Showing papers by "Texas A&M University published in 2013"
Kyle S. Dawson1, David J. Schlegel2, Christopher P. Ahn1, Scott F. Anderson3 +181 more•Institutions (51)
TL;DR: The Baryon Oscillation Spectroscopic Survey (BOSS) as discussed by the authors was designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure.
Abstract: The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure. BOSS uses 1.5 million luminous galaxies as faint as i = 19.9 over 10,000 deg2 to measure BAO to redshifts z < 0.7. Observations of neutral hydrogen in the Lyα forest in more than 150,000 quasar spectra (g < 22) will constrain BAO over the redshift range 2.15 < z < 3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Lyα forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance dA to an accuracy of 1.0% at redshifts z = 0.3 and z = 0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyα forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate DA (z) and H –1(z) parameters to an accuracy of 1.9% at z ~ 2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.
1,938 citations
TL;DR: The attributes of BODIPY dyes for PDT are summarized, and substituents with appropriate oxidation potentials are summarized in some related areas.
Abstract: BODIPY dyes tend to be highly fluorescent, but their emissions can be attenuated by adding substituents with appropriate oxidation potentials. Substituents like these have electrons to feed into photoexcited BODIPYs, quenching their fluorescence, thereby generating relatively long-lived triplet states. Singlet oxygen is formed when these triplet states interact with 3O2. In tissues, this causes cell damage in regions that are illuminated, and this is the basis of photodynamic therapy (PDT). The PDT agents that are currently approved for clinical use do not feature BODIPYs, but there are many reasons to believe that this situation will change. This review summarizes the attributes of BODIPY dyes for PDT, and in some related areas.
1,599 citations
Alternatives1, John Innes Centre2, University of Bonn3, University of North Carolina at Chapel Hill4, University of Wisconsin-Madison5, University of Utah6, University of Southern California7, University of Edinburgh8, University of Warwick9, Harvard University10, University College Cork11, University of Queensland12, University of Hertfordshire13, University of Potsdam14, University of California, San Diego15, Goethe University Frankfurt16, University of California, San Francisco17, University of Delaware18, Uppsala University19, Medical University of Vienna20, J. Craig Venter Institute21, University of Hawaii at Manoa22, Leibniz Association23, University of Iowa24, University of Aberdeen25, Georgia Institute of Technology26, University of California, Berkeley27, University of Groningen28, Princeton University29, University of Marburg30, University of Illinois at Urbana–Champaign31, Saarland University32, Norwegian University of Life Sciences33, Massey University34, Toyama Prefectural University35, ETH Zurich36, University of Saskatchewan37, Rutgers University38, Scripps Research Institute39, University of Helsinki40, Texas A&M University41, National Institutes of Health42, Technical University of Berlin43, University of Otago44, University of Cambridge45, University of Alberta46, Michigan State University47, Hofstra University48
TL;DR: This review presents recommended nomenclature for the biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs), a rapidly growing class of natural products.
1,560 citations
TL;DR: Studies of Pavlovian fear conditioning and extinction in rodents and humans suggest that a neural circuit including the hippocampus, amygdala and medial prefrontal cortex is involved in the learning and memory processes that enable context-dependent behaviour.
Abstract: Contexts surround and imbue meaning to events; they are essential for recollecting the past, interpreting the present and anticipating the future. Indeed, the brain's capacity to contextualize information permits enormous cognitive and behavioural flexibility. Studies of Pavlovian fear conditioning and extinction in rodents and humans suggest that a neural circuit including the hippocampus, amygdala and medial prefrontal cortex is involved in the learning and memory processes that enable context-dependent behaviour. Dysfunction in this network may be involved in several forms of psychopathology, including post-traumatic stress disorder, schizophrenia and substance abuse disorders.
1,196 citations
TL;DR: The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250 GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude, showing the existence of new physical phenomena.
Abstract: A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250 GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.
1,100 citations
Book•
16 Jun 2013TL;DR: Results for Curvilinear Coordinates III are presented, showing clear trends in 3-D Incompressible Elasticity and Cellular Responses to Applied Loads and in Constitutive Framework, respectively.
Abstract: 1. INTRODUCTION. 1.1 Historical Prelude, 1.2 Basic Cell Biology, 1.3 The Extracellular Matrix, 1.4 Soft Tissue Behavior, 1.5 Needs and General Approach, 1.6 Exercises, 1.7 References. 2. MATHEMATICAL PRELIMINARIES 2.1 A Direct Tensor Notation, 2.2 Cartesian Components, 2.3 Further Results in Tensor Calculus, 2.4 Orthogonal Curvilinear Components, 2.5 Matrix Methods, 2.6 Exercises, 2.7 References, 3. CONTINUUM MECHANICS 3.1 Kinematics, 3.2 Forces, Tractions and Stresses, 3.3 Balance Relations, 3.4 Constitutive Formulations, 3.5 Boundary and Initial Conditions, 3.6 Exercises, 3.7 References, 4. FINITE ELASTICITY 4.1 Introduction, 4.2 Incompressible Isotropic Elasticity, 4.3 Solutions in 3-D Incompressible Elasticity, 4.4 Compressible Isotropic Elasticity, 4.5 Membrane Hyperelasticity, 4.6 Exercises, 4.7 References 5. EXPERIMENTAL METHODS 5.1 General Philosophy, 5.2 Measurement of Strain, 5.3 Measurement of Applied Loads, 5.4 Testing Conditions, 5.5 Parameter Estimation and Statistics, 5.6 Exercises, 5.7 References 6. Finite Element Methods 6.1 Fundamental Equations, 6.2 Interpolation, Integration, and Solvers, 6.3 An Illustrative Formulation, 6.4 Inflation of a Membrane, 6.5 Inverse Finite Elements, 6.6 Exercises, 6.7 References PART II - VASCULAR MECHANICS 7. THE NORMAL ARTERIAL WALL 7.1 Structure and Function, 7.2 General Characteristics, 7.3 Constitutive Framework, 7.4 Experimental Methods, 7.5 Specific Constitutive Relations, 7.6 Stress Analyses, 7.7 Exercises, 7.8 References 8. VASCULAR DISORDERS 8.1 Hypertension, 8.2 Intracranial Aneurysms, 8.3 Atherosclerosis, 8.4 Aortic Aneurysms, 8.5 Additional Topics, 8.6 Exercises, 8.7 References 9. VASCULAR ADAPTATION 9.1 Mechanical Preliminaries, 9.2 Cellular Responses to Applied Loads, 9.3 Arterial Response to Hypertension, 9.4 Arterial Response to Altered Flow, 9.5 Vessel Response to Injury, 9.6 Veins as Arterial Grafts, 9.7 Aging, 9.8 Exercises, 9.9 References PART III CARDIAC MECHANICS 10. THE NORMAL HEART 10.1 Structure and Function, 10.2 General Characteristics, 10.3 Constitutive Framework, 10.4 Constitutive Relations, 10.5 Stress Analyses, 10.6 Exercises, 10.7 References 11. EPILOGUE APPENDICES I. Nomenclature, Abbreviations, and Conversions II. Results for Curvilinear Coordinates III. Material Frame Indifference 11. CARDIAC DISORDERS 11.1 Ischemia 11.2 Volume Overload 11.3 Hypertrophy 11.4 Cardiac Aneurysms 11.5 Additional Topics
1,079 citations
University of Florida1, University of Bonn2, Goddard Institute for Space Studies3, Commonwealth Scientific and Industrial Research Organisation4, Institut national de la recherche agronomique5, Agro ParisTech6, Michigan State University7, Blaise Pascal University8, International Water Management Institute9, University of Leeds10, CGIAR11, Counterintelligence Field Activity12, University of Tübingen13, University of Alberta14, International Atomic Energy Agency15, University of Reading16, University of Guelph17, University of Hohenheim18, Joint Global Change Research Institute19, Potsdam Institute for Climate Impact Research20, Indian Agricultural Research Institute21, Aarhus University22, Rothamsted Research23, Washington State University24, Wageningen University and Research Centre25, Chinese Academy of Sciences26, International Trademark Association27, Texas A&M University28
TL;DR: In this article, the authors present the largest standardized model intercomparison for climate change impacts so far, finding that individual crop models are able to simulate measured wheat grain yields accurately under a range of environments, particularly if the input information is sufficient.
Abstract: Projections of climate change impacts on crop yields are inherently uncertain(1). Uncertainty is often quantified when projecting future greenhouse gas emissions and their influence on climate(2). However, multi-model uncertainty analysis of crop responses to climate change is rare because systematic and objective comparisons among process-based crop simulation models(1,3) are difficult(4). Here we present the largest standardized model intercomparison for climate change impacts so far. We found that individual crop models are able to simulate measured wheat grain yields accurately under a range of environments, particularly if the input information is sufficient. However, simulated climate change impacts vary across models owing to differences in model structures and parameter values. A greater proportion of the uncertainty in climate change impact projections was due to variations among crop models than to variations among downscaled general circulation models. Uncertainties in simulated impacts increased with CO2 concentrations and associated warming. These impact uncertainties can be reduced by improving temperature and CO2 relationships in models and better quantified through use of multi-model ensembles. Less uncertainty in describing how climate change may affect agricultural productivity will aid adaptation strategy development and policymaking.
1,049 citations
TL;DR: The results showed that justice-performance relationships were mediated by positive and negative affect, with the relevant affect dimension varying across justice and performance variables, and the merit in integrating the social exchange and affect lenses in future research is discussed.
Abstract: Although a flurry of meta-analyses summarized the justice literature at the turn of the millennium, interest in the topic has surged in the decade since. In particular, the past decade has witnessed the rise of social exchange theory as the dominant lens for examining reactions to justice, and the emergence of affect as a complementary lens for understanding such reactions. The purpose of this meta-analytic review was to test direct, mediating, and moderating hypotheses that were inspired by those 2 perspectives, to gauge their adequacy as theoretical guides for justice research. Drawing on a review of 493 independent samples, our findings revealed a number of insights that were not included in prior meta-analyses. With respect to social exchange theory, our results revealed that the significant relationships between justice and both task performance and citizenship behavior were mediated by indicators of social exchange quality (trust, organizational commitment, perceived organizational support, and leader‐member exchange), though such mediation was not apparent for counterproductive behavior. The strength of those relationships did not vary according to whether the focus of the justice matched the target of the performance behavior, contrary to popular assumptions in the literature, or according to whether justice was referenced to a specific event or a more general entity. With respect to affect, our results showed that justice‐performance relationships were mediated by positive and negative affect, with the relevant affect dimension varying across justice and performance variables. Our discussion of these findings focuses on the merit in integrating the social exchange and affect lenses in future research.
961 citations
TL;DR: A method to edit the C. elegans genome using the clustered, regularly interspersed, short palindromic repeats (CRISPR) RNA-guided Cas9 nuclease and homologous recombination and it is demonstrated that Cas9 is able to induce DNA double-strand breaks with specificity for targeted sites.
Abstract: Study of the nematode Caenorhabditis elegans has provided important insights in a wide range of fields in biology. The ability to precisely modify genomes is critical to fully realize the utility of model organisms. Here we report a method to edit the C. elegans genome using the clustered, regularly interspersed, short palindromic repeats (CRISPR) RNA-guided Cas9 nuclease and homologous recombination. We demonstrate that Cas9 is able to induce DNA double-strand breaks with specificity for targeted sites and that these breaks can be repaired efficiently by homologous recombination. By supplying engineered homologous repair templates, we generated gfp knock-ins and targeted mutations. Together our results outline a flexible methodology to produce essentially any desired modification in the C. elegans genome quickly and at low cost. This technology is an important addition to the array of genetic techniques already available in this experimentally tractable model organism.
894 citations
TL;DR: In this article, the authors argue that greater regulatory and normative pressures concerning environmental issues positively influence companies' propensity to engage in environmental innovation, and they find that this effect is stronger when asset specificity is high, and that the availability of resources plays different roles depending on the type of pressures.
Abstract: Drawing on institutional theory and innovation literature, we argue that greater regulatory and normative pressures concerning environmental issues positively influence companies' propensity to engage in environmental innovation. Analysis of environment-related patents of 326 publicly traded firms from polluting industries in the United States suggests that institutional pressures can trigger such innovation, especially in those firms displaying a greater deficiency gap (i.e., firms polluting relatively more than their industry peers). Moreover, we find that this effect is stronger when asset specificity is high, and that the availability of resources plays different roles depending on the type of pressures (regulatory vs. normative).Copyright © 2012 John Wiley & Sons, Ltd.
855 citations
TL;DR: A series of highly stable MOFs with 3-D nanochannels, namely PCN-224 (no metal, Ni, Co, Fe), have been assembled with six-connected Zr6 cluster and metalloporphyrins by a linker-elimination strategy.
Abstract: A series of highly stable MOFs with 3-D nanochannels, namely PCN-224 (no metal, Ni, Co, Fe), have been assembled with six-connected Zr6 cluster and metalloporphyrins by a linker-elimination strategy. The PCN-224 series not only exhibits the highest BET surface area (2600m2/g) among all the reported porphyrinic MOFs but also remains intact in pH = 0 to pH = 11 aqueous solution. Remarkably, PCN-224(Co) exhibits high catalytic activity for the CO2/propylene oxide coupling reaction and can be used as a recoverable heterogeneous catalyst.
TL;DR: HOTAIR expression is increased in pancreatic tumors compared with non-tumor tissue and is associated with more aggressive tumors, and HOTAIR uniquely suppressed several interferon-related genes and gene sets related to cell cycle progression in Pancic cancer cells and tumors.
Abstract: HOTAIR is a long intervening non-coding RNA (lincRNA) that associates with the Polycomb Repressive Complex 2 (PRC2) and overexpression is correlated with poor survival for breast, colon and liver cancer patients. In this study, we show that HOTAIR expression is increased in pancreatic tumors compared with non-tumor tissue and is associated with more aggressive tumors. Knockdown of HOTAIR (siHOTAIR) by RNA interference shows that HOTAIR has an important role in pancreatic cancer cell invasion, as reported in other cancer cell lines. In contrast, HOTAIR knockdown in Panc1 and L3.6pL pancreatic cancer cells that overexpress this lincRNA decreased cell proliferation, altered cell cycle progression and induced apoptosis, demonstrating an expanded function of HOTAIR in pancreatic cancer cells compared with other cancer cell lines. Results of gene array studies showed that there was minimal overlap between HOTAIR-regulated genes in pancreatic cells and breast cancer cells, and HOTAIR uniquely suppressed several interferon-related genes and gene sets related to cell cycle progression in pancreatic cancer cells and tumors. Analysis of selected genes suppressed by HOTAIR in Panc1 and L3.6pL cells showed by knockdown of EZH2 and chromatin immunoprecipitation assays that HOTAIR-mediated gene repression was both PRC2-dependent and -independent. HOTAIR knockdown in L3.6pL cells inhibited tumor growth in mouse xenograft model, further demonstrating the pro-oncogenic function of HOTAIR in pancreatic cancer.
TL;DR: The results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles.
TL;DR: It is shown that nitrate generated as a by-product of the inflammatory response conferred a growth advantage to the commensal bacterium Escherichia coli in the large intestine of mice.
Abstract: Changes in the microbial community structure are observed in individuals with intestinal inflammatory disorders. These changes are often characterized by a depletion of obligate anaerobic bacteria, whereas the relative abundance of facultative anaerobic Enterobacteriaceae increases. The mechanisms by which the host response shapes the microbial community structure, however, remain unknown. We show that nitrate generated as a by-product of the inflammatory response conferred a growth advantage to the commensal bacterium Escherichia coli in the large intestine of mice. Mice deficient in inducible nitric oxide synthase did not support the growth of E. coli by nitrate respiration, suggesting that the nitrate generated during inflammation was host-derived. Thus, the inflammatory host response selectively enhances the growth of commensal Enterobacteriaceae by generating electron acceptors for anaerobic respiration.
TL;DR: Modifications of common standards of evidence are proposed to reduce the rate of nonreproducibility of scientific research by a factor of 5 or greater and to correct the problem of unjustifiably high levels of significance.
Abstract: Recent advances in Bayesian hypothesis testing have led to the development of uniformly most powerful Bayesian tests, which represent an objective, default class of Bayesian hypothesis tests that have the same rejection regions as classical significance tests. Based on the correspondence between these two classes of tests, it is possible to equate the size of classical hypothesis tests with evidence thresholds in Bayesian tests, and to equate P values with Bayes factors. An examination of these connections suggest that recent concerns over the lack of reproducibility of scientific studies can be attributed largely to the conduct of significance tests at unjustifiably high levels of significance. To correct this problem, evidence thresholds required for the declaration of a significant finding should be increased to 25–50:1, and to 100–200:1 for the declaration of a highly significant finding. In terms of classical hypothesis tests, these evidence standards mandate the conduct of tests at the 0.005 or 0.001 level of significance.
TL;DR: A systematic literature review (SLR) was conducted by as discussed by the authors to identify empirical studies that explored servant leadership theory by engaging a sample population in order to assess and synthesize the mechanisms, outcomes, and impacts of servant leadership.
Abstract: A new research area linked to ethics, virtues, and morality is servant leadership. Scholars are currently seeking publication outlets as critics debate whether this new leadership theory is significantly distinct, viable, and valuable for organizational success. The aim of this study was to identify empirical studies that explored servant leadership theory by engaging a sample population in order to assess and synthesize the mechanisms, outcomes, and impacts of servant leadership. Thus, we sought to provide an evidence-informed answer to how does servant leadership work, and how can we apply it? We conducted a systematic literature review (SLR), a methodology adopted from the medical sciences to synthesize research in a systematic, transparent, and reproducible manner. A disciplined screening process resulted in a final sample population of 39 appropriate studies. The synthesis of these empirical studies revealed: (a) there is no consensus on the definition of servant leadership; (b) servant leadership theory is being investigated across a variety of contexts, cultures, and themes; (c) researchers are using multiple measures to explore servant leadership; and (d) servant leadership is a viable leadership theory that helps organizations and improves the well-being of followers. This study contributes to the development of servant leadership theory and practice. In addition, this study contributes to the methodology for conducting SLRs in the field of management, highlighting an effective method for mapping out thematically, and viewing holistically, new research topics. We conclude by offering suggestions for future research.
TL;DR: In this article, a detailed description of the analysis used by the CMS Collaboration in the search for the standard model Higgs boson in pp collisions at the LHC, which led to the observation of a new boson.
Abstract: A detailed description is reported of the analysis used by the CMS Collaboration in the search for the standard model Higgs boson in pp collisions at the LHC, which led to the observation of a new boson. The data sample corresponds to integrated luminosities up to 5.1 inverse femtobarns at sqrt(s) = 7 TeV, and up to 5.3 inverse femtobarns at sqrt(s) = 8 TeV. The results for five Higgs boson decay modes gamma gamma, ZZ, WW, tau tau, and bb, which show a combined local significance of 5 standard deviations near 125 GeV, are reviewed. A fit to the invariant mass of the two high resolution channels, gamma gamma and ZZ to 4 ell, gives a mass estimate of 125.3 +/- 0.4 (stat) +/- 0.5 (syst) GeV. The measurements are interpreted in the context of the standard model Lagrangian for the scalar Higgs field interacting with fermions and vector bosons. The measured values of the corresponding couplings are compared to the standard model predictions. The hypothesis of custodial symmetry is tested through the measurement of the ratio of the couplings to the W and Z bosons. All the results are consistent, within their uncertainties, with the expectations for a standard model Higgs boson.
TL;DR: A CRISPR-Cas system is used to induce genomic DNA fragment deletion in mice by coinjecting two single-guide RNAs (sgRNAs) targeting the Uhrf2 locus with Cas9 mRNA by means of a single microinjection.
Abstract: To the Editor: CRISPR-Cas systems have been developed as an efficient gene editing technology in cells and model organisms. Here we use a CRISPR-Cas system to induce genomic DNA fragment deletion in mice by coinjecting two single-guide RNAs (sgRNAs) targeting the Uhrf2 locus with Cas9 mRNA. Furthermore, we report the generation of a Mc3R and Mc4R double-gene knockout rat by means of a single microinjection. High germline-transmission efficiency was observed in both mice and rats. The clustered, regularly interspaced, short palindromic repeats (CRISPR)associated protein (Cas) system has evolved in bacteria and archaea as an RNA-based adaptive immune system against viral and plasmid invasion1. Based on gene conservation and locus organization, three major types of CRISPR systems have been identified2,3. In the type II systems, the complex of a CRISPR RNA (crRNA) annealed to a trans-activating crRNA (tracrRNA) is sufficient to guide the Cas9 endonuclease to a specific genomic sequence to generate double-strand breaks in target DNA4. Previous studies established a strategy for multiplex genome engineering with the Cas9 RNA-guided endonuclease in mammalian cells5,6. Recently, efficient genome editing by the CRISPR-Cas system has been shown in multiple organisms, including zebrafish, mice and bacteria7–9. Several groups have demonstrated that compared with zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), CRISPR-Cas–mediated gene targeting has similar or greater efficiency in cells and zebrafish5–7,10. Although it has been demonstrated that multiple genes can be disrupted in individual mouse embryos using CRISPR-Cas–mediated systems9, germline transmission of Cas9-mediated mutations in animals has not yet been reported. In addition, whether long, specific, genomic DNA target fragments
TL;DR: The main idea of the proposed approach is to construct a small dimensional local solution space that can be used to generate an efficient and accurate approximation to the multiscale solution with a potentially high dimensional input parameter space.
TL;DR: A reaction between a Zr(IV) salt and a porphyrinic tetracarboxylic acid leads to a metal-organic framework (MOF) with two types of open channels, representing a MOF featuring a (4,8)-connected sqc net.
Abstract: A reaction between a Zr IV salt and a porphyrinic tetracarboxylic acid leads to a metal−organic framework (MOF) with two types of open channels, representing a MOF featuring a (4,8)-connected sqc net. The MOF remains intact in both boiling water and aqueous solutions with pH ranging from 1 to 11, a remarkably extensive pH range that a MOF can sustain. Given its exceptional stability and pH- dependent fluorescent intensity, the MOF can potentially be applied in fluorescent pH sensing.
Proceedings Article•
26 Feb 2013TL;DR: This paper introduces FRESCO, an OpenFlow security application development framework designed to facilitate the rapid design, and modular composition of OF-enabled detection and mitigation modules, and demonstrates the utility of FRESCO through the implementation of several well-known security defenses as Open Flow security services.
Abstract: OpenFlow is an open standard that has gained tremendous interest in the last few years within the network community. It is an embodiment of the software-defined networking paradigm, in which higher-level flow routing decisions are derived from a control layer that, unlike classic network switch implementations, is separated from the data handling layer. The central attraction to this paradigm is that by decoupling the control logic from the closed and proprietary implementations of traditional network switch infrastructure, researchers can more easily design and distribute innovative flow handling and network control algorithms. Indeed, we also believe that OpenFlow can, in time, prove to be one of the more impactful technologies to drive a variety of innovations in network security. OpenFlow could offer a dramatic simplification to the way we design and integrate complex network security applications into large networks. However, to date there remains a stark paucity of compelling OpenFlow security applications. In this paper, we introduce FRESCO, an OpenFlow security application development framework designed to facilitate the rapid design, and modular composition of OF-enabled detection and mitigation modules. FRESCO, which is itself an OpenFlow application, offers a Click-inspired [19] programming framework that enables security researchers to implement, share, and compose together, many different security detection and mitigation modules. We demonstrate the utility of FRESCO through the implementation of several well-known security defenses as OpenFlow security services, and use them to examine various performance and efficiency aspects of our proposed framework.
TL;DR: In this paper, a detailed chemical kinetic mechanism for hydrogen and H2/CO (syngas) mixtures has been updated, rate constants have been adjusted to reflect new experimental information obtained at high pressures and new rate constant values recently published in the literature, and good agreement was observed.
TL;DR: Students were less satisfied with the flipped classroom method than with either of the other methods, suggesting that blending new teaching technologies with interactive classroom activities can result in improved learning but not necessarily improved student satisfaction.
Abstract: This study aimed to determine the effects of a flipped classroom (i.e., reversal of time allotment for lecture and homework) and innovative learning activities on academic success and the satisfaction of nursing students. A quasi-experimental design was used to compare three approaches to learning: traditional lecture only (LO), lecture and lecture capture back-up (LLC), and the flipped classroom approach of lecture capture with innovative classroom activities (LCI). Examination scores were higher for the flipped classroom LCI group (M = 81.89, SD = 5.02) than for both the LLC group (M = 80.70, SD = 4.25), p = 0.003, and the LO group (M = 79.79, SD = 4.51), p < 0.001. Students were less satisfied with the flipped classroom method than with either of the other methods (p < 0.001). Blending new teaching technologies with interactive classroom activities can result in improved learning but not necessarily improved student satisfaction.
TL;DR: In this paper, two-particle angular correlations for charged particles emitted in pPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV are presented.
04 Nov 2013
TL;DR: This paper introduces an extension to the OpenFlow data plane called "connection migration", which dramatically reduces the amount of data-to-control-plane interactions that arise during attacks, and introduces "actuating triggers" over the data plane's existing statistics collection services.
Abstract: Among the leading reference implementations of the Software Defined Networking (SDN) paradigm is the OpenFlow framework, which decouples the control plane into a centralized application. In this paper, we consider two aspects of OpenFlow that pose security challenges, and we propose two solutions that could address these concerns. The first challenge is the inherent communication bottleneck that arises between the data plane and the control plane, which an adversary could exploit by mounting a "control plane saturation attack" that disrupts network operations. Indeed, even well-mined adversarial models, such as scanning or denial-of-service (DoS) activity, can produce more potent impacts on OpenFlow networks than traditional networks. To address this challenge, we introduce an extension to the OpenFlow data plane called "connection migration", which dramatically reduces the amount of data-to-control-plane interactions that arise during such attacks. The second challenge is that of enabling the control plane to expedite both detection of, and responses to, the changing flow dynamics within the data plane. For this, we introduce "actuating triggers" over the data plane's existing statistics collection services. These triggers are inserted by control layer applications to both register for asynchronous call backs, and insert conditional flow rules that are only activated when a trigger condition is detected within the data plane's statistics module. We present Avant-Guard, an implementation of our two data plane extensions, evaluate the performance impact, and examine its use for developing more scalable and resilient SDN security services.
TL;DR: The measurements indicate that well completion emissions are lower than previously estimated; the data also show emissions from pneumatic controllers and equipment leaks are higher than Environmental Protection Agency (EPA) national emission projections.
Abstract: Engineering estimates of methane emissions from natural gas production have led to varied projections of national emissions. This work reports direct measurements of methane emissions at 190 onshore natural gas sites in the United States (150 production sites, 27 well completion flowbacks, 9 well unloadings, and 4 workovers). For well completion flowbacks, which clear fractured wells of liquid to allow gas production, methane emissions ranged from 0.01 Mg to 17 Mg (mean = 1.7 Mg; 95% confidence bounds of 0.67–3.3 Mg), compared with an average of 81 Mg per event in the 2011 EPA national emission inventory from April 2013. Emission factors for pneumatic pumps and controllers as well as equipment leaks were both comparable to and higher than estimates in the national inventory. Overall, if emission factors from this work for completion flowbacks, equipment leaks, and pneumatic pumps and controllers are assumed to be representative of national populations and are used to estimate national emissions, total annual emissions from these source categories are calculated to be 957 Gg of methane (with sampling and measurement uncertainties estimated at ±200 Gg). The estimate for comparable source categories in the EPA national inventory is ∼1,200 Gg. Additional measurements of unloadings and workovers are needed to produce national emission estimates for these source categories. The 957 Gg in emissions for completion flowbacks, pneumatics, and equipment leaks, coupled with EPA national inventory estimates for other categories, leads to an estimated 2,300 Gg of methane emissions from natural gas production (0.42% of gross gas production).
TL;DR: Functional AA, defined as those AA that participate in and regulate key metabolic pathways to improve health, survival, growth, development, lactation, and reproduction of the organisms, hold great promise in prevention and treatment of metabolic diseases.
Abstract: The recent years have witnessed growing interest in biochemistry, physiology and nutrition of amino acids (AA) in growth, health and disease of humans and other animals. This results from the discoveries of AA in cell signaling involving protein kinases, G protein-coupled receptors, and gaseous molecules (i.e., NO, CO and H2S). In addition, nutritional studies have shown that dietary supplementation with several AA (e.g., arginine, glutamine, glutamate, leucine, and proline) modulates gene expression, enhances growth of the small intestine and skeletal muscle, or reduces excessive body fat. These seminal findings led to the new concept of functional AA, which are defined as those AA that participate in and regulate key metabolic pathways to improve health, survival, growth, development, lactation, and reproduction of the organisms. Functional AA hold great promise in prevention and treatment of metabolic diseases (e.g., obesity, diabetes, and cardiovascular disorders), intrauterine growth restriction, infertility, intestinal and neurological dysfunction, and infectious disease (including viral infections).
TL;DR: Glycine plays an important role in metabolic regulation, anti-oxidative reactions, and neurological function and has been used to prevent tissue injury, promote protein synthesis and wound healing, and improve immunity.
Abstract: Glycine is a major amino acid in mammals and other animals It is synthesized from serine, threonine, choline, and hydroxyproline via inter-organ metabolism involving primarily the liver and kidneys Under normal feeding conditions, glycine is not adequately synthesized in birds or in other animals, particularly in a diseased state Glycine degradation occurs through three pathways: the glycine cleavage system (GCS), serine hydroxymethyltransferase, and conversion to glyoxylate by peroxisomal d-amino acid oxidase Among these pathways, GCS is the major enzyme to initiate glycine degradation to form ammonia and CO2 in animals In addition, glycine is utilized for the biosynthesis of glutathione, heme, creatine, nucleic acids, and uric acid Furthermore, glycine is a significant component of bile acids secreted into the lumen of the small intestine that is necessary for the digestion of dietary fat and the absorption of long-chain fatty acids Glycine plays an important role in metabolic regulation, anti-oxidative reactions, and neurological function Thus, this nutrient has been used to: (1) prevent tissue injury; (2) enhance anti-oxidative capacity; (3) promote protein synthesis and wound healing; (4) improve immunity; and (5) treat metabolic disorders in obesity, diabetes, cardiovascular disease, ischemia-reperfusion injuries, cancers, and various inflammatory diseases These multiple beneficial effects of glycine, coupled with its insufficient de novo synthesis, support the notion that it is a conditionally essential and also a functional amino acid for mammals (including pigs and humans)
TL;DR: The results of these 15 studies were largely positive, suggesting that iPods, iPod Touch, iPads, and related devices are viable technological aids for individuals with developmental disabilities.
Mississippi State University1, Lawrence Berkeley National Laboratory2, Northwestern University3, Texas A&M University4, University of Cambridge5, Swiss Institute of Bioinformatics6, University College London7, University of Maryland, Baltimore8, European Bioinformatics Institute9, Medical College of Wisconsin10, New York University11, Stanford University12, Carnegie Institution for Science13, University of Southern California14, California Institute of Technology15, University of Oregon16
TL;DR: The Gene Ontology (GO) Consortium is a community-based bioinformatics resource that classifies gene product function through the use of structured, controlled vocabularies and has been expanded not only to cover new areas of biology through focused interaction with experts, but also to capture greater specificity in all areas of the ontology.
Abstract: The Gene Ontology (GO) Consortium (GOC, http://www.geneontology.org) is a community-based bioinformatics resource that classifies gene product function through the use of structured, controlled vocabularies. Over the past year, the GOC has implemented several processes to increase the quantity, quality and specificity of GO annotations. First, the number of manual, literature-based annotations has grown at an increasing rate. Second, as a result of a new 'phylogenetic annotation' process, manually reviewed, homology-based annotations are becoming available for a broad range of species. Third, the quality of GO annotations has been improved through a streamlined process for, and automated quality checks of, GO annotations deposited by different annotation groups. Fourth, the consistency and correctness of the ontology itself has increased by using automated reasoning tools. Finally, the GO has been expanded not only to cover new areas of biology through focused interaction with experts, but also to capture greater specificity in all areas of the ontology using tools for adding new combinatorial terms. The GOC works closely with other ontology developers to support integrated use of terminologies. The GOC supports its user community through the use of e-mail lists, social media and web-based resources.