julilili42/papers huggingface dataset:
Novel regulatory SNPs in the promoter region of the TNFRSF18 gene in a Gabonese population
2011-04-01

Parasites are accountable for driving diversity within immune gene families. We identified and investigated regulatory single nucleotide polymorphisms (SNPs) in the promoter regions of the tumor necrosis factor receptor superfamily member 18 (TNFRSF18) gene by direct sequencing in a group of male Gabonese individuals exposed to a wide array of parasitic diseases such as malaria, filariasis and schistosomiasis. Two new promoter variants were identified in 40 individuals. Both novel variants were heterozygous and were linked to SNP #rs3753344 (C/T), which has been described. One of the SNP variants (ss2080581728) was close to the general transcription factor site, the TATA box. We further validated these new promoter variants for their allelic gene expression using transient transfection assays. One new promoter variant with two base changes (C/T - ss2080581728/rs3753344) displayed an altered expression of the marker gene. Both novel variants remained less active at the non-induced state in comparison to the major allele. The allele frequencies observed in this study were consistent with data for other African populations. The detection and analysis of these human immune gene polymorphisms contribute to a better understanding of the interaction between host-parasite and expression of Treg activity.
Why do blind listeners use visual cortex for understanding ultra-fast speech?
2011-04-01

Individuals with vision impairment of a peripheral, e.g., retinal origin, may learn to understand spoken language at a rate of up to 22 syllables (syl) per second, exceeding by far the maximum performance level of sighted listeners (ca. 8 syl/s). To delineate the brain network subserving this skill, 14 blind individuals (different proficiency in understanding ultra-fast speech) and a sighted control group underwent functional magnetic resonance imaging. In addition to perisylvian cortex and left-hemisphere supplementary motor area (SMA), significant hemodynamic activation of right-hemisphere primary visual cortex (V1), left-hemisphere fusiform gyrus (FG), and bilateral pulvinar emerged during ultra-fast speech perception (16 syl/s) in trained blind people. Dynamic causal modeling analysis revealed skill-dependent intrinsic connections from Heschl’s gyrus (right &amp;gt; left) and pulvinar to V1, from V1 to perisylvian areas and SMA as well as from FG to Broca’s area. Conceivably, cooperation of right-hemisphere Heschl’s gyrus, V1, and left SMA enhances the temporal sequencing of syllable structure of ultra-fast utterances which, in turn, accelerates the segmentation of speech sounds at the level of perisylvian cortex and left-hemisphere FG. The pulvinar—an audiovisual relais station–might support the synchronization of V1 activity with central-auditory processing. [Work supported by the German Research Foundation (DFG; SFB 550/B1) and the Hertie Institute for Clinical Brain Research, Tuebingen.]
Functional approaches to infrared Yang-Mills theory in the Coulomb gauge
2011-04-01

We present the current status of ongoing efforts to use functional methods,\\nDyson-Schwinger equations and functional renormalization group equations, for\\nthe description of the infrared regime of nonabelian (pure) gauge theories in\\nthe Coulomb gauge. In particular, we present a new determination of the\\ncolor-Coulomb potential with the help of the functional renormalization group\\nthat results in an almost linearly rising potential between static color\\ncharges at large spatial distances.\\n
A spatially homogeneous and isotropic Einstein–Dirac cosmology
2011-04-01

We consider a spatially homogeneous and isotropic cosmological model where Dirac spinors are coupled to classical gravity. For the Dirac spinors we choose a Hartree–Fock ansatz where all one-particle wave functions are coherent and have the same momentum. If the scale function is large, the universe behaves like the classical Friedmann dust solution. If however the scale function is small, quantum effects lead to oscillations of the energy-momentum tensor. It is shown numerically and proven analytically that these quantum oscillations can prevent the formation of a big bang or big crunch singularity. The energy conditions are analyzed. We prove the existence of time-periodic solutions which go through an infinite number of expansion and contraction cycles.
Magnetic brain activity directly reflects syllable onsets and pitch periodicity of a perceived speech signal.
2011-04-01

Continuous speech evokes electrophysiological brain activity following the speech envelope (ENV), resembling the N100 responses to single acoustic events. Using magnetoencephalography (MEG), the present study tested further aspects of evoked activity, considering the positive part of the first derivative of the speech envelope (SYL), emphasizing syllable onsets, and a sinosoidal signal representing pitch periodicity (PIT), obtained by 50–180 Hz bandpass filtering of the rectified speech signal. MEG signals, recorded while the participants (n = 10) listened to 4-s portions of natural or formant-synthesized speech at a moderately fast or ultrafast speaking rate, were cross-correlated with ENV, SYL, or PIT. Using dipole models, the cross-correlated MEG signals were evaluated with respect to latency and amplitude of typical components. As expected, the ENV derivate showed an M100-like response that was stronger over the right as compared to the left hemisphere. Regarding the SYL derivate, a more anterior component could be isolated, in addition to M50/M100-like responses in the auditory system, presumably representing a late frontal component of the M50 deflection. The PIT derivate showed multiple peaks of alternating polarity bound to a central-auditory source. The strength of these MEG components depended on rate and signal type.
Archaeological Approaches to Cognitive Evolution
2011-04-01

This chapter contains sections titled: Cognitive Space and the Potential of Paleoanthropological and Archaeological Remains Theoretical Approaches to Cognitive Archaeology Anglo-American Cognitive Archaeology From Theory to Practice in Cognitive Archaeology The French Way: The Technological Concept of Chaînes Opératoires and the Schéma Conceptuel Models of Cognitive Evolution The Paleontology of Human Thought Early Homo Capabilities in the Light of Piaget's Theory From Domain-Specific Intelligence to a Fluent Mind Language and Symbolic Behavior as Milestones of Cognition The Frontal Lobe – Home of Modernity Increasing Distances Between Problems and Solutions Conclusions References
The Differential Role of SGK3 from SGK1 and SGK2 in Activation of NHE3 by Glucocorticoid
2011-04-01

NHE3 is the major Na+/H+ transporter located in the apical membrane of epithelial cells in the intestine and renal proximal tubule. We have previously shown that SGK1 is involved in activation of NHE3 by dexamethasone (DEX). In this study, we examined whether SGK2 and SGK3 are also involved in DEX stimulation of NHE3 as both SGK2 and SGK3 are expressed in the small intestine. We used PS120/NHE3V and Caco-2BBe/hNHE3V cells as the models. Overexpression of either SGK2 or SGK3 in PS120/NHE3V cells caused an increase in NHE3 activity by potentiating exocytosis of NHE3 to the plasma membrane. Importantly, in contrast to SGK1 and SGK2, SGK3-activated NHE3 occurred as early as 15 min in both PS120 and Caco2-BBe cells after DEX treatment. Similarly, kinase assay showed that SGK3 but not SGK1 or SGK2 activity was clearly increased at 15 min after DEX. Immunofluorescence staining showed that SGK3 is located in endosomes, whereas SGK1 and SGK2 are ubiquitously distributed throughout the cell. Interestingly, a mutation of SGK3 (R90A) caused disruption of its endosomal localization and delays of NHE3 activation. In addition, we showed that activation of SGK3 and SGK3-mediated NHE3 activation by DEX are dependent on glucocorticoid receptor (GR) and PI3K. In conclusion, the endosomal location of SGK3 makes it distinct from SGK1 and SGK2 by mediating an early response of NHE3 to DEX in a GR-PI3K dependent manner.
Recognizing Dynamic Scenes: Influence of Processing Orientation
2011-04-01

From face recognition studies, it is known that instructions are able to change processing orientation of stimuli, leading to an impairment of recognition performance. The present study examined instructional influences on the visual recognition of dynamic scenes. A global processing orientation without any instruction was assumed to lead to highest recognition performance, whereas instructions focusing participants' attention on certain characteristics of the event should lead to a local processing orientation with an impairment of visual recognition performance as a direct consequence. Since the pattern of results provided evidence for this hypothesis, theoretical contributions were discussed.
Lateralized processing of audiovisual speech: Combining dichotic listening with visual hemifield effects.
2011-04-01

The perception of acoustically presented speech syllables can be influenced by simultaneous visual presentation of a speaker’s face uttering different syllables. Furthermore, previous studies have shown that the visual influence on the phonetic percept depends on the video signal being presented to the left or right hemifield, indicating lateralized processing of visual phonological information. The present study, combining a dichotic listening paradigm (/pa/ and /ta/ syllables) with visual hemifield presentation, investigated the interactions between auditory right-ear advantage, visual hemifield effects, and participants’ gender. Most of the items were perceived as /ta/, /pa/, or /pta/. Apart from a strong and highly significant right-ear advantage, single consonant responses showed a right-hemifield advantage, irrespective of place of articulation and gender. By contrast, /pta/ responses were more frequent in females than males and showed an interaction of video side with place of articulation. The largest number of double articulations was perceived if right-ear /ta/ was combined with labial left-hemifield presentation and left-ear /pa/. These results can be taken as an indicator that the mechanisms resulting in a fused single-consonant percept are different from the ones leading to more complex responses requiring cross-modal combinations of phonological information.
HR outsourcing and service quality: theoretical framework and empirical evidence
2011-04-02

Purpose The purpose of this article is to analyse the relationship between HR outsourcing and service quality by focusing on motivational and incentive aspects. Design/methodology/approach The paper applies a game‐theoretic model of procurement decisions allowing for variable degrees of vertical integration and confronts the implications of its analysis with HR outsourcing data on a large sample of German firms. Findings The paper presents evidence for HR service quality being generally higher when procured from an external instead of an in‐house provider. Furthermore, the relationship between HR outsourcing and service quality is considerably stronger if the provided services are complex and if the potential for monitoring an internal provider is low. Practical implications The findings have immediate practical implications concerning the make‐or‐buy decision of HR services: the more complex the HR service under consideration and the lower the potential to monitor its in‐house provision, the more attractive is the external provision of HR services. Originality/value While most of the literature on HR outsourcing is based on transaction cost theory or follows a resource‐based approach, this paper uses a game‐theoretic model to analyse the make‐or‐buy decision of HR services, allowing the incentives of an internal or external provider to deliver high‐quality services to be focused on. Furthermore, for the empirical analysis the paper uses an original data set comprising more than 1,000 German firms.
Mitochondria can recognize and assemble fragments of a β-barrel structure
2011-04-02

β-barrel proteins are found in the outer membranes of eukaryotic organelles of endosymbiotic origin as well as in the outer membrane of Gram-negative bacteria. Precursors of mitochondrial β-barrel proteins are synthesized in the cytosol and have to be targeted to the organelle. Currently, the signal that assures their specific targeting to mitochondria is poorly defined. To characterize the structural features needed for specific mitochondrial targeting and to test whether a full β-barrel structure is required, we expressed in yeast cells the β-barrel domain of the trimeric autotransporter Yersinia adhesin A (YadA). Trimeric autotransporters are found only in prokaryotes, where they are anchored to the outer membrane by a single 12-stranded β-barrel structure to which each monomer is contributing four β-strands. Importantly, we found that YadA is solely localized to the mitochondrial outer membrane, where it exists in a native trimeric conformation. These findings demonstrate that, rather than a linear sequence or a complete β-barrel structure, four β-strands are sufficient for the mitochondria to recognize and assemble a β-barrel protein. Remarkably, the evolutionary origin of mitochondria from bacteria enables them to import and assemble even proteins belonging to a class that is absent in eukaryotes.
Peralkylated Barium Complexes
2011-04-04

Alkyl aluminate/gallate exchange: Homoleptic barium tetraethylaluminate, synthesized from [(Ba{N(SiHMe2)2}2)n] and AlEt3 according to an extended silylamide elimination protocol, can be efficiently converted into the respective tetraethylgallate complex by diethyl ether assisted [AlEt4]/[GaEt4] exchange. Distinct Group 13 metal–alkyl bonding is featured in polymeric and toluene-coordinated dibarium solid-state structures. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Synthesis and Structure of Tetrameric Germa‐closo‐dodecaborate Silver Halides
2011-04-04

Abstract The reaction of germa‐ closo ‐dodecaborate with oneequivalent of silver halide Ag X ( X = Cl, Br) leads to the tetrameric1:1 adducts [Et 3 MeN] 8 [{AgCl(GeB 11 H 11 )} 4 ] ( 1 ) and [Et 3 MeN] 8 [{AgBr(GeB 11 H 11 )} 4 ] ( 2 ). A cubane‐like structure was determined in the solid state by single‐crystal X‐ray diffraction. The compounds were characterized by crystal structure analysis, 11 B NMR spectroscopy and elemental analysis.
The Mirror Neuron System
2011-04-05

Mirror neurons are a class of visuomotor neurons in the monkey premotor and parietal cortices that discharge during the execution and observation of goal-directed motor acts. They are deemed to be at the basis of primates’ social abilities. In this review, the authors provide a fresh view about two still open questions about mirror neurons. The first question is their possible functional role. By reviewing recent neurophysiological data, the authors suggest that mirror neurons might represent a flexible system that encodes observed actions in terms of several behaviorally relevant features. The second question concerns the possible developmental mechanisms responsible for their initial emergence. To provide a possible answer to question, the authors review two different aspects of sensorimotor development: facial and hand movements, respectively. The authors suggest that possibly two different “mirror” systems might underlie the development of action understanding and imitative abilities in the two cases. More specifically, a possibly prewired system already present at birth but shaped by the social environment might underlie the early development of facial imitative abilities. On the contrary, an experience-dependent system might subserve perception-action couplings in the case of hand movements. The development of this latter system might be critically dependent on the observation of own movements.
Synthesis and Stability of Homoleptic Metal(III) Tetramethylaluminates
2011-04-05

Whereas a number of homoleptic metal(III) tetramethylaluminates M(AlMe(4))(3) of the rare earth metals have proven accessible, the stability of these compounds varies strongly among the metals, with some even escaping preparation altogether. The differences in stability may seem puzzling given that this class of metals usually is considered to be relatively uniform with respect to properties. On the basis of quantum chemically obtained relative energies and atomic and molecular descriptors of homoleptic tris(tetramethylaluminate) and related compounds of rare earth metals, transition metals, p-block metals, and actinides, multivariate modeling has identified the importance of ionic metal-methylaluminate bonding and small steric repulsion between the methylaluminate ligands for obtaining stable homoleptic compounds. Low electronegativity and a sufficiently large ionic radius are thus essential properties for the central metal atom. Whereas scandium and many transition metals are too small and too electronegative for this task, all lanthanides and actinides covered in this study are predicted to give homoleptic compounds stable toward loss of trimethylaluminum, the expected main decomposition reaction. Three of the predicted lanthanide-based compounds Ln(AlMe(4))(3) (Ln = Ce, Tm, Yb) have been prepared and fully characterized in the present work, in addition to Ln(OCH(2)tBu)(3)(AlMe(3))(3) (Ln = Sc, Nd) and [Eu(AlEt(4))(2)](n). At ambient temperature, donor-free hexane solutions of Ln(AlMe(4))(3) of the Ln(3+)/Ln(2+) redox-active metal centers display enhanced reduction to [Ln(AlMe(4))(2)](n) with decreasing negative redox potential, in the order Eu ≫ Yb ≫ Sm. Whereas Eu(AlMe(4))(3) could not be identified, Yb(AlMe(4))(3) turned out to be isolable in low yield. All attempts to prepare the putative Sc(AlMe(4))(3), featuring the smallest rare earth metal center, failed.
Identification of a blood-based biomarker panel for classification of Alzheimer's disease
2011-04-05

An ideal diagnostic test for Alzheimer's disease (AD) should be non-invasive and easily applicable. Thus, there is a clear need to search for biomarkers in blood. In the present study, we have used multivariate data analysis [support vector machine (SVM)] to investigate whether a blood-based biomarker panel allows discrimination between AD patients and healthy controls at the individual level. We collected a total of 155 serum samples from individuals with early AD and age-matched healthy controls and measured serum levels of 24 markers involved in several biological pathways by ELISA. The dataset was randomly split into a training set for predictor discovery and classification training and a test set for class prediction of blinded samples (3:1 ratio) to evaluate the chosen predictors and parameters. After selection of a feature group of the three most discriminative parameters (cortisol, von Willebrand factor, oxidized LDL antibodies) in the training set, the application of SVM to the training/independent test dataset resulted in an 81.7%/87.1% correct classification for AD and control subjects. In conclusion, we identified a panel of three blood markers, which allowed SVM-based distinguishing of AD patients from healthy controls on a single-subject classification level with clinically relevant accuracy and validity. Blood-based biomarkers might have utility in AD diagnostics as screening tool before further classification with CSF biomarkers and imaging. Future studies should examine whether blood-based biomarkers may also be useful to differentiate AD patients from other dementias.
Pharmacophore Modeling and Virtual Screening for Novel Acidic Inhibitors of Microsomal Prostaglandin E2 Synthase-1 (mPGES-1)
2011-04-05

Microsomal prostaglandin E(2) synthase-1 (mPGES-1) catalyzes prostaglandin E(2) formation and is considered as a potential anti-inflammatory pharmacological target. To identify novel chemical scaffolds active on this enzyme, two pharmacophore models for acidic mPGES-1 inhibitors were developed and theoretically validated using information on mPGES-1 inhibitors from literature. The models were used to screen chemical databases supplied from the National Cancer Institute (NCI) and the Specs. Out of 29 compounds selected for biological evaluation, nine chemically diverse compounds caused concentration-dependent inhibition of mPGES-1 activity in a cell-free assay with IC(50) values between 0.4 and 7.9 μM, respectively. Further pharmacological characterization revealed that also 5-lipoxygenase (5-LO) was inhibited by most of these active compounds in cell-free and cell-based assays with IC(50) values in the low micromolar range. Together, nine novel chemical scaffolds inhibiting mPGES-1 are presented that may possess anti-inflammatory properties based on the interference with eicosanoid biosynthesis.
Persistent Nasal Carriage of Staphylococcus aureus Is Associated with Deficient Induction of Human β-Defensin 3 after Sterile Wounding of Healthy Skin In Vivo
2011-04-05

ABSTRACT Persistent nasal carriage of Staphylococcus aureus is the primary reservoir for this pathogen and a risk factor for infection. The nares of 12 to 30% of healthy individuals are persistently colonized with staphylococci. Elucidating the yet enigmatic determinants of this phenomenon is of major public health interest. We hypothesized that differences in the levels of antimicrobial peptides (AMPs) that are found in human skin and have pronounced antistaphylococcal activity may contribute to this phenomenon. We compared constitutive and induced mRNA levels of RNase 7 and human β-defensin 3 (HBD-3) in healthy and experimentally wounded gluteal skin of 60 volunteers after ascertaining their carrier status through repeated nasal cultures. We found that levels of HBD-3 expression in skin of persistent nasal carriers of S. aureus were lower: induced levels in carriers were 63% (95% confidence interval, 43 to 94%; P = 0.02) and constitutive levels were 76% (95% confidence interval, 52 to 110%; P = 0.14) of those found in noncarriers. No such associations were present for RNase 7. In conjunction with existing knowledge, these findings suggest that healthy individuals with deficient HBD-3 expression in keratinocytes are more prone to persistent nasal colonization with S. aureus .