bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimized handover and resource management: an 802.21‐based scheme to optimize handover and resource management in hybrid satellite‐terrestrial networks
Authors: Dhaou Riadh , Ben‐El‐Kezadri Ryad , Fasson Julien , Arnal Fabrice , Dubois Emmanuel , Gelard Patrick
Published: November 2013

Satellite communications can provide fourth generation (4G) networks with large‐scale coverage. However, their integration to 4G is challenging because satellite networks have not been designed with handover in mind. The setup of satellite links takes time, and so, handovers must be anticipated long before. This paper proposes a generic scheme based on the Institute of Electrical and Electronics Engineers 802.21 standard to optimize handover and resource management in hybrid satellite‐terrestrial networks. Our solution, namely optimized handover and resource management (OHRM), uses the terrestrial interface to prepare handover, which greatly speeds up the establishment of the satellite link. We propose two mechanisms to minimize the waste of bandwidth due to wrong handover predictions. First, we leverage the support of 802.21 in the terrestrial access network to shorten the path of the signaling messages towards the satellite resource manager. Second, we cancel the restoration of the satellite resources when the terrestrial link rolls back. We use OHRM to interconnect a digital video broadcasting and a wireless 4G terrestrial network. However for the simulation tool, we use a WiMAX as the terrestrial technology to illustrate the schemes. The simulation results show that OHRM minimizes the handover delay and the signaling overhead in the terrestrial and satellite networks. Copyright © 2013 John Wiley & Sons, Ltd.
Memshepherd: comprehensive memory bug fault‐tolerance system
Authors: Zou Deqing , Zheng Weide , Jiang Wenbin , Jin Hai , Chen Gang
Published: November 2013

Among all software vulnerabilities, memory bugs are most common and dangerous. Programs written in unsafe languages such as C and C++ are vulnerable to stack‐based buffer overflow, heap buffer overflow, dangling pointer, and double free. Although there are a number of proposed solutions to tolerate heap related bugs, most of the existing solutions terminates the vulnerable program after a stack‐based buffer overflow attempt. There is no comprehensive solution to actively tolerate all of the four kinds of bugs mentioned previously currently. This paper presents Memshepherd, a system that can probabilistically prevent software from both stack and heap memory bugs and guarantee soundness of the software execution. It dynamically reallocates stack‐based buffers in the heap space during software execution, thus transforms a stack memory problem into a heap memory problem. By adaptively sizing buffers to be M times of their defined size and randomly placing them, Memshepherd keeps the buffers far from each other. When a buffer is to be deallocated, Memshepherd checks invalid and double frees. A Linux prototype is implemented and tested against four kinds of memory bugs. The experiment results prove that Memshepherd is effective in eliminating crashes, erroneous execution, as well as security vulnerability. Copyright © 2013 John Wiley & Sons, Ltd.
Exposure to Discrimination and Heart Rate Variability Reactivity to Acute Stress among Women with Diabetes
Authors: Wagner Julie , Lampert Rachel , Tennen Howard , Feinn Richard
Published: November 2013

Exposure to racial discrimination has been linked to physiological reactivity. This study investigated self‐reported exposure to racial discrimination and parasympathetic [high‐frequency heart rate variability (HF‐HRV)] and sympathetic (norepinephrine and cortisol) activity at baseline and then again after acute laboratory stress. Lifetime exposure to racial discrimination was measured with the Schedule of Racist Events scale. Thirty‐two women (16 Black and 16 White) with type 2 diabetes performed a public speaking stressor. Beat‐to‐beat intervals were recorded on electrocardiograph recorders, and HF‐HRV was calculated using spectral analysis and natural log transformed. Norepinephrine and cortisol were measured in blood. Higher discrimination predicted lower stressor HF‐HRV, even after controlling for baseline HF‐HRV. When race, age, A1c and baseline systolic blood pressure were also controlled, racial discrimination remained a significant independent predictor of stressor HF‐HRV. There was no association between lifetime discrimination and sympathetic markers. In conclusion, preliminary data suggest that among women with type 2 diabetes mellitus (T2DM), exposure to racial discrimination is adversely associated with parasympathetic, but not sympathetic, reactivity. Copyright © 2013 John Wiley & Sons, Ltd.
Long‐Term Maternal Stress and Post‐traumatic Stress Symptoms Related to Developmental Outcome of Extremely Premature Infants
Authors: Zerach Gadi , Elsayag Adi , Shefer Shahar , Gabis Lidia
Published: November 2013

In this study, we examined the relations between the severity of developmental outcomes of extremely low birth weight (ELBW) children and their mothers' stress and post‐traumatic stress disorder (PTSD) symptoms, 4–16 years after birth. Israeli mothers (N = 78) of a cohort of extremely premature infants (24–27 weeks) born 4–16 years earlier were asked to report about the medical and developmental condition of their child and their current perceived stress and PTSD symptoms. Results show that mothers of ELBW children with normal development reported the lowest perceived stress compared with mothers of ELBW children with developmental difficulties. We also found that 25.6% of the mothers had the potential to suffer from PTSD following the birth of an ELBW child. Furthermore, the severity of prematurity developmental outcomes made a significant contribution to mothers' perceived stress. To sum, mothers of ELBW infants' perceived stress is related to their children's severity of prematurity developmental outcomes, 4–16 years after birth. Clinical implications of these findings are discussed. Copyright © 2013 John Wiley & Sons, Ltd.
The Demand‐Induced Strain Compensation Questionnaire: A Cross‐national Validation Study
Authors: Bova Nicoletta , De Jonge Jan , Guglielmi Dina
Published: November 2013

The demand‐induced strain compensation model is a theoretical job stress model that has been tested in different kinds of empirical study in several countries. To measure key concepts in the model (job demands and job resources), the demand‐induced strain compensation questionnaire (DISQ) was developed and has been used in many empirical studies. However, most studies neither focused on the psychometric properties of the DISQ nor tested it cross‐nationally. In this study, we examined the psychometric properties of the DISQ tested on Italian (n = 422) and Dutch (n = 1629) employees. Results indicated that the six‐factor model, consisting of cognitive, emotional and physical job demands as well as cognitive, emotional and physical job resources, provided a better fit to the data than an alternative two‐factor model (demands and resources only). Findings were invariant across Italian and Dutch samples. Internal consistencies were satisfactory. Additionally, the six dimensions of DISQ were found to be meaningfully related to employee active learning behaviour, emotional exhaustion and musculoskeletal disorders. Results suggest the DISQ questionnaire is a valid and reliable instrument to measure the proposed dimensions of job demands and job resources in both Italian and Dutch work contexts. Copyright © 2013 John Wiley & Sons, Ltd.
In praise of a green stimulus
Authors: Zenghelis Dimitri
Published: November 2013

Macroeconomic conditions make this a relatively favorable time to kick‐start investments necessary to transition to a resource‐efficient economy. There is no lack of private money, just a perceived lack of opportunity. Resource costs are low and the potential to crowd out alternative investment and employment is greatly reduced. It is often argued that the short‐term macroeconomic merit of an investment, in terms of what constitutes a good economic stimulus, can be judged against established criteria. These include tests on whether an investment is timely, temporary, and targeted. Although these are important, the evidence presented here suggests that a more important criterion for a sustainable economic impact is the ability to generate private sector confidence in profitable and enduring new markets. The world is likely to transition to a resource‐efficient, low‐carbon economy over this century and managing this transition has early pay‐offs. Clear and credible green policies have the potential restore confidence and generate growth. Providing credible early incentives to invest in resource‐efficiency could generate investment and growth in the long and the short run. WIREs Clim Change 2014, 5:7–14. doi: 10.1002/wcc.256

This article is categorized under:

Climate Economics > Economics of Mitigation
Criticizing green stimulus
Authors: Brahmbhatt Milan
Published: November 2013

The outbreak of the global economic crisis in 2008 led to a revival of interest in fiscal policy as an instrument for counter‐cyclical stimulus. A feature of this revival was a focus on undertaking ‘Green Stimulus’ as a way to stimulate short‐run economic activity while also advancing long‐term environmental goals, such as tackling climate change. The thesis of this paper is that, while some elements of Green Stimulus may have met the stated dual objectives, many are likely to have been relatively ineffective as fiscal stimulus, or as green instruments, or as both. We note some general reasons to qualify the case for Green Stimulus before taking a look at the limited empirical evidence on the effectiveness of Green Stimulus, as well as at some flaws of specific Green Stimulus policy instruments adopted in many countries, for example Renewable Energy and ‘Green Infrastructure’. Finally why, if green stimulus is likely to be relatively ineffective, has it garnered so much support? The answer perhaps lies in the realm of politics rather than economics, in particular the famous ‘Rahm Emmanuel Doctrine’ that ‘you never want a serious crisis to go to waste’. WIREs Clim Change 2014, 5:15–21. doi: 10.1002/wcc.257

This article is categorized under:

Climate Economics > Economics of Mitigation
Synthesis and Characterization of the New Copper Indium Phosphate Cu8In8P4O30
Authors: Hanzelmann Christian , Weimann Iren , Feller Jörg , Žak Zdirad
Published: November 2013

The system CuO/In2O3/P2O5 has been investigated using solid state reaction between CuO, In2O3 and (NH4)2HPO4 in silica glass crucibles at 900 °C. The powder samples were characterized by X‐ray diffraction, thermal analysis and FT‐IR spectroscopy. Orange single crystals of the new quaternary phase were achieved by the process of crystallization with mineralizers in sealed silica glass ampoules. They were then analyzed with EDX and single‐crystal X‐ray analysis in which the composition Cu8In8P4O30 with the triclinic space group P$\bar{1}$ (No 2) with a = 7,2429(14) Å, b = 8,8002(18) Å, c = 10,069(2) Å, α = 103,62(3)°, β = 106,31(3)°, γ = 101,55(3)° and Z = 1 was found. The three‐dimensional framework consists of [InO6] octahedra and distorted [CuO6] octahedra, overcaped [InO7] prisms and [PO4] tetrahedra, also trigonal [(CuIn)O5] bipyramids and distorted [(CuIn)O6] octahedra, where copper and indium are partly exchanged against each other. Cu8In8P4O30 exhibits an incongruent melting point at 1023 °C.
On three-algebra and bi-fundamental matter amplitudes and integrability of supergravity
Authors: Huang Yu-tin , Johansson Henrik , Lee Sangmin
Published: November 2013

Abstract

We explore tree-level amplitude relations for SU(N) × SU(M) bi-fundamental matter theories. Embedding the group-theory structure in a Lie three-algebra, we derive Kleiss-Kuijf-like relations for bi-fundamental matter theories in general dimension. We investigate the three-algebra color-kinematics duality for these theories. Unlike the Yang-Mills two-algebra case, the three-algebra Bern-Carrasco-Johansson relations depend on the spacetime dimension and on the detailed symmetry properties of the structure constants. We find the presence of such relations in three and two dimensions, and absence in D > 3. Surprisingly, beyond six point, such relations are absent in the Aharony-Bergman-Jafferis-Maldacena theory for general gauge group, while the Bagger-Lambert-Gustavsson theory, and its supersymmetry truncations, obey the color-kinematics duality like clockwork. At four and six points the relevant partial amplitudes of the two theories are bijectively related, explaining previous results in the literature. In D = 2 the color-kinematics duality gives results consistent with integrability of two-dimensional
$ \mathcal{N} $
= 16 supergravity: the four-point amplitude satisfies a Yang-Baxter equation; the six- and eight-point amplitudes vanish for certain kinematics away from factorization channels, as expected from integrability.
MbtH homology codes to identify gifted microbes for genome mining
Authors: Baltz Richard H
Published: November 2013

Advances in DNA sequencing technologies have made it possible to sequence large numbers of microbial genomes rapidly and inexpensively. In recent years, genome sequencing initiatives have demonstrated that actinomycetes with large genomes generally have the genetic potential to produce many secondary metabolites, most of which remain cryptic. Since the numbers of new and novel pathways vary considerably among actinomycetes, and the correct assembly of secondary metabolite pathways containing type I polyketide synthase or nonribosomal peptide synthetase (NRPS) genes is costly and time consuming, it would be advantageous to have simple genetic predictors for the number and potential novelty of secondary metabolite pathways in targeted microorganisms. For secondary metabolite pathways that utilize NRPS mechanisms, the small chaperone-like proteins related to MbtH encoded by Mycobacterium tuberculosis offer unique probes or beacons to identify gifted microbes encoding large numbers of diverse NRPS pathways because of their unique function(s) and small size. The small size of the mbtH-homolog genes makes surveying large numbers of genomes straight-forward with less than ten-fold sequencing coverage. Multiple MbtH orthologs and paralogs have been coupled to generate a 24-mer multiprobe to assign numerical codes to individual MbtH homologs by BLASTp analysis. This multiprobe can be used to identify gifted microbes encoding new and novel secondary metabolites for further focused exploration by extensive DNA sequencing, pathway assembly and annotation, and expression studies in homologous or heterologous hosts.
Characterization of a marine-derived dextranase and its application to the prevention of dental caries
Authors: Jiao Yu-Liang , Wang Shu-Jun , Lv Ming-Sheng , Jiao Bing-Hua , Li Wei-Juan , Fang Yao-Wei , Liu Shu
Published: November 2013

The dextranase added in current commercial dextranase-containing mouthwashes is largely from fungi. However, fungal dextranase has shown much higher optimum temperature than bacterial dextranase and relatively low activity when used in human oral cavities. Bacterial dextranase has been considered to be more effective and suitable for dental caries prevention. In this study, a dextranase (Dex410) from marine Arthrobacter sp. was purified and characterized. Dex410 is a 64-kDa endoglycosidase. The specific activity of Dex410 was 11.9 U/mg at optimum pH 5.5 and 45 °C. The main end-product of Dex410 was isomaltotriose, isomaltoteraose, and isomaltopentaose by hydrolyzing dextran T2000. In vitro studies showed that Dex410 effectively inhibited the Streptococcus mutans biofilm growth in coverage, biomass, and water-soluble glucan (WSG) by more than 80, 90, and 95 %, respectively. The animal experiment revealed that for short-term use (1.5 months), both Dex410 and the commercial mouthwash Biotene (Laclede Professional Products, Gardena, CA, USA) had a significant inhibitory effect on caries (p = 0.0008 and 0.0001, respectively), while for long-term use (3 months), only Dex410 showed significant inhibitory effect on dental caries (p = 0.005). The dextranase Dex410 from a marine-derived Arthrobacter sp. strain possessed the enzyme properties suitable to human oral environment and applicable to oral hygiene products.
Arthroscopic Dorsal Wrist Ganglion Excision with Color-Aided Visualization of the Stalk: Minimum 1-Year Follow-Up
Authors: Ahsan Zahab S. , Yao Jeffrey
Published: November 2013

Background

Dorsal wrist ganglia (DWG) are a common, benign soft-tissue mass of the wrist. Excision of DWG is a common procedure performed by hand surgeons and may be performed using either open or arthroscopic techniques. This study aims to evaluate the frequency of stalk visualization with intralesional injection of inert dye in the course of arthroscopic excision along with incidence of recurrence with a minimum of 1-year follow-up.

Methods

Upon IRB approval, a retrospective chart review was performed identifying 27 patients who had consecutively undergone arthroscopic excision of a DWG with the coloraided technique at our institution with a minimum follow-up duration of 12 months. Intraoperative findings were reviewed. Patients were contacted to investigate for incidence of recurrence.

Results

Of the 27-patient cohort, the ganglion stalk was identified in 100 % of the color-aided arthroscopic DWG excisions. Ganglion recurrence was identified in one patient, an incidence of 3.7 %.

Conclusions

The color-aided technique for arthroscopic DWG visualization was found to be a safe and valuable tool for surgeons performing arthroscopic DWG resection. The intraarticular ganglion stalk was identified in 100 % of cases and patients responded well with a low incidence of recurrence.
Mechanical Properties and Microstructure of AZ31B Magnesium Alloy Processed by I-ECAP
Authors: Gzyl Michal , Rosochowski Andrzej , Pesci Raphael , Olejnik Lech , Yakushina Evgenia , Wood Paul
Published: November 2013

Incremental equal channel angular pressing (I-ECAP) is a severe plastic deformation process used to refine grain size of metals, which allows processing very long billets. As described in the current article, an AZ31B magnesium alloy was processed for the first time by three different routes of I-ECAP, namely, A, BC, and C, at 523 K (250 °C). The structure of the material was homogenized and refined to ~5 microns of the average grain size, irrespective of the route used. Mechanical properties of the I-ECAPed samples in tension and compression were investigated. Strong influence of the processing route on yield and fracture behavior of the material was established. It was found that texture controls the mechanical properties of AZ31B magnesium alloy subjected to I-ECAP. SEM and OM techniques were used to obtain microstructural images of the I-ECAPed samples subjected to tension and compression. Increased ductility after I-ECAP was attributed to twinning suppression and facilitation of slip on basal plane. Shear bands were revealed in the samples processed by I-ECAP and subjected to tension. Tension–compression yield stress asymmetry in the samples tested along extrusion direction was suppressed in the material processed by routes BC and C. This effect was attributed to textural development and microstructural homogenization. Twinning activities in fine- and coarse-grained samples have also been studied.
Synthesis, Purification, and Acyl Migration Kinetics of 2‐Monoricinoleoylglycerol
Authors: Compton David L. , Laszlo Joseph A. , Appell Michael , Vermillion Karl E. , Evans Kervin O.
Published: November 2013

2‐Monoricinoleoylglycerol (2‐MRG) was synthesized by the Novozym 435 catalyzed alcoholysis of castor oil in excess ethanol (1:70 mol:mol) at ambient temperature. Due to the fatty acid C12‐OH group, conventional liquid–liquid extraction methods developed for less polar, non‐hydroxylated 2‐monoacylglycerols (2‐MAG) proved inadequate for 2‐MRG purification. Alternatively, 2‐MRG was purified by normal‐phase flash chromatography (FC) on silica gel using a binary acetone‐hexane gradient mobile phase. Gram quantities of 2‐MRG were isolated in 63 % yield and contained no residual diacylglycerol (DAG), which fail to separate using liquid–liquid extraction methods. The 2‐MRG was obtained at ~90 mol% relative to 1‐MRG, proving that the FC method did not appreciably catalyze acyl migration. 1H‐NMR spectroscopy was used to monitor the spontaneous acyl migration of isolated 2‐MRG from 20 to 80 °C. The relative energy of activation calculated from the Arrhenius relationship of the 2‐MRG acyl migration rate constants was 82.9 kJ/mol. This was ~two‐fold higher than the theoretical ΔG298.15 calculated from molecular modeling using density functional calculations (B3LYP/6−31 + G*) of 2‐MRG, the ketal ring transition state, and 1‐monoricinoleoylglycerol (1‐MRG). The synthesis and isolation methods reported herein provide a convenient means to access useful intermediates for functionalized structured lipids.
Cachexia vs obesity: where is the real unmet clinical need?
Authors: von Haehling Stephan , Anker Stefan D.
Published: November 2013

A striking discrepancy exists in the number of publications on obesity as compared to cachexia or wasting disorders. In PubMed, the number of entries that contain “cachexia” as a title word is only 1,825, whereas the number of entries for “obesity” in the title is 47,828, giving a ratio of 1:26 in favor of “obesity” publications. The difference in publication activities in these two fields has further broadened over the last years. Looking at guidance from national or international guidelines, PubMed analysis is even more depressing with 147 entries for obesity, but only four for cachexia. None of the latter provides guidance for the everyday care of cachectic patients. This publication activity is in stark contrast to the mortality impact of cachexia vs obesity at the time of diagnosis, which is at least 20 times higher for cachexia over the first 5 years. We assume, the mismatch is even bigger when it comes to public research support for these two medical conditions, which likely is a big part of the reason for this publication imbalance. Another reason may be that there is a perception bias in the research community, the public and hence also among healthcare providers and politicians as to what is important in medicine. We think, cachexia is at least as big an unmet need as is obesity. For shorter‐term outcomes, cachexia is certainly a much bigger medical need than obesity. We hope that the current research efforts will change the situation for the better of our patients.
Chromosome instability and carcinogenesis: Insights from murine models of human pancreatic cancer associated with BRCA2 inactivation
Authors: Cassidy Liam D. , Liau Siong-Seng , Venkitaraman Ashok R.
Published: November 2013

Chromosomal instability is a hallmark of human cancer cells, but its role in carcinogenesis remains poorly resolved. Insights into this role have emerged from studies on the tumour suppressor BRCA2, whose inactivation in human cancers causes chromosomal instability through the loss of essential functions of the BRCA2 protein in the normal mechanisms responsible for the replication, repair and segregation of DNA during cell division. Humans who carry heterozygous germline mutations in the BRCA2 gene are highly predisposed to cancers of the breast, ovary, pancreas, prostate and other tissues. Here, we review recent studies that describe genetically engineered mouse models (GEMMs) for pancreatic cancer associated with BRCA2 mutations. These studies not only surprisingly show that BRCA2 does not follow the classical Knudson “two hit” paradigm for tumour suppression, but also highlight features of the interplay between TP53 inactivation and carcinogenesis in the context of BRCA2 deficiency. Thus, the models reveal novel aspects of cancer evolution in carriers of germline BRCA2 mutations, provide new insights into the tumour suppressive role of BRCA2, and establish valuable new preclinical settings for testing approaches to pancreatic cancer therapy; together, these features emphasize the value of GEMMs in cancer research.
Threshold shear stress for the transition between tumbling and tank-treading of red blood cells in shear flow: dependence on the viscosity of the suspending medium
Authors: Fischer Thomas M. , Korzeniewski Rafal
Published: November 2013

Red blood cells are the subject of diverse studies. One branch is the observation and theoretical modelling of their behaviour in a shear flow. This work deals with the flow of single red cells suspended in solutions much more viscous than blood plasma. Below a critical shear rate (${\dot {\gamma } }_{t} $) the red cells rotate with little change of their resting shape. Above that value they become elongated and aligned in the shear field. We measured${\dot {\gamma } }_{t} $at viscosities (${\eta }_{0} $) ranging from 10.7 to 104 mPa s via observation along the vorticity of a Poiseuille flow in a glass capillary;${\eta }_{0} {\dot {\gamma } }_{t} $decreased steeply with increasing${\eta }_{0} $up to a value of 25 mPa s and remained constant for higher values. Present theoretical models are not in keeping with the measured data. Modifications of basic model assumptions are suggested.
Cardiac involvement in geleophysic dysplasia in three siblings of a Saudi family
Authors: Elhoury Motea E. , Faqeih Eissa , Almoukirish Abdulrahman S. , Galal Mohammed O.
Published: November 2013

Geleophysic dysplasia is an extremely rare acromelic skeletal dysplasia resembling lysosomal storage disease. It is characterised by characteristic facial phenotype, short stature, micromelia, joint contracture, and early cardiac valvular involvement. It has been described worldwide in <40 patients. Herein, we describe the cardiac features in three Saudi sisters with proved autosomal recessive geleophysic dysplasia who showed different levels of severity of their cardiac involvement.
Procollagen type III amino-terminal propeptide: a serum biomarker of left ventricular remodelling in paediatric dilated cardiomyopathy
Authors: Kaufman Beth D. , Videon Nancy , Zhang Xuemei , Harris Matthew A. , Shaddy Robert E. , Goldmuntz Elizabeth
Published: November 2013

Background

Procollagen type III amino-terminal propeptide is a collagen III cleavage product released in blood. The serum levels of this propeptide in adults with dilated cardiomyopathy are associated with cardiac remodelling and prognosis. The utility of procollagen type III amino-terminal propeptide as a biomarker in paediatric dilated cardiomyopathy is unknown.

Methods

This was a prospective, longitudinal study of children with dilated cardiomyopathy and changes in procollagen type III amino-terminal propeptide. The serum level of propeptide was measured serially, compared with paediatric normal values, and correlated with clinical status and left ventricular size and function on echocardiograms and cardiac magnetic resonance imaging.

Results

Procollagen type III amino-terminal propeptide was measured serially in 149 samples from 39 patients, age 9.0±6.4 years, followed up for 16.8±16.3 months. Procollagen type III amino-terminal propeptide in dilated cardiomyopathy was higher than in normal children. On multivariate analyses, procollagen type III amino-terminal propeptide had a positive correlation with left ventricular dilation, left ventricular end-diastolic diameter index (p<0.0001), and left ventricular end-diastolic diameter Z-score (p=0.0003), and a negative correlation with shortening fraction changes over time (p=0.001). Patients with myocarditis (n=12) had higher procollagen type III amino-terminal propeptide values than those with idiopathic dilated cardiomyopathy (n=20).

Conclusions

Procollagen type III amino-terminal propeptide increases with left ventricular dilation and decreases with improvement in systolic function in paediatric dilated cardiomyopathy, indicating a role as a biomarker of cardiac remodelling in children. The diagnostic utility of procollagen type III amino-terminal propeptide to differentiate myocarditis from idiopathic dilated cardiomyopathy warrants further investigation.
A temporal analysis of the spatial clustering of food outlets around schools in Christchurch, New Zealand, 1966 to 2006
Authors: Day Peter L , Pearce Jamie R , Pearson Amber L
Published: November 2013

Objective

To explore changes in urban food environments near schools, as potential contributors to the rising prevalence of overweight and obesity among children.

Design

Addresses of food premises and schools in 1966, 1976, 1986, 1996 and 2006 were geo-coded. For each year, the number and proportion of outlets by category (supermarket/grocery; convenience; fast-food outlet) within 800 m of schools were calculated. The degree of spatial clustering of outlets was assessed using a bivariate K-function analysis. Food outlet categories, school level and school social deprivation quintiles were compared.

Setting

Christchurch, New Zealand.

Subjects

All schools and food outlets at 10-year snapshots from 1966 to 2006.

Results

Between 1966 and 2006, the median number of supermarkets/grocery stores within 800 m of schools decreased from 5 to 1, convenience stores decreased from 2 to 1, and fast-food outlets increased from 1 to 4. The ratio of fast-food outlets to total outlets increased from 0·10 to 0·67. The clustering of fast-food outlets was greatest within 800 m of schools and around the most socially deprived schools. Over the 40-year study period, school food environments in Christchurch can be characterized by increased densities of fast-food outlets within walking distance of schools, especially around the most deprived schools.

Conclusions

Since the 1960s, there have been substantial changes to the food environments around schools which may increasingly facilitate away-from-home food consumption for children and provide easily accessible, cheap energy-dense foods, a recognized contributor to the rise in prevalence of overweight and obesity among young people.
Selective Neuronal Loss in Ischemic Stroke and Cerebrovascular Disease
Authors: Baron Jean-Claude , Yamauchi Hiroshi , Fujioka Masayuki , Endres Matthias
Published: November 2013

As a sequel of brain ischemia, selective neuronal loss (SNL)—as opposed to pannecrosis (i.e. infarction)—is attracting growing interest, particularly because it is now detectable in vivo. In acute stroke, SNL may affect the salvaged penumbra and hamper functional recovery following reperfusion. Rodent occlusion models can generate SNL predominantly in the striatum or cortex, showing that it can affect behavior for weeks despite normal magnetic resonance imaging. In humans, SNL in the salvaged penumbra has been documented in vivo mainly using positron emission tomography and 11C-flumazenil, a neuronal tracer validated against immunohistochemistry in rodent stroke models. Cortical SNL has also been documented using this approach in chronic carotid disease in association with misery perfusion and behavioral deficits, suggesting that it can result from chronic or unstable hemodynamic compromise. Given these consequences, SNL may constitute a novel therapeutic target. Selective neuronal loss may also develop at sites remote from infarcts, representing secondary ‘exofocal’ phenomena akin to degeneration, potentially related to poststroke behavioral or mood impairments again amenable to therapy. Further work should aim to better characterize the time course, behavioral consequences—including the impact on neurological recovery and contribution to vascular cognitive impairment—association with possible causal processes such as microglial activation, and preventability of SNL.
Rho-Kinase Inhibition Improves Ischemic Perfusion Deficit in Hyperlipidemic Mice
Authors: Shin Hwa Kyoung , Huang Paul L , Ayata Cenk
Published: November 2013

Hyperlipidemia is a major cardiovascular risk factor associated with progressive cerebrovascular dysfunction and diminished collateral perfusion in stroke. Rho-associated kinase (ROCK) may be an important mediator of hyperlipidemic vascular dysfunction. We tested the efficacy of acute or chronic ROCK inhibition on the size of dynamic perfusion defect using laser speckle flowmetry in hyperlipidemic apolipoprotein E knockout mice fed on a high-fat diet for 8 weeks. Mice were studied at an age before the development of flow-limiting atherosclerotic stenoses in aorta and major cervical arteries. Focal ischemia was induced by distal middle cerebral artery occlusion (dMCAO) during optical imaging. The ROCK inhibitor fasudil (10 mg/kg) was administered either as a single dose 1 hour before ischemia onset, or daily for 4 weeks. Fasudil decreased both baseline arterial blood pressure and cerebrovascular resistance (CVR) by ∼15%, and significantly improved tissue perfusion during dMCAO. Interestingly, peri-infarct depolarizations were also reduced. Chronic treatment did not further enhance these benefits compared with acute treatment with a single dose. These data show that ROCK inhibition improves CVR and ischemic tissue perfusion in hyperlipidemic mice.
Highly mobile and reactive state of hydrogen in metal oxide semiconductors at room temperature
Authors: Chen Wan Ping , He Ke Feng , Wang Yu , Chan Helen Lai Wah , Yan Zijie
Published: November 2013

Hydrogen in metal oxides usually strongly associates with a neighboring oxygen ion through an O-H bond and thus displays a high stability. Here we report a novel state of hydrogen with unusually high mobility and reactivity in metal oxides at room temperature. We show that freshly doped hydrogen in Nb2O5 and WO3 polycrystals via electrochemical hydrogenation can reduce Cu2+ ions into Cu0 if the polycrystals are immersed in a CuSO4 solution, while this would not happen if the hydrogenated polycrystals have been placed in air for several hours before the immersion. Time-dependent studies of electrochemically hydrogenated rutile single crystals reveal two distinct states of hydrogen: one as protons covalently bonded to oxygen ions, while the other one is highly unstable with a lifetime of just a few hours. Observation of this mobile and reactive state of hydrogen will provide new insight into numerous moderate and low temperature interactions between metal oxides and hydrogen.
SO3H-functionalized Brønsted acidic ionic liquids as efficient catalysts for the synthesis of isoamyl salicylate
Authors: Tao Duan-Jian , Wu Jing , Wang Zhen-Zhen , Lu Zhang-Hui , Yang Zhen , Chen Xiang-Shu
Published: November 2013

Six Brønsted acidic ionic liquids (BAILs) composed of [HSO4] were prepared, characterized, and used as catalysts of low dosage in the synthesis of isoamyl salicylate.
Negative voltage surge resistant circuit design in HVIC
Authors: Zhu Jing , Sun Guodong , Sun Weifeng , Zhang Yunwu
Published: November 2013

A reliable and methodical solution to restrain transient undershoot on VS pin for a high‐voltage gate drive circuit with a transient negative voltage detector circuit (TNVDC) is proposed. The proposed TNVDC circuit does not consume any quiescent current while the chip works normally and it is totally integrated in a high‐voltage integrated circuit (HVIC) without any additional discrete devices in the system. The proposed circuit could send a control signal to the drive stage of the HVIC for decreasing the sink current while the transient undershoot of the VS is excessive. The measurement shows that the negative voltage surge tolerance is −98 V of the HVIC with TNVDC.
High‐voltage EDMOS transistor with dual work function gate
Authors: Baek K.‐J. , Lee D.‐H. , Kim Y.‐S. , Na K.‐Y.
Published: November 2013

A high‐voltage extended drain MOS (EDMOS) transistor with a dual work function gate (DWFG) is discussed. This device enhances device performance by modifying the electric field in the channel. For DWFG EDMOS device fabrication, the polycrystalline silicon gates on the source and drain sides are doped by p + and n + ion implantation, respectively. Experimental results from the fabricated DWFG EDMOS devices show improved transconductance (gm), drain conductance (gds) and specific on‐resistance (RON) characteristics without breakdown voltage reduction.
Reducing dimensionality effect in importance sampling simulations
Authors: Sanz‐González J.L. , Zazo S. , Álvarez‐Vaquero F.
Published: November 2013

The dimensionality effect is avoided by the use of sufficient statistics in event probability estimators realised by importance sampling. If the system function is not a sufficient statistic, an approach is proposed to reduce the dimensionality effect in the estimators. Simulation results of false‐alarm probability estimations, applied to radar detection, confirm a clear concordance with the theoretical results.
Resistorless switched‐capacitor bandgap voltage reference with low sensitivity to process variations
Authors: Klimach H. , Costa A.L.T. , Monteiro M.F.C. , Bampi S.
Published: November 2013

A novel switched‐capacitor bandgap voltage reference circuit is presented that dispenses entirely with the use of resistors. Since capacitors are used instead of resistors, variability problems from devices mismatch and process spread are reduced, compared with traditional topologies. The proportional‐to‐absolute‐temperature drift and the complementary‐to‐absolute‐temperature drift voltages are both generated by the same PNP vertical bipolar transistor obtained in bulk CMOS, minimising mismatch problems even further. A switched‐capacitor circuit stores, amplifies and sums these voltages, generating the bandgap voltage after five clock cycles. The operational amplifier offset voltage is also cancelled by the switching scheme proposed. The current sources which are used to generate different junction current densities are averaged in the switching process, reducing their mismatch impact on the circuit performance. A systematic comparison to a traditional bandgap topology with resistors is presented, both designed in the CMOS 180 nm process, and demonstrates the better performance of the new topology with respect to the former. Monte Carlo simulations show significantly lower spread resulting from devices mismatch in the output reference voltage (VREF) and also in its temperature coefficient.
Research on temperature characteristic of thermoelectric microwave power sensors based on GaAs MMIC technology
Authors: Wang De‐Bo , Liao Xiaoping
Published: November 2013

The effect of temperature on thermoelectric microwave power sensors is researched in order to extend its application field. The fabrication of this microwave power sensor is divided into a front side and a back side processing using GaAs MMIC process and MEMS technology. The measurement results show that the temperature has a significant effect on the performance of thermoelectric microwave power sensors. The obtained temperature coefficient is about 0.488 mV/(W · K), which has an important reference value for the thermoelectric microwave power sensors. The reason is that the accuracy of microwave power measurement will be realised as long as the environment temperature is tracked.
Charge recycling dual‐rail voltage supply for battery‐powered tags with sleep and active mode operation
Authors: Gim Yeong‐Gyo , Kim Shiho
Published: November 2013

A charge recycling dual‐rail voltage supply is proposed for battery‐powered radio frequency identification tags. By utilising a capacitor voltage divider and recycling charge from the upper to the lower rail with a virtual ground balancing circuit, an implicit on‐chip DC–DC converter can be achieved. The proposed dual voltage scheme provides an effective way of reducing power consumption both in sleep and active modes of operation.
Extraordinary electromagnetic transmission through a circular aperture surrounded by surface corrugations
Authors: Na Dong Yeop , Kim Ji Hyung , Park Yong Bae , Jung Kyung‐Young
Published: November 2013

The authors investigate extraordinary electromagnetic transmission through a circular aperture surrounded by surface corrugations. An electromagnetic boundary‐value problem of a circular aperture surrounded by surface corrugations in a conducting plane is solved based on the mode matching method. The eigenfunction expansion and Hankel transform are used to represent the scattered fields in terms of the discrete and continuous modes, respectively. The boundary conditions are enforced to obtain a set of simultaneous equations. The transmission coefficient and the radiated fields are represented in a fast‐convergent series. Computation is performed to illustrate the behaviours of transmission and radiation against the corrugation geometries. The effects of the corrugation geometries on the extraordinary electromagnetic transmission are discussed.
Adaptive quality of service aware multi‐mobility anchor point registration in hierarchical mobile IPv6 wireless access networks
Authors: Barkoosaraei Ana Mirsayar , Aghvami A. Hamid , Pangalos Paul
Published: November 2013

In hierarchical mobile IPv6 (HMIPv6), mobility anchor points (MAPs) are introduced to reduce the signalling cost by localising the signalling traffic of mobile nodes (MNs). However, the presence of MAPs introduces areas of bottleneck within the network. This study evaluates the impact of overlapped domains of consecutive MAPs in HMIPv6 access networks. In this novel network architecture, an MAP registration algorithm is also proposed to enable MNs to register with more than one MAP simultaneously. For each flow, the proposed algorithm determines a primary and a secondary MAP according to the quality of service (QoS) requirements of the traffic flow. Load balancing is also introduced to provide an even distribution of load among MAPs. In addition, an extended router advertisement is proposed to enable multiple MAP registration of MNs. The impact of the proposed algorithm in the new HMIPv6 network architectures is compared with a non‐QoS aware multi‐MAP registration algorithm in access network with no overlapped MAP domains. The simulation‐based comparison study illustrates a maximum of 71 and 74% improvements in total amount of rejected bandwidth and the mean satisfied flow requests in network, respectively.
Modified one‐cycle‐controlled three‐phase pulse‐width modulation rectifiers under low‐output DC voltage conditions
Authors: Wei Zheng , Chen Jie , Chen Xin , Gong Chun‐ying , Fan Yi
Published: November 2013

The saddle pulse‐width modulation (PWM) that can be obtained by injecting third harmonic current into sampled three‐phase input currents is proposed to introduce in the conventional one‐cycle control (OCC) strategy‐based three‐phase PWMrectifier on this study. In addition, for the three‐level boost‐type neutral‐point‐clamped structure rectifiers such as three‐phase Vienna rectifier, the fluctuation in the neutral‐point‐potential (NPP) is analysed under modified OCC strategy. The proposed control scheme can not only improve the utilisation of DC bus voltage and the efficiency of converter without sacrificing the advantages of the conventional OCC scheme, such as no phase‐locked loop and constant switching frequency, but also is beneficial to suppress the ripple in the DC‐link voltage. Moreover, the neutral‐point voltage loop is added in the proposed OCC scheme, and the neutral‐point voltage controller is employed for controlling the unbalance DC voltage in the NPP which caused by the non‐uniformity of parameters of components. The validity of the theoretical analysis and feasibility of the modified OCC strategy are verified by system simulation and experimental results based on a 5‐kW prototype.
Improvement of vibration energy harvesters through a two-stage design: Power production at single frequency excitation
Authors: Fernando Joseph S. , Sun Qiao
Published: November 2013

A vibration harvester is usually designed to work in resonance responding to source vibration. Many existing types of harvesters use a single mechanical resonator to amplify the excitation vibrations. However, these harvesters are inherently limited in the amount of power that they can produce, due to their design, particularly in the limited number of design parameters. In our study, we propose a two-stage design to improve a harvester's performance both in power production and in bandwidth widening. In this paper, we demonstrate that a two-stage design can increase the power production when the device is intended to operate under a single frequency excitation. Harvester parameters are optimized to provide maximum power production. Power production comparisons between single-stage and two-stage harvesters are made through numerical simulation and experiments.
An atomistic description of the high-field degradation of dielectric polyethylene
Authors: Bealing Clive R. , Ramprasad R.
Published: November 2013

A microscopic mechanism governing the initiating step in the high-field aging of crystalline polyethylene is proposed, based on density functional calculations and ab initio molecular dynamics simulations. It is assumed that electrons, holes, and excitons are present in the system. While the additional individual electrons or holes are not expected to lead to significant degradation, the presence of triplet excitons are concluded to be rather damaging. The electron and hole states of the exciton localize on a distorted region of polyethylene, significantly weakening nearby C–H bonds and facilitating C–H bond scission. The barrier to cleavage of the weakened C–H bonds is estimated and is comparable to the thermal energy, suggesting that this mechanism may be responsible for the degradation of polyethylene when placed under electrical stress, e.g., in high-voltage cables.
Arbitrarily small amounts of correlation for arbitrarily varying quantum channels
Authors: Boche H. , Nötzel J.
Published: November 2013

As our main result show that in order to achieve the randomness assisted message and entanglement transmission capacities of a finite arbitrarily varying quantum channel it is not necessary that sender and receiver share (asymptotically perfect) common randomness. Rather, it is sufficient that they each have access to an unlimited amount of uses of one part of a correlated bipartite source. This access might be restricted to an arbitrary small (nonzero) fraction per channel use, without changing the main result. We investigate the notion of common randomness. It turns out that this is a very costly resource – generically, it cannot be obtained just by local processing of a bipartite source. This result underlines the importance of our main result. Also, the asymptotic equivalence of the maximal- and average error criterion for classical message transmission over finite arbitrarily varying quantum channels is proven. At last, we prove a simplified symmetrizability condition for finite arbitrarily varying quantum channels.
Field ionization characteristics of an ion source array for neutron generators
Authors: Bargsten Johnson B. , Schwoebel P. R. , Resnick P. J. , Holland C. E. , Hertz K. L. , Chichester D. L.
Published: November 2013

A new deuterium ion source is being developed to improve the performance of existing compact neutron generators. The ion source is a microfabricated array of metal tips with an integrated gate (i.e., grid) and produces deuterium ions by field ionizing (or field desorbing) a supply of deuterium gas. Deuterium field ion currents from arrays at source temperatures of 77 K and 293 K are studied. Ion currents from single etched-wire tips operating under the same conditions are used to help understand array results. I-F characteristics of the arrays were found to follow trends similar to those of the better understood single etched-wire tip results; however, the fields achieved by the arrays are limited by electrical breakdown of the structure. Neutron production by field ionization at 293 K was demonstrated for the first time from microfabricated array structures with integrated gates.