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Biodemography Of Human Longevity
Biodemography is a multidisciplinary approach, integrating biological knowledge (studies on human biology and animal models) with demographic research on human longevity and survival. Biodemographic studies are important for understanding the driving forces of the current longevity revolution (dramatic increase in human life expectancy), forecasting the future of human longevity, and identification of new strategies for further increase in healthy and productive life span. Theory Biodemographic studies have found a remarkable similarity in survival dynamics between humans and laboratory animals. Specifically, three general biodemographic laws of survival are found: # Gompertz–Makeham law of mortality # Compensation law of mortality # Late-life mortality deceleration (now disputed *) The Gompertz–Makeham law states that death rate is a sum of age-independent component ( Makeham term) and age-dependent component (Gompertz function), which increases exponentially with age. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gompertz–Makeham Law Of Mortality
The Gompertz–Makeham law states that the human death rate is the sum of an age-dependent component (the Gompertz function, named after Benjamin Gompertz), which increases exponentially with age and an age-independent component (the Makeham term, named after William Makeham). In a protected environment where external causes of death are rare (laboratory conditions, low mortality countries, etc.), the age-independent mortality component is often negligible. In this case the formula simplifies to a Gompertz law of mortality. In 1825, Benjamin Gompertz proposed an exponential increase in death rates with age. The Gompertz–Makeham law of mortality describes the age dynamics of human mortality rather accurately in the age window from about 30 to 80 years of age. At more advanced ages, some studies have found that death rates increase more slowly – a phenomenon known as the late-life mortality deceleration – but more recent studies disagree. The decline in the human mortali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biodemography
Biodemography is the science dealing with the integration of biological theory and demography. Overview Biodemography is a new branch of human (classical) demography concerned with understanding the complementary biological and demographic determinants of and interactions between the birth and death processes that shape individuals, cohorts and populations. The biological component brings human demography under the unifying theoretical umbrella of evolution, and the demographic component provides an analytical foundation for many of the principles upon which evolutionary theory rests including fitness, selection, structure, and change. Biodemographers are concerned with birth and death processes as they relate to populations in general and to humans in particular, whereas population biologists specializing in life history theory are interested in these processes only insofar as they relate to fitness and evolution. Traditionally, evolutionary biologists seldom focused on older, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerontology
Gerontology ( ) is the study of the social, cultural, psychological, cognitive, and biological aspects of aging. The word was coined by Ilya Ilyich Mechnikov in 1903, from the Greek , ''geron'', "old man" and , ''-logia'', "study of". The field is distinguished from geriatrics, which is the branch of medicine that specializes in the treatment of existing disease in older adults. Gerontologists include researchers and practitioners in the fields of biology, nursing, medicine, criminology, dentistry, social work, physical and occupational therapy, psychology, psychiatry, sociology, economics, political science, architecture, geography, pharmacy, public health, housing, and anthropology. The multidisciplinary nature of gerontology means that there are a number of sub-fields which overlap with gerontology. There are policy issues, for example, involved in government planning and the operation of nursing homes, investigating the effects of an aging population on society, and the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ageing
Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In a broader sense, ageing can refer to single cells within an organism which have ceased dividing, or to the population of a species. In humans, ageing represents the accumulation of changes in a human being over time and can encompass physical, psychological, and social changes. Reaction time, for example, may slow with age, while memories and general knowledge typically increase. Ageing increases the risk of human diseases such as cancer, Alzheimer's disease, diabetes, cardiovascular disease, stroke and many more. Of the roughly 150,000 people who die each day across the globe, about two-thirds die from age-related causes. Current ageing theories are assigned to the damage concept, whereby the accumulation of damage (such as DNA ox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reliability Theory Of Aging And Longevity
The reliability theory of aging is an attempt to apply the principles of reliability theory to create a mathematical model of senescence. The theory was published in Russian by Leonid A. Gavrilov and Natalia S. Gavrilova as ''Biologiia prodolzhitelʹnosti zhizni'' in 1986, and in English translation as ''The Biology of Life Span: A Quantitative Approach'' in 1991. One of the models suggested in the book is based on an analogy with the reliability theory. The underlying hypothesis is based on the (previously suggested) premise that humans are born in a highly defective state. This is then made worse by environmental and mutational damage; exceptionally high Redundancy (engineering), redundancy due to the extremely high number of low-reliable components (e.g.., cell (biology), cells) allows the organism to survive for a while. The theory suggests an explanation of two aging phenomena for higher organisms: the Gompertz law of exponential increase in mortality rates with age and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Life Extension-related Topics
Following is a list of topics related to life extension: __NOTOC__ A * ACE inhibitor * Actuarial escape velocity * Adenosine triphosphate (ATP) * Advanced Cell Technology Corporation * Aerobic exercise * Age-adjusted life expectancy * Ageless * Age-Related Eye Disease Study * Age-Related Macular Degeneration * Aging * Aging and memory * Aging-associated diseases * Aging brain * Aging population * Alcor Life Extension Foundation * Alternative medicine * American Aging Association * American Academy of Anti-Aging Medicine (A4M) * Amyloid * Amyloid plaque * Amyotrophic lateral sclerosis (ALS), e.g., Lou Gehrig's disease * Antagonistic Pleiotropy * Antioxidant ** Polyphenol antioxidant * Antisense therapy * Apoptosis * Atherosclerosis * ATP (adenosine triphosphate) * Autoimmune disease B * Biodemography * Biodemography of human longevity * Bioethics * Biological clock * Biogerontology * Biological immortality * Biomarkers of aging * Biotechnology * Brain–computer interface C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Life Extension
Life extension is the concept of extending the human life expectancy, lifespan, either modestly through improvements in medicine or dramatically by increasing the maximum lifespan beyond its generally-settled oldest people, limit of 125 years. Several researchers in the area, along with "life extensionists", "immortalists" or "longevists" (those who wish to achieve longer lives themselves), postulate that future breakthroughs in tissue rejuvenation (aging), rejuvenation, stem cells, regenerative medicine, molecular repair, gene therapy, pharmaceuticals and organ (anatomy), organ replacement (such as with artificial organs or xenotransplantations) will eventually enable humans to have indefinite lifespans (agerasia) through complete rejuvenation to a healthy youthful condition. The ethical ramifications, if life extension becomes a possibility, are debated by bioethicists. The sale of purported anti-aging products such as supplements and hormone replacement is a lucrative global i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longevity
The word " longevity" is sometimes used as a synonym for "life expectancy" in demography. However, the term ''longevity'' is sometimes meant to refer only to especially long-lived members of a population, whereas ''life expectancy'' is always defined statistically as the average number of years remaining at a given age. For example, a population's life expectancy at birth is the same as the average age at death for all people born in the same year (in the case of cohorts). Longevity is best thought of as a term for general audiences meaning 'typical length of life' and specific statistical definitions should be clarified when necessary. Reflections on longevity have usually gone beyond acknowledging the brevity of human life and have included thinking about methods to extend life. Longevity has been a topic not only for the scientific community but also for writers of travel, science fiction, and utopia A utopia ( ) typically describes an imaginary community or society that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demography
Demography () is the statistics, statistical study of populations, especially human beings. Demographic analysis examines and measures the dimensions and Population dynamics, dynamics of populations; it can cover whole societies or groups defined by criteria such as education, nationality, religion, and ethnicity. Educational institutions usually treat demography as a field of sociology, though there are a number of independent demography departments. These methods have primarily been developed to study human populations, but are extended to a variety of areas where researchers want to know how populations of Social actions, social actors can change across time through processes of birth, death, and Human migration, migration. In the context of human biological populations, demographic analysis uses Public records, administrative records to develop an independent Approximation, estimate of the population. Demographic analysis estimates are often considered a reliable stan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compensation Law Of Mortality
The compensation law of mortality (or late-life mortality convergence) states that the relative differences in death rates between different populations of the same biological species decrease with age, because the higher initial death rates in disadvantaged populations are ''compensated'' by lower pace of mortality increase with age. The age at which this imaginary (extrapolated) convergence of mortality trajectories takes place is named the "species-specific life span" (see Gavrilov and Gavrilova, 1979). For human beings, this human species-specific life span is close to 95 years (Gavrilov and Gavrilova, 1979; 1991). Compensation law of mortality is a paradoxical empirical observation, and it represents a challenge for methods of survival analysis based on proportionality assumption (proportional hazard models). The compensation law of mortality also represents a great challenge for many theories of aging and mortality, which usually fail to explain this phenomenon. On the other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reliability Theory Of Aging And Longevity
The reliability theory of aging is an attempt to apply the principles of reliability theory to create a mathematical model of senescence. The theory was published in Russian by Leonid A. Gavrilov and Natalia S. Gavrilova as ''Biologiia prodolzhitelʹnosti zhizni'' in 1986, and in English translation as ''The Biology of Life Span: A Quantitative Approach'' in 1991. One of the models suggested in the book is based on an analogy with the reliability theory. The underlying hypothesis is based on the (previously suggested) premise that humans are born in a highly defective state. This is then made worse by environmental and mutational damage; exceptionally high Redundancy (engineering), redundancy due to the extremely high number of low-reliable components (e.g.., cell (biology), cells) allows the organism to survive for a while. The theory suggests an explanation of two aging phenomena for higher organisms: the Gompertz law of exponential increase in mortality rates with age and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late-life Mortality Plateau
In gerontology, late-life mortality deceleration is the disputed theory that hazard rate increases at a decreasing rate in late life rather than increasing exponentially as in the Gompertz law. Late-life mortality deceleration is a well-established phenomenon in insects, which often spend much of their lives in a constant hazard rate region, but it is much more controversial in mammals. Rodent studies have found varying conclusions, with some finding short-term periods of mortality deceleration in mice, others not finding such. Baboon studies show no mortality deceleration. An analogous deceleration occurs in the failure rate of manufactured products; this analogy is elaborated in the reliability theory of aging and longevity. Late-life mortality deceleration was first proposed as occurring in human aging in (which also introduced the Gompertz law), and observed as occurring in humans in , and has since become one of the pillars of the biodemography of human longevity – s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
