bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a score to predict clinical deterioration in hospitalized children
Authors: Bonafide Christopher P. , Holmes John H. , Nadkarni Vinay M. , Lin Richard , Landis J. Richard , Keren Ron
Published: November 2011

BACKGROUND:

Identification of the characteristics that put hospitalized children at high risk of deterioration may help to target patients whose physiologic status should be intensively monitored for signs of deterioration, and reduce unnecessary monitoring in patients at very low risk. Previous studies have evaluated vital sign‐based early warning scores to detect deterioration that has already begun.

OBJECTIVE:

To develop a predictive score for deterioration using non‐vital sign patient characteristics in order to risk‐stratify hospitalized children before signs of deterioration are detectable.

DESIGN:

Case‐control study.

SETTING:

A 460‐bed children's hospital.

PATIENTS:

Cases (n = 141) were children who deteriorated while receiving care on non‐intensive care unit (non‐ICU) inpatient units. Controls (n = 423) were randomly selected.

MEASUREMENTS:

The exposures were complex chronic conditions, other patient characteristics, and laboratory studies. The outcome was clinical deterioration, defined as cardiopulmonary arrest, acute respiratory compromise, or urgent ICU transfer.

RESULTS:

The 7‐item score included age <1 year, epilepsy, congenital/genetic conditions, history of transplant, enteral tube, hemoglobin <10 g/dL, and blood culture drawn in the preceding 72 hours. We grouped the patients into risk strata based on their scores. The very low‐risk group's probability of deterioration was less than half of baseline risk. The high‐risk group's probability of deterioration was more than 80‐fold higher than the baseline risk.

CONCLUSIONS:

We identified a set of characteristics associated with clinical deterioration in children. Used in combination as a score, these characteristics may be useful in triaging the intensity of monitoring and surveillance for deterioration that children receive while hospitalized on non‐ICU units. Journal of Hospital Medicine 2012;
Heuristic linear mapping of physiological parameters in dynamic contrast‐enhanced MRI without T1 measurement and contrast agent concentration
Authors: Yuan Jing , Chow Steven K.K. , King Ann D. , Yeung David K.W.
Published: November 2011

Purpose:

To present a novel heuristic linear mapping method to individually estimate physiological parameters for Tofts model without T1 measurement and contrast agent concentration.

Materials and Methods:

A linear relationship was used for kep mapping through a heuristic time intensity curve (TIC) shape factor (TSF). Ktrans maps were subsequently estimated using kep maps and another approximate linear model derived from the Tofts model. Twenty‐seven patients with head‐and‐neck squamous cell carcinoma received dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI). Physiological parameters maps were obtained using this heuristic linear mapping method and compared to the maps obtained by the normal nonlinear least‐square fitting with T1 measurement.

Results:

High linearity (R2 >0.95) between kep and TSF was found in all patients for kep <5/min. This linearity is robust for TSF timepoint selection. The kep maps generated by this linear fitting were highly consistent with those by the normal nonlinear approach (P > 0.05). The Ktrans maps were consistent with the normally derived maps in pattern distribution but the absolute value might be scaled due to the assumption of the reference Ktrans value.

Conclusion:

This novel method generates reliable and consistent physiological parameter maps with significantly lower computation complexity than the multiparameter nonlinear fitting. The DCE‐MRI scan time can be greatly shortened without T1 mapping. J. Magn. Reson. Imaging 2012;35:916–925. © 2011 Wiley Periodicals, Inc.
The quality of life trajectory of resected gastric cancer
Authors: Munene Gitonga , Francis Wesley , Garland Sheila N. , Pelletier Guy , Mack Lloyd A. , Bathe Oliver F.
Published: November 2011

Background

Few studies describe quality of life (QoL) outcomes following gastrectomy for gastric cancer using a validated instrument. The gastric cancer module for the Functional Assessment of Cancer Therapy system of QoL measurement tools (FACT‐Ga) was utilized to determine the changes in QoL following gastrectomy, and during the disease course.

Methods

In 43 patients undergoing gastrectomy for gastric cancer, outcome such as complications, recurrence, and survival were annotated. Karnofsky performance status (KPS) and QoL were determined preoperatively and at each follow‐up visit.

Results

Nineteen (44%) patients and 24 (56%) patients underwent partial gastrectomy (PG) and total gastrectomy (TG), respectively. Complications occurred in 30%, and one mortality (2.3%) occurred. Median survival was 23 months. KPS, FACT‐G, and FACT‐Ga scores all decreased after surgery, and normalized by 6 months. There was no significant difference in QoL in patients who had a PG or TG, although the type of gastrectomy did affect KPS. QoL dropped on average 4.4 ± 3.6 months prior to death.

Conclusions

Surgery adversely affects QoL for up to 6 months. Thereafter, QoL mirrors changes in disease status. More studies are required to document the QoL cost‐benefit ratio in gastric cancer, which often is accompanied by short survival benefits. J. Surg. Oncol. 2012;105:337–341. © 2011 Wiley Periodicals, Inc.
Decreased expression of Beclin 1 correlates with a metastatic phenotypic feature and adverse prognosis of gastric carcinomas
Authors: Chen Ying‐Bo , Hou Jing‐Hui , Feng Xing‐Yu , Chen Shi , Zhou Zhi‐Wei , Zhang Xiao‐Shi , Cai Mu‐Yan
Published: November 2011

Background and Objectives

Beclin 1 plays a critical role in the regulation of autophagy, apoptosis, differentiation and the development and progression of cancer. The clinicopathological significance of Beclin 1 expression in patients with gastric carcinoma (GC) has not been yet elucidated.

Methods

Immunohistochemistry (IHC) was performed to investigate the Beclin 1 expression in GCs and normal mucosal tissues. Receiver operating characteristic curve analysis, spearman's rank correlation, Kaplan–Meier plots and Cox proportional hazards regression model were used to analyze the data.

Results

The highly expressed Beclin 1 was observed in 90/155 (58.1%) of GCs, in 24/60 (40.0%) adjacent mucosal tissues and in 13/30 (43.3%) of normal gastric mucosa tissues (P = 0.036). Decreased expression of Beclin 1 in cancer cells was significantly correlated with poor differentiation, nodal and distant metastasis, advanced TNM stage, and tumor relapse. More importantly, Decreased expression of Beclin 1 was associated with shorter survival as evidenced by univariate and multivariate analysis.

Conclusions

Our findings provide a basis for the concept that decreased expression of Beclin 1 in GC may be important in the acquisition of a metastatic phenotype, suggesting that decreased Beclin 1 expression, as examined by IHC, is an independent biomarker for poor prognosis of patients with GC. J. Surg. Oncol. 2012; 105:542–547. © 2011 Wiley Periodicals, Inc.
Using gas chromatography to determine winter diets of greater sage‐grouse in Utah
Authors: Thacker Eric T. , Gardner Dale R. , Messmer Terry A. , Guttery Michael R. , Dahlgren Dave K.
Published: November 2011

Sagebrush (Artemisia spp.) constitutes the majority (>99%) of sage‐grouse (Centrocercus spp.) winter diets. Thus, identification and protection of important winter habitats is a conservation priority. However, not all sagebrush may be alike. More information is needed regarding sage‐grouse sagebrush winter dietary preferences for application to management. The objective of our research was to determine if chemical analysis of fecal pellets could be used to characterize winter sage‐grouse diets as a substitute for more invasive methods. We collected and analyzed fecal pellets and sagebrush samples from 29 different sage‐grouse flock locations in northwestern and southcentral Utah. Using gas chromatography, we were able to identify crude terpene profiles that were unique to Wyoming sagebrush (A. tridentata wyomingensis) and black sagebrush (A. nova). We subsequently used the profiles to determine sagebrush composition of sage‐grouse fecal pellets, thus reflecting sage‐grouse winter diets. This technique provides managers with a tool to determine which species or subspecies of sagebrush may be important in the winter diets of sage‐grouse populations. © 2011 The Wildlife Society.
Assessing the Degradation Profile of Functional Aliphatic Polyesters with Precise Control of the Degradation Products
Authors: Höglund Anders , Målberg Sofia , Albertsson Ann‐Christine
Published: November 2011

The pre‐polymer poly(but‐2‐ene‐1,4‐diyl malonate) (PBM) and a series of PBM‐based materials are shown to be degradable under physiological conditions in vitro and they are therefore presented as potential materials for biomedical applications. Four different PBM‐based materials are synthesized: a PBM homopolymer, crosslinked PBM with and without spacer, and a triblock copolymer of PBM and PLLA with the PBM as an amorphous middle block. The polymers are subjected to hydrolytic degradation in phosphate‐buffered saline at pH = 7.4 and 37 °C. The results show that all the PBM‐based materials degrade without a rapid release of acidic degradation products or any substantial lowering of the pH that might jeopardize their biocompatibility.

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Novel Epoxide Initiators for the Carbocationic Polymerization of Isobutylene
Authors: Puskas Judit E. , Soytaş Serap Hayat , Lim Goy Teck
Published: November 2011

Summary: We recently reported the synthesis of polyisobutylene (PIB) via direct initiation by epoxycyclohexyl isobutyl polyhedral oligomeric silsesquioxane (POSS®) (Figure 1) in conjunction with titanium tetrachloride (TiCl4). This system successfully initiated the living carbocationic polymerization of isobutylene (IB) in hexane/methyl chloride (Hx/MeCl ‐60/40, v/v) at T = −80 °C, yielding an asymmetric telechelic PIB with one POSS® cage head group and one tert‐Cl end group.1 This paper will discuss IB polymerizations initiated by 1,2‐epoxycyclohexane and bis[3,4‐(epoxycyclohexyl)ethyl]‐tetramethyl‐disiloxane, in conjunction with TiCl4.
A reconstruction method for three‐dimensional pore space using multiple‐point geology statistic based on statistical pattern recognition and microstructure characterization
Authors: Xu Zhi , Teng Qizhi , He Xiaohai , Li Zhengji
Published: November 2011

To predict the macroscopic properties (e.g., transport, electromagnetic, and mechanical properties) of porous media, it is necessary to have a three‐dimensional (3D) representation of porous media. We reconstruct the geologically realistic 3D structure of Fontainebleau sandstone based on the two‐dimensional (2D) thin sections by using the multiple‐point statistics method. For this method, the size of template is an important parameter that reflects the perceived scale of spatial structure of porous media. In this paper, we take advantage of entropy method to obtain the appropriate size of the template, which is proven to be correct and feasible. The reconstruction method proposed by us combines successive 2D MPS simulations as well as 3D MPS simulation, which takes account into the pore structure information (e.g., heterogeneity and connectivity) both intralayer and interlayer. This reconstruction method is tested on Fontainebleau sandstone for which 3D images from micro‐CT scanning are available. Applying local percolation theory analysis, this new approach can depict the expected patterns of geological heterogeneities. In addition, it also can well reproduce a high degree of connectivity of the pore space better than other reconstruction methods based on lower‐order statistics. Copyright © 2011 John Wiley & Sons, Ltd.
A variational‐inequality approach to stochastic boundary value problems with inequality constraints and its application to contact and elastoplasticity
Authors: Arnst M. , Ghanem R.
Published: November 2011

This paper is concerned with stochastic boundary value problems (SBVPs) whose formulation involves inequality constraints. A class of stochastic variational inequalities (SVIs) is defined, which is well adapted to characterize the solution of specified inequality‐constrained SBVPs. A methodology for solving such SVIs is proposed, which involves their discretization by projection onto polynomial chaos and collocation of the inequality constraints, followed by the solution of a finite‐dimensional constrained optimization problem. Simulation studies in contact and elastoplasticity are provided to demonstrate the proposed framework. Copyright © 2011 John Wiley & Sons, Ltd.
A new weight‐function enrichment in meshless methods for multiple cracks in linear elasticity
Authors: Barbieri E. , Petrinic N. , Meo M. , Tagarielli V. L.
Published: November 2011

A new enriched weight function for meshless methods is proposed for the numerical treatment of multiple arbitrary cracks in two dimensions. The main novelty consists in modifying the weight function with an intrinsic enrichment which is discontinuous over the finite length of the crack, represented by a segment, but continuous all around the crack tips. An analytical function is used to introduce discontinuities that are incorporated in the kernel in a simple, multiplicative manner.

The resulting method allows a more straightforward implementation and simulation of the presence of multiple cracks, crack branching and crack propagation in a meshless framework without using any of the existing algorithms such as visibility, transparency, and diffraction and without using additional unknowns and additional equations for the evolution of the level‐sets, as in extrinsic partition of unity‐based methods.

Stress intensity factors calculated using the J‐integral demonstrate excellent agreement with analytical solutions for classical fracture mechanics benchmarks. Copyright © 2011 John Wiley & Sons, Ltd.
Pharmakologie der Betasympathomimetika
Authors: Gnadt Mirjam
Published: November 2011

Die Pharmakokinetik inhalativ verabreichter Betasympathomimetika bestimmt maßgeblich das Ausmaß und die Dauer der erwünschten Atemwegserweiterung sowie der unerwünschten Nebenwirkungen. Das Zusammenspiel der pharmakokinetischen Vorgänge ist jedoch komplex, da zusätzlich zu der pulmonal resorbierten Dosisfraktion auch ein gewisser Prozentsatz durch gastrointestinale Absorption in den systemischen Kreislauf umverteilt wird. Eine lange Verweildauer im Lungengewebe durch Erhöhung der lipophilen Eigenschaften und eine geringe Tendenz zur Umverteilung aus dem Gastrointestinaltrakt in den systemischen Kreislauf durch einen hohen Firstpass‐Effekt sind daher notwendig, um eine pulmonale Selektivität der Therapie zu erzielen. Die Pharmakodynamik kurz‐ und langwirksamer β2‐Agonisten, charakterisiert durch den Wirkeintritt und ‐dauer und das Ausmaß der Bronchodilatation, ist nach gegenwärtiger Forschung nicht nur von den Substanzeigenschaften abhängig, sondern unterliegt auch verschiedenen Toleranzmechanismen und dem individuellen Genotyp des β2‐Rezeptors, die die Effektivität der Asthmatherapie einschränken können.
Darreichungsformen, Formulierungen und Depositionscharakteristika
Authors: Klar Fabian , Urbanetz Nora Anne
Published: November 2011

Betasympathomimetika stehen für ihre beiden Hauptindikationsgebiete, die Tokolyse und die Therapie obstruktiver Atemwegserkrankungen, in unterschiedlichen Darreichungsformen zur Verfügung. Dabei kommen zur Tokolyse neben parenteralen Arzneiformen auch perorale Darreichungsformen zur Anwendung. Zur Therapie von Atemwegserkrankungen stehen neben parenteralen Zubereitungen perorale und insbesondere pulmonale Arzneiformen zur Verfügung. In der großen Gruppe der pulmonalen Darreichungsformen unterscheidet man prinzipiell Formulierungen, die mithilfe von Verneblern zur Anwendung kommen und solche, die mithilfe von Druckgasdosieraerosolen oder Pulverinhalatoren appliziert werden. Die unterschiedlichen Funktionsprinzipien und auch die Verfügbarkeit unterschiedlicher Wirkstärken der genannten pulmonalen Darreichungsformen gewährleisten eine adäquate Behandlung von Atemwegserkrankungen im Hinblick auf Indikationsstellung, Schwere der Erkrankung und die Bedürfnisse verschiedener Patientengruppen.
Betasympathomimetika und andere Arzneimittel zur Feuchtinhalationstherapie
Authors: Krämer Irene , Klemmer Anja
Published: November 2011

Die Feuchtinhalation von vernebelten Inhalationslösungen oder Inhalationssuspensionen dient der pulmonalen Applikation von Arzneimitteln bei spezifischen Patientengruppen. Die Applikation an den Wirkort verbessert die Wirksamkeit und ist mit einer geringen systemischen Toxizität verbunden.

Theoretische und praktische Aspekte der Verneblung von Inhalativa sowie die Information und Beratung der Patienten zur Feuchtinhalation werden nachfolgend vorgestellt. Insbesondere wird über Untersuchungen zur Kompatibilität von Arzneimitteln zur Feuchtinhalation im Verneblerreservoir und den Einfluss auf die Aerosoleigenschaften bei simultaner Verneblung berichtet.
Medizinische Chemie der β2‐Sympathomimetika
Authors: Lamers Christina , Schubert‐Zsilavecz Manfred
Published: November 2011

Die Gruppe der β2‐Sympathomimetika spielt trotz kontroverser Diskussionen über die Sicherheit und Wirksamkeit eine wichtige Rolle in der Therapie der obstruktiven Atemwegserkrankungen. Über eine Aktivierung der β2‐Adrenozeptoren erreichen sie eine schnelle Bronchodilatation. Beim Blick in die Pipeline lässt sich ein Trend zu ultra‐langwirksamen und enantiomerenreinen Strukturen erkennen. Kristallstrukturanalysen haben zu erfolgreichen Strukturaufklärung des β2‐Rezeptors beitragen.
A Sociocultural Approach to Narcissism: The Case of Modern China
Authors: Cai Huajian , Kwan Virginia S. Y. , Sedikides Constantine
Published: November 2011

Using large Internet samples, we examined the possible influence of sociodemographic factors on the Chinese self–concept and in particular, on the level of narcissism. We found that (i) younger persons are more narcissistic than older ones; (ii) persons from higher socioeconomic classes are more narcissistic than those from lower socioeconomic classes; (iii) persons from only–child families are more narcissistic than those from families with multiple children; (iv) persons from urban areas are more narcissistic than those from rural areas; and (v) individualistic values are predictive of individual differences in narcissism. The findings suggest that sociocultural changes contribute to the rise of narcissism in China. Copyright © 2011 John Wiley & Sons, Ltd.
An investigation of band profile around the grain boundary of Cu(InGa)Se2 solar cell material by scanning probe microscopy
Authors: Takihara Masaki , Minemoto Takashi , Wakisaka Youichi , Takahashi Takuji
Published: November 2011

We performed scanning tunneling spectroscopy on an as‐grown Cu(InGa)Se2 (CIGS) thin film and photo‐assisted Kelvin probe force microscopy on a CIGS solar cell. From these measurements, we estimated the band profile around the grain boundaries (GBs). The results indicate both downward bending of the conduction band edge and broadening of the band gap near GBs. We can therefore conclude that photo‐generated electrons and holes are easily separated by the built‐in field near GBs, and consequently their recombination at the GBs should be suppressed. Copyright © 2011 John Wiley & Sons, Ltd.
Proteomic analysis of berry‐sizing effect of GA3 on seedless Vitis vinifera L.
Authors: Wang Zeng , Zhao Fengxia , Zhao Xiao , Ge Hui , Chai Lijuan , Chen Shangwu , Perl Avihai , Ma Huiqin
Published: November 2011

Gibberellin (GA) is widely used in the table grape and raisin industries to enlarge the berries of seedless varieties. However, the mechanism underlying its berry‐sizing effect is poorly understood. In this study, clusters of Centennial Seedless (Vitis vinifera L.) were treated with 30 ppm GA3 on day 12 after flowering, and berries were sampled at development stages I, II and III for proteomic analysis. Among the 1479 proteins detected on 2‐DE maps, 19, 70 and 69 spots in stages I, II and III, respectively, showed an at least twofold difference in volume between treatments and controls. Of these, 125 proteins were successfully identified and assigned to eight functional groups, chief among them are metabolism and energy, stress response, expression regulation and cytoskeleton proteins. Stress‐response proteins were predominantly down‐regulated in GA3‐treated berries in stages I and II, and significantly up‐regulated in stage III. Up‐regulation of cytoskeleton, cell‐wall modification and other important proteins was found in the two latter stages of berry development. Our proteomic results and subsequent validation revealed, for the first time, the role of redox homeostasis in GA3‐induced berry enlargement and markedly remodeled cellular protein expression in treated berries.
Revisiting the folding kinetics of bacteriorhodopsin
Authors: Schlebach Jonathan P. , Cao Zheng , Bowie James U. , Park Chiwook
Published: November 2011

The elucidation of the physical principles that govern the folding and stability of membrane proteins is one of the greatest challenges in protein science. Several insights into the folding of α‐helical membrane proteins have come from the investigation of the conformational equilibrium of H. halobium bacteriorhodopsin (bR) in mixed micelles using SDS as a denaturant. In an effort to confirm that folded bR and SDS‐denatured bR reach the same conformational equilibrium, we found that bR folding is significantly slower than has been previously known. Interrogation of the effect of the experimental variables on folding kinetics reveals that the rate of folding is dependent not only on the mole fraction of SDS but also on the molar concentrations of mixed micelle components, a variable that was not controlled in the previous study of bR folding kinetics. Moreover, when the molar concentrations of mixed micelle components are fixed at the concentrations commonly employed for bR equilibrium studies, conformational relaxation in the transition zone is slower than hydrolysis of the retinal Schiff base. As a result, the conformational equilibrium between folded bR and SDS‐denatured bR cannot be achieved under the conventional condition. Our finding suggests that the molar concentrations of mixed micelle components are important experimental variables in the investigation of the kinetics and thermodynamics of bR folding and should be accounted for to ensure the accurate assessment of the conformational equilibrium of bR without the interference of retinal hydrolysis.
Highly controlled InAs nanowires on Si(111) wafers by MOVPE
Authors: Ghalamestani Sepideh Gorji , Johansson Sofia , Borg B. Mattias , Dick Kimberly A. , Wernersson Lars‐Erik
Published: November 2011

We have investigated epitaxial growth of InAs layers on 2″ Si (111) substrates by Metalorganic Vapor Phase Epitaxy. Structural and morphological characterization results confirm high quality of the obtained thin layers. Then, we have utilized the InAs layers as substrates for InAs nanowire growth and Au nanoparticles were lithographically defined at various positions on the surface. Statistical analysis performed on the InAs nanowires grown on 2″ substrates demonstrates our full control on the position, diameter and vertical alignment across the wafer. One possible device application of the aforementioned structure is wrap‐gated Metal‐Oxide‐Semiconductor Field‐Effect Transistors where the InAs layer is employed as the bottom contact and the InAs nanowires act as channel materials. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical analysis of short‐gate GaN HEMTs with Fe‐doped buffer layers
Authors: Hirose Mayumi , Takada Yoshiharu , Tsuda Kunio
Published: November 2011

The influence of Fe‐doped GaN buffer layers on microwave GaN HEMT performance was analyzed using a two‐dimensional numerical model. The device structure model was based on a fabricated Ka‐band AlGaN/GaN HEMT with a 0.2‐µm gate. Deep acceptors brought about by Fe doping were introduced in the GaN buffer layer model, and the concentration profile was based on the Fe concentration profile measured by SIMS. The slow turn‐off of Fe doping was taken into account. The simulated drain current showed a sharp current‐off in the 0.2‐µm gate device, and it was found that this characteristic was influenced by the slow turn‐off Fe‐doping profile. To discuss the effect on drain current collapse in high‐frequency large‐signal operation, ionized deep acceptor concentrations were simulated and compared between the on‐state and off‐state. The results showed that the ionized concentration increases in the off‐state in the area of slow turn‐off Fe‐doping. It is expected that the ionization is one of the causes of drain current collapse in the 0.2‐µm gate device. The simulated results also indicated enhanced collapse in the 0.2‐µm gate device in comparison with the results for a 0.6‐µm gate device (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preliminary study for rapid determination of phycotoxins in microalgae whole cells using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Paz Beatriz , Riobó Pilar , Franco José Mariano
Published: November 2011

Rapid and sensitive methods for identification of several phycotoxins produced by microalgae species such as yessotoxins (YTXs) for Protoceratium reticulatum, okadaic acid (OA) and pectenotoxins (PTXs) for Prorocentrum spp. and Dinophysis spp., Palytoxins (PLTXs) for Ostreopsis spp., ciguatoxins (CTXs) for Gambierdiscus spp. or domoic acid (DA) for Pseudo‐nitzschia spp. are of great importance to the shellfish and fish industry. In this study, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) was used to detect several phycotoxins in whole cells of some microalgae which are known as toxin producers. To achieve an appropriate MALDI matrix and a sample preparation method, several matrices and solvent mixtures were tested. The most appropriate matrix system for toxin detection was obtained with 10 µg μL–1 of DHB in 0.1% TFA/ACN (3:7, v/v) by mixing the intact cells with the matrix solution directly on the MALDI target (dried‐droplet technique). Toxin detection by this procedure is much faster than current procedures based on solvent extraction and chromatographic separation. This method allowed the rapid detection of main phycotoxins in some dinoflagellate cells of genus Ostreopsis, Prorocentrum, Protoceratium, Gambierdiscus, Dinophysis and diatoms from Pseudo‐nitzschia genus. Copyright © 2011 John Wiley & Sons, Ltd.
Self-Renewal of Leukemia Stem Cells in Friend Virus-Induced Erythroleukemia Requires Proviral Insertional Activation of Spi1 and Hedgehog Signaling but Not Mutation of p53
Authors: Hegde Shailaja , Hankey Pamela , Paulson Robert F.
Published: November 2011

Friend virus induces erythroleukemia through a characteristic two-stage progression. The prevailing model proposes that during the initial, polyclonal stage of disease most of the infected cells terminally differentiate, resulting in acute erythrocytosis. In the late stage of disease, a clonal leukemia develops through the acquisition of new mutations—proviral insertional activation of Spi1/Pu.1 and mutation of p53. Previous work from our laboratory demonstrated that Friend virus activates the bone morphogenic protein 4 (BMP4)-dependent stress erythropoiesis pathway, which leads to the rapid expansion of stress erythroid progenitors, which are the targets for Friend virus in the spleen. We recently showed that stress erythroid progenitors have intrinsic self-renewal ability and therefore could function as leukemia stem cells (LSCs) when infected with Friend virus. Here, we show that the two stages of Friend virus-induced disease are caused by infection of distinct stress progenitor populations in the spleen. The development of leukemia relies on the ability of the virus to hijack the intrinsic self-renewal capability of stress erythroid progenitors leading to the generation of LSCs. Two signals are required for the self-renewal of Friend virus LSCs proviral insertional activation of Spi1/Pu.1 and Hedgehog-dependent signaling. Surprisingly, mutation of p53 is not observed in LSCs. These data establish a new model for Friend virus-induced erythroleukemia and demonstrate the utility of Friend virus as a model system to study LSC self-renewal.

Disclosure of potential conflicts of interest is found at the end of this article.
Further delineation of pontocerebellar hypoplasia type 6 due to mutations in the gene encoding mitochondrial arginyl‐tRNA synthetase, RARS2
Authors: Glamuzina Emma , Brown Ruth , Hogarth Kieran , Saunders Dawn , Russell‐Eggitt Isabelle , Pitt Matthew , de Sousa Carlos , Rahman Shamima , Brown Garry , Grunewald Stephanie
Published: November 2011

Pontocerebellar hypoplasia type 6 (PCH6) (MIM #611523) is a recently described disorder caused by mutations in RARS2 (MIM *611524), the gene encoding mitochondrial arginyl‐transfer RNA (tRNA) synthetase, a protein essential for translation of all mitochondrially synthesised proteins. This case confirms that progressive cerebellar and cerebral atrophy with microcephaly and complex epilepsy are characteristic features of PCH6. Additional features of PCH subtypes 2 and 4, including severe dystonia, optic atrophy and thinning of the corpus callosum, are demonstrated. Congenital lactic acidosis can be present, but respiratory chain dysfunction may be mild or absent, suggesting that disordered mitochondrial messenger RNA (mRNA) translation may not be the only mechanism of impairment or that a secondary mechanism exists to allow some translation. We report two novel mutations and expand the phenotypic spectrum of this likely underdiagnosed PCH variant, where recognition of the characteristic neuroradiological phenotype could potentially expedite genetic diagnosis and limit invasive investigations.
Glycine Surfactants Derived from Dodecenyl Succinic Anhydride
Authors: Dix Leslie , Moon Andrew
Published: November 2011

We report the synthesis and properties of two surfactants with a novel head group based on glycine. A monocarboxylic surfactant N‐glycine methyl ester (2‐dodecen‐1‐yl succinamic acid) (I) was prepared by ring opening of an n‐alkyl succinic anhydride. Hydrolysis of the ester functionality yields a dicarboxylic acid II. The sodium salts of I and II were effective surfactants at neutral pH giving a low minimum surface tension (<30 mN m−1 at 20 °C). At high pH (~12) the surface activity of both surfactants is reduced compared to neutral pH, indicating that at neutral pH an ‘acid soap’ is formed. The pKa of the acid form of the surfactants was determined. Addition of calcium ions reduced the CMC of II but did not reduce the surface tension above the CMC. The resistance of II to calcium ion precipitation was measured at pH 7.
Solid–mush interface conditions for mushy layers
Authors: Gewecke Nicholas R. , Schulze Tim P.
Published: November 2011

A subtle issue in the study of mushy zones which form during the solidification of binary alloys is that there are two distinct types of solid–mush interfaces which may occur. One of these is a eutectic front and the other is a front which separates the mushy layer and, assuming complete solute rejection, a layer of pure solid. For semi-infinite-domain configurations that admit similarity solutions, such as those at a uniform initial temperature and concentration with an imposed cold temperature at the lower boundary, only one of the two types appears, and the type of front is determined by the various parameters of the system. In a finite domain, it is possible for each type of front to appear at different times. Specifically, the advance of the eutectic front is restricted by the isotherm associated with the eutectic temperature, and the other front type will appear over a longer time scale. Leading up to the time when the front changes type, the concentration being frozen into the solid decreases. This process writes a history of the system into the solid.
NEW PROPERTIES OF THE TOTAL TIME ON TEST TRANSFORM ORDER
Authors: Hu Taizhong , Wang Yashi , Zhuang Weiwei
Published: November 2011

The total time on test transform (ttt) order was introduced in Kochar, Li, and Shaked (2002) for nonnegative random variables, which has a close connection to the location independent riskier and the excess wealth orders. In this article, the ttt order is redefined for comparing not necessarily nonnegative random variables. Such an extension will lead us to conveniently derive several new intrinsic properties of the ttt order. In particular, we establish an interesting separation result on the connection between the ttt and the excess wealth orders. As two applications of this separation result, we obtain the generating process of the ttt order in terms of mean-decreasing right stretches and the closure property of the ttt order under convolutions. The generating process of the ttt order parallels those of the location independent riskier and the excess wealth orders established by Landsberger and Meilijson (1994).
Nicht-invasive Hirnstimulation: Neuromodulation durch transkranielle elektrische Stimulation und deren Wirkung auf neuropsychologische Erkrankungen
Authors: Schmicker Marlen , Sabel Bernhard A. , Gall Carolin
Published: November 2011

Transkranielle Gleichstromstimulation (tDCS) kann durch Erhöhung (anodale tDCS) oder Verringerung (kathodale tDCS) der Erregbarkeit von Neuronen die Aktivität verschiedener Gehirnregionen modulieren. Stimulationseffekte sind abhängig von der Elektrodenposition und -größe, Dauer und Stromstärke der tDCS. Diese Überblicksarbeit behandelt Gedächtnis- und Sprachstudien mit gesunden Probanden und Patienten (Morbus Parkinson, Morbus Alzheimer, Aphasie). Anodale Stimulation führt im Allgemeinen zu Leistungsverbesserungen, nach kathodaler Stimulation wurden häufiger keine Effekte oder Leistungsverschlechterungen beobachtet. Weitere Untersuchungen sollten die Wechselwirkung der Stimulationsparameter bei tDCS und das Potential transorbitaler Wechselstromstimulation (tACS) betrachten, die möglicherweise zu länger anhaltenden Stimulationseffekten führt. Stabile Gesichtsfeldverbesserungen von Patienten mit Nervus opticus Läsionen wurden im 2-Monate-Follow-up nach 10-tägiger tACS beobachtet. Es ist zu erwarten, dass nicht-invasive Hirnstimulationsverfahren zunehmende Bedeutung in der klinischen Anwendung erhalten werden.
Perceptual Learning Induced by Short-Term Training with Visual Stimuli: Effects of Retinal Position and Stimulus Type
Authors: Skrandies Wolfgang
Published: November 2011

We investigated perceptual learning in 85 healthy adults with stereoscopic information contained in dynamic random dot stimuli or with vernier targets. Stimuli were flashed simultaneously at 8 locations at an eccentricity of 1.15° or 2.3°, and subjects had to detect a target in an “8 Alternative Forced Choice” task. For training at a given eccentricity stimuli at the other eccentricity served as a “no training” control. Viewing of visual targets for about 20 minutes resulted in a significant increase of discrimination performance only for the trained stimuli (significant interaction between training and time). Thus, learning is position specific: improved performance can be demonstrated only when test and training stimuli are presented to the same retinal areas. In combination with our earlier electrophysiological results, this study illustrates how perceptual training induces stimulus and visual field specific neural plasticity in adults.
The fate of evaporated water from the Ganges basin
Authors: Tuinenburg O. A. , Hutjes R. W. A. , Kabat P.
Published: November 2011

This research studies river basin moisture recycling rates in order to determine the atmospheric part of the water cycle and the influence of the land surface there on. For river basins in India (Ganges and Indus), the fraction of evaporation that falls again as precipitation in the same river basin (the moisture recycling) is determined. Furthermore, the seasonal variance of moisture recycling and the fraction of precipitation that originates from evaporation from the same river basin is quantified. Using a quasi‐isentropic moisture tracking scheme, evaporation from land surfaces in India is tracked through the atmosphere until precipitation brings it back to the land surface. This scheme is forced with ERA‐Interim reanalysis data from 1990 to 2009. With the information about the atmospheric paths of water vapor, the distance between evaporation and precipitation location is determined. To get an approximation of the influence of land use on the atmospheric moisture budget, the atmospheric paths of water vapor from two bordering areas with different evaporative regimes are compared. Results show a strong annual cycle in the recycling ratio. For the Ganges basin, the recycling ranges from 5% during the winter months (November–March) to 60% during the June–July–August season. The comparison of two focus areas in the Ganges basin with a difference in March–August evaporation shows that during the premonsoon months (March–May), up to 70% of the evaporation difference between the two areas recycles within the Ganges basin. Analysis of the soil moisture nudging terms in ERA‐Interim compared to independent irrigation data strongly suggest this evaporation difference can be attributed to large‐scale irrigation. The importance of basin moisture recycling for precipitation shows an annual cycle as well. An annual average of 4.5% of Ganges precipitation originates from water evaporating in the Ganges basin. During the dry winter monsoon, any precipitation originates from sources outside the basin. During March–April–May and October–November, 10% of the precipitation originates from evaporation within the basin. During the summer monsoon season, the large influx of moisture from the Indian Ocean dominates the precipitation, and recycling is 5% of precipitation.
Resource partitioning in relation to cohabitation of Lactobacillus species in the mouse forestomach
Authors: Tannock Gerald W , Wilson Charlotte M , Loach Diane , Cook Gregory M , Eason Jocelyn , O'Toole Paul W , Holtrop Grietje , Lawley Blair
Published: November 2011

Phylogenetic analysis of gut communities of vertebrates is advanced, but the relationships, especially at the trophic level, between commensals that share gut habitats of monogastric animals have not been investigated to any extent. Lactobacillus reuteri strain 100–23 and Lactobacillus johnsonii strain 100–33 cohabit in the forestomach of mice. According to the niche exclusion principle, this should not be possible because both strains can utilise the two main fermentable carbohydrates present in the stomach digesta: glucose and maltose. We show, based on gene transcription analysis, in vitro physiological assays, and in vivo experiments that the two strains can co-exist in the forestomach habitat because 100–23 grows more rapidly using maltose, whereas 100–33 preferentially utilises glucose. Mutation of the maltose phosphorylase gene (malA) of strain 100–23 prevented its growth on maltose-containing culture medium, and resulted in the numerical dominance of 100–33 in the forestomach. The fundamental niche of L. reuteri 100–23 in the mouse forestomach can be defined in terms of ‘glucose and maltose trophism’. However, its realised niche when L. johnsonii 100–33 is present is ‘maltose trophism’. Hence, nutritional adaptations provide niche differentiation that assists cohabitation by the two strains through resource partitioning in the mouse forestomach. This real life, trophic phenomenon conforms to a mathematical model based on in vitro bacterial doubling times, in vitro transport rates, and concentrations of maltose and glucose in mouse stomach digesta.
Exploring binding site of human RBP4 towards discovery of novel inhibitor for treatment of cardiovascular diseases
Authors: Lakshmi Narayana Rao C , Raziya Beevi LA , Umamaheswari Amineni
Published: November 2011

Retinol binding proteins (RBPs) are transport proteins that act by solubilizing and protecting their labile ligands in aqueous spaces. In addition, RBPs have diverse and specific functions in regulating the disposition, metabolism and activities of retinoids. Elevated levels of retinol-binding protein 4 (RBP4) are observed in cardiovascular disease conditions, which prompts it as a potential drug target. Therefore, computational approach methods were implemented herein to design a novel inhibitor for RBP4. Crystal structure (2wq9) of RBP4 was retrieved and investigated to locate retinol binding site residues (Lys29, Pro32, Leu35, Phe36, Leu37, Phe45, Ala55, Ala57, Met73, Val74, Gly75, Met88, Try90, His104, Gln117, Arg121, Try133, Phe135, Phe137). Five existing inhibitors of RBP4 were explored against more than one million entries of the Ligand.Info metadatabase to create an in-house library of 2000 compounds. A ligand dataset was prepared using LigPrep and filtered based on Lipinski’s rule of five and reactive group constraints. The crystal structure was optimized and energy minimized applying OPLS force field in Maestro v9.2. Thirteen leads were found to have good binding affinity towards RBP4 through virtual screening workflow of Maestro. Lead 1, namely equilenin (-12.87 kcal/mol) which showed better XPG score was proposed as a potential RBP4 inhibitor. Analysis of docking complexes for the proposed lead revealed a stable hydrogen bond network with good van der Waal interactions and binding orientations. Thus, equilenin would be useful for developing potential drug molecules for cardiovascular diseases.
Silicon carbide-based photonic crystal nanocavities for ultra-broadband operation from infrared to visible wavelengths
Authors: Yamada Shota , Song Bong-Shik , Asano Takashi , Noda Susumu
Published: November 2011

To realize nanophotonic devices that operate in both the infrared and visible wavelength ranges on a single wafer, we investigated the optical characteristics of silicon carbide (SiC)-based photonic crystal nanocavities. By fabricating nanocavities with lattice constants ranging from 150 to 600 nm, we experimentally demonstrated resonant wavelengths of individual cavities ranging from 550 to 1450 nm on a single SiC wafer. Furthermore, this ultra-broadband operation reveals the material dispersion of the thin SiC wafer, which is estimated as nSiC = 2.34 + 9.18 × 104/λ2, over the wide range of aforementioned wavelengths.
Particle-particle particle-mesh method for dipolar interactions: On error estimates and efficiency of schemes with analytical differentiation and mesh interlacing
Authors: Cerdà Joan J. , Ballenegger V. , Holm C.
Published: November 2011

The interlaced and non-interlaced versions of the dipolar particle-particle particle-mesh (P3M) method implemented using the analytic differentiation scheme (AD-P3M) are presented together with their respective error estimates for the calculation of the forces, torques, and energies. Expressions for the optimized lattice Green functions, and for the Madelung self-forces, self-torques and self-energies are given. The applicability of the theoretical error estimates are thoroughly tested and confirmed in several numerical examples. Our results show that the accuracy of the calculations can be improved substantially when the approximate (mesh computed) Madelung self-interactions are subtracted. Furthermore, we show that the interlaced dipolar AD-P3M method delivers a significantly higher accuracy (which corresponds approximately to using a twice finer mesh) than the conventional method, allowing thereby to reduce the mesh size with respect to the non-interlaced version for a given accuracy. In addition, we present similar expressions for the dipolar ik-differentiation interlaced scheme, and we perform a comparison with the AD interlaced scheme. Rough tests for the relative speed of the dipolar P3M method using ik-differentiation and the interlaced/non-interlaced AD schemes show that when FFT computing time is the bottleneck, usually when working at high precisions, the interlaced AD-scheme can be several times faster than the other two schemes. For calculations with a low accuracy requirement, the interlaced version can perform worse than the ik and the non-interlaced AD schemes.
Kinetics of the reaction of the heaviest hydrogen atom with H2, the 4Heμ + H2 → 4HeμH + H reaction: Experiments, accurate quantal calculations, and variational transition state theory, including kinetic isotope effects for a factor of 36.1 in isotopic mass
Authors: Fleming Donald G. , Arseneau Donald J. , Sukhorukov Oleksandr , Brewer Jess H. , Mielke Steven L. , Truhlar Donald G. , Schatz George C. , Garrett Bruce C. , Peterson Kirk A.
Published: November 2011

The neutral muonic helium atom 4Heμ, in which one of the electrons of He is replaced by a negative muon, may be effectively regarded as the heaviest isotope of the hydrogen atom, with a mass of 4.115 amu. We report details of the first muon spin rotation (μSR) measurements of the chemical reaction rate constant of 4Heμ with molecular hydrogen, 4Heμ + H2 → 4HeμH + H, at temperatures of 295.5, 405, and 500 K, as well as a μSR measurement of the hyperfine coupling constant of muonic He at high pressures. The experimental rate constants, kHeμ, are compared with the predictions of accurate quantum mechanical (QM) dynamics calculations carried out on a well converged Born–Huang (BH) potential energy surface, based on complete configuration interaction calculations and including a Born–Oppenheimer diagonal correction. At the two highest measured temperatures the agreement between the quantum theory and experiment is good to excellent, well within experimental uncertainties that include an estimate of possible systematic error, but at 295.5 K the quantum calculations for kHeμ are below the experimental value by 2.1 times the experimental uncertainty estimates. Possible reasons for this discrepancy are discussed. Variational transition state theory calculations with multidimensional tunneling have also been carried out for kHeμ on the BH surface, and they agree with the accurate QM rate constants to within 30% over a wider temperature range of 200–1000 K. Comparisons between theory and experiment are also presented for the rate constants for both the D + H2 and Mu + H2 reactions in a novel study of kinetic isotope effects for the H + H2 reactions over a factor of 36.1 in isotopic mass of the atomic reactant.
Characterizing molecular motion in H2O and H3O+ with dynamical instability statistics
Authors: Green Jason R. , Hofer Thomas S. , Berry R. Stephen , Wales David J.
Published: November 2011

Sets of finite-time Lyapunov exponents characterize the stability and instability of classically chaotic dynamical trajectories. Here we show that their sample distributions can contain subpopulations identifying different types of dynamics. In small isolated molecules these dynamics correspond to distinct elementary motions, such as isomerizations. Exponents are calculated from constant total energy molecular dynamics simulations of H2O and H3O+, modelled with a classical, reactive, all-atom potential. Over a range of total energy, exponent distributions for these systems reveal that phase space exploration is more chaotic near saddles corresponding to isomerization and less chaotic near potential energy minima. This finding contrasts with previous results for Lennard-Jones clusters, and is explained in terms of the potential energy landscape.