Search results
Results from the WOW.Com Content Network
The challenge for abiogenesis (origin of life) [7] [8] [9] researchers is to explain how such a complex and tightly interlinked system could develop by evolutionary steps, as at first sight all its parts are necessary to enable it to function. For example, a cell, whether the LUCA or in a modern organism, copies its DNA with the DNA polymerase ...
A scenario is a set of related concepts pertinent to the origin of life (abiogenesis), such as the iron-sulfur world. Many alternative abiogenesis scenarios have been proposed by scientists in a variety of fields from the 1950s onwards in an attempt to explain how the complex mechanisms of life could have come into existence. These include ...
Growth arrest lines, also known as Harris lines, are lines of increased bone density that represent the position of the growth plate at the time of insult to the organism and formed on long bones due to growth arrest. They are only visible by radiograph or in cross-section. The age at which the lines were formed can be estimated from a radiograph.
A pathologic fracture is a bone fracture caused by weakness of the bone structure that leads to decrease mechanical resistance to normal mechanical loads. [1] This process is most commonly due to osteoporosis, but may also be due to other pathologies such as cancer, infection (such as osteomyelitis), inherited bone disorders, or a bone cyst.
Bone tissue is removed by osteoclasts, and then new bone tissue is formed by osteoblasts. Both processes utilize cytokine (TGF-β, IGF) signalling.In osteology, bone remodeling or bone metabolism is a lifelong process where mature bone tissue is removed from the skeleton (a process called bone resorption) and new bone tissue is formed (a process called ossification or new bone formation).
In particular, physical exercise can be beneficial for bone density in postmenopausal women, [140] and lead to a slightly reduced risk of a bone fracture (absolute difference 4%). [141] Weight bearing exercise has been found to cause an adaptive response in the skeleton, [142] promoting osteoblast activity and protecting bone density. [143]
Studies suggest that this was due to fewer medical professionals providing these advanced treatments to Black populations and government policies limiting care in low-income communities, on top of ...
Large doses of Sr-90, nicknamed bone seeker, increases the risk of bone cancer and leukemia in animals and is presumed to do so in people. [10] There is no clear association between water fluoridation and cancer or deaths due to cancer, both for cancer in general and also specifically for bone cancer and osteosarcoma. [11]