19 research outputs found

    Data-driven estimation of EMG muscular activity and fatigue through infrared thermal imaging

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    Purpose: Superficial electromyography (sEMG) is the recording, from the surface of the body, of the electrical signal associated to muscle activation. Usually, sEMG is assessed through electrodes with electrolytic gel often causing skin irritation. To overcome this issue, capacitive contactless electrodes have been developed. However, contactless EMG sensors are still quite sensitive to motion artifacts and could be not comfortable for long monitoring. In this study, a non-invasive contactless method to assess muscular activity through infrared thermal imaging (IRI) is presented. Methods: 10 healthy participants (age: 21.8 ± 2.9 years) were enrolled in the study. The participants underwent to 5 series of bodyweight squat exercise until exhaustion separated by 1 min of rest. The vastus medialis activity was assessed through EMG system Encephalan Mini AP-10. Concurrently, the temperature of the same muscle was measured through thermal camera FLIR A655. Regarding the EMG, the Average Rectified Value (ARV) and the median frequency of the Power Spectral Density (MDF) were evaluated for each series. Specifically, ARV is indicative of muscular activity and MDF of the muscular fatigue. Concerning the IRI, the average and the standard deviation of the temperature in a temporal window of 10 s after each series, and the thermal spatial gradient of the considered region were computed. Several Machine Learning regressors were tested employing the IRI features as input and, separately, the ARV and MDF as output. The data were normalized (z-score) and the leave-one-subject-out cross validation was used to test the generalization performance of the models. Results: Concerning the ARV, the Gaussian Process Regression delivered the best performance, with a correlation coefficient r = 0.75 (p\ 0.001) and root mean square error (RMSE) of 0.02 mV. Regarding the MDF, the Support Vector Machine with a radial basis function kernel allowed to obtain the best regression (r = 0.66, p \0.001; RMSE=0.67 Hz). Conclusion: The proposed method estimated the EMG parameters indicative of muscular activity and fatigue. These results indicate that the muscular activity influences skin temperature, suggesting a modification of the superficial blood circulation linked to the muscular need of oxygen during exercising. These results could pave the way to the employment of contactless methods to monitor the muscular activity and evaluate fatigue in a non-invasive and comfortable manner in sports and clinical applications

    Effects of knee extension with different speeds of movement on muscle and cerebral oxygenation

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    Background One of the mechanisms responsible for enhancing muscular hypertrophy is the high metabolic stress associated with a reduced muscular oxygenation occurring during exercise, which can be achieved by reducing the speed of movement. Studies have tested that lowered muscle oxygenation artificially induced by an inflatable cuff, could provoke changes in prefrontal cortex oxygenation, hence, to central fatigue. It was hypothesized that (1) exercising with a slow speed of movement would result in greater increase in cerebral and greater decrease in muscle oxygenation compared with exercises of faster speed and (2) the amount of oxygenation increase in the ipsilateral prefrontal cortex would be lower than the contralateral one. Methods An ISS Imagent frequency domain near infrared spectroscopy (NIRS) system was used to quantify oxygenation changes in the vastus lateralis muscle and prefrontal cortex (contra- and ipsilateral) during unilateral resistance exercises with different speeds of movement to voluntary fatigue. After one maximal repetition (1RM) test, eight subjects performed three sets of unilateral knee extensions ( 3c50% of 1RM), separated by 2 min rest periods, following the pace of 1 s, 3 s and 5 s for both concentric and eccentric phases, in a random order, during separate sessions. The amount of change for NIRS parameters for muscle (\u394Hb: deoxyhemoglobin, \u394HbO: oxyhemoglobin, \u394HbT: total hemoglobin, \u394StO2: oxygen saturation) were quantified and compared between conditions and sets by two-way ANOVA RM. Differences in NIRS parameters between contra- and ipsilateral (lobe) prefrontal cortex and conditions were tested. Results Exercising with slow speed of movement was associated to larger muscle deoxygenation than normal speed of movement, as revealed by significant interaction (set 7 condition) for \u394Hb (p = 0.01), and by significant main effects of condition for \u394HbO (p = 0.007) and \u394StO2 (p = 0.016). With regards to the prefrontal cortex, contralateral lobe showed larger oxygenation increase than the ipsilateral one for \u394Hb, \u394HbO, \u394HbT, \u394StO2 in each set (main effect of lobe: p < 0.05). Main effects of condition were significant only in set1 for all the parameters, and significant interaction lobe 7 condition was found only for \u394Hb in set1 (p < 0.05). Discussion These findings provided evidence that speed of movement influences the amount of muscle oxygenation. Since the lack of oxygen in muscle is associated to increased metabolic stress, manipulating the speed of movement may be useful in planning resistance-training programs. Moreover, consistent oxygenation increases in both right and left prefrontal lobes were found, suggesting a complementary interaction between the ipsi- and contralateral prefrontal cortex, which also seems related to fatigue

    Isolation of a novel species of Bifidobacteriaceae from the herbivourous primates Theropitecus gelada

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    The Theropitecus gelada (fig.1), sometimes called the\ua0bleeding-heart monkey for their unmistakable red and hairless spot at the center of the chest, useful to indicate the social and reproductive status of the individual, are rocks monkeys living on the stony plateaus of Central Ethiopia, between 1,800 and 4,400 meters high. [1][2] These primates are perfectly suited to running and moving on the ground and find their natural habitat in rocky slopes, especially near rivers and streams. They are diurnal monkeys, and the most important trait of this animals is that they are the only known species of primates to be exclusively herbivores. After a trip of about a thousand kilometers, 6 monkeys of this species are housed in Italy, in the Natura Viva Park of Verona

    Impact of Saccharomyces cerevisiae and non-Saccharomyces yeasts to improve traditional sparkling wines production

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    In this study the effect of a co-inoculum of S. cerevisiae (F6789) with Torulaspora delbrueckii (TB1) or Starmerella bacillaris (SB48) on the oenological and aroma characteristics of sparkling wines obtained with the Champenoise method was investigated. The autolytic outcome and the sensory profile of sparkling wines were also evaluated. The secondary fermentations were completed by all mixed and single starter cultures with the only exception of those guided by Starm. bacillaris. Sparkling wines produced with S. cerevisiae F6789+Starm. bacillaris SB48 showed the highest amounts of glycerol (6.51 g/L). The best autolytic potential was observed in sparkling wines produced with +Starm. bacillaris (81.98 mg leucin/L) and S. cerevisiae+T. delbrueckii (79.03 mg leucin/L). The lowest value was observed for sparkling wines obtained with S. cerevisiae F6789 (53.96 mg leucin/L). Sparkling wines showed different aroma and sensory profiles. Esters were mainly present in sparkling wines obtained with S. cerevisiae F6789 (88.09 mg/L) followed by those obtained with S. cerevisiae+T. delbrueckii (87.20 mg/L), S. cerevisiae +Starm. bacillaris (81.93 mg/L). The content of esters decreased over time, and that might be related to the adsorption on lees and chemical hydrolysis. The highest concentrations of higher alcohols were found in sparkling wines produced with S. cerevisiae+T. delbrueckii (27.50 mg/L). Sparkling wines obtained with S. cerevisiae +Starm. bacillaris were well differentiated from the others due to their high score for the descriptor for spicy, bread crust, freshness and floral. Tailored strains with different autolytic potential might represent an interesting strategy to improve traditional sparkling wine production and favour their differentiation

    Occurrence of Bifidobacteriaceae in herbivorous primate Theropithecus gelada

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    Primates in general exhibit a wide dietary diversity, enabling them to occupy various ecological niches. It is well know that the diet greatly influences microbial diversity of gut microbiota and generally, a fibre rich diet promotes the growth of microbial groups producing short fatty acids, thus playing an important beneficial role in the host health. The Bifidobacteriaceae are grampositive, pleomorphically branched, non-motile, non-spore-forming that constitute a significant proportion of the microbiota in the gut. They can be grouped on the basis of one of six different ecological niches that they occupy: the human intestine, oral cavity, food, the animal gastrointestinal tract, the insect intestine, and sewage. Although nearly all primates are to some extent omnivorous, most primates can be primarily categorized as fruit-, insect- or leaf-eaters. However, in all primate diversity, there is only one species of modern primate that feeds on particularly nutrient-poor plant material is the gelada baboon (Theropithecus gelada). Native to the highlands of Ethiopia, they subsist largely as grazers, the only modern primate species to do so. Aim of this work was to investigate the occurrence of Bifidobacteriaceae in six adult males of Theropithecus gelada housed in Parco Natura Viva Garda Zoological Park (Bussolengo, Verona, Italy). Different selective media were tested for their suitability in the isolation of the Bifidobacteriaceae strains. All sixteen isolates were clones as resulted from BOX-PCR fingerprinting, a technique allowing the molecular typing. Comparative analysis of the 16S rRNA gene sequences revealed low sequence similarity of isolates to known Bifidobacteriaceae and the highest similarity (96.1 %) was found to Alloscardovia criceti. Therefore the isolates are phylogenetically not closely related to known species and are possible novel species in the genus Alloscardovia of the Bifidobacteriaceae family. For the first time member of Bifidobacteriaceae family have been found in Theropithecus gelada and further studies are needed to better analyse the importance of their presence in these very peculiar group of monkeys

    SIGNOR: a database of causal relationships between biological entities

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    Assembly of large biochemical networks can be achieved by confronting new cell-specific experimental data with an interaction subspace constrained by prior literature evidence. The SIGnaling Network Open Resource, SIGNOR (available on line at http://signor.uniroma2.it), was developed to support such a strategy by providing a scaffold of prior experimental evidence of causal relationships between biological entities. The core of SIGNOR is a collection of approximately 12 000 manually-annotated causal relationships between over 2800 human proteins participating in signal transduction. Other entities annotated in SIGNOR are complexes, chemicals, phenotypes and stimuli. The information captured in SIGNOR can be represented as a signed directed graph illustrating the activation/inactivation relationships between signalling entities. Each entry is associated to the post-translational modifications that cause the activation/inactivation of the target proteins. More than 4900 modified residues causing a change in protein concentration or activity have been curated and linked to the modifying enzymes (about 351 human kinases and 94 phosphatases). Additional modifications such as ubiquitinations, sumoylations, acetylations and their effect on the modified target proteins are also annotated. This wealth of structured information can support experimental approaches based on multi-parametric analysis of cell systems after physiological or pathological perturbations and to assemble large logic models

    SIGNOR: A database of causal relationships between biological entities

    No full text
    Assembly of large biochemical networks can be achieved by confronting new cell-specific experimental data with an interaction subspace constrained by prior literature evidence. The SIGnaling Network Open Resource, SIGNOR (available on line at http://signor.uniroma2.it), was developed to support such a strategy by providing a scaffold of prior experimental evidence of causal relationships between biological entities. The core of SIGNOR is a collection of approximately 12 000 manually-annotated causal relationships between over 2800 human proteins participating in signal transduction. Other entities annotated in SIGNOR are complexes, chemicals, phenotypes and stimuli. The information captured in SIGNOR can be represented as a signed directed graph illustrating the activation/inactivation relationships between signalling entities. Each entry is associated to the post-translational modifications that cause the activation/inactivation of the target proteins. More than 4900 modified residues causing a change in protein concentration or activity have been curated and linked to the modifying enzymes (about 351 human kinases and 94 phosphatases). Additional modifications such as ubiquitinations, sumoylations, acetylations and their effect on the modified target proteins are also annotated. This wealth of structured information can support experimental approaches based on multi-parametric analysis of cell systems after physiological or pathological perturbations and to assemble large logic models

    Microorganisms, the ultimate tool for clean label foods?

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    Clean label is an important trend in the food industry. It aims at washing foods of chemicals perceived as unhealthy by consumers. Microorganisms are present in many foods (usually fermented), they exhibit a diversity of metabolism and some can bring probiotic properties. They are usually well considered by consumers and, with progresses in the knowledge of their physiology and behavior, they can become very precise tools to produce or degrade specific compounds. They are thus an interesting means to obtain clean label foods. In this review, we propose to discuss some current research to use microorganisms to produce clean label foods with examples improving sensorial, textural, health and nutritional properties

    Characterization of Bifidobacterium species in feaces of the Egyptian fruit bat: Description of B. vespertilionis sp. nov. and B. rousetti sp. nov

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    Fifteen bifidobacterial strains were obtained from faeces of Rousettus aegyptiacus; after grouping them by RAPD PCR only eight were selected and characterized. Analysis of 16S rRNA and of five housekeeping (hsp60, rpoB, clpC, dnaJ, dna G) genes revealed that these eight strains were classified into five clusters: Cluster I (RST 8 and RST 16T), Cluster II (RST 9T and RST 27), Cluster III (RST 7 and RST 11), Cluster IV (RST 19), Cluster V (RST 17) were closest to Bifidobacterium avesanii DSM 100685T (96.3%), Bifidobacterium callitrichos DSM 23973T (99.2% and 99.7%), Bifidobacterium tissieri DSM 100201T (99.7 and 99.2%), Bifidobacterium reuteri DSM 23975 T (98.9%) and Bifidobacterium myosotis DSM 100196T (99.3%), respectively. Strains in Cluster I and strain RST 9 in Cluster II could not be placed within any recognized species while the other ones were identified as known species. The average nucleotide identity values between two novel strains, RST 16T and RST 9T and their closest relatives were lower than 79% and 89%, respectively. In silico DNA-DNA hybridization values for those closest relatives were 32.5 and 42.1%, respectively. Phenotypic and genotypic tests demonstrated that strains in Cluster I and RST 9T in Cluster II represent two novel species for which the names Bifidobacterium vespertilionis sp. nov. (RST 16T=BCRC 81138T=NBRC 113380T=DSM 106025T ; RST 8=BCRC 81135=NBRC 113377) and Bifidobacterium rousetti sp. nov. (RST 9T=BCRC 81136T=NBRC 113378T=DSM 106027T) are proposed
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