1,955 research outputs found

    Methods of isolation and identification of pathogenic and potential pathogenic bacteria from skins and tannery effluents

    Get PDF
    Currently there is no standard protocol available within the leather industry to isolate and identify pathogenic bacteria from hides, skins or tannery effluent. This study was therefore carried out to identify simple but effective methods for isolation and identification of bacterial pathogens from the effluent and skins during leather processing. Identification methods based on both phenotypic and genotypic characteristics were investigated. Bacillus cereus and Pseudomonas aeruginosa were used as indicator bacteria to evaluate the isolation and identification methods. Decontaminated calfskins were inoculated with a pure culture of the above mentioned bacterial species followed by a pre-tanning and chromium tanning processes. Effluent samples were collected and skins were swabbed at the end of each processing stage. Bacterial identification was carried out based on the phenotypic characteristics; such as colony appearance on selective solid media, cell morphology following a standard Gram-staining and spore staining techniques, and biochemical reactions, e.g., the ability of a bacterial species to ferment particular sugars and ability to produce certain enzymes. Additionally, an identification system based on bacterial phenotypic characteristics, known as Biolog® system was applied. A pulsed-filed gel electrophoresis (PFGE) method for bacterial DNA fingerprinting was also evaluated and used for the identification of the inoculated bacteria. The methods described in the study were found to be effective for the identification of pathogenic bacteria from skins and effluent

    Phase transition in the Sznajd model with independence

    Full text link
    We propose a model of opinion dynamics which describes two major types of social influence -- conformity and independence. Conformity in our model is described by the so called outflow dynamics (known as Sznajd model). According to sociologists' suggestions, we introduce also a second type of social influence, known in social psychology as independence. Various social experiments have shown that the level of conformity depends on the society. We introduce this level as a parameter of the model and show that there is a continuous phase transition between conformity and independence

    Optimal Uncertainty Quantification

    Get PDF
    We propose a rigorous framework for Uncertainty Quantification (UQ) in which the UQ objectives and the assumptions/information set are brought to the forefront. This framework, which we call \emph{Optimal Uncertainty Quantification} (OUQ), is based on the observation that, given a set of assumptions and information about the problem, there exist optimal bounds on uncertainties: these are obtained as values of well-defined optimization problems corresponding to extremizing probabilities of failure, or of deviations, subject to the constraints imposed by the scenarios compatible with the assumptions and information. In particular, this framework does not implicitly impose inappropriate assumptions, nor does it repudiate relevant information. Although OUQ optimization problems are extremely large, we show that under general conditions they have finite-dimensional reductions. As an application, we develop \emph{Optimal Concentration Inequalities} (OCI) of Hoeffding and McDiarmid type. Surprisingly, these results show that uncertainties in input parameters, which propagate to output uncertainties in the classical sensitivity analysis paradigm, may fail to do so if the transfer functions (or probability distributions) are imperfectly known. We show how, for hierarchical structures, this phenomenon may lead to the non-propagation of uncertainties or information across scales. In addition, a general algorithmic framework is developed for OUQ and is tested on the Caltech surrogate model for hypervelocity impact and on the seismic safety assessment of truss structures, suggesting the feasibility of the framework for important complex systems. The introduction of this paper provides both an overview of the paper and a self-contained mini-tutorial about basic concepts and issues of UQ.Comment: 90 pages. Accepted for publication in SIAM Review (Expository Research Papers). See SIAM Review for higher quality figure

    From 2000 Bush-Gore to 2006 Italian elections: Voting at fifty-fifty and the Contrarian Effect

    Get PDF
    A sociophysical model for opinion dynamics is shown to embody a series of recent western hung national votes all set at the unexpected and very improbable edge of a fifty-fifty score. It started with the Bush-Gore 2000 American presidential election, followed by the 2002 Stoiber-Schr\H{o}der, then the 2005 Schr\H{o}der-Merkel German elections, and finally the 2006 Prodi-Berlusconi Italian elections. In each case, the country was facing drastic choices, the running competing parties were advocating very different programs and millions of voters were involved. Moreover, polls were given a substantial margin for the predicted winner. While all these events were perceived as accidental and isolated, our model suggests that indeed they are deterministic and obey to one single universal phenomena associated to the effect of contrarian behavior on the dynamics of opinion forming. The not hung Bush-Kerry 2005 presidential election is shown to belong to the same universal frame. To conclude, the existence of contrarians hints at the repetition of hung elections in the near future.Comment: 17 pages, 8 figure

    Lactobacillus plantarum CUL66 can impact cholesterol homeostasis in Caco-2 enterocytes

    Get PDF
    Hypercholesterolemia drives the development of cardiovascular disease, the leading cause of mortality in western society. Supplementation with probiotics that interfere with cholesterol metabolism may provide a contribution to disease prevention. Lactobacillus plantarum CUL66 (NCIMB 30280) has been assessed in vitro for its ability to impact cholesterol absorption. L. plantarum CUL66 tested positive for bile salt hydrolase activity and the ability to assimilate cholesterol from culture media. RT-qPCR analysis showed that the bacterium significantly decreased the expression of Niemann-Pick C1-like 1 and ATP-binding cassette transporter-1 in polarised Caco-2 cells after 6 h exposure. Conversely, the expression of ATP-binding cassette sub-family G member (ABCG)-5 and ABCG-8, and 3-hydroxy-3-methylglutaryl-CoA reductase were significantly increased. Using a radiolabelled assay, we also observed significant reductions in the uptake and basolateral efflux of cholesterol by Caco-2 cells exposed to L. plantarum CUL66. This in vitro study identified L. plantarum CUL66 as a cholesterol lowering bacteria by highlighting its ability to beneficially regulate multiple in vitro events associated with intestinal cholesterol metabolism and provides evidence of efficacy for its inclusion in future in vivo studies

    Deteksi Logam pada Penggilingan Batu Berbasis SMS Gateway dan Mikrokontroler

    Full text link
    Berdasarkan hasil survei di lapangan, seringkali kualitas batu yang dihasilkan oleh mesin penggilingan batu kurang memuaskan. Hal tersebut disebabkan oleh beberapa faktor, salah satunya dikarenakan mesin penggiling yang bekerja kurang maksimal akibat banyak logam atau besi yang melalui mesin penggiling. Pada penelitian ini dibuat alat pendeteksi logam pada penggilingan. Sensor logam akan mendeteksi logam saat terjadi Perubahan frekuensi melalui bantuan coil. Saat terjadi Perubahan frekuensi tersebut maka Arduino akan mengirimkan perintah ke relay, alarm buzzer dan LED, serta modul GSM SIM900 secara bersamaan. Berdasarkan hasil pengujian, sensor akan mendeteksi saat benda logam berada pada jarak 0-2,1 cm. Selain itu sensor dapat mendeteksi berbagai jenis benda logam seperti gunting, paku, handphone, dan lain-lain. Akan tetapi sensor tidak dapat mendeteksi keberadaan induktansi pada benda berbahan logam mulia. Pada saat terdeteksi adanya logam, perangkat SMS gateway mengirimkan notifikasi kepada operator

    A new formulation for the treatment of acid-deterioration (Red Rot) in historic leathers

    Get PDF
    Conservation of acid-deteriorated historic leather (also commonly known as red rot) is an on-going concern as current treatment options are limited. Various products such as aqueous-based buffer salts, imidazole, ammonia vapour and aluminium di(isopropoxide) acetoacetate ester chelate (referred to as aluminium alkoxide in this study) have been used to treat acid-deterioration in historic leathers. Among the various products studied, aluminium alkoxide was found to be the most effective. However the effect of aluminium alkoxide when applied on its own may be limited due to its short-term stabilisation effect. A new formulation consisting of aluminium alkoxide and 5-ethyl-1-aza-3, 7-dioxabicyclo [3.3.0] octane (oxazolidine II) was used to treat acid-deterioration in historic leather. Acid-deteriorated leathers were treated with the new formulation and aged further by exposure to an acidic environment at 40°C and 30% relative humidity for up to 12 weeks. The acidic environment was created using sulfur dioxide and nitrogen dioxide. Corresponding untreated acid-deteriorated historic leathers were used as a negative control. The impact of the treatments and artificial ageing was determined by measuring the hydrothermal stability of the leather samples using differential scanning calorimetry (DSC) and pH of the aqueous extract. The results obtained showed that the formulation has collagen-stabilising properties, acid-buffering capacity as well as the capability to provide long-term protection against an artificially-created acidic environment

    From working in the wheat field to managing wheat: women innovators in Nepal

    Get PDF
    This article presents research conducted in Nepal’s Terai plains in 2014-15 showing that women are innovating in wheat to the extent that wheat farming is experiencing a shift from feminization of agricultural labor towards women taking control over decision making. Processes accounting for this include male out-migration, non-governmental organizations working on promoting women’s equality that has developed women’s confidence, individual support from extension agents, and strong cooperation between women to foster each other’s “innovation journeys.

    Work-Related Mental Health and Job Performance: Can Mindfulness Help?

    Get PDF
    Work-related mental health issues such as work-related stress and addiction to work impose a significant health and economic burden to the employee, the employing organization, and the country of work more generally. Interventions that can be empirically shown to improve levels of work-related mental health – especially those with the potential to concurrently improve employee levels of work performance – are of particular interest to occupational stakeholders. One such broad-application interventional approach currently of interest to occupational stakeholders in this respect is mindfulness-based interventions (MBIs). Following a brief explication of the mindfulness construct, this paper critically discusses current research directions in the utilization of mindfulness in workplace settings and assesses its suitability for operationalization as an organization-level work-related mental health intervention. By effecting a perceptual-shift in the mode of responding and relating to sensory and cognitive-affective stimuli, employees that undergo mindfulness training may be able to transfer the locus of control for stress from external work conditions to internal metacognitive and attentional resources. Therefore, MBIs may constitute cost-effective organization-level interventions due to not actually requiring any modifications to human resource management systems and practises. Based on preliminary empirical findings and on the outcomes of MBI studies with clinical populations, it is concluded that MBIs appear to be viable interventional options for organizations wishing to improve the mental health of their employees
    corecore