Macro- and microscale variables regulate stent haemodynamics,fibrin deposition and thrombomodulin expression

Drug eluting stents are associated with late stent thrombosis (LST), delayed healing and prolonged exposure of stent struts to blood flow. Using macroscale disturbed and undisturbed fluid flow waveforms, we numerically and experimentally determined the effects of microscale model strut geometries upon the generation of prothrombotic conditions that are mediated by flow perturbations. Rectangular cross-sectional stent strut geometries of varying heights and corresponding streamlined versions were studied in the presence of disturbed and undisturbed bulk fluid flow. Numerical simulations and particle flow visualization experiments demonstrated that the interaction of bulk fluid flow and stent struts regulated the generation, size and dynamics of the peristrut flow recirculation zones. In the absence of endothelial cells, deposition of thrombin-generated fibrin occurred primarily in the recirculation zones. When endothelium was present, peristrut expression of anticoagulant thrombomodulin (TM) was dependent on strut height and geometry. Thinner and streamlined strut geometries reduced peristrut flow recirculation zones decreasing prothrombotic fibrin deposition and increasing endothelial anticoagulant TM expression. The studies define physical and functional consequences of macro- and microscale variables that relate to thrombogenicity associated with the most current stent designs, and particularly to LST.     

Test-data generation for control coverage by proof

Many tools can check if a test set provides control coverage; they are, however, of little or no help when coverage is not achieved and the test set needs to be completed. In this paper, we describe how a formal characterisation of a coverage criterion can be used to generate test data; we present a procedure based on traditional programming techniques like normalisation, and weakest precondition calculation. It is a basis for automation using an algebraic theorem prover. In the worst situation, if automation fails to produce a specific test, we are left with a specification of the compliant test sets. Many approaches to model-based testing rely on formal models of a system under test. Our work, on the other hand, is not concerned with the use of abstract models for testing, but with coverage based on the text of programs.     

From information processing to dialogical meaning making: an experiential approach to cognitive ergonomics

In this paper, we argue that modelling human action as the execution of predetermined goals and cognition as information processing does not account for peoples experience with emerging technologies, which is as much about values, trust and identity as about executing tasks. We offer a complementary approach to information processing within cognitive ergonomics, which builds on Bruners characterisation of cognition as meaningmaking, and which sees human action as simultaneously creating and executing goals and human cognition as dialogical meaning making. An analysis of field work carried out in two ambulance control centres is employed to exemplify aspects of the creativity and responsivity of work activity that are central to our approach. Finally, in this context, we briefly consider how technological artefacts could be conceptualised as centres of value in an approach to cognitive ergonomics that attempts to accommodate the intellectual, emotional and valuative aspects of work activity.     

Psychology and pediatrics: Prospects for cooperative efforts to promote child health: A discussion with Morris Green.

Because families seek help from pediatricians for a variety of child behavioral and psychological problems, interdisciplinary collaboration between pediatrics and psychology has much potential. Such a collaboration would offer new opportunities for psychologists in primary health care settings and could help fulfill the significant psychosocial training needs of pediatricians delivering primary, secondary, and tertiary services. These needs are particularly acute for secondary care, with its increasing emphasis on child development, psychosocial aspects of pediatrics, developmental disabilities, adolescence, and school problems. Additionally, collaboration could enhance treatment of a wide variety of problems with both medical and psychological components such as hyperactivity, enuresis, juvenile onset obesity, and childrearing problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cardiac tamponade as a presentation of primary hypothyroidism in a young woman

Pericardial effusion (PE) as a hypothyroidism associated sign, is something that can be found with relative frequency; nevertheless, cardiac tamponade (CT) as the first sign of this disease may be considered exceptional especially in young patients. We report a 31 years old woman with clinical symptoms and signs of CT that in the forward workshop was diagnosed of primary hypothyroidism as cause of the CT. We shortly describe the case and review the literature, emphasizing the importance of the knowledge of CT trigger factors in myxedematous PE, as well as its usual benign evolution with hormonal treatment, without recurrences of the CT after pericardiocentesis is performed. This justify a conservative approach, in spite of the slow resolution of the PE what can take as long as 1.5 years.     

Recovery of heterokaryons at high cell densities following isolation using irreversible biochemical inhibitors

The selection of heterokaryons using irreversible biochemical inhibitors provides an effective method for isolating fusion products between any types of cultured cells. One weakness of the technique is that the surviving heterokaryons can only be obtained at low culture densities, making their analysis cumbersome. This report describes the use of Ficoll-sodium diatrizoate gradients to partially separate viable from nonviable cells and characterizes the effects of initial plating density and medium volume on heterokaryon survival. The combined result of optimizing these parameters increases cell rescue and permits heterokaryons to attach at densities of 60,000 cells/cm 2 instead of 600 cells/cm 2. These modifications substantially improve the ease of using irreversible biochemical inhibitors to isolate purified populations of heterokaryons.     

Unique peptide maps of the three largest proteins specified by the flavivirus Kunjin

Tryptic digests of four polypeptides found in Kunjin virus-infected Vero cells, NV5, NV4, V3, and NV3, were compared by peptide mapping. The polypeptides to be analyzed were labeled with radioactive methionine and separated by electrophoresis through polyacrylamide gels containing sodium dodecyl sulfate. Because infection of Vero cells by Kunjin virus does not inhibit host cell protein synthesis, radioactively labeled viral polypeptides prepared from infected cells migrate coincidentally during sodium dodecyl sulfate-gel electrophoresis with some of the labeled host proteins. Thus, the genuine viral methionine-containing peptides in tryptic digests of viral proteins have been identified by co-analyzing polypeptides from [3H]methionine-labeled uninfected cells and [35S]methionine-labeled infected cells and determining the 35S/3H ratio in the peptides resolved in two dimensions on thin-layer chromatography plates. The peptide map of NV3 demonstrated that it is host coded, whereas NV5, NV4, and V3 have unique peptide maps and, therefore, account for approximately one-half of the coding potential of Kunjin virus RNA.     

Effects of semantic priming on visual encoding of pictures.

We investigated the effects of semantic priming on initial encoding of briefly presented pictures of objects and scenes. Pictures in 4 experiments were presented for varying durations and were followed immediately by a mask. In Exps 1 and 2, pictures of simple objects were either preceded or not preceded by the object's category name (e.g., dog). In Exp 1 we measured immediate object identification; in Exp 2 we measured delayed old/new recognition in which targets and distractors were from the same categories. In Exp 3 naturalistic scenes were either preceded or not preceded by the scene's category name (e.g., supermarket). We measured delayed recognition in which targets and distractors were described by the same category names. In Exps 1–3, performance was better for primed than for unprimed pictures. Exp 4 was similar to Exp 2 in that we measured delayed recognition for simple objects. As in Exps 1–3, a prime that preceded the object improved subsequent memory performance for the object. However, a prime that followed the object did not affect subsequent performance. Together, these results imply that priming leads to more efficient information acquisition. We offer a picture-processing model that accounts for these results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of high temperature plastic flow on the superconducting transition in A15 compounds

Low temperature heat capacity measurements have been made on hot isostatically pressed Nb₃Sn and arc cast, homogenized, and A15 transformation annealed V-23.3 at. pct Ga and V-18.1 at. pct Ga. The heat capacity measurements display the superconducting transition temperature (T _c), and have been used to evaluate the effects of plastic deformation on theT _c range. Plastic deformation to the extent of 15 pct compression at 1525 and 1650 °C does not alter the superconducting transition in polycrystalline Nb₃Sn. Plastic deformation to the extent of 15 pct compression at 1050 and 1200 °C does not alter the superconducting transition in polycrystalline V-23.3Ga, transformed to A15 structure with a fifty-hour 1150 °C anneal. The same statement can be made for A15 V-18.1Ga, deformed at 1050 °C after a fifty-hour, 1150 °C anneal. With onlyfive hours annealing at 1150 °C, A15 V-23.2Ga displays a lowering and broadening of theT _c range upon 1050 and 1200 °C plastic deformation. With onlyfive hours annealing at 1150 °C, A15 V-18.1Ga displays a broad, but increasedT _c range after plastic deformation at 1050 °C.