Factors bearing upon egg size and embryonic period in Opisthobranch molluscs

Um conjunto de dados derivados de observações sobre mais de 60 espécies de moluscos opistobrânguios dos oceanos Atlântico e Pacífico, incluindo espécies planctotróficas, lecitotróficas e não-pelágicas, foi submetido à análise para encontrar uma expressão que ajuste a massa de observações de modo aceitável. A principal finalidade foi quantificar as relações entre tamanho do ovo, período embrionário e temperatura de criação de opistobrânquios. A temperatura provou ser de importância capital na medida que uma mudança de 283 para 296 graus absolutos aumentou a taxa de desenvolvimento por um fator de 2.07. O tamanho do ovo foi quase tão importante: um aumento no diâmetro do ovo de 73 para 181 micrômetros aumentou o período embrionário por um fator de 2.02. O tempo de desenvolvimento fez apenas ligeira diferença e diferenças negligenciáveis puderam ser atribuídas ao fato das espécies serem atlânticas ou pacíficas

Computational fluid dynamics of vortex flow controls at low flow rates

PublishedJournal ArticleA vortex flow control with differing outlet shapes is investigated computationally at low flow rates. The volume of fluid method was utilised to track the moving free surface. In order to achieve a smooth free surface, interface compression coupled with the inter-gamma compressive scheme was used. The turbulent evolution of the two-phase flow was modelled by solving the Reynolds-averaged Navier-Stokes equations with the k-ε model for turbulent quantities. Validation of the results was carried out by analysing the total head and discharge coefficient for the three outlet shapes at various flow rates and comparing these results with experimental data. Very good agreement with the experimental data was obtained

Neurosyphilis: Old Disease, New Implications for Emergency Physicians

Recent epidemiologic data demonstrate increasing rates of neurosyphilis, particularly among those in the community of men who have sex with men and those coinfected with the human immunodeficiency virus (HIV). Here we discuss a case of early neurosyphilis and new HIV diagnosis in a 27-year-old previously-healthy trans woman presenting for the second time with progressive, ascending weakness and cranial nerve VI palsy. Emergency physicians should consider this rare but highly morbid diagnosis, given the rising prevalence of neurosyphilis among at-risk patients and those with new neurologic deficits

Enhancing Industry Exposure, Discovery-Based and Cooperative Learning in Mechanics of Solids

BACKGROUND Mechanics of Solids is a second year undergraduate subject, undertaken by both Civil and Mechanical engineering students at the University of Technology, Sydney (UTS). Mechanics of Solids has been delivered for many years in a traditional format with lectures and problem solving tutorials. As part of a national Australian project “Enhancing Industry Exposure in Engineering Degrees”, UTS in partnership with other universities and industry partners in Australia has sought industry involvement to engage students with the real-world challenges of engineering practice. PURPOSE The main objective of this project is to design, develop and implement learning modules in Mechanis of Solids that integrate industry exposure to provide context for the concepts included in this subject. DESIGN The project consisted of six guest lectures by industry representatives on topics related to typical Mechanics of Solids subject matter and two seminars on using MDSolids software. Students completed a collaborative assignment aligned with one of the industry presentations. Their reports and presentations were assessed on assessment criteria which included contextual understanding, judgement, effective collaboration and creativity, and their perceptions were captured to evaluate the impact of industry engagement in this subject. RESULTS One of the major benefits of this project was students’ better understanding of engineering practice. There were also positive effects on students’ motivation for learning engineering. CONCLUSIONS This paper reports the major findings, outcomes and challenges for implementing enhancing industry exposure approach in Mechanics of Solids subject at UTS. The main finding of this research concluded that this project is very valuable to both students as it promotes exposure to real-world engineering challenges. The students’ exposure to real and substantive challenges improves their contextual understanding, plus their judgement, practice based planning, teamwork, and initiative learning skills

Multiple enhancers contribute to spatial but not temporal complexity in the expression of the proneural gene, amos

BACKGROUND: The regulation of proneural gene expression is an important aspect of neurogenesis. In the study of the Drosophila proneural genes, scute and atonal, several themes have emerged that contribute to our understanding of the mechanism of neurogenesis. First, spatial complexity in proneural expression results from regulation by arrays of enhancer elements. Secondly, regulation of proneural gene expression occurs in distinct temporal phases, which tend to be under the control of separate enhancers. Thirdly, the later phase of proneural expression often relies on positive autoregulation. The control of these phases and the transition between them appear to be central to the mechanism of neurogenesis. We present the first investigation of the regulation of the proneural gene, amos. RESULTS: Amos protein expression has a complex pattern and shows temporally distinct phases, in common with previously characterised proneural genes. GFP reporter gene constructs were used to demonstrate that amos has an array of enhancer elements up- and downstream of the gene, which are required for different locations of amos expression. However, unlike other proneural genes, there is no evidence for separable enhancers for the different temporal phases of amos expression. Using mutant analysis and site-directed mutagenesis of potential Amos binding sites, we find no evidence for positive autoregulation as an important part of amos control during neurogenesis. CONCLUSION: For amos, as for other proneural genes, a complex expression pattern results from the sum of a number of simpler sub-patterns driven by specific enhancers. There is, however, no apparent separation of enhancers for distinct temporal phases of expression, and this correlates with a lack of positive autoregulation. For scute and atonal, both these features are thought to be important in the mechanism of neurogenesis. Despite similarities in function and expression between the Drosophila proneural genes, amos is regulated in a fundamentally different way from scute and atonal

Ice Patch Archaeology in Alaska: 2000–10

In the past decade, ice patch archaeological research has been initiated in several areas of Alaska, including Wrangell-St. Elias National Park and Preserve, the Amphitheater Mountains, Lake Clark National Park and Preserve, Denali National Park and Preserve, Gates of the Arctic National Park and Preserve, Chugach National Forest, and Katmai National Park. Although still in its formative stages, this research demonstrates that high-altitude ice patches have been an important part of the annual subsistence cycles of Alaskan people for at least 4000 years. Researchers have found cultural materials at 13 Alaskan ice patches. Most artifacts recovered are related to caribou hunting; however, a growing body of evidence demonstrates that ice patches were the foci for a wide range of subsistence activities, such as hunting birds, harvesting berries, and snaring small mammals. Site interpretations are based on ethnographically documented cultural practices, animal behavior, alpine ecology and geology, and archaeological analyses.Au cours de la dernière décennie, des recherches archéologiques ont été entreprises dans plusieurs névés de l’Alaska, notamment dans les régions suivantes : Wrangell-St. Elias National Park and Preserve, monts Amphitheater, Lake Clark National Park and Preserve, Denali National Park and Preserve, Gates of the Arctic National Park and Preserve, Chugach National Forest et Katmai National Park. Bien que ces recherches en soient toujours au stade embryonnaire, elles ont déjà permis de constater que les névés en haute altitude ont joué un rôle important dans les cycles de subsistance annuels des peuples de l’Alaska pendant au moins 4 000 ans. Les chercheurs ont récupéré du matériel culturel dans 13 névés de l’Alaska. La plupart des artefacts qui ont été trouvés se rapportent à la chasse au caribou. Cependant, de plus en plus d’artefacts prouvent que les névés étaient le point de convergence d’une vaste gamme d’activités de subsistance, comme la chasse aux oiseaux, la récolte des petits fruits et le piégeage des petits mammifères. L’interprétation des sites s’appuie sur les pratiques culturelles documentées de manière ethnographique, sur le comportement animal, sur l’écologie et la géologie alpines ainsi que sur les analyses archéologiques