233 research outputs found

    Is Reducing Uncertain Control the Key to Successful Test Anxiety Intervention for Secondary School Students? Findings From a Randomized Control Trial.

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    The aim of the study was to conduct a randomized control trial of a targeted, facilitated, test anxiety intervention for a group of adolescent students, and to examine the mediating role of uncertain control. Fifty-six participants (male = 19, white = 21, mean age = 14.7 years) were randomly allocated to an early intervention or wait-list control group. Participants completed the Revised Test Anxiety Scale and the Uncertain Control Scale from the Motivation and Engagement Scale at baseline, after the early intervention group had received the intervention, and again, after the wait-list control group had received the intervention. Participants showed moderate to large reductions in the worry and tension components of test anxiety, and uncertain control, after the intervention. The reduction in worry and tension was partially mediated by the reduction in uncertain control. Findings contribute to the evidence base for test anxiety interventions designed for school age populations and highlight uncertain control as an important factor in test anxiety intervention

    Homological algebra and friezes

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    PhD ThesisOver the last decade frieze patterns, as introduced by Conway and Coxeter in the 1970's, have been generalised in many ways. One such exciting development is a homological interpretation of frieze patterns, which we call friezes. A frieze in the modern sense is a map from a triangulated category C to some ring. A frieze X is characterised by the propety that if x ! y ! x is an Auslander-Reiten triangle in C, then X( x)X(x)X(y) = 1. A canonical example of a frieze is the Caldero-Chapoton map. The more general notion of a generalised frieze was introduced by Holm and J rgensen in [25] and [26]. A generalised frieze X0 carries the more general property that X0( x)X0(x) X0(y) 2 f0; 1g. In [25] and [26] Holm and J rgensen also introduced a modi ed Caldero- Chapoton map, which satis es the properties of a generalised frieze. This thesis consists of six chapters. The rst chapter provides a detailed outline of the thesis, whilst setting some of the main results in context and explaining their signi cance. The second chapter provides a necessary background to the notions used throughout the remaining four chapters. We introduce triangulated categories, the derived category, quivers and path algebras, Auslander-Reiten theory and cluster categories, including the polygonal models associated to the cluster categories of Dynkin types An and Dn. The third chapter is based around the proof of a multiplication formula for the modi ed Caldero-Chapoton map, which signi cantly simpli es its computation in practice. We de ne Condition F for two maps and , and show that when our category is 2-Calabi- Yau, Condition F implies that the modi ed Caldero-Chapoton map is a generalised frieze. We then use this to prove our multiplication formula. The de nition of the modi ed Caldero-Chapoton map requires a rigid subcategory R that sits inside a cluster tilting subcategory T. Chapter 4 proves several results showing that in the case of the cluster category of Dynkin type An, the modi ed Caldero-Chapoton map depends only on the rigid subcategory R. These results then allow us to prove a general formula for the group Ksplit 0 (T)=N, which is used in the de nition of the modi ed Caldero-Chapoton map. Chapter 5 provides a comprehensive list of exchange triangles in the cluster category of Dynkin type Dn. Chapter 6 then proves several similar results to Chapter 4 in the case of the cluster category of Dynkin type Dn. We prove that the modi ed Caldero-Chapoton map depends only on the rigid subcategory R before again producing a general formula for Ksplit 0 (T)=

    Exploring the educational experiences of young homeless people.

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    The research explored the educational experiences of young homeless people. It is acknowledged that the outcomes and difficulties experienced within education, are different from those of the homeless population and their housed peers. 7 participants were recruited from Centrepoint, a UK based youth homeless charity, all aged 18-19. Interviews were used to capture the experiences of the young people, and Smith, Flowers & Larkin's IPA stages used to analyse them. Participants’ individual experiences are presented within the research as well as overarching themes found within the participant group. These overarching themes were found to be: 1) needing additional support in school; 2) behavioural or academic failings at school; 3) avoiding failure and building a future; 4) motivation or change in motivation towards education; 5) lack of drive towards education; 6) support from professionals and external organisations; 6) support from teachers; 7) unsupportive educational settings/professionals; 8) challenges meeting basic needs and accessing resources. The findings are discussed within the context of youth homelessness in education, and alongside current research. The research encourages educational professionals to consider how these experiences might impact an individual’s ability to access education, and what school settings can do to support the experience of homeless individuals. Limitations of the research are considered, and opportunities for future research are identified

    Mangroves enhance the biomass of coral reef fish communities in the Caribbean

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    Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs

    Contaminations of soil and two Capsicum annuum generations irrigated by reused urban wastewater treated by different reed beds

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    Background: In order to save potable water, this study aims to evaluate the contamination of soil and Capsicum annuum L. (chilli) watered with urban wastewater (sewage) pre-treated by various wetland systems. Methods: The appropriateness of wetland outflow for irrigation when applying reused wastewater with high contamination of minerals and pathogens was assessed. The impact of wastewaters pre-treated by various wetlands on soil and harvest was tested in terms of mineral and biological contamination risk. Results: The wetlands met the standards for irrigation water for most water quality variables. However, the thresholds for key water quality parameters were significantly (p < 0.05) exceeded. The highest values for total coliforms, ammonium-nitrogen, phosphorus and potassium were 157,072 CFU/100 mL, 8.5 mg/L, 5.0 mg/L, and 7.0 mg/L, respectively. The harvest was moderately polluted only by zinc according to vegetable quality standards (threshold of 50 mg/kg). Zinc concentrations for Filters 2, 4, 6, 7 and 8 were 35.8, 60.6, 65.1, 65.5 and 53.2 mg/kg, respectively. No bacterial contamination was detected. Conclusions: Treatment of domestic wastewater applying constructed wetlands and subsequent recycling of the treated wastewater for irrigation of crops is a good substitute to the traditional application of drinking water for irrigation purposes

    Phloem sap intricacy and interplay with aphid feeding

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    Aphididae feed upon the plant sieve elements (SE), where they ingest sugars, nitrogen compounds and other nutrients. For ingestion, aphid stylets penetrate SE, and because of the high hydrostatic pressure in SE, phloem sap exudes out into the stylets. Severing stylets to sample phloem exudates (i.e. stylectomy) has been used extensively for the study of phloem contents. Alternative sampling techniques are spontaneous exudation upon wounding that only works in a few plant species, and the popular EDTA-facilitated exudation technique. These approaches have allowed fundamental advances on the understanding of phloem sap composition and sieve tube physiology, which are surveyed in this review. A more complete picture of metabolites, ions, proteins and RNAs present in phloem sap is now available, which has provided large evidence for the phloem role as a signalling network in addition to its primary role in partitioning of photo-assimilates. Thus, phloem sap sampling methods can have remarkable applications to analyse plant nutrition, physiology and defence responses. Since aphid behaviour is suspected to be affected by phloem sap quality, attempts to manipulate phloem sap content were recently undertaken based on deregulation in mutant plants of genes controlling amino acid or sugar content of phloem sap. This opens up new strategies to control aphid settlement on a plant host

    Measuring the impact of genetic heterogeneity and chromosomal inversions on the efficacy of CRISPR-Cas9 gene drives in different strains of Anopheles gambiae

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    The human malaria vector Anopheles gambiae is becoming increasingly resistant to insecticides, spurring the development of genetic control strategies. CRISPR-Cas9 gene drives can modify a population by creating double-stranded breaks at highly specific targets, triggering copying of the gene drive into the cut site (‘homing’), ensuring its inheritance. The DNA repair mechanism responsible requires homology between the donor and recipient chromosomes, presenting challenges for the invasion of lab-developed gene drives into wild populations of target species An. gambiae species complex, which show high levels of genome variation. Two gene drives (vas2-5958 and zpg-7280) were introduced into three An. gambiae strains collected across Africa with 5.3-6.6% variation around the target sites, and the effect of this variation on homing was measured. Gene drive homing across different karyotypes of the 2La chromosomal inversion was also assessed. No decrease in gene drive homing was seen despite target site heterology, demonstrating the applicability of gene drives to wild populations
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