Support for maternal manipulation of developmental nutrition in a facultatively eusocial bee, <Emphasis Type="Italic">Megalopta genalis</Emphasis> (Halictidae)

Developmental maternal effects are a potentially important source of phenotypic variation, but they can be difficult to distinguish from other environmental factors. This is an important distinction within the context of social evolution, because if variation in offspring helping behavior is due to maternal manipulation, social selection may act on maternal phenotypes, as well as those of offspring. Factors correlated with social castes have been linked to variation in developmental nutrition, which might provide opportunity for females to manipulate the social behavior of their offspring. Megalopta genalis is a mass-provisioning facultatively eusocial sweat bee for which production of males and females in social and solitary nests is concurrent and asynchronous. Female offspring may become either gynes (reproductive dispersers) or workers (non-reproductive helpers). We predicted that if maternal manipulation plays a role in M. genalis caste determination, investment in daughters should vary more than for sons. The mass and protein content of pollen stores provided to female offspring varied significantly more than those of males, but volume and sugar content did not. Sugar content varied more among female eggs in social nests than in solitary nests. Provisions were larger, with higher nutrient content, for female eggs and in social nests. Adult females and males show different patterns of allometry, and their investment ratio ranged from 1.23 to 1.69. Adult body weight varied more for females than males, possibly reflecting increased variation in maternal investment in female offspring. These differences are consistent with a role for maternal manipulation in the social plasticity observed in M. genalis.     

Removal of Volatile Aliphatic Hydrocarbons in a Soil Bioreactor

Soil removal of propane, isobutane and n-butane from a waste air stream was evaluated in the laboratory and in a prototype soil bioreactor. Laboratory investigations indicated first-order kinetics and the potential to degrade light aliphatic hydrocarbons and trichlorethylene, a compound ordinarily resistant to aerobic biological treatment. The predicted behavior of the bioreactor, based on laboratory studies, agreed closely with the actual behavior of the Reid system. The prototype bioreactor reduced the hydrocarbon concentrations in the air by at least 90percent with a residence time of 15 minutes and a pressure drop of 85 cm of water. The bioreactor functioned well through a range of temperatures, 12°C to 24°C.     

Assessment of health risk associated with persistent organic pollutants in water

This paper presents the results of analyses of water samples taken from water intakes supplying one of the districts located near the city of Wroc?aw. Surprisingly high concentrations of polychlorinated biphenyls and chloroorganic pesticides, classified as persistent organic pollutants (POPs), were detected in the monitored sites. Basing on the analytical and toxicological data, the individual health risks related to carcinogenic effects (excess cancer risk over a lifetime) in humans were assessed, resulting from direct ingestion of community water. Also noncarcinogenic effects resulting from exposure to the examined POPs were determined. The conservative approach to risk assessment, taking into account a safety margin for data incompleteness, was adopted. The carcinogenic risk was found to slightly exceed the unconditionally acceptable risk of 10^?6 in the case of polychlorinated biphenyls and hexachlorocyclohexane, for all the inhabitant populations. The determined values of noncarcinogenic effects expressed by hazard quotient and hazard index indicate that the water pollutants and their concentrations do not cause an increase in noncarcinogenic incidences in the inhabitants using the monitored water sources.     

Social Planning for Mall Redevelopment: an Australian case-study

This paper provides a case study of recent work undertaken in Melbourne relating to a mall re-development project. It begins by discussing the nature of shopping centres as sites of consumption and non-commercial social activities. It then describes planning and development strategies that provide innovative and socially progressive interventions in regard to the social, physical and regulatory environments of public malls. The importance of seeing such sites as 'community spaces', of promoting activities on the basis of social inclusion, of creating a safe, convivial atmosphere, and of establishing low-key friendly sorts of mall management, are highlighted.     

Land Conversion for Suburban Housing: A Study of Urbanization Around Warsaw and Olsztyn,Poland

In Poland of the 1990s, urban demand for housing land around city agglomerations increased rapidly. The decreasing profitability of agricultural production also caused farmers to become interested in the sale of agricultural land for nonagricultural purposes, and new land legislation granted them the right to sell their land. Polish counties simultaneously received self-governing status, which allowed them to define the priorities for local development. Counties received additional responsibility for land management and quickly demonstrated strong support for land conversion, which was perceived as a factor of local development. This paper argues that decentralization and the extension of private control over land have led to a loss of rural landscapes in Poland because farmers, county governments, and rural society in general gained from the conversion of agricultural to housing land. Rapid urbanization has significantly reduced the availability of open space around cities and threatened valuable landscapes, for it has occurred in the absence of environmental safeguards. This paper reports findings from research in two counties, located in regions with diverse economic growth rates. Decentralization is particularly problematic if tax regulations and intergovernmental fiscal relations reward local authorities for urbanization but not environmental protection. Note: This version was published online in June 2005 with the cover date of August 2004.     

Conflict of interest related to clinical practice is underreported: The case of noninvasive prenatal testing

Authors of policy statements from the American College of Obstetricians and Gynecologists and from the Society for Maternal-Fetal Medicine do not acknowledge the potential for their clinical income to influence their opinions, or the positions of the societies they represent. These policy statements were published in Obstetrics and Gynecology and the American Journal of Obstetrics and Gynecology, again, without acknowledgment of the potential for conflict of interest. The case of noninvasive prenatal testing, which has threatened the role of maternal-fetal medicine in the practice of prenatal screening and diagnosis, and has significantly reduced the demand for invasive prenatal diagnosis, illustrates the importance of identifying this potential conflict.     

一种改进的多学习教与学优化算法

针对传统教与学算法在解决复杂多峰函数优化问题时,具有局部最优且搜索开发能力较差的缺点,提出了一种改进的多学习教与学优化算法,新算法为学员的每一维加入不同的教学因子,设计了基于学员均值比较的教师选择策略和向教师及学员学习的多学习策略。基于多个单峰和多峰函数的仿真结果表明,新算法跟传统的、改进的教与学算法相比,在稳定性、寻优精度和收敛速度方面更具优势。     

A life history continuum in the males of a Neotropical ant assemblage: refuting the sperm vessel hypothesis

Animal lifespans range from a few days to many decades, and this life history diversity is especially pronounced in ants. Queens can live for decades. Males, in contrast, are often assumed to act as ephemeral sperm delivery vessels that die after a brief mating flight—a view developed from studies of lekking species in temperate habitats. In a tropical ant assemblage, we found that males can live days to months outside the nest, a trait hypothesized to be associated with female calling, another common mating system. We combined feeding experiments with respirometry to show that lifespan can be enhanced over 3 months by feeding outside the nest. In one focal female calling species, Ectatomma ruidum, feeding enhanced male lifespan, but not sperm content. Extended lifespans outside the nest suggest stronger than expected selection on premating traits of male ants, although the ways these traits shape male mating success remain poorly understood.