Immunization in pregnancy clinical research in low- and middle-income countries - Study design, regulatory and safety considerations.

Immunization of pregnant women is a promising public health strategy to reduce morbidity and mortality among both the mothers and their infants. Establishing safety and efficacy of vaccines generally uses a hybrid design between a conventional interventional study and an observational study that requires enrolling thousands of study participants to detect an unknown number of uncommon events. Historically, enrollment of pregnant women in clinical research studies encountered many barriers based on risk aversion, lack of knowledge, and regulatory ambiguity. Conducting research enrolling pregnant women in low- and middle-income countries can have additional factors to address such as limited availability of baseline epidemiologic data on disease burden and maternal and neonatal outcomes during and after pregnancy; challenges in recruiting and retaining pregnant women in research studies, variability in applying and interpreting assessment methods, and variability in locally acceptable and available infrastructure. Some measures to address these challenges include adjustment of study design, tailoring recruitment, consent process, retention strategies, operational and logistical processes, and the use of definitions and data collection methods that will align with efforts globally

Hyperbolic planforms in relation to visual edges and textures perception

We propose to use bifurcation theory and pattern formation as theoretical probes for various hypotheses about the neural organization of the brain. This allows us to make predictions about the kinds of patterns that should be observed in the activity of real brains through, e.g. optical imaging, and opens the door to the design of experiments to test these hypotheses. We study the specific problem of visual edges and textures perception and suggest that these features may be represented at the population level in the visual cortex as a specific second-order tensor, the structure tensor, perhaps within a hypercolumn. We then extend the classical ring model to this case and show that its natural framework is the non-Euclidean hyperbolic geometry. This brings in the beautiful structure of its group of isometries and certain of its subgroups which have a direct interpretation in terms of the organization of the neural populations that are assumed to encode the structure tensor. By studying the bifurcations of the solutions of the structure tensor equations, the analog of the classical Wilson and Cowan equations, under the assumption of invariance with respect to the action of these subgroups, we predict the appearance of characteristic patterns. These patterns can be described by what we call hyperbolic or H-planforms that are reminiscent of Euclidean planar waves and of the planforms that were used in [1, 2] to account for some visual hallucinations. If these patterns could be observed through brain imaging techniques they would reveal the built-in or acquired invariance of the neural organization to the action of the corresponding subgroups.Comment: 34 pages, 11 figures, 2 table

Entwicklung einer evolutiven Biotechnologie mit Anwendung zur Naturstoffsynthese -(RNA, Protein) -Synthese und Entwicklung antiviraler Strategien Abschlussbericht

SIGLEAvailable from TIB Hannover: F96B330+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

The Landscape of the Traveling Salesman Problem

The landscapes of Traveling Salesman Problems are investigated by random walk techniques. The autocorrelation functions for different metrics on the space of tours are calculated. The landscape turns out to be AR(1) for symmetric TSPs. For asymmetric problems there can be a random contribution superimposed on an AR(1) behaviour. y Author to whom correspondence should be sent: Peter F. Stadler Institut fur Theoretische Chemie, University of Vienna Wahringerstr. 17, A-1090 Wien, Austria Phone: (*43 1) 43 61 41 / 70, Bitnet: A8443GAD@AWIUNI11 P.F.Stadler & W.Schnabl: The Landscape of TSP 1. Introduction The traveling salesman problem (TSP) [1] is the most prominent classical example of an NP-complete [2] combinatorial optimization problem. Given a distribution of cities the task is to find the shortest tour visiting each city once and returning to the starting point with prescribed costs j ij for traveling from i to j. The symmetric problem j ij = j ji has applications in X-ray cryst..

NMR-Tomografie und Spektroskopie. Entwicklungen und Anwendungen in der biomedizinischen Forschung Schlussbericht

At the beginning of this project the development of both magnetic resonance instruments and medical applications were in a period of extensive change caused by the invention of a rapid scan technique in the course of the preceeding project 01VF242. Primary aim of the present studies was an extension of rapid imaging sequences to improve their diagnostic specificity and a further development of MR techniques to gain new insights into metabolic and functional aspects of human organ systems beyond imaging of anatomic structures. In order to accomplish these goals new developments included specialized rapid MR imaging sequences (measuring times of less than 1 second, diffusion-weighting, T2"*-weighting) and image-controlled localized MR spectroscopy. In particular, the successful implementation of localized proton MR spectroscopy using stimulated echoes for the first time allowed systematic investigations of metabolites in the human brain under both physiologic and pathologic conditions (stroke, neoplasms, neurodegenerative and neurometabolic diseases). For specific questions (pharmalogic intervention, cerebral ischemia) the concept was adopted for studies of animal models (rat). A most recent result of utmost importance is mapping of functional activation of human primary cortices and subcortical nuclei at high spatial resolution. This approach by far extends the capabilities of competing modalities such as positron emission tomography. (orig.)SIGLEAvailable from TIB Hannover: DtF QN1(24,53) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman