2,603 research outputs found
Estimation of effective vaccination rate for pertussis in New Zealand as a case study
In some cases vaccination is unreliable. For example vaccination against pertussis has comparatively high level of primary and secondary failures. To evaluate efficiency of vaccination we introduce the idea of effective vaccination rate and suggest an approach to estimate it. We consider pertussis in New Zealand as a case study. The results indicate that the level of immunity failure for pertussis is considerably higher than was anticipated
Blau\u27s Theory of Structural Differentiation Revisited: A Theory of Structural Change or Scale?
The major objective of this study was to determine if Blau\u27s (1970) theory of structural differentiation better captures differences in scale between organizations or structural changes within organizations. Data gathered on 134 Ph.D.-granting universities over nine years permitted us to compare results of within-organizations tests of Blau\u27s theory those from both cross-sectional and longitudinal between-organization tests. The findings suggest that the theory\u27s power lies in explaining structural differences between organizations rather than in explaining structural change
Alzheimer disease genetic risk factor APOE e4, and cognitive abilities in 111,739 UK Biobank participants
Background: the apolipoprotein (APOE) e4 locus is a genetic risk factor for dementia. Carriers of the e4 allele may be more
vulnerable to conditions that are independent risk factors for cognitive decline, such as cardiometabolic diseases.
Objective: we tested whether any association with APOE e4 status on cognitive ability was larger in older ages or in those
with cardiometabolic diseases.
Subjects: UK Biobank includes over 500,000 middle- and older aged adults who have undergone detailed medical and cognitive
phenotypic assessment. Around 150,000 currently have genetic data. We examined 111,739 participants with complete
genetic and cognitive data.
Methods: baseline cognitive data relating to information processing speed, memory and reasoning were used. We tested for
interactions with age and with the presence versus absence of type 2 diabetes (T2D), coronary artery disease (CAD) and hypertension.
Results: in several instances, APOE e4 dosage interacted with older age and disease presence to affect cognitive scores. When
adjusted for potentially confounding variables, there was no APOE e4 effect on the outcome variables.
Conclusions: future research in large independent cohorts should continue to investigate this important question, which has
potential implications for aetiology related to dementia and cognitive impairment
Reducing energy demand: a review of issues, challenges and approaches
Most commentators expect improved energy efficiency and reduced energy demand to provide the dominant contribution to tackling global climate change. But at the global level, the correlation between increased wealth and increased energy consumption is very strong and the impact of policies to reduce energy demand is both limited and contested. Different academic disciplines approach energy demand reduction in different ways: emphasising some mechanisms and neglecting others, being more or less optimistic about the potential for reducing energy demand and providing insights that are more or less useful for policymakers. This article provides an overview of the main issues and challenges associated with energy demand reduction, summarises how this challenge is âframedâ by key academic disciplines, indicates how these can provide complementary insights for policymakers and argues that a âsociotechnicalâ perspective can provide a deeper understanding of the nature of this challenge and the processes through which it can be achieved. The article integrates ideas from the natural sciences, economics, psychology, innovation studies and sociology but does not give equal weight to each. It argues that reducing energy demand will prove more difficult than is commonly assumed and current approaches will be insufficient to deliver the transformation required
Microstructure and coercivity in alnico 9
Magnetic property enhancement of alnico, a rare-earth free permanent magnet, is highly dependent on both the initial microstructure and the evolution of the spinodal decomposition (SD) inside each grain during the heat treatment process. The size, shape and distribution of the magnetic FeCo-rich (α1) phase embedded in continuous non-magnetic AlNi-rich (α2) phase as well as a minor Cu-enriched phase residing in between are shown to be crucial in controlling coercivity. Phase and magnetic domain morphology in a commercial alnico 9 alloy was studied using a combination of structural characterization techniques, including scanning electron microscopy, electron backscatter diffraction, aberration-corrected scanning transmission electron microscopy and Lorentz microscopy. Our results showed that casting created structural nonuniformity and defects, such as porosity, TiS2 precipitates and grain misorientation, are heterogeneously distributed, with the center section having the best crystallographic orientation and minimal defects. The optimal spinodal is a âmosaic structureâ, composed of rod-shape α1 phase with {1â1â0} or {1â0â0} planar faceting and diameter of âŒ30â45âŻnm. There is also a Cu-enriched phase residing at the corners of two ă1â1â0ă facets of the α1 phase. It was observed that grain boundary phase reverse magnetization direction at lower external magnetic field compared to the SD region inside the grain. Improving grain orientation uniformity, reducing detrimental grain boundary phase volume fraction, and the branching of the α1 rods, as well as their diameter, are promising routes to improve energy product of alnico
Patientsâ preferences for nutrition-related health outcomes in liver disease : a preliminary study using an electronic questionnaire
Background: Patients with liver disease frequently have nutritional problems but intervening to improve these is challenging. Healthcare interventions that respond to patientsâ needs are associated with better health outcomes but no studies investigating patientsâ preferences for nutrition-related outcomes in liver disease have been published. The aim of this study was to identify nutrition-related health outcomes that are important to patients with liver disease. Methodology: An electronic questionnaire was devised and reviewed by patients and dietitians with relevant experience. It comprised Likert scale and open questions focussing on six domains considered pertinent to patients with liver disease. An invitation to participate was posted on the website of a national liver charity and sent to liver patient support groups. Results: Fifty-one patients participated (22 men / 29 women). Responses indicated a wide range of preferred nutrition-related outcomes with those identified as very important most frequently focussing on gaining knowledge about which foods to eat more or less of, and on understanding why nutrition is important in liver disease. Women tended to score outcomes as more important than men. Participants who considered themselves overweight scored outcomes on body size and shape as more important than those with other nutritional problems. Additional outcomes were identified and included increased knowledge of healthy eating, interactions between medication and food, and supplementation. Conclusions: The study identified a wide range of nutrition-related outcomes that were important to this small sample of patients with liver disease and these may be useful to guide the direction of future nutrition-related management.Peer reviewedFinal Accepted Versio
Hepatitis C test uptake among historic blood transfusion recipients following media coverage of the Penrose Inquiry and an awareness-raising campaign
Coupled sea surface temperature-seawater delta O-18 reconstructions in the Arabian Sea at the millennial scale for the last 35 ka
Two sediment cores from the western (905; 10.46°9âČN, 51.56°4âČE, water depth 1586 m) and eastern (SK17; 15°15âČN, 72°58âČE, water depth 840 m) Arabian Sea were used to study past sea surface temperatures (SST) and seawater ÎŽ 18O (ÎŽ 18Ow) variations for the past 35 ka. We used coupled Mg/Ca-ÎŽ 18O calcite variability in two planktonic foraminiferal species: Globigerinoides ruber, which thrives throughout the year, and Globigerina bulloides, which occurs mainly when surface waters contain high nutrients during upwelling or convective mixing. SSTs in both areas based on Mg/Ca in G. ruber were âŒ3 to 4°C lower during the Last Glacial Maximum (LGM; âŒ21 ka) than today and the Holocene period. The SST records based on G. bulloides also indicate general cooling, down to 18°C in both areas. SSTs in the western Arabian Sea based on G. bulloides were always lower than those based on G. ruber, indicating the presence of strong seasonal temperature contrast during the Holocene and LGM. We interpret the consistent presence of this seasonal temperature contrast to reflect a combination of seasonal summer upwelling (SW monsoon) and winter convective mixing (NE monsoon) in the western Arabian Sea. In the eastern Arabian Sea, G. bulloides-based SSTs were slightly lower (about 1°C) than G. ruber-based SSTs during the Holocene, indicating the almost absence of a seasonal temperature gradient, similar to today. However, a large seasonal temperature contrast occurred during the LGM which favors the assumption that strong NE monsoon winds forced winter upwelling or convective mixing offshore Goa. SST and ÎŽ 18Ow reconstructions reveal evidence of millennial-scale cycles, particularly in the eastern Arabian Sea. Here, the stadial periods (Northern Hemisphere cold periods such as Younger Dryas and Heinrich events) are marked by increasing SSTs and salty sea surface conditions relative to those during the interstadial periods. Indeed, the ÎŽ 18Ow record shows evidence of low-saline surface waters during interstadial periods, indicating increased freshwater runoff from the Western Ghats as a consequence of enhanced SW monsoon intensity
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