Shale is a fine-grained sedimentary rock formed from mud. The mud is a mix of flakes of clay minerals and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering or bedding less than one centimeter in thickness, called "fissility" (= ~splitting). Mudstones, on the other hand, are similar in composition but do not show the fissility.
Shales and mudrocks contain roughly 95 percent of the organic matter in all sedimentary rocks. However, this amounts to less than one percent by mass in an average shale. Black shales form in anoxic (without oxygen) conditions. They contain free carbon and iron sulfides such as pyrite. This produces the black colouration.
Shales are typically deposited in very slow moving water and are often found in lakes and lagoonal deposits, in river deltas, on floodplains and offshore from beach sands. They can also be deposited on the continental shelf, in relatively deep, quiet water. This process could have taken millions of years to complete.
'Black shales' are dark, as a result of being especially rich in unoxidized carbon. Black shales are deposited in anoxic or low oxygen environments, such as in stagnant water columns. They are common in some Palaeozoic and Mesozoic strata, Some black shales contain abundant heavy metals such as molybdenum, uranium, vanadium, and zinc. The heavy metals may have got there by slow accumulation.
Zooid
A zooid is a term for a small individual animal, part of a marine colony. The zooids in a colony are usually clones, and may be cytoplasmically connected. Though genetically identical, the zooids in a colony may serve different functions. This is the same as would be the case with a normal metazoan animal, but in a zooid colony the members are more like individuals.
The word is pronounced "zō-oid", not like zoo. Some examples:
Organic farms
Organic farms grow foods without using man-made chemicals (like pesticides or herbicides) which can harm the environment or wildlife.
Organic farmers usually use animal manure respectively organic substances rather than man-made chemical fertilizers which add extra nutrients to the soil. Organic foods are unique to the way other products are produced as chemically treated food can cause a lot of harm to the environment by decreasing the quality of soil and increasing energy use, carbon emissions, pesticides and nitrate pollution. Also the used chemicals can cause severe damage to human cells and long term consumption can cause diseases like colon cancer (colorectal cancer), decrease fertility and take impact on the brain development of unborn children.
Organic farming maintains the soil health the cropping system of organic farming keeps insect, pest and weeds under check. Even farm waste are recycled in organic farming and it prevents the pollution of any component of our environment.
Organic farming finds usage for animal welfare, as livestock is bred with solely organic fodder. There are animal farms that are exclusively built for organic farming and are only distributing organic meat. In recent past many of those regional farms are using online shops for distribution like "Das Gute Fleisch" (which means "the good meat") from germany. Therefore a wider audience has comfortable access to organic meat whereas the demand for organic meat is rapidly growing.
Flower growers and ordinary home gardens can use organic methods too. An example of organic farming which is often used in the garden is biological control. Biological control means using natural methods to get rid of pests, instead of using poisons. For example by encouraging Ladybirds (ladybugs) into the garden as they eat aphids (greenfly).
There are certain organisations per country wich regulate the standards for organic farming. In the USA e.g. the USDA is distributing official "USDA Organic Labels" for products that fullfill the criterias of the organisation to accept them as organic food.
Other than the US versions wich differ in a "100 % organic label" and labels that state that the products are not fully organic, there is only one organic label for the EU that covers similar criterias as the "100 % label". Therefore it's harder to get organic farming certified in the EU.
There are also non-official labels by private companies that are rating products or using similar criterias to categorise the organic farms. They commonly have a high reputation so customers can rely on their rating.
Bronchus
Bronchi (one Bronchus) are the large air tubes leading from the trachea to the lungs. They carry air to the lungs.
The trachea (windpipe) divides to form the right and left main bronchi. These divide to form smaller and smaller tubes called bronchioles. Eventually the bronchioles end in the alveoli (small air sacs). At the alveoli, oxygen from the air we breathe into our lungs is moved into the blood. The blood then carries oxygen around to the rest of the body, which needs oxygen to survive. Without the bronchi, air would never get into the lungs, and oxygen would never get into our bodies.
The bronchi's walls are made of cartilage.
The right bronchus (shown on the left in the image on this page) is shorter, wider, and straighter than the left bronchus.
ChessBase
ChessBase GmbH is a German company that markets chess software. It also has a chess news website, and uses a server for online chess. Set up in 1998, it builds and sells large databases, with up to three million games, classified in various ways. A smaller fraction have notes, about 60,000 at present. It is possible to connect the database with one or more "chess engines" which calculate likely good moves. Databases organize data from past games; engines do calculations and use look-up tables for standard information, having, for example, answers to special endgame problems.
Bill Ayers
William Charles "Bill" Ayers (born December 26, 1944) is an American elementary education theorist. He is a former head of the Weather Underground. Ayers is known for speaking out against the Vietnam War in the 1960s. He is also known for his current work in trying to help make learning and teaching better. In 1969, Ayers started the Weather Underground. The Weather Underground is a group that call themselves a "communist revolutionary group". They carried out bombings against public buildings during the 1960s and 1970s. This was because the United States was being a part of the Vietnam War. Ayers is a professor in the College of Education at the University of Illinois at Chicago. He has the titles of Distinguished Professor of Education and Senior University Scholar. During the 2008 U.S. Presidential election, a controversy was brought up over ties between Ayers and then Senator Barack Obama. Ayers is married to Bernadine Dohrn. She was also a member of the Weather Underground.
Bill Ayers grew up in Glen Ellyn, Illinois. Glen Ellyn is just outside Chicago. He went to public schools there until his second year of high school. After this he started going to Lake Forest Academy. It is a smaller prep school. Ayers received a B.A. from the University of Michigan in American studies in 1968. He is the son of Thomas G. Ayers. His father used to be Chairman and CEO of Commonwealth Edison.