The effects of sodium bicarbonate concentration, population density, and temperature on the maintenance of an outdoor monoculture of the cyanobacterium Spirulina platensis were studied. A clear response by Spirulina to the concentration of bicarbonate was evident, with 0.2M bicarbonate representing the lowest concentration in which a monoculture could be maintained. When the temperatures fell d...

Four new species of the genus Thoracophorus Motschulsky, 1857 of the Neotropical region are described: T. verhaaghi n. sp., T. zicsii n. sp., T. struyvei n. sp., and T. perplexus n. sp. The new species originate from French Guiana, Peru, and Ecuador. Similar species T. filum Sharp, 1887, T. proximus Irmler, 1985, T. exilis (Erichson, 1840) and T. aequalis Sharp, 1887 are compared to discuss dif...

Recently, BMI screening in public schools has stirred sharp controversy with the emergence of letters sent home to parents indicating their child’s BMI percentile and weight category. In Massachusetts, these letters have been deemed, “fat letters,” and have appeared on late night comedy shows, newspapers, and televised news reports. Not only has screening come under harsh criticism, but the inc...

ƒ Typically, fertility has a pro-cyclical relationship with economic growth. Recessions often lead to a temporary decline in period fertility levels one or two years later, partly reflecting a postponement of childbearing that is often later compensated during the period of improved economic conditions. ƒ Theories suggesting a counter-cyclical relationship between economic trends and fertility ...

Background The reduction in fertility and increase in the number of single-child families in Iran will result in an increased risk of population aging. One of the factors affecting fertility is women's empowerment. This study aimed to evaluate the relationship between women's empowerment and fertility in single-child and multi-child families. Materials and Methods This case-control study was ...

BACKGROUND: This paper is motivated by the theory that developmental idealism has been disseminated globally and has become an international force for family and demographic change. Developmental idealism is a set of cultural beliefs and values about development and how development relates to family and demographic behavior. It holds that modern societies are causal forces producing modern fami...

Abstract Despite a half century of below-replacement fertility, Japan is typically not included in discussions and evaluations the second demographic transition (SDT), widely referenced framework for understanding family changes attitudinal shifts associated with very low fertility. I address this limitation by drawing upon range published research data sources to provide an empirical basis thi...

Nearly half of the world's population in 2000 lived in countries with fertility rates at or below replacement level, and nearly all countries will reach low fertility levels in the next two decades. Concerns about low fertility, fertility that is well below replacement, are widespread. But there are both persistent rationales for having children and institutional adjustments that can make the w...