bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alpha‐ketoglutarate dehydrogenase complex‐dependent succinylation of proteins in neurons and neuronal cell lines
Authors: Gibson Gary E. , Xu Hui , Chen Huan‐Lian , Chen Wei , Denton Travis T. , Zhang Sheng 
Published: March 2015

AbstractReversible post‐translation modifications of proteins are common in all cells and appear to regulate many processes. Nevertheless, the enzyme(s) responsible for the alterations and the significance of the modification are largely unknown. Succinylation of proteins occurs and causes large changes in the structure of proteins; however, the source of the succinyl groups, the targets, and the consequences of these modifications on other proteins remain unknown. These studies focused on succinylation of mitochondrial proteins. The results demonstrate that the α‐ketoglutarate dehydrogenase complex (KGDHC) can serve as a trans‐succinylase that mediates succinylation in an α‐ketoglutarate‐dependent manner. Inhibition of KGDHC reduced succinylation of both cytosolic and mitochondrial proteins in cultured neurons and in a neuronal cell line. Purified KGDHC can succinylate multiple proteins including other enzymes of the tricarboxylic acid cycle leading to modification of their activity. Inhibition of KGDHC also modifies acetylation by modifying the pyruvate dehydrogenase complex. The much greater effectiveness of KGDHC than succinyl‐CoA suggests that the catalysis owing to the E2k succinyltransferase is important. Succinylation appears to be a major signaling system and it can be mediated by KGDHC.
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Reversible post‐translation modifications of proteins are common and may regulate many processes. Succinylation of proteins occurs and causes large changes in the structure of proteins. However, the source of the succinyl groups, the targets, and the consequences of these modifications on other proteins remains unknown. The results demonstrate that the mitochondrial α‐ketoglutarate dehydrogenase complex (KGDHC) can succinylate multiple mitochondrial proteins and alter their function. Succinylation appears to be a major signaling system and it can be mediated by KGDHC.
The exploratory power of sleep effort, dysfunctional beliefs and arousal for insomnia severity and polysomnography‐determined sleep
Authors: Hertenstein Elisabeth , Nissen Christoph , Riemann Dieter , Feige Bernd , Baglioni Chiara , Spiegelhalder Kai 
Published: March 2015

SummaryDifferences between subjective sleep perception and sleep determined by polysomnography (PSG) are prevalent, particularly in patients with primary insomnia, indicating that the two measures are partially independent. To identify individualized treatment strategies, it is important to understand the potentially different mechanisms influencing subjective and PSG‐determined sleep. The aim of this study was to investigate to what extent three major components of insomnia models, i.e. sleep effort, dysfunctional beliefs and attitudes about sleep, and presleep arousal, are associated with subjective insomnia severity and PSG‐ determined sleep. A sample of 47 patients with primary insomnia according to DSM‐IV criteria and 52 good sleeper controls underwent 2 nights of PSG and completed the Glasgow Sleep Effort Scale, the Dysfunctional Beliefs and Attitudes about Sleep Scale, the Pre‐Sleep Arousal Scale and the Insomnia Severity Index. Regression analyses were conducted to investigate the impact of the three predictors on subjective insomnia severity and PSG‐ determined total sleep time. All analyses were adjusted for age, gender, depressive symptoms and group status. The results showed that subjective insomnia severity was associated positively with sleep effort. PSG‐determined total sleep time was associated negatively with somatic presleep arousal and dysfunctional beliefs and attitudes about sleep. This pattern of results provides testable hypotheses for prospective studies on the impact of distinct cognitive and somatic variables on subjective insomnia severity and PSG‐determined total sleep time.
Phylogeographic study on the chub mackerel (Scomber japonicus) in the Northwestern Pacific indicates the late Pleistocene population isolation
Authors: Yan Shuai , Catanese Gaetano , Brown Christopher L. , Wang Ming , Yang Chaopin , Yang Tingbao 
Published: March 2015

AbstractIn the present study, the population genetic structure and historical demography of the chub mackerel, Scomber japonicus, in the Northwestern Pacific were examined based on the full‐length sequences of the mitochondrial control region and cytochrome b gene. A total of 320 individuals was sampled from 11 localities along the coast of China and Japan from August 2011 to May 2013. Two main clades representing Chinese and Japanese populations, respectively, were detected, suggesting population isolation of S. japonicus during the late Pleistocene era. The Chinese clade was further divided into two small clades and the distribution of haplotypes were not related to sampling locality, which may be a signature of secondary contact following past division. Analyses of molecular variance and pairwise FST revealed significant genetic differentiation between the Chinese and Japanese populations, but a lack of genetic structure for the populations along the coast of China. Both neutrality tests and mismatch distribution analysis suggested that the populations along the coast of China experienced population expansion during the late Pleistocene. Historical events, biological characteristics and other extrinsic forces such as ocean currents may all be associated with the current phylogeographic pattern of S. japonicus in the Northwestern Pacific.
Feed the Brain: Insights into the Study of Neurovascular Coupling
Authors: Welsh Donald G. , Ledoux Jonathan 
Published: March 2015

AbstractThe microcirculation is tightly regulated by a diverse range of mechanisms which share the common goal of matching blood flow delivery with tissue metabolic demand. Despite in‐depth examination of tissues like skeletal muscle, brain microcirculation has remained largely unexplored due to methodological limitations. Recent, technological advances have, however, started to grant greater access to this vital microcirculatory bed. This overview is part of a Special Topics Issue centered on the methodology, theory, and mechanistic basis of neurovascular coupling. Solicited manuscripts have been purposely written in an opinionated manner to provoke thought and to illuminate new emerging areas of investigation.
Role of hydrogen sulfide within the dorsal motor nucleus of the vagus in the control of gastric function in rats
Authors: Sun H.‐Z. , Yu K.‐H. , Ai H.‐B. 
Published: March 2015

AbstractBackgroundHydrogen sulfide (H2S) is a gaseous messenger and serves as an important neuromodulator in the central nervous system. This study aimed to clarify the role of H2S within the dorsal motor nucleus of the vagus (DMV) in the control of gastric function in rats.MethodsCystathionine β‐synthetase (CBS) is an important generator of endogenous H2S in the brain. We investigated the distribution of CBS in the DMV using immunohistochemical method, and the effects of H2S on gastric motility and on gastric acid secretion.Key ResultsCBS‐immunoreactive (IR) neurons were detected in the rostral, intermediate and caudal DMV, with the highest number of CBS‐IR neurons in the caudal DMV, and the lowest in the intermediate DMV. We also found that microinjection of the exogenous H2S donor NaHS (0.04 and 0.08 mol/L; 0.1 μL; n = 6; p < 0.05) into the DMV significantly inhibited gastric motility with a dose‐dependent trend, and promoted gastric acid secretion in Wistar rats. Microinjection of the same volume of physiological saline (PS; 0.1 μL, n = 6, p > 0.05) at the same location did not noticeably change gastric motility and acid secretion.Conclusions & InferencesThe data from these experiments suggest that the CBS that produces H2S is present in the DMV, and microinjection of NaHS into the DMV inhibited gastric motility and enhanced gastric acid secretion in rats.
Generalizedx‐to‐C in Germanic
Authors: Leu Thomas 
Published: March 2015

AbstractThis paper highlights striking similarities of three well‐known but hitherto disparately treated alternations in Germanic morphosyntax: (i) the positional alternation of the finite verb between a low and a left peripheral (V2) position; (ii) the morphological alternation in adnominal adjectives between so‐called weak and strong agreement; and (iii) the contrast in definiteness marking between a free DP‐initial definite article and a so‐called suffixed article. The number and kinds of punctual similarities among these alternations suggest that we are dealing with a parallelism that is non‐accidental (even if not always fully surface apparent).In an attempt to propose a principled account of this parallelism, I argue that the familiar syntactic CP/DP analogy must (A) be extended to include the extended adjectival projection (xAP), and (B) that it is more than an analogy. It is, I claim, a point‐wise isomorphism. I identify a shared complementizer head C, which, I claim, extended projections of all colors converge on. In Germanic, C is either lexicalized/identified qua head, asd‐, or it attracts the lexical category of its containing extended projection, indiscriminately of whether it is verbal, nominal, or adjectival. Movement of the lexical category to the left periphery results, in many cases, in its preceding material which it does not precede in the absence of such movement, notably inflectional material.If correct, the proposed isomorphism hypothesis has consequences for the analysis of the phenomena involved in that it allows us to transfer insights from one domain to another. In particular, it supports an analysis of the adjectival inflection alternation in terms of adjective movement; and an analysis of V2 as involving two merger steps.
Tectonically induced change in lake evolution recorded by seismites in the Eocene Green River Formation, Wyoming
Authors: Törő Balázs , Pratt Brian R. , Renaut Robin W. 
Published: March 2015

AbstractSeismogenic sedimentary structures – seismites – provide an opportunity to understand the effects of syndepositional tectonics on lacustrine sedimentation. The lowermost Wilkins Peak Member (Eocene Green River Formation, Wyoming, USA) contains laterally extensive intervals displaying folds, load structures, mixed brittle–ductile deformation, microfaults, breccias and sedimentary dykes, which formed intrastratally in a low‐energy, sublittoral lacustrine environment. They developed in situ by liquefaction and plastic or brittle behaviour of semi‐lithified sediment, or by remobilization and injection of granular material. Their morphological attributes and lateral extent, zonation in deformation intensity and the depositional setting all imply deformation triggered by earthquake‐induced stresses in shallow‐buried sediment. Their stratigraphic distribution coincides with a shift in hydrological conditions from a balanced‐filled to an underfilled lake type, independent of climate change. This study is the first to ascribe seismites to a pulse of tectonic activity that caused a synchronous change in lacustrine evolution.
Marr and Reductionism
Authors: Bickle John 
Published: March 2015

AbstractDavid Marr's three‐level method for completely understanding a cognitive system and the importance he attaches to the computational level are so familiar as to scarcely need repeating. Fewer seem to recognize that Marr defends his famous method by criticizing the “reductionistic approach.” This sets up a more interesting relationship between Marr and reductionism than is usually acknowledged. I argue that Marr was correct in his criticism of the reductionists of his time—they were only describing (cellular activity), not explaining (cognitive functions). But a careful metascientific account of reductionistic neuroscience over the past two decades reveals that Marr's criticisms no longer have force. Contemporary neuroscience now explains cognition directly, although in a fashion—causal‐mechanistically—quite different than Marr recommended. So while Marr was correct to reject the reductionism of his day and offer an alternative method for genuinely explaining cognition, contemporary cognitive scientists now owe us a new defense of Marr's famous method and the advantages of its explanations over the type now pursued successfully in current reductionist neuroscience. There are familiar reasons for thinking that this debt will not be paid easily.
Thermostructural Analyses Supporting the Design of the HYPROB Heat Sink Subscale Breadboard
Authors: Ferraiuolo M. , Martucci A. , Battista F. , Ricci D. 
Published: March 2015

Today’s rocket engines regeneratively cooled using high energy cryogenic propellants (e.g. LOX and LH2, LOX and LCH4) play a major role due to the high combustion enthalpy (10–13.4 kJ/kg) and the high specific impulse of these propellants. In the frame of the HYPROB/Bread project, whose main goal is to design build and test a 30 kN regeneratively cooled thrust chamber, a breadboard has been conceived in order to:
• investigate the behavior of the injector that will be employed in the full scale final demonstrator,
• to obtain a first estimate of the heat flux on the combustion chamber for models validation,
• to implement a “battleship” chamber for a first verification of the stability of the combustion
The breadboard is called HS (Heat Sink) and it is made of CuCrZr (Copper Chromium Zirconium alloy), Inconel 718 and TZM (Titanium Zirconium Molybdenum alloy). The aim of the present paper is to illustrate the thermostructural design conducted on the breadboard by means of a Finite Element Method code taking into account the viscoplastic behavior of the adopted materials. An optimization process has been carried out in order to keep the structural integrity of the breadboard maximizing the life cycles of the component. Heat fluxes generated by combustion gases have been evaluated by means of CFD quick analyses, while convection and radiation with the external environment have not been considered in order to be as conservative as possible from a thermostructural point of view. Transient thermal analyses and static structural analyses have been performed by means of ANSYS code adopting an axisymmetric model of the chamber. These analyses have demonstrated that the Breadboard can withstand the design goal of 3 thermo-mechanical cycles with a safety factor equal to 4 considering a firing time equal to 3 seconds.
RQL Combustion as an Effective Strategy to NOx Reduction in Gas Turbine Engines
Authors: Ingenito Antonella , Agresta Antonio , Andriani Roberto , Gamma Fausto 
Published: March 2015

The growing need to drastically reduce aircrafts CO2 emissions has led engineers and scientists in the last years to develop a clean, renewable and sustainable energy system. Hydrogen as a fuel in aviation has shown to be a good choice, since it has an energy release much higher than common and long chain hydrocarbons (119.96 MJ/kg vs ∽42.8 MJ/kg, respectively), a wide flammability limits, a high diffusivity and a very short ignition time. Its thermal conductivity, the highest among all gases, its high heat capacity and its very low dynamic viscosity provide superior cooling properties for operation at high flight speeds and at combustor high temperatures. Furthermore, its low molecular weight makes it the fuel with the higher specific impulse (ISP), ∼450 s: this means that burning 1 kg/s of hydrogen with oxygen produces a thrust of 450 kg-force.
However, for its high combustion temperature, it has been demonstrated to be disadvantageous in terms of NOx production. Although NOx pollution is a relatively small part of global human pollution (less than 4%), a particular feature of air transport is that pollutants from air traffic are emitted at high altitudes, in the upper troposphere/lower stratosphere (8 to 12 km), where they are of greater influence than those emitted at ground level. Moreover, further emission reductions need to be achieved by the air transport community, since air traffic has a growth (3% to 5% per year) which exceeds the technology improvement rate.
Emissions may be controlled by operating at lean or very lean equivalence ratios (thanks to the wider flammability limits of the hydrogen-air flames compared to kerosene-air flames), or reducing the combustor length (thanks to the higher flame speed of hydrogen compared to other fuels), or via innovative strategies. In this paper, the RQL (Rich-Quench-Lean) strategy for the NOx abatement will be proposed for a high speed hydrogen fuelled vehicle.
A Numerical Study of High Temperature and High Velocity Gaseous Hydrogen Flow in a Cooling Channel of a Nuclear Thermal Rocket Core
Authors: Akyuzlu K. M. 
Published: March 2015

Two mathematical models (a one-dimensional and a two-dimensional) were adopted to study, numerically, the thermal hydrodynamic characteristics of flow inside the cooling channels of a Nuclear Thermal Rocket (NTR) engine. In the present study, only a single one of the cooling channels of the reactor core is simulated. The one-dimensional model adopted here assumes the flow in this cooling channel to be steady, compressible, turbulent, and subsonic. The physics based mathematical model of the flow in the channel consists of conservation of mass, momentum, and energy equations subject to appropriate boundary conditions as defined by the physical problem stated above. The working fluid (gaseous hydrogen) is assumed to be compressible through a simple ideal gas relation. The physical and transport properties of the hydrogen is assumed be temperature dependent. The governing equations of the compressible flow in cooling channels are discretized using the second order accurate MacCormack finite difference scheme. Convergence and grid independence studies were done to determine the optimum computational cell mesh size and computational time increment needed for the present simulations. The steady state results of the proposed model were compared to the predictions by a commercial CFD package (Fluent.) The two-dimensional CFD solution was obtained in two domains: the coolant (gaseous hydrogen) and the ZrC fuel cladding. The wall heat flux which varied along the channel length (as described by the nuclear variation in the nuclear power generation) was given as an input.
Numerical experiments were carried out to simulate the thermal and hydrodynamic characteristics of the flow inside a single cooling channel of the reactor for a typical NERVA type NTR engine where the inlet mass flow rate was given as an input. The time dependent heat generation and its distribution due to the nuclear reaction taking place in the fuel matrix surrounding the cooling channel. Numerical simulations of flow and heat transfer through the cooling channels were generated for steady state gaseous hydrogen flow. The temperature, pressure, density, and velocity distributions of the hydrogen gas inside the coolant channel are then predicted by both one-dimensional and two-dimensional model codes. The steady state predictions of both models were compared to the existing results and it is concluded that both models successfully predict the steady state fluid temperature and pressure distributions experienced in the NTR cooling channels. The two dimensional model also predicts, successfully, the temperature distribution inside the nuclear fuel cladding.
Sheet Metal Blank Development of a Deep Drawing Fan Support Using Theoretical Rules and FEM
Authors: Garcia Zugasti Pedro de Jesus , Salcedo Murillo Erick M. , Medellín Castillo Hugo I. , De Lange Dirk Frederik , Granja Juan Gabriel Sandoval 
Published: March 2015

Deep drawing is a cost effective sheet metal forming process to produce many industrial components. However, complex geometrical drawn parts are difficult to form due to several modes and conditions of the material flow. Commonly problems associated to the forming operation are wrinkling and tearing defects, which affect the cost and quality of the parts. Actually, there are not theoretical methods developed in the literature yet, so the trial and error method are used to reduce or eliminate the deep drawing defects or inclusive is utilized in the earlier production stages, resulting in higher costs and longer production times.
This paper describe a proposed solution to reduce or eliminate the wrinkles defects on the flanges of an industrial fan support that result from applying the forming process. An analysis procedure based on the development of the correct sheet metal blank considering three different blank geometries was proposed. The analysis include the analytical methods available in the literature, the simulation with a computer program based on the Finite Element Method (FEM) and experimentation. FEM model, simulation and results, these were validated by measuring the thickness profile on the flanges of a deep drawing part, before and after the procedure implementation. The results have shown that combining both the analytical and FEM methods, were possible to know the influence degree of the sheet metal blank geometry to reduce or eliminate the wrinkle defect and these can be used as an effective design tool.
Elastoplastic Analysis of the Erichsen Cupping Test Using Comsol Multiphysics FEM Code
Authors: Salazar Julio Alberto Boix , de Lange Dirk F. , Medellín Castillo Hugo I. 
Published: March 2015

One of the standard procedures to test the formability of sheet material is the Erichsen cupping test, in which the metal sheet blank is held in its place over a circular space and depressed by a semi-spherical punch. The depth of depression that can be reached is the measure of the formability. In this work the elastoplastic deformation of the sheet is analyzed by multipurpose Finite Element Method software Comsol Multiphysics. The Comsol package is not specifically developed or focused on the analysis of solid mechanical problems with elastoplastic model behavior and contact problems, and still limited literature is available in which sheet forming processes are analyzed with Comsol. In this work, the development and testing of a simulation model in Comsol is reported and comparison is made with results reported with other FEM software.
The development and testing is realized in successive steps of increasing complexity. First a uniaxial stretching is simulated in order to evaluate the implementation of the elastoplastic material behavior. Next, the bending of a plate over a straight line is analyzed, adding the contact boundary condition between tool and sheet surface into the model. Finally, the axisymmetric model of the Erichsen cupping test is implemented.
It is found that the default Von Mises yield function results in incorrect stresses, and needs to be replaced by a yield function in which the Von Mises stress is calculated based on the Cauchy tensor. The non-linear contact condition is a source of oscillations in the local stresses near the zone where contact is established. The simulation results obtained with the final model are compared with punch forces, stresses and strains obtained in literature, showing an adequate comparison.