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Cross-species Transmission
Cross-species transmission (CST), also called interspecies transmission, host jump, or spillover, is the transmission of an infectious pathogen, such as a virus, between hosts belonging to different species. Once introduced into an individual of a new host species, the pathogen may cause disease for the new host and/or acquire the ability to infect other individuals of the same species, allowing it to spread through the new host population. The phenomenon is most commonly studied in virology, but cross-species transmission may also occur with bacterial pathogens or other types of microorganisms. Steps involved in the transfer of pathogens to new hosts include contact between the pathogen and the host; the successful infection of an initial individual host, which may lead to amplification and an outbreak; and the adaptation of the pathogen, within either the original or new host, which may render it capable of spreading efficiently between individuals in populations of the new h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission (medicine)
In medicine, public health, and biology, transmission is the passing of a pathogen causing Infectious disease, communicable disease from an infected host (biology), host individual or group to a particular individual or group, regardless of whether the other individual was previously infected. The term strictly refers to the transmission of microorganisms directly from one individual to another by one or more of the following means: * airborne transmission – very small dry and wet particles that stay in the air for long periods of time allowing airborne contamination even after the departure of the host. Particle size 5 μm. * direct physical contact – touching an infected individual, including sexual contact * indirect physical contact – usually by touching a contaminated surface, including soil (fomite) * fecal–oral route, fecal–oral transmission – usually from unwashed hands, contaminated food or water sources due to lack of sanitation and hygiene, an important tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunological Defense
The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as cancer cells, parasitic worms, and also objects such as wood splinters, distinguishing them from the organism's own healthy tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use molecules and cells to perform their functions. Nearly all organisms have some kind of immune system. Bacteria have a rudimentary immune system in the form of enzymes that protect against viral infections. Other basic immune mechanisms evolved in ancient plants and animals and remain in their modern descendants. These mechanisms include phagocytosis, antim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodents
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/ricochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Once included with rodents, rabbits, hares, and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Zoonosis
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in mutualistic, commensal and paras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oran
Oran () is a major coastal city located in the northwest of Algeria. It is considered the second most important city of Algeria, after the capital, Algiers, because of its population and commercial, industrial and cultural importance. It is west-southwest from Algiers. The total population of the city was 803,329 in 2008, while the metropolitan area has a population of approximately 1,500,000, making it the second-largest city in Algeria. Etymology The word ''Wahran'' comes from the Berber expression ''wa - iharan'' (place of lions). A locally popular legend tells that in the period around AD 900, there were sightings of Barbary lions in the area. The last two lions were killed on a mountain near Oran, and it became known as ''la montagne des lions'' ("The Mountain of Lions"). Two giant lion statues stand in front of Oran's city hall, symbolizing the city. History Overview During the Roman Empire, a small settlement called ''Unica Colonia'' existed in the area of the current ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bubonic Plague
Bubonic plague is one of three types of Plague (disease), plague caused by the Bacteria, bacterium ''Yersinia pestis''. One to seven days after exposure to the bacteria, flu-like symptoms develop. These symptoms include fever, headaches, and vomiting, as well as Lymphadenopathy, swollen and painful lymph nodes occurring in the area closest to where the bacteria entered the skin. Acral necrosis, the dark discoloration of skin, is another symptom. Occasionally, swollen lymph nodes, known as "buboes", may break open. The three types of plague are the result of the route of infection: bubonic plague, septicemic plague, and pneumonic plague. Bubonic plague is mainly spread by infected fleas from small animals. It may also result from exposure to the body fluids from a dead plague-infected animal. Mammals such as rabbits, hares, and some cat species are susceptible to bubonic plague, and typically die upon contraction. In the bubonic form of plague, the bacteria enter through the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildlife Management
Wildlife management is the management process influencing interactions among and between wildlife, its Habitat, habitats and people to achieve predefined impacts. Wildlife management can include wildlife conservation, population control, gamekeeping, wildlife contraceptive and pest control. Wildlife management aims to halt the Holocene extinction event, loss in the Earth's biodiversity, by taking into consideration ecological principles such as carrying capacity, Disturbance (ecology), disturbance and Ecological succession, succession, and environmental conditions such as physical geography, Pedology (soil study), pedology and hydrology.Hunter, M. L. (1996). Fundamentals of Conservation Biology. Blackwell Science Inc., Cambridge, Massachusetts., .Groom, M.J., Meffe, G.K. and Carroll, C.R. (2006) Principles of Conservation Biology (3rd ed.). Sinauer Associates, Sunderland, MA. Most wildlife biologists are concerned with the conservation and improvement of habitats; although rewil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agriculture
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in the cities. While humans started gathering grains at least 105,000 years ago, nascent farmers only began planting them around 11,500 years ago. Sheep, goats, pigs, and cattle were domesticated around 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. In the 20th century, industrial agriculture based on large-scale monocultures came to dominate agricultural output. , small farms produce about one-third of the world's food, but large farms are prevalent. The largest 1% of farms in the world are greater than and operate more than 70% of the world's farmland. Nearly 40% of agricultural land is found on farms larger than . However, five of every six farm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the determinants of health of a population and the threats it faces is the basis for public health. The ''public'' can be as small as a handful of people or as large as a village or an entire city; in the case of a pandemic it may encompass several continents. The concept of ''health'' takes into account physical, psychological, and Well-being, social well-being, among other factors.What is the WHO definition of health? from the Preamble to the Constitution of WHO as adopted by the Internationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Livestock
Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animals which are raised for consumption, and sometimes used to refer solely to farmed ruminants, such as cattle, sheep, and goats. The breeding, maintenance, slaughter and general subjugation of livestock called ''animal husbandry'', is a part of modern agriculture and has been practiced in many cultures since humanity's transition to farming from hunter-gatherer lifestyles. Animal husbandry practices have varied widely across cultures and periods. It continues to play a major economic and cultural role in numerous communities. Livestock farming practices have largely shifted to intensive animal farming. Intensive animal farming increases the yield of the various commercial outputs, but also nega ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildlife
Wildlife refers to domestication, undomesticated animals and uncultivated plant species which can exist in their natural habitat, but has come to include all organisms that grow or live wilderness, wild in an area without being species, introduced by humans. Wildlife was also synonymous to game (hunting), game: those birds and mammals that were trophy hunting, hunted for sport. Wildlife can be found in all ecosystems. Deserts, plains, grasslands, woodlands, forests, and other areas including the most developed urban areas, all have distinct forms of wildlife. While the term in popular culture usually refers to animals that are untouched by human factors, most scientists agree that much wildlife is human impact on the environment, affected by human behavior, human activities. Some wildlife threaten human safety, health, property and quality of life. However, many wild animals, even the dangerous ones, have value to human beings. This value might be economic, educational, or emotio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures is Scientific consensus on climate change, driven by human activities, especially fossil fuel burning since the Industrial Revolution. Fossil fuel use, Deforestation and climate change, deforestation, and some Greenhouse gas emissions from agriculture, agricultural and Environmental impact of concrete, industrial practices release greenhouse gases. These gases greenhouse effect, absorb some of the heat that the Earth Thermal radiation, radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary gas driving global warming, Carbon dioxide in Earth's atmosphere, has increased in concentratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
