3,555 research outputs found
Computational screening of magnetocaloric alloys
An exciting development over the past few decades has been the use of
high-throughput computational screening as a means of identifying promising
candidate materials for a variety of structural or functional properties.
Experimentally, it is often found that the highest-performing materials contain
substantial atomic site disorder. These are frequently overlooked in
high-throughput computational searches however, due to difficulties in dealing
with materials that do not possess simple, well-defined crystallographic unit
cells. Here we demonstrate that the screening of magnetocaloric materials with
the help of the density functional theory-based magnetic deformation proxy can
be extended to systems with atomic site disorder. This is accomplished by
thermodynamic averaging of the magnetic deformation for ordered supercells
across a solid solution. We show that the highly non-monotonic magnetocaloric
properties of the disordered solid solutions Mn(CoFe)Ge and
(MnNi)CoGe are successfully captured using this method.Comment: Main text: 8 pages, 6 figures. Supplemental Material: 2 pages, 2
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Non-invasive Diabetes Detection using Gabor Filter: A Comparative Analysis of Different Cameras
This paper compares and explores the performance of both mobile device camera
and laptop camera as convenient tool for capturing images for non-invasive
detection of Diabetes Mellitus (DM) using facial block texture features.
Participants within age bracket 20 to 79 years old were chosen for the dataset.
12mp and 7mp mobile cameras, and a laptop camera were used to take the photo
under normal lighting condition. Extracted facial blocks were classified using
k-Nearest Neighbors (k-NN) and Support Vector Machine (SVM). 100 images were
captured, preprocessed, filtered using Gabor, and iterated. Performance of the
system was measured in terms of accuracy, specificity, and sensitivity. Best
performance of 96.7% accuracy, 100% sensitivity, and 93% specificity were
achieved from 12mp back camera using SVM with 100 images.Comment: 11 pages, 5 figures, 3 tables, conferenc
Provider reported implementation of nutrition-related practices in childcare centers and family childcare homes in rural and urban Nebraska
Approximately 15 million children under age 6 are in childcare settings, offering childcare providers an opportunity to influence children’s dietary intake. Childcare settings vary in organizational structure – childcare centers (CCCs) vs. family childcare homes (FCCHs) – and in geographical location – urban vs. rural. Research on the nutrition-related best practices across these childcare settings is scarce. The objective of this study is to compare nutrition-related best practices of CCCs and FCCHs that participate in the Child and Adult Care Food Program (CACFP) in rural and urban Nebraska. Nebraska providers (urban n = 591; rural n = 579) reported implementation level, implementation difficulty and barriers to implementing evidence-informed food served and mealtime practices. Chi-square tests comparing CCCs and FCCHs in urban Nebraska and CCCs and FCCHs in rural Nebraska showed sub-optimal implementation for some practices across all groups, including limiting fried meats and high sugar/ high fat foods, using healthier foods or non-food treats for celebrations and serving meals family style. Significant differences (p \u3c .05) between CCCs and FCCHs also emerged, especially with regard to perceived barriers to implementing best practices. For example, CCCs reported not having enough money to cover the cost of meals for providers, lack of control over foods served and storage problems, whereas FCCHs reported lack of time to prepare healthier foods and sit with children during mealtimes. Findings suggest that policy and public health interventions may need to be targeted to address the unique challenges of implementing evidence-informed practices within different organizational structures and geographic locations
Lack of the Sodium-Driven Chloride Bicarbonate Exchanger NCBE Impairs Visual Function in the Mouse Retina
Regulation of ion and pH homeostasis is essential for normal neuronal function. The sodium-driven chloride bicarbonate exchanger NCBE (Slc4a10), a member of the SLC4 family of bicarbonate transporters, uses the transmembrane gradient of sodium to drive cellular net uptake of bicarbonate and to extrude chloride, thereby modulating both intracellular pH (pHi) and chloride concentration ([Cl-]i) in neurons. Here we show that NCBE is strongly expressed in the retina. As GABAA receptors conduct both chloride and bicarbonate, we hypothesized that NCBE may be relevant for GABAergic transmission in the retina. Importantly, we found a differential expression of NCBE in bipolar cells: whereas NCBE was expressed on ON and OFF bipolar cell axon terminals, it only localized to dendrites of OFF bipolar cells. On these compartments, NCBE colocalized with the main neuronal chloride extruder KCC2, which renders GABA hyperpolarizing. NCBE was also expressed in starburst amacrine cells, but was absent from neurons known to depolarize in response to GABA, like horizontal cells. Mice lacking NCBE showed decreased visual acuity and contrast sensitivity in behavioral experiments and smaller b-wave amplitudes and longer latencies in electroretinograms. Ganglion cells from NCBE-deficient mice also showed altered temporal response properties. In summary, our data suggest that NCBE may serve to maintain intracellular chloride and bicarbonate concentration in retinal neurons. Consequently, lack of NCBE in the retina may result in changes in pHi regulation and chloride-dependent inhibition, leading to altered signal transmission and impaired visual function
Fundamental limits on the rate of bacterial growth
Recent years have seen an experimental deluge interrogating the relationship between bacterial growth rate, cell size, and protein content, quantifying the abundance of proteins across growth conditions with unprecedented resolution. However, we still lack a rigorous understanding of what sets the scale of these quantities and when protein abundances should (or should not) depend on growth rate. Here, we seek to quantitatively understand this relationship across a collection of Escherichia coli proteomic data covering ≈ 4000 proteins and 36 growth rates. We estimate the basic requirements for steady-state growth by considering key processes in nutrient transport, cell envelope biogenesis, energy generation, and the central dogma. From these estimates, ribosome biogenesis emerges as a primary determinant of growth rate. We expand on this assessment by exploring a model of proteomic regulation as a function of the nutrient supply, revealing a mechanism that ties cell size and growth rate to ribosomal content
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