DUF1220 protein domains drive proliferation in human neural stem cells and are associated with increased cortical volume in anthropoid primates.

Genome sequences encoding DUF1220 protein domains show a burst in copy number among anthropoid species and especially humans, where they have undergone the greatest human lineage-specific copy number expansion of any protein coding sequence in the genome. While DUF1220 copy number shows a dosage-related association with brain size in both normal populations and in 1q21.1-associated microcephaly and macrocephaly, a function for these domains has not yet been described. Here we provide multiple lines of evidence supporting the view that DUF1220 domains function as drivers of neural stem cell proliferation among anthropoid species including humans. First, we show that brain MRI data from 131 individuals across 7 anthropoid species shows a strong correlation between DUF1220 copy number and multiple brain size-related measures. Using in situ hybridization analyses of human fetal brain, we also show that DUF1220 domains are expressed in the ventricular zone and primarily during human cortical neurogenesis, and are therefore expressed at the right time and place to be affecting cortical brain development. Finally, we demonstrate that in vitro expression of DUF1220 sequences in neural stem cells strongly promotes proliferation. Taken together, these data provide the strongest evidence so far reported implicating DUF1220 dosage in anthropoid and human brain expansion through mechanisms involving increasing neural stem cell proliferation.

Flexible work schedules, older workers, and retirement.

Older workers in the United States indicate that they would prefer flexible work arrangements rather than abrupt retirement, yet management has done very little to make this possible. A review of two bodies of literature from the late 1980s is presented: social science writings including sociological, gerontological, and economic literature, and business and management literature. There is a clash between the way jobs are traditionally scheduled and the needs of growing numbers of older workers. Workers continue to be subject to obstacles to phased retirement due to the structuring of health care and pension benefits, downsizing, organizational inflexibility, and "corporate culture." Thus, general views among social scientists regarding the desirability of flexible schedules toward retirement will not produce real changes unless management becomes committed to such changes and they are securely embedded in company policies.

Effects of microwave and radio frequency electromagnetic fields on lichens.

The effects of electromagnetic fields on lichens were investigated. Field experiments of long duration (1-3 years) were combined with laboratory experiments and theoretical considerations. Samples of the lichen species Parmelia tiliacea and Hypogymnia physodes were exposed to microwaves (2.45 GHz; 0.2, 5, and 50 mW/cm2; and control). Both species showed a substantially reduced growth rate at 50 mW/cm2. A differentiation between thermal and nonthermal effects was not possible. Temperature measurements on lichens exposed to microwaves (2.45 GHz, 50 mW/cm2) showed a substantial increase in the surface temperature and an accelerated drying process. The thermal effect of microwave on lichens was verified. The exposure of lichens of both species was repeated near a short-wave broadcast transmitter (9.5 MHz, amplitude modulated; maximum field strength 235 V/m, 332 mA/m). No visible effects on the exposed lichens were detected. At this frequency, no thermal effects were expected, and the experimental results support this hypothesis. Theoretical estimates based on climatic data and literature showed that the growth reductions in the initial experiments could very likely have been caused by drying of the lichens from the heating with microwaves. The results of the other experiments support the hypothesis that the response of the lichens exposed to microwaves was mainly due to thermal effects and that there is a low probability of nonthermal effects.

Poverty among single elderly women under different systems of old-age security: a comparative review.

This study takes stock of available comparative research on the economic status of elderly single women in six industrialized countries: France, Germany, the Netherlands, Sweden, Switzerland, and the United States. A systematic comparison of income has become easier due to such standardized data bases as the Luxembourg Income Study. But an explanation for different poverty rates among older women who are on their own requires a further, differentiated assessment of the countries' retirement benefit structures. This article attempts such a review. It makes use of a variety of single-country sources and takes into account the institutional heterogeneity of old-age security systems. The study concludes with a view of the effectiveness of different old-age security systems in preventing poverty among older single women.

The aged in the world's constitutions.

This article presents a review of legal provisions benefitting the elderly as anchored in the constitutions of countries around the globe. While it is of interest to examine the sheer range of such provisions, it is also possible to gauge from the comparison whether the presence of constitutional guarantees is connected with levels of economic development, conditions of population aging, or other differences among nations. A cross-check with the institutionalization of social security systems is included in the analysis. The results allow an assessment of major differences by world regions, an appraisal of unique cases, and an appreciation of where nations stand today in formulating guarantees and policies regarding the elderly.