Showing papers by "University of Warsaw published in 2008"
TL;DR: The Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) at CERN as mentioned in this paper was designed to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10(34)cm(-2)s(-1)
Abstract: The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10(34)cm(-2)s(-1) (10(27)cm(-2)s(-1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4 pi solid angle. Forward sampling calorimeters extend the pseudo-rapidity coverage to high values (vertical bar eta vertical bar <= 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.
5,193 citations
TL;DR: A special issue on entrepreneurship in emerging economies examines the literature that exists to date in this important domain and reviews the research that was generated as part of this special issue as mentioned in this paper, concluding with a discussion of the critical future research needs in this area.
Abstract: Emerging economies are characterized by an increasing market orientation and an expanding economic foundation. The success of many of these economies is such that they are rapidly becoming major economic forces in the world. Entrepreneurship plays a key role in this economic development. Yet to date, little is known about entrepreneurship in emerging economies. This introductory article to the special issue on entrepreneurship in emerging economies examines the literature that exists to date in this important domain. It then reviews the research that was generated as part of this special issue on this topic. The article concludes with a discussion of the critical future research needs in this area.
872 citations
TL;DR: It is shown that, through controlling the modal structure of the photon pair emission, one can generate pairs in factorable states and thence eliminate the need for spectral filters in multiple-source interference schemes.
Abstract: We present an experimental demonstration of heralded single photons prepared in pure quantum states from a parametric down-conversion source. It is shown that, through controlling the modal structure of the photon pair emission, one can generate pairs in factorable states and thence eliminate the need for spectral filters in multiple-source interference schemes. Indistinguishable heralded photons were generated in two independent spectrally engineered sources and Hong-Ou-Mandel interference observed between them without spectral filters. The measured visibility of 94.4% sets a minimum bound on the mean photon purity.
590 citations
02 Sep 2008
TL;DR: The main purpose of this book is to study weighted spaces and to obtain conditions on the weights that are necessary and sufficient to achieve various notions of tractability, depending on how to measure the lack of exponential dependence.
Abstract: In this paper I present a history of tractability of continuous problems, which has its beginning in the successful numerical tests for highdimensional integration of finance problems. Tractability results will be illustrated for two multivariate problems, integration and linear tensor products problems, in the worst case setting. My talk at FoCM'08 in Hong Kong and this paper are based on the book Tractability of Multivariate Problems , written jointly with Erich Novak. The first volume of our book has been recently published by the European Mathematical Society. Introduction Many people have recently become interested in studying the tractability of continuous problems. This area of research addresses the computational complexity of multivariate problems defined on spaces of functions of d variables, with d that can be in the hundreds or thousands; in fact, d can even be arbitrarily large. Such problems occur in numerous applications including physics, chemistry, finance, economics, and the computational sciences. As with all problems arising in information-based complexity, we want to solve multivariate problems to within ∈, using algorithms that use finitely many functions values or values of some linear functionals. Let n (∈, d ) be the minimal number of function values or linear functionals that is needed to compute the solution of the d -variate problem to within ∈. For many multivariate problems defined over standard spaces of functions n (∈, d ) is exponentially large in d .
569 citations
09 Sep 2008
TL;DR: The Handbook of Granular Computing offers a comprehensive reference source for the granular computing community, edited by and with contributions from leading experts in the field, and represents a significant and valuable contribution to the literature.
Abstract: Although the notion is a relatively recent one, the notions and principles of Granular Computing (GrC) have appeared in a different guise in many related fields including granularity in Artificial Intelligence, interval computing, cluster analysis, quotient space theory and many others. Recent years have witnessed a renewed and expanding interest in the topic as it begins to play a key role in bioinformatics, e-commerce, machine learning, security, data mining and wireless mobile computing when it comes to the issues of effectiveness, robustness and uncertainty. The Handbook of Granular Computing offers a comprehensive reference source for the granular computing community, edited by and with contributions from leading experts in the field. Includes chapters covering the foundations of granular computing, interval analysis and fuzzy set theory; hybrid methods and models of granular computing; and applications and case studies. Divided into 5 sections: Preliminaries, Fundamentals, Methodology and Algorithms, Development of Hybrid Models and Applications and Case Studies. Presents the flow of ideas in a systematic, well-organized manner, starting with the concepts and motivation and proceeding to detailed design that materializes in specific algorithms, applications and case studies. Provides the reader with a self-contained reference that includes all pre-requisite knowledge, augmented with step-by-step explanations of more advanced concepts. The Handbook of Granular Computing represents a significant and valuable contribution to the literature and will appeal to a broad audience including researchers, students and practitioners in the fields of Computational Intelligence, pattern recognition, fuzzy sets and neural networks, system modelling, operations research and bioinformatics.
543 citations
TL;DR: This article investigated collective memory in inhabitants of two twin cities, Lviv (Ukraine, previously Lwow, Poland) and Wroc"aw (Poland, previously Breslau, Germany).
539 citations
Pennsylvania State University1, Special Astrophysical Observatory2, University of Hertfordshire3, Purple Mountain Observatory4, Brera Astronomical Observatory5, University College London6, Liverpool John Moores University7, Goddard Space Flight Center8, University of Leicester9, University of Warsaw10, University of Nevada, Las Vegas11, Universities Space Research Association12, University of Milan13, University of Amsterdam14, Marshall Space Flight Center15, Hebrew University of Jerusalem16, University of Bologna17, Spanish National Research Council18, European Southern Observatory19, Space Telescope Science Institute20, ASTRON21, Leiden University22, Swinburne University of Technology23, University of Ljubljana24, Warsaw University of Technology25, INAF26, University of Warwick27, Aryabhatta Research Institute of Observational Sciences28, Joint Institute for VLBI in Europe29, University of California, Santa Cruz30, University of Perugia31
TL;DR: Observations of the extraordinarily bright prompt optical and γ-ray emission of GRB 080319B that provide diagnostics within seconds of its formation, followed by broadband observations of the afterglow decay that continued for weeks.
Abstract: Long-duration gamma-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation from the collapse of massive stars Previous early optical observations of even the most exceptional GRBs (990123 and 030329) lacked both the temporal resolution to probe the optical flash in detail and the accuracy needed to trace the transition from the prompt emission within the outflow to external shocks caused by interaction with the progenitor environment Here we report observations of the extraordinarily bright prompt optical and gamma-ray emission of GRB 080319B that provide diagnostics within seconds of its formation, followed by broadband observations of the afterglow decay that continued for weeks We show that the prompt emission stems from a single physical region, implying an extremely relativistic outflow that propagates within the narrow inner core of a two-component jet
524 citations
TL;DR: It is claimed that although young people demonstrate an apparent ease and familiarity with computers, they rely heavily on search engines, view rather than view, and much of the impact of ICTs on the young has been overestimated.
Abstract: Purpose – This article is an edited version of a report commissioned by the British Library and JISC to identify how the specialist researchers of the future (those born after 1993) are likely to access and interact with digital resources in five to ten years' time. The purpose is to investigate the impact of digital transition on the information behaviour of the Google Generation and to guide library and information services to anticipate and react to any new or emerging behaviours in the most effective way.Design/methodology/approach – The study was virtually longitudinal and is based on a number of extensive reviews of related literature, survey data mining and a deep log analysis of a British Library and a JISC web site intended for younger people.Findings – The study shows that much of the impact of ICTs on the young has been overestimated. The study claims that although young people demonstrate an apparent ease and familiarity with computers, they rely heavily on search engines, view rather than rea...
479 citations
TL;DR: In this paper, the authors focus on metal oxides for photoelectrolysis of water and show that careful design of thin films of photocatalyst material can eliminate potential losses in performance, i.e., recombination at grain boundaries.
Abstract: The development of sustainable hydrogen production is a key target in the further facilitation of a hydrogen economy. Solar hydrogen generation through the photolytic splitting of water sensitised by semiconductor materials is attractive as it is both renewable and does not lead to problematic by-products, unlike current hydrogen sources such as natural gas. Consequently, the development of these semiconductor materials has undergone considerable research since their discovery over 30 years ago and it would seem prescient to review the more practical results of this research. Among the critical factors influencing the choice of semiconductor material for photoelectrolysis of water are the band-gap energies, flat band potentials and stability towards photocorrosion; the latter of these points directs us to focus on metal oxides. Careful design of thin films of photocatalyst material can eliminate potential routes of losses in performance, i.e., recombination at grain boundaries. Methods to overcome these problems are discussed such as coupling a photoanode for photolysis of water to a photovoltaic cell in a “tandem cell” device.
455 citations
TL;DR: An overview of the current understanding of electro-oxidation of Pd in aqueous acidic and basic electrolytes is presented in this paper, where various experimental procedures commonly used to determine the real surface area of Palladium electrodes are outlined and compared.
390 citations
University of Zurich1, University of Notre Dame2, CERN3, Brookhaven National Laboratory4, Durham University5, University of Hamburg6, Max Planck Society7, Autonomous University of Madrid8, University of Victoria9, Technische Universität München10, University of Cagliari11, Instituto Superior Técnico12, University of British Columbia13, International School for Advanced Studies14, University of Valencia15, University of Warsaw16, University of Lyon17, Yale University18, University of Manchester19, University of Pisa20, RWTH Aachen University21, University of Wisconsin-Madison22, University of Sussex23, University of Tokyo24, Argonne National Laboratory25, Helsinki Institute of Physics26, University of Oregon27, University of Zagreb28, KEK29, University of Southampton30, Paul Scherrer Institute31, Petersburg Nuclear Physics Institute32, University of California33, University of Paris34, University of Rome Tor Vergata35, Bulgarian Academy of Sciences36, University of Salento37, Boston University38, University of Würzburg39, International Centre for Theoretical Physics40, University of Murcia41, University of Michigan42, Indian Institute of Science43
TL;DR: In this article, the authors discuss the theoretical, phenomenological and experimental issues related to flavor phenomena in the charged lepton sector and in flavor conserving CP-violating processes.
Abstract: This chapter of the report of the “Flavor in the era of the LHC” Workshop discusses the theoretical, phenomenological and experimental issues related to flavor phenomena in the charged lepton sector and in flavor conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavor structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the standard model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.
TL;DR: The aim of this mini-review is to illustrate the main analytical applications of Raman Spectroscopy-especially SERS spectroscopy, and mainly focus on the applications developed within the period from 2004 up to now.
Goethe University Frankfurt1, Warsaw University of Technology2, Pusan National University3, Polish Academy of Sciences4, Max Planck Society5, Eötvös Loránd University6, Hungarian Academy of Sciences7, Stony Brook University8, GSI Helmholtz Centre for Heavy Ion Research9, National and Kapodistrian University of Athens10, Joint Institute for Nuclear Research11, University of Washington12, Charles University in Prague13, Massachusetts Institute of Technology14, University of Marburg15, University of Warsaw16, Comenius University in Bratislava17, CERN18, Bulgarian Academy of Sciences19
TL;DR: In this paper, results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies.
Abstract: Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. Around 30A GeV a rapid change of the energy dependence for the yields of pions and kaons as well as for the shape of the transverse mass spectra is observed. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low CERN Super Proton Synchroton energies.
Ohio State University1, University of Notre Dame2, University of Warsaw3, Tel Aviv University4, Lawrence Livermore National Laboratory5, Princeton University6, University of Concepción7, University of Cambridge8, Chungbuk National University9, Korea Astronomy and Space Science Institute10, Nagoya University11, Massey University12, University of Auckland13, University of Canterbury14, Victoria University of Wellington15, Konan University16, University of Manchester17, Vaughn College of Aeronautics and Technology18, University of Exeter19, Centre national de la recherche scientifique20, Liverpool John Moores University21, University of St Andrews22, University of Tasmania23, Paul Sabatier University24, Dartmouth College25, University of Oxford26
TL;DR: Two planets with masses that could not have been detected with other techniques are identified; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common.
Abstract: Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the detection of a multiple-planet system with microlensing. We identify two planets with masses of ∼0.71 and ∼0.27 times the mass of Jupiter and orbital separations of ∼2.3 and ∼4.6 astronomical units orbiting a primary star of mass ∼0.50 solar mass at a distance of ∼1.5 kiloparsecs. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common.
TL;DR: The data disfavor two alternative explanations for the disappearance of neutrinos in flight: namely, neutrino decays into lighter particles and quantum decoherence of neutRinos, at the 3.7 and 5.7 standard-deviation levels, respectively.
Abstract: This Letter reports new results from the MINOS experiment based on a two-year exposure to muon neutrinos from the Fermilab NuMI beam. Our data are consistent with quantum-mechanical oscillations of neutrino flavor with mass splitting |Δm^2|=(2.43±0.13)×10^-3 eV^2 (68% C.L.) and mixing angle sin^2(2θ)>0.90 (90% C.L.). Our data disfavor two alternative explanations for the disappearance of neutrinos in flight: namely, neutrino decays into lighter particles and quantum decoherence of neutrinos, at the 3.7 and 5.7 standard-deviation levels, respectively.
TL;DR: In this paper, the authors study the flavor structure of 5D warped models that provide a dual description of a composite pseudo-Goldstone Higgs model and compare it to those in the RS model.
Abstract: We study the flavor structure of 5D warped models that provide a dual description of a composite pseudo-Goldstone Higgs. We first carefully re-examine the flavor constraints on the mass scale of new physics in the standard Randall-Sundrum-type scenarios, and find that the KK gluon mass should generically be heavier than about 21 TeV. We then compare the flavor structure of the composite Higgs models to those in the RS model. We find new contributions to flavor violation, which while still are suppressed by the RS-GIM mechanism, will enhance the amplitudes of flavor violations. In particular, there is a kinetic mixing term among the SM fields which (although parametrically not enhanced) will make the flavor bounds even more stringent than in RS. This together with the fact that in the pseudo-Goldstone scenario Yukawa couplings are set by a gauge coupling implies the KK gluon mass to be at least about 33 TeV. For both the RS and the composite Higgs models the flavor bounds could be stronger or weaker depending on the assumption on the value of the gluon boundary kinetic term. These strong bounds seem to imply that the fully anarchic approach to flavor in warped extra dimensions is implausible, and there have to be at least some partial flavor symmetries appearing that eliminate part of the sources for flavor violation. We also present complete expressions for the radiatively generated Higgs potential of various 5D implementations of the composite Higgs model, and comment on the 1–5 percent level tuning needed in the top sector to achieve a phenomenologically acceptable vacuum state.
TL;DR: It is shown that yeast Dis3 has an additional endoribonuclease activity mediated by the PIN domain located at the amino terminus of this multidomain protein, showing the mode of action of eukaryotic exosome cores in RNA processing and degradation should be reconsidered, taking into account the cooperation between its multiple ribonucleolytic activities.
Abstract: The exosome is a major eukaryotic nuclease located in both the nucleus and the cytoplasm that contributes to the processing, quality control and/or turnover of a large number of cellular RNAs. This large macromolecular assembly has been described as a 3'-->5' exonuclease and shown to contain a nine-subunit ring structure evolutionarily related to archaeal exosome-like complexes and bacterial polynucleotide phosphorylases. Recent results have shown that, unlike its prokaryotic counterparts, the yeast and human ring structures are catalytically inactive. In contrast, the exonucleolytic activity of the yeast exosome core was shown to be mediated by the RNB domain of the eukaryote-specific Dis3 subunit. Here we show, using in vitro assays, that yeast Dis3 has an additional endoribonuclease activity mediated by the PIN domain located at the amino terminus of this multidomain protein. Simultaneous inactivation of the endonucleolytic and exonucleolytic activities of the exosome core generates a synthetic growth phenotype in vivo, supporting a physiological function for the PIN domain. This activity is responsible for the cleavage of some natural exosome substrates, independently of exonucleolytic degradation. In contrast with current models, our results show that eukaryotic exosome cores have both endonucleolytic and exonucleolytic activities, mediated by two distinct domains of the Dis3 subunit. The mode of action of eukaryotic exosome cores in RNA processing and degradation should be reconsidered, taking into account the cooperation between its multiple ribonucleolytic activities.
TL;DR: This work is a review of the Poisson–Boltzmann (PB) continuum electrostatics theory and its modifications, with a focus on salt effects and counterion binding, and discusses the conventional PB equation, the corresponding functionals of the electrostatic free energy, including a connection to DFT.
Abstract: This work is a review of the Poisson-Boltzmann (PB) continuum electrostatics theory and its modifications, with a focus on salt effects and counterion binding. The PB model is one of the mesoscopic theories that describes the electrostatic potential and equilibrium distribution of mobile ions around molecules in solution. It serves as a tool to characterize electrostatic properties of molecules, counterion association, electrostatic contributions to solvation, and molecular binding free energies. We focus on general formulations which can be applied to large molecules of arbitrary shape in all-atomic representation, including highly charged biomolecules such as nucleic acids. These molecules present a challenge for theoretical description, because the conventional PB model may become insufficient in those cases. We discuss the conventional PB equation, the corresponding functionals of the electrostatic free energy, including a connection to DFT, simple empirical extensions to this model accounting for finite size of ions, the modified PB theory including ionic correlations and fluctuations, the cell model, and supplementary methods allowing to incorporate site-bound ions in the PB calculations.
01 Nov 2008-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The main injector neutrino oscillation search (MINOS) experiment as mentioned in this paper uses an accelerator-produced Neutrino beam to perform precision measurements of the neutrinos oscillation parameters.
Abstract: The Main Injector Neutrino Oscillation Search (MINOS) experiment uses an accelerator-produced neutrino beam to perform precision measurements of the neutrino oscillation parameters in the “atmospheric neutrino” sector associated with muon neutrino disappearance. This long-baseline experiment measures neutrino interactions in Fermilab's NuMI neutrino beam with a near detector at Fermilab and again 735 km downstream with a far detector in the Soudan Underground Laboratory in northern Minnesota. The two detectors are magnetized steel-scintillator tracking calorimeters. They are designed to be as similar as possible in order to ensure that differences in detector response have minimal impact on the comparisons of event rates, energy spectra and topologies that are essential to MINOS measurements of oscillation parameters. The design, construction, calibration and performance of the far and near detectors are described in this paper.
University of Notre Dame1, Massey University2, University of Warsaw3, Nagoya University4, University of Canterbury5, University of Auckland6, Victoria University of Wellington7, Konan University8, University of Manchester9, Vaughn College of Aeronautics and Technology10, University of Concepción11, University of Cambridge12, Institut d'Astrophysique de Paris13, European Southern Observatory14, Heidelberg University15, Paris Diderot University16
TL;DR: In this paper, the authors reported the detection of an extrasolar planet of mass ratio q~2×10-4 in microlensing event MOA-2007-BLG-192.
Abstract: We report the detection of an extrasolar planet of mass ratio q~2×10-4 in microlensing event MOA-2007-BLG-192. The best-fit microlensing model shows both the microlensing parallax and finite source effects, and these can be combined to obtain the lens masses of M=0.060+0.028-0.021 Msolar for the primary and m=3.3+4.9-1.6 M? for the planet. However, the observational coverage of the planetary deviation is sparse and incomplete, and the radius of the source was estimated without the benefit of a source star color measurement. As a result, the 2 ? limits on the mass ratio and finite source measurements are weak. Nevertheless, the microlensing parallax signal clearly favors a substellar mass planetary host, and the measurement of finite source effects in the light curve supports this conclusion. Adaptive optics images taken with the Very Large Telescope (VLT) NACO instrument are consistent with a lens star that is either a brown dwarf or a star at the bottom of the main sequence. Follow-up VLT and/or Hubble Space Telescope (HST) observations will either confirm that the primary is a brown dwarf or detect the low-mass lens star and enable a precise determination of its mass. In either case, the lens star, MOA-2007-BLG-192L, is the lowest mass primary known to have a companion with a planetary mass ratio, and the planet, MOA-2007-BLG-192Lb, is probably the lowest mass exoplanet found to date, aside from the lowest mass pulsar planet.
CERN1, Durham University2, University of Colorado Boulder3, Tel Aviv University4, Indian Institute of Science5, Stanford University6, University of Vienna7, Daresbury Laboratory8, University of Liverpool9, University of Freiburg10, University of Bonn11, University of Würzburg12, Fermilab13, Uppsala University14, Waseda University15, University of Warsaw16, RWTH Aachen University17, Cornell University18, University of Southampton19, Heidelberg University20, Nagoya University21, KEK22, University of Bergen23, Istituto Nazionale di Fisica Nucleare24, University of Zurich25, Spanish National Research Council26, Physical Research Laboratory27, Lancaster University28, University of Mainz29, University of California, Berkeley30, Max Planck Society31, University of Kansas32, University of Paris33
TL;DR: In this paper, the International Linear Collider (ILC) is used for discovering physics beyond the Standard Model and for unraveling the structure of the underlying physics, and the physics return can be maximized by the use of polarized beams.
TL;DR: The results argue in favor of the involvement of immunological events in the process of neurodegeneration in AP and PD.
TL;DR: In this article, a Gibbs sampling framework is proposed for joint component separation and CMB power spectrum estimation, based on a parametric model of the foreground signals, which can estimate the exact joint foreground-CMB posterior distribution and all marginal distributions such as the CMB spectral index posteriors.
Abstract: We describe and implement an exact, flexible, and computationally efficient algorithm for joint component separation and CMB power spectrum estimation, building on a Gibbs sampling framework. Two essential new features are (1) conditional sampling of foreground spectral parameters and (2) joint sampling of all amplitude-type degrees of freedom (e.g., CMB, foreground pixel amplitudes, and global template amplitudes) given spectral parameters. Given a parametric model of the foreground signals, we estimate efficiently and accurately the exact joint foreground- CMB posterior distribution and, therefore, all marginal distributions such as the CMB power spectrum or foreground spectral index posteriors. The main limitation of the current implementation is the requirement of identical beam responses at all frequencies, which restricts the analysis to the lowest resolution of a given experiment. We outline a future generalization to multiresolution observations. To verify the method, we analyze simple models and compare the results to analytical predictions. We then analyze a realistic simulation with properties similar to the 3 yr WMAP data, downgraded to a common resolution of 3 deg FWHM. The results from the actual 3 yr WMAP temperature analysis are presented in a companion Letter.
TL;DR: The reproductive capacity of mice lacking Bmal1 (Arntl, Mop3), one of the central circadian clock genes, is investigated, and expression of the steroidogenic acute regulatory protein (StAR) gene and protein, which regulates the rate-limiting step of steroidogenesis, was decreased in testes from B mal1 KO mice.
Abstract: Although it is well established that the circadian clock regulates mammalian reproductive physiology, the molecular mechanisms by which this regulation occurs are not clear. The authors investigated the reproductive capacity of mice lacking Bmal1 (Arntl, Mop3), one of the central circadian clock genes. They found that both male and female Bmal1 knockout (KO) mice are infertile. Gross and microscopic inspection of the reproductive anatomy of both sexes suggested deficiencies in steroidogenesis. Male Bmal1 KO mice had low testosterone and high luteinizing hormone serum concentrations, suggesting a defect in testicular Leydig cells. Importantly, Leydig cells rhythmically express BMAL1 protein, suggesting peripheral control of testosterone production by this clock protein. Expression of steroidogenic genes was reduced in testes and other steroidogenic tissues of Bmal1 KO mice. In particular, expression of the steroidogenic acute regulatory protein (StAR) gene and protein, which regulates the rate-limiting ste...
TL;DR: In this paper, a general analysis on the possibility of obtaining metastable vacua with spontaneously broken N = 1 supersymmetry and non-negative cosmological constant in the moduli sector of string models is presented.
Abstract: We perform a general analysis on the possibility of obtaining metastable vacua with spontaneously broken N = 1 supersymmetry and non-negative cosmological constant in the moduli sector of string models. More specifically, we study the condition under which the scalar partners of the Goldstino are non-tachyonic, which depends only on the Kahler potential. This condition is not only necessary but also sufficient, in the sense that all of the other scalar fields can be given arbitrarily large positive square masses if the superpotential is suitably tuned. We consider both heterotic and orientifold string compactifications in the large-volume limit and show that the no-scale property shared by these models severely restricts the allowed values for the 'sGoldstino' masses in the superpotential parameter space. We find that a positive mass term may be achieved only for certain types of compactifications and specific Goldstino directions. Additionally, we show how subleading corrections to the Kahler potential which break the no-scale property may allow to lift these masses.
TL;DR: A positive relationship between social interaction, assessed via amount of actual social contact, and cognitive functioning in people from three age groups including younger adults is found and a small amount of social interaction can facilitate cognitive performance.
Abstract: Social interaction is a central feature of people's life and engages a variety of cognitive resources. Thus, social interaction should facilitate general cognitive functioning. Previous studies suggest such a link, but they used special populations (e.g., elderly with cognitive impairment), measured social interaction indirectly (e.g., via marital status), and only assessed effects of extended interaction in correlational designs. Here the relation between mental functioning and direct indicators of social interaction was examined in a younger and healthier population. Study 1 using survey methodology found a positive relationship between social interaction, assessed via amount of actual social contact, and cognitive functioning in people from three age groups including younger adults. Study 2 using an experimental design found that a small amount of social interaction (10 min) can facilitate cognitive performance. The findings are discussed in the context of the benefits social relationships have for so many aspects of people's lives.
TL;DR: The solid-phase extraction procedure (SPE) for isolation and preconcentration of phenolic acids and some flavonols from honey samples prior to their determination by HPLC is reported.
TL;DR: In this paper, it was shown that various holomorphic quantities in supersymmetric gauge theories can be conveniently computed by configurations of D4-branes and D6branes, which intersect along a Riemann surface described by a holomorphic curve in a complex surface.
Abstract: We show that various holomorphic quantities in supersymmetric gauge theories can be conveniently computed by configurations of D4-branes and D6-branes. These D-branes intersect along a Riemann surface that is described by a holomorphic curve in a complex surface. The resulting I-brane carries two-dimensional chiral fermions on its world-volume. This system can be mapped directly to the topological string on a large class of non-compact Calabi-Yau manifolds. Inclusion of the string coupling constant corresponds to turning on a constant B-field on the complex surface, which makes this space non-commutative. Including all string loop corrections the free fermion theory is elegantly formulated in terms of holonomic D-modules that replace the classical holomorphic curve in the quantum case.
TL;DR: The crystal structure of S. cerevisiae Rrp44 provides a molecular rationale for the observed biochemical properties of the RNase R family of nucleases.