3,198 research outputs found

    Effects of diamagnetic levitation on bacterial growth in liquid

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    Diamagnetic levitation is a technique that uses a strong, spatially-varying magnetic field to levitate diamagnetic materials, such as water and biological cells. This technique has the potential to simulate aspects of weightlessness, on the Earth. In common with all ground-based techniques to simulate weightlessness, however, there are effects introduced by diamagnetic levitation that are not present in space. Since there have been few studies that systematically investigate these differences, diamagnetic levitation is not yet being fully exploited. For the first time, we critically assess the effect of diamagnetic levitation on a bacterial culture in liquid. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 hours, in a series of experiments to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture. The speed of sedimentation of the bacterial cells to the bottom of the container is considerably reduced. Further experiments and microarray gene analysis show that the growth enhancement is due to greater oxygen availability in the magnetically levitated sample. We demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid, an effect not present in microgravity. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause the liquid to become unstable to convection when the consumption of oxygen by the bacteria generates an oxygen concentration gradient. We propose that this convection enhances oxygen availability by transporting oxygen around the sample. Since convection is absent in space, these results are of significant importance and timeliness to researchers considering using diamagnetic levitation to explore weightless effects on living organisms and a broad range of other topics in the physical and life sciences

    CCAFS Gender and Social Inclusion Strategy

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    The CCAFS Gender and Social Inclusion (GSI) Strategy is an update of the CCAFS 2012 Gender Strategy. The new strategy addresses gender as well as social inclusion for different social groups while bearing in mind that women are central to agriculture in developing countries. The CCAFS approach to GSI allies with the CGIAR objectives to create opportunities for women, young people and marginalized groups and to promote equitable access to resources, information and power in the agri-food system for men and women in order to close the gender gap by 2030

    RNAi reveals proteins for metabolism and protein processing associated with Langat virus infection in Ixodes scapularis (black-legged tick) ISE6 cells

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    Tick-borne flaviviruses (TBFs) cause thousands of human cases of encephalitis worldwide each year, with some TBF infections progressing to hemorrhagic fever. TBFs are of medical and veterinary importance and strategies to reduce flavivirus transmission by the tick vector may have significant application. Analyses of the proteome of ISE6 cells derived from the black legged tick, Ixodes scapularis infected with the TBF, Langat virus (LGTV), have provided insights into proteins and cellular processes involved with LGTV infection. Methods: RNA interference (RNAi)-induced knockdown of transcripts was used to investigate the role of ten tick proteins in the LGTV infection cycle in ISE6 cells. LGTV-infected cells were separately transfected with dsRNA corresponding to each gene of interest and the effect on LGTV genome replication and release of infectious virus was assessed by RT-qPCR and plaque assays, respectively. Results: RNAi-induced knockdown of transcripts for two enzymes that likely function in amino acid, carbohydrate, lipid, terpenoid/polykeytide and vitamin metabolism, and a transcript for one protein of unknown function were associated with decreased replication of the LGTV genome and release of infectious virus from cells. The knockdown of transcripts for five enzymes predicted to function in metabolism, a protein likely associated with folding, sorting and degradation, and a protein of unknown function was associated with a decrease only in the amount of infectious LGTV released from cells. Conclusions: These data suggest tick proteins potentially associated with metabolism and protein processing may be involved in LGTV infection of ISE6 cells. Our study provides information to begin to elucidate the function of these proteins and identify targets for the development of new interventions aimed at controlling the transmission of TBFs

    Is investment in Indigenous land and sea management going to the right places to provide multiple co-benefits?

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    Indigenous land and sea management (ILSM) has been the focus of large government investment in Australia and globally. Beyond environmental benefits, such investments can deliver a suite of social, cultural and economic co-benefits, aligning with the objectives of Indigenous communities and of governments for culturally appropriate socio-economic development. Nevertheless, there have been very few studies done on the spatial distribution of this investment and the extent to which its associated co-benefits address socio-economic disadvantage, which is unevenly distributed across Australia. This study draws on Australian ILSM programmes to examine the spatial and temporal distribution of investment for ILSM between 2002–2012 and considers implications for the distribution of associated co-benefits. Mapping and analysis of 2600 conservation projects revealed that at least $462M of investment in ILSM projects had occurred at 750 discrete sites throughout Australia. More than half of this investment in ILSM has been concentrated in northern Australia, in disadvantaged remote and very remote areas where a high percentage of the population is Indigenous, and Indigenous land ownership extensive. Our research has shown that ILSM investment has successfully been spatially distributed to areas with high needs for multiple social, economic, environmental and health and well-being co-benefit outcomes

    Predictors of benefit following pulmonary rehabilitation for interstitial lung disease

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    SummaryBackgroundPulmonary rehabilitation improves functional capacity and symptoms in the interstitial lung diseases (ILDs), however there is marked variation in outcomes between individuals. The aim of this study was to establish the impact of the aetiology and severity of ILD on response to pulmonary rehabilitation.MethodsForty-four subjects with ILD, including 25 with idiopathic pulmonary fibrosis (IPF), underwent eight weeks of pulmonary rehabilitation. Relationships between disease aetiology, markers of disease severity and response to pulmonary rehabilitation were assessed after eight weeks and six months, regardless of program completion.ResultsIn IPF, greater improvements in 6-minute walk distance (6MWD) immediately following pulmonary rehabilitation were associated with larger forced vital capacity (r = 0.49, p = 0.01), less exercise-induced oxyhaemoglobin desaturation (rS = 0.43, p = 0.04) and lower right ventricular systolic pressure (r = −0.47, p = 0.1). In participants with other ILDs there was no relationship between change in 6MWD and baseline variables. Less exercise-induced oxyhaemoglobin desaturation at baseline independently predicted a larger improvement in 6MWD at six month follow-up. Fewer participants with IPF had clinically important reductions in dyspnoea at six months compared to those with other ILDs (25% vs 56%, p = 0.04). More severe dyspnoea at baseline and diagnosis other than IPF predicted greater improvement in dyspnoea at six months.ConclusionsPatients with IPF attain greater and more sustained benefits from pulmonary rehabilitation when disease is mild, whereas those with other ILDs achieve benefits regardless of disease severity. Early referral to pulmonary rehabilitation should be considered in IPF

    Impaired chronotropic response to 6-min walk test and reduced survival in interstitial lung disease

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    SummaryBackgroundReduced chronotropic response to maximal exercise has been associated with poor survival in people without respiratory disease. The contribution of chronotropic response to exercise limitation and survival in interstitial lung disease (ILD) is not well defined. This study investigated the relationships between chronotropic response during 6-min walk test, exercise capacity and survival in ILD.MethodsEligible participants had ILD, were ambulant and free of heart failure and beta blocker therapy. Chronotropic response during the 6-min walk test was defined as peak heart rate (HR) minus resting HR. Survival was recorded at four years.ResultsSixty-two participants (40 idiopathic pulmonary fibrosis) were included, with mean (SD) TLCO 50(18)% predicted and 6-min walk distance (6MWD) 377 (127) metres. A smaller chronotropic response was associated with reduced 6MWD (r = 0.65, p < 0.001). Independent predictors of 6MWD were chronotropic response, peak oxygen uptake on cardiopulmonary exercise test; right ventricular systolic pressure on echocardiogram; and age. This model explained 83% of the variance in 6MWD, with 24% of the variance attributable to chronotropic response. A chronotropic response during 6-min walk test of less than 20 beats per minute was an independent predictor of death at four years (odds ratio 10.71, 95% confidence interval 2.67–42.94) in a model that also included oxygen desaturation and forced vital capacity.ConclusionsImpaired chronotropic response to 6-min walk test is associated with reduced 6MWD and reduced survival in ILD, independent of physical fitness and pulmonary hypertension. Investigation of the mechanisms underlying attenuated HR response to exercise in ILD is warranted

    Oral complementary medicine and alternative practitioner use varies across chronic conditions and attitudes to risk

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    Objectives: To determine whether chronic conditions and patient factors, such as risk perception and decision-making preferences, are associated with complementary medicine and alternative practitioner use in a representative longitudinal population cohort. Participants and setting: Analysis of data from Stage 2 of the North West Adelaide Health Study of 3161 adults who attended a study clinic visit in 2004–2006. The main outcome measures were the medications brought by participants to the study clinic visit, chronic health conditions, attitudes to risk, levels of satisfaction with conventional medicine, and preferred decision-making style. Results: At least one oral complementary medicine was used by 27.9% of participants, and 7.3% were visiting alternative practitioners (naturopath, osteopath). Oral complementary medicine use was significantly associated with arthritis, osteoporosis, and mental health conditions, but not with other chronic conditions. Any pattern of complementary medicine use was generally significantly associated with female gender, age at least 45 years, patient-driven decision-making preferences(odds ratio [OR] 1.38, 95% confidence interval [CI]: 1.08–1.77), and frequent general practitioner visits (.five per year; OR 3.62, 95% CI: 2.13–6.17). Alternative practitioner visitors were younger, with higher levels of education (diploma/trade [OR 1.88, 95% CI: 1.28–2.76], bachelor’s degree [OR 1.77, 95% CI: 1.11–2.82], income . $80,000 (OR 2.28, 95% CI: 1.26–4.11), female gender (OR 3.15, 95% CI: 2.19–4.52), joint pain not diagnosed as arthritis (OR 1.68, 95% CI: 1.17–2.41), moderate to severe depressive symptoms (OR 2.15, 95% CI: 1.04–4.46), and risk-taking behaviour (3.26, 1.80–5.92), or low-to-moderate risk aversion (OR 2.08, 95% CI: 1.26–4.11). Conclusion: Although there is widespread use of complementary medicines in the Australian community, there are differing patterns of use between those using oral complementary medicines and those using alternative practitioners.Robert J Adams, Sarah L Appleton, Antonia Cole, Tiffany K Gill, Anne W Taylor and Catherine L Hil

    Construction and evaluation of multisite recombinatorial (Gateway) cloning vectors for Gram-positive bacteria

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    <p>Abstract</p> <p>Background</p> <p>The Gateway recombinatorial cloning system allows easy and rapid joining of DNA fragments. Here we report the construction and evaluation of three different Gram-positive vectors that can be used with the Multisite Gateway cloning system to rapidly produce new gene arrangements in plasmid constructs for use in a variety of Gram-positive bacteria.</p> <p>Results</p> <p>Comparison of patterns of reporter gene expression with conventionally constructed clones show that the presence of residual recombination (att) sites does not have an effect on patterns of gene expression, although overall levels of gene expression may vary. Rapid construction of these new vectors allowed vector/gene combinations to be optimized following evaluation of plasmid constructs in different bacterial cells and demonstrates the benefits of plasmid construction using Gateway cloning.</p> <p>Conclusion</p> <p>The residual <it>att </it>sites present after Gateway cloning did not affect patterns of promoter induction in Gram-positive bacteria and there was no evidence of differences in mRNA stability of transcripts. However overall levels of gene expression may be reduced, possibly due to some post-transcriptional event. The new vectors described here allow faster, more efficient cloning in range of Gram-positive bacteria.</p
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