570 research outputs found

    The time-dependent localization of Ki 67 antigen-positive cells in human skin wounds

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    A total of 77 human skin wounds with a post-infliction interval between 3 h and 7 months were investigated and the proliferation marker antigen Ki 67 was visualized in paraffin sections using a specific monoclonal antibody (MIB). The re-built epidermal layer covering the former lesional area showed only a few basal cells positively staining for Ki 67 antigen. No enhanced reactivity was found when compared to uninjured skin. In basal cells of the epidermis adjacent to the wound area, however, varying numbers of positive cells occurred, but no information useful for a reliable time estimation of skin wounds could be obtained due to the considerable variability in the number of Ki 67 positive epidermal basal cells found in non-damaged skin. Fibroblastic cells in the wound area revealed an increased number of Ki 67-positive sites which could first be detected in a 1.5-day-old skin lesion. Positive results could be obtained in every specimen investigated after a post-infliction interval of 6 days up to 1.5 months. Only the scar tissue of the oldest wound examined (wound age 7 months) revealed no increase in the number of positively staining fibroblasts. Therefore, positive results indicate a wound age of at least approximately 1.5 days and the lack of an increased number of positive fibroblastic cells in a sufficient number of specimens indicates at a wound age of less than 6 days, but cannot totally exclude longer post-infliction intervals

    Validity of the new lifestyles NL-1000 accelerometer for measuring time spent in moderate-to-vigorous physical activity in school settings

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    Current interest in promoting physical activity in the school environment necessitates an inexpensive, accurate method of measuring physical activity in such settings. Additionally, it is recognized that physical activity must be of at least moderate intensity in order to yield substantial health benefits. The purpose of the study, therefore, was to determine the validity of the New Lifestyles NL-1000 (New Lifestyles, Inc., Lee's Summit, Missouri, USA) accelerometer for measuring moderate-to-vigorous physical activity in school settings, using the Actigraph GT1M (ActiGraph, Pensacola, Florida, USA) as the criterion. Data were collected during a cross-country run (n = 12), physical education (n = 18), and classroom-based physical activities (n = 42). Significant and meaningful intraclass correlations between methods were found, and NL-1000 estimates of moderate-to-vigorous physical activity were not meaningfully different from GT1M-estimated moderate- to-vigorous physical activity. The NL-1000 therefore shows promising validity evidence as an inexpensive, convenient method of measuring moderate-to-vigorous physical activity in school settings

    Using genetic algorithms to generate test sequences for complex timed systems

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    The generation of test data for state based specifications is a computationally expensive process. This problem is magnified if we consider that time con- straints have to be taken into account to govern the transitions of the studied system. The main goal of this paper is to introduce a complete methodology, sup- ported by tools, that addresses this issue by represent- ing the test data generation problem as an optimisa- tion problem. We use heuristics to generate test cases. In order to assess the suitability of our approach we consider two different case studies: a communication protocol and the scientific application BIPS3D. We give details concerning how the test case generation problem can be presented as a search problem and automated. Genetic algorithms (GAs) and random search are used to generate test data and evaluate the approach. GAs outperform random search and seem to scale well as the problem size increases. It is worth to mention that we use a very simple fitness function that can be eas- ily adapted to be used with other evolutionary search techniques

    Obesity: A Biobehavioral Point of View

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    Excerpt: If you ask an overweight person, ā€œWhy are you fat?ā€™, you will, almost invariably, get the answer, ā€œBecause 1 eat too much.ā€ You will get this answer in spite of the fact that of thirteen studies, six find no significant differences in the caloric intake of obese versus nonobese subjects, five report that the obese eat significantly less than the nonobese, and only two report that they eat significantly more

    Molecular Analysis of Virulent Determinants of Enterovirus 71

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    Enterovirus 71 (EV71) is the most important causative agent of hand, foot and mouth disease (HFMD) in children. In most cases, it is a self-limiting illness. However some EV71 infectious cases can develop severe clinical outcomes, such as encephalitis, meningitis, poliomyelitis like paralysis, and even death. To identify the determinants of virulence, the deduced amino acid sequence of polyprotein and nucleotide sequence of 5ā€²-NTR and 3ā€²-NTR in 25 SC-EV71 strains (strains from severe cases) and 31 MC-EV71 strains (strains from mild cases) were analyzed. Results showed four amino acids on two positions (GlyP710/GlnP710/ArgP710 and GluP729) on the DE and EF loop of VP1, one (LysP930) on the surface of protease 2A and four nucleotides on three positions (GP272, UP488 and AP700/UP700) in the 5'-NTR region are associated with EV71 virulent phenotype. Predicted secondary structure of RNA using the consensus sequence of 5'-NTR by RNAStructure showed the mutation of nucleotide at position 488 in strain BJ08-Z004-3 (position 491 in prototype strain BrCr) can result in the discrepancy of an additional pair of nucleotides and thus change the stability of the second structure of IRES. Fragment base content analysis showed that in the region 696 to 714 bp at the 5'-NTR, where the AP700/UP700 was located, the nucleotide constitution ratios differed significantly between SC-EV71 and MC-EV71 strains. In conclusion, comparative genomic analysis showed that virulence of EV71 strains are mainly determined by the amino acids on two positions of VP1, one position of protease 2A and the nucleotides on three positions in 5'-NTR

    A Procedure for the Calculation of the Perceived Loudness of Sonic Booms

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    Implementing a method to calculate the human earā€™s perceived loudness of a sonic boom requires consulting scattered literature with varying amounts of detail. This work describes a comprehensive implementation of Stevensā€™ Mark VII in Python, called PyLdB. References to literary works are included in enough detail so that the reader could use this work as a guide to implement the Mark VII algorithm. The details behind the mathematics of the Mark VII algorithm are included and PyLdB is used to calculate the perceived loudness of an example pressure signature. PyLdB is benchmarked against a widely used and validated code by NASA called the Loudness Code for Asymmetric Sonic Booms that also implements the Mark VII methodology. PyLdB can be applied in conjunction with other tools to calculate the perceived loudness of sonic booms and facilitate the optimization of aircraft to reduce loudness levels

    Adaptive mutations in the genomes of enterovirus 71 strains following infection of mouse cells expressing human P-selectin glycoprotein ligand-1

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    We recently identified human P-selectin glycoprotein ligand-1 (PSGL-1) as a functional enterovirus 71 (EV71) receptor and demonstrated PSGL-1-dependent replication for some EV71 strains in human leukocytes. Here, we report that four out of five PSGL-1-binding strains of EV71 replicated poorly in mouse L929 cells stably expressing human PSGL-1 (L-PSGL-1 cells). Therefore, we compared the replication kinetics and entire genomic sequence of five original EV71 strains and the corresponding EV71 variants (EV71-LPS), which were propagated once in L-PSGL-1 cells. Direct sequence comparison of the entire genome of the original EV71 strains and EV71-LPS variants identified several possible adaptive mutations during the course of replication in L-PSGL-1 cells, including a putative determinant of the adaptive phenotype in L-PSGL-1 cells at VP2-149. The results suggest that an adaptive mutation, along with a PSGL-1-binding phenotype, may facilitate efficient PSGL-1-dependent replication of the EV71 strains in L-PSGL-1 cells

    Far upstream element binding protein 1 binds the internal ribosomal entry site of enterovirus 71 and enhances viral translation and viral growth

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    Enterovirus 71 (EV71) is associated with severe neurological disorders in children, and has been implicated as the infectious agent in several large-scale outbreaks with mortalities. Upon infection, the viral RNA is translated in a cap-independent manner to yield a large polyprotein precursor. This mechanism relies on the presence of an internal ribosome entry site (IRES) element within the 5ā€²-untranslated region. Virusā€“host interactions in EV71-infected cells are crucial in assisting this process. We identified a novel positive IRES trans-acting factor, far upstream element binding protein 1 (FBP1). Using binding assays, we mapped the RNA determinants within the EV71 IRES responsible for FBP1 binding and mapped the protein domains involved in this interaction. We also demonstrated that during EV71 infection, the nuclear protein FBP1 is enriched in cytoplasm where viral replication occurs. Moreover, we showed that FBP1 acts as a positive regulator of EV71 replication by competing with negative ITAF for EV71 IRES binding. These new findings may provide a route to new anti-viral therapy
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