Increase In Female Mortality Research Articles

Sex differences in mortality in Denmark during half a century, 1943-92

The emphasis of this study is on the relative mortality of 45-74-year-old men and women in Denmark in 1943-92, following economic and political changes that have affected the social meaning of gender over the last 50 years, and which have diminished former sex differences in health behaviour. Sex ratios of total mortality and mortality from major non-sex-specific causes of death were calculated on computerized mortality data from the Danish National Cause of Death Register that covers all deaths in Denmark since 1943. In the early 1940s the sex ratio of all-cause mortality was low, 1.0-1.1, it increased to a peak level in the late 1970s and early 1980s, but has since decreased due to an increase in female mortality and a more favourable trend in male mortality. Gender equality, employment, and economic autonomy may have beneficial health effects on both men and women, but the effects are inconsistent. The trend in smoking is the major explanatory factor for the more recent trends in gender differentials in mortality in Denmark.

Population stability in relation to resource availability in an introduced population of an herbivorous lady beetle

AbstractMechanisms responsible for population stability in relation to resource availability were studied in an introduced herbivorous lady beetle, Epilachna niponica. The introduced population was relatively constant over a seven‐year study period. Egg density was related to the variation in host‐plant abundance in different years, and was highly stabilized during the period from reproductive adult to egg stage. Two density‐dependent processes were identified in the reproductive season: (1) density‐dependent reduction in fecundity and (2) density‐dependent increase in female mortality and/or emigration, all of which operated early in the season. As a result, temporal variability in cumulative egg density was greatly reduced by mid‐May, by which time approximately 40% of total eggs were laid. A field cage experiment demonstrated that egg‐laying of individual females was largely limited by resource availability even at low levels of leaf herbivory. Since movement activity of ovipositing females increased in a density‐dependent manner, inter‐plant movement is more likely to cause density‐dependent reduction in fecundity and female loss, due to enhanced energy expendiditure. The introduced population was less stable than the source population, probably because of decreased inter‐plant movement of females and the unlikelihood of egg resorption, both of which contribute significantly to the temporal stability of E. niponica population densities.

Decreasing bladder cancer mortality in The Netherlands.

To evaluate the prediction that the observed increasing trend in male bladder cancer mortality in the Netherlands between 1955 and 1988 would change to a decreasing trend. Using demographic and mortality data from the Netherlands Central Bureau of Statistics, male and female bladder cancer mortality per 10(5) person-years from 1955 to 1994 were calculated. Changes in the age structure of the Dutch population were adjusted using direct standardization to the European "standard' population. The effects of age, calendar period and birth cohort on the temporal trend in mortality were evaluated using log-linear modelling. Male mortality from bladder cancer increased from 6.2 per 10(5) in 1955 to 12.6 per 10(5) in 1990, but decreased thereafter. Female mortality from bladder cancer has remained stable throughout the study period, at 2.8 and 2.7 per 10(5) in 1955 and 1994, respectively. The changing trend among men is consistent with an increasing risk for successive birth cohorts until the 1910 cohort and a decreasing risk for cohorts born after 1930. This cohort effect is probably caused by changes in the smoking behaviour of the male Dutch population. There were no differences in risk for successive birth cohorts of females. Male mortality from bladder cancer in the Netherlands will probably decrease for at least another decade. A future increase in female mortality from bladder cancer, as recorded for lung cancer, is unlikely.

Significance of wounding to female reproductive success in Hawaiian monk seals (Monachus schauinslandi) at Laysan Island

We studied reproductive rate, length of lactation period, pup survival, and mortality of injured and uninjured female Hawaiian monk seals (Monachus schauinslandi) on Laysan Island, northwestern Hawaiian Islands, in 1983 – 1989. The severity and timing of nonfatal injuries were influential in determining their effect on female reproductive success. There was a tendency towards a shorter mean lactation period and lower survival rate of pups for females with major injuries than for uninjured females. Females with minor injuries were similar to uninjured females in terms of reproductive rate, length of lactation, and pup survival. For females injured shortly before the birth of their pup or during lactation, pup survival was lower than for uninjured females, whereas for females injured during the year prior to pupping, measures of reproductive success were not significantly different from those for uninjured females. Immature (aged 4 – 8 years) females entering the reproductive population were injured by adult male seals significantly more often than females aged 0 – 3 years, but at a similar rate to adult females. The major effect of injuries on female reproductive success is an increase in female mortality: 87.5 % of the adult females (n = 16) that died on Laysan Island in 1983 – 1989 sustained injuries from adult male seals.

Thromboembolic Disorders And Oral Contraceptives

To the Editor:— Drill and Calhoun ( 206 :77, 1968) list the annual death rates in England and Wales from thromboembolic disorders for females and males 20 to 44 years of age and conclude that there was some increase in the death rate for both women and men, but there was no significant change in the ratio of female to male deaths during the period of large-scale use of oral contraceptives since 1961. Correct interpretation of mortality ratios can be difficult, since an increase in the ratio of female to male deaths could be the result of a decrease in the death rates for males as well as an increase in the death rates for females. If we are trying to learn whether there has been a greater increase in female mortality we must primarily rely on comparison of trends of rates rather than ratios . In fact, in England and Wales,