10,806 research outputs found
An Analysis of the Influence of CEO Characteristics on Research and Development Expenditures in Large American Corporations (2005 Data)
This study analyzes the influence exerted by CEO characteristics (specifically, CEO stockholding percentages and CEO age) on research and development (R&D) expenditures in large American corporations over the twenty year period from 1986 to 2005. Using the Herfindahl-Hirschman Index (HHI) to measure market share concentrations, and making specific reference to two Schumpeterian hypotheses on the correlation between R&D and increases in firm size, this study establishes a positive linear relationship between the dependent variable, R&D expenditure, and the independent variables of CEO stockholding, CEO age, firm size, and market share. This study next describes the corporate and market conditions which promote the development of a positive linear relationship between CEO characteristics and R&D and concludes by identifying the point of high market concentration at which the prominence of R&D activity is superseded by expenditures for advertising
Preparative Synthesis of dTDP-L-Rhamnose Through Combined Enzymatic Pathways
dTDP-L-rhamnose, an important precursor of O-antigen, was prepared on a large scale from dTMP by executing an one-pot reaction in which six enzymes are involved. Two enzymes, dTDP-4-keto-6-deoxy-D-glucose 3,5-epimerase and dTDP-4-keto-rhamnose reductase, responsible for the conversion of dTDP-4-keto-6-deoxy- D-glucose to dTDP-L-rhamnose, were isolated from their putative sequences in the genome of Mesorhizobium loti, functionally expressed in Escherichia coli, and their enzymatic activities were identified. The two enzymes were combined with an enzymatic process for dTDP-4- keto-6-deoxy-D-glucose involving TMP kinase, acetate kinase, dTDP-glucose synthase, and dTDP-glucose 4,6- dehydratase, which allowed us to achieve a preparative scale synthesis of dTDP-L-rhamnose using dTMP and glucose-1-phosphate as starting materials. About 82% yield of dTDP-L-rhamnose was obtained based on initial dTMP concentration at 20 mM dTMP, 1 mM ATP, 10 mM NADH, 60 mM acetyl phosphate, and 80 mM glucose-1- phosphate. From the reaction with 20 ml volume, approximately 180 mg of dTDP-L-rhamnose was obtained in an overall yield of 60% after two-step purification, that is, anion exchange chromatography and gel filtration for desalting. The purified product was identifiedbyHPLC, ESI-MS,andNMR,showingabout95%purity
Echovirus 30 Induced Neuronal Cell Death through TRIO-RhoA Signaling Activation
BACKGROUND: Echovirus 30 (Echo30) is one of the most frequently identified human enteroviruses (EVs) causing aseptic meningitis and encephalitis. However the mechanism underlying the pathogenesis of Echo30 infection with significant clinical outcomes is not completely understood. The aim of this investigation is to illustrate molecular pathologic alteration in neuronal cells induced by Echo30 infection using clinical isolate from young patient with neurologic involvement. METHODOLOGY/PRINCIPAL FINDINGS: To characterize the neuronal cellular response to Echo30 infection, we performed a proteomic analysis based on two-dimensional gel electrophoresis (2-DE) and MALDI-TOF/TOF Mass Spectrophotometric (MS) analysis. We identified significant alteration of several protein expression levels in Echo30-infected SK-N-SH cells. Among these proteins, we focused on an outstanding up-regulation of Triple functional domain (TRIO) in Echo30-infected SK-N-SH cells. Generally, TRIO acts as a key component in the regulation of axon guidance and cell migration. In this study, we determined that TRIO plays a role in the novel pathways in Echo30 induced neuronal cell death. CONCLUSIONS/SIGNIFICANCE: Our finding shows that TRIO plays a critical role in neuronal cell death by Echo30 infection. Echo30 infection activates TRIO-guanine nucleotide exchange factor (GEF) domains (GEFD2) and RhoA signaling in turn. These results suggest that Echo30 infection induced neuronal cell death by activation of the TRIO-RhoA signaling. We expect the regulation of TRIO-RhoA signaling may represent a new therapeutic approach in treating aseptic meningitis and encephalitis induced by Echo30
Finite-size effect and the components of multifractality in financial volatility
Many financial variables are found to exhibit multifractal nature, which is
usually attributed to the influence of temporal correlations and fat-tailedness
in the probability distribution (PDF). Based on the partition function approach
of multifractal analysis, we show that there is a marked finite-size effect in
the detection of multifractality, and the effective multifractality is the
apparent multifractality after removing the finite-size effect. We find that
the effective multifractality can be further decomposed into two components,
the PDF component and the nonlinearity component. Referring to the normal
distribution, we can determine the PDF component by comparing the effective
multifractality of the original time series and the surrogate data that have a
normal distribution and keep the same linear and nonlinear correlations as the
original data. We demonstrate our method by taking the daily volatility data of
Dow Jones Industrial Average from 26 May 1896 to 27 April 2007 as an example.
Extensive numerical experiments show that a time series exhibits effective
multifractality only if it possesses nonlinearity and the PDF has impact on the
effective multifractality only when the time series possesses nonlinearity. Our
method can also be applied to judge the presence of multifractality and
determine its components of multifractal time series in other complex systems.Comment: 9 RevTex pages including 9 eps figures. Comments and suggestions are
warmly welcom
KMT-2016-BLG-1107: A New Hollywood-Planet Close/Wide Degeneracy
We show that microlensing event KMT-2016-BLG-1107 displays a new type of
degeneracy between wide-binary and close-binary Hollywood events in which a
giant-star source envelops the planetary caustic. The planetary anomaly takes
the form of a smooth, two-day "bump" far out on the falling wing of the light
curve, which can be interpreted either as the source completely enveloping a
minor-image caustic due to a close companion with mass ratio , or
partially enveloping a major-image caustic due to a wide companion with
. The best estimates of the companion masses are both in the planetary
regime ( and ) but differ by an even larger factor than the mass ratios due to
different inferred host masses. We show that the two solutions can be
distinguished by high-resolution imaging at first light on next-generation
("30m") telescopes. We provide analytic guidance to understand the conditions
under which this new type of degeneracy can appear.Comment: 23 pages, 7 figures, accepted for publication in A
SOD2 rs4880 CT/CC genotype predicts poor survival for Chinese gastric cancer patients received platinum and fluorouracil based adjuvant chemotherapy
published_or_final_versio
KMT-2018-BLG-1990Lb: A Nearby Jovian Planet From A Low-Cadence Microlensing Field
We report the discovery and characterization of KMT-2018-BLG-1990Lb, a Jovian
planet orbiting a late M dwarf
, at a distance
(D_L=1.23_{-0.43}^{+1.06}\,\kpc), and projected at times the
snow line distance, i.e., a_{\rm snow}\equiv 2.7\,\au (M/M_\odot), This is
the second Jovian planet discovered by KMTNet in its low cadence () fields, demonstrating that this population will be well
characterized based on survey-only microlensing data.Comment: 24 pages, 7 figures, 4 table
Emission Characteristics of Organic Light-Emitting Diodes and Organic Thin-Films with Planar and Corrugated Structures
In this paper, we review the emission characteristics from organic light-emitting diodes (OLEDs) and organic molecular thin films with planar and corrugated structures. In a planar thin film structure, light emission from OLEDs was strongly influenced by the interference effect. With suitable design of microcavity structure and layer thicknesses adjustment, optical characteristics can be engineered to achieve high optical intensity, suitable emission wavelength, and broad viewing angles. To increase the extraction efficiency from OLEDs and organic thin-films, corrugated structure with micro- and nano-scale were applied. Microstructures can effectively redirects the waveguiding light in the substrate outside the device. For nanostructures, it is also possible to couple out the organic and plasmonic modes, not only the substrate mode
Coupling characteristics of surface modes in truncated two-dimensional photonic crystals
On 1 February, 1994 the Republic of Austria concluded the Accession Treaty and on 1 January, 1995 became a full member of the European Union. Membership obliged Austrians to ‘provide’ the Community with appropriate personnel to take up different posts in various EU authorities, as well as in the European Parliament. The most important issue was to alter particular statutory regulations and the Austrian Constitution to adjust to the new situation.The paper aims at presenting the Austrian solutions in this matter in the context of European Union law, with particular emphasis on regulations which are uncommon or specific to the Republic of Austria. The matter of interest is the constitutional practice of EU member states and the reader’s perspective is taken into account. The latter approach not only evaluates the Austrian solutions in the context of the electoral law to the European Parliament contained in the Election Code, but could also suggest some ideas in regard to prospective amendments. The authors would, in particular, like to pay attention to two issues: the lowering of the voting age, and the single constituency electoral system. The Austrian solutions might be valuable to refer to in the countries where a system of correspondence voting is just being introduced. These resolutions are particularly interesting taking into consideration prospective, possible amendments to the electoral laws of the EU member states.Republika Austrii, 1 lutego 1994 r. podpisała traktat akcesyjny i z dniem 1 stycznia 1995 r. stała się pełnoprawnym członkiem Unii Europejskiej. Członkostwo zobowiązało Austriaków do “dostarczenia” Wspólnocie odpowiednich osób do objęcia różnych stanowisk w różnych unijnych organach. Nie inaczej było także w przypadku Parlamentu Europejskiego. Ważnym aspektem stało się dostosowanie poszczególnych norm ustawowych i własnej konstytucji do nowych rozwiązań. Celem niniejszego opracowania jest właśnie przedstawianie austriackich rozwiązań w tym temacie na tle rozwiązań europejskich, ze szczególnym uwzględnieniem unormowań rzadko spotykanych lub wręcz odrębności sytemu Republiki Austrii. Rzecz wydaje się być interesująca zarówno z punktu widzenia praktyki ustrojowej państw członkowskich Unii Europejskiej, jak i z punktu widzenia czytelnika. To drugie podejście pozwoli na ocenę austriackich rozwiązań na tle niedawno wprowadzonej ordynacji wyborczej do PE zawartej w Kodeksie Wyborczym, ale również może podsunąć pewne pomysły, co do przyszłych nowelizacji. Autorzy zwrócili szczególną uwagę na dwa rozwiązania: obniżenie cenzusu wieku czynnego prawa wyborczego oraz jednookręgowy system wyborczy. Austriackie doświadczenia mogą być również pomocne państwom, które wprowadzają możliwość głosowania korespondencyjnego. Są to propozycje szczególnie interesujące z punktu widzenia przyszłych, możliwych nowelizacji systemów wyborczych państw członkowskich
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