How has the Invention of Contact Lenses affected peoples Sight Essay Example

How has the Invention of Contact Lenses affected peoples Sight Essay People with sight troubles have had the possibility of wearing glasses for a really long time, but the new technology made available contact lenses. In this essay, I am going to look at the different contact lenses types that exist, at who invented them and when, for which vision problems they are solution, at how to take care of them, at how common they are in our society and finally, I will write about my own opinion.What contact lenses areAccording to the Macmillan Dictionary (2002), contact lens may be defined as a plastic lens that you wear in your eye to help you see more clearly.A very wide variety of contact lenses are available in todays society, including hard and soft (even if soft is by far more common now), disposable and extended wear; this makes it easy for each person to chose the appropriate type of contact lens for her. The main types of contact lenses are listed below:* Soft lenses: As these lenses are soft, they are made of a large percentage of water, and this al lows oxygen to pass through the lens and reach the cornea. They are also more comfortable and easier to adapt to.* Rigid-gas permeable lenses: these lenses are not made of water so they are not as comfortable as the soft ones, but they do allow a larger amount of oxygen to pass through them. Their best advantage is that they offer a excellent sight correction.* Disposable lenses: Disposable means that the lenses are worn for a definite period (from two weeks to six months depending on the lenses) of time before being thrown away and replaces by a fresh new pair. The fact of throwing out the lenses helps making sure the lenses are always very clean, so healthier and more comfortable.* Extended wear lenses: these lenses are made to be worn 24h a day, and up to seven days on a row (a new type made of silicone hydrogel allows more oxygen to flow in so that they can be kept for up to 30 days without taking them off).* Bifocal contact lenses: this type of lens has two major functions: to correct distance vision and to correct near vision. There are two main designs: the power or seeing far is concentrated at the top and the one of seeing nearby at the bottom, or the different powers are blended on different parts of the lens.* Coloured contact lenses: they can be used to correct existent sight troubles, but also just to look prettier, as they come in a large variety of colours, from hazel to blue, passing by grey, purple and green.However the lenses type that is mostly used today is a combination of both soft and disposable lenses, simply called the disposable soft contact lenses, because they are the healthiest ones, more comfortable, and major prices differences from an average model of these different types of lenses do not exist.When and by who they were inventedThe famous Italian inventor Leonardo da Vinci was the first one to come up with contact lenses sketches and explanations, at the beginning of the 16th century. It is only in 1801 that Thomas Young develo ped the idea Rene Descartes had had more than 150 years before. Thomas Young, who was a British physician, took small lenses from his microscope, covered the edges of them in soft wax and put them into his own eyes to correct his vision.In 1887, the glassblower F.E. Muller produces the first lens designed to be seen through and tolerated; (however, according to the book 100 greatest medical discoveries, it is the American Louis J. Girard who developed the first contact lens this same year). Almost half a century later, the American William Feinbloom is the first one who creates an US-made contact lens and introduces the use of plastic in it.After few improvements such as making the inner-surface of the corneal lens follow the eyes shape (instead of sitting flat) or also the use of a new material, a softy water absorbing plastic, it is in 1971 that the soft lens became available for commercial distribution in the United States. New models of lenses, each time with more improvement, w ere then created and commercialised (around a new model every two years).In 1987, a great evolution can be established: disposable soft contact lenses and the first multipurpose lens care product (explained in more details further) were available for commercial distribution, as well as a soft contact lens able o change the eye colour: this is the start of contact lens use in fashion.For who (explanation of vision troubles)Contact lenses were designed for people who cannot see properly, and nowadays they are definitely developed enough to be able to correct almost all the vision troubles. The 5 main vision conditions are the following:* Astigmatism: this condition usually affects both nearsightedness and farsightedness because the corneas curvature is rather oval when it should be round. Their sight is not prà ¯Ã‚ ¿Ã‚ ½cised and for example, they can confuse the letters M, N and H, or B and D. It is often associated to myopia or hyperopia.* Hyperopia: this is a long-sightedness cond ition, and people affected by it have difficulties to focus on close objects, while the sight of distant objects stays correct. It might be because the cornea is too bulging, or because the crystalline lens (see eye diagram) of the eye is too flat.* Myopia: also known as short-sightedness, people affected by this condition are able to do tasks that require a vision of nearby objects, such as reading or sewing; but they see distance objects blurred so for example, they cannot read highway signs.* Presbyopia: this long-sightedness condition cannot be avoided because it touches everyone at some point in life (usually around 40-50 years old). It is due to a loss in flexibility of the lens and loss of power of the ciliary muscles and it cause the person to have difficulties in focusing on nearby objects. A person affected by this condition will for example hold her newspapers further away from her eyes to see it better (we say that the arm grows shorter because it is not able to hold the object at a distance long enough for these people to see anymore).* Strabismus: this condition, also called lazy eye, makes us squint; there is a lack of coordination between the muscles of the two eyes, and this means that the vision axes of our two eyes are not parallel so they dont point out at the same direction. This affects our depth perception.The following eye diagram will help understand which parts of the eyes are damaged by the previously explained conditions:How to use themYou definitely need to consult a specialist who will tell you the type of contact lenses that are the most appropriate to your case: the optometrist will prescribe the lenses to you and the oculist will provide them. Your ophthalmologist will explain you how to put them on; it might look hard at the beginning but its just a matter of getting used to it. But two rules are still primordial: to make sure you have clean hands before you put your lenses in your eyes and not to wear them for than the indica ted time.It is very important to take care of you contact lenses; indeed they need regular cleaning and disinfecting to retain clear vision and prevent infections. Eyes were not designed to have a foreign object in them. Plus this foreign object prevents the air to reach the eye, while this sight organ needs to receive oxygen. Contact lenses make your eyes vulnerable to all sorts of things so by cleaning them, they are less likely to breed bacteria and they are more air permeable. A large variety of products is nowadays available to clean, rinse and disinfect your lenses:* Saline solution: once the lens was cleaned, this solution is used to rinse it.* Daily cleaner: this cleaner is used once a day, to clean the lenses. With a few droplets of the cleaner on it, the lens is rubbed for about 20 seconds on each side. Long nails mean to be extra careful with the rubbing!* Multipurpose solution: this solution is used for rinsing, disinfecting, cleaning and storing the lenses. It can be us ed only for disinfection and storage if it is associated with another rinsing product (eg: Saline solution) and a cleaning one (eg: daily cleaner).Some products may contain preservatives such as thimerosal. To avoid any kind of problems due to these preservatives (even if many brands no longer use products that contain preservatives), it is safer to chose products with the label for sensitive eyes, and these products usually have an expiration date.How common they are in todays societyContact lenses are greatly used in todays society. Even if they are basically made to cure vision troubles, they are more and more used for appearance aspects: many people would rather wear contact lenses than glasses because they look prettier, and because you have fewer troubles with them. few examples include the nerd stereotype changing from glasses and becomes beautiful, or the athlete who can play sports without fear of shattered glasses, or also the actor able to switch his eye colour from brown to red, passing by blue, depending on the role. Teens are the main people wanting to switch their glasses for contact lenses, for cosmetic reasons: they will feel more self-confident and good looking without their glasses. But before contact lenses are prescribed to this category of people, it is important to make sure that they are responsible enough to take care of their contacts. Teens are also the best costumers to buy colour contact lenses in order to change their appearance: more than just changing the colour of your eye, special contact lenses are now available for special occasions, such as Halloween with contacts that give you cats or vampires eyes.So it is very common nowadays to see people wearing eye contacts even though they dont need them for their sight. However, a prescription is always needed because wearing contact lenses is still considered as a medical application. And the fact that they are more and more common in todays society should not make us forget their first aim was for helping see and so they need special care, even if they are only being used as a fashion accessory. More than that, secondary effects might happen, such as fatigue and headaches, and those are stronger if it takes time for the eyes to adapt to the contacts.Also be careful when putting make up on: always put your contacts before the make up and take them off before you use makeup remover. Also it is preferable to use non-allergenic makeup.Own opinionI personally dont wear contact lenses because I dont have any vision troubles and I dont resent the need to change the colour of my eye or anything, but I really think that they are very useful and helpful. I do know some people who hated wearing glasses, and after they tried contact lenses, they felt prettier and better. I also think that contacts are helpful for people who play sports; even in the schools basketball team, few girls wear contacts and it is very useful because this way they dont get hurt; also there is a French commercial for contact lenses that is performed by three famous French athletes, proving that athletes do use contacts. I also think it is nice that actors are able to change their eye colour in order to add little details that make the character more reliable.Nevertheless, contacts are still foreign objects put into your eyes, they might cause secondary effects (such as headaches, seen before) and they need special cleaning equipment. So I think that we have to be careful because if they become too common only as a fashion accessory, then people are going to forget a little bit the medical side of contacts and so they might damage someones eyes if they are not being used properly.ConclusionIn conclusion, the invention of contact lenses has greatly affected peoples sight: eyeglasses are not the first solution to solve vision troubles anymore, because contact lenses have replaced them. They have been so successful because they are easier to use, more discrete and practical as well. And it is more and more common to see people wearing coloured ones them only for the fashion side.However it is important to remind that their first purpose was for medicine, and they require special care that people have to follow, even if they just contacts as fashion accessories.

Writing a Research Paper MLA

Writing a Research Paper MLA Writing a Research Paper MLA Writing a Research Paper MLA: Things to Remember While writing a research paper you should pay attention to all the aspects, among other things to the design as well. Moreover, the proper design of your paper gives you additional points. So, lets consider some information concerning writing a research paper MLA style that will be helpful for you. It should be mentioned that MLA style is used in writing research papers in arts and humanities. Writing a research paper MLA format supposes the number of requirements that must be fulfilled while dealing with it. Lets name the main of them12-point Times New Roman font 1-inch margins at all sides half an inch-indented paragraphs double-spaced text As for page numbers they should be typed in the upper right-hand corner of each page, half an inch from the top and an inch from the right-hand edge (the first page should be numbered as well). Remember: your last name should be stated before each page number! Writing a research paper MLA: the first page A peculiar feature of writing a research paper MLA is the absence of the title page. The point is that you should type your name, your tutors name, the course and the date in four lines in the upper left-hand corner of the page. Do not forget that the text should double-space. Put the title of your research paper in the centre of the next line. It should not be italicized, underlined or put in quotation marks. Use the standard capitalization (do not write the title in all capital letters). The title should not end with a period; but you may use a question mark or an exclamation mark if it is necessary. Then start typing the text of your research paper from the next line of the same page (do not forget about double space!). Writing a research paper MLA: the system of headlines Writing a research paper MLA means also the usage of headings of several levels. They are 5 in the MLA style:Left-aligned, boldface headings Left-aligned, italicized headings Centered, bold face headings Centered, italicized headings Left-aligned, underlined headings First of all, you should use the first level headings. For example, if you have some classification of several levels, you should use the first level headlines for the first one, the second level headlines for the second one and so on. Pay attention: these are the general requirements of writing a research paper MLA but you should also consult your tutor concerning the format of your paper.

Application of CRM in the life insurance Company in China and in a Dissertation

Application of CRM in the life insurance Company in China and in a company of Ping An Life Insurance of China - Dissertation Example Ping An Life Company understands customer behaviour, focus, and focus on the customers who can deliver long terms profits since they are of great benefit to the company. This company stresses much on customer retention as opposed new customer acquisition since the latter is very expensive. Studies show that retained customers generate over twice as much gross income than new customers in any business hence businesses should focus more on customer retention (Gouthier and Stefan, 2003). The considerable improvement in technology and innovation is making it possible to improve on the customer retention methods through improved customer relationship management. The first step in customer relationship management is to construct a customer database where transaction and customer contact information is accumulated to enable easier follow up on the customer behaviour with time. This task involves seeking historical customer data from operative internal sources such as accounting and customer relations, which since they already have the customer information (Ramashesham, Bejou, Subhash, Mason and Pancras, 2006). Since this company uses a web-based business, this transaction is relatively cheap when compared to other methods, which do not use web-based operations. The database collected from the customer includes the transactions, descriptive information among others. Winer 2001 argues that every satisfied customer brings at least three more while dissatisfied customers discourage at least ten more potential customers. They also assert that regular customers exhibit less price sensitivity than new customers thus customer orient companies can charge higher prices than their competitors without negatively feeling the heat of the competition. Customers expect the sales people to be accountable and continuously solve their problems. They also expect them to be accessible at all times and be creative in responding to their needs. The provision of customer relationship management offers a number of advantages and disadvantages to both the company, which carries the initiative, and the customers who enjoy the benefits, which come with the initiatives. CRM provides the company with the advantage of internal and external information flow thus enhancing the customer satisfaction with the company. Strategies of CRM used in Life Insurance Company This company is applying the new customer relationship approach, which combines advanced technology and sophisticated billing analytical identities, which secures payment before the customer reaches the collection gate. The first strategy used by this insurance company is to choose the right people for the job of customer relationship management. The people chosen for the task should be well trained so that they possess the individuals skills needed in handling the customers

Discuss the importance of process and materials in the work of your Essay

Discuss the importance of process and materials in the work of your artist or designer ( Rex Brandt ) - Essay Example Further, as a teacher, he inspired innumerable students to paint skillfully with watercolours. To Brandt (p.9), working with this oldest medium known to man was exciting because the transparent colours glowed like stained glass. Thesis Statement: The purpose of this paper is to investigate the watercolour artist Rex Brandt’s paintings, and determine the importance of process and materials in his works. The Importance of Process and Materials in the Work of Rex Brandt Brandt (a) (p.119) considered drawing to be the at the heart of watercolour painting. He advocated the importance of sketching as a primary step even in the case of landscapes, and the development of an individual style in executing a painting (Brandt (b) 16). Another requirement was an appropriate choice of materials for achieving best results, and he took into consideration the key role of paper for the medium of transparent pigment or watercolours. The artist appreciated the sparkling white paper adjacent with the transparent, colourful dark hues which forms a unique feature of watercolours. According to Brandt (p.81), â€Å"pure or transparent watercolour is universally appealing† because of its clarity and directness in portraying the image or scene. The artist used three basic watercolour techniques: the wash or control method, wet-into-wet, and dry brush and line. All the three methods may be used in the same painting (Brandt 145). It was considered essential to master the techniques of flat and gradated washes before progressing to the wet-into-wet, drybrush and line methods. Brandt focused equally on controlling the wash, handling colour through the different techniques as given above, correcting mistakes, and on matting and framing the completed art work. Further, the way thin watercolour on white paper reflects light has been compared by Brandt (p.11) to â€Å"the luster of a sea-shell, the translucence of a tide pool, and the luminosity of coloured glass against the sunâ € . After evaporation of the water and the gumbinder taking hold, each small nuance of the painting becomes fixed to the white surface of the paper. However, the main charm of using watercolours is its distinctive potential for gradation which contributes to the visual excitement created by the paintings. This effect is produced by arpeggios or flowing series of gradations in colour and value, as seen in Fig.1. below. Thus, watercolour is a special medium which readily accommodates an interchange of colours as well as gradation, which in turn can modulate its characteristic movement, liquidity and bounce. Fig.1. August at South Beach by Rex Brandt (California Watercolour (1), 2011) In watercolour paintings, accents with with the help of light watercolours are not completed as finishing touches, since light shades cannot cover dark watercolours. Working from light to dark is most effective in such paintings; similarly, it is advisable to work from very broad areas to smaller areas â€Å"since the progressively darker washes will overlay and obscure the lighter ones† (Brandt 98). The artist provided accents using the extremes of light and dark colours; while the grays acted as amalgams thereby giving a sense of unification to the entire picture. A vast number of Brandt’

Summarize five articles Essay Example | Topics and Well Written Essays - 250 words

Summarize five articles - Essay Example The author is entitled to royalties to compensate for his/her work. Patent is the right to sell and control an invention. Patents are issued by the federal government and are valid for several years after which it becomes void. Patents are given to inventions, industrial designs and model, and know how. Patent can only be registered by the inventor of the product. The holder of the patent has the right to prevent others from disclosing or using the know-how. If someone infringes these rights, the owner may seek court directions for compensation. A trademark is a unique mark, logo, slogan, brand name, motto, symbol, device, design or word applied by a manufacturer to distinguish its products from those manufactured by other companies. Trademarks in the UAE are registered so that they can be protected. The period of registration is ten years after which it has to be registered again. The owner of the trademark can give the rights to third party to use the trademark through a notarized contract. Under article 37 p.1, the act of infringing a trademark or passing off is the same and is liable for

Ecology and the Biosphere

Ecology and the Biosphere Ch. 50 (Introduction to Ecology and the Biosphere) I. Ecology is the scientific study of the interactions between organisms and the environment. Events that occur in the framework of ecological time translate into effects over the longer scale of evolutionary time. The environment of any organism includes two components. Abiotic, or nonliving, components chemical and physical factors such as temperature, light, water, and nutrients. Biotic, or living, components all the organisms, or the biota, that are part of the individuals environment. Ecology can be divided into areas of study ranging from the ecology of individual organisms to the dynamics of ecosystems and landscapes. Organismal ecology: Can be subdivided into the disciplines of physiological ecology, evolutionary ecology, and behavioral ecology. Concerns how an organisms structure, physiology, and behavior meet the challenges posed by the environment Population ecology: Concentrates mainly on factors that affect how many individuals of a particular species live in an area. Population group of individuals of the same species living in a particular geographic area. Community ecology: Deals with the whole array of interacting species in a community. Community all the organisms of all the species that inhabit a particular area Ecosystem ecology: The emphasis in this ecology is on energy flow and chemical cycling among the various biotic and abiotic components. Ecosystem all the abiotic factors in addition to the entire community of species that exist in a certain area. Landscape ecology: Deals with arrays of ecosystems and how they are arranged in a geographic region. Patchiness is an environmental characteristic where a landscape or seascape consists of a mosaic of different types of patches. Focuses on the factors controlling exchanges of energy, materials, and organisms among the ecosystem patches. The biosphere is the global ecosystem, the sum of all the planets ecosystems. II. Interactions between organisms and the environment limit the distribution of species Biogeography is the study of the past and present distribution of individual species, in the context of evolutionary theory It provides a good starting point for understanding what limits the geographic distribution of a species. Factors limiting a species distribution may include: Dispersal. Behavior. Biotic factors. Abiotic factors. Dispersal is the movement of individuals away from centers of high population density or from their area of origin One way to determine if dispersal is a key factor limiting distribution is to observe the results of transplants of a species For a transplant to be considered successful, organisms must survive and reproduce in the new area If it is successful, the potential range of the species is larger than its actual range. Behavior and habitat selection may limit distribution. Plants may select their habitats by producing seeds that germinate only under a restricted set of environmental conditions Female mosquitoes select specific habitats for oviposition, or the depositing of eggs Biotic factors that limit the distribution of a species may include: Predation Disease Parasitism Competition Abiotic factors may also limit distribution. Environmental temperature is an important factor in the distribution of organisms because of its effect on biological processes Cells may rupture if the water they contain freezes Proteins of most organisms denature at temperatures above 45 degrees C. Water availability is another important factor. Freshwater and marine organisms live submerged in aquatic environments. Terrestrial organisms face a nearly constant threat of desiccation Sunlight provides the energy that drives all ecosystems, although only plants and other photosynthetic organisms use this energy source directly Wind amplifies the effects of environmental temperature on organisms by increasing heat loss due to evaporation and convection It also contributes to water loss in organisms by increasing the rate of evaporative cooling and transpiration The physical structure, pH, and mineral composition of rocks and soil limit the distribution of plants Temperature, water, sunlight, and wind are the major components of climate Global climate patterns: Earths curved shape causes latitudinal variation in the intensity of sunlight Sunlight strikes the tropics most directly, and the most heat and light are delivered there Earths tilt causes seasonal variation in the intensity of solar radiation. June solstice Northern Hemisphere tilts toward sun; summer begins March equinox equator faces sun directly; 12 hours of daylight and darkness December solstice Northern Hemisphere tilts away from sun; winter begins September equinox equator faces sun directly Intense solar radiation near the equator initiates a global pattern of air circulation and precipitation Air flowing close to Earths surface creates predictable global wind patterns Macroclimate are patterns on the global, regional, and local level Ocean currents influence climate along the coasts of continents by heating or cooling overlying air masses, which may then pass across the land. Mountains have a significant effect on the amount of sunlight reaching an area, as well as on local temperature and rainfall. In addition to the global changes in day length, solar radiation, and temperature, the changing angle of the sun affects local environments During the summer and winter, many lakes in temperate regions are thermally stratified, or layered vertically according to temperature Lakes undergo a semiannual mixing of their waters as a result of changing temperature profiles, a process called turnover. Microclimate are very fine patterns, such as those encountered by a community underneath a log Many features in the environment influence microclimates by casting shade, affecting evaporation from soil, and changing wind patterns. III. Abiotic and biotic factors influence the structure and dynamics of aquatic biomes Biomes are major types of ecological associations that occupy broad geographic regions of land or water Aquatic biomes account of the largest part of the biosphere. These biomes are physically and chemically stratified There is sufficient light for photosynthesis in the upper photic zone Little light penetrates in the lower aphotic zone At the bottom, the subtrate is called the benthic zone It is made up of sand and organic and inorganic sediments It is occupied by communities of organisms collectively called benthos A major source of food for the benthos is dead organic matter called detritus Thermal energy from sunlight warms surface waters to whatever depth the sunlight penetrates. In the ocean and in most lakes, a narrow stratum of rapid temperature change called a thermocline separates the more uniformly warm upper layer from more uniformly cold deeper waters Major aquatic biomes: Lakes are standing bodies of water covering thousands of square kilometers Oligotrophic lakes are nutrient poor and generally oxygen rich Eutrophic lakes are nutrient rich and often depleted of oxygen if ice-covered in winter and in the deepest zone during summer The littoral zone is the shallow, well-lighted waters close to shore The limnetic zone is further away from shore and is too deep to support rooted aquatic plants A wetland is an area covered with water for a long enough period to support aquatic plants The most prominent physical characteristic of streams and rivers is current Headwater streams are generally cold, clear, turbulent, and swift Rivers are generally warmer and more turbid, since they carry more sediment than their headwaters. An estuary is a transition area between river and sea They have very complex flow patterns An intertidal zone is periodically submerged and exposed by the tides, twice daily on most marine shores The oceanic pelagic biome is a vast realm of open blue water, constantly mixed by wind-driven oceanic currents Reef building corals are limited to the photic zone of relatively stable tropical marine environments with high water clarity A coral reef, which is formed largely from the calcium carbonate skeletons of corals, develops over a long time on oceanic islands The marine benthic zone consists of the seafloor below the surface waters of the costal, or neritic, zone and the offshore, pelagic zone. Organisms in the very deep benthic or abyssal, zone are adapted to continuous cold and extremely high water pressure IV. Climate largely determines the distribution and structure of terrestrial biomes A climograph is a plot of the temperature and precipitation in a particular region Vertical stratification is an important feature of terrestrial biomes In many forests, the layers consist of the upper canopy, the low-tree stratum, the shrub understory, the ground layer of herbaceous plants, the forest floor, and the root layer Terrestrial biomes usually grade into each other, without sharp boundaries The area of intergradation is called an ecotone and may be wide or narrow Major terrestrial biomes: In tropical rain forests, rainfall is relatively constant, and in tropical dry forests, precipitation is highly seasonal Tropical forests are stratified Deserts occur in a band near 30 degrees north and south latitude or at other latitudes in the interior of continents Precipitation is low and highly variable Temperature is variable seasonally and daily The savanna is warm year-round, but with somewhat more seasonal variation than in tropical forests Chaparral occurs in midlatitude coastal regions on several continents It is dominated by shrubs and small trees, along with a high diversity of grasses and herbs Temperate grasslands cover parts of South Africa, Hungary, Argentina, Uruguay, Russia, and North America. The dominant plants are grasses and forbs The northern coniferous forest, or taiga, is the largest terrestrial biome on earth Precipitation ranges from 30 to 70 cm, and periodic droughts are common Cone-bearing trees dominate these forests A mature temperate broadleaf forest has distinct, highly diverse, vertical layers. Tundra covers expansive areas of the Arctic, amounting to 20% of Earths land surface A permanently frozen layer of soil called permafrost generally prevents water infiltration. Ch. 51 (Behavioral Ecology) I. Behavioral ecology extends observations of animal behavior by studying how such behavior is controlled and how it develops, evolves, and contributes to survival and reproductive success. II. Behavioral ecologists distinguish between proximate and ultimate causes of behavior. Behavior traits are also a part of an animals phenotype It includes muscular as well as nonmuscular activity Is everything that an animal does and how it does it. Learning is also considered a behavioral process. Proximate questions focus on the environmental stimuli that trigger a behavior, as well as the genetic, physiological, and anatomical mechanisms underlying a behavioral act These are how questions Ultimate questions address the evolutionary significance of a behavior These are why questions Ethology is the scientific study of animal behavior, particularly in natural environments. Tindenbergen suggested four questions that must be answered to fully understand any behavior What is the mechanistic basis of the behavior, including chemical, anatomical, and physiological mechanisms? How does development of the animal, from zygote to mature individual, influence behavior? What is the evolutionary history of the behavior? How does the behavior contribute to survival and reproduction? The fixed action pattern is a sequence of unlearned behavioral acts that Is essentially unchangeable and is carried to completion A FAP is triggered by an external sensory stimulus known as a sign stimulus Imprinting is a type of behavior that includes both learning and innate components and is generally irreversible A sensitive period is a limited phase in an animals development that is the only time when certain behaviors can be learned III. Many behaviors have a strong genetic component. Biologists study the ways both genes and the environment influence development of behavioral phenotypes. Nature and nurture Innate behaviors are behavior that is developmentally fixed and are under strong genetic influence Kinesis is a simple change in activity or turning rate Taxis is an oriented movement toward or away from some stimulus. Trout automatically swim or orient themselves in an upstream direction, exhibiting rheotaxis Bird migration is partly under genetic control. Animal communication consists of the transmission of, reception of, and response to signals A signal is a behavior that causes a change in another animals behavior It is an essential element of interactions between individuals Many animals that communicate through odors emit chemical substances called pheromones They are typically very concentrated Many animals also communicate by auditory communication A variety of mammalian behaviors are under relatively strong genetic control. Research has revealed the genetic and neural basis for the mating and parental behavior of male prairie voles. IV. Environment, interacting with an animals genetic makeup, influences the development of behaviors. Laboratory experiments have demonstrated that the type of food eaten during larval development strongly influences later mate selection by Drosophila mojavensis females Cross-fostering studies of California mice and white-footed mice have uncovered an influence of social environment on the aggressive and parental behaviors of mice. Learning is the modification of behavior based on specific experiences. Special learning is the modification of behavior based on experience with the special structure of the environment This makes use of landmarks, or location indicators A cognitive map is an internal representation or code of the spatial relationships between objects in an animals surroundings Associative learning is the ability of many animals to associate one feature of the environment with another Classical conditioning is a type of associative learning in which an arbitrary stimulus is associated with a reward or punishment operant conditioning is called trial-and-error learning Cognition is the ability of an animals nervous system to perceive, store, process, and use information gathered by sensory receptors. The study of animal cognition, called cognitive ethology, examines the connection between an animals nervous system and its behavior. Habituation is a loss of responsiveness to stimuli that convey little or no information V. Behavioral traits can evolve by natural selection. When behavioral variation within a species corresponds to variation in environmental conditions, it may be evidence of past evolution An example of genetically based variation in behavior within a species is pretty selection by the garter snake Thamnophis elegans Foraging is behavior associated with recognizing, searching for, capture, and consuming food Laboratory studies of Drosophila populations raised in high and low density conditions show a clear divergence in behavior linked to specific genes D. melangogaster living at low population density followed a foraging path shorter than that of D. melanogaster living at high population density VI. Natural selection favors behaviors that increase survival and reproductive success. Optimal foraging theory states that natural selection should favor foraging behavior that minimizes the costs of foraging and maximizing the benefits. How mate choice enhances reproductive success varies, depending on the species mating system. In promiscuous mating, there are no strong pair bonds or lasting relationships In monogamous mating, one male mates with one female In polygamous mating, an individual of one sex mates with several of the other In polygyny, one males mates with many females In polyandry, one female mates with several males Males competition for mates is a source of intrasexual selection that can reduce variation among males agonistic behavior is an often ritualized contest that determines which competitor gains access to a resource, such as food or mates Game theory provides a way of thinking about evolution in situations where the fitness of a particular behavioral phenotype is influenced by other behavioral phenotypes in the population. VII. The concept of inclusive fitness can account for most altruistic social behavior. On occasion, animals behave in altruistic ways that reduce their individual fitness but increase the fitness of the recipient of the behavior. For example, if a squirrel sees a predator approach, the squirrel gives off an alarm, alerting unaware individuals but increasing the risk to itself This behavior can be explained by the concept of inclusive fitness It is the total effect an individual has on proliferating its genes by producing its own offspring and by providing aid that enables other close relatives to produce offspring The three key variables in an act of altruism are the benefit to the recipient (B), the cost to the altruist (C), and the coefficient of relatedness (r). Hamiltons rule states that rB > C Kin selection favors altruistic behavior by enhancing the reproductive success of relatives Altruistic behavior toward unrelated individuals can be adaptive if the aided individual returns the favor in the future, an exchange of aid called reciprocal altruism. Social learning forms the roots of culture, which can be defined as a system of information transfer through observation or teaching that influences the behavior of individuals in a population. Male choice copying is a behavior in which individuals in a population copy the mate choice of others Human culture is related to evolutionary theory in the discipline of sociobiology, whose main premise is that certain behavior characteristics exist because they are expressions of genes that have been perpetuated by natural selection. Ch. 52 I. Population ecology is the study of populations in relation to the environment, including environmental influences on population density and distribution. A population is a group of individuals of a single species living in the same general area II. Dynamic biological processes influence population density, dispersion, and demography. Population density, the number of individuals per area or volume, results from the combination of births, deaths, immigration, and emigration. Dispersion is the pattern of spacing among individuals within the boundaries of the population Environmental and social factors influence the spacing of individuals In clumped patterns, individuals are aggregated in patches In uniform patterns, individuals are evenly spaced Animals often exhibit uniform dispersion as a result of antagonistic social interactions, such as territoriality, the defense of a bounded physical space against encroachment by other individuals In random dispersion, individuals are unpredictably spaced, and the position of each individual is independent of others This occurs in the absence of strong attraction or repulsions among individuals of a population Populations grow from births and immigration and shrink from deaths and emigration Immigration is the influx of new individuals from other areas Emigration is the movement of individuals out of a population Demography is the study of the vital statistics of populations and how they change over time Of particularly interest to demographers are birth rates and how they vary among individuals and death rates Life tables are age-specific summaries of the survival pattern of a population the best way to construct one is to follow the fate of a cohort, a group of individuals of the same age, from birth until all are dead A survivorship curve is a plot of the proportion or numbers in a cohort still alive at each age Idealized survivorship curves: Type I curve is flat at the start, reflecting low death rates during early and middle life, then drops steeply as death rates increase among older age groups Type II curves are intermediate, with a constant death rate over the organisms life span Type III curve drops sharply at the start, reflecting very high death rates for the young, but the flattens out as death rates decline for those individuals that have survived to a critical age Reproductive tables, or fertility schedules, are age specific summaries of the reproductive rates in a population III. The traits that affect an organisms schedule of reproduction and survival from birth through reproduction to death make up its life history. They are evolutionary outcomes reflected in the development, physiology, and behavior of an organism. Semelparous organisms reproduce a single time and die. When the survival rate of offspring is low, as in highly variable or unpredictable environments, this is favored Iteroparous organisms produce offspring repeatedly. When environments are dependable and where competition for resources may be intense, this is favored. Life history traits such as brood size, age at maturity, and parental caregiving represent trade-offs between conflicting demands for limited time, energy, and nutrients. IV. The exponential model describes population growth in an idealized, unlimited environment. The per capita birth rate (b) is the number of offspring produced per unit time by an average member of the population The per capita death rate (m) is the number of individuals of a population that die per unit time The per capita rate of increase (r), or a populations growth rate, equals birth rate minus death rate. R = b m Growth occurs when r>0 and decline occurs when r C Kin selection favors altruistic behavior by enhancing the reproductive success of relatives Altruistic behavior toward unrelated individuals can be adaptive if the aided individual returns the favor in the future, an exchange of aid called reciprocal altruism. Social learning forms the roots of culture, which can be defined as a system of information transfer through observation or teaching that influences the behavior of individuals in a population. Male choice copying is a behavior in which individuals in a population copy the mate choice of others Human culture is related to evolutionary theory in the discipline of sociobiology, whose main premise is that certain behavior characteristics exist because they are expressions of genes that have been perpetuated by natural selection. Ch. 52 I. Population ecology is the study of populations in relation to the environment, including environmental influences on population density and distribution. A population is a group of individuals of a single species living in the same general area II. Dynamic biological processes influence population density, dispersion, and demography. Population density, the number of individuals per area or volume, results from the combination of births, deaths, immigration, and emigration. Dispersion is the pattern of spacing among individuals within the boundaries of the population Environmental and social factors influence the spacing of individuals In clumped patterns, individuals are aggregated in patches In uniform patterns, individuals are evenly spaced Animals often exhibit uniform dispersion as a result of antagonistic social interactions, such as territoriality, the defense of a bounded physical space against encroachment by other individuals In random dispersion, individuals are unpredictably spaced, and the position of each individual is independent of others This occurs in the absence of strong attraction or repulsions among individuals of a population Populations grow from births and immigration and shrink from deaths and emigration Immigration is the influx of new individuals from other areas Emigration is the movement of individuals out of a population Demography is the study of the vital statistics of populations and how they change over time Of particularly interest to demographers are birth rates and how they vary among individuals and death rates Life tables are age-specific summaries of the survival pattern of a population the best way to construct one is to follow the fate of a cohort, a group of individuals of the same age, from birth until all are dead A survivorship curve is a plot of the proportion or numbers in a cohort still alive at each age Idealized survivorship curves: Type I curve is flat at the start, reflecting low death rates during early and middle life, then drops steeply as death rates increase among older age groups Type II curves are intermediate, with a constant death rate over the organisms life span Type III curve drops sharply at the start, reflecting very high death rates for the young, but the flattens out as death rates decline for those individuals that have survived to a critical age Reproductive tables, or fertility schedules, are age specific summaries of the reproductive rates in a population III. The traits that affect an organisms schedule of reproduction and survival from birth through reproduction to death make up its life history. They are evolutionary outcomes reflected in the development, physiology, and behavior of an organism. Semelparous organisms reproduce a single time and die. When the survival rate of offspring is low, as in highly variable or unpredictable environments, this is favored Iteroparous organisms produce offspring repeatedly. When environments are dependable and where competition for resources may be intense, this is favored. Life history traits such as brood size, age at maturity, and parental caregiving represent trade-offs between conflicting demands for limited time, energy, and nutrients. IV. The exponential model describes population growth in an idealized, unlimited environment. The per capita birth rate (b) is the number of offspring produced per unit time by an average member of the population The per capita death rate (m) is the number of individuals of a population that die per unit time The per capita rate of increase (r), or a populations growth rate, equals birth rate minus death rate. R = b m Growth occurs when r>0 and decline occurs when r

Raku Ware And Staffordshire Pottery :: essays research papers

Raku Ware was originally from Japan in the town of Kyoto and was named after the Raku family during the 16th Century. At this time, the Emperor Hideyoshi had conquered Korea and the native potters immigrated to Japan bringing with them pottery techniques and knowledge.The pots were produced for the Zan Buddhist tea ceremony and the decorating and firing of the pots were part of the tea ceremony. Bernard Leach introduced Raku into the west after living in Japan and China setting up pottery in St. Ives, England in 1920. It is still popular today, and made almost worldwide. Raku Ware is still produced today by the 14th generation, of the same Japanese family.Staffordshire was a large and important part of Britain for earthenware production. The first known examples of Staffordshire slipware date back to early Seventeenth Century. Even though lead-glazed earthenware seemed to be established before this time, the market generally went beyond Staffordshire. Butter pots made in Staffordshire were well known for their quality by dairy farmers in England and surrounding areas. Slipwares are named for their decoration with liquid clays, usually poured or trailed onto the pot. Although this was a highly developed technique in Staffordshire it was used in other surrounding areas such as London and Wrotham.Staffordshire slipware usually has three categories flatware which are plates, dishes and bowls, jugs and lidded pots are classified as hollow ware, and miscellaneous ware includes money boxes, cradles and candle sticks.Just as tea was important in the development of Raku Ware in Japan, so the Elers brothers who studied salt glazes in Europe and moved to Staffordshire in the 1690s, produced small tea pots, tea canisters, teacups and jugs. They used finely prepared red clay which was thrown on the wheel, and then lathed when leather hard. (Common salt is thrown into the kiln during firing 1200oc to produce a salt glaze)In Raku any clay that copes with the firing technique must be able to withstand heat shock without warping, distorting or cracking. The clay needs to have particles in it to allow water to escape quickly so calcinated China clay or clay with temper (grog, flint or shell) added to it, is successful. This clay occurred naturally in Japan. Many contemporary potters have favourite clay recipes for their clay bodies when making Raku Ware.Staffordshire slipware clays usually have trouble withstanding higher temperatures without distorting and warping while stoneware can.