470 research outputs found

    THE APPLICATION OF A SPORT-SPECIFIC 3D STEREOSCOPIC STIMULUS TO EXAMINE PRE-PLANNING TIME AND GAZE CHARACTERISTICS DURING EVASIVE SIDE-STEPPING MANOEUVRES

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    It is well established that anterior cruciate ligament (ACL) injuries are serious, debilitating and costly for an individual, while also creating a significant public health burden at a societal level. ACL injuries occur when inappropriate external loads are applied to the knee and most commonly occur during the performance of a side-stepping (Ssg) manoeuvre (Besier et al., 2001a). Previous laboratory based investigations of evasive Ssg have employed generic light or mannequin visual stimuli in an effort to simulate the time and space constraints experienced by athletes, in the preparation and execution of the Ssg manoeuvre (Besier et al., 2001b; Besier et al., 2003; Mclean et al., 2004). However, a possible outcome of attempts to impose these constraints in lab environments is that the use of unrealistic visual stimuli may not accurately reflect or identify the relationship of the perceptual demands of the task with injury risk variables, during a sidestep in game based situations. This study proposes that the presentation of a three dimensional (3D) stereoscopic stimulus (3DSS), featuring a 3D video based sport specific reconstruction of an opposing defender(s) simulating a tackle, may improve the ecological validity of laboratory based investigations. Additionally, the incorporation of the 3DSS tool with eye tracking will allow for the subject’s gaze characteristics (fixations, durations on the 3DSS image) to be assessed. The general aims of this study were to: Technical • develop a 3DSS that delivers realistic sport-specific constraints to footballers during evasive Ssg manoeuvres, • create 3DSS scenarios that incorporate realistic game based variations of imposed time and space constraints (e.g. 3DSS tackle scenarios with one or two defenders), • develop an interface and protocol that integrates the 3DSS system with a commercial eye tracking system (ASL Eye Tracking Recorder), for the purpose of quantifying the lab based subject’s gaze characteristics on the projected stimulus during a Ssg manoeuvre, Experimental • identify differences in biomechanical variables (kinematic, kinetic and neuromuscular) associated with increased injury risk during Ssg manoeuvres, using a traditional light (light emitting diode) based stimulus (LBSS) compared with a 3DSS stimuli

    The effects of iron fortification on the gut microbiota in African children: a randomized controlled trial in Cote d'Ivoire.

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    BACKGROUND: Iron is essential for the growth and virulence of many pathogenic enterobacteria, whereas beneficial barrier bacteria, such as lactobacilli, do not require iron. Thus, increasing colonic iron could select gut microbiota for humans that are unfavorable to the host. OBJECTIVE: The objective was to determine the effect of iron fortification on gut microbiota and gut inflammation in African children. DESIGN: In a 6-mo, randomized, double-blind, controlled trial, 6-14-y-old Ivorian children (n = 139) received iron-fortified biscuits, which contained 20 mg Fe/d, 4 times/wk as electrolytic iron or nonfortifoed biscuits. We measured changes in hemoglobin concentrations, inflammation, iron status, helminths, diarrhea, fecal calprotectin concentrations, and microbiota diversity and composition (n = 60) and the prevalence of selected enteropathogens. RESULTS: At baseline, there were greater numbers of fecal enterobacteria than of lactobacilli and bifidobacteria (P < 0.02). Iron fortification was ineffective; there were no differences in iron status, anemia, or hookworm prevalence at 6 mo. The fecal microbiota was modified by iron fortification as shown by a significant increase in profile dissimilarity (P < 0.0001) in the iron group as compared with the control group. There was a significant increase in the number of enterobacteria (P < 0.005) and a decrease in lactobacilli (P < 0.0001) in the iron group after 6 mo. In the iron group, there was an increase in the mean fecal calprotectin concentration (P < 0.01), which is a marker of gut inflammation, that correlated with the increase in fecal enterobacteria (P < 0.05). CONCLUSIONS: Anemic African children carry an unfavorable ratio of fecal enterobacteria to bifidobacteria and lactobacilli, which is increased by iron fortification. Thus, iron fortification in this population produces a potentially more pathogenic gut microbiota profile, and this profile is associated with increased gut inflammation. This trial was registered at controlled-trials.com as ISRCTN21782274

    Tissue-specific regulation of mouse MicroRNA genes in endoderm-derived tissues

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    MicroRNAs fine-tune the activity of hundreds of protein-coding genes. The identification of tissue-specific microRNAs and their promoters has been constrained by the limited sensitivity of prior microRNA quantification methods. Here, we determine the entire microRNAome of three endoderm-derived tissues, liver, jejunum and pancreas, using ultra-high throughput sequencing. Although many microRNA genes are expressed at comparable levels, 162 microRNAs exhibited striking tissue-specificity. After mapping the putative promoters for these microRNA genes using H3K4me3 histone occupancy, we analyzed the regulatory modules of 63 microRNAs differentially expressed between liver and jejunum or pancreas. We determined that the same transcriptional regulatory mechanisms govern tissue-specific gene expression of both mRNA and microRNA encoding genes in mammals

    Sum rules and electrodynamics of high-Tc cuprates in the pseudogap state

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    We explore connections between the electronic density of states (DOS) in a conducting system and the frequency dependence of the scattering rate 1/τ(ω)1/\tau(\omega) inferred from infrared spectroscopy. We show that changes in the DOS upon the development of energy gaps can be reliably tracked through the examination of the 1/τ(ω)1/\tau(\omega) spectra using the sum rules discussed in the text. Applying this analysis to the charge dynamics in high-TcT_c cuprates we found radically different trends in the evolution of the DOS in the pseudogap state and in the superconducting state.Comment: 4 pages, 3 figure

    Accumulation of Polychlorinated Biphenyls in Adipocytes: Selective Targeting to Lipid Droplets and Role of Caveolin-1

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    Background : Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that preferentially accumulate in lipid-rich tissues of contaminated organisms. Although the adipose tissue constitutes a major intern reservoir of PCBs and recent epidemiological studies associate PCBs to the development of obesity and its related disorders, little is known about the mechanisms involved in their uptake by the adipose tissue and their intracellular localization in fat cells

    Measurement of the rate of nu_e + d --> p + p + e^- interactions produced by 8B solar neutrinos at the Sudbury Neutrino Observatory

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    Solar neutrinos from the decay of 8^8B have been detected at the Sudbury Neutrino Observatory (SNO) via the charged current (CC) reaction on deuterium and by the elastic scattering (ES) of electrons. The CC reaction is sensitive exclusively to nu_e's, while the ES reaction also has a small sensitivity to nu_mu's and nu_tau's. The flux of nu_e's from ^8B decay measured by the CC reaction rate is \phi^CC(nu_e) = 1.75 +/- 0.07 (stat)+0.12/-0.11 (sys.) +/- 0.05(theor) x 10^6 /cm^2 s. Assuming no flavor transformation, the flux inferred from the ES reaction rate is \phi^ES(nu_x) = 2.39+/-0.34 (stat.)+0.16}/-0.14 (sys) x 10^6 /cm^2 s. Comparison of \phi^CC(nu_e) to the Super-Kamiokande Collaboration's precision value of \phi^ES(\nu_x) yields a 3.3 sigma difference, providing evidence that there is a non-electron flavor active neutrino component in the solar flux. The total flux of active ^8B neutrinos is thus determined to be 5.44 +/-0.99 x 10^6/cm^2 s, in close agreement with the predictions of solar models.Comment: 6 pages (LaTex), 3 figures, submitted to Phys. Rev. Letter

    First Neutrino Observations from the Sudbury Neutrino Observatory

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    The first neutrino observations from the Sudbury Neutrino Observatory are presented from preliminary analyses. Based on energy, direction and location, the data in the region of interest appear to be dominated by 8B solar neutrinos, detected by the charged current reaction on deuterium and elastic scattering from electrons, with very little background. Measurements of radioactive backgrounds indicate that the measurement of all active neutrino types via the neutral current reaction on deuterium will be possible with small systematic uncertainties. Quantitative results for the fluxes observed with these reactions will be provided when further calibrations have been completed.Comment: Latex, 7 pages, 10 figures, Invited paper at Neutrino 2000 Conference, Sudbury, Canada, June 16-21, 2000 to be published in the Proceeding

    Выращивание из поликристаллического кремния солнечного качества квазимонокристаллических (mono-like) слитков методом направленной кристаллизации

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    In the frame of permanent objective to increase solar cell efficiency and to decrease production cost the monolike ingot process was designed which combine multicrystalline (mc) productivity and monocrystalline structure performances. As a raw material the mc-Solar Grade silicon (SoG-Si) was used because it is less expensive than the Si purified by gas chemical route (Siemens process or equivalent), Usage of the mc-SoG-Si for growing silicon ingots by monolike process should contribute to the ingot and wafer manufacturing cost decrease. SoG silicon using would be developed all the more fast since it enables to produce high efficiency solar cells. It is why the monolike process have been tested and optimized for Kazakhstan mc-SoG silicon. The objective of this work was study of the higher level content impurities influences on the crystal defect generation (mainly dislocations) of the monocrystalline structure. Visual monocrystalline structure, minority carrier lifetime mapping, and photoluminescence techniques were used to study the monolike ingots obtained from Kazakhstan’s mc-SoG silicon.В целях повышения эффективности солнечных элементов и снижение затрат на производство разработан процесс получения слитков кремния, по так называемой mono-like-технологии. Mono-like-процесс предназначен для получения монокристаллических слитков при использовании технологии производства мультикристаллического кремния (МК-Si). При этом в качестве сырья используют поликристаллический кремний (ПК-Si) «солнечного» качества (solar grade — SoG), технология получения которого является менее затратной, чем очистка кремния газохимическим процессом (Сименс-процесс или его эквивалент). Использование ПК-Si SoG для выращивания слитков по mono-like технологии должно способствовать снижению затрат на получение слитков и пластин. Новые технологии производства солнечных элементов, использующие ПК-Si SoG, разрабатываются быстрыми темпами, так как это позволяет производить при меньших затратах солнечные элементы с достаточно высоким КПД. Именно поэтому mono-like-процесс апробирован и оптимизирован для казахстанского ПК-Si SoG. Изучено влияние более высокой концентрации примесей в ПК-Si SoG на образование кристаллических дефектов (главным образом дислокаций) в монокристаллических структурах. Для исследования свойств mono-like слитка, полученного в промышленных масштабах из казахстанского ПК-Si SoG, использованы визуализация монокристаллической структуры, картирование времени жизни неосновных носителей заряда и фотолюминесценция

    Endogenous antigen processing drives the primary CD4+ T cell response to influenza.

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    By convention, CD4+ T lymphocytes recognize foreign and self peptides derived from internalized antigens in combination with major histocompatibility complex class II molecules. Alternative pathways of epitope production have been identified, but their contributions to host defense have not been established. We show here in a mouse infection model that the CD4+ T cell response to influenza, critical for durable protection from the virus, is driven principally by unconventional processing of antigen synthesized within the infected antigen-presenting cell, not by classical processing of endocytosed virions or material from infected cells. Investigation of the cellular components involved, including the H2-M molecular chaperone, the proteasome and γ-interferon-inducible lysosomal thiol reductase revealed considerable heterogeneity in the generation of individual epitopes, an arrangement that ensures peptide diversity and broad CD4+ T cell engagement. These results could fundamentally revise strategies for rational vaccine design and may lead to key insights into the induction of autoimmune and anti-tumor responses

    Writing Toward Readers\u27 Better Health: A Case Study Examining the Development of Online Health Information

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    Each year, more people search the Internet for health information. Through a case study conducted at a prominent health information company, I will show that technical communicators are well suited to contribute to the development of online health information. Like other technical communicators, online health information developers must make rhetorical choices based on audience needs, function within specific social contexts, and work through challenges of writing, editing, and project management
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