bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms of fatigue crack growth – a critical digest of theoretical developments
Authors: Chowdhury P. , Sehitoglu H. 
Published: February 2016

ABSTRACTRecent advances in the processing technology are permitting the manufacture of novel metallic materials with superior fatigue properties via microstructure tailoring. In the light of these promising developments, there is a rising need for establishing a synergy between state‐of‐the‐art experimental characterizations and physically based theoretical underpinnings. A revisit to the existing predictive literature is thus a timely requirement prior to furthering new design guidelines against cyclic damage. To that end, this paper recounts an overview of the key mechanistic and analytical theories on the fatigue crack growth mechanisms. Emphasis is placed on categorizing the proposed modelling endeavours based on their fundamental principles. In doing so, contributions and limitations thereof are carefully examined on the basis of most updated experimental revelations. The objective is to provide a perspective to the current generation of engineers and researchers alike. This concise yet critical narrative would essentially assist in formulating even more advanced microstructure–damage relationships in the modern context. A commentary is added at the end outlining the promising avenues for future research.
An experimental methodology for quantitative characterization of multi‐site fatigue crack nucleation in high‐strength Al alloys
Authors: Jin Y. , Cai P. , Tian Q. B. , Liang C. Y. , Ke D. J. , Wang G. , Zhai T. 
Published: February 2016

AbstractAn experimental method was developed to quantify the multi‐site fatigue crack initiation behaviour of engineering alloys in four‐point bend fatigue testing under stress control. In this method, fatigue crack initiation sites [fatigue weak‐links (FWLs)] were measured on the sample surface at different cyclic stress levels. The FWL density in an alloy could be best described using a three‐parameter Weibull function of stress, although other types of sigmoidal functions might also be used to quantify the relation between weak‐link density and stress. The strength distribution of the FWLs was derived from the Weibull function determined by fitting the weak‐link versus stress curve experimentally obtained. As material properties, FWL density and strength distribution could be used to characterize the fatigue crack nucleation behaviour of engineering alloys quantitatively and evaluate the alloy quality in terms of weak‐link density and strength distribution. In this work, the effects of environment, types of microstructural heterogeneities and loading direction on FWLs were all studied in detail in AA7075 T651, AA2026 T3511, A713 alloys, etc. It was also found that FWL should be quantified as a Weibull‐type function of strain instead of stress, when the applied maximum cyclic stress exceeded the yield strength of the tested alloy.
Students' Perspectives on Communities‐Oriented Goals
Authors: White Kelsey D. 
Published: February 2016

AbstractScholars and professional organizations have described participation in target language (TL) communities as one of the primary aims of language learning, but little work has been done to determine how students define those communities or envision their own involvement within them. This exploratory study drew on questionnaire and interview data to investigate the extent to which beginning‐level learners of German (n = 23) valued the goals that are outlined in the World‐Readiness Standards for Language Learning (National Standards Collaborative Board, 2015)—particularly the Communities‐oriented goals—and examined the ways in which these students delineated a TL community and conceived of participation in that community. Findings suggest that, relative to other goal areas, the items representing the Communities standard on the whole were rated as unimportant to these learners; however, there were some specific aspects of Communities that were rated much more favorably. Regardless of their alignment with those goals, learners' definition of what constituted a TL community focused on native speaker status and geographical location and excluded groups that met in local settings (e.g., German classes).
Comparing estimates of number of breeders Nb based on microsatellites and single nucleotide polymorphism of three groups of brown trout (Salmo trutta L.)
Authors: Linløkken A. N. , Haugen T. O. , Mathew P. K. , Johansen W. , Lien S. 
Published: February 2016

AbstractMicrosatellites (10 MSs) and single nucleotide polymorphism (3871 SNPs) were analysed in three closely related, single‐cohort groups of brown trout, Salmo trutta L. Autumn (W/0+) and subsequent year (W/1+) samples of brown trout of the same stream were retrieved using electric fishing, and one sample of artificially reared brown trout (H/1+), bred from wild parents, was collected from a hatchery. The number of breeders, Nb, was estimated based on each total sample set and from subsets of loci by means of the software LDNe, and by means of Colony2, NeEstimator and ONeSAMP softwares. MS‐based estimates were consequently higher than those based on SNPs. ML‐Relate and Colony2 software was used to estimate putative full‐sib pairs, and there was considerable variation between methods. For monitoring species and populations, both methods are recommended, but to compare Nb across samples and years, the same markers of MSs or SNPs must be used as estimates varied across markers within sample.
Going against the flow: a case for upstream dispersal and detection of uncommon dispersal events
Authors: Wubs E. R. Jasper , Fraaije Rob G. A. , de Groot G. Arjen , Erkens Roy H. J. , Garssen Annemarie G. , Kleyheeg Erik , Raven Bart M. , Soons Merel B. 
Published: February 2016

Summary

Dispersal and colonisation are key processes determining species survival, and their importance is increasing as a consequence of ongoing habitat fragmentation, land‐use change and climate change. Identification of long‐distance dispersal events, including upstream dispersal, and of the dispersal mechanisms and resulting spatial dispersal patterns involved provides much‐needed information for conservation in an era of rapid environmental change.

However, quantifying contemporary dispersal among populations is far from straightforward. We used the relatively well‐defined, typically linear, spatial structure of streams, rivers and their associated riparian and aquatic plant populations to illustrate this. We performed a literature review on studies where dispersal and its directionality (upstream versus downstream) were explicitly quantified.

Upstream dispersal was detected in the majority (75%) of examined stream and riparian plant species and mediated mainly by waterfowl, but also by other animals and wind. However, upstream movements are generally less frequent than downstream. Upstream dispersal can occur in excess of tens and sometimes even hundreds of kilometres.

Most of the reviewed studies suffer from important methodological limitations that generate difficulties in detecting uncommon dispersal events. Major limitations include use of molecular ecological analyses based on unrealistic assumptions, and the inability to separate seed from pollen flow. On the basis of these findings, we outline a flexible research design using DNA‐based assignment methods that allows quantification of contemporary dispersal in future studies. We suggest four key improvements: (i) assignment of propagules and/or seedlings; (ii) use of spatial models to inform sampling design; (iii) reducing the influence of unsampled populations and (iv) combined use of nuclear and uniparentally inherited DNA markers to separate gene flow (including pollen and sperm) in general from propagule‐mediated dispersal. In combination with direct measurements of seed dispersal these facilitate empirical quantification of dispersal and the detection of uncommon dispersal events, allowing more realistic assessment of spatial population dynamics, relevant for sedentary and relatively immobile organisms.
Biogeographical patterns of the genus Merodon Meigen, 1803 (Diptera: Syrphidae) in islands of the eastern Mediterranean and adjacent mainland
Authors: Vujić Ante , Petanidou Theodora , Tscheulin Thomas , Cardoso Pedro , Radenković Snežana , Ståhls Gunilla , Baturan Željana , Mijatović Gorana , Rojo Santos , Pérez‐Bañón Celeste , Devalez Jelle , Andrić Andrijana , Jovičić Snežana , Krašić Dušanka , Markov Zlata , Radišić Dimitrije , Tataris Giorgos 
Published: February 2016

Abstract

The objective of this study was to obtain a biogeographical perspective on the hoverfly genus Merodon (Diptera, Syrphidae) based on data from 32 islands in the Aegean and Ionian archipelagoes vis‐à‐vis the adjacent mainland. In this part of the world, the genus comprises 57 species, out of more than 160 species described worldwide.

The importance of eco‐geographical variables (area, elevation, distance to the nearest island and distance to the nearest mainland) and the species–area relationship (SAR) were studied in order to explain patterns of species richness. All tests supported the dynamic equilibrium concept.

The area and distance to closest island were found to be the most important drivers of species richness on the Aegean and Ionian archipelagoes. Out of three SAR models evaluated in this study, the exponential function fitted our data best. It was found that a power model with no intercept value (C = 1) performed even better by using symbolic regression for non‐linear equation optimisation.

The cluster and null‐model analyses performed to detect inter‐island similarities and origins of the insular Merodon fauna indicated a clear influence of colonisation history of the species on different islands.

The results imply that the current distributions of Merodon species in the study area exhibit the combined effects of historical and present‐day processes.
Efficacy of naringenin against permethrin‐induced testicular toxicity in rats
Authors: Mostafa Heba El‐Sayed , Abd El‐Baset Samia A. , Kattaia Asmaa A. A. , Zidan Rania A. , Al Sadek Mona M. A. 
Published: February 2016

SummaryPermethrin (PM), a synthetic pyrethroid insecticide, has broad toxicity spectra. We aimed to investigate the effects of PM on the testes of adult albino rats, examine the recovery response and evaluate the efficacy of naringenin (NG) supplementation. Adult male albino rats were randomly assigned to five groups of six each: control, NG (50 mg/kg), PM (70 mg/kg), recovery (after subsequent withdrawal of PM) and NG‐PM group. All treatments were given by oral gavage for 6 weeks and another 3 weeks for the recovery group. At the time of sacrifice, each testis was weighed. Biochemical analysis of epididymal sperm count and serum testosterone level was performed. Testes were processed for histological, ultrastructural and c‐Kit immunohistochemical study. PM toxicity was evidenced by a highly significant decrease in testicular weight, epididymal sperm count and serum testosterone level compared to control. Furthermore, testicular structure abnormalities and reduced c‐Kit immunoreactions were observed. Stoppage of PM in the recovery group partially reversed PM‐induced changes. There was a mild decrease in testicular weight and biochemical parameters compared to control. The structure of seminiferous tubules was partially retained. The NG‐PM group showed an overall improvement in testicular weight and biochemical alterations which were confirmed by light and electron microscopic examination. In conclusion, PM induced testicular toxicity, which was ameliorated by NG co‐administration. However, stoppage of PM exposure was associated with partial recovery.
Prescribing or dispensing medication represents the best opportunity for GPs and pharmacists to engage older people in alcohol-related clinical conversations
Authors: Wilkinson Celia , Dare Julie , French Michelle , McDermott Marie- Louise , Lo Johnny , Allsop Steve 
Published: February 2016

Abstract

Objectives
This research aimed to identify older Australian drinkers’ knowledge about Australian Alcohol Guidelines and their beliefs about the risks and benefits of alcohol; their recall of alcohol-related issues being raised with them by their community pharmacist and General Practitioner (GP); and their receptiveness to alcohol-related information being provided by either health professional.

Methods
This research was conducted in Perth, Western Australia. Flyers calling for participants were placed in local health and service centres, and advertisements were placed in local media. Participants who met eligibility requirements were posted a survey pack (n = 190) including an information letter, consent form, quantitative survey, and return addressed, postage paid envelope. 188 people aged over 60 years returned completed questionnaires.

Key findings
Women were more familiar with national alcohol guidelines, and were more conservative about the potential health benefits of alcohol. While 90% of participants were receptive to their GP asking about their alcohol use, only 30% of men and 20% of women recalled their GP raising this issue with them in the prior 12 months. Of these, high-risk drinkers were six times more likely than low-risk drinkers to have been asked by their GP. Likewise, 50% of men and 65% of women were receptive to having alcohol-related health conversations with their community pharmacist, but less than 4% recalled their pharmacist raising this issue. Participants were most receptive to receiving information about alcohol-medication interactions.

Conclusions
This research highlights that prescribing and dispensing medication represents the ideal opportunity for health professionals to deliver alcohol-related information to older people.
Analysis of bacterial community profiles of endodontically infected primary teeth using pyrosequencing
Authors: Yun Kwan Hee , Lee Hyo‐Seol , Nam Ok Hyung , Moon Chan Yang , Lee Jae‐Hyung , Choi Sung Chul 
Published: February 2016

SummaryObjectiveThe purpose of this study was to identify the endodontic microbiome in primary teeth with dental caries using high‐throughput pyrosequencing and to establish data on the oral microbiome of primary teeth with endodontic infection.MethodsTen primary teeth with dental caries and endodontic infection were included. Samples were collected from root canals using sterilized paper points and analyzed by pyrosequencing, based on the V1‐V3 hypervariable region of the 16S rRNA gene. The data were analyzed using the CLcommunity software.ResultsAnalysis of the 10 samples yielded a total of 64,291 16S rRNA gene sequences. In total, 1586 OTUs (range, 91–235), six bacterial phyla, including unclassified, and 187 genera were assigned. At the genus level, Neisseria (group A), Acinetobacter (group B), and Fusobacterium (group C) were prominent. These predominant microorganisms were associated with the clinical condition and reflected the progression of endodontic infection in primary teeth.ConclusionsThis study revealed a relationship between the oral microbiome and endodontic infection in primary teeth. Additionally, anaerobic bacteria such as Fusobacterium species were dominant in the teeth with apical abscesses.
Enhancing Self‐Determination in Health: Results of an RCT of the Ask Project, a School‐Based Intervention for Adolescents with Intellectual Disability
Authors: McPherson Lyn , Ware Robert S. , Carrington Suzanne , Lennox Nicholas 
Published: February 2016

BackgroundAdolescents with intellectual disability have high levels of unrecognized disease and inadequate health screening/promotion which might be addressed by improving health advocacy skills.MethodsA parallel‐group cluster randomized controlled trial was conducted to investigate whether a health intervention package, consisting of classroom‐based health education, a hand‐held health record and a health check, increased carer‐reported health advocacy in adolescents with intellectual disabilities.ResultsCarers of 388 adolescents responded. Adolescents allocated to receive the health intervention package were significantly more likely to go to the doctor on their own, ask questions and explain their health problems to the doctor without help. Carers reported their adolescent had benefited, gaining increased knowledge and responsibility for their own health. They themselves reported an increase in knowledge and better ability to support the young person.ConclusionsAn educational initiative based on the Ask Health Diary led to improved healthcare autonomy for adolescents with intellectual disabilities.
Proprotein convertase 7 rs236918 associated with liver fibrosis in Italian patients with HFE‐related hemochromatosis
Authors: Pelucchi Sara , Galimberti Stefania , Greni Federico , Rametta Raffaela , Mariani Raffaella , Pelloni Irene , Girelli Domenico , Busti Fabiana , Ravasi Giulia , Valsecchi Maria Grazia , Valenti Luca , Piperno Alberto 
Published: February 2016

AbstractBackground and Aimp.Cys282Tyr homozygosity is the prevalent genotype in (HFE)‐related Hereditary Hemochromatosis with low penetrance and variable expression. However, liver cirrhosis and hepatocellular carcinoma remain the main causes of mortality in these patients. Detection of genetic modifiers identifying patients at risk for liver damage would be relevant for their clinical management. We evaluated proprotein convertase 7 (PCSK7) rs236918 as genetic marker of risk of liver fibrosis in an Italian cohort of p.Cys282Tyr homozygotes.MethodsLiver fibrosis was histologically assessed by Ishak score. We evaluated PCSK7 alleles and genotypes frequencies according to single or grouped staging scores: absent/mild fibrosis (stage: 0–2), moderate (stage: 3–4), and severe fibrosis/cirrhosis (stage: 5–6). Single nucleotide polymorphism genotyping was performed by restriction fragment length polymorphism or Taqman 5′‐nuclease assays.ResultsThe rs236918 allele C frequency increased from stages 0–2 to 5–6 (7.1% vs 13.6%, vs 21.9%, P = 0.003). The wild‐type genotype was significantly more frequent in the absent/mild fibrosis group (54.2%) compared with only 17% in patients with severe fibrosis/cirrhosis. At univariate proportional odds model, patients with GC + CC genotypes were 2.77 times (P = 0.0018) more likely to have worse liver staging scores than wild‐type patients. In the adjusted analysis, odds ratio was 2.37 (P = 0.0218), and 2.56 (P = 0.0233) when the analysis was restricted to males. An exploratory mediation analysis suggested a direct effect of genotype on severe fibrosis/cirrhosis (odds ratio = 3.11, P = 0.0157), and a mild non‐significant indirect effect mediated through iron accounting for 28%.ConclusionsThese findings confirm that PCSK7 rs236918 C allele is a risk factor for cirrhosis development in Italian patients with HFE‐Hemochromatosis.
Effects of Home‐Based Tai Chi and Lower Extremity Training and Self‐Practice on Falls and Functional Outcomes in Older Fallers from the Emergency Department—A Randomized Controlled Trial
Authors: Hwang Hei‐Fen , Chen Sy‐Jou , Lee‐Hsieh Jane , Chien Ding‐Kuo , Chen Chih‐Yi , Lin Mau‐Roung 
Published: February 2016

ObjectivesTo compare the effects of guided home‐based tai chi chuan (TCC) and lower extremity training (LET) and of levels of self‐practice on falls and functional outcomes in older fallers.DesignRandomized controlled trial.SettingTaipei, Taiwan.ParticipantsIndividuals aged 60 and older who had fall‐related emergency department visits at least 6 months before participating in the study and ambulated independently at baseline (N = 456).InterventionSix months of TCC or LET.MeasurementsFour types of fall measures (falls, time to first fall, fallers, recurrent fallers) and six functional measures (handgrip strength, balance, mobility, fear of falling, depression, cognitive function).ResultsThe TCC group was significantly less likely than the LET group to experience any falls during the 6‐month intervention (incidence rate ratio (IRR) = 0.30, 95% confidence interval (CI) = 0.15–0.60), and the effects remained significant after 12 months of follow‐up (IRR = 0.32, 95% CI = 0.14–0.71). These effects remained significant for injurious falls during the 6‐month intervention (IRR = 0.33, 95% CI = 0.16–0.68) and the entire 18‐month study (IRR = 0.39, 95% CI = 0.18–0.83). Similar results were obtained when another two fall measures (time to first fall, number of fallers) were used. Moreover, participants who independently practiced TCC or LET seven times per week or more were significantly less likely to experience injurious falls during the 6‐month intervention (IRR = 0.41, 95% CI = 0.20–0.83) and the 18‐month study (IRR = 0.43, 95% CI = 0.21–0.87) than their counterparts, had a significantly longer time to first injurious fall, and were significantly less likely to have an injurious fall during the 6‐month intervention. Cognitive function improved to a greater extent in the TCC group than in the LET group over the 18‐month study.ConclusionHome‐based TCC may reduce the incidence of falls and injurious falls more than conventional LET in older fallers, and the effects may last for at least 1 year.
Enhanced ubiquitination and proteasomal degradation of catalytically deficient human choline acetyltransferase mutants
Authors: Morey Trevor M. , Albers Shawn , Shilton Brian H. , Rylett R. Jane 
Published: February 2016

AbstractCholine acetyltransferase (ChAT) is essential for cholinergic neuron function as it mediates synthesis of the neurotransmitter acetylcholine. ChAT mutations have been linked to the neuromuscular disorder congenital myasthenic syndrome (CMS). One CMS‐related ChAT mutation, V18M, reduces enzyme activity and cellular protein levels, and is positioned within a highly conserved proline‐rich motif with the sequence 14PKLPVPP20. We demonstrate that N‐terminal truncation that includes this proline‐rich motif, as well as mutation of prolines‐17/19 together to alanine (P17A/P19A), dramatically reduces ChAT steady‐state protein levels and cellular activity when expressed in cholinergic SN56 neural cells. The in vitro activity of bacterially expressed recombinant P17A/P19A‐ChAT is also reduced, although this is not caused by changes in protein secondary structure or thermal stability. Treatment of SN56 cells with the proteasome inhibitor MG132 increases cellular P17A/P19A‐ChAT steady‐state protein levels, and by immunoprecipitation we found that ChAT is ubiquitinated and that polyubiquitination of P17A/P19A‐ChAT is increased compared to wild‐type (WT) ChAT. Using a novel fluorescent‐biorthogonal pulse‐chase protocol in SN56 cells, we determined that the protein half‐life of P17A/P19A‐ChAT (2.2 h) is substantially reduced compared to WT‐ChAT (19.7 h). Lastly, we show that two CMS‐related ChAT mutants (V18M and A513T) have enhanced ubiquitination, and that treatment with MG132 can partially restore both the steady‐state protein levels as well as cellular activity of some CMS‐mutant ChAT. These results identify a novel mechanism for regulation of ChAT through the ubiquitin–proteasome system that is influenced by the conserved N‐terminal proline‐rich motif of ChAT and may be implicated in CMS pathology.
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Choline acetyltransferase (ChAT) synthesizes acetylcholine in cholinergic neurons. In this study we find that steady‐state protein levels of human 69‐kDa ChAT are regulated by the ubiquitin–proteasome system. Mutation of a highly conserved N‐terminal proline‐rich motif in human 69‐kDa ChAT reduces both cellular ChAT protein levels, through enhanced ubiquitination and proteasomal degradation, and enzyme activity. Ubiquitination of catalytically deficient congenital myasthenic syndrome (CMS)‐mutant ChAT is increased in cells, and importantly proteasome inhibition partially restores steady‐state protein levels as well as cellular activity of some CMS‐mutant ChAT proteins.