144 research outputs found

    Solid-State Microprocessor Controlled Detector for Doublet Peak Measurements in Flow Injection Analysis

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    A solid-state detector for time-based transmission measurements in flow-injection analysis (FIA) based on alight-emitting diode (LED) source and photodiode (PD) transducer with microprocessor controller is described. Theinstrument components cost less than US$ 500. A simple peak-finding algorithm was capable of accurate measurementsof the time interval between doublet peaks (.:1t). Comparison of results, obtained using the detector, withtheory for an acid-base reaction with bromothymol blue indicator is made. Linear relationships between themeasured lit and the logarithm of the injected concentration were obtained for two systems whose injection volumeswere 987 and 1650 ÎĽ.l. The correlation coefficients, based on 14 and 13 data points, were 0.999 and 0.992 ,respectively. The detector could measure transmittance signals corresponding to 0.00098 absorbance above thebaseline

    Nature Connectedness Moderates the Effect of Nature Exposure on Explicit and Implicit Measures of Emotion

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    Previous research indicates that both short-term and long-term exposure to natural environments is associated with higher levels of emotional well-being. However, less research has examined whether person-related factors may impact the salutogenic effects of nature. In the current study, we examined whether trait-level nature connectedness moderates the effect of exposure to nature on explicit and implicit measures of affect. Participants (n = 89) completed baseline measurements of trait nature connectedness and affective state. Approximately two weeks later, participants viewed a lab-based immersive simulation of either a natural or built environment and then again completed measures of affective state. Findings indicated that trait nature connectedness moderated the effect of nature on affect, with more positive outcomes of nature exposure observed among those high in nature connectedness. These findings suggest that interacting with nature may be especially beneficial for those who already feel a strong sense of connectedness to the natural environment

    Nature Connectedness Moderates the Effect of Nature Exposure on Explicit and Implicit Measures of Emotion

    Get PDF
    Previous research indicates that both short-term and long-term exposure to natural environments is associated with higher levels of emotional well-being. However, less research has examined whether person-related factors may impact the salutogenic effects of nature. In the current study, we examined whether trait-level nature connectedness moderates the effect of exposure to nature on explicit and implicit measures of affect. Participants (n = 89) completed baseline measurements of trait nature connectedness and affective state. Approximately two weeks later, participants viewed a lab-based immersive simulation of either a natural or built environment and then again completed measures of affective state. Findings indicated that trait nature connectedness moderated the effect of nature on affect, with more positive outcomes of nature exposure observed among those high in nature connectedness. These findings suggest that interacting with nature may be especially beneficial for those who already feel a strong sense of connectedness to the natural environment

    Development and testing of a reference transaction assessment instrument

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    published or submitted for publicatio

    Nematode-Bacterium Symbioses—Cooperation and Conflict Revealed in the “Omics” Age

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    Nematodes are ubiquitous organisms that have a significant global impact on ecosystems, economies, agriculture, and human health. The applied importance of nematodes and the experimental tractability of many species have promoted their use as models in various research areas, including developmental biology, evolutionary biology, ecology, and animal-bacterium interactions. Nematodes are particularly well suited for the investigation of host associations with bacteria because all nematodes have interacted with bacteria during their evolutionary history and engage in a variety of association types. Interactions between nematodes and bacteria can be positive (mutualistic) or negative (pathogenic/parasitic) and may be transient or stably maintained (symbiotic). Furthermore, since many mechanistic aspects of nematode-bacterium interactions are conserved, their study can provide broader insights into other types of associations, including those relevant to human diseases. Recently, genome-scale studies have been applied to diverse nematode-bacterial interactions and have helped reveal mechanisms of communication and exchange between the associated partners. In addition to providing specific information about the system under investigation, these studies also have helped inform our understanding of genome evolution, mutualism, and innate immunity. In this review we discuss the importance and diversity of nematodes, “omics”' studies in nematode-bacterial systems, and the wider implications of the findings

    NilD CRISPR RNA contributes to Xenorhabdus nematophila colonization of symbiotic host nematodes

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    The bacterium Xenorhabdus nematophila is a mutualist of entomopathogenic Steinernema carpocapsae nematodes and facilitates infection of insect hosts. X. nematophila colonizes the intestine of S. carpocapsae which carries it between insects. In the X. nematophila colonization-defective mutant nilD6::Tn5, the transposon is inserted in a region lacking obvious coding potential. We demonstrate that the transposon disrupts expression of a single CRISPR RNA, NilD RNA. A variant NilD RNA also is expressed by X. nematophila strains from S. anatoliense and S. websteri nematodes. Only nilD from the S. carpocapsae strain of X. nematophila rescued the colonization defect of the nilD6::Tn5 mutant, and this mutant was defective in colonizing all three nematode host species. NilD expression depends on the presence of the associated Cas6e but not Cas3, components of the Type I-E CRISPR-associated machinery. While cas6e deletion in the complemented strain abolished nematode colonization, its disruption in the wild-type parent did not. Likewise, nilD deletion in the parental strain did not impact colonization of the nematode, revealing that the requirement for NilD is evident only in certain genetic backgrounds. Our data demonstrate that NilD RNA is conditionally necessary for mutualistic host colonization and suggest that it functions to regulate endogenous gene expression

    Mobile applications for obesity and weight management: current market characteristics

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    Mobile-Health (mHealth) is the fastest-developing eHealth sector, with over 100 000 health applications (apps) currently available. Overweight/obesity is a problem of wide public concern that is potentially treatable/preventable through mHealth. This study describes the current weight-management app-market. Five app stores (Apple, Google, Amazon, Windows and Blackberry) in UK, US, Russia, Japan and Germany, Italy, France, China, Australia and Canada were searched for keywords: 'weight', 'calorie', 'weight-loss', 'slimming', 'diet', 'dietitian' and 'overweight' in January/February 2016 using App-Annie software. The 10 most downloaded apps in the lifetime of an app were recorded. Developers' lists and the app descriptions were searched to identify any professional input with keywords 'professional', 'dietitian' and 'nutritionist'. A total of 28 905 relevant apps were identified as follows: Apple iTunes=8559 (4634, 54% paid), Google Play=1762 (597, 33.9% paid), Amazon App=13569 (4821, 35.5% paid), Windows=2419 (819, 17% paid) and Blackberry=2596 (940, 36% paid). The 28 905 identified apps focused mainly on physical activity (34%), diet (31%), and recording/monitoring of exercise, calorie intake and body weight (23%). Only 17 apps (0.05%) were developed with identifiable professional input. Apps on weight management are widely available and very popular but currently lack professional content expertise. Encouraging app development based on evidence-based online approaches would assure content quality, allowing healthcare professionals to recommend their use

    Self-assembly and surface behaviour of pure and mixed zwitterionic amphiphiles in a deep eutectic solvent

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    Recent investigations have shown that deep eutectic solvents provide a suitable environment for self-organisation of biomolecules, in particular phospholipids and proteins. However, the solvation of complex lyophilic moieties by deep eutectic solvents still remains unclear. Here we explore the behaviour of zwitterionic surfactants in choline chloride:glycerol eutectic mixture. Dodecyl-2-(trimethylammonio)ethylphosphate and N-alkyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (alkyl = dodecyl, tetradecyl) surfactants were investigated by means of surface tension, X-ray reflectivity and small-angle neutron scattering. These surfactants were found to remain surface active and form globular micelles in deep eutectic solvents. Still, the surface behaviour of these species was found to differ depending on the headgroup and tail structure. The morphology of the micelles also slightly varies between surfactants, demonstrating differences in the packing of individual monomers. The characteristics of mixtures of the dodecyl surfactants is also reported, showing a deviation from ideal mixing associated with attractive interactions between sulfobetaine and phosphocholine headgroups. Such non-ideality results in variation of the surface behaviour and self-assembly of these surfactant mixtures. The results presented here will potentially lead to the development of new alternatives for drug-delivery, protein solubilisation and biosensing through a better fundamental understanding of the behaviour of zwitterionic surfactants in deep eutectic solvents
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