468 research outputs found

    Mycotoxin exposure and human cancer risk : a systematic review of epidemiological studies

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    In recent years, there has been an increasing interest in investigating the carcinogenicity of mycotoxins in humans. This systematic review aims to provide an overview of data linking exposure to different mycotoxins with human cancer risk. Publications (2019 and earlier) of case–control or longitudinal cohort studies were identified in PubMed and EMBASE. These articles were then screened by independent reviewers and their quality was assessed according to the Newcastle–Ottawa scale. Animal, cross‐sectional, and molecular studies satisfied criteria for exclusion. In total, 14 articles were included: 13 case–control studies and 1 longitudinal cohort study. Included articles focused on associations of mycotoxin exposure with primary liver, breast, and cervical cancer. Overall, a positive association between the consumption of aflatoxin‐contaminated foods and primary liver cancer risk was verified. Two case–control studies in Africa investigated the relationship between zearalenone and its metabolites and breast cancer risk, though conflicting results were reported. Two case–control studies investigated the association between hepatocellular carcinoma and fumonisin B1 exposure, but no significant associations were observed. This systematic review incorporates several clear observations of dose‐dependent associations between aflatoxins and liver cancer risk, in keeping with IARC Monograph conclusions. Only few human epidemiological studies investigated the associations between mycotoxin exposures and cancer risk. To close this gap, more in‐depth research is needed to unravel evidence for other common mycotoxins, such as deoxynivalenol and ochratoxin A. The link between mycotoxin exposures and cancer risk has mainly been established in experimental studies, and needs to be confirmed in human epidemiological studies to support the evidence‐based public health strategies

    Development of Best Practices for Right-of-Way Valuations and Negotiations in Transportation Projects

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    The valuations of properties and the negotiations with property owners are two major tasks in the right-of-way acquisition process for transportation projects. If improved, those tasks can increase the overall project delivery efficiency. The Texas Department of Transportation (TxDOT) funded a research project that aimed to recommend some best practices for successful valuations and negotiations in Texas. The authors reviewed the different strategies and procedures followed in TxDOT by conducting interviews and surveys with right-of-way personnel. Guidelines supported by recommended practices were identified for both valuation and negotiation and then reviewed and validated by experts. Lastly, implementation guides were developed

    Statistical mechanics of transcription-factor binding site discovery using Hidden Markov Models

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    Hidden Markov Models (HMMs) are a commonly used tool for inference of transcription factor (TF) binding sites from DNA sequence data. We exploit the mathematical equivalence between HMMs for TF binding and the "inverse" statistical mechanics of hard rods in a one-dimensional disordered potential to investigate learning in HMMs. We derive analytic expressions for the Fisher information, a commonly employed measure of confidence in learned parameters, in the biologically relevant limit where the density of binding sites is low. We then use techniques from statistical mechanics to derive a scaling principle relating the specificity (binding energy) of a TF to the minimum amount of training data necessary to learn it.Comment: 25 pages, 2 figures, 1 table V2 - typos fixed and new references adde

    Satisfaction of patients on chronic haemodialysis and peritoneal dialysis

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    BACKGROUND: In contrast to quality of life, patient satisfaction on chronic haemodialysis (HD) and peritoneal dialysis (PD) has only rarely been studied. PATIENTS AND METHODS: All chronic HD and PD patients of the 19 centres located in western Switzerland were asked to complete a specific questionnaire, assessing dialysis centre characteristics, treatment modalities, and information received before and during dialysis treatment. Comparison between satisfaction with PD and HD was carried out on the patients in the nine centres offering both treatment modalities. RESULTS: Of the 558 questionnaires distributed to chronic HD patients, 455 were returned (response rate 82%). Fifty of 64 PD patients (78%) returned the questionnaire. The two groups were similar in age, gender, and duration of dialysis treatment. Completion rates were >90% for a majority of questions, with the lowest rate for information on sexuality (49% in HD and 54% in PD respectively). The lowest scores were recorded for information received about complications and costs of dialysis, and impact of end-stage kidney disease on sexuality. Satisfaction was lower in anonymous questionnaires. Satisfaction of PD patients was significantly better in 50% of the questions, particularly session tolerance (p<0.001), information about dialysis sessions (p=0.007), and complications (p=0.006). CONCLUSIONS: PD patients were on average more satisfied with their treatment than HD patients. Satisfaction could be improved with more information about potential adverse treatment effects

    Reactive scattering of H2 from Cu(100): comparison of dynamics calculations based on the specific reaction parameter approach to density functional theory with experiment

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    We present new experimental and theoretical results for reactive scattering of dihydrogen from Cu(100). In the new experiments, the associative desorption of H2 is studied in a velocity resolved and final rovibrational state selected manner, using time-of-flight techniques in combination with resonance-enhanced multi-photon ionization laser detection. Average desorption energies and rota- tional quadrupole alignment parameters were obtained in this way for a number of (v = 0, 1) ro- tational states, v being the vibrational quantum number. Results of quantum dynamics calculations based on a potential energy surface computed with a specific reaction parameter (SRP) density func- tional, which was derived earlier for dihydrogen interacting with Cu(111), are compared with the results of the new experiments and with the results of previous molecular beam experiments on sticking of H2 and on rovibrationally elastic and inelastic scattering of H2 and D2 from Cu(100). The calculations use the Born-Oppenheimer and static surface approximations. With the functional derived semi-empirically for dihydrogen + Cu(111), a chemically accurate description is obtained of the molecular beam experiments on sticking of H2 on Cu(100), and a highly accurate descrip- tion is obtained of rovibrationally elastic and inelastic scattering of D2 from Cu(100) and of the orientational dependence of the reaction of (v = 1, j = 2 − 4) H2 on Cu(100). This suggests that a SRP density functional derived for H2 interacting with a specific low index face of a metal will yield accurate results for H2 reactively scattering from another low index face of the same metal, and that it may also yield accurate results for H2 interacting with a defected (e.g., stepped) surface of that same metal, in a system of catalytic interest. However, the description that was obtained of the average desorption energies, of rovibrationally elastic and inelastic scattering of H2 from Cu(100), and of the orientational dependence of reaction of (v = 0, j = 3 − 5, 8) H2 on Cu(100) compares less well with the available experiments. More research is needed to establish whether more accurate SRP-density functional theory dynamics results can be obtained for these observables if surface atom motion is added to the dynamical model. The experimentally and theoretically found dependence of the rotational quadrupole alignment parameter on the rotational quantum number provides evidence for rotational enhancement of reaction at low translational energies.Fil: Sementa, L.. Leiden University; Países Bajos. Istituto per i Processi Chimico-Fisici of the Consiglio Nazionale delle Ricerche; ItaliaFil: Wijzenbroek, M.. Leiden University; Países BajosFil: Van Kolck, B. J.. Leiden University; Países BajosFil: Somers, M. F.. Leiden University; Países BajosFil: Al-Halabi, A.. Leiden University; Países BajosFil: Busnengo, Heriberto Fabio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Olsen, R. A.. Leiden University; Países Bajos. SINTEF Materials and Chemistry; NoruegaFil: Kroes, G. J.. Leiden University; Países BajosFil: Rutkowski, M.. Westfalische Wilhelms Universitat; AlemaniaFil: Thewes, C.. Westfalische Wilhelms Universitat; AlemaniaFil: Kleimeier, N. F.. Westfalische Wilhelms Universitat; AlemaniaFil: Zacharias, H.. Westfalische Wilhelms Universitat; Alemani

    Immersive virtual reality in improving communication skills in children with Autism

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    Individuals in the Autism Spectrum often encounter situations where they have to respond to questions and situations that they do not know how to respond to, such as, questions asked by strangers including ones related to daily-life activities. A variety of research has been done to improve social and communication impairments in children with autism using technology. Immersive virtual reality is a relatively recent technology with a potential to bring an effective solution and used as a therapeutic tool to develop different skills. This paper presents a virtual reality solution to reduce the gap experienced by autistic children due to their inability to establish a communication. An interactive scenario-based system that uses role-play and turn-taking technique was implemented to evaluate and verify the effectiveness of immersive environment on the social performance of an autistic child. Preliminary testing of the system demonstrated the feasibility of VR-based system as a tool for improving the communication skill in Autism Spectrum Disorder (ASD) children. The results of the comparative usability study show the effectiveness of immersive VR in motivating and satisfying the autistic.Scopu

    Design of immersive virtual reality system to improve communication skills in individuals with autism

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    Individuals with autism spectrum disorder (ASD) regularly experience situations in which they need to give answers but do not know how to respond; for example, questions related to everyday life activities that are asked by strangers. Research geared at utilizing technology to mend social and communication impairments in children with autism is actively underway. Immersive virtual reality (VR) is a relatively recent technology that has the potential of being an effective therapeutic tool for developing various skills in autistic children. This paper presents an interactive scenario-based VR system developed to improve the communications skills of autistic children. The system utilizes speech recognition to provide natural interaction and role-play and turntaking to evaluate and verify the effectiveness of the immersive environment on the social performance of autistic children. In experiments conducted, participants showed more improved performance with a computer augmented virtual environment (CAVE) than with a head mounted display (HMD) or a normal desktop. The results indicate that immersive VR could be more satisfactory and motivational than desktop for children with ASD.Scopu

    Potential Adverse Effects of Resveratrol: A Literature Review.

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    Due to its health benefits, resveratrol (RE) is one of the most researched natural polyphenols. Resveratrol's health benefits were first highlighted in the early 1990s in the French paradox study, which opened extensive research activity into this compound. Ever since, several pharmacological activities including antioxidant, anti-aging, anti-inflammatory, anti-cancerous, anti-diabetic, cardioprotective, and neuroprotective properties, were attributed to RE. However, results from the available human clinical trials were controversial concerning the protective effects of RE against diseases and their sequelae. The reason for these conflicting findings is varied but differences in the characteristics of the enrolled patients, RE doses used, and duration of RE supplementation were proposed, at least in part, as possible causes. In particular, the optimal RE dosage capable of maximizing its health benefits without raising toxicity issues remains an area of extensive research. In this context, while there is a consistent body of literature on the protective effects of RE against diseases, there are relatively few reports investigating its possible toxicity. Indeed, toxicity and adverse effects were reported following consumption of RE; therefore, extensive future studies on the long-term effects, as well as the in vivo adverse effects, of RE supplementation in humans are needed. Furthermore, data on the interactions of RE when combined with other therapies are still lacking, as well as results related to its absorption and bioavailability in the human body. In this review, we collect and summarize the available literature about RE toxicity and side effects. In this process, we analyze in vitro and in vivo studies that have addressed this stilbenoid. These studies suggest that RE still has an unexplored side. Finally, we discuss the new delivery methods that are being employed to overcome the low bioavailability of RE

    Laboratory evidence for efficient water formation in interstellar ices

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    Even though water is the main constituent in interstellar icy mantles, its chemical origin is not well understood. Three different formation routes have been proposed following hydrogenation of O, O2, or O3, but experimental evidence is largely lacking. We present a solid state astrochemical laboratory study in which one of these routes is tested. For this purpose O2 ice is bombarded by H- or D-atoms under ultra high vacuum conditions at astronomically relevant temperatures ranging from 12 to 28 K. The use of reflection absorption infrared spectroscopy (RAIRS) permits derivation of reaction rates and shows efficient formation of H2O (D2O) with a rate that is surprisingly independent of temperature. This formation route converts O2 into H2O via H2O2 and is found to be orders of magnitude more efficient than previously assumed. It should therefore be considered as an important channel for interstellar water ice formation as illustrated by astrochemical model calculations.Comment: 15 pages, 4 figures. ApJ, in pres
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