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Sinistrality and reduced longevity: reply to Coren and Halpern's replay.

Coren and Halpern's response to Fudin, Renninger, Lembessis, and Hirshon's 1993 report of a nonsignificant difference in longevity between left-handed and right-handed baseball players contained errors of fact, theory, and omission. Especially disturbing is that they ignored the fact that our negative findings were found not only with parametric tests but with the same nonparametric tests that they had used. We defend our use of parametric tests given the particular data we analyzed, and we comment on the databases that we and Halpern and Coren considered and the results of studies of handedness and longevity.

Aged↗

Left-handed major-league baseball players and longevity re-examined.

We re-examined the relationship between handedness and age at death for major league baseball players who died before 2002. This study extended the most recent examination of this issue by 13 years allowing us to compare 870 left-handers, 4,092 right-handers, and 1,092 bimanual players. Our study also took into account year of birth and player's position, both of which are related to longevity. Our analysis yielded no significant differences in longevity related to handedness (F(2,6035) = 0.13).

Aged↗

Longevity and lifetime productivity of cows in a purebred Hereford and two multibreed synthetic groups under range conditions.

Records on 983 cows born during a period of 10 yr (1966 to 1975) were used to estimate longevity and lifetime productivity of cows raised under range conditions. The cows were from a purebred Hereford and two multibreed synthetic groups, one composed of beef breeds (Beef Synthetic #1) and the other composed of two-thirds dairy breeds and one-third beef breeds (Dairy Synthetic). The cows were raised under a stringent culling system in which all heifers were exposed to bulls as yearlings and were expected to wean a calf each year thereafter or they were culled. Cows were also culled for other reasons, such as severe calving problems, bad udders, and leg and feet problems. The mean longevity was 4.2 yr; cows from the synthetic breed groups produced longer (P < .01) than Hereford cows, due to a relatively faster rate of removal at all ages in the purebred Hereford group. The mean values per cow for lifetime productivity traits were 2.7 and 2.5 for number of calves born and weaned and 101.9 kg and 482.9 kg for weight of calf born and weaned, respectively. Male calves were not castrated, and weights of female calves were adjusted to a male basis. Over their lifetimes, Dairy Synthetic cows were more productive, in terms of number and weight of calves born and weaned, than Beef Synthetic #1 cows, which in turn were more productive than purebred Hereford cows (P < .01).

Animal Husbandry↗

Low mitochondrial free radical production per unit O2 consumption can explain the simultaneous presence of high longevity and high aerobic metabolic rate in birds.

Birds are unique since they can combine a high rate of oxygen consumption at rest with a high maximum life span (MLSP). The reasons for this capacity are unknown. A similar situation is present in primates including humans which show MLSPs higher than predicted from their rates of O2 consumption. In this work rates of oxygen radical production and O2 consumption by mitochondria were compared between adult male rats (MLSP = 4 years) and adult pigeons (MLSP = 35 years), animals of similar body size. Both the O2 consumption of the whole animal at rest and the O2 consumption of brain, lung and liver mitochondria were higher in the pigeon than in the rat. Nevertheless, mitochondrial free radical production was 2-4 times lower in pigeon than in rat tissues. This is possible because pigeon mitochondria show a rate of free radical production per unit O2 consumed one order of magnitude lower than rat mitochondria: bird mitochondria show a lower free radical leak at the respiratory chain. This result, described here for the first time, can possibly explain the capacity of birds to simultaneously increase maximum longevity and basal metabolic rate. It also suggests that the main factor relating oxidative stress to aging and longevity is not the rate of oxygen consumption but the rate of oxygen radical production. Previous inconsistencies of the rate of living theory of aging can be explained by a free radical theory of aging which focuses on the rate of oxygen radical production and on local damage to targets relevant for aging situated near the places where free radicals are continuously generated.

Aerobiosis↗

[Longevity science research retrieval system using the thesaurus specifically developed for the science].

Gerontology is a new field including various disciplines such as medicine, engineering science, social science etc, and is sometimes called as "longevity science". Because of the wide area of the field, it is important to show the scope of the science and the development of its thesaurus contributes to this end. We developed a relevant thesaurus based on the research funded by Longevity Science Promotion Organization, and using the thesaurus, we also developed a database and retrieval system of the gerontology research. This system can be accessed on the Internet.

Aged↗

[Longevity, disease, and duration of disability].

Disability and the resulting lowered quality of life are serious issues accompanying increased longevity. Active life expectancy #(8) can be to used to distinguish the number of years without disability from the number with disability; increases were found in both in longevity #(9, 19). With the same rate of age-related new disability in the cohorts between 1970 and 1990, the total disability increased three fold #(11). In elderly patients I showed that 1) the duration of disability of those at a specific age at death (predeath) #(1) increased with age, and it decreased in those who remained without disability, 2) the cumulative number of days of disability for patients who died at a specific age (a convolution function of predeath and mortality) #(2), approached a normal distribution, which is consistent with the central limit theorem, 3) competing risk with chronic disease in a patient greatly affects the incidence and duration of disability, 4) using the central limit theorem we can predict that preventing dementia will retard premature rectangularization of the disability-free survival curve, and will thus reduce the total disability, 5) disability is an example of how variation and selection of chronic diseases (disease Darwinism) can alter population structure. Insights into the evolution of senescence #(14-21), pleiotropy, and slower rates of molecular evolution in the core than at the border #(26, 27), reveal that the central nervous system is relatively robust and conservative for pleiotropy and may senesce relatively slowly, which support a new way of thinking #(3, 4) about old age. To minimize disability, public knowledge and education about an ideal lifestyle and the evolution of senescence is essential.

Aged↗

[Okinawa Longevity Study. Molecular genetic analysis of HLA genes in the very old].

We analyzed HLA class II genes of Okinawan centenarians using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to identify primary genetic factors in the major histo-compatibility complex (MHC) region associated with human longevity. Gene frequencies of centenarians were compared with those of normal adults of the same ethnicity who were selected in the same vicinity as the centenarians. The following differences were identified in the HLA-DQB1 and DQA1 genes: the frequencies of DQB1*0503, DQA1*0101 (04) and DQA1*05 were increased in the centenarians, whereas those of DQA1*0102, DQA1*0103 and DQB1*0604 were decreased. Similarly, for the DRB1 gene, the frequencies of DRB1*0101, DRB1*1201 and DRB1*1401 were increased in the centenarians, whereas those of DRB1*0403 and DRB1*1302 were decreased. These data suggest that several alleles of the HLA-DRB1 and/or HLA-DQ genes are involved in human longevity.

Adult↗

Implementation of a routine genetic evaluation for longevity based on survival analysis techniques in dairy cattle populations in Switzerland.

Genetic evaluation of sires for functional longevity of their daughters based on survival analysis has been implemented in the populations of Braunvieh, Simmental, and Holstein cattle in Switzerland. A Weibull mixed sire-maternal grandsire survival model was used to estimate breeding values of sires with data on cows that calved since April 1, 1980. Data on Braunvieh and Simmental cows included about 1.1 million records, data on Holstein cows comprised about 220,000 records. Data contained approximately 20 to 24% right-censored records and 6 to 9% left-truncated records. Besides the random sire and maternal grandsire effects, the model included effects of herd-year-season, age at first calving, parity, stage of lactation, alpine pasturing (Braunvieh and Simmental), and relative milk yield and relative fat and protein percentage within herd to account for culling for production. Heritability of functional longevity, estimated on a subset of data including approximately 150,000 animals, were 0.181, 0.198, and 0.184 for Braunvieh, Simmental, and Holstein, respectively. Breeding values were estimated for all sires with at least six daughters or three granddaughters in the data. Breeding values of sires are expressed in months of functional productive life and published in sire catalogs along with breeding values for production traits.

Animals↗

Comparison between a Weibull proportional hazards model and a linear model for predicting the genetic merit of US Jersey sires for daughter longevity.

Predicted transmitting abilities (PTA) of US Jersey sires for daughter longevity were calculated using a Weibull proportional hazards sire model and compared with predictions from a conventional linear animal model. Culling data from 268,008 Jersey cows with first calving from 1981 to 2000 were used. The proportional hazards model included time-dependent effects of herd-year-season contemporary group and parity by stage of lactation interaction, as well as time-independent effects of sire and age at first calving. Sire variances and parameters of the Weibull distribution were estimated, providing heritability estimates of 4.7% on the log scale and 18.0% on the original scale. The PTA of each sire was expressed as the expected risk of culling relative to daughters of an average sire. Risk ratios (RR) ranged from 0.7 to 1.3, indicating that the risk of culling for daughters of the best sires was 30% lower than for daughters of average sires and nearly 50% lower than than for daughters of the poorest sires. Sire PTA from the proportional hazards model were compared with PTA from a linear model similar to that used for routine national genetic evaluation of length of productive life (PL) using cross-validation in independent samples of herds. Models were compared using logistic regression of daughters' stayability to second, third, fourth, or fifth lactation on their sires' PTA values, with alternative approaches for weighting the contribution of each sire. Models were also compared using logistic regression of daughters' stayability to 36, 48, 60, 72, and 84 mo of life. The proportional hazards model generally yielded more accurate predictions according to these criteria, but differences in predictive ability between methods were smaller when using a Kullback-Leibler distance than with other approaches. Results of this study suggest that survival analysis methodology may provide more accurate predictions of genetic merit for longevity than conventional linear models.

Animals↗

Assessment of the impact of somatic cell count on functional longevity in Holstein and Jersey cattle using survival analysis methodology.

Survival analysis in a Weibull proportional hazards model was used to evaluate the impact of somatic cell count (SCC) on the involuntary culling rate of US Holstein and Jersey cows with first calvings from 1990 to 2000. The full data set, consisting of records from 978,043 Holstein and 250,835 Jersey cows, was divided into subsets (5 for Holsteins and 3 for Jerseys) based on herd average lactation SCC values. Functional longevity (also known as herd life or length of productive life) was defined as days from first calving until culling or censoring, after correcting for milk production. Our model included the time-dependent effects of herd-year-season, parity by stage of lactation interaction, within-herd-year quintile ranking for mature equivalent production, and lactation average SCC (rounded to the nearest 50,000 cells/mL), as well as the time-independent effect of age at first calving. Parameters of the Weibull distribution, as well as variance components for herd-year-season effects, were estimated within each group of herds. Mean failure and censoring times decreased as herd average SCC increased, and a nonlinear relationship was observed between SCC and longevity in all groups. The risk of culling for Holstein cows with lactation average SCC > 700,000 cells/mL was 3.4, 2.7, or 2.3 times greater, respectively, than that of Holstein cows with SCC of 200,000 to 250,000 cells/mL in herds with low, medium, or high average SCC. Likewise, the risk of culling for Jersey cows with lactation average SCC > 700,000 cells/mL was 4.0, 2.9, or 2.2 times greater, respectively, than that of Jersey cows with SCC of 200,000 to 250,000 cells/mL in low, medium, or high SCC herds. These trends may reflect more stringent culling of high SCC cows in herds with few mastitis problems. In addition, cows with lactation average SCC <100,000 cells/mL had a slightly higher risk of culling than cows with SCC of 100,000 to 200,000 cells/mL in both breeds, particularly in herds with high average SCC, where exposure to mastitis pathogens was likely.

Aging↗

Genetic and phenotypic relationships among locomotion type traits, profit, production, longevity, and fertility in Spanish dairy cows.

The phenotypic and genetic relationships of 3 locomotion traits with profit, production, longevity, and fertility traits were studied to determine the importance of locomotion traits for dairy producers. Two data sets including official milk records and type classification scores of 62,293 cows, and reproductive records of 24,561 cows from the Basque and Navarra Autonomous Regions were analyzed. Higher scores for feet and legs (FL), foot angle (FA), and rear legs set (RLS) were positively related to production and functional traits, whereas fertility was not significantly affected. The cows that scored the highest for FL were $213/yr more profitable, produced 575 kg more milk per year, and remained in the herd for 307 more functional days than the cows scoring the lowest. Feet and legs was the trait most genetically correlated to profit, although a low value (0.10) was obtained, whereas RLS was the trait most correlated to milk production (0.12). Genetic correlations among FL, FA, RLS, and longevity traits (from -0.10 to 0.05) were low. Quadratic curves were the best fit for both profit and functional herd life for EBV of each of the 3 locomotion traits. Further studies dealing with profitability and lameness, instead of using conformation traits, could be performed directly if a larger data pool of lameness was routinely recorded.

Animals↗

Analysis of the relationship between somatic cell score and functional longevity in Canadian dairy cattle.

The aim of this study was to assess the level of somatic cell count (SCC) and to explore the impact of somatic cell score (SCS) on the functional longevity of Canadian dairy cattle by using a Weibull proportional hazards model. Data consisted of 1,911,428 cows from 15,970 herds sired by 7,826 sires for Holsteins, 80,977 cows in 2,036 herds from 1,153 sires for Ayrshires, and 53,114 cows in 1,372 herds from 1,758 sires for Jerseys. Functional longevity was defined as the number of days from the first calving to culling, death, or censoring. The test-day SCC was transformed to a linear score, and the resulting SCS were averaged within each lactation. The average SCS were grouped into 10 classes. The statistical model included the effects of stage of lactation; season of production; annual change in herd size; type of milk recording supervision; age at first calving; effects of milk, fat, and protein yields, calculated as within-herd-year-parity deviations; herd-year-season of calving; SCS class; and sire. The relative culling rate was calculated for animals in each SCS class after accounting for the aforementioned effects. The overall average SCC for Holsteins was 167,000 cells/mL, for Ayrshires was 155,000 cells/mL, and for the Jerseys was 212,000 cells/mL. In all breeds there were no appreciable differences in the relative risk of culling among classes of SCS breed averages (i.e., up to a SCS of 5). However, as the SCS increased beyond the breed average, the relative risk of cows being culled increased considerably. For instance, Holstein, Ayrshire, and Jersey cows with the highest classes of SCS had, respectively, a 4.95, 6.73, and 6.62 times greater risk of being culled than cows with average SCS.

Age Factors↗

Achievement age-death age correlations alone cannot provide unequivocal support for the precocity-longevity hypothesis.

This study is a further exploration (see S. J. H. McCann, 2001) of the capacity of the selection bias and life expectancy artifacts to produce correlations between peak achievement ages and death ages that could be mistakenly construed as support for the precocity-longevity hypothesis that those who reach career pinnacles earlier tend to have shorter lives. For 1,672 governors, 10 fake achievement age variables and 10 fake death age variables were randomly generated. Fake achievement age variables were correlated with real death age; fake death age variables were correlated with real achievement age. However, the real age correlations were much larger than the fake age correlations, and when the 2 artifacts were controlled through a subsample strategy, only real age correlations were significant. Overall, the results support the precocity-longevity hypothesis.

Achievement↗

The longevity and mortality of American physicians, 1969-1973.

This paper analyzes the mortality experience of male and female physicians during the five-year period 1969 through 1973 in terms of age, sex, geographic location, and medical specialty. Physician mortality and longevity are then compared with the experience prevailing among the U.S. white population of the same age and sex. Relationships between socioeconomic status and mortality suggest that physicians should have a better mortality experience than the general population and as such have a greater overall expectation of life. Previous studies of physician mortality in the United States using data from the records of the American Medical Association, have examined physician mortality relative to comparable groups of white males. No studies of physician mortality utilizing a population-based approach have been reported since that of the 1949 to 1951 population of physicians, and previous studies may have been subject to certain limitations in the data. Empirical findings are presented which demonstrate the improvement in physician longevity since 1925. The relationship between age- and sex-specific mortality and geographic location and medical specialization is also discussed.

Adult↗

Familial versus sporadic longevity and MHC markers.

We have studied the polymorphism of HLA-A, B, in 2 elderly populations (> or = 90 years) compared to a control series of 429 healthy unrelated individuals less advanced in age. The aged population issued from the CHRONOS cohort consisted of 336 centenarians without familial history of longevity, and 102 nonagenarians index cases randomly selected from families. Almost all individuals (310) were previously typed for HLA-DRB1. The increased allelic frequency of HLA DR11 was observed in familial nonagenarians (18.3%) compared to controls (10%) (p < .001) and to sporadic centenarians (11.8%). Concerning HLA Class I alleles, only rare alleles (A30, B70) remain significantly different from the controls after correction of the p value. No distortion of the Mendelian sharing of haplotypes was observed among sibling pairs of familial nonagenarians. A protective effect of the HLA-DR11 molecule itself, presenting adequately immunogenic-infectious peptides, is probable rather than genes in disequilibrium. Our study strongly supports the heterogeneity of longevity, the association of HLA-DR11 in its familial form in aged populations.

Adult↗

Continued United States longevity increases.

1998 was another banner year for U.S. life expectancy. Average remaining future lifetime for all newborns established a new high of 76.6 years. A new peak was also recorded for infant boys--73.7 years--but longevity for baby girls fell by 0.1 years from the 1997 record level of 79.4 years. As a result, the sex differential in expectation of life at birth narrowed to just 5.6 years. The life expectancy disparity in favor of newborn girls was as little as 2.0 years during 1919-21 and gradually widened to as much as 7.6 years in 1969-71. Taking into account recent trends, projections indicate that the sex differential in average remaining lifetime may diminish to only 2.2 years by 2025. Since 1989-91, males experienced considerably larger longevity increases than females. Additionally, black Americans also recorded greater expectancy gains than their white counterparts. Nonetheless, the life expectancy gap still remains much larger among blacks than for whites.

Adolescent↗

[Problems of longevity in Tadzhikistan].

The influence of natural and man-made factors on the longevity of people in Tadzhikistan was studied. The studies indicated that high-altitude hypoxia had an adverse effect on their longevity while premountain and low-mountain areas of the republic were the most beneficial.

Aged↗

Aging and longevity genes.

The genetics of aging has made substantial strides in the past decade. This progress has been confined primarily to model organisms, such as filamentous fungi, yeast, nematodes, fruit flies, and mice, in which some thirty-five genes that determine life span have been cloned. These genes encode a wide array of cellular functions, indicating that there must be multiple mechanisms of aging. Nevertheless, some generalizations are already beginning to emerge. It is now clear that there are at least four broad physiological processes that play a role in aging: metabolic control, resistance to stress, gene dysregulation, and genetic stability. The first two of these at least are common themes that connect aging in yeast, nematodes, and fruit flies, and this convergence extends to caloric restriction, which postpones senescence and increases life span in rodents. Many of the human homologs of the longevity genes found in model organisms have been identified. This will lead to their use as candidate human longevity genes in population genetic studies. The urgency for such studies is great: The population is graying, and this research holds the promise of improvement in the quality of the later years of life.

Aging↗