bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relationship Between Suicidal Thinking and Dating Violence in a Sample of Adolescent Abortion Patients
Authors: Ely Gretchen E. , Nugent William R. , Cerel Julie , Vimbba Mholi
Published: July 2011

Background: The relationship between suicidal thinking and adolescent dating violence has not been previously explored in a sample of adolescent abortion patients. Aims: This paper highlights a study where the relationship between dating violence and severity of suicidal thinking was examined in a sample of 120 young women ages 14–21 seeking to terminate an unintended pregnancy. Methods: The Multidimensional Adolescent Assessment Scale and the Conflict in Adolescent Relationships Scale was used to gather information about psychosocial problems and dating violence so that the relationship between the two problems could be examined, while controlling for the other psychosocial problems. Results: The results suggest that dating violence was related to severity of suicidal thinking, and that the magnitude of this relationship was moderated by the severity of problems with aggression. Conclusions: Specifically, as the severity of participant’s general problems with aggression increased, the magnitude of the relationship between dating violence and severity of suicidal thinking increased. Limitations of the study and implications for practice are discussed.
The Incidence of Hospital-Treated Attempted Suicide in Oviedo, Spain
Authors: Jimenez-Trevino Luis , Saiz Pilar A. , Corcoran Paul , Garcia-Portilla M. Paz , Buron Patricia , Garrido Marlen , Diaz-Mesa Eva , Al-Halabi Susana , Bobes Julio
Published: July 2011

Background: The incidence of hospital-treated attempted suicide has not been well established in Spain. Aims: To determine the incidence of suicide attempters presenting to a hospital in Oviedo, Spain, to describe the nature of the suicidal behavior, and to identify sociodemographic subgroups of the population with high rates. Methods: All admitted to the Hospital Universitario Central de Asturias, Oviedo, during the period 1 May 2008 to 30 April 2009 were examined and those meeting the internationally-recognized case definition were identified. Results: A total of 308 suicide attempt presentations (39% male, 61% female) were made by 279 individuals. Almost 90% of the suicide attempts involved a drug overdose. The age-adjusted total, male, and female attempted suicide rates were 83, 66, and 99 per 100,000, respectively. The highest rate was among 35–44-year-olds for men and women (141.1 and 191.8 per 100,000, respectively). Incidence rates varied widely by sociodemographic characteristics with especially high rates among separated/divorced men (2.4%) and women (1.1%). Conclusions: The reported incidence of hospital-treated attempted suicide is below average in the European context but higher than that reported by previous Spanish studies. Persons separated or divorced constitute a high-risk group.
Structurally Anchored Organizational Democracy
Authors: Unterrainer Christine , Palgi Michal , Weber Wolfgang G. , Iwanowa Anna , Oesterreich Rainer
Published: July 2011

Six hundred and six employees in 33 enterprises (Austria, Germany, Israel, and Italy) that represent different levels of structurally anchored organizational democracy were examined in a multi-method, cross-level study. Based on a typology of democratic enterprises, we investigated the extent to which democratic structures impact employees’ individually perceived participation, affective commitment, and humanitarian ethical orientation. We found support for the expected relationships. Whereas cross-level mediation tests suggest that individually perceived participation fully mediates the positive relationship between democratic structures and affective commitment, they provide no support to our prediction that the influence of democratic structures on humanitarian ethic will be mediated by individually perceived participation.
On the Experience of Conducting a Systematic Review in Industrial, Work, and Organizational Psychology
Authors: Rojon Céline , McDowall Almuth , Saunders Mark N. K.
Published: July 2011

Systematic Review methodology (SRm) is an increasingly popular choice for literature reviews in the Social Sciences. While compared to traditional narrative reviews SRm appears time-consuming and laborious, transparency and replicability of the methodology is argued to facilitate greater clarity of review. Nevertheless, researchers in Industrial, Work, and Organizational (IWO) Psychology have yet to embrace this methodology. Drawing on experience from conducting a Systematic Review (SR) of individual workplace performance we explore the premise: The advantages of SRm to IWO Psychology researchers outweigh the disadvantages. We offer observations, insights, and potential solutions to challenges faced during the reviewing process, concluding that SRm is worthwhile for IWO Psychology researchers.
Dynamical suppression of sea level rise along the Pacific coast of North America: Indications for imminent acceleration
Authors: Bromirski Peter D. , Miller Arthur J. , Flick Reinhard E. , Auad Guillermo
Published: July 2011

Long‐term changes in global mean sea level (MSL) rise have important practical implications for shoreline and beach erosion, coastal wetlands inundation, storm surge flooding, and coastal development. Altimetry since 1993 indicates that global MSL rise has increased about 50% above the 20th century rise rate, from 2 to 3 mm yr−1. At the same time, both tide gauge measurements and altimetry indicate virtually no increase along the Pacific coast of North America during the satellite epoch. Here we show that the dynamical steric response of North Pacific eastern boundary ocean circulation to a dramatic change in wind stress curl, τxy, which occurred after the mid‐1970s regime shift, can account for the suppression of regional sea level rise along this coast since 1980. Alarmingly, mean τxy over the North Pacific recently reached levels not observed since before the mid‐1970s regime shift. This change in wind stress patterns may be foreshadowing a Pacific Decadal Oscillation regime shift, causing an associated persistent change in basin‐scale τxy that may result in a concomitant resumption of sea level rise along the U.S. West Coast to global or even higher rates.
Two‐dimensional transient scattering using the Nyström method and finite difference delay modeling
Authors: Lin Yuan Qu , Weile Daniel S.
Published: July 2011

A method is proposed to solve the two‐dimensional time domain integral equations of electromagnetic theory. The method discretizes the equations spatially using a locally corrected Nyström method and temporally by finite difference delay modeling. Numerical results demonstrate the stability and accuracy of the proposed method.
Hydraulics, morphology, and energy dissipation in an alpine step‐pool channel
Authors: Wilcox Andrew C. , Wohl Ellen E. , Comiti Francesco , Mao Luca
Published: July 2011

To investigate the relationship between hydraulics and channel morphology in step‐pool channels, we combined three‐dimensional velocity measurements with an acoustic Doppler velocimeter and topographic surveys in a steep step‐pool channel, the Rio Cordon, Italy. Measurements were organized around step, pool, and tread units and occurred within a range of 36%–57% of bankfull discharges. As flow moved from steps to their downstream pools in our study reach, an average of approximately two thirds of the total energy was dissipated, as measured by relative head loss through step‐pool sequences. Much of this head loss was achieved by elevation (potential energy) loss rather than velocity reductions. Although an overall, expected pattern of flow acceleration toward step crests and deceleration in pools was present, pool velocities were high, especially where upstream step crests were irregular and where residual pool depths were low. Many steps were porous or “leaky,” with irregular cross‐channel bed and water surface topography, producing high‐velocity jets and less flow resistance than channel‐spanning dammed steps. Longitudinal variations in hydraulics are thus often overshadowed by lateral variations arising from morphologic complexities. Velocity and turbulence characteristics in the Rio Cordon show marked differences from data we have collected in a more stable and wood‐rich channel in the Colorado Rockies, in which “ponded” steps are more prevalent and pools are slower and more turbulent. Comparison of these channels illustrates that step‐pool structure and hydraulics are strongly influenced by flow regime, sediment supply, lithology, time since the last step‐forming flood, and availability of in‐stream wood.
Downwelling then upwelling again of the upwelled Kuroshio water in the southern East China Sea
Authors: Chen Chen‐Tung Arthur
Published: July 2011

As has been well known for several decades, the subsurface Kuroshio waters upwell onto the East China Sea when the Kuroshio impinges on the continental shelf northeast of Taiwan. Based on hydrological and geochemical data, our previous study demonstrated that the upwelled Kuroshio waters downwell then upwell again northwest of Taiwan in August. A subsequent effort attributed this complex phenomenon to varying vorticity or the Rossby number at the study area, which encompasses two strong currents, i.e., the Kuroshio and the Taiwan Warm Current. Moreover, downwelling‐favorable winds coincided with the observation period. This study demonstrates that the above phenomenon does not occur in the northern Taiwan Strait, but appears to surface outside of the strait during all seasons. In general, downwelling of previously upwelled Kuroshio waters from the east brings down waters from the surface, explaining why the recipient bottom waters show a horizontal maximum temperature but a minimum salinity, σt and NO3 + NO2. The downwelled waters subsequently upwell again. Since the recipient near‐surface waters arise from the depth, there exists a horizontal minimum in temperature but a maximum salinity, σt and NO3 + NO2 is found. However, whether wind patterns play a critical role in generating these vertical water movements remains unclear.
Low‐frequency variability in coastal sea level from tide gauges and altimetry
Authors: Vinogradov Sergey V. , Ponte Rui M.
Published: July 2011

Long sea level observations are fundamental for studies of the low‐frequency changes in ocean circulation and climate. Tide gauges provide records several decades long, but their locations are geographically sparse and confined to the coastline. To assess the extent to which tide gauge point measurements represent broader‐scale conditions in the adjacent ocean, we compare tide gauge records to altimeter data in their vicinity for the period 1993–2008. The analysis is based on detrended annual mean series and focuses on interannual variability. The best agreement between tide gauge and altimeter series is found for mid‐ocean islands in the tropical Pacific and Indian oceans and along the coast of western Australia. Elsewhere, along most continental coasts, root‐mean‐square differences between the two sea level estimates can be substantial when compared to the observed variability or the expected measurement noise, with the worst correspondence found in western South America, Japan, and eastern Australia. Differences in magnitude as well as poor correlations between the tide gauge and altimeter estimates are involved. Although land motions and measurement errors can be a factor, results point to the presence of considerable short spatial structure in coastal sea level at interannual time scales, which can be related to the low‐frequency dynamics of coastally trapped circulations, western boundary currents and associated eddy regimes, or response to river runoff. Knowing whether coastal sea level variability becomes more spatially homogeneous at longer time scales must await longer sea level records.
GTP binding to the ROC domain of DAP‐kinase regulates its function through intramolecular signalling
Authors: Carlessi Rodrigo , Levin‐Salomon Vered , Ciprut Sara , Bialik Shani , Berissi Hanna , Albeck Shira , Peleg Yoav , Kimchi Adi
Published: July 2011

Death‐associated protein kinase (DAPk) was recently suggested by sequence homology to be a member of the ROCO family of proteins. Here, we show that DAPk has a functional ROC (Ras of complex proteins) domain that mediates homo‐oligomerization and GTP binding through a defined P‐loop motif. Upon binding to GTP, the ROC domain negatively regulates the catalytic activity of DAPk and its cellular effects. Mechanistically, GTP binding enhances an inhibitory autophosphorylation at a distal site that suppresses kinase activity. This study presents a new mechanism of intramolecular signal transduction, by which GTP binding operates in cis to affect the catalytic activity of a distal domain in the protein.
Distribution patterns of fish communities with respect to environmental gradients in Korean streams
Authors: Yoon Ju-Duk , Kim Jeong-Hui , Byeon Myeong-Seop , Yang Hyung-Jae , Park Jong-Young , Shim Jae-Hwan , Song Ho-Bok , Yang Hyun , Jang Min-Ho
Published: July 2011

Stream development can generate environmental changes that impact fish communities. In temperate streams, the distribution of fish species is associated with environmental gradients. To analyze the relevant factors, large-scale exploration is required. Thus, to evaluate the distribution patterns of fish in Korea, sampling was conducted on a national scale at 720 sites over a 6-week period in 2009. A total of 124 fish species in 27 families were identified; Zacco platypus and Zacco koreanus of the Cyprinidae were the dominant and subdominant species, respectively. Of the species found, 46 (37.1%) were endemic and 4 (3.2%) exotic; of the latter, Micropterus salmoides and Lepomis macrochirus were widely distributed. Upon canonical correspondence analysis (CCA), both altitude and biological oxygen demand (BOD) were highly correlated with CCA axes 1 and 2, respectively. This explained 62.5% of the species–environment relationship. Altitude and stream order were longitudinally related to species distribution. The numbers of both total and endemic species gradually increased as streams grew in size to the fourth–fifth-order, and decreased in sixth-order, streams. Overall, fish communities were stable throughout the entire watershed, whereas some species showed site-specific occurrence patterns due to the paleogeomorphological characteristics of Korean peninsula. However, various anthropogenic activities may negatively affect fish communities. Therefore, both short- and long-term sustainable management strategies are required to conserve native fish fauna.
On radial geodesic forcing of zonal modes
Authors: Kendl A.
Published: July 2011

The elementary local and global influence of geodesic field line curvature on radial dispersion of zonal modes in magnetised plasmas is analysed with a primitive drift wave turbulence model. A net radial geodesic forcing of zonal flows and geodesic acoustic modes can not be expected in any closed toroidal magnetic confinement configuration, since the flux surface average of geodesic curvature identically vanishes. Radial motion of poloidally elongated zonal jets may occur in the presence of geodesic acoustic mode activity. Phenomenologically a radial propagation of zonal modes shows some characteristics of a classical analogon to second sound in quantum condensates.
On the effect of electron correlation on the static second hyperpolarizability of π conjugated oligomer chains
Authors: Limacher Peter A. , Li Qingxu , Lüthi Hans P.
Published: July 2011

In this article, we report on the ab initio calculation of the static longitudinal second hyperpolarizability (γ) of π conjugated unsaturated oligomer chains using polyacetylene and polyyne as model compounds. The common observation is that the electron correlation enhances γ in these systems. The present study reveals that for extended chain lengths the opposite appears to be true: Electron correlation may have a damping effect on this property. For double-zeta basis sets, a negative contribution from electron correlation to γ is found within the range of chain lengths investigated. For triple-zeta basis sets, the same behavior must be anticipated at larger chain lengths based on extrapolation schemes. The analysis of the excitation energies and transition moments shows that transition moments between excited states as predicted by the Hartree-Fock and coupled cluster methods have a different response to chain length extension. There also are indications that higher order correlation effects will enhance γ.
Multimode calculations of rovibrational energies and dipole transition intensities for polyatomic molecules with torsional motion: Application to H2O2
Authors: Carter Stuart , Sharma Amit R. , Bowman Joel M.
Published: July 2011

We report rigorous calculations of rovibrational energies and dipole transition intensities for hydrogen peroxide using a new version of MULTIMODE as applied to molecules with torsional (reaction path) motion. The key features which permit such calculations for moderately sized polyatomic molecules of this general type are briefly described. A previous, accurate potential energy surface and a new high-level ab initio dipole moment surface are employed in these calculations. Detailed comparisons are made with high-resolution experimental spectral intensities from the HITRAN database.
Coded apertures allow high-energy x-ray phase contrast imaging with laboratory sources
Authors: Ignatyev K. , Munro P. R. T. , Chana D. , Speller R. D. , Olivo A.
Published: July 2011

This work analyzes the performance of the coded-aperture based x-ray phase contrast imaging approach, showing that it can be used at high x-ray energies with acceptable exposure times. Due to limitations in the used source, we show images acquired at tube voltages of up to 100 kVp, however, no intrinsic reason indicates that the method could not be extended to even higher energies. In particular, we show quantitative agreement between the contrast extracted from the experimental x-ray images and the theoretical one, determined by the behavior of the material’s refractive index as a function of energy. This proves that all energies in the used spectrum contribute to the image formation, and also that there are no additional factors affecting image contrast as the x-ray energy is increased. We also discuss the method flexibility by displaying and analyzing the first set of images obtained while varying the relative displacement between coded-aperture sets, which leads to image variations to some extent similar to those observed when changing the crystal angle in analyzer-based imaging. Finally, we discuss the method’s possible advantages in terms of simplification of the set-up, scalability, reduced exposure times, and complete achromaticity. We believe this would helpful in applications requiring the imaging of highly absorbing samples, e.g., material science and security inspection, and, in the way of example, we demonstrate a possible application in the latter.
Effects of substrate temperature and film thickness on properties of CuIn3Te5 thin films and solar cells
Authors: Mise Takahiro , Nakada Tokio
Published: July 2011

The effects of substrate temperature (Tsub) and film thickness (dCIT) on the properties of CuIn3Te5 thin films and solar cells were investigated. CuIn3Te5 thin films (dCIT = 1.8–4.0 μm) were grown on both bare and Mo-coated soda-lime glass substrates at Tsub of 250–400 °C by single-step co-evaporation using a molecular beam epitaxy system. The microstructural properties were examined using scanning electron microscopy and x-ray diffraction. Well-developed (112)-oriented CuIn3Te5 grains were obtained by increasing the dCIT for Tsub of 250 °C. Cathodoluminescence analysis and temperature-dependent Hall measurements indicate the formation of shallow defect levels in the CuIn3Te5 films grown at higher Tsub. An optimum solar cell fabricated using CuIn3Te5 thin films (Tsub = 250 °C, and dCIT = 4.0 μm) yielded a total area (0.504 cm2) efficiency of 6.28%. Recombination mechanisms in the CdS/CuIn3Te5 thin-film solar cells are discussed on the basis of the temperature-dependent electrical properties of the films and solar cells.
Thin-film solar-chemical battery: Photo-charging and discharging in amorphous AgAsS2 films
Authors: Terakado Nobuaki , Tanaka Keiji
Published: July 2011

We have fabricated a rechargeable photo-chemical battery using ion-hole conducting AgAsS2 films. An asymmetrically-electroded Al/AgAsS2/SnO2 yields photocurrents and upon illumination it is concomitantly charged up. When the illumination is stopped, the stack discharges electricity into an external circuit. This photo-charging and discharging phenomenon is attributed to a photo-chemical modification of Ag-ion distribution in amorphous AgAsS2.
Effects of ion solvation on phase equilibrium and interfacial tension of liquid mixtures
Authors: Wang Rui , Wang Zhen-Gang
Published: July 2011

We study the bulk thermodynamics and interfacial properties of electrolyte solution mixtures by accounting for electrostatic interaction, ion solvation, and inhomogeneity in the dielectric medium in the mean-field framework. Difference in the solvation energy between the cations and anions is shown to give rise to local charge separation near the interface, and a finite Galvani potential between two coexisting solutions. The ion solvation affects the phase equilibrium of the solvent mixture, depending on the dielectric constants of the solvents, reflecting the competition between the solvation energy and translation entropy of the ions. Miscibility is decreased if both solvents have low dielectric constants and is enhanced if both solvents have high dielectric constant. At the mean-field level, the ion distribution near the interface is determined by two competing effects: accumulation in the electrostatic double layer and depletion in a diffuse interface. The interfacial tension shows a nonmonotonic dependence on the salt concentration: it increases linearly with the salt concentration at higher concentrations and decreases approximately as the square root of the salt concentration for dilute solutions, reaching a minimum near 1 mM. We also find that, for a fixed cation type, the interfacial tension decreases as the size of anion increases. These results offer qualitative explanations within one unified framework for the long-known concentration and ion size effects on the interfacial tension of electrolyte solutions.
Phase separation in thermoelectric delafossite CuFe1−xNixO2 observed by soft x-ray magnetic circular dichroism
Authors: Kang J.-S. , Kim D. H. , Hwang Jihoon , Lee Eunsook , Nozaki T. , Hayashi K. , Kajitani T. , Park B.-G. , Kim J.-Y. , Min B. I.
Published: July 2011

Electronic structures of Ni-doped CuFe1−xNixO2 delafossite oxides (0 ≤ x ≤ 0.03) have been investigated by employing soft x-ray magnetic circular dichroism (XMCD). Finite XMCD signals are observed for Fe, Ni, and Cu 2p states, and valence states of Cu, Fe, and Ni ions are nearly monovalent (Cu+), trivalent (Fe3+), and divalent (Ni2+), respectively, for all x ≤ 0.03. Tiny magnetic impurities could be detected by employing XMCD. Fe and Ni 2p XMCD signals are identified due to ferrimagnetic spinel impurities of CuFe2O4 and NiFe2O4. XMCD signals for Cu 2p states arise from divalent Cu2+ ions. Thermoelectrical properties are found to be very sensitive to the very little impurity phase present in delafossite oxides.
Scaling of reliability of gold interconnect lines subjected to alternating current
Authors: Wang M. , Zhang B. , Zhang G. P. , Liu C. S.
Published: July 2011

We present an investigation of damage morphologies of small-scale gold interconnect lines subjected to thermal fatigue strain generated by alternating current. Fractal dimension analysis reveals a general scaling relation between the critical strain range causing thermal fatigue damage and the ratio of the width to the thickness of the metal line. Such the scaling rule may be useful in controlling reliability of the metal interconnect lines subjected to long-term thermal cyclic strain.
Loss of tooth-supporting bone in the koala (Phascolarctos cinereus) with age
Authors: Lee Elizabeth F. , Varanasi Srinivas , Pettett Lyndall M. , Bird Philip S. , Symons Anne L.
Published: July 2011

This study investigated changes in alveolar bone height in free-ranging koalas of different age groups. Twenty-seven free-ranging Queensland koalas (15 female, 12 male), admitted to the Moggill Koala Hospital, Brisbane, were used in this study. Koalas were divided into three groups (young, adult, old) on the basis of tooth wear, each group containing nine animals. Defleshed jaws were examined for the presence of alveolar bone defects. The distance from the cemento-enamel junction and the interproximal crestal alveolar bone height was measured on the buccal aspects of the second and third molars. Jaws were photographed and radiographed. Bone defects (dehiscences and fenestrations) were observed in both jaws and were predominantly located on the buccal aspect of the alveolar process. The loss of height of crestal alveolar bone, relative to the cemento-enamel junction, increased with age, with 25 koalas showing moderate to severe bone loss and only two koalas having none/mild loss levels at all measurement sites. Female koalas had higher frequency of ‘none/mild’ cases of bone loss than did males. There was no variation in levels of alveolar bone loss between the upper and lower jaws or the corresponding right and left arches.
Maps of protein structure space reveal a fundamental relationship between protein structure and function
Authors: Osadchy Margarita , Kolodny Rachel
Published: July 2011

To study the protein structure–function relationship, we propose a method to efficiently create three-dimensional maps of structure space using a very large dataset of > 30,000 Structural Classification of Proteins (SCOP) domains. In our maps, each domain is represented by a point, and the distance between any two points approximates the structural distance between their corresponding domains. We use these maps to study the spatial distributions of properties of proteins, and in particular those of local vicinities in structure space such as structural density and functional diversity. These maps provide a unique broad view of protein space and thus reveal previously undescribed fundamental properties thereof. At the same time, the maps are consistent with previous knowledge (e.g., domains cluster by their SCOP class) and organize in a unified, coherent representation previous observation concerning specific protein folds. To investigate the function–structure relationship, we measure the functional diversity (using the Gene Ontology controlled vocabulary) in local structural vicinities. Our most striking finding is that functional diversity varies considerably across structure space: The space has a highly diverse region, and diversity abates when moving away from it. Interestingly, the domains in this region are mostly alpha/beta structures, which are known to be the most ancient proteins. We believe that our unique perspective of structure space will open previously undescribed ways of studying proteins, their evolution, and the relationship between their structure and function.
Derepression of ethylene-stabilized transcription factors (EIN3/EIL1) mediates jasmonate and ethylene signaling synergy in
Arabidopsis
Authors: Zhu Ziqiang , An Fengying , Feng Ying , Li Pengpeng , Xue Li , A Mu , Jiang Zhiqiang , Kim Jong-Myong , To Taiko Kim , Li Wei , Zhang Xinyan , Yu Qiang , Dong Zhi , Chen Wen-Qian , Seki Motoaki , Zhou Jian-Min , Guo Hongwei
Published: July 2011

Jasmonate (JA) and ethylene (ET) are two major plant hormones that synergistically regulate plant development and tolerance to necrotrophic fungi. Both JA and ET induce the expression of several pathogenesis-related genes, while blocking either signaling pathway abolishes the induction of these genes by JA and ET alone or in combination. However, the molecular basis of JA/ET coaction and signaling interdependency is largely unknown. Here, we report that two
Arabidopsis
ET-stabilized transcription factors (EIN3 and EIL1) integrate ET and JA signaling in the regulation of gene expression, root development, and necrotrophic pathogen defense. Further studies reveal that JA enhances the transcriptional activity of EIN3/EIL1 by removal of JA-Zim domain (JAZ) proteins, which physically interact with and repress EIN3/EIL1. In addition, we find that JAZ proteins recruit an RPD3-type histone deacetylase (HDA6) as a corepressor that modulates histone acetylation, represses EIN3/EIL1-dependent transcription, and inhibits JA signaling. Our studies identify EIN3/EIL1 as a key integration node whose activation requires both JA and ET signaling, and illustrate transcriptional derepression as a common mechanism to integrate diverse signaling pathways in the regulation of plant development and defense.
Genome-wide analysis reveals conserved and divergent features of Notch1/RBPJ binding in human and murine T-lymphoblastic leukemia cells
Authors: Wang Hongfang , Zou James , Zhao Bo , Johannsen Eric , Ashworth Todd , Wong Hoifung , Pear Warren S. , Schug Jonathan , Blacklow Stephen C. , Arnett Kelly L. , Bernstein Bradley E. , Kieff Elliott , Aster Jon C.
Published: July 2011

Notch1 regulates gene expression by associating with the DNA-binding factor RBPJ and is oncogenic in murine and human T-cell progenitors. Using ChIP-Seq, we find that in human and murine T-lymphoblastic leukemia (TLL) genomes Notch1 binds preferentially to promoters, to RBPJ binding sites, and near imputed ZNF143, ETS, and RUNX sites. ChIP-Seq confirmed that ZNF143 binds to ∼40% of Notch1 sites. Notch1/ZNF143 sites are characterized by high Notch1 and ZNF143 signals, frequent cobinding of RBPJ (generally through sites embedded within ZNF143 motifs), strong promoter bias, and relatively low mean levels of activating chromatin marks. RBPJ and ZNF143 binding to DNA is mutually exclusive in vitro, suggesting RBPJ/Notch1 and ZNF143 complexes exchange on these sites in cells. K-means clustering of Notch1 binding sites and associated motifs identified conserved Notch1-RUNX, Notch1-ETS, Notch1-RBPJ, Notch1-ZNF143, and Notch1-ZNF143-ETS clusters with different genomic distributions and levels of chromatin marks. Although Notch1 binds mainly to gene promoters, ∼75% of direct target genes lack promoter binding and are presumably regulated by enhancers, which were identified near
MYC
,
DTX1
,
IGF1R
,
IL7R
, and the
GIMAP
cluster. Human and murine TLL genomes also have many sites that bind only RBPJ. Murine RBPJ-only sites are highly enriched for imputed REST (a DNA-binding transcriptional repressor) sites, whereas human RPBJ-only sites lack REST motifs and are more highly enriched for imputed CREB sites. Thus, there is a conserved network of
cis
-regulatory factors that interacts with Notch1 to regulate gene expression in TLL cells, as well as unique classes of divergent RBPJ-only sites that also likely regulate transcription.
THE GUEST FROM ENGLAND: EXPLORING ISSUES OF POSITIONALITY IN A FOREIGN AND YET FAMILIAR SETTING
Authors: Jones Marion
Published: July 2011

By adopting a reflective–reflexive approach, the paper explores aspects of positionality in relation to gender and culture and examines in what way they affect the generation of status and power within the relationships and social interactions of the research participants. By drawing on my personal experience as a female researcher operating in a male-dominated, foreign and yet familiar setting, I will analyse the mechanisms involved in the negotiation of the positions occupied by the various players and how this determined my status in terms of insider/outsidership. Particular attention will be paid to the facilitation of access to the field and the construction of knowledge. The data informing this paper were collected as part of a study of school-based models of initial teacher training in Germany, including contributions from the directors, tutors and mentors of three teacher training Seminars as well as my own observations. The relatively small sample of respondents and the researcher's subjective perspective of reporting and interpreting the findings preclude any conclusions of a general nature to be drawn. However, interesting data emerged, suggesting that aspects of gender and culture as well as the researcher's biographical background constitute powerful factors in the positioning of the research participants, which have methodological and epistemological implications. In the light of these findings I would argue that by adopting a reflective–reflexive approach the quality of the research account can be enhanced by making the mechanisms involved in the negotiation of positions of power and control more transparent. Finally, the analysis presented is intended to act as a caveat against the simplistic assumption that a researcher's familiarity and biographical affiliation with the setting will assist him/her in establishing and maintaining control over the research process.
High aspect ratio lithium niobate ridge waveguides fabricated by optical grade dicing
Authors: Courjal Nadège , Guichardaz Blandine , Ulliac Gwenn , Rauch Jean-Yves , Sadani Benattou , Lu Hui-Hui , Bernal Maria-Pilar
Published: July 2011

We report the development of a quick process for fabricating lithium niobate ridge waveguides with smooth walls, aspect ratios larger than 500 and side-wall verticality of 88°. The method is based on optical grade dicing, and allows the fabrication of ridges with a top width of 1 µm and a depth of more than 500 µm. Smart-cut ridge waveguides and strongly confined proton exchanged ridge waveguides are demonstrated. We show that the method enables the fabrication of ridge waveguides with propagation losses as low as 0.5 dB cm−1. A new fabrication process is thus proposed for the fabrication of optical components with enhanced acousto-optic, electro-optic or nonlinear interactions. The high aspect ratios open opportunities towards the development of 3D photonic components in thin films of LiNbO3, and towards hybrid integration of LiNbO3 components.
Structure and optical properties of thin As2S3–In2S3 films
Authors: Todorov R , Tsankov D , Pirov J , Petkov K
Published: July 2011

This paper deals with the optical properties of thin As2S3–In2S3 films. The thin layers were deposited by thermal co-evaporation of As2S3 and In2S3. The composition of the coatings was controlled by x-ray microanalysis; it was found to be close to the expected one. The refractive index n and optical band gap
were calculated from the transmittance and reflectance spectra. The results showed that the refractive index of thin As–S films is not affected by the addition of 1 at% indium and it increases from 2.46 to 2.58 for thin film with 13 at% In. A decrease in the changes in the refractive index, Δn, after exposure to light or annealing with addition of indium in arsenic sulfide is observed. To explain the influence of the indium on the photoinduced changes in the optical properties of thin As–S–In films, the glass structure was investigated by infrared spectroscopy. The calculated values of the optical constants were compared with those obtained from ellipsometric measurements.
Analysis of tungsten melt-layer motion and splashing under tokamak conditions at TEXTOR
Authors: Coenen J.W. , Philipps V. , Brezinsek S. , Bazylev B. , Kreter A. , Hirai T. , Laengner M. , Tanabe T. , Ueda Y. , Samm U.
Published: July 2011

Behaviour and characteristics of W plasma-facing components under impinging high heat fluxes are investigated in view of the material choices for the divertor in future devices such as ITER and DEMO. Experiments have been carried out in the plasma edge of the TEXTOR tokamak to study melt-layer motion, macroscopic tungsten erosion from the melt layer as well as the changes in material properties such as grain size and abundance of voids or bubbles. The parallel heat flux at the radial position of the plasma-facing components (PFCs) in the plasma ranges around q
‖ ∼ 45 MW m−2 allowing samples to be exposed at an impact angle of 35° to 20–30 MW m−2. Melt-layer motion perpendicular to the magnetic field is observed following a Lorentz force originating from thermoelectric emission of the hot sample. Up to 3 g of molten W are redistributed forming mountain-like structures at the edge of the sample. The typical melt-layer thickness is 1–1.5 mm. Those hills are, due to the changes in the local geometry, particularly susceptible to even higher heat fluxes of up to the full q
‖. Locally the temperature can reach up to 6000 K, high levels of evaporation are causing significant erosion in the form of continuous fine-spray (∼1 × 1024 atoms m−2 s−1). Strong evaporation cooling is observed hindering the further heating of the samples. In addition, the formation of ligaments and splashes occurs several times during the melt phase ejecting droplets in the order of several 10 µm up to 100 µm probably caused by an instability evolving in the melt. In terms of material degradation several aspects are considered: formation of leading edges by redistributed melt, bubble formation and recrystallization. Bubbles are occurring in sizes between 1 and 200 µm while recrystallization increases the grain size up to 1.5 mm. The power-handling capabilities are thus severely degraded. Melting of tungsten (W) in future devices is highly unfavourable and needs to be avoided especially in light of uncontrolled transients and possible unshaped PFCs
Modelling of the edge plasma of MAST in the presence of resonant magnetic perturbations
Authors: Rozhansky V. , Molchanov P. , Kaveeva E. , Voskoboynikov S. , Kirk A. , Nardon E. , Coster D. , Tendler M.
Published: July 2011

The transport code B2SOLPS5.2 is used to simulate L- and H-mode discharges on MAST with and without resonant magnetic perturbations (RMP). The simulated variation of the radial electric field (less negative for RMP) and toroidal rotation (spin-up in the co-current direction for RMP) is in agreement with the experiment. The pump-out effect in the L-modes with high and medium plasma density and in the H-mode is caused by the additional neoclassical radial plasma flow in the electric field modified due to the electron loss along the stochastic field lines. The pump-out in the low-density L-mode can be reproduced only by a significant rise in the turbulent transport coefficients. The modelling suggests strong RMP screening. An analytical model for RMP screening is proposed.
Experimental demonstration of particle energy, conversion efficiency and spectral shape required for ion-based fast ignition
Authors: Hegelich B.M. , Jung D. , Albright B.J. , Fernandez J.C. , Gautier D.C. , Huang C. , Kwan T.J. , Letzring S. , Palaniyappan S. , Shah R.C. , Wu H.-C. , Yin L. , Henig A. , Hörlein R. , Kiefer D. , Schreiber J. , Yan X.Q. , Tajima T. , Habs D. , Dromey B. , Honrubia J.J.
Published: July 2011

Research on fusion fast ignition (FI) initiated by laser-driven ion beams has made substantial progress in the last years. Compared with electrons, FI based on a beam of quasi-monoenergetic ions has the advantage of a more localized energy deposition, and stiffer particle transport, bringing the required total beam energy close to the theoretical minimum. Due to short pulse laser drive, the ion beam can easily deliver the 200 TW power required to ignite the compressed D–T fuel. In integrated calculations we recently simulated ion-based FI targets with high fusion gain targets and a proof of principle experiment [1]. These simulations identify three key requirements for the success of ion-driven fast ignition (IFI): (1) the generation of a sufficiently high-energetic ion beam (≈400–500 MeV for C), with (2) less than 20% energy spread at (3) more than 10% conversion efficiency of laser to beam energy. Here we present for the first time new experimental results, demonstrating all three parameters in separate experiments. Using diamond nanotargets and ultrahigh contrast laser pulses we were able to demonstrate >500 MeV carbon ions, as well as carbon pulses with ΔE/E < 20%. The first measurements put the total conversion efficiency of laser light into high energy carbon ions on the order of 10%.
Equivalences between fusion systems of finite groups of Lie type
Authors: Broto Carles , Møller Jesper , Oliver Bob
Published: July 2011

We prove, for certain pairsG,G′G,G’of finite groups of Lie type, that thepp-fusion systemsFp(G)\mathcal {F}_p(G)andFp(G′)\mathcal {F}_p(G’)are equivalent. In other words, there is an isomorphism between a Sylowpp-subgroup ofGGand one ofG′G’which preservespp-fusion. This occurs, for example, whenG=G(q)G=\mathbb {G}(q)andG′=G(q′)G’=\mathbb {G}(q’)for a simple Lie “type”G\mathbb {G}, andqqandq′q’are prime powers, both prime topp, which generate the same closed subgroup ofpp-adic units. Our proof uses homotopy-theoretic properties of thepp-completed classifying spaces ofGGandG′G’, and we know of no purely algebraic proof of this result.
Regulation of exit from mitosis in multinucleateAshbya gossypiicells relies on a minimal network of genes
Authors: Finlayson Mark R. , Helfer-Hungerbühler A. Katrin , Philippsen Peter
Published: July 2011

In Saccharomyces cerevisiae, mitosis is coupled to cell division by the action of the Cdc fourteen early anaphase release (FEAR) and mitotic exit network (MEN) regulatory networks, which mediate exit from mitosis by activation of the phosphatase Cdc14. The closely related filamentous ascomycete Ashbya gossypii provides a unique cellular setting to study the evolution of these networks. Within its multinucleate hyphae, nuclei are free to divide without the spatial and temporal constraints described for budding yeast. To investigate how this highly conserved system has adapted to these circumstances, we constructed a series of mutants lacking homologues of core components of MEN and FEAR and monitored phenomena such as progression through mitosis and Cdc14 activation. MEN homologues in A. gossypii were shown to have diverged from their anticipated role in Cdc14 release and exit from mitosis. We observed defects in septation, as well as a partial metaphase arrest, in Agtem1Δ, Agcdc15Δ, Agdbf2/dbf20Δ, and Agmob1Δ. A. gossypii homologues of the FEAR network, on the other hand, have a conserved and more pronounced role in regulation of the M/G1 transition. Agcdc55Δ mutants are unable to sequester AgCdc14 throughout interphase. We propose a reduced model of the networks described in yeast, with a low degree of functional redundancy, convenient for further investigations into these networks.
Kif18B interacts with EB1 and controls astral microtubule length during mitosis
Authors: Stout Jane R. , Yount Amber L. , Powers James A. , LeBlanc Chantal , Ems-McClung Stephanie C. , Walczak Claire E.
Published: July 2011

Regulation of microtubule (MT) dynamics is essential for proper spindle assembly and organization. Kinesin-8 family members are plus-end-directed motors that modulate plus-end MT dynamics by acting as MT depolymerases or as MT plus-end capping proteins. In this paper, we show that the human kinesin-8 Kif18B functions during mitosis to control astral MT organization. Kif18B is a MT plus-tip-tracking protein that localizes to the nucleus in interphase and is enriched at astral MT plus ends during early mitosis. Knockdown of Kif18B caused spindle defects, resulting in an increased number and length of MTs. A yeast two-hybrid screen identified an interaction of the C-terminal domain of Kif18B with the plus-end MT-binding protein EB1. EB1 knockdown disrupted Kif18B targeting to MT plus ends, indicating that EB1/Kif18B interaction is physiologically important. This interaction is direct, as the far C-terminal end of Kif18B is sufficient for binding to EB1 in vitro. Overexpression of this domain is sufficient for plus-end MT targeting in cells; however, targeting is enhanced by the motor domain, which cooperates with the tail to achieve proper Kif18B localization at MT plus ends. Our results suggest that Kif18B is a new MT dynamics regulatory protein that interacts with EB1 to control astral MT length.
Structural and functional analysis of the repressor complex in the Notch signaling pathway ofDrosophila melanogaster
Authors: Maier Dieter , Kurth Patricia , Schulz Adriana , Russell Andrew , Yuan Zhenyu , Gruber Kim , Kovall Rhett A. , Preiss Anette
Published: July 2011

In metazoans, the highly conserved Notch pathway drives cellular specification. On receptor activation, the intracellular domain of Notch assembles a transcriptional activator complex that includes the DNA-binding protein CSL, a composite of human C-promoter binding factor 1, Suppressor of Hairless of Drosophila melanogaster [Su(H)], and lin-12 and Glp-1 phenotype of Caenorhabditis elegans. In the absence of ligand, CSL represses Notch target genes. However, despite the structural similarity of CSL orthologues, repression appears largely diverse between organisms. Here we analyze the Notch repressor complex in Drosophila, consisting of the fly CSL protein, Su(H), and the corepressor Hairless, which recruits general repressor proteins. We show that the C-terminal domain of Su(H) is necessary and sufficient for forming a high-affinity complex with Hairless. Mutations in Su(H) that affect interactions with Notch and Mastermind have no effect on Hairless binding. Nonetheless, we demonstrate that Notch and Hairless compete for CSL in vitro and in cell culture. In addition, we identify a site in Hairless that is crucial for binding Su(H) and subsequently show that this Hairless mutant is strongly impaired, failing to properly assemble the repressor complex in vivo. Finally, we demonstrate Hairless-mediated inhibition of Notch signaling in a cell culture assay, which hints at a potentially similar repression mechanism in mammals that might be exploited for therapeutic purposes.
Oxygen reduction in the strict anaerobe Desulfovibrio vulgaris Hildenborough: characterization of two membrane-bound oxygen reductases
Authors: Lamrabet O. , Pieulle L. , Aubert C. , Mouhamar F. , Stocker P. , Dolla A. , Brasseur G.
Published: July 2011

AlthoughDesulfovibrio vulgarisHildenborough (DvH) is a strictly anaerobic bacterium, it is able to consume oxygen in different cellular compartments, including extensive periplasmic O2reduction with hydrogen as electron donor. The genome of DvH revealed the presence ofcydABandcoxgenes, encoding a quinol oxidasebdand a cytochromecoxidase, respectively. In the membranes of DvH, we detected both quinol oxygen reductase [inhibited by heptyl-hydroxyquinoline-N-oxide (HQNO)] and cytochromecoxidase activities. Spectral and HPLC data for the membrane fraction revealed the presence ofo-,b- andd-type haems, in addition to a majority ofc-type haems, but noa-type haem, in agreement with carbon monoxide-binding analysis. The cytochromecoxidase is thus of thecc(o/b)o3type, a type not previously described. The monohaem cytochromec553is an electron donor to the cytochromecoxidase; its encoding gene is located upstream of thecoxoperon and is 50-fold more transcribed thancoxIencoding the cytochromecoxidase subunit I. Even when DvH is grown under anaerobic conditions in lactate/sulfate medium, the two terminal oxidase-encoding genes are expressed. Furthermore, the quinol oxidasebd-encoding genes are more highly expressed than thecoxgenes. Thecoxoperon exhibits an atypical genomic organization, with the genecoxIIlocated downstream ofcoxIV. The occurrence of these membrane-bound oxygen reductases in other strictly anaerobic Deltaproteobacteria is discussed.