64 research outputs found

    Arbuscular mycorrhizal fungi reduce nitrous oxide emissions from N2O hotspots.

    Get PDF
    Nitrous oxide (N 2O) is a potent, globally important, greenhouse gas, predominantly released from agricultural soils during nitrogen (N) cycling. Arbuscular mycorrhizal fungi (AMF) form a mutualistic symbiosis with two-thirds of land plants, providing phosphorus and/or N in exchange for carbon. As AMF acquire N, it was hypothesized that AMF hyphae may reduce N 2O production. AMF hyphae were either allowed (AMF) or prevented (nonAMF) access to a compartment containing an organic matter and soil patch in two independent microcosm experiments. Compartment and patch N 2O production was measured both before and after addition of ammonium and nitrate. In both experiments, N 2O production decreased when AMF hyphae were present before inorganic N addition. In the presence of AMF hyphae, N 2O production remained low following ammonium application, but increased in the nonAMF controls. By contrast, negligible N 2O was produced following nitrate application to either AMF treatment. Thus, the main N 2O source in this system appeared to be via nitrification, and the production of N 2O was reduced in the presence of AMF hyphae. It is hypothesized that AMF hyphae may be outcompeting slow-growing nitrifiers for ammonium. This has significant global implications for our understanding of soil N cycling pathways and N 2O production

    Sedimentological characterization of Antarctic moraines using UAVs and Structure-from-Motion photogrammetry

    Get PDF
    In glacial environments particle-size analysis of moraines provides insights into clast origin, transport history, depositional mechanism and processes of reworking. Traditional methods for grain-size classification are labour-intensive, physically intrusive and are limited to patch-scale (1m2) observation. We develop emerging, high-resolution ground- and unmanned aerial vehicle-based ‘Structure-from-Motion’ (UAV-SfM) photogrammetry to recover grain-size information across an moraine surface in the Heritage Range, Antarctica. SfM data products were benchmarked against equivalent datasets acquired using terrestrial laser scanning, and were found to be accurate to within 1.7 and 50mm for patch- and site-scale modelling, respectively. Grain-size distributions were obtained through digital grain classification, or ‘photo-sieving’, of patch-scale SfM orthoimagery. Photo-sieved distributions were accurate to <2mm compared to control distributions derived from dry sieving. A relationship between patch-scale median grain size and the standard deviation of local surface elevations was applied to a site-scale UAV-SfM model to facilitate upscaling and the production of a spatially continuous map of the median grain size across a 0.3 km2 area of moraine. This highly automated workflow for site scale sedimentological characterization eliminates much of the subjectivity associated with traditional methods and forms a sound basis for subsequent glaciological process interpretation and analysis

    Pacific integrated island management: principles, case studies and lessons learned

    Get PDF

    Implementation, Evalution and Maintenance of a Social-Emotional Skills Training Program for Children with an Autism Spectrum Disorder in a Specialist School Setting

    Get PDF
    Socialization difficulties in children with an Autism Spectrum Disorder (ASD) are often associated with peer rejection and impaired academic achievement. Schools might appear to offer an ideal setting for social-emotional skills (SES) instruction. However, common challenges to successful implementation of school-based programs include inadequate staffing and resourcing, and a lack of ASD-specific staff training. This paper describes how barriers to program implementation were overcome in a project evaluating the Secret Agent Society (SAS) SES training intervention within Autism Spectrum Australia (Aspect) specialist classes. Questionnaire data was collected from school staff over a one-year period. Findings supported the effectiveness of the adoption process used, and suggest that SAS was feasible and acceptable to school staff

    MeCP2/H3meK9 are involved in IL-6 gene silencing in pancreatic adenocarcinoma cell lines

    Get PDF
    The aim of the present study was to analyse the molecular mechanisms involved in the Interleukin-6 (IL-6) silencing in pancreatic adenocarcinoma cell lines. Our results demonstrate that TNF-α, a major IL-6 inducer, is able to induce IL-6 only in three out of six cell lines examined. 5-aza-2′-deoxycytidine (DAC), but not trichostatin A (TSA), activates the expression of IL-6 in all cell lines, indicating that DNA methylation, but not histone deacetylation, plays an essential role in IL-6 silencing. Indeed, the IL-6 upstream region shows a methylation status that correlates with IL-6 expression and binds MeCP2 and H3meK9 only in the non-expressing cell lines. Our results suggest that critical methylations located from positions –666 to –426 relative to the transcription start site of IL-6 may act as binding sites for MeCP2

    Sedimentological characterisation of Antarctic moraines using UAVs and Structure-from-Motion photogrammetry

    Get PDF
    In glacial environments particle-size analysis of moraines provides insights into clast origin, transport history, depositional mechanism and processes of reworking. Traditional methods for grain-size classification are labour-intensive, physically intrusive and are limited to patch-scale (1m2) observation. We develop emerging, high-resolution ground- and unmanned aerial vehicle-based ‘Structure-from-Motion’ (UAV-SfM) photogrammetry to recover grain-size information across an moraine surface in the Heritage Range, Antarctica. SfM data products were benchmarked against equivalent datasets acquired using terrestrial laser scanning, and were found to be accurate to within 1.7 and 50mm for patch- and site-scale modelling, respectively. Grain-size distributions were obtained through digital grain classification, or ‘photo-sieving’, of patch-scale SfM orthoimagery. Photo-sieved distributions were accurate to <2mm compared to control distributions derived from dry sieving. A relationship between patch-scale median grain size and the standard deviation of local surface elevations was applied to a site-scale UAV-SfM model to facilitate upscaling and the production of a spatially continuous map of the median grain size across a 0.3 km2 area of moraine. This highly automated workflow for site scale sedimentological characterization eliminates much of the subjectivity associated with traditional methods and forms a sound basis for subsequent glaciological process interpretation and analysis

    Cost-Effectiveness of a Telephone-Delivered Intervention for Physical Activity and Diet

    Get PDF
    Background: Given escalating rates of chronic disease, broad-reach and cost-effective interventions to increase physical activity and improve dietary intake are needed. The cost-effectiveness of a Telephone Counselling intervention to improve physical activity and diet, targeting adults with established chronic diseases in a low socio-economic area of a major Australian city was examined. Methodology/Principal Findings: A cost-effectiveness modelling study using data collected between February 2005 and November 2007 from a cluster-randomised trial that compared Telephone Counselling with a “Usual Care” (brief intervention) alternative. Economic outcomes were assessed using a state-transition Markov model, which predicted the progress of participants through five health states relating to physical activity and dietary improvement, for ten years after recruitment. The costs and health benefits of Telephone Counselling, Usual Care and an existing practice (Real Control) group were compared. Telephone Counselling compared to Usual Care was not cost-effective (78,489perqualityadjustedlifeyeargained).However,theUsualCaregroupdidnotrepresentexistingpracticeandisnotausefulcomparatorfordecisionmaking.ComparingTelephoneCounsellingoutcomestoexistingpractice(RealControl),theinterventionwasfoundtobecosteffective(78,489 per quality adjusted life year gained). However, the Usual Care group did not represent existing practice and is not a useful comparator for decision making. Comparing Telephone Counselling outcomes to existing practice (Real Control), the intervention was found to be cost-effective (29,375 per quality adjusted life year gained). Usual Care (brief intervention) compared to existing practice (Real Control) was also cost-effective ($12,153 per quality adjusted life year gained). Conclusions/Significance: This modelling study shows that a decision to adopt a Telephone Counselling program over existing practice (Real Control) is likely to be cost-effective. Choosing the ‘Usual Care’ brief intervention over existing practice (Real Control) shows a lower cost per quality adjusted life year, but the lack of supporting evidence for efficacy or sustainability is an important consideration for decision makers. The economics of behavioural approaches to improving health must be made explicit if decision makers are to be convinced that allocating resources toward such programs is worthwhile

    A Multisite Preregistered Paradigmatic Test of the Ego-Depletion Effect

    Get PDF
    We conducted a preregistered multilaboratory project (k = 36; N = 3,531) to assess the size and robustness of ego-depletion effects using a novel replication method, termed the paradigmatic replication approach. Each laboratory implemented one of two procedures that was intended to manipulate self-control and tested performance on a subsequent measure of self-control. Confirmatory tests found a nonsignificant result (d = 0.06). Confirmatory Bayesian meta-analyses using an informed-prior hypothesis (δ = 0.30, SD = 0.15) found that the data were 4 times more likely under the null than the alternative hypothesis. Hence, preregistered analyses did not find evidence for a depletion effect. Exploratory analyses on the full sample (i.e., ignoring exclusion criteria) found a statistically significant effect (d = 0.08); Bayesian analyses showed that the data were about equally likely under the null and informed-prior hypotheses. Exploratory moderator tests suggested that the depletion effect was larger for participants who reported more fatigue but was not moderated by trait self-control, willpower beliefs, or action orientation.</p

    Within- and cross-language contributions of morphological awareness to word reading development in Chinese-English bilingual children

    Get PDF
    A growing body of cross-linguistic research has suggested that morphological awareness plays a key role in both L1 and L2 word reading among bilingual readers. However, little is known about the interaction and development of L1 and L2 morphological awareness in relation to word reading. We addressed this issue by evaluating the unique contributions of L1 Chinese and L2 English morphological awareness to word reading in both Chinese and English across Grades 2 (N = 150), 5 (N = 158), and 8 (N = 159) Hong Kong Chinese–English bilingual children. Children completed five tasks of Chinese morphological awareness which tapped for compounding awareness, homophone awareness, homographic awareness, semantic radical awareness, and affix awareness, and six English morphological judgment and analogy tasks that assessed morphological awareness at three levels: inflection, derivation, and compounding. English phonological awareness, Chinese and English vocabulary, and nonverbal ability were measured as controls. Word reading was assessed in both languages. Within-language analyses revealed that Chinese morphological awareness accounted for 27, 22, and 12% of unique variances in Chinese word reading above the control measures in Grades 2, 5, and 8 respectively. In contrast, English morphological awareness explained small but significant unique variances in English word reading, i.e., 4, 8, and 2%, across Grades 2, 5, and 8 respectively. Critically, there were cross-language influences: Chinese morphological awareness explained 4% of unique variance in English word reading in Grade 2 after controlling for IQ, English vocabulary, English phonological awareness, and English morphological awareness; English morphological awareness explained significant variances in Chinese word reading, i.e., 4, 3, and 4% in Grades 2, 5, and 8 respectively, after the relevant controls. These findings suggest a bi-directional cross-language transfer of morphological awareness to word reading in L1 Chinese and L2 English. However, the direction of its transfer may be constrained by some language-specific morphological features
    corecore