bluuebunny/crossref_metadata_2025 huggingface dataset:
Hantaviral mechanisms driving HLA class I antigen presentation require both RIG‐I and TRIF
Authors: Lalwani Pritesh , Raftery Martin J. , Kobak Lidija , Rang Andreas , Giese Thomas , Matthaei Markus , van den Elsen Peter J. , Wolff Thorsten , Krüger Detlev H. , Schönrich Günther
Published: July 2013

Hantaviruses are emerging human pathogens. They induce an unusually strong antiviral response of human HLA class I (HLA‐I) restricted CD8+ T cells that may contribute to tissue damage and hantavirus‐associated disease. In this study, we analyzed possible hantaviral mechanisms that enhance the HLA‐I antigen presentation machinery. Upon hantavirus infection of various human and primate cell lines, we observed transactivation of promoters controlling classical HLA molecules. Hantavirus‐induced HLA‐I upregulation required proteasomal activity and was associated with increased TAP expression. Intriguingly, human DCs acquired the capacity to cross‐present antigen upon hantavirus infection. Furthermore, knockdown of TIR domain containing adaptor inducing IFN‐β or retinoic acid inducible gene I abolished hantavirus‐driven HLA‐I induction. In contrast, MyD88‐dependent viral sensors were not involved in HLA‐I induction. Our results show that hantaviruses strongly boost the HLA‐I antigen presentation machinery by mechanisms that are dependent on both retinoic acid inducible gene I and TIR domain containing adaptor inducing IFN‐β.
Rational Design of Rhodium Complexes Featuring κ4‐N,N,N,N‐ and κ5‐N,N,N,P,P‐Bis(imino)pyridine Ligands
Authors: Ben‐Daat Hagit , Hall Gabriel B. , Groy Thomas L. , Trovitch Ryan J.
Published: July 2013

The addition of aminoalkyl‐substituted 2,6‐bis(imino)pyridine (or pyridine diimine, PDI) ligands to [(COD)RhCl]2 (COD = 1,5‐cyclooctadiene) resulted in the formation of rhodium monochloride complexes with the general formula (NPDI)RhCl (NPDI = iPr2NEtPDI or Me2NPrPDI). The investigation of (iPr2NEtPDI)RhCl and (Me2NPrPDI)RhCl by single‐crystal X‐ray diffraction verified the absence of amine arm coordination and a pseudo square‐planar geometry about rhodium. Replacement of the chloride ligand with an outer‐sphere anion was achieved by adding AgBF4 directly to (iPr2NEtPDI)RhCl to form [(iPr2NEtPDI)Rh][BF4]. Alternatively, this complex was prepared by chelate addition following the salt metathesis reaction between AgBF4 and [(COD)RhCl]2. Using the latter method, both [(NPDI)Rh][BF4] complexes were isolated and found to exhibit κ4‐N,N,N,N‐PDI coordination regardless of arm length or steric bulk. In contrast, the metallation of PPDI chelates featuring alkylphosphane imine substituents (PPDI = Ph2PEtPDI or Ph2PPrPDI) resulted in the formation of cationic complexes featuring κ5‐N,N,N,P,P‐PDI coordination in all instances, [(PPDI)Rh][X] (X = Cl, BF4). Adjusting the metallation stoichiometry allowed the preparation of [(Ph2PPrPDI)Rh][(COD)RhCl2], as validated by multinuclear NMR spectroscopy and single‐crystal X‐ray diffraction.
Building a Macrocyclic Toolbox from C‐Linked Carbohydrates Identifies Antiangiogenesis Agents from Zebrafish Assay
Authors: Jogula Srinivas , Dasari Bhanudas , Khatravath Mahender , Chandrasekar Gayathri , Kitambi Satish Srinivas , Arya Prabhat
Published: July 2013

We report the synthesis of four different types of macrocyclic‐derived glycohybrids from carbohydrates that have an amino acid moiety in the large‐ring skeleton. These macrocyclic glycohybrids were obtained from α‐C‐1H‐ and β‐C‐1H‐linked carbohydrates. In one series, we utilized ring‐closing metathesis as the “stitching technology” to obtain two different macrocycles, i.e., trans equatorial–axial C‐1H and C‐5H and cis axial–axial C‐1H and C‐5H. The click approach was the key reaction in our second series to obtain two other macrocyclic compounds, i.e., trans equatorial–axial C‐1H and C‐5H and cis axial–axial C‐1H and C‐5H. The evaluation of this toolbox resulted in the identification of two unique compounds as antiangiogenesis agents in an embryonic zebrafish assay. Interestingly, in both cases, the macrocyclic compounds that have a cis relationship (i.e., axial–axial orientation) between C‐1H and C‐5H showed activity and their other diastereomers (i.e., equatorial–axial C‐1H and C‐5 H) with a trans relationship did not show any effect.
A pilot evaluation of a brief non‐verbal executive function assessment in Parkinson's disease
Authors: Hobson Peter James , Meara Robert Jolyon , Evans Rachel
Published: July 2013

Objective

Screening for cognitive impairment in the clinical or community setting is often hampered by the lack of a suitable assessment that is not overburdened with complex administration and scoring methods. We have developed non‐verbal cognitive screening instrument: the Weigl Token Test (WTT) from two existing instruments, the Weigl's Colour‐Form Sorting Test (WCFST) and the Token Test. The aim of this investigation is to compare the modified WTT with a battery of ‘Gold Standard’ cognitive assessments, to determine its utility, sensitivity and specificity as a brief cognitive screen in a cohort of Parkinson's disease (PD) patients.

Methods

A total of 50 PD patients consented to participate in this investigation. All participants were assessed with a battery of cognitive screening instruments including the WCFST, Mini Mental Status Examination, Addenbrooke's Cognitive Examination—Revised and Delis Kaplan Executive Function Systems. The sensitivity and specificity of the WTT to detect cognitive impairment were based upon psychiatric interview, neuropsychological assessment and application of DSM‐IV criteria.

Results

The optimal cut‐point of the WTT was 116/120, and its sensitivity and specificity to detect cognitive impairment were 88% and 89%, respectively. The diagnostic accuracy of the WTT as calculated by the area under the receiver operating curve was 0.83 (95% CI 0.76–0.95), suggesting that this instrument has acceptable psychometric properties to discriminate between case and non‐cases of cognitive impairment.

Conclusions

The WTT demonstrated excellent concurrent validity with existing ‘Gold Standard’ assessments of cognitive impairment. We believe that this instrument will prove to be a valuable additional screening assessment in epidemiological, primary care, specialist mental health or clinical investigations. Copyright © 2013 John Wiley & Sons, Ltd.
The US2 protein is involved in the penetration and cell‐to‐cell spreading of DEVin vitro
Authors: Wei Shuangshi , Liu Xiaomei , Ma Bo , Wu Yihan , Liu Yan , Gao Mingchun , Fu Peifen , Wang Junwei
Published: July 2013

Previous studies have shown that the unique short 2 (US2) protein contributes to the infection of several herpesviruses. However, little is known about whether the US2 protein of duck enteritis virus (DEV) could also contribute to the DEV infection in susceptible cells. This study is aimed at investigating the role of US2 protein in the DEV infection in vitro. The US2 gene was amplified from DEV and cloned into pET32a (+). The expression of recombinant US2 protein was induced in Escherichia coli. After purification, the recombinant US2 protein was immunized into rabbits to generate anti‐US2 sera. The immunoreactivity of anti‐US2 sera was determined by Western blot and immunofluorescent assays. The US2 protein was detected in the cytoplasm and plasma membrane of DEV‐infected duck embryo fibroblast (DEF) cells by immunofluorescent assay using the anti‐US2 serum. When DEV infected DEF cells in vitro, pre‐treatment with anti‐US2 serum did not affect the attachment of virus, but significantly reduced the penetration and cell‐to‐cell spreading of DEV in DEF cells. Our data suggest that the US2 protein is involved in the penetration and cell‐to‐cell spreading during the DEV infection of susceptible cells in vitro.
Customer Satisfaction, Competition, and Firm Performance: An Empirical Investigation
Authors: Simon Daniel H. , Gómez Miguel I.
Published: July 2013

We conduct two empirical studies to test two hypotheses: (1) rivals' customer satisfaction increases a firm's own customer satisfaction; and (2) rivals' customer satisfaction reduces a firm's sales. Study One uses a panel dataset of annual store‐level customer satisfaction data from a supermarket chain for the periods 1998–2001. Study Two considers a range of industries by using a panel dataset of brand‐level customer satisfaction ratings from the American Customer Satisfaction Index spanning the periods 1994–2003. Results from both studies provide support for our hypotheses. Copyright © 2013 John Wiley & Sons, Ltd.
Quantitative metabolic profiling of lipid mediators
Authors: Balgoma David , Checa Antonio , Sar Daniel García , Snowden Stuart , Wheelock Craig E.
Published: July 2013

Lipids are heterogeneous biological molecules that possess multiple physiological roles including cell structure, homeostasis, and restoration of tissue functionality during and after inflammation. Lipid metabolism constitutes a network of pathways that are related at multiple biosynthetic hubs. Disregulation of lipid metabolism can lead to pathophysiological effects and multiple lipid mediators have been described to be involved in physiological processes, (e.g. inflammation). Accordingly, a thorough description of these pathways may shed light on putative relations in multiple complex diseases, including chronic obstructive pulmonary disease, asthma, Alzheimer's disease, multiple sclerosis, obesity, and cancer. Due to the structural complexity of lipids and the low abundance of many lipid mediators, mass spectrometry is the most commonly employed method for analysis. However, multiple challenges remain in the efforts to analyze every lipid subfamily. In this review, the biological role of sphingolipids, glycerolipids, oxylipins (e.g. eicosanoids), endocannabinoids, and N‐acylethanolamines in relation to health and disease and the state‐of‐the‐art analyses are summarized. The characterization and understanding of these pathways will increase our ability to examine for interrelations among lipid pathways and improve the knowledge of biological mechanisms in health and disease.
Good learners: How top management teams affect the success and frequency of acquisitions
Authors: Nadolska Anna , Barkema Harry G.
Published: July 2013

We develop new theory and hypotheses on how a firm's top management team learns from acquisition experience, why, in consequence, the composition of the team is crucial, and how this affects acquisition frequency and success. We focus on the diversity of the top team and argue that heterogeneous teams, as compared to homogenous ones, acquire less but benefit more from their acquisition experience and are more successful with their acquisitions because they avoid mis‐transferring their experiences. We tested our hypotheses on acquisition frequency and success using longitudinal data on more than 2,000 acquisitions by 25 Dutch companies over four decades (1966 to 2006). Copyright © 2013 John Wiley & Sons, Ltd.
Case‐finding in Fabry disease: experience from the North of England
Authors: Brennan Paul , Parkes Oliver
Published: July 2013

The advent of effective therapy for Fabry disease (FD) creates two challenges: (1) how do we identify individuals with the condition early in its natural history, and (2) how many people have the condition and require expensive therapy? Between 1981 and 2011, 17 new FD families were referred to the Northern Genetics Service in the North of England, the majority between 2005 and 2001. Since 2009 we have employed biochemical screening in dried blood spots from individuals with high risk phenotypes, such as left ventricular hypertrophy and unexplained renal failure, to identify four of the new index cases; and we have offered comprehensive cascade genetic testing to identify pre‐symptomatic and symptomatic cases of FD in their 233 ‘at risk’ relatives. Overall, this combined approach identified a further 23 symptomatic cases of FD and 38 asymptomatic cases. The uptake of cascade genetic testing in this cohort was 48 %, which is similar to other inherited disorders for which there is an effective intervention. The minimum prevalence of GLA mutation in the North of England population at the end of 2011 was 1 in 40,800 and the prevalence of symptomatic FD was 1 in 64,600. Improved uptake of cascade genetic testing would increase these estimates to a maximum of 1 in 21,800 and 1 in 49,000 respectively. We suggest that any protocol for case identification should consist of targeted biochemical screening and coordinated cascade genetic testing.
Steuerungspotenziale der Agrar- und Raumordnungspolitik für ökologisch und ökonomisch nachhaltige ländliche Regionen
Authors: Kaufer Ricardo , Krott Max , Hubo Christiane , Giessen Lukas
Published: July 2013

European and german spatial planning policy and agricultural policy contain the policy objective to promote sustainable land use in rural areas. Both policies promise to promote comprehensive developments in rural areas, aiming at ecological target states, economic development, adaptation to economic globalization processes and strengthening regional stock flows to conserve resources. Analyzing these policies by testing their policy objectives and instruments in regard to sustainable land use delivers that only less instruments can support these objectives. Most instruments focus on economic development and adaptation to economic globalization processes. Ecological target states and strengthening regional stock flows are not supported by sufficient instruments.
Cohesin: Functions beyond sister chromatid cohesion
Authors: Mehta Gunjan D. , Kumar Ravinder , Srivastava Sanjeeva , Ghosh Santanu Kumar
Published: July 2013

Faithful segregation of chromosomes during mitosis and meiosis is the cornerstone process of life. Cohesin, a multi‐protein complex conserved from yeast to human, plays a crucial role in this process by keeping the sister chromatids together from S‐phase to anaphase onset during mitosis and meiosis. Technological advancements have discovered myriad functions of cohesin beyond its role in sister chromatid cohesion (SCC), such as transcription regulation, DNA repair, chromosome condensation, homolog pairing, monoorientation of sister kinetochore, etc. Here, we have focused on such functions of cohesin that are either independent of or dependent on its canonical role of sister chromatid cohesion. At the end, human diseases associated with malfunctioning of cohesin, albeit with mostly unperturbed sister chromatid cohesion, have been discussed.
Sprouty2 but not Sprouty4 is a potent inhibitor of cell proliferation and migration of osteosarcoma cells
Authors: Rathmanner Nadine , Haigl Barbara , Vanas Vanita , Doriguzzi Angelina , Gsur Andrea , Sutterlüty-Fall Hedwig
Published: July 2013

As negative regulators of receptor tyrosine kinase‐mediated signalling, Sprouty proteins fulfil important roles during carcinogenesis. In this report, we demonstrate that Sprouty2 protein expression inhibits cell proliferation and migration in osteosarcoma‐derived cells. Although earlier reports describe a tumour‐promoting function, these results indicate that Sprouty proteins also have the potential to function as tumour suppressors in sarcoma. In contrast to Sprouty2, Sprouty4 expression failed to interfere with proliferation and migration of the osteosarcoma‐derived cells, possibly due to a less pronounced interference with mitogen‐activated protein kinase activity. Sequences within the NH2‐terminus are responsible for the specific inhibitory function of Sprouty2 protein.
Immobilized amyloid Aβ peptides support platelet adhesion and activation
Authors: Canobbio Ilaria , Catricalà Silvia , Di Pasqua Laura G. , Guidetti Gianni , Consonni Alessandra , Manganaro Daria , Torti Mauro
Published: July 2013

Accumulation of amyloidogenic Aβ peptides in the brain contributes to the onset of Alzheimer disease. Aβ peptide deposits are also present in blood vessel walls, mainly deriving from circulating platelets. However, their effect on platelet function is unclear. We demonstrate that immobilized Aβ peptides induce platelet adhesion and spreading through metalloproteinase‐sensitive surface receptors. Aβ peptides also fasten platelet spreading on collagen, and support the time‐ and ADP‐dependent activation of adherent platelets, leading to stimulation of several signalling proteins. Our results indicate a potential role for peripheral Aβ peptides in promoting platelet adhesion and activation in the initiation of thrombus formation.
Ca2+‐binding properties and regulatory roles of lobster troponin C sites II and IV
Authors: Tanaka Hiroyuki , Takahashi Hiroki , Ojima Takao
Published: July 2013

Invertebrate troponin C typically contains Ca2+‐specific binding sites, sites II and IV, in the N‐ and C‐terminal domains, respectively. To investigate the roles of these sites for Ca2+‐dependent regulation of muscle contraction, we generated lobster troponin C mutants, and analyzed their Ca2+‐binding properties and regulatory effects on actomyosin–tropomyosin Mg‐ATPase activity. The results suggest that Ca2+ binding to site IV is responsible for regulation at relatively low Ca2+ concentrations, while site II has an essential role in full activation at higher Ca2+ concentrations.
A model of yeast glycolysis based on a consistent kinetic characterisation of all its enzymes
Authors: Smallbone Kieran , Messiha Hanan L. , Carroll Kathleen M. , Winder Catherine L. , Malys Naglis , Dunn Warwick B. , Murabito Ettore , Swainston Neil , Dada Joseph O. , Khan Farid , Pir Pınar , Simeonidis Evangelos , Spasić Irena , Wishart Jill , Weichart Dieter , Hayes Neil W. , Jameson Daniel , Broomhead David S. , Oliver Stephen G. , Gaskell Simon J. , McCarthy John E.G. , Paton Norman W. , Westerhoff Hans V. , Kell Douglas B. , Mendes Pedro
Published: July 2013

We present an experimental and computational pipeline for the generation of kinetic models of metabolism, and demonstrate its application to glycolysis in Saccharomyces cerevisiae. Starting from an approximate mathematical model, we employ a “cycle of knowledge” strategy, identifying the steps with most control over flux. Kinetic parameters of the individual isoenzymes within these steps are measured experimentally under a standardised set of conditions. Experimental strategies are applied to establish a set of in vivo concentrations for isoenzymes and metabolites. The data are integrated into a mathematical model that is used to predict a new set of metabolite concentrations and reevaluate the control properties of the system. This bottom‐up modelling study reveals that control over the metabolic network most directly involved in yeast glycolysis is more widely distributed than previously thought.
Market Freedom as Antipower
Authors: TAYLOR ROBERT S.
Published: July 2013

Historically, republicans were of different minds about markets: some, such as Rousseau, reviled them, while others, like Adam Smith, praised them. The recent republican resurgence has revived this issue. Classical liberals such as Gerald Gaus contend that neorepublicanism is inherently hostile to markets, while neorepublicans like Richard Dagger and Philip Pettit reject this characterization—though with less enthusiasm than one might expect. I argue here that the right republican attitude toward competitive markets is celebratory rather than acquiescent and that republicanism demands such markets for the same reason it requires the rule of law: because both are essential institutions for protecting individuals from arbitrary interference. I reveal how competition restrains—and in the limit, even eradicates—market power and thereby helps us realize “market freedom,” i.e., freedom as nondomination in the context of economic exchange. Finally, I show that such freedom necessitates “Anglo-Nordic” economic policies.
A re-description of Physocephalus dromedarii stat. nov. (Nematoda: Spirocercidae), an abomasal nematode of dromedaries (Camelus dromedarius)
Authors: Schuster R.K. , Wibbelt G. , Kinne J.
Published: July 2013

Physocephalus dromedarii stat. nov. was found in the abomasum of two adult female dromedaries originating from a farm in Dubai. Previously, this nematode has been misidentified as a subspecies of Ph. sexalatus but morphological differences are striking enough for it to be upgraded to a species. Physocephalus dromedarii is larger than Ph. sexalatus and has longer spicules. There are 20–22 oblique crests at the ventral surface between the caudal alae of the male compared to 7–8 in the case of Ph. sexalatus. The most significant differences are the presence of two pairs of papillae between cloaca and postcloacal plate of the male and the existence of a swelling in the second half of the female body formed by loops of both uterine horns.
A Decreased Micronucleus Frequency in Human Lymphocytes after Folate and Vitamin B12 Intervention: a Preliminary Study in a Yunnan Population
Authors: Ni Juan , Liang Ziqing , Zhou Tao , Cao Neng , Xia Xiaolin , Wang Xu
Published: July 2013

Background: Micronucleus (MN) is a validated biomarker for DNA damage in peripheral blood lymphocytes (PBL) and is a reflection of the changes of human nutritional status. Folate (FA) and vitamin B12 are one-carbon metabolism-related micronutrients, which play important roles in maintaining genomic stability. Objective: To investigate the correcting effects of FA and B12 intervention on DNA damage in PBL. Method: One hundred fifty-six volunteers without history of cancer were divided into 5 age groups (20 - 69 y, 47.4 % male) for establishing the baseline of chromosomal damage by means of cytokinesis-block micronucleus assay. Twelve individuals whose MN frequency was higher than the median value in each age group were selected for a four-month FA (200 - 400 μg/day)-B12 (3.125 - 25 μg/day) intervention dosed as to age and MTHFR genotypes. Results: There were significantly positive correlations between age and MN frequency in all groups (p < 0.01). Among all age groups, the baseline MN frequencies were higher in females than that in males. The MN frequencies from 10 volunteers were reduced by 33.5 % after the intervention with the two micronutrients (p < 0.01), and two individuals did not show any changes. Conclusion: Dietary supplement intake of FA and B12 based on MTHFR genotypes could protect the genome from damage and benefit genome health.
The Effects of Physical Activity on Dietary Habits in Young Adults from Madrid
Authors: Perea Sánchez José Miguel , Peñas Ruiz Carlos , Navia Lombán Beatriz , Aparicio Vizuete Aránzazu , Villalobos Cruz Tania Karina , Ortega Rosa M.
Published: July 2013

Background: The main objective of the study was to analyze the relation between the physical activity levels and diet quality of a group of young adults from Madrid. Methods: The nutritional and activity records of a group of 222 young adults (113 females and 109 males), with ages ranging from 18 to 30 years, were evaluated using dietary and activity questionnaires, and anthropometric measurements. From the data collected, the food, energy, macro and micronutrients intake, activity coefficient, body mass index, and body fat percentage were calculated. Results: The study revealed that 67.1 % of the individuals evaluated (82.3 % of the females and 51.3 % of the males) were classified as sedentary. The sedentary individuals had a higher percentage of body fat compared to active individuals. Generally, active individuals consumed more cereals and less fat. The nutritional intake of the participants did not follow the recommended daily intake, however the nutritional intake of the active individuals was closer to the recommended, with higher micronutrient intakes. Conclusion: These results suggest that active individuals follow healthier diets and keep a more adequate body weight, which provides protection against several chronic diseases.
Proposal and Validation of a Quick Question to Rate the Influence of Sun Exposure in Geriatric Epidemiological Studies on Vitamin D
Authors: Annweiler Cédric , Schott Anne-Marie , Beauchet Olivier
Published: July 2013

Background: Vitamin D is synthesized in the skin under the action of solar ultraviolet-B radiation. The objective of this study was to determine whether a simple question exploring sun exposure (When weather is nice, do you stay more than 15 minutes exposed to the sun (face and hands uncovered) between 11am and 3pm?) could be associated with serum 25-hydroxyvitamin D status among 751 older community-dwelling women (mean age, 80.2 ± 3.5 years). Methods: Two groups were distinguished based on the binary Yes versus No answer. Hypovitaminosis D was defined as serum 25-hydroxyvitamin D < 30 ng/mL. Results: Fewer women with hypovitaminosis D answered Yes to the question on sun exposure (p = 0.042). Answering Yes was inversely associated with hypovitaminosis D (OR = 0.56, p = 0.049) after adjustment for demographic characteristics and exogenous sources of vitamin D, with a positive predictive value of 88 %. Conclusion: This simple question may reflect the suns influence on vitamin D status and identify older community-dwellers with hypovitaminosis D.
Patients with inferior vena cava thrombosis frequently present with lower back pain and bilateral lower-extremity deep vein thrombosis
Authors: Kraft Christiane , Hecking Carola , Schwonberg Jan , Schindewolf Marc , Lindhoff-Last Edelgard , Linnemann Birgit
Published: July 2013

Background: Inferior vena cava (IVC) thrombosis is rare, and data about the clinical presentation of patients are scarce. Therefore, we reviewed all cases of IVC thrombosis consecutively registered in the MAISTHRO (MAin-ISar-THROmbosis) database and described patients characteristics in terms of their clinical presentations in the acute setting of IVC thrombosis. Patients and methods: From the MAISTHRO registry, which enrolled 1470 consecutive patients with documented histories of venous thromboembolism, we identified 60 patients (0,4 %; females 60 %) with IVC thrombosis and 888 patients (60.4 %; females 55 %) with isolated lower-extremity deep vein thrombosis (LE-DVT). Results: The median age at the time of IVC thrombosis manifestation was 36.5 years (9 to 83). IVC thrombosis was the initial VTE event in 47 patients (78 %). In the majority of cases, IVC thrombosis extended to the lower-extremity veins, and both lower extremities were affected in 17 cases (28 %). The initial clinical symptom of IVC thrombosis was lower back or abdominal pain which preceded typical symptoms of LE-DVT in 29 (48 %) patients. Symptomatic pulmonary embolism was more frequently observed in IVC thrombosis patients when compared to a sex- and age-matched subgroup of LE-DVT patients, although the difference was not significant (27 % vs. 12 %; p = 0.064). Malignant disease was the only established VTE risk factor with a higher prevalence among IVC thrombosis patients than patients with isolated LE-DVT (27 % vs. 9 %; p = 0.015). Congenital IVC anomalies were identified in another eight IVC thrombosis patients (13 %). Conclusions: IVC thrombosis should be considered a differential diagnosis for inexplicable lower back or abdominal pain especially in young patients. Malignant disease and congenital IVC anomalies seem to be predisposing factors for thrombosis involving the inferior vena cava.
Relatedness among arbuscular mycorrhizal fungi drives plant growth and intraspecific fungal coexistence
Authors: Roger Aurélien , Colard Alexandre , Angelard Caroline , Sanders Ian R
Published: July 2013

Arbuscular mycorrhizal fungi (AMF) form symbioses with most plant species. They are ecologically important determinants of plant growth and diversity. Considerable genetic variation occurs in AMF populations. Thus, plants are exposed to AMF of varying relatedness to each other. Very little is known about either the effects of coexisting AMF on plant growth or which factors influence intraspecific AMF coexistence within roots. No studies have addressed whether the genetics of coexisting AMF, and more specifically their relatedness, influences plant growth and AMF coexistence. Relatedness is expected to influence coexistence between individuals, and it has been suggested that decreasing ability of symbionts to coexist can have negative effects on the growth of the host. We tested the effect of a gradient of AMF genetic relatedness on the growth of two plant species. Increasing relatedness between AMFs lead to markedly greater plant growth (27% biomass increase with closely related compared to distantly related AMF). In one plant species, closely related AMF coexisted in fairly equal proportions but decreasing relatedness lead to a very strong disequilibrium between AMF in roots, indicating much stronger competition. Given the strength of the effects with such a shallow relatedness gradient and the fact that in the field plants are exposed to a steeper gradient, we consider that AMF relatedness can have a strong role in plant growth and the ability of AMF to coexist. We conclude that AMF relatedness is a driver of plant growth and that relatedness is also a strong driver of intraspecific coexistence of these ecologically important symbionts.
Payment cost minimisation auction for deregulated electricity market using mixed‐integer linear programming approach
Authors: Jamalzadeh Reza , Ardehali Morteza Mohammadi , Hosseinian Seyed Hossein , Choopani Mahdi
Published: July 2013

In deregulated electricity markets, currently, most independent system operators adopt the offer cost minimisation (OCM) auction, and pay‐as‐market clearing price (MCP) mechanism is used as settlement rule to determine the amount of payments. In such a structure, auction mechanism and settlement rule are not completely compatible because minimised costs differ from payment costs. In this regard, payment cost minimisation (PCM) mechanism is an alternative option as it minimises the total payment cost directly. Although, there exist numerous efficient solution methods for solving the OCM problem, the solution methods for solving PCM problem are very restricted and deficient. As the objective of study, the mixed‐integer linear programming (MILP) formulation for solving the PCM problem is presented. Based on several case studies, the effectiveness of the MILP method for solving PCM problem, in comparison with the only acceptable existing method, is illustrated. Additionally, a novel solution methodology is presented for solving MILP formulation of PCM problems. Further, in this study, exponential start up cost curves are utilised instead of single block start up cost functions, as considered in previous studies. In addition, the effects of the shape of load profile on the performance of OCM mechanism, in comparison with PCM, are analysed.
Enhancement of voltage stability margin in radial distribution system with squirrel cage induction generator based distributed generators
Authors: Raja Pitchaimuthu , Selvan Manickavasagam Parvathy , Kumaresan Natarajan
Published: July 2013

This study investigates the effect of voltage profile and steady‐state voltage stability margin when a wind‐driven squirrel cage induction generator (SCIG)‐based distributed generator (DG) is integrated with radial distribution system (RDS). The study has been carried out considering different configurations of SCIG. The node at which a DG has to be installed is identified based on voltage collapse index (VCI), which is a measure of steady‐state voltage stability margin. The computational procedure for studying the voltage profile of RDS without and with DG has been developed. The developed algorithm has been tested on the 33‐bus RDS with 1 MW SCIG integrated at the identified node and results are furnished. Finally, a configuration of SCIG having star and delta switching arrangements with permanently connected capacitor across each phase winding of the stator is found to be superior in providing improved system performance over a wide range of wind velocity. A switching criterion for this type of DG is proposed based on VCI for the improved performance of RDS.
Spectral features for the classification of partial discharge signals from selected insulation defect models
Authors: Ambikairajah Raji , Phung Bao Toan , Ravishankar Jayashri , Blackburn Trevor
Published: July 2013

Time‐domain features of partial discharge (PD) signals are often used to classify PD patterns. This paper proposes spectral features that are extracted using a filter bank, consisting of band‐pass filters. By applying the fast Fourier transform to the PD signal, the resulting frequency bins are grouped into L octave frequency sub‐bands. Two new features called the octave frequency moment coefficients (OFMC) and octave frequency Cepstral coefficients (OFCC) are defined in this paper. In addition, time–frequency domain coefficients (TFDC) obtained via wavelet analysis are also analysed. A PD signal can now be represented as an L‐dimensional feature vector of OFMC, OFCC or TFDC. These features are compared with discrete wavelet transform‐based higher‐order statistical features (HOSF) using three different classifiers: probabilistic neural network, support vector machine and the recently emerged sparse representation classifier. Results show that the proposed spectral features are robust and provide a better classification accuracy of PD signals, compared with HOSF.
Strapdown inertial navigation system alignment based on marginalised unscented Kalman filter
Authors: Chang Lubin , Hu Baiqing , Li An , Qin Fangjun
Published: July 2013

This study concerns the strapdown inertial navigation system (SINS) initial alignment under marine mooring condition with large initial error. The ten‐dimensional state initial alignment error functions of the SINS with inclusion of non‐linear characteristics have been derived. It is pointed out for the first time that the non‐linear functions are applied to only a subset of the elements of the state vector, that is, the velocities error and the misalignment angles. Then a computationally efficient refinement of the unscented transformation (UT) called marginalised UT (MUT) is investigated in these special non‐linear systems with a linear substructure. A performance comparison between the extended Kalman filter (EKF), the UT‐based Kalman filter (UKF) and the MUT‐based Kalman filter (MUKF) demonstrates that both the UKF and the MUKF can outperform the EKF and the MUKF and can achieve, if not better, at least a comparable performance to the UKF, at a significantly lower expense.
Theoretical determination of power law coefficients based on aerosol number concentrations
Authors: Mandija Florian , Vila Floran , Zoga Piro
Published: July 2013

One of the most important parameters indicating the state of aerosol presence in the atmosphere is their size distribution. It can be used several distribution functions for characterising aerosol size distribution, depending on their size range. Also there are available many instruments that make measurements of aerosol number concentrations, like multi‐channel aerosol/particle counters or aerosol spectrometers. In this study, the author have set the focus on a method to determine coefficients of power law distribution, based only on the measurement results taken by these aerosol/particle counters. The determination of these coefficients is based only on the measurement results taken by the aerosol/particle counters. Measurement instruments give aerosol concentrations in different measuring channels, and then using this algorithm it can be possible to estimate Junge coefficients, and so on to determine the size distribution of aerosol particles. This method facilitates the process for determination of aerosol size distribution, because it does not require several parameters as in other methods, however, this determination can be realised knowing only aerosol number concentrations in several bins of the measurement instrument. The accuracy of this method depends on the size of the channels of the measurement instrument. In short, the larger is the number of channels that have one measurement instrument, the more accurate can be the application of above mentioned method.
Soliton solutions for quasilinear Schrödinger equations
Authors: Yang Jun , Wang Youjun , Abdelgadir Ahamed Adam
Published: July 2013

It is established the existence of nontrivial solutions for quasilinear Schrödinger equations with subcritical or critical exponents, which appear from plasma physics as well as high-power ultrashort laser in matter.
Automated setup for spray assisted layer-by-layer deposition
Authors: Mundra Paul , Otto Tobias , Gaponik Nikolai , Eychmüller Alexander
Published: July 2013

The design for a setup allowing the layer-by-layer (LbL) assembly of thin films consisting of various colloidal materials is presented. The proposed system utilizes the spray-assisted LbL approach and is capable of autonomously producing films. It provides advantages to existing LbL procedures in terms of process speed and applicability. The setup offers several features that are advantageous for routine operation like an actuated sample holder, stainless steel spraying nozzles, or an optical liquid detection system. The applicability is demonstrated by the preparation of films containing semiconductor nanoparticles, namely, CdSe/CdS quantum dots and a polyelectolyte. The films of this type are of potential interest for applications in optoelectronic devices such as light-emitting diodes or solar cells.
Similarity transformed coupled cluster response (ST-CCR) theory - A time-dependent similarity transformed equation-of-motion coupled cluster (STEOM-CC) approach
Authors: Landau Arie
Published: July 2013

This paper presents a new method for calculating spectroscopic properties in the framework of response theory utilizing a sequence of similarity transformations (STs). The STs are preformed using the coupled cluster (CC) and Fock-space coupled cluster operators. The linear and quadratic response functions of the new similarity transformed CC response (ST-CCR) method are derived. The poles of the linear response yield excitation-energy (EE) expressions identical to the ones in the similarity transformed equation-of-motion coupled cluster (STEOM-CC) approach. ST-CCR and STEOM-CC complement each other, in analogy to the complementarity of CC response (CCR) and equation-of-motion coupled cluster (EOM-CC). ST-CCR/STEOM-CC and CCR/EOM-CC yield size-extensive and size-intensive EEs, respectively. Other electronic-properties, e.g., transition dipole strengths, are also size-extensive within ST-CCR, in contrast to STEOM-CC. Moreover, analysis suggests that in comparison with CCR, the ST-CCR expressions may be confined to a smaller subspace, however, the precise scope of the truncation can only be determined numerically. In addition, reformulation of the time-independent STEOM-CC using the same parameterization as in ST-CCR, as well as an efficient truncation scheme, is presented. The shown convergence of the time-dependent and time-independent expressions displays the completeness of the presented formalism.
Amorphization and reduction of thermal conductivity in porous silicon by irradiation with swift heavy ions
Authors: Newby Pascal J. , Canut Bruno , Bluet Jean-Marie , Gomès Séverine , Isaiev Mykola , Burbelo Roman , Termentzidis Konstantinos , Chantrenne Patrice , Fréchette Luc G. , Lysenko Vladimir
Published: July 2013

In this article, we demonstrate that the thermal conductivity of nanostructured porous silicon is reduced by amorphization and also that this amorphous phase in porous silicon can be created by swift (high-energy) heavy ion irradiation. Porous silicon samples with 41%-75% porosity are irradiated with 110 MeV uranium ions at six different fluences. Structural characterisation by micro-Raman spectroscopy and SEM imaging show that swift heavy ion irradiation causes the creation of an amorphous phase in porous Si but without suppressing its porous structure. We demonstrate that the amorphization of porous silicon is caused by electronic-regime interactions, which is the first time such an effect is obtained in crystalline silicon with single-ion species. Furthermore, the impact on the thermal conductivity of porous silicon is studied by micro-Raman spectroscopy and scanning thermal microscopy. The creation of an amorphous phase in porous silicon leads to a reduction of its thermal conductivity, up to a factor of 3 compared to the non-irradiated sample. Therefore, this technique could be used to enhance the thermal insulation properties of porous Si. Finally, we show that this treatment can be combined with pre-oxidation at 300 °C, which is known to lower the thermal conductivity of porous Si, in order to obtain an even greater reduction.
Magnetism driven ferroelectricity above liquid nitrogen temperature in Y2CoMnO6
Authors: Sharma G. , Saha J. , Kaushik S. D. , Siruguri V. , Patnaik S.
Published: July 2013

We report multiferroic behaviour in double perovskite Y2CoMnO6 with ferroelectric transition temperature Tc = 80 K. Both X-ray diffraction and neutron scattering data confirm a centro-symmetric crystal structure of space group P21/n at room temperature. The saturation polarization and magnetization are estimated to be 65 μC/m2 and 6.2 μB/f.u. respectively. The magneto-electric coupling parameter, on the other hand, is small as a 5 T field suppresses the electric polarization by only ∼8%. The origin of ferroelectricity is associated with magnetic ordering of Co2+ and Mn4+ moments in ↑↑-↓↓ arrangement. A model based on exchange-striction is proposed to explain the observed high temperature ferroelectricity.
Electric field enhancement in surface plasmon resonance bimetallic configuration based on chalcogenide prism
Authors: Kumar Maharana Pradeep , Bharadwaj Sriram , Jha Rajan
Published: July 2013

An aluminium-gold configuration for electric field enhancement based on surface plasmon resonance phenomenon is proposed. Our results and study show that for optimized bimetallic configuration (6 nm Au and 29 nm Al) along with chalcogenide prism, the electric field enhancement at the metal-analyte interface is more than 15 times greater and its probing depth is more than 300% longer than that of the gold based BK7 configuration thereby opening a new window for monitoring the biomolecular interactions in the vicinity of metal-analyte interface for various applications.
Present status of solar home and photovoltaic micro utility systems in Bangladesh and recommendation for further expansion and upgrading for rural electrification
Authors: Najmul Hoque S. M. , Kumar Das Barun
Published: July 2013

Only 47% of the populations in Bangladesh have access to electricity and per capita electricity use is 183 kWh p.a. which is very low compared to other developing countries. The government has the policy and vision to supply electricity to all citizens by 2020. Decentralized electricity generation by renewable energy can help the country to fulfill its Vision 2020. This paper discusses about the present status of solar home system (SHS) and photovoltaic (PV) micro utility in Bangladesh. Recommendation for further expansion and upgrading also described with the village electrification model and implementation model. Around 1.4 × 106, solar home systems are installed in the rural areas of Bangladesh by February 2013 by various installers. PV systems increase the quality of life, generate income, improve children education by providing good quality of light, and reduce health hazard and risk of fire by reducing kerosene burning. Under the PV micro utility model, an entrepreneur installs the PV system at his own premise and shares the electricity generated with neighbors. These systems are popular at rural market places in Bangladesh as users of this kind no need to buy PV system. Study suggests that 10 000 such systems are installed so far and most preferred micro utility is 50 Wp by the users. It is understood that appropriate policy towards PV micro utility, initiative to available PV accessories locally within the country and proper monitoring and dedicated maintenance support can make PV micro utility program more successful in Bangladesh like SHSs.
Structure and magnetism in strained Ge1−x−ySnxMny films grown on Ge(001) by low temperature molecular beam epitaxy
Authors: Prestat E. , Barski A. , Bellet-Amalric E. , Jacquot J.-F. , Morel R. , Tainoff D. , Jain A. , Porret C. , Bayle-Guillemaud P. , Jamet M.
Published: July 2013

In this letter, we study the structural and magnetic properties of Ge1−x−ySnxMny films grown on Ge(001) by low temperature molecular beam epitaxy using X-ray diffraction, high resolution transmission electron microscopy, and superconducting quantum interference device. Like in Mn doped Ge films, Mn atoms diffuse during the growth and aggregate into vertically aligned Mn-rich nanocolumns of a few nanometers in diameter. Transmission electron microscopy observations in plane view clearly indicate that the Sn incorporation is not uniform with concentration in Mn rich vertical nanocolumns lower than the detection limit of electron energy loss spectroscopy. The matrix exhibits a GeSn solid solution while there is a Sn-rich GeSn shell around GeMn nanocolumns. The magnetization in Ge1−x−ySnxMny layers is higher than in Ge1−xMnx films. This magnetic moment enhancement in Ge1−x−ySnxMny is probably related to the modification of the electronic structure of Mn atoms in the nanocolumns by the Sn-rich shell, which is formed around the nanocolumns.
Optical manipulation of the charge state of nitrogen-vacancy center in diamond
Authors: Chen Xiang-Dong , Zou Chang-Ling , Sun Fang-Wen , Guo Guang-Can
Published: July 2013

The conversion between two nitrogen vacancy (NV) center charge states (NV0 and NV−) was experimentally studied with laser in the range from 378 to 492 nm. The wavelength and power dependent charge state conversion was proved to be single-photon process at short wavelength and two-photon process at long wavelength. Also, the presence of metastable state in NV− significantly affected the conversion process, which can be used to increase NV− population from 72.5% to 80.5% by applying a magnetic field under 532 nm excitation. The method can be used for improving the fidelity of charge state polarization and subsequently optimizing the quantum control with NV center and resolution in the magnetometric and biological sensoring.
Realizing strain enhanced dielectric properties in BaTiO3 films by liquid phase assisted growth
Authors: Harris David T. , Burch Matthew J. , Ihlefeld Jon F. , Lam Peter G. , Li Jing , Dickey Elizabeth C. , Maria Jon-Paul
Published: July 2013

The addition of a liquid-forming flux to barium titanate thin films promotes densification and grain growth, improves nonlinear dielectric properties, and allows residual strain to be sustained in polycrystalline films without cracking at thicknesses relevant to device fabrication. Relative tuning, an excellent indicator of crystalline quality and an important material property for tunable microwave devices, increases from 20% to 70%. Films exhibit 0.15% residual differential thermal expansion mismatch strain, resulting in a shift to the paraelectric-ferroelectric phase transition of 50 °C. This result is in excellent agreement with theory, demonstrating the ability to tune ferroic transitions without epitaxial approaches.