Chemical reactions can be classified in several ways. The most common is the one that uses as a parameter the types of reactant and resulting substances. Synthesis or Addition In this reaction, two or more reagents (A and B) combine to form only one product (AB). Some examples: Analysis or Decomposition This is the reaction in which only one reagent (AB) produces two or more products (A and B).
Yellow fever is an infectious disease caused by a flavivirus (the yellow fever virus) for which a highly effective vaccine is available. The disease is transmitted by mosquitoes and occurs exclusively in Central America, South America and Africa. In Brazil, yellow fever is usually acquired when an unvaccinated person enters wild transmission areas (cerrado regions, forests).
The lack of clean drinking water and treated sewage facilitates the transmission of diseases that are estimated to cause around 30,000 deaths daily worldwide. Most of these occur among children, especially those from the poorest classes, who die dehydrated from diarrhea caused by microbes. In Brazil, unfortunately, more than 3 million families do not receive treated water and two and a half times more homes have no sewage.
It consists of a polyurethane tube with one end closed and the other open, coupled to two flexible rings also polyurethane in the uterine cervix, vaginal walls and vulva. The product is already lubricated and should be used only once, highlighting that polyurethane, being more resistant than latex, can be used with various types of lubricants.
It may also be called venereal cancer. It is popularly known as horse. It manifests through painful soft-based wounds. The first symptoms appear two to five days after unprotected intercourse with the person with the disease, a period that can extend up to two weeks. At first, one or more small pus wounds appear.
The term AIDS comes from the English acronym cquired immuno d efficiencies syndrome, which means acquired immunodeficiency syndrome. Although AIDS is commonly identified as a disease, it is actually a syndrome. The word syndrome characterizes a set of signs and symptoms that can be produced by more than one cause.
Human life, like that of all living beings, depends on water. But our dependence on water goes beyond biological needs: we need it to clean our homes, wash our clothes and our bodies. What's more, to clean machines and equipment, irrigate crops, dissolve chemicals, create new substances, generate energy.
Originally from Asia, more precisely from India and Bangladesh, cholera spread to other continents from 1817. It arrived in Brazil in 1885, invading the states of Amazonas, Bahia, Pará and Rio de Janeiro. In 1893 the disease reached São Paulo, spreading both in the capital and in the interior of the state.
Many mosquitoes lay eggs in standing water. From eggs come out larvae, which then become adult mosquitoes. One way to combat mosquito-borne diseases is to prevent the accumulation of standing water in potted plants, empty cans, old tires, bottles, etc. Water tanks, tanks and other reservoirs should always be capped.
The contraceptive patch should be glued to the skin at various locations on the body, remaining in position for one week. The biggest advantage is that women will not have to take the pill every day nor will they forget. Another advantage is that hormones will be absorbed directly into the circulation, avoiding some unpleasant side effects of the oral pill.
The French mathematician Blaise Pascal (1623-1662) took a barometer up a mountain. After many observations, measurements and notes, he found that air pressure decreases with height. The air becomes thinner (decreases the number of molecules present in it), gradually, as the altitude increases.
An interesting phenomenon in the atmosphere is that of thermal inversion, when the action of air pollutants can be greatly aggravated. It works like this: Normally, the air near the ground surface is in constant vertical movement due to the convective process (convection currents). Solar radiation heats the surface of the ground, which in turn heats the air that bathes it; This hot air is less dense than cold air, so hot air rises (upward vertical movement) and denser cold air goes down (vertical downward movement).
The air temperature is measured by thermometers. Weather reports usually indicate the maximum and minimum temperatures expected for a given period. Water vapor in the air helps retain heat. Thus we find that in drier places there is less heat retention in the atmosphere and the difference between maximum and minimum temperature is greater.
It is the most present gas in the air. This substance is fundamental to life on Earth, as it is part of the composition of proteins, which are molecules present in all living organisms. Nitrogen is a gas that can hardly be combined with other elements or substances. Thus, it enters and leaves our body during breathing (and also the body of other animals and plants) without changes.
The deserts have a very varied location and are characterized by very sparse vegetation. The soil is very arid and the rainfall is low and irregular, below 250 mm of annual water. During the day the temperature is high, but at night there is rapid heat loss that radiates into the atmosphere and the temperature becomes excessively low.
It was once the great Brazilian coastal forest. It went from Rio Grande do Norte to Rio Grande do Sul. In some places it entered the continent, such as Paraná, where it occupied 98% of Paranaense territory. It was also the richest Brazilian biome in biodiversity. It is still in terms of km². Today is the most devastated of our biomes.
Populations have their own measurable characteristics. Each member of a population can be born, grow, and die, but only one population as a whole has specific birth and growth rates, and a pattern of dispersion in time and space. The size of a population can be assessed by its density. Population density may change.
It is the association in which only one species (tenant) benefits by seeking shelter or support in the body of another species (host) without harming it. It is an association similar to commensalism, not involving food. Examples: Garfish and Holoturia - Garfish have a thin, elongated body and protect themselves against the action of predators by sheltering themselves inside the holoturias (sea cucumbers) without harming them.
The Pantanal suggests animals, rivers, fish, woods, and anything like Paradise. It is a geologically new biome. The Paraguay riverbed is still in formation. “The Pantanal is the largest floodplain in the world and has one of the highest concentrations of wildlife on earth. Situated in the heart of South America, the Pantanal extends across Brazil, Bolivia and Paraguay with a total area of 210,000 km2.
The path of substances from the abiotic environment to the world of living beings and their return to the abiotic world complete what we call the biogeochemical cycle. The term is derived from the fact that there is a cyclic movement of elements that form living organisms (“bio”) and the geological environment (“geo”), where chemical changes intervene.
In an ecosystem, there are many types of interactions between the components of the various species. We can classify relationships between living beings initially into two groups: intraspecific, which occur between beings of the same species, and interspecific, between beings of different species. It is common to differentiate relations into harmonic or positive and inharmonious or negative.