1,189 research outputs found

    A simple method of equine limb force vector analysis and its potential applications

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    Background Ground reaction forces (GRF) measured during equine gait analysis are typically evaluated by analyzing discrete values obtained from continuous force-time data for the vertical, longitudinal and transverse GRF components. This paper describes a simple, temporo-spatial method of displaying and analyzing sagittal plane GRF vectors. In addition, the application of statistical parametric mapping (SPM) is introduced to analyse differences between contra-lateral fore and hindlimb force-time curves throughout the stance phase. The overall aim of the study was to demonstrate alternative methods of evaluating functional (a)symmetry within horses. Methods GRF and kinematic data were collected from 10 horses trotting over a series of four force plates (120 Hz). The kinematic data were used to determine clean hoof contacts. The stance phase of each hoof was determined using a 50 N threshold. Vertical and longitudinal GRF for each stance phase were plotted both as force-time curves and as force vector diagrams in which vectors originating at the centre of pressure on the force plate were drawn at intervals of 8.3 ms for the duration of stance. Visual evaluation was facilitated by overlay of the vector diagrams for different limbs. Summary vectors representing the magnitude (VecMag) and direction (VecAng) of the mean force over the entire stance phase were superimposed on the force vector diagram. Typical measurements extracted from the force-time curves (peak forces, impulses) were compared with VecMag and VecAng using partial correlation (controlling for speed). Paired samples t-tests (left v. right diagonal pair comparison and high v. low vertical force diagonal pair comparison) were performed on discrete and vector variables using traditional methods and Hotelling’s T2 tests on normalized stance phase data using SPM. Results Evidence from traditional statistical tests suggested that VecMag is more influenced by the vertical force and impulse, whereas VecAng is more influenced by the longitudinal force and impulse. When used to evaluate mean data from the group of ten sound horses, SPM did not identify differences between the left and right contralateral limb pairs or between limb pairs classified according to directional asymmetry. When evaluating a single horse, three periods were identified during which differences in the forces between the left and right forelimbs exceeded the critical threshold (p < .01). Discussion Traditional statistical analysis of 2D GRF peak values, summary vector variables and visual evaluation of force vector diagrams gave harmonious results and both methods identified the same inter-limb asymmetries. As alpha was more tightly controlled using SPM, significance was only found in the individual horse although T2 plots followed the same trends as discrete analysis for the group. Conclusions The techniques of force vector analysis and SPM hold promise for investigations of sidedness and asymmetry in horses

    The Law of Genetic Privacy: Applications, Implications, and Limitations

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    Recent advances in technology have significantly improved the accuracy of genetic testing and analysis, and substantially reduced its cost, resulting in a dramatic increase in the amount of genetic information generated, analysed, shared, and stored by diverse individuals and entities. Given the diversity of actors and their interests, coupled with the wide variety of ways genetic data are held, it has been difficult to develop broadly applicable legal principles for genetic privacy. This article examines the current landscape of genetic privacy to identify the roles that the law does or should play, with a focus on federal statutes and regulations, including the Health Insurance Portability and Accountability Act (HIPAA) and the Genetic Information Nondiscrimination Act (GINA). After considering the many contexts in which issues of genetic privacy arise, the article concludes that few, if any, applicable legal doctrines or enactments provide adequate protection or meaningful control to individuals over disclosures that may affect them. The article describes why it may be time to shift attention from attempting to control access to genetic information to considering the more challenging question of how these data can be used and under what conditions, explicitly addressing trade-offs between individual and social goods in numerous applications

    The silicon trypanosome

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    African trypanosomes have emerged as promising unicellular model organisms for the next generation of systems biology. They offer unique advantages, due to their relative simplicity, the availability of all standard genomics techniques and a long history of quantitative research. Reproducible cultivation methods exist for morphologically and physiologically distinct life-cycle stages. The genome has been sequenced, and microarrays, RNA-interference and high-accuracy metabolomics are available. Furthermore, the availability of extensive kinetic data on all glycolytic enzymes has led to the early development of a complete, experiment-based dynamic model of an important biochemical pathway. Here we describe the achievements of trypanosome systems biology so far and outline the necessary steps towards the ambitious aim of creating a , a comprehensive, experiment-based, multi-scale mathematical model of trypanosome physiology. We expect that, in the long run, the quantitative modelling enabled by the Silicon Trypanosome will play a key role in selecting the most suitable targets for developing new anti-parasite drugs

    Hard X-Rays From Supernova 1993J

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    The OSSE experiment on the Compton Observatory observed SN 1993J during three intervals, approximately 9--15, 23--36, and 93--121 days after outburst. There is evidence for continuum emission below 200 keV in the first two of these periods. Power-law fits yield intensities at 100 keV of (1.82+/-0.39)*E(-3) photons cm(-2) s(-1) MeV(-1) and (0.89+/-0.35)*E(-3) photons cm(-2) s(-1) MeV(-1) , and photon indices of -2.3+/-0.5 and -2.2+/-0.9, respectively. There is no evidence for any emission in the longer, more sensitive, third observation. These continua are too bright and too steep to be entirely due to Comptonized gamma-rays from radioactive (56) Ni and (56) Co alone. A thermal bremsstrahlung spectrum, for example, also adequately describes the OSSE data, with kT =~ 75 keV. These continua extrapolate well above nearly contemporaneous measurements at lower energies. Instead, a power-law of fixed photon index -1.2 fit to the first OSSE observation extrapolates approximately to the total luminosity measured by ASCA (Tanaka IAU Circ. 5753) from 1--10 keV, one day earlier. For a thermal spectrum a higher temperature, near 200 keV, can also fit both data sets---but only marginally. This emission cannot be unambiguously attributed to SN 1993J. Because of the large OSSE field of view, SN 1993J cannot be separated from other sources such as the nucleus of M81 or even M82. However, OSSE did observe this region twice earlier, 597 and 443 days before SN 1993J and no continuum emission was detected at either time. The apparent decline of the emission does seem to correlate well with those of SN 1993J as seen by ASCA and ROSAT. No evidence for line emission is seen in any observation. This work is supported by NASA DPR S-10987C

    Antithymocyte Globulin Plus G-CSF Combination Therapy Leads to Sustained Immunomodulatory and Metabolic Effects in a Subset of Responders With Established Type 1 Diabetes.

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    Low-dose antithymocyte globulin (ATG) plus pegylated granulocyte colony-stimulating factor (G-CSF) preserves β-cell function for at least 12 months in type 1 diabetes. Herein, we describe metabolic and immunological parameters 24 months following treatment. Patients with established type 1 diabetes (duration 4-24 months) were randomized to ATG and pegylated G-CSF (ATG+G-CSF) (N = 17) or placebo (N = 8). Primary outcomes included C-peptide area under the curve (AUC) following a mixed-meal tolerance test (MMTT) and flow cytometry. "Responders" (12-month C-peptide ≥ baseline), "super responders" (24-month C-peptide ≥ baseline), and "nonresponders" (12-month C-peptide &lt; baseline) were evaluated for biomarkers of outcome. At 24 months, MMTT-stimulated AUC C-peptide was not significantly different in ATG+G-CSF (0.49 nmol/L/min) versus placebo (0.29 nmol/L/min). Subjects treated with ATG+G-CSF demonstrated reduced CD4+ T cells and CD4+/CD8+ T-cell ratio and increased CD16+CD56hi natural killer cells (NK), CD4+ effector memory T cells (Tem), CD4+PD-1+ central memory T cells (Tcm), Tcm PD-1 expression, and neutrophils. FOXP3+Helios+ regulatory T cells (Treg) were elevated in ATG+G-CSF subjects at 6, 12, and 18 but not 24 months. Immunophenotyping identified differential HLA-DR expression on monocytes and NK and altered CXCR3 and PD-1 expression on T-cell subsets. As such, a group of metabolic and immunological responders was identified. A phase II study of ATG+G-CSF in patients with new-onset type 1 diabetes is ongoing and may support ATG+G-CSF as a prevention strategy in high-risk subjects

    Environmental interventions to reduce fear of crime: systematic review of effectiveness

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    Background: Fear of crime is associated with negative health and wellbeing outcomes, and may mediate some impacts of the built environment on public health. A range of environmental interventions have been hypothesized to reduce the fear of crime. Methods: This review aimed to synthesize the literature on the effectiveness of interventions in the built environment to reduce the fear of crime. Systematic review methodology, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance, was used. Studies of environmental interventions which reported a fear of crime outcome and used any prospective evaluation design (randomized controlled trial (RCT), trial or uncontrolled before-and-after study) were included. Eighteen databases were searched. The Hamilton tool was used to assess quality. A narrative synthesis of findings was undertaken. Results: A total of 47 studies were included, 22 controlled and 25 uncontrolled, with total sample sizes ranging from n = 52 to approximately n = 23,000. Thirty-six studies were conducted in the UK, ten studies in the USA and one study in the Netherlands. The quality of the evidence overall is low. There are some indications that home security improvements and non-crime-related environmental improvements may be effective for some fear of crime outcomes. There is little evidence that the following reduce fear of crime: street lighting improvements, closed-circuit television (CCTV), multi-component environmental crime prevention programs or regeneration programs. Conclusions: There is some evidence for the effectiveness of specific environmental interventions in reducing some indicators of fear of crime, but more attention to the context and possible confounders is needed in future evaluations of complex social interventions such as these

    Proinsulin-Reactive CD4 T Cells in the Islets of Type 1 Diabetes Organ Donors

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    Proinsulin is an abundant protein that is selectively expressed by pancreatic beta cells and has been a focus for development of antigen-specific immunotherapies for type 1 diabetes (T1D). In this study, we sought to comprehensively evaluate reactivity to preproinsulin by CD4 T cells originally isolated from pancreatic islets of organ donors having T1D. We analyzed 187 T cell receptor (TCR) clonotypes expressed by CD4 T cells obtained from six T1D donors and determined their response to 99 truncated preproinsulin peptide pools, in the presence of autologous B cells. We identified 14 TCR clonotypes from four out of the six donors that responded to preproinsulin peptides. Epitopes were found across all of proinsulin (insulin B-chain, C-peptide, and A-chain) including four hot spot regions containing peptides commonly targeted by TCR clonotypes derived from multiple T1D donors. Of importance, these hot spots overlap with peptide regions to which CD4 T cell responses have previously been detected in the peripheral blood of T1D patients. The 14 TCR clonotypes recognized proinsulin peptides presented by various HLA class II molecules, but there was a trend for dominant restriction with HLA-DQ, especially T1D risk alleles DQ8, DQ2, and DQ8-trans. The characteristics of the tri-molecular complex including proinsulin peptide, HLA-DQ molecule, and TCR derived from CD4 T cells in islets, provides an essential basis for developing antigen-specific biomarkers as well as immunotherapies
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