bluuebunny/crossref_metadata_2025 huggingface dataset:
Pregnancy outcomes of women with and without a history of anorexia nervosa
Authors: Eagles J. M. , Lee A. J. , Raja E. Amalraj , Millar H. R. , Bhattacharya S.
Published: March 2012

Background

When women have a history of anorexia nervosa (AN), the advice given about becoming pregnant, and about the management of pregnancies, has usually been cautious. This study compared the pregnancy outcomes of women with and without a history of AN.

Method

Women with a confirmed diagnosis of AN who had presented to psychiatric services in North East Scotland from 1965 to 2007 were identified. Those women with a pregnancy recorded in the Aberdeen Maternal and Neonatal Databank (AMND) were each matched by age, parity and year of delivery of their first baby with five women with no history of AN. Maternal and foetal outcomes were compared between these two groups of women. Comparisons were also made between the mothers with a history of AN and all other women in the AMND.

Results

A total of 134 women with a history of AN delivered 230 babies and the 670 matched women delivered 1144 babies. Mothers with AN delivered lighter babies but this difference did not persist after adjusting for maternal body mass index (BMI) in early pregnancy. Standardized birthweight (SBW) scores suggested that the AN mothers were more likely to produce babies with intrauterine growth restriction (IUGR) [relative risk (RR) 1.54, 95% confidence interval (CI) 1.11–2.13]. AN mothers were more likely to experience antepartum haemorrhage (RR 1.70, 95% CI 1.09–2.65).

Conclusions

Mothers with a history of AN are at increased risk of adverse pregnancy outcomes. The magnitude of these risks is relatively small and should be appraised holistically by psychiatric and obstetric services.
Treatment effects on insular and anterior cingulate cortex activation during classic and emotional Stroop interference in child abuse-related complex post-traumatic stress disorder
Authors: Thomaes K. , Dorrepaal E. , Draijer N. , de Ruiter M. B. , Elzinga B. M. , van Balkom A. J. , Smit J. H. , Veltman D. J.
Published: March 2012

Background

Functional neuroimaging studies have shown increased Stroop interference coupled with altered anterior cingulate cortex (ACC) and insula activation in post-traumatic stress disorder (PTSD). These brain areas are associated with error detection and emotional arousal. There is some evidence that treatment can normalize these activation patterns.

Method

At baseline, we compared classic and emotional Stroop performance and blood oxygenation level-dependent responses (functional magnetic resonance imaging) of 29 child abuse-related complex PTSD patients with 22 non-trauma-exposed healthy controls. In 16 of these patients, we studied treatment effects of psycho-educational and cognitive behavioural stabilizing group treatment (experimental treatment; EXP) added to treatment as usual (TAU)versusTAU only, and correlations with clinical improvement.

Results

At baseline, complex PTSD patients showed a trend for increased left anterior insula and dorsal ACC activation in the classic Stroop task. Only EXP patients showed decreased dorsal ACC and left anterior insula activation after treatment. In the emotional Stroop contrasts, clinical improvement was associated with decreased dorsal ACC activation and decreased left anterior insula activation.

Conclusions

We found further evidence that successful treatment in child abuse-related complex PTSD is associated with functional changes in the ACC and insula, which may be due to improved selective attention and lower emotional arousal, indicating greater cognitive control over PTSD symptoms.
Framing entextualization in improv: Intertextuality as an interactional resource
Authors: Trester Anna Marie
Published: March 2012

This study explores a type of language play among a community of improvisational theater (improv) performers, focusing on their strategic deployment of texts in interactions collected backstage while the troupe prepares for performance. Building on the work of Bauman & Briggs (1990), I adopt a process approach to the analysis of intertextuality, suggesting that community-specific ways of using entextualization, decontextualization, and recontextualization add to the work that has been done on intertextuality, given that it is not merely what texts are used but crucially how they are reshaped that can serve an important social function or the why of intertextuality—in this case explored in the context of member socialization. (Intertextuality, interactional sociolinguistics, ethnography of communication, improvisational theater, improv)*
THE USE OF A MARSHALLIAN MACROECONOMIC MODEL FOR POLICY EVALUATION: CASE OF SOUTH AFRICA
Authors: Ngoie Jacques Kibambe , Zellner Arnold
Published: March 2012

Using a disaggregated Marshallian macroeconomic model, this paper investigates how the adoption of a set of “free market reforms” may affect the economic growth rate of South Africa. Our findings suggest that the institution of the proposed policy reforms would yield substantial growth in aggregate annual real GDP. The resulting annual GDP growth rate could range from 5.3% to 9.8%, depending on which variant of the reform policies was implemented.
Interannual North Equatorial Countercurrent variability and its relation to tropical Atlantic climate modes
Authors: Hormann Verena , Lumpkin Rick , Foltz Gregory R.
Published: March 2012

A synthesis product of the surface geostrophic circulation is used to quantify the interannual variability of the wind‐driven North Equatorial Countercurrent (NECC). The first mode of a complex empirical orthogonal function (CEOF) decomposition of zonal geostrophic velocity in the NECC region reveals pronounced latitudinal displacements in addition to variations in current strength. While north‐south migrations of the NECC are mainly captured by the real pattern, the imaginary pattern accounts for variations in its strength. Associated with these spatial patterns is prevailing propagation toward the northwest that is most pronounced northward of the mean NECC position (∼6°N). There is evidence that the zonal propagation characteristics are consistent with long Rossby waves forced in the northeastern tropical Atlantic. The relationship between interannual NECC variations and the tropical Atlantic climate modes is investigated through regression and composite analyses. Sea surface temperature and wind stress patterns resembling the meridional and zonal modes are found for the CEOF regression. Composite analysis further shows consistent patterns for warm phases of the meridional mode and cold phases of the zonal mode; the response of the NECC to a positive meridional and negative zonal mode event may be viewed as a northward shift of its core and a current strengthening, respectively. These results support a link between the two dominant tropical Atlantic climate modes and show that the relation between interannual NECC variability and the meridional and zonal modes can primarily be regarded as a response to changes in the wind field.
A model‐based evaluation of woody plant encroachment effects on coupled carbon and water cycles
Authors: O'Donnell F. C. , Caylor K. K.
Published: March 2012

The conversion of grasslands to shrublands by woody plant encroachment is a common occurrence in arid and semi‐arid regions that can have significant effects on ecosystem hydrology and biogeochemistry, including changes in soil organic carbon stocks. The mechanisms determining the direction and magnitude of soil carbon change due to encroachment are unknown but appear to depend on factors that vary along a gradient of mean annual precipitation. We present a model of coupled steady‐state soil moisture and carbon dynamics that accounts for the effects of structural heterogeneity at the scale of vegetation patches by representing the local effects of root systems and canopies. We applied the model to paired grasslands and woody encroachment‐produced shrublands spanning a climate gradient in the American Southwest, and model results were consistent with measured values. Modeled transpiration, which was used to determine productivity, was 5%–57% greater in shrublands, with the greatest difference occurring where the relative difference in leaf area index between grass and shrub patches was small and vegetation density was low. Patterns of soil carbon abundance were mainly driven by patterns of productivity, but decomposition rates were also affected by vegetation structure. Woody encroachment increases heterogeneity in soil carbon decomposition rates and has the net effect of increasing soil carbon residence times by 3.6–4.9 years. Our model represents an important step toward a mechanistic and quantitative understanding of the effect of vegetation structure on soil moisture and carbon dynamics and highlights the need for a better description of belowground vegetation structure in ecosystem models.
Real‐time inversion of GPS data for finite fault modeling and rapid hazard assessment
Authors: Crowell Brendan W. , Bock Yehuda , Melgar Diego
Published: March 2012

Responses to recent great earthquakes and ensuing tsunamis in Sumatra, Chile, and Japan, with the resulting loss of life and damage to infrastructure demonstrate that our ability to ascertain the full extent of slip of catastrophic earthquakes and their tsunamigenic potential in the first minutes after the initiation of rupture is problematic. Regional GPS networks such as those in western North America and Japan are complementary to seismic networks by being able to directly measure displacements close to the source during large earthquakes in real time. We report on rapid modeling of two large earthquakes, the 2003 Mw 8.3 Tokachi‐oki earthquake 100 km offshore Hokkaido Island using 356 GEONET stations and the 2010 Mw 7.2 El Mayor‐Cucapah earthquake in northern Baja California using 95 CRTN stations in southern California about 75 km northwest of the epicenter. Working in a simulated real‐time mode, we invert for finite fault slip in a homogeneous elastic half‐space using Green's functions obtained from Okada's formulation. We compare two approaches: the first starts with a catalog of pre‐defined faults, while the second uses a rapid centroid moment tensor solution to provide an initial estimate of the ruptured fault plane. In either case, we are able to characterize both earthquakes in less than two minutes, reducing the time necessary to obtain finite fault slip and moment magnitude for medium and greater earthquakes compared to traditional methods by an order of magnitude.
Management and provision of computational models
Authors: Laibe Camille
Published: March 2012

Quantitative models of biological systems provide an understanding of chemical and biological phenomena based on their underlying mechanisms. Moreover, they can be used for example, to predict the behaviour of a system under given conditions or direct future experiments. This has made quantitative models the perfect tools to answer a variety of questions in the biological sciences and has lead to a steady growth of the number of published models.To maximise the benefits of this growing body of models, the field needs centralised model repositories that will encourage, facilitate and promote model dissemination and reuse. BioModels Database(http://www.ebi.ac.uk/biomodels/) has been developed to exactly fulfil those needs. In order to ensure the correctness of the models distributed, their structure and behaviour are thoroughly checked. To ease their understanding, the model elements are annotated with terms from controlled vocabularies as well as linked to relevant data resources. Finally, to allow their reuse, the models are provided encoded in community supported and standardised formats.However, the modelling field is constantly evolving and data providers, like BioModels Database, are faced with new challenges. For example, models are getting more and more complex (with for instance the availability of whole organism metabolic network reconstructions) and this has a direct impact on the performance of hosting infrastructures and annotation procedures. Also, models are now being developed collaboratively: this requires new methodologies and systems, akin to the ones used in software development (with for example versioned repositories of models). Moreover, very different kinds of models are being developed by diverse communities, but ultimately their data management needs are very similar.This talk will introduce the needs which lead to the development of BioModels Database, present the resource and its current infrastructure and finally discuss the challenges that we are facing today and the plans to overcome them.
Associations Between Eating Frequency, Adiposity, Diet, and Activity in 9–10 year old Healthy‐Weight and Centrally Obese Children
Authors: Jennings Amy , Cassidy Aedín , van Sluijs Esther M.F. , Griffin Simon J. , Welch Ailsa A.
Published: March 2012

The rising prevalence of childhood obesity is a key public health issue worldwide. Increased eating frequency (EF) is one aspect of diet that has been beneficially associated with obesity, although the mechanisms are unclear. The aims of the current study were to determine whether increased EF was associated with improved adiposity in children, and if this was due to differences in dietary and activity behaviors. Cross‐sectional data from 1,700 children aged 9–10 year were analyzed to examine the associations between EF, as estimated from diet diaries, measures of adiposity, and activity measured by accelerometer. Analyses were stratified by obesity status using waist‐to‐height ratio to define obesity as it has been shown to be a good predictor of adverse health outcomes. Mean EF was 4.3 occasions/day and after adjustment for underreporting, energy intake (EI), and activity significant relative mean differences of −2.4% for body weight (P = 0.001), −1.0% for BMI (P = 0.020), −33% for BMI z‐score (P = 0.014), and −0.6% for waist circumference (P = 0.031) per increase in eating occasion were found in healthy‐weight but not centrally obese children. Differences between the extreme quartiles of EF were observed for total fat intake at breakfast (−18%, P < 0.001), fruit and vegetables from snacks (201% healthy‐weight and 209% centrally obese children, P < 0.01), and for healthy‐weight children, vigorous activity (4%, P = 0.003). Increased EF was favorably associated with adiposity, diet quality, and activity behaviors in healthy‐weight but not centrally obese children. Future obesity interventions should consider the mediating role of diet quality and activity in the relationship between EF and adiposity in children.
A glycosynthase derived from an inverting GH19 chitinase from the moss Bryum coronatum
Authors: Ohnuma Takayuki , Fukuda Tatsuya , Dozen Satoshi , Honda Yuji , Kitaoka Motomitsu , Fukamizo Tamo
Published: March 2012

BcChi-A, a GH19 chitinase from the moss Bryum coronatum, is an endo-acting enzyme that hydrolyses the glycosidic bonds of chitin, (GlcNAc)n [a β-1,4-linked polysaccharide of GlcNAc (N-acetylglucosamine) with a polymerization degree of n], through an inverting mechanism. When the wild-type enzyme was incubated with α-(GlcNAc)2-F [α-(GlcNAc)2 fluoride] in the absence or presence of (GlcNAc)2, (GlcNAc)2 and hydrogen fluoride were found to be produced through the Hehre resynthesis–hydrolysis mechanism. To convert BcChi-A into a glycosynthase, we employed the strategy reported by Honda et al. [(2006) J. Biol. Chem. 281, 1426–1431; (2008) Glycobiology 18, 325–330] of mutating Ser102, which holds a nucleophilic water molecule, and Glu70, which acts as a catalytic base, producing S102A, S102C, S102D, S102G, S102H, S102T, E70G and E70Q. In all of the mutated enzymes, except S102T, hydrolytic activity towards (GlcNAc)6 was not detected under the conditions we used. Among the inactive BcChi-A mutants, S102A, S102C, S102G and E70G were found to successfully synthesize (GlcNAc)4 as a major product from α-(GlcNAc)2-F in the presence of (GlcNAc)2. The S102A mutant showed the greatest glycosynthase activity owing to its enhanced F− releasing activity and its suppressed hydrolytic activity. This is the first report on a glycosynthase that employs amino sugar fluoride as a donor substrate.
Free radical biology of the cardiovascular system
Authors: Chen Alex F. , Chen Dan-Dan , Daiber Andreas , Faraci Frank M. , Li Huige , Rembold Christopher M. , Laher Ismail
Published: March 2012

Most cardiovascular diseases (CVDs), as well as age-related cardiovascular alterations, are accompanied by increases in oxidative stress, usually due to increased generation and/or decreased metabolism of ROS (reactive oxygen species; for example superoxide radicals) and RNS (reactive nitrogen species; for example peroxynitrite). The superoxide anion is generated by several enzymatic reactions, including a variety of NADPH oxidases and uncoupled eNOS (endothelial NO synthase). To relieve the burden caused by this generation of free radicals, which also occurs as part of normal physiological processes, such as mitochondrial respiratory chain activity, mammalian systems have developed endogenous antioxidant enzymes. There is an increased usage of exogenous antioxidants such as vitamins C and E by many patients and the general public, ostensibly in an attempt to supplement intrinsic antioxidant activity. Unfortunately, the results of large-scale trails do not generate much enthusiasm for the continued use of antioxidants to mitigate free-radical-induced changes in the cardiovascular system. In the present paper, we review the clinical use of antioxidants by providing the rationale for their use and describe the outcomes of several large-scale trails that largely display negative outcomes. We also describe the emerging understanding of the detailed regulation of superoxide generation by an uncoupled eNOS and efforts to reverse eNOS uncoupling. SIRT1 (sirtuin 1), which regulates the expression and activity of multiple pro- and anti-oxidant enzymes, could be considered a candidate molecule for a ‘molecular switch’.
Evidence of stable high-temperature Dx-CO intermediates on the Ru(0001) surface
Authors: Ueta Hirokazu , Groot Irene M. N. , Juurlink Ludo B. F. , Kleyn Aart W. , Gleeson Michael A.
Published: March 2012

We demonstrate the formation of complexes involving attractive interactions between D and CO on Ru(0001) that are stable at significantly higher temperatures than have previously been reported for such intermediate species on this surface. These complexes are evident by the appearance of new desorption features upon heating of the sample. They decompose in stages as the sample temperature is increased, with the most stable component desorbing at >500 K. The D:CO ratio remaining on the surface during the final stages of desorption tends towards 1:1. The new features are populated during normally incident molecular beam dosing of D2 on to CO pre-covered Ru(0001) surfaces (180 K) when the CO coverage exceeds 50% of the saturation value. The amount of complex formed decreases somewhat with increasing CO pre-coverage. It is almost absent in the case of dosing on to the fully saturated surface. The results are interpreted in terms of both local and long-range rearrangements of the overlayer that give rise to the observed CO coverage dependence and limit the amount of complex that can be formed.
Tailoring chirp in spin-lasers
Authors: Boéris Guilhem , Lee Jeongsu , Výborný Karel , Žutić Igor
Published: March 2012

The usefulness of semiconductor lasers is often limited by the undesired frequency modulation, or chirp, a direct consequence of the intensity modulation, and carrier dependence of the refractive index in the gain medium. In spin-lasers, realized by injecting, optically or electrically, spin-polarized carriers, we elucidate paths to tailoring chirp. We provide a generalized expression for chirp in spin-lasers and introduce modulation schemes that could simultaneously eliminate chirp and enhance the bandwidth, as compared to the conventional (spin-unpolarized) lasers.
Discontinuous structure transition in a Debye cluster
Authors: Sheridan T. E.
Published: March 2012

We consider the structural phases of a cluster of identical particles confined in a two-dimensional biharmonic well and interacting through a screened Coulomb (Yukawa) potential (e.g., dusty plasma). For n = 6 particles, we show that there are one discontinuous and three continuous structure transitions, giving five structure phases. Two of these phases, the straight line and zigzag configurations, have previously been studied experimentally. We experimentally verify the discontinuous transition and observe the remaining three phases.
High-charge energetic electron bunch generated by 100 TW laser pulse
Authors: Shen Baifei , Wu Yuchi , Dong Kegong , Zhu Bin , Gu Yuqiu , Ji Liangliang , Jiao Chunye , Teng Jian , Hong Wei , Zhao Zhongqing , Cao Leifeng , Wang Xiaofang , Yu M. Y.
Published: March 2012

Energetic electron bunches with more than 20 nC charge are generated from 100 TW level laser pulse interaction with 2% critical density plasma. Three-dimensional particle-in-cell simulations show that the unexpected high bunch-charge can be attributed to the multiple intensity peaks of the laser pulse and the resulting multiple-bubble wake structure. This charge is one of the highest among experiments on electron-bunch generation by laser-plasma interaction. Such highly charged ultra-short electron bunches are crucial for producing sufficiently bright Bremsstrahlung x-rays required in high-resolution flash radiography of large samples.
Bipolar pulsed excitation of erbium-doped nanosilicon light emitting diodes
Authors: Anopchenko A. , Tengattini A. , Marconi A. , Prtljaga N. , Ramírez J. M. , Jambois O. , Berencén Y. , Navarro-Urrios D. , Garrido B. , Milesi F. , Colonna J.-P. , Fedeli J.-M. , Pavesi L.
Published: March 2012

High quantum efficiency erbium doped silicon nanocluster (Si-NC:Er) light emitting diodes (LEDs) were grown by low-pressure chemical vapor deposition (LPCVD) in a complementary metal-oxide-semiconductor (CMOS) line. Erbium (Er) excitation mechanisms under direct current (DC) and bipolar pulsed electrical injection were studied in a broad range of excitation voltages and frequencies. Under DC excitation, Fowler-Nordheim tunneling of electrons is mediated by Er-related trap states and electroluminescence originates from impact excitation of Er ions. When the bipolar pulsed electrical injection is used, the electron transport and Er excitation mechanism change. Sequential injection of electrons and holes into silicon nanoclusters takes place and nonradiative energy transfer to Er ions is observed. This mechanism occurs in a range of lower driving voltages than those observed in DC and injection frequencies higher than the Er emission rate.
Spin current and polarization reversal through a single-molecule magnet with ferromagnetic electrodes
Authors: Xie Haiqing , Wang Qiang , Chang Bo , Jiao Hujun , Liang J.-Q.
Published: March 2012

We theoretically study the spin-polarized transport through a single-molecule magnet, which is weakly coupled to ferromagnetic leads, by means of the rate-equation approach. We consider both the ferromagnetic and antiferromagnetic exchange-couplings between the molecular magnet and transported electron-spin in the nonlinear tunneling regime. For the ferromagnetic exchange-coupling, spin current exhibits step- and basin-like behaviors in the parallel and antiparallel configurations respectively. An interesting observation is that the polarization reversal of spin-current can be realized and manipulated by the variation of bias voltage in the case of antiferromagnetic exchange-coupling with antiparallel lead-configuration, which may be useful in the development of spintronic devices, while the bias voltage can only affect the magnitude of spin-polarization in the ferromagnetic coupling.
Towards a state minimizing the output entropy of a tensor product of random quantum channels
Authors: Collins Benoît , Fukuda Motohisa , Nechita Ion
Published: March 2012

We consider the image of some classes of bipartite quantum states under a tensor product of random quantum channels. Depending on natural assumptions that we make on the states, the eigenvalues of their outputs have new properties which we describe. Our motivation is provided by the additivity questions in quantum information theory, and we build on the idea that a Bell state sent through a product of conjugated random channels has at least one large eigenvalue. We generalize this setting in two directions. First, we investigate general entangled pure inputs and show that Bell states give the least entropy among those inputs in the asymptotic limit. We then study mixed input states, and obtain new multi-scale random matrix models that allow to quantify the difference of the outputs’ eigenvalues between a quantum channel and its complementary version in the case of a non-pure input.
Infrared thermometry and interferential microscopy for analysis of crater formation at the surface of fused silica under CO2 laser irradiation
Authors: Robin Lucile , Combis Patrick , Cormont Philippe , Gallais Laurent , Hebert David , Mainfray Christelle , Rullier Jean-Luc
Published: March 2012

In situ spatial and temporal temperature measurements of a fused silica surface heated by a 10.6 μm CO2 laser were performed using an infrared camera. These measurements were derived from heat flux emission of the fused silica. High temperature measurements—in the range 400–2500 K—were performed at the surface of a semi-transparent media with a high spatial resolution. Particular attention was given to the experimental conception and to the calibration of the infrared device. Moreover, both conventional and interferential microscopes were used to characterize the silica surfaces after CO2 laser irradiation. By associating these results with thermal camera measurements we identified the major surface temperature levels of silica transformation when heated during 250 ms. Surface deformation of silica is observed for temperatures <2000 K. This is consistent with other recent work using CO2 laser heating. At higher temperatures, matter ejection, as deduced from microscope observations, occurs at temperatures that are still much lower than the standard boiling point. Such evaporation is described by a thermodynamical approach, and calculations show very good agreement with experiment.
Elastic-plastic behavior of cyclotrimethylene trinitramine single crystals under spherical indentation: Modeling and simulation
Authors: Clayton J. D. , Becker R.
Published: March 2012

A nonlinear anisotropic elastic-plastic model is developed for single crystals of the energetic material cyclotrimethylene trinitramine (RDX). Numerical simulations of spherical indentation on oriented single crystals are performed; predictions are compared with experimental data and observations from the literature. Model predictions for elastic response and initial yield using elastic constants obtained from resonant ultrasound spectroscopy agree with experimental data; predicted forces using constants obtained from Brillouin scattering tend to exceed experimental data. Influences of elastic anisotropy and elastic nonlinearity are significant. Predicted slip system activity is in reasonable agreement with that deduced from experimental surface profiles when a uniform strength of G/20 is assigned to all six slip systems, with G an effective elastic shear modulus. Predicted indentation forces in the post-yield regime exceed those observed in experiments, suggesting that surface and possibly subsurface fractures may contribute to a loss of stiffness in experiments at larger indentation depths.
Electroforming and Ohmic contacts in Al-Al2O3-Ag diodes
Authors: Hickmott T. W.
Published: March 2012

Electroforming of metal-insulator-metal (MIM) diodes is a non-destructive dielectric breakdown process that changes the diode from its initial high resistance state (HRS) to a low resistance state (LRS). After electroforming, resistance switching memories (RSMs) use voltages to switch from HRS to LRS and back. Many MIM combinations are proposed for use in RSMs. In many cases conduction in the LRS is nearly temperature independent at low temperatures; an Ohmic contact with a barrier to electron injection of ∼0 eV results from electroforming. Electroforming of Al-Al2O3-Ag diodes with amorphous anodic Al2O3 thicknesses between 12 and 41 nm has been studied. Two anodizing electrolytes have been used; 0.1 M ammonium pentaborate (bor-H2O) and a solution of 0.1 M of ammonium pentaborate per liter of ethylene glycol (bor-gly). Polarization of Al2O3 and negative charge in Al2O3 are much larger when Al2O3 is formed in bor-H2O solution than when Al is anodized in bor-gly solution. Electroforming of Al-Al2O3-Ag diodes results in an Ohmic contact at the Al-Al2O3 interface, voltage-controlled negative resistance (VCNR) in the current-voltage (I–V) characteristics, electroluminescence (EL), and electron emission into vacuum (EM) from filamentary conducting channels. Two distinct modes of electroforming occur for Al-Al2O3-Ag diodes. α-forming occurs for 2.5 V ≲ VS ≲ 5 V, where VS is the applied voltage. It is characterized by an abrupt current jump with the simultaneous appearance of EL and EM. β-forming occurs for VS ≳ 7 V. I–V curves, EL, and EM develop gradually and are smaller than for α-forming. Electroforming occurs more readily for diodes with Al2O3 formed in bor-H2O that have greater defect densities. Fully developed I-V curves have similar VCNR, EL, and EM after α-forming or β-forming. A model is proposed in which excited states of F-centers, oxygen vacancies in amorphous anodic Al2O3, form defect conduction bands. Electroforming that results in an Ohmic contact requires injection of positive charge at the Al-Al2O3 interface. α-forming is the result of ionization of F-center recombination centers with energies that are close to the Al Fermi level. Hole injection by high-field ionization of valence band states of Al2O3 causes β-forming.
Electrostatically coupled vibration modes in unimorph complementary microcantilevers
Authors: Lebedev V. , Heidrich N. , Knöbber F. , Sah R. E. , Pletschen W. , Raynor B. , Polyakov V. , Cimalla V. , Ambacher O.
Published: March 2012

To extend the tuning capabilities of radio frequency devices, coupled microelectromechanical systems are often employed. In this letter, we demonstrate piezoelectrically actuated, electrically tuneable resonator systems based on coupled micromechanical oscillators operating in a flexural vibration mode. The substantial enhancement in electrostatic coupling was achieved due to the implementation of lateral nanogaps of 100-200 nm between single resonator bars. This allows for resonator synchronization and precise system frequency tuning by over a factor of two, relative to its initial value. Additionally, a simple electro-mechanical model has been developed to describe the dynamic behavior of the electrostatically coupled oscillators.
A comparative study of the low energy HD+o-/p-H2 rotational excitation/de-excitation collisions and elastic scattering
Authors: Sultanov Renat A. , Guster Dennis , Adhikari S. K.
Published: March 2012

The Diep and Johnson (DJ) H2-H2 potential energy surface (PES) obtained from the first principles [P. Diep, K. Johnson, J. Chem. Phys. 113, 3480 (2000); P. Diep, K. Johnson, J. Chem. Phys. 114, 222 (2000)], has been adjusted through appropriate rotation of the three-dimensional coordinate system and applied to low-temperature (T < 300 K) HD+o-/p-H2 collisions of astrophysical interest. A non-reactive quantum mechanical close-coupling method is used to carry out the computation for the total rotational state-to-state cross sections \documentclass[12pt]{minimal}\begin{document}$\sigma _{j_1j_2\rightarrow j^{\prime }_1j^{\prime }_2}(\epsilon )$\end{document}σj1j2→j1′j2′(ε) and corresponding thermal rate coefficients \documentclass[12pt]{minimal}\begin{document}$k_{j_1j_2\rightarrow j^{\prime }_1j^{\prime }_2}(T)$\end{document}kj1j2→j1′j2′(T). A rather satisfactory agreement has been obtained between our results computed with the modified DJ PES and with the newer H4 PES [A. I. Boothroyd, P. G. Martin, W. J. Keogh, M. J. Peterson, J. Chem. Phys. 116, 666 (2002)], which is also applied in this work. A comparative study with previous results is presented and discussed. Significant differences have been obtained for few specific rotational transitions in the H2/HD molecules between our results and previous calculations. The low temperature data for \documentclass[12pt]{minimal}\begin{document}$k_{j_1j_2\rightarrow j^{\prime }_1j^{\prime }_2}(T)$\end{document}kj1j2→j1′j2′(T) calculated in this work can be used in a future application such as a new computation of the HD cooling function of primordial gas, which is important in the astrophysics of the early Universe.
The proteomes of Sydney rock oysters vary spatially according to exposure to acid sulfate runoff
Authors: Amaral Valter , Thompson Emma L. , Bishop Melanie J. , Raftos David A.
Published: March 2012

Runoff from acid sulfate soils (ASS) has severe environmental and economic impacts on estuarine ecosystems. Oysters display reduced abundance, growth rate and shell thickness when exposed to ASS runoff, yet the molecular underpinnings of their responses have not been explored. We hypothesised that the proteomes of wild Sydney rock oysters, Saccostrea glomerata, would differ between populations recurrently exposed to ASS compared with those unaffected by runoff from ASS. We used two-dimensional electrophoresis to compare protein abundances in the gills of S. glomerata collected from two sites close to (acidified) and two sites away from (reference) major ASS outflow drains in a south-east Australian estuary. Approximately 5% of the proteome was differentially expressed between oysters from acidified and reference sites, with five protein spots more abundant and one less abundant at the sites close to drains. Another protein spot was present only in oysters from reference sites. This study is the first screening of spatial variation in the protein expression of S. glomerata with respect to discharge from ASS. Altered protein expression may underpin short-term inducible responses to ASS runoff, or genetic resistance acquired through recurrent exposure of populations to the stressor.
Breeding to improve grain yield in water-limited environments: the CSIRO experience with wheat.
Authors: Richards R. A. , Rebetzke G. J. , Condon A. G. , Watt M.
Published: March 2012

In this chapter, the traits of wheat (including xylem vessel diameter of seminal roots, tiller inhibition, early seedling vigour, gibberellic acid-responsive dwarfing genes, extended vegetative growth, root growth and architecture, waxiness/glaucousness, transpiration efficiency, stem carbohydrate storage and remobilization and leaf-rolling) studied by CSIRO (Commonwealth Scientific and Industrial Research Organisation) are described, together with an outline of the environments where they are likely to be most effective, ways to select for them, results of validation, proof-of-concept tests and whether they are currently incorporated in breeding programmes. These traits are shown in a table, together with the components of the Passioura identity (Water use × Water-use efficiency × Harvest index) that are likely to be increased so that grain yield may be increased.
Molecular breeding for a changing climate: bridging ecophysiology and molecular biology.
Authors: Tuberosa R. , Maccaferri M. , Colalongo C. , Salvi S.
Published: March 2012

Th is chapter surveys how genomics approaches have helped to elucidate the genetic basis of crop performance under abiotic constraints, such as drought, salinity, soil toxicity and low nutrients. Additionally, the review shows how this information has been used in breeding programmes to improve crop performance and how it might help agriculture better to withstand the negative effects of climate change. Future perspectives are given.
Crop management to cope with global change: a systems perspective aided by information technologies.
Authors: McMaster G. S. , Ascough J. C., II
Published: March 2012

This chapter provides a general overview on the diversity of information technologies and how these technologies have captured knowledge related to assessing crop-ecophysiological responses to global change. Emphasis is given on information technologies related to crop simulation models, decision support technology, integrated assessment technology, and some critical information databases. The adoption and application of these technologies to explore opportunities and risks in crop management are discussed.
3,5-Bis(adamantan-1-yl)-1-methoxybenzene
Authors: Li Peng-Fei , Sun Jian-Zi , Wang Ling , Lv Ya-Li , Liu Li-Hong
Published: March 2012

In title compound, C27H36O, all cyclohexane rings within the adamantyl groups adopt chair conformations. There are no obvious intermolecular hydrogen bonds in the structure, so that van der Waals attractions stabilize the crystal.
1,3-Bis(1-phenylethyl)imidazolidine-2-thione
Authors: Umar M. Naveed , Tahir M. Nawaz , Shoaib Mohammad , Ali Akbar , Khan Imran
Published: March 2012

The complete molecule of the title compound, C19H22N2S, is generated by crystallographic twofold symmetry with the C=S group lying on the rotation axis. The imidazolidine ring adopts a flattened twist conformation. The dihedral angle between the asymmetric part of the imidazolidine-2-thione fragment and the benzene ring is 89.49 (17)°.
R‐SNARE ykt6 resides in membrane‐associated protease‐resistant protein particles and modulates cell cycle progression when over‐expressed
Authors: Thayanidhi Nandhakumar , Liang Yingjian , Hasegawa Haruki , Nycz Deborah C. , Oorschot Viola , Klumperman Judith , Hay Jesse C.
Published: March 2012

Background information

The arginine‐type soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (R‐SNARE) ykt6 possesses several atypical properties including selective high expression in neurons, a lipidated C‐terminus, localization to punctae that do not correspond with known endomembrane markers, a potent ability to protect the secretory pathway from alpha‐synuclein over‐expression and specific up‐regulation in tumors. We have followed up on several of these features that together suggest nontraditional SNARE structures and functions.

Results

A significant portion of ykt6 in PC12 cells was found in a protease‐resistant state suggestive of a large complex or aggregate. Other endoplasmic reticulum/Golgi SNAREs were not protease resistant, demonstrating that SNARE complexes per se did not cause protease resistance. Mutagenesis indicated that lipidation of the ykt6 C‐terminus was also not involved, implicating its longin domain in particle formation. Immunogold electron microscopy revealed ykt6 labeling of ∼100 nm electron densities associated with diverse membranes. Density gradient analysis of the protease‐resistant structures confirmed their tight association with membranes. Since excess ykt6 has been correlated with tumorigenesis, we tested whether ykt6 over‐expression in normal rat kidney cells that normally express little ykt6 affected the cell cycle. Ykt6 over‐expression was found to result in altered cell division cycles as evidenced by significantly smaller cells, a higher mitotic index and increased DNA synthesis. Mutagenesis studies dis‐correlated SNARE function with the cell cycle effects; instead, the cell cycle effects correlated better with ykt6 properties related to the longin domain or particle formation.

Conclusions

The ykt6 particles/aggregates may represent ykt6 engaged in a non‐SNARE function(s) or else nonfunctional, stored and/or excess ykt6. Whether the particulate ykt6 structures represent a means of buffering the apparent proliferative activity or are in fact mechanistically related to this activity will be of future interest in neuroscience and cancer biology.
Stable‐isotope analysis of a deep‐sea benthic‐fish assemblage: evidence of an enriched benthic food web
Authors: Boyle M. D. , Ebert D. A. , Cailliet G. M.
Published: March 2012

In this study, fishes and invertebrates collected from the continental slope (1000 m) of the eastern North Pacific Ocean were analysed using stable‐isotope analysis (SIA). Resulting trophic positions (TP) were compared to known diets and habitats from the literature. Dual isotope plots indicated that most species groups (invertebrates and fishes) sorted as expected along the carbon and nitrogen axes, with less intraspecific variability than interspecific variability. Results also indicated an isotopically distinct benthic and pelagic food web, as the benthic food web was more enriched in both nitrogen and carbon isotopes. Trophic positions from SIA supported this finding, resulting in the assignment of fishes to different trophic positions from those expected based on published dietary information. These differences can be explained largely by the habitat of the prey and the percentage of the diet that was scavenged. A mixing model estimated dietary contributions of prey similar to those of the known diet of Bathyraja trachura from stomach‐content analysis (SCA). Linear regressions indicated that trophic positions calculated from SIA and SCA, when plotted against B. trachura total length for 32 individuals, exhibited similar variation and patterns. Only the TP from SCA yielded significant results (stomach content: P < 0·05, stable isotope: P > 0·05).
Interstitial 9q deletion in T‐lymphoid/myeloid biphenotypic leukaemia
Authors: Akashi Koichi , Shibuya Tsunefumi , Harada Mine , Oogami Akiko , Teshima Takanori , Takamatsu Yasushi , Kikuchi Masahiro , Niho Yoshiyuki
Published: March 2012

Summary. We report the biological characteristics of leukaemic blasts from two cases of acute leukaemia with an interstitial deletion of the long arm of chromosome 9 (9q−). Case 1 (FAB: M1) showed del(9)(q12q22) as the sole karyotypic anomaly, and case 2 (FAB: M1) presented del(9) (q12q22) in association with trisomy 10. In both cases, leukaemic blasts presented unique cytological features, such as prominent vacuoles on Giemsa staining, or strong localization of myeloperoxidase resembling ‘pseudo‐Chediak‐Higashi’ granules. Immunophenotyping of blasts revealed the biphenotypic expression of T‐lymphoid/myeloid antigens (CD2, CD7/CD33) in addition to CD34. Neither T‐cell receptor β (TCRB), T‐cell receptor γ (TCRG) nor Ig heavy chain (IGH) genes were clonally rearranged. Furthermore, there was neither rearrangement nor expression of ABL, which is located at 9q34, indicating that the deletion involved bands centrometric to 9q34 did not induce the activation of ABL. DNA synthesis of the blasts was stimulated (stimulation index > 2·0) in the presence of interleukin (IL)‐3, IL‐4, granulocyte colony‐stimulating factor or erythropoietin (Epo). IL‐3 and IL‐4 could also support the in vitro growth of leukaemic blast colonies, and the IL‐3‐ or IL‐4‐dependent blast colony growth was synergistically enhanced by the addition of IL‐6 or Epo. These observations imply that T‐lymphoid/myeloid or pluripotent stem cells may be closely involved in the development of 9q− AML.
Vascular architecture and collagen type IV in primary myelofibrosis and polycythaemia vera: an immunomorphometric study on trephine biopsies of the bone marrow
Authors: Thiele Juergen , Rompcik Volker , Wagner Stephan , Fischer Robert
Published: March 2012

Summary. Using a monoclonal antibody against collagen type IV, an immunohistochemical and morphometric study was performed on trephine biopsies of the bone marrow to determine the vascular architecture of the myeloid stroma as well as the occurrence of subendothelial collagen type IV deposits. In comparison with a control group (20 patients), we investigated specimens from 20 patients with polycythaemia vera (P. vera) and 40 patients showing primary (idiopathic) osteomyelofibrosis/‐sclerosis (OMF). Morphometric analysis disclosed a significant increase in the number of sinusoids and also in the extent of collagen type IV deposits in the latter disorder. Sinusoids of P. vera showed only a dilatation of their lumina corresponding with enlarged areas of sectioned vascular profiles. Contrary to this finding, in OMF sinusoidal distension was accompanied by an excessive deviation from a circular profile and prominent intravascular haematopoiesis. Furthermore, there was a significant formation of basement membrane collagen (collagen type IV). All these features were far less pronounced in early hypercellular stages of OMF than in the late fibro‐osteosclerotic subtypes. Our morphometric findings confirm haemodynamic studies on advanced stages of OMF which revealed an increased vascularity. Moreover, these results are in keeping with the assumption that angiogenesis in the evolution of the fibro‐osteosclerotic marrow process is mediated by certain growth factors. The increase in collagen type IV formation is thought to be generated by the pronounced endothelial cell proliferation in the course of neovascularization.
Degree of dental anxiety in children with and without toothache: prospective assessment
Authors: RAMOS‐JORGE JOANA , MARQUES LEANDRO S. , HOMEM MÁRCIO A. , PAIVA SAUL M. , FERREIRA MEIRE C. , OLIVEIRA FERREIRA FERNANDA , RAMOS‐JORGE MARIA L.
Published: March 2012

International Journal of Paediatric Dentistry 2013; 23: 125–130

Background.  Few prospective studies on the anxiety of children in the dental office have been published.

Aims.  To monitor dental anxiety levels in children with and without previous experience with toothache over a period of six consecutive visits.

Design.  A longitudinal study was carried out involving 167 children treated at a public dental service. Levels of anxiety in the dental setting were assessed in children without toothache (G1) and those with toothache (G2) using the modified Venham picture test (VPT). Data acquisition was carried out over a 6‐week period, with each child treated in the dental office once a week. Six assessments of anxiety were performed in the waiting room prior to dental treatment.

Results.  A significant reduction in anxiety scores occurred between appointments in both groups. In the inter‐group comparison, G2 had significantly higher anxiety scores than G1. Although statistically significant reductions in anxiety scores occurred through to the fifth appointment, a tendency toward stagnation in anxiety scores was observed beginning with the fourth appointment.

Conclusions.  Dental anxiety scores were reduced over the course of six appointments. Children with toothache had higher levels of dental anxiety than those that had never experienced toothache.
The promoter architectural landscape of the Salmonella PhoP regulon
Authors: Zwir Igor , Latifi Tammy , Perez J. Christian , Huang Henry , Groisman Eduardo A.
Published: March 2012

The DNA‐binding protein PhoP controls virulence and Mg2+ homeostasis in the Gram‐negative pathogen Salmonella enterica serovar Typhimurium. PhoP regulates expression of a large number of genes that differ both in their ancestry and in the biochemical functions and physiological roles of the encoded products. This suggests that PhoP‐regulated genes are differentially expressed. To understand how a bacterial activator might generate varied gene expression behaviour, we investigated the cis‐acting promoter features (i.e. the number of PhoP binding sites, as well as their orientation and location with respect to the sites bound by RNA polymerase and the sequences that constitute the PhoP binding sites) in 23 PhoP‐activated promoters. Our results show that natural PhoP‐activated promoters utilize only a limited number of combinations of cis‐acting features – or promoter architectures. We determine that PhoP activates transcription by different mechanisms, and that ancestral and horizontally acquired PhoP‐activated genes have distinct promoter architectures.