bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on Molecular Conductors: From Organic Semiconductors to Molecular Metals and Superconductors
Authors: Kobayashi Hayao , Kobayashi Akiko , Tajima Hiroyuki
Published: May 2011

The field of molecular conductors was pioneered by works on the semiconducting properties of phthalocyanines and condensed aromatic hydrocarbons in the middle of the last century. Around three decades ago, the first organic superconductor was reported. Since then, various new molecular superconductors based on multichalcogen π molecules such as bis(ethylenedithio)tetrathiafulvalene (BEDT‐TTF), dimethyl(ethylenedithio)diselenadithiafulvalene (DMET), BETS (or BEDT‐TSF=bis(ethylenedithio)tetraselenafulvalene), and [M(dmit)2] (M=Ni, Pd; dmit=4,5‐dimercapto‐1,3‐dithiole‐2‐thione) including unprecedented antiferromagnetic and field‐induced organic superconductors and the first single‐component molecular metals were developed by the members in the Department of Chemistry of the University of Tokyo along with outside collaborators. Studies on the physical properties—especially optical properties—of various types of molecular conductors are also extensively examined.
Spice simulation of intracellular transport: Free diffusion
Authors: Vasilescu Gabriel , Chen Luonan
Published: May 2011

Diffusion is the main mechanism to transport substances (e.g. amino‐acids and proteins) within a cell. In any biological process the number of molecules is too small to satisfy the statistical assumptions implicit in diffusion theory. As an alternative, various methods to simulate diffusion have been developed, which are rather microscopic. Consequently, the time‐scale and volume simulated are forcefully restricted and the final steady‐state cannot be reached. In this paper we propose a macroscopic method, based on the analogy established between diffusing particles and the free electrons moving in a resistor–capacitor (RC) circuit. The purpose of this work is to extend simulation beyond the actual limits of microscopic approaches and thus to obtain additional insight into the essential mechanism of biological systems. Analysis is performed with a publicly‐released package (PSPICE). A procedure to build the electrical model and to fit its parameters is proposed. Simulation yields time‐evolution of particle densities including the final steady‐state and transport efficiency evaluation. Our method equally allows accounting for the presence of a crowded area in the diffusion pathway, the impact of several bursts of fabricated protein, as well as the case of transport simultaneously occurring on many directions. Several examples and a case study are provided to illustrate the effectiveness of our approach.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Synthesis and characterization of gold glyconanoparticles functionalized with sugars of sweet sorghum syrup
Authors: Kumar C. Ganesh , Mamidyala Suman Kumar , Sreedhar Bojja , Reddy Belum V. S.
Published: May 2011

Gold glyconanoparticles were synthesized by a simple, rapid, and eco‐friendly method by using sweet Sorghum syrup for application in biomedicine and biotechnology. The nanostructures of the prepared gold nanoparticles were confirmed by using UV‐visible absorbance, TEM, SAED, FTIR, EDAX, XRD, and photoluminescence analyses. The formation of gold nanoparticles at both room and boiling temperatures and kinetics of the reaction were monitored by UV‐visible spectroscopy and TEM studies. TEM analysis revealed that the obtained nanoparticles were mono‐dispersed and spherical in shape with an average particle size of 7 nm. The size of the nanoparticles was influenced by the concentration of Sorghum syrup. The presence of elemental gold was confirmed by EDAX analysis. Based on the FTIR analysis, it was observed that the sugars present in the Sorghum syrup possibly acts as capping agents. The zeta potential analysis revealed that the glyconanoparticles were negatively charged with a potential of −25 mV. The XRD and SAED patterns also suggest that the nanoparticles were crystalline in nature and these particles were found to exhibit visible photoluminescence. Fructose and glucose present in sweet Sorghum syrup were demonstrated as responsible sugars for the reduction of gold ions, and sucrose stabilized the formed nanoparticles. The proposed mechanism for the formation and stabilization of gold glyconanoparticles is based on the phenomenon of “macromolecular crowding.” This is the first report on the use of sweet Sorghum syrup for the green synthesis of gold glyconanoparticles at both room and boiling temperatures. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Regulators of macrophage activation
Authors: Martinez Fernando O.
Published: May 2011

Macrophages are ubiquitous phagocytes that can constitute up to 15% of the cellular content of tissues. These heterogeneous cells of the innate immune system perform important functions during health and disease. Equipped with receptors for the T helper cell cytokines INF‐γ and IL‐4, macrophages undergo specific activation programs during Th1 or Th2 immune responses. These activation profiles, termed classical (M1) or alternative (M2) activation respectively, are further tuned by the presence and recognition of microbial‐associated molecular patterns, other cytokines, lipids, and even adhesion to the substratum. The activation of macrophages also relies on the maturation background of the cells, elicitation of complicated intracellular signalling cascades, and the crosstalk between the different signalling elements. Of interest, not all genes participating in the activation‐related signalling cascades are equally important for the elicitation of functional profiles and a regulator gene hierarchy is emerging for the different types of activation. In this issue of the European Journal of Immunology, two papers add to our understanding of how cellular kinases and phosphatases, related to the PI3K pathway, regulate M1 or M2 activation programmes in macrophages.
Sequential Combination of Ruthenium‐, Base‐, and Gold‐Catalysis – A New Approach to the Synthesis of Medicinally Important Heterocycles
Authors: Ramachary Dhevalapally B. , Narayana Vidadala V.
Published: May 2011

A general approach to the high‐yielding synthesis of medicinally important heterocycles was achieved through the sequential combination of ring‐closing metathesis, base‐induced ring opening (BIRO), hydroamination, and a Diels–Alder reaction of functionalized allyl‐(2‐allylphenyl)amines in the presence of a catalytic amount of Grubbs' second‐generation catalyst, base (tBuOK), and [AuCl(PPh3)]/AgOTf. Herein, we also demonstrate the important electronic factors in the BIRO of N‐substituted‐benzo[b]azepines for the regioselective synthesis of functionalized (Z)‐N‐substituted‐2‐(buta‐1,3‐dienyl)phenylamines in very good yields with high purity; these are very good, useful compounds in medicinal chemistry. We also discovered the selective cascade synthesis of privileged hexahydrophenanthridines from (Z)‐N‐substituted‐2‐(buta‐1,3‐dienyl)phenylamines by gold catalysis in moderate to good yields with >99 % diastereomeric excess. The possible reaction mechanism for the unusual hydroamination followed by [4+2] cycloaddition of functionalized (Z)‐N‐substituted‐2‐(buta‐1,3‐dienyl)phenylamines through gold catalysis is discussed in this work.
What should these rivers look like? Historical range of variability and human impacts in the Colorado Front Range, USA
Authors: Wohl Ellen
Published: May 2011

Historical range of variability (HRV) describes the range of temporal and spatial variations in river variables such as flow regime or channel planform prior to intensive human alteration of the ecosystem. In mountainous river networks, HRV is most usefully applied to spatially differentiated geomorphic process domains with distinctive form and process. Using the Colorado Front Range as an example, three examples of how knowledge of HRV can assist river management and restoration are discussed. The examples involve instream wood load and channel morphology, beaver colonies and valley‐bottom form and process, and flow thresholds in regulated rivers. The question of what a river should look like – that is, what range of process and form the river included prior to intensive human alteration – can be addressed by (i) placing the river within a process domain, (ii) establishing correlations between form parameters that can be remotely sensed and reach‐scale process and form, so that the spatial extent, connectivity, and rarity of process domains within a river network or a region can be quickly assessed, (iii) inferring characteristics of the river prior to intensive alteration by documenting characteristics of the least altered reference rivers and by using proxy indicators of pre‐alteration conditions, and (iv) establishing process thresholds that must be exceeded to maintain form (e.g. flow thresholds to mobilize bed sediment). Once this context has been established, resource managers can better evaluate the options for restoring altered riverine form and function. Copyright © 2011 John Wiley & Sons, Ltd.
Functional alterations of large‐scale brain networks related to cognitive control in obsessive‐compulsive disorder
Authors: Cocchi Luca , Harrison Ben J , Pujol Jesus , Harding Ian H , Fornito Alex , Pantelis Christos , Yücel Murat
Published: May 2011

Objectives: Neuroimaging studies have consistently implicated alterations of the basal ganglia and orbitofrontal cortex in the pathophysiology of OCD, however, recent work also emphasizes more diffuse patterns of brain alteration as occurring in this disorder. The goal of this study was to extend such observations by investigating large‐scale brain functional network correlates of cognitive‐control performance in OCD patients. Experimental design: We combined fMRI with a validated task of cognitive control and a multivariate statistical method to assess multiple functional networks encompassing broad task‐relevant cortical regions in OCD patients and matched controls. Functional networks of interest were targeted a priori and the groups were compared in terms of the spatiotemporal profile of network responses (functional connectivity) during the task performance in a data‐driven manner. Principal observations: Task performance was equivalent in both groups and each distinct network demonstrated strong overlap in its general response during task. However, significant differences in functional connectivity were also observed between groups that appeared driven by specific phases of task performance. Such differences were most pronounced during rest‐task transitions and mainly involved dorsal anterior cingulate and insular cortices within the paralimbic network. Relative heightened functional connectivity of insula in patients during task correlated with a measure of patients' state anxiety. Conclusions: Our findings provide a novel functional imaging characterization of brain network alterations associated with cognitive‐control in OCD. Additionally, these findings raise questions about the role of patients' arousal states on the performance of cognitive imaging tasks that are otherwise assumed to be emotionally neutral. Hum Brain Mapp, 2011. © 2011 Wiley‐Liss, Inc.
COMPARING AND DECOMPOSING DIFFERENCES IN PREVENTIVE AND HOSPITAL CARE: USA VERSUS TAIWAN
Authors: Hsiou Tiffany R. , Pylypchuk Yuriy
Published: May 2011

As the USA expands health insurance coverage, comparing utilization of healthcare services with countries like Taiwan that already have universal coverage can highlight problematic areas of each system. The universal coverage plan of Taiwan is the newest among developed countries, and it is known for readily providing access to care at low costs. However, Taiwan experiences problems on the supply side, such as inadequate compensation for providers, especially in the area of preventive care. We compare the use of preventive, hospital, and emergency care between the USA and Taiwan. The rate of preventive care use is much higher in the USA than in Taiwan, whereas the use of hospital and emergency care is about the same. Results of our decomposition analysis suggest that higher levels of education and income, along with inferior health status in the USA, are significant factors, each explaining between 7% and 15% of the gap in preventive care use. Our analysis suggests that, in addition to universal coverage, proper remuneration schemes, education levels, and cultural attitudes towards health care are important factors that influence the use of preventive care. Copyright © 2011 John Wiley & Sons, Ltd.
Deficiency of the mitochondrial transporter of aspartate/glutamate aralar/AGC1 causes hypomyelination and neuronal defects unrelated to myelin deficits in mouse brain
Authors: Ramos Milagros , Pardo Beatriz , Llorente‐Folch Irene , Saheki Takeyori , del Arco Araceli , Satrústegui Jorgina
Published: May 2011

The aralar/AGC1 knockout (KO) mouse shows a drastic decrease in brain aspartate and N‐acetylaspartate levels and global hypomyelination, which are attributed to the lack of neuron‐produced NAA used by oligodendrocytes as precursor of myelin lipid synthesis. In addition, these mice have a gradual drop in brain glutamine synthesis. We show here that hypomyelination is more pronounced in gray than in white matter regions. We find a lack of neurofilament‐labelled processes in hypomyelinated fiber tracks from cerebral cortex but not from those of the cerebellar granule cell layer, which correspond to Purkinje neurons. Therefore, the impaired development or degeneration of neuronal processes in cerebral cortex is independent of hypomyelination. An increase in O4‐labelled, immature oligodendrocytes is observed in gray and white matter regions of the aralar KO brain, suggesting a block in maturation compatible with the lack of NAA supplied by neurons. However, no defects in oligodendrocyte maturation were observed in in‐vitro‐cultured mixed astroglial cultures. We conclude that the primary defect of pyramidal neurons in cerebral cortex is possibly associated with a progressive failure in glutamatergic neurotransmission and may be among the main causes of the pathology of aralar/AGC1 deficiency. © 2011 Wiley‐Liss, Inc.
Determination of parabens in cosmetic products by solid‐phase microextraction of poly(ethylene glycol) diacrylate thin film on fibers and ultra high‐speed liquid chromatography with diode array detector
Authors: Fei Ting , Li Haifang , Ding Mingyu , Ito Masahito , Lin Jin‐Ming
Published: May 2011

The fabrication of a solid‐phase microextraction (SPME) fiber through UV‐induced polymerization of poly(ethylene glycol) diacrylate (PEG‐DA) for determination of parabens in cosmetic products is presented in this work. The PEG‐DA polymer coating was covalently attached to the fiber by introducing a surface modification with 3‐(trichlorosilyl)propyl methacrylate (TPM). The PEG‐DA polymer thin film coated on the fiber was homogeneous and wrinkled, which led to an increase of the surface area and high extraction efficiency. The extraction performances of the prepared SPME fibers were assessed by preconcentration of parabens including methylparaben, ethylparaben, propylparaben and benzylparaben from cosmetic products. The analysis was performed on an ultra high‐speed liquid chromatography with diode array detector. The prepared SPME fibers exhibited good repeatability (for one fiber) and reproducibility (fiber‐to‐fiber) with RSDs of 5.4 and 6.9%, respectively. The optimized SPME method supported a wide linear range of 0.50–160 μg/mL and the detection limits for parabens were in the range of 0.12–0.15 μg/mL (S/N=3). The developed method was successfully applied for determination of parabens in cosmetic products with different natures.
Could 13C MRI assist clinical decision‐making for patients with heart disease?
Authors: Malloy Craig R. , Merritt Matthew E. , Dean Sherry A.
Published: May 2011

Even at this early stage of development, it is clear that the imaging of hyperpolarized 13C‐enriched molecules and their metabolic products offers a new approach to the study of the physiology and disease of the heart. The technology is practical in humans and, for this reason, we consider whether a role in clinical decision‐making should motivate further development. The range of interventions available to treat coronary and valvular heart disease is already extensive, and new options are imminent. Yet the appropriate management of patients with left ventricular dysfunction can be challenging because the mechanism of reduced function may be unclear and the ability of the ventricle to respond to therapy may be difficult to predict. Pyruvate is a promising early target for development as a diagnostic agent because it lies at a critical branch point in cardiac biochemistry. The rate of metabolism of hyperpolarized pyruvate to CO2 relative to lactate may prove to be a useful indicator of preserved mitochondrial function, and therefore provide a specific signal of viable myocardium. Other species including physiological substrates and nonphysiological molecules may provide additional information. Once suitable technology becomes available, it is likely that clinical research will progress quickly. The ability to monitor directly specific metabolic pathways may lead to an improvement in the selection of patients who will benefit from interventions, pharmacologic or otherwise. Copyright © 2011 John Wiley & Sons, Ltd.
Using next‐generation sequencing for the diagnosis of rare disorders: a family with retinitis pigmentosa and skeletal abnormalities
Authors: Schrader Kasmintan A , Heravi‐Moussavi Alireza , Waters Paula J , Senz Janine , Whelan James , Ha Gavin , Eydoux Patrice , Nielsen Torsten , Gallagher Barry , Oloumi Arusha , Boyd Niki , Fernandez Bridget A , Young Terry‐Lynn , Jones Steven JM , Hirst Martin , Shah Sohrab P , Marra Marco A , Green Jane , Huntsman David G
Published: May 2011

Linkage analysis with subsequent candidate gene sequencing is typically used to diagnose novel inherited syndromes. It is now possible to expedite diagnosis through the sequencing of all coding regions of the genome (the exome) or full genomes. We sequenced the exomes of four members of a family presenting with spondylo‐epiphyseal dysplasia and retinitis pigmentosa and identified a six‐base‐pair (6‐bp) deletion in GNPTG, the gene implicated in mucolipidosis type IIIγ. The diagnosis was confirmed by biochemical studies and both broadens the mucolipidosis type III phenotype and demonstrates the clinical utility of next‐generation sequencing to diagnose rare genetic diseases. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Fattening by deprivation: methyl balance and perinatal cardiomyopathy
Authors: Joseph Jacob
Published: May 2011

Folate deficiency during pregnancy is associated with reduced birth weight, and a low birth weight is associated with increased cardiometabolic risk in adulthood. In the study by Moreno Garcia, Guéant‐Rodriguez and colleagues reported in the current issue of the Journal of Pathology, the effect of methyl group deprivation in pregnancy on the neonatal myocardium was investigated. By utilizing a diet deficient in folate, vitamin B12 and choline, the authors created a significant deficit of methyl groups in the fetus. During the weaning period and the concomitant shift from the relative hypoxia and glucose dependence of the gestational period to the aerobic, milk‐derived high‐fat metabolic environment of the weaning phase, the offspring developed a myocardial hypertrophy associated with disordered fatty acid oxidation and mitochondrial dysfunction. The functionality of PGC‐1α, a master regulator of metabolic pathways including mitochondrial energetics and fatty acid oxidation, was found to be reduced in the methyl‐deprived group, due to an imbalance in the ratio of methylation to acetylation. This study demonstrates that maternal methyl deprivation could ‘prime’ the fetus by reducing its ability to oxidize fatty acids in the myocardium, thereby causing lipid accumulation and myocardial hypertrophy during exposure to high‐fat diet in the weaning phase. This study has important implications for clinical perinatal cardiomyopathy and for the effect of maternal methyl group deprivation on the future risk of cardiovascular disease, and also potentially in enhancing the understanding of the elusive link between hyperhomocysteinaemic states in the adult and cardiovascular disease. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Reducing charging effects in scanning electron microscope images by Rayleigh contrast stretching method (RCS)
Authors: Wan Ismail W. Z. , Sim K. S. , Tso C. P. , Ting H. Y.
Published: May 2011

To reduce undesirable charging effects in scanning electron microscope images, Rayleigh contrast stretching is developed and employed. First, re‐scaling is performed on the input image histograms with Rayleigh algorithm. Then, contrast stretching or contrast adjustment is implemented to improve the images while reducing the contrast charging artifacts. This technique has been compared to some existing histogram equalization (HE) extension techniques: recursive sub‐image HE, contrast stretching dynamic HE, multipeak HE and recursive mean separate HE. Other post processing methods, such as wavelet approach, spatial filtering, and exponential contrast stretching, are compared as well. Overall, the proposed method produces better image compensation in reducing charging artifacts. SCANNING 33: 233–251, 2011. © 2011 Wiley Periodicals, Inc.
Post‐traumatic Stress Disorder, Anxiety and Depression among the Elderly: A Survey of the Hard‐hit Areas a Year after the Wenchuan Earthquake
Authors: Zhang Zhen , Shi Zhanbiao , Wang Li , Liu Mingxin
Published: May 2011

Few studies to date have examined psychological sequelae of natural disasters among the elderly in China. The aim of this study was to investigate the prevalence rates of probable post‐traumatic stress disorder (PTSD), anxiety and depression in the elderly survivors a year after the Wenchuan earthquake as well as to analyse related risk factors. The community‐based sample of the study consisted of 284 elderly survivors (≥60 years). PTSD was assessed by the PTSD Checklist—Civilian version, and anxiety and depression were assessed by the Hopkins Symptoms Checklist. In total, the estimated prevalence rates of probable PTSD, anxiety and depression were 26.3%, 42.9% and 35.2%, respectively. Nearly a fifth of the elderly participants reported symptoms that meet the criteria for all three of these mental disorders. Results indicated that some factors associated with earthquake‐exposure intensity, which included loss of livelihood, bereavement, injury and initial fear during the earthquake, were among the significant risk factors for these mental disorders. Women had a higher risk of suffering from probable anxiety as compared to men. Finally, the significance and limitations of this study were also discussed. Copyright © 2011 John Wiley & Sons, Ltd.
The Comparative Study of Empires
Authors: Vasunia Phiroze
Published: May 2011

On the basis of a random sample of English-language internet websites about empires, we can now formulate the first law of comparative imperialisms as follows: as an online discussion of empire grows longer, the probability of a comparison involving the Roman Empire approaches 1. (This is a variant of the general law that states that ‘as an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches 1’.) The comparative study of empires is thriving, and the recent intensity of interest is connected, at least in part, to the international military interventions of the United States. But comparisons between empires are nothing new, and, in the 1960s, Peter Brunt wrote an insightful article on British and Roman imperialism. That analysis was the product of the age of decolonization, an age which also acted as a spur to comparative approaches within classical scholarship: witness Nicole Loraux's suggestion that it was anti-colonial movements associated with the Algerian and Vietnam wars that led Jean-Pierre Vernant to embark on his series of comparative investigations into Greek thought and religion. Brunt's article was written in a retrospective key at a time when it was possible to look back to the completion, or the near completion, of a major period of European colonialism and arrive at a sort of reckoning. Some two generations prior to Brunt, in the early twentieth century and at the apogee of the British Empire, Lord Cromer delivered an address to the Classical Association on ‘Ancient and Modern Imperialism’ in which he found it unimaginable to think of independence for Britain's overseas colonies. Francis Haverfield responded sympathetically to Cromer and in his own writings associated the British and the Roman empires. Any discussion of comparative imperialisms, therefore, will need to consider not just the recent concentration of debates over empire but also a lengthy trajectory that extends back to Cromer and Haverfield and indeed further beyond into the eighteenth century. None of the books under review reflects in detail on the intellectual history in which they may be situated, but this is a subject that at least needs to be acknowledged and that we shall have occasion to return to later.
Extended Statistical Learning as an account for slow vocabulary growth*
Authors: STOKES STEPHANIE F. , KERN SOPHIE , SANTOS CHRISTOPHE DOS
Published: May 2011

Stokes (2010) compared the lexicons of English-speaking late talkers (LT) with those of their typically developing (TD) peers on neighborhood density (ND) and word frequency (WF) characteristics and suggested that LTs employed learning strategies that differed from those of their TD peers. This research sought to explore the cross-linguistic validity of this conclusion. The lexicons (production, not recognition) of 208 French-speaking two-year-old children were coded for ND and WF. Regression revealed that ND and WF together predicted 62% of the variance in vocabulary size, with ND and WF uniquely accounting for 53% and 9% of that variance respectively. Epiphenomenal findings were ruled out by comparison of simulated data sets with the actual data. A generalized Mann–Whitney test showed that children with small vocabularies had significantly higher ND values and significantly lower WF values than children with large vocabularies. An extended statistical learning theory is proposed to account for the findings.
Adult congenital cardiac surgery in Indonesia
Authors: Wilamarta Karina V. , Yuniadi Yoga , Rachmat Jusuf , Fakhri Dicky , Hakim Tarmizi , Anwar Maizul
Published: May 2011

Background

Successful paediatric cardiac surgery and cardiology treatment has resulted in an increase in the use of surgery as a method of treatment of congenital cardiac disease in adult population. However, late detection and lower socio-economic condition in developing countries might change patients’ characteristics by the time they come for treatment. This study aimed to elaborate the long-term surgical results of adult congenital cardiac disease in Indonesia as a developing country.

Methods and results

We reviewed retrospectively all adult congenital cardiac disease patients with a mean age of 28 years plus or minus 9.5 years, who underwent surgery at National Cardiovascular Center. The types of procedures used were corrective in 338 patients (89.2%), palliative in 10 patients (2.6%), and re-operations in 31 patients (8.2%). The overall hospital mortality rate was 2.6% but as high as 20% with palliative surgery. Post-operative New York Heart Association class III–IV is the only independent predictor of death at 60 months (hazard ratio 61.48, 95% confidence interval 9.41–401.69, p<0.001). The survival rates were 96.3% and 95% for overall and non-atrial septal defect in patients at 60 months, which was highest in corrective procedures (97.6%). The percentage of patients free of re-operation at 5 years’ follow-up was 85.4% and 42.7% at 10 years.

Conclusion

In developing countries, surgical treatment of adult congenital cardiac disease is effective and safe, with an overall survival rate of 96.3% at 60 months. Due to high mortality rate, palliative surgery of a non-atrial septal defect patient is recommended to be discontinued. The independent predictor of mortality was post-operative New York Heart Association functional class III–IV.
Silent rupture of sinus of Valsalva aneurysm: a refutation of the Okham's razor principle
Authors: Dayan Joseph , Sett Suvro , Krishnan Usha
Published: May 2011

Aneurysm of the sinus of Valsalva is an uncommon congenital lesion rarely reported in children. Unruptured aneurysms commonly go undiagnosed until a rupture has occurred. Usually, ruptured sinus of Valsalva presents with cardiac failure. There may be a history of trauma or infective endocarditis preceding the rupture. Asymptomatic paediatric presentation of ruptured sinus of Valsalva is rare. We discuss the cases of two children who presented with a murmur and were diagnosed with ruptured sinus of Valsalva. This unusual presentation in children highlights the importance of careful routine physical examinations and the evaluation of new murmurs. The Okham's razor principle states that “when you hear hoofbeats – think horses not zebras”. Sometimes, it is important to think beyond the usual in medicine, to avoid missing lesions that, if left untreated, could lead to adverse outcomes.
A differential equation for specific catchment area
Authors: Gallant John C. , Hutchinson Michael F.
Published: May 2011

Analysis of the behavior of specific catchment area in a stream tube leads to a simple nonlinear differential equation describing the rate of change of specific catchment area along a flow path. The differential equation can be integrated numerically along a flow path to calculate specific catchment area at any point on a digital elevation model without requiring the usual estimates of catchment area and width. The method is more computationally intensive than most grid‐based methods for calculating specific catchment area, so its main application is as a reference against which conventional methods can be tested. This is the first method that provides a benchmark for more approximate methods in complex terrain with both convergent and divergent areas, not just on simple surfaces for which analytical solutions are known. Preliminary evaluation of the D8, M8, digital elevation model networks (DEMON), and D∞ methods indicate that the D∞ method is the best of those methods for estimating specific catchment area, but all methods overestimate in divergent terrain.
Organophosphorus Chemistry
Authors: Keglevich Gyorgy , Odinets Irina , Migaud M , Roeschenthaler Gerd-Volker , Balczewski Piotr , Stewart Frederick , Slinn Robert
Published: May 2011

Organophosphorus Chemistry provides a comprehensive and critical review of the recent literature. Coverage includes phosphines and their chalcogenides, phosphonium salts, low coordination number phosphorus compounds, penta- and hexa- coordinated compounds, quiquevalent phosphorus acids, nucleotides and nucleic aicds, ylides and related compounds, phosphazenes and the application of physical methods in the study of organophosphorus compounds.

This is the 40th in a series of volumes which first appeared in 1970 under the editorship of Stuart Trippett and which covered the literature of organophosphorus chemistry published in the period from January 1968 to June 1969, citing some 1370 publications. The present volume covers the literature from January 2009 to January 2010, citing more than 2200 publications, continuing our efforts to provide an up to date survey of progress in an area of chemistry that has expanded significantly over the past 40 years.
Study of the influence of vane angle on shaft output of a multivane air turbine. II. Different rotor to casing diameter ratios with optimal injection angle
Authors: Singh Bharat Raj , Singh Onkar
Published: May 2011

This paper describes new results towards performance evaluations of a compressed air driven vane type rotary novel air turbine/engine. The compressed air has potential of becoming nearly zero pollution power source for running the prime-mover/engine of the small bikes/motorbikes. The proposed air turbine will transform the energy of compressed air into mechanical shaft work in place of the internal combustion engine. The effect of isobaric admission and adiabatic expansion of high pressure air for different rotor to casing diameter ratios at optimum injection and vane angles are considered in the mathematical model presented in this paper. The results are evaluated with optimal vane angles, injection angles, different rotor/casing ratios, and different casing diameters. It is seen that the power output is optimum to the typical values of rotor/casing diameter ratios (d/D). In this study, the maximum power outputs for linear expansion (i.e., for minimum air consumptions) are obtained as 3.98 kW (5.41 HP) at d/D = 0.70, 5.50 kW (7.48 HP) at d/D = 0.80, and 6.08 kW (8.27 HP) at d/D = 0.85 when casing diameters (D) are 100 mm, 150 mm, and 200 mm, respectively, at injection pressure 90 psi (6 bar) and speed of rotation 2500 rpm.
First-principle calculation of stacking fault energies in Ni and Ni-Co alloy
Authors: Chandran Mahesh , Sondhi S. K.
Published: May 2011

The (111) intrinsic stacking fault energy γISF in Ni and Ni-Co alloy was calculated and compared using two different ab initio methods, viz., the supercell approach and the axial interaction model (AIM), based on density functional theory. The supercell approach uses energies of crystal structure in slab geometry with and without the stacking fault. In the AIM approach, the problem is mapped to a 1D spin-model and the interaction parameters are obtained using energies for ordered structures, thus obviating the need to handle faulted structure. For elemental Ni, the calculated values of γISF from AIM and supercell approaches differ by not more than by 2%, and compares well with experimental value. For Ni-Co alloy, AIM predicts a slightly faster decrease in γISF with increasing Co concentration compared to supercell approach and experimental data. Overall, there is good agreement between the two approaches.
Electronic properties of highly-doped and compensated solar-grade silicon wafers and solar cells
Authors: Veirman J. , Dubois S. , Enjalbert N. , Garandet J.-P. , Lemiti M.
Published: May 2011

Compensation effects are intensively studied on two highly doped ingots grown from solar-grade silicon feedstocks purified using metallurgical routes, through a comparison of the electrical properties at iso-carrier densities. Working at given carrier densities enables a clearer extraction of the compensation effects, at the wafer and solar cell levels. At the wafer level, the majority carrier mobility and the carrier lifetime are investigated. Regarding the mobilities, it was found that current models may underestimate the amount of incomplete ionization of boron leading to underestimated mobilities. In addition, the majority carrier mobility was found to be strongly affected at high compensation level. Regarding the carrier lifetimes, our results show that after a phosphorus diffusion step, dopants alone — and especially boron — can limit the lifetime in highly doped solar-grade silicon. At the cell level, I-V characteristics under standard illumination were studied. In particular, the observed reductions in short-circuit current on solar cells having a very high compensation level could be explained in terms of a compensation-induced reduction in the minority carrier mobility. We also report high conversion efficiencies of up to 15.9% on solar cells showing a boron content greater than two ppmw (2.6 × 1017 cm−3), which is generally considered unsuitable for solar cell manufacturing.
Duality relations in the auxiliary field method
Authors: Silvestre-Brac Bernard , Semay Claude
Published: May 2011

The eigenenergies ε(N)(m; {ni, li}) of a system of N identical particles with a mass m are functions of the various radial quantum numbers ni and orbital quantum numbers li. Approximations E(N)(m; Q) of these eigenenergies, depending on a principal quantum number Q({ni, li}), can be obtained in the framework of the auxiliary field method. We demonstrate the existence of numerous exact duality relations linking quantities E(N)(m; Q) and E(p)(m′; Q′) for various forms of the potentials (independent of m and N) and for both nonrelativistic and semirelativistic kinematics. As the approximations computed with the auxiliary field method can be very close to the exact results, we show with several examples that these duality relations still hold, with sometimes a good accuracy, for the exact eigenenergies ε(N)(m; {ni, li}).
Commuting to the Centre in Different Urban Structures
Authors: Helminen Ville , Rita Hannu , Ristimäki Mika , Kontio Panu
Published: May 2011

Density gradients have been a common approach when estimating decentralisation processes with monocentric models. In this study the gradient approach is applied to measure the traditional pattern of commuting to the centre from surrounding areas. Availability of empirical origin–destination data on commuting enables comparisons between increasing numbers of different urban areas. Empirical data on commuting patterns in nine cities from Finland and the United Kingdom are used. In the model the probability of commuting depends on the distance to the centre. The result is the parameterisation of the distance-decay curve of commuting. The estimated parameter values enable identification of different urban structures.
Evolution of the knowledge system for agricultural development in the Yaqui Valley, Sonora, Mexico
Authors: McCullough Ellen B. , Matson Pamela A.
Published: May 2011

Knowledge systems—networks of linked actors, organizations, and objects that perform a number of knowledge-related functions that link knowledge and know how with action—have played a key role in fostering agricultural development over the last 50 years. We examine the evolution of the knowledge system of the Yaqui Valley, Mexico, a region often described as the home of the green revolution for wheat, tracing changes in the functions of critical knowledge system participants, information flows, and research priorities. Most of the knowledge system's key players have been in place for many decades, although their roles have changed in response to exogenous and endogenous shocks and trends (e.g., drought, policy shifts, and price trends). The system has been agile and able to respond to challenges, in part because of the diversity of players (evolving roles of actors spanning research–decision maker boundaries) and also because of the strong and consistent role of innovative farmers. Although the agricultural research agenda in the Valley is primarily controlled from within the agricultural sector, outside voices have become an important influence in broadening development- and production-oriented perspectives to sustainability perspectives.
Inflammatory disease protective R381Q IL23 receptor polymorphism results in decreased primary CD4+ and CD8+ human T-cell functional responses
Authors: Sarin Ritu , Wu Xingxin , Abraham Clara
Published: May 2011

The SNP (c.1142G > A;p.R381Q) in the IL-23 receptor (IL23R) confers protection from multiple inflammatory diseases, representing one of the most significant human genetic polymorphisms in autoimmunity. We, therefore, sought to define the functional consequences of this clinically significant variant. We find that CD4+CD45RO+ and CD8+ T cells from healthy R381Q IL23R carriers show decreased IL-23–dependent IL-17 and IL-22 production relative to WT IL23R individuals. This was associated with a lower percentage of circulating Th17 and Tc17 cells. Furthermore, CD8+ T cells from R381Q IL23R individuals showed decreased IL-23–dependent expansion and signal transducer and activator of transcription 3 (STAT3) activation compared with WT CD8+ T cells. Importantly, cells transfected with the IL23R glutamine variant show decreased IL-23–mediated signaling compared with the IL23R arginine allele. Our results show that the R381Q IL23R variant leads to selective, potentially desirable, loss of function alterations in primary human CD4+ and CD8+ T cells, resulting in highly significant protection against autoimmunity.
CCCTC-binding factor (CTCF) and cohesin influence the genomic architecture of the
Igh
locus and antisense transcription in pro-B cells
Authors: Degner Stephanie C. , Verma-Gaur Jiyoti , Wong Timothy P. , Bossen Claudia , Iverson G. Michael , Torkamani Ali , Vettermann Christian , Lin Yin C. , Ju Zhongliang , Schulz Danae , Murre Caroline S. , Birshtein Barbara K. , Schork Nicholas J. , Schlissel Mark S. , Riblet Roy , Murre Cornelis , Feeney Ann J.
Published: May 2011

Compaction and looping of the ~2.5-Mb
Igh
locus during V(D)J rearrangement is essential to allow all V
H
genes to be brought in proximity with D
H
-J
H
segments to create a diverse antibody repertoire, but the proteins directly responsible for this are unknown. Because CCCTC-binding factor (CTCF) has been demonstrated to be involved in long-range chromosomal interactions, we hypothesized that CTCF may promote the contraction of the
Igh
locus. ChIP sequencing was performed on pro-B cells, revealing colocalization of CTCF and Rad21 binding at ~60 sites throughout the V
H
region and 2 other sites within the
Igh
locus. These numerous CTCF/cohesin sites potentially form the bases of the multiloop rosette structures at the
Igh
locus that compact during Ig heavy chain rearrangement. To test whether CTCF was involved in locus compaction, we used 3D-FISH to measure compaction in pro-B cells transduced with CTCF shRNA retroviruses. Reduction of CTCF binding resulted in a decrease in
Igh
locus compaction. Long-range interactions within the
Igh
locus were measured with the chromosomal conformation capture assay, revealing direct interactions between CTCF sites 5′ of
DFL16
and the 3′ regulatory region, and also the intronic enhancer (Eμ), creating a D
H
-J
H
-Eμ-C
H
domain. Knockdown of CTCF also resulted in the increase of antisense transcription throughout the D
H
region and parts of the V
H
locus, suggesting a widespread regulatory role for CTCF. Together, our findings demonstrate that CTCF plays an important role in the 3D structure of the
Igh
locus and in the regulation of antisense germline transcription and that it contributes to the compaction of the
Igh
locus.
Targeting and imaging single biomolecules in living cells by complementation-activated light microscopy with split-fluorescent proteins
Authors: Pinaud Fabien , Dahan Maxime
Published: May 2011

Single-molecule (SM) microscopy allows outstanding insight into biomolecular mechanisms in cells. However, selective detection of single biomolecules in their native environment remains particularly challenging. Here, we introduce an easy methodology that combines specific targeting and nanometer accuracy imaging of individual biomolecules in living cells. In this method, named complementation-activated light microscopy (CALM), proteins are fused to dark split-fluorescent proteins (split-FPs), which are activated into bright FPs by complementation with synthetic peptides. Using CALM, the diffusion dynamics of a controlled subset of extracellular and intracellular proteins are imaged with nanometer precision, and SM tracking can additionally be performed with fluorophores and quantum dots. In cells, site-specific labeling of these probes is verified by coincidence SM detection with the complemented split-FP fusion proteins or intramolecular single-pair Förster resonance energy transfer. CALM is simple and combines advantages from genetically encoded and synthetic fluorescent probes to allow high-accuracy imaging of single biomolecules in living cells, independently of their expression level and at very high probe concentrations.
Transfer characteristics of a thermosensory synapse in
Caenorhabditis elegans
Authors: Narayan Anusha , Laurent Gilles , Sternberg Paul W.
Published: May 2011

Caenorhabditis elegans
is a compact, attractive system for neural circuit analysis. An understanding of the functional dynamics of neural computation requires physiological analyses. We undertook the characterization of transfer at a central synapse in
C. elegans
by combining optical stimulation of targeted neurons with electrophysiological recordings. We show that the synapse between AFD and AIY, the first stage in the thermotactic circuit, exhibits excitatory, tonic, and graded release. We measured the linear range of the input-output curve and estimate the static synaptic gain as 0.056 (<0.1). Release showed no obvious facilitation or depression. Transmission at this synapse is peptidergic. The AFD/AIY synapse thus seems to have evolved for reliable transmission of a scaled-down temperature signal from AFD, enabling AIY to monitor and integrate temperature with other sensory input. Combining optogenetics with electrophysiology is a powerful way to analyze
C. elegans
’ neural function.
Actin polymerization driven by WASH causes V-ATPase retrieval and vesicle neutralization before exocytosis
Authors: Carnell Michael , Zech Tobias , Calaminus Simon D. , Ura Seiji , Hagedorn Monica , Johnston Simon A. , May Robin C. , Soldati Thierry , Machesky Laura M. , Insall Robert H.
Published: May 2011

WASP and SCAR homologue (WASH) is a recently identified and evolutionarily conserved regulator of actin polymerization. In this paper, we show that WASH coats mature Dictyostelium discoideum lysosomes and is essential for exocytosis of indigestible material. A related process, the expulsion of the lethal endosomal pathogen Cryptococcus neoformans from mammalian macrophages, also uses WASH-coated vesicles, and cells expressing dominant negative WASH mutants inefficiently expel C. neoformans. D. discoideum WASH causes filamentous actin (F-actin) patches to form on lysosomes, leading to the removal of vacuolar adenosine triphosphatase (V-ATPase) and the neutralization of lysosomes to form postlysosomes. Without WASH, no patches or coats are formed, neutral postlysosomes are not seen, and indigestible material such as dextran is not exocytosed. Similar results occur when actin polymerization is blocked with latrunculin. V-ATPases are known to bind avidly to F-actin. Our data imply a new mechanism, actin-mediated sorting, in which WASH and the Arp2/3 complex polymerize actin on vesicles to drive the separation and recycling of proteins such as the V-ATPase.
The physiology of acute pain
Authors: Bromley Lesley
Published: May 2011

Acute pain as a result of tissue damage is self-limiting.

Impulses are generated in primary sensory nerves by chemical mediators released from the damaged tissues.

The spinal cord receives these impulses in the dorsal horn.

At the level of the spinal cord, the impulses can be amplified or reduced in amplitude by descending inputs.

At the level of the spinal cord, the representation of the painful area and the sensitivity of other, surrounding areas can be modified.

At the level of the brainstem and thalamus, further modification can take place.

The final perception of the pain can be modified by other central phenomena such as anxiety and fear.

New imaging techniques have allowed a greater understanding of cortical representation of pain.

The role of the glia in maintaining painful states is evolving.
Acute pain in children
Authors: Howard Richard F.
Published: May 2011

Age and maturity affect the perception and expression of pain in children.

A variety of pain assessment tools are needed to cover different age groups.

The British National Formulary for Children is a source of correct formulations and doses of analgesics for children of different ages.

Neonates show very high interindividual response to analgesic drugs.

Between 2yrs and 12yrs, the clearance of drugs exceeds that of adults and relatively higher doses may be needed.

Patient-controlled, nurse-controlled, and neuraxial analgesia can all be used in infants and children.

Reducing procedural pain in children is important and requires a combination of pharmacological and non-pharmacological methods.