5,622 research outputs found
Policies to create and destroy human capital in Europe
Trends in skill bias and greater turbulence in modern labor markets put wages and employment prospects of unskilled workers under pressure. Weak incentives to utilize and maintain skills over the life-cycle become manifest with the ageing of the population. Reinvention of human capital policies is required to avoid increasing welfare state dependency among the unskilled and to reduce inefficiencies in human capital formation. Policy makers should acknowledge strong dynamic complementarities in skill formation. Investments in the human capital of children should expand relative to investment in older workers. There is no trade-off between equity and efficiency at early ages of human development but there is a substantial trade-off at later ages. Later remediation of skill deficits acquired in early years is often ineffective. Active labor market and training policies should therefore be reformulated. Skill formation is impaired when the returns to skill formation are low due to low skill use and insufficient skill maintenance later on in life. High marginal tax rates and generous benefit systems reduce labor force participation rates and hours worked and thereby lower the utilization rate of human capital. Tax-benefit systems should be reconsidered as they increasingly redistribute resources from outsiders to insiders in labor markets which is both distortionary and inequitable. Early retirement and pension schemes should be made actuarially fairer as they entail strong incentives to retire early and human capital is thus written off too quickly
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Salmonella Infection After Craniotomy.
Salmonella is an uncommon cause of meningitis, especially after neurosurgery. Here, we present a case of Salmonella meningitis after craniotomy, likely due to physical contact with a snake after surgery, with contiguous spread from the patient's hand to her wound. The purpose of this report is to serve as a reminder that patients undergoing neurosurgery should avoid contact with pets, including snakes and other reptiles, in the postoperative period and practice good hand hygiene
Antarctic Ocean polynyas
The spatial and temporal variability of sea ice concentrations derived from Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) brightness temperatures are presented. Emphasis is on the continental shelf region of the Ross Sea during 1984, when supporting data were obtained from oceanographic stations and moored instruments. The effects of the large spring polynya in the Ross Sea on summer insolation, surface heat layer storage, and late autumn ice formation are described
Linking an integrated framework with appropriate methods for measuring QoE
Quality of Experience (QoE) has recently gained recognition for being an important determinant of the success of new technologies. Despite the growing interest in QoE, research into this area is still fragmented. Similar - but separate - efforts are being carried out in technical as well as user oriented research domains, which are rarely communicating with each other. In this paper, we take a multidisciplinary approach and review both user oriented and technical definitions on Quality of Experience (including the related concept of User Experience). We propose a detailed and comprehensive framework that integrates both perspectives. Finally, we take a first step at linking methods for measuring QoE with this framework
The biogeochemical influence of nitrate, dissolved oxygen, and dissolved organic carbon on stream nitrate uptake
Streams are potential hotspots for retention and removal of NO3−, and understanding the mechanisms that enhance NO3− reactivity in stream systems is critical for predicting and preventing eutrophication. Both dissolved organic C (DOC) and dissolved O2 (DO) influence NO3− removal processes. Assessing the individual impacts of NO3−, DO, and DOC concentrations on stream NO3− removal is difficult because these factors covary and are coupled through the C and N cycles. We used an experimental approach to quantify the influences of NO3−, DOC, and DO on NO3− transport in headwater streams of the Ipswich and Parker River watersheds (Massachusetts, USA) with contrasting levels of DOC and DO. In a 1st set of experiments, we added NO3− to address how uptake kinetics differed between a low-DO/high-DOC stream (Cedar Swamp Creek) and a high-DO/low-DOC stream (Cart Creek). In a 2nd set of experiments, we manipulated, for the first time at the reach scale, both DO and DOC in a factorial experiment. DO was added to the low-DO stream by injecting O2 and was removed from the high-DO stream by adding sodium sulfite. DOC was added both alone and in combination with the DO manipulations. NO3− concentration was an important control of NO3− uptake velocity in our study streams, consistent with previous findings. The results of the DOC and DO manipulations suggested that DO determines whether a stream has net NO3− uptake or production and that the presence of DOC magnifies the DO response processes. Addition of DOC by itself did not lead to increased NO3− uptake. In addition, we observed organic matter priming effects, wherein the addition of labile organic matter resulted in accelerated metabolism of naturally occurring DOC in the water column. Priming effects have not been reported previously in stream systems. Results from our experiments suggest that NO3− uptake in streams might arise from complex interactions among DOC, DO, and NO3−, and ultimately, from the influence of DO on dominant stream processes
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Associations of body composition measures and C2, a marker for small artery elasticity: The MESA.
ObjectiveLower C2, a continuous blood pressure waveform characteristic asserted to represent small artery elasticity, predicts future cardiovascular disease events. It is hypothesized that the paradoxical positive association between body mass index (BMI) and C2 may reflect muscle instead of excess fat.MethodsIn a multi-ethnic, community-living cohort of 1,960 participants, computed tomography scans of the abdomen were used to measure visceral adipose tissue (VAT) and total abdominal muscle tissue (TAMT), and applanation tonometry of the radial arteries was used to assess C2. The period cross-sectional associations between BMI, TAMT, and VAT with C2 were ascertained.ResultsThe mean age was 62 ± 9 years and 51% were male. After adjustments for age, gender, ethnicity, pack years smoking cigarettes, diabetes, hypertension, and total and HDL cholesterol, higher BMI (standardized beta = 0.09, P-value < 0.01) and more TAMT (standardized beta = 0.12, P-value < 0.01) were significantly associated with higher C2. In contrast, more VAT (standardized beta = -0.09, P-value < 0.01) was associated with lower C2.ConclusionsIn multivariable analysis, VAT, in contrast to TAMT and BMI, was associated with less compliant small arteries. Visceral fat may be a better marker for detrimental excess body fat than BMI
Diagnostic performance of a novel loop-mediated isothermal amplification (LAMP) assay targeting the apicoplast genome for malaria diagnosis in a field setting in sub-Saharan Africa.
BACKGROUND: New diagnostic tools to detect reliably and rapidly asymptomatic and low-density malaria infections are needed as their treatment could interrupt transmission. Isothermal amplification techniques are being explored for field diagnosis of malaria. In this study, a novel molecular tool (loop-mediated isothermal amplification-LAMP) targeting the apicoplast genome of Plasmodium falciparum was evaluated for the detection of asymptomatic malaria-infected individuals in a rural setting in The Gambia. METHODS: A blood was collected from 341 subjects (median age 9 years, range 1-68 years) screened for malaria. On site, a rapid diagnostic test (RDT, SD Bioline Malaria Antigen P.f) was performed, thick blood films (TBF) slides for microscopy were prepared and dry blood spots (DBS) were collected on Whatman(®) 903 Specimen collection paper. The TBF and DBS were transported to the field laboratory where microscopy and LAMP testing were performed. The latter was done on DNA extracted from the DBS using a crude (methanol/heating) extraction method. A laboratory-based PCR amplification was done on all the samples using DNA extracted with the Qiagen kit and its results were taken as reference for all the other tests. RESULTS: Plasmodium falciparum malaria prevalence was 37 % (127/341) as detected by LAMP, 30 % (104/341) by microscopy and 37 % (126/341) by RDT. Compared to the reference PCR method, sensitivity was 92 % for LAMP, 78 % for microscopy, and 76 % for RDT; specificity was 97 % for LAMP, 99 % for microscopy, and 88 % for RDT. Area under the receiver operating characteristic (ROC) curve in comparison with the reference standard was 0.94 for LAMP, 0.88 for microscopy and 0.81 for RDT. Turn-around time for the entire LAMP assay was approximately 3 h and 30 min for an average of 27 ± 9.5 samples collected per day, compared to a minimum of 10 samples an hour per operator by RDT and over 8 h by microscopy. CONCLUSION: The LAMP assay could produce reliable results the same day of the screening. It could detect a higher proportion of low density malaria infections than the other methods tested and may be used for large campaigns of systematic screening and treatment
Loss of Nmp4 optimizes osteogenic metabolism and secretion to enhance bone quality
A goal of osteoporosis therapy is to restore lost bone with structurally sound tissue. Mice lacking the transcription factor Nuclear Matrix Protein 4 (Nmp4, Zfp384, Ciz, ZNF384) respond to several classes of osteoporosis drugs with enhanced bone formation compared to wild type (WT) animals. Nmp4-/- mesenchymal stem/progenitor cells (MSPCs) exhibit an accelerated and enhanced mineralization during osteoblast differentiation. To address the mechanisms underlying this hyper-anabolic phenotype, we carried out RNA-sequencing and molecular and cellular analyses of WT and Nmp4-/- MSPCs during osteogenesis to define pathways and mechanisms associated with elevated matrix production. We determined that Nmp4 has a broad impact on the transcriptome during osteogenic differentiation, contributing to the expression of over 5,000 genes. Phenotypic anchoring of transcriptional data was performed for the hypothesis-testing arm through analysis of cell metabolism, protein synthesis and secretion, and bone material properties. Mechanistic studies confirmed that Nmp4-/- MSPCs exhibited an enhanced capacity for glycolytic conversion- a key step in bone anabolism. Nmp4-/- cells showed elevated collagen translation and secretion. Expression of matrix genes that contribute to bone material-level mechanical properties were elevated in Nmp4-/- cells, an observation that was supported by biomechanical testing of bone samples from Nmp4-/- and WT mice. We conclude that loss of Nmp4 increases the magnitude of glycolysis upon the metabolic switch, which fuels the conversion of the osteoblast into a super-secretor of matrix resulting in more bone with improvements in intrinsic quality
Planet Hunters. V. A Confirmed Jupiter-Size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data
We report the latest Planet Hunter results, including PH2 b, a Jupiter-size
(R_PL = 10.12 \pm 0.56 R_E) planet orbiting in the habitable zone of a
solar-type star. PH2 b was elevated from candidate status when a series of
false positive tests yielded a 99.9% confidence level that transit events
detected around the star KIC 12735740 had a planetary origin. Planet Hunter
volunteers have also discovered 42 new planet candidates in the Kepler public
archive data, of which 33 have at least three transits recorded. Most of these
transit candidates have orbital periods longer than 100 days and 20 are
potentially located in the habitable zones of their host stars. Nine candidates
were detected with only two transit events and the prospective periods are
longer than 400 days. The photometric models suggest that these objects have
radii that range between Neptune to Jupiter. These detections nearly double the
number of gas giant planet candidates orbiting at habitable zone distances. We
conducted spectroscopic observations for nine of the brighter targets to
improve the stellar parameters and we obtained adaptive optics imaging for four
of the stars to search for blended background or foreground stars that could
confuse our photometric modeling. We present an iterative analysis method to
derive the stellar and planet properties and uncertainties by combining the
available spectroscopic parameters, stellar evolution models, and transiting
light curve parameters, weighted by the measurement errors. Planet Hunters is a
citizen science project that crowd-sources the assessment of NASA Kepler light
curves. The discovery of these 43 planet candidates demonstrates the success of
citizen scientists at identifying planet candidates, even in longer period
orbits with only two or three transit events.Comment: 35 pages, 11 figures, 6 tables, accepted and published on ApJ ApJ,
776, 1
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