منابع مشابه
Shaping human mortality patterns through intrinsic and extrinsic vitality processes
BACKGROUND While historical declines in human mortality are clearly shaped by lifestyle and environmental improvements, modeling patterns is difficult because intrinsic and extrinsic processes shape mortality through complex stochastic interactions. OBJECTIVE To develop a stochastic model describing intrinsic and extrinsic mortality rates and quantify historical mortality trends in terms of par...
متن کاملCatalytic efficiency and vitality of HIV-1 proteases from African viral subtypes.
The vast majority of HIV-1 infections in Africa are caused by the A and C viral subtypes rather than the B subtype prevalent in the United States and Western Europe. Genomic differences between subtypes give rise to sequence variations in the encoded proteins, including the HIV-1 protease. Because some amino acid polymorphisms occur at sites that have been associated with drug resistance in the...
متن کاملEffects of thermal vitality tests on human dental pulp.
Experiments were conducted to determine the effects of thermal pulp testing agents on the human dental pulp. Histological evaluation of the pulps of premolar teeth to which heated gutta-percha had been applied for up to 10 s revealed no evidence of injury. Teeth to which carbon dioxide (CO=) snow was applied for as long as 5 min were found to have structurally intact pulps. When the thermal tes...
متن کاملStudying the Effect of Accessibility and Vitality on Urban Space Efficiency in Iran (Case Study: Hamadan City)
This research seeks the role and effect strength of accessibility and vitality on urban spaces. Urban space is a phenomenon organized by information manifested in various forms, functions and meaning. It is the context of forming and improving social life, representing culture and urbanization of a culture. According to desirable cities, it is deliberated that the cause of this magnificence is ...
متن کاملPhysical activity and cognitive vitality.
We examine evidence supporting the associations among physical activity (PA), cognitive vitality, neural functioning, and the moderation of these associations by genetic factors. Prospective epidemiological studies provide evidence for PA to be associated with a modest reduction in relative risk of cognitive decline. An evaluation of the PA-cognition link across the life span provides modest su...
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ژورنال
عنوان ژورنال: Nature
سال: 1943
ISSN: 0028-0836,1476-4687
DOI: 10.1038/151476b0