julilili42/papers huggingface dataset:
ARHGEF7 (BETA-PIX) Acts as Guanine Nucleotide Exchange Factor for Leucine-Rich Repeat Kinase 2
2010-10-29

Downstream effects of phosphorylation of ARHGEF7 through LRRK2 could be (i) a feedback control mechanism for LRRK2 activity as well as (ii) an impact of LRRK2 on actin cytoskeleton regulation. A newly identified familial mutation N1437S, localized within the GTPase domain of LRRK2, further underlines the importance of the GTPase domain of LRRK2 in Parkinson's disease pathogenesis.
Mechanism of 2-oxoglutarate signaling by the Synechococcus elongatus P II signal transduction protein
2010-11-01

P II proteins control key processes of nitrogen metabolism in bacteria, archaea, and plants in response to the central metabolites ATP, ADP, and 2-oxoglutarate (2-OG), signaling cellular energy and carbon and nitrogen abundance. This metabolic information is integrated by P II and transmitted to regulatory targets (key enzymes, transporters, and transcription factors), modulating their activity. In oxygenic phototrophs, the controlling enzyme of arginine synthesis, N -acetyl-glutamate kinase (NAGK), is a major P II target, whose activity responds to 2-OG via P II . Here we show structures of the Synechococcus elongatus P II protein in complex with ATP, Mg 2+ , and 2-OG, which clarify how 2-OG affects P II –NAGK interaction. P II trimers with all three sites fully occupied were obtained as well as structures with one or two 2-OG molecules per P II trimer. These structures identify the site of 2-OG located in the vicinity between the subunit clefts and the base of the T loop. The 2-OG is bound to a Mg 2+ ion, which is coordinated by three phosphates of ATP, and by ionic interactions with the highly conserved residues K58 and Q39 together with B- and T-loop backbone interactions. These interactions impose a unique T-loop conformation that affects the interactions with the P II target. Structures of P II trimers with one or two bound 2-OG molecules reveal the basis for anticooperative 2-OG binding and shed light on the intersubunit signaling mechanism by which P II senses effectors in a wide range of concentrations.
Modelling the Extensive Margin of World Trade: New Evidence on GATT and WTO Membership
2010-11-01

Recent literature has argued that, contrary to the results of a seminal paper by Rose (2004), General Agreement on Tariffs and Trade (GATT)/World Trade Organization (WTO) membership does promote bilateral trade, at least for developed economies and if membership includes non-formal compliance. We review the literature to identify open issues. We then develop a simple extension of the gravity model that gives rise to an extensive country margin of trade separating positive trade from zero trade country pairs. The model is used to identify WTO membership effects at both the intensive and the extensive margins. Empirical estimation of this model, based on Poisson pseudo‐maximum likelihood methods with exporter and importer fixed effects, allows us to readdress the empirical issue of whether GATT/WTO membership does or does not promote trade. We find that GATT membership was successful on the extensive margin of world trade but not on the intensive margin. For the recent WTO episode (1995–2008), we find consistent and robust evidence for a substantial trade‐creating role of membership which is driven primarily by the intensive margin. WTO membership results in higher bilateral trade of about 40 per cent.
RELATIVISTIC EFFECTS IN NUCLEAR MATTER AND NUCLEI
2010-11-01

The status of relativistic nuclear many-body calculations of nuclear systems to be built up in terms of protons and neutrons is reviewed. In detail, relativistic effects on several aspects of nuclear matter such as the effective mass, saturation mechanism, and the symmetry energy are considered. This review will especially focus on isospin asymmetric issues, since these aspects are of high interest in astrophysical and nuclear structure studies. Furthermore, from the experimental side these aspects are experiencing an additional boost from a new generation of radioactive beam facilities, e.g., the future GSI facility FAIR in Germany or SPIRAL2 at GANIL/France. Finally, the prospects of studying finite nuclei in microscopic calculations which are based on realistic NN interactions by including relativistic effects in calculations of low momentum interactions are discussed.
Precise time of flight measurements in IEEE 802.11 networks by cross-correlating the sampled signal with a continuous Barker code
2010-11-01

Wireless LAN devices can be used for two-way time of arrival (TOA) measurements even with off-the-shelf hardware that has only a measurement resolution of 1 μs. However, to get a good locating and tracking performance the send and arrival times as well as the durations of IEEE 802.11 MAC packets must be measured precisely. In this paper, we calculate a cross-correlation between the received and sampled signal and a time continuous Barker code sequence to determine the TOA. Our adaptive sampling offset algorithm helps to efficiently obtain a subsample resolution. We implemented our algorithm and an IEEE 802.11 receiver as a Software-Defined-Radio (SDR) program. In our experiments, the algorithm needs fewer observations in comparison to previously published approaches that measure the time of flight between two WLAN devices.
Chimeric receptors of theArabidopsis thalianapattern recognition receptors EFR and FLS2
2010-11-01

FLS2 and EFR are pattern recognition receptors in Arabidopsis thaliana perceiving the bacterial proteins flagellin and Elongation factor Tu (EF-Tu). Both receptors belong to the > 200 membered protein family of Leucine-Rich Repeat Receptor Kinases (LRR-RKs) in Arabidopsis. FLS2 and EFR are engaged in the activation of a common intracellular signal output and they belong to the same subfamily of LRR-RKs, sharing structural features like the intracellular kinase domain and the ectodomain organized in LRRs. On the amino acid sequence level, however, they are only < 50 % identical even in their kinase domains. In our recently published paper1 we demonstrated that it is possible to create chimeric receptors of EFR and FLS2 which are fully functional in ligand binding and receptor activation. Chimeric receptors consisting of the complete EFR ectodomain and the FLS2 kinase domain proved to be sensitive to elf18, the minimal peptide required for EF-Tu recognition, similar to the native EFR. In chimeric receptors where parts of the FLS2 ectodomain were swapped into the EFR LRR-domain, the receptor function was strongly affected even in cases with only small fragments exchanged. In this addendum we want to address problems and limits but also possibilities and chances of studying receptor functions using a chimeric approach.
A microsensor system to probe physiological environments and tissue response
2010-11-01

Foreign body responses and bio-fouling caused by the physiological environment impair sensor performance due to alteration of the sensor/tissue interface. For in vivo applications longterm stability is a critical prerequisite and often affected due to host response towards the implant. In order to assess tissue response towards implants, we propose continuous measurements at the implant/tissue interface employing a microsensor device placed in contact with the chorioallantoic membrane (CAM) of the avian embryo. We introduce a biostable microsensor implant (MSI) to measure oxygen, pH and electrical impedance in situ. These parameters were chosen for their sensitivity with respect to the composition and properties of biological tissue. Micro fabrication technology in combination with electrochemical electrode functionalization was used to combine all sensors in a small planar array. The chorioallantoic membrane assay (CAM-assay) of avian ex ovo cultures served as a quasi-in vivo environment. Here we established an immune-active and -deficient in vivo model, enabling comparison between weak and strong immune responses in the same organism. A miniaturized potentiostat unit ("MiniPot") was developed for controlling the MSI in humid culture environments. Here we performed continuous measurements of all sensor parameters at the implant/tissue interface with the microsensor device placed in contact with the CAM of the avian embryo.
Therapeutic implications of the enhanced short and long-term cytotoxicity of radiation treatment followed by oncolytic Parvovirus H-1 infection in high-grade glioma cells
2010-11-01

The prognosis of malignant brain tumors remains extremely bad in spite of moderate improvements of conventional treatments. A promising alternative approach is the use of oncolytic viruses. Strategies to improve viral toxicity include the combination of oncolytic viruses with standard therapies. Parvovirus H-1 (H-1PV) is an oncolytic virus with proven toxicity in glioma cells. Recently it has been demonstrated that the combination of ionizing radiation (IR) with H-1PV showed promising results. Previously irradiated glioma cells remained fully permissive for H-1PV induced cytotoxicity supporting the use of H-1PV for recurrent gliomas, which typically arise from irradiated cell clones. When glioma cells were infected with H-1PV shortly (24 h) after IR, cell killing improved and only the combination of both treatments lead to complete long-term tumor cell killing. The latter finding raises the question whether IR in combination with H-1PV exerts an additional therapeutic effect on highly resistant glioma stem cells. A likely translation into current clinical treatment protocols is to use stereotactic radiation of non-resectable recurrent gliomas followed by intratumoral injection of H-1PV to harvest the synergistic effects of combination treatment.
Non-viral genetic transfection of rat Schwann cells with FuGENE HD©lipofection and AMAXA©nucleofection is feasible but impairs cell viability
2010-11-01

Purpose: To determine transfection efficiency of FuGENE HD © lipofection and AMAXA © nucleofection on rat Schwann cells (SC). Methods: The ischiadic and median nerves of 6-8 week old Lewis rats were cultured in modified melanocyte-growth medium. SCs were genetically transfected with green fluorescent protein (GFP) as reporter gene using FuGENE HD © lipofection and AMAXA © nucleofection. Transfection rates were determined by visualization of GFP fluorescence under fluorescence microscopy and cell counting. Transfected cell to non-transfected cell relation was determined. Results: Purity of Schwann cell culture was 88% as determined by immunohistologic staining. Transfection rate of FuGENE HD © lipofection was 2%, transfection rate of AMAXA © nucleofection was 10%. With both methods, Schwann cells showed pronounced aggregation behavior which made them unfeasible for further cultivation. Settling of Schwann cells on laminin and poly- l -ornithine coated plates was compromised by either method. Conclusion: Non-viral transfection of rat SC with FuGENE HD © lipofection and AMAXA © nucleofection is basically possible with a higher transfection rate for nucleofection than for lipofection. As cell viability is compromised by either method however, viral transfection is to be considered if higher efficiency is required.
Improved particle‐packed HPLC/MS microchips for proteomic analysis
2010-11-01

Abstract The influence of packing process parameters (packing pressure, application of ultrasound) and the stationary phase particle size (3.5 and 5 μm) on the chromatographic performance of HPLC/MS chips was systematically investigated for proteomic samples. First, reproducibility and detection limits of the separation were evaluated with a low‐complexity sample of tryptic BSA peptides. The influence of adsorbent packing quality on protein identification was then tested with a typical proteomics sample of high complexity, a human plasma protein fraction (Cohn fraction IV‐4). All HPLC/MS chips provided highly reproducible separations of these proteomic samples, but improved packing conditions and smaller particle sizes resulted in chromatograms with narrower peaks and correspondingly higher signal intensities. Improved separation performance increased the peak capacity, the number of identified peptides, and thus the sequence coverage in the proteomic samples, particularly for low sample amounts.
Elevation-induced variations of pollen assemblages in the North-western Alps: An analysis of their value as temperature indicators
2010-11-01

Seventy-seven modern pollen samples from various elevations (350–2680 m a.s.l.) in two different areas of the north-western Alps (the Aosta Valley, Italy and the Taillefer Massif, France) were statistically analyzed to derive correlations between pollen assemblages, elevation and temperature at the sampled points. Numerical classifications were performed on pollen data to judge similarities between the two areas. The results show that a strong relationship exists between altitude and variations in pollen taxa percentages despite some floristic differences between the two areas. As a test, transfer functions from pollen percentages to elevation and temperature were calculated from pollen data. The reconstruction appears to be reliable, with a higher reliability at sites located over 1000 m. This analysis aims to serve as a basis for further quantitative reconstruction of temperature changes during the Holocene based on fossil pollen data from sensitive regions that encompass a significant altitudinal gradient.
Perspectives of Sport in a Global World
2010-11-01

Social change and sports development are related each to the other. Industrial societies are following the idea of 'modernization' and so does the system of sports. Since decades a change of paradigms is occuring and the system of sports is facing new challenges. Increasing risks are to be mastered.
Self-aligned gold nanocone probe tips
2010-11-01

Spatial resolution and optical near-field enhancement of scanning probes for apertureless near-field scanning optical microscopy depend strongly on the properties and geometry of the scanning probe. A new approach for very sharp probes with well-defined geometry based on gold nanocones is described and demonstrated on planar substrates. The fabrication involves a combination of thin-film deposition, electron beam lithography, and reactive ion etching or ion-milling, respectively. Well-defined gold nanocones with a tip radius of 10 nm and less on silica and bismuth pillars are obtained in a self-aligned process. The numerical simulations of the field distribution near the tip apex and the experimental verification via a photoluminescence intensity measurement are given, showing that these novel probes are suitable for performing optical measurements.
Measuring the light yield in a CaMoO4 scintillating crystal
2010-11-01

The light yield in CaMoO4 scintillating crystals irradiated with α particles and γ rays from 241Am and 137Cs radioactive isotopes, respectively, have been measured. It is shown that the light yield in this crystal for γ rays, measured in the wavelength range of 400–700 nm at room temperature (22°C), is ∼3000 photons/MeV, and the ratio α/β is ∼0.25.
The model-independent analysis indications for spectroscopy of scalar mesons. Proof for the K 0 * (900)
2010-11-01

In a model-independent approach the data on ππ → ππ, K , ηη, ηη′ in the I G J PC = 0+0++ channel and on the Kπ scattering in the channel are analyzed jointly for studying the status and QCD nature of the f 0- and the K*0-mesons. It is shown that in the 1500-MeV region, there are two states, wide (interpreted as a glueball) and narrow (q ). In the Kπ-scattering data analysis, the proof for the K*0(900) is given.
Attenuation Correction for Whole Body PET/MR: Quantitative Evaluation and Lung Attenuation Estimation with Consistency Information
2010-11-01

A subchronic toxicity study of N-acetylglucosamine (GlcNAc), a monomeric form of chitin, was conducted in groups of 10 male and 10 female F344 rats fed pelleted diets containing 0, 0.625, 1.25, 2.5 or 5% concentrations for 13 weeks. All animals survived until the end of the experiment. Slight, non-significant increase in body weights was observed in males receiving 0.625, 1.25 or 2.5% from week 4 until the end of the experiment, when significant elevation was found for the males receiving 0.625, 1.25 or 2.5% at the terminal sacrifice to result in decreased relative weights of many organs in these cases. However, there were no obvious indications of toxicity in any group receiving GlcNAc in terms of clinical signs, food intake, hematology, serum biochemistry, and histopathological findings. Thus, it was concluded that orally administered GlcNAc exerts no obvious toxicity to F344 rats at concentrations up to 5% in the diet for 13 weeks. Based on the present toxicity data, > or =5% was determined to be a no-observed-adverse-effect level, translated into 2476 and 2834 mg/kg/day for male and female rats, respectively.
Sensing in harsh conditions: How to protect SnO 2 sensing layer
2010-11-01

The detection of low CO amounts in fuel cell conditions - high hydrogen background in almost the absence of oxygen - is a challenging problem for SnO 2 based gas sensors. SnO 2 - the most used material for metal-oxide based gas sensors - is not stable in hydrogen-rich atmospheres at high temperatures being reduced to metallic tin. To prevent SnO 2 reduction, a SnO 2 based sensing layer, previously deposited by screen-printing onto an alumina substrate, was coated with the additional microporous ceramic Si-B-C-N layer. The ceramic coating prevents the reduction of SnO 2 and allow for the diffusion of the target gas molecules towards the SnO 2 layer for their detection, acting as a filter. The Si-B-C-N coated SnO 2 sensors show stable sensor signals towards hydrogen and carbon monoxide in the absence of oxygen whereas the unprotected SnO 2 sample becomes reduced over time.
Antiplatelet Treatment: The Search for Optimal Therapy Continues
2010-11-01

Optimal antiplatelet therapy has been a source of contention, primarily due to conflicting trial data. There remain many unanswered questions regarding the role of platelet response testing, drug interactions, and bleeding risk in the clinical setting.
Sensing in harsh conditions: How to protect SnO<inf>2</inf> sensing layer
2010-11-01

The detection of low CO amounts in fuel cell conditions - high hydrogen background in almost the absence of oxygen - is a challenging problem for SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> based gas sensors. SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> - the most used material for metal-oxide based gas sensors - is not stable in hydrogen-rich atmospheres at high temperatures being reduced to metallic tin. To prevent SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> reduction, a SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> based sensing layer, previously deposited by screen-printing onto an alumina substrate, was coated with the additional microporous ceramic Si-B-C-N layer. The ceramic coating prevents the reduction of SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and allow for the diffusion of the target gas molecules towards the SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> layer for their detection, acting as a filter. The Si-B-C-N coated SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> sensors show stable sensor signals towards hydrogen and carbon monoxide in the absence of oxygen whereas the unprotected SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> sample becomes reduced over time.
Olympic Challenges
2010-11-01

The Chinese hosts are not the only people who see the Olympic Games in Beijing as a great success. All active participants experienced the games as unique in many different respects; and apart from a few exceptions they received great appreciation from the participating nations. It is also very significant that the games obviously have had a lasting impact on Chinese society. This becomes evident not only in the infrastructural achievements but first and foremost in the opening up of Chinese society, a process that has been greatly accelerated by the Olympic Games. Changing the perspective and viewing the Chinese games from the angle of the IOC, however, might produce a somewhat different verdict, which could be summed up in the following statement: disaster was close for the IOC – they just made it. The Olympic movement has long been confronted with problems which are frequently not recognized and the solutions to which are, for the most part, not yet in sight. Necessary processes of change are put off again and again. Possible solutions are not vehemently pursued. Some of these problems prove to be of such complexity that – it must be admitted in all fairness – the search for solutions will still be extremely difficult in the future. If we also want Olympic Games to be successful in the future however, these problems need to be openly addressed and discussed and it must be recognized that we are on the way to suitable solutions. In the following, selected problems and challenges will be outlined, as they have become evident during the games in Beijing and afterwards.
Relationships between hepatic stearoyl-CoA desaturase-1 activity and mRNA expression with liver fat content in humans
2010-11-02

Stearoyl-CoA desaturase-1 (SCD1) has gained much interest as a future drug target to treat fatty liver and its consequences. However, there are few and inconsistent human data about expression and activity of this important enzyme. We investigated activity and expression of SCD1 and their relationships with liver fat (LF) content in human liver samples. Fifty subjects undergoing liver surgery were studied. SCD1 activity was estimated from the ratio of oleate (C18:1) to stearate (C18:0) within lipid subfractions. Furthermore, SCD1 mRNA expression and LF content were measured. Similarly to previous studies, we observed a strong positive correlation between LF content and the C18:1/C18:0 ratio in the combined fatty acid (FA) fractions ( r = 0.96, P &lt; 0.0001), which could be interpreted as higher SCD1 activity with increasing LF. However, hepatic SCD1 mRNA expression did not correlate with LF ( r = 0.16, P = 0.13). To solve these conflicting data, we analyzed the FA composition of hepatic lipid subfractions. With increasing LF content the amount of FAs from the triglyceride (TG) fraction increased ( r = 0.96, P &lt; 0.0001), whereas the FAs from the phospholipid (PL) fraction remained unchanged ( r = −0.17, P = 0.19). Of these two major lipid fractions, the C18:1/C18:0 ratio in TG was 16-fold higher than in PL. Supporting the SCD1 mRNA expression data, the C18:1/C18:0 ratio of the TG or PL fraction did not correlate with LF ( r = 0.26, P = 0.12 and r = 0.08, P = 0.29). We provide novel information that SCD1 activity and mRNA expression appear not to be elevated in subjects with high LF content. We suggest that the FA composition of lipid subclasses, rather than of mixed lipids, should be analyzed to estimate SCD1 activity.