1,190 research outputs found
Maternal zinc intakes and homeostatic adjustments during pregnancy and lactation.
Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating effects, systematic reviews and meta-analysis of the effect of maternal zinc supplementation on pregnancy outcomes have consistently shown a limited benefit. We hypothesize, therefore, that zinc homeostatic adjustments during pregnancy and lactation improve zinc utilization sufficiently to provide the increased zinc needs in these stages and, therefore, mitigate immediate detrimental effects due to a low zinc intake. The specific questions addressed are the following: How is zinc utilization altered during pregnancy and lactation? Are those homeostatic adjustments influenced by maternal zinc status, dietary zinc, or zinc supplementation? These questions are addressed by critically reviewing results from published human studies on zinc homeostasis during pregnancy and lactation carried out in different populations worldwide
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A proposed nutrient density score that includes food groups and nutrients to better align with dietary guidance.
Current research on diets and health focuses on composite food patterns and their likely impact on health outcomes. The Dietary Guidelines for Americans (DGA) have likewise adopted a more food group-based approach. By contrast, most nutrient profiling (NP) models continue to assess nutrient density of individual foods, based on a small number of individual nutrients. Nutrients to encourage have included protein, fiber, and a wide range of vitamins and minerals. Nutrients to limit are typically saturated fats, total or added sugars, and sodium. Because current NP models may not fully capture the healthfulness of foods, there is a case for advancing a hybrid NP approach that takes both nutrients and desirable food groups and food ingredients into account. Creating a nutrient- and food-based NP model may provide a more integrated way of assessing a foods nutrient density. Hybrid nutrient density scores will provide for a better alignment between NP models and the DGA, a chief instrument of food and nutrition policy in the United States. Such synergy may lead ultimately to improved dietary guidance, sound nutrition policy, and better public health
The Nature and Extent of Instructors’ Use of Learning Analytics in Higher Education to Inform Teaching and Learning
The utilization of learning analytics to support teaching and learning has emerged as a newer phenomenon combining instructor-oriented action research, the mining of educational data, and the analyses of statistics and patterns. Learning analytics have documented, quantified and graphically displayed students’ interactions, engagement, and performance to gain a more complex understanding of teaching and learning. Researchers and scholars have hailed learning analytics as one of the future game-changers in higher education. This study addressed important questions. How have instructors at institutions of higher learning explored learning analytics to reflect upon their teaching practice—specifically, curriculum, pedagogy, student learning and outcomes? What have been the perceived key challenges to the adoption and implementation of learning analytics by instructors at institutions of higher learning? A reflection on technology integration with an emphasis on the affordances and rhetoric of learning analytics to inform teaching and learning was presented. An exploratory study was undertaken consisting of a two-phased research approach–a dominant-less dominant design, addressing the nature and extent of instructors’ use of learning analytics in higher education. The findings failed to substantiate extensive buy-in by instructors; challenges included a lack of time to learn and implement analytics, a culture of resistance, issues with change, and insufficient professional development, training and incentives. When learning analytics were used, it often involved supervisory and pro-active affordances for students
Pseudotypes: your flexible friends
Pseudotype viruses: applications and troubleshooting' (EuroSciCon 2013), a 1-day conference held at Cineworld: The O2 (London, UK) on 2 October 2013, focused on the technique of pseudotyping enveloped viruses (for a review of the technique, see [1]). The talks and posters covered the challenges and successes of pseudotyping viruses from a broad range of families (Retroviridae, Flaviviridae, Orthomyxoviridae, Bunyaviridae and Rhabdoviridae) for a variety of applications. The conference was chaired by Nigel Temperton, University of Kent (UK), who placed a strong emphasis on using this event to explore the technical challenges of pseudotyping viruses, especially during the poster and afternoon question and answer sessions
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Cytological profiling: providing more haystacks for chemists' needles
Conventional high-throughput 'chemical genetic' screening seeks to identify small-molecule inhibitors of a specific protein or pathway. A recent study describes how unbiased screening of cellular morphology, followed by affinity purification to identify targets of compounds with interesting effects, can lead to the identification of novel inhibitors
Identification of a Hemolysis Threshold That Increases Plasma and Serum Zinc Concentration.
Background: Plasma or serum zinc concentration (PZC or SZC) is the primary measure of zinc status, but accurate sampling requires controlling for hemolysis to prevent leakage of zinc from erythrocytes. It is not established how much hemolysis can occur without changing PZC/SZC concentrations.Objective: This study determines a guideline for the level of hemolysis that can significantly elevate PZC/SZC.Methods: The effect of hemolysis on PZC/SZC was estimated by using standard hematologic variables and mineral content. The calculated hemolysis threshold was then compared with results from an in vitro study and a population survey. Hemolysis was assessed by hemoglobin and iron concentrations, direct spectrophotometry, and visual assessment of the plasma or serum. Zinc and iron concentrations were determined by inductively coupled plasma spectrometry.Results: A 5% increase in PZC/SZC was calculated to result from the lysis of 1.15% of the erythrocytes in whole blood, corresponding to ∼1 g hemoglobin/L added into the plasma or serum. Similarly, the addition of simulated hemolysate to control plasma in vitro caused a 5% increase in PZC when hemoglobin concentrations reached 1.18 ± 0.10 g/L. In addition, serum samples from a population nutritional survey were scored for hemolysis and analyzed for changes in SZC; samples with hemolysis in the range of 1-2.5 g hemoglobin/L showed an estimated increase in SZC of 6% compared with nonhemolyzed samples. Each approach indicated that a 5% increase in PZC/SZC occurs at ∼1 g hemoglobin/L in plasma or serum. This concentration of hemoglobin can be readily identified directly by chemical hemoglobin assays or indirectly by direct spectrophotometry or matching to a color scale.Conclusions: A threshold of 1 g hemoglobin/L is recommended for PZC/SZC measurements to avoid increases in zinc caused by hemolysis. The use of this threshold may improve zinc assessment for monitoring zinc status and nutritional interventions
Seroprevalence of Schmallenberg virus in the United Kingdom and Republic of Ireland: 2011-2013
Since its identification in late 2011, Schmallenberg virus (SBV) spread rapidly across Europe. Using archived samples from domestic ruminants collected between October 2011 and June 2013, the seroprevalence in the United Kingdom (UK) and Republic of Ireland (IE) was estimated using a serum neutralisation test. There was no significant difference (P > 0.05) in seroprevalence between sheep and cows suggesting that neither species is significantly more at risk of SBV infection in the UK. A single 2011 sample tested positive; the sample was taken in November from a cow in Wiltshire. There was a steady increase in overall seroprevalence during the first three quarters of 2012, which then more than doubled in quarter 4 (October–December), which may reflect a peak of vector activity. By the end of June 2013, overall seroprevalence was around 72%. However, although seroprevalence was over 50% in Wales and southern and central counties of England, it was below 50% in all other areas of the UK and IE. This suggests that there were still substantial numbers of animals at risk of infection in the latter half of 2013
The Poetics of Dissolution: The Representation of Maori Culture in Janet Frame's Fiction
This essay examines Janet Frame's early short story "The Lagoon", and argues that the
story alludes to Maori experience, albeit tangentially, in a way which anticipates similar
evocations in novels such as A State of Siege and The Carpathians. A close reading
shows that cultural imperialism in Frame runs parallel to, or is a side-effect of,
interpersonal appropriations. These, in turn, seem to be rooted in human beings'
reluctance to accommodate otherness. Recurrently Janet Frame points to a model of
cultural and interpersonal interaction which is detached from proprietorial forms of
appropriation, but which entails nothing less than the dissolution of the ruling ego. Selfdissolution
shall emerge in this reading as the key to a utopian state consisting of the total
permeability between the self and the remainder of the world. In this state, transactions
become reciprocal since the divisions between self and non-self no longer exist
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