5,845 research outputs found

    The use of biomimetic surfaces to reduce single- and dual-species biofilms of Escherichia coli and Pseudomonas putida

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    The ability of bacteria to adhere to and form biofilms on food contact surfaces poses serious challenges, as these may lead to the cross-contamination of food products. Biomimetic topographic surface modifications have been explored to enhance the antifouling performance of materials. In this study, the topography of two plant leaves, Brassica oleracea var. botrytis (cauliflower, CF) and Brassica oleracea capitate (white cabbage, WC), was replicated through wax moulding, and their antibiofilm potential was tested against single- and dual-species biofilms of Escherichia coli and Pseudomonas putida. Biomimetic surfaces exhibited higher roughness values (SaWC = 4.0 ± 1.0 μm and SaCF = 3.3 ± 1.0 μm) than the flat control (SaF = 0.6 ± 0.2 μm), whilst the CF surface demonstrated a lower interfacial free energy (ΔGiwi) than the WC surface (−100.08 mJ m−2 and −71.98 mJ m−2, respectively). The CF and WC surfaces had similar antibiofilm effects against single-species biofilms, achieving cell reductions of approximately 50% and 60% for E. coli and P. putida, respectively, compared to the control. Additionally, the biomimetic surfaces led to reductions of up to 60% in biovolume, 45% in thickness, and 60% in the surface coverage of single-species biofilms. For dual-species biofilms, only the E. coli strain growing on the WC surface exhibited a significant decrease in the cell count. However, confocal microscopy analysis revealed a 60% reduction in the total biovolume and surface coverage of mixed biofilms developed on both biomimetic surfaces. Furthermore, dual-species biofilms were mainly composed of P. putida, which reduced E. coli growth. Altogether, these results demonstrate that the surface properties of CF and WC biomimetic surfaces have the potential for reducing biofilm formation

    Outcomes of a state-wide salt reduction initiative in adults living in Victoria, Australia

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    Purpose: To assess any effects of a state-wide sodium reduction intervention on sodium intake, sources of dietary sodium and discretionary salt use at a population level. Methods: Data (24-h urinary sodium excretion, self-report survey, a 24-h dietary recall) were collected cross-sectionally at baseline (2016/2017) and follow-up (2020) from adults in Victoria, Australia. Intervention activities included consumer awareness advertising campaign, public debate generation via mass media, strengthening existing policy initiatives and supporting food innovation with industry. Results: There were 339 participants at baseline and 211 at follow-up, with 144 and 90 of participants completing a 24-h dietary recall, respectively. There was no difference in adjusted 24-h urinary sodium excretion between baseline and follow-up (134 vs 131 mmol/24 h; p = 0.260). There were no differences in the percentage of participants adding salt during cooking (63% vs 68%; p = 0.244), adding salt at the table (34% vs 37%; p = 0.400) or regularly taking action to control salt/sodium intake (22% vs 21%; p = 0.793). There were large differences in the quantity of dietary sodium sourced from retail stores (57% vs 77%, p < 0.001), and less sodium was sourced from foods at fresh food markets (13% vs 2%; p ≤ 0.001) at follow-up. No large differences were apparent for foods with different levels of processing or for food groups. Conclusion: There was no clear population-level effect of the 4-year multi-component Victorian Salt Reduction Intervention on sodium intake with Victorian adults continuing to consume sodium above recommended levels. The findings indicate that more intensive and sustained efforts aiming at the retail and food industry with national level support are likely to be required to achieve a measurable improvement in sodium intake at a state level

    Evaluation of a Salt-Reduction Consumer Awareness Campaign Targeted at Parents Residing in the State of Victoria, Australia

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    From 2015 to 2020 a state-wide salt-reduction initiative was launched in Victoria, Australia, including an awareness campaign focused on parents with children <18 years of age. To evaluate the impact of the campaign on salt-related knowledge, attitudes and behaviors (KABs) we have assessed trends in salt-related KAB pre- and post-delivery of the campaign in parents, as well as within the wider adult population. Cross-sectional surveys of adults aged 18–65 years were undertaken pre- (2015: n = 821 parents; n = 1527 general sample) and post-campaign (2019: n = 935 parents; n = 1747 general sample). KABs were assessed via an online survey. Data were analyzed with regression models and adjusted for covariates. Among parents, around one-quarter of salt-related KABs shifted in a positive direction, but changes were small: there was a 6% (95% CI 2, 11%) increase in the percentage who knew the main source of salt in the diet and reductions in the percentage who reported placing a salt shaker on the table (−8% (95%CI −12, −3)) and that their child added salt at the table (−5% (95% −9, −0.2)). Among the wider adult sample, even fewer shifts in KAB were observed, with some behaviors worsening at follow-up. These findings indicate that this consumer awareness campaign had minimum impact

    USE OF SPECIES OF URBAN TREES IN ENVIRONMENTAL POLLUTION BIOMONITORING

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    O biomonitoramento consiste na utiliza\ue7\ue3o de organismos vivos para apontar poss\uedveis polui\ue7\uf5es ambientais. Objetivou-se neste estudo avaliar a influ\ueancia da intensidade do tr\ue1fego urbano na disponibilidade de elementos e s\uf3lidos em suspens\ue3o, bem como identificar a potencialidade no ac\ufamulo e reten\ue7\ue3o das subst\ue2ncias em diferentes esp\ue9cies arb\uf3reas, utilizando suas folhas como biomonitores passivos e de acumula\ue7\ue3o. Como amostras utilizaram-se folhas de \ue1rvores coletadas em duas \ue1reas no munic\uedpio de Vit\uf3ria da Conquista - BA: com tr\ue2nsito de ve\uedculos e atividades antr\uf3picas moderadas; e em uma zona de maior tr\ue1fego e com atividades intensas. Foram determinados o material particulado (MP) depositado nas folhas pelo m\ue9todo gravim\ue9trico e os elementos Fe, Cu, Ni, Co e Cd por espectrometria de absor\ue7\ue3o at\uf4mica em forno de grafite (EAA FG). O Fe se distinguiu significativamente das demais vari\ue1veis, com concentra\ue7\uf5es superiores aos outros metais. Utilizaram-se an\ue1lises estat\uedsticas multivariadas para a interpreta\ue7\ue3o dos dados. A an\ue1lise de agrupamento hier\ue1rquico separou dois grupos de acordo com a espacialidade e a an\ue1lise de componentes principais permitiu a explica\ue7\ue3o desta tend\ueancia amostral. Um grupo foi constitu\ueddo por MP, Fe e Cd, pelo fato de serem originados do desgaste dos ve\uedculos e queima de combust\uedveis f\uf3sseis. As esp\ue9cies da fam\uedlia Fabaceae apresentaram uma maior similaridade em rela\ue7\ue3o ao elemento Cu, isto, porque a atividade metab\uf3lica do Cu tem comportamento inversamente proporcional \ue0 concentra\ue7\ue3o de nitrog\ueanio. O tr\ue2nsito de ve\uedculos influiu diretamente na disponibilidade de alguns elementos t\uf3xicos e na concentra\ue7\ue3o de part\uedculas s\uf3lidas depositadas. Conclui-se que a esp\ue9cie influi no ac\ufamulo dos elementos qu\uedmicos e apresentam diferentes potenciais de capta\ue7\ue3o. A arboriza\ue7\ue3o pode ser utilizada como biomonitora passiva de acumula\ue7\ue3o.Biomonitoring is the use of living organisms to identify possible environmental pollution. The objective of this study was to evaluate the influence of intensity of urban traffic in the availability of elements and suspended solids as well as identify the potential in the accumulation and retention of substances in different tree species using its leaves as passive biomonitors and for accumulation. As samples we used tree leaves collected from two areas in the municipality of Vitoria da Conquista (BA state), with transit vehicles and moderate human activities, and in a zone of increased traffic and intense activities. We determined the particulate matter (MP) deposited in the leaves by the gravimetric method and the elements Fe, Cu, Ni, Co and Cd by atomic absorption spectrometry with graphite furnace (GF AAS). Fe was significantly distinguished from other variables, with higher concentrations than other metals. The data was interpreted by multivariate analysis. Cluster analysis separated two groups, one consisting of MP, Fe and Cd, because they are originated from the wear and tear of vehicles and burning fossil fuels. The species of the family Fabaceae showed greater similarity to Cu element, namely, because the Cu metabolic activity is inversely proportional to the concentration of nitrogen behavior. The vehicle traffic directly influenced the availability of some toxic elements and the concentration of the deposited solid particles. It is concluded that the species influences the accumulation of chemical elements and have different catchment potentials. The trees can be utilized as biomonitors which are passive of accumulation

    A Computational Approach for Designing Tiger Corridors in India

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    Wildlife corridors are components of landscapes, which facilitate the movement of organisms and processes between intact habitat areas, and thus provide connectivity between the habitats within the landscapes. Corridors are thus regions within a given landscape that connect fragmented habitat patches within the landscape. The major concern of designing corridors as a conservation strategy is primarily to counter, and to the extent possible, mitigate the effects of habitat fragmentation and loss on the biodiversity of the landscape, as well as support continuance of land use for essential local and global economic activities in the region of reference. In this paper, we use game theory, graph theory, membership functions and chain code algorithm to model and design a set of wildlife corridors with tiger (Panthera tigris tigris) as the focal species. We identify the parameters which would affect the tiger population in a landscape complex and using the presence of these identified parameters construct a graph using the habitat patches supporting tiger presence in the landscape complex as vertices and the possible paths between them as edges. The passage of tigers through the possible paths have been modelled as an Assurance game, with tigers as an individual player. The game is played recursively as the tiger passes through each grid considered for the model. The iteration causes the tiger to choose the most suitable path signifying the emergence of adaptability. As a formal explanation of the game, we model this interaction of tiger with the parameters as deterministic finite automata, whose transition function is obtained by the game payoff.Comment: 12 pages, 5 figures, 6 tables, NGCT conference 201

    Exercise twice-a-day potentiates markers of mitochondrial biogenesis in men

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    Endurance exercise begun with reduced muscle glycogen stores seems to potentiate skeletal muscle protein abundance and gene expression. However, it is unknown whether this greater signaling responses is due to performing two exercise sessions in close proximity-as a first exercise session is necessary to reduce the muscle glycogen stores. In the present study, we manipulated the recovery duration between a first muscle glycogen-depleting exercise and a second exercise session, such that the second exercise session started with reduced muscle glycogen in both approaches but was performed either 2 or 15 hours after the first exercise session (so-called twice-a-day and once-daily approaches, respectively). We found that exercise twice-a-day increased the nuclear abundance of transcription factor EB (TFEB) and nuclear factor of activated T cells (NFAT) and potentiated the transcription of peroxisome proliferator-activated receptor-ɣ coactivator 1-alpha (PGC-1α), peroxisome proliferator-activated receptor-alpha (PPARα), and peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) genes, in comparison with the once-daily exercise. These results suggest that part of the elevated molecular signaling reported with previous train-low approaches might be attributed to performing two exercise sessions in close proximity. The twice-a-day approach might be an effective strategy to induce adaptations related to mitochondrial biogenesis and fat oxidation

    The RNA-binding protein hnRNP K mediates the effect of BDNF on dendritic mRNA metabolism and regulates synaptic NMDA receptors in hippocampal neurons

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    Brain-derived neurotrophic factor (BDNF) is an important mediator of long-term synaptic potentiation (LTP) in the hippocampus. The local effects of BDNF depend on the activation of translation activity, which requires the delivery of transcripts to the synapse. In this work, we found that neuronal activity regulates the dendritic localization of the RNA-binding protein heterogeneous nuclear ribonucleoprotein K (hnRNP K) in cultured rat hippocampal neurons by stimulating BDNF-Trk signaling. Microarray experiments identified a large number of transcripts that are coimmunoprecipitated with hnRNP K, and about 60% of these transcripts are dissociated from the protein upon stimulation of rat hippocampal neurons with BDNF. In vivo studies also showed a role for TrkB signaling in the dissociation of transcripts from hnRNP K upon high-frequency stimulation (HFS) of medial perforant path-granule cell synapses of male rat dentate gyrus (DG). Furthermore, treatment of rat hippocampal synaptoneurosomes with BDNF decreased the coimmunoprecipitation of hnRNP K with mRNAs coding for glutamate receptor subunits, Ca2+- and calmodulin-dependent protein kinase IIβ (CaMKIIβ) and BDNF. Downregulation of hnRNP K impaired the BDNF-induced enhancement of NMDA receptor (NMDAR)-mediated mEPSC, and similar results were obtained upon inhibition of protein synthesis with cycloheximide. The results demonstrate that BDNF regulates specific populations of hnRNP-associated mRNAs in neuronal dendrites and suggests an important role of hnRNP K in BDNF-dependent forms of synaptic plasticity.publishe

    Engaging Undergraduates in Science Research: Not Just About Faculty Willingness.

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    Despite the many benefits of involving undergraduates in research and the growing number of undergraduate research programs, few scholars have investigated the factors that affect faculty members' decisions to involve undergraduates in their research projects. We investigated the individual factors and institutional contexts that predict faculty members' likelihood of engaging undergraduates in their research project(s). Using data from the Higher Education Research Institute's 2007-2008 Faculty Survey, we employ hierarchical generalized linear modeling to analyze data from 4,832 science, technology, engineering, and mathematics (STEM) faculty across 194 institutions to examine how organizational citizenship behavior theory and social exchange theory relate to mentoring students in research. Key findings show that faculty who work in the life sciences and those who receive government funding for their research are more likely to involve undergraduates in their research project(s). In addition, faculty at liberal arts or historically Black colleges are significantly more likely to involve undergraduate students in research. Implications for advancing undergraduate research opportunities are discussed

    Likelihood analysis of the pMSSM11 in light of LHC 13-TeV data

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    We use MasterCode to perform a frequentist analysis of the constraints on a phenomenological MSSM model with 11 parameters, the pMSSM11, including constraints from ∼36 /fb of LHC data at 13 TeV and PICO, XENON1T and PandaX-II searches for dark matter scattering, as well as previous accelerator and astrophysical measurements, presenting fits both with and without the (g−2)μ constraint. The pMSSM11 is specified by the following parameters: 3 gaugino masses M1,2,3 , a common mass for the first-and second-generation squarks mq~ and a distinct third-generation squark mass mq~3 , a common mass for the first-and second-generation sleptons mℓ~ and a distinct third-generation slepton mass mτ~ , a common trilinear mixing parameter A, the Higgs mixing parameter μ , the pseudoscalar Higgs mass MA and tanβ . In the fit including (g−2)μ , a Bino-like χ~01 is preferred, whereas a Higgsino-like χ~01 is mildly favoured when the (g−2)μ constraint is dropped. We identify the mechanisms that operate in different regions of the pMSSM11 parameter space to bring the relic density of the lightest neutralino, χ~01 , into the range indicated by cosmological data. In the fit including (g−2)μ , coannihilations with χ~02 and the Wino-like χ~±1 or with nearly-degenerate first- and second-generation sleptons are active, whereas coannihilations with the χ~02 and the Higgsino-like χ~±1 or with first- and second-generation squarks may be important when the (g−2)μ constraint is dropped. In the two cases, we present χ2 functions in two-dimensional mass planes as well as their one-dimensional profile projections and best-fit spectra. Prospects remain for discovering strongly-interacting sparticles at the LHC, in both the scenarios with and without the (g−2)μ constraint, as well as for discovering electroweakly-interacting sparticles at a future linear e+e− collider such as the ILC or CLIC
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