165 research outputs found

    Changes in University Club Athletes’ and Non-Athlete Students’ Stress and Perceived Gains Across a Semester

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    To examine the relationship between club rugby participation, collegiate experiences, and perceived gains, 25 rugby players and 25 non-athlete students completed the Student-Athlete Experiences Inventory-Revised, Student-Athlete Gains Inventory, and Perceived Stress Scale at the start and end of a semester. A RM-ANOVA and partial-η2 effect sizes determined if group and time differences were present. We selected variables associated with the post-scores for practical and liberal arts gains with the lasso method. Rugby players engaged in more diverse social interactions (partial-η2 = 0.091) and were more actively involved on campus (partial-η2 = 0.0914) than non-athlete students, but paradoxically had lower practical arts gains (p \u3c 0.0001). All students reported increasing stress levels from start to end of the semester (partial-η2 = 0.109), which contributed to decreasing practical arts gains. Students need help with stress management near semester’s end. Club rugby players should seek support services on campus to improve career preparedness

    Análise AMMI da produtividade de grãos em linhagens de soja selecionadas para resistência à ferrugem asiática.

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    O objetivo deste trabalho foi quantificar os efeitos da interação genótipo x ambiente (GxE) sobre a produtividade de grãos em progênies de soja pré-selecionadas para resistência à ferrugem asiática (Phakopsora pachyrhizi). Doze ensaios de avaliação de progênies (linhagens F6 e F7) foram conduzidos em diferentes ambientes (combinação de locais, anos e tratamentos fungicidas para controle de doenças de final de ciclo, incluindo ou não a ferrugem). A análise ?additive main effects and multiplicative interaction? (AMMI) capturou, como padrão da interação GxE, 57% da variação associada aos resíduos de não aditividade, dos quais 44% foram retidos no primeiro componente principal de interação e o restante, no segundo. O primeiro componente associou-se a diferenças entre os anos de avaliação, o que denota imprevisibilidade na predição. O segundo componente, no entanto, associou-se ao manejo diferenciado do cultivo, no que se refere ao controle ou não das doenças. Entre os genótipos de ampla adaptabilidade produtiva, as linhagens USP 02‑16.045 e USP 10‑10 apresentaram desempenho destacado

    Individual Physiological Adaptations Enable Selected Bacterial Taxa To Prevail during Long-Term Incubations

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    Enclosure experiments are frequently used to investigate the impact of changing environmental conditions on microbial assemblages. Yet, how the incuba- tion itself challenges complex bacterial communities is thus far unknown. In this study, metaproteomic profiling, 16S rRNA gene analyses, and cell counts were com- bined to evaluate bacterial communities derived from marine, mesohaline, and oli- gohaline conditions after long-term batch incubations. Early in the experiment, the three bacterial communities were highly diverse and differed significantly in their compositions. Manipulation of the enclosures with terrigenous dissolved organic car- bon resulted in notable differences compared to the control enclosures at this early phase of the experiment. However, after 55 days, bacterial communities in the ma- nipulated and the control enclosures under marine and mesohaline conditions were all dominated by gammaproteobacterium Spongiibacter. In the oligohaline enclo- sures, actinobacterial cluster I of the hgc group (hgc-I) remained abundant in the late phase of the incubation. Metaproteome analyses suggested that the ability to use outer membrane-based internal energy stores, in addition to the previously de- scribed grazing resistance, may enable the gammaproteobacterium Spongiibacter to prevail in long-time incubations. Under oligohaline conditions, the utilization of ex- ternal recalcitrant carbon appeared to be more important (hgc-I). Enclosure experi- ments with complex natural microbial communities are important tools to investi- gate the effects of manipulations. However, species-specific properties, such as individual carbon storage strategies, can cause manipulation-independent effects and need to be considered when interpreting results from enclosures.This study was financially supported by the SAW-funded ATKiM project, which provided funds to D. P. R. Herlemann, C. Meeske, K. Jürgens, S. Markert, and T. Schweder. D. P. R. Herlemann was also supported by the European Regional Develop- ment Fund/Estonian Research Council funded Mobilitas Plus Top Researcher grant MOBTT24. We thank the crew and captain of the RV Meteor (M86, M87) for support during the research cruise. The computations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at the PDC Centre for High Performance Computing (PDC-HPC) and Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX). We thank Jana Matulla for excellent technical assis- tance and Stephan Fuchs for his help and advice in MS database construction. We also thank Stefan E. Heiden for valuable help with the CDD BLAST analyses.This study was financially supported by the SAW-funded ATKiM project, which provided funds to D. P. R. Herlemann, C. Meeske, K. Jürgens, S. Markert, and T. Schweder. D. P. R. Herlemann was also supported by the European Regional Develop- ment Fund/Estonian Research Council funded Mobilitas Plus Top Researcher grant MOBTT24. We thank the crew and captain of the RV Meteor (M86, M87) for support during the research cruise. The computations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at the PDC Centre for High Performance Computing (PDC-HPC) and Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX). We thank Jana Matulla for excellent technical assis- tance and Stephan Fuchs for his help and advice in MS database construction. We also thank Stefan E. Heiden for valuable help with the CDD BLAST analyses

    XRCC1 Deficiency Sensitizes Human Lung Epithelial Cells to Genotoxicity by Crocidolite Asbestos and Libby Amphibole

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    Background: Asbestos induces DNA and chromosomal damage, but the DNA repair pathways protecting human cells against its genotoxicity are largely unknown. Polymorphisms in XRCC1 have been associated with altered susceptibility to asbestos-related diseases. However, it is unclear whether oxidative DNA damage repaired by XRCC1 contributes to asbestos-induced chromosomal damage

    New Insight into Intrachromosomal Deletions Induced by Chrysotile in the gpt delta Transgenic Mutation Assay

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    BACKGROUND: Genotoxicity is often a prerequisite to the development of malignancy. Considerable evidence has shown that exposure to asbestos fibers results in the generation of chromosomal aberrations and multilocus mutations using various in vitro approaches. However, there is less evidence to demonstrate the contribution of deletions to the mutagenicity of asbestos fibers in vivo. OBJECTIVES: In the present study, we investigated the mutant fractions and the patterns induced by chrysotile fibers in gpt delta transgenic mouse primary embryo fibroblasts (MEFs) and compared the results obtained with hydrogen peroxide (H(2)O(2)) in an attempt to illustrate the role of oxyradicals in fiber mutagenesis. RESULTS: Chrysotile fibers induced a dose-dependent increase in mutation yield at the redBA/gam loci in transgenic MEF cells. The number of λ mutants losing both redBA and gam loci induced by chrysotiles at a dose of 1 μg/cm(2) increased by > 5-fold relative to nontreated controls (p < 0.005). Mutation spectra analyses showed that the ratio of λ mutants losing the redBA/gam region induced by chrysotiles was similar to those induced by equitoxic doses of H(2)O(2). Moreover, treatment with catalase abrogated the accumulation of γ-H2AX, a biomarker of DNA double-strand breaks, induced by chrysotile fibers. CONCLUSIONS: Our results provide novel information on the frequencies and types of mutations induced by asbestos fibers in the gpt delta transgenic mouse mutagenic assay, which shows great promise for evaluating fiber/particle mutagenicity in vivo

    Particle length-dependent titanium dioxide nanomaterials toxicity and bioactivity

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    <p>Abstract</p> <p>Background</p> <p>Titanium dioxide (TiO<sub>2</sub>) nanomaterials have considerable beneficial uses as photocatalysts and solar cells. It has been established for many years that pigment-grade TiO<sub>2 </sub>(200 nm sphere) is relatively inert when internalized into a biological model system (in vivo or in vitro). For this reason, TiO<sub>2 </sub>nanomaterials are considered an attractive alternative in applications where biological exposures will occur. Unfortunately, metal oxides on the nanoscale (one dimension < 100 nm) may or may not exhibit the same toxic potential as the original material. A further complicating issue is the effect of modifying or engineering of the nanomaterial to be structurally and geometrically different from the original material.</p> <p>Results</p> <p>TiO<sub>2 </sub>nanospheres, short (< 5 μm) and long (> 15 μm) nanobelts were synthesized, characterized and tested for biological activity using primary murine alveolar macrophages and in vivo in mice. This study demonstrates that alteration of anatase TiO<sub>2 </sub>nanomaterial into a fibre structure of greater than 15 μm creates a highly toxic particle and initiates an inflammatory response by alveolar macrophages. These fibre-shaped nanomaterials induced inflammasome activation and release of inflammatory cytokines through a cathepsin B-mediated mechanism. Consequently, long TiO<sub>2 </sub>nanobelts interact with lung macrophages in a manner very similar to asbestos or silica.</p> <p>Conclusions</p> <p>These observations suggest that any modification of a nanomaterial, resulting in a wire, fibre, belt or tube, be tested for pathogenic potential. As this study demonstrates, toxicity and pathogenic potential change dramatically as the shape of the material is altered into one that a phagocytic cell has difficulty processing, resulting in lysosomal disruption.</p

    Nanotoksikologija za varno in trajnostno nanotehnologijo

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    Nanotechnology is the term given to those areas of science and engineering where the phenomena take place at nanoscale dimensions. Nanoparticles are particles with <100 nm in one dimension. They have different physical, chemical, electrical and optical properties than those that occur in bulk samples of the same material. Understanding these nanoscale properties and finding ways to engineer new nanomaterials will have a revolutionary impact, from more efficient energy generation and data storage to improved methods for diagnosing and treating diseases. Nanotechnology is poised to become a major factor in the world’s economy and part of our everyday lives in the near future. Hundreds of tonnes of nanoparticles already enter the environment annually, but still very little is known of their interactions with biological systems. Recent studies indicate that some nanoparticles are not completely benign to biological and environmental targets. The challenge for toxicologists is to identify key factors that can be used to predict toxicity, permit targeted screening, and allow material scientists to generate new, safer nanoparticles with this structure-toxicity information in mind. The aim of this paper is to summarize some known facts about nanomaterials and discuss future perspectives, regulatory issues and tasks of the emerging branch of toxicology, that is, nanotoxicology.Nanomateriali izboljćujejo kvaliteto naćega življenja, zato bo njihova uporaba na različnih področjih življenja dramatično narasla. Po nekaterih ocenah bo imela nanotehnologija večji vpliv na družbno kot ga je imela industrijska revolucija. Kot posledica razmaha nanotehnologije se bo povečala poklicna in javna izpostavljenost nanodelcem ter izpostavljenost okolja. Nanodelci, ki nas najbolj zanimajo, so strukture, ki imajo v eni dimenziji manj kot 100 nm, in jih je izdelal človek. Njihove lastnosti se zaradi njihove majhnosti bistveno razlikujejo od lastnosti, ki jih imajo večji delci enake kemijske sestave. Šele v zadnjem času so se začela pojavljati vpraćanja in vzpodbujati raziskave o potencialni nevarnosti nanodelcev. Trenutni rezultati toksikoloćkih ćtudij potrjujejo kvarne učinke nanodelcev in navajajo, da nanodelci najverjetneje delujejo na organizem preko oksidativnega stresa. Študije nakazujejo ćtevilne posebnosti nanodelcev pri interakcijah s celicami, tkivi in organizmi. Najverjetneje je ta trenutek pomembno pridobiti čim več ustreznega znanja za oblikovanje regulative na področju varne proizvodnje in uporabe nanodelcev. Namen prispevka je povzeti že znana dejstva o nanodelcih in predstaviti naloge nove smeri v toksikologiji, nanotoksikologije. V prispevku je povzeta najnovejća regulativa na področju ugotavljanja in zagotavljanja varnosti proizvodov nanotehnologij, navedene so nekatere koristne baze podatkov, razprave ter nacionalne in mednarodne smernice na področju nanotehnologije

    DNA copy number loss and allelic imbalance at 2p16 in lung cancer associated with asbestos exposure

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    Five to seven percent of lung tumours are estimated to occur because of occupational asbestos exposure. Using cDNA microarrays, we have earlier detected asbestos exposure-related genomic regions in lung cancer. The region at 2p was one of those that differed most between asbestos-exposed and non-exposed patients. Now, we evaluated genomic alterations at 2p22.1-p16.1 as a possible marker for asbestos exposure. Lung tumours from 205 patients with pulmonary asbestos fibre counts from 0 to 570 million fibres per gram of dry lung, were studied by fluorescence in situ hybridisation (FISH) for DNA copy number alterations (CNA). The prevalence of loss at 2p16, shown by three different FISH probes, was significantly increased in lung tumours of asbestos-exposed patients compared with non-exposed (P=0.05). In addition, a low copy number loss at 2p16 associated significantly with high-level asbestos exposure (P=0.02). Furthermore, 27 of the tumours were studied for allelic imbalances (AI) at 2p22.1–p16.1 using 14 microsatellite markers and also AI at 2p16 was related to asbestos exposure (P=0.003). Our results suggest that alterations at 2p16 combined with other markers could be useful in diagnosing asbestos-related lung cancer

    Preventing carbon nanoparticle-induced lung inflammation reduces antigen-specific sensitization and subsequent allergic reactions in a mouse model

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    BACKGROUND: Exposure of the airways to carbonaceous nanoparticles can contribute to the development of immune diseases both via the aggravation of the allergic immune response in sensitized individuals and by adjuvant mechanisms during the sensitization against allergens. The cellular and molecular mechanisms involved in these adverse pathways are not completely understood. We recently described that the reduction of carbon nanoparticle-induced lung inflammation by the application of the compatible solute ectoine reduced the aggravation of the allergic response in an animal system. In the current study we investigated the influence of carbon nanoparticles on the sensitization of animals to ovalbumin via the airways. Ectoine was used as a preventive strategy against nanoparticle-induced neutrophilic lung inflammation. METHODS: Balb/c mice were repetitively exposed to the antigen ovalbumin after induction of airway inflammation by carbon nanoparticles, either in the presence or in the absence of ectoine. Allergic sensitization was monitored by measurement of immunoglobulin levels and immune responses in lung and lung draining lymph nodes after challenge. Furthermore the role of dendritic cells in the effect of carbon nanoparticles was studied in vivo in the lymph nodes but also in vitro using bone marrow derived dendritic cells. RESULTS: Animals exposed to antigen in the presence of carbon nanoparticles showed increased effects with respect to ovalbumin sensitization, to the allergic airway inflammation after challenge, and to the specific T(H)2 response in the lymph nodes. The presence of ectoine during the sensitization significantly reduced these parameters. The number of antigen-loaded dendritic cells in the draining lymph nodes was identified as a possible cause for the adjuvant effect of the nanoparticles. In vitro assays indicate that the direct interaction of the particles with dendritic cells is not able to trigger CCR7 expression, while this endpoint is achieved by lung lavage fluid from nanoparticle-exposed animals. CONCLUSIONS: Using the intervention strategy of applying ectoine into the airways of animals we were able to demonstrate the relevance of neutrophilic lung inflammation for the adjuvant effect of carbon nanoparticles on allergic sensitization. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12989-015-0093-5) contains supplementary material, which is available to authorized users
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