cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Meropenem Plasma and Interstitial Soft Tissue Concentrations in Obese and Nonobese Patients—A Controlled Clinical Trial
Creators: name: Simon, Philipp
name: Petroff, David
name: Busse, David
name: Heyne, Jana
name: Girrbach, Felix
name: Dietrich, Arne
name: Kratzer, Alexander Ludwig
name: Zeitlinger, Markus
name: Kloft, Charlotte
name: Kees, Frieder
name: Wrigge, Hermann
name: Dorn, Christoph
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: antibiotic dosing; concentrations; meropenem; microdialysis; obesity; pharmacokinetics; soft tissue; pharmacodynamics
subject: 615 Pharmazie

description: Background: This controlled clinical study aimed to investigate the impact of obesity on plasma and tissue pharmacokinetics of meropenem. Methods: Obese (body mass index (BMI) ≥ 35 kg/m2) and age-/sex-matched nonobese (18.5 kg/m2 ≥ BMI ≤ 30 kg/m2) surgical patients received a short-term infusion of 1000-mg meropenem. Concentrations were determined via high performance liquid chromatography-ultraviolet (HPLC-UV) in the plasma and microdialysate from the interstitial fluid (ISF) of subcutaneous tissue up to eight h after dosing. An analysis was performed in the plasma and ISF by noncompartmental methods. Results: The maximum plasma concentrations in 15 obese (BMI 49 ± 11 kg/m2) and 15 nonobese (BMI 24 ± 2 kg/m2) patients were 54.0 vs. 63.9 mg/L (95% CI for difference: −18.3 to −3.5). The volume of distribution was 22.4 vs. 17.6 L, (2.6–9.1), but the clearance was comparable (12.5 vs. 11.1 L/h, −1.4 to 3.1), leading to a longer half-life (1.52 vs. 1.31 h, 0.05–0.37) and fairly similar area under the curve (AUC)8h (78.7 vs. 89.2 mg*h/L, −21.4 to 8.6). In the ISF, the maximum concentrations differed significantly (12.6 vs. 18.6 L, −16.8 to −0.8) but not the AUC8h (28.5 vs. 42.0 mg*h/L, −33.9 to 5.4). Time above the MIC (T > MIC) in the plasma and ISF did not differ significantly for MICs of 0.25–8 mg/L. Conclusions: In morbidly obese patients, meropenem has lower maximum concentrations and higher volumes of distribution. However, due to the slightly longer half-life, obesity has no influence on the T > MIC, so dose adjustments for obesity seem unnecessary.
Security Operations Center: A Systematic Study and Open Challenges
Creators: name: Vielberth, Manfred
name: Böhm, Fabian
name: Fichtinger, Ines
name: Pernul, Günther
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Security management, security operations center, security operations, SOC
subject: 004 Informatik
subject: 330 Wirtschaft

description: Since the introduction of Security Operations Centers (SOCs) around 15 years ago, their importance has grown significantly, especially over the last five years. This is mainly due to the paramount necessity to prevent major cyber incidents and the resulting adoption of centralized security operations in businesses. Despite their popularity, existing academic work on the topic lacks a generally accepted view and focuses mainly on fragments rather than looking at it holistically. These shortcomings impede further innovation. In this paper, a comprehensive literature survey is conducted to collate different views. The discovered literature is then used to determine the current state-of-the-art of SOCs and derive primary building blocks. Current challenges within a SOC are identified and summarized. A notable shortcoming of academic research is its focus on the human and technological aspects of a SOC while neglecting the connection of these two areas by specific processes (especially by non-technical processes). However, this area is essential for leveraging the full potential of a SOC in the future.
Ontology-Based and Architecture-Based Method for the Development of Interoperable Care Systems for Type 2 Diabetes Mellitus
Creators: name: Uribe, G. A.
name: Blobel, Bernd
name: Lopez, D. M.
name: Schulz, Stefan
name: Ruiz, Alonso A.
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: 610 Medizin

description: Processes like the care of type 2 diabetes mellitus patients require support by information systems considering the heterogeneity of the actors from different domains involved, enabling harmonization and integration of their specific methodologies and knowledge representation approaches towards interdisciplinary cooperation. Currently, the development of systems starts from the simplified information world, ignoring the aforementioned heterogeneity and specificity of real-world processes. This paper aims to demonstrate the feasibility of developing an adaptive, interoperable and intelligent system that supports the major aspects of type 2 diabetes mellitus care based on the Generic Component Model as formal methodology for modelling universal systems. The result is a deployable solution based on a formal representation of the diabetes care system, its objectives, and the intended business process. The implemented system enables reasoning over the data, inferring medical diagnosis. The effectiveness of the inference was evaluated, obtaining an F-measure of 0.89. The methods presented in this paper helps to build high quality models based on computation-independent aspects, which enable the construction of knowledge-based adaptive, intelligent and interoperable eHealth systems.
Littlewood-Richardson coefficients for reflection groups
Creators: name: Berenstein, Arkady
name: Richmond, Edward
Publisher: name: arXiv
Year: 2010
Subjects: subject: Representation Theory (math.RT)
subject: Algebraic Topology (math.AT)
subject: Combinatorics (math.CO)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics

description: In this paper we explicitly compute all Littlewood-Richardson coefficients for semisimple or Kac-Moody groups G, that is, the structure coefficients of the cohomology algebra H^*(G/P), where P is a parabolic subgroup of G. These coefficients are of importance in enumerative geometry, algebraic combinatorics and representation theory. Our formula for the Littlewood-Richardson coefficients is given in terms of the Cartan matrix and the Weyl group of G. However, if some off-diagonal entries of the Cartan matrix are 0 or -1, the formula may contain negative summands. On the other hand, if the Cartan matrix satisfies $a_{ij}a_{ji}\ge 4$ for all $i,j$, then each summand in our formula is nonnegative that implies nonnegativity of all Littlewood-Richardson coefficients. We extend this and other results to the structure coefficients of the T-equivariant cohomology of flag varieties G/P and Bott-Samelson varieties Gamma_\ii(G).
description: 51 pages, AMSLaTeX, typos corrected
Activation of Epidermal Growth Factor Receptor Sensitizes Glioblastoma Cells to Hypoxia-Induced Cell Death
Creators: name: Luger, Anna-Luisa
name: Lorenz, Nadja I.
name: Urban, Hans
name: Divé, Iris
name: Engel, Anna L.
name: Strassheimer, Florian
name: Dettmer, Katja
name: Zeiner, Pia S.
name: Shaid, Shabnam
name: Struve, Nina
name: Kriegs, Malte
name: Hofmann, Ute
name: Oefner, Peter J.
name: Harter, Patrick N.
name: Steinbach, Joachim P.
name: Ronellenfitsch, Michael W.
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: EGFR; EGFRvIII mutation; glioblastoma; hypoxia; starvation
subject: 610 Medizin

description: Background: The epidermal growth factor receptor (EGFR) signaling pathway is genetically activated in approximately 50% of glioblastomas (GBs). Its inhibition has been explored clinically but produced disappointing results, potentially due to metabolic effects that protect GB cells against nutrient deprivation and hypoxia. Here, we hypothesized that EGFR activation could disable metabolic adaptation and define a GB cell population sensitive to starvation. Methods: Using genetically engineered GB cells to model different types of EGFR activation, we analyzed changes in metabolism and cell survival under conditions of the tumor microenvironment. Results: We found that expression of mutant EGFRvIII as well as EGF stimulation of EGFR-overexpressing cells impaired physiological adaptation to starvation and rendered cells sensitive to hypoxia-induced cell death. This was preceded by adenosine triphosphate (ATP) depletion and an increase in glycolysis. Furthermore, EGFRvIII mutant cells had higher levels of mitochondrial superoxides potentially due to decreased metabolic flux into the serine synthesis pathway which was associated with a decrease in the NADPH/NADP+ ratio. Conclusions: The finding that EGFR activation renders GB cells susceptible to starvation could help to identify a subgroup of patients more likely to benefit from starvation-inducing therapies.
Does the Attentional Boost Effect Depend on the Intentionality of Encoding? Investigating the Mechanisms Underlying Memory for Visual Objects Presented at Behaviorally Relevant Moments in Time
Creators: name: Hutmacher, Fabian
name: Kuhbandner, Christof
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: attentional boost effect, visual long-term memory, incidental encoding, intentional encoding, perceptual long-term memory
subject: 150 Psychologie

description: Pictures in a rapid serial visual presentation (RSVP) stream are better remembered when they are simultaneously presented with targets of an unrelated detection task than when they are presented with distractors. However, it is unclear whether this so-called “attentional boost effect” depends on the intentionality of encoding. While there are studies suggesting that the attentional boost effect even occurs when encoding is incidental, there are several methodological issues with these studies, which may have undermined the incidental encoding instructions. The present study (N = 141) investigated the role of the intentionality of encoding with an improved experimental design. Specifically, to prevent a spill-over of intentional resources to the pictures in the RSVP stream, the speed of the stream was increased (to four pictures per second) and each picture was presented only once during the course of the experiment. An attentional boost effect was only found when encoding was intentional but not when encoding was incidental. Interestingly, memory performance for incidentally encoded pictures was nevertheless substantially above chance, independently of whether images were presented with search-relevant targets or distractors. These results suggest that the attentional boost effect is a memory advantage that occurs only under intentional encoding conditions, and that perceptual long-term memory representations are formed as a natural product of perception, independently of the presence of behaviorally relevant events.
Does Open Access Foster Interdisciplinary Citation? Decomposing Open Access Citation Advantage
Creators: name: Nishikawa, Kai
name: Murakami, Akiyoshi
Publisher: name: arXiv
Year: 2024
Subjects: subject: Digital Libraries (cs.DL)
subject: FOS: Computer and information sciences

description: The existence of an open access (OA) citation advantage, that is, whether OA increases citations, has been a topic of interest for many years. Although numerous previous studies have focused on whether OA increases citations, expectations for OA go beyond that. One such expectation is the promotion of knowledge transfer across various fields. This study aimed to clarify whether OA, especially gold OA, increases interdisciplinary citations in various natural science fields. Specifically, we measured the effect of OA on interdisciplinary and within-discipline citation counts by decomposing an existing metric of the OA citation advantage. The results revealed that OA increases both interdisciplinary and within-discipline citations in many fields and increases only interdisciplinary citations in chemistry, computer science, and clinical medicine. Among these fields, clinical medicine tends to obtain more interdisciplinary citations without being influenced by specific journals or papers. The findings indicate that OA fosters knowledge transfer to different fields, which extends our understanding of its effects.
Synchrosqueezing-based Recovery of Instantaneous Frequency from Nonuniform Samples
Creators: name: Thakur, Gaurav
name: Wu, Hau-Tieng
Publisher: name: arXiv
Year: 2010
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We propose a new approach for studying the notion of the instantaneous frequency of a signal. We build on ideas from the Synchrosqueezing theory of Daubechies, Lu and Wu and consider a variant of Synchrosqueezing, based on the short-time Fourier transform, to precisely define the instantaneous frequencies of a multi-component AM-FM signal. We describe an algorithm to recover these instantaneous frequencies from the uniform or nonuniform samples of the signal and show that our method is robust to noise. We also consider an alternative approach based on the conventional, Hilbert transform-based notion of instantaneous frequency to compare to our new method. We use these methods on several test cases and apply our results to a signal analysis problem in electrocardiography.
description: 19 pages, 9 figures
Habitat matters – Strong genetic and epigenetic differentiation in Linum catharticum from dry and wet grasslands
Creators: name: Pagel, Ellen
name: Poschlod, Peter
name: Reisch, Christoph
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: calcareous grasslands, ecotypes, epigenetics, habitat differentiation, Linum catharticum, litter meadows
subject: 580 Pflanzen (Botanik)

description: Plant species differ in their ecological amplitude, with some species occurring in very different habitats under strongly differentiated environmental conditions. We were interested in to what extent the occurrence of Linum catharticum in dry calcareous grasslands (Bromion) and wet litter meadows (Molinion), two habitats on opposing ends concerning, for example, moisture level, is reflected on the genetic and epigenetic level. Using AFLP (amplified fragment length polymorphisms) and MSAP (methylation sensitive amplification polymorphisms) analyses, we studied the genetic and epigenetic variation of L. catharticum from calcareous grasslands and litter meadows. From each habitat, we included five study sites with 16 individuals per sampling location. We observed lower genetic than epigenetic diversity, but considerable differentiation among habitats, which was stronger on the genetic than the epigenetic level. Additionally, we observed a strong correlation of genetic and epigenetic distance, irrespective of geographic distance. The dataset included a large portion of fragments exclusively found in individuals from one or the other habitat. Some epigenetic fragments even occurred in different methylation states depending on the habitat. We conclude that environmental effects act on both the genetic and epigenetic level, producing the clear differentiation among plant individuals from calcareous grasslands and litter meadows. These results may also point into the direction of ecotype formation in this species.
title: CERN Proceedings, Vol 1 (2019): Proceedings of the 15th International Conference on Nuclear Reaction Mechanisms
title: Proceedings of the 15th International Conference on Nuclear Reaction Mechanisms
titleType: AlternativeTitle
Creators: name: CERN Proceedings
Publisher: name: CERN Proceedings
Year: 2019

description: Varenna (Italy), Villa Monastero, June 11–15, 2018

Editors: F. Cerutti, A. Ferrari, T. Kawano, F. Salvat-Pujol, and P. Talou

 ISBN 978-92-9083-519-6 (paperback)  ISBN 978-92-9083-520-2 (PDF)
Minimal representations via Bessel operators
Creators: name: Hilgert, Joachim
name: Kobayashi, Toshiyuki
name: Möllers, Jan
Publisher: name: arXiv
Year: 2011
Subjects: subject: Representation Theory (math.RT)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 22E45 (Primary) 17C30, 33E30 (Secondary)

description: We construct an L^2-model of "very small" irreducible unitary representations of simple Lie groups G which, up to finite covering, occur as conformal groups Co(V) of simple Jordan algebras V. If $V$ is split and G is not of type A_n, then the representations are minimal in the sense that the annihilators are the Joseph ideals. Our construction allows the case where G does not admit minimal representations. In particular, applying to Jordan algebras of split rank one we obtain the entire complementary series representations of SO(n,1)_0. A distinguished feature of these representations in all cases is that they attain the minimum of the Gelfand--Kirillov dimensions among irreducible unitary representations. Our construction provides a unified way to realize the irreducible unitary representations of the Lie groups in question as Schroedinger models in L^2-spaces on Lagrangian submanifolds of the minimal real nilpotent coadjoint orbits. In this realization the Lie algebra representations are given explicitly by differential operators of order at most two, and the key new ingredient is a systematic use of specific second-order differential operators (Bessel operators) which are naturally defined in terms of the Jordan structure.
Importance of berries in the Inuit biocultural system : a multidisciplinary investigation in the Canadian North
Creators: name: Boulanger-Lapointe, Noémie
Publisher: name: University of British Columbia
Year: 2017

description: In the Canadian North, the fruits of berry producing species are a highly nutritious source of food available to both animals and humans. Although relatively well-documented in boreal and subarctic environments, little information on the ecology and cultural importance of berry species is available for the Arctic. This research aims to fill that gap using archives, interviews, ecological monitoring as well as remote sensing tools. An overview of the different uses and roles of berry plants and berry picking as reported in close to 200 interviews conducted with Elders and active land users across Inuit Nunangat since the 1980s was compiled. Through extensive fieldwork and remote sensing analyses, local availability and animal consumption of berries were investigated in detail in the vicinity of Arviat, Nunavut. Finally, an overall assessment of berry productivity in the Canadian North was conducted using berry productivity data collected between 2007 and 2015 at 10 sites from Nain, Nunatsiavut, and Kugluktuk, Nunavut, to Alexandra Fiord, Ellesmere Island, Nunavut. Results showed the extensive and intimate knowledge of berry plants throughout Inuit Nunangat; berries were and remain culturally and nutritionally important for Inuit. Detailed landscape analyses in Arviat, revealed the large number of berries produced and the relatively large amount consumed by animals, mainly geese. Nevertheless, animals only eat a marginal portion of the total production at the site. Perceived competition for the resource may be linked to the small number of productive and accessible patches in the vicinity of the community. The analysis of inter-annual and regional variations in berry productivity illustrated that the abundance of berries in the Arctic is comparable or greater to certain forested areas in North America and Fennoscandia. The most productive sites were located in the low Arctic, in dry-mesic sites dominated by semi-prostrate dwarf shrubs. Inter-annual productivity analyses showed the complex interaction of winter and spring precipitation as well as summer temperature on productivity. Overall, this research demonstrates the cultural and ecological importance of berry species across Inuit Nunangat and suggests ongoing impacts of community development, pollution and recent climate change on the quality and availability of this important resource.
Attenuation of hypoxic pulmonary vasoconstriction by acetazolamide and methazolamide : a randomized crossover study.
Creators: name: Boulet, Lindsey
Publisher: name: University of British Columbia
Year: 2017

description: Context: Acetazolmaide (AZ) is used in the prophylactic treatment of altitude illnesses. AZ is also known to attenuate HPV and increase alveolar ventilation. Methazolamide (MZ) is an analog to AZ and its effects on ventilation and HPV are unknown. Objective. To determine if MZ can improve oxygenation and attenuate HPV to a similar extent as AZ in healthy humans exposed to poikilocapnic hypoxia. Design, Setting, Participants and Interventions: A randomized, placebo controlled, double-blinded trial was performed in healthy participants at the Cardiopulmonary Lab for Experimental and Applied Physiology. Prior to each of the three experimentation days, participants were administered one of three treatments (AZ, MZ, & placebo) at random for two days. Each treatment was separated by a 10-day washout period to avoid contamination from previous trials. During each trial, participants were exposed to poikilocapnic hypoxia (FIO2 ≈ 0.12) for 60 minutes. Primary Outcome Measures: Partial pressure of alveolar O₂ (PAO₂) represented oxygenation while pulmonary artery systolic pressure (PASP) and total pulmonary resistance (TPR) were chosen to represent the HPV response. Results: All participants (n = 11) completed all three trials. Change in Q̇ from baseline to hypoxia was not different between treatments. Change in PASP was significantly lower with the AZ (8.0 ± 0.7 mmHg) and MZ (9.0 ± 0.9 mmHg) treatments compared to placebo (PASP: 14.1 ± 1.3 mmHgP < 0.05). Change in PAO₂ was also decreased with both drug treatments (AZ: 54.8 ± 1.3 mmHg; MZ: 53.9 ± 1.3 mmHg) compared to placebo (48.5 ± 1.6 mmHg; P < 0.05). Conclusion: MZ attenuated HPV to the same degree as AZ. MZ also resulted in a similar improvement in PAO₂ as AZ during hypoxia compared to placebo. Trial Registration: This study was registered with the U.S. National Institutes of Health: NCT02760121 Funding: This project was funded by the Canadian Foundation for Innovation and by the Natural Science and Engineering Council of Canada.
‘Wait and wait, that is the only thing they can say’: a qualitative study exploring experiences of immigrated Syrian doctors applying for medical license in Germany
Creators: name: Loss, Julika
name: Aldoughle, Yamen
name: Sauter, Alexandra
name: von Sommoggy, Julia
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Licensure process, Syrian doctors, Qualitative research, Migration experiences, Germany
subject: 610 Medizin

description: Background Due to the civil war in Syria, many Syrian citizens have had to flee their country during recent years, among them many physicians. Germany is among the preferred immigration countries. Immigrant Syrian physicians could help overcome the prevailing shortage of medical specialists in Germany. This study explores the experiences and perceptions of Syrian physicians of the licensure process and job application. The study aims at understanding barriers in integrating Syrian doctors into the German health care system. Methods We conducted 20 semi standardized interviews with Syrian doctors (n = 17 m; n = 3 f) living in different federal states in Germany. The interviews dealt with the procedure of the accreditation process, its speed and challenges, the interactions with authorities, and the job application process; they were transcribed verbatim. A detailed content analysis was performed. Results All interviewees described the licensure process as a complex, lengthy, ever-changing and non-transparent procedure, which is perceived as a partly unfair, sometimes arbitrary bureaucracy. They often feel at mercy of Government employees and report experiences with reviewers who ask for absurd and impossible accomplishments, refuse to give information, and act at random. As a consequence, the interviewees describe themselves as depressed, irritated and/or in despair. According to the interviews, informational and practical support from official institutions was scarce. Instead, the Syrian doctors relied on peers or, in some cases, German friends to understand the requirements and seek information about the licensure process. To find a job placement, it was very helpful, if not essential, to have a German acquaintance establishing contact with possible employers. All three interviewed female doctors reported that their wearing a Hijab led to episodes of discrimination in their job search. Conclusions The study points towards the necessity to establish an official information source which provides immigrant doctors with accurate and detailed information about the licensure process, e.g. required documents, estimated waiting times, regulation for courses and exams, criteria regarding credentials, sources of help, etc. Additionally, it seems advisable to consider providing help with regard to the job search and sensitize hospital management for cultural and religious diversity to avoid discrimination.
Influence of quality of intensive care on quality of life/return to work in survivors of the acute respiratory distress syndrome: prospective observational patient cohort study (DACAPO)
Creators: name: Apfelbacher, Christian J.
name: Brandstetter, Susanne
name: Blecha, Sebastian
name: Dodoo-Schittko, Frank
name: Brandl, Magdalena
name: Karagiannidis, Christian
name: Quintel, Michael
name: Kluge, Stefan
name: Putensen, Christian
name: Bercker, Sven
name: Ellger, Björn
name: Kirschning, Thomas
name: Arndt, Christian
name: Meybohm, Patrick
name: Weber-Carstens, Steffen
name: Bein, Thomas
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: ARDS, Quality of care, Volume, ICU, Health-related quality of life, Return to work
subject: 610 Medizin

description: Background Significant long-term reduction in health-related quality of life (HRQoL) is often observed in survivors of the acute respiratory distress syndrome (ARDS), and return to work (RtW) is limited. There is a paucity of data regarding the relationship between the quality of care (QoC) in the intensive care unit (ICU) and both HRQoL and RtW in ARDS survivors. Therefore, the aim of our study was to investigate associations between indicators of QoC and HRQoL and RtW in a cohort of survivors of ARDS. Methods To determine the influence of QoC on HRQoL and RtW 1 year after ICU-discharge, ARDS patients were recruited into a prospective multi-centre patient cohort study and followed up regularly after discharge. Patients were asked to complete self-report questionnaires on HRQoL (Short Form 12 physical component scale (PCS) and mental component scale (MCS)) and RtW. Indicators of QoC pertaining to volume, structural and process quality, and general characteristics were recorded on ICU level. Associations between QoC indicators and HrQoL and RtW were investigated by multivariable linear and Cox regression modelling, respectively. B values and hazard ratios (HRs) are reported with corresponding 95% confidence intervals (CIs). Results 877 (of initially 1225 enrolled) people with ARDS formed the DACAPO survivor cohort, 396 were finally followed up to 1 year after discharge. The twelve-month survivors were characterized by a reduced HRQoL with a greater impairment in the physical component (Md 41.2 IQR [34–52]) compared to the mental component (Md 47.3 IQR [33–57]). Overall, 50% of the patients returned to work. The proportion of ventilated ICU patients showed significant negative associations with both 12 months PCS (B = − 11.22, CI −20.71; − 1,74) and RtW (HR = 0,18, CI 0,04;0,80). All other QoC indicators were not significantly related to outcome. Conclusions Associations between ICU QoC and long-term HrQoL and RtW were weak and largely non-significant. Residual confounding by case mix, treatment variables before or during ICU stay and variables pertaining to the post intensive care period (e.g. rehabilitation) cannot be ruled out.
Zero Variance Markov Chain Monte Carlo for Bayesian Estimators
Creators: name: Mira, Antonietta
name: Solgi, Reza
name: Imparato, Daniele
Publisher: name: arXiv
Year: 2010
Subjects: subject: Computation (stat.CO)
subject: FOS: Computer and information sciences
subject: 62

description: Interest is in evaluating, by Markov chain Monte Carlo (MCMC) simulation, the expected value of a function with respect to a, possibly unnormalized, probability distribution. A general purpose variance reduction technique for the MCMC estimator, based on the zero-variance principle introduced in the physics literature, is proposed. Conditions for asymptotic unbiasedness of the zero-variance estimator are derived. A central limit theorem is also proved under regularity conditions. The potential of the idea is illustrated with real applications to probit, logit and GARCH Bayesian models. For all these models, a central limit theorem and unbiasedness for the zero-variance estimator are proved (see the supplementary material available on-line).
description: 26 pages, 4 figures. This is an updated version: the results are the same as the previous one, but presentation is more essential
Dynamical Coulomb Blockade Observed in Nano-Sized Electrical Contacts
Creators: name: Brun, Christophe
name: Müller, Konrad H.
name: Hong, I-Po
name: Patthey, François
name: Flindt, Christian
name: Schneider, Wolf-Dieter
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Electrical contacts between nano-engineered systems are expected to constitute the basic building blocks of future nano-scale electronics. However, the accurate characterization and understanding of electrical contacts at the nano-scale is an experimentally challenging task. Here we employ low-temperature scanning tunneling spectroscopy to investigate the conductance of individual nano-contacts formed between flat Pb islands and their supporting substrates. We observe a suppression of the differential tunnel conductance at small bias voltages due to dynamical Coulomb blockade effects. The differential conductance spectra allow us to determine the capacitances and resistances of the electrical contacts which depend systematically on the island--substrate contact area. Calculations based on the theory of environmentally assisted tunneling agree well with the measurements.
description: 5 pages, 3 figures, to appear in PRL
Further Validation of Measures of Target Detection and Stereotype Activation in the Stereotype Misperception Task
Creators: name: Reichardt, Regina
name: Rivers, Andrew M.
name: Reichardt, Joerg
name: Sherman, Jeffrey W.
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: implicit, stereotyping, multinomial modeling, automatic, stereotype activation
subject: 150 Psychologie

description: Previous research presented a multinomial model to estimate four latent processes (target detection, stereotype activation, stereotype application, guessing) that contribute to responses in the Stereotype Misperception Task, an indirect measure of stereotyping (Krieglmeyer and Sherman, 2012). The present research further investigates the validity of the target detection (D) and stereotype activation (SAC) parameters. To this end, the data from Experiment 2 and Experiment 4 in Krieglmeyer and Sherman (2012) were re-analyzed using a bootstrap method to investigate the robustness of the results. Furthermore, two conceptual replication studies were conducted and analyzed with the same bootstrap method. A manipulation of target distinctness influenced the D parameter as predicted. A manipulation of prime prototypicality influenced the SAC parameter as predicted. Taken together, the results support the validity of the D and SAC model parameters.
Expression of Generalized Newton Iteration Method via Generalized Local Fractional Taylor Series
Creators: name: Xiao-Jun, Yang
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 65F08, 28A80, 26A18, 26A99

description: Local fractional derivative and integrals are revealed as one of useful tools to deal with everywhere continuous but nowhere differentiable functions in fractal areas ranging from fundamental science to engineering. In this paper, a generalized Newton iteration method derived from the generalized local fractional Taylor series with the local fractional derivatives is reviewed. Operators on real line numbers on a fractal space are induced from Cantor set to fractional set. Existence for a generalized fixed point on generalized metric spaces may take place.
description: Yang, X.J.Expression of generalized Newton iteration method via generalized local fractional Taylor series, Advances in Computer Science and its Applications, 1(2) (2012) 89-92
Towards individualized cortical thickness assessment for clinical routine
Creators: name: Tahedl, Marlene
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Cortical thickness, Neuroimaging, Magnetic resonance imaging (MRI), Individual diagnosis, Atrophy, Neurological assessment
subject: 610 Medizin

description: Background Cortical thickness measures the width of gray matter of the human cortex. It can be calculated from T1-weighted magnetic resonance images (MRI). In group studies, this measure has been shown to correlate with the diagnosis/prognosis of a number of neurologic and psychiatric conditions, but has not been widely adapted for clinical routine. One of the reasons for this might be that there is no reference system which allows to rate individual cortical thickness data with respect to a control population. Methods To address this problem, this study compared different methods to assess statistical significance of cortical thinning, i.e. atrophy. All compared methods were nonparametric and encompassed rating an individual subject’s data set with respect to a control data population. Null distributions were calculated using data from the Human Connectome Project (HCP, n = 1000), and an additional HCP data set (n = 113) was used to calculate sensitivity and specificity to compare the different methods, whereas atrophy was simulated for sensitivity assessment. Validation measures were calculated for the entire cortex (“cumulative”) and distinct brain regions (“regional”) where possible. Results The approach yielding the highest combination of specificity and sensitivity implemented generating null distributions for anatomically distinct brain regions, based on the most extreme values observed in the population. With that method, while regional variations were observed, cumulative specificity of 98.9% and cumulative sensitivity at 80% was achieved for simulated atrophy of 23%. Conclusions This study shows that validated rating of individual cortical thickness measures is possible, which can help clinicians in their daily routine to discover signs of atrophy before they become visually apparent on an unprocessed MRI. Furthermore, given different pathologies present with distinct atrophy patterns, the regional validation proposed here allows to detect distinct patterns of atrophy, which can further enhance differential diagnosis/prognosis.
Spotlight on Alkali Metals: The Structural Chemistry of Alkali Metal Thallides
Creators: name: Gärtner, Stefanie
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: thallide; alkali metal; X-ray crystal structure; Zintl phases
subject: 540 Chemie

description: Alkali metal thallides go back to the investigative works of Eduard Zintl about base metals in negative oxidation states. In 1932, he described the crystal structure of NaTl as the first representative for this class of compounds. Since then, a bunch of versatile crystal structures has been reported for thallium as electronegative element in intermetallic solid state compounds. For combinations of thallium with alkali metals as electropositive counterparts, a broad range of different unique structure types has been observed. Interestingly, various thallium substructures at the same or very similar valence electron concentration (VEC) are obtained. This in return emphasizes that the role of the alkali metals on structure formation goes far beyond ancillary filling atoms, which are present only due to charge balancing reasons. In this review, the alkali metals are in focus and the local surroundings of the latter are discussed in terms of their crystallographic sites in the corresponding crystal structures.
Simply connected surfaces of general type in positive characteristic via deformation theory
Creators: name: Lee, Yongnam
name: Nakayama, Noboru
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14J29 (Primary) 14B07, 14J17 (Secondary)

description: Algebraically simply connected surfaces of general type with p_g=q=0 and 1\le K^2\le 4 in positive characteristic (with one exception in K^2=4) are presented by using a Q-Gorenstein smoothing of two-dimensional toric singularities, a generalization of Lee-Park's construction in the field of complex numbers to the positive characteristic case, and Grothendieck's specialization theorem for the fundamental group.
description: 78 pages, 16 figures, Final version will appear in Proc. London Math
Optical discovery of probable stellar tidal disruption flares
Creators: name: van Velzen, Sjoert
name: Farrar, Glennys R.
name: Gezari, Suvi
name: Morrell, Nidia
name: Zaritsky, Dennis
name: Ostman, Linda
name: Smith, Mathew
name: Gelfand, Joseph
name: Drake, Andrew J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Using archival SDSS multi-epoch imaging data (Stripe 82), we have searched for the tidal disruption of stars by super-massive black holes in non-active galaxies. Two candidate tidal disruption events (TDEs) are identified. They have optical black-body temperatures 2 10^4 K and observed peak luminosities M_g=-18.3 and -20.4; their cooling rates are very low, qualitatively consistent with expectations for tidal disruption flares. Their properties are examined using i) SDSS imaging to compare them to other flares observed in the search, ii) UV emission measured by GALEX and iii) spectra of the hosts and of one of the flares. Our pipeline excludes optically identifiable AGN hosts, and our variability monitoring over 9 years provides strong evidence that these are not flares in hidden AGNs. The spectra and color evolution of the flares are unlike any SN observed to date, their strong late-time UV emission is particularly distinctive, and they are nuclear at high resolution, arguing against their being first cases of a previously-unobserved class of SNe or more extreme examples of known SN types. Taken together, the observed properties are difficult to reconcile with a SN or AGN-flare explanation, although an entirely new process specific to the inner few-hundred parsecs of non-active galaxies cannot be excluded. Our observed rate and method show the feasibility of obtaining a candidate TDE sample of hundreds of events and O(1) purity, using geometric resolution and host and flare color alone. A by-product of this work is quantification of the power-spectrum of extreme flares in AGNs.
description: Accepted for publication in ApJ; 25 pages, 21 figures, 5 tables. The rate estimate of the first version has been moved to a separate, forthcoming paper
Modules over algebraic cobordism
Creators: name: Elmanto, Elden
name: Hoyois, Marc
name: Khan, Adeel
name: Sosnilo, Vladimir
name: Yakerson, Maria
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: 510 Mathematik

description: We prove that the ∞-category of MGL-modules over any scheme is equivalent to the ∞-category of motivic spectra with finite syntomic transfers. Using the recognition principle for infinite P1-loop spaces, we deduce that very effective MGL -modules over a perfect field are equivalent to grouplike motivic spaces with finite syntomic transfers. Along the way, we describe any motivic Thom spectrum built from virtual vector bundles of nonnegative rank in terms of the moduli stack of finite quasi-smooth derived schemes with the corresponding tangential structure. In particular, over a regular equicharacteristic base, we show that Ω∞P1MGL is the A1-homotopy type of the moduli stack of virtual finite flat local complete intersections, and that for n>0, Ω∞P1ΣnP1MGL is the A1-homotopy type of the moduli stack of finite quasi-smooth derived schemes of virtual dimension −n.
Floquet oscillations in periodically driven Dirac systems
Creators: name: Junk, Vanessa
name: Reck, Phillipp
name: Gorini, Cosimo
name: Richter, Klaus
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Floquet, Bloch, Floquet-Bloch oscillations, time periodic systems
subject: 530 Physik

description: Electrons in a lattice exhibit time-periodic motion, known as Bloch oscillation, when subject to an additional static electric field. Here we show that a corresponding dynamics can occur upon replacing the spatially periodic potential by a time-periodic driving: Floquet oscillations of charge carriers in a spatially homogeneous system. The time lattice of the driving gives rise to Floquet bands that, for systems with linear dispersion, take on the role of the usual Bloch bands. For two cases, harmonic driving and periodic kicking through pulses, we numerically demonstrate the existence of such oscillations, both by directly propagating wave packets and based on a complementary Floquet analysis. The Floquet oscillations feature richer oscillation patterns than their Bloch counterpart and enable the imaging of Floquet bands. Moreover, their period can be directly tuned through the driving frequency. Such oscillations should be experimentally observable in effective Dirac systems, such as graphene, when illuminated with circularly polarized light.
Conserved genomic neighborhood is a strong but no perfect indicator for a direct interaction of microbial gene products
Creators: name: Esch, Robert
name: Merkl, Rainer
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Protein-protein interaction, Complex formation, Sequence similarity network, Genome neighborhood network, Binary classifier
subject: 570 Biowissenschaften, Biologie

description: Background The order of genes in bacterial genomes is not random; for example, the products of genes belonging to an operon work together in the same pathway. The cotranslational assembly of protein complexes is deemed to conserve genomic neighborhoods even stronger than a common function. This is why a conserved genomic neighborhood can be utilized to predict, whether gene products form protein complexes. Results We were interested to assess the performance of a neighborhood-based classifier that analyzes a large number of genomes. Thus, we determined for the genes encoding the subunits of 494 experimentally verified hetero-dimers their local genomic context. In order to generate phylogenetically comprehensive genomic neighborhoods, we utilized the tools offered by the Enzyme Function Initiative. For each subunit, a sequence similarity network was generated and the corresponding genome neighborhood network was analyzed to deduce the most frequent gene product. This was predicted as interaction partner, if its abundance exceeded a threshold, which was the frequency giving rise to the maximal Matthews correlation coefficient. For the threshold of 16%, the true positive rate was 45%, the false positive rate 0.06%, and the precision 55%. For approximately 20% of the subunits, the interaction partner was not found in a neighborhood of ± 10 genes. Conclusions Our phylogenetically comprehensive analysis confirmed that complex formation is a strong evolutionary factor that conserves genome neighborhoods. On the other hand, for 55% of the cases analyzed here, classification failed. Either, the interaction partner was not present in a ± 10 gene window or was not the most frequent gene product.
Limitation for linear maps in a class for detection and quantification of bipartite nonclassical correlation
Creators: name: SaiToh, Akira
name: Rahimi, Robabeh
name: Nakahara, Mikio
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: 15A86, 81P45

description: Eigenvalue-preserving-but-not-completely-eigenvalue-preserving (EnCE) maps were previously introduced for the purpose of detection and quantification of nonclassical correlation, employing the paradigm where nonvanishing quantum discord implies the existence of nonclassical correlation. It is known that only the matrix transposition is nontrivial among Hermiticity-preserving (HP) linear EnCE maps when we use the changes in the eigenvalues of a density matrix due to a partial map for the purpose. In this paper, we prove that this is true even among not-necessarily HP (nnHP) linear EnCE maps. The proof utilizes a conventional theorem on linear preservers. This result imposes a strong limitation on the linear maps and promotes the importance of nonlinear maps.
description: 10 pages, no figure, v1: 6 pages, v2: 13 pages, minor revision, style changed, proofs in Section 4 changed, v3: minor revision, Remark 2 added, to appear in QIC
Thick branes with a nonminimally coupled bulk-scalar field
Creators: name: Guo, Heng
name: Liu, Yu-Xiao
name: Zhao, Zhen-Hua
name: Chen, Feng-Wei
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper, we investigate thick branes with a nonminimally coupled background scalar field, whose solution is a single-kink or a double-kink. The effects of the nonminimal coupling constant $ξ$ on the structure of the thick branes and the localization of gravity, fermions, scalars and vectors are discussed. It is shown that each brane will split into two sub-branes as increasing the nonminimal coupling constant $ξ$. By investigating the tensor perturbation equations of gravity and the general covariant Dirac equation of fermions, we find that both the gravity zero mode and left-chiral fermion zero mode are localized at the center of the single-kink branes and localized between the two sub-branes generated by the double-kink, which indicates that the constant $ξ$ does not effect the localization of these zero modes. However, the zero mode of scalars is localized on each sub-brane (for both single-kink and double-kink branes) when $ξ$ is larger than its critical value $ξ_0$. The effects of the nonminimal coupling constant $ξ$ on the resonances of gravity and fermions with finite lifetime on the branes are also discussed.
description: V2: 33 pages, 17 figures, 3 tables, published version