking for school can result (Battistich, Solomon, Delucchi, 1993). Ability grouping can be carried out between-class or within-class (Dukmak 2009). Between-class ability grouping refers to a schools practice of forming classrooms that contains students of similar ability. Within-class grouping refers to a teachers practice of forming groups of students of similar ability within an individual class (Gamoran, 1992; Hollified, 1987). A review of the literature on cooperative learning shows that students benefit academically and socially from cooperative, small-group learning (Gillies, 2002). Mixed-ability grouping is based on cooperative learning which demonstrates positive success related to students achievement. In this type of grouping, students work collaboratively to successfully achieve a desired educational outcome and develop a greater understanding and respect for individual differences. All forms of diversity within the learning environment are embraced (Felder Brent, 2001; Freeman, 1993; Saleh, Lazonder, DeJong, 2005). Moreover, in a mixed-ability, teachers respond to the individualized needs of all learners (Kulik Kulik, 1992). The most compelling argument against ability grouping is the creation of academic elites a practice which goes against democratic ideals (Slavin, 1987). Johnson and Johnson (1999) and Johnson, Johnson and Smith (1998) say that cooperative learning has five basic elements positive interdependence, individual accountability, promotive interaction, appropriate use of social skills, and periodic processing of how to improve the effectiveness of the group (Johnson Johnson1999 ). When these elements are properly implemented, the research has shown that group collaboration in the classroom can increase learning and achievement, social skills, self-esteem, and attitudes toward classmates and school (Slavin, 1990 as cited in Webb, Nemer Zuniga 2002). Placing students in teams or cooperative learning groups has many advantages. It helps to build a students communication skills, can help increase tolerance and the acceptance of diversity, promotes higher level reasoning, promotes increased generation of new ideas, promotes greater transfer of information from one situation to another, increases retention, builds teamwork skills, reduces stress , and increased willingness to attempt challenging tasks (Baker Campbell, 2005; Huss, 2006; Lin, 2006; Payne Monk-Turner, 2006; Patrick, Bangel, Jeon 2005; Kim 2004; Vaughn, 2002; Johnson Johnson, 1999; Johnson, Johnson Smith, 1998; Slavin, 1996). The cooperative learning experience also [gives] students the opportunity to review and learn information that they did not understand before the cooperative learning activity (Webb, 2002). According to Lin (2006 ), research has concluded that cooperative learning is the top ranked teaching model that promotes greater higher-order thinking, problem solving, and achievement. Students can remember 75-90% of materials when they learn it in cooperative learning situations (Lin, 2006). In a survey of college students after an experiment involving group work, Payne and Monk-Turner (2006) found that 90% of students favored group work and that 90% learned from their group members. Since 1924, 168 studies have been conducted that compare cooperative learning to competitive and individual learning. These studies have shown that cooperative learning yields higher academic achievement than individual and competitive learning (Johnson, Johnson Smith, 1998). Cooperative learning groups are also said to be particularly beneficial to low academic achieving students and students of color (Huss, 2006; Vaughn, 2002). Cooperative learning groups appear to be effective in many ways. Students work as an influential part of the group when they believe their efforts will add to the success of the group (Baker Campbell, 2005). Students are successful and learn in cooperative learning groups because they learn by doing rather than listening (Payne, Monk-Turner, Smith 2006 ) They are also actively using the material and information (Zimbardo, Butler, Wolfe, 2003). Cooperative learning also strengthens students social interactions, it gives them the desire to achieve, to develop more positive interpersonal relationships, and have greater psychological health than competitive or individualistic learning efforts (Johnson, Johnson, Holubec, 1994 as cited in Morgan, 2003,). Cooperative learning can teach students that knowledge can be, or should be, shared with fellow students; that differences in opinion can be rationally negotiated even under conditions of test pressures; and that cooperative learning pr ocedures can be enjoyable and productive (Zimbardo et al., 2003, ). These types of lessons enable students to learn how to work well with others. The interdependent relationships that develop within a group help to facilitate the groups success. Everyone feels the goal of the group will be met if everyone achieves their individual goals (Vaughn, 2002; Morgan, 2004). According to Morgan (2004), group members should also be aware of the fact that a single group member can affect how and/or if the goal is achieved. The cooperative learning experience is most effective when the participants work well together and they successfully achieve their goal. There are many characteristics to successful teams. Some of these characteristics include open communication, effectively listening, open-mindedness, clear roles, an established leader, clearly defined tasks, teamwork where everyone works together and contributes, there are well developed attainable goals (Payne, Monk-Turner, 2006; Baker Campbell, 2005), and a timeline (Payne Monk-Turner, 2006). In a classroom, there are also many things a teacher can do to help insure the success of a group activity. The teacher should provide strong guidance (Payne Monk-Turner, 2006; Baker Campbell, 2005), model the desired behavior, provide immediate feedback, and reward desired behavior (Lin, 2006; Baker Campbell, 2005). The teacher can also use checks and balances to monitor productivity, employ various problem solving strategies (Friend Cook, 2007), leng then the amount of time the group spends together, provide proper group behavior training, establish ground rules (Mitchell, Reilly, Bramwell, 2004) and allow group members rate each other (Lin, 2006). If the teacher monitors, provides rewards and allows the students to rate each other, it may reduce the effects of a slacker and keep students from getting a grade they do not deserve (Payne Monk-Turner, 2006). Students that slack off can demotivate hard working students and give them a negative feeling about group work (Ashraf, 2004). Many studies have been conducted that demonstrate the success of teaming. Robert Slavin has conducted extensive research on the implementation of cooperative learning models in schools. He has examined the effects schools becoming complete cooperative learning centers on their academic achievement. He has found many successful situations where lower performing schools were transformed because they converted to a cooperative learning format (Slavin, 1999 22-23). Payne and Monk Turner (2006) conducted a study that examined how students felt about teams. In this study, they assigned students to groups, gave them an assignment, and then asked them how they felt about the assignment after the group project was completed. They found that 90% of the students had a favorable experience, 90% of the students learned from their group members, and 85% of the students felt they learned teaming skills that could be transcended into business. Baker and Campbell (2005) conducted a study in which stu dents were placed in groups and observed that the students who worked in groups, as opposed to working individually, were more successful because they had more access to knowledge, they felt pressured to succeed to keep the group from failing, and the various personalities helped alleviate the stress of the problems. For example a member often told jokes to help lesson the tension. Additionally, members often provided positive reinforcement and motivation. Placing students in groups to take tests is another way to use cooperative learning and group work. Morgan examined the benefits and non benefits of college students completing exams using cooperative learning groups. She concluded that The increased depth of understanding, the feelings of support, respect for others contributions, and the clarification of information produced more students with a greater awareness of the material and more developed social skills to be contributing members of teams (Morgan, 2004 ). The understanding of successful cooperative learning group models not only affects groups in grade school; it also affects groups in jobs and college. According to Payne, Monk-Turner, and Smith (2006) employers want college graduates that have developed teamwork skills. Miglietti (2002) says that group work is commonly used in the workplace and employers want to hire people with these skills. Furthermore, these skills can be learned when students are placed in successful t eams where the goals have been reached. Socialization and communication are examples of skills that students learn in groups that can help their transition into the business world (Payne et al., 2006). In a survey of college students, after a study involving group work, Payne and Monk-Turner (2006) found that 85% of college students admitted that doing group work would probably work on teams in future jobs. Homogeneous grouping Homogeneous grouping has been proposed and implemented as a potential solution for meeting the needs of the mixed ability classes, suggesting that students of different abilities can be gathered in groups of same ability for the purpose of facilitating teaching (Slavin, 1987). This type of grouping is based on the pedagogical belief that the teacher has the advantage of focusing instruction at the level of all students in particular groups (Ansalone, 2000). An extensive research has been conducted on ability grouping suggesting that academically, high-achieving students achieve and learn more when they are grouped with other high-achieving students (Gentry Owens, 2002; Grossen, 1996; Hollified, 1987; Page Keith, 1996). In mixed-ability grouping it is difficult to provide an adequate environment for teaching to everyone. Since students differ in knowledge, skills, developmental stage, and learning rate, one lesson might be easier for some students and more difficult for the others (Slavin, 1987). In ability grouping, high-achieving students view their own abilities more realistically and feel that they are appropriately challenged with their peers (Fiedler, Lange, and Wine-Brenner, 2002). It is suggested that teachers of mixed ability classes can raise instruction level for high achievers and increase the pace of teaching whereas low level students can have individual attention. As a result advanced pupils can be taught more difficult concepts while low achievers can deal with simple and fewer things. Advocates of homogeneous grouping opine that it is an outstanding means of individualizing instruction. Achievement is thought to increase as teachers would adjust the pace of instruction to students needs. Kulik and Kulik (1982) and Slavin (1987) carried out meta-analyses of studies at the elementary school level, finding benefits of within-class ability grouping. Both low ability students and more advanced ones placed in separate groups, benefited from instruction addressed to their level. More recently, Mulkey et al (2005) found that same ability grouping has constant instructional benefits for both high and low level students. Marsh (1987) supports homogeneous grouping as a technique to cope with mixed ability classes assuming that grouping children homogeneously enables those in lower ability groups to profit with respect to self-evaluation by being isolated from advanced peers. Furthermore, Allan (1991) supports that pupils model their behaviour after the behaviour of similar ability children who are coping well with their school work. The proponents of homogeneous grouping conclude that research fails to support that homogeneous grouping doesnt accomplish anything (Loveless, 1998 ). Although teachers of mixed ability classes seem to have positive attitudes towards homogeneous grouping (Scherer, 1993, Mulkey et al, 2005), a severe criticism of ability grouping has been raised in the last quarter of the 20th century. It has been stated that this type of grouping stigmatizes lower ability students, providing them with inferior instruction. A number of researchers attack homogeneous grouping for not guaranteeing that all advanced or all weak students are alike. Matthews (1997) conducted a relevant research with students in grades 6 through 8 and concluded that gifted students are noticeably more diverse than they are homogeneous. They are of different degrees in their abilities, their learning styles and interests, their advancement, their social/emotional development and their test-taking skills. Ability grouping may reduce the self-esteem and aspirations of low ability children and therefore slow down their academic progress. Welner and Mickelson (2000) carried out an extensive research review and found that low ability children are exposed to lowered expectations, reduced resources and rote learning. Childrens self-concept is affected and expectations are internalized (Ireson and Hallam, 1999, Gamoran, 1987). This implies that students of low ability in mixed ability classes are provided with low expectations if placed in same ability groups causing them feelings of inferiority. This is confirmed by Ansalone (2001) and Hallinan (1994) who demonstrated that children assigned to lower ability groups, are exposed to less and more simplified versions of the curriculum whereas high ability groups have broader and more challenging material covered. In this sense, Oakes (1992) and Wheelock (2005) support that educational benefits in mixed ability settings are not provided by homog eneous grouping but rather by a challenging curriculum and high expectations. Heterogeneous grouping Heterogeneous grouping, that is gathering children of varying abilities in same groups has been proposed by many researchers as an effective strategy to promote academic development of students having diverse background knowledge and abilities. Brimfield, Masci and Defiore (2002) believe that all students deserve an academically challenging curriculum (p.15). So, our goal is to find a way to engage all pupils of the mixed ability classroom in the lesson irrespective of their abilities. The authors point out that by creating mixed-ability groups, we send the compelling message that everybody is expected to work at the highest possible level as high and low ability students deal with the same challenges. Disadvantaged pupils are at reduced risk of being stigmatized and exposed to a dumped-down curriculum in a mixed-ability setting. Teachers expectations for all pupils are maintained at higher levels and less able students have opportunities to be assisted by more able peers. It is assumed that heterogeneous grouping provides pupils access to more learning opportunities. Johnson and Johnson (1987) recommend assigning children of high, medium, and low abilities in the same group maximizing the heterogeneous make up of each group. Such ability diversity within the same group creates an effective learning environment (Manlove and Baker, 1995) providing learning opportunities for low-level students as well as opportunities to more advanced children to provide explanations to others revising, consolidating and using some things they have encountered before. The teachers can use cooperative tasks among high and low achievers of mixed ability groups or pairs in order to promote task engagement of all students in the mixed ability class as advanced children can provide explanations and guidance in carrying out a task. Cooperative tasks among high and low achievers are valued by the sociocultural theory of Vygotsky (1978). Pupils of mixed ability classes differ at their competence level and prior linguistic experiences. Vygotsky supports that children who are exposed to books and other out-of-school factors which contribute to linguistic development i.e .prior knowledge of English from private institutional instruction, are expected to have already run through a large part of their ZPD. On the other hand, pupils with poor literacy opportunities i.e. without prior knowledge of English may possess a larger Zone of Proximal Development (Van der Veer and Valsiner, 1991). So, they may benefit greatly from peer interactions which are likely to help low level students reach higher levels of performance. In this framework, Lyle (1999) showed that both low and high achieving students value the opportunity to work together as all pupils believed that they benefited. It was concluded that peer interactions can facilitate literacy development especially of low ability students. In this vein, Guralnick (1992) points out that social competence acquired in group work affects the elaboration of all students cognitive competencies, implying that both low and advanced learners of mixed ability classes may gain from such settings. The role of peer learning as contributing to language development has also been emphasized by Mize, Ladd and Price (1985) Webb (1989), Jacob et al (1996) and Slavin (1996). Rogoff (1993) refers to childrens social sharing of their cognition through interaction. When pupils participate in collective activities, they guide each others efforts. According to Tudge and Winterhoff (1993) advanced children give constant feedback through conversation forcing peers to strive for reaching higher levels of performance. Various studies have indicated a positive correlation between cooperative learning and achievement in mixed ability classes. For example, Walters (2000) asserts that cooperative learning is suitable for teachers dealing with increasingly diverse classrooms as it easily accommodates individual differences in achievement. Accordingly, Fulk and King (2001) support that class-wide peer tutoring improves all students learning. They add that serving in the role of tutor seems to be particularly beneficial for improving the self-esteem of students with low achievement while they may, for example, grade their partners reading. Therefore, it appears that CL may satisfy the needs of a mixed ability class. Studies conducted by Pica and Doughty (1985), Porter (1986), and Cotterall (1990) indicate that learners of different abilities produce more in mixed ability pair and group work by helping one another to overcome cognitive obstacles. This conclusion is consistent with Urzuas (1987) finding that the mixed ability children in the observational study conducted, appeared to have developed a sense of power in language through the process of working with trusted peers i.e. writing and revising. The benefits of cooperative learning are more touchable

Analysis Of The South West Airlines

Analysis Of The South West Airlines The South west airlines are part of the airline industry in U.S.A and are a low cost airline located in Dallas U.S.A. An external analysis of the environment in the airline industry was carried out through a PEST analysis and the 5 forces of the Porters model and the below conclusions were reached. Political environment-the policies that governments have come up with. For instance the UK government and environmental activists that aviation degrades the environment greatly and should therefore be controlled. A government is a very powerful entity and therefore it could pose a threat to airlines if it decided to impose regulatory practices on airlines.Limitations regarding the terms and legal obligations of the airline may make it hard for the airline. Scanning the political environment in this case, we find that south west airlines sought to make use of the opportunity created by the airline Deregulation Act passed by the U.S congress in 1978.this law permitted interstate flights. But Southwests attempt to becoming an inter-state airline soon faced political obstacles. Southwest wanted to operate all its interstate flights from Love Field Airport which was very close to downtown Dallas. On the other hand, all the other airlines operated from Dallas Fort Worth Airport, which was far away from the main city. Rival airlines fearing that South west would get a larger share of passengers, tried to use their political influence to ban operation of flights from Love Field, Congressman Jim wright tried to pass this law. Social environment. These have positively affected the industry in that with the introduction of more and more airlines, even people from the middle-class can now travel by air. Beyond that, there has also been more job creation through the establishment of these airlines. An important aspect of the social environment concerns the values consumers hold. Values mainly revolve around a number of fundamental concerns regarding time, quality, total environment, financial conditions and diversity. The ultimate taste of a business is its social relevance. When it entered the airline industry, the social environment for air passengers was discouraging, the fares were too high, flight schedules were not convenient for passengers and the time required for travelling from the city , to park and take off from the airport was lengthy and tiring. The aptitude of managers of southwest airlines is seen whereby they refuse to move their flight operations from Love Field. This was a clear indication that they were observing the social environment and building their organization against this. With this recognition of the social environment, the southwest Airlines gained popularity among the citizens and thus attracted more customers. Economic environment. These can take several dimensions, first how the industries that airlines depend on affect airlines and how the airlines are directly affected by a countrys economy. The changes in the economy have had a tremendous effect on the airline industry. Another thing that the economy is affecting the airline industry is the competing airlines. The bigger airlines can afford lower fares which make it hard for the smaller airlines to compete. Different airlines have plans to expand but will not be able to until the cost of fuel is under control.Fuel price hauls and fluctuations are a major reason for the Southwest for not incurring more profitable operations. (Southwest counters this by strict financial spending on fuel i-e fuel-hedging) For the low carriers who allow advanced booking, they will need to work on a plan to avoid bankruptcy. This will make the airline industry continue to boost prices due to the fact that oil prices are expected to continue rising due to th e supply. Traveling by air is both elastic and inelastic depending on whom it is that is traveling. If a family is planning a trip just to take a vacation and the price of an airline ticket is extremely high, more than likely they will decide to wait on the trip until the prices are lower. This shows that the airline industry in considered elastic. However, if a businessman needs to be at a seminar across the country by the next day, he will need an airline ticket regardless of the cost. In this example, the airline industry would be considered inelastic because it is a necessity. The current market has a big part in the supply and demand in the airline industry. For instance, with the price of oil rapidly increasing, the cost of an airline ticket is also increasing and the demand for leisure travel is decreasing. After the bombing of the World Trade Centre on September 9th 2001, people were afraid there would be another terrorist attack involving a plane and the demand decreased. Another factor in the cost of an airline ticket is the date it is purchased. If there is an emergency and someone purchases a ticket close to the departure date, even though there are unsold seats available the cost will increase. Technological environment. This basically means that some technological advancement has proven, and may in future prove to affect the airline industry negatively thus a decrease in the air travel demand. A good instance would be video conferencing which reduces the need for people to constantly travel. If not planned for properly, an airline could suffer greatly from ignorance to technology. Social networking sites like Facebook and Skype allow for people around the world to share information they may not have been able to before. One can chat with a relative and avoiding travelling by air throughout the world. The 5 forces of Porters model Threats of new entrants. There has been a never ending expansion of the aviation industry with new airlines coming up every day. Airline managers should therefore ensure that they are prepared and have a strategy on how to deal with new entrants into the industry. This can be clearly portrayed by the way Braniff and Texas international Airlines reacted to the entry of a new airline, Southwest Airlines, they even decided to work together in a bid to destroy the airline even before it started their operations. This would go to show that the treat of new entrants in the airline industry is very high. Availability of substitutes. They exist because there is more than one way of doing anything. For instance when travelling, one can use vehicles, trains bicycles, airplanes, ship and so forth. Apart from alternative methods of transport, technology has gifted us with the gift to do a lot of things without moving. The ease of substitution in the airline industry is surprisingly very high the greatest contribution being from technological advancement. This has led to a drop in the demand for air travel causing airlines to constantly register losses. The ease of substitution in the Airline industry is very high since other alternatives have come up mostly due to technological developments. Degree of rivalry among competitors. How competitive is the industry? Is there a dominant airline and many other small airlines or are there many powerful airlines how many other airlines are there in the industry. These are some of the questions that are raised under competition. If theres one dominant airline then the degree of competition is quite low in the industry. The airline industry in the USA is very competitive and has a lot of rivalry going on. In the case of southwest airlines, its major competitors, Texas International and Braniff Airlines even joined hands in a bid to destroy the southwest airlines even before they started operations. This goes to illustrate how competitive the airline industry in USA can get, the competitors were threatened by an airline that hadnt even started operations. Bargaining power of suppliers. The bargaining power of suppliers is basically quite low in the industry in that, much bargaining doesnt take place. Suppliers are mostly big shot aviation companies and can only compromise prices with airlines so that during their low period, they are able to negotiate prices with their buyers. It may not be exactly bargaining but it counts for something. And therefore the bargaining power of suppliers will be considered to be low. Bargaining power of customers. The airline industry rarely allows room for customer bargaining, you can either afford to travel by air or not and with more and more new airlines coming up, almost all social classes are catered for. South airlines however havent classified their passengers which reduces discrimination. Through observing the social environment, the Airline has been able to cater for the diverse needs of the customers, this though does not count as bargaining power of the customers towards the airline. The bargaining power of customers in the airline industry is quite low compared to other industries. Conclusion After carrying out the PEST analysis and analysing the environment using the Porters Model the following conclusions were reached. There are threats and opportunities that affect the Southwest airlines Threats The decreasing demand for air travel Fuel price hauls and fluctuations. Terrorist activities make it more of a threat to travel. Opportunities There are still many national and international markets that are still untapped. There are many industrial opportunities for development in the airline industry. It can haul longer flights to cover more expansion. It can also tap the travel business option for the business class passengers, and offer private flights. It can get the latest technology, which would give it a further cost effective lead, as well as providing new services and products.

The Crisis of the American Teen Essay -- Teenager Youth

The Crisis of the American Teen Premature adulthood is imposed upon teenagers in today’s society. It affects them in two different but closely related ways. One is in which a teenagers needs to find a sense of self and needs protection on trying to do so. The other is the stress that is being forced upon them. Teenagers need to be given time , support and guidance to form from child to adult, but that must come from the parents. Many parents either feel powerless to give a child what they need in life because the child can get it else where: they may do whatever it is that they want behind a parent’s back. They could also be insecure about themselves and that they did not receive the guidance themselves when they needed in growing up. Teenagers need protection against the dangers that they may face so that they can be prepared for the future. Teenagers now are highly stressed. There are more things for teenagers to stress about then there was years ago. Since teenagers are given so much freedom which doesn’t give them much time to focus on their future. Freedom also makes it hard for a teenager to adapt to new situations because they are already conformed to do what they want rather then for what is best in that situation. In relation to the two different ways in which premature adulthood is forced upon today’s teenagers is that it can be hard for a teenager to form a sense of identity because they are faced with many challenges in life. Since they are given so...

Essay --

Odonata The damselfly species is part of an insect group called Odonata. Odonata consists of dragonflies, which are the suborder Anisoptera, and damselflies, which are the suborder Zygoptera. The insect group Odonata is very small, probably containing only about 5,000 living species (Corbet, 1999). Odonata, typically called Odonates, are usually found close to bodies of water, looking for small insects to eat. Adult Odonates catch their prey while in flight, while younger Odonates, called nymphs, hunt for their prey at the bottom of the body of water they live in. Nymphs eat almost any insect small enough for them to digest (book on iCloud). Nymphs Nymphs live in water throughout their entire developmental stage, which can take anywhere from three weeks to more than eight years, depending on the species of the nymph and it’s location and habitat. They undergo eight to seventeen molts (Corbet, 1999), although the amount of molts undergone depends on the species. When a nymph’s developmental stage is complete, it climbs out of it’s previous home in the water, a final molt is undergone, and an adult damselfly appears (Encyclopedia Britannica, 2010). Nymphs have a set of gills along their abdomen, which are used for breathing as well as a transportation device and a way of escaping from predators in an emergency. Water is ushered into the gills, and then forcefully emitted, propelling themselves forward and farther away from their enemies (Encyclopedia Britannica, 2010). Nymphs, despite their excellent predatorily abilities, are usually hunted by fish, although occasionally they are also hunted by birds, crayfish, frogs, and each other. When their development is complete and they are finally an adult dams... .... Transferring sperm depends on the species of damselfly because the sex organs are particularly elaborate and specific to the each species. Organs in the male damselflies that allow the end of its’ abdomen to attach to the back of the females’ head correspond between each individual species, making mating between separate species nearly impossible. Some species of damselflies lay their eggs either inside or on plant tissue, which is either above or in water. Some females climb beneath the surface of the water to position their eggs and remain there for an hour, or perhaps more. Some species submerge their abdomen in the water, so the eggs wash off, or put them on leaves close to the water’s edge. This is sometimes done while the damselfly is in flight. Other species simply allow their eggs to drop onto the surface of the water while they are flying (Corbet, 1999).

United States Men’s National Soccer Team

While rival drug cartels warred in the streets and the country’s murder rate climbed to highest in the world, the Colombian national soccer team set out to blaze a new image for their country. What followed was a mysteriously rapid rise to glory, as the team catapulted out of decades of obscurity to become one of the best teams in the world. Central to this success were two men named Escobar: Andrà ©s, the captain and poster child of the National Team, and Pablo, the infamous drug baron who pioneered the phenomenon known in the underworld as â€Å"Narco-soccer.† But just when Colombia was expected to win the 1994 World Cup and transform its international image, the shocking murder of Andres Escobar dashed the hopes of a nation. Through the glory and the tragedy, The Two Escobars daringly investigates the secret marriage of crime and sport, and uncovers the surprising connections between the murders of Andres and Pablo. Personal Statement Our films tend to focus on disenfranchised communities in the process of rising up and transforming their political and economic circumstances. We choose these stories due to the scale of their historic importance—this is where societies are shaped. By comparison, sports have often felt like mere diversion, games limited to the playing field. At times, we have both drifted from the passion for sports we shared as young athletes and fans, engaging ourselves in other endeavors as seasons of professional competition passed by. Then, invariably, definitive moments in sports history would grab our attention and turn our logic upside down. Like in 1994, when an athlete named Andres Escobar was murdered for accidentally scoring an own goal that cost the Colombian National Team a chance at winning the World Cup and transforming its negative image on the international stage. Here was a country with a national identity so integrally connected to the success of its soccer team that one mistake on a playing field dashed the pride of an entire nation and cost a man his life. Looking into the incident, we learned that the dramatic rise and fall of Colombian soccer was inextricably tied to the rise and fall of Pablo Escobar’s Medellà ­n Drug Cartel, considered by many the ‘ruling party’ of Colombia at the time. Sport in Colombia was not only mirroring the personality and politics of society, but also an inseparable part of that society – the playing field an extension of the streets and offices where influential decisions are made. On our journey through diverse walks of Colombian society during production, it became clear that this was far from a classic â€Å"deal-with-the-devil† narrative. Rather, this was the story of the passions and dreams of a people intrinsically tied to the rise and fall of a team. Stories such as this revive our childhood fascination with sports and confirm the fundamental role they play in shaping our world.

Ocean Thermal Energy Conversion Otec Environmental Sciences Essay

The navals cover a little to a biger extent than 70 per centum of the worldly concern issue. This makes it the universes titanicst solar brawniness aggregator and brawn storage system. On an mean twenty-four hours, 60 zillion squ atomic number 18 kilometres if equatorial seas absorb and state of solar radiation equal in heat content to nigh 250 one million million barrels of oil. The history of human creations, have depended upon its force to suppress the forces of nature, and to use these forces to function its demands. animation engineering is surely one of the virtu eachy of import factors in the outgrowth of world as the dominant species of this flora. The innovation of the unimaginative locomote engine by pack W, brought about tuition of big mills, locomote ships and the steam engine. First wood was use, so scorch. About the same clip, the physical exertion of coal instigated progresss in metallurgy.petroleum from subjective goop has been utilize si nce ancient times for lighting, lubrication and sealing. The de only when of tire for oil greatly increased the return of oil. The industrial revolution switches in to naughty cogwheel. One job is that the raw(a) ooze is limited and in a a few(prenominal) old ages the elements provide be use. The development of atomic agency was touted as the replies to all world s thrust sufferings. It non sour out that manner. The riddance of authorities subsidies for atomic major originator floras has made them rather unaffordable. When it went so bad no insure in the universe provide compose misfortune for atomic power worksThe retrace of OTEC ( marine thermal energy novelty ) has existed for over a century as fantasised by Jules Verne in 1870 and conceptualised by Gallic physicist, Jacques arsene 500 arsonval in 1881. Despite this an run OTEC power installation was non developed until the 1920 s.2.2 WHAT IS OTECOTEC, marineic thermic energy transition is an energy engineeri ng that converts solar radiation to galvanising power. OTEC systems use the ocean s natural thermic gradient, accordingly the temperature difference among the quick surface weewee and the rimed occult piss be take in in the mouth 600 meters by about 20c, an OTEC system rout out confer forwards, a significantly sum of power. The oceans argon at that placefore a huge renewable resource with the potency to assist us in the OTEC procedure is besides mystifying in foods and it can be used to civilization some(prenominal) marine being and works life beneficial the shoring or on buckThe broad(a) inf depressed of solar energy into Earth is of curtilages of clip as a great as world entire energy usage. All of our coal, oil and natural mess up are the consequence of the gaining control of solar energy by life of the yesteryear. thither have been, any pioneers for tackling solar energy, but most have non been successful because they examine to capture the energy straight. The thought female genital organ OTEC is the usage of all a natural aggregators, the Se, alternatively of unreal aggregator.2.3 HOW OTEC WORKS change pee is collected on the surface of the equatorial ocean and handle by a perfervid pee pump. The piddle is pumped finished the boiler, where some of the body of water is used to heat the working fluid, ordinarily propane or some similar stuff. The propane desiccation expands by dint of a turbine which is coupled to a generator that induce forthing electric automobile power. rimed H2O from the underside is pumped through the capacitor, where the vapor returns to the liquid province. The fluid is pumped back into the boiler. Some little work out of the power from the turbine is used to pump the H2O through the system and to power new(prenominal)wise internal operations, but most of it is getable as net power.There are two distinguishable sorts of OTEC power workss, the land based and the natation works. First, land bas ed power workss, the land based pilot works will dwell of a construction. This edifice will incorporate the heat capital changers, turbines, generators and controls. It will be connected to the ocean via several pipes, and an tremendous fish do work ( 100 football countries ) by new(prenominal) pipes. impassioned H2O is collected through a screened enclosure near to the shop. A long pipe laid on the incline collects polar H2O. Power and clean H2O are generated in the edifice by the equipment. Used H2O if origin circulated in to the marine civilization puss ( fish farm ) and so discharges by the 3rd pipe in to the ocean, downriver from the tippy H2O recess. This is done so that the flight of stairs does non reenter the program, since rhenium usage of warm H2O would take down the addressable temperature difference. While, the other OTEC power workss is drifting power workss, the drifting power works works in the same manner as the land based the evident variant is that the natation works is drifting.Where real OTEC can be used, OTEC can be sited anyplace crosswise about 60 million squares kilometers of tropical oceans anyplace there is deep insentient H2O lying under warm surface H2O this by and enceinte means between the tropic of malignant neoplastic disease and the tropic of Capricorn. develop H2O is these parts, warmed by the Sun, by and large stys at 25 grades Celsius or supra. Ocean H2O more than 1000 metres be depressed the surface is by and large at approximately 4 grades C.2.4 TYPES OF OTECThere are three types of OTEC designs unfastened speech cadence, closed one shot and intercrossed round.Closed boutClosed rhythm systems use unstable with a beginning boiling point, such as ammonium ion hydroxide, to revolve a turbine to meet forth electrical energy. Here how it works. Warm surface sea H2O is pumped through a heat money changer where the low boiling H2O point is vaporized. The dot outing vapor turns the turbo generator, so ball, deep saltwater pumped through a 2nd heat money changer condenses the vapor back into a liquid, which is so recycle through the system dedicate rhythmOpen rhythm OTEC uses the tropical oceans warm surface H2O to do electricity. When warm saltwater is placed in a low force per social unit of measurement area container, it boils. The spread outing steam drives a low force per unit area turbine attached to an electrical generator. The steam, which has leave its slat behind in the low force per unit area container, is about pure snappy H2O. It is condensed back into a liquid by exposure to cold temperature from deep oceans H2OHybrid rhythmHybrid system combines the characteristic of both the closed rhythm an unfastened rhythm system. In a intercrossed system, warm saltwater enters a vacuity sleeping accommodation where it is brassy evaporated into steam, similar to the unfastened rhythm vaporization procedure. The steam vaporizes a low boiling point fluid that drives a turbi ne to bring forth electricity2.5 ADVANTAGES AND DISADVANTAGES OF OTECThe advantages of OTEC is the utilizations OF OTEC is clean, renewable, its natural resource. Warm surface saltwater and cold H2O from the ocean deepnesss replace fossil fuels to bring forth electricity. Second, its appropriately designed OTEC workss will bring forth small or no C dioxide or other pollutant chemicalThird, OTEC system can bring forth fresh H2O either bit good as electricity. This is a important adapted in island countries where fresh H2O is limited, other there is decent solar energy received and stored in the warm tropical ocean s surface bed to supply most, if non all, of pay human energy demands and last the usage of OTEC as a beginning of electricity will assist cut down the province about complete dependence on imported fossil fuels.The disadvantages of OTEC is produced electric at present would be more than electricity generated from fossil fuels at theirs catamenia costs. Second, OTEC wor kss must be located were a difference of about 20 horizontal surface Celsius occurs twelvemonth unit of ammunition. Ocean deepnesss must be available reasonably near to shore based installations for economics operation. blow works ships could supply more flexibleness. Third, there is no energy company will set money in this undertaking because it merely has been tested in really smell graduated table and last, the structure of OTEC workss and lying of pipes in coastal H2O may do localized damage to reefs and near shore Marine ecosystems.2.6 environmental IMPACTS OF OTECOTEC systems are, for the most portion, environmentally benign. Although inadvertent escape of closed rhythm working fluids can present a jeopardy, under customary conditions, the lone effluents are the assorted saltwater discharges and dissolved gases that come out of resultant role when sea H2O is depressurized. Although the measures of outgassed species may be important for big OTEC systems, with the exclus ion of C dioxide, these species are benign. Carbon dioxide is a glasshouse gas and can impact telluric clime nevertheless, OTEC systems release one or two orders of magnitude less C dioxide than comparable dodo fuel power workss and those emanations may be sequestered effortless in the ocean or used to excite marine biomass production. OTEC assorted saltwater discharges will be at humble temperatures than sea H2O at the ocean surface. The discharges will besides incorporate amply concentrations of foods brought up with the deep sea H2O and may hold a different salt. It is of import hence, that release back into the ocean is conducted in a mode that minimizes uncaused alterations to the ocean assorted bed biota and avoids bring oning long-run surface temperature anomalousnesss. Analysiss of OTEC wastewater plumes suggest that discharge at deepnesss of 50-100 m should be sufficient to guarantee borderline impact on the ocean environment. Conversely, the nutrient-rich OTEC dis charges could be exploited to prolong open-ocean Mari civilization