The Ins and Outs of the Madreporite

The madreporite is an essential part of the circulation system in echinoderms. Through this plate, which is also called a sieve plate, the echinoderm draws in seawater and expels water to fuel its vascular system. The madreporite functions like a trap door through which water can move in and out in a controlled manner. Composition of the Madreporite The name of this structure came from its resemblance to a genus of stony corals called madrepora. These corals have grooves and many small pores. The madreporite is made of calcium carbonate and is covered in pores. It also looks grooved like some stony corals.   Function of the Madreporite Echinoderms dont have a circulatory system of blood. Instead, they rely on water for their  circulatory system, which is called a water vascular system. But the water doesnt flow freely in and out - it flows in and out through a valve, which is the madreporite. Cilia beating in the pores of the madreporite bring the water in and out.   Once the water is inside the echinoderms body, it flows into canals throughout the body. While water can enter a sea stars body through other pores, the madreporite plays an important part in maintaining the osmotic pressure needed to maintain the sea stars body structure. The madreporite also may help protect the sea star and keep it functioning properly. Water drawn in through the madreporite passes into   Tiedemanns bodies, which are pockets where the water picks up  amoebocytes, cells that can move throughout the body and help with different functions.    Examples of Animals With a Madreporite Most echinoderms have a madreporite. Animals in this phylum include sea stars, sand dollars, sea urchins and sea cucumbers. Some animals, like some large species of sea stars, may have multiple madreporites. The madreporite is located on the aboral (top) surface in sea stars, sand dollars, and sea urchins, but in brittle stars, the madreporite is on the oral (bottom) surface. Sea cucumbers have a madreporite, but its located inside the body. Can You See the Madreporite? Exploring a tide pool and find an echinoderm? If youre looking to see the madreporite, it is probably most visible on sea stars.  The madreporite on a  sea star  (starfish) is often visible as a small, smooth spot on the sea stars upper side, located off-center. It is often made up of a color that contrasts with the rest of the sea star (e.g., a bright white, yellow, orange, etc.). Sources Coulombe, D.A. 1984. The Seaside Naturalist. Simon Schuster. 246pp.Ferguson, J.C. 1992. The Function of the Madreporite in Body Fluid Volume Maintenancy by an Intertidal Starfish, Pisaster ochraceus. Biol.Bull. 183:482-489.Mah, C.L. 2011.  Secrets of the Starfish Sieve Plate Madreporite Mysteries. The Echinoblog. Accessed September 29, 2015.Meinkoth, N.A. 1981. National Audubon Society Field Guide to North American Seashore Creatures. Alfred A. Knopf: New York.

Genetic And Environmental Factors That Shape A Child s...

Human Development Theorists have studied people looking for answers to explain, how, why, what we are. â€Å"Briefly, the study of human development is how and why people change over time† (Berger, 1994, p. 4). Developmental scientists study development in six domains of human development: physical; cognitive; social; language; emotional and spiritual development. Are these aspects affected by nature or nurture or both? †Developmentalists consider everything from genetic codes that lay down the foundations of growth to the countless environmental factors that shape development across the life span† (Berger, 1994, p. 6). Both genetic and environmental factors can shape a child’s development. Early childhood teachers cannot change genes of a child, but they can endeavour to foster learning and development. The first five years of development come on apace and are faster than at any other time. So early childhood teachers need to understand developmental norms and what will affect children. Then children can be given opportunities to experience all their skills to develop comprehensively and pay attention to the things that impact on them. Piaget (Berger, 1994) is a well know cognitive theorist whose concept of cognitive development placed great importance on early childhood education. Piaget’s theory has four specific stages. He deemed that children learn by actively involving themselves in their domain. Piaget is also linked to the Constructivist Theoryï ¼Å¡children constructShow MoreRelatedThe Role Of Nature And Nurture Development At Childhood Stages1603 Words   |  7 Pages Childhood Development Student’s Name University Name â€Æ' Childhood Development Introduction Twins who have the same genetic makeup raised up in a different environment have portrayed variation in performance and other dynamics of intelligence quotients, physical development, and socioemotional development. Research on adoptions has also revealed interesting results concerning biological and nature in the development of the children. Therefore, this raises the question about the roles of nature andRead MoreThe Evolutionary Factors That Have Shaped The Genetics That We Inherit From Our Parents1049 Words   |  5 PagesINTRODUCTION NATURE This refers to all the evolutionary factors that have that have shaped the genetics that we inherit from our parents. Nature determine the range of our human potential.Naturists believe that the knowledge humans have about the world is innate. Therefore human development is determined by heredity. NURTURE This has to deal with our environment; it refers to all the environmental factors that have influenced us since we began to grow. Nurture affects the way our human potentialRead MorePsy / 280 Human Growth And Development1029 Words   |  5 PagesDeondra Braden January 19, 2015 PSY/280 Human Growth and Development Human Development Paper As a human race, in most circumstances we all go through similar stages of development. What most also be taken into account when assessing development is our ranging variations of individualism. Our individual development is subject to a never ending list on influences. Some influences we are born with and some are due to our own life experiences. Our personality comes from all that we are; weRead MoreEssay on Unit 7 Ps3301380 Words   |  6 PagesUnit 7 Project PS330: Personality Development Prof: Benjamin Anderson 1. What is the relationship between cognition and personality development? Put simply, developmental theories of personality follow quite closely the same developmental timetable as cognitive development. The Oral stage of Freud occurs during the Sensor motor period of Piaget; the anal stage, Pre-conceptual stage; the phallic stage, Concrete Operational Stage;Read MoreThe Effects Of Birth Defects On The Development Of The Fetus899 Words   |  4 PagesPrenatal development is the process in which a human embryo or fetus gestates during pregnancy, from fertilization until birth (Prenatal Development). Most cases of unhealthy development can be avoided, however there are some genetic and environmental factors that cannot. Some genetic factors that affect the development of the fetus are Phenylketonuria, Sickle-cell Anemia, Tay-Sachs Disease, and Down Syndrome (Feldman 402). Some environmental teratogens that affect the development of the fetus areRead MoreHuman Behavior: Nature vs. Nurture Essay1733 Words   |  7 Pagesto this debate, nature can be describe d as, the behavior of a person is occurring because of their genetic makeup. Since the behavior of a person is due to their genetic makeup, then, it (nature) should also influence a person’s growth and development for the duration of their life. However, the nurture side of the debate says, the cause for an individual’s behavior is because of environmental factors. This would mean that the influence from our family (immediate and extended), friends and other individualsRead MoreThe Theory Of Human Development1060 Words   |  5 PagesTheories of human development deliver a framework to deliberate human growth, development, and learning. Understanding the theories can deliver useful contents into individuals and society a set of principles and concepts that describe life span development. Development perspectives are the psychoanalytic theory, behavior theory, humanistic approach and cognitive theory. Each theory focuses on different aspects of human development. The p sychoanalytic is â€Å"the approach stating that behavior is motivatedRead MoreNature Vs. Nurture Debate1366 Words   |  6 Pageswhich our genetics or environment, affects our behaviour and developmental stages. Nature is described as the genetic material that makes up an individual. Nurture can be described as the way in which the environment and experiences of an individual influence their behavior and development. 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This fact has led many scientists to think that a set pf psychological characteristicsRead MoreThe Potential Effects Of Five Different Life Factors On The Development Of An Individual1716 Words   |  7 Pagesdifferent life factors on the development of an individual Introduction There are different factors that can influence an individual’s development. When an individual is developing there are different biological and environmental factors that can determine the way they are, the way they act and the way they develop. It all depends on a combination of both environmental and biological influences. In this assignment I will talk about the five life factors that affect the development of an individual

Media Effects Theory Free Essays

This is a short discourse on the research of the Media Effects Theories, showing how the new theories or current information that is available currently support old theories such as the cultivation theory, spiral of silence theory, and uses-and-gratifications theories among others. This will begin with a brief discussion on Media Effects Theory and proceed to highlight the current developments in this scholarly field and finally show how these theories support different effects models. The developments in media have accelerated at an enormous rate given the recent advances in technology. We will write a custom essay sample on Media Effects Theory or any similar topic only for you Order Now New forms of media such as DVD and the internet have changed the way media is delivered to the audience and also the way it is perceived thus raising the question of whether or not the conventional theories on Media Effect are still viable for the current scenario (Berger 1997). To properly understand this, it is important to first delve into the nature of Media Effects Theories. Media Effects Theory. Media Effects theory can be generally defined as the theory that postulates that any level of exposure to representations or depictions of violence in any of various media cause or have the potential to cause increased aggression or violence in the behavior of the audience (Bryant 2002). Media Effects Theories are developed to provide a better understanding and to gain a deeper insight into the effects that media has had with respect to society and also the role that media plays in influencing social and political change (MacQuail 2000). The recent developments in media however have raised new concerns regarding the perspectives and a proliferation of approaches concerning the Media Effects Theory including its research methodology, communications education, and public policy issues (Berger 1997). Given these criticisms of the theories on media effects, it becomes relevant to examine the existing theories and to examine how an application of the current theories and research may help in addressing this concern. Existing Media Effects Theories This section will briefly discuss a few of the more predominant and influential Media Effects Theories today. The first discussion will be on the Hypodermic Needle Model, which is a theory that the influence of media is so powerful that it can be used to â€Å"inject† messages into the minds of the audience and control them (Baran et al 1995). This model was developed by the Marxist Frankfurt School of intellectuals in the 1930s. The current application of this theory today is criticized by many because the Hypodermic Needle Model was mainly a result of the fear and concern that was generated during the practice of political propaganda and psychological warfare during World War I (Baran et al 1995). The second Media Effect Theory that will be discussed is the Empiricist Tradition which as the term suggests employs an application of the methodologies and principles of the natural sciences to attempt to measure the direct effects on audiences that may be attributed to media exposure (Mass Media Effects: A Study 4). Paul Lazarsfeld, an important researcher who contributed much to the development of empirical conducted a study into voting behavior carried out in the 1940s which to the development of the highly influential Two Step Flow Model of mass communication (Bandura 2001). There have been many criticisms with regard to this theory. While early on it was regarded as influential in this field with the theory of the â€Å"Limited Effects†, there have been studies conducted in Europe that show the exact opposite (MacQuail 2000). The current application of this theory now might be made more credible by improving the methodological diversity which scientists and social theorists have criticized (MacQuail 2000). Another influential Media Effect Theory is the Cultural Effects Approach which basically tries to analyze the social, political and cultural effects (MacQuail 2000). The advocates of this approach fall into two (2) categories, the Marxist Approach and the Literary Criticism Approach (Mass Media Effects: A Study 6). While these two (2) views have gained a strong following among many, the most common criticism is that given the technological advances today, there must be a method by which these theorists are able to provide empirical evidence supporting their assertions (Chomsky et al 2002). The other influential perspective is the Uses and Gratification Approach which allows insight into precisely how the â€Å"new† media differ from the â€Å"old† insofar as audiences utilizes these media (Gauntlett 1998). This focuses primarily on how the audience or people in general use the media to gratify their needs. While this approach is still widely used, the problem of different needs and uses particular to a single individual makes the approach unreliable to some. As MacQuail pointed out, â€Å"it’s very difficult to connect a particular need with a particular type of media content since media use may be considered to supply at one time or another all the benefits named (57)† Now that it has been shown how these approaches have defined and been applied in Media Effects Theories, an examination of the current theories and research prevailing today must be done. Current Theories and Research As previously mentioned, the recent technological advances have altered the way that media is perceived and received by the audience, allowing for arguably greater effect or influence upon the general public. This section will attempt to discuss how the traditional approaches may utilize the current theories and research available to be able to adapt with the ever changing needs and demands of this field of study. The first critical issue to be discussed is the rising influence of postmodernist thought on the approaches to Media Effects Theory (Fisher et al 2004). The main ideas of this theory rely on the fact that the ideas and perceptions of individuals has already been preconditioned by media in a sense that whatever input or meaning that is derived from media is already placed in a predefined context (MacQuail 2000). This school of thought therefore suggests that in analyzing the behavior and effects the fact that media has already preconditioned the minds of the individuals and influenced the â€Å"reception. Miller 2005)† An approach that is closely linked with this development is the New Audience Research, which focuses primarily on the ethnographic studies of audiences while not totally disregarding the â€Å"theory† aspect of the matter (Fisher et al 2004). This approach uses the reception analysis, which has developed from a combination of traditional qualitative resear ch strategies in sociology with some of the ideas of reader response theory in literary criticism (Mass Media Effects: A Study 8). The important aspect of this approach is ability to confront and properly address the issues concerning the origins and influences of meaning that an individual conceptualizes with regard to the media input that he is exposed to. Another important factor to consider is the cultivation theory, which was primarily concerned with concerned with the â€Å"cumulative and overarching impact it (media) has on the way we see the world in which we live (Miller 2005). † This theory has recently been discussed in the research of James Shanahan and Michael Morgan which tackled the issue of the cultivation theory and television. The main idea of this research revealed that television programming cultivates a mainstream world view that reflects and perpetuates the interests of social and political elites and their stakes in maintaining the status quo (Shanahan and Morgan 2000). This type of analysis reveals the relevance of this approach to the Theories on Media Effects because of the fact that this approach considers the context within which the images presented in media with respect to the changing times and culture (Bandura 2001). While this approach may not be necessarily complete and is not without its criticisms, when combined with the Empirical Tradition, a new method which combines the stronger features of the scientific method and the approach of the cultural method may prove to be credible enough to silence its critics. Application of Media Effects Theories In order to arrive at a more concrete understanding of the issue at hand, it is interesting to apply what has been discussed to a current issue. One of these issues is the effect of media on the moral fiber of today’s youth. This will be discussed in brief to provide an accurate detail of just how these media effects theories can be applied to today’s social problems. As a quick glimpse at the recent events that grace the newspaper’s headlines show, there is indeed a growing concern over the violence that happens in schools all over the country (Chomsky et al 2002). The issue is not limited to the increased teenage pregnancies or even drug abuse. It encompasses a whole range of issues such as bullying and perhaps the most frightening, schools shootings (Chomsky et al 2002). With all of these problems plaguing not only the education system but also the entire nation as of late, the question that comes up is whether or not this is actually caused by the violent television shows and movies in the cable TV programming. While there has been no irrefutable data that lends credence to the theory that violent shows in television is the real culprit behind today’s misguided and often violent youth, there can also be no argument against the statement that though violence on television may not be the sole cause, it is one of the contributory causes (Fisher et al 2004). There are a number of media effects theories that solidify the argument that it is violence in media or in television that has led to the deterioration in the moral foundation of today’s youth (Gauntlett 1998). A good example of this would be the â€Å"Hypodermic Needle Model†, which is a theory that the influence of media is so powerful that it can be used to â€Å"inject† messages into the minds of the audience and control them (Gauntlett 1998). While it is not being suggested that television is being used a medium to brainwash today’s youth and turn them into an army of zombies for the media, it is being proposed, however, that the programming and quality of shows on television, such as violent programs, has a profound effect upon the youth (Shanahan and Morgan 2000). The influence, therefore, that television has upon the youth is undeniable. While this influence may have waned in the advent of the internet age and YouTube, it still bears a considerably large amount of influence over the younger children who are not able to access such media devices (Fisher et al 2004). Therein lays the danger; young children with impressionable minds are exposed to violence on television leading to a deterioration in the moral and ethical foundations of today’s generation. Another interesting theory to correlate the cause, violence in television, with the effect, violent behavior of the youth, is the postmodernist thought on the approaches to the Media Effects Theory (Gauntlett 1998). The main ideas of this theory rely on the fact that the ideas and perceptions of individuals has already been preconditioned by media in a sense that whatever input or meaning that is derived from media is already placed in a predefined context (Fisher et al 2004). This school of thought therefore suggests that in analyzing the behavior and effects the fact that media has already preconditioned the minds of the individuals and influenced the reception (Shanahan and Morgan 2000). As such, given the volatile nature of the mind of a child, the input that a child receives from violent programming on the television creates a preconceived notion of what the real world is like. By showing violence on television, a child may think and perceive that such behavior is actually socially acceptable (Fisher et al 2004). Studies have shown that there have been causal links found between aggressive and violent behavior in children and the type of television programs that these children generally watch. This can also be applied to the infamous Columbine shooting wherein the investigators have theorized that the motivation for the shooters may have been influenced by forms of media (Fisher et al 2004). As stated in one of the reports, â€Å"Among the many theories that have surfaced regarding the motivation for this incident the most prevalent one remains the effect that media has on the minds of today’s youth. (Fisher et al 2004) While there are those who theorize that it was the fact that the shooters were isolated from the rest of their classmates thus prompting feelings of helplessness, insecurity and depression, as well as cultivating a strong desire for attention, the attention has been focused on the effect violent video games such as Doom, which the shooters frequently played, and rock m usic such as Rammstein. Every day the world searches for answers for many of the would-be â€Å"avoidable† tragedies such as school shootings, gang wars and juvenile teen violence. The reason for the term â€Å"avoidable† stems from the fact that many consider these as effects of media influences and morally condemnable social behavior (Fisher et al 2004). While media and television, in particular, are not the main causes for these tragedies, it cannot be denied that they have contributed to these problems (Fisher et al 2004). There may not be an easy solution for this but by identifying the causes that have led to this dilemma a big step has been taken to rectify this situation and to prevent more disasters such as this from ever happening again. Conclusion From this discussion, it is apparent that the application of these Media Effects theories is versatile to say the least. There are a number of social phenomena that occur in today’s world that can be partly explained by these theories. Events such as the impact of media on today’s youth, school violence, teen drug abuse and even consumer patterns are all within the ambit of these media effects theories. It is interesting to note, however, that while suitable media effects theories are present in this discussion, the field of media studies is constantly evolving. The introduction and use of new technology that aids in the proliferation and dissemination of media could prove to challenge many of these conventional theories if not alter them. Other future concerns in this area would also have to deal with the present legislative stance on certain forms of media and their content. It remains to be seen in the future just how these events will change the understanding and function of media in present day society. There will always be debate concerning the correct approach to Media Effect. Certain schools of thought will always insist on the application of a more totalitarian perspective that incorporates unquantifiable characteristics or effects while others will insist on an empiricists approach and the application of the principles and information that the natural sciences provide. The key to resolving this issue may very well lie in which school of thought is regarded as authoritative or persuasive enough to convince the other of the credibility and validity of their findings. While this may not seem possible, events in the past have shown that even for brief moments a single school of thought or approach was held in high regard (see Empiricist Tradition). The use of these current theories on the approaches to Media Effects Theories may however be the final factor which determines what school of thought or media model will prevail. The way these current researches have incorporated the key aspects of the technological development in media as well as the way that they have addressed the previous concerns or criticisms regarding the traditional approaches makes them a valuable tool indeed in providing a deeper understanding of human nature and the relationship that it has to media. How to cite Media Effects Theory, Papers