bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microglia and neuroprotection
Authors: Chen Zhihong , Trapp Bruce D. 
Published: February 2015

AbstractMicroglia were first identified over a century ago, but our knowledge about their ontogeny and functions has significantly expanded only recently. Microglia colonize the central nervous system (CNS) in utero and play essential roles in brain development. Once neural development is completed, microglia function as the resident innate immune cells of the CNS by surveying their microenvironment and becoming activated when the CNS is challenged by infection, injury, or disease. Despite the traditional view of microglia as being destructive in neurological diseases, recent studies have shown that microglia maintain CNS homeostasis and protect the CNS under various pathological conditions. Microglia can be prophylactically activated by modeling infection with systemic lipopolysaccharide injections and these activated microglia can protect the brain from traumatic injury through modulation of neuronal synapses. Microglia can also protect the CNS by promoting neurogenesis, clearing debris, and suppressing inflammation in diseases such as stroke, autism, and Alzheimer's.
imageMicroglia are the resident innate immune cells of the CNS. Despite the traditional view of microglia as being destructive in neurological diseases, recent studies have shown that they maintain tissue homeostasis and protect the CNS under various pathological conditions. They achieve so by clearing debris, promoting neurogenesis, suppressing inflammation and stripping inhibitory synapses. This review summarizes recent advances of our understanding on the multi‐dimensional neuroprotective roles of microglia.
Expression of the synaptic exocytosis‐regulating molecule complexin 2 in taste buds and its participation in peripheral taste transduction
Authors: Kurokawa Azusa , Narukawa Masataka , Ohmoto Makoto , Yoshimoto Joto , Abe Keiko , Misaka Takumi 
Published: February 2015

AbstractTaste information from type III taste cells to gustatory neurons is thought to be transmitted via synapses. However, the molecular mechanisms underlying taste transduction through this pathway have not been fully elucidated. In this study, to identify molecules that participate in synaptic taste transduction, we investigated whether complexins (Cplxs), which play roles in regulating membrane fusion in synaptic vesicle exocytosis, were expressed in taste bud cells. Among four Cplx isoforms, strong expression of Cplx2 mRNA was detected in type III taste cells. To investigate the function of CPLX2 in taste transduction, we observed taste responses in CPLX2‐knockout mice. When assessed with electrophysiological and behavioral assays, taste responses to some sour stimuli in CPLX2‐knockout mice were significantly lower than those in wild‐type mice. These results suggested that CPLX2 participated in synaptic taste transduction from type III taste cells to gustatory neurons.image
A part of taste information is thought to be transmitted via synapses. However, the molecular mechanisms have not been fully elucidated. To identify molecules that participate in synaptic taste transduction, we investigated complexins (Cplxs) expression in taste bud cells. Strong expression of Cplx2 mRNA was detected in taste bud cells. Furthermore, taste responses to some sour stimuli in CPLX2‐ knockout mice were significantly lower than those in wild‐type mice. These suggested that CPLX2 participated in synaptic taste transduction.
Interactions among proteins of floral MADS‐box genes in Nuphar pumila (Nymphaeaceae) and the most recent common ancestor of extant angiosperms help understand the underlying mechanisms of the origin of the flower
Authors: Li Lin , Yu Xian‐Xian , Guo Chun‐Ce , Duan Xiao‐Shan , Shan Hong‐Yan , Zhang Rui , Xu Gui‐Xia , Kong Hong‐Zhi 
Published: February 2015

AbstractFloral organ identity genes, most of which are MADS‐box genes, play key roles in flower development and floral organ identity determination. To specify the identities of different floral organ types, proteins of the floral MADS‐box genes need to form dimers and higher‐level complexes before they bind to the control regions of downstream genes and regulate their expression. Previous studies have shown that understanding the evolution of the interactions among proteins of the floral MADS‐box genes may be an excellent step towards uncovering the underlying mechanisms of the origin of the flower. Yet, due to the lack of such information in early‐branching angiosperm lineages, it has been difficult to determine the evolutionary changes of the protein–protein interactions (PPIs) before and after the origin of the flower. In this study, we first isolated counterparts of the floral MADS‐box genes from Nuphar pumila (Timm) D.C., a representative of the basalmost angiosperms Nymphaeales, and investigated the interactions among their proteins by carrying out yeast two‐hybrid assays. We then estimated the PPIs in the most recent common ancestor of extant angiosperms by using two different methods: ancestral character state reconstruction and ancestral sequence reconstruction followed by yeast two‐hybrid assay. Based on these results, we examined the evolutionary transitions of the PPIs before and after the occurrence of extant angiosperms, and discussed their contributions to the origin of the flower. We found that duplication and diversification of floral MADS‐box genes, as well as non‐random losses of some once‐existed PPIs, have been the driving force of the origin of the flower.
Brain‐Based Learning and Educational Neuroscience: Boundary Work
Authors: Edelenbosch Rosanne , Kupper Frank , Krabbendam Lydia , Broerse Jacqueline E. W. 
Published: February 2015

ABSTRACTMuch attention has been given to “bridging the gap” between neuroscience and educational practice. In order to gain better understanding of the nature of this gap and of possibilities to enable the linking process, we have taken a boundary perspective on these two fields and the brain‐based learning approach, focusing on boundary‐spanning actors, boundary objects, and boundary work. In 26 semistructured interviews, neuroscientists and education professionals were asked about their perceptions in regard to the gap between science and practice and the role they play in creating, managing, and disrupting this boundary. Neuroscientists and education professionals often hold conflicting views and expectations of both brain‐based learning and of each other. This leads us to argue that there are increased prospects for a neuroscientifically informed learning practice if science and practice work together as equal stakeholders in developing and implementing neuroscience research.
Neuromyths Among Teachers and Student Teachers
Authors: Tardif Eric , Doudin Pierre‐André , Meylan Nicolas 
Published: February 2015

ABSTRACTMany so‐called brain‐based educational approaches have been strongly criticized for their lack of empirical support and occasionally for their use of pseudoscientific concepts. As a result, several use the term neuromyths to refer to false beliefs or misinterpretations regarding neuroscientific facts. We surveyed both teachers and student teachers concerning their agreement toward hemispheric dominance, modality dominance, and the Brain Gym© method. Results suggest that teachers as well as student teachers believe in the reality of hemispheric and modality dominance but only a few were aware of the Brain Gym© method. Correlation analyses show moderate relationships across different beliefs and/or their perceived benefits in education. Teachers believed more than student teachers in hemispheric dominance and its pedagogical relevance. Together with other studies, the results suggest that teachers and student teachers could benefit from appropriate training in this new field of research.
Progress on the Advanced Turbine Technology Applications Project (ATTAP)
Authors: Berenyi S. G. 
Published: February 2015

This technology project, sponsored by the U.S. Department of Energy, is intended to advance the technological readiness of the ceramic automotive gas turbine engine. Of the several technologies requiring development before such an engine becomes a commercial reality, structural ceramic components represent the greatest technical challenge, and are the prime project focus. The ATTAP aims at developing and demonstrating such ceramic components that have a potential for: (1) competitive automotive engine life cycle cost and (2) operating for 3500 hr in a turbine engine environment at turbine inlet temperatures up to 1371°C (2500°F).
Allison is addressing the ATTAP goal using internal technical resources, an extensive technology and data base from General Motors (GM), technical resources from several subcontracted domestic ceramic suppliers, and supporting technology developments from Oak Ridge and other federal programs.
The development activities have resulted in the fabrication and delivery of numerous ceramic engine components, which have been characterized through laboratory evaluation, cold spin testing, hot rig testing, and finally through engine testing as appropriate. These component deliveries are the result of the ATTAP design/process development/fabrication/characterization/test cycles.
Ceramic components and materials have been characterized in an on-going program using nondestructive and destructive techniques. So far in ATTAP, significant advancements include:
• evolution of a correlated design procedure for monolithic ceramic components
• evolution of materials and processes to meet the demanding design and operational requirements of high temperature turbines
• demonstration of ceramic component viability through thousands of hours of both steady-slate and transient testing while operating at up to full design speed, and at turbine inlet temperatures up to 1371°C (2500°F)
• completion of hundreds of hours of durability cyclic testing utilizing several “all ceramic” gasifier turbine assemblies
• demonstration of ceramic rotor survivability under conditions of extreme foreign object ingestion, high speed turbine tip rub, severe start-up transients, and a very demanding durability cycle
In addition to the ceramic component technology, progress has been made in the areas of low emission combustion technology and regenerator design and development.
Operating Experience and Economic Benefit of a 3-MW Gas Turbine in an Industrial Peak Shaving Application
Authors: Jones Michael H. , Nall L. M. (Matt) 
Published: February 2015

In the late 1970’s, due to increasing electric energy costs and the potential for power interruption at Solar Turbines Incorporated’s Harbor Drive manufacturing facility, management evaluated several self-generating options available at the time. With large fluctuating loads and a very limited need for thermal energy, the appropriate solution was determined to be peak shaving.
In 1980, a 2.5-MW dual fuel industrial gas turbine generator set was installed. Its intended operating cycle was during on-peak billing periods, 5 days a week throughout the year. Through August 31, 1993, the system has accumulated 22,743 hours of use and 3879 starts. Its overall start reliability has been 99.9% with an availability of 98.2%. Payback on the installation was in 4.2 years. It has continued to generate savings since installation, with net savings for 1992 alone exceeding $470,000.
This paper highlights the key aspects of the economic methodology justifying installation of the peak shaving system, operating procedures, maintenance practices and system modifications put in place over the life of the installation.
The Development of Fast Response Aerodynamic Probes for Flow Measurements in Turbomachinery
Authors: Ainsworth Roger W. , Allen John L. , Batt J. Julian M. 
Published: February 2015

The advent of a new generation of transient rotating turbine simulation facilities, where engine values of Reynolds and Mach number are matched simultaneously together with the relevant rotational parameters for dimensional similitude (Dunn et al [1988], Epstein et al [1984]. Ainsworth et al [1988]), has provided the stimulus for developing improved instrumentation for investigating the aerodynamic flows in these stages.
Much useful work has been conducted in the past using hot-wire and laser anemometers. However, hot-wire anemometers are prone to breakage in the high pressure flows required for correct Reynolds numbers, Furthermore some laser techniques require a longer runtime than these transient facilites permit, and generally yield velocity information only, giving no data on loss production.
Advances in semiconductor aerodynamic probes are beginning to fulfil this perceived need. This paper describes advances made in the design, construction, and testing of two and three dimensional fast response aerodynamic probes, where semiconductor pressure sensors are mounted directly on the surface of the probes, using techniques which have previously been successfully used on the surface of rotor blades (Ainsworth, Dietz and Nunn [1991]). These are to be used to measure Mach number and flow direction in compressible unsteady flow regimes.
In the first section, a brief review is made of the sensor and associated technology which has been developed to permit a flexible design of fast response aerodynamic probe. Following this, an extensive programme of testing large scale aerodynamic models of candidate geometries for suitable semiconductor scale probes is described, and the results of these discussed. The conclusions of these experiments, conducted for turbine representative mean and unsteady flows, yielded new information for optimising the design of the small scale semiconductor probes, in terms of probe geometry, sensor placement, and aerodynamic performance.
Details are given of a range of wedge and pyramid semiconductor probes constructed, and the procedures used in calibrating and making measurements with them. Differences in performance are discussed, allowing the experimenter to choose an appropriate probe for the particular measurement required.
Finally, the application of prototype semiconductor probes in a transient rotor experiment at HP turbine representative conditions is described, and the data so obtained is compared with (PD solutions of the unsteady viscous flow-field.
Windage Heating of Air Passing Through Labyrinth Seals
Authors: Millward J. A. , Edwards M. F. 
Published: February 2015

The viscous drag on rotating components in gas turbine engines represents both a direct loss of power from the cycle and an input of heat into the secondary (cooling) air system. Hotter cooling air in turn means increased flow requirements. The effects of windage on performance are therefore compounded.
To facilitate accurate temperature predictions of highly stressed components, information is needed on windage characteristics of all elements in the secondary cooling system. Much information is available in the literature for discs, cones, cylinders, bolts etc but little has been published on windage heating in high speed seals.
Results are presented for experiments carried out (at representative non-dimensional conditions) on different designs of labyrinth seals. The results are compared with values calculated from the simple momentum balance theory suggested by McGreeham and Ko (1989) and with several values determined from CFD analysis.
Vibration and Control of a Flexible Rotor in Magnetic Bearings Using Hybrid Method and H∞ Control Theory
Authors: Shiau Ting Nung , Sheu Geeng Jen , Yang Clann Dong 
Published: February 2015

The vibration and active control of a flexible rotor system with magnetic bearings is investigated using Hybrid Method (HM) and H∞ control theory with consideration of gyroscopic effect. The hybrid method which combines the merits of finite element method (FEM) and generalized ploynomial expansion method (GPEM) is employed to model the flexible rotor system with small order of plant. The mixed sensitivity problem of H∞ control theory is applied to design the control of system vibration with spillover phenomena for the reduced order plant. The H2 control design is also employed for the comparison to the H∞ design.
The experimental simulation is used to illustrate the effects of control design. It is shown that the H∞ controller design can be very effective to suppress spillover phenomena. In addition, HM control design has robustness to the variation of the parameters of the model. The application of hybrid method (HM) together with H∞ control design is highly recommended for the vibration control of flexible rotor system with magnetic bearings.
Adaptive Finite-Volume Solution of the Two-Dimensional Euler Equations on Unstructured Meshes
Authors: Irmisch Stefan 
Published: February 2015

This paper presents a finite-volume method for solving the compressible, two-dimensional Euler equations using unstructured triangular meshes. The integration in time, to a steady-state solution, is performed using an explicit, multistage Runge-Kutta algorithm. A special treatment of the artificial viscosity along the boundaries reduces the production of numerical losses. Convergence acceleration is achieved by employing local time-stepping, implicit residual smoothing and a multigrid technique.
The use of unstructured meshes, based on Delaunay triangulation, automatically adapted to the solution, allows arbitrary geometries and complex flow features to be treated easily. The employed refinement criterion does not only detect strong shocks, but also weak flow features.
Solutions are presented for several subsonic and transonic standard test cases and cascade flows that illustrate the capability of the algorithm.
Influence of Radial Inflow on Rotor-Stator Cavity Pressure Distributions
Authors: Hart Kenneth J. , Turner Alan B. 
Published: February 2015

Rig tests and computational fluid dynamic (CFD) modelling have been used to improve the understanding of the effects of component geometry and air bleed flows on the pressure and velocity variations in the rotor-stator cavity found typically behind the impeller of a gas turbine engine centrifugal compressor.
Ranges of axial gap ratio and bleed throughflow typical of those found in current gas turbine engine design have been investigated with close attention to radial inflow (centripetal) bleeds with and without initial swirl.
CFD models have been constructed corresponding to the test conditions to assist in the understanding of the test data and to validate the computational methods. These methods can be used to extend the ranges of geometry, rotational Reynolds number and throughflows studied with greater confidence, thereby providing a design tool for direct use in the gas turbine industry.
Modelling and Analysis of the Dynamic Behavior of an Active Journal Bearing
Authors: Sun Linxiang , Krodkiewski Janusz M. , Zhang Nong 
Published: February 2015

Modelling and analysis of a rotor-bearing system with a new type of active oil bearing are presented. The active bearing basically consists of a flexible sleeve and a pressure chamber. The deformation of the sleeve can be controlled by the chamber pressure during the operation, and so can the pressure distribution of the oil film.
Finite Element Methods (FEMs) and the Guyan condensation technique were utilised to create mathematical models for both the rotor and the flexible sleeve. The hydrodynamic pressure distribution of the oil film, for the instantaneous positions and velocities of the flexible sleeve and rotor, was approximated by Reynolds equation. The influence of the chamber pressure on the stability of the rotor system was investigated by numerical simulation based on the nonlinear model. The results showed that the stability of the rotor-bearing system can be improved effectively by implementation of the active bearing.
Parameter Identification With Noncollocation of Force and Measurement Locations Using Nonsynchronous Perturbation and Optimization Techniques
Authors: Franklin Wesley D. , Muszynska Agnes , Bently Donald E. 
Published: February 2015

Nonsynchronous perturbation techniques developed over the last few years have proven to be a very powerful tool for parameter identification of rotating systems. In order to obtain interpretable results, some limitations have had to be imposed on the analytical models and rotor systems used in the process, such as applied forces, and measurement transducers had to be located near major masses on the rotor. In the laboratory environment these limitations can usually be accommodated, but not always, while in the field, compliance is almost impossible. This paper explores the use of finite element modeling, measured vibration response data, and optimization techniques to extend the applicability of parameter identification through nonsynchronous perturbation techniques to those systems in which the perturbation forces and/or resultant response measurements cannot be conveniently located at the mass centers. In this technique, a finite element model of the rotor system is constructed, and all known information about the system parameters input to a computer program designed to operate on a personal computer. The program then computes the theoretical response of the system, by processing user-supplied initial conditions for the unknown system parameters, and compares these results with the vibration responses measured on the machine, and collected by the data acquisition system. The unknown parameters are then modified using local convergence optimization techniques until the error between the theoretical and measured responses is acceptably small. If the system parameters under investigation coincide with the unknown parameters in the computer program, they are identified in the process.
This technique was applied to an experimental rotor system constructed such that the parameters under investigation, the direct and quadrature dynamic stiffness components for a plain oil-lubricated journal bearing operating at low eccentricity, could be determined by both this technique and conventional unbalance force testing. The results of the nonsynchronous tests are presented in the paper.
Experimental and Numerical Study of Orifice Discharge Coefficients in High Speed Rotating Disks
Authors: Wittig S. , Kim S. , Jakoby R. , Weißert I. 
Published: February 2015

Experimental and numerical results of the flow through orifices in rotating disks are presented, with emphasis on basic physical phenomena. It is shown, that rotational effects strongly influence the massflow discharged, a phenomenon which cannot be modelled by a stationary setup.
The study includes the determination of discharge coefficients under variation of the length to diameter ratio, pressure ratio and rotational speed. The pressure ratio covers low as well as critical values, the maximum rotational speed is 10000 rpm which is equivalent to a tangential velocity of 110 m/s. In order to understand the flow structure, local flow velocities were measured by means of a 2D Laser-Doppler-Velocimeter. Phase-resolved measurements have been carried out in front of and behind the orifices.
A 3D Finite-Volume-Code with bodyfitted coordinates in a rotating frame of reference is employed for the numerical analysis and the verification of its possibilities and limitations. The results reveal a very complex flow field, which is dominated by high velocity gradients in close vicinity to the orifices. The comparison of the computational solutions with the experimental data shows good agreement. Based on the measurements in combination with the numerical solution, a detailed insight into the physical properties of the flow is achieved.