Worker honeybees, Apis mellifera, police each other's reproduction by killing worker-laid eggs. Previous experiments demonstrated that worker policing is effective, killing most (∼98%) worker-laid eggs. However, many queen-laid eggs were also killed (∼50%) suggesting that effective policing may have high costs. In these previous experiments, eggs were transferred using forceps into test cells, ...

HIV prevalence is disproportionately high among female sex workers compared to the general population. Many African countries lack useful data on the size of female sex worker populations to inform national HIV programmes. A female sex worker size estimation exercise using three different venue-based methodologies was conducted among female sex workers in all provinces of Rwanda in August 2010....

The quantity of effective labor in the work force depends not only on the number of workers employed but on how hard they work. Many explanations of the superior performance of the Japanese economy stress this fact. Japanese workers seem more dedicated and motivated than their American counterparts. We examine this phenomenon by comparing the effects of worker attitude on productivity and produ...

background: tourniquets used repeatedly on patients for blood sampling are a potential source of nosocomial infections. they harbor numerous microorganisms, including methicillin‑resistant staphylococcus aureus (mrsa). the aim of this study was to investigate tourniquets for the presence of microorganisms and to ascertain the infection control practices of health care workers. methods: a cross‑...

background: benzene, toluene, ethylbenzene and xylene (btex) are the most important toxic volatile compounds in the air and could be easily absorbed through the respiratory tract. in recent years, the risk of exposure to btex compounds, especially benzene as a carcinogen, has been considered in petroleum depot stations. objective: to assess the occupational exposure of petroleum depot workers i...

background: the lack of satisfaction and balance between the workload and abilities and limitations of individuals in various occupations may influence their general health. the aim of this study was to determine the effect of workload and job satisfaction on the general health of industrial workers.   materials and methods: this was a cross-sectional and correlational study on 215 workers of a...

Introduction DNA damage is among the main consequences of radiation. Of many different classes of DNA damage, double-strand breaks are the most deleterious. Development of a sensitive biodosimetry method, which utilizes a detection material with a similar construction to the body, seems essential for monitoring radiation workers. In this study, histone H2AX protein was examined as a potential  ...

This paper deals with the task-scheduling and worker-allocation problem, in which each skillful worker is capable to perform multiple tasks and has various regular and worker capacity to perform tasks, and the task allocation is operated with daily overhead. We propose a worker assignment model and develop a heuristic algorithm that is genetic algorithm whose performance is to be evaluated agai...