893 research outputs found

    Electrostatic curved electrode actuators

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    This paper presents the design and performance of an electrostatic actuator consisting of a laterally compliant cantilever beam and a fixed curved electrode, both suspended above a ground plane. A theoretical description of the static behavior of the cantilever as it is pulled into contact with the rigid fixed-electrode structure is given. Two models are presented: a simplified semi-analytical model based on energy methods, and fully three-dimensional (3-D) coupled electromechanical numerical simulations using CoSolve-EM. The two models are in qualitative agreement with each other, and predict stable actuator behavior when the beam deflection becomes constrained by the curved electrode geometry before electrostatic pull-in can occur. The pull-in behavior depends on the shape of the curved electrode. Test devices have been fabricated by polysilicon surface micromachining techniques. Experimental results confirm the basic theoretical results. Stable behavior with relatively large displacements and forces can be generated by these curved electrode actuators. Depending on the design, or as a result of geometrical imperfections, regions of unstable (pull-in) deflection behavior are also observe

    Success for Boys: Indigenous boys' module

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    [Extract] In this module, participants canvass a broad range of issues related to the education of Indigenous boys. They examine the main issues influencing the educational participation rates and educational achievement of Indigenous boys, including the causes of alienation of Indigenous boys, and problems in the relationships between schools and teachers and Indigenous boys. They develop familiarity with the perspectives of Indigenous people, so that these perspectives can be applied within the conceptual framework for expanding the repertoires of practice that were introduced in the Core module. They select from a range of strategies shown to be effective in improving learning outcomes for Indigenous boys. Finally, participants are assisted to commence school-based strategic planning for improving Indigenous boys' engagement with school and their educational achievement, using the 'inquiry in action' process introduced in the Core module

    Towards large-cohort comparative studies to define the factors influencing the gut microbial community structure of ASD patients.

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    Differences in the gut microbiota have been reported between individuals with autism spectrum disorders (ASD) and neurotypical controls, although direct evidence that changes in the microbiome contribute to causing ASD has been scarce to date. Here we summarize some considerations of experimental design that can help untangle causality in this complex system. In particular, large cross-sectional studies that can factor out important variables such as diet, prospective longitudinal studies that remove some of the influence of interpersonal variation in the microbiome (which is generally high, especially in children), and studies transferring microbial communities into germ-free mice may be especially useful. Controlling for the effects of technical variables, which have complicated efforts to combine existing studies, is critical when biological effect sizes are small. Large citizen-science studies with thousands of participants such as the American Gut Project have been effective at uncovering subtle microbiome effects in self-collected samples and with self-reported diet and behavior data, and may provide a useful complement to other types of traditionally funded and conducted studies in the case of ASD, especially in the hypothesis generation phase

    Migraines Are Correlated with Higher Levels of Nitrate-, Nitrite-, and Nitric Oxide-Reducing Oral Microbes in the American Gut Project Cohort.

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    Nitrates, such as cardiac therapeutics and food additives, are common headache triggers, with nitric oxide playing an important role. Facultative anaerobic bacteria in the oral cavity may contribute migraine-triggering levels of nitric oxide through the salivary nitrate-nitrite-nitric oxide pathway. Using high-throughput sequencing technologies, we detected observable and significantly higher abundances of nitrate, nitrite, and nitric oxide reductase genes in migraineurs versus nonmigraineurs in samples collected from the oral cavity and a slight but significant difference in fecal samples. IMPORTANCE Recent work has demonstrated a potentially symbiotic relationship between oral commensal bacteria and humans through the salivary nitrate-nitrite-nitric oxide pathway (C. Duncan et al., Nat Med 1:546-551, 1995, http://dx.doi.org/10.1038/nm0695-546). Oral nitrate-reducing bacteria contribute physiologically relevant levels of nitrite and nitric oxide to the human host that may have positive downstream effects on cardiovascular health (V. Kapil et al., Free Radic Biol Med 55:93-100, 2013, http://dx.doi.org/10.1016/j.freeradbiomed.2012.11.013). In the work presented here, we used 16S rRNA Illumina sequencing to determine whether a connection exists between oral nitrate-reducing bacteria, nitrates for cardiovascular disease, and migraines, which are a common side effect of nitrate medications (U. Thadani and T. Rodgers, Expert Opin Drug Saf 5:667-674, 2006, http://dx.doi.org/10.1517/14740338.5.5.667)

    Educating world citizens: A curriculum for citizenship education

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    The doctoral curriculum: needs and directions in research training

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    [Extract] The past decade has seen unprecedented scrutiny of the purposes and practices of doctoral education as a form of research training. Regarded as the pinnacle of university scholarship, the doctorate has faced a growing range of challenges to its traditional forms and status. Of particular importance are concerns about the quality and breadth of research training in Australian universities expressed in a number of government reports and inquiries (Review Committee on Higher Education Financing and Policy (West Report), 1998; Kemp, 1999; Gallagher, 2000). However, these same issues have been raised across national boundaries and fields of study, indicating that, rather than being a problem in any particular system of higher education or research training, the concerns signal deep-seated and wide-ranging challenges to the traditions of the doctoral curriculum

    Success for Boys: planning guide and core module

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    Experimental phage therapy of burn wound infection : difficult first steps

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    Antibiotic resistance has become a major public health problem and the antibiotics pipeline is running dry. Bacteriophages (phages) may offer an ‘innovative’ means of infection treatment, which can be combined or alternated with antibiotic therapy and may enhance our abilities to treat bacterial infections successfully. Today, in the Queen Astrid Military Hospital, phage therapy is increasingly considered as part of a salvage therapy for patients in therapeutic dead end, particularly those with multidrug resistant infections. We describe the application of a well-defined and quality controlled phage cocktail, active against Pseudomonas aeruginosa and Staphylococcus aureus, on colonized burn wounds within a modest clinical trial (nine patients, 10 applications), which was approved by a leading Belgian Medical Ethical Committee. No adverse events, clinical abnormalities or changes in laboratory test results that could be related to the application of phages were observed. Unfortunately, this very prudent ‘clinical trial’ did not allow for an adequate evaluation of the efficacy of the phage cocktail. Nevertheless, this first ‘baby step’ revealed several pitfalls and lessons for future experimental phage therapy and helped overcome the psychological hurdles that existed to the use of viruses in the treatment of patients in our burn unit
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