Adequate calcium intake levels suggested for the United States of America are higher than those accepted internationally, and extend the increased needs of adolescents to young adults. Peak bone mass continues to increase until age of 24 years. Results of bone density measurements support the need for calcium intake beyond that required for calcium balance and retention for growth.
However, the situation in most Asian countries suggests that their populations may have sufficient calcium retention and bone mass despite lower levels of intake.
Calcium intake may need to be adjusted for dietary factors (e.g. observed animal protein, sodium intake, vitamin D intake) and for sun exposure, since both affect calcium retention.
A sharp distinction between humans and “animals” is essential if we are to bend them to our will, make them work for us, wear them, eat them–without any disquieting tinges of guilt or regret. It is unseemly of us, who often behave so unfeeling toward other animals, to contend that only humans can suffer. The behavior of other animals renders such pretensions specious. They are just too much like us.
Archaea and bacteria (eubacteria) are single-celled organisms that do not have a nucleus or organelles. Archaea have a distinct evolutionary history and biochemistry compared with bacteria.
Archaea - a domain of single-celled microorganisms. These microbes are prokaryotes. Archaea can survive in extreme and harsh environments like hot springs, salt lakes, marshlands, oceans, gut of ruminants and humans.
Bacteria - a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Eubacteria are ubiquitous and are found in soil, hot springs, radioactive waste water, Earth's crust, organic matter, bodies of plants and animals, etc.