Showing papers by "Radboud University Nijmegen published in 2006"
TL;DR: In this paper, it was shown that the Klein paradox can be tested in a conceptually simple condensed-matter experiment using electrostatic barriers in single and bi-layer graphene, showing that quantum tunnelling in these materials becomes highly anisotropic, qualitatively different from the case of normal, non-relativistic electrons.
Abstract: The so-called Klein paradox—unimpeded penetration of relativistic particles through high and wide potential barriers—is one of the most exotic and counterintuitive consequences of quantum electrodynamics. The phenomenon is discussed in many contexts in particle, nuclear and astro-physics but direct tests of the Klein paradox using elementary particles have so far proved impossible. Here we show that the effect can be tested in a conceptually simple condensed-matter experiment using electrostatic barriers in single- and bi-layer graphene. Owing to the chiral nature of their quasiparticles, quantum tunnelling in these materials becomes highly anisotropic, qualitatively different from the case of normal, non-relativistic electrons. Massless Dirac fermions in graphene allow a close realization of Klein’s gedanken experiment, whereas massive chiral fermions in bilayer graphene offer an interesting complementary system that elucidates the basic physics involved.
3,402 citations
TL;DR: Evidence of declines (pre-versus post-1980) in local bee diversity in Britain and the Netherlands is found and a causal connection between local extinctions of functionally linked plant and pollinator species is strongly suggested.
Abstract: Despite widespread concern about declines in pollination services, little is known about the patterns of change in most pollinator assemblages. By studying bee and hoverfly assemblages in Britain and the Netherlands, we found evidence of declines (pre-versus post-1980) in local bee diversity in both countries; however, divergent trends were observed in hoverflies. Depending on the assemblage and location, pollinator declines were most frequent in habitat and flower specialists, in univoltine species, and/or in nonmigrants. In conjunction with this evidence, outcrossing plant species that are reliant on the declining pollinators have themselves declined relative to other plant species. Taken together, these findings strongly suggest a causal connection between local extinctions of functionally linked plant and pollinator species.
2,616 citations
TL;DR: These probabilities allow urologists to easily calculate a superficial bladder cancer patient's short- and long-term risks of recurrence and progression after transurethral resection to determine the most appropriate treatment and frequency of follow-up.
2,459 citations
TL;DR: The OARSI cartilage OA histopathology grading system appears consistent and simple to apply as discussed by the authors, however, further studies are required to confirm the system's utility, as well as their reproducibility and validity.
1,813 citations
TL;DR: In this paper, a third type of integer quantum Hall effect is reported in bilayer graphene, where charge carriers have a parabolic energy spectrum but are chiral and show Berry's phase 2π affecting their quantum dynamics.
Abstract: There are two known distinct types of the integer quantum Hall effect. One is the conventional quantum Hall effect, characteristic of two-dimensional semiconductor systems1,2, and the other is its relativistic counterpart observed in graphene, where charge carriers mimic Dirac fermions characterized by Berry’s phase π, which results in shifted positions of the Hall plateaus3,4,5,6,7,8,9. Here we report a third type of the integer quantum Hall effect. Charge carriers in bilayer graphene have a parabolic energy spectrum but are chiral and show Berry’s phase 2π affecting their quantum dynamics. The Landau quantization of these fermions results in plateaus in Hall conductivity at standard integer positions, but the last (zero-level) plateau is missing. The zero-level anomaly is accompanied by metallic conductivity in the limit of low concentrations and high magnetic fields, in stark contrast to the conventional, insulating behaviour in this regime. The revealed chiral fermions have no known analogues and present an intriguing case for quantum-mechanical studies.
1,665 citations
TL;DR: How studies on joint attention, action observation, task sharing, action coordination and agency contribute to the understanding of the cognitive and neural processes supporting joint action are outlined.
1,598 citations
TL;DR: The Scale for the Assessment and Rating of Ataxia is a reliable and valid measure of ataxia, making it an appropriate primary outcome measure for clinical trials.
Abstract: OBJECTIVE: To develop a reliable and valid clinical scale measuring the severity of ataxia. METHODS: The authors devised the Scale for the Assessment and Rating of Ataxia (SARA) and tested it in two trials of 167 and 119 patients with spinocerebellar ataxia. RESULTS: The mean time to administer SARA in patients was 14.2 +/- 7.5 minutes (range 5 to 40). Interrater reliability was high, with an intraclass coefficient (ICC) of 0.98. Test-retest reliability was high with an ICC of 0.90. Internal consistency was high as indicated by Cronbach's alpha of 0.94. Factorial analysis revealed that the rating results were determined by a single factor. SARA ratings showed a linear relation to global assessments using a visual analogue scale, suggesting linearity of the scale (p < 0.0001, r(2) = 0.98). SARA score increased with the disease stage (p < 0.001) and was closely correlated with the Barthel Index (r = -0.80, p < 0.001) and part IV (functional assessment) of the Unified Huntington's Disease Rating Scale (UHDRS-IV) (r = -0.89, p < 0.0001), whereas it had only a weak correlation with disease duration (r = 0.34, p < 0.0002). CONCLUSIONS: The Scale for the Assessment and Rating of Ataxia is a reliable and valid measure of ataxia, making it an appropriate primary outcome measure for clinical trials.
1,392 citations
Lille University of Science and Technology1, Goddard Space Flight Center2, Goddard Institute for Space Studies3, Texas A&M University4, University of Maryland, Baltimore County5, University of Amsterdam6, Spanish National Research Council7, Royal Netherlands Meteorological Institute8, Radboud University Nijmegen9
TL;DR: In this article, the authors used shape mixtures of randomly oriented spheroids for modeling desert dust aerosol light scattering, and the results indicated that nonspherical particles with aspect ratios similar to 1.5 dominate in desert dust plumes, while in the case of background maritime aerosol spherical particles are dominant.
Abstract: [ 1] The possibility of using shape mixtures of randomly oriented spheroids for modeling desert dust aerosol light scattering is discussed. For reducing calculation time, look-up tables were simulated for quadrature coefficients employed in the numerical integration of spheroid optical properties over size and shape. The calculations were done for 25 bins of the spheroid axis ratio ranging from similar to 0.3 ( flattened spheroids) to similar to 3.0 ( elongated spheroids) and for 41 narrow size bins covering the size parameter range from similar to 0.012 to similar to 625. The look-up tables were arranged into a software package, which allows fast, accurate, and flexible modeling of scattering by randomly oriented spheroids with different size and shape distributions. In order to evaluate spheroid model and explore the possibility of aerosol shape identification, the software tool has been integrated into inversion algorithms for retrieving detailed aerosol properties from laboratory or remote sensing polarimetric measurements of light scattering. The application of this retrieval technique to laboratory measurements by Volten et al. ( 2001) has shown that spheroids can closely reproduce mineral dust light scattering matrices. The spheroid model was utilized for retrievals of aerosol properties from atmospheric radiation measured by AERONET ground-based Sun/sky-radiometers. It is shown that mixtures of spheroids allow rather accurate fitting of measured spectral and angular dependencies of observed intensity and polarization. Moreover, it is shown that for aerosol mixtures with a significant fraction of coarse-mode particles ( radii >= similar to 1 mu m), the nonsphericity of aerosol particles can be detected as part of AERONET retrievals. The retrieval results indicate that nonspherical particles with aspect ratios similar to 1.5 and higher dominate in desert dust plumes, while in the case of background maritime aerosol spherical particles are dominant. Finally, the potential of using AERONET derived spheroid mixtures for modeling the effects of aerosol particle nonsphericity in other remote sensing techniques is discussed. For example, the variability of lidar measurements ( extinction to backscattering ratio and signal depolarization ratio) is illustrated and analyzed. Also, some potentially important differences in the sensitivity of angular light scattering to parameters of nonspherical versus spherical aerosols are revealed and discussed.
1,260 citations
TL;DR: It is shown that the direct, anaerobic oxidation of methane coupled to denitrification of nitrate is possible and that the reaction presented here may make a substantial contribution to biological methane and nitrogen cycles.
Abstract: Modern agriculture has accelerated biological methane and nitrogen cycling on a global scale. Freshwater sediments often receive increased downward fluxes of nitrate from agricultural runoff and upward fluxes of methane generated by anaerobic decomposition. In theory, prokaryotes should be capable of using nitrate to oxidize methane anaerobically, but such organisms have neither been observed in nature nor isolated in the laboratory. Microbial oxidation of methane is thus believed to proceed only with oxygen or sulphate. Here we show that the direct, anaerobic oxidation of methane coupled to denitrification of nitrate is possible. A microbial consortium, enriched from anoxic sediments, oxidized methane to carbon dioxide coupled to denitrification in the complete absence of oxygen. This consortium consisted of two microorganisms, a bacterium representing a phylum without any cultured species and an archaeon distantly related to marine methanotrophic Archaea. The detection of relatives of these prokaryotes in different freshwater ecosystems worldwide indicates that the reaction presented here may make a substantial contribution to biological methane and nitrogen cycles.
1,171 citations
TL;DR: This work uses environmental genomics—the reconstruction of genomic data directly from the environment—to assemble the genome of the uncultured anammox bacterium Kuenenia stuttgartiensis from a complex bioreactor community, and identifies candidate genes responsible for ladderane biosynthesis and biological hydrazine metabolism.
Abstract: Ten years ago a fortuitous discovery led to the identification of oceanic bacteria capable of anaerobic ammonium oxidation (anammox). It was soon recognized that the anammox reaction has great ecological significance, as it is responsible for removing up to 50% of fixed nitrogen from the oceans. The genome of the anammox bacterium Kuenenia stuttgartiensis has now been sequenced in a remarkable feat of what is called environmental genomics. Anammox bacteria grow very slowly and are not available in pure culture. For genome analysis an inoculum of wastewater sludge was grown in a bioreactor for one year, clocking up 10–15 generations. The DNA of the whole microbial community was sequenced and the genome of this one anammox bacterium was deduced from the results. With the genome sequence known, it will be possible to gain insight into the metabolism and evolution of these important bacteria. The genome of Kuenenia stuttgartiensis has been sequenced to learn more about anaerobic ammonium oxidation. Anaerobic ammonium oxidation (anammox) has become a main focus in oceanography and wastewater treatment1,2. It is also the nitrogen cycle's major remaining biochemical enigma. Among its features, the occurrence of hydrazine as a free intermediate of catabolism3,4, the biosynthesis of ladderane lipids5,6 and the role of cytoplasm differentiation7 are unique in biology. Here we use environmental genomics8,9—the reconstruction of genomic data directly from the environment—to assemble the genome of the uncultured anammox bacterium Kuenenia stuttgartiensis10 from a complex bioreactor community. The genome data illuminate the evolutionary history of the Planctomycetes and allow us to expose the genetic blueprint of the organism's special properties. Most significantly, we identified candidate genes responsible for ladderane biosynthesis and biological hydrazine metabolism, and discovered unexpected metabolic versatility.
1,099 citations
Leeds General Infirmary1, Saarland University2, Johns Hopkins University3, University of Paris4, Radboud University Nijmegen5, University of Duisburg-Essen6, Royal Melbourne Hospital7, St George's Hospital8, City of Hope National Medical Center9, Trinity College, Dublin10, University of Naples Federico II11, University of Ulm12, Cleveland Clinic13, Case Western Reserve University14, Alexion Pharmaceuticals15
TL;DR: Eculizumab is an effective therapy for PNH and Clinically significant improvements were found in the quality of life, as measured by scores on the Functional Assessment of Chronic Illness Therapy-Fatigue instrument and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire.
Abstract: BACKGROUND We tested the safety and efficacy of eculizumab, a humanized monoclonal antibody against terminal complement protein C5 that inhibits terminal complement activation, in patients with paroxysmal nocturnal hemoglobinuria (PNH). METHODS We conducted a double-blind, randomized, placebo-controlled, multicenter, phase 3 trial. Patients received either placebo or eculizumab intravenously; eculizumab was given at a dose of 600 mg weekly for 4 weeks, followed 1 week later by a 900-mg dose and then 900 mg every other week through week 26. The two primary end points were the stabilization of hemoglobin levels and the number of units of packed red cells transfused. Biochemical indicators of intravascular hemolysis and the patients' quality of life were also assessed. RESULTS Eighty-seven patients underwent randomization. Stabilization of hemoglobin levels in the absence of transfusions was achieved in 49% (21 of 43) of the patients assigned to eculizumab and none (0 of 44) of those assigned to placebo (P<0.001). During the study, a median of 0 units of packed red cells was administered in the eculizumab group, as compared with 10 units in the placebo group (P<0.001). Eculizumab reduced intravascular hemolysis, as shown by the 85.8% lower median area under the curve for lactate dehydrogenase plotted against time (in days) in the eculizumab group, as compared with the placebo group (58,587 vs. 411,822 U per liter; P<0.001). Clinically significant improvements were also found in the quality of life, as measured by scores on the Functional Assessment of Chronic Illness Therapy-Fatigue instrument (P<0.001) and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire. Of the 87 patients, 4 in the eculizumab group and 9 in the placebo group had serious adverse events, none of which were considered to be treatment-related; all these patients recovered without sequelae. CONCLUSIONS Eculizumab is an effective therapy for PNH.
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TL;DR: In this article, an anomalous quantum Hall effect was observed in the first two-dimensional carbon material, which is known as Graphene, and it also provides a bridge between condensed matter physics and quantum electrodynamics and opens new perspectives for carbon-based electronics.
Abstract: Carbon is one of the most intriguing elements in the Periodic Table. It forms many allotropes, some being known from ancient times (diamond and graphite) and some discovered ten to twenty years ago (fullerenes, nanotubes). Quite interestingly, the two-dimensional form (graphene) has been obtained only very recently, and immediately attracted great deal of attention. Electrons in graphene, obeying linear dispersion relation, behave like massless relativistic particles, which results in a number of very peculiar electronic properties observed in this first two-dimensional material: from an anomalous quantum Hall effect to the absence of localization. It also provides a bridge between condensed matter physics and quantum electrodynamics and opens new perspectives for carbon-based electronics.
TL;DR: Graphene weak-localization magnetoresistance is strongly suppressed and, in some cases, completely absent, due to mesoscopic corrugations of graphene sheets which can cause a dephasing effect similar to that of a random magnetic field.
Abstract: Low-field magnetoresistance is ubiquitous in low-dimensional metallic systems with high resistivity and well understood as arising due to quantum interference on self-intersecting diffusive trajectories. We have found that in graphene this weak-localization magnetoresistance is strongly suppressed and, in some cases, completely absent. The unexpected observation is attributed to mesoscopic corrugations of graphene sheets which can cause a dephasing effect similar to that of a random magnetic field.
TL;DR: Enhanced neuronal gamma-band synchronization and shortened neuronal response latencies to an attended stimulus seem to have direct effects on visually triggered behaviour, reflecting an early neuronal correlate of efficient visuo-motor integration.
Abstract: Our capacity to process and respond behaviourally to multiple incoming stimuli is very limited. To optimize the use of this limited capacity, attentional mechanisms give priority to behaviourally relevant stimuli at the expense of irrelevant distractors. In visual areas, attended stimuli induce enhanced responses and an improved synchronization of rhythmic neuronal activity in the gamma frequency band (40–70 Hz)1,2,3,4,5,6,7,8,9,10,11. Both effects probably improve the neuronal signalling of attended stimuli within and among brain areas1,12,13,14,15,16. Attention also results in improved behavioural performance and shortened reaction times. However, it is not known how reaction times are related to either response strength or gamma-band synchronization in visual areas. Here we show that behavioural response times to a stimulus change can be predicted specifically by the degree of gamma-band synchronization among those neurons in monkey visual area V4 that are activated by the behaviourally relevant stimulus. When there are two visual stimuli and monkeys have to detect a change in one stimulus while ignoring the other, their reactions are fastest when the relevant stimulus induces strong gamma-band synchronization before and after the change in stimulus. This enhanced gamma-band synchronization is also followed by shorter neuronal response latencies on the fast trials. Conversely, the monkeys' reactions are slowest when gamma-band synchronization is high in response to the irrelevant distractor. Thus, enhanced neuronal gamma-band synchronization and shortened neuronal response latencies to an attended stimulus seem to have direct effects on visually triggered behaviour, reflecting an early neuronal correlate of efficient visuo-motor integration.
TL;DR: This methods review shows that most challenges are resolved when taking into account the principles that guide the conduct of conventional surveys.
Abstract: The World Wide Web (WWW) is increasingly being used as a tool and platform for survey research. Two types of electronic or online surveys available for data collection are the email and Web based survey, and they constitute the focus of this paper. We address a multitude of issues researchers should consider before and during the use of this method of data collection: advantages and liabilities with this form of survey research, sampling problems, questionnaire design considerations, suggestions in approaching potential respondents, response rates and aspects of data processing. Where relevant, the methodological issues involved are illustrated with examples from our own research practice. This methods review shows that most challenges are resolved when taking into account the principles that guide the conduct of conventional surveys.
TL;DR: TREX1, encoding the major mammalian 3′ → 5′ DNA exonuclease, is the AGS1 gene, and AGS-causing mutations result in abrogation of TREX1 enzyme activity, and failure of which results in the triggering of an abnormal innate immune response.
Abstract: Aicardi-Goutieres syndrome (AGS) presents as a severe neurological brain disease and is a genetic mimic of the sequelae of transplacentally acquired viral infection. Evidence exists for a perturbation of innate immunity as a primary pathogenic event in the disease phenotype. Here, we show that TREX1, encoding the major mammalian 3' --> 5' DNA exonuclease, is the AGS1 gene, and AGS-causing mutations result in abrogation of TREX1 enzyme activity. Similar loss of function in the Trex1(-/-) mouse leads to an inflammatory phenotype. Our findings suggest an unanticipated role for TREX1 in processing or clearing anomalous DNA structures, failure of which results in the triggering of an abnormal innate immune response.
TL;DR: It is concluded that the chronic situation of sustained physiological activation and incomplete recovery is an important pathway to chronic health impairment.
Abstract: This contribution aims at shedding light on the mechanisms that may underlie the relationship between acute reactions to stressful work characteristics and employee health in the long run. Recovery, a process of psychophysiological unwinding after effort expenditure, is considered a vital link in this relationship. This link is explained on the basis of assumptions from theories on effort, recovery, and sustained activation. It is argued that recovery after work (external recovery) is particularly necessitated when recovery opportunities during worktime (internal recovery) are insufficient. It is further argued that two conditions may impede the recovery process by sustaining physiological activation, prolonged exposure to work demands (working long hours) and cognitive stress-related processes (such as rumination). These theoretical assumptions are substantiated by empirical support from previous laboratory and field research. It is concluded that the chronic situation of sustained physiological activation and incomplete recovery is an important pathway to chronic health impairment.
University of California, Los Angeles1, University of Toronto2, Leiden University3, Charité4, Chapel Allerton Hospital5, University of Texas Southwestern Medical Center6, Hospital for Special Surgery7, University of Erlangen-Nuremberg8, University of California, San Diego9, Guy's and St Thomas' NHS Foundation Trust10, University of Washington11, MetroHealth12, Medical University of Vienna13, Radboud University Nijmegen14, Cedars-Sinai Medical Center15, Oregon Health & Science University16
TL;DR: The consensus statement is annotated to document the credibility of the data supporting it as much as possible and the number of possible references has become so large that reviews are sometimes included; if they contain category A references, they will be referred to as category A evidence.
Abstract: As in previous years, the consensus group to consider the use of biological agents in the treatment of rheumatic diseases met during the 13th Annual Workshop on Advances in Targeted Therapies in April, 2011. The group consisted of rheumatologists from a number of universities among the continents of Europe, North America, South America, Australia and Asia.
Pharmaceutical industry support was obtained from a number of companies for the annual workshop itself, but these companies had no part in the decisions about the specific programme or about the academic participants at this conference. Representatives of the supporting sponsors participated in the initial working groups to supply factual information. The sponsors did not participate in the drafting of the consensus statement.
This consensus was prepared from the perspective of the treating physician.
In view of the new data for abatacept, B cell-specific agents, interleukin 1 (IL-1) antagonists, tocilizumab (TCZ) and tumour necrosis factor α blocking agents (TNF inhibitors), an update of the previous consensus statement is appropriate. To allow ease of updating, the 2010 (data from March 2009 to January 2010) updates are incorporated into the body of the article, while 2011 updates (February 2010–January 2011) are separated and highlighted. The consensus statement is annotated to document the credibility of the data supporting it as much as possible. This annotation is that of Shekelle et al and is described in appendix 1.1 We have modified the Shekelle annotation by designating all abstracts as ‘category D evidence’, whether they describe well-controlled trials or not, as details of the study were often not available in the abstracts. Further, the number of possible references has become so large that reviews are sometimes included; if they contain category A references, they will be referred to as category A evidence.
The rheumatologists and bioscientists who attended …
TL;DR: These studies establish germline KRAS mutations as a cause of human disease and infer that the constellation of developmental abnormalities seen in Noonan syndrome spectrum is, in large part, due to hyperactive Ras.
Abstract: Noonan syndrome (MIM 163950) is characterized by short stature, facial dysmorphism and cardiac defects. Heterozygous mutations in PTPN11, which encodes SHP-2, cause approximately 50% of cases of Noonan syndrome. The SHP-2 phosphatase relays signals from activated receptor complexes to downstream effectors, including Ras. We discovered de novo germline KRAS mutations that introduce V14I, T58I or D153V amino acid substitutions in five individuals with Noonan syndrome and a P34R alteration in a individual with cardio-facio-cutaneous syndrome (MIM 115150), which has overlapping features with Noonan syndrome. Recombinant V14I and T58I K-Ras proteins show defective intrinsic GTP hydrolysis and impaired responsiveness to GTPase activating proteins, render primary hematopoietic progenitors hypersensitive to growth factors and deregulate signal transduction in a cell lineage-specific manner. These studies establish germline KRAS mutations as a cause of human disease and infer that the constellation of developmental abnormalities seen in Noonan syndrome spectrum is, in large part, due to hyperactive Ras.
TL;DR: This paper examined the effects of transformational and transactional leadership on teachers' job satisfaction, organizational commitment, and organizational citizenship behavior in the context of schools in a specific developing country context, that of Tanzania.
Abstract: This article examines the effects of transformational and transactional leadership on teachers' job satisfaction, organizational commitment, and organizational citizenship behavior in the context of schools in a specific developing country context, that of Tanzania. It does so by testing a model of such effects using a set of data collected from a sample of Tanzanian primary school teachers. Regression analyses show transformational leadership dimensions to have strong effects on teachers' job satisfaction, organizational commitment, and organizational citizenship behavior. Transformational leadership had significant add-on effects to transactional leadership in prediction of job satisfaction, organizational commitment, and organizational citizenship behavior. Job satisfaction appears to be a mediator of the effects of transformational leadership on teachers' organizational commitment and organizational citizenship behavior. Implications and directions for future research are discussed.
TL;DR: A review of some recent efforts to construct highly ordered assemblies of porphyrins, phthalocyanines, and perylenes by means of self-assembly in solution and on surfaces, and by attaching them to polymeric scaffolds is given in this paper.
Abstract: Porphyrins, phthalocyanines, and perylenes are compounds with great potential for serving as components of molecular materials that possess unique electronic, magnetic and photophysical properties. In general, a highly specific communication between a large number of these chromophores is required in order to express their function to a maximal level, and for this reason it is of importance to construct arrays in which the molecules are organized in well-defined geometries with respect to their neighbors. This review is an account of some recent efforts to construct highly ordered assemblies of porphyrins, phthalocyanines, and perylenes by means of self-assembly in solution and on surfaces, and by attaching them to polymeric scaffolds.
TL;DR: It is found that similarity between phenotypes reflects biological modules of interacting functionally related genes, including relatedness at the level of protein sequence, protein motifs, functional annotation, and direct protein–protein interaction.
Abstract: A number of large-scale efforts are underway to define the relationships between genes and proteins in various species. But, few attempts have been made to systematically classify all such relationships at the phenotype level. Also, it is unknown whether such a phenotype map would carry biologically meaningful information. We have used text mining to classify over 5000 human phenotypes contained in the Online Mendelian Inheritance in Man database. We find that similarity between phenotypes reflects biological modules of interacting functionally related genes. These similarities are positively correlated with a number of measures of gene function, including relatedness at the level of protein sequence, protein motifs, functional annotation, and direct protein-protein interaction. Phenotype grouping reflects the modular nature of human disease genetics. Thus, phenotype mapping may be used to predict candidate genes for diseases as well as functional relations between genes and proteins. Such predictions will further improve if a unified system of phenotype descriptors is developed. The phenotype similarity data are accessible through a web interface at http://www.cmbi.ru.nl/MimMiner/.
TL;DR: In this article, the authors examined whether foreign and domestic banks in Central and Eastern Europe react differently to business cycles and banking crises and found that during crisis periods domestic banks contracted their credit base, whereas greenfield foreign banks did not.
Abstract: We examine whether foreign and domestic banks in Central and Eastern Europe react differently to business cycles and banking crises. Our panel dataset comprises data of more than 250 banks for the period 1993–2000, with information on bank ownership and mode of entry. During crisis periods domestic banks contracted their credit base, whereas greenfield foreign banks did not. Also, home country conditions matter for foreign bank growth, as there is a significant negative relationship between home country economic growth and host country credit by greenfields. Finally, greenfield foreign banks’ credit growth is influenced by the health of the parent bank.
TL;DR: In this article, the appearance of a finite conductivity without scattering is shown to be a characteristic property of Dirac chiral fermions in two dimensions, based on the Kubo and Landauer formulas.
Abstract: It has been recently demonstrated experimentally that graphene, or single-layer carbon, is a gapless semiconductor with massless Dirac energy spectrum. A finite conductivity per channel of order of e2/h in the limit of zero temperature and zero charge carrier density is one of the striking features of this system. Here we analyze this peculiarity based on the Kubo and Landauer formulas. The appearance of a finite conductivity without scattering is shown to be a characteristic property of Dirac chiral fermions in two dimensions.
TL;DR: Over the course of the entire study, hippocampal activity for correct confident recognition continued to decrease, whereas activity in a ventral medial prefrontal region increased, which may prompt a revision of classical consolidation theory, incorporating a transfer of putative linking nodes from hippocampal to prelimbic prefrontal areas.
Abstract: Retrieval of recently acquired declarative memories depends on the hippocampus, but with time, retrieval is increasingly sustainable by neocortical representations alone. This process has been conceptualized as system-level consolidation. Using functional magnetic resonance imaging, we assessed over the course of three months how consolidation affects the neural correlates of memory retrieval. The duration of slow-wave sleep during a nap/rest period after the initial study session and before the first scan session on day 1 correlated positively with recognition memory performance for items studied before the nap and negatively with hippocampal activity associated with correct confident recognition. Over the course of the entire study, hippocampal activity for correct confident recognition continued to decrease, whereas activity in a ventral medial prefrontal region increased. These findings, together with data obtained in rodents, may prompt a revision of classical consolidation theory, incorporating a transfer of putative linking nodes from hippocampal to prelimbic prefrontal areas.
King's College London1, Trinity College, Dublin2, Radboud University Nijmegen3, Memorial Hospital of South Bend4, University of Göttingen5, Ghent University6, Shaare Zedek Medical Center7, University of Valencia8, University Medical Center Groningen9, University of Zurich10, VU University Amsterdam11, University of Southampton12, State University of New York Upstate Medical University13
TL;DR: In this article, the authors examined 1038 single-nucleotide polymorphisms (SNPs) spanning 51 candidate genes involved in the regulation of neurotransmitter pathways, particularly dopamine, norepinephrine and serotonin pathways, in addition to circadian rhythm genes.
Abstract: Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder, starting in early childhood and persisting into adulthood in the majority of cases. Family and twin studies have demonstrated the importance of genetic factors and candidate gene association studies have identified several loci that exert small but significant effects on ADHD. To provide further clarification of reported associations and identify novel associated genes, we examined 1038 single-nucleotide polymorphisms (SNPs) spanning 51 candidate genes involved in the regulation of neurotransmitter pathways, particularly dopamine, norepinephrine and serotonin pathways, in addition to circadian rhythm genes. Analysis used within family tests of association in a sample of 776 DSM-IV ADHD combined type cases ascertained for the International Multi-centre ADHD Gene project. We found nominal significance with one or more SNPs in 18 genes, including the two most replicated findings in the literature: DRD4 and DAT1. Gene-wide tests, adjusted for the number of SNPs analysed in each gene, identified associations with TPH2, ARRB2, SYP, DAT1, ADRB2, HES1, MAOA and PNMT. Further studies will be needed to confirm or refute the observed associations and their generalisability to other samples.
TL;DR: Compared with use of T2-weighted MR imaging, use of dynamic contrast-enhanced MR imaging and 3D MR spectroscopic imaging facilitated significantly improved accuracy in prostate cancer localization.
Abstract: Purpose: To prospectively determine the accuracies of T2-weighted magnetic resonance (MR) imaging, dynamic contrast material–enhanced MR imaging, and quantitative three-dimensional (3D) proton MR spectroscopic imaging of the entire prostate for prostate cancer localization, with whole-mount histopathologic section findings as the reference standard. Materials and Methods: This study was approved by the institutional review board, and informed consent was obtained from all patients. Thirty-four consecutive men with a mean age of 60 years and a mean prostate-specific antigen level of 8 ng/mL were examined. The median biopsy Gleason score was 6. T2-weighted MR imaging, dynamic contrast-enhanced MR imaging, and 3D MR spectroscopic imaging were performed, and on the basis of the image data, two readers with different levels of experience recorded the location of the suspicious peripheral zone and central gland tumor nodules on each of 14 standardized regions of interest (ROIs) in the prostate. The degree of di...
TL;DR: In this article, a comparison of specific sets of inequalities (class, race/ethnicity, sexual orientation and gender) is made and the authors argue that a "one size fits all" approach to addressing multiple discrimination is based on an incorrect assumption of sameness or equivalence of the social categories connected to inequalities.
Abstract: The European Union (EU), a pioneer in gender equality policies, is moving from predominantly attending to gender inequality, towards policies that address multiple inequalities. This article argues that there are tendencies at EU level to assume an unquestioned similarity of inequalities, to fail to address the structural level and to fuel the political competition between inequalities. Based upon a comparison of specific sets of inequalities (class, race/ethnicity, sexual orientation and gender), this article explores where and how structural and political intersectionality might be relevant. It argues that a ‘one size fits all' approach to addressing multiple discrimination is based on an incorrect assumption of sameness or equivalence of the social categories connected to inequalities and of the mechanisms and processes that constitute them. Focusing on similarities ignores the differentiated character and dynamics of inequalities. It also overlooks the political dimension of equality goals. Moreover, it has become clear that attention to structural mechanisms and to the role of the state and the private sphere in reproducing inequalities is much needed. The final part of the article presents constructive ideas for a more comprehensive way of addressing multiple inequalities.
TL;DR: Recommendations for the use of G-CSF in adult cancer patients at risk of chemotherapy-induced neutropenia are formulated and it is recommended that patient-related adverse risk factors such as elderly age, be evaluated in the overall assessment of FN risk prior to administering each cycle of chemotherapy.
TL;DR: In this paper, four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the minimal supersymmetric standard model (MSSM).
Abstract: The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric standard model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of “benchmark” models, including CP-conserving and CP-violating scenarios. These interpretations lead in all cases to large exclusions in the MSSM parameter space. Absolute limits are set on the parameter cosβ and, in some scenarios, on the masses of neutral Higgs bosons.