5,822 research outputs found

    Increasing vertical mixing to reduce Southern Ocean deep convection in NEMO3.4

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    Most CMIP5 (Coupled Model Intercomparison Project Phase 5) models unrealistically form Antarctic Bottom Water by open ocean deep convection in the Weddell and Ross seas. To identify the mechanisms triggering Southern Ocean deep convection in models, we perform sensitivity experiments on the ocean model NEMO3.4 forced by prescribed atmospheric fluxes. We vary the vertical velocity scale of the Langmuir turbulence, the fraction of turbulent kinetic energy transferred below the mixed layer, and the background diffusivity and run short simulations from 1980. All experiments exhibit deep convection in the Riiser-Larsen Sea in 1987; the origin is a positive sea ice anomaly in 1985, causing a shallow anomaly in mixed layer depth, hence anomalously warm surface waters and subsequent polynya opening. Modifying the vertical mixing impacts both the climatological state and the associated surface anomalies. The experiments with enhanced mixing exhibit colder surface waters and reduced deep convection. The experiments with decreased mixing give warmer surface waters, open larger polynyas causing more saline surface waters and have deep convection across the Weddell Sea until the simulations end. Extended experiments reveal an increase in the Drake Passage transport of 4 Sv each year deep convection occurs, leading to an unrealistically large transport at the end of the simulation. North Atlantic deep convection is not significantly affected by the changes in mixing parameters. As new climate model overflow parameterisations are developed to form Antarctic Bottom Water more realistically, we argue that models would benefit from stopping Southern Ocean deep convection, for example by increasing their vertical mixing

    The Effect of Botanical Tinctures and Essential Oils on the Growth and Morphogenesis of Candida albicans

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    Objective: Candida albicans is an opportunistic and polymorphic fungal pathogen that affects mucosal membranes and squamous epithelia as well as being part of the normal human flora. Historically, there have been many botanical-based remedies used to treat fungal conditions, including C. albicans. This study examined the efficacy of both botanical tinctures and essential oils on the growth and morphological differentiation of C. albicans. Methods: The in vitro growth and differentiation of C. albicans was monitored following treatment with ethanol-based tinctures and essential oils prepared from several commonly used botanicals. Results: Results demonstrated that all ethanol-based botanical tinctures tested did not inhibit the growth of C. albicans, but several tinctures, including Marsdenia condurango, Juglans nigra (Black walnut), Anemopsis californica (Yerba mansa) and Piper cubeba (Cubeb berry), significantly reduced the morphological differentiation of the yeast into the invasive hyphae form. Alternatively, several botanical essential oils, including those from Thymus vulgaris (Thyme), Rosmarinus officinalis (Rosemary) and Cymbopogon citratus (Lemon grass) had a dramatic effect on inhibiting the growth of C. albicans. Conclusions: These results suggest that botanical tinctures commonly used in the treatment of C. albicans infections may act by blocking the differentiation of the yeast into a more virulent hyphal form while not affecting the growth rate. In comparison, therapeutic essential oils may target both the differentiation and growth rate of C. albicans. The results support that different active constituents are present in botanical tinctures as compared to oils thereby contributing to our understanding of how these botanicals may be effective therapeutics in the treatment of C. albicans infections

    Pregnancy has a minimal impact on the acute transcriptional signature to vaccination.

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    Vaccination in pregnancy is an effective tool to protect both the mother and infant; vaccines against influenza, pertussis and tetanus are currently recommended. A number of vaccines with a specific indication for use in pregnancy are in development, with the specific aim of providing passive humoral immunity to the newborn child against pathogens responsible for morbidity and mortality in young infants. However, the current understanding about the immune response to vaccination in pregnancy is incomplete. We analysed the effect of pregnancy on early transcriptional responses to vaccination. This type of systems vaccinology approach identifies genes and pathways that are altered in response to vaccination and can be used to understand both the acute inflammation in response to the vaccine and to predict immunogenicity. Pregnant women and mice were immunised with Boostrix-IPV, a multivalent vaccine, which contains three pertussis antigens. Blood was collected from women before and after vaccination and RNA extracted for analysis by microarray. While there were baseline differences between pregnant and non-pregnant women, vaccination induced characteristic patterns of gene expression, with upregulation in interferon response and innate immunity gene modules, independent of pregnancy. We saw similar patterns of responses in both women and mice, supporting the use of mice for preclinical screening of novel maternal vaccines. Using a systems vaccinology approach in pregnancy demonstrated that pregnancy does not affect the initial response to vaccination and that studies in non-pregnant women can provide information about vaccine immunogenicity and potentially safety

    Food Chemistry: Experiments for Labs and Kitchens

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    A manual of kitchen experiments designed to demonstrate the chemical properties of foods and flavors, experienced through the human senses. We share this lab manual with you free of charge in light of the worldwide concerns of the novel coronavirus of 2019, and the COVID-19 disease outbreaks around the world in 2020. Please be warned, this manual is not “complete.” There will be typos. There will be errors. Some labs may not work perfectly. But, we hope you may find it useful—especially if your school was closed or you were quarantined/isolated for the sake of slowing the spread of this global virus. The only thing we ask in return is that you send us a message if you are able to use our experiments. This helps us demonstrate that our work had an effect, which is a key component of an academic career. Dr. Running’s email is: [email protected]. She can also provide instructors with data for analysis, and with the solution keys. Many thanks to Ms. Patsy Mellott, whose sponsorship of the Purdue College of Health and Human Sciences Patsy Mellott Teaching Innovation Award made the development of these labs possible

    Quantum Chessboards in the Deuterium Molecular Ion

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    We present a new algorithm for vibrational control in deuterium molecules that is feasible with current experimental technology. A pump mechanism is used to create a coherent superposition of the D2+ vibrations. A short, intense infrared control pulse is applied after a chosen delay time to create selective interferences. A `chessboard' pattern of states can be realized in which a set of even- or odd-numbered vibrational states can be selectively annihilated or enhanced. A technique is proposed for experimental realization and observation of this effect using 5 fs pulses of 790 nm radiation, with intermediate intensity (5e13 W/cm2)Comment: 12 pages, 5 figure

    Exercise induced skeletal muscle metabolic stress is reduced after pulmonary rehabilitation in COPD

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    SummaryIn COPD, skeletal muscle ATP resynthesis may be insufficient to meet demand during exercise due to excessive anaerobic and reduced oxidative (mitochondrial) energy production, leading to metabolic stress. We investigated the effect of outpatient pulmonary rehabilitation (PR) on the metabolic response (measured by exercise-induced accumulation of plasma ammonia) and determined whether this response predicted functional improvement following PR.25 subjects with stable COPD [mean (SD) age 67 (8)years and FEV1 47 (18)% predicted] performed maximal cycling ergometry before and after PR. Plasma ammonia was measured at rest, during exercise and 2 min post-exercise.Following PR, there were significant increases in peak cycle WR and ISWT performance (Mean (SEM) changes 13.1 (2.0) W and 93 (15) m respectively, p < 0.001). Mean (SEM) rise in plasma ammonia was reduced at peak (Pre vs Post-PR: 29.0 (4.5) vs 20.2 (2.5) μmol/l, p < 0.05) and isotime (Pre vs Post-PR: 29.0 (4.5) vs 10.6 (1.7) μmol/l, p < 0.001) exercise. Improvements in exercise performance after PR were similar among subgroups who did versus those who did not show a rise in ammonia at baseline.The results suggest that muscle cellular energy production was better matched to the demands of exercise following PR. We conclude that a pragmatic outpatient PR programme involving high intensity walking exercise results in significant adaptation of the skeletal muscle metabolic response with a reduction in exercise-related metabolic stress. However, the outcome of PR could not be predicted from baseline metabolic response

    Effects of Acute Physical Activity on NIH Toolbox-Measured Cognitive Functions Among Children in Authentic Education Settings

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    Introduction: Identifying a dose of physical activity (PA) that can improve cognitive function in children has important implications for school-day PA recommendations. Researchers and educators have interest in this link as it relates to both health and academic performance. This study examined the dose-response relationship between PA and improvement in cognition in a sample of fifth and sixth grade students. Methods: Participants (n = 156) from eight classes each completed two of four different cognitive assessments on an iPad, both before and after exposure to one of four randomized, 10-min PA conditions (sedentary, light, moderate, and vigorous). Conditions were standardized through use of videos to lead movement, and participants wore accelerometers to confirm fidelity to PA condition. The four cognitive assessments were selected from the NIH Toolbox Cognition Battery, and included Dimensional Change Card Sort, Flanker, Pattern Comparison, and Picture Sequence Memory tests. Hierarchical linear regression models were used to estimate the effects of condition on each test using an intention to treat analysis. Results: Fidelity to PA condition was acceptable for sedentary and light conditions, but became less precise for moderate and vigorous conditions. No significant time by condition interaction was observed for any of the cognitive assessment scores. Conclusions: Results did not substantiate a dose-response link between PA intensity and selected measures of cognitive function. More research is needed to investigate the potentially nuanced effects of short bouts of PA on cognitive functioning in children

    Differential effects of the poly (ADP-ribose) polymerase (PARP) inhibitor NU1025 on topoisomerase I and II inhibitor cytotoxicity in L1210 cells in vitro

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    The potent novel poly(ADP-ribose) polymerase (PARP) inhibitor, NU1025, enhances the cytotoxicity of DNA-methylating agents and ionizing radiation by inhibiting DNA repair. We report here an investigation of the role of PARP in the cellular responses to inhibitors of topoisomerase I and II using NU1025. The cytotoxicity of the topoisomerase I inhibitor, camptothecin, was increased 2.6-fold in L1210 cells by co-incubation with NU1025. Camptothecin-induced DNA strand breaks were also increased 2.5-fold by NU1025 and exposure to camptothecin-activated PARP. In contrast, NU1025 did not increase the DNA strand breakage or cytotoxicity caused by the topoisomerase II inhibitor etoposide. Exposure to etoposide did not activate PARP even at concentrations that caused significant levels of apoptosis. Taken together, these data suggest that potentiation of camptothecin cytotoxicity by NU1025 is a direct result of increased DNA strand breakage, and that activation of PARP by camptothecin-induced DNA damage contributes to its repair and consequently cell survival. However, in L1210 cells at least, it would appear that PARP is not involved in the cellular response to etoposide-mediated DNA damage. On the basis of these data, PARP inhibitors may be potentially useful in combination with topoisomerase I inhibitor anticancer chemotherapy. © 2001 Cancer Research Campaign http://www.bjcancer.co
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