bluuebunny/crossref_metadata_2025 huggingface dataset:
Vorinostat in der Behandlung kutaner T‐Zell‐Lymphome. Therapie mit Histon‐Desacetylase‐Inhibitoren
Authors: Zirlik Katja , Nashan Dorothée , Veelken Hendrik
Published: April 2010

Derzeit werden verschiedene epigenetische Ansätze in der Krebstherapie untersucht. Im Fokus dieser Übersicht steht die Inhibition von Histon‐Desacetylasen, welche Genregulation und kontrollierten Zelltod (Apoptose) beeinflussen. Ein Vertreter dieser neuen Substanzklasse ist Vorinostat. In den USA ist die Substanz bereits für die Drittlinientherapie der kutanen T‐Zell‐Lymphome zugelassen.
Die Entzifferung der fünften DNA‐Base. Das Methylom des Menschen
Authors: Winckler Thomas , Zündorf Ilse , Dingermann Theo
Published: April 2010

5‐Methylcytosin ist die “fünfte Base” in der DNA humaner Zellen. Die Methylierung bestimmter Cytosine im Genom unserer Zellen ändert nicht die Kodierung der in der DNA gespeicherten Information, spielt aber eine entscheidende Rolle bei der epigenetischen Transkriptionskontrolle. Fehlregulationen der epigenetischen Modulation der DNA können zu schweren Krankheiten beitragen. In diesem Artikel fassen wir zusammen, wie heute mit modernen Methoden der DNA‐Sequenzierung genomweite Unterschiede in der DNA‐Methylierung funktionell untersucht werden.
Supportive Therapie bei Myelodysplastischem Syndrom (MDS). Unverzichtbare Säule im multimodalen Behandlungskonzept
Authors: Göbel Alexandra , Lubrich Beate
Published: April 2010

Das Myelodysplastische Syndrom (MDS) umfasst eine heterogene Gruppe von Stammzellerkrankungen. Onkogene Transformation von hämatopoetischen Stammzellen führt zur Störung von Proliferation, Differenzierung und Apoptose. Die Hämatopoese ist stark beeinträchtigt und es besteht ein hohes Risiko für die Entwicklung einer akuten myeloischen Leukämie (AML).
Mit Antisense gegen Krebs?
Authors: Edris E. , Möller A.‐M. , Oberhauser E. M. , Zündorf, I. , Dingermann T.
Published: April 2010

Mittlerweile sind bereits ein paar Wirkstoffe zugelassen, die die Versorgung eines soliden Tumors mit Sauerstoff unterbinden, vor allem über die Unterdrückung des Wachstums von Blutgefäßen in das Tumorgewebe. Eine ganz andere Zielstruktur wird jetzt mit EZN‐2968 attackiert: die mRNA des Hypoxie‐induzierbaren Faktors 1α.
Neuer Ansatz zur Bestimmung der pharmakodynamischen Effekte von Histon‐Desacetylase‐Hemmstoffen
Authors: Wagner Julia M. , Jung Manfred
Published: April 2010

Hemmstoffe der Histon‐Desacetylasen (HDACi) traten in den letzten Jahren vermehrt in die klinischen Phasen der Arzneistoffprüfung ein. Erste Inhibitoren (Vorinostat, Zolinza™; Romidepsin, Istodax™) sind bereits für die Behandlung des kutanen T‐Zell‐Lymphoms (CTCL) zugelassen.
Rauschfreie Röntgenbilder mit Medipix. Bildgebende Pixeldetektoren
Authors: Anton Gisela , Michel Thilo
Published: April 2010

Die photonenzählenden, bildgebenden Pixeldetektoren entstammen einer Entwicklung aus der Teilchenphysik. Sie bieten als bildgebende Verfahren mannigfaltige Anwendungsmöglichkeiten im Bereich der Grundlagenforschung, Medizin und Materialforschung. Ein gutes Beispiel sind die Generationen des Medipix‐Röntgendetektors, die in einer großen Kollaboration aus dem CERN heraus entstanden sind. Ein besonderer Vorteil ist ihre Fähigkeit, auch schwache Röntgensignale in rauschfreie Bilder umzusetzen. Die Technik ermöglicht eine hohe örtliche, zeitliche und energetische Auflösung der Messsignale. Ein Hybriddetektor auf Basis der Medipix‐Technologie kann auch einzelne Photonen des sichtbaren Spektrums hochempfindlich messen.
Heiße Action dank cooler Physik. Eishockey‐Weltmeisterschaft 2010
Authors: Mathelitsch Leopold , Thaller Sigrid
Published: April 2010

Eishockey ist die schnellste Mannschaftssportart. Eis ist sehr gleitfähig, weil seine Oberfläche ein quasiflüssiger Wassermolekülfilm überzieht, der leicht verschiebbar ist. Für Geschwindigkeit sorgen zudem Schlagschüsse, bei denen der gebogene Schläger dem Puck wie eine Feder zusätzliche Energie mitgibt. Die Schutzkleidung des Tormanns bremst den Puck beim Aufprall. Sie erlaubt ihm aber auch, das Tor besser zu verdecken.
Farbige Moiré‐Muster als Naturphänomen. Spielwiese
Authors: Schlichting Hans‐Joachim , Suhr Wilfried
Published: April 2010

Konzentrische Ringwellen auf der Oberfläche eines Schwimmbeckens können ein überraschendes Moiré‐Muster erzeugen. Es ähnelt der Überlagerung zweier Kreissysteme, die aus Fresnelschen Zonenplatten bestehen. Da die ringförmigen Wellen wie Zylinderlinsen wirken, ruft die Dispersion besonders an den Kreuzungspunkten zwischen den Ringen starke Farbränder hervor. Aus der Distanz führen diese zu dem in Spektralfarben erscheinenden Ringsystem.
Aufgeblasene Pommes
Authors: Vilgis Thomas
Published: April 2010

Die Verwandlung von Kartoffelscheiben in aufgeblasene knusprige Kissen ist die Krönung der Kartoffelküche. “Pommes Soufflées” gelten stets als großes Beiwerk in der Haute Cuisine. Deren Herstellung ist auch ein Paradebeispiel angewandter Kochphysik. Zweimaliges “Frittieren” in unterschiedlich heißen Ölbädern ist die Krux dieses Experiments.
The secreted proteome profile of developing Dictyostelium discoideum cells
Authors: Bakthavatsalam Deenadayalan , Gomer Richard H.
Published: April 2010

Dictyostelium discoideum is a unicellular eukaryote that, when starved, aggregates to form multicellular structures. In this report, we identified the proteins secreted by developing Dictyostelium cells using MS‐based proteomics. A total of 349 different secreted proteins were identified, indicating that at least 2.6% of the 13 600 predicted proteins in the Dictyostelium genome are secreted. Gene ontology analysis suggests that many of the secreted proteins are involved in protein and carbohydrate metabolism, and proteolysis.
Mitochondrial oxidative phosphorylation system is recruited to detergent‐resistant lipid rafts during myogenesis
Authors: Kim Bong‐Woo , Lee Joong‐Won , Choo Hyo‐Jung , Lee Chang Seok , Jung Soon‐Young , Yi Jae‐Sung , Ham Young‐Mi , Lee Joo‐Hyung , Hong Jin , Kang Min‐Ju , Chi Sung‐Gil , Hyung Seok‐Won , Lee Sang‐Won , Kim Hwan Myung , Cho Bong Rae , Min Do‐Sik , Yoon Gyesoon , Ko Young‐Gyu
Published: April 2010

Since detergent‐resistant lipid rafts play important roles in the signal transduction for myogenesis, their comprehensive proteomic analysis could provide new insights to understand their function in myotubes. Here, the detergent‐resistant lipid rafts were isolated from C2C12 myotubes and analyzed by capillary RPLC/MS/MS. Among the 327 proteins (or protein groups) identified, 28% were categorized to the plasma membrane or raft proteins, 29% to mitochondria, 20% to microsomal proteins, 10% to other proteins, and 13% to unknown proteins. The localization of oxidative phosphorylation (OXPHOS) complexes in the sarcolemma lipid rafts was further confirmed from C2C12 myotubes by cellular fractionation, surface‐biotin labeling, immunofluorescence, and lipid raft fractionation. After adding exogenous cytochromec, the sarcolemma isolated from myotubes had an ability to consume oxygen in the presence of NADH or succinate. The generation of NADH‐dependent extracellular superoxide was increased by inhibiting or downregulating OXPHOS I, III, and IV in myotubes, indicating that OXPHOS proteins are major sources for extracellular ROS in skeletal muscle. With all these data, we can conclude that OXPHOS proteins are associated with the sarcolemma lipid rafts during C2C12 myogenesis to generate extracellular ROS.
Scanning X‐ray fluorescence microspectroscopy of metallic impurities in solar‐grade silicon
Authors: Macdonald Daniel , Rougieux Fiacre , Mansoulie Yves , Tan Jason , Paterson David , Howard Daryl L. , de Jonge Martin D. , Ryan Chris G.
Published: April 2010

A rapid scanning synchrotron‐based X‐ray fluorescence microprobe technique is applied to relatively impure crystalline silicon feedstock for solar cells. The results reveal the distributions of metallic impurities in the material over regions several millimetres in size, allowing scans across several grains. Relatively high concentrations of Fe, Cu and Zn were observed, with traces of Mn and Ni. The metals were mostly present as discrete particles up to 60 µm in size, while Cu was more uniformly distributed. More than 50% of the detected Fe was present as large particles at the grain boundaries, probably due to diffusion and precipitation during cooling. In contrast, less than 5% of the Cu resided in such large particles. The particles contained multiple metallic elements, with strongly varying proportions of their metal constituents.
Perinatal and early surgical outcome for the fetus with hypoplastic left heart syndrome: a 5‐year single institutional experience
Authors: Rychik J. , Szwast A. , Natarajan S. , Quartermain M. , Donaghue D. D. , Combs J. , Gaynor J. W. , Gruber P. J. , Spray T. L. , Bebbington M. , Johnson M. P.
Published: April 2010

Objectives

To review our experience with the prenatal diagnosis of hypoplastic left heart syndrome (HLHS). Our goal was to establish the benchmark for perinatal and early surgical outcome in the current era, from a center with an aggressive surgical approach and a cohort with a high level of intention‐to‐treat.

Methods

Outcome was assessed in fetuses with HLHS following stratification into high‐risk and standard‐risk categories. High risk was defined as the presence of any of the following: extracardiac, genetic or chromosomal anomalies; prematurity of < 34 weeks' gestation; additional cardiac findings such as intact or highly restrictive atrial septum, severe degree of tricuspid regurgitation or severe ventricular dysfunction. Standard risk was defined as absence of these risk factors.

Results

Of 240 fetuses evaluated over 5 years, 162 (67.5%) were in the standard‐risk group and 78 (32.5%) were in the high‐risk group. Of the 240 sets of parents, 38 (15.8%) chose termination or non‐intervention at birth at initial prenatal counseling and 185 of the neonates (77.1%) underwent first‐stage Norwood surgery with 155 surviving and 30 deaths, giving an overall Norwood operative survival of 83.8%. Breakdown by risk class reveals a significant Norwood operative survival advantage for the standard‐risk group (92.8%) over the high‐risk group (56.5%) (P < 0.001).

Conclusions

Following prenatal diagnosis of HLHS, families should be strongly encouraged to undertake comprehensive prenatal evaluation in order to obtain an accurate prognosis. One‐third have additional risk factors that limit survival outcome, however two‐thirds do not and have an excellent chance of early survival. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Crystal Structure and Formation of TlPd3and its new Hydride TlPd3H
Authors: Kurtzemann Nadine , Kohlmann Holger
Published: April 2010

TlPd3was synthesised from the elements in evacuated silica tubes at 600 °C. Alternatively, TlPd3was yielded by reduction of TlPd3O4in N2gas atmosphere. Reduction of the oxide in H2gas atmosphere resulted in the formation of the new hydride TlPd3H. The structure of tetragonal TlPd3(ZrAl3type, space groupI4/mmm,a= 410.659(9) pm,c= 1530.28(4) pm) was reinvestigated by X‐ray and also by neutron powder diffraction as well as the structure of its previously unknown hydride TlPd3H (cubicanti‐perovskite type structure, space groupPm\bar{3}m,a= 406.313(1) pm). In situ DSC measurements of TlPd3in hydrogen gas atmosphere showed a broad exothermic signal over a wide temperature range with two maxima at 280 °C and at 370 °C, which resulted in the product TlPd3H. A dependency of lattice parameters of the intermetallic phase on reaction conditions is observed and discussed. Results of hydrogenation experiments at room temperature with gas pressures up to 280 bar hydrogen and at elevated temperatures with very low hydrogen gas pressures (1–2 bar) as well as results of dehydrogenation of the hydrides under vacuum will be discussed.
Exploration Of Factors Related To Hara-Kiri As A Method Of Suicide And Suicidal Behavior
Authors: Takai M. , Yamamoto K. , Iwamitsu Y. , Miyaji S. , Yamamoto H. , Tatematsu S. , Yukawa M. , Ide A. , Kamijo Y. , Soma K. , Miyaoka H.
Published: April 2010

Objective

The objective of this study was to explore factors associated with hara-kiri as a method of suicide and suicidal behavior in contemporary Japan.

Methods

A retrospective study was conducted on medical records of 421 patients (174 male; 247 female) who were considered suicidal and treated at the Kitasato University Hospital Emergency Medical Center in Japan between January 2006 and March 2008. We compared hara-kiri and all other methods regarding sociodemographics and clinical features of all suicidal patients.

Results

Instances of hara-kiri suicide attempt had the highest proportion of males (63%) among all suicide and suicidal behavior. One-way analysis of variance revealed significant differences between hara-kiri and other suicide attempt methods in the age of the suicidal patients. Result of multiple logistic regression analysis indicated that those who attempted hara-kiri suicide were likely to be male, be diagnosed with schizophrenia, survive, and be married.

Conclusion

Our findings indicate that hara-kiri as a method of suicide and suicidal behavior remain prevalent in Japan, and the study findings also suggest that both clinical and cultural factors might play a role in hara-kiri as a method of suicide and suicidal behavior.
The Response of Corporate Financing and Investment to Changes in the Supply of Credit
Authors: Lemmon Michael , Roberts Michael R.
Published: April 2010

We examine how shocks to the supply of credit impact corporate financing and investment using the collapse of Drexel Burnham Lambert, Inc.; the passage of the Financial Institutions Reform, Recovery, and Enforcement Act of 1989; and regulatory changes in the insurance industry as an exogenous contraction in the supply of below-investment-grade credit after 1989. A difference-in-differences empirical strategy reveals that substitution to bank debt and alternative sources of capital (e.g., equity, cash balances, and trade credit) was limited, leading to an almost one-for-one decline in net investment with the decline in net debt issuances. Despite this sharp change in behavior, corporate leverage ratios remained relatively stable, a result of the contemporaneous decline in debt issuances and investment. Overall, our findings highlight how even large firms with access to public credit markets are susceptible to fluctuations in the supply of capital.
Testing all six person-oriented principles in dynamic factor analysis
Authors: Molenaar Peter C. M.
Published: April 2010

All six person-oriented principles identified by Sterba and Bauer's Keynote Article can be tested by means of dynamic factor analysis in its current form. In particular, it is shown how complex interactions and interindividual differences/intraindividual change can be tested in this way. In addition, the necessity to use single-subject methods in the analysis of developmental processes is emphasized, and attention is drawn to the possibility to optimally treat developmental psychopathology by means of new computational techniques that can be integrated with dynamic factor analysis.
Developing the person-oriented approach: Theory and methods of analysis
Authors: von Eye Alexander
Published: April 2010

The development of paradigms, or perspectives of research takes place at the level of theory, in the domain of methodology, and in the context of existing paradigms and perspectives. The development of the person-oriented approach has made considerable progress at the level of theory. In addition, the approach has found a large number of applications. Sterba and Bauer's Keynote Article has closed a gap by discussing methodological implications of the person-oriented approach. In particular, the authors have discussed whether and, if yes, how the tenets of the person-oriented approach can be tested using tools of applied statistics popular in current empirical psychological research. Continuing this discussion, this article focuses on recent developments in all three areas. First, the importance and the implications of the concept of dimensional identity are discussed. It is argued that dimensional identity needs to be established across time and individuals for comparisons to be valid, both in person-oriented and in variable-oriented research. Second, methods not covered in Sterba and Bauer's Keynote are discussed and their application is exemplified. One focus of this discussion is on configural frequency analysis, which allows researchers to make statements about particular cells or groups of cells in cross-classifications of categorical variables. Third, person-oriented research is compared to differential psychology. It is argued that the concept of dimensional identity represents the next step in the development of a psychological subdiscipline that allows one to consider that individuals differ and develop in unique ways. These differences not only manifest in means but in any parameter, including covariance structures, and they can also manifest in the differential meaningfulness of variables for the description of individuals.
Is adolescence-onset antisocial behavior developmentally normative?
Authors: Roisman Glenn I. , Monahan Kathryn C. , Campbell Susan B. , Steinberg Laurence , Cauffman Elizabeth ,   The National Institute of Child Health and Human Development Early Child Care Research Network
Published: April 2010

Largely because of the influence of Moffitt's useful distinction between adolescence-limited and life-course persistent antisocial behavior, it has become increasingly common to view problem behavior that makes its first appearance in adolescence as developmentally normative. This study prospectively examined the lives of individuals in the NICHD Study of Early Child Care and Youth Development whose patterns of antisocial behavior varied with respect to age of onset and stability from kindergarten through age 15. Consistent with past research, early-onset, persistently deviant youth experienced more contextual adversity and evinced higher levels of intraindividual disadvantages than their peers from infancy through midadolescence. However, relative to youth who never showed significantly elevated antisocial behavior through age 15, children who showed antisocial behavior primarily in adolescence also were more disadvantaged from infancy forward, as were youth who only demonstrated significant externalizing problems in childhood. Findings generally replicated across sex and did not vary as a function of whether antisocial behavior groups were defined using T-scores normed within sex or identified using an empirically driven grouping method applied to raw data.
Time-dependent changes in positively biased self-perceptions of children with attention-deficit/hyperactivity disorder: A developmental psychopathology perspective
Authors: Hoza Betsy , Murray-Close Dianna , Arnold L. Eugene , Hinshaw Stephen P. , Hechtman Lily ,   The MTA Cooperative Group
Published: April 2010

This study examined changes in the degree of positive bias in self-perceptions of previously diagnosed 8- to 13-year-old children with attention-deficit/hyperactivity disorder (ADHD;n= 513) and comparison peers (n= 284) over a 6-year period. The dynamic association between biased self-perceptions and dimensional indices of depressive symptoms and aggression also were considered. Across the 6-year time span, comparison children exhibited less bias than children with ADHD, although a normative bolstering of social self-views during early adolescence was observed. Decreases in positive biases regarding social and behavioral competence were associated with increases in depressive symptoms over time, whereas increases in levels of positively biased self-perceptions in the behavioral (but not social) domain were predictive of greater aggression over time. ADHD status moderated the dynamic association between biases and adjustment. Finally, evidence indicated that there was a bidirectional relationship between biases and aggression, whereas depressive symptoms appeared to inversely predict later bias.
Pott's puffy-Tumor – Schwerer Verlauf einer Sinusitis
Authors: Stienen  , Hermann  , Breuer  , Gautschi
Published: April 2010

Das Krankheitsbild Pott's puffy-Tumor beschreibt eine lokale Stirnbeinosteomyelitis, die meist durch einen äusseren Infekt mit konsekutiver sub­periostaler Abszedierung entsteht. Die klinische Manifestation entsteht schleichend und die sichtbare Erhebung ist oftmals indolent. Die Symptome sind vor allem Folgen komplizierender Sekundärmorbiditäten. Wir präsentieren einen komplizierten Verlauf mit intrakranieller Ausbreitung der initialen Sinusitis.
Environmental water incentive policy and return flows
Authors: Qureshi M. E. , Schwabe K. , Connor J. , Kirby M.
Published: April 2010

With increasing urban, industrial, and agricultural water demand and projected reduced supply under climate change, allocations to the environment are critically low in many arid and semiarid basins. Consequently, many governments are striving to augment environmental flows, often through market‐oriented mechanisms that involve compensating irrigated agriculture, the largest water user in most basins, for reducing diversions. A widely documented challenge with policies to recover water for the environment arises because part of the water diversion reduction can form the basis for downstream consumptive water rights or environmental flows. This article gives an empirical comparison of two incentive policies to acquire water for environmental flows for a part of the Murray‐Darling Basin (MDB), Australia. One policy consists of paying irrigators and water delivery firms to make capital and management investments that improve on‐farm irrigation and water‐conveyance; the other policy consists of having the government buy water from irrigators on the active MDB water market. The results show that the first option results in relatively larger return flow reduction, while the second option tends to induce significant irrigated land retirement with relatively large reductions in consumptive use and small reductions in return flow. In cases where irrigation losses result in little useful return flow (e.g., evaporative loss reduction or during drought in some instances), efficiency‐improving investments may provide some cost‐effective opportunities. Where a large portion of loss forms valuable return flow, it is difficult to make a case for the cost‐effectiveness of policies involving payments for investments in irrigation and conveyance system upgrades.
Modulations of the 27 day solar rotation signal in stratospheric ozone from Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) (2003–2008)
Authors: Dikty Sebastian , Weber Mark , von Savigny Christian , Sonkaew Thiranan , Rozanov Alexei , Burrows John P.
Published: April 2010

Here we investigate the modulating nature of the 27 day solar rotation forcing on stratospheric ozone using a new ozone profile data set from Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY, 2003–2008). Continuous wavelet transform (CWT), fast Fourier transform (FFT), and cross correlations (CC) have been applied to SCIAMACHY ozone in the tropics (<20° latitude) between 20 and 60 km altitude. The maximum correlation between Mg II index and ozone is weaker during the maximum of solar cycle 23 (r = 0.38) than in the previous two solar cycles that have been investigated in earlier studies using different data sets. The magnitude of the ozone signal is highly time dependent and may vanish for several solar rotations even close to solar maximum conditions. The FFT analysis reveals, besides the 27 day signal, several frequencies close to 27 days. The ozone sensitivity (ozone change in percent per percent change in 205 nm solar flux) is on average about 0.2%/% above 30 km altitude and smaller by about a factor of 2 compared to earlier studies. For selected 3 month periods the sensitivity may rise beyond 0.6%/% in better agreement with earlier studies. The analysis of the 27 day solar forcing was also carried out with stratospheric temperatures from European Centre for Medium‐Range Weather Forecasts operational analysis. Although direct radiation effects on temperature are weak in the upper stratosphere, temperature signals with statistically significant periods in the 25–35 day range similar to ozone could be found with the applied methods.
Simulating the heterogeneity in braided channel belt deposits: 1. A geometric‐based methodology and code
Authors: Ramanathan Ramya , Guin Arijit , Ritzi Robert W. , Dominic David F. , Freedman Vicky L. , Scheibe Timothy D. , Lunt Ian A.
Published: April 2010

A geometric‐based simulation methodology was developed and incorporated into a computer code to model the hierarchical stratal architecture, and the corresponding spatial distribution of permeability, in braided channel belt deposits. The code creates digital models of these deposits as a three‐dimensional cubic lattice, which can be used directly in numerical aquifer or reservoir models for fluid flow. The digital models have stratal units defined from the kilometer scale to the centimeter scale. These synthetic deposits are intended to be used as high‐resolution base cases in various areas of computational research on multiscale flow and transport processes, including the testing of upscaling theories. The input parameters are primarily univariate statistics. These include the mean and variance for characteristic lengths of sedimentary unit types at each hierarchical level, and the mean and variance of log‐permeability for unit types defined at only the lowest level (smallest scale) of the hierarchy. The code has been written for both serial and parallel execution. The methodology is described in part 1 of this paper. In part 2 (Guin et al., 2010), models generated by the code are presented and evaluated.
Simulating the heterogeneity in braided channel belt deposits: 2. Examples of results and comparison to natural deposits
Authors: Guin Arijit , Ramanathan Ramya , Ritzi Robert W. , Dominic David F. , Lunt Ian A. , Scheibe Timothy D. , Freedman Vicky L.
Published: April 2010

In part 1 of this paper (Ramanathan et al., 2010b) we presented a methodology and a code for modeling the hierarchical sedimentary architecture in braided channel belt deposits. Here in part 2, the code was used to create a digital model of this architecture and the corresponding spatial distribution of permeability. The simulated architecture was compared to the real stratal architecture observed in an abandoned channel belt. The comparisons included assessments of similarity which were both qualitative and quantitative. The qualitative comparisons show that the geometries of unit types within the synthetic deposits are generally consistent with field observations. The unit types in the synthetic deposits would generally be recognized as representing their counterparts in nature, including cross stratasets, lobate and scroll bar deposits, and channel fills. Furthermore, the synthetic deposits have a hierarchical spatial relationship among these units consistent with observations from field exposures and geophysical images. In quantitative comparisons the proportions and the length, width, and height of unit types at different scales, across all levels of the stratal hierarchy, compare well between the synthetic and the natural deposits. A number of important attributes of the synthetic channel belt deposits are shown to be influenced by more than one level within the hierarchy of stratal architecture. First, the high‐permeability open‐framework gravels connected across all levels and thus formed preferential flow pathways; open‐framework gravels are known to form preferential flow pathways in natural channel belt deposits. The nature of a connected cluster changed across different levels of the stratal hierarchy, and as a result of the geologic structure, the connectivity occurs at proportions of open‐framework gravels below the theoretical percolation threshold for random infinite media. Second, when the channel belt model was populated with permeability distributions by lowest‐level unit type, the composite permeability semivariogram contained structures that were identifiable at more than one scale, and each of these structures could be directly linked to unit types of different scales existing at different levels within the hierarchy of strata. These collective results are encouraging with respect to our goal that this model be relevant for testing ideas in future research on flow and transport in aquifers and reservoirs with multiscale heterogeneity.
New AGU Executive Director Outlines Goals and Priorities
Authors: Showstack Randy
Published: April 2010

When Christine W. McEntee takes the helm at AGU as the new executive director on 30 August, she will bring with her a number of key qualities: more than 25 years of successful association leadership and management experience, a passion for the Earth and space sciences to benefit humanity, a commitment to working to ensure the planet's sustainability, a respect for AGU's distinguished legacy, and the desire and ability to help AGU grow to a higher level of effectiveness.
European Biospheric Network Takes Off: Opening Symposium of the TERRABITES Network; Hamburg, Germany, 9–11 February 2010
Authors: Brovkin Victor , Reick Christian , van Bodegom Peter
Published: April 2010

The huge amount of recently acquired information about the functioning of the terrestrial biosphere and the ever increasing spatial resolution of Earth system models call for a new level of integrating efforts among biosphere modelers, developers of ecological theory, and data‐gathering communities. Responding to this call, a new European network, Terrestrial Biosphere in the Earth System (TERRABITES), held its opening symposium in Germany.
Recent large reduction in sulfur dioxide emissions from Chinese power plants observed by the Ozone Monitoring Instrument
Authors: Li Can , Zhang Qiang , Krotkov Nickolay A. , Streets David G. , He Kebin , Tsay Si‐Chee , Gleason James F.
Published: April 2010

The Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite observed substantial increases in total column SO2 and tropospheric column NO2 from 2005 to 2007, over several areas in northern China where large coal‐fired power plants were built during this period. The OMI‐observed SO2/NO2 ratio is consistent with the SO2/NOx emissions estimated from a bottom‐up approach. In 2008 over the same areas, OMI detected little change in NO2, suggesting steady electricity output from the power plants. However, dramatic reductions of SO2 emissions were observed by OMI at the same time. These reductions confirm the effectiveness of the flue‐gas desulfurization (FGD) devices in reducing SO2 emissions, which likely became operational between 2007 and 2008. This study further demonstrates that the satellite sensors can monitor and characterize anthropogenic emissions from large point sources.
Blockade of the MEK/ERK Pathway with a Raf Inhibitor Prevents Activation of Pro-Inflammatory Mediators in Cerebral Arteries and Reduction in Cerebral Blood Flow after Subarachnoid Hemorrhage in a Rat Model
Authors: Maddahi Aida , Ansar Saema , Chen Qingwen , Edvinsson Lars
Published: April 2010

Cerebral ischemia that develops after subarachnoid hemorrhage (SAH) carries high morbidity and mortality. Inflammatory mediators are involved in the development of cerebral ischemia through activation of the mitogen-activated protein kinase pathway. We hypothesized that blockade of the MAPkinase/ERK (MEK)/extracellular signal-regulated kinase (ERK) pathway upstream with a specific raf inhibitor would prevent SAH-induced activation of the cerebrovascular inflammatory response. The raf inhibitor SB-386023-b was injected intracisternally in our rat model at 0, 6, or 12 hours after the SAH. After 48 hours, cerebral arteries were harvested, and iNOS, interleukin (IL)-6, IL-1β, matrix metalloproteinase (MMP)-9, tissue inhibitors of metalloproteinase (TIMP)-1, and phosphorylated ERK1/2 were investigated by immunofluorescence, real-time polymerase chain reaction (PCR), and Western blot analysis. Cerebral blood flow (CBF) was measured using autoradiography. Protein levels of MMP-9, TIMP-1, iNOS, IL-6, and IL-1β were increased after SAH, as were mRNA levels of IL-6, MMP-9, and TIMP-1. After SAH, pERK1/2 was increased, but CBF was reduced. Treatment with SB-386023-b at 0 or 6 hours after SAH normalized CBF and prevented SAH-induced upregulation of MMPs, pro-inflammatory cytokines, and pERK1/2 proteins. These results suggested that inhibition of MEK/ERK signal transduction by a specific raf inhibitor administered up to 6 hours after SAH normalized the expression of pro-inflammatory mediators and extracellular matrix-related genes.
Two Binding Sites for [3H]PBR28 in Human Brain: Implications for TSPO PET Imaging of Neuroinflammation
Authors: Owen David R , Howell Owain W , Tang Sac-Pham , Wells Lisa A , Bennacef Idriss , Bergstrom Mats , Gunn Roger N , Rabiner Eugenii A , Wilkins Martin R , Reynolds Richard , Matthews Paul M , Parker Christine A
Published: April 2010

[11C]PBR28, a radioligand targeting the translocator protein (TSPO), does not produce a specific binding signal in approximately 14% of healthy volunteers. This phenomenon has not been reported for [11C]PK11195, another TSPO radioligand. We measured the specific binding signals with [3H]PK11195 and [3H]PBR28 in brain tissue from 22 donors. Overall, 23% of the samples did not generate a visually detectable specific autoradiographic signal with [3H]PBR28, although all samples showed [3H]PK11195 binding. There was a marked reduction in the affinity of [3H]PBR28 for TSPO in samples with no visible [3H]PBR28 autoradiographic signal ( K i=188±15.6 nmol/L), relative to those showing normal signal ( K i=3.4±0.5 nmol/L, P<0.001). Of this latter group, [3H]PBR28 bound with a two-site fit in 40% of cases, with affinities ( K i) of 4.0±2.4 nmol/L (high-affinity site) and 313±77 nmol/L (low-affinity site). There was no difference in Kd or Bmax for [3H]PK11195 in samples showing no [3H]PBR28 autoradiographic signal relative to those showing normal [3H]PBR28 autoradiographic signal. [3H]PK11195 bound with a single site for all samples. The existence of three different binding patterns with PBR28 (high-affinity binding (46%), low-affinity binding (23%), and two-site binding (31%)) suggests that a reduction in [11C]PBR28 binding may not be interpreted simply as a reduction in TSPO density. The functional significance of differences in binding characteristics warrants further investigation.
SnoRNA microarray analysis reveals changes in H/ACA and C/D RNA levels caused by dyskerin ablation in mouse liver
Authors: Ge Jingping , Crosby Seth D. , Heinz Michael E. , Bessler Monica , Mason Philip J.
Published: April 2010

snoRNAs (small nucleolar RNAs) are key components of snoRNP (small nucleolar ribonucleoprotein) particles involved in modifying specific residues of ribosomal and other RNAs by pseudouridylation (H/ACA snoRNAs) or methylation (C/D snoRNAs). They are encoded within the introns of host genes, which tend to be genes whose products are involved in ribosome biogenesis or function. Although snoRNPs are abundant, ubiquitous and their components highly conserved, information concerning their expression during development or how their expression is altered in diseased states is sparse. To facilitate these studies we have developed a snoRNA microarray platform for the analysis of the abundance of snoRNAs in different RNA samples. In the present study we show that the microarray is sensitive and specific for the detection of snoRNAs. A mouse snoRNA microarray was used to monitor changes in abundance of snoRNAs after ablation of dyskerin, an H/ACA snoRNA protein component, from mouse liver, which causes a decrease in ribosome production. H/ACA snoRNAs were decreased in abundance in these livers while, unexpectedly, C/D snoRNAs were increased. The increase in C/D snoRNAs corresponded with an increase in the abundance of the mRNAs transcribed from snoRNA host genes, suggesting the increase may be part of a cellular response to defective ribosome synthesis.
Lipotoxicity in obese pregnancy and its potential role in adverse pregnancy outcome and obesity in the offspring
Authors: Jarvie Eleanor , Hauguel-de-Mouzon Sylvie , Nelson Scott M. , Sattar Naveed , Catalano Patrick M. , Freeman Dilys J.
Published: April 2010

Increasing maternal obesity is a challenge that has an impact on all aspects of female reproduction. Lean and obese pregnant women gain similar fat mass, but lean women store fat in the lower-body compartment and obese women in central compartments. In the non-pregnant, central storage of fat is associated with adipocyte hypertrophy and represents a failure to adequately store excess fatty acids, resulting in metabolic dysregulation and ectopic fat accumulation (lipotoxicity). Obese pregnancy is associated with exaggerated metabolic adaptation, endothelial dysfunction and increased risk of adverse pregnancy outcome. We hypothesize that the preferential storage of fat in central rather than ‘safer’ lower-body depots in obese pregnancy leads to lipotoxicity. The combination of excess fatty acids and oxidative stress leads to the production of oxidized lipids, which can be cytotoxic and influence gene expression by acting as ligands for nuclear receptors. Lipid excess and oxidative stress provoke endothelial dysfunction. Oxidized lipids can inhibit trophoblast invasion and influence placental development, lipid metabolism and transport and can also affect fetal developmental pathways. As lipotoxicity has the capability of influencing both maternal endothelial function and placental function, it may link maternal obesity and placentally related adverse pregnancy outcomes such as miscarriage and pre-eclampsia. The combination of excess/altered lipid nutrient supply, suboptimal in utero metabolic environment and alterations in placental gene expression, inflammation and metabolism may also induce obesity in the offspring.
Critical thickness of β-InN/GaN/MgO structures
Authors: Pérez Caro M. , Rodríguez A. G. , López-Luna E. , Vidal M. A. , Navarro-Contreras H.
Published: April 2010

InN films were grown on MgO substrates with a β-GaN buffer layer using the gas source molecular beam epitaxy technique. Initially, at typical growth rates from 0.09 to 0.28 ML/sec and at 500 °C substrate temperature, the growth was performed in a layer by layer way as revealed by in situ reflection high-energy electron diffraction (RHEED). In all samples studied, a critical thickness of ∼5 ML in InN pseudomorphic layer was measured with a frame by frame analysis of RHEED patterns recorded on video. After reaching critical thickness, the InN films undergo a relaxation process, going from two-dimensional growth to three-dimensional, as evidenced by the transformation of the RHEED patterns that change from streaky to spotty. Depending on the In cell temperature, either nanocolumnar InN or flat cubic final films are grown, as can be corroborated by scanning electron microscopy. The experimental critical thickness (hc) value of 5 ML is compared to values calculated from different critical thickness models.
Experimental and theoretical response of distributed read-out imaging devices with imperfect charge confinement
Authors: Hijmering R. A. , Kozorezov A. G. , Verhoeve P. , Martin D. D. E. , Wigmore J. K. , Venn R. , Groot P. J.
Published: April 2010

We present a model to describe the responsivity of distributed read-out imaging devices following photon absorption in the absorber or in the base or top film of the superconducting tunnel junctions at either end of the absorber. The model describes the processes most relevant for photon detection, taking into account diffusion of quasiparticles across the absorber and imperfect confinement in the superconducting tunnel junctions via exchange of quasiparticles between absorber and the junction. It incorporates diffusion mismatch between superconducting tunnel junction and absorber, possible asymmetry between the two junctions and asymmetry between base and top electrodes within each junction. We have conducted dedicated experiments in which different experimental conditions were varied in order to test the model. A good agreement was found between the experimental results and model predictions.
Dependence of facet stress on reliability of AlGaInAs edge-emitting lasers
Authors: Ichikawa Hiroyuki , Kumagai Akiko , Kono Naoya , Matsukawa Shinji , Fukuda Chie , Iwai Keiko , Ikoma Nobuyuki
Published: April 2010

The relationship between facet stress and reliability of AlGaInAs edge-emitting lasers is unclear despite it being an important issue. We prepared two 1.3 μm AlGaInAs Fabry–Pérot buried-heterostructure (BH) lasers that were identical except that they had tensile and compressive stress at the facet. The magnitude of the facet stress was controlled to be approximately 200 MPa in both lasers. We performed three reliability tests. In forward-biased electrostatic discharge tests, which can evaluate the resistance to optical damage, the cumulative degradation ratio of the compressive stressed laser was 33% lower than that of the tensile stressed laser. This result indicates a reduction in the optical absorption due to enlargement of the energy band gap at the facet. In the long-term aging of the light output power of 8 mW at 85 °C over 5 000 h, no dependence of the facet stress on the lifetime was observed. Since a major limitation of InP-based BH lasers is the BH interface, the aging results are reasonable. In the accelerated aging of a large current of 200 mA at 85 °C over 800 h, degradation (defined as an increase in the threshold current of over 10%) was observed only in the tensile stressed laser. This degradation differed completely from that caused by optical absorption; dislocation loops covered the entire active layer at the facet. To the best of our knowledge, this is the first time such degradation has been reported. We found the degradation depends on the facet stress and that compressive stress can suppress the degradation.
Spin-orbit effects on electronic delocalization. Aromaticity in a discrete square tetrapalladium sandwich complex
Authors: Muñoz-Castro A. , Mac-Leod Carey D. , Arratia-Pérez R.
Published: April 2010

In this article, we report the relativistic electronic structure, including spin-orbit interaction, employing all-electron density functional theory calculations on the multimetallic sandwich compound [(CNT)Pd4(COT)]1+ (1), which can be considered as a [Pd4]2+ fragment flanked by two ring-ligands, namely, cyclononatetraenyl (CNT1−) and cyclooctatetraene (COT), as well as the dimer of 1, hereafter 2. The calculations suggest that the Pd4-ligand interaction is mainly electrostatic, being the main responsible term for the stabilization of the almost fully occupied 4d shell [Pd4]2+ fragment. The ring currents and electronic delocalization estimated via the nuclear independent chemical shifts indices and electron localization function, allow us to describe a significant σ-aromaticity at the center of the Pd4 square in 1, which in conjunction with the aromaticity arising from the ligands induce considerable aromatic character inside of the multimetallic metallocene.
Ionic effects on the electric field needed to orient dielectric lamellae
Authors: Putzel G. Garbès , Andelman David , Tsori Yoav , Schick M.
Published: April 2010

We consider the effect of mobile ions on the applied potential needed to reorient a lamellar system of two different materials placed between two planar electrodes. The reorientation occurs from a configuration parallel to the electrodes favored by surface interactions to an orientation perpendicular to the electrodes favored by the electric field. The system consists of alternating A and B layers with different dielectric constants. The mobile ions are assumed to be insoluble in the B layers and hence confined to the A layers. We find that the ions reduce the needed voltage most strongly when they are constrained such that each A lamella is electrically neutral. In this case, a macroscopic separation of charge and its concomitant lowering of free energy, is attained only in the perpendicular orientation. When the ions are free to move between different A layers, such that charge neutrality is only required globally, their effect is smaller and depends upon the preferred surface interaction of the two materials. Under some conditions, the addition of ions can actually stabilize the parallel configuration. Our predictions are relevant to recent experiments conducted on lamellar phases of diblock copolymer films with ionic selective impurities.
A study of the mechanical vibrations of a table-top extreme ultraviolet interference nanolithography tool
Authors: Prezioso S. , De Marco P. , Zuppella P. , Santucci S. , Ottaviano L.
Published: April 2010

A prototype low cost table-top extreme ultraviolet (EUV) laser source (1.5 ns pulse duration, λ=46.9 nm) was successfully employed as a laboratory scale interference nanolithography (INL) tool. Interference patterns were obtained with a simple Lloyd’s mirror setup. Periodic structures on Polymethylmethacrylate/Si substrates were produced on large areas (8 mm2) with resolutions from 400 to 22.5 nm half pitch (the smallest resolution achieved so far with table-top EUV laser sources). The mechanical vibrations affecting both the laser source and Lloyd’s setup were studied to determine if and how they affect the lateral resolution of the lithographic system. The vibration dynamics was described by a statistical model based on the assumption that the instantaneous position of the vibrating mechanical parts follows a normal distribution. An algorithm was developed to simulate the process of sample irradiation under different vibrations. The comparison between simulations and experiments allowed to estimate the characteristic amplitude of vibrations that was deduced to be lower than 50 nm. The same algorithm was used to reproduce the expected pattern profiles in the λ/4 half pitch physical resolution limit. In that limit, a nonzero pattern modulation amplitude was obtained from the simulations, comparable to the peak-to-valley height (2–3 nm) measured for the 45 nm spaced fringes, indicating that the mechanical vibrations affecting the INL tool do not represent a limit in scaling down the resolution.
Low molecular weight oligomers of amyloid peptides display β-barrel conformations: A replica exchange molecular dynamics study in explicit solvent
Authors: De Simone Alfonso , Derreumaux Philippe
Published: April 2010

The self-assembly of proteins and peptides into amyloid fibrils is connected to over 40 pathological conditions including neurodegenerative diseases and systemic amyloidosis. Diffusible, low molecular weight protein and peptide oligomers that form in the early steps of aggregation appear to be the harmful cytotoxic species in the molecular etiology of these diseases. So far, the structural characterization of these oligomers has remained elusive owing to their transient and dynamic features. We here address, by means of full atomistic replica exchange molecular dynamics simulations, the energy landscape of heptamers of the amyloidogenic peptide NHVTLSQ from the beta-2 microglobulin protein. The simulations totaling 5 μs show that low molecular weight oligomers in explicit solvent consist of β-barrels in equilibrium with amorphous states and fibril-like assemblies. The results, also accounting for the influence of the pH on the conformational properties, provide a strong evidence of the formation of transient β-barrel assemblies in the early aggregation steps of amyloid-forming systems. Our findings are discussed in terms of oligomers cytotoxicity.