1,083 research outputs found

    cis-Jasmone Elicits Aphid-Induced Stress Signalling in Potatoes

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    Elicitation of plant defense signaling that results in altered emission of volatile organic compounds (VOCs) offers opportunities for protecting plants against arthropod pests. In this study, we treated potato, Solanum tuberosum L., with the plant defense elicitor cis-jasmone (CJ), which induces the emission of defense VOCs and thus affects the behavior of herbivores. Using chemical analysis, electrophysiological and behavioral assays with the potato-feeding aphid Macrosiphum euphorbiae, we showed that CJ treatment substantially increased the emission of defense VOCs from potatoes compared to no treatment. Coupled GC-electroantennogram (GC-EAG) recordings from the antennae of M. euphorbiae showed robust responses to 14 compounds present in induced VOCs, suggesting their behavioral role in potato/aphid interactions. Plants treated with CJ and then challenged with M. euphorbiae were most repellent to alate M. euphorbiae. Principal component analysis (PCA) of VOC collections suggested that (E)-2-hexenal, (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), (E)-ÎČ-farnesene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate (MeSA), CJ, and methyl benzoate (MeBA) were the main VOCs contributing to aphid behavioral responses, and that production of TMTT, (E)-ÎČ-farnesene, CJ, and DMNT correlated most strongly with aphid repellency. Our findings confirm that CJ can enhance potato defense against aphids by inducing production of VOCs involved in aphid-induced signalling

    Natural zeolite (chabazite/phillipsite) dietary supplementation influences faecal microbiota and oxidant status of working dogs

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    We evaluated whether chabazite/phillipsite dietary supplementation might affect the faecal microbiota, oxidant and antioxidant status of working dogs at rest undergone to a trial test. Forty English Setter dogs were involved in two replicate trials. At each replicate, dogs were divided into two homogeneous groups (10 dogs/group). During a period of 28 days, diet was supplemented (Z group) or not supplemented (C group) with chabazite/phillipsite at the dose of 5 g/head/day. On day 29, dogs were subjected to a trial test. Faecal characteristics were assessed at 0 and 29 days (within two hours from the end of the trial test). Faecal consistency was not affected by dietary supplementation (p > .05). On day 29, Lactobacillus spp. and Enterococcus spp. counts were higher and Enterobacteriaceae were lower in Z than in C group (p  .05). Our results suggest that chabazite/phillipsite dietary supplementation, improves the intestinal microbiota ecosystem and may counteract the oxidative damage caused by physical stress in hunting dogs at the beginning of the working season

    Inspiratory muscle training reduces blood lactate concentration during volitional hyperpnoea

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    Although reduced blood lactate concentrations ([lac−]B) have been observed during whole-body exercise following inspiratory muscle training (IMT), it remains unknown whether the inspiratory muscles are the source of at least part of this reduction. To investigate this, we tested the hypothesis that IMT would attenuate the increase in [lac−]B caused by mimicking, at rest, the breathing pattern observed during high-intensity exercise. Twenty-two physically active males were matched for 85% maximal exercise minute ventilation (V˙Emax) and divided equally into an IMT or a control group. Prior to and following a 6 week intervention, participants performed 10 min of volitional hyperpnoea at the breathing pattern commensurate with 85% V˙Emax

    Accuracy of biplane x-ray imaging combined with model-based tracking for measuring in-vivo patellofemoral joint motion

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    <p>Abstract</p> <p>Background</p> <p>Accurately measuring <it>in-vivo</it> motion of the knee's patellofemoral (PF) joint is challenging. Conventional measurement techniques have largely been unable to accurately measure three-dimensional, <it>in-vivo</it> motion of the patella during dynamic activities. The purpose of this study was to assess the accuracy of a new model-based technique for measuring PF joint motion.</p> <p>Methods</p> <p>To assess the accuracy of this technique, we implanted tantalum beads into the femur and patella of three cadaveric knee specimens and then recorded dynamic biplane radiographic images while manually flexing and extending the specimen. The position of the femur and patella were measured from the biplane images using both the model-based tracking system and a validated dynamic radiostereometric analysis (RSA) technique. Model-based tracking was compared to dynamic RSA by computing measures of bias, precision, and overall dynamic accuracy of four clinically-relevant kinematic parameters (patellar shift, flexion, tilt, and rotation).</p> <p>Results</p> <p>The model-based tracking technique results were in excellent agreement with the RSA technique. Overall dynamic accuracy indicated errors of less than 0.395 mm for patellar shift, 0.875° for flexion, 0.863° for tilt, and 0.877° for rotation.</p> <p>Conclusion</p> <p>This model-based tracking technique is a non-invasive method for accurately measuring dynamic PF joint motion under <it>in-vivo</it> conditions. The technique is sufficiently accurate in measuring clinically relevant changes in PF joint motion following conservative or surgical treatment.</p

    Determining the Veracity of Rumours on Twitter

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    While social networks can provide an ideal platform for up-to-date information from individuals across the world, it has also proved to be a place where rumours fester and accidental or deliberate mis- information often emerges. In this article, we aim to support the task of making sense from social media data, and specifically, seek to build an autonomous message-classifier that filters relevant and trustworthy information from Twitter. For our work, we collected about 100 million public tweets, including users’ past tweets, from which we identified 72 rumours (41 true, 31 false). We considered over 80 trustworthiness measures including the authors’ profile and past behaviour, the social network connections (graphs), and the content of tweets themselves. We ran modern machine-learning classifiers over those measures to produce trustworthiness scores at various time windows from the outbreak of the rumour. Such time-windows were key as they allowed useful insight into the progression of the rumours. From our findings, we identified that our model was significantly more accurate than similar studies in the literature. We also identified critical attributes of the data that give rise to the trustworthiness scores assigned. Finally we developed a software demonstration that provides a visual user interface to allow the user to examine the analysis

    Violent video games and morality: a meta-ethical approach

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    This paper considers what it is about violent video games that leads one reasonably minded person to declare "That is immoral" while another denies it. Three interpretations of video game content a re discussed: reductionist, narrow, and broad. It is argued that a broad interpretation is required for a moral objection to be justified. It is further argued that understanding the meaning of moral utterances – like "x is immoral" – is important to an understanding of why there is a lack of moral consensus when it comes to the content of violent video games. Constructive ecumenical expressivism is presented as a means of explaining what it is that we are doing when we make moral pronouncements and why, when it comes to video game content, differing moral attitudes abound. Constructive ecumenical expressivism is also presented as a means of illuminating what would be required for moral consensus to be achieved

    A Condensation-Ordering Mechanism in Nanoparticle-Catalyzed Peptide Aggregation

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    Nanoparticles introduced in living cells are capable of strongly promoting the aggregation of peptides and proteins. We use here molecular dynamics simulations to characterise in detail the process by which nanoparticle surfaces catalyse the self- assembly of peptides into fibrillar structures. The simulation of a system of hundreds of peptides over the millisecond timescale enables us to show that the mechanism of aggregation involves a first phase in which small structurally disordered oligomers assemble onto the nanoparticle and a second phase in which they evolve into highly ordered beta-sheets as their size increases

    Kinematic analisys of the knee when climbing up/down stairs in patellofemoral instability

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    OBJECTIVE: To analyze and to identify possible gait adaptations by individuals with objective patellofemoral instability when climbing up/down stairs. METHODS: A control group (group A) composed by nine women with mean age = 25 years (±1.87), height = 1.62 m (±0.05) and weight = 56.20 kg (±7.34), and; nine women with objective patellofemoral instability (group B) with mean age = 24 years (±6.02), height = 1.62 m (±0.06) and weight = 60.33 kg (±10.31) were analyzed. The groups underwent kinematic analysis while climbing up/down stairs, in a previously determined area. Images were obtained by six cameras (Qualysis) and data analysis utilized the Q gait software program. RESULTS: Group B presented, in the support phase, less knee flexion when climbing up (p = 0.0268), and lower speed (p = 0.0076/ p =0.0243) and pace (p = 0.0027/ p = 0.0165) when climbing up and down stairs, respectively. CONCLUSION: It is suggested that group B used functional changes such as reduced knee flexion, speed and pace when climbing up and down stairs.OBJETIVO: Analisar e identificar possĂ­veis adaptaçÔes da marcha em indivĂ­duos com diagnĂłstico de instabilidade patelofemoral objetiva, durante a atividade de subida e descida de escada. MÉTODOS: Foram analisados um grupo controle (grupo A), composto por 9 mulheres com mĂ©dia de idade de 25 anos (±1,87), mĂ©dia de altura de 1,62m (±0,05) e mĂ©dia de peso de 56,20kg (±7,34); e, um grupo de 9 mulheres com instabilidade patelofemoral objetiva (grupo B), mĂ©dia de idade de 24 anos (±6,02), mĂ©dia de altura de 1,62m (±0,06) e mĂ©dia de peso de 60,33kg (±10,31). Os grupos foram submetidos a uma anĂĄlise cinemĂĄtica, onde as voluntĂĄrias subiram e desceram degraus, em uma ĂĄrea previamente selecionada. As imagens foram obtidas por seis cĂąmeras (Qualysis) e a anĂĄlise dos dados foi realizada atravĂ©s do programa Q gait. RESULTADOS: O grupo B apresentou, no perĂ­odo de apoio, menor flexĂŁo do joelho durante a subida (p=0,0268), alĂ©m de menores velocidade (p=0,0076/ p=0,0243) e cadĂȘncia (p=0,0027/ p=0,0165) na subida e na descida, respectivamente. CONCLUSÃO: Sugere-se que o grupo B utilizou adaptaçÔes funcionais como redução da flexĂŁo do joelho, da velocidade e da cadĂȘncia, durante a subida e a descida de degraus.UNICAMP FCM Departamento de Ortopedia e TraumatologiaUniversidade Federal de SĂŁo Paulo (UNIFESP)UNIFESPSciEL
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