bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of magnetic topology on particle acceleration in a three-dimensional reconnecting current sheet: a test-particle approach
Authors: ZHARKOVA V. V. , AGAPITOV O. V. 
Published: December 2008

AbstractElectron and proton acceleration by a drifted super-Dreicer electric field is investigated in a strongly compressed non-neutral reconnecting current sheet (NRCS). The guiding field is assumed to be constant within a reconnecting current sheet (RCS) and parallel to the direction of the drifted electric field. The other two magnetic field components, transverse and tangential, are considered to vary exponentially and linearly with distances from the X-nullpoint. The proton and electron energy spectra are calculated numerically in a model RCS with different magnetic field topologies by solving an equation of motion in the test-particle approach with some test with a particle-in-cell (PIC) approach. Three kinds electric field generated inside a RCS are considered: a drifted electric field caused by the plasma inflows formed during a magnetic reconnection process; a polarization electric field induced by the accelerated protons and electrons; and a turbulent electric field induced by instabilities generated by accelerated particles. Electron and proton densities, and energy spectra inside a RCS and at ejection are found to be strongly affected by the magnetic field topology: for stronger magnetic fields the spectra are softer having a small higher-energy cutoff while for weaker magnetic fields the spectra are harder with much larger upper cutoff energies. Depending on the magnetic component ratios and drifted electric field magnitude, particles are found to be ejected either as quasi-thermal flows with very high temperatures or as focused power-law beams. A polarization field is found to reduce the acceleration time inside a RCS and to increase the energy gained by particles at acceleration by a pure drifted electric field by a few orders of magnitude. The turbulent electric field induced by the two beam instabilities of the same kind of particles leads to a significant increase in the number of particles with higher energies resulting in a flattening of their energy spectra.
Drift wave excitation in a collisional dusty magnetoplasma with multi-ion species
Authors: SHUKLA P. K. , ROSENBERG M. 
Published: December 2008

AbstractWe investigate the drift dissipative instability in a non-uniform magnetized plasma composed of electrons, positive ions, negative ions and negatively charged dust particles. We use a multi-fluid plasma model and derive a dispersion relation for the electrostatic drift waves with frequencies much smaller than the ion gyrofrequencies and wavelengths longer than the ion gyroradii. The presence of the negatively charged, massive dust grains affects the drift wave frequency and the growth rate of the drift dissipative instability. The present results may be relevant to space and laboratory magnetoplasmas containing negative ions and charged dust grains.
Inverse bremsstrahlung cross section estimated within evolving plasmas using effective ion potentials
Authors: WANG F. , WECKERT E. , ZIAJA B. 
Published: December 2008

AbstractWe estimate the total cross sections for field-stimulated photoemissions and photoabsorptions by quasi-free electrons within a non-equilibrium plasma evolving from the strong coupling to the weak coupling regime. Such a transition may occur within laser-created plasmas, when the initially created plasma is cold but the heating of the plasma by the laser field is efficient. In particular, such a transition may occur within plasmas created by intense vacuum ultraviolet (VUV) radiation from a free-electron laser (FEL) as indicated by the results of the first experiments performed by Wabnitz at the FLASH facility at DESY. In order to estimate the inverse bremsstrahlung cross sections, we use point-like and effective atomic potentials. For ions modelled as point-like charges, the total cross sections are strongly affected by the changing plasma environment. The maximal change of the cross sections may be of the order of 75 at the change of the plasma parameters: inverse Debye length, κ, in the range κ = 0 − 3 Å−1 and the electron density, ρe, in the range ρe = 0.01 − 1 Å−3. These ranges correspond to the physical conditions within the plasmas created during the first cluster experiments performed at the FLASH facility at DESY. In contrast, for the effective atomic potentials the total cross sections for photoemission and photoabsorption change only by a factor of seven at most in the same plasma parameter range. Our results show that the inverse bremsstrahlung cross section estimated with the effective atomic potentials is not affected much by the plasma environment. This observation validates the estimations of the enhanced heating effect obtained by Walters, Santra and Greene. This is important as this effect may be responsible for the high-energy absorption within clusters irradiated with VUV radiation.
The reluctant hosts: Soviet Antarctic expedition ships visit Australia and New Zealand in 1956
Authors: Gan Irina 
Published: December 2008

ABSTRACTRussian and Australian primary sources were examined in an attempt to reconstruct the voyage of the first composite Soviet Antarctic expedition to Antarctica and from thence to Leningrad [St Petersburg]. This expedition had the aim of constructing a base for the Soviet International Geophysical Year (IGY) commitment. In a time of cold war tension and unresolved Antarctic claims, the Australian and New Zealand governments were wary of Soviet intentions and barely tolerated visits by Soviet expeditions. However, in their interactions with Australians and New Zealanders, the Soviets were careful to underline the friendly nature of their visits and avoided any sensitive political questions. The two governments’ apparent lack of enthusiasm for Ob and Lena entering their ports after fulfilling their task in Antarctica is contrasted with the generally more enthusiastic attitude of the Australian and New Zealand scientists and expedition members, with whom the Soviet personnel came into contact, some of whom developed lasting scientific relationships with the visitors.
Differential predictors of critical comments and emotional over-involvement in first-episode psychosis
Authors: Álvarez-Jiménez M. , Gleeson J. F. , Cotton S. M. , Wade D. , Crisp K. , Yap M. B. H. , McGorry P. D. 
Published: December 2008

BackgroundLittle research has focused on delineating the specific predictors of emotional over-involvement (EOI) and critical comments (CC) in the early course of psychosis. The purpose of this study was to investigate the differential relationships of EOI and CC with relevant predictors in relatives of first-episode psychosis (FEP) patients.MethodBaseline patient-related factors including psychotic symptoms, depression and duration of untreated psychosis (DUP) and carer attributes comprising CC, EOI, burden of care and carers' stress and depression were assessed in a cohort of 63 remitted FEP patients and their relatives. Carers were reassessed at 7 months follow-up.ResultsBaseline analysis showed that EOI was more strongly correlated with family stress compared with CC, whereas CC yielded a stronger association with DUP than EOI. Carers' CC at follow-up was not significantly predicted by either baseline family stress, burden of care or patient-related variables. Conversely, baseline EOI predicted both family stress and burden of care at 7 months follow-up. Finally, family burden of care at follow-up was a function of baseline EOI and patients' depressive symptoms.ConclusionsThis study provides preliminary support to the postulate that EOI and CC may be influenced by separate factors early in the course of psychosis and warrant future research and therapeutic interventions as separate constructs. Implications for family interventions in the early phase of psychosis and the prevention of CC and EOI are discussed.
Perception of a fragmented landscape by neotropical marsupials: effects of body mass and environmental variables
Authors: Forero-Medina Germán , Vieira Marcus Vinícius 
Published: December 2008

Abstract:Perceptual range is used as a measure of the ability of animals to perceive the landscape, and can be used to infer functional connectivity between habitat patches such as forest remnants. A relationship of perceptual range with body mass was proposed by Mech and Zollner, but effects of life-history traits and environmental conditions were also acknowledged. We evaluated perceptual ranges and the influence of body mass, wind speed and direction, and grass height in four marsupial species of the Atlantic Forest of south-eastern Brazil. Release experiments were conducted and orientation towards the forest was determined using the spool-and-line technique. In 111 animals released, Didelphis aurita had the highest perceptual range (200 m), followed by Philander frenatus and Micoureus paraguayanus (100 m), and by Marmosops incanus (< 100 m). None of the species presented homing behaviour, and there was no difference in orientation abilities between sexes. Perceptual range was overestimated based on the equations of Mech and Zollner, but species were ordered in perceptual range according to their body size. Distance to the forest was a common determinant of the orientation in P. frenatus and M. paraguayanus, but grass height and wind direction were also important. Orientation of Didelphis aurita was determined by wind direction, showing anemotactic behaviour. Body mass is likely to affect perceptual ranges in didelphid marsupials, but only in interspecific comparisons. Within a species perception depends on the environmental context. Variables other than distance must be considered to estimate functional connectivity of the landscape based on perceptual range.
Dispersal limitation in epiphytic bromeliad communities in a Costa Rican fragmented montane landscape
Authors: Cascante-Marín Alfredo , von Meijenfeldt Noemi , de Leeuw Hanneke M. H. , Wolf Jan H. D. , Oostermeijer J. Gerard B. , den Nijs Joannes C. M. 
Published: December 2008

Abstract:Transformation of tropical forests is likely to affect seed-dispersal patterns and influence the composition of epiphytic plant communities in human-altered habitats. We tested this hypothesis by carrying out a comparative study of seed influx, survival and growth of transplanted seedlings of epiphytic bromeliads among isolated trees in six pasture areas, six forest edges and six forest sites in a montane area in Costa Rica. In total, 72 traps trapped 1285 seeds over a 2-mo period in the dry season of 2003. For all four investigated bromeliad genera, Catopsis, Guzmania, Tillandsia and Werauhia, the number of trapped seeds in each habitat followed a pattern similar to the number of fruiting individuals in the vicinity of the traps. Traps in forest edges (30) were 1.9 times more likely to collect seeds than traps at forest interiors (30) and pasture trees (12), the latter showing similar probabilities of catching seeds. After 1 y, survival and growth of 3660 transplanted seedlings from three bromeliad species was significantly higher in forest interiors, providing no explanation for the lower abundance of fruiting adults in that habitat. These results suggest that the successful establishment of epiphytic bromeliads in forest interiors is mainly dispersal-limited. If corroborated, differences in abundance among species at each habitat are likely related to differences in growth rates and reproductive success. Further studies on the growth and mortality of seedlings up to the flowering stage, however, are needed.
Première classe de Stiefel–Whitney des espaces d'applications stables réelles en genre zéro vers une surface convexe
Authors: Puignau Nicolas 
Published: December 2008

RésuméSoit (X, cX) une surface projective convexe munie d'une structure réelle. L'espace de module des applications stables $\smash{\overline{\mathcal{M}}_{0,k}(X,d)}$ peut être équipé de plusieurs structures réelles associées à cX et à un élément d'ordre deux τ du groupe des permutations Sk qui agit sur les points marqués. La partie réelle correspondant à chaque structure ℝτ$\smash{\overline{\mathcal{M}}_{0,k}(X,d)}$ est une variété réelle projective et normale. Puisque le lieu singulier est de codimension au moins deux, ces espaces possèdent une première classe de Stiefel–Whitney pour laquelle on détermine un représentant dans le cas k = c1(X)d − 1 où c1(X) désigne la première classe de Chern du fibré tangent de X. Plus précisément, nous donnons une description homologique des classes de Stiefel–Whitney en termes de partie réelle de certains diviseurs de la frontière de l'espace des applications stables.
Identification of Common Genetic Variants Predisposing to Neurobehavioral Disease by way of Genome-Wide SNP Association Studies
Authors: Craig David 
Published: December 2008

AbstractDr. David Craig began by explaining expression and linkage studies. He then focused on genome-wide association studies (GWAS), giving examples from Diabetes Type 2 and Alzheimer’s research. Dr. Craig concluded with the recognition that GWAS cannot at the present adequately account for environmental influences on disease.To watch Dr. Craig’s presentation, please see the Panel 3 "Google Video posting.":http://video.google.com/videoplay?docid=-7775076897136846879&hl=en
Safety and efficacy of rasburicase (SR29142) in a Japanese phase II study
Authors: Ishizawa Kenichi , Ogura Michinori , Hamaguchi Motohiro , Hotta Tomomitsu , Ohnishi Kazunori , Sasaki Tsuneo , Sakamaki Hisashi , Yokoyama Hisayuki , Harigae Hideo , Morishima Yasuo 
Published: December 2008

The purpose of this study was to investigate the safety profile of SR29142 when administered as a single agent both prior to chemotherapy and during treatment, and to compare the efficacy of SR29142 administered at two dose levels in adult Japanese patients with leukemia or lymphoma. During this open‐label, multicenter, phase II study, patients received SR29142 for 5 days, administered at either 0.15 or 0.20 mg/kg per day. Chemotherapy was started 4–24 h after the first infusion of SR29142. The primary end‐point was overall response rate, defined as the normalization of plasma uric acid to 7.5 mg/dL or less, from 48 h after the first infusion to 24 h after the last infusion of SR29142. SR29142‐related adverse events including hypersensitivity (allergic) reactions were assessed. Overall, 50 patients received SR29142 at either 0.15 mg/kg per day (n = 25) or 0.20 mg/kg per day (n = 25) followed by chemotherapy. The overall response rate was 100.0% (95% confidence interval, 86.3–100.0%) with 0.15 mg/kg and 96.0% (95% confidence interval, 79.6–99.9%) with 0.20 mg/kg. Both dose levels of SR29142 were equally effective at reducing plasma uric acid levels. In six patients, seven drug‐related adverse events of grade 1/2 occurred before chemotherapy. SR29142‐related, hypersensitivity‐associated reactions occurred in three patients, and rash, anorexia, application site pain and pyrexia occurred in one patient each; only five patients (10%) showed anti‐SR29142 antibodies by day 29. In conclusion, SR29142 is effective at reducing plasma uric acid levels with a tolerable safety profile as a single agent both prior to chemotherapy and during treatment. (Trial register: ClinicalTrials.gov, NCT00631579.) (Cancer Sci 2009; 100: 357–362)
Newer antifungal agents for invasive fungal infections in patients with haematological malignancy
Authors: Rogers Thomas R. , Frost Susanna 
Published: December 2008

SummarySince 2001 five new systemically administered antifungal agents have been approved for clinical use. This represents a major advance for antifungal therapy in haematological malignancy patients undergoing chemotherapy or haematopoietic stem cell transplant (HSCT). The echinocandins are a new class of antifungals with a novel mode of action. Capsofungin has already established itself as a valuable therapy for candidaemia and salvage therapy of invasive aspergillosis. Although both anidulafungin and micafungin are approved for treatment of candidiasis, their role in invasive aspergillosis requires more clinical trial evaluation. Of the two newer triazoles, voriconazole has been recommended in international guidelines as primary therapy for acute invasive aspergillosis. Posaconazole has a broad spectrum of activity in vitro and a potentially key role in antifungal prophylaxis in high‐risk HSCT recipients and during prolonged neutropenia. Although some of these drugs have important interactions with other medications, and potential toxicities, they are safer to use and more efficacious than amphotericin B deoxycholate. Their arrival gives more choices to treat rarer mycoses and will facilitate clinical trial assessment of combination therapy of aspergillosis where single agent therapy gives less than 50% success rates.
Why, when and how do fish populations decline, collapse and recover? The example of brown trout (Salmo trutta) in Rio Chaballos (northwestern Spain)
Authors: LOBÓN‐CERVIÁ JAVIER 
Published: December 2008

Summary1. Around the year 2000, historically abundant populations of brown trout (Salmo trutta) and Atlantic salmon (S. salar) co‐occurring in rivers flowing along the Cantabrian corridor of north‐western Spain showed a dramatic decline to alarming levels. For one reason or another, fishing was not banned and fishing pressure continued to reduce the few survivors. Unexpectedly, the populations recovered ‘naturally’ in a very short time period to the extent that in 2004–06 numbers had attained population sizes comparable to those of the mid 1980s.2. The population of brown trout in Rio Chaballos showed a boom‐and‐bust pattern concurrent with those observed across broader geographical scales. This study revisits a 22‐year data set to explore the nature of the severe decline and rapid recovery of this population.3. Recruitment was related to stream discharge in March that covers the emergence period and the earliest search stages for food. Coefficients of variation for discharge and recruitment increased over the years and were highly correlated with each other, demonstrating that increased temporal variability in recruitment is strongly linked to increased variability in stream discharge. In turn, recruitment appears to be the major determinant of year‐class strength and hence, of population size.4. A number of factors appeared to operate as resilience mechanisms, permitting the population to increase rapidly when environmental conditions are optimal. These include strong recruitment‐discharge relationships, short life‐span, small stocks of eggs or offspring required to fill the amount of space suitable for the youngest juveniles and a few females surviving to spawn for a second time.5. Implications for fishery management and conservation are discussed in the context of the expectation that these populations will vary over the coming years within ranges similar to those in this study.
Distribution of selected cariogenic bacteria in five different intra‐oral habitats in young children
Authors: GIZANI SOTIRIA , PAPAIOANNOU WILLIAM , HAFFAJEE ANNE D , KAVVADIA KATERINA , QUIRYNEN MARC , PAPAGIANNOULIS LIZA 
Published: December 2008

Background.  Knowledge of the colonization patterns and composition of the oral microbiota can lead to a better understanding of disease initiation.Aim.  The aim of this study was to examine the distribution of selected cariogenic bacteria in samples from five different oral habitats in young Greek children.Design.  Ninety‐three children 3–12 years old (mean + SD 7.9 ± 2.5) (60.2% male, 39.8% female) participated and split into three different age groups: primary (3–6 years), early mixed (6–9 years), and mixed dentition (9–12 years). Samples for bacterial enumeration were taken from saliva, supragingival and subgingival plaque, tongue dorsum, and soft tissues from each child, and were further analysed using checkerboard DNA–DNA hybridization.Results.  Mean counts and proportions of all the test bacteria differed significantly among sample locations. Cariogenic bacteria were present in almost all healthy children. Mean proportions of Streptococcus mutans isolated from soft tissue and Streptococcus sanguinis from soft tissue, subgingival and saliva samples increased significantly with age, whereas the opposite was seen for Lactobacillus acidophilus.Conclusions.  Cariogenic bacteria were present in almost all young children. Soft tissues, saliva, and tongue were more often colonized by cariogenic streptococcal species than teeth. These surfaces may serve as reservoirs for oral pathogens, requiring attention during preventive interventions.
Characterization and comparison of bone marrow and peripheral blood mononuclear cells used for cellular therapy in critical leg ischaemia: towards a new cellular product
Authors: Capiod J.‐C. , Tournois C. , Vitry F. , Sevestre M.‐A. , Daliphard S. , Reix T. , Nguyen P. , Lefrère J.‐J. , Pignon B. 
Published: December 2008

Background and Objectives  Autologous transplantation of either bone marrow (BM) or peripheral blood (PB) mononuclear cells (MNC) induces therapeutic angiogenesis in patients with peripheral arterial occlusive disease. Yet, the precise nature of the cellular product obtained from BM or PB and used in these therapeutic strategies remains unclear.Materials and Methods  We have analysed the characteristics of BM‐MNC and PB‐MNC collected without mobilization and implanted in patients with critical limb ischaemia in a clinical trial of cellular therapy including 16 individuals treated by BM‐MNC and eight by PB‐MNC. These MNCs were characterized by cell counts, viability assessment and enumeration of leucocyte subsets, CD34 stem and endothelial progenitor cells (EPCs) (CD34+/CD133+/VEGF‐R2+) by flow cytometry. Mean fluorescence intensity ratios were determined for CD34, CD133 and VEGF‐R2 markers. All analyses were simultaneously performed in two laboratories.Results  Accuracy and reliability between both laboratories were achieved. BM‐MNCs and PB‐MNCs were quantitatively and qualitatively heterogeneous and quite different from each other. Stem cells and EPCs were significantly more present in BM‐ compared to PB‐cell products, but with similar mean fluorescence intensity ratios. A weakly positive correlation was observed between CD34+ cell counts and EPCs levels, confirming the specificity of cell identification.Conclusion  A great variability was observed in cell product characteristics according to their origin and also between individuals. These data stress the necessity of optimal characterization of cell products especially in multicentric clinical trials.