Lesson 1: Introduction to Epidemiology Section 10: Chain of Infection As described above‚ the traditional epidemiologic triad model holds that infectious diseases result from the interaction of agent‚ host‚ and environment. More specifically‚ transmission occurs when the agent leaves its reservoir or host through a portal of exit‚ is conveyed by some mode of transmission‚ and enters through an appropriate portal of entry to infect a susceptible host. This sequence is sometimes called the chain
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Rory Atteridge 0603612E Sex Pheromones in the Insects Introduction Sex pheromones are chemicals or odours given off by an individual in order to invoke a sexual response or behaviour change on individuals of the same species (Shorey 1973). These chemicals can be released by males and/or females‚ depending on the species (Gieselhardt et al. 2008‚ Ayasse et al. 2001). Pheromones generally consist of a carbon backbone of between 10 and 20 carbon atoms (in Lepidoptera)‚ these are however
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Background information Daphnia Magna is an arthropod that can grow up to 5 mm. It is a filter feeder meaning it feeds off of suspended particles in the water. Daphnia can consume particles that range from 1µ to 50µ. The heart of Daphnia is located dorsally meaning it’s located in the back. The heart rate of Daphnia can range due to many variables‚ one being temperature. "At a temperature averaging 20o C its heart rate is about 200 beats per minute."2 As the temperature surrounding the Daphnia
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Tabanus spp. Horse fly/ Breeze fly/ Gad fly These are very large flies with very large eyes and gap between them is small. Antennae are projected forward in front of the head and have 3 segments. The first 2 segments of the antenna are small‚ the third segment has 4 annulations and has a tooth like projection called spur. Flies hold their wings horizontally at rest. Proboscis is short The mouth part consists of two jointed well-developed palps‚ a pair of well developed mandibles and maxillae
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Patterns in Nature 1. Organisms are made of cells that have similar structural characteristics * Outline the historical development of the cell theory‚ in particular the contributions of Robert Hooke and Robert Brown Robert Hooke was the first person to observe a cell through a compound microscope in 1665. Franscesco Redi used a microscope to observe that flies do not spontaneously appear but develop from eggs laid by other flies. Many years later‚ Robert Brown observed a large body in
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Crayfish Invertebrate Research Paper Crayfish are interesting animals to study. Through invertebrate research‚ experimentation‚ and observation‚ there has been much to learn about with these animals. There is much to know about these creatures‚ including their classification in the "animal kingdom." Anatomy as well as how the crayfish reproduce is an important aspect of these organisms. Perhaps the most important part of the crayfish is there ecology. Studying ecology alone can give substantial
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Evolution by natural selection is slow but can be observed in certain situations. How to spot evolution in real time: Artificial selection – manipulation by humans such as breeding dogs or growing corn. Repro-rate – rate of reproduction. Stochastic Event: unexpected disaster like a volcano eruption or tornado. (Research geological time) LIVING THINGS: Biology – Study of living things. Living things – all the organisms descended from a single-celled ancestor. * Characteristics:
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Biodiversity is the degree of variation of life forms within a given ecosystem‚ biome‚ or an entire planet. Biodiversity is one measure of the health of ecosystems. Life on Earth today consists of many millions of distinct biological species. The United Nations declared the year 2010 as the International Year of Biodiversity. Biodiversity is not consistent across the Earth. In the terrestrial context for example‚ tropical regions are typically rich whereas polar regions support fewer species. Rapid
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Comparison of Muscle Proteins to Infer Evolutionary Relationships of Mammals‚ Fish and Birds Abstract This experiment used electrophoresis to examine the makeup of muscle proteins from two mammals (cow‚ Bos taurus; bear‚ Ursus americanus)‚ two aves (chicken‚ Gallus gallus; turkey‚ Meleagris gallopavo)‚ and two fish (King Salmon‚ Oncorhynchus tshawytscha; Albacore Tuna‚ Scombridae unclassified). The hypothesis was that as species have diverged evolutionarily‚ the makeup of their muscle proteins
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Umahmaa Ibrahim Thomas Orf Geography 1 10/ 6/ 2013 Chapter 11 Key Terms Q1: Contrast and explain the concepts of ecosystem and biome. A: An ecosystem is a natural unit consisting of all plants‚ animals and micro-organisms in an area functioning together with all the non-living physical factors of the environment. Among terrestrial ecosystems‚ the type that provides the most appropriate scale for understanding world distribution pattern is called a biome. Q2: What is an ecotone
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