8,647 research outputs found
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Genome-wide patterns of polymorphism in an inbred line of the African malaria mosquito Anopheles gambiae.
Anopheles gambiae is a major mosquito vector of malaria in Africa. Although increased use of insecticide-based vector control tools has decreased malaria transmission, elimination is likely to require novel genetic control strategies. It can be argued that the absence of an A. gambiae inbred line has slowed progress toward genetic vector control. In order to empower genetic studies and enable precise and reproducible experimentation, we set out to create an inbred line of this species. We found that amenability to inbreeding varied between populations of A. gambiae. After full-sib inbreeding for ten generations, we genotyped 112 individuals--56 saved prior to inbreeding and 56 collected after inbreeding--at a genome-wide panel of single nucleotide polymorphisms (SNPs). Although inbreeding dramatically reduced diversity across much of the genome, we discovered numerous, discrete genomic blocks that maintained high heterozygosity. For one large genomic region, we were able to definitively show that high diversity is due to the persistent polymorphism of a chromosomal inversion. Inbred lines in other eukaryotes often exhibit a qualitatively similar retention of polymorphism when typed at a small number of markers. Our whole-genome SNP data provide the first strong, empirical evidence supporting associative overdominance as the mechanism maintaining higher than expected diversity in inbred lines. Although creation of A. gambiae lines devoid of nearly all polymorphism may not be feasible, our results provide critical insights into how more fully isogenic lines can be created
Breast Cancer Survival, Work, and Earnings
Relying on data from the Health and Retirement Study, we examine differences between breast cancer survivors and a non-cancer control group in employment, hours worked, wages, and earnings. Overall, breast cancer has a negative impact on the decision to work. However, among survivors who work, hours of work and, correspondingly, annual earnings are higher compared to women in the non-cancer control group. These findings suggest that while breast cancer has a negative effect on women's employment, breast cancer may not be debilitating for those who remain in the work force. We explore numerous possible biases underlying our estimates especially selection based on information in the Health and Retirement Study, and examine related evidence from supplemental data sources.
Malaria : old infections, changing epidemiology
The epidemiology of malaria has always varied between different parts of the world because of widely varying vectorial capacity. Mortality from malaria can be measured from clinical records or the rise of mortality during an epidemic, but better from observing the fall of mortality during control or from the population frequency of protective host genes. Holoendemic malaria may have doubled the infant and young-child mortality rate in Africa in the recent past, but death rates have fallen because of chemotherapy. The epidemiological pattern is changing. In the Sahel, water-resource developments tend to lengthen the transmission season, though less than might be expected, and urbanization tends to decrease transmission in Africa, not in Asia. The spread of multiple drug resistance of the parasites is making case management harder and deaths may rise. Malaria control has always been unsatisfactory in sub-Saharan Africa owing to the highly effective vector. The main current hopes for control are the use of the effective insecticideimpregnated bed nets and better case management. No simple concept of an epidemiological transition can reflect the very diverse changes occurring in human malaria worldwide
The Effects of Health Shocks on Employment and Health Insurance: The Role of Employer-Provided Health Insurance
We study how menâs dependence on their own employer for health insurance affects labor supply responses and loss of health insurance coverage when faced with a serious health shock. Men with employment-contingent health insurance (ECHI) are more likely to remain working following some kinds of adverse health shocks, and are more likely to lose insurance. With the passage of health care reform, the tendency of men with ECHI as opposed to other sources of insurance to remain employed following a health shock may be diminished, along with the likelihood of losing health insurance.
Electricity load profile classification using Fuzzy C-Means method
This paper presents the Fuzzy C-Means (FCM) clustering method. The FCM technique assigns a degree of membership for each data set to several clusters, thus offering the opportunity to deal with load profiles that could belong to more than one group at the same time. The FCM algorithm is based on minimising a c-means objective function to determine an optimal classification. The simulation of FCM was carried out using actual sample data from Indonesia and the results are presented. Some validity index measurements was carried out to estimate the compactness of the resulting clusters or to find the optimal number of clusters for a data set
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Federal Programs Available to Unemployed Workers
[Excerpt] Four groups of federal programs target unemployed workers: unemployment insurance, health care assistance, job search assistance, and training. This report presents information on federal programs targeted to unemployed workers specifically, but does not attempt to discuss means-tested programs (such as Medicaid or SSI) that are available regardless of employment status.
This report will be updated with major new legislation
Employment-Contingent Health Insurance, Illness, and Labor Supply of Women: Evidence from Married Women with Breast Cancer
We examine the effects of employment-contingent health insurance on married women's labor supply following a health shock. First, we develop a theoretical model that examines the effects of employment-contingent health insurance on the labor supply response to a health shock, to clarify under what conditions employment-contingent health insurance is likely to dampen the labor supply response. Second, we empirically evaluate this relationship using primary data. The results from our analysis find that -- as the model suggests is likely -- health shocks decrease labor supply to a greater extent among women insured by their spouse's policy than among women with health insurance through their own employer. Employment-contingent health insurance appears to create incentives to remain working and to work at a greater intensity when faced with a serious illness.
Using a fuzzy inference system to control a pumped storage hydro plant
The paper discusses the development of a fuzzy inference system (FIS) based governor control for a pumped storage hydroelectric plant. The First Hydro Company's plant at Dinorwig in North Wales is the largest of its kind in Europe and is mainly used for frequency control of the UK electrical grid. In previous investigations, a detailed model of the plant was developed using MATLAB(R)/SIMULINK(R) and this is now being used to compare FIS governor operation with the proportional-integral-derivative (PID) controller currently used. The paper describes the development of an FIS governor, and shows that its response to a step increase in load is superior to the PID under certain conditions of load. The paper proceeds to discuss the implications of these results in view of the possible practical application of an FIS governor at the Dinorwig plant
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