Effect of Nordic hamstring exercise and straight leg deadlift on hamstring fatigue post repeated sprint

The purpose of this study was to investigate whether the nordic hamstring exercise (NHE) or straight leg deadlift (SLD) had greater effect of fascicle length (FL), pennation angle (PA) as well as peak force (PF) following a repeated sprint fatiguing protocol. The NHE uses short muscle contractions while the SLD uses long muscle contractions, the effects each exercise has on the maintenance of peak force following repeated sprints was of interest. Eighteen youth football players playing at a professional Football League 1 club were randomly allocated into 2 groups, NHE and SLD. A pre- test-post- test experimental design was utilised with each participant performing 12 progressive strength sessions over a 6- week period. Each participant performed 15 x 30 meter repeated sprints followed by a Nordbord PF measurement both pre and post training intervention. Both PA and FL were measured by means of ultrasound. The Results state that PF was higher in the SLD group post training intervention (P < 0.05) there was no significant difference in the NHE group. The SLD group also showed a medium effect size d=.55 while the NHE group showed a small effect size d= .24. Mean PA was significantly higher post intervention compared to pre intervention in the SLD group only (P < 0.05), there was also a medium effect size d=.59 while the NHE group showed a small effect size d=.16. Similarly, the FL score was significantly higher post intervention than pre intervention, however, only in the SLD group (P < 0.05) there was also a medium effect size d=.68 while the NHE group showed a small effect size d=.12. The SLD may be an appropriate exercise in order to reduce the effects of fatigue in the hamstrings during repeated sprint activity as well as induce positive architectural changes in the hamstring muscles. The findings in this study offer what may be a novel method for training the hamstrings in order to reduce the effects of fatigue. The findings suggest that this may be an appropriate pilot study for future research

Effect of Nordic hamstring exercise and straight leg deadlift on hamstring fatigue post repeated sprint

The purpose of this study was to investigate whether the nordic hamstring exercise (NHE) or straight leg deadlift (SLD) had greater effect of fascicle length (FL), pennation angle (PA) as well as peak force (PF) following a repeated sprint fatiguing protocol. The NHE uses short muscle contractions while the SLD uses long muscle contractions, the effects each exercise has on the maintenance of peak force following repeated sprints was of interest. Eighteen youth football players playing at a professional Football League 1 club were randomly allocated into 2 groups, NHE and SLD. A pre- test-post- test experimental design was utilised with each participant performing 12 progressive strength sessions over a 6- week period. Each participant performed 15 x 30 meter repeated sprints followed by a Nordbord PF measurement both pre and post training intervention. Both PA and FL were measured by means of ultrasound. The Results state that PF was higher in the SLD group post training intervention (P < 0.05) there was no significant difference in the NHE group. The SLD group also showed a medium effect size d=.55 while the NHE group showed a small effect size d= .24. Mean PA was significantly higher post intervention compared to pre intervention in the SLD group only (P < 0.05), there was also a medium effect size d=.59 while the NHE group showed a small effect size d=.16. Similarly, the FL score was significantly higher post intervention than pre intervention, however, only in the SLD group (P < 0.05) there was also a medium effect size d=.68 while the NHE group showed a small effect size d=.12. The SLD may be an appropriate exercise in order to reduce the effects of fatigue in the hamstrings during repeated sprint activity as well as induce positive architectural changes in the hamstring muscles. The findings in this study offer what may be a novel method for training the hamstrings in order to reduce the effects of fatigue. The findings suggest that this may be an appropriate pilot study for future research

The use of equine influenza pseudotypes for serological screening

Standard assays used for influenza serology present certain practical issues, such as inter-laboratory variability, complex protocols and the necessity for handling certain virus strains in high biological containment facilities. In an attempt to address this, avian and human influenza HA pseudotyped retroviruses have been successfully employed in antibody neutralization assays. In this study we generated an equine influenza pseudotyped lentivirus for serological screening. This was achieved by co-transfection of HEK293T cells with plasmids expressing the haemagglutinin (HA) protein of an H3N8 subtype equine influenza virus strain, HIV gag-pol and firefly luciferase reporter genes and harvesting virus from supernatant. In order to produce infective pseudotype particles it was necessary to additionally co-transfect a plasmid encoding the TMPRSS2 endoprotease to cleave the HA. High titre pseudotype virus (PV) was then used in PV antibody neutralization assays (PVNAs) to successfully distinguish between vaccinated and non-vaccinated equines. The sera were also screened by single radial haemolysis (SRH) assay. There was a 65% correlation between the results of the two assays, with the PVNA assay appearing slightly more sensitive. Future work will extend the testing of the PVNA with a larger number of serum samples to assess sensitivity/specificity, inter/intra-laboratory variability and to define a protective titre

Treatment of chronic pain for adults 65 and over: analyses of outcomes and changes in psychological flexibility following interdisciplinary acceptance and commitment therapy (ACT)

Objective. The purpose of this study was to examine the effectiveness of acceptance and commitment therapy (ACT) for older adults with chronic pain. Secondarily, we examined the associations between changes on processes of psychological flexibility and treatment outcome variables. Subjects. Participants were 60 adults with chronic pain age 65 and older selected from a larger consecutive sample of 928 adults of any age. All participants had longstanding pain that was associated with significant distress and disability. Methods. Participants completed measures of pain, functioning, and depression, and processes of psychological flexibility at baseline, immediately posttreatment, and at a 9-month follow-up. Treatment consisted of a 2- or 4-week residential program based on principles of ACT delivered by an interdisciplinary team. Treatment was designed to increase daily functioning by enhancing key processes of psychological flexibility, including openness, awareness, and committed action. Results. Participants showed significant improvements in functioning and mental health at posttreatment. Participants also showed significant increases in pain acceptance and committed action from pre to post-treatment. Small effect sizes were observed for most treatment outcome and process variables in the pre-treatment to follow-up intervals; however, these improvements were not statistically significant. In secondary analyses, changes in facets of psychological flexibility were significantly associated with improvements in social functioning and mental health. Conclusion. This study supports the potential effectiveness of ACT for chronic pain among older adults. Future research is needed to determine how to maximize the impact of this treatment, particularly through greater impact on psychological flexibility

Single-molecule studies of nucleic acid dynamics using carbon nanotube-based field-effect transistors

This thesis describes the development and implementation of single-molecule carbon nanotube-based field-effect transistors (smFETs) for studies of nucleic acid dynamics. Single-molecule techniques, most notably fluorescence resonance energy transfer (smFRET) and single-molecule force spectroscopy, have been employed to investigate biomolecular dynamics due to their ability to directly observe discrete, rare events, as well as to characterize structural motions in a diverse ensemble. However, these techniques are hampered by difficulties in measuring millisecond-scale dynamics, such as base pair rearrangements, as well as the inability to observe unperturbed individual molecules for long times. Alternatively, smFETs allow observation of the dynamics of charged biomolecules, such as charged amino acids in proteins or the phosphate groups of nucleic acid backbones, with microsecond temporal resolution. Structural rearrangements of a single charged molecule on the surface of a single-walled carbon nanotube (CNT) transistor can lead to measureable fluctuations in conductance through the CNT. Thus, this technique allows for simultaneous characterization of fast events and, due to the label-free and minimally-invasive nature of smFET technology, the quantification of how the frequency of these events change over long time-scales. A portion of this work describes smFET fabrication, focusing on improvements to the functionalization method, a critical step to reliably generate individual attachment sites on the CNT for subsequent single-molecule studies. A new synthetic chemistry approach is performed in ultraminiaturized, nanofabricated reaction chambers; using lithographically-defined nanowells, single-point attachments are achieved on hundreds of individual carbon nanotube transistors, providing robust statistics and unprecedented spatial control in adduct positioning. Each device acts as a sensor to detect, in real-time and through quantized changes in conductance, single-point functionalization of the nanotube, as well as consecutive chemical reactions and subsequent molecular interactions molecular conformational changes. In particular, this thesis is focused on studying the dynamics of nucleic acids using smFET technology. First, the smFET technique presented is verified by studying the thermodynamics and kinetics of DNA hybridization, the results of which compare favorably both with predicted values and previous smFET studies using alternative device architectures. Next, the reversible folding of a single-stranded telomeric DNA sequence known to form a G-quadruplex structure is studied, revealing the characteristic increased stability of the G-quadruplex structure in the presence of potassium ions relative to sodium ions. Finally, smFET studies of the dynamics of the adenine-sensing pbuE riboswitch aptamer found in Bacillus subtilis are discussed. These results demonstrate how long-lived, ligand-dependent intermediates form at a base-pair level and suggest that these intermediates have consequences for riboswitch-regulation by adenine binding to the aptamer. With the increased time resolution of smFET technology, this work has achieved the first observation of RNA zipping and unzipping at the single-molecule level, as well as label-free observations of the effects of a three-way junction motif on helix zipping and unzipping

The Optimisation of Pseudotyped Viruses for the Characterisation of Immune Responses to Equine Influenza Virus

Pseudotyped viruses (PVs) produced by co-transfecting cells with plasmids expressing lentiviral core proteins and viral envelope proteins are potentially powerful tools for studying various aspects of equine influenza virus (EIV) biology. The aim of this study was to optimise production of equine influenza PVs. Co-transfection of the HAT protease to activate the haemagglutinin (HA) yielded a higher titre PV than TMPRSS2 with the HA from A/equine/Richmond/1/2007 (H3N8), whereas for A/equine/Newmarket/79 (H3N8), both proteases resulted in equivalent titres. TMPRSS4 was ineffective with the HA of either strain. There was also an inverse relationship between the amount of protease-expression plasmids and the PV titre obtained. Interestingly, the PV titre obtained by co-transfection of a plasmid encoding the cognate N8 NA was not as high as that generated by the addition of exogenous neuraminidase (NA) from Clostridium perfringens to allow the release of nascent PV particles. Finally, initial characterisation of the reliability of PV neutralisation tests (PVNTs) demonstrated good intra-laboratory repeatability. In conclusion, we have demonstrated that equine influenza PV production can be readily optimised to provide a flexible tool for studying EIV

A systematic review of the effect of individualized risk communication strategies on screening uptake and its psychological predictors: the role of psychology theory

People might be more likely to attend for health screening if they are told their individual risk of an illness. The way this risk of ill-health is communicated might have an effect on screening uptake or its psychological proxies. It is possible that the format, presentation, and details of the information as well as the complexity of an intervention and use of psychological theory to inform the intervention may impact the effectiveness of individual risk communication. This systematic review collates, analyses and synthesizes the evidence for effectiveness of these aspects of individual risk communication. The synthesis indicated that written, individualized risk scores or categories are effective at supporting screening uptake and its psychological proxies. Complex, or theory-based interventions, surprisingly, are no more effective than simpler or atheoretical interventions

Spatio-Velocity CSF as a Function of Retinal Velocity Using Unstabilized Stimuli

LCD televisions have LC response times and hold-type data cycles that contribute to the appearance of blur when objects are in motion on the screen. New algorithms based on studies of the human visual system\u27s sensitivity to motion are being developed to compensate for these artifacts. This paper describes a series of experiments that incorporate eyetracking in the psychophysical determination of spatio-velocity contrast sensitivity in order to build on the 2D spatiovelocity contrast sensitivity function (CSF) model first described by Kelly and later refined by Daly. We explore whether the velocity of the eye has an additional effect on sensitivity and whether the model can be used to predict sensitivity to more complex stimuli. There were a total of five experiments performed in this research. The first four experiments utilized Gabor patterns with three different spatial and temporal frequencies and were used to investigate and/or populate the 2D spatio-velocity CSF. The fifth experiment utilized a disembodied edge and was used to validate the model. All experiments used a two interval forced choice (2IFC) method of constant stimuli guided by a QUEST routine to determine thresholds. The results showed that sensitivity to motion was determined by the retinal velocity produced by the Gabor patterns regardless of the type of motion of the eye. Based on the results of these experiments the parameters for the spatio-velocity CSF model were optimized to our experimental conditions