Experimental Studies of the Drag of an Axisymmetric Submarine Hull

The purpose of these studies was to measure the drag coefficient of a small model submarine to add data to a Reynolds number study. First, a laser Doppler velocimeter (LDV) was used to measure the flow characteristics of the Mississippi State University water tunnel. The velocity and turbulence intensity profiles were measured for a range of freestream velocities of 8.6 m/s to 10.7 m/s. Several wake velocity profiles were taken for a model submarine at downstream distances of x/d = 10 to x/d = 28, with a freestream velocity of 8.6 m/s. A formula for the drag coefficient that uses only mean velocity measurements in the wake was derived for an axisymmetric body using the assumptions of a self-similar wake and a power law behavior of the wake scales. The experimental drag coefficient results are compared to computational fluid dynamic (CFD) solutions

Common Representation of Information Flows for Dynamic Coalitions

We propose a formal foundation for reasoning about access control policies within a Dynamic Coalition, defining an abstraction over existing access control models and providing mechanisms for translation of those models into information-flow domain. The abstracted information-flow domain model, called a Common Representation, can then be used for defining a way to control the evolution of Dynamic Coalitions with respect to information flow

Dichroism in helicoidal crystals

Accounting for the interactions of light with heterogeneous, anisotropic, absorbing, optically active media is part of the characterization of complex, transparent materials. Stained biological structures in thin tissue sections share many of these features, but systematic optical analyses beyond the employ of the simple petrographic microscopes have not be established. Here, this accounting is made for polycrystalline, spherulitic bundles of twisted d-mannitol lamellae grown from melts containing light-absorbing molecules. It has long been known that a significant percentage of molecular crystals readily grow as helicoidal ribbons with mesoscale pitches, but a general appreciation of the commonality of these non-classical crystal forms has been lost. Helicoidal crystal twisting was typically assayed by analyzing refractivity modulation in the petrographic microscope. However, by growing twisted crystals from melts in the presence of dissolved, light-absorbing molecules, crystal twisting can be assayed by analyzing the dichroism, both linear and circular. The term "helicoidal dichroism" is used here to describe the optical consequences of anisotropic absorbers precessing around radii of twisted crystalline fibrils or lamellae. d-Mannitol twists in two polymorphic forms, α and δ. The two polymorphs, when grown from supercooled melts in the presence of a variety of histochemical stains and textile dyes, are strongly dichroic in linearly polarized white light. The bis-azo dye Chicago sky blue is modeled because it is most absorbing when parallel and perpendicular to the radial axes in the respective spherulitic polymorphs. Optical properties were measured using Mueller matrix imaging polarimetry and simulated by taking into account the microstructure of the lamellae. The optical analysis of the dyed, patterned polycrystals clarifies aspects of the mesostructure that can be difficult to extract from bundles of tightly packed fibrils

Justifications-on-demand as a device to promote shifts of attention associated with relational thinking in elementary arithmetic

Student responses to arithmetical questions that can be solved by using arithmetical structure can serve to reveal the extent and nature of relational, as opposed to computational thinking. Here, student responses to probes which require them to justify-on-demand are analysed using a conceptual framework which highlights distinctions between different forms of attention. We analyse a number of actions observed in students in terms of forms of attention and shifts between them: in the short-term (in the moment), medium-term (over several tasks), and long-term (over a year). The main factors conditioning students´ attention and its movement are identified and some didactical consequences are proposed

Evidence for the presence of multilineage chimerism and progenitors of donor dendritic cells in the peripheral blood of bone marrow-augmented organ transplant recipients

We have postulated that the donor leukocyte microchimerism plays a seminal role in the acceptance of allografts by inducing and perpetuating variable degree of donor-specific nonreactivity in long-surviving organ recipients. Limited information is available, however, concerning the phenotype and function of these chimeric cells in humans. The unequivocal presence of donor dendritic cells (DCs), a prominent lineage in the microchimerism observed in rodents and clinical organ recipients, was difficult to demonstrate in bone marrow (BM)-augmented organ transplant recipients. This enigma was resolved by the recent description of a method for propagating circulating human DCs from their progenitors by culture in a medium enriched with granulocyte-macrophage colony-stimulating factor and interleukin 4, a condition known to inhibit outgrowth of monocytes, thus providing a selective growth advantage to committed progenitors of the myeloid lineage. Cells from BM-augmented organ recipients and normal control subjects harvested from 12- to 14-day cultures exhibited dendritic morphology and potent allostimulatory capacity. Using appropriate primers, the presence of donor DNA was verified by polymerase chain reaction within the lineage(null)/class II(bright) sorted DC. Phenotypic analysis of cultured DCs from BM-augmented patients, unlike that of controls, exhibited a marked down- regulation of B7-1 (CD80) while retaining normal levels of expression of B7- 2 (CD86) cell surface molecules. The presence of donor DNA was also confirmed by polymerase chain reaction in individually sorted lineage+ (T, B, and NK) cells and macrophages, suggesting that the chimerism in BM-augmented patients is multilineage. The presence of progenitors of donor DCs in the peripheral blood of BM-augmented patients further substantiates the already convincing evidence of stem cell engraftment

Підручник зі слов’янського фольклору в Канаді

Рецензія на підручник: Kononenko N. Slavic Folklore: a Handbook. - Westport (Connecticut); London: Greenwood Press, 2007. - 209 pp

Reducing disease burden and health inequalities arising from chronic disease among Indigenous children: an early childhood caries intervention

Background: This study seeks to determine if implementing a culturally-appropriate early childhood caries (ECC) intervention reduces dental disease burden and oral health inequalities among Indigenous children living in South Australia, Australia. Methods/Design: This paper describes the study protocol for a randomised controlled trial conducted among Indigenous children living in South Australia with an anticipated sample of 400. The ECC intervention consists of four components: (1) provision of dental care; (2) fluoride varnish application to the teeth of children; (3) motivational interviewing and (4) anticipatory guidance. Participants are randomly assigned to two intervention groups, immediate (n = 200) or delayed (n = 200). Provision of dental care (1) occurs during pregnancy in the immediate intervention group or when children are 24-months in the delayed intervention group. Interventions (2), (3) and (4) occur when children are 6-, 12- and 18-months in the immediate intervention group or 24-, 30- and 36-months in the delayed intervention group. Hence, all participants receive the ECC intervention, though it is delayed 24 months for participants who are randomised to the control-delayed arm. In both groups, self-reported data will be collected at baseline (pregnancy) and when children are 24- and 36-months; and child clinical oral health status will be determined during standardised examinations conducted at 24- and 36-months by two calibrated dental professionals. Discussion: Expected outcomes will address whether exposure to a culturally-appropriate ECC intervention is effective in reducing dental disease burden and oral health inequalities among Indigenous children living in South Australia.Jessica Merrick, Alwin Chong, Eleanor Parker, Kaye Roberts-Thomson, Gary Misan, John Spencer, John Broughton, Herenia Lawrence and Lisa Jamieso

Cuidados biomédicos de saúde em Angola e na Companhia de Diamantes de Angola, c. 1910-1970

Pretende-se caracterizar a prestação de cuidados biomédicos em Angola durante a atividade da Companhia de Diamantes de Angola. Uma análise comparativa de políticas e práticas de saúde pública de vários atores coloniais, como os serviços de saúde da Companhia, sua congénere do Estado e outras empresas coloniais, revelará diferenças de investimento na saúde, isto é, instalações e pessoal de saúde, e tratamentos. Este escrutínio bem como as condições de vida iluminarão o carácter idiossincrático e central dos serviços de saúde da Companhia em termos de morbimortalidade em Angola, e a centralidade destes para as representações de um império cuidador