bluuebunny/crossref_metadata_2025 huggingface dataset:
First multi‐scale, finite‐frequency tomography illuminates 3‐D anatomy of the Tibetan Plateau
Authors: Hung Shu‐Huei , Chen Wang‐Ping , Chiao Ling‐Yun , Tseng Tai‐Lin
Published: March 2010

With a new multi‐scale parameterization, 3‐D images from finite‐frequency seismic tomography, including the very first images beneath central Tibet from S‐waves, reveal that regions of low electric resistivity in the crust, previously observed along active rifts in southern Tibet, correlate well with regions of low P‐ and S‐wave speeds (V). However, such regions are not interconnected, indicating that a prevailing south‐directed, channel‐like crustal flow seems inactive or this popular geodynamic model needs modification. In the upper mantle, there is no clear indication of regional down‐welling between depths of 100 to 400 km. Instead, a strong, lateral boundary between high and low V extends up to 33°N, marking the northern limit of sub‐horizontally advancing Indian lithospheric mantle.
Tree ring precipitation reconstruction in the Chifeng‐Weichang region, China, and East Asian summer monsoon variation since A.D. 1777
Authors: Liu Yu , Tian Hua , Song Huiming , Liang Jianming
Published: March 2010

The total precipitation of previous August to current July was reconstructed on the basis of the Pinus tabulaeformis ring widths from three sites in Chifeng and Weichang regions, China, for the past 236 years. The explained variance of reconstruction is 47.4%. The intervals with below‐average precipitation (1768–2003) comprise 1779–1806, 1853–1883, 1926–1972, and 1980–1989. The intervals with above average precipitation consist of 1807–1852, 1884–1925, 1973–1979, and 1990–1999. Precipitation in the study area is dependent on the East Asian summer monsoon strength. The reconstructed series is significantly correlated with the average dryness/wetness index series of Datong and Beijing, as well as with previous results from Baiyinaobao, Helan Mountains, and even the state of Mongolia. A significant negative correlation (r = −0.63, p < 0.0001) is also found between the reconstruction and our previously reconstructed temperatures of Weichang for the period 1884–2002. Our result suggests that the variations of the East Asian summer monsoon on a decadal scale are coincident with the other regions within the environmentally sensitive zone of northern China as well as Mongolia for the past 236 years, and our reconstruction is representative of regional climate patterns.
On the practical applicability of the VPMS routing method for rating curve development at ungauged river sites
Authors: Perumal Muthiah , Moramarco Tommaso , Sahoo Bhabagrahi , Barbetta Silvia
Published: March 2010

This paper presents a novel approach for enhancing the accuracy of the variable parameter Muskingum stage hydrograph routing method proposed by Perumal et al. (2007) for rating curve development at ungauged river sites having irregular cross sections. The approach has been well tested for the reproduction of stage and discharge hydrographs and for rating curve development at an ungauged section of the Tiber River in central Italy considering two different natural channel reaches.
A rapid, global and prolonged electron radiation belt dropout observed with the Global Positioning System constellation
Authors: Morley S. K. , Friedel R. H. W. , Cayton T. E. , Noveroske E.
Published: March 2010

A rapid loss of energetic (>230 keV) electrons from the outer radiation belt was observed with the GPS constellation between 1430 and 1730 UTC on 7 May 2007. The rapid loss occurred from 4 < L* < 6 over all measured energies above 230 keV. Currently accepted rapid loss mechanisms include magnetopause shadowing and/or outward diffusion, and precipitation to the atmosphere due to wave‐particle interactions. Here the loss timescale is ∼2 hr, and the magnetopause is near L = 8, which requires unrealistically high outward diffusion rates. Current estimates of the loss timescales associated with EMIC waves, plasmaspheric hiss and whistler‐mode chorus are too long, even in combination, to explain the observed losses inside L* ≃ 6.
Conductin/axin2 and Wnt signalling regulates centrosome cohesion
Authors: Hadjihannas Michel V , Brückner Martina , Behrens Jürgen
Published: March 2010

Activated Wnt/β‐catenin signalling is a characteristic of many cancers and drives cell‐cycle progression. Here, we report a mechanism linking Wnt/β‐catenin signalling to centrosome separation. We show that conductin/axin2, a negative regulator of β‐catenin, localizes at the centrosomes by binding to the centriole‐associated component C‐Nap1. Knockout or knockdown of conductin leads to premature centrosome separation—that is, splitting—which is abolished by knockdown of β‐catenin. Conductin promotes phosphorylation of the amino‐terminal serine (Ser 33/37) and threonine (Thr 41) residues of centrosome‐associated β‐catenin. β‐Catenin mutated at these residues causes centrosomal splitting, whereas a phospho‐mimicking mutant of β‐catenin does not. Importantly, β‐catenin‐induced splitting is not inhibited by blocking β‐catenin‐dependent transcription. Treatment with Wnts and inhibition of glycogen synthase kinase 3 block β‐catenin phosphorylation and induce centrosomal splitting. These data indicate that Wnt/β‐catenin signalling and conductin regulate centrosomal cohesion by altering the phosphorylation status of β‐catenin at the centrosomes.
Zero sense in European approach to GM
Authors: Wager Robert , McHughen Alan
Published: March 2010

The EU not only has banned the growing of nearly all GM crops but also refuses to import most GM plants and plant products. As Robert Wager and Alan McHughen argue, this may have dramatic consequences for the European livestock industry and European consumers as the rest of the world grows more and more GM crops.
Metabolism and cancer mix in Madrid
Authors: Shaw Reuben J
Published: March 2010

The CNIO Cancer Conference ‘The Energy of Cancer’ held last November was a bridge between metabolic and cancer research, emphasizing the interdisciplinary nature of the field. It confirmed that the outlines of the main pathways involved in coordinating nutrient uptake and metabolism with cell growth have begun to emerge.
Autotransplantations dentaires
et orthodontie
Authors: Mockers O. , Roche P. , Catherine J.H.
Published: March 2010

L’amélioration considérable au cours de ces deux dernières décennies des techniques
d’autotransplantation dentaire fait qu’une transplantation doit être considérée actuellement
comme un acte chirurgical fiable. La réalisation de transplantations dentaires est particulièrement
indiquée dans une population jeune et de nombreuses situations cliniques
peuvent engendrer des indications d’autotransplantation au sein du plan de traitement
orthodontique. Quatre cas cliniques d’autotransplantation de molaires, prémolaires et
canines illustrent notre propos.
Signal-to-noise ratios in high-signal-transfer-rate read heads composed of spin-torque oscillators
Authors: Mizushima K. , Kudo K. , Nagasawa T. , Sato R.
Published: March 2010

An application of spin-torque oscillators (STOs) to high-signal-transfer-rate read heads beyond 3 Gbits/s is considered and the signal-to-noise ratios (SNRs) of the output signals under the thermal magnetization fluctuations are calculated by using the results of recent nonlinear theories. The STO head senses the media field as a modulation in the oscillation frequency, enabling high signal transfer rates beyond the limit of ferromagnetic relaxation. The output (digital) signal is obtained by frequency modulation (FM) detection, which is commonly used in communication technologies. As the problem of rapid phase diffusion in nonlinear STOs caused by the thermal fluctuations is overcome by employing a delay detection method, the sufficiently large SNRs are obtained even in nonlinear STOs less than 30×30 nm2 in size.
Dielectric function of quantum dots in the strong confinement regime
Authors: Holmström P. , Thylén L. , Bratkovsky A.
Published: March 2010

The complex dielectric function of quantum dots (QDs) with a core-shell structure is modeled in the strong confinement regime. These results should be useful for the design of negative epsilon optical metamaterials, where the gain due to QDs could be an essential ingredient. Using the dielectric function it is also shown that conventional expressions for the gain substantially overestimate it for narrow linewidths.
Indecomposable representations of the Diamond Lie algebra
Authors: Casati Paolo , Minniti Stefania , Salari Valentina
Published: March 2010

We study classes of indecomposable representations of the Diamond Lie algebra: a four-dimensional solvable Lie algebra, which is the central extension of the Poincaré Lie algebra in two dimensions. These representations are obtained first (inspired by Douglas and Premat [Commun. Algebra 35, 1433 (2007)]) by embedding the Diamond Lie algebra in the simple Lie algebras A2 and C2, and then by regarding it as a subalgebra of a truncated current Lie algebra.
Random attractors for first order stochastic retarded lattice dynamical systems
Authors: Yan Weiping , Li Yong , Ji Shuguan
Published: March 2010

This paper is concerned with the existence of random attractors for a general first order stochastic retarded lattice dynamical systems. It shows that, under suitable dissipative conditions, such a system possesses a random attractor which is a random compact invariant set. Furthermore, the ergodicity of the system is also proven.
Bounds on diatomic molecules in a relativistic model
Authors: Gilka Natalie
Published: March 2010

We consider diatomic systems in which the kinetic energy of the electrons is treated in a simple relativistic model. The Born–Oppenheimer approximation is assumed. We investigate questions of stability, deducing bounds on the number N of electrons, the binding energy ΔEb, and the equilibrium bond distance R0. We use a known localization argument adopted to the present relativistic setting, with particular consideration of the critical point of stability, as well as the recently proved relativistic Scott correction.
Evolution of barrier-resistance noise in CoFeB/MgO/CoFeB tunnel junctions during annealing
Authors: Stearrett Ryan , Wang W. G. , Shah L. R. , Gokce Aisha , Xiao J. Q. , Nowak E. R.
Published: March 2010

The low-frequency resistance noise in sputtered-deposited magnetic tunnel junctions with MgO barriers has been measured as a function of annealing time at different annealing temperatures. The noise has a 1/f spectrum and it is quantified by a Hooge-like parameter α given in units of μm2. Unannealed devices have the highest noise levels and their α parameters exhibit a pronounced dependence on the voltage bias across the junction. A significant increase in tunneling magnetoresistance (TMR) is observed for short annealing times (on the order of minutes) at high temperatures and it is correlated with a large reduction in noise and in its bias dependence. The maximum TMR and minimum noise levels are reached at a later time that depends on temperature, being shorter at higher annealing temperatures. Devices annealed at 380 and at 430 °C exhibit the same minimum noise levels, α≈2×10−10 μm2. The origin of the resistance noise, its annealing time evolution, and its bias dependence are discussed and they are attributed to vacancy defects in the MgO barriers.
Correlated d ferromagnetism and photoluminescence in undoped ZnO nanowires
Authors: Xing Guozhong , Wang Dandan , Yi Jiabao , Yang Lili , Gao Ming , He Mi , Yang Jinghai , Ding Jun , Sum Tze Chien , Wu Tom
Published: March 2010

We report the correlated d0 ferromagnetism and photoluminescence in undoped single-crystalline ZnO nanowires synthesized by using a vapor transport method. We systematically tune the oxygen deficiency in the ZnO nanowires from 4% to 20% by adjusting the growth conditions, i.e., selecting different catalyst (Au or Ag) and varying the growth temperature. Our study suggests that oxygen vacancies induce characteristic photoluminescence and significantly boost the room-temperature ferromagnetism. Such undoped ZnO nanowires with tunable magnetic and optical properties are promising to find applications in multifunctional spintronic and photonic nanodevices.
Systematic study of anisotropic magnetoresistance effect in (311)A GaMnAs films
Authors: He H. T. , Cao X. C. , Zhang T. , Wang Y. Q. , Wang J. N.
Published: March 2010

Anisotropic magnetoresistance effect has been studied systematically in (311)A-oriented as-grown and annealed GaMnAs films at different temperatures. Besides a uniaxial term, the measured angular dependence of longitudinal and transverse magnetoresistivities contains higher order terms arising from the crystal symmetry of GaMnAs. A third order crystalline term accounts for the observed antisymmetric planar Hall effect which is intrinsic to (311)A-oriented GaMnAs films. The uniaxial term persists above the Curie temperature, while the higher order terms can only be observed below the Curie temperature, with their magnitudes increasing with decreasing temperatures. It is revealed that the higher order crystalline terms originate from the long range ferromagnetic (FM) phase and the uniaxial one from isolated magnetic polarons (MPs) as well as the FM phase. With decreasing temperatures, the dominant contribution to the uniaxial term changes from isolated MPs to the FM phase. In addition, low temperature annealing of GaMnAs films is found to increase the magnitudes of all these terms.
Hydration of cyanin dyes
Authors: Calzolari Arrigo , Monti Susanna , Ruini Alice , Catellani Alessandra
Published: March 2010

We investigated the hydration properties of the cyanin dye molecule in the ionic flavylium configuration, through massive classical (force field) and ab initio (Car–Parrinello) molecular dynamics simulations at room temperature. Classical and quantum mechanical results coherently describe the structure of the first solvation shell. We discuss the hydrophobicity/hydrophilicity of the molecule in terms of attractive lateral hydroxyl-water and repulsive carbon π-water interactions. The analysis of the electronic structure shows a net polarization and a molecular orbital redistribution induced by the polar solvent on the intrinsic (gas phase) properties of the dye. Changing the properties of the molecule, the hydration effects should be carefully taken into account in the further interactions of cyanin with the external environment.
Near-infrared quantum cutting via cooperative energy transfer in Gd2O3:Bi3+,Yb3+ phosphors
Authors: Huang X. Y. , Zhang Q. Y.
Published: March 2010

An efficient near-infrared (NIR) quantum-cutting (QC) by converting broadband ultraviolet (UV) into NIR via cooperative down-conversion (CD) has been demonstrated in Gd2O3:Bi3+,Yb3+ phosphors. Upon excitation of UV photon varying from 320–390 nm, NIR emissions has been obtained from transitions of the transition-metal Bi3+:P31 level to the rare-earths Yb3+:F25/2 level. The authors have analyzed the measured luminescence spectra and decay lifetimes and proposed a mechanism to rationalize the CD effect. Application of the broadband NIR-QC phosphors might greatly enhance response of silicon-based solar cells by means of down-conversion of UV part of the solar spectrum to NIR photons with a twofold increase in the photon number.
Observation of earlier two-to-three dimensional structural transition in gold cluster anions by isoelectronic substitution: MAun− (n=8–11; M=Ag,Cu)
Authors: Wang Lei-Ming , Pal Rhitankar , Huang Wei , Zeng Xiao Cheng , Wang Lai-Sheng
Published: March 2010

The effects of isoelectronic substitution on the electronic and structural properties of gold clusters are investigated in the critical size range of the two-dimensional (2D)-three-dimensional (3D) structural transition (MAun−, n=8–11; M=Ag,Cu) using photoelectron spectroscopy and density functional calculations. Photoelectron spectra of MAun− are found to be similar to those of the bare gold clusters Aun+1−, indicating that substitution of a Au atom by a Ag or Cu atom does not significantly alter the geometric and electronic structures of the clusters. The only exception occurs at n=10, where very different spectra are observed for MAu10− from Au11−, suggesting a major structural change in the doped clusters. Our calculations confirm that MAu8− possesses the same structure as Au9− with Ag or Cu simply replacing one Au atom in its C2v planar global minimum structure. Two close-lying substitution isomers are observed, one involves the replacement of a center Au atom and another one involves an edge site. For Au10− we identify three coexisting low-lying planar isomers along with the D3h global minimum. The coexistence of so many low-lying isomers for the small-sized gold cluster Au10− is quite unprecedented. Similar planar structures and isomeric forms are observed for the doped MAu9− clusters. Although the global minimum of Au11− is planar, our calculations suggest that only simulated spectra of 3D structures agree with the observed spectra for MAu10−. For MAu11−, only a 3D isomer is observed, in contrast to Au12− which is the critical size for the 2D-3D structural transition with both the 2D and 3D isomers coexisting. The current work shows that structural perturbations due to even isoelectronic substitution of a single Au atom shift the 2D to 3D structural transition of gold clusters to a smaller size.
Interfacial self cleaning during atomic layer deposition and annealing of HfO2 films on native (100)-GaAs substrates
Authors: Suri Rahul , Lichtenwalner Daniel J. , Misra Veena
Published: March 2010

The reduction in native oxides on GaAs surface during atomic layer deposition (ALD) of HfO2 using tetrakis-dimethylamino-hafnium precursor was investigated using x-ray photoelectron spectroscopy. The role of the ALD growth temperature on the reaction between surface oxides and precursor was studied. Interfacial oxide reduction was found to be insignificant for ALD at 200 °C, while nearly complete for growth at 300 °C. During postdeposition annealing at 400 °C, any arsenic oxides present were found to decompose, resulting in an increase in the interfacial gallium oxides. Thus, control of the ALD process plays a large role in determining interface properties.
Temperature and pressure dependence of the optimized soft-sticky dipole-quadrupole-octupole water model
Authors: Te Jerez A. , Ichiye Toshiko
Published: March 2010

The soft-sticky dipole-quadrupole-octupole (SSDQO) potential energy function for a coarse-grained single-site water model has Lennard-Jones interactions and an approximate multipole expansion for the electrostatics. Here, the Lennard-Jones parameters and multipole moments of SSDQO were optimized so that the structural, thermodynamic, dynamic, and dielectric properties agreed with experimental values of liquid water at ambient conditions. Using these parameters, the temperature and pressure dependence of various properties were shown to be in good agreement with experiment, including a temperature of maximum density at ∼260 K. This new parametrization, referred to as SSDQO1, is both computationally faster and generally more accurate over a wide range of conditions than traditional three-site water models, which demonstrates that a model with a single dipole, quadrupole, and octupole on each water molecule can reproduce the tetrahedral hydrogen bonded network of water.
A coupled cluster approach with a hybrid treatment of connected triple excitations for bond-breaking potential energy surfaces
Authors: Shen Jun , Xu Enhua , Kou Zhuangfei , Li Shuhua
Published: March 2010

An approximate coupled cluster singles, doubles, and triples (CCSDT) method based on the unrestricted Hartree–Fock (UHF) reference, in which the contribution of triple excitations is approximately treated in a hybrid manner [denoted as CCSD(T)-h], is presented. In this approach, canonical UHF molecular orbitals are first transformed into corresponding orbitals so that each α-spin orbital is paired with only one β-spin orbital. Then, active orbitals (occupied or virtual) are automatically selected by setting a threshold for the overlap integrals of corresponding orbitals. With the concept of active orbitals, triple excitations can be divided into two subsets: (1) “active” triples involving at least one occupied active orbital and one virtual active orbital and (2) the remaining triples. The amplitudes of these two classes of triple excitations are obtained via two different approaches. When the present method is employed to study bond-breaking processes, it computationally scales as the seventh power of the system size, because the number of active orbitals involved in such processes is relatively small compared to the total number of the orbitals, and is usually independent on the system size. It has been applied to study the bond-breaking potential energy surfaces in the H8 model and five small molecules (HF, F2, CH4, H2O, and N2). For all systems under study, the overall performance of CCSD(T)-h is very competitive with that of CCSDT, and much better than that of the UHF-based CCSD(T).
An instrument for evaluation of performance of heat dissipative coatings
Authors: Suryawanshi Chetan N. , Kim Taesam , Lin Chhiu-Tsu
Published: March 2010

An instrument is developed to evaluate the performance of heat dissipative coatings. The instrument has features to measure the apparent emissivity of a given surface under different input power settings. The emissivity of aluminum (Al Q-panel) and copper, as measured from 60–135 °C, showed a value of 0.15±0.03 and 0.42±0.05, respectively, consistent with reported values in literature. The relative emissivity of a heat dissipative coating, called as molecular fan carbon nanotube “MF-CNT,” was found to be ∼0.97. A simple mathematical model is built to evaluate the role of different heat transfer mechanisms (convection and radiation) on cooling performance, and it was observed that convection plays a dominant role in cooling, with more than 90% of heat transferred by convection. In presence of MF-CNT coating, radiation heat transfer increases to ∼30% and lowers the steady state temperature by 10 °C. It is illustrated that radiative cooling could be a significant factor in thermal management.
Epitaxial stabilization of ε-Fe2O3 (00l) thin films on SrTiO3 (111)
Authors: Gich M. , Gazquez J. , Roig A. , Crespi A. , Fontcuberta J. , Idrobo J. C. , Pennycook S. J. , Varela M. , Skumryev V. , Varela M.
Published: March 2010

Thin films of the metastable and elusive ε-Fe2O3 have been epitaxially stabilized on SrTiO3 (111) substrates. The ε-Fe2O3 films present a (001) orientation perpendicular to the substrate and three in-plane domains measuring a few nanometers and showing atomically sharp interfaces. We argue that this domain structure, rather than the epitaxial-strain, plays an essential role in stabilizing the ε-Fe2O3 by minimizing the energy of (100) surfaces. The ε-Fe2O3 films show a large in-plane coercivity ∼8 kOe which combined with the magnetoelectric character claimed for this oxide may lead to novel applications in spintronics.
Surface sensitivity in scanning transmission x-ray microspectroscopy using secondary electron detection
Authors: Hub C. , Wenzel S. , Raabe J. , Ade H. , Fink R. H.
Published: March 2010

The successful integration of electron detection into an existing scanning transmission x-ray microspectroscope (STXM) at the Swiss Light Source is demonstrated. In conventional x-ray detection using a photomultiplier, STXM offers mainly bulk sensitivity combined with high lateral resolution. However, by implementation of a channeltron electron multiplier, the surface sensitivity can be established by the detection of secondary electrons emitted from the sample upon resonant excitation. We describe the experimental setup and discuss several relevant aspects, in particular the schemes to correct for self-absorption in the specimen due to back illumination in case of thicker films.
Measuring the temperature of a mesoscopic electron system by means of single electron statistics
Authors: Prati Enrico , Belli Matteo , Fanciulli Marco , Ferrari Giorgio
Published: March 2010

We measure the temperature of a mesoscopic system consisting of an ultradilute two-dimensional electron gas at the Si/SiO2 interface in a metal-oxide-semiconductor field effect transistor (MOSFET) by means of the capture and emission of an electron in a point defect close to the interface. We show that the capture and emission by point defects in Si n-MOSFETs can be temperature dependent down to 800 mK. As the finite quantum grand canonical ensemble applies, the time domain charge fluctuation in the defect is used to define the temperature of the few electron gas in the channel.
Comparing magnetotransport and surface magnetic properties of half-metallic CrO2 films grown by low pressure and atmospheric pressure chemical vapor deposition
Authors: Pathak M. , Zhong X. , Wang J. , Zhang X. , Klein T. M. , LeClair P. , Gupta A.
Published: March 2010

CrO 2 films prepared by low pressure chemical vapor deposition (LPCVD) using Cr(CO)6 precursor have been investigated and compared with epitaxial half metallic CrO2 films prepared at atmospheric pressure (APCVD) using CrO3 precursor for their magnetotransport and surface magnetic properties. LPCVD films showed higher resistivity than APCVD epitaxial (100) CrO2 films prepared on (100) TiO2 substrates. Magnetoresistance of LPCVD films is comparable to that of APCVD films. X-ray magnetic circular dichroism suggests a reduced surface magnetic moment for LPCVD films. This reduced magnetic moment is attributed to antiferromagnetic alignment of the uncompensated Cr spins in the Cr2O3 surface layer.
Frontiers in electronic structure theory
Authors: Sherrill C. David
Published: March 2010

Current and emerging research areas in electronic structure theory promise to greatly extend the scope and quality of quantum chemical computations. Two particularly challenging problems are the accurate description of electronic near-degeneracies (as occur in bond-breaking reactions, first-row transition elements, etc.) and the description of long-range dispersion interactions in density functional theory. Additionally, even with the emergence of reduced-scaling electronic structure methods and basis set extrapolation techniques, quantum chemical computations remain very time-consuming for large molecules or large basis sets. A variety of techniques, including density fitting and explicit correlation methods, are making rapid progress toward solving these challenges.
Change in the moving bodymind: Quantitative results from a pilot study on the use of the BodyMind approach (BMA) to psychotherapeutic group work with patients with medically unexplained symptoms (MUSs)
Authors: Payne Helen , Stott David
Published: March 2010

Background: This article reports quantitative results from a pilot study in primary care (PC) undertaken from 2004–2007. The intervention programme, derived from movement psychotherapy, was termed ‘Learning groups: the BodyMind approach (BMA),’ and emphasised a verbal and non‐verbal integrated model, awareness of the inter‐relationship between body and mind and a self‐managing framework. Aim: To evaluate systematically the outcomes of a 12‐week group BMA intervention programme with patients suffering from anxiety/depression with at least one chronic (over two years) medically unexplained symptom (MUS), another term for a psychosomatic condition or somatoform disorder. Method: A mixed method was applied to a single‐case design. Outcome measures completed at baseline, mid‐, post‐ intervention and three‐month follow‐up were the Measure Yourself Medical Outcome Profile (MYMOP) and the Counselling Outcome Routine Evaluation (CORE). Results: Increased activity levels and well‐being; more effective coping/functioning strategies; reduction in anxiety/depression, GP‐consultation and medication usage, and symptom distress. All changes were maintained at three‐month follow‐up.
Encoding and representation of simultaneous and sequential arrays in visuospatial working memory
Authors: Blalock Lisa Durrance , Clegg Benjamin A.
Published: March 2010

The effect of presentation type on organization in visuospatial working memory (VSWM) was examined. Stimuli were presented sequentially or simultaneously at study, and participants made same/different judgements at test. The test array varied in four different spatial configuration conditions: one featuring no changes from study, one in which two items switched, one in which the same array repeated but in a different location, and one in which a completely novel test stimulus appeared. Results indicated the use of a global configuration for both simultaneous and sequential presentations and showed increased impairment of item-level knowledge with sequential presentations. Overall, these results support the use of a global configuration organization as a fundamental aspect of VSWM processing.
Economic Burden of Ventilator-Associated Pneumonia Based on Total Resource
Utilization
Authors: Restrepo Marcos I. , Anzueto Antonio , Arroliga Alejandro C. , Afessa Bekele , Atkinson Mark J. , Ho Ngoc J. , Schinner Regina , Bracken Ronald L. , Kollef Marin H.
Published: March 2010

Objectives.

To characterize the current economic burden of ventilator-associated
pneumonia (VAP) and to determine which services increase the cost of VAP in
North American hospitals.

Design and Setting.

We performed a retrospective, matched cohort analysis of mechanically
ventilated patients enrolled in the North American Silver-Coated Endotracheal
Tube (NASCENT) study, a prospective, randomized study conducted from 2002 to
2006 in 54 medical centers, including 45 teaching institutions
(83.3%).

Methods.

Case patients with microbiologically confirmed VAP
(n = 30) were identified from 542 study
participants with claims data and were matched by use of a primary diagnostic
code, and subsequently by the Acute Physiology and Chronic Health Evaluation II
score, to control patients without VAP (n = 90).
Costs were estimated by applying hospital-specific cost-to-charge ratios based
on all-payer inpatient costs associated with VAP diagnosis-related
groups.

Results.

Median total charges per patient were $198,200 for case patients and
$96,540 for matched control patients (P
<.001); corresponding median hospital costs were $76,730 for case
patients and $41,250 for control patients (P =
.001). After adjusting for diagnosis-related group payments, median losses to
hospitals were $32,140 for case patients and $19,360 for control patients
(P = .151). The median duration of intubation was
longer for case patients than for control patients (10.1 days vs 4.7 days;
P < .001), as were the median duration of
intensive care unit stay (18.5 days vs 8.0 days; P
< .001) and the median duration of hospitalization (26.5 days vs 14.0
days; P < .001). Examples of services likely
to be directly related to VAP and having higher median costs for case patients
were hospital care (P < .05) and respiratory
therapy (P < .05).

Conclusions.

VAP was associated with increased hospital costs, longer duration of
hospital stay, and a higher number of hospital services being affected, which
underscores the need for bundled measures to prevent VAP.

Trial Registration.

NASCENT study ClinicalTrials.gov Identifier: NCT00148642.
Measurement of the electromagnetic torque in rotating DIII-D plasmas
Authors: Logan N C , Strait E J , Reimerdes H
Published: March 2010

The electromagnetic torque due to either static or rotating magnetic perturbations, or both, on a rotating DIII-D plasma is studied by deriving an estimate of the torque from measurements of various components of the magnetic perturbation at the wall. This approach is based on the Maxwell stress tensor formalism (Hutchinson 2001 Plasma Phys. Control. Fusion
43 145). For the locking of large tearing modes, this measurement of the electromagnetic torque at the time of the locking is consistent with the equation of motion. Measurements and modeling show that for mode rotation frequencies above a few hundred hertz the momentum transfer between magnetic perturbations and the graphite tiles is no longer negligible, revealing the necessity for a new two-wall model of the tokamak. The shielding effect of the tiles on magnetic field measurements is calculated, and shown to be consistent with unrealistically small torques measured during high frequency modes. The electromagnetic torque proves to be an important factor in determining plasma rotation at a wide range of mode frequencies from zero to the kilohertz range. It can be comparable to other sources of torque, such as tangential neutral beam injection for heating.
SeSAW: balancing sequence and structural information in protein functional mapping
Authors: Standley Daron M. , Yamashita Reiko , Kinjo Akira R. , Toh Hiroyuki , Nakamura Haruki
Published: March 2010

Motivation: Functional similarity between proteins is evident at both the sequence and structure levels. SeSAW is a web-based program for identifying functionally or evolutionarily conserved motifs in protein structures by locating sequence and structural similarities, and quantifying these at the level of individual residues. Results can be visualized in 2D, as annotated alignments, or in 3D, as structural superpositions. An example is given for both an experimentally determined query structure and a homology model.

Availability and Implementation: The web server is located at http://www.pdbj.org/SeSAW/

Contact:  standley@ifrec.osaka-u.ac.jp
HALO—a Java framework for precise transcript half-life determination
Authors: Friedel Caroline C. , Kaufmann Stefanie , Dölken Lars , Zimmer Ralf
Published: March 2010

Summary: Recent improvements in experimental technologies now allow measurements of de novo transcription and/or RNA decay at whole transcriptome level and determination of precise transcript half-lives. Such transcript half-lives provide important insights into the regulation of biological processes and the relative contributions of RNA decay and de novo transcription to differential gene expression. In this article, we present HALO (Half-life Organizer), the first software for the precise determination of transcript half-lives from measurements of RNA de novo transcription or decay determined with microarrays or RNA-seq. In addition, methods for quality control, filtering and normalization are supplied. HALO provides a graphical user interface, command-line tools and a well-documented Java application programming interface (API). Thus, it can be used both by biologists to determine transcript half-lives fast and reliably with the provided user interfaces as well as software developers integrating transcript half-life analysis into other gene expression profiling pipelines.

Availability: Source code, executables and documentation are available at http://www.bio.ifi.lmu.de/software/halo

Contact:  caroline.friedel@bio.ifi.lmu.de
ArchSchema: a tool for interactive graphing of related Pfam domain architectures
Authors: Tamuri Asif U. , Laskowski Roman A.
Published: March 2010

Summary: ArchSchema is a Java Web Start application that generates a dynamic 2D network of related Pfam domain architectures. Each node corresponds to a different architecture (shown as a sequence of coloured boxes) and indicates whether any 3D structural information is available in the PDB. Satellite nodes can show either the UniProt codes or the PDB codes of proteins having the given architecture. Search options allow search by UniProt code or Pfam domain identifier, and results can be filtered by domain, organism, or by selecting only proteins in the PDB.

Availability: ArchSchema can be freely accessed at http://www.ebi.ac.uk/Tools/archschema

Contact:  roman@ebi.ac.uk
Depression and Suicidal Behaviour in Children and Adolescents
Authors: Gledhill Julia , Hodes Matthew
Published: March 2010

This article provides an overview of the diagnosis and management of depression, focusing on the primary care setting. We also discuss suicidal behaviour, which may be a symptom of depressive disorder but can also be indicative of other difficulties. Therapeutic interventions for suicidal behaviour are described.
Celiac Disease and Eosinophilic Esophagitis: A True Association
Authors: Leslie Connull , Mews Catherine , Charles Adrian , Ravikumara Madhur
Published: March 2010

Background and Aim:

Celiac disease (CD) and eosinophilic esophagitis (EE) are distinct disorders with specific clinico‐pathological characteristics. Recent reports suggest an association between the 2. The aim of this study was to estimate the prevalence of EE among children diagnosed with CD in our institution in the last 8 years.

Materials and Methods:

Princess Margaret Hospital in Western Australia is the state's only pediatric referral center and the Department of Anatomic Pathology handles almost all of the pediatric gastrointestinal biopsy specimens. All of the children who had histological confirmation of CD between January 2000 and November 2007 were identified. Among this cohort, those who had concurrent esophageal biopsies performed were obtained and those with histology consistent with EE identified. The slides of all of these cases were reviewed. Case notes of children with CD and EE were reviewed for demographic details, symptoms, endoscopic findings, and follow‐up data.

Results:

Among the total of 250 children diagnosed with CD during the study period, 121 had concurrent esophageal biopsies. Ten children had histological findings consistent with EE, although only 7 had endoscopic findings suggestive of EE. Median eosinophil count in these esophageal biopsies was 52 per high power field (range 23–80). Four children had follow‐up endoscopies and all 4 demonstrated recovery of duodenal mucosa but persistent esophageal eosinophilia on gluten‐free diet. In 3 children resolution of EE occurred after specific treatment of EE.

Conclusions:

The prevalence of EE in this cohort of children with CD is at least 4%. This is likely to be an underestimation because only 121 of 250 children had concurrent esophageal biopsies. Coexistent EE should be kept in mind in children undergoing endoscopy for suspected CD, and esophageal biopsies should be obtained, irrespective of whether esophageal mucosa appears normal or abnormal at endoscopy.
Use of Complementary and Alternative Medicine in Pediatric Chronic Viral Hepatitis
Authors: Erlichman Jessi , Salam Abdul , Haber Barbara A
Published: March 2010

Objective:

The objectives of the present study were to assess the prevalence, frequency and type of complementary and alternative medicine (CAM) used by children with chronic viral hepatitis infection, and to determine correlates of use and estimates of nondisclosure regarding CAM use.

Patients and Methods:

In this cross‐sectional pilot study, families of 68 children receiving care for chronic viral hepatitis at a tertiary medical center were administered a survey regarding use of CAM.

Results:

Forty‐six percent of these families reported using CAM for their child at least once since diagnosis with chronic viral hepatitis and 31% used CAM monthly or more frequently. Of all of the CAM therapies, biologically based products such as herbals and dietary supplements were used most often. Use of CAM was independently associated with the current or previous use of antiviral medications for viral hepatitis, parent's use of CAM, and child having a nonliver comorbidity. Rates of physician nondisclosure regarding CAM use were >60%.

Conclusions:

This is the first report of CAM use in children with chronic viral hepatitis. Use of CAM in this population is common, and despite published adult reports, there is infrequent dialogue between patients and pediatric health care providers regarding use of CAM.
Outcomes of Catheter‐associated Infections in Pediatric Patients With Short Bowel Syndrome
Authors: Greenberg Rachel G , Moran Cassandra , Ulshen Martin , Smith P Brian , Benjamin Daniel K , Cohen‐Wolkowiez Michael
Published: March 2010

Children with short bowel syndrome requiring long‐term total parenteral nutrition are at high risk for catheter‐associated infections. The optimal management of catheter infections in this patient population is unknown. We conducted a retrospective observational study in children with short bowel syndrome to compare outcomes of catheter‐associated infections treated with catheter removal plus antibiotic therapy versus antibiotic therapy alone.
Fatal vancomycin- and linezolid-resistant Enterococcus faecium sepsis in a child undergoing allogeneic haematopoietic stem cell transplantation for beta-thalassaemia major
Authors: Fossati Marco , Cappelli Barbara , Biral Erika , Chiesa Robert , Biffi Alessandra , Ossi Cristina , Moro Matteo , Cirillo Daniela Maria , Clementi Massimo , Soliman Clara , Ciceri Fabio , Roncarolo Maria Grazia , Fumagalli Luca , Marktel Sarah
Published: March 2010

Recently vancomycin-resistant and sporadically linezolid-resistant Enterococcus species have been described in adults. We report what we believe to be the first case of a child with prolonged bone marrow aplasia following haematopoietic stem cell transplantation developing a fatal sepsis caused by Enterococcus faecium resistant to glycopeptides and linezolid.
Hydrogen peroxide induces apoptosis-like death in Entamoeba histolytica trophozoites
Authors: Nandi Nilay , Sen Abhik , Banerjee Rajdeep , Kumar Sudeep , Kumar Vikash , Ghosh Amar Nath , Das Pradeep
Published: March 2010

Programmed cell death (PCD) is an essential process in the growth and development of multicellular organisms. However, accumulating evidence indicates that unicellular eukaryotes can also undergo PCD with apoptosis-like features. This study demonstrates that after exposure to 0.8 mM H2O2for 9 hEntamoeba histolyticapresents morphological and biochemical evidence of apoptosis-like death. Morphological characteristics of apoptosis-like death including DNA fragmentation, increased vacuolization, nuclear condensation and cell rounding were observed for H2O2-exposed trophozoites with preservation of membrane integrity. Biochemical alteration in ion fluxes is also a key feature in PCD, and H2O2-exposed trophozoites showed overproduction of reactive oxygen species, increased cytosolic Ca2+and decreased intracellular pH. Phosphatidylserine was also found to be expressed in the outer leaflet of the plasma membrane of the H2O2-treated trophozoites. Pretreatment with the cysteine protease inhibitor E-64d, the extracellular and intracellular Ca2+chelators EGTA and BAPTA/AM, and the Ca2+influx inhibitor verapamil prior to H2O2exposure abolished DNA fragmentation. The oxidatively stressed trophozoites also showed an increased calpain activity, indicating involvement of Ca2+-dependent calpain-like cysteine proteases in PCD ofE. histolytica. A homogeneous caspase assay showed no significant caspase activity, and administration of caspase 1 inhibitor also did not prevent the death phenotype for the oxidatively stressed trophozoites, indicating a caspase-independent apoptosis-like death. Our observations clearly demonstrate that there is a distinct calpain-dependent but caspase-independent pathway for apoptosis-like death in oxidatively stressedE. histolyticatrophozoites.
The Hem and Has haem uptake systems in Serratia marcescens
Authors: Benevides-Matos Najla , Biville Francis
Published: March 2010

Serratia marcescens, like several other Gram-negative bacteria, possesses two functional haem uptake systems. The first, referred to as the Hem system, can transport haem present at a concentration equal to or above 10−6 M. It requires an active outer-membrane receptor which uses proton-motive force energy transmitted by the inner-membrane TonB protein. The other system, Has, takes up haem at lower concentrations and utilizes a small secreted haem-binding protein (haemophore) and its cognate TonB-dependent outer-membrane receptor HasR. Various combinations of mutations were used to examine haem uptake activity by the two systems in S. marcescens. The Hem uptake system enables S. marcescens to take up haem at a concentration of 10−6 M in the presence of various levels of iron depletion. The Has system, which enables such uptake even in the presence of lower haem concentrations, requires higher iron depletion conditions for function. Has haem uptake requires the presence of HasB, a TonB paralogue encoded by the has operon. These two systems enable S. marcescens to take up haem under various conditions from different sources, reflecting its capacity to confront conditions encountered in natural biotopes.
Effect of alkaline growth pH on the expression of cell envelope proteins in Fusobacterium nucleatum
Authors: Zilm Peter S. , Mira Alex , Bagley Christopher J. , Rogers Anthony H.
Published: March 2010

Fusobacterium nucleatum is a Gram-negative anaerobic organism that plays a central role in the development of periodontal diseases. The progression of periodontitis is associated with a rise in pH of the gingival sulcus which promotes the growth and expression of virulence factors by periodontopathic bacteria. We have previously reported that the expression of specific cytoplasmic proteins is altered by a shift in growth pH. In the present study we have compared cell envelope protein expression of F. nucleatum during chemostat growth at pH 7.2 and 7.8. From a total of 176 proteins resolved from the cell envelope, 15 were found to have altered expression in response to an increase in growth pH and were identified by MS. Upregulated proteins included an outer membrane porin which has been identified as playing a role in virulence, a periplasmic chaperone which assists in the folding of outer membrane proteins, and a transporter thought to be involved with iron uptake. Proteins downregulated at pH 7.8 were consistent with our previous findings that the bacterium reduces its catabolism of energy-yielding substrates in favour of energy-storage pathways. Among the downregulated proteins, two transporters which are involved in the uptake of C4 dicarboxylates and phosphate were identified. A putative protease and an enzyme associated with the metabolism of glutamate were also identified. A high proportion of the cell envelope proteins suggested by these data to play a role in the organism's response to alkaline growth pH may have arisen by lateral gene transfer. This would support the hypothesis that genes that provide an ability to adapt to the changing conditions of the oral environment may be readily shared between oral bacteria.