OBJECTIVE This report analyzes the patterns of childlessness, and conversely, the first-birth patterns of three birth cohorts of American women. For this report, a cohort refers to women born in the same year. The cohorts compared were women born in 1910, 1935, and 1960-who, consequently, turned 25 during the Great Depression, the Baby Boom, and lastly, the post-Baby Boom period. The purpose of...

Introductory Population dynamics.................................................................................. 2 Logistic Equation ............................................................................................................ 2 Malthusian parameter ................................................................................................. 3 Carrying capacity................

Many variables of biological, ecological and cultural nature affect the biological dynamics of human populations. A religious denomination was an element of the cultural system which had an impact on the attitude towards birth control and sexuality. The aim of this paper is to show how religion shaped the fertility figures in the Catholic and Lutheran populations of historical Poland. Two metho...

habrobracon hebetor say (hymenoptera: braconidae) as an ectoparasitoid of larval stage of lepidopterous pests is widely used in biological control programs. in the present research, the effect of field recommended doses of imidacloprid, indoxacarb and deltamethrin were studied on life table parameters of h. hebetor in pupal stage treatment. one hundred, two-day-old pupae were treated with 1 mic...

demographic parameters of the pink stem borer, sesamia creticalederer (lepidoptera: noctuidae) were estimatedon its two main host plants, maize and sugarcane. the present studywas conducted under laboratory conditions at 27±1˚c, 50±10% relative humidity (rh %), and a photoperiod of 0:24 (l:d) hour for the larval stage and 16:8 (l:d) hour for the other life stages. the raw data were analyzed bas...

AbstractThe coccinellids Eriopis connexa (Germar), Harmonia axyridis (Pallas) and Olla v-nigrum (Mulsant) are important natural biological control agents. The purpose of this paper was to study the biology and create a fertility life table of these three coccinellid species. For the biology study, 50 insects/species were used and kept in groups of 10 in glass vials (2300cm3). For the three spec...

The paper provides an extensive descriptive analysis and comparison of recent trends in union formation and fertility in Bulgaria and Russia. The analysis is based on data from the Generation and Gender Surveys (GGS) carried out in 2004. We generate a large number of singleand multi-decrement life tables describing various life course events: leaving home and separation from the parental family...

reproductive performance and life expectancy of the two-spotted spider mite (tssm), tetranychus urticae koch were determined on seven eggplant cultivars (isfahan, dezful, shend-abad, neishabour, bandar-abbas, jahrom and borazjan) at 25 ± 1°c, 60 ± 5% r.h. and a photoperiod of 16:8 (l:d) hours. the results revealed that the tssm gross hatch rate varied from 59% on bandar-abbas to 83% on dezful. ...