julilili42/papers huggingface dataset:
Identification of a topoisomerase IV in actinobacteria: purification and characterization of ParYR and GyrBR from the coumermycin A1 producer Streptomyces rishiriensis DSM 40489
2004-03-01

The biosynthetic gene clusters of the gyrase inhibitors coumermycin A(1) and clorobiocin contain two different resistance genes (gyrB(R) and parY(R)). Both genes code for B subunits of type II topoisomerases. The authors have now overexpressed and purified the encoded proteins, as well as the corresponding A subunits GyrA and ParX. Expression was carried out in Streptomyces lividans in the form of hexahistidine fusion proteins, allowing purification by nickel affinity chromatography. The complex of GyrA and GyrB(R) was found to catalyse ATP-dependent supercoiling of DNA, i.e. to function as a gyrase, whereas the complex of ParX and ParY(R) catalysed ATP-dependent decatenation and relaxation, i.e. the functions of topoisomerase IV (topo IV). This is believed to represent the first topo IV identified in the class of actinobacteria, and the first demonstration of the formation of a topo IV as a resistance mechanism of an antibiotic producer.
Identification of an HLA-A*0201-restricted T-cell epitope derived from the prostate cancer-associated protein prostein
2004-03-01

The development of T-cell-based immunotherapies of cancer largely depends on the availability of tumour-associated antigens capable of eliciting tumour-directed cytotoxic T-cell responses. In prostate cancer, the number of antigens defined as suitable targets of cytotoxic T lymphocytes (CTLs) is still limited. Recently, prostein was identified as a transmembrane protein that is highly restricted to prostate tissues. In our study, prostein transcripts were found to be abundant in both malignant and nonmalignant prostate tissue samples. To identify immunogenic CD8+ T-cell epitopes, human leucocyte antigen-A(*)0201-binding peptides were selected from the amino-acid sequence of prostein and were used for the in vitro stimulation of CD8+ T lymphocytes. Specific CTLs were raised against the prostein-derived peptide CLAAGITYV that were capable of lysing prostate cancer cells, indicating that this peptide is naturally generated by tumour cells. Our data suggest that prostein is a suitable candidate to be included in a T-cell-based immunotherapy of prostate cancer.
Phase III results with a totally implantable piezoelectric middle ear implant: Speech audiometry, spatial hearing and psychosocial adjustment
2004-03-01

Treatment of SNHL with a totally implantable hearing system can be an efficient method for those patients unable to wear hearing aids. However, in order to avoid implantation in non-responders, there is a need for more specific audiological indication criteria.
Accretion disc evolution in DW Ursae Majoris: A photometric study
2004-03-01

We present an analysis of CCD photometric observations of the eclipsing novalike cataclysmic variable DW UMa obtained in two different luminosity states: high and intermediate. The star presents eclipses with very different depth: ~1.2 mag in the high and ~3.4 mag in the intermediate state. Eclipse mapping reveals that this difference is almost entirely due to the changes in the accretion disc radius: from ~0.5RL1 in the intermediate state to ~0.75RL1 in the high state (RL1 is the distance from the white dwarf to the first Lagrangian point). In the intermediate state, the entire disc is eclipsed while in the high state, its outer part remains visible. We also find that the central intensity of the disc is nearly the same in the two luminosity states and that it is the increase of the disc radius that is responsible for the final rise from the 1999/2000 low state. We find that the intensity profile of the disc is rather flat and suggest a possible explanation. We also discuss the effect of using a more realistic limb-darkening law on the disc temperatures inferred from eclipse mapping experiments. Periodogram analysis of the high state data reveals "positive superhumps" with a period of 0.1455 in 2002 and 0.1461 in 2003, in accord with the results of Patterson et al. However, we cannot confirm the quasi-periodic oscillations reported by these authors. We obtain an updated orbital ephemeris of DW UMa: Tmin[HJD]=2446229.00687(9)+0.136606527(3)E.
What children need: cooperative religious education in German schools—results from an empirical study
2004-03-01

This article gives a report on a recent empirical study on cooperative religious education in German primary schools. Special emphasis is given to the views, needs, and rights of children. Results from interviews with the children and with the teachers as well as from classroom observation form the basis for the authors' suggestions concerning the future shape of religious education.
Regioselective Conversion of Anhydro Sugars into Halohydrins and X-Ray Study
2004-03-01

A rapid, easy, regio- and stereoselective synthesis of 3-halo-3-deoxy sugars using titanium tetrahalides is described. To fully confirm the stereochemistry of the synthetic products, the X-ray structure of benzyl 3-chloro-3-deoxy-β -L-xylopyranoside was determined
Observations of the pulsating subdwarf B star Feige 48: Constraints on evolution and companions
2004-03-01

Since pulsating subdwarf B (sdBV or EC14026) stars were first discovered, observational efforts have tried to realize their potential for constraining the interior physics of extreme horizontal branch stars. Difficulties encountered along the way include uncertain mode identifications and a lack of stable pulsation mode properties. Here we report on Feige 48, an sdBV star for which follow-up observations have been obtained spanning more than four years. These observations show some stable pulsation modes. We resolve the temporal spectrum into five stable pulsation periods in the range 340–380 s with amplitudes less than 1 per cent, and two additional periods that appear in one data set each. The three largest amplitude periodicities are nearly equally spaced, and we explore the consequences of identifying them as a rotationally split l= 1 triplet by consulting a representative stellar model. The general stability of the pulsation amplitudes and phases allows us to use the pulsation phases to constrain the time-scale of evolution for this sdBV star. Additionally, we are able to place interesting limits on any stellar or planetary companion to Feige 48.
Source Consistency, Distinctiveness, and Consensus: The Three Dimensions of the Kelley ANOVA Model in Persuasion
2004-03-01

Based on a conceptual analysis and existing research, the authors propose that the three source dimensions specified in the ANOVA model play similar roles in persuasion as other source characteristics (e.g., expertise). Two studies test assumptions derived from this approach regarding the effects of different combinations of consistency and consensus (Study 1) and distinctiveness and consensus (Study 2). Combinations resulting in contradictory (vs. similar) inferences regarding message validity should affect judgmental confidence and, consequently, affect message scrutiny. Study 1 shows that, as predicted, high consistency/low consensus and low consistency/high consensus (incongruent combinations) lead to higher desired confidence and more extensive message elaboration than high consistency/high consensus and low consistency/low consensus (congruent combinations). Similarly, Study 2 reveals heightened message scrutiny given incongruent (vs. congruent) combinations of distinctiveness and consensus. Results are discussed with respect to majority/minority influence processes and multiple source characteristics.
Antimalarial activity of extracts of Abutilon grandiﬂorum G. Don – a traditional Tanzanian medicinal plant
2004-03-01

Abstract The Tanzanian medicinal plant Abutilon grandiflorum G. Don was studied for its in vivo and in vitro antiplasmodial effects. The ethyl acetate extract showed prominent in vivo activity against P. vinckei vinckei in mice and in vitro against P. falciparum strains HB3 and FCB. The extract was only moderately cytotoxic if tested in vitro against the colon cell line HT29. In the in vivo study, the results were significantly influenced by the treatment schedule used, i.e. early treatment with higher doses was more successful than applying the same overall amount over a longer period. Phytochemical analysis of the extract provided no conclusive evidence for the observed parasitological effects. Copyright © 2004 John Wiley &amp; Sons, Ltd.
Addition of a Defibrillation Electrode in the Low Right Atrium to a Right Ventricular Lead Does Not Reduce Ventricular Defibrillation Thresholds
2004-03-01

Transvenous unipolar active can defibrillation systems have proven to be effective in treating ventricular tachyarrhythmias. However, a further reduction of ventricular defibrillation thresholds (V‐DFT) would increase the longevity, reduce the size of pulse generators, and help to avoid additional leads in patients with inacceptable high V‐DFTs. In a finite difference computer model, the extension of the right ventricular (RV) defibrillation coil into the low right atrium led to a 40% reduction of unipolar V‐DFT. To evaluate this finding, we conducted a prospective, randomized study in 11 patients receiving an ICD. Extension of the RV electrode was simulated by adding a second coil placed in the low right atrium with the same polarity. Using a binary search protocol, V‐DFT was determined with and without the additional electrode in each patient. Total shock impedance was significantly lower in the two coil (low RA) configuration, compared to the single coil (RV) configuration. Corresponding values were 49.9 ± 6.7 Ohm and 61.1 ± 9.3 Ohm, respectively (P &lt; 0.01, paired t‐test). However, there was no reduction, but even a nonsignificant increase in V‐DFTs. Mean V‐DFT in the RV configuration was 12.0 ± 5.6 J and 16.3 ± 7.8 J in the low RA configuration (P = 0.09, paired t‐test). Despite a reduction in total impedance, the addition of a defibrillation coil in the low right atrium does not reduce ventricular defibrillation thresholds. (PACE 2004; 27:346–351)
Pulsed saturation of the standard two‐pool model for magnetization transfer. Part I: The steady state
2004-03-01

Abstract A general framework for magnetization transfer (MT) of a two‐pool system with linear exchange for arbitrary saturation by periodic radio‐frequency pulses was derived. It is based on a novel parameterization adapted to the time evolution of saturation recovery. The conditions in tissue permit a description in analogy to partial saturation of a homogeneous liquid. In this approximation, the direct saturation of bulk water is amplified by MT. Rapid transfer equilibrates the saturation of the pools in the early phase of free evolution. This kinetic “pre‐equilibrium” relaxes slowly with a common relaxation rate. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part A 21A: 37–49, 2004
Pulsed saturation of the standard two‐pool model for magnetization transfer. Part II: The transition to steady state
2004-03-01

Abstract The transition of the tissue signal to steady state under periodic selective saturation of macromolecular magnetization can be observed by single‐shot echo‐planar imaging. The general solution for a two‐pool system with linear exchange kinetics contains two transient components. The rapid minor transient causes an initial delay of the transition for fast pulse repetition ( PR ) and weak saturation. The slow major transient combines progressive direct saturation and transferred saturation. Its PR ‐dependence provides similar information as the steady state, but is less sensitive to direct saturation and fitting errors. Sampling at different PR allows to quantify all system parameters. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part A 21A: 50–62, 2004
Processes of silicate karstification associated with pan formation in the Darwin–Koolpinya area of northern Australia
2004-03-01

Abstract Lyons Lagoon, one of many small pans near Darwin, Northern Australia, occurs in lateritized terrain. Formation by structurally facilitated silicate karstification of the parent Cretaceous sandy sediments was earlier proposed. This paper presents the results of thin section microscopy and scanning electron microscopy with energy‐dispersive X‐ray study of pan sediments with a view to assessing the extent to which they reflect the geomorphological/hydrogeological history. Severe corrosion was found to overprint the impact features of the primary sands, attributed to aggressive leaching and consistent with formation of the depression by karstification when the water table was low. Formation of a smectitic matrix is considered to have followed when the water table was high. Upon subsequent lowering of the water level leaching was resumed, altering smectite to kaolinite and resulting in incongruent dissolution of kaolinite to leave a siliceous residuum. At least two cycles of high followed by low water levels are recognized. Such periodic changes of levels are considered essential to pan formation within freely draining lateritic terrain. The processes of pan formation and alteration of pan sediments (essentially residual deposits) is ongoing, biocorrosion being implicated as an important mechanism. Incongruent kaolinite dissolution, to leave a silica residuum, a hitherto apparently unrecognized process, raises the possibility that silcrete may form as a relative accumulation which is synchronous with lateritic leaching in more elevated topographic positions. Copyright © 2004 John Wiley &amp; Sons, Ltd.
The time back to the most recent common ancestor in exchangeable population models
2004-03-01

A class of haploid population models with population size N , nonoverlapping generations and exchangeable offspring distribution is considered. Based on an analysis of the discrete ancestral process, we present solutions, algorithms and strong upper bounds for the expected time back to the most recent common ancestor which hold for arbitrary sample size n ∈ {1,..., N }. New insights into the asymptotic behaviour of the expected time back to the most recent common ancestor for large population size are presented relating the results to coalescent theory.
Amauromyces farinaceous, rare known species and new record from Taiwan
2004-03-01

Amauromyces farinaceous is investigated. The species is a rare corticiaceous Homobasidiomycete recently collected in Taiwan. The unique basidial morphology, cell walls and septal pores of the hyphae are studied by transmission electron microscopy. The study demonstrates the gradual thickening of cell walls in the lower parts of young basidia, leaving only a small asymmetric cytoplasmic channel in mature stages. Systematics of genus Amauromyces are discussed by comparing it with Athelia, Athelopsis, Chaetoderma, Columnocystis, Gloeosoma, Paullicorticium, Sistotremastrum, Trechispora, Tulasnella and Veluticeps.
Creating coordination in the Cerebellum
2004-03-01

Different forms of synaptic plasticity in the cerebellum are mediated by metabotropic glutamate receptors (mGluRs). At parallel fiber (PF) to Purkinje cell (PC) synapses activation of mGluR gives rise to a well known slow synaptic current inhibited by antagonists ofmGluR1. The distribution of mGluR types in the climbing fiber (CF) to PC synapses is not well known. Only recently an mGluR1-mediated all-or-none post-synaptic current was also demonstrated at the CF-PC synapse (Dzubay &amp; Otis, Neuron 2002; 36: 1159). Using whole cell patch-clamp recordings from PCs in rat cerebellar slices with AMPA receptors blocked(NBQX, 10 or CNQX, 20mM) and impaired glutamate uptake (TBOA, 100 mM) we demonstrate a more complex pharmacology of a current obtained by single or train (10 or 100 Hz) CF stimulation. The mGluR1 specific antagonist CPCCOEt, 100 mM in a group of cells suppressed this response while in a similar number of other cells it induced a potentiating effect. The antagonists of mGluR groups II and III (LY341495 and MSOP, respectively) predominantly suppressed the current. In addition, 100 mM MSOP did not occlude the inhibition by 0.2 mM LY341495. The ambiguous effect of CPCCOEt was checked by measuring the paired-pulse depression of the CF EPSC, which was not changed with the antagonist. The paired-pulse plasticity was also not changed by CPCCOEt in low (0.5mM) external Ca2+ (used to prevent saturation of AMPARs), thus excluding a presynaptic effect. However, CPCCOEt induced arise in the amplitude (by 25%) as well as a prolongation of the decay time of CF EPSCs at normal 2mM Ca2+, i.e. under conditions of AMPAR saturation (11.7 ± 0.7 ms vs. 15.8 ± 1.5 ms), thus indicating an effect of postsynaptic origin. In 0.5 mM Ca2+ the decay of CF EPSCs was faster (7.5 ± 1.2 ms) but it was also prolonged by CPCCOEt (8.8 ± 1.2 ms). However, the CF EPSC amplitude was not significantly affected indicating an underlying Ca2 2+-dependent mechanism. Thus, the pharmacology of the PC mGluR-mediated response points to a dual postsynaptic role of mGluR1 giving rise to a slow postsynaptic current but also regulating other presumably mGluR-dependent currents via second messenger molecules and Ca2 i. The additional electrophysiological role of mGluR II &amp; III types was also indicated. Such a complex regulatory mechanism may have an important role in them GluR-dependent forms of homosynaptic plasticity and motor learning at the CF-PC synapse.
Specialization on a Technologically Stagnant Sector Need Not Be Bad for Growth
2004-03-01

This paper presents a simple North-South model of endogenous growth, based on learning by doing, which is consistent with the following empirical observations: (i) the price of investment goods relative to consumption goods has been falling for the last 40 years in most industrialized countries, (ii) poor countries are net importers of investment equip-ment and (iii) after a period of initial convergence, the sample of open economies exhibits remarkable stability of the per capita income distribution. In contrast to the research tradition started by Lucas (1988), in the proposed model, specialization on the techno-logically stagnant consumption sector does not entail a growth penalty.
Zum Wandel von Krieg und Kriegslegitimation in der Neuzeit
2004-03-01

On the Transformation of War and its Legitimation in Modern Times The history of war in the twentieth century is characterised by two overriding developments. 1. The state's monopoly over war declined. 2. The separation between combatants and the civilian population was systematically undermined. Thus two important developments that had been under way since the seventeenth century were put into reverse. The article first discusses the typical war of the twentieth century: namely the asymmetrical war. Then the anthropological factors common to the situation of human beings at war are summarised. The main part of the article recounts how in Europe wars for the purpose of state-building have been acknowledged as legitimate ever since the Middle Ages. But around 1800 the idea of the nation as the embodiment of the principle of legitimacy reached new heights, signifying a major international turning-point in the history of the legitimation of war. From then on the concept of a people's war or a national war dominated political thinking, though wars in Europe during the nineteenth century would henceforth be managed according to the tradition of ‹limited› war – one of the important achievements of that century in thinking about questions of nationality.
Amauromyces farinaceous, Rare Known Species and New Record from Taiwan
2004-03-01

Amauromyces farinaceous is investigated. The species is a rare corticiaceous Homobasidiomycete recently collected in Taiwan. The unique basidial morphology, cell walls and septal pores of the hyphae are studied by transmission electron microscopy. The study demonstrates the gradual thickening of cell walls in the lower parts of young basidia, leaving only a small asymmetric cytoplasmic channel in mature stages. Systematics of genus Amauromyces are discussed by comparing it with Athelia, Athelopsis, Chaetoderma, Columnocystis, Gloeosoma, Paullicorticium, Sistotremastrum, Trechispora, Tulasnella and Veluticeps.
Cardiovascular Magnetic Resonance Assessment of Human Myocarditis
2004-03-02

Background— Myocarditis can occasionally lead to sudden death and may progress to dilated cardiomyopathy in up to 10% of patients. Because the initial onset is difficult to recognize clinically and the diagnostic tools available are unsatisfactory, new strategies to diagnose myocarditis are needed. Methods and Results— Cardiovascular MR imaging (CMR) was performed in 32 patients who were diagnosed with myocarditis by clinical criteria. To determine whether CMR visualizes areas of active myocarditis, endomyocardial biopsy was taken from the region of contrast enhancement and submitted to histopathologic analysis. Follow-up was performed 3 month later. Contrast enhancement was present in 28 patients (88%) and was usually seen with one or several foci in the myocardium. Foci were most frequently located in the lateral free wall. In the 21 patients in whom biopsy was obtained from the region of contrast enhancement, histopathologic analysis revealed active myocarditis in 19 patients (parvovirus B19, n=12; human herpes virus type 6 [HHV 6], n=5). Conversely, in the remaining 11 patients, in whom biopsy could not be taken from the region of contrast enhancement, active myocarditis was found in one case only (HHV6). At follow-up, the area of contrast enhancement decreased from 9±11% to 3±4% of left ventricular mass as the left ventricular ejection fraction improved from 47±19% to 60±10%. Conclusions— Contrast enhancement is a frequent finding in the clinical setting of suspected myocarditis and is associated with active inflammation defined by histopathology. Myocarditis occurs predominantly in the lateral free wall. Contrast CMR is a valuable tool for the evaluation and monitoring of inflammatory heart disease.
The sphingosine 1-phosphate receptor agonist FTY720 supports CXCR4-dependent migration and bone marrow homing of human CD34+ progenitor cells
2004-03-02

Abstract The novel immunosuppressant FTY720 activates sphingosine 1-phosphate receptors (S1PRs) that affect responsiveness of lymphocytes to chemokines such as stromal cell-derived factor 1 (SDF-1), resulting in increased lymphocyte homing to secondary lymphoid organs. Since SDF-1 and its receptor CXCR4 are also involved in bone marrow (BM) homing of hematopoietic stem and progenitor cells (HPCs), we analyzed expression of S1PRs and the influence of FTY720 on SDF-1/CXCR4-mediated effects in human HPCs. By reverse transcriptase-polymerase chain reaction (RT-PCR), S1PRs were expressed in mobilized CD34+ HPCs, particularly in primitive CD34+/CD38- cells. Incubation of HPCs with FTY720 resulted in prolonged SDF-1-induced calcium mobilization and actin polymerization, and substantially increased SDF-1-dependent in vitro transendothelial migration, without affecting VLA-4, VLA-5, and CXCR4 expression. In nonobese diabetic-severe combined immunodeficient (NOD/SCID) mice, the number of CD34+/CD38- cells that homed to the BM after 18 hours was significantly raised by pretreatment of animals and cells with FTY720, tending to result in improved engraftment. In addition, in vitro growth of HPCs (week-5 cobblestone area-forming cells [CAFCs]) was 2.4-fold increased. We conclude that activation of S1PRs by FTY720 increases CXCR4 function in HPCs both in vitro and in vivo, supporting homing and proliferation of HPCs. In the hematopoietic microenvironment, S1PRs are involved in migration and maintenance of HPCs by modulating the effects of SDF-1. (Blood. 2004;103:4478-4486)