bluuebunny/crossref_metadata_2025 huggingface dataset:
Mozart: The 'Haydn' Quartets
Authors: Irving John
Published: December 2009

The six string quartets dedicated to his friend Joseph Haydn represent a turning point in Mozart's compositional development. In addition to providing a full synopsis of each quartet this book examines the music in relation to Mozart's earlier quartets, considers the genesis of the six 'Haydn' quartets through close examination of the autograph revisions and looks at contemporary eighteenth-century analytical models. John Irving also charts the reception of the quartets, drawing upon a broad range of sources: Mozart's letters and diary entries, early newspaper reports, harmony/compositional textbooks, contemporary criticism and early biographies.
Transformations of Mind
Authors: McGhee Michael
Published: December 2009

The book offers a conception of philosophy as a form of self-enquiry which begins not in reflection, but in silence and meditation, conceived as conditions for the emergence and cessation of contending states of mind which influence perception and action. The philosopher thus becomes a kind of cartographer of a shifting interior landscape. This underlying perspective explains the personal nature of the writing and its mixing of genres. The book draws on both the Greek and Buddhist traditions, recognising that it is time for Western thinkers to acknowledge and respond to an intercultural canon. It aims to integrate ethics and a non-theistic philosophy of religion through the medium of aesthetics, mapping Buddhist 'mindfulness' and the Greek virtues and vices of temperance and licentiousness, continence and incontinence, onto an account of the development of moral sentiments and their relation to practical judgement in the context of oppressive political and social realities.
Spatial Pattern Analysis in Plant Ecology
Authors: Dale Mark R. T.
Published: December 2009

The predictability of the physical arrangement of plants, at whatever scale it is viewed, is referred to as their spatial pattern. Spatial pattern is a crucial aspect of vegetation which has important implications not only for the plants themselves, but also for other organisms which interact with plants, such as herbivores and pollinators, or those animals for which plants provide a habitat. This book describes and evaluates methods for detecting and quantifying a variety of characteristics of spatial pattern. As well as discussing the concepts on which these techniques are based, examples from real field studies and worked examples are included, which, together with numerous line figures, help guide the reader through the text. The result is a book that will be of value to graduate students and research workers in the fields of vegetation science, conservation biology and applied ecology.
Principles of Plasma Diagnostics
Authors: Hutchinson I. H.
Published: December 2009

This book provides a systematic introduction to the physics behind measurements on plasmas. It develops from first principles the concepts needed to plan, execute, and interpret plasma diagnostics. The book is therefore accessible to graduate students and professionals with little specific plasma physics background, but is also a valuable reference for seasoned plasma physicists. Most of the examples are taken from laboratory plasma research, but the focus on principles makes the treatment useful to all experimental and theoretical plasma physicists, including those interested in space and astrophysical applications. This second edition is thoroughly revised and updated, with new sections and chapters covering recent developments in the field. Specific areas of added coverage include neutral-beam-based diagnostics, flow measurement with mach probes, equilibrium of strongly shaped plasmas and fusion product diagnostics.
Problems and Solutions in Quantum Mechanics
Authors: Tamvakis Kyriakos
Published: December 2009

This collection of solved problems corresponds to the standard topics covered in established undergraduate and graduate courses in Quantum Mechanics. Problems are also included on topics of interest which are often absent in the existing literature. Solutions are presented in considerable detail, to enable students to follow each step. The emphasis is on stressing the principles and methods used, allowing students to master new ways of thinking and problem-solving techniques. The problems themselves are longer than those usually encountered in textbooks and consist of a number of questions based around a central theme, highlighting properties and concepts of interest. For undergraduate and graduate students, as well as those involved in teaching Quantum Mechanics, the book can be used as a supplementary text or as an independent self-study tool.
The Reluctant Economist
Authors: Easterlin Richard A.
Published: December 2009

Where is rapid economic growth taking us? Why has its spread throughout the world been so limited? What are the causes of the great twentieth century advance in life expectancy? Of the revolution in childbearing that is bringing fertility worldwide to near replacement levels? Have free markets been the source of human improvement? Economics provides a start on these questions, but only a start, argues economist Richard A. Easterlin. To answer them calls for merging economics with concepts and data from other social sciences, and with quantitative and qualitative history. Easterlin demonstrates this approach in seeking answers to these and other questions about world or American experience in the last two centuries, drawing on economics, demography, sociology, history, and psychology. The opening chapter gives an autobiographical account of the evolution of this approach, and why Easterlin is a 'reluctant economist'.
Property in the Body
Authors: Dickenson Donna
Published: December 2009

New developments in biotechnology radically alter our relationship with our bodies. Body tissues can now be used for commercial purposes, while external objects, such as pacemakers, can become part of the body. Property in the Body: Feminist Perspectives transcends the everyday responses to such developments, suggesting that what we most fear is the feminisation of the body. We fear our bodies are becoming objects of property, turning us into things rather than persons. This book evaluates how well-grounded this fear is, and suggests innovative models of regulating what has been called 'the new Gold Rush' in human tissue. This is an up-to-date and wide-ranging synthesis of market developments in body tissue, bringing together bioethics, feminist theory and lessons from countries that have resisted commercialisation of the body, in a theoretically sophisticated and practically significant approach.
Structural Nanocrystalline Materials
Authors: Koch Carl , Ovid'ko Ilya , Seal Sudipta , Veprek Stan
Published: December 2009

Nanocrystalline materials exhibit exceptional mechanical properties, representing an exciting new class of structural materials for technological applications. The advancement of this important field depends on the development of new fabrication methods, and an appreciation of the underlying nano-scale and interface effects. This authored book addresses these essential issues, presenting for the first time a fundamental, coherent and current account at the theoretical and practical level of nanocrystalline and nanocomposite bulk materials and coatings. The subject is approached systematically, covering processing methods, key structural and mechanical properties, and a wealth of applications. This is a valuable resource for graduate students studying nanomaterials science and nanotechnologies, as well as researchers and practitioners in materials science and engineering.
The English Historical Constitution
Authors: Allison J. W. F.
Published: December 2009

The fundamental legal and institutional changes of recent decades have brought the English constitution into question. Accompanying issues have been the extent to which its traditional character and main features have been changed, lost their former appeal and retained their distinctness in the European Union. These issues are not readily addressed in everyday thinking about a constitution simply conceived as unwritten or in constitutional accounts variously preoccupied with abstract analysis, political accountability or transcendent norms. The English Historical Constitution addresses these issues by developing a historical constitutional approach and thus elaborating on continuity and change in the constitution's main doctrines and institutions. From an English legal perspective, it offers a complement or corrective to analytical, political and normative approaches by reforming an old conception of the historical constitution and of its history, partly obscured and long neglected through the modern analytical preoccupation with its law as an abstract scheme of rules, principles and practices.
The Dignity of Legislation
Authors: Waldron Jeremy
Published: December 2009

Jeremy Waldron here attempts to restore the good name of legislation in political theory. Focused in particular on the writings of Aristotle, Locke and Kant, this book recovers and highlights ways of thinking about legislation that present it as a dignified mode of governance and a respectable source of law. The focus is particularly on legislation by assemblies, large gatherings of representatives who air their disagreements in ferocious debate and make laws by deliberation and voting. Jeremy Waldron has published extensively in law, philosophy and political theory. Here he presents a unique study of the place of legislation in the canon of political thought - a study which emphasises the positive features of democracy and representative assemblies. The Dignity of Legislation is original in conception, trenchantly argued and very clearly presented, and will be of interest to a wide range of scholars and thinkers.
Rate Equations in Semiconductor Electronics
Authors: Carroll J. E.
Published: December 2009

This book presents a novel approach to the teaching of dynamic aspects of the operation of semiconductor and opto-electronic devices. Such dynamic aspects often determine the steady state conditions. Also, the dynamical operation of such devices is of increasing importance as modern methods of communicating data and information require electronic devices that switch electrical or optical signals at ever faster rates. The author discusses the rates at which electrons and holes can reach equilibrium, the rates at which transistors and diodes can switch, and the rates at which electrons and holes can interact with photons, and with protons. He also applies the rate equations in a unified way to models of light-emitting diodes, injection lasers and photodiodes. Finally, the author discusses more-advanced topics on the photon statistics of injection lasers, mode-locking and the application of rate equations and Maxwell's equations to opto-electronic devices.
Electron-Beam-Induced Carbon Contamination on Silicon: Characterization Using Raman Spectroscopy and Atomic Force Microscopy
Authors: Lau Deborah , Hughes Anthony E. , Muster Tim H. , Davis Timothy J. , Glenn A. Matthew
Published: December 2009

Electron-beam-induced carbon film deposition has long been recognized as a side effect of scanning electron microscopy. To characterize the nature of this type of contamination, silicon wafers were subjected to prolonged exposure to 15 kV electron beam energy with a probe current of ∼300 pA. Using Raman spectroscopy, the deposited coating was identified as an amorphous carbon film with an estimated crystallite size of 125 Å. Using atomic force microscopy, the cross-sectional profile of the coating was found to be raised and textured, indicative of the beam raster pattern. A map of the Raman intensity across the coating showed increased intensity along the edges and at the corner of the film. The intensity profile was in excess of that which could be explained by thickness alone. The enhancement was found to correspond with a modeled local field enhancement induced by the coating boundary and showed that the deposited carbon coating generated a localized disturbance in the opto-electrical properties of the substrate, which is compared and contrasted with Raman edge enhancement that is produced by surface structure in silicon.
Supplementary Stonor Letters and Papers (1314–1482)
Authors: Kingsford C. L.
Published: December 2009

These supplementary documents do not call for any further Introduction beyond the Notes, though special attention may be directed to the additional documents relating to the shrievalty of Edmund de Stonor
Impact of sudden Arctic sea‐ice loss on stratospheric polar ozone recovery
Authors: Scinocca J. F. , Reader M. C. , Plummer D. A. , Sigmond M. , Kushner P. J. , Shepherd T. G. , Ravishankara A. R.
Published: December 2009

We investigate the sensitivity of Northern Hemisphere polar ozone recovery to a scenario in which there is rapid loss of Arctic summer sea ice in the first half of the 21st century. The issue is addressed by coupling a chemistry climate model to an ocean general circulation model and performing simulations of ozone recovery with, and without, an external perturbation designed to cause a rapid and complete loss of summertime Arctic sea ice. Under this extreme perturbation, the stratospheric response takes the form of a springtime polar cooling which is dynamical rather than radiative in origin, and is caused by reduced wave forcing from the troposphere. The response lags the onset of the sea‐ice perturbation by about one decade and lasts for more than two decades, and is associated with an enhanced weakening of the North Atlantic meridional overturning circulation. The stratospheric dynamical response leads to a 10 DU reduction in polar column ozone, which is statistically robust. While this represents a modest loss, it has the potential to induce a delay of roughly one decade in Arctic ozone recovery estimates made in the 2006 Scientific Assessment of Ozone Depletion.
Event-Based Concepts for User-Driven Visualization
Authors: Tominski Christian
Published: December 2009

Visualization has become an increasingly important tool to support exploration and analysis of the large volumes of data we are facing today. However, interests and needs of users are still not being considered sufficiently. The goal of this work is to shift the user into the focus. To that end, we apply the concept of event-based visualization that combines event-based methodology and visualization technology. Previous approaches that make use of events are mostly specific to a particular application case, and hence, can not be applied otherwise. We introduce a novel general model of event-based visualization that comprises three fundamental stages. (1) Users are enabled to specify what their interests are. (2) During visualization, matches of these interests are sought in the data. (3) It is then possible to automatically adjust visual representations according to the detected matches. This way, it is possible to generate visual representations that better reflect what users need for their task at hand. The model's generality allows its application in many visualization contexts. We substantiate the general model with specific data-driven events that focus on relational data so prevalent in today's visualization scenarios. We show how the developed methods and concepts can be implemented in an interactive event-based visualization framework, which includes event-enhanced visualizations for temporal and spatio-temporal data.
Discrepancies between sounds and graphs
Authors: Eom Ik-sang
Published: December 2009

This article attempts to analyze the causes of the irregular readings of Chinese characters both in Mandarin and in Sino-Korean (i.e. Korean pronunciations of Chinese characters). Cultural taboo, avoidance of confusion and residues of historical and/ or regional sound changes are the main causes for irregular readings in Mandarin. Semantic readings, euphony, mismatched palatalization, confusion and erroneous readings are the main reasons in Sino-Korean, among many others. This article also examines how well the graph of a Chinese character conveys the sound if it is a phonetic compound, which consists of a phonetic element and a semantic element. The discussion highlights that the function of conveying the exact pronunciation of a Chinese character is not straightforward although DeFrancis (1984b: 19) suggests that “Chinese is basically a phonetic system of writing of the syllabic type.”
TEMPORAL PROPERTIES OF GX 301−2 OVER A YEAR-LONG OBSERVATION WITH SuperAGILE
Authors: Evangelista Y. , Feroci M. , Costa E. , Monte E. Del , Donnarumma I. , Lapshov I. , Lazzarotto F. , Pacciani L. , Rapisarda M. , Soffitta P. , Argan A. , Barbiellini G. , Boffelli F. , Bulgarelli A. , Caraveo P. , Cattaneo P.W. , Chen A. , D’Ammando F. , Cocco G. Di , Fuschino F. , Galli M. , Gianotti F. , Giuliani A. , Labanti C. , Lipari P. , Longo F. , Marisaldi M. , Mereghetti S. , Moretti E. , Morselli A. , Pellizzoni A. , Perotti F. , Piano G. , Picozza P. , Pilia M. , Prest M. , Pucella G. , Rappoldi A. , Sabatini S. , Striani E. , Tavani M. , Trifoglio M. , Trois A. , Vallazza E. , Vercellone S. , Vittorini V. , Zambra A. , Antonelli L. A. , Cutini S. , Pittori C. , Preger B. , Santolamazza P. , Verrecchia F. , Giommi P. , Salotti L.
Published: December 2009

We present the long-term monitoring of the high-mass X-ray binary GX 301−2 performed with the SuperAGILE (SA) instrument on-board the Astro-rivelatore Gamma ad Immagini LEggero (AGILE) mission. The source was monitored in the 20–60 keV energy band during the first year of the mission from 2007 July 17 to 2008 August 31, covering about one whole orbital period and three more pre-periastron (PP) passages for a total net observation time of about 3.7 Ms. The SA data set represents one of the most continuous and complete monitoring at hard X-ray energies of the 41.5 days long binary period available to date. The source behavior was characterized at all orbital phases in terms of hard X-ray flux, spectral hardness, spin-period history, pulsed fraction, and pulse shape profile. We also complemented the SA observations with the soft X-ray data of the Rossi X-Ray Timing Explorer/All-Sky Monitor. Our analysis shows a clear orbital modulation of the spectral hardness, with peaks in correspondence with the PP flare and near phase 0.25. The hardness peaks, we found, could be related with the wind-plus-stream accretion model proposed in order to explain the orbital light-curve modulation of GX 301−2. Timing analysis of the pulsar spin period shows that the secular trend of the ∼680 s pulse period is consistent with the previous observations, although there is evidence of a slight decrease in the spin-down rate. The analysis of the hard X-ray-pulsed emission also showed a variable pulse shape profile as a function of the orbital phase, with substructures detected near the passage at the periastron, and a clear modulation of the pulsed fraction, which appears in turn strongly anticorrelated with the source intensity.
Environmental stresses mediate endophyte–grass interactions in a boreal archipelago
Authors: Saona Nora M. , Albrectsen Benedicte Riber , Ericson Lars , Bazely Dawn R.
Published: December 2009

1. Both evolutionary theory and empirical evidence from agricultural research support the view that asexual, vertically transmitted fungal endophytes are typically plant mutualists that develop high infection frequencies within host grass populations. In contrast, endophyte–grass interactions in natural ecosystems are more variable, spanning the range from mutualism to antagonism and comparatively little is known about their range of response to environmental stress.

2. We examined patterns in endophyte prevalence and endophyte–grass interactions across nutrient and grazing (from Greylag and Canada geese) gradients in 15 sites with different soil moisture levels in 13 island populations of the widespread grass Festuca rubra in a boreal archipelago in Sweden.

3. In the field, endophyte prevalence levels were generally low (range = 10–53%) compared with those reported from agricultural systems. Under mesic‐moist conditions endophyte prevalence was constantly low (mean prevalence = 15%) and was not affected by grazing pressure or nutrient availability. In contrast, under conditions of drought, endophyte prevalence increased from 10% to 53% with increasing nutrient availability and increasing grazing pressure.

4. In the field, we measured the production of flowering culms, as a proxy for host fitness, to determine how endophyte‐infected plants differed from uninfected plants. At dry sites, endophyte infection did not affect flowering culm production. In contrast, at mesic‐moist sites production of flowering culms in endophyte‐infected plants increased with the covarying effects of increasing nutrient availability and grazing pressure, indicating that the interaction switched from antagonistic to mutualistic.

5. A concurrent glasshouse experiment showed that in most situations, the host appears to incur some costs for harbouring endophytes. Uninfected grasses generally outperformed infected grasses (antagonistic interaction), while infected grasses outperformed uninfected grasses (mutualistic interaction) only in dry, nutrient‐rich conditions. Nutrient and water addition affected tiller production, leaf number and leaf length differently, suggesting that tillers responded with different strategies. This emphasizes that several response variables are needed to evaluate the interaction.

6. Synthesis. This study found complex patterns in endophyte prevalence that were not always correlated with culm production. These contrasting patterns suggest that the direction and strength of selection on infected plants is highly variable and depends upon a suite of interacting environmental variables that may fluctuate in the intensity of their impact, during the course of the host life cycle.
Haemodialysis decreases finger pressures independent of artificial kidney blood flow
Authors: VAN HOEK FRANK , SCHELTINGA MARC R , HOUTERMAN SASKIA , BEERENHOUT CHARLES H
Published: December 2009

Background:  During haemodialysis, some patients experience intensification of symptoms of haemodialysis access‐induced distal ischaemia. Aim of this study is to compare the effects of two different regimens of arterial blood flow in patients with an arteriovenous access.

Methods:  A questionnaire identified 10 patients that subjectively experienced ischaemic symptoms during haemodialysis. Systolic blood pressure, heart rate, finger pressure (Pdig), finger temperature (Tdig), oxygen saturation and ischaemic scores were monitored during two different arterial blood flow dialysis sessions.

Results:  Before dialysis, Pdig and Tdig of the arteriovenous access hand were significantly lower compared with the other hand. Haemodialysis induced a drop of Pdig in both hands. All changes in Pdig occurred independent of the artificial kidney's blood flow level.

Conclusion:  Systemic hypotension following onset of haemodialysis further intensifies an already diminished hand perfusion. Measures preventing dialytic hypotension will likely attenuate symptoms associated with haemodialysis access‐induced distal ischaemia during haemodialysis.
Sequential change of asymmetric dimethylarginine levels after initiation of peritoneal dialysis in patients with end‐stage renal disease
Authors: LEE KWAN‐HYUN , GIL HYO‐WOOK , YANG JONG‐OH , LEE EUN‐YOUNG , HONG SAE‐YONG
Published: December 2009

Background:  We hypothesized that the asymmetric dimethylarginine (ADMA) metabolism in end‐stage renal disease may be linked to the rate of protein turnover and to the vast pool of amino acids. In order to determine a correlation between the plasma levels of ADMA and the protein catabolic rate, we measured the ADMA levels as well as nutritional markers such as the normalized protein catabolic rate (nPCR) in patients with newly initiated continuous ambulatory peritoneal dialysis (CAPD).

Methods:  Twenty‐four patients were recruited for this study. All patients were on the standard CAPD protocol, and followed for at least 1 year. Blood samples were collected at baseline before the initiation of peritoneal dialysis, and every 6 months for 1 year. The blood parameters studied included the serum albumin, total cholesterol, glucose, urea nitrogen, creatinine and ADMA. Peritoneal equilibrium test and measurements of weekly Kt/Vurea and nPCR were performed within 4 weeks of the blood sampling.

Results:  The change of ADMA levels over 1 year was positively correlated with that of haemoglobin (r = 0.592, P = 0.002) and nPCR during the same period (r = 0.508, P = 0.026).

Conclusion:  The findings of our study suggest that nPCR might influence the change of ADMA levels after initiation of CAPD.
Private Sector Imprinting: An Examination of the Impacts of Private Sector Job Experience on Public Manager's Work Attitudes
Authors: Boardman Craig , Bozeman Barry , Ponomariov Branco
Published: December 2009

What are the attitudes of public managers who have had full‐time private sector work experience? Public managers with private sector work experience report different perspectives when compared to their counterparts who have spent their entire careers in the public sector. Though private sector work experience negatively correlates with job satisfaction, it only does so for the “new switcher,” whose last job was in the private sector. As careers advance, the negative impact seems to wane, leaving a public sector workforce that, in part as a result of their private sector work experience, are relatively more intrinsically motivated and involved in their jobs. We conclude with discussion of implications for human resources management.
Conserved Motifs within Ebola and Marburg Virus VP40 Proteins Are Important for Stability, Localization, and Subsequent Budding of Virus-Like Particles
Authors: Liu Yuliang , Cocka Luis , Okumura Atsushi , Zhang Yong-An , Sunyer J. Oriol , Harty Ronald N.
Published: December 2009

The filovirus VP40 protein is capable of budding from mammalian cells in the form of virus-like particles (VLPs) that are morphologically indistinguishable from infectious virions. Ebola virus VP40 (eVP40) contains well-characterized overlapping L domains, which play a key role in mediating efficient virus egress. L domains represent only one component required for efficient budding and, therefore, there is a need to identify and characterize additional domains important for VP40 function. We demonstrate here that the
96
LPLGVA
101
sequence of eVP40 and the corresponding
84
LPLGIM
89
sequence of Marburg virus VP40 (mVP40) are critical for efficient release of VP40 VLPs. Indeed, deletion of these motifs essentially abolished the ability of eVP40 and mVP40 to bud as VLPs. To address the mechanism by which the
96
LPLGVA
101
motif of eVP40 contributes to egress, a series of point mutations were introduced into this motif. These mutants were then compared to the eVP40 wild type in a VLP budding assay to assess budding competency. Confocal microscopy and gel filtration analyses were performed to assess their pattern of intracellular localization and ability to oligomerize, respectively. Our results show that mutations disrupting the
96
LPLGVA
101
motif resulted in both altered patterns of intracellular localization and self-assembly compared to wild-type controls. Interestingly, coexpression of either Ebola virus GP-WT or mVP40-WT with eVP40-ΔLPLGVA failed to rescue the budding defective eVP40-ΔLPLGVA mutant into VLPs; however, coexpression of eVP40-WT with mVP40-ΔLPLGIM successfully rescued budding of mVP40-ΔLPLGIM into VLPs at mVP40-WT levels. In sum, our findings implicate the LPLGVA and LPLGIM motifs of eVP40 and mVP40, respectively, as being important for VP40 structure/stability and budding.
The Foamy Virus Genome Remains Unintegrated in the Nuclei of G1/S Phase-Arrested Cells, and Integrase Is Critical for Preintegration Complex Transport into the Nucleus
Authors: Lo Yung-Tsun , Tian Tao , Nadeau Peter E. , Park Jeonghae , Mergia Ayalew
Published: December 2009

Foamy viruses are a member of the spumavirus subfamily of retroviruses with unique mechanisms of virus replication. Foamy virus replication is cell cycle dependent; however, the genome is found in the nuclei of cells arrested in the G1/S phase. Despite the presence of genome in the nuclei of growth-arrested cells, there is no viral gene expression, thus explaining its dependency on cell cycle. This report shows that the foamy virus genome remains unintegrated in G1/S phase-arrested cells. The foamy virus genome is detected by confocal microscopy in the nuclei of both dividing and growth-arrested cells. Alu PCR revealed foamy virus-specific DNA amplification from genomic DNA isolated in cycling cells at 24 h postinfection. In arrested cells no foamy virus DNA band was detected in cells harvested at 1 or 7 days after infection, and a very faint band that is significantly less than DNA amplified from cycling cells was observed at day 15. After these cells were arrested at the G1/S phase for 1, 7, or 15 days they were allowed to cycle, at which time foamy virus-specific DNA amplification was readily observed. Taken together, these results suggest that the foamy virus genome persists in nondividing cells without integrating. We have also established evidence for the first time that the foamy virus genome and Gag translocation into the nucleus are dependent on integrase in cycling cells, implicating the role of integrase in transport of the preintegration complex into the nucleus. Furthermore, despite the presence of a nuclear localization signal sequence in Gag, we observed no foamy virus Gag importation into the nucleus in the absence of integrase.
SUPERCONDUCTING PROPERTIES OF MgB2 COMPOSITES CONTAINING TYPE I SUPERCONDUCTING METALS
Authors: AHN JUNG-HO , OH SANGJUN
Published: December 2009

We have examined superconducting property of MgB 2, containing Type 1 elemental superconductor, Pb . The results showed double transition temperatures of superconductivity. Although the addition of Pb considerably improved grain connectivity of MgB 2, the presence of Type I superconducting phase ( Pb ) degraded the superconductivity of composites by flux creep.
Thrombin induces endothelial arginase through AP-1 activation
Authors: Zhu Weifei , Chandrasekharan Unni M. , Bandyopadhyay Smarajit , Morris Sidney M. , DiCorleto Paul E. , Kashyap Vikram S.
Published: December 2009

Arterial thrombosis is a common disease leading to severe ischemia beyond the obstructing thrombus. Additionally, endothelial dysfunction at the site of thrombosis can be rescued by l-arginine supplementation or arginase blockade in several animal models. Exposure of rat aortic endothelial cells (RAECs) to thrombin upregulates arginase I mRNA and protein levels. In this study, we further investigated the molecular mechanism of thrombin-induced arginase changes in endothelial cells. Thrombin strikingly increased arginase I promoter and enzyme activity in primary cultured RAECs. Using different deletion and point mutations of the promoter, we demonstrated that the activating protein-1 (AP-1) consensus site located at −3,157 bp in the arginase I promoter was a thrombin-responsive element. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay further confirmed that upon thrombin stimulation, c-Jun and activating transcription factor-2 (ATF-2) bound to the AP-1 site, which initiated the transactivation. Moreover, loss-of-function studies using small interfering RNA confirmed that recruitment of these two transcription factors to the AP-1 site was required for thrombin-induced arginase upregulation. In the course of defining the signaling pathway leading to the activation of AP-1 by thrombin, we found thrombin-induced phosphorylation of stress-activated protein kinase/c-Jun-NH2-terminal kinase (SAPK/JNK or JNK1/2/3) and p38 mitogen-activated protein kinase, which were followed by the phosphorylation of both c-Jun and ATF-2. These findings reveal the basis for thrombin induction of endothelial arginase I and indicate that arginase inhibition may be an attractive therapeutic alternative in the setting of arterial thrombosis and its associated endothelial dysfunction.
Ischemia induces regulator of G protein signaling 2 (RGS2) protein upregulation and enhances apoptosis in astrocytes
Authors: Endale Mehari , Kim Sung Dae , Lee Whi Min , Kim Sangseop , Suk Kyoungho , Cho Jae Youl , Park Hwa Jin , Wagley Yadav , Kim Suk , Oh Jae-Wook , Rhee Man Hee
Published: December 2009

Regulator of G protein signaling (RGS) family members, such as RGS2, interact with Gα subunits of heterotrimeric G proteins, accelerating the rate of GTP hydrolysis and attenuating the intracellular signaling triggered by the G protein-coupled receptor-ligand interaction. They are also reported to regulate G protein-effector interactions and form multiprotein signaling complexes. Ischemic stress-induced changes in RGS2 expression have been described in astrocytes, and these changes are associated with intracellular signaling cascades, suggesting that RGS2 upregulation may be an important mechanism by which astrocytes may regulate RGS2 function in response to physiological stress. However, information on the functional roles of stress-induced modulation of RGS2 protein expression in astrocyte function is limited. We report the role of ischemic stress in RGS2 protein expression in rat C6 astrocytoma cells and primary mouse astrocytes. A marked increase in RGS2 occurred after ischemic stress induced by chemicals (sodium azide and 2-deoxyglucose) or oxygen-glucose deprivation (OGD, real ischemia). RGS2 mRNA expression was markedly enhanced by 1 h of exposure to chemical ischemia or 6 h of OGD followed by 2 or 6 h of recovery, respectively. This enhanced expression in primary astrocytes and C6 cells was restored to baseline levels after 12 h of recovery from chemically induced ischemic stress or 4–6 h of recovery from OGD. RGS2 protein was also significantly expressed at 12–24 h of recovery from ischemic insult. Ischemia-induced RGS2 upregulation was associated with enhanced apoptosis. It significantly increased annexin V-positive cells, cleaved caspase-3, and enhanced DNA ladder formation and cell cycle arrest. However, a small interfering RNA (siRNA)-mediated RGS2 knockdown reversed the apoptotic cell death associated with ischemia-induced RGS2 upregulation. Upregulated RGS2 was significantly inhibited by SB-203580, a p38 MAPK inhibitor. Rottlerin, a potent inhibitor of PKCδ, completely abrogated the increased RGS2 expression. We also examine whether ischemia-induced RGS2-mediated apoptosis is affected by siRNA-targeted endogenous PKCδ downregulation or its phosphorylation. Although RGS2 upregulation was not affected, siRNA transfection significantly suppressed endogenous PKCδ mRNA and protein expressions. Ischemia-induced PKCδ phosphorylation and caspase-3 cleavage were dose dependently inhibited by PKCδ knockdown, and this endogenous PKCδ suppression reversed ischemia-induced annexin V-positive cells. This study suggests that ischemic stress increases RGS2 expression and that this condition contributes to enhanced apoptosis in C6 cells and primary astrocytes. The signaling it follows may involve PKCδ and p38 MAPK pathways.
Angiotensin II AT2receptor regulates ureteric bud morphogenesis
Authors: Song Renfang , Spera Melissa , Garrett Colleen , El-Dahr Samir S. , Yosypiv Ihor V.
Published: December 2009

ANG II AT2receptor (AT2R)-deficient mice exhibit abnormal ureteric bud (UB) budding, increased incidence of double ureters, and vesicoureteral reflux. However, the role of the AT2R during UB morphogenesis and the mechanisms by which aberrant AT2R signaling disrupts renal collecting system development have not been fully defined. In this study, we mapped the expression of the AT2R during mouse metanephric development, examined the impact of disrupted AT2R signaling on UB branching, cell proliferation, and survival, and investigated the cross talk of the AT2R with the glial-derived neurotrophic factor ( GDNF)/ c-Ret/Wnt11 signaling pathway. Embryonic mouse kidneys express AT2R in the branching UB and the mesenchyme. Treatment of embryonic day 12.5 ( E12.5) metanephroi with the AT2R antagonist PD123319 or genetic inactivation of the AT2R in mice inhibits UB branching, decreasing the number of UB tips compared with control (34 ± 1.0 vs. 43 ± 0.6, P < 0.01; 36 ± 1.8 vs. 48 ± 1.3, P < 0.01, respectively). In contrast, treatment of metanephroi with the AT2R agonist CGP42112 increases the number of UB tips compared with control (48 ± 1.8 vs. 39 ± 12.3, P < 0.05). Using real-time quantitative RT-PCR and whole mount in situ hybridization, we demonstrate that PD123319 downregulates the expression of GDNF, c-Ret, Wnt11, and Spry1 mRNA levels in E12.5 metanephroi grown ex vivo. AT2R blockade or genetic inactivation of AT2R stimulates apoptosis and inhibits proliferation of the UB cells in vivo. We conclude that AT2R performs essential functions during UB branching morphogenesis via control of the GDNF/c-Ret/Wnt11 signaling pathway, UB cell proliferation, and survival.
The Functional Anatomy of a Perceptual Decision in the Human Brain
Authors: Kayser Andrew S. , Buchsbaum Bradley R. , Erickson Drew T. , D'Esposito Mark
Published: December 2009

Our ability to make rapid decisions based on sensory information belies the complexity of the underlying computations. Recently, “accumulator” models of decision making have been shown to explain the activity of parietal neurons as macaques make judgments concerning visual motion. Unraveling the operation of a decision-making circuit, however, involves understanding both the responses of individual components in the neural circuitry and the relationships between them. In this functional magnetic resonance imaging study of the decision process in humans, we demonstrate that an accumulator model predicts responses to visual motion in the intraparietal sulcus (IPS). Significantly, the metrics used to define responses within the IPS also reveal distinct but interacting nodes in a circuit, including early sensory detectors in visual cortex, the visuomotor integration system of the IPS, and centers of cognitive control in the prefrontal cortex, all of which collectively define a perceptual decision-making network.
Effect of Conditioned Stimulus Parameters on Timing of Conditioned Purkinje Cell Responses
Authors: Svensson Pär , Jirenhed Dan-Anders , Bengtsson Fredrik , Hesslow Germund
Published: December 2009

Pavlovian eyeblink conditioning is a useful experimental model for studying adaptive timing, an important aspect of skilled movements. The conditioned response (CR) is precisely timed to occur just before the onset of the expected unconditioned stimulus (US). The timing can be changed immediately, however, by varying parameters of the conditioned stimulus (CS). It has previously been shown that increasing the intensity of a peripheral CS or the frequency of a CS consisting of a train of stimuli to the mossy fibers shortens the latency of the CR. The adaptive timing of behavioral CRs probably reflects the timing of an underlying learned inhibitory response in cerebellar Purkinje cells. It is not known how the latency of this Purkinje cell CR is controlled. We have recorded form Purkinje cells in conditioned decerebrate ferrets while increasing the intensity of a peripheral CS or the frequency of a mossy fiber CS. We observe changes in the timing of the Purkinje cell CR that match the behavioral effects. The results are consistent with the effect of CS parameters on behavioral CR latency being caused by corresponding changes in Purkinje cell CRs. They suggest that synaptic temporal summation may be one of several mechanisms underlying adaptive timing of movements.
Calculating the potential for within-flight transmission of influenza A (H1N1)
Authors: Wagner Bradley G , Coburn Brian J , Blower Sally
Published: December 2009

Background

Clearly air travel, by transporting infectious individuals from one geographic location to another, significantly affects the rate of spread of influenza A (H1N1). However, the possibility of within-flight transmission of H1N1 has not been evaluated; although it is known that smallpox, measles, tuberculosis, SARS and seasonal influenza can be transmitted during commercial flights. Here we present the first quantitative risk assessment to assess the potential for within-flight transmission of H1N1.

Methods

We model airborne transmission of infectious viral particles of H1N1 within a Boeing 747 using methodology from the field of quantitative microbial risk assessment.

Results

The risk of catching H1N1 will essentially be confined to passengers travelling in the same cabin as the source case. Not surprisingly, we find that the longer the flight the greater the number of infections that can be expected. We calculate that H1N1, even during long flights, poses a low to moderate within-flight transmission risk if the source case travels First Class. Specifically, 0-1 infections could occur during a 5 hour flight, 1-3 during an 11 hour flight and 2-5 during a 17 hour flight. However, within-flight transmission could be significant, particularly during long flights, if the source case travels in Economy Class. Specifically, two to five infections could occur during a 5 hour flight, 5-10 during an 11 hour flight and 7-17 during a 17 hour flight. If the aircraft is only partially loaded, under certain conditions more infections could occur in First Class than in Economy Class. During a 17 hour flight, a greater number of infections would occur in First Class than in Economy if the First Class Cabin is fully occupied, but Economy class is less than 30% full.

Conclusions

Our results provide insights into the potential utility of air travel restrictions on controlling influenza pandemics in the winter of 2009/2010. They show travel by one infectious individual, rather than causing a single outbreak of H1N1, could cause several simultaneous outbreaks. These results imply that, during a pandemic, quarantining passengers who travel in Economy on long-haul flights could potentially be an important control strategy. Notably, our results show that quarantining passengers who travel First Class would be unlikely to be an effective control strategy.
Activation of PKA, p38 MAPK and ERK1/2 by gonadotropins in cumulus cells is critical for induction of EGF-like factor and TACE/ADAM17 gene expression during in vitro maturation of porcine COCs
Authors: Yamashita Yasuhisa , Hishinuma Mitsugu , Shimada Masayuki
Published: December 2009

Objectives

During ovulation, it has been shown that LH stimulus induces the expression of numerous genes via PKA, p38 MAPK, PI3K and ERK1/2 in cumulus cells and granulosa cells. Our recent study showed that EGF-like factor and its protease (TACE/ADAM17) are required for the activation of EGF receptor (EGFR), cumulus expansion and oocyte maturation of porcine cumulus-oocyte complexes (COCs). In the present study, we investigated which signaling pathways are involved in the gene expression of EGF-like factor and in Tace/Adam17 expression in cumulus cells of porcine COC during in vitro maturation.

Methods

Areg, Ereg, Tace/Adam17, Has2, Tnfaip6 and Ptgs2 mRNA expressions were detected in cumulus cells of porcine COCs by RT-PCR. Protein level of ERK1/2 phosphorylation in cultured cumulus cells was analyzed by westernblotting. COCs were visualized using a phase-contrast microscope.

Results

When COCs were cultured with FSH and LH up to 2.5 h, Areg, Ereg and Tace/Adam17 mRNA were expressed in cumulus cells of COCs. Areg, Ereg and Tace/Adam17 gene expressions were not suppressed by PI3K inhibitor (LY294002), whereas PKA inhibitor (H89), p38 MAPK inhibitor (SB203580) and MEK inhibitor (U0126) significantly suppressed these gene expressions. Phosphorylation of ERK1/2, and the gene expression of Has2, Tnfaip6 and Ptgs2 were also suppressed by H89, SB203580 and U0126, however, these negative effects were overcome by the addition of EGF to the medium, but not in the U0126 treatment group.

Conclusion

The results showed that PKA, p38 MAPK and ERK1/2 positively controlled the expression of EGF-like factor and TACE/ADMA17, the latter of which impacts the cumulus expansion and oocyte maturation of porcine COCs via the EGFR-ERK1/2 pathway in cumulus cells.
Bayesian analysis of mixtures in structural equation models with non‐ignorable missing data
Authors: Cai Jing‐Heng , Song Xin‐Yuan
Published: December 2009

Structural equation models (SEMs) have become widely used to determine the interrelationships between latent and observed variables in social, psychological, and behavioural sciences. As heterogeneous data are very common in practical research in these fields, the analysis of mixture models has received a lot of attention in the literature. An important issue in the analysis of mixture SEMs is the presence of missing data, in particular of data missing with a non‐ignorable mechanism. However, only a limited amount of work has been done in analysing mixture SEMs with non‐ignorable missing data. The main objective of this paper is to develop a Bayesian approach for analysing mixture SEMs with an unknown number of components and non‐ignorable missing data. A simulation study shows that Bayesian estimates obtained by the proposed Markov chain Monte Carlo methods are accurate and the Bayes factor computed via a path sampling procedure is useful for identifying the correct number of components, selecting an appropriate missingness mechanism, and investigating various effects of latent variables in the mixture SEMs. A real data set on a study of job satisfaction is used to demonstrate the methodology.
Social structure, social cognition, and physical activity: A test of four models
Authors: Godin Gaston , Sheeran Paschal , Conner Mark , Bélanger‐Gravel Ariane , Gallani Maria Cecília B. J. , Nolin Bertrand
Published: December 2009

Objective

This study investigated the combined influence of social structural factors (e.g. income) and cognitions in predicting changes in physical activity. Four models were tested: (a) direct effects (social structural factors influence behaviour controlling for cognitions), (b) mediation (cognitions mediate social structural influence), (c) moderation (social structural factors moderate cognition–behaviour relations), and (d) mediated moderation (cognitions mediate the moderating effects of social structural position).

Design

Baseline and 3‐month follow‐up surveys.

Methods

A random sample of 1,483 adults completed self‐report measures of physical activity at baseline and 3‐month follow‐up. Measures of age, gender, education, income, material and social deprivation, intention, perceived behavioural control (PBC), and intention stability also were taken.

Results

Apart from age, social structural factors exhibited very small or marginal effects on behaviour change, and only education moderated the intention–behaviour relation. In contrast, the magnitude of direct effects of the social cognition variables was comparatively large and intention stability mediated the moderating effect of education.

Conclusions

Stable intentions and PBC are the key predictors of changes in physical activity. Consequently, our findings would suggest the value of focusing on cognitions rather than social structural variables when modelling the determinants of physical activity.