48 research outputs found

    The Reliability of Electromyographic Normalization Methods for Cycling Analyses

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    Electromyography (EMG) is normalized in relation to a reference maximum voluntary contraction (MVC) value. Different normalization techniques are available but the most reliable method for cycling movements is unknown. This study investigated the reliability of different normalization techniques for cycling analyses. Twenty‐five male cyclists (age 24.13 ± 2.79 years, body height 176.22 ± 4.87 cm and body mass 67.23 ± 4.19 kg, BMI = 21.70 ± 2.60 kg∙m‐1) performed different normalization procedures on two occasions, within the same testing session. The rectus femoris, biceps femoris, gastrocnemius and tibialis anterior muscles were examined. Participants performed isometric normalizations (IMVC) using an isokinetic dynamometer. Five minutes of submaximal cycling (180 W) were also undertaken, allowing the mean (DMA) and peak (PDA) activation from each muscle to serve as reference values. Finally, a 10 s cycling sprint (MxDA) trial was undertaken and the highest activation from each muscle was used as the reference value. Differences between reference EMG amplitude, as a function of normalization technique and time, were examined using repeated measures ANOVAs. The test‐retest reliability of each technique was also examined using linear regression, intraclass correlations and Cronbach’s alpha. The results showed that EMG amplitude differed significantly between normalization techniques for all muscles, with the IMVC and MxDA methods demonstrating the highest amplitudes. The highest levels of reliability were observed for the PDA technique for all muscles; therefore, our results support the utilization of this method for cycling analyses

    Timing and presence of an attachment person affect sensitivity of aggression tests in shelter dogs

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    Different test series have been developed and used to measure behaviour in shelter dogs in order to reveal individuals not suitable for re-homing due to their aggressive tendencies. However, behavioural tests previously validated on pet dogs seem to have relatively low predictability in the case of shelter dogs. Here, we investigate the potential effects of (1) timing of the behaviour testing and (2) presence of a human companion on dogs' aggressive behaviour. In Study I, shelter dogs (n=25) showed more aggression when tested in a short test series two weeks after they had been placed in the shelter compared to their responses in the same test performed 1–2 days after arrival. In Study II, the occurrence of aggressive behaviour was more probable in pet dogs (n=50) in the presence than in the absence of their passive owner. We conclude that the sensitivity of aggression tests for shelter dogs can be increased by running the test in the presence of a caretaker, and after some period of acclimatisation to the new environment. This methodology could also provide better chances for successful adoption

    Genetic architecture of common bunt resistance in winter wheat using genome-wide association study

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    Background: Common bunt (caused by Tilletia caries and T. foetida) has been considered as a major disease in wheat (Triticum aestivum) following rust (Puccinia spp.) in the Near East and is economically important in the Great Plains, USA. Despite the fact that it can be easily controlled using seed treatment with fungicides, fungicides often cannot or may not be used in organic and low-input fields. Planting common bunt resistant genotypes is an alternative. Results: To identify resistance genes for Nebraska common bunt race, the global set of differential lines were inoculated. Nine differential lines carrying nine different genes had 0% infected heads and seemed to be resistant to Nebraska race. To understand the genetic basis of the resistance in Nebraska winter wheat, a set of 330 genotypes were inoculated and evaluated under field conditions in two locations. Out of the 330 genotypes, 62 genotypes had different degrees of resistance. Moreover, plant height, chlorophyll content and days to heading were scored in both locations. Using genome-wide association study, 123 SNPs located on fourteen chromosomes were identified to be associated with the resistance. Different degrees of linkage disequilibrium was found among the significant SNPs and they explained 1.00 to 9.00% of the phenotypic variance, indicating the presence of many minor QTLs controlling the resistance. Conclusion: Based on the chromosomal location of some of the known genes, some SNPs may be associated with Bt1, Bt6, Bt11 and Bt12 resistance loci. The remaining significant SNPs may be novel alleles that were not reported previously. Common bunt resistance seems to be an independent trait as no correlation was found between a number of infected heads and chlorophyll content, days to heading or plant height

    A transcriptomic analysis of gene expression in the venom gland of the snake Bothrops alternatus (urutu)

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    <p>Abstract</p> <p>Background</p> <p>The genus <it>Bothrops </it>is widespread throughout Central and South America and is the principal cause of snakebite in these regions. Transcriptomic and proteomic studies have examined the venom composition of several species in this genus, but many others remain to be studied. In this work, we used a transcriptomic approach to examine the venom gland genes of <it>Bothrops alternatus</it>, a clinically important species found in southeastern and southern Brazil, Uruguay, northern Argentina and eastern Paraguay.</p> <p>Results</p> <p>A cDNA library of 5,350 expressed sequence tags (ESTs) was produced and assembled into 838 contigs and 4512 singletons. BLAST searches of relevant databases showed 30% hits and 70% no-hits, with toxin-related transcripts accounting for 23% and 78% of the total transcripts and hits, respectively. Gene ontology analysis identified non-toxin genes related to general metabolism, transcription and translation, processing and sorting, (polypeptide) degradation, structural functions and cell regulation. The major groups of toxin transcripts identified were metalloproteinases (81%), bradykinin-potentiating peptides/C-type natriuretic peptides (8.8%), phospholipases A<sub>2 </sub>(5.6%), serine proteinases (1.9%) and C-type lectins (1.5%). Metalloproteinases were almost exclusively type PIII proteins, with few type PII and no type PI proteins. Phospholipases A<sub>2 </sub>were essentially acidic; no basic PLA<sub>2 </sub>were detected. Minor toxin transcripts were related to L-amino acid oxidase, cysteine-rich secretory proteins, dipeptidylpeptidase IV, hyaluronidase, three-finger toxins and ohanin. Two non-toxic proteins, thioredoxin and double-specificity phosphatase Dusp6, showed high sequence identity to similar proteins from other snakes. In addition to the above features, single-nucleotide polymorphisms, microsatellites, transposable elements and inverted repeats that could contribute to toxin diversity were observed.</p> <p>Conclusions</p> <p><it>Bothrops alternatus </it>venom gland contains the major toxin classes described for other <it>Bothrops </it>venoms based on trancriptomic and proteomic studies. The predominance of type PIII metalloproteinases agrees with the well-known hemorrhagic activity of this venom, whereas the lower content of serine proteases and C-type lectins could contribute to less marked coagulopathy following envenoming by this species. The lack of basic PLA<sub>2 </sub>agrees with the lower myotoxicity of this venom compared to other <it>Bothrops </it>species with these toxins. Together, these results contribute to our understanding of the physiopathology of envenoming by this species.</p

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Infant BCG vaccination and risk of pulmonary and extrapulmonary tuberculosis throughout the life course: a systematic review and individual participant data meta-analysis.

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    BACKGROUND: BCG vaccines are given to more than 100 million children every year, but there is considerable debate regarding the effectiveness of BCG vaccination in preventing tuberculosis and death, particularly among older children and adults. We therefore aimed to investigate the age-specific impact of infant BCG vaccination on tuberculosis (pulmonary and extrapulmonary) development and mortality. METHODS: In this systematic review and individual participant data meta-analysis, we searched MEDLINE, Web of Science, BIOSIS, and Embase without language restrictions for case-contact cohort studies of tuberculosis contacts published between Jan 1, 1998, and April 7, 2018. Search terms included "mycobacterium tuberculosis", "TB", "tuberculosis", and "contact". We excluded cohort studies that did not provide information on BCG vaccination or were done in countries that did not recommend BCG vaccination at birth. Individual-level participant data for a prespecified list of variables, including the characteristics of the exposed participant (contact), the index case, and the environment, were requested from authors of all eligible studies. Our primary outcome was a composite of prevalent (diagnosed at or within 90 days of baseline) and incident (diagnosed more than 90 days after baseline) tuberculosis in contacts exposed to tuberculosis. Secondary outcomes were pulmonary tuberculosis, extrapulmonary tuberculosis, and mortality. We derived adjusted odds ratios (aORs) using mixed-effects, binary, multivariable logistic regression analyses with study-level random effects, adjusting for the variable of interest, baseline age, sex, previous tuberculosis, and whether data were collected prospectively or retrospectively. We stratified our results by contact age and Mycobacterium tuberculosis infection status. This study is registered with PROSPERO, CRD42020180512. FINDINGS: We identified 14 927 original records from our database searches. We included participant-level data from 26 cohort studies done in 17 countries in our meta-analysis. Among 68 552 participants, 1782 (2·6%) developed tuberculosis (1309 [2·6%] of 49 686 BCG-vaccinated participants vs 473 [2·5%] of 18 866 unvaccinated participants). The overall effectiveness of BCG vaccination against all tuberculosis was 18% (aOR 0·82, 95% CI 0·74-0·91). When stratified by age, BCG vaccination only significantly protected against all tuberculosis in children younger than 5 years (aOR 0·63, 95% CI 0·49-0·81). Among contacts with a positive tuberculin skin test or IFNγ release assay, BCG vaccination significantly protected against tuberculosis among all participants (aOR 0·81, 95% CI 0·69-0·96), participants younger than 5 years (0·68, 0·47-0·97), and participants aged 5-9 years (0·62, 0·38-0·99). There was no protective effect among those with negative tests, unless they were younger than 5 years (0·54, 0·32-0·90). 14 cohorts reported on whether tuberculosis was pulmonary or extrapulmonary (n=57 421). BCG vaccination significantly protected against pulmonary tuberculosis among all participants (916 [2·2%] in 41 119 vaccinated participants vs 334 [2·1%] in 16 161 unvaccinated participants; aOR 0·81, 0·70-0·94) but not against extrapulmonary tuberculosis (106 [0·3%] in 40 318 vaccinated participants vs 38 [0·2%] in 15 865 unvaccinated participants; 0·96, 0·65-1·41). In the four studies with mortality data, BCG vaccination was significantly protective against death (0·25, 0·13-0·49). INTERPRETATION: Our results suggest that BCG vaccination at birth is effective at preventing tuberculosis in young children but is ineffective in adolescents and adults. Immunoprotection therefore needs to be boosted in older populations. FUNDING: National Institutes of Health

    Centros de Saúde: ciência e ideologia na reordenação da saúde pública no século XX

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    Influence of posture on the range of axial rotation and coupled lateral flexion of the thoracic spine

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    ObjectiveThis study examines the influence of posture on the range of axial rotation of the thorax and the range and direction of the coupled lateral flexion.MethodsThe ranges of mid thoracic axial rotation and coupled lateral flexion were measured in 52 asymptomatic subjects (aged 18-43 years) using an optical motion analysis system. To examine the influence of posture on primary and coupled motion, we initiated axial rotation from a neutral sitting posture and from end-range thoracic flexion and extension.ResultsThere was a significant decrease in the range of thoracic rotation in flexion compared with the neutral and extended postures (P &lt; .001). The mean range of coupled lateral flexion was 8.9% of the axial rotation range in the neutral posture and increased to 14.3% and 23.2% in the extended and flexed postures, respectively. Patterns of coupled motion varied between subjects, but an ipsilateral pattern was more common in the flexed posture, whereas a contralateral pattern was more common in the neutral and extended postures.ConclusionsThe ranges and patterns of coupled motion of the thorax appear to be strongly influenced by the posture from which the movement is initiated. This has important implications in relation to the interpretation of clinical tests of thoracic motion and in consideration of mechanisms of development of thoracic pain disorders.<br /

    Postural neck pain : an investigation of habitual sitting posture, perception of \u27good\u27 posture and cervicothoracic kinaesthesia

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    Impairments of cervico-cephalic kinaesthesia and habitual forward head posture have been considered important in the aetiology of postural neck pain, yet these factors have not been specifically examined in a homogeneous clinical population. The objective of this study was to compare the habitual sitting posture (HSP), perception of good posture and postural repositioning error (PRE) of the cervico-thoracic (CT) spine in individuals with postural neck pain, with a matched group of asymptomatic subjects. Twenty-one subjects with postural neck pain and 22 asymptomatic control subjects were recruited into the study. An optical motion analysis system was used to measure the HSP and perceived &lsquo;good&rsquo; sitting posture. PRE was measured over six trials where the subject attempted to replicate their self-selected &lsquo;good&rsquo; posture. There was no difference between the groups in the HSP but significant differences were identified in the perception of &lsquo;good&rsquo; posture. Posture repositioning error was higher for the head posture variables than for CT and shoulder girdle variables in both groups. However, there was no significant difference in posture repositioning error between groups for any of the posture measures. The findings suggest that individuals with postural neck pain may have a different perception of &lsquo;good&rsquo; posture, but no significant difference in HSP or kinaesthetic sensibility compared with matched asymptomatic subjects.<br /

    Personality Consistency in Dogs: A Meta-Analysis

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    Jamie L. Fratkin is with UT Austin; David L. Sinn is with UT Austin and University of Tasmania; Samuel D. Gosling is with UT Austin; Erika A. Patall is with UT Austin.Personality, or consistent individual differences in behavior, is well established in studies of dogs. Such consistency implies predictability of behavior, but some recent research suggests that predictability cannot be assumed. In addition, anecdotally, many dog experts believe that ‘puppy tests’ measuring behavior during the first year of a dog's life are not accurate indicators of subsequent adult behavior. Personality consistency in dogs is an important aspect of human-dog relationships (e.g., when selecting dogs suitable for substance-detection work or placement in a family). Here we perform the first comprehensive meta-analysis of studies reporting estimates of temporal consistency of dog personality. A thorough literature search identified 31 studies suitable for inclusion in our meta-analysis. Overall, we found evidence to suggest substantial consistency (r = 0.43). Furthermore, personality consistency was higher in older dogs, when behavioral assessment intervals were shorter, and when the measurement tool was exactly the same in both assessments. In puppies, aggression and submissiveness were the most consistent dimensions, while responsiveness to training, fearfulness, and sociability were the least consistent dimensions. In adult dogs, there were no dimension-based differences in consistency. There was no difference in personality consistency in dogs tested first as puppies and later as adults (e.g., ‘puppy tests’) versus dogs tested first as puppies and later again as puppies. Finally, there were no differences in consistency between working versus non-working dogs, between behavioral codings versus behavioral ratings, and between aggregate versus single measures. Implications for theory, practice, and future research are discussed.Funding provided by the US Department of Homeland Security, Contract HSHQDC-10-C-00085. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Psycholog
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