bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of measurement error on Monte Carlo integration estimators of tree volume: critical height sampling and vertical Monte Carlo methods
Authors: Lynch Thomas B.
Published: December 2014

The effects of measurement error on Monte Carlo (MC) integration estimators of individual-tree volume that sample upper-stem heights at randomly selected cross-sectional areas (termed vertical methods) were studied. These methods included critical height sampling (on an individual-tree basis), vertical importance sampling (VIS), and vertical control variate sampling (VCS). These estimators were unbiased in the presence of two error models: additive measurement error with mean zero and multiplicative measurement error with mean one. Exact mathematical expressions were derived for the variances of VIS and VCS that include additive components for sampling error and measurement error, which together comprise total variance. Previous studies of sampling error for MC integration estimators of tree volume were combined with estimates of upper-stem measurement error obtained from the mensurational literature to compute typical estimates of total standard errors for VIS and VCS. Through examples, it is shown that measurement error can substantially increase the total root mean square error of the volume estimate, especially for small trees.
The lightest of black holes
Authors: Calmet Xavier
Published: December 2014

In this paper, we consider general relativity in the large N limit, where N stands for the number of particles in the model. Studying the resummed graviton propagator in the linearized regime, we propose to interpret its complex poles as black hole precursors. Our main result is the calculation of the mass and width of the lightest of black holes. We show that the values of the masses of black hole precursors depend on the number of fields in the theory. Their masses can be lowered down to the TeV region by increasing the number of fields in a hidden sector that only interacts gravitationally with the Standard Model.
EFFECT OF CEREBROSPINAL FLUID MODELED WITH DIFFERENT MATERIAL PROPERTIES ON A HUMAN FINITE ELEMENT HEAD MODEL
Authors: JIN JING-XU , ZHANG JUN-YUAN , SONG XUE-WEI , HU HAO , SUN XIAO-YAN , GAO ZHEN-HAI
Published: December 2014

The aim of this study was to enhance head-injury prediction, this paper investigated the behavior of cerebrospinal fluid (CSF) in finite element (FE) modeling. Nine different material properties selected according to material definitions and property values were used to represent CSF in FE head models. To evaluate the influence of CSF material parameters on brain mechanical responses, the models were validated against available cadaver experiment data. Results showed that coup pressure increased whereas contrecoup pressure decreased when the head sustained purely translational impact with increased bulk modulus when CSF was modeled as fluid. However, with increased bulk modulus, coup pressure, contrecoup pressure and relative skull-brain motions decreased under rotational impact. When CSF was assumed to be an elastic material, coup pressure increased whereas contrecoup pressure decreased with increased elastic modulus when the head was subjected to purely translational impact. However, the variation trend was not obvious during head rotation. Results also indicated that when subjected to brain strain and von Mises stress, the model was prone to underestimate brain injury when CSF was modeled as an elastic material, especially during purely translational impact to the head. The model with CSF as fluid reduced the strain rate of brain, which was more likely to be realistic than the model with CSF as a viscoelastic material. These findings suggested that significantly higher values of the bulk modulus of CSF modeled as fluid were needed to predict intracranial dynamic responses and brain injury during head impact.
Demand-Driven Innovation: An Integrative Systems-Based Review of the Literature
Authors: Frenkel Amnon , Maital Shlomo , Leck Eran , Israel Emil
Published: December 2014

In this paper, we provide a comprehensive review of the literature on demand-driven innovation, using a generic national innovation ecosystem map as a unifying framework. We organize the literature review around four key innovation dimensions and seven related demand-driven processes. Our review reveals that business networking which accelerates access to new markets and technologies is vital for free markets. But classical competition alone cannot sustain the creation of new technologies or innovation paths. Rather, national policy is essential in creating lead markets. On the other hand the private sector has a crucial task in leading R&D activity. We found that the relationship between R&D stock and productivity is mostly positive. With regard to cluster strategies our literature review suggests that increased variety of innovative activities strengthens regional economic growth through "spillover effects" between products and industries. Based on the literature, we found that universities are evolving to play a major role in the research of innovation. The enormous innovative potential of universities therefore should be directed toward shaping more effective tools for public–private cooperation. But innovation, whether its origin is in academe or elsewhere, must follow a standardization process in order to converge into a well-defined technology. Our paper highlights a fundamental paradox underlying pro-innovation policies: while innovators often express the desire for a liberal, open and flexible market system with minimal bureaucracy and governmental interference, to allow market-driven innovation to flourish, they often benefit greatly from a variety of governmental interventions that include direct or indirect financial support (such as tax credits).
Application of the algorithm based on the PSO and improved SVDD for the personal credit rating
Authors: Pang Sulin , Li Shuqing , Xiao Jinwang
Published: December 2014

Considering the question of personal credit rating, this paper proposes a hybrid method for credit assessment based on an improved Support Vector Data Description (SVDD) algorithm combined with the particle swarm optimization (PSO) algorithm. First, the paper carries out data preprocess, and then it solves the two problems: parameters optimization and feature selection at the same time using the PSO algorithm combined with the improved SVDD algorithm and assesses the credit data using the optimized parameters and features. Finally, the method constructed is tested through two data sets in practice, and the results show that the hybrid method constructed in this paper can obtain higher classification accuracy compared with some other existing credit scoring methods.
Lessons from Reproductive Technology Research
Authors: Seidel George E.
Published: December 2014

A plethora of assisted reproductive technologies (ARTs) have come into routine use over the past half century. Some of these procedures were used much earlier experimentally. For example, Spallanzani performed artificial insemination in the dog in the late 1700s, and Heape did successful embryo transfer in the rabbit in 1890. Truly revolutionary tools and concepts important for ART occur at approximately half-decade intervals, for example, recombinant DNA procedures, transgenic technology, somatic cell nuclear transplantation, the polymerase chain reaction, and microRNAs. Similarly, obvious technologies sometimes take decades to come into practical use, such as sexing sperm and in vitro fertilization. I have categorized ARTs into five somewhat arbitrary categories in terms of perceived difficulty and feasibility: (a) when the seemingly possible turns out to be (essentially) impossible, e.g., homozygous, uniparental females; (b) when the seemingly impossible becomes possible, e.g., cryopreservation of embryos and transgenesis; (c) when the seemingly difficult turns out to be relatively easy, e.g., cryopreservation of sperm; (d) when the seemingly easy turns out to be difficult in key species, e.g., in vitro fertilization; and (e) when the seemingly difficult remains difficult, e.g., making true embryonic stem cells. The adage that “it is easy when you know how” applies repeatedly. The boundaries between what appears impossible/possible and difficult/easy change constantly owing to new tools and insights, one of the more important lessons learned. ARTs frequently are synergistic with each other. For example, somatic cell nuclear transplantation has made many kinds of experiments feasible that otherwise were impractical. Another example is that sexing sperm is useless for application without artificial insemination or in vitro fertilization. ARTs frequently are perceived as neat tricks and stimulate further thinking. This is useful for both teaching and research.
RNA-Directed DNA Methylation: The Evolution of a Complex Epigenetic Pathway in Flowering Plants
Authors: Matzke Marjori A. , Kanno Tatsuo , Matzke Antonius J.M.
Published: December 2014

RNA-directed DNA methylation (RdDM) is an epigenetic process in plants that involves both short and long noncoding RNAs. The generation of these RNAs and the induction of RdDM rely on complex transcriptional machineries comprising two plant-specific, RNA polymerase II (Pol II)–related RNA polymerases known as Pol IV and Pol V, as well as a host of auxiliary factors that include both novel and refashioned proteins. We present current views on the mechanism of RdDM with a focus on evolutionary innovations that occurred during the transition from a Pol II transcriptional pathway, which produces mRNA precursors and numerous noncoding RNAs, to the Pol IV and Pol V pathways, which are specialized for RdDM and gene silencing. We describe recently recognized deviations from the canonical RdDM pathway, discuss unresolved issues, and speculate on the biological significance of RdDM for flowering plants, which have a highly developed Pol V pathway.
The Molecular Biology of Meiosis in Plants
Authors: Mercier Raphaël , Mézard Christine , Jenczewski Eric , Macaisne Nicolas , Grelon Mathilde
Published: December 2014

Meiosis is the cell division that reshuffles genetic information between generations. Recently, much progress has been made in understanding this process; in particular, the identification and functional analysis of more than 80 plant genes involved in meiosis have dramatically deepened our knowledge of this peculiar cell division. In this review, we provide an overview of advancements in the understanding of all aspects of plant meiosis, including recombination, chromosome synapsis, cell cycle control, chromosome distribution, and the challenge of polyploidy.
Engineering Plastid Genomes: Methods, Tools, and Applications in Basic Research and Biotechnology
Authors: Bock Ralph
Published: December 2014

The small bacterial-type genome of the plastid (chloroplast) can be engineered by genetic transformation, generating cells and plants with transgenic plastid genomes, also referred to as transplastomic plants. The transformation process relies on homologous recombination, thereby facilitating the site-specific alteration of endogenous plastid genes as well as the precisely targeted insertion of foreign genes into the plastid DNA. The technology has been used extensively to analyze chloroplast gene functions and study plastid gene expression at all levels in vivo. Over the years, a large toolbox has been assembled that is now nearly comparable to the techniques available for plant nuclear transformation and that has enabled new applications of transplastomic technology in basic and applied research. This review describes the state of the art in engineering the plastid genomes of algae and land plants (Embryophyta). It provides an overview of the existing tools for plastid genome engineering, discusses current technological limitations, and highlights selected applications that demonstrate the immense potential of chloroplast transformation in several key areas of plant biotechnology.
The Twin-Arginine Protein Translocation Pathway
Authors: Berks Ben C.
Published: December 2014

The twin-arginine translocation (Tat) system, found in prokaryotes, chloroplasts, and some mitochondria, allows folded proteins to be moved across membranes. How this transport is achieved without significant ion leakage is an intriguing mechanistic question. Tat transport is mediated by complexes formed from small integral membrane proteins from just two protein families. Atomic-resolution structures have recently been determined for representatives of both these protein families, providing the first molecular-level glimpse of the Tat machinery. I review our current understanding of the mechanism of Tat transport in light of these new structural data.
Biochemical Properties and Biological Functions of FET Proteins
Authors: Schwartz Jacob C. , Cech Thomas R. , Parker Roy R.
Published: December 2014

Members of the FET protein family, consisting of FUS, EWSR1, and TAF15, bind to RNA and contribute to the control of transcription, RNA processing, and the cytoplasmic fates of messenger RNAs in metazoa. FET proteins can also bind DNA, which may be important in transcription and DNA damage responses. FET proteins are of medical interest because chromosomal rearrangements of their genes promote various sarcomas and because point mutations in FUS or TAF15 can cause neurodegenerative diseases such as amyotrophic lateral sclerosis and frontotemporal lobar dementia. Recent results suggest that both the normal and pathological effects of FET proteins are modulated by low-complexity or prion-like domains, which can form higher-order assemblies with novel interaction properties. Herein, we review FET proteins with an emphasis on how the biochemical properties of FET proteins may relate to their biological functions and to pathogenesis.
Endoplasmic Reticulum Stress in Immunity
Authors: Bettigole Sarah E. , Glimcher Laurie H.
Published: December 2014

Immune responses occur in the midst of a variety of cellular stresses that can severely perturb endoplasmic reticulum (ER) function. The unfolded protein response is a three-pronged signaling axis dedicated to preserving ER homeostasis. In this review, we highlight many important and emerging functional roles for ER stress in immunity, focusing on how the bidirectional cross talk between immunological processes and basic cell biology leads to pleiotropic signaling outcomes and enhanced sensitivity to inflammatory stimuli. We also discuss how dysregulated ER stress responses can provoke many diseases, including autoimmunity, firmly positioning the unfolded protein response as a major therapeutic target in human disease.
T Cell Antigen Receptor Recognition of Antigen-Presenting Molecules
Authors: Rossjohn Jamie , Gras Stephanie , Miles John J. , Turner Stephen J. , Godfrey Dale I. , McCluskey James
Published: December 2014

The Major Histocompatibility Complex (MHC) locus encodes classical MHC class I and MHC class II molecules and nonclassical MHC-I molecules. The architecture of these molecules is ideally suited to capture and present an array of peptide antigens (Ags). In addition, the CD1 family members and MR1 are MHC class I–like molecules that bind lipid-based Ags and vitamin B precursors, respectively. These Ag-bound molecules are subsequently recognized by T cell antigen receptors (TCRs) expressed on the surface of T lymphocytes. Structural and associated functional studies have been highly informative in providing insight into these interactions, which are crucial to immunity, and how they can lead to aberrant T cell reactivity. Investigators have determined over thirty unique TCR-peptide-MHC-I complex structures and twenty unique TCR-peptide-MHC-II complex structures. These investigations have shown a broad consensus in docking geometry and provided insight into MHC restriction. Structural studies on TCR-mediated recognition of lipid and metabolite Ags have been mostly confined to TCRs from innate-like natural killer T cells and mucosal-associated invariant T cells, respectively. These studies revealed clear differences between TCR-lipid-CD1, TCR-metabolite-MR1, and TCR-peptide-MHC recognition. Accordingly, TCRs show remarkable structural and biological versatility in engaging different classes of Ag that are presented by polymorphic and monomorphic Ag-presenting molecules of the immune system.
Inorganic Graphene Analogs
Authors: Rao C.N.R. , Maitra Urmimala
Published: December 2014

In the last four to five years, there has been a great resurgence of research on two-dimensional inorganic materials, partly because of the impetus received from graphene research. Unlike graphene, which is a gap-less material, most inorganic layered materials are semiconductors or insulators. Some of them, as exemplified by MoS2, exhibit unexpected properties, not unlike graphene, with possible applications. Thus, layered metal chalcogenides are being explored intensely, and MoS2is emerging as a wonder material. In this article, we present the synthesis and properties of nanosheets composing single or few layers of these fascinating materials. Besides metal chalcogenides, boron nitride, borocarbonitrides (BxCyNz), metal oxides, and metal-organic frameworks are also discussed.
Vasopressin Receptor Antagonists, Heart Failure, and Polycystic Kidney Disease
Authors: Torres Vicente E.
Published: December 2014

The synthesis of nonpeptide orally bioavailable vasopressin antagonists devoid of agonistic activity (vaptans) has made possible the selective blockade of vasopressin receptor subtypes for therapeutic purposes. Vaptans acting on the vasopressin V2 receptors (aquaretics) have attracted attention as a possible therapy for heart failure and polycystic kidney disease. Despite a solid rationale and encouraging preclinical testing, aquaretics have not improved clinical outcomes in randomized clinical trials for heart failure. Additional clinical trials with select population targets, more flexible dosing schedules, and possibly a different drug type or combination (balanced V1a/V2 receptor antagonism) may be warranted. Aquaretics are promising for the treatment of autosomal dominant polycystic kidney disease and have been approved in Japan for this indication. More studies are needed to better define their long-term safety and efficacy and optimize their utilization.
Time in Individual-Level Organizational Studies: What Is It, How Is It Used, and Why Isn’t It Exploited More Often?
Authors: Shipp Abbie J. , Cole Michael S.
Published: December 2014

Time is an important concern in organizational science, yet we lack a systematic review of research on time within individual-level studies. Following a brief introduction, we consider conceptual ideas about time and elaborate on why temporal factors are important for micro-organizational studies. Then, in two sections—one devoted to time-related constructs and the other to the experience of time as a within-person phenomenon—we selectively review both theoretical and empirical studies. On the basis of this review, we note which topics have received more or less attention to inform our evaluation of the current state of research on time. Finally, we develop an agenda for future research to help move micro-organizational research to a completely temporal view.
The Statistical Mechanics of Dynamic Pathways to Self-Assembly
Authors: Whitelam Stephen , Jack Robert L.
Published: December 2014

This review describes some important physical characteristics of the pathways (i.e., dynamical processes) by which molecular, nanoscale, and micrometer-scale self-assembly occurs. We highlight the existence of features of self-assembly pathways that are common to a wide range of physical systems, even though those systems may differ with respect to their microscopic details. We summarize some existing theoretical descriptions of self-assembly pathways and highlight areas—notably, the description of self-assembly pathways that occur far from equilibrium—that are likely to become increasingly important.
Ultrafast Dynamics of Electrons in Ammonia
Authors: Vöhringer Peter
Published: December 2014

Solvated electrons were first discovered in solutions of metals in liquid ammonia. The physical and chemical properties of these species have been studied extensively for many decades using an arsenal of electrochemical, spectroscopic, and theoretical techniques. Yet, in contrast to their hydrated counterpart, the ultrafast dynamics of ammoniated electrons remained completely unexplored until quite recently. Femtosecond pump-probe spectroscopy on metal-ammonia solutions and femtosecond multiphoton ionization spectroscopy on the neat ammonia solvent have provided new insights into the optical properties and the reactivities of this fascinating species. This article reviews the nature of the optical transition, which gives the metal-ammonia solutions their characteristic blue appearance, in terms of ultrafast relaxation processes involving bound and continuum excited states. The recombination processes following the injection of an electron via photoionization of the solvent are discussed in the context of the electronic structure of the liquid and the anionic defect associated with the solvated electron.
Reaction Dynamics at Liquid Interfaces
Authors: Benjamin Ilan
Published: December 2014

The liquid interface is a narrow, highly anisotropic region, characterized by rapidly varying density, polarity, and molecular structure. I review several aspects of interfacial solvation and show how these affect reactivity at liquid/liquid interfaces. I specifically consider ion transfer, electron transfer, and SN2 reactions, showing that solvent effects on these reactions can be understood by examining the unique structure and dynamics of the liquid interface region.
GCN2 is required to increase fibroblast growth factor 21 and maintain hepatic triglyceride homeostasis during asparaginase treatment
Authors: Wilson Gabriel J. , Lennox Brittany A. , She Pengxiang , Mirek Emily T. , Al Baghdadi Rana J. T. , Fusakio Michael E. , Dixon Joseph L. , Henderson Gregory C. , Wek Ronald C. , Anthony Tracy G.
Published: December 2014

The antileukemic agent asparaginase triggers the amino acid response (AAR) in the liver by activating the eukaryotic initiation factor 2 (eIF2) kinase general control nonderepressible 2 (GCN2). To explore the mechanism by which AAR induction is necessary to mitigate hepatic lipid accumulation and prevent liver dysfunction during continued asparaginase treatment, wild-type and Gcn2 null mice were injected once daily with asparaginase or phosphate buffered saline for up to 14 days. Asparaginase induced mRNA expression of multiple AAR genes and greatly increased circulating concentrations of the metabolic hormone fibroblast growth factor 21 (FGF21) independent of food intake. Loss of Gcn2 precluded mRNA expression and circulating levels of FGF21 and blocked mRNA expression of multiple genes regulating lipid synthesis and metabolism including Fas, Ppara, Pparg, Acadm, and Scd1 in both liver and white adipose tissue. Furthermore, rates of triglyceride export and protein expression of apolipoproteinB-100 were significantly reduced in the livers of Gcn2 null mice treated with asparaginase, providing a mechanistic basis for the increase in hepatic lipid content. Loss of AAR-regulated antioxidant defenses in Gcn2 null livers was signified by reduced Gpx1 gene expression alongside increased lipid peroxidation. Substantial reductions in antithrombin III hepatic expression and activity in the blood of asparaginase-treated Gcn2 null mice indicated liver dysfunction. These results suggest that the ability of the liver to adapt to prolonged asparaginase treatment is influenced by GCN2-directed regulation of FGF21 and oxidative defenses, which, when lost, corresponds with maladaptive effects on lipid metabolism and hemostasis.
Fiber type effects on contraction-stimulated glucose uptake and GLUT4 abundance in single fibers from rat skeletal muscle
Authors: Castorena Carlos M. , Arias Edward B. , Sharma Naveen , Bogan Jonathan S. , Cartee Gregory D.
Published: December 2014

To fully understand skeletal muscle at the cellular level, it is essential to evaluate single muscle fibers. Accordingly, the major goals of this study were to determine if there are fiber type-related differences in single fibers from rat skeletal muscle for: 1) contraction-stimulated glucose uptake and/or 2) the abundance of GLUT4 and other metabolically relevant proteins. Paired epitrochlearis muscles isolated from Wistar rats were either electrically stimulated to contract (E-Stim) or remained resting (No E-Stim). Single fibers isolated from muscles incubated with 2-deoxy-d-[3H]glucose (2-DG) were used to determine fiber type [myosin heavy chain (MHC) isoform protein expression], 2-DG uptake, and abundance of metabolically relevant proteins, including the GLUT4 glucose transporter. E-Stim, relative to No E-Stim, fibers had greater ( P < 0.05) 2-DG uptake for each of the isolated fiber types (MHC-IIa, MHC-IIax, MHC-IIx, MHC-IIxb, and MHC-IIb). However, 2-DG uptake for E-Stim fibers was not significantly different among these five fiber types. GLUT4, tethering protein containing a UBX domain for GLUT4 (TUG), cytochrome c oxidase IV (COX IV), and filamin C protein levels were significantly greater ( P < 0.05) in MHC-IIa vs. MHC-IIx, MHC-IIxb, or MHC-IIb fibers. TUG and COX IV in either MHC-IIax or MHC-IIx fibers exceeded values for MHC-IIxb or MHC-IIb fibers. GLUT4 levels for MHC-IIax fibers exceeded MHC-IIxb fibers. GLUT4, COX IV, filamin C, and TUG abundance in single fibers was significantly ( P < 0.05) correlated with each other. Differences in GLUT4 abundance among the fiber types were not accompanied by significant differences in contraction-stimulated glucose uptake.
Inhibition of anandamide hydrolysis attenuates nociceptor sensitization in a murine model of chemotherapy-induced peripheral neuropathy
Authors: Uhelski Megan L. , Khasabova Iryna A. , Simone Donald A.
Published: December 2014

Painful neuropathy frequently develops as a consequence of commonly used chemotherapy agents for cancer treatment and is often a dose-limiting side effect. Currently available analgesic treatments are often ineffective on pain induced by neurotoxicity. Although peripheral administration of cannabinoids, endocannabinoids, and inhibitors of endocannabinoid hydrolysis has been effective in reducing hyperalgesia in models of peripheral neuropathy, including chemotherapy-induced peripheral neuropathy (CIPN), few studies have examined cannabinoid effects on responses of nociceptors in vivo. In this study we determined whether inhibition of fatty acid amide hydrolase (FAAH), which slows the breakdown of the endocannabinoid anandamide (AEA), reduced sensitization of nociceptors produced by chemotherapy. Over the course of a week of daily treatments, mice treated with the platinum-based chemotherapy agent cisplatin developed robust mechanical allodynia that coincided with sensitization of cutaneous C-fiber nociceptors as indicated by the development of spontaneous activity and increased responses to mechanical stimulation. Administration of the FAAH inhibitor URB597 into the receptive field of sensitized C-fiber nociceptors decreased spontaneous activity, increased mechanical response thresholds, and decreased evoked responses to mechanical stimuli. Cotreatment with CB1 (AM281) or CB2 (AM630) receptor antagonists showed that the effect of URB597 was mediated primarily by CB1 receptors. These changes following URB597 were associated with an increase in the endocannabinoid anandamide in the skin. Our results suggest that enhanced signaling in the peripheral endocannabinoid system could be utilized to reduce nociceptor sensitization and pain associated with CIPN.
Feature attention for binocular disparity in primate area MT depends on tuning strength
Authors: Ruff Douglas A. , Born Richard T.
Published: December 2014

Attending to a stimulus modulates the responses of sensory neurons that represent features of that stimulus, a phenomenon named “feature attention.” For example, attending to a stimulus containing upward motion enhances the responses of upward-preferring direction-selective neurons in the middle temporal area (MT) and suppresses the responses of downward-preferring neurons, even when the attended stimulus is outside of the spatial receptive fields of the recorded neurons (Treue S, Martinez-Trujillo JC. Nature 399: 575–579, 1999). This modulation renders the representation of sensory information across a neuronal population more selective for the features present in the attended stimulus (Martinez-Trujillo JC, Treue S. Curr Biol 14: 744–751, 2004). We hypothesized that if feature attention modulates neurons according to their tuning preferences, it should also be sensitive to their tuning strength, which is the magnitude of the difference in responses to preferred and null stimuli. We measured how the effects of feature attention on MT neurons in rhesus monkeys ( Macaca mulatta) depended on the relationship between features—in our case, direction of motion and binocular disparity—of the attended stimulus and a neuron's tuning for those features. We found that, as for direction, attention to stimuli containing binocular disparity cues modulated the responses of MT neurons and that the magnitude of the modulation depended on both a neuron's tuning preferences and its tuning strength. Our results suggest that modulation by feature attention may depend not just on which features a neuron represents but also on how well the neuron represents those features.
Selective activation of parvalbumin- or somatostatin-expressing interneurons triggers epileptic seizurelike activity in mouse medial entorhinal cortex
Authors: Yekhlef Latefa , Breschi Gian Luca , Lagostena Laura , Russo Giovanni , Taverna Stefano
Published: December 2014

GABAergic interneurons are thought to play a critical role in eliciting interictal spikes (IICs) and triggering ictal discharges in temporal lobe epilepsy, yet the contribution of different interneuronal subtypes to seizure initiation is still largely unknown. Here we took advantage of optogenetic techniques combined with patch-clamp and field recordings to selectively stimulate parvalbumin (PV)- or somatostatin (SOM)-positive interneurons expressing channelrhodopsin-2 (CHR-2) in layers II–III of adult mouse medial entorhinal cortical slices during extracellular perfusion with the proconvulsive compound 4-aminopyridine (4-AP, 100–200 μM). In control conditions, blue laser photostimulation selectively activated action potential firing in either PV or SOM interneurons and, in both cases, caused a robust GABAA-receptor-mediated inhibition in pyramidal cells (PCs). During perfusion with 4-AP, brief photostimuli (300 ms) activating either PV or SOM interneurons induced patterns of epileptiform activity that closely replicated spontaneously occurring IICs and tonic-clonic ictal discharges. Laser-induced synchronous firing in both interneuronal types elicited large compound GABAergic inhibitory postsynaptic currents (IPSCs) correlating with IICs and preictal spikes. In addition, spontaneous and laser-induced epileptic events were similarly initiated in concurrence with a large increase in extracellular potassium concentration. Finally, interneuron activation was unable to stop or significantly shorten the progression of seizurelike episodes. These results suggest that entorhinal PV and SOM interneurons are nearly equally effective in triggering interictal and ictal discharges that closely resemble human temporal lobe epileptic activity.
Polycystin-1 and Gα12 regulate the cleavage of E-cadherin in kidney epithelial cells
Authors: Xu Jen X. , Lu Tzong-Shi , Li Suyan , Wu Yong , Ding Lai , Denker Bradley M. , Bonventre Joseph V. , Kong Tianqing
Published: December 2014

Interaction of polycystin-1 (PC1) and Gα12 is important for development of kidney cysts in autosomal dominant polycystic kidney disease (ADPKD). The integrity of cell polarity and cell-cell adhesions (mainly E-cadherin-mediated adherens junction) is altered in the renal epithelial cells of ADPKD. However, the key signaling pathway for this alteration is not fully understood. Madin-Darby canine kidney (MDCK) cells maintain the normal integrity of epithelial cell polarity and adherens junctions. Here, we found that deletion of Pkd1 increased activation of Gα12, which then promoted the cystogenesis of MDCK cells. The morphology of these cells was altered after the activation of Gα12. By using liquid chromatography-mass spectrometry, we found several proteins that could be related this change in the extracellular milieu. E-cadherin was one of the most abundant peptides after active Gα12 was induced. Gα12 activation or Pkd1 deletion increased the shedding of E-cadherin, which was mediated via increased ADAM10 activity. The increased shedding of E-cadherin was blocked by knockdown of ADAM10 or specific ADAM10 inhibitor GI254023X. Pkd1 deletion or Gα12 activation also changed the distribution of E-cadherin in kidney epithelial cells and caused β-catenin to shift from cell membrane to nucleus. Finally, ADAM10 inhibitor, GI254023 X, blocked the cystogenesis induced by PC1 knockdown or Gα12 activation in renal epithelial cells. Our results demonstrate that the E-cadherin/β-catenin signaling pathway is regulated by PC1 and Gα12 via ADAM10. Specific inhibition of this pathway, especially ADAM10 activity, could be a novel therapeutic regimen for ADPKD.
Conditional disruption of miR17-92 cluster in collagen type I-producing osteoblasts results in reduced periosteal bone formation and bone anabolic response to exercise
Authors: Mohan Subburaman , Wergedal Jon E. , Das Subhashri , Kesavan Chandrasekhar
Published: December 2014

In this study, we evaluated the role of the microRNA (miR)17-92 cluster in osteoblast lineage cells using a Cre-loxP approach in which Cre expression is driven by the entire regulatory region of the type I collagen α2 gene. Conditional knockout (cKO) mice showed a 13–34% reduction in total body bone mineral content and area with little or no change in bone mineral density (BMD) by DXA at 2, 4, and 8 wk in both sexes. Micro-CT analyses of the femur revealed an 8% reduction in length and 25–27% reduction in total volume at the diaphyseal and metaphyseal sites. Neither cortical nor trabecular volumetric BMD was different in the cKO mice. Bone strength (maximum load) was reduced by 10% with no change in bone toughness. Quantitative histomorphometric analyses revealed a 28% reduction in the periosteal bone formation rate and in the mineral apposition rate but with no change in the resorbing surface. Expression levels of periostin, Elk3, Runx2 genes that are targeted by miRs from the cluster were decreased by 25–30% in the bones of cKO mice. To determine the contribution of the miR17-92 cluster to the mechanical strain effect on periosteal bone formation, we subjected cKO and control mice to 2 wk of mechanical loading by four-point bending. We found that the periosteal bone response to mechanical strain was significantly reduced in the cKO mice. We conclude that the miR17-92 cluster expressed in type I collagen-producing cells is a key regulator of periosteal bone formation in mice.
Toxic Anterior Segment Syndrome following Phacoemulsification Secondary to Overdose of Intracameral Gentamicin
Authors: Koban Yaran , Genc Selim , Bilgin Gorkem , Cagatay Halil Huseyin , Ekinci Metin , Gecer Melin , Yazar Zeliha
Published: December 2014

Objective. To report a case of toxic anterior segment syndrome (TASS) that was caused by inadvertent anterior chamber and cornea stromal injection with high dose gentamicin following cataract surgery.Methods. Case report.Results. We report a 72-year-old female patient who developed TASS that was caused by high dose gentamicin (20 mg/0.5 mL), which was inadvertently used during the formation of the anterior chamber and hydration of the corneal incision. Unlike previous cases, hyphema and hemorrhagic fibrinous reaction were seen in the anterior chamber. Despite treatment, bullous keratopathy developed and penetrating keratoplasty was performed. The excised corneal button was sent for histopathological examination.Conclusions. Subconjunctival gentamicin is highly toxic to the corneal endothelium and anterior chamber structures. Including it on the surgical table carries a potentially serious risk for contamination of the anterior chamber.
Serum Clusterin as a Tumor Marker and Prognostic Factor for Patients with Esophageal Cancer
Authors: Guo Wei , Ma Xiao , Xue Christine , Luo Jianfeng , Zhu Xiaoli , Xiang Jiaqing , Lu Bo , Li Hecheng
Published: December 2014

Background. Recent studies have revealed that clusterin is implicated in many physiological and pathological processes, including tumorigenesis. However, the relationship between serum clusterin expression and esophageal squamous cell carcinoma (ESCC) is unclear.Methods. The serum clusterin concentrations of 87 ESCC patients and 136 healthy individuals were examined. An independent-samples Mann-WhitneyUtest was used to compare serum clusterin concentrations of ESCC patients to those of healthy controls. Univariate analysis was conducted using the log-rank test and multivariate analyses were performed using the Cox proportional hazards model.Results. In healthy controls, the mean clusterin concentration was288.8±75.1 μg/mL, while in the ESCC patients, the mean clusterin concentration was higher at412.3±159.4 μg/mL (P<0.0001). The 1-, 2-, and 4-year survival rates for the 87 ESCC patients were 89.70%, 80.00%, and 54.50%. Serum clusterin had an optimal diagnostic cut-off point (serum clusterin concentration = 335.5 μg/mL) for esophageal squamous cell carcinoma with sensitivity of 71.26% and specificity of 77.94%. And higher serum clusterin concentration (>500 μg/mL) indicated better prognosis (P=0.030).Conclusions. Clusterin may play a key role during tumorigenesis and tumor progression of ESCC and it could be applied in clinical work as a tumor marker and prognostic factor.
Microbiological Analysis of Surfaces of Leonardo Da Vinci’sAtlantic Codex: Biodeterioration Risk
Authors: Tarsitani Gianfranco , Moroni Catia , Cappitelli Francesca , Pasquariello Giovanna , Maggi Oriana
Published: December 2014

Following the discovery of discoloration on some pages of theAtlantic Codex (AC)of Leonardo da Vinci kept in the Biblioteca Ambrosiana in Milan, some investigations have been carried out to verify the presence of microorganisms, such as bacteria and fungi. To verify the presence of microorganisms a noninvasive method of sampling has been used that was efficient and allowed us to highlight the microbial facies of the material that was examined using conventional microbiological techniques. The microclimatic conditions in the storage room as well as the water content of the volume were also assessed. The combined observations allowed the conclusion that the discoloration of suspected biological origin on some pages ofACis not related to the presence or current attack of microbial agents.
Mathematical Analysis of Queue with Phase Service: An Overview
Authors: Sharma Richa
Published: December 2014

We discuss various aspects of phase service queueing models. A large number of models have been developed in the area of queueing theory incorporating the concept of phase service. These phase service queueing models have been investigated for resolving the congestion problems of many day-to-day as well as industrial scenarios. In this survey paper, an attempt has been made to review the work done by the prominent researchers on the phase service queues and their applications in several realistic queueing situations. The methodology used by several researchers for solving various phase service queueing models has also been described. We have classified the related literature based on modeling and methodological concepts. The main objective of present paper is to provide relevant information to the system analysts, managers, and industry people who are interested in using queueing theory to model congestion problems wherein the phase type services are prevalent.
Assessment of Serum Enzymatic Antioxidant Levels in Patients with Recurrent Aphthous Stomatitis: A Case Control Study
Authors: Gupta Ishita , Shetti Arvind , Keluskar Vaishali , Bagewadi Anjana
Published: December 2014

Background and Aim. Recurrent aphthous stomatitis (RAS) is a common oral mucosal disorder characterized by recurrent, painful oral aphthae. Despite extensive research, the exact etiology of RAS remains elusive. Recently oxidant-antioxidant imbalance of the body has been implicated in the pathogenesis of recurrent aphthous stomatitis. Thus, the aim of the study was to evaluate the enzymatic antioxidant levels in patients with recurrent aphthous stomatitis. Materials and Methods. The serum levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were measured in 30 patients with recurrent aphthous stomatitis and compared to the control group, which included 30 healthy subjects. Student’s t-test was performed for statistical evaluation. Results. The mean levels of superoxide dismutase (130.2 ± 15.94 U/mL) and glutathione peroxidase (3527.93 ± 488.32 U/L) were found to be significantly lower in study group as compared to control group (211.9 ± 20.93 U/mL, 8860.93 ± 1105.31 U/L, resp.) (P=0.000) while level of catalase in study group was significantly higher when compared to control group (10981.00 ± 1018.07 U/mL versus 9764.00 ± 1621.19 U/mL) (P=0.000). Conclusion. Enzymatic antioxidant system is impaired in recurrent aphthous stomatitis patients and seems to play a crucial role in its pathogenesis.
Meat Production in a Feedlot System of Zebu—Holstein Steers and Heifers with Dairy Genetics: Productive and Biological Analyses
Authors: Menezes Gustavo Chamon de Castro , Valadares Filho Sebastião de Campos , Ruas José Reinaldo Mendes , Detmann Edenio , Menezes Arismar de Castro , Zanett Diego , Mariz Lays Débora Silva , Rennó Luciana Navajas , Silva Junior Jarbas Miguel da
Published: December 2014

The aim of this study was to evaluate the productive and biological efficiency of steers and heifers from dairy genetics in a feedlot system in terms of meat production. Twenty-four steers and 24 heifers at 10 monthes of age, (3/4) Zebu × (1/4) Holstein were utilized. They were distributed over four feedlot times, 30, 60, 90, and 120 days with four replications for each sex, and were slaughtered at the end of each period. The productive and biological analyses were performed through comparative slaughter to determine the body composition. Heifers presented with greater intakes (P<0.05) of dry matter in grams per kg of body weight. Steers presented with a greater (P<0.05) final empty body weight, carcass gain, cold carcass weight, and meat proportion in the carcass; however, heifers presented with a greater subcutaneous fat thickness (P<0.05) and, consequently, a greater (P<0.05) fat proportion in the carcass. We conclude that steers are more efficient in their productive performance than heifers in a feedlot. For the finishing carcass fat cover, heifers need 90 days in the feedlot. The net energy requirements for maintenance are 67 kcal/EBW0.75/d, and the net requirements of energy (NEg) and protein (NPg) for gain can be estimated by the following equations:NEg(Mcal/d)=0.067×EBW0.75×  EBG1.095andNPg=162×EBG-5.62×REfor the two sexes.
Appendicitis in Children: Evaluation of the Pediatric Appendicitis Score in Younger and Older Children
Authors: Salö Martin , Friman Gustav , Stenström Pernilla , Ohlsson Bodil , Arnbjörnsson Einar
Published: December 2014

Background. This study aimed to evaluate Pediatric Appendicitis Score (PAS), diagnostic delay, and factors responsible for possible late diagnosis in children <4 years compared with older children who were operated on for suspected appendicitis.Method. 122 children, between 1 and 14 years, operated on with appendectomy for suspected appendicitis, were retrospectively analyzed. The cohort was divided into two age groups: ≥4 years (n=102) and <4 years (n=20).Results. The mean PAS was lower among the younger compared with the older patients (5.3 and 6.6, resp.;P=0.005), despite the fact that younger children had more severe appendicitis (75.0% and 33.3%, resp.;P=0.001). PAS had low sensitivity in both groups, with a significantly lower sensitivity among the younger patients. Parent and doctor delay were confirmed in children <4 years of age with appendicitis. PAS did not aid in patients with doctor delay. Parameters in patient history, symptoms, and abdominal examination were more diffuse in younger children.Conclusion. PAS should be used with caution when examining children younger than 4 years of age. Diffuse symptoms in younger children with acute appendicitis lead to delay and to later diagnosis and more complicated appendicitis.
Water Quality Assessment of the Central Himalayan Lake, Nainital
Authors: Sharma Madhuben
Published: December 2014

The Nainital Lake, situated in the central Himalayas of India, is an important water body and a major tourist spot. This study aims to identify factors or processes that determine the water quality of the lake. For this purpose, water samples from two different points were collected—highly polluted (Mallital) and least polluted (Tallital)—to represent the actual level of pollution in the lake in four different seasons (January, April, July, and October). The collected samples were analyzed for different physical and chemical parameters. In order to assess the state of the lake’s water quality, the samples were compared with the standard water quality values. Turbidity, electrical conductivity, total alkalinity, and heavy metal (lead, iron, and copper) concentration were found to be above the desirable limit of the prescribed national and international standards in all four seasons at both Mallital and Tallital. Reasons affecting the water quality were found to be natural (thermal stratification and lead-bearing rocks) and anthropogenic (domestic sewage, runoff, and illegal construction activities in the vicinity of lake). Various lake restoration alternatives/interventions have been suggested that can lead to an improvement in the lake’s water quality, such as afforestation, phytoremediation, and sediment basin.
Insight into the Willgerodt-Kindler Reaction of ω-Haloacetophenone Derivatives: Mechanistic Implication
Authors: Kasséhin Urbain C. , Gbaguidi Fernand A. , Kapanda Coco N. , McCurdy Christopher R. , Poupaert Jacques H.
Published: December 2014

This paper reports efforts aimed at tuning up the synthesis of a compound library centered on the general template 2-amino-1-phenyl-2-thioxoethanone taking the condensation of ω-haloacetophenone, octasulfur, and morpholine as pilot reaction. Considerations about atomic economy were found extremely precious in selecting the best starting halo-reagent. A one-pot practical method based on use of 2-bromo-1-phenylethanone as substrate and N,N-dimethylformamide as solvent can be easily scaled up to gram amounts (72% yield). Based on this synthetic approach, some more specific examples are reported.
Experimental Evaluation of Sodium Silicate-Based Nanosilica against Chloride Effects in Offshore Concrete
Authors: Kim Kyoung-Min , Kim Hak-Young , Heo Young-Sun , Jung Sang-Jin
Published: December 2014

This study investigates the effect of a new pore filling material, named sodium silicate-based nanosilica (SS), on resisting the diffusion of the chloride ions. The proposed SS is chosen, mainly due to its smaller particle size, compared to the conventional ethyl silicate-based nanosilica. Each particle of SS is chemically treated to have the negative (−) charge on its surface. Four types of mixes with different amounts of partial replacement with fly ash and slag are prepared. Effect of water to binder ratios (0.35, 0.40, and 0.45) is also examined. Test results showed that the inclusion of SS was significantly beneficial for protecting the concrete from chloride attack. At a given strength, the SS inclusion in concrete was up to three times more effective than the control concrete without SS. It is believed that these excellent results are attributed to the small particle size and the chemical surface treatment of SS. In this study, experiments of compressive strength, hydration heat, accelerated neutralization, and sulfate erosion tests were also conducted to find the general effect of SS inclusion on the fundamental properties and durability of concrete.