971 research outputs found

    The Potential of Hyperspectral Patterns of Winter Wheat to Detect Changes in Soil Microbial Community Composition

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    Reliable information on soil status and crop health is crucial for detecting and mitigating disasters like pollution or minimizing impact from soil-borne diseases. While infestation with an aggressive soil pathogen can be detected via reflected light spectra, it is unknown to what extent hyperspectral reflectance could be used to detect overall changes in soil biodiversity. We tested the hypotheses that spectra can be used to (1) separate plants growing with microbial communities from different farms; (2) to separate plants growing in different microbial communities due to different land use; and (3) separate plants according to microbial species loss. We measured hyperspectral reflectance patterns of winter wheat plants growing in sterilized soils inoculated with microbial suspensions under controlled conditions. Microbial communities varied due to geographical distance, land use and microbial species loss caused by serial dilution. After 3 months of growth in the presence of microbes from the two different farms plant hyperspectral reflectance patterns differed significantly from each other, while within farms the effects of land use via microbes on plant reflectance spectra were weak. Species loss via dilution on the other hand affected a number of spectral indices for some of the soils. Spectral reflectance can be indicative of differences in microbial communities, with the Renormalized Difference Vegetation Index the most common responding index. Also, a positive correlation was found between the Normalized Difference Vegetation Index and the bacterial species richness, which suggests that plants perform better with higher microbial diversity. There is considerable variation between the soil origins and currently it is not possible yet to make sufficient reliable predictions about the soil microbial community based on the spectral reflectance. We conclude that measuring plant hyperspectral reflectance has potential for detecting changes in microbial communities yet due to its sensitivity high replication is necessary and a strict sampling design to exclude other ā€˜noiseā€™ factors.</p

    Physical-activity support for people with intellectual disabilities:A theory-informed qualitative study exploring the direct support professionalsā€™ perspective

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    Purpose: The study aims to explore factors that influence (facilitate or impede) direct support professionals supporting people with intellectual disabilities in engaging in physical activity. Influencing factors will be synthesized into a conceptual model to set the stage for developing future interventions and policies to change direct support professional behavior. Method: Based on the Theoretical Domains Framework, semi-structured interviews were conducted with 25 direct support professionals of people with mild to profound intellectual disabilities. Influencing factors were analyzed using both inductive and deductive coding strategies. The theoretical sources of behavior (i.e., capability, opportunity, and motivation) were leading components in the development of a conceptual model. Results: Five influential factors facilitating or impeding physical-activity support were isolated that related to direct support professionalsā€™ capability, eight to the opportunities afforded them, and 11 to their motivation. Another six inductively emerged, which related to the characteristics of people with intellectual disabilities and which then influenced the capability, opportunity, or motivation to engage in physical-activity support by direct support professionals. Conclusions: Although experiences differed, the conceptual model developed here provides theoretically based targets for a comprehensive approach to changing direct support professional behavior and thus promoting the support of physical activity in people with intellectual disabilities

    Risk factors associated with challenging behaviour in people with profound intellectual and multiple disabilities

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    BACKGROUND: Several factors that correlate with the onset or continuation of challenging behaviour are mentioned in research. These are factors related to persons with ID, but also to direct support professionals and the context. Although many of these factors seem to affect the onset or continuation of challenging behaviour in people with ID in general, results are often inconclusive and have little focus on people with profound intellectual and multiple disabilities (PIMD). The present study aimed to assess the extent to which known factors related to challenging behaviour are also applicable to a group of 198 people with PIMD. METHOD: To determine which factors were associated with challenging behaviour, univariate analyses on associations between known risk factors and challenging behaviour were conducted. The associated factors were then subject to a regression analysis to determine the extent to which they explain the prevalence of challenging behaviour and can thus be seen as factors associated with challenging behaviour. RESULTS: The results show that, in particular, factors concerning the personal characteristics of people with PIMD, such as sleeping problems and auditory problems, were related to the variance in mean frequency of challenging behaviour. Only one factor related to the direct support professionals was found: when these professionals had been offered training on the subject of challenging behaviour in people with intellectual disabilities in general, they identified significantly more withdrawn behaviour. We found no contextual factors related to challenging behaviour. CONCLUSION: These findings are generally consistent with findings reported in other studies, especially concerning the personal characteristics of people with PIMD. Further research should focus on the effects of providing safe auditory environments and appropriate sleep schedules for people with PIMD on the occurrence of challenging behaviour

    Parallel age-related cognitive effects in autism:A cross-sectional replication study

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    Findings on ageā€related cognitive effects in autism in adulthood are inconsistent across studies. As these studies substantially differ in their methodology, replication studies are needed. In this replication study frequentist (i.e., nullā€hypothesis significance testing), and Bayesian statistics were used to investigate the hypothesis that in autistic adults compared to nonā€autistic adults mostly parallel, but also protective ageā€related cognitive effects can be observed. Participants were 88 autistic adults, and 88 nonā€autistic matched comparisons (age range: 30ā€“89ā€‰years, mean age: 55ā€‰years). Cognitive measures were administered on the following six domains: verbal memory, visual memory, working memory, Theory of Mind (ToM), verbal fluency, and processing speed, and selfā€reported cognitive failures. Nonā€autistic adults outperformed autistic adults on ToM, verbal fluency, and verbal memory, but only the first two were confirmed with Bayesian replication analyses. Also, more cognitive failures were reported by autistic adults. No interactions between group and age were observed, suggesting a parallel ageā€related effect on all cognitive domains. In sum, previously observed difficulties in ToM and verbal fluency were replicated which seem to persist at older age. Previously reported parallel ageā€related cognitive patterns were replicated, yet no evidence for protective ageā€related patterns was found. LAY SUMMARY: We investigated whether our previous findings on cognitive aging in autism could be confirmed in a new study measuring the cognitive effects of age in autistic and nonā€autistic adults. As expected, tasks that younger autistic adults had difficulties with (theory of mind, fluency) were also difficult for older autistic adults, and the effect of age itself was similar in autistic and nonā€autistic adults. Unexpectedly, we observed no protective effects (less cognitive aging) in autism

    Zinc allocation and re-allocation in rice

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    Aims: Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Methods: Two solution culture experiments using 70Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. Results: A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg-1 dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. Conclusions: In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement

    Vegetation development in coastal foredunes -179

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    Abstract. In coastal foredunes marram grass (Ammophila arenaria) is used to stabilize windblown sand. The development of traditionally planted Ammophila into a more natural foredune vegetation may take 5 -10 yr. For economic reasons, traditional planting may be replaced by alternative techniques such as planting seeds or disk-harrowing rhizome fragments. In this paper, we compare the initial vegetation development of traditionally planted stands with stands established from seeds and from rhizomes. The experiments were conducted on an artificial foredune originating from dredged sea sand. The total experimental area covered more than 100 ha and the vegetation development was studied for 6 yr. The data were analysed by a priori grouping of plant species according to their ecology, as well as by Principal Components Analysis (PCA) and Redundancy Analysis (RA) of the percentage ground cover per plant species. Comparing ecological groups of plants showed that all planting methods delivered equal numbers of plant species that are indicative for coastal dunes. PCA and RA showed that methods based on the use of rhizome material resulted in a higher percentage cover of clonal perennials (Calammophila baltica, Festuca rubra ssp. arenaria, Carex arenaria and Cirsium arvense) than the traditionally planted stands and the stands obtained from seeds. The latter two were characterized by the dominance of annuals, bi-annuals and (mostly nonrhizomatous) perennials. Initially, the rates of succession were highest in the stands obtained from rhizomes. However, after 3 -6 yr there were no differences between the various stands. During the first four years, the percentage cover by rhizomatous foredune plants developed faster than that of annuals, bi-annuals and perennials. After 6 yr, the latter contributed almost as much to the percentage cover as the clonal species. Keywords: Clonal plant; Dune management; Dune reinforcement; Sand dune; Sand stabilization; Succession. Nomenclature
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