Flaw growth behavior in thick welded plates of 2219-T87 aluminum at room and cryogenic temperatures

Axial load fatigue and fracture tests were conducted on thick welded plates of 2219-T87 aluminum alloy to determine the tensile strength properties and the flaw growth behavior in electron beam, gas metal arc, and pulse current gas tungsten arc welds for plates 6.35 centimeters (2.5 in.) thick. The tests were conducted in room temperature air and in liquid nitrogen environments. Specimens were tested in both the as-welded and the aged after welding conditions. The experimental crack growth rate were correlated with theoretical crack growth rate predictions for semielliptical surface flaws

The diet of the Tasmanian Devil, Sarcophilus harrisii, as determined from analysis of scat and stomach contents

Knowledge of the diets of carnivores is an essential precursor to understanding their role as predators in ecosystems. To date, understanding of the diet of Tasmanian Devils, Sarcophilus harrisii, is limited and based upon largely qualitative descriptions. We examined the diets of Tasmanian Devils at six sites by identifying undigested hair, bone and feathers found in their scats. These sites range across different habitat types in coastal and inland Tasmania, and encompass devil populations that are known as both free of the Devil Facial Tumour Disease (DFTD) and populations that are infected by the disease. Tasmanian Devil scats at coastal sites (n=27) contained ten species of mammal, as well as birds, fish and insects. Scats collected from inland sites (n= 17) were comprised of six mammalian species, birds and invertebrates. The most common food items were birds, Common Brushtail and Ringtail possums (Trichosurus vulpecula and Pseudocheirus peregrinus respectively), Tasmanian Pademelons (Thylogale billardierii) and Bennett's Wallabies (Macropus ruftgriseus). O fall the scats, 61% contained only one food group, 32% contained two groups, 4% contained three food items and only one scat (2%) contained four food groups. We supplement this information with stomach contents from road-killed devils, and compare our results with those of previous studies, with a view to furthering our understanding ofthe ecology ofthe threatened Tasmanian Devil. Such information will be important for the management of wild and captive devil populations, particularly in light of DFTD

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The HIV pandemic continues to impose enormous morbidity, mortality and economic burdens across the globe. Simultaneously, innovations in antiretroviral therapy, diagnostic approaches and vaccine development are providing novel tools for treatment-as-prevention and prophylaxis. We developed a mathematical model to evaluate the added benefit of an HIV vaccine in the context of goals to increase rates of diagnosis, treatment, and viral suppression in 127 countries. Under status quo interventions, we predict a median of 49 million [1st and 3rd quartiles 44M, 58M] incident cases globally from 2015 to 2035. Achieving the UNAIDS 95–95–95 target was estimated to avert 25 million [20M, 33M] of these new infections, and an additional 6.3 million [4.8M, 8.7M] reduction was projected with the 2020 introduction of a 50%-efficacy vaccine gradually scaled up to 70% coverage. This added benefit of prevention through vaccination motivates imminent and ongoing clinical trials of viable candidates to realize the goal of HIV control

A novel mouse model of Campylobacter jejuni enteropathy and diarrhea

Campylobacter infections are among the leading bacterial causes of diarrhea and of ‘environmental enteropathy’ (EE) and growth failure worldwide. However, the lack of an inexpensive small animal model of enteric disease with Campylobacter has been a major limitation for understanding its pathogenesis, interventions or vaccine development. We describe a robust standard mouse model that can exhibit reproducible bloody diarrhea or growth failure, depending on the zinc or protein deficient diet and on antibiotic alteration of normal microbiota prior to infection. Zinc deficiency and the use of antibiotics create a niche for Campylobacter infection to establish by narrowing the metabolic flexibility of these mice for pathogen clearance and by promoting intestinal and systemic inflammation. Several biomarkers and intestinal pathology in this model also mimic those seen in human disease. This model provides a novel tool to test specific hypotheses regarding disease pathogenesis as well as vaccine development that is currently in progress

Rat Stem-Cell Factor Induces Splenocytes Capable Of Regenerating The Thymus

Cytokine regulation of prethymic T-lymphoid progenitor-cell proliferation and/or differentiation has not been well-defined, although much is known of cytokine regulation of hemopoietic stem- and progenitor-cell development. Here we use a recently identified hemopoietic growth factor, stem-cell factor (SCF) (a form of the c-kit ligand), and a transplant model of thymocyte regeneration to assess the effect of SCF on the in vivo generation of prethymic, thymocyte progenitor-cell activity. We show that recombinant rat SCF (rrSCF164 administered to weanling rats selectively induces an increase in thymocyte progenitor activity in the spleens of treated rats as compared to rats treated with vehicle, polyethylene glycol (PEG)-conjugated rat albumin, or recombinant human granulocyte colony-stimulating factor (rhG-CSF). These data demonstrate that administration of SCF in vivo affects extrathymic-origin thymocyte regenerating cells and may influence, directly or indirectly, early prethymic stages of T-cell lymphopoiesis in addition to its known effect on early stages of myelopoiesis and erythropoiesis