122 research outputs found

    Motor skill acquisition in children with poor motor coordination

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    Physical Activity is essential for growth, development and wellbeing. Children with poor motor coordination are known to have lower levels of participation in physical activity and exercise in comparison to their typically developing peers, at least partly due to the difficulty in acquiring the motor skills they need for participation. Reduced participation in physical activity in childhood increases the risk of developing obesity, cardiovascular disease and psychosocial problems which persist throughout adolescence and adulthood. Poor motor coordination in these children has been largely attributed to their difficulty in acquiring and performing motor skills. However, motor skill acquisition is not yet well understood in this group, in particular whether these children are able to improve the quality of their movement and the pattern of motor skill acquisition. The following thesis aims to investigate the motor skill acquisition in a group of children with motor coordination difficulties and is comprised of two main studies. The first one aims at creating a simple and easy tool for screening coordination in large cohorts of children in mainstream schools in order to identify children with poor motor coordination. The second study is a pilot/feasibility study aimed at informing the implementation of a fully powered follow-up motor learning intervention trial. It involved detection of a sample of children with poor motor coordination using the designed screening tool in 3 mainstream schools and recruiting them into a physical training intervention with an embedded practice of a novel rhythmic stepping task. The characteristics of their performance throughout the training program were investigated by instrumenting the stepping ask and comparing the performance with a group of children with normal motor coordination. Applying a reduction analysis on a large set of motor screening data (which included test items from The Bruininks-Oseretsky Test of Motor Proficiency-Short Form (BOT-SF) as well as Fundamental Movement Skill), we successfully designed a test which has face validity for detection of children with poor coordination. Using this test, we screened a total of 571 students (273 females and 298 males) from 3 main stream schools in Oxfordshire and invited students who scored below the 25th percentile on our screening test (117; 53 girls and 64 boys) to an 11 week training intervention. Thirty-three students attended the intervention (21 girls and 12 boys) with a great difference in recruitment and retention rates between the schools. The learning of the novel motor skill was measured by analysis of the participants’ performance on a novel stepping task, in which they stepped rhythmically in accordance to a sequence of visual stimuli presented on a computer screen. The performance (movement time), measured using accelerometry, was significantly worse in children with coordination problems (p<.001) mean±SD= 1.193±.036. Importantly, children with poor motor coordination were able to improve their performance on the task with no significant differences between the groups. However, we observed a tendency for difference in the pattern of improvement over time (p=.06). Given the nature of the conducted studies, i.e. as feasibility studies, our findings don’t allow of a straightforward generalisation. Still, they entail important implications in clinical and school-based training interventions, directed towards children with poor motor coordination, and it is recommended that a follow-up trial take place which takes into account the suggestions mentioned in this thesis with regards to the involvement of schools, importance of applying successful recruitment strategy and the requirements of successful intervention

    Enhanced magnetic properties in ZnCoAlO caused by exchangecoupling to Co nanoparticles

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    We report the results of a sequence of magnetisation and magneto-optical studies on laser ablated thin films of ZnCoAlO and ZnCoO that contain a small amount of metallic cobalt. The results are compared to those expected when all the magnetization is due to isolated metallic clusters of cobalt and with an oxide sample that is almost free from metallic inclusions. Using a variety of direct magnetic measurements and also magnetic circular dichroism we find that there is ferromagnetism within both the oxide and the metallic inclusions, and furthermore that these magnetic components are exchange-coupled when aluminium is included. This enhances both the coercive field and the remanence. Hence the presence of a controlled quantity of metallic nanoparticles in ZnAlO can improve the magnetic response of the oxide, thus giving great advantages for applications in spintronics

    Pan-cancer analysis of whole genomes identifies driver rearrangements promoted by LINE-1 retrotransposition

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    About half of all cancers have somatic integrations of retrotransposons. Here, to characterize their role in oncogenesis, we analyzed the patterns and mechanisms of somatic retrotransposition in 2,954 cancer genomes from 38 histological cancer subtypes within the framework of the Pan-Cancer Analysis of Whole Genomes (PCAWG) project. We identified 19,166 somatically acquired retrotransposition events, which affected 35% of samples and spanned a range of event types. Long interspersed nuclear element (LINE-1; L1 hereafter) insertions emerged as the first most frequent type of somatic structural variation in esophageal adenocarcinoma, and the second most frequent in head-and-neck and colorectal cancers. Aberrant L1 integrations can delete megabase-scale regions of a chromosome, which sometimes leads to the removal of tumor-suppressor genes, and can induce complex translocations and large-scale duplications. Somatic retrotranspositions can also initiate breakage–fusion–bridge cycles, leading to high-level amplification of oncogenes. These observations illuminate a relevant role of L1 retrotransposition in remodeling the cancer genome, with potential implications for the development of human tumors

    Patterns of somatic structural variation in human cancer genomes.

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    A key mutational process in cancer is structural variation, in which rearrangements delete, amplify or reorder genomic segments that range in size from kilobases to whole chromosomes1-7. Here we develop methods to group, classify and describe somatic structural variants, using data from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA), which aggregated whole-genome sequencing data from 2,658 cancers across 38 tumour types8. Sixteen signatures of structural variation emerged. Deletions have a multimodal size distribution, assort unevenly across tumour types and patients, are enriched in late-replicating regions and correlate with inversions. Tandem duplications also have a multimodal size distribution, but are enriched in early-replicating regions-as are unbalanced translocations. Replication-based mechanisms of rearrangement generate varied chromosomal structures with low-level copy-number gains and frequent inverted rearrangements. One prominent structure consists of 2-7 templates copied from distinct regions of the genome strung together within one locus. Such cycles of templated insertions correlate with tandem duplications, and-in liver cancer-frequently activate the telomerase gene TERT. A wide variety of rearrangement processes are active in cancer, which generate complex configurations of the genome upon which selection can act

    Separation – integration – and now …? - An historical perspective on the relationship between German management accounting and financial accounting

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    German accounting has traditionally followed a dual ledger approach with strictly separated internal cost accounting, as the basis for management information, and external financial accounting focusing on creditor protection and based on the commercial law. However, the increased adoption of integrated accounting system implies a significant change in the relationship between financial and management accounting systems. We use Hegelian dialectic to trace the historical development of German accounting from separated systems towards antithetical propositions of full integration, and the emergence of partial integration as the synthesis of this transformation process. For this reason, our paper provides a comprehensive analysis of the literature on the relationship between financial and management accounting in Germany. On this basis, we elaborate how financial accounting in Germany has been shaped by its economic context and legislation, and how financial accounting – accompanied by institutional pressures – in turn influenced management accounting. We argue that the changing relationship between management and financial accounting in the German context illustrates how current accounting practice is shaped not only by its environment, but also by its historical path. Based on this reasoning, we discuss several avenues for future research

    Pan-cancer analysis of whole genomes identifies driver rearrangements promoted by LINE-1 retrotransposition.

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    About half of all cancers have somatic integrations of retrotransposons. Here, to characterize their role in oncogenesis, we analyzed the patterns and mechanisms of somatic retrotransposition in 2,954 cancer genomes from 38 histological cancer subtypes within the framework of the Pan-Cancer Analysis of Whole Genomes (PCAWG) project. We identified 19,166 somatically acquired retrotransposition events, which affected 35% of samples and spanned a range of event types. Long interspersed nuclear element (LINE-1; L1 hereafter) insertions emerged as the first most frequent type of somatic structural variation in esophageal adenocarcinoma, and the second most frequent in head-and-neck and colorectal cancers. Aberrant L1 integrations can delete megabase-scale regions of a chromosome, which sometimes leads to the removal of tumor-suppressor genes, and can induce complex translocations and large-scale duplications. Somatic retrotranspositions can also initiate breakage-fusion-bridge cycles, leading to high-level amplification of oncogenes. These observations illuminate a relevant role of L1 retrotransposition in remodeling the cancer genome, with potential implications for the development of human tumors
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