29 research outputs found

    Morphology of the toe flexor muscles in older people with toe deformities

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    Objective: Despite suggestions that atrophied, or weak toe flexor muscles are associated with the formation of toe deformities, there has been little evidence to support this theory. This study aimed to determine whether the size of the toe flexor muscles differed in older people with and without toe deformities. Methods: Forty-four older adults (>60 years) were recruited for the study. Each participant had their feet assessed for the presence of hallux valgus or lesser toe deformities. Intrinsic and extrinsic toe flexor muscles were imaged with an ultrasound system using a standardised protocol. Assessor blinded muscle thickness and cross-sectional area was measured using Image J software. Results: Participants with lesser toe deformities (n=20) were found to have significantly smaller quadratus plantae (p=0.003), flexor digitorum brevis (p=0.013), abductor halluces (p=0.004) and flexor halluces brevis (p=0.005) muscles than the participants without any toe deformities (n=19). Female participants with hallux valgus (n=10) were found to have significantly smaller abductor hallucis (p=0.048) and flexor halluces brevis (p=0.013) muscles than the female participants without any toe deformities (n=10; p<0.05). Conclusion: This is the first study to use ultrasound to investigate the size of the toe flexor muscles in older people with hallux valgus and lesser toe deformities compared to otherwise healthy older adults. The size of the abductor hallucis and flexor hallucis brevis muscles were decreased in participants with hallux valgus whereas the quadratus plantae, flexor digitorum brevis, abductor hallucis and flexor halluces brevis muscles were smaller in those participants with lesser toe deformities

    Rubin-Euclid Derived Data Products:Initial Recommendations

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    This report is the result of a joint discussion between the Rubin and Euclid scientific communities. The work presented in this report was focused on designing and recommending an initial set of Derived Data products (DDPs) that could realize the science goals enabled by joint processing. All interested Rubin and Euclid data rights holders were invited to contribute via an online discussion forum and a series of virtual meetings. Strong interest in enhancing science with joint DDPs emerged from across a wide range of astrophysical domains: Solar System, the Galaxy, the Local Volume, from the nearby to the primaeval Universe, and cosmology

    Inoculum pre-treatment affects the fermentative activity of hydrogen-producing communities in the presence of 5-hydroxymethylfurfural

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    To enhance the productivity of mixed microbial cultures for fermentative bio-hydrogen production, chemical-physical pre-treatments of the original seed are needed to suppress the activity of hydrogen (H2)-consuming microbes. This approach might influence negatively the composition and diversity of the hydrogen-producing community with consequences on the functional stability of the H2-producing systems in case of perturbations. In this study, we aimed at investigating the effect of different types of pre-treatment on the performance of hydrogen production systems in the presence of an inhibitor, such as 5-hydroxymethylfurfural (HMF). The efficiency and the microbial community structure of batch reactors amended with HMF and inoculated with non-pretreated and pretreated (acid, heat shock, and aeration) anaerobic sludge were evaluated and compared with control systems. The type of pre-treatments influenced the microbial community assembly and activity in inhibited systems, with significant effect on the performance. Cumulative H2 production tests showed that the pre-aerated systems (control and HMF inhibited) were the most efficient, while the difference of the lag phase of the pre-acidified control and HMF-added test was negligible. Analyses of the structure of the enriched microbial community in the systems through PCR-denaturing gradient gel electrophoresis (DGGE) followed by band sequencing revealed that the differences in performance were mostly related to shifts in the metabolic pathways rather than in the predominant species. In conclusion, the findings suggest that the use of specific inoculum pre-treatment could contribute to regulate the metabolic activity of the fermentative H2-producing bacteria in order to enhance the bio-energy production

    A Fast, Reliable, and Sensitive Method for Detection and Quantification of Listeria monocytogenes and Escherichia coli O157:H7 in Ready-to-Eat Fresh-Cut Products by MPN-qPCR

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    In the present work we developed a MPN quantitative real-time PCR (MPN-qPCR) method for a fast and reliable detection and quantification of Listeria monocytogenes and Escherichia coli O157:H7 in minimally processed vegetables. In order to validate the proposed technique, the results were compared with conventional MPN followed by phenotypic and biochemical assays methods. When L. monocytogenes and E. coli O157:H7 were artificially inoculated in fresh-cut vegetables, a concentration as low as 1 CFU g−1 couldbe detected in48hours for bothpathogens. qPCRalone allowed a limit of detectionof 101 CFU g−1 after 2 hours of enrichment for L. monocytogenes and E. coli O157:H7. Since minimally processed ready-to-eat vegetables are characterized by very short shelf life, ourmethod can potentially address the consistent reduction of time for microbial analysis, allowing a better management of quality control. Moreover, the occurrences of both pathogenic bacteria in mixed salad samples and fresh-cut melons were monitored in two production plants from the receipt of the rawmaterials to the early stages of shelf life. No sample was found to be contaminated by L. monocytogenes. One sample of raw mixed salad was found positive to an H7 enterohemorrhagic serotype

    Evaluation of an ELISA Method to Detect Listeria monocytogenes in Fresh-Cut Rocket

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    Leafy vegetables are consumed fresh after harvest with bland washes, not always efficient in removing pathogenic bacteria that may be attached to the external skin or surfaces. In this work, an optimized ELISA based method developed in our laboratory was used to detect the presence of Listeria monocytogenes in fresh-cut rocket leaves. From a certain quantity (5 g) of fresh rocket leaves contaminated with Listeria monocytogenes, bacteria were isolated and the pathogen was detected using an ELISA protocol. The preliminary results are promising in the use of antibody-antigen interaction to verify the presence of L. monocytogenes in the minimally processed vegetable distribution chain

    Non-conventional pretreatments mitigate the inhibitory effect of 5-hydroxymethylfurfural in dark fermentation process

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    Dark fermentation carried out by mixed microbial cultures is considered a promising process for the production H2 biofuel. However, this process is still not cost effective and unreliable. In mixed culture based systems, the H2 production is enhanced by pretreating the initial seed to suppress the H2 consumers activity. However, this approach has been reported to influence the structure and diversity of H2 producing bacteria (HPB), which may have negative effects on the resilience and resistance of the system when changes of environmental conditions, or presence of inhibitors, occurs. 2. Objectives This study evaluates the effect of pretreatments on the performance and structure of the enriched microbial community and its potential response to an inhibitor (5-hydroxymethylfurfural, HMF). All systems produced hydrogen with a yield ranging between 0.6-0.9 mol H2/mol glucose. HMF decreased the H2 production of 19.1±2.9 % in most of the systems. However, in the pre-aerated systems the hydrogen potential was 22% higher than the other systems without significant difference between C and HMF reactors. Extended lag phases were observed in the pre-acidified tests, though the discrepancy of the lag time in the C and HMF tests was smaller than the other bottles. The high performance of the pre-aerated and acidified HMF was due to increased metabolic activity of the main taxa observed in the systems (Paenibacillus and Clostridium spp.) rather than significant changes in the community composition. In conclusion, pre-aeration and acidification of the initial inoculum can mitigate the negative effect of the HMF. The stressful conditions applied to the original inoculum may have activated cell/community response mechanisms able to counteract the toxicity of the HMF

    Listeria monocytogenes, biofilm formation and fresh cut produce

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    The risk of pathogen contamination and growth is one of the main safety concerns associated with fresh-cut produce, as highlighted by the increasing number of produce-linked foodborne outbreaks in recent years. The pathogens of major concern in freshcut produce are Listeria monocytogenes, pathogenic Escherichia coli, and Salmonella spp. Listeria monocytogenes is able to grow and multiply in vegetables packaged and stored in modified atmosphere. Biofilms formed by Listeria monocytogenes pose a serious threat to the safety of fresh cut produce as they can persist for long periods of time in the food processing environment and thus represent a source of recurrent contamination. Moreover the occurrence of naturally formed biofilms on fresh produce has been demonstrated. In this article the microbiological safety of fresh-cut produce and factors affecting Listeria monocytogenes survival and growth on fresh-cut produce are discussed. Moreover, the structure and physiology of Listeria monocytogenes biofilms are reviewed

    Detection and Enumeration of Listeria monocytogenes in Fresh Cut Vegetables Using MPN-Real-Time PCR.

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    Listeria monocytogenes is a gram positive, rod shaped, pathogenic bacterium, causative agent of a severe infection generally known as listeriosis. Packaging and storage conditions of fresh cut vegetables may favour the growth of this psychrotrophic pathogen leading to potential health threat. Detection and enumeration of L. monocytogenes in concentrations up to 103 CFU/g, usually implies use of the most-probable-number technique (MPN) which may take up to seven days for verified identification of the pathogen. We developed a fast and reliable protocol combining MPN with a Real-Time quantitative PCR (qPCR) approach. Samples of fresh cut salads (25 g) purchased at local shops were spiked with 1 to 105 CFU/g of L. monocytogenes. Samples were homogenized, and triplicate series of tubes containing 10-5 to 10 g of food were incubated in Fraser broth at 30 °C for 48 h for standard MPN analysis. After incubation, broth samples were taken from each tube and DNA was extracted. DNA from enrichment tubes was used as template in a qPCR assay targeting a 64 bp hlyA gene sequence of L. monocytogenes. Results of this assay were than compared with those of standard MPN analysis and a complete accordance was observed. Furthermore, we tested an enrichment free approach using the same qPCR assay. Samples were prepared as described for MPN-qPCR while DNA extraction was performed prior to enrichment of inoculated salads. This approach allowed us to identify L. monocytogenes in samples spiked with 10-105 CFU/g. The whole process, including DNA extraction, required less than four hours, thus providing a fast and reliable tool for detection of L. monocytogenes in fresh cut vegetables
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