bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mediation analysis with principal stratification
Authors: Gallop Robert , Small Dylan S. , Lin Julia Y. , Elliott Michael R. , Joffe Marshall , Ten Have Thomas R. 
Published: January 2009

AbstractIn assessing the mechanism of treatment efficacy in randomized clinical trials, investigators often perform mediation analyses by analyzing if the significant intent‐to‐treat treatment effect on outcome occurs through or around a third intermediate or mediating variable: indirect and direct effects, respectively. Standard mediation analyses assume sequential ignorability, i.e. conditional on covariates the intermediate or mediating factor is randomly assigned, as is the treatment in a randomized clinical trial. This research focuses on the application of the principal stratification (PS) approach for estimating the direct effect of a randomized treatment but without the standard sequential ignorability assumption. This approach is used to estimate the direct effect of treatment as a difference between expectations of potential outcomes within latent subgroups of participants for whom the intermediate variable behavior would be constant, regardless of the randomized treatment assignment. Using a Bayesian estimation procedure, we also assess the sensitivity of results based on the PS approach to heterogeneity of the variances among these principal strata. We assess this approach with simulations and apply it to two psychiatric examples. Both examples and the simulations indicated robustness of our findings to the homogeneous variance assumption. However, simulations showed that the magnitude of treatment effects derived under the PS approach were sensitive to model mis‐specification. Copyright © 2009 John Wiley & Sons, Ltd.
Engineering of Dominant Active Basic Helix-Loop-Helix Proteins That Are Resistant to Negative Regulation by Postnatal Central Nervous System Antineurogenic Cues
Authors: Geoffroy Cédric G. , Critchley James A. , Castro Diogo S. , Ramelli Sandra , Barraclough Christelle , Descombes Patrick , Guillemot Francois , Raineteau Olivier 
Published: January 2009

Abstract
Neural precursor cells (NPCs) are present in most regions of the adult central nervous system (CNS). Using NPCs in a therapeutical perspective, that is, to regenerate CNS tissue after injury or in neurodegenerative diseases, will require the efficient manipulation of their fate. Proneural gene overexpression in NPCs represents a promising strategy to promote neuronal differentiation. The activity of the proneural proteins is, however, context-dependent and can be inhibited/modulated by binding with other bHLH (basic helix-loop-helix) or HLH transcription factors. In this study, we show that the two proneural proteins, Ngn2 and Mash1, are differentially sensitive to negative regulation by gliogenic factors or a gliogenic substrate (i.e., postnatal spinal cord slices). Coexpressing E-proteins with proneural proteins was efficient to rescue proneural proteins neurogenic activity, suggesting a central role for E-protein sequestration in mediating postnatal CNS gliogenic inhibition. Tethering of proneural proteins with E47 further insulated Mash1 from negative environmental influences whereas this strategy was not successful with Ngn2, suggesting that mechanisms of inhibition differ in between these two proneural proteins. Our results demonstrate that a better understanding of proneural protein modulation by environmental cues is a prerequisite to develop innovative approaches that will permit the manipulation of the fate of NPCs in the adult CNS after trauma or disease.
Disclosure of potential conflicts of interest is found at the end of this article.
Precursors with Glial Fibrillary Acidic Protein Promoter Activity Transiently Generate GABA Interneurons in the Postnatal Cerebellum
Authors: Silbereis John , Cheng Elise , Ganat Yosif M. , Ment Laura R. , Vaccarino Flora M. 
Published: January 2009

Abstract
Neural stem or progenitor cells (NSC/NPCs) able to generate the different neuron and glial cell types of the cerebellum have been isolated in vitro, but their identity and location in the intact cerebellum are unclear. Here, we use inducible Cre recombination in GFAPCreERT2 mice to irreversibly activate reporter gene expression at P2 (postnatal day 2), P5, and P12 in cells with GFAP (glial fibrillary acidic protein) promoter activity and analyze the fate of genetically tagged cells in vivo. We show that cells tagged at P2-P5 with β-galactosidase or enhanced green fluorescent proteins reporter genes generate at least 30% of basket and stellate GABAergic interneurons in the molecular layer (ML) and that they lose their neurogenic potential by P12, after which they generate only glia. Tagged cells in the cerebellar white matter (WM) were initially GFAP/S100β+ and expressed the NSC/NPCs proteins LeX, Musashi1, and Sox2 in vivo. One week after tagging, reporter+ cells in the WM upregulated the neuronal progenitor markers Mash1, Pax2, and Gad-67. These Pax2+ progenitors migrated throughout the cerebellar cortex, populating the ML and leaving the WM by P18. These data suggest that a pool of GFAP/S100β+ glial cells located in the cerebellar WM generate a large fraction of cerebellar interneurons for the ML within the first postnatal 12 days of cerebellar development. This restricted critical period implies that powerful inhibitory factors may restrict their fate potential in vivo at later stages of development.
Disclosure of potential conflicts of interest is found at the end of this article.
Dopaminergic modulation of brain systems subserving decision making under uncertainty: A study with fMRI and methylphenidate challenge
Authors: Schlösser R.G.M. , Nenadic I. , Wagner G. , Zysset S. , Koch K. , Sauer H. 
Published: January 2009

AbstractThere is evidence that the dopaminergic system is involved in probabilistic reinforcement learning and reward‐related decision‐making. However, little is known about the effects of external dopaminergic challenges on processing of uncertainty in decision‐making tasks. Therefore, the present study examined changes in fMRI activation patterns in a natural sampling paradigm. Decision making under uncertainty was examined before and after administration of a single dose of 40 mg methylphenidate as an acute dopaminergic pharmacological challenge. We found that the level of uncertainty was positively correlated with activations in the prefrontal cortex. Conversely, negative correlations with uncertainty were found in the left hippocampus, right amygdale, and right middle temporal gyrus. The drug intervention with methylphenidate revealed a differential picture. Uncertain information processing was associated with higher activation in the parietal association cortex and posterior cingulate cortex after placebo relative to methylphenidate. The methylphenidate challenge relative to placebo was associated with higher left and right parahippocampal as well as cerebellar activation under uncertainty. Apparently, the pro‐dopaminergic pharmacological influence induces a relative shift towards recruitment of hippocampal areas under uncertainty, whereas under placebo conditions, higher levels of parietal cortex activations are involved in the task. The findings suggest a role of dopamine in uncertainty processing and shed light on the pharmacological mechanisms of methylphenidate. Synapse 63:429–442, 2009. © 2009 Wiley‐Liss, Inc.
Current trends of international standardization activities on ultra‐high‐voltage technologies
Authors: Hidaka Kunihiko , Ikeda Hisatoshi 
Published: January 2009

AbstractA world economy expands over boundaries between countries and regions. In Japan, there are many splendid technologies which the world requires. In order to transfer these technologies to the world an international standard which includes them as a standard is necessary. Activities by which 1100 kV UHV technologies are standardized in the IEC standard were conducted by starting with discussions in IEC/SB1. The activity has been followed by IEC/JICCG which coordinates IEC and CIGRE activities. The horizontal standards were started in advance at TC 8 and TC 28. The equipment standards will start from 2009 after the CIGRE committee finishes their reports by the end of 2008. Activities by the IEEJ standard committee have been carried horizontally to proceed with the UHV standardization rapidly and efficiently. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Technical requirements for UHV substation equipment
Authors: Ito Hiroki 
Published: January 2009

AbstractCIGRE Study Committee A3 established WG A3.22 ‘Technical requirements for substation equipment exceeding 800 kV’ to review the state‐of‐the‐art technical specifications for substation equipment exceeding 800kV in accordance with a request from IEC SC 17A. WG A3.22 conducted the initial surveys and submitted the first Technical Brochure on technical specifications for substation equipment such as gas circuit breaker (GCB), disconnecting switches (DS), earthing switches (ES), high‐speed grounding switches (HSGS) and metal oxide surge arrester (MOSA) applied to 800 kV and 1100/1200 kV networks. The investigations include the insulation level, first‐pole‐to‐clear factor, DC time constants, transient recovery voltage (TRV), line surge impedance and secondary arc extinction time. WG A3.22 will provide the technical background of all aspects of the available specifications with the intention of identifying the best practice for ultra high voltage (UHV) transmission systems. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Development of 1100 kV gas circuit breakers —Background, specifications, and duties—
Authors: Yamagata Yoshibumi 
Published: January 2009

AbstractIn Japan, for the UHV AC transmission system, 1100 kV, 50 kA two‐breaks gas circuit breakers (GCBs) were developed. They apply a resistance closing and opening scheme to suppress switching overvoltages that dominate the tower size of transmission lines. To secure high reliability and economy, specifications for the interruption duties were determined by detailed system analyses considering the phenomena arising from the inherent characteristics of UHV systems. The transient recovery voltage (TRV) duties were specified based on the resistance interruption and high‐performance metal oxide surge arresters (MOSAs) arrangement, both of which effectively relax the TRV. Developed GCBs were subjected to various verification tests, and their long‐term reliability and performance have been confirmed by the field testing since 1996 at the UHV Test Station of Tokyo Electric Power Company (TEPCO). Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Development of 1100 kV a.c. high‐performance GIS‐arrester and its verification tests
Authors: Ishizaki Yoshihiro 
Published: January 2009

AbstractFor the purpose of realizing 1100 kV a.c. power transmission system to meet the demands for electricity in future Japan, the 1100 kV a.c. high performance gas‐insulated metal enclosed arrester (GIS‐arrester) was developed and its high reliability was confirmed by a long‐term performance verification test. The high‐peformance GIS‐arrester is a key component to determine the insulation level of 1100 kV a.c. power transmission systems and substation equipments. As part of a series of activities started around 1975 by the Special Committee on 1100 kV a.c. Power‐Transmission system, the high‐performance GIS‐arrester with the superior protective performance of the world highest level was developed by applying the ZnO elements developed and commercialized in Japan.This paper introduces the application effects, duties, specifications, progress of development, and results of verification tests for the high‐performance GIS‐arresters for 1100 kV a.c. power transmission system. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Development and long‐term field tests for UHV, 3000‐MVA transformers in Japan
Authors: Shirasaka Yukiyasu 
Published: January 2009

AbstractDevelopment of UHV transformer in Japan has two big stages on 1970s and 1990s. First stage had been developed basic technology for a new insulation system, main elements like as an 1100‐kV lead, etc. and a test of prototype UHV transformer with performances and long‐term energizing in the factory. Second stage is including a fix of specification, test by prototype UHV transformer same as full size of one tank, a full size of factory test for completely assembled UHV transformer with some number of special tests and field tests with verifying of transportation, installation, and long‐term operation. This field test is continuing with energizing of higher voltage and simulated loading for over 10 years in the actual 500‐kV substation. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Radar cross‐section measurement method using a spatial filtering within a near zone
Authors: Yamazaki Hiroyoshi , Koshiji Kohji 
Published: January 2009

AbstractA spatial filtering is a useful method for suppressing unwanted reflection from undesired scatters on radar cross‐section (RCS) measurements. Highly accurate RCS measurements for stealth‐designed targets are generally performed by using full‐scale models. However, it is difficult to carry out a measurement of a large full‐scale target, because a vast RCS measurement site which satisfies the far‐field criterion without undesired scatters is required. In this paper, we have applied the filtering method to RCS measurements in a near field and investigated the validity of that method by varying the scanning angular span. First, a distribution of scattering sources including undesired scatters is predicted from near‐field spherical‐ or cylindrical‐scanning data. Next, undesired scatters are suppressed using the spatial filtering. Finally, RCS values of the test target are calculated by taking the Fourier transform of the filtered scattering source distribution. Using electromagnetic simulations, we have validated the RCS measurement method by comparing predicted RCS with reference data as far‐field RCS of the test target. As a result, predicted RCS profiles closely matched with reference data. In conclusion, the proposed method is useful for RCS measurements within the unsuitable near zone. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Influence of transcranial magnetic stimulation on muscle activity during finger movement
Authors: Odagaki Masato , Fukuda Hiroshi , Hiwaki Osamu 
Published: January 2009

AbstractIn the present study, muscle activity was measured after transcranial magnetic stimulation (TMS) was applied over the primary motor cortex during finger tapping. The duration of finger tapping was increased by the application of TMS. A remarkable change in electromyogram (EMG) of hand muscles was also observed during and after finger tapping. The silent period, in which voluntary EMG during the finger tapping was suppressed by TMS, was observed. Integral EMG revealed that TMS increased muscle activity at the completion of the finger tap after silent period. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Observation of neutral density variations accompanying streamer progression across air gaps
Authors: Fukuchi Tetsuo , Nemoto Koshichi 
Published: January 2009

AbstractNeutral density variations accompanying progression of streamers across needle‐to‐rod air gaps of length 0.75 and 1 m were observed with the use of a laser shadowgraph system consisting of astronomical telescopes for beam expansion and reduction, and an acousto‐optic laser deflector for high‐speed imaging. The system had a spatial resolution of about 1 mm over an annular observation region of outer diameter 28 cm and inner diameter 11 cm, and a temporal resolution in the order of microseconds. The system was also used to observe neutral density variations accompanying shock waves which resulted from a spark discharge. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Surface temperature of Pd/C catalyst under microwave irradiation in dechlorination process of PCBs
Authors: Kumada Akiko , Hidaka Kunihiko , Amano Kouji , Itoh Kohichi 
Published: January 2009

AbstractIn recent years, a new effective method of processing for polychlorinated biphenyls (PCBs) has been developed: It enables PCBs to become harmless by dechlorinating them using a 2.45 GHz microwave (MW). Compared with conventional thermal heating, MW processing hardly produces any harmful byproduct materials, and has high reaction velocity. To investigate such promotion of chemical reaction by MW irradiation, the surface temperature of the catalyst is measured by an infrared camera just after the irradiation by MW. It is recognized that there are some heated regions on the catalyst and the temperature is not uniform. It is natural to say that chemical reaction is promoted well on such a heated region. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Effect of trehalose accumulation on response to saline stress in Saccharomyces cerevisiae
Authors: Mahmud Siraje Arif , Nagahisa Keisuke , Hirasawa Takashi , Yoshikawa Katsunori , Ashitani Kengo , Shimizu Hiroshi 
Published: January 2009

AbstractTo examine the effect of trehalose accumulation on response to saline stress in Saccharomyces cerevisiae, we constructed deletion strains of all combinations of the trehalase genes ATH1, NTH1 and NTH2 and examined their growth behaviour and intracellular trehalose accumulation under non‐stress and saline‐stress conditions. Saline stress was induced in yeast cells by NaCl addition at the exponential growth phase. All deletion strains showed similar specific growth rates and trehalose accumulation to their parent strain under non‐stress conditions. However, under the saline stress condition, one single deletion strain, nth1Δ, two double deletion strains, nth1Δ ath1Δ and nth1Δ nth2Δ, and the triple deletion strain nth1Δnth2Δ ath1Δ, all of which carry the nth1Δ deletion, showed increased trehalose accumulation as compared to the parent and other deletion strains. In particular, our statistical analysis revealed that the triple deletion strain showed a higher growth rate under the saline stress condition than the parent strain. Moreover, some deletion strains showed further trehalose accumulation under non‐stress conditions by overexpression of the TPS1 or TPS2 genes encoding the enzymes related to trehalose biosynthesis at the mid‐exponential phase. Such increased trehalose accumulation prior to NaCl addition could improve the growth of these strains under saline stress. Our results indicate that high trehalose accumulation prior to NaCl addition, rather than after NaCl addition, is necessary to achieve high growth activity under stress conditions. Copyright © 2009 John Wiley & Sons, Ltd.
HIV‐1 integrase trafficking in S. cerevisiae: a useful model to dissect the microtubule network involvement of viral protein nuclear import
Authors: Desfarges S. , Salin B. , Calmels C. , Andreola M. L. , Parissi V. , Fournier M. 
Published: January 2009

AbstractIntracellular transport of karyophilic cargos comprises translocation to the nuclear envelope and subsequent nuclear import. Small cargos such as isolated proteins can reach the nuclear envelope by diffusion but movement of larger structures depends on active translocation, typically using microtubules. Centripetal transport ends at the perinuclear microtubule organizing centre called the spindle pole body (SPB) in yeast. Previously, we found by two hybrids that the karyophilic lentiviral‐encoded integrase (IN) interacts with two yeast microtubule‐associated proteins, Dyn2p (dynein light chain protein) and Stu2p, a centrosomal protein (de Soultrait et al., 2002). Thus, to investigate the hinge between cytoplasmic retrograde transport and nuclear import, we decided to analyse HIV‐1 IN trafficking in yeast as the model, since each of these biological mechanisms is evolutionarily conserved in eukaryotic cells. Here, we found an accumulation of IN at the SPB in yeast via Stu2p colocalization. Disruption of the microtubule network by nocodazole or IN expression in a dynein 2‐deficient yeast strain prevented IN accumulation in the nuclear periphery and additionally inhibited IN transport into the nucleus. By mutagenesis, we showed that trafficking of IN towards the SPB requires the C‐terminus of the molecule. Taking our findings together, we proposed a model in which IN nuclear import seems to depend on an essential intermediate step in the SPB. We found that Dyn2p and Stu2p play an important role in driving IN toward MTOC and could optimize nuclear entry of the retroviral enzyme. Our results suggest a new hypothesis in keeping with the current HIV‐1 intracellular trafficking model. Copyright © 2009 John Wiley & Sons, Ltd.
SpOPT1, a member of the oligopeptide family (OPT) of the fission yeast Schizosaccharomyces pombe, is involved in the transport of glutathione through the outer membrane of the cell
Authors: Dworeck Tamara , Wolf Klaus , Zimmermann Martin 
Published: January 2009

AbstractA protein involved in the transport of glutathione has been identified, cloned and characterized from the fission yeast Schizosaccharomyces pombe. Database searches revealed the Sz. pombe ORF SPAC29B12.10c as a close homologue to several members of the OPT family, including the Saccharomyces cerevisiae high‐affinity glutathione transporter Hgt1p. The gene product of SPAC29B12.10c has been identified as a protein, named SpOPT1, localized within the plasma membrane, transporting the tripeptide glutathione. Disruption of SPAC29B12.10c led to strains inable to grow on media containing glutathione as a sole source of sulphur, due to the inability to internalize the tripeptide. Disruptants contained significantly less glutathione than wild‐type cells. Furthermore, ΔSpopt1 strains were non‐viable in a glutathione biosynthesis‐defective (Δgsh2) background. However, it was possible to complement the disruption of Spopt1 by overexpressing the intact ORF in the disrupted strain. Copyright © 2009 John Wiley & Sons, Ltd.
Learning curve in tissue sparing total hip replacement: comparison between different approaches
Authors: D’Arrigo Carmelo , Speranza Attilio , Monaco Edoardo , Carcangiu Alessandro , Ferretti Andrea 
Published: January 2009

Abstract

Background
The tissue sparing surgery (TSS) concept means not only smaller incisions but also less tissue disruption, allowing decreased blood loss and improved function. However, TSS techniques can result in more complications related to the learning curve. The aim of this study was to compare the learning curve of an experienced surgeon with different TSS approaches for total hip replacement (THR) from a clinical and surgical point of view, focussing especially on complications related to the use of different geometric stems.

Materials and methods
Sixty patients scheduled to be operated for a primary THR were enrolled in the study and were randomly assigned to surgery by one of three different TSS approaches: lateral with mini incision (group A), minimally invasive anterior (group B) and minimally invasive antero-lateral (group C). Results from the three TSS groups were compared with a control group of 149 patients (group D).

Results
Our results reveal significantly reduced blood loss in the TSS groups compared with the control group, with no differences between the TSS groups. We found better early functional scores in the two minimally invasive groups (anterior and anterolateral), and a lower rate of complications with the antero-lateral TSS approach.

Conclusion
The antero-lateral TSS approach seems to be safer and less demanding than standard THR surgery, and is suitable for use with different stems.