University of Aberdeen

About: University of Aberdeen is a education organization based out in Aberdeen, United Kingdom. It is known for research contribution in the topics: Population & Randomized controlled trial. The organization has 21174 authors who have published 49962 publications receiving 2105479 citations. The organization is also known as: Aberdeen University.

A Modified Principal Component Technique Based on the LASSO

Abstract: In many multivariate statistical techniques, a set of linear functions of the original p variables is produced. One of the more difficult aspects of these techniques is the interpretation of the linear functions, as these functions usually have nonzero coefficients on all p variables. A common approach is to effectively ignore (treat as zero) any coefficients less than some threshold value, so that the function becomes simple and the interpretation becomes easier for the users. Such a procedure can be misleading. There are alternatives to principal component analysis which restrict the coefficients to a smaller number of possible values in the derivation of the linear functions, or replace the principal components by “principal variables.” This article introduces a new technique, borrowing an idea proposed by Tibshirani in the context of multiple regression where similar problems arise in interpreting regression equations. This approach is the so-called LASSO, the “least absolute shrinkage and selection o...

Factors affecting the utilization of antenatal care in developing countries: systematic review of the literature

Abstract: Title. Factors affecting the utilization of antenatal care in developing countries: systematic review of the literature. Aim. This paper is a report of a systematic review to identify and analyse the main factors affecting the utilization of antenatal care in developing countries. Background. Antenatal care is a key strategy for reducing maternal mortality, but millions of women in developing countries do not receive it. Data sources. A range of electronic databases was searched for studies conducted in developing countries and published between 1990 and 2006. English-language publications were searched using relevant keywords, and reference lists were hand-searched. Review methods. A systematic review was carried out and both quantitative and qualitative studies were included. Results. Twenty-eight papers were included in the review. Studies most commonly identified the following factors affecting antenatal care uptake: maternal education, husband’s education, marital status, availability, cost, household income, women’s employment, media exposure and having a history of obstetric complications. Cultural beliefs and ideas about pregnancy also had an influence on antenatal care use. Parity had a statistically significant negative effect on adequate attendance. Whilst women of higher parity tend to use antenatal care less, there is interaction with women’s age and religion. Only one study examined the effect of the quality of antenatal services on utilization. None identified an association between the utilization of such services and satisfaction with them. Conclusion. More qualitative research is required to explore the effect of women’s satisfaction, autonomy and gender role in the decision-making process. Adequate utilization of antenatal care cannot be achieved merely by establishing health centres; women’s overall (social, political and economic) status needs to be considered.

Microorganisms and climate change: terrestrial feedbacks and mitigation options

Abstract: Microbial processes have a central role in the global fluxes of the key biogenic greenhouse gases (carbon dioxide, methane and nitrous oxide) and are likely to respond rapidly to climate change. Whether changes in microbial processes lead to a net positive or negative feedback for greenhouse gas emissions is unclear. To improve the prediction of climate models, it is important to understand the mechanisms by which microorganisms regulate terrestrial greenhouse gas flux. This involves consideration of the complex interactions that occur between microorganisms and other biotic and abiotic factors. The potential to mitigate climate change by reducing greenhouse gas emissions through managing terrestrial microbial processes is a tantalizing prospect for the future.