julilili42/papers huggingface dataset:
Tectono-metamorphic evolution of the Wadi Hafafit Culmination (central Eastern Desert, Egypt). Implication for Neoproterozoic core complex exhumation in NE Africa
2009-04-28

The Neoproterozoic rock assemblages in the Wadi Hafafit Culmination (WHC) can be subdivided into two main units which are separated by the Nugrus Thrust. The structurally higher Nugrus unit is mainly composed of low grade micaschists, metavolcanic, serpentinites, and metagabbros. The overthrusted Hafafit unit forms the Hafafit domes and is composed of ortho- and para-gneisses associated with amphibolite and ultramafic rocks. Mineral chemistry and thermobarometry indicate that the WHC was affected by two main metamorphic phases. The first metamorphic phase (M1), observed in the micaschists of the Nugrus unit, is characterized by greenschist- facies conditions. Garnet-biotite and garnet-muscovite geothermometry, as well as temperatures calculated by means of the TWEEQU program yield temperatures of 400°–550°C, whereas the white mica geobarometer reveals pressure of 3.7-4.9 kbar for this metamorphic phase (M1). The second metamorphic phase (M2), observed in gneisses and amphibolites of the Hafafit unit, is characterized by amphibolite-facies conditions. Garnet-biotite, garnet-amphibole and amphibole-plagioclase geothermometry yield temperatures of 600°–750°C, whereas the garnet-hornblende-plagioclase-quartz geobarometer indicates pressures of 6-8 kbar for the second metamorphic phase (M2). Sm-Nd and Rb-Sr whole rock-mineral isochron ages around 590 Ma for gneisses and amphibolites probably represent cooling from the metamorphic thermal peak which was attained around 600 Ma or slightly earlier. A 3-stage geologic evolution model is proposed for the tectonic evolution of the WHC. The first stage started earlier than 680 Ma ago with rifting and ocean floor spreading at a time which is as yet unspecified. It was followed by a second stage of subduction and emplacement of subduction-related granitoids around 620-640 Ma. At this time, the Hafafit region has become an active margin with the production of large amounts of calc-alkaline subduction-related volcanic and plutonic sequences. Subduction was terminated by collision and NW-ward Nugrus Nappe thrusting under greenschist-facies conditions (M1) around 620-640 Ma. At this stage, rocks of Hafafit unit were subjected to intense deformation and metamorphism in amphibolite facies (M2). Next came the third stage of late-orogenic extension and crustal thinning that was controlled by the Najd transform faults (620-580 my) and that resulted in exhumation of the Hafafit domes through a combination of transpression and lateral extrusion.
AGE–modified albumin containing infusion solutions boosts septicaemia and inflammation in experimental peritonitis
2009-04-28

Abstract Advanced glycation endproducts (AGEs) act as potential contaminants of infusion solutions boosting inflammation in experimental sepsis. HSA preparations for i.v. use are administered in critically ill patients. Although increasing intravascular osmotic pressure seems to be a pathophysiologically orientated treatment, clinical trials do not indicate a benefit for mortality in HSA–treated patients. Instead, there is evidence for inflammatory reactions upon infusion of different HSA batches. A neglected issue concerning the safety and quality of these therapeutics is processing–related post–transcriptional protein modifications, such as AGEs. We therefore tested the hypothesis that commercially available infusion solutions contain AGEs and studied whether these protein modifications influence outcome and inflammation in a murine model of sepsis induced by CLP. Screening of different HSA and Ig preparations in this study revealed an up to approximate tenfold difference in the amount of AGE modifications. Application of clinically relevant concentrations of CML–modified HSA in CLP led to increased inflammation and enhanced mortality in wild–type mice but not in mice lacking the RAGE. Lethality was paralleled by increased activation of the proinflammatory transcription factor NF–κB, NF–κB–dependent gene expression, and infiltration of inflammatory cells in the peritoneal cavity. This study implies that infusion solutions containing a high load of the AGE–modified protein have the potential to activate RAGE/NF–κB–mediated inflammatory reactions, causing increased mortality in experimental peritonitis.
pH measurement as quality control on human post mortem brain tissue: a study of the BrainNet Europe consortium
2009-04-29

Aims: Most brain diseases are complex entities. Although animal models or cell culture experiments mimic some disease aspects, human post mortem brain tissue remains essential to advance our understanding of brain diseases using biochemical and molecular techniques. Post mortem artefacts must be properly understood, standardized, and either eliminated or factored into such experiments. Here we examine the influence of several premortem and post mortem factors on pH, and discuss the role of pH as a biochemical marker for brain tissue quality. Methods: We assessed brain tissue pH in 339 samples from 116 brains provided by 8 different European and 2 Australian brain bank centres. We correlated brain pH with tissue source, post mortem delay, age, gender, freezing method, storage duration, agonal state and brain ischaemia. Results: Our results revealed that only prolonged agonal state and ischaemic brain damage influenced brain tissue pH next to repeated freeze/thaw cycles. Conclusions: pH measurement in brain tissue is a good indicator of premortem events in brain tissue and it signals limitations for post mortem investigations.
Detection of very high energy radiation from HESS J1908+063 confirms the Milagro unidentified source MGRO J1908+06
2009-04-29

Aims. Detection of a γ-ray source above 300 GeV is reported, confirming the unidentified source MGRO J1908+06, discovered by the Milagro collaboration at a median energy of 20 TeV. Methods. The source was observed during 27 h as part of the extension of the HESS Galactic plane survey to longitudes &gt;30◦. Results. HESS J1908+063 is detected at a significance level of 10.9σ with an integral flux above 1 TeV of (3.76 ± 0.29 stat± 0.75sys) × 10−12 ph cm−2 s−1, and a spectral photon index Γ = 2.10 ± 0.07 stat ± 0.2sys. The positions and fluxes of HESS J1908+063 and MGRO J1908+06 are in good agreement. Possible counterparts at other wavelengths and the origin of the γ-ray emission are discussed. The nearby unidentified GeV source, GRO J1908+0556 (GeV) which also remains unidentified and the new Fermi pulsar 0FGL J1907.5+0617, may be connected to the TeV source.
Updating the orbital ephemeris of Hercules X-1; rate of decay and eccentricity of the orbit
2009-04-29

We present an update of the orbital ephemeris of the binary X-ray pulsar Her\\nX-1 and determine an improved value for the rate of orbital decay. In addition,\\nwe report the first measurement of the orbital eccentricity. We have analyzed\\npulse timing data of Her X-1 from X-ray observations by RXTE (Rossi X-Ray\\nTiming Explorer) and INTEGRAL over the period 1996-2007. Accurate pulse arrival\\ntimes were determined from solar system bary-centered photon arrival times by\\ngenerating pulse profiles averaged over appropriately short integration times.\\nApplying pulse phase connection techniques, it was possible to determine\\nsufficiently accurate local ephemeris data for seven observation periods\\ndistributed over 12 years. Combining the new local T90 values with historical\\nvalues from the literature we update the orbital ephemeris of Her X-1 to T90 =\\nMJD 46359.871940(6) and Porb = 1.700167590(2) d and measure a continuous change\\nof the orbital period of dPorb/dt = -(4.85 +/- 0.13) x 10-11 s/s. For the first\\ntime, a value for the eccentricity of the orbit of Her X-1 is measured to be e\\n= (4.2 +/- 0.8) x 10-4.\\n
Models of magnetized neutron star atmospheres: thin atmospheres and partially ionized hydrogen atmospheres \\nwith vacuum polarization
2009-04-29

\\n Context. Observed X-ray spectra of some isolated magnetized neutron stars \\ndisplay absorption features, sometimes interpreted as ion cyclotron lines. Modeling the observed spectra is necessary to check this hypothesis and to evaluate neutron star parameters.\\n Aims. We develop a computer code for modeling magnetized neutron star atmospheres\\nin a wide range of magnetic fields ( G) and\\neffective temperatures ( K). Using this code, we study the possibilities to explain the soft X-ray spectra of isolated neutron stars\\nby different atmosphere models.\\n Methods. The atmosphere is assumed to consist either of fully ionized electron-ion plasmas or of partially ionized hydrogen. Vacuum resonance and partial mode conversion are taken into account. Any inclination of the magnetic field relative\\nto the stellar surface is allowed. We use modern opacities of fully or partially ionized plasmas in strong magnetic fields and solve the coupled radiative transfer equations for the normal electromagnetic modes in the plasma.\\n Results. Spectra of outgoing radiation are calculated for various atmosphere models:\\nfully ionized semi-infinite atmosphere, thin atmosphere, partially ionized hydrogen atmosphere, or novel “sandwich” atmosphere (thin atmosphere with a hydrogen layer above a helium layer). Possibilities of applications of these results are discussed. In particular, the outgoing spectrum using the “sandwich” model is constructed. Thin partially ionized hydrogen atmospheres with vacuum polarization are shown to be able to improve the fit to the observed spectrum of the nearby isolated neutron star RBS 1223 (RX J1308.8+2127).\\n
Models of magnetized neutron star atmospheres: thin atmospheres and partially ionized hydrogen atmospheres with vacuum polarization
2009-04-29

Observed X-ray spectra of some isolated magnetized neutron stars display absorption features, sometimes interpreted as ion cyclotron lines. Modeling the observed spectra is necessary to check this hypothesis and to evaluate neutron star parameters.We develop a computer code for modeling magnetized neutron star atmospheres in a wide range of magnetic fields (10^{12} - 10^{15} G) and effective temperatures (3 \\times 10^5 - 10^7 K). Using this code, we study the possibilities to explain the soft X-ray spectra of isolated neutron stars by different atmosphere models. The atmosphere is assumed to consist either of fully ionized electron-ion plasmas or of partially ionized hydrogen. Vacuum resonance and partial mode conversion are taken into account. Any inclination of the magnetic field relative to the stellar surface is allowed. We use modern opacities of fully or partially ionized plasmas in strong magnetic fields and solve the coupled radiative transfer equations for the normal electromagnetic modes in the plasma. Spectra of outgoing radiation are calculated for various atmosphere models: fully ionized semi-infinite atmosphere, thin atmosphere, partially ionized hydrogen atmosphere, or novel "sandwich" atmosphere (thin atmosphere with a hydrogen layer above a helium layer. Possibilities of applications of these results are discussed. In particular, the outgoing spectrum using the "sandwich" model is constructed. Thin partially ionized hydrogen atmospheres with vacuum polarization are shown to be able to improve the fit to the observed spectrum of the nearby isolated neutron star RBS 1223 (RX J1308.8+2127).
Quasi-periodic propagation in time of some classical/quantum systems: Nielsen's conserved quantity and Floquet properties
2009-04-29

We consider classical and quantum propagators for two different time intervals. If these propagators follow one another in a Fibonacci sequence we get a discrete quasiperiodic system. A theorem due to Nielsen provides a novel conserved quantity for this system. The Nielsen quantity controls the transition between commutative and non-commutative propagation in time. The quasiperiodically kicked oscillator moreover is dominated by quasiperiodic analogues of the Floquet theorem.
Flg22 regulates the release of an ethylene response factor substrate from MAP kinase 6 in Arabidopsis thaliana via ethylene signaling
2009-04-30

Mitogen-activated protein kinase (MAPK)–mediated responses are in part regulated by the repertoire of MAPK substrates, which is still poorly elucidated in plants. Here, the in vivo enzyme–substrate interaction of the Arabidopsis thaliana MAP kinase, MPK6, with an ethylene response factor (ERF104) is shown by fluorescence resonance energy transfer. The interaction was rapidly lost in response to flagellin-derived flg22 peptide. This complex disruption requires not only MPK6 activity, which also affects ERF104 stability via phosphorylation, but also ethylene signaling. The latter points to a novel role of ethylene in substrate release, presumably allowing the liberated ERF104 to access target genes. Microarray data show enrichment of GCC motifs in the promoters of ERF104–up-regulated genes, many of which are stress related. ERF104 is a vital regulator of basal immunity, as altered expression in both erf104 and overexpressors led to more growth inhibition by flg22 and enhanced susceptibility to a non-adapted bacterial pathogen.
The relationship between homework time and achievement is not universal: evidence from multilevel analyses in 40 countries
2009-04-30

Although homework is generally believed to be an important supplement to in-school learning, research has not yet fully clarified the relationship between homework and achievement. This cross-cultural study analyzed the relationship between homework time and mathematics achievement drawing on data from 231,759 students in 9,791 schools and 40 countries who participated in the Programme for International Student Assessment (PISA) 2003. Multilevel analyses found a positive association between school-average homework time and mathematics achievement in almost all countries, but the size of the association decreased considerably once socioeconomic background and school track were controlled. At the student level, no clear-cut relationship was established between homework time and achievement across the 40 countries. The results highlight the need to use multilevel analyses and to control for confounding variables in homework research.
Effect of deviation of nuchal translucency measurements on the performance of screening for trisomy 21
2009-04-30

Abstract Objectives To examine the effect of deviations in median nuchal translucency thickness (NT) and the spread in measurements on the performance of screening for trisomy 21 by maternal age and fetal NT, and by maternal age, fetal NT and maternal serum biochemistry. Methods We simulated the NT and multiples of the median values for pregnancy‐associated plasma protein‐A (PAPP‐A) and free β‐human chorionic gonadotropin (β‐hCG) for 500 000 euploid and 500 000 trisomy 21 pregnancies at 12 weeks of gestation. Detection rates for trisomy 21 and false‐positive rates were calculated without adjustments in NT and by adding or subtracting values ranging from 0.1 to 1.0 mm to each observed measurement. In addition, the effects of variation in the scatter of NT measurements were examined by applying a multiplicative factor ranging from 0.5 to 2 to the SD. Results The detection rate of trisomy 21 for a fixed false‐positive rate of 3% in screening by maternal age and fetal NT was 72%, and in screening by maternal age, fetal NT and serum free β‐hCG and PAPP‐A it was 86%. A consistent underestimate or overestimate in the measured NT reduced the detection rate of trisomy 21 for a fixed‐false positive rate. At a fixed screen‐positive cut‐off an underestimate in fetal NT reduced the detection rate whereas an overestimate in NT increased the false‐positive rate. A widening in the scatter of measurements had only a small impact on the detection rate but it caused a major increase in the false‐positive rate. Conclusions High performance of screening necessitates appropriate measurement of fetal NT. This paper demonstrates the effect of deviations in the median and SD of NT from the expected on the performance of screening and can form the basis of audit of results of individual sonographers. Copyright © 2009 ISUOG. Published by John Wiley &amp; Sons, Ltd.
Consumption volatility and financial openness
2009-04-30

Abstract\\n Economic theory predicts that the integration of financial markets lowers the volatility of consumption. In this paper, we study long-term trends in the consumption volatility of the G7 countries. Using different measures of financial openness, we find evidence that greater financial openness has been associated with lower consumption volatility. However, volatility of consumption relative to output has not declined.
Path following for an omnidirectional mobile robot based on model predictive control
2009-05-01

In this paper, the path following problem of an omnidirectional mobile robot has been studied. Given the error dynamic model derived from the robot state vector and the path state vector, model predictive control (MPC) is employed to design the control law, which can deal explicitly with the rate of progression of a virtual vehicle to be followed along the path. The distinct advantage over other control strategies is that input and system constraints are able to be handled straightforwardly in the optimization problem so that the robot can travel safely with a high velocity. Unlike nonholonomic mobile robots, omnidirectional mobile robots, which we focus on in this paper, have simultaneously and independently controlled rotational and translational motion capabilities. Then, our purposed MPC controller was validated by experiments with a real omnidirectional mobile robot.
Five Polymorphisms and Breast Cancer Risk: Results from the Breast Cancer Association Consortium
2009-05-01

Abstract Previous studies have suggested that minor alleles for ERCC4 rs744154, TNF rs361525, CASP10 rs13010627, PGR rs1042838, and BID rs8190315 may influence breast cancer risk, but the evidence is inconclusive due to their small sample size. These polymorphisms were genotyped in more than 30,000 breast cancer cases and 30,000 controls, primarily of European descent, from 30 studies in the Breast Cancer Association Consortium. We calculated odds ratios (OR) and 95% confidence intervals (95% CI) as a measure of association. We found that the minor alleles for these polymorphisms were not related to invasive breast cancer risk overall in women of European descent: ECCR4 per-allele OR (95% CI) = 0.99 (0.97-1.02), minor allele frequency = 27.5%; TNF 1.00 (0.95-1.06), 5.0%; CASP10 1.02 (0.98-1.07), 6.5%; PGR 1.02 (0.99-1.06), 15.3%; and BID 0.98 (0.86-1.12), 1.7%. However, we observed significant between-study heterogeneity for associations with risk for single-nucleotide polymorphisms (SNP) in CASP10, PGR, and BID. Estimates were imprecise for women of Asian and African descent due to small numbers and lower minor allele frequencies (with the exception of BID SNP). The ORs for each copy of the minor allele were not significantly different by estrogen or progesterone receptor status, nor were any significant interactions found between the polymorphisms and age or family history of breast cancer. In conclusion, our data provide persuasive evidence against an overall association between invasive breast cancer risk and ERCC4 rs744154, TNF rs361525, CASP10 rs13010627, PGR rs1042838, and BID rs8190315 genotypes among women of European descent. (Cancer Epidemiol Biomarkers Prev 2009;18(5):1610–6)
A new species ofPalatobaena(Testudines: Baenidae) and a maximum parsimony and Bayesian phylogenetic analysis of Baenidae
2009-05-01

New Palatobaena material from the Hell Creek Formation (Maastrichtian), including the first skull and shell association, from southwestern North Dakota represents a new species named herein Palatobaena cohen. the material consists of 4 skulls, 2 lower jaws, and 2 shells and represents a true biological population (spatially and temporally restricted), which provides unprecedented access to ontogenetic and other intraspecific variation found in this taxon. the skull's round shape and lack of a lingual ridge on the greatly expanded triturating surface indicate its Palatobaena affinities, but it differs from both previously existing Palatobaena taxa in a number of features. the addition of shell characters to the most inclusive baenid phylogenetic analyses (Maximum parsimony and Bayesian) to date indicate that Pa. cohen is sister taxon to the other Palatobaena taxa. Notably, both the maximum parsimony analysis and Bayesian analysis provide strong support for Plesiobaena antiqua as sister to the Palatobaena clade. in addition, both analyses provide strong support for Stygiochelys estesi as sister to the Eocene clade of Baena arenosa and Chisternon undatum , which significantly reduces this clades' ghost lineage. the baenid topology reveals a demonstrably homoplastic trend towards the reduction of the temporal emargination and unique thickening of the posterior portion of the parietals that corresponds with the K/T boundary and is hypothesized to have provided limited protection from increasingly effective mammalian predators.
Successful Structure-Based Design of Recent p38 MAP Kinase Inhibitors
2009-05-01

Inflammation is a complex immune response to cellular and tissue damage caused by physical, chemical, immunological, or microbial stimuli [1]. Prior to the successful launch of the anti-cytokine biologics [2-4], therapeutic approaches for the treatment of chronic inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease were associated with severe side effects. Although biological agents have revolutionized the treatment of inflammatory disorders, the high costs and inconvenient dosing regimens would greatly benefit from novel safe and effective orally active inhibitors of tumor necrosis factor (TNF) alpha and interleukin (IL) 1beta. The clinical benefit of anti-cytokine therapy [5] and the central role of the p38 mitogen-activated protein (MAP) kinase in up-regulation of pro-inflammatory cytokines such as IL-1beta and TNF-alpha [6] suggest that p38 MAP kinase is a promising target for anti-inflammatory therapy [7-14]. Since 1993 an immense number of inhibitors of p38 MAP kinase have been characterized. To date, aside from the well known pyridinylimidazoles, multiple novel scaffolds have been identified, but only a small number have advanced into clinical phase II studies [15], probably due to high toxicity and poor selectivity [16]. To gain safe drug profiles, high potency, marginal CYP450 (cytochrome P450) interaction and toxicity, as well as high levels of selectivity would be desirable. This review will summarize current knowledge on p38 MAP kinase inhibitors and will critically discuss proceedings and strategies toward achieving selectivity and potency.
Visualization of Group Members' Participation
2009-05-01

Previous research has shown that people involved in a computer-mediated information-exchange situation are strongly influenced by the behavior of other participants. In order to avoid being exploited by the other group members, people use the current cooperation level of the rest of the group as an orientation for their own willingness to cooperate. In a highly cooperative group, this leads to a positive development. However, the question arises as to how a negative development can be dealt with, without reinforcing a mutual decline in cooperation. In order to empirically answer this question, the study reported here considers an idea from information-visualization research and experimentally varies information presentation formats. Results show that a cumulative information presentation format supports people's contribution behavior. Moreover, the highest cooperation rate was found for those individuals with a dispositionally high need to engage in social comparison in a situation with a cumulative group feedback format.