bluuebunny/crossref_metadata_2025 huggingface dataset:
Ab initio fragment molecular orbital calculations on specific interactions between aryl hydrocarbon receptor and dioxin
Authors: Miyagi Satoshi , Sawamura Satoshi , Yoshikawa Eri , Dedachi Kenichi , Itoh Satoshi , Ishihara‐Sugano Mitsuko , Kurita Noriyuki
Published: July 2011

Aryl hydrocarbon receptor (AhR) regulates expression of genes in a ligand‐dependent manner. Although AhR was found to contain basic helix‐loop‐helix and Per‐Arnt‐Sim (PAS) domains, three‐dimensional structures of AhR and its complex with ligand have not been determined yet. We here obtain some modeled structures for the PAS domain of mouse AhR by using homology modeling and classical molecular mechanics methods. In addition, the stable structure of solvated AhR–dioxin complex is determined by the protein–ligand docking and the classical molecular dynamics simulations, and the specific interactions between AhR and dioxin are investigated at an electronic level by using ab initio fragment molecular orbital method. The computed results highlight the important amino acid residues of AhR for the binding between AhR and dioxin. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Liquid extraction surface analysis (LESA) of food surfaces employing chip‐based nano‐electrospray mass spectrometry
Authors: Eikel Daniel , Henion Jack
Published: July 2011

An automated surface‐sampling technique called liquid extraction surface analysis (LESA), coupled with infusion nano‐electrospray high‐resolution mass spectrometry and tandem mass spectrometry (MS/MS), is described and applied to the qualitative determination of surface chemical residues resulting from the artificial spraying of selected fresh fruits and vegetables with representative pesticides. Each of the targeted pesticides was readily detected with both high‐resolution and full‐scan collision‐induced dissociation (CID) mass spectra. In the case of simazine and sevin, a mass resolution of 100 000 was insufficient to distinguish the isobaric protonated molecules for these compounds. When the surface of a spinach leaf was analyzed by LESA, trace levels of diazinon were readily detected on the spinach purchased directly from a supermarket before they were sprayed with the five‐pesticide mixture. A 30 s rinse under hot running tap water appeared to quantitatively remove all remaining residues of this pesticide. Diazinon was readily detected by LESA analysis on the skin of the artificially sprayed spinach. Finally, incurred pyrimethanil at a level of 169 ppb in a batch slurry of homogenized apples was analyzed by LESA and this pesticide was readily detected by both high‐resolution mass spectrometry and full‐scan CID mass spectrometry, thus showing that pesticides may also be detected in whole fruit homogenized samples. This report shows that representative pesticides on fruit and vegetable surfaces present at levels 20‐fold below generally allowed EPA tolerance levels are readily detected and confirmed by the title technologies making LESA‐MS as interesting screening method for food safety purposes. Copyright © 2011 John Wiley & Sons, Ltd.
Adaptation of continuous‐flow cavity ring‐down spectroscopy for batch analysis of δ13C of CO2 and comparison with isotope ratio mass spectrometry
Authors: Berryman E. M. , Marshall J. D. , Rahn T. , Cook S. P. , Litvak M.
Published: July 2011

Measurements of δ13C in CO2 have traditionally relied on samples stored in sealed vessels and subsequently analyzed using magnetic sector isotope ratio mass spectrometry (IRMS), an accurate but expensive and high‐maintenance analytical method. Recent developments in optical spectroscopy have yielded instruments that can measure δ13CO2 in continuous streams of air with precision and accuracy approaching those of IRMS, but at a fraction of the cost. However, continuous sampling is unsuited for certain applications, creating a need for conversion of these instruments for batch operation. Here, we present a flask (syringe) adaptor that allows the collection and storage of small aliquots (20–30 mL air) for injection into the cavity ring‐down spectroscopy (CRDS) instrument. We demonstrate that the adaptor's precision is similar to that of traditional IRMS (standard deviation of 0.3‰ for 385 ppm CO2 standard gas). In addition, the concentration precision (±0.3% of sample concentration) was higher for CRDS than for IRMS (±7% of sample concentration). Using the adaptor in conjunction with CRDS, we sampled soil chambers and found that soil‐respired δ13C varied between two different locations in a piñon‐juniper woodland. In a second experiment, we found no significant discrimination between the respiration of a small beetle (~5 mm) and its diet. Our work shows that the CRDS system is flexible enough to be used for the analysis of batch samples as well as for continuous sampling. This flexibility broadens the range of applications for which CRDS has the potential to replace magnetic sector IRMS. Copyright © 2011 John Wiley & Sons, Ltd.
Neuroendocrine Changes and Natriuresis in Response to Social Stress in Rats
Authors: Niebylski A. , Boccolini A. , Bensi N. , Binotti S. , Hansen C. , Yaciuk R. , Gauna H.
Published: July 2011

Sympathetic activation is detected by the tachycardic, hypertensive and hyperthermic responses during social conflicts in rodents and primates. Sympathetic nervous system activation promoting sodium retention has long been recognized to play a significant role in the development and maintenance of salt‐sensitive hypertension. The objective was to investigate neuroendocrine activation and renal sodium excretion in response to chronic social stress. Male Wistar rats were subjected to social stress in accordance with the resident–intruder paradigm. Intruder rats were subjected to social confrontation once daily for 6 days. After the last confrontation, plasma corticosterone and urinary catecholamines were determined to assess the neuroendocrine activation. Plasma aldosterone, plasma and urinary creatinine, Na+, K+ and urinary volume were also measured. Chronic social stress increased the urinary norepinephrine, dopamine and plasma corticosterone levels, with no changes in epinephrine levels. On the other hand, high plasma aldosterone levels and low urinary sodium excretion without differences in creatinine clearance were observed. In conclusion, social stress had a strong antinatriuretic effect, which is coincident with noradrenergic and corticoadrenal activation and an increase in plasma aldosterone levels. Activation of these factors may promote sodium retention, which has long been recognized to play a significant role in the development and maintenance of hypertension. Copyright © 2011 John Wiley & Sons, Ltd.
The data type of spatial objects
Authors: Johnson Kenneth , Tucker John V.
Published: July 2011

A spatial object consists of data assigned to points in a space. Spatial objects, such as memory states and three dimensional graphical scenes, are diverse and ubiquitous in computing. We develop a general theory of spatial objects by modelling abstract data types of spatial objects as topological algebras of functions. One useful algebra is that of continuous functions, with operations derived from operations on space and data, and equipped with the compact-open topology. Terms are used as abstract syntax for defining spatial objects and conditional equational specifications are used for reasoning. We pose a completeness problem:Given a selection of operations on spatial objects, do the terms approximate all the spatial objects to arbitrary accuracy?We give some general methods for solving the problem and consider their application to spatial objects with real number attributes.
Gluconeogenesis and protein-induced satiety
Authors: Veldhorst Margriet A. B. , Westerterp Klaas R. , Westerterp-Plantenga Margriet S.
Published: July 2011

Increased gluconeogenesis (GNG) has been suggested to contribute to protein-induced satiety via modulation of glucose homoeostasis. The objective was to determine GNG and appetite in healthy human subjects after a high-proteinv.a normal-protein diet and to assess whether GNG contributes to protein-induced satiety. A total of twenty-two healthy subjects (ten men and twelve women: age 23 (sem1) years, BMI 22·1 (sem0·5) kg/m2) received an isoenergetic high-protein (30/0/70 % of energy from protein/carbohydrate/fat) or normal-protein diet (12/55/33 % of energy from protein/carbohydrate/fat) for 1·5 d in a randomised cross-over design. Appetite ratings were measured using visual analogue scales (VAS); endogenous glucose production and GNG were measured via infusion of [6,6-2H2]glucose and ingestion of2H2O. Moreover, fasting glucose and β-hydroxybutyrate concentrations were measured. Glycogen stores were lowered at the start with a glycogen-lowering exercise test. During the high-protein compared with the normal-protein diet, GNG was increased and appetite was suppressed (GNG: 148 (sem7)v.133 (sem6) g/24 h,P < 0·05; and 24 h area under the curve for hunger: 694 (sem46)v.1055 (sem52) mmVAS × 24 h,P < 0·001; fullness: 806 (sem59)v.668 (sem64) mm VAS × 24 h,P < 0·05; desire to eat: 762 (sem48)v.1004 (sem66) mm VAS × 24 h,P < 0·001). There was no correlation between appetite ratings and GNG. Glucose concentration was lower (4·09 (sem0·10)v.4·89 (sem0·06) mmol/l,P < 0·001) and β-hydroxybutyrate concentration was higher (1349 (sem139)v.234 (sem25) μmol/l,P < 0·001) after the high-protein compared with the normal-protein diet. In conclusion, after a high-protein diet, GNG was increased and appetite was lower compared with a normal-protein diet; however, these were unrelated to each other. An increased concentration of β-hydroxybutyrate may have contributed to appetite suppression on the high-protein diet.
DNA topoisomerase 2 mutant allele mildly delays the mitotic progression and activates the checkpoint protein kinase Chk1 in fission yeast Schizosaccharomyces pombe
Authors: YADAV SUDHANSHU , VERMA SUMIT KUMAR , AHMED SHAKIL
Published: July 2011

DNA topoisomerases are specialized nuclear enzymes that perform topological modifications on double-stranded DNA (dsDNA) and hence are essential for DNA metabolism such as replication, transcription, recombination, condensation and segregation. In a genetic screen, we identified a temperature-sensitive mutant allele of topoisomerase 2 that exhibits conditional synthetic lethality with a chk1 knockout strain. The mutant allele of topoisomerase 2 is defective in chromosome segregation at a non-permissive temperature and there was increase in chromosome segregation defects in the double mutant of top2–10 and chk1 delete at a non-permissive temperature. More importantly, topoisomearse 2 mutant cells mildly delay the mitotic progression at non-permissive temperature that is mediated by checkpoint protein kinase Chk1. Additionally, top2–10 mutant cells also activate the Chk1 at a non-permissive temperature and this activation of Chk1 takes place at the time of mitosis. Interestingly, top2–10 mutant cells retain their viability at a non-permissive temperature if the cells are not allowed to enter into mitosis. Taking together our results, we speculate that in the top2–10 mutant, the segregation of entangled chromatids during mitosis could result in delaying the mitotic progression through the activation of Chk1 kinase.
Genetic variation of dietary restriction and the effects of nutrient-free water and amino acid supplements on lifespan and fecundity ofDrosophila
Authors: DICK KENNETH B. , ROSS CHELSEA R. , YAMPOLSKY LEV Y.
Published: July 2011

We measure genetic variation in lifespan and fecundity at two food levels in 34 core lines of theDrosophilaGenetic Reference Panel collection. Lines were significantly different from each other in lifespan and fecundity at both restricted and full food. There was a strong food-by-line interaction for the slope of age-specific mortality, fecundity and proportion of fertilized eggs, indicating the presence of genetic variation for the strength of the dietary restriction effect, likely to represent standing genetic variation in a natural population from which the lines used have originated. No trade-off between fecundity and lifespan manifested in life-history variation among inbred lines. Our data partially corroborate the recent proposition that availability of nutrient-free water eliminates the apparent dietary restriction at least in some conditions. Although flies on full food with water added had lifespan slightly higher than those without a water source, it was still significantly lower than that in flies on restricted food, with no indication of interaction. We fully corroborate the recently discovered effect of addition of essential amino acids to the medium: addition of 1·5 mM methionine to restricted food significantly increased fecundity without a measurable decrease in lifespan; addition of each of 10 essential amino acids increased fecundity and decreased females lifespan to the levels observed on full food, again with no evidence of line-by-food interactions. We propose a mechanistic hypothesis explaining the observed data, based on the assumption that food consumption by flies is adjusted according to flies’ saturation in water and methionine.
Ancestral polymorphisms inDrosophila pseudoobscuraandDrosophila miranda
Authors: NOWELL REUBEN W. , CHARLESWORTH BRIAN , HADDRILL PENELOPE R.
Published: July 2011

Ancestral polymorphisms are defined as variants that arose by mutation prior to the speciation event that generated the species in which they segregate. Their presence may complicate the interpretation of molecular data and lead to incorrect phylogenetic inferences. They may also be used to identify regions of the genome that are under balancing selection. It is thus important to take into account the contribution of ancestral polymorphisms to variability within species and divergence between species. Here, we extend and improve a method for estimation of the proportion of ancestral polymorphisms within a species, and apply it to a dataset of 33 X-linked and 34 autosomal protein-coding genes for which sequence polymorphism data are available in bothDrosophila pseudoobscuraandDrosophila miranda, usingDrosophila affinisas an outgroup. We show that a substantial proportion of both X-linked and autosomal synonymous variants in these two species are ancestral, and that a small number of additional genes with unusually high sequence diversity seem to have an excess of ancestral polymorphisms, suggestive of balancing selection.
Bias in genomic predictions for populations under selection
Authors: VITEZICA Z. G. , AGUILAR I. , MISZTAL I. , LEGARRA A.
Published: July 2011

Prediction of genetic merit or disease risk using genetic marker information is becoming a common practice for selection of livestock and plant species. For the successful application of genome-wide marker-assisted selection (GWMAS), genomic predictions should be accurate and unbiased. The effect of selection on bias and accuracy of genomic predictions was studied in two simulated animal populations under weak or strong selection and with several heritabilities. Prediction of genetic values was by best-linear unbiased prediction (BLUP) using data either from relatives summarized in pseudodata for genotyped individuals (multiple-step method) or using all available data jointly (single-step method). The single-step method combined genomic- and pedigree-based relationship matrices. Predictions by the multiple-step method were biased. Predictions by a single-step method were less biased and more accurate but under strong selection were less accurate. When genomic relationships were shifted by a constant, the single-step method was unbiased and the most accurate. The value of that constant, which adjusts for non-random selection of genotyped individuals, can be derived analytically.
The covariance of heterozygosity as a measure of linkage disequilibrium between blocks of linked and unlinked sites in Hapmap
Authors: SVED JOHN A.
Published: July 2011

The covariance of heterozygosity serves as a measure of linkage disequilibrium (LD) between genes at two loci, although one that does not have as much information as a parameter such asr2. However, it may be extended to blocks of loci (single nucleotide polymorphisms, SNPs) along a chromosome. This has two advantages when searching for significant associations between different chromosomal regions. Calculations for a data set such as Hapmap are complicated by the large number of pairs of loci (SNPs) that need to be considered. For example, a search for significant associations between SNPs on different chromosomes involves around 1012calculations for a single population. Furthermore, this may not be an efficient way of detecting associations sincer2values calculated from neighbouring pairs will not be independent of each other. The covariance of heterozygosity provides an average measure of association between blocks of any size, and reduces the number of calculations by a factor ofb2, wherebis the block size. Unlike the calculation ofr2, the covariance of heterozygosity uses just diploid data and is not biased by sample size. Calculations using a block size of 50 have been used to look for associations in the Hapmap data set between regions within and between chromosomes. Within chromosomes, a signal is detected up to around 10 cM. No obviously significant associations have been detected between regions on different chromosomes, although there is a low level of association consistent with departures from random mating.
VARIATION OF HUMAN SEX RATIOS AT BIRTH BY THE SEX COMBINATIONS OF THE EXISTING SIBS, AND BY REPRODUCTIVE STOPPING RULES: COMMENTS ON GARENNE (2009)
Authors: JAMES WILLIAM H.
Published: July 2011

Garenne (2009) presented data on the sex ratio of a present birth by the numbers of previous brothers and sisters. In unisexual sibships, the probability of a further girl increases with the number of previous girls; and the probability of a further boy increases with the number of previous boys. Garenne noted that there is an asymmetry in that the effect is stronger with regard to girls than boys. He was uncertain of the cause of this. Here I suggest a potential solution to this problem. Garenne also seems to imply that parental reproductive stopping rules cause heterogeneity of sex ratios. I suggest that they may reveal it – but do not cause it. Moreover, I suggest that the effects of such stopping rules may be counter-intuitive.
Invasive species threat: parasite phylogenetics reveals patterns and processes of host-switching between non-native and native captive freshwater turtles
Authors: VERNEAU O. , PALACIOS C. , PLATT T. , ALDAY M. , BILLARD E. , ALLIENNE J.-F. , BASSO C. , DU PREEZ L. H.
Published: July 2011

One of the major threats to biodiversity involves biological invasions with direct consequences on the stability of ecosystems. In this context, the role of parasites is not negligible as it may enhance the success of invaders. The red-eared slider,Trachemys scripta elegans, has been globally considered among the worst invasive species. Since its introduction through the pet trade,T. s. elegansis now widespread and represents a threat for indigenous species. BecauseT. s. eleganscoexists withEmys orbicularisandMauremys leprosain Europe, it has been suggested it may compete with the native turtle species and transmit pathogens. We examined parasite transfer from American captive to the two native species that co-exist in artificial pools of a Turtle Farm in France. As model parasite species we used platyhelminth worms of the family Polystomatidae (Monogenea) because polystomes have been described from American turtles in their native range. Phylogenetic relationships among polystomes parasitizing chelonian host species that are geographically widespread show patterns of diversification more complex than expected. Using DNA barcoding to identify species from adult and/or polystome eggs, several cases of host switching from exotic to indigenous individuals were illustrated, corroborating that parasite transmission is important when considering the pet trade and in reintroduction programmes to reinforce wild populations of indigenous species.
Immunological footprint: the development of a child's immune system in environments rich in microorganisms and parasites
Authors: DJUARDI YENNY , WAMMES LINDA J. , SUPALI TANIAWATI , SARTONO ERLIYANI , YAZDANBAKHSH MARIA
Published: July 2011

The shaping of a child's immune system startsin utero, with possible long-term consequences in later life. This review highlights the studies conducted on the development of the immune system in early childhood up to school-age, discussing the impact that environmental factors may have. Emphasis has been put on studies conducted in geographical regions where exposure to micro-organisms and parasites are particularly high, and the effect that maternal exposures to these may have on an infant's immune responses to third-party antigens. In this respect we discuss the effect on responses to vaccines, co-infections and on the development of allergic disorders. In addition, studies of the impact that such environmental factors may have on slightly older (school) children are highlighted emphasizing the need for large studies in low to middle income countries, that are sufficiently powered and have longitudinal follow-up components to understand the immunological footprint of a child and the consequences throughout life.
An evaluation of melarsomine hydrochloride efficacy for parasitological cure in experimental infection of dairy cattle with Trypanosoma evansi in Thailand
Authors: DESQUESNES MARC , KAMYINGKIRD KETSARIN , VERGNE TIMOTHÉE , SARATAPHAN NACHAI , PRANEE RODTIAN , JITTAPALAPONG SATHAPORN
Published: July 2011

Melarsomine hydrochloride can cure Trypanosoma evansi infection in camels at a dose of 0·25 mg/kg, but at that dose relapses occur in cattle. In our study, the efficacy of an intramuscular injection of melarsomine hydrochloride at 0·5 mg/kg was assessed in 3 normal and 3 splenectomized dairy cattle experimentally infected with a stock of T. evansi from Thailand. The animals were monitored for 5 months by haematocrit centrifugation, blood- or cerebrospinal fluid-mouse inoculation, polymerase chain reaction, the card agglutination test (CATT) for T. evansi, and the enzyme-linked immunosorbent assay‑T. evansi. Parasitological and DNA tests became and remained negative just after treatment. By the end of the experiment, CATT was negative and ELISA scores were below or very close to the cut-off value. One of the splenectomized cattle died from anaplasmosis during the experiment, but tested negative for surra. It was concluded that the parasites had been cleared from the cattle, and melarsomine hydrochloride at 0·5 mg/kg can be recommended for treatment against T. evansi infection in dairy cattle in Thailand. Further work is necessary to validate the efficacy of the treatment in the event of confirmed CSF-infection.
Characterization of monomeric DNA-binding protein Histone H1 inLeishmania braziliensis
Authors: CARMELO EMMA , GONZÁLEZ GLORIA , CRUZ TERESA , OSUNA ANTONIO , HERNÁNDEZ MARIANO , VALLADARES BASILIO
Published: July 2011

Histone H1 inLeishmaniapresents relevant differences compared to higher eukaryote counterparts, such as the lack of a DNA-binding central globular domain. Despite that, it is apparently fully functional since its differential expression levels have been related to changes in chromatin condensation and infectivity, among other features. The localization and the aggregation state ofL. braziliensisH1 has been determined by immunolocalization, mass spectrometry, cross-linking and electrophoretic mobility shift assays. Analysis of H1 sequences from theLeishmaniaGenome Database revealed that our protein is included in a very divergent group of histones H1 that is present only inL. braziliensis.An antibody raised against recombinantL. braziliensisH1 recognized specifically that protein by immunoblot inL. braziliensisextracts, but not in otherLeishmaniaspecies, a consequence of the sequence divergences observed amongLeishmaniaspecies. Mass spectrometry analysis andin vitroDNA-binding experiments have also proven thatL. braziliensisH1 is monomeric in solution, but oligomerizes upon binding to DNA. Finally, despite the lack of a globular domain,L. braziliensisH1 is able to form complexes with DNAin vitro, with higher affinity for supercoiled compared to linear DNA.
The role of treatment delay in predicting 5-year outcomes in an early intervention program
Authors: Norman R. M. G. , Manchanda R. , Windell D. , Harricharan R. , Northcott S. , Hassall L.
Published: July 2011

Background

Past research on the relationship between treatment delay and outcomes for first-episode psychosis has primarily focused on the role of duration of untreated psychosis (DUP) in predicting symptomatic outcomes up to 2 years. In the current study we examine the influence of both DUP and duration of untreated illness (DUI) on symptoms and functioning at 5 years follow-up while controlling for other early characteristics.

Method

A total of 132 patients with first-episode psychosis and treated in an early intervention program were prospectively followed up for 5 years. Outcomes assessed included positive and negative symptoms, overall functioning, weeks on disability pension and weeks of full-time competitive employment.

Results

While DUP showed a significant correlation with level of positive symptoms at follow-up, this was not independent of pre-morbid social adjustment. DUI emerged as a more robust independent predictor of negative symptoms, social and occupational functioning and use of a disability pension.

Conclusions

Delay between onset of non-specific symptoms and treatment may be a more important influence on long-term functioning for first-episode patients than DUP. This suggests the possible value of treating such signs and symptoms as early as possible regardless of the effectiveness of such interventions in reducing likelihood or severity of psychotic symptoms.
Concepts and religious experiences: Wayne Proudfoot on the cultural construction of experiences
Authors: BUSH STEPHEN S.
Published: July 2011

The constructivist position, that mystical experiences are determined by the experiencer's cultural context, is now more prevalent among scholars of religion than the perennialist position, which maintains that mystical experiences have a common core that is cross-culturally universal. In large part, this is due to the efforts of Wayne Proudfoot in his widely accepted book,Religious Experience. In this article, I identify some significant unresolved issues in Proudfoot's defence of constructivism. My aim is not to defend perennialism, but to specify some objections to the constructivist thesis that constructivists need to address more adequately.
Older People in Canada: Their Victimization and Fear of Crime
Authors: Hayman Stephanie
Published: July 2011

Les personnes âgées sont davantage touchées par la peur du crime et de la victimisation, tout en étant à faible risque pour les dommages que n’importe quel autre groupe de la population canadienne. Le crime, la victimisation et la peur ne sont pas ressentis d’une manière uniforme chez les citoyens canadiens et résidents plus âgées, en partie parce que les personnes âgées ne forment pas un groupe homogène. Faire partie d’une minorité ethnique, religieuse ou sexuelle, ou d’être fragile mentalement, peuvent avoir un impact sur la perception et l’expérience du risque d’un individu. Cette analyse explore la victimisation des personnes âgées, tout en soulignant le manque de cohérence dans les données disponibles.
Social Support, Caregiving, and Aging
Authors: Chappell Neena L. , Funk Laura M.
Published: July 2011

Cet article examine la littérature internationale rédigée en anglais sur le thème du soutien social et des soins gérontologiques depuis le début des années 1990. La littérature s’est développée, mais il manque de consensus sur le sens des termes et sur la mesure. L’intérêt reste une constante pour l’aide pratique, les prestations de soutien social, et la demande et les résultats négatifs pour les aidants, avec de plus en plus de questions plus théoriques, auxquelles on accorde de moins en moins d’importance, sur les résultats négatifs du soutien reçu, ainsi que sur les conséquences positives de la prestation de soins. Le soutien social, néanmoins, est dûment reconnu comme un déterminant social de la santé et reçoit l’attention au niveau des politiques—qui sont tous deux d’importants changements à partir de deux décennies—et ajoutent a l’intérêt ce domaine recevra de chercheurs dans les décennies à venir. Il reste de nombreuses questions sans réponses quant à l’évolution du contexte sociétal, mais il est clair que le soutien social des personnes – y compris la vieillesse et tout au long de la vie – se poursuivra dans l’avenir, quoique dans des formes toujours renouvelées.
Acute Chikungunya and persistent musculoskeletal pain following the 2006 Indian epidemic: a 2-year prospective rural community study
Authors: CHOPRA A. , ANURADHA V. , GHORPADE R. , SALUJA M.
Published: July 2011

Chikungunya virus (CHIKV) data from population studies are sparse. During the 2006 epidemic, 509 clinical cases (43% attack rate) were identified in a village survey (West India); laboratory investigations demonstrated normal blood cell counts, elevated acute-phase reactants [erythrocyte sedimentation rate, C-reactive protein and interleukin-6 (IL-6)] and excluded malaria and dengue. Acute CHIKV was characterized by high fever, severe peripheral polyarthralgias, axial myalgias and intense fatigue in over 90% of cases; skin rash (34%) and headache (19%) were uncommon. There were 49% and 62% of survey cases seropositive for IgM (rapid assay) and IgG (immunofluorescence) anti-CHIKV antibodies, respectively. Sixty-five percent of cases recovered within 4 weeks. None of the cases died. Of the population, 4·1% and 1·6% suffered from persistent rheumatic pains, predominantly non-specific, at 1 and 2 years, respectively. Chronic inflammatory arthritis was uncommon (0·3% at 1 year) although serum IL-6 often remained elevated in chronic cases. A larger population study is required to describe post-CHIKV rheumatism and its prognosis.
Comparing two definitions of ethnicity for identifying young persons at risk for chlamydia
Authors: HAASNOOT A. , KOEDIJK F. D. H. , DE COUL E. L. M. OP , GÖTZ H. M. , VAN DER SANDE M. A. B. , VAN DEN BROEK I. V. F.
Published: July 2011

Ethnic disparities in chlamydia infections in The Netherlands were assessed, in order to compare two definitions of ethnicity: ethnicity based on country of birth and self-defined ethnicity. Chlamydia positivity in persons aged 16–29 years was investigated using data from the first round of the Chlamydia Screening Implementation (CSI, 2008–2009) and surveillance data from STI centres (2009). Logistic regression modelling showed that being an immigrant was associated with chlamydia positivity in both CSI [adjusted odds ratio (aOR) 2·3, 95% confidence interval (CI) 2·0–2·6] and STI centres (aOR 1·4, 95% CI 1·3–1·5). In both settings, 60% of immigrants defined themselves as Dutch. Despite the difference, classification by self-defined ethnicity resulted in similar associations between (non-Dutch) ethnicity and chlamydia positivity. However, ethnicity based on country of birth explained variation in chlamydia positivity better, and is objective and constant over time and therefore more useful for identifying young persons at higher risk for chlamydia infection.
Dust: Small‐scale processes with global consequences
Authors: Okin Gregory S. , Bullard Joanna E. , Reynolds Richard L. , Ballantine John‐Andrew C. , Schepanski Kerstin , Todd Martin C. , Belnap Jayne , Baddock Matthew C. , Gill Thomas E. , Miller Mark E.
Published: July 2011

Desert dust, both modern and ancient, is a critical component of the Earth system. Atmospheric dust has important effects on climate by changing the atmospheric radiation budget, while deposited dust influences biogeochemical cycles in the oceans and on land. Dust deposited on snow and ice decreases its albedo, allowing more light to be trapped at the surface, thus increasing the rate of melt and influencing energy budgets and river discharge. In the human realm, dust contributes to the transport of allergens and pathogens and when inhaled can cause or aggravate respiratory diseases. Dust storms also represent a significant hazard to road and air travel. Because it affects so many Earth processes, dust is studied from a variety of perspectives and at multiple scales, with various disciplines examining emissions for different purposes using disparate strategies. Thus, the range of objectives in studying dust, as well as experimental approaches and results, has not yet been systematically integrated. Key research questions surrounding the production and sources of dust could benefit from improved collaboration among different research communities. These questions involve the origins of dust, factors that influence dust production and emission, and methods through which dust can be monitored.
Honors
Authors: Anonymous
Published: July 2011

Frederick Cook was awarded the 2011 J. Tuzo Wilson Medal by the Canadian Geophysical Union (CGU) in recognition of his outstanding career contributions to Canadian geophysics. CGU cited Cook for his “seminal discoveries of fundamental importance that have changed our view of how mountain belts are created” and for helping to propel Canada's LITHOPROBE program to international prominence. Masaki Hayashi, Canada Research Chair in Physical Hydrology and professor in the Department of Geoscience, University of Calgary, Calgary, received the 2011 CGU Meritorious Service Award in recognition of extraordinary and unselfish contributions to the operation and management of CGU. He was cited for revamping the CGU Web site and being an active and valued decision maker of the CGU executive, among other services. Michael Riedel of the Pacific Geoscience Centre, Geological Survey of Canada, Sidney, received the 2011 CGU Young Scientist Award in recognition of outstanding research contributions by Canadian scientists who are within 10 years of their Ph.D. Riedel was cited for having made major advances in understanding the occurrence of natural gas hydrate beneath the seafloor and Arctic permafrost.
Alzheimer's disease is TH17 related autoimmune disease against misfolded beta amyloid
Authors: Hu Wan-Jiung
Published: July 2011

Alzheimer's disease is a common neurodegenerative disorder. However, its exact etiology is still unknown. There were several mechanisms proposed such as the tau hypothesis and amyloid hypothesis. However, there is evidence challenging the above two hypotheses. Here, I propose the immune-amyloid hypothesis as a mechanism for Alzheimer's disease. Th17 related autoimmunity contributes to the disease pathogenesis. Accumulation of misfolded beta amyloid can trigger heat shock protein which in turn induces TH17 immunity. By microarray analysis of peripheral blood mononuclear cells, there is up-regulation of many TH17 related molecules after Alzheimer's disease. After knowing the exact disease pathogenesis, we can develop new therapeutic strategies to prevent or treat the detrimental disorder.
Development and Evaluation of an Efficient Process for the Detoxification of Jatropha Oil and Meal
Authors: Gaur Sarthak , Viswanathan Balaji , Seemamahannop Rachadaporn , Kapila Shubhender , Book Neil
Published: July 2011

The poster deals with an often mentioned bioenergy plant - Jatopha curcas. The potential of the plant as a sustainable energy source has been hampered by toxicity of its oil and protein rich seeds. The research done by our group describes a simple process for detoxification of the protein rich Jatropha meal thereby making it suitable for animal feed. The process will accelerate use of Jatropha as an energy and feed source thereby enhancing its economic viability.
Nanostructural organization in carbon disulfide/ionic liquid mixtures: Molecular dynamics simulations and optical Kerr effect spectroscopy
Authors: Yang Peng , Voth Gregory A. , Xiao Dong , Hines Larry G. , Bartsch Richard A. , Quitevis Edward L.
Published: July 2011

In this paper, the nanostructural organization and subpicosecond intermolecular dynamics in the mixtures of CS2 and the room temperature ionic liquid (IL) 1-pentyl-3-methylimidazolium bis{(trifluoromethane)sulfonyl}amide ([C5mim][NTf2]) were studied as a function of concentration using molecular dynamics (MD) simulations and optical heterodyne-detected Raman-induced Kerr effect spectroscopy. At low CS2 concentrations (<10 mol.% CS2/IL), the MD simulations indicate that the CS2 molecules are localized in the nonpolar domains. In contrast, at higher concentrations (≥10 mol.% CS2/IL), the MD simulations show aggregation of the CS2 molecules. The optical Kerr effect (OKE) spectra of the mixtures are interpreted in terms of an additivity model with the components arising from the subpicosecond dynamics of CS2 and the IL. Comparison of the CS2-component with the OKE spectra of CS2 in alkane solvents is consistent with CS2 mainly being localized in the nonpolar domains, even at high CS2 concentrations, and the local CS2 concentration being higher than the bulk CS2 concentration.
A handheld preconcentrator for the rapid collection of cancerous cells using dielectrophoresis generated by circular microelectrodes in stepping electric fields
Authors: Jen Chun-Ping , Chang Ho-Hsien
Published: July 2011

The ability to concentrate biological cells, such as circulating tumor cells, circulating fetal cells, and stem cells, is an important issue in medical diagnostics and characterization. The present study develops a handheld device capable of effectively preconcentrating cancerous cells. Circular microelectrodes were designed to generate a stepping electric field by switching the electric field to an adjacent electrode pair by relays. Cancerous cells with a positive dielectrophoretic response are guided toward the center of the circular microelectrodes due to the region of high electric field between the adjacent electrodes being gradually decreased in the direction of the stepping electric field. Numerical simulations of the electric fields were performed to demonstrate the concept of the proposed design. The preconcentration of HeLa cells, which are a human cervical carcinoma cell line, was achieved in 160 s with an efficiency of around 76%, with an applied peak-to-peak voltage of 16 V at a frequency of 1 MHz.
Kinetic aspects of the thermostatted growth of ice from supercooled water in simulations
Authors: Weiss Volker C. , Rullich Markus , Köhler Christof , Frauenheim Thomas
Published: July 2011

In experiments, the growth rate of ice from supercooled water is seen to increase with the degree of supercooling, that is, the lower the temperature, the faster the crystallization takes place. In molecular dynamics simulations of the freezing process, however, the temperature is usually kept constant by means of a thermostat that artificially removes the heat released during the crystallization by scaling the velocities of the particles. This direct removal of energy from the system replaces a more realistic heat-conduction mechanism and is believed to be responsible for the curious observation that the thermostatted ice growth proceeds fastest near the melting point and more slowly at lower temperatures, which is exactly opposite to the experimental findings [M. A. Carignano, P. B. Shepson, and I. Szleifer, Mol. Phys. 103, 2957 (2005)10.1080/00268970500243796]. This trend is explained by the diffusion and the reorientation of molecules in the liquid becoming the rate-determining steps for the crystal growth, both of which are slower at low temperatures. Yet, for a different set of simulations, a kinetic behavior analogous to the experimental finding has been reported [H. Nada and Y. Furukawa, J. Crystal Growth 283, 242 (2005)10.1016/j.jcrysgro.2005.05.057]. To clarify this apparent contradiction, we perform relatively long simulations of the TIP4P/Ice model in an extended range of temperatures. The temperature dependence of the thermostatted ice growth is seen to be more complex than was previously reported: The crystallization process is very slow close to the melting point at 270 K, where the thermodynamic driving force for the phase transition is weak. On lowering the temperature, the growth rate initially increases, but displays a maximum near 260 K. At even lower temperatures, the freezing process slows down again due to the reduced diffusivity in the liquid. The velocity of the thermostatted melting process, in contrast, shows a monotonic increase upon raising the temperature beyond the normal melting point. In this case, the effects of the increasing thermodynamic driving force and the faster diffusion at higher temperatures reinforce each other. In the context of this study, we also report data for the diffusion coefficient as a function of temperature for the water models TIP4P/Ice and TIP4P/2005.
Scaling of the magnetic reconnection rate with symmetric shear flow
Authors: Cassak P. A. , Otto A.
Published: July 2011

The scaling of the reconnection rate during (fast) Hall magnetic reconnection in the presence of an oppositely directed bulk shear flow parallel to the reconnecting magnetic field is studied using two-dimensional numerical simulations of Hall reconnection with two different codes. Previous studies noted that the reconnection rate falls with increasing flow speed and shuts off entirely for super-Alfvénic flow, but no quantitative expression for the reconnection rate in sub-Alfvénic shear flows is known. An expression for the scaling of the reconnection rate is presented.
Sub-wavelength phononic crystal liquid sensor
Authors: Ke Manzhu , Zubtsov Mikhail , Lucklum Ralf
Published: July 2011

We introduce an acoustic liquid sensor based on phononic crystals consisting of steel plate with an array of holes filled with liquid. We both theoretically and experimentally demonstrate sensor properties considering the mechanism of the extraordinary acoustic transmission as underlying phenomenon. The frequency of this resonant transmission peak is shown to rely on the speed of sound of the liquid, and the resonant frequency can be used as a measure of speed of sound and related properties, like concentration of a component in the liquid mixture. The finite-difference time domain method has been applied for sensor design. Ultrasonic transmission experiments are performed. Good consistency of the resonant frequency shift has been found between theoretical results and experiments. The proposed scheme offers a platform for an acoustic liquid sensor.
Thermal conductivity of GeTe/Sb2Te3 superlattices measured by coherent phonon spectroscopy
Authors: Hase Muneaki , Tominaga Junji
Published: July 2011

We report on evaluation of lattice thermal conductivity of GeTe/Sb2Te3 superlattice (SL) by using femtosecond coherent phonon spectroscopy at various lattice temperatures. The time-resolved transient reflectivity obtained in amorphous and crystalline GeTe/Sb2Te3 SL films exhibits the coherent A1 optical modes at terahertz (THz) frequencies with picoseconds dephasing time. Based on the Debye theory, we calculate the lattice thermal conductivity, including scattering by grain boundary and point defect, umklapp process, and phonon resonant scattering. The results indicate that the thermal conductivity in amorphous SL is less temperature dependent, being attributed to dominant phonon-defect scattering.
Effect of contact doping in superlattice-based minority carrier unipolar detectors
Authors: Nguyen B.-M. , Chen G. , Hoang A. M. , Abdollahi Pour S. , Bogdanov S. , Razeghi M.
Published: July 2011

We report the influence of the contact doping profile on the performance of superlattice-based minority carrier unipolar devices for mid-wave infrared detection. Unlike in a photodiode, the space charge in the p-contact of a pMp unipolar device is formed with accumulated mobile carriers, resulting in higher dark current in the device with highly doped p-contact. By reducing the doping concentration in the contact layer, the dark current is decreased by one order of magnitude. At 150 K, 4.9 μm cut-off devices exhibit a dark current of 2 × 10−5A/cm2 and a quantum efficiency of 44%. The resulting specific detectivity is 6.2 × 1011 cm Hz1/2/W at 150 K and exceeds 1.9 × 1014 cm Hz1/2/W at 77 K.
Internal photopumping of Nd3+ (2H9/2, 4F5/2) states in yttrium aluminum garnet by excitation transfer from oxygen deficiency centers and Fe3+ continuum emission
Authors: Hewitt J. D. , Spinka T. M. , Senin A. A. , Eden J. G.
Published: July 2011

Photoexcitation of Nd3+ (2H9/2, 4F5/2) states by the broad (∼70 nm FWHM), near-infrared continuum provided by Fe3+ has been observed at 300 K in bulk yttrium aluminum garnet (YAG) crystals doped with trace concentrations (<50 ppm) of Fe, Cr, and Eu. Irradiation of YAG at 248 nm with a KrF laser, which excites the oxygen deficiency center (ODC) in YAG having peak absorption at ∼240 nm, culminates in ODC→Fe3+ excitation transfer and subsequent Fe3+ emission. This internal optical pumping mechanism for rare earth ions is unencumbered by the requirement for donor-acceptor proximity that constrains conventional Förster-Dexter excitation transfer in co-doped crystals.
High quality InAlN single layers lattice-matched to GaN grown by molecular beam epitaxy
Authors: Gačević Ž. , Fernández-Garrido S. , Rebled J. M. , Estradé S. , Peiró F. , Calleja E.
Published: July 2011

We report on properties of high quality ∼60 nm thick InAlN layers nearly in-plane lattice-matched to GaN, grown on c-plane GaN-on-sapphire templates by plasma-assisted molecular beam epitaxy. Excellent crystalline quality and low surface roughness are confirmed by X-ray diffraction, transmission electron microscopy, and atomic force microscopy. High annular dark field observations reveal a periodic in-plane indium content variation (8 nm period), whereas optical measurements evidence certain residual absorption below the band-gap. The indium fluctuation is estimated to be ± 1.2% around the nominal 17% indium content via plasmon energy oscillations assessed by electron energy loss spectroscopy with sub-nanometric spatial resolution.
Inversion type InP metal oxide semiconductor field effect transistor using novel atomic layer deposited BeO gate dielectric
Authors: Yum J. H. , Akyol T. , Lei M. , Ferrer D. A. , Hudnall Todd. W. , Downer M. , Bielawski C. W. , Bersuker G. , Lee J. C. , Banerjee S. K.
Published: July 2011

We present results on n-channel inversion-type indium phosphide (InP) metal-oxide-semiconductor field-effect transistors (MOSFETs) with atomic layer deposited (ALD) beryllium oxide (BeO) gate dielectric using the gate-last process. InP MOSFETs with the BeO gate stack were realized with high performance including the improved drive current, subthreshold swing, and a peak effective electron mobility. The transmission electron microscopy and x-ray photoemission spectroscopy measurements demonstrate an interface between BeO and InP substrates with high quality and efficient thermal stability. The use of ALD BeO as a gate dielectric may be a potential solution for future III-V MOS device fabrication.
Synthesis, Structure, and Theoretical Investigations of an Alkaline Earth Vanadate Oxide Compound (Ca4V4O14): Electronic, Optical, and Chemical Bond Properties
Authors: Tong Yi-Ping , Luo Guo-Tian , Jin Zhen , Lin Yan-Wen
Published: July 2011

One novel purely inorganic d0 polyoxovanadate compound Ca4V4O14 (1) was obtained and characterized structurally. The chain-like [V4O14]8– anion, built up from distorted VO5 trigonal bipyramids and VO4 tetrahedras is rarely observed. The reason for structural distortions is ascribed to the second-order Jahn-Teller effect. The band structure, the density of states, linear optical response functions, the dielectric constants of the static case ϵ(0), and refractive indexes were calculated by the density functional theory method. The nature of the V–O and Ca–O bonds, and of the electronic absorption peak are discussed in detail.