bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphology and properties of the biosourced poly(lactic acid)/poly(ethylene oxide‐b‐amide‐12) blends
Authors: Han Lijing , Han Changyu , Dong Lisong 
Published: December 2012

AbstractBiosourced poly(lactic acid) (PLA) blends with different content of poly(ethylene oxide‐b‐amide‐12) (PEBA) were prepared by melt compounding. The miscibility, phase structure, crystallization behavior, mechanical properties, and toughening mechanism were investigated. The blend was an immiscible system with the PEBA domains evenly dispersed in the PLA matrix. The PEBA component suppressed the nonisothermal melt crystallization of PLA. With the addition of PEBA, marked improvement in toughness of PLA was achieved. The maximum for elongation at break and impact strength of the blend reached the level of 346% and 60.5 kJ/m2, respectively. The phase morphology evolution in the PLA/PEBA blends after tensile and impact tests was investigated, and the corresponding toughening mechanism was discussed. It was found that the PLA matrix demonstrates obvious shear yielding in the blend during the tensile and impact tests, which induced energy dissipation and therefore lead to improvement in toughness of the PLA/PEBA blends. POLYM. COMPOS., 2013. © 2012 Society of Plastics Engineers
Statins in the prevention of dementia and Alzheimer's disease: A meta‐analysis of observational studies and an assessment of confounding
Authors: Wong William B. , Lin Vincent W. , Boudreau Denise , Devine Emily Beth 
Published: December 2012

ABSTRACTBackgroundStudies demonstrate the potential for statins to prevent dementia and Alzheimer's disease (AD), but the evidence is inconclusive.ObjectiveConduct a meta‐analysis to estimate any benefit of statins in preventing dementia and examine the potential effect of study design and confounding on the benefit of statins in dementia. A secondary goal is to explore factors that may elucidate the mechanisms by which statins exert their potentially beneficial effect.MethodsPerformed systematic literature review to identify relevant publications. Relative risk (RR) estimates were pooled using both fixed and random effect models. Studies were stratified by study design and potential confounding factors.ResultsThe pooled results for all‐type dementia suggest that use of statins is associated with a lower RR of dementia when compared to non‐statin users (random effects model: RR 0.82 (95%CI [0.69, 0.97]). The pooled results for AD also suggested a lower RR with statin user compared to non‐statin users in random effects models (RR: 0.70, 95% CI [0.60, 0.83]). Study design and methods used to address biases may influence the results.ConclusionThese pooled results suggest that statins may provide a slight benefit in the prevention of AD and all‐type dementia. This benefit observed in both disease states should be interpreted with caution as observational studies are subject to bias, and it is possible that the slight benefit observed may disappear when these biases are addressed in a well‐designed randomized controlled trial. Copyright © 2012 John Wiley & Sons, Ltd.
Stability results for random discrete structures
Authors: Samotij Wojciech 
Published: December 2012

AbstractTwo years ago, Conlon and Gowers, and Schacht proved general theorems that allow one to transfer a large class of extremal combinatorial results from the deterministic to the probabilistic setting. Even though the two papers solve the same set of long‐standing open problems in probabilistic combinatorics, the methods used in them vary significantly and therefore yield results that are not comparable in certain aspects. In particular, the theorem of Schacht yields stronger probability estimates, whereas the one of Conlon and Gowers also implies random versions of some structural statements such as the famous stability theorem of Erdős and Simonovits. In this paper, we bridge the gap between these two transference theorems. Building on the approach of Schacht, we prove a general theorem that allows one to transfer deterministic stability results to the probabilistic setting. We then use this theorem to derive several new results, among them a random version of the Erdős‐Simonovits stability theorem for arbitrary graphs, extending the result of Conlon and Gowers, who proved such a statement for so‐called strictly 2‐balanced graphs. The main new idea, a refined approach to multiple exposure when considering subsets of binomial random sets, may be of independent interest.Copyright © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 44, 269‐289, 2014
Notch signaling in the pancreas: patterning and cell fate specification
Authors: Afelik Solomon , Jensen Jan 
Published: December 2012

AbstractNotch signaling is an evolutionarily conserved mechanism adapted to control binary fate decisions. The first evidence of Notch in pancreatic development focused on its critical role in controlling endocrine fate decisions. Since then, we have come to understand that this signaling system operates iteratively in the pancreas, and is not limited to the control of endocrine fate decision. Notch appears to play a role in early organ development, then during organ domain patterning, and only during a final refinement process, in the control of terminal cell fates. In so doing, Notch receptors and their ligands are under the influence of a wealth of genetic components that together help orchestrate the building of a complex, glandular organ. WIREs Dev Biol 2012, 2:531–544. doi: 10.1002/wdev.99This article is categorized under:

Establishment of Spatial and Temporal Patterns > Repeating Patterns and Lateral Inhibition
Defining the epidemiology of bloodstream infections: the ‘gold standard’ of population-based assessment
Authors: LAUPLAND K. B. 
Published: December 2012

SUMMARYBloodstream infections (BSIs) are a major cause of morbidity and mortality. Although population-based studies have been proposed as an optimal means to define their epidemiology, the merit of these designs has not been well documented. This report investigated the potential value of using population-based designs in defining the epidemiology of BSIs. Population-based BSI surveillance was conducted in Calgary, Canada (population 1·24 million) and illustrative comparisons were made between the overall and selected subgroup cohorts within five main themes. The value of population denominator data, and age and gender standardization for calculation and comparison of incidence rates were demonstrated. In addition, a number of biases including those related to differential admission rates, selected hospital admission, and referral bias were highlighted in non-population-based cohorts. Due to their comprehensive nature and intrinsic minimization of bias, population-based designs should be considered the gold standard means of defining the epidemiology of an infectious disease.
Microbial enhancement of seed germination in Rosa corymbifera ‘Laxa’
Authors: Morpeth David R. , Hall Avice M. 
Published: December 2012

AbstractGermination of native tree and shrub species from seed can be unpredictable. Germination of Rosa corymbifera ‘Laxa’ was 2% under normal commercial conditions. This was obtained in the presence of the natural microflora found on the seeds. The microflora originated on the hips and the seeds become inoculated during extraction. Exclusion of microbes from such pretreatments resulted in no germination. Inoculation of surface sterilized seeds with members of the natural microflora resulted in 3% germination. The addition of GarottaTM, a commercial compost activator, to the commercial pretreatment increased germination to 95%. This high germination percentage was sustained over a 5 year period using seeds from the same stock bushes. Addition of the compost activator resulted in a 20-fold increase of microbial activity in the pretreatment mixture, indicating that enhanced microbial growth resulted in higher and more predictable germination percentages.
Prevalent Glucocorticoid and Androgen Activity in US Water Sources
Authors: Stavreva Diana A. , George Anuja A. , Klausmeyer Paul , Varticovski Lyuba , Sack Daniel , Voss Ty C. , Schiltz R. Louis , Blazer Vicki S. , Iwanowicz Luke R. , Hager Gordon L. 
Published: December 2012

AbstractContamination of the environment with endocrine disrupting chemicals (EDCs) is a major health concern. The presence of estrogenic compounds in water and their deleterious effect are well documented. However, detection and monitoring of other classes of EDCs is limited. Here we utilize a high-throughput live cell assay based on sub-cellular relocalization of GFP-tagged glucocorticoid and androgen receptors (GFP-GR and GFP-AR), in combination with gene transcription analysis, to screen for glucocorticoid and androgen activity in water samples. We report previously unrecognized glucocorticoid activity in 27% and androgen activity in 35% of tested water sources from 14 states in the US. Steroids of both classes impact body development, metabolism and interfere with reproductive, endocrine and immune systems. This prevalent contamination could negatively affect wildlife and human populations.
Subarachnoid Hemorrhage from a Thoracic Radicular Artery Pseudoaneurysm after Methamphetamine and Synthetic Cannabinoid Abuse: Case Report
Authors: Ray Wilson Z. , Krisht Khaled M. , Schabel Alex , Schmidt Richard H. 
Published: December 2012

Background Context Isolated spinal artery aneurysms not associated with vascular malformations are exceedingly rare. Purpose To present a rare case of subarachnoid hemorrhage after thoracic radiculomedullary artery pseudoaneurysm rupture in a patient who abused synthetic cannabinoids and methamphetamines. Study Design Case report. Methods A 41-year-old man with a history of polysubstance abuse presented with acute-onset headache, back pain, and transient bilateral lower-extremity numbness. He reported daily use of the synthetic cannabinoid “Spice.” He denied use of other illegal drugs, but laboratory testing was positive for methamphetamines. Magnetic resonance imaging showed a focal hematoma at T2–3, and spinal angiography was negative for vascular abnormalities; however, a follow-up angiogram 6 days later revealed interval development of an irregular dilation of the left T3 radiculomedullary artery originating from the left supreme intercostal artery. Results Surgical trapping and resection of the lesion yielded a good clinical outcome. Conclusions Although two previous case reports have described patients with thoracic radiculomedullary pseudoaneurysm causing spinal subarachnoid hemorrhage (SAH), this is the first reported case associated with synthetic cannabinoids and methamphetamine abuse. Although this diagnosis is exceptionally rare, clinical presentation of SAH with associated back pain and lower-extremity symptoms warrants an aggressive imaging workup. Even in the setting of negative angiography, repeat cerebral and spinal angiograms may be necessary to identify a potentially treatable cause of spinal SAH.
Non-local residue–residue contacts in proteins are more conserved than local ones
Authors: Noivirt-Brik Orly , Hazan Gershon , Unger Ron , Ofran Yanay 
Published: December 2012

Abstract
Non-covalent residue–residue contacts drive the folding of proteins and stabilize them. They may be local—i.e. involve residues that are close in sequence, or non-local. It has been suggested that, in most proteins, local contacts drive protein folding by providing crucial constraints of the conformational space, thus allowing proteins to fold. We compared residues that are involved in local contacts to residues that are involved in non-local contacts and found that, in most proteins, residues in non-local contacts are significantly more conserved evolutionarily than residues in local contacts. Moreover, non-local contacts are more structurally conserved: a contact between positions that are distant in sequence is more likely to exist in many structural homologues compared with a contact between positions that are close in sequence. These results provide new insights into the mechanisms of protein folding and may allow for better prediction of critical intra-chain contacts.
Supplementary information: Supplementary data are available at Bioinformatics online.
Contact: yanay@ofranlab.org
Tissue-Specific Silencing of ArabidopsisSU(VAR)3-9 HOMOLOG8by miR171a
Authors: Manavella Pablo A. , Koenig Daniel , Rubio-Somoza Ignacio , Burbano Hernán A. , Becker Claude , Weigel Detlef 
Published: December 2012

AbstractMicroRNAs (miRNAs) are produced from double-stranded precursors, from which a short duplex is excised. The strand of the duplex that remains more abundant is usually the active form, the miRNA, while steady-state levels of the other strand, the miRNA*, are generally lower. The executive engines of miRNA-directed gene silencing are RNA-induced silencing complexes (RISCs). During RISC maturation, the miRNA/miRNA* duplex associates with the catalytic subunit, an ARGONAUTE (AGO) protein. Subsequently, the guide strand, which directs gene silencing, is retained, while the passenger strand is degraded. Under certain circumstances, the miRNA*s can be retained as guide strands. miR170 and miR171 are prototypical miRNAs in Arabidopsis (Arabidopsis thaliana) with well-defined targets. We found that the corresponding star molecules, the sequence-identical miR170* and miR171a*, have several features of active miRNAs, such as sequence conservation and AGO1 association. We confirmed that active AGO1-miR171a* complexes are common in Arabidopsis and that they trigger silencing of SU(VAR)3-9 HOMOLOG8, a new miR171a* target that was acquired very recently in the Arabidopsis lineage. Our study demonstrates that each miR171a strand can be loaded onto RISC with separate regulatory outcomes.
Marine cyanophages exhibit local and regional biogeography
Authors: Marston Marcia F. , Taylor Samantha , Sme Noel , Parsons Rachel J. , Noyes Timothy J. E. , Martiny Jennifer B. H. 
Published: December 2012

SummaryBiogeographic patterns have been demonstrated for a wide range of microorganisms. Nevertheless, the biogeography of marine viruses has been slower to emerge. Here we investigate biogeographic patterns of marine cyanophages that infect Synechococcus sp. WH7803 across multiple spatial and temporal scales. We compared cyanophage myoviral communities from nine coastal sites in Southern New England (SNE), USA, one site in Long Island NY, and four sites from Bermuda's inshore waters by assaying cyanophage isolates using the myoviral g43 DNA polymerase gene. Cyanophage community composition varied temporally at each of the sites. Further, 6 years of sampling at one Narragansett Bay site revealed annual seasonal variations in community composition, driven by the seasonal reoccurrence of specific viral taxa. Although the four Bermuda communities were similar to one another, they were significantly different than the North American coastal communities, with almost no overlap of taxa between the two regions. Among the SNE sites, cyanophage community composition also varied significantly and was correlated with the body of water sampled (e.g. Narragansett Bay, Cape Cod Bay, Vineyard Sound), although here, the same viral taxa were found at multiple sites. This study demonstrates that marine cyanophages display striking seasonal and spatial biogeographic patterns.
Case for mandatory reporting of ‘body packers’
Authors: Mitra Biswadev , Smit De Villiers , O'Shea William P 
Published: December 2012

AbstractBody packing is the term used to describe the ingestion of illicit substances for transport across control lines. Where the diagnosis of body packing is made independently in the ED, the issue of reporting the case to law enforcement officials poses a difficult scenario given the legal obligations of patient confidentiality. We describe a case of a body packer brought into the ED and subsequently reported to the police. The conflicts between patient confidentiality versus statutory exceptions to confidentiality along with case law regarding this scenario are discussed.
Cutoff Values for Alcoholic Liver Fibrosis Using Magnetic Resonance Elastography Technique
Authors: Bensamoun Sabine F. , Leclerc Gwladys E. , Debernard Laëtitia , Cheng Xiaobin , Robert Ludovic , Charleux Fabrice , Rhein Colette , Latrive Jean‐Paul 
Published: December 2012

BackgroundDue to the lack of cutoff values validated for specific liver diseases, the purpose of this study was to set up specific magnetic resonance elastography (MRE) cutoff values for asymptomatic liver fibrosis in alcoholic patients.MethodsNinety patients underwent 3 clinical exams. The liver stiffness was measured locally with the Fibroscan, and globally through cartographies of shear modulus generated with MRE. The Fibroscan method was chosen as the gold standard to classify the fibrosis. The liver score was also obtained with the Fibrometer A, and the diagnostic performance of the methods was analyzed with receiver‐operating characteristic (ROC) curves and cutoff values were calculated.ResultsSpearman correlation and area under the ROC curve revealed that MRE is a better diagnostic method than the Fibrometer A, to identify various levels of fibrosis. The results showed that the Fibrometer A was adapted for severe fibrosis. The MRE cutoff values are F1:2.20 kPa, F2:2.57 kPa, F3:3.31 kPa, and F4:4 kPa and were not influenced by the glutamic oxaloacetic transaminase level. By using the ultrasound cutoff values attributed for alcoholism, 66% of patients had a similar liver fibrosis diagnosis as the MRE cutoffs. However, both imaging techniques did not provide the same distribution for minor fibrosis.ConclusionsNone of the imaging techniques (Fibroscan, MRE) could replace the gold standard of the biopsy. However, due to the risk and the unnecessary procedure for the present recruited alcoholic patients, the Fibroscan method was chosen as the reference. Since MRE is currently being used as a clinical exam, the present MRE cutoffs could aid clinicians with their diagnosis of liver fibrosis for alcoholism disease.
Mapping Tropical Forest Trees Using High‐Resolution Aerial Digital Photographs
Authors: Garzon‐Lopez Carol X. , Bohlman Stephanie A. , Olff Han , Jansen Patrick A. 
Published: December 2012

AbstractThe spatial arrangement of tree species is a key aspect of community ecology. Because tree species in tropical forests occur at low densities, it is logistically challenging to measure distributions across large areas. In this study, we evaluated the potential use of canopy tree crown maps, derived from high‐resolution aerial digital photographs, as a relatively simple method for measuring large‐scale tree distributions. At Barro Colorado Island, Panama, we used high‐resolution aerial digital photographs (~0.129 m/pixel) to identify tree species and map crown distributions of four target tree species. We determined crown mapping accuracy by comparing aerial and ground‐mapped distributions and tested whether the spatial characteristics of the crown maps reflect those of the ground‐mapped trees. Nearly a quarter (22%) of the common canopy species had sufficiently distinctive crowns to be good candidates for reliable mapping. The errors of commission (crowns misidentified as a target species) were relatively low, but the errors of omission (missed canopy trees of the target species) were high. Only 40 percent of canopy individuals were mapped on the air photographs. Despite failing to accurately predict exact abundances of canopy trees, crown distributions accurately reproduced the clumping patterns and spatial autocorrelation features of three of four tree species and predicted areas of high and low abundance. We discuss a range of ecological and forest management applications for which this method can be useful.
Effects of immunosuppressive agents on Th17 cells involved in transplantation
Authors: Wang Xiao‐Fei , van Velkinburgh Jennifer C. , Zhang Yi , Ni Bing , Yang Zhan‐Yu 
Published: December 2012

AbstractThe lymphocyte‐derived helper T (Th) cells are critical regulators of the adaptive immune response and are associated with inflammatory disease. The most recently recognized Th‐cell lineage, Th17, plays an important role in host defense against extracellular pathogens by secreting the proinflammatory cytokine, interleukin 17, and recruiting reactive oxygen species (ROS)‐producing monocytes to the site of infection. However, accumulating evidence has implicated Th17‐cell dysregulation as an underlying cause for some immune‐related pathogenic conditions, including allograft rejection. Recent studies of human transplant patients have indicated that Th17 cells exhibit resistance to current immunosuppressive therapies that would otherwise prevent allograft rejection. In this review, we will discuss the most current research findings related to Th17‐cell function in various kinds of allografts.
Validity of scores from communication skills instruments for patients and their dental student‐clinicians
Authors: Winning T. A. , Kinnell A. , Wener M. E. , Mazurat N. , J Schönwetter D. 
Published: December 2012

AbstractThe development of appropriate communication skills by healthcare providers is central to providing quality patient‐centred care. Patients can provide valuable feedback to practitioners about their clinical communication. However, in oral health care, their involvement is uncommon and instruments specific for communication in oral health care have not been available. Recently, two complementary instruments have been developed by the Faculty of Dentistry, University of Manitoba for evaluating student‐clinicians' clinical communication: one for patient evaluation and one for student self‐evaluation. The aim of the current study was to provide validity evidence for the scores related to the internal structure of the revised 2007 versions of these instruments in two dental clinical/education contexts, namely the Universities of Manitoba, Canada (UM) and Adelaide, Australia (UA). The proposed factor structure and loadings, and their stability across contexts were assessed using confirmatory factor analysis, and the adequacy of the internal consistency reliability of the scores was analysed using Cronbach's alpha. The factor structure of the current 2007 versions of the patient and student instruments, derived from the previously developed longer versions of these instruments, was confirmed and was consistent across the two clinical/educational contexts. A model of partial invariance provided the best fit for these data due to variations in the magnitude of the factor loadings between sites. The internal consistency reliability of scores was high with a range of 0.88–0.97. In conclusion, the current study provides preliminary evidence regarding the validity of the scores of the current 2007 instruments, in terms of the internal structure, as measuring the five factors well. Replication of the factor structure of these instrument scores with more participants at both UA and other institutions is required.