julilili42/papers huggingface dataset:
Steady state migratory RelB+ langerin+ dermal dendritic cells mediate peripheral induction of antigen‐specific CD4+CD25+Foxp3+ regulatory T cells
2011-03-07

Abstract Tolerance to self‐antigens expressed in peripheral organs is maintained by CD4 + CD25 + Foxp3 + Treg cells, which are generated as a result of thymic selection or peripheral induction. Here, we demonstrate that steady‐state migratory DCs from the skin mediated Treg conversion in draining lymph nodes of mice. These DCs displayed a partially mature MHC II int CD86 int CD40 hi CCR7 + phenotype, used endogenous TGF‐β for conversion and showed nuclear RelB translocation. Deficiency of the alternative NF‐κB signaling pathway (RelB/p52) reduced steady‐state migration of DCs. These DCs transported and directly presented soluble OVA provided by s.c. implanted osmotic minipumps, as well as cell‐associated epidermal OVA in transgenic K5‐mOVA mice to CD4 + OVA‐specific TCR‐transgenic OT‐II T cells. The langerin + dermal DC subset, but not epidermal Langerhans cells, mediated conversion of naive OT‐II×RAG‐1 −/− T cells into proliferating CD4 + CD25 + Foxp3 + Tregs. Thus, our data suggest that steady‐state migratory RelB + TGF‐β + langerin + dermal DCs mediate peripheral Treg conversion in response to epidermal antigen in skin‐draining lymph nodes.
Improving the performance of superconducting microwave resonators in magnetic fields
2011-03-07

The operation of superconducting coplanar waveguide cavities, as used for\\ncircuit quantum electrodynamics and kinetic inductance detectors, in\\nperpendicular magnetic fields normally leads to a reduction of the device\\nperformance due to energy dissipating Abrikosov vortices. We experimentally\\ninvestigate the vortex induced energy losses in such Nb resonators with\\ndifferent spatial distributions of micropatterned pinning sites (antidots) by\\ntransmission spectroscopy measurements at 4.2 K. In comparison to resonators\\nwithout antidots we find a significant reduction of vortex induced losses and\\nthus increased quality factors over a broad range of frequencies and applied\\npowers in moderate fields.\\n
The termination region of high-mass microquasar\\n jets
2011-03-07

\\n Context. The environment of high-mass X-ray binaries can be\\n characterized either by the supernova remnant that forms these systems or by the wind from\\n the companion massive star. These regions should be tenuous but very hot and surrounded by\\n a dense and cold shocked ISM shell. The interaction between the jet and such a complex\\n medium, also affected by the system proper motion, can lead to very different jet\\n termination structures.\\n Aims. The evolution of the jet termination regions during the life of a\\n high-mass microquasar is simulated to improve our present understanding of these\\n structures. Also, the evolving emission characteristics are modeled to inform potential\\n observational campaigns of this class of object.\\n Methods. We performed 2D numerical simulations of jets propagating in\\n different scenarios, corresponding to different epochs after the formation of the\\n high-mass X-ray binary, using the code Ratpenat. We also made simple\\n estimates of the nonthermal emission that could be produced in the jet termination\\n regions.\\n Results. We find that, in the way through the hot and tenuous medium of\\n the shocked wind/supernova ejecta, the jet suffers recollimation shocks in which it loses\\n part of its thrust and ends in a strong shock inflating a hot cocoon. The jet head\\n propagates with a speed that is similar to the medium sound speed, until it eventually\\n reaches the denser and colder shocked ISM and the unperturbed ISM later on. In these last\\n stages of evolution, the jet is significantly slowed down and can be disrupted. For\\n relatively old sources, the microquasar peculiar velocity becomes important, leading to\\n complete jet destruction. Extended nonthermal radiation can be generated in the jet\\n termination regions, and hard X-rays and TeV photons are the wavelengths best suited for\\n observing these structures. \\n
Effect of Host Tree Traits on Epiphyte Diversity in Natural and Anthropogenic Habitats in Ecuador
2011-03-08

ABSTRACT Vascular epiphytes represent a highly diverse element of tropical rain forests, but they depend strongly on the structure and taxonomic composition of their tree communities. For conservation planning, it is therefore critical to understand the effect of host tree characteristics on epiphyte species richness in natural and anthropogenically transformed vegetation. Our study compares the effect of human land‐use on epiphyte diversity based on 220 study plots in a lowland rain forest and an Andean cloud forest in western Ecuador. We evaluate the relevance of host tree size and taxonomic identity for epiphyte species richness in contiguous primary forests, forest fragments, isolated remnant trees (IRTs), and secondary forests. At both study sites, epiphyte diversity was highest in primary forests, and it was lowest on IRTs and in secondary forests. Epiphyte species numbers of forest fragments were significantly reduced compared with the contiguous primary forest at the lowland study site, but not in the cloud forest area. Host tree size was a core predictor among secondary forests, but it had less significance within other habitat types. Taxonomic identity of the host trees also explained up to 61 percent of the variation in epiphyte diversity, especially for IRTs. The structural and taxonomic composition of the tree community in anthropogenically transformed habitat types proved to be fundamental to epiphyte diversity. This highlights the importance of deliberate selection of tree species for reforestation in conservation programs and the possible negative effects of selective logging in primary forests. Abstract in Spanish is available at http://www.blackwell‐synergy.com/loi/btp .
Structure and morphology of coevaporated pentacene-perfluoropentacene thin films
2011-03-08

The structural properties of coevaporated thin films of pentacene (PEN) and perfluoropentacene (PFP) on SiO2 were studied using x-ray reflectivity and grazing incidence x-ray diffraction. Reciprocal space maps of the coevaporated thin films with different volume fractions reveal the coexistence of two different molecular mixed PEN-PFP phases together with the pure PEN and PFP crystallites. The crystal structure of PEN:PFP blends does not change continuously with volume fraction, instead the proportion of the appropriate phases changes, as seen from the diffraction analysis. Additional temperature dependent experiments reveal that the fraction of the two mixed PEN-PFP phases varies with growth temperature. The λ-phase (molecular plane parallel to the substrate) is metastable and induced by low growth temperature. The σ-phase (molecular plane nearly perpendicular to the substrate) is thermally stable and nucleates predominantly at high growth temperatures.
Modelling and simulation of [18F]fluoromisonidazole dynamics based on histology-derived microvessel maps
2011-03-08

Hypoxia can be assessed non-invasively by positron emission tomography (PET) using radiotracers such as [(18)F]fluoromisonidazole (Fmiso) accumulating in poorly oxygenated cells. Typical features of dynamic Fmiso PET data are high signal variability in the first hour after tracer administration and slow formation of a consistent contrast. The purpose of this study is to investigate whether these characteristics can be explained by the current conception of the underlying microscopic processes and to identify fundamental effects. This is achieved by modelling and simulating tissue oxygenation and tracer dynamics on the microscopic scale. In simulations, vessel structures on histology-derived maps act as sources and sinks for oxygen as well as tracer molecules. Molecular distributions in the extravascular space are determined by reaction-diffusion equations, which are solved numerically using a two-dimensional finite element method. Simulated Fmiso time activity curves (TACs), though not directly comparable to PET TACs, reproduce major characteristics of clinical curves, indicating that the microscopic model and the parameter values are adequate. Evidence for dependence of the early PET signal on the vascular fraction is found. Further, possible effects leading to late contrast formation and potential implications on the quantification of Fmiso PET data are discussed.
A new MRI rating scale for progressive supranuclear palsy and multiple system atrophy: validity and reliability
2011-03-08

The scale is suitable for use in the context of multicentre studies and can reliably and consistently measure MRI abnormalities in PSP and MSA. Clinical Trial Registration Number The study protocol was filed in the open clinical trial registry (http://www.clinicaltrials.gov) with ID No NCT00211224.
Association of TCF7L2 SNPs with age at onset of type 2 diabetes and proinsulin/insulin ratio but not with glucagon‐like peptide 1
2011-03-08

Abstract Background Variants in TCF7L2 have been associated with the age at onset of type 2 diabetes in Mexican Americans. However, there is a lack of data on this relationship in Caucasians. Furthermore, risk alleles in TCF7L2 have been suggested to account for decreased conversion of proinsulin to insulin and decreased expression of GLP‐1. We investigated the effect of the allelic variants rs1225537 and rs7903146 in TCF7L2 on the age at onset of type 2 diabetes, the plasma concentrations of proinsulin and GLP‐1, and the ratio of proinsulin to insulin in a German cohort. Methods We studied 3185 participants of the LUdwigshafen RIsk and Cardiovascular health (LURIC) study. Among these, 1021 subjects had type 2 diabetes. Data on age at onset of diabetes were available in 925 subjects. OGTTs were performed in a subgroup not previously known to have diabetes. Results Carriers of the risk alleles in rs1225537 and rs7901346 had increased risk of type 2 diabetes and elevated HbA 1c (all p &lt; 0.001). The risk alleles were also associated with early onset of type 2 diabetes, decreased insulin secretion and markedly increased proinsulin and proinsulin to insulin ratio (all p &lt; 0.03). GLP‐1 was not significantly related to the TCF7L2 genotype. Conclusions Our data demonstrate that TCF7L2 variants are associated with an early age of onset of type 2 diabetes in Caucasians and affects the conversion of proinsulin to insulin. However, TCF7L2 is not consistently associated with fasting GLP‐1. Copyright © 2011 John Wiley &amp; Sons, Ltd.
New insight on a possible mechanism of progestogens in terms of breast cancer risk
2011-03-08

Abstract Objectives: Progestogens influence mammary gland development and probably breast cancer tumorigenesis by regulating a broad spectrum of physiological processes. We investigated receptor membrane-initiated actions of progestogens in MCF-7 breast cancer cells overexpressing progesterone receptor membrane component 1 (PGRMC1). Design: MCF-7 cells were stably transfected with PGRMC1 expression plasmid (MCF-7/PGRMC1-3HA) and overexpression of PGRMC1 was verified by immune fluorescent analysis and Western blot. To test the effects of progestogens on cell proliferation, MCF-7 and MCF-7/PGRMC1-3HA cells were stimulated with a membrane-impermeable progesterone: BSA-fluorescein-isothiocyanate conjugate (P4-BSA-FITC), unconjugated progesterone (P4), medroxyprogesterone acetate (MPA), norethisterone (NET) and drospirenone (DRSP). Furthermore, reverse phase protein technology was applied to identify modified downstream signaling. Results: Progesterone did not elicit any proliferative effect on MCF-7/PGRMC1-3HA cells. By contrast, P4-BSA-FITC, DRSP, MPA and NET significantly triggered proliferation of MCF-7/PGRMC1-3HA cells, the effect being more pronounced for NET. Almost no effect of progestogens on proliferation was observed in MCF-7 cells. In MCF-7/PGRMC1-3HA cells, expression of Erk1/2 was significantly reduced by 40% compared to MCF-7 cells. Conclusions: Our data indicate that PGRMC1 mediates a progestogen-dependent proliferative signal in MCF-7 cells. Of significant interest is that progesterone and synthetic progestins that are used for hormone therapy are different in their proliferative effects on MCF-7 and MCF-7/PGRMC1-3HA cells. Progesterone appears to act neutrally, whereas MPA, NET and DRSP trigger proliferation and thus might increase breast cancer risk. The data presented are very important in terms of the positive results of progestogens and breast cancer risk in clinical studies so far.
Towards improved instrumentation for assessing river-groundwater interactions in a restored river corridor
2011-03-08

Abstract. River restoration projects have been launched over the last two decades to improve the ecological status and water quality of regulated rivers. As most restored rivers are not monitored at all, it is difficult to predict consequences of restoration projects or analyze why restorations fail or are successful. It is thus necessary to implement efficient field assessment strategies, for example by employing sensor networks that continuously measure physical parameters at high spatial and temporal resolution. This paper focuses on the design and implementation of an instrumentation strategy for monitoring changes in bank filtration, hydrological connectivity, groundwater travel time and quality due to river restoration. We specifically designed and instrumented a network of monitoring wells at the Thur River (NE Switzerland), which is partly restored and mainly channelized since more than 100 years. Our results show that bank filtration – especially in a restored section with alternating riverbed morphology – is variable in time and space. Consequently, our monitoring network sensing physical and sampling chemical water quality parameters was adapted in response to that variability. Although not available at our test site, we consider long-term measurements – ideally initialized before and continued after restoration – as a fundamental step, towards predicting consequences of river restoration for groundwater quality. As a result, process-based models could be adapted and evaluated using these types of high-resolution data sets.
The Putzig-NURF Nucleosome Remodeling Complex Is Required for Ecdysone Receptor Signaling and Innate Immunity in Drosophila melanogaster
2011-03-09

Abstract Putzig (Pzg) was originally identified as being an integral component of the TRF2/DREF complex in Drosophila melanogaster, thereby regulating the transcriptional activation of replication-related genes. In a DREF-independent manner, Pzg was shown to mediate Notch target gene activation. This function of Pzg entails an association with the nucleosome remodeling factor complex NURF, which directly binds the ecdysone receptor EcR and coregulates targets of the EcR via the NURF-specific subunit Nurf-301. In contrast, Nurf-301 acts as a negative regulator of JAK/STAT signaling. Here, we provide evidence to show that Pzg is fundamental for these functions of NURF, apart from the regulation of Notch signaling activity. A jump-out mutagenesis provided us with a pzg null mutant displaying early larval lethality, defects in growth, and molting accompanied by aberrant feeding behavior. We show that Pzg is associated with EcR in vivo and required for the transcriptional induction of EcR target genes, whereas reduced ecdysteroid levels imply a NURF-independent function of Pzg. Moreover, pzg interferes with JAK/STAT-signaling activity by acting as a corepressor of Ken. Lamellocyte differentiation was consistently affected in a JAK/STAT mutant background and the expression level of defense response genes was elevated in pzg mutants, leading to the formation of melanotic tumors. Our results suggest that Pzg acts as an important partner of NURF in the regulation of EcR and JAK/STAT signaling.
Differential effects of intranasal insulin and caffeine on cerebral blood flow
2011-03-09

Abstract Insulin is an important modulator of brain functions such as memory and appetite regulation. Besides the effect on neuronal activity, it is also possible that insulin has a direct vasodilatory effect on cerebral blood flow (CBF). We investigated the impact of increased insulin levels in the central nervous system on basal and task‐induced CBF as well as blood oxygenation level‐dependent (BOLD) response in the visual cortex using pulsed arterial spin‐labeling MRI. An intranasal insulin application was used to avoid peripheral hyperinsulinaemia, which would lead to a cascade of hormonal changes. In a control experiment, caffeine was applied due to its well‐known impact on the vasculature of the brain leading to a reliable reduction of CBF. Eight lean subjects were included in the study. On 2 separate days, intranasal human insulin or caffeine tablets were given to the subjects after fasting over night. On each day, basal CBF and task‐induced CBF were measured before and 30 min after application of insulin or caffeine in each subject. During the task condition, a flickering checkerboard was presented. Insulin had no effect on basal CBF and task‐induced CBF in comparison with drug‐free baseline measurement in the visual cortex and control regions. After caffeine application, however, there was a significant decrease of CBF during stimulation in the visual cortex. The BOLD response was not altered by insulin or caffeine between pre‐ and postdose measurements. In conclusion, we found no evidence for a direct vasodilatory effect of intranasal insulin on the cerebral vascular system in this study. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
Staphylococcus aureus physiological growth limitations: Insights from flux calculations built on proteomics and external metabolite data
2011-03-09

Abstract Comparing proteomics and metabolomics allows insights into Staphylococcus aureus physiological growth. We update genome and proteome information and deliver strain‐specific metabolic models for three S. aureus strains (COL, N315, and Newman). We find a number of differences in metabolism and enzymes. Growth experiments (glucose or combined with oxygen limitation) were conducted to measure external metabolites. Fluxes of the central metabolism were calculated from these data with low error. In exponential phase, glycolysis is active and amino acids are used for growth. In later phases, dehydroquinate synthetase is suppressed and acetate metabolism starts. There are strain‐specific differences for these phases. A time series of 2‐D gel protein expression data on COL strain delivered a second data set (glucose limitation) on which fluxes were calculated. The comparison with the metabolite‐predicted fluxes shows, in general, good correlation. Outliers point to different regulated enzymes for S. aureus COL under these limitations. In exponential growth, there is lower activity for some enzymes in upper glycolysis and pentose phosphate pathway and stronger activity for some in lower glycolysis. In transition phase, aspartate kinase is expressed to meet amino acid requirements and in later phases there is high expression of glyceraldehyde‐3‐phosphate dehydrogenase and lysine synthetase. Central metabolite fluxes and protein expression of their enzymes correlate in S. aureus .
Antibody Responses to a Spore Carbohydrate Antigen as a Marker of Nonfatal Inhalation Anthrax in Rhesus Macaques
2011-03-09

ABSTRACT The Bacillus anthracis exosporium protein BclA contains an O-linked antigenic tetrasaccharide whose terminal sugar is known as anthrose (J. M. Daubenspeck et al., J. Biol. Chem. 279:30945–30953, 2004). We hypothesized that serologic responses to anthrose may have diagnostic value in confirming exposure to aerosolized B. anthracis . We evaluated the serologic responses to a synthetic anthrose-containing trisaccharide (ATS) in a group of five rhesus macaques that survived inhalation anthrax following exposure to B. anthracis Ames spores. Two of five animals (RM2 and RM3) were treated with ciprofloxacin starting at 48 hours postexposure and two (RM4 and RM5) at 72 h postexposure; one animal (RM1) was untreated. Infection was confirmed by blood culture and detection of anthrax toxin lethal factor (LF) in plasma. Anti-ATS IgG responses were determined at 14, 21, 28, and 35 days postexposure, with preexposure serum as a control. All animals, irrespective of ciprofloxacin treatment, mounted a specific, measurable anti-ATS IgG response. The earliest detectable responses were on days 14 (RM1, RM2, and RM5), 21 (RM4), and 28 (RM3). Specificity of the anti-ATS responses was demonstrated by competitive-inhibition enzyme immunoassay (CIEIA), in which a 2-fold (wt/wt) excess of carbohydrate in a bovine serum albumin (BSA) conjugate of the oligosaccharide (ATS-BSA) effected &gt;94% inhibition, whereas a structural analog lacking the 3-hydroxy-3-methyl-butyryl moiety at the C-4" of the anthrosyl residue had no inhibition activity. These data suggest that anti-ATS antibody responses may be used to identify aerosol exposure to B. anthracis spores. The anti-ATS antibody responses were detectable during administration of ciprofloxacin.
Impact of oncogenic K-RASon YB-1 phosphorylation induced by ionizing radiation
2011-03-10

IR induces YB-1 phosphorylation. YB-1 phosphorylation induced by oncogenic K-Ras or IR enhances repair of DNA-DSB and postirradiation survival via erbB1 downstream PI3K/Akt and MAPK/ERK signaling pathways.
Object-based Neglect Varies with Egocentric Position
2011-03-10

Abstract Different reference frames have been identified to influence neglect behavior. In particular, neglect has been demonstrated to be related to the contralesional side of the subject's body (egocentric reference frames) as well as to the contralesional side of individual objects irrespective of their position to the patient (object-based reference frame). There has been discussion whether this distinction separates neglect into body- and object-based forms. The present experiment aimed to prove possible interactions between object-based and egocentric aspects in spatial neglect. Neglect patients' eye and head movements were recorded while they explored objects at five egocentric positions along the horizontal dimension of space. The patients showed both egocentric as well as object-based behavior. Most interestingly, data analysis revealed that object-based neglect varied with egocentric position. Although the neglect of the objects' left side was strong at contralesional egocentric positions, it ameliorated at more ipsilesional egocentric positions of the objects. The patients showed steep, ramp-shaped patterns of exploration for objects located on the far contralesional side and a broadening of these patterns as the locations of the objects shifted more to the ipsilesional side. The data fitted well with the saliency curves predicted by a model of space representation, which suggests that visual input is represented in two modes simultaneously: in veridical egocentric coordinates and in within-object coordinates.