Influence of stair descent strategies and step height on centre of mass and gait kinetics in the elderly

Age-associated alterations in balance mechanisms and deteriorations in muscle strength may necessitate alternate stair descent strategies to ensure safe negotiation. The aim of the study was to compare the influence of increased step height and stair negotiation strategies; step-over-step (SoS) and step-by-step (SbS) on gait patterns in the elderly. Eleven elderly participants descended a four step custom built instrumented staircase at a self-selected speed. Participants descended using a SoS or SbS strategy on two step configurations: a rise height of 170mm (STD) and a rise height of 255mm (INC). A 3D motion analysis system synchronised with force platforms embedded into the staircase, was used to capture whole body centre of mass (CoM) velocity, acceleration and kinetic data of the leading limb.Compared to STDSoS, STDSbS resulted in reduced CoM vertical (-0.48m/s vs -0.09m/s) and A/P velocity (0.50m/s vs 0.21m/s) during late stance and swing transition with similar reductions in vertical and A/P velocity in INCSoS vs INCSbS (-0.67m/s vs -0.11m/s and 0.49m/s vs 0.23m/s). INCSoS resulted in increased plantarflexor (1.10Nm/kg vs 1.45Nm/kg) and hip extensor moment (-0.08Nm/kg vs 0.43Nm/kg) compared to STDSoS with no differences seen in SbS strategy. An alternate stair descent strategy offers greater CoM control in the potentially dangerous transition between stance and swing. Concurrently, the tandem double stance period negates the need for increased muscle moments in late stance required to eccentrically control the falling body mass in the traditional SoS strategy. SbS could offer increased CoM control and stability during stair descent

A universal protocol to generate consensus level genome sequences for foot-and-mouth disease virus and other positive-sense polyadenylated RNA viruses using the Illumina MiSeq

BACKGROUND: Next-Generation Sequencing (NGS) is revolutionizing molecular epidemiology by providing new approaches to undertake whole genome sequencing (WGS) in diagnostic settings for a variety of human and veterinary pathogens. Previous sequencing protocols have been subject to biases such as those encountered during PCR amplification and cell culture, or are restricted by the need for large quantities of starting material. We describe here a simple and robust methodology for the generation of whole genome sequences on the Illumina MiSeq. This protocol is specific for foot-and-mouth disease virus (FMDV) or other polyadenylated RNA viruses and circumvents both the use of PCR and the requirement for large amounts of initial template. RESULTS: The protocol was successfully validated using five FMDV positive clinical samples from the 2001 epidemic in the United Kingdom, as well as a panel of representative viruses from all seven serotypes. In addition, this protocol was successfully used to recover 94% of an FMDV genome that had previously been identified as cell culture negative. Genome sequences from three other non-FMDV polyadenylated RNA viruses (EMCV, ERAV, VESV) were also obtained with minor protocol amendments. We calculated that a minimum coverage depth of 22 reads was required to produce an accurate consensus sequence for FMDV O. This was achieved in 5 FMDV/O/UKG isolates and the type O FMDV from the serotype panel with the exception of the 5′ genomic termini and area immediately flanking the poly(C) region. CONCLUSIONS: We have developed a universal WGS method for FMDV and other polyadenylated RNA viruses. This method works successfully from a limited quantity of starting material and eliminates the requirement for genome-specific PCR amplification. This protocol has the potential to generate consensus-level sequences within a routine high-throughput diagnostic environment

Alternate stair descent strategies for reducing joint moment demands in older individuals.

Descending stairs requires elevated joint moment-generating capability in the lower limbs, making it a challenging daily activity, particularly for older individuals. The aim of the study was to investigate the influence of three different strategies for descending standard and increased height stairs: step-over-step (SoS), step-by-step (SbS) and side-step (SS) on lower limb kinetics in older people. Eleven participants (mean ± SD age: 74.8 ± 3.1 years, height: 1.63 ± 0.07 m, mass: 67.7 ± 9.5 kg) descended a four-step custom built instrumented staircase at a self-selected speed, adopting each of the three strategies, at two configurations: a step-rise height of 170 mm (standard; STD) and a step-rise height of 255 mm (increased; INC). 3D motion capture, synchronised with embedded force plates enabled the calculation of joint kinetics of lead and trail limbs. Data were analysed using a Linear Mixed Model with gait speed selected as a covariate during weight acceptance (WA) and controlled lowering (CL) phases. A large increase in hip extensor moment in both WA and CL in the lead limb was evident during both SoS and SbS at INC step height compared to STD (P < .015 for all), with no such increase in hip flexor moment evident in SS strategy (P = .519). Lead limb knee extensor moment decreased and plantarflexor moment increased in INC SoS compared to STD SoS during CL (P < .001 for both). In the trail limb, increased hip extensor and plantarflexor moments were seen in INC SS compared to STD SS (P < .001 for both). The alternate strategies result in the overall task demand being split between the lead limb (weight acceptance) and trail limb (controlled lowering). Differential demand distribution patterns exist between strategies that imply targeted interventions and/or advice could be provided to older individuals in order to promote safe descent of stairs, particularly for those with specific muscle weaknesses or at high risk of falls

Control of the Centre of Mass during different stair descent strategies in the elderly

The elderly are at an increased risk of falls and trips during stair descent due to the increased musculoskeletal demand imposed by this task (Reeves et al. 2008). Reduced functional capacity, muscle recruitment, coordination or strength may limit the ability to adjust the limb to safely control the body in instances of unexpected instability (Buckley et al. 2013). The aim of this study was to determine how the elderly controlled their centre of mass (CoM) during different stair descent strategies. Eleven elderly participants descended a four step custom built instrumented staircase at a self-selected speed. Two step configurations were tested: 1) a standard rise height of 170mm using a step over step strategy (STD SoS) and 2) a rise height of 255mm using step over step, (INC SoS), step by step (INC SbS) and side step (INC SS) strategies. The going stayed constant at 280mm. Centre of pressure (CoP) and whole body model accelerations and A/P displacement were captured at 1080Hz and 120Hz respectively. Data were analysed using a repeated measures GLM. Significance was accepted at p<0.05.Significantly reduced CoP-CoM A/P separation during the landing phase was evident in STD SoS compared to INC SoS and INC SbS (6.1vs10.6 and 10.7cm, p<0.05). INC SS resulted in significantly greater separation during mid-stance compared to STD SoS, INC SbS, INC SS (10.4vs-4.3,-2.2,-2.5cm, p<0.01). During toe off, INC SbS resulted in a larger A/P acceleration compared to STD SoS and INC SoS (0.8vs-0.7 and -1.0m/s/s, p<0.01) with a reduced CoP-CoM separation compared to INC SoS and INC SS (2.5vs10.0 and 6.2cm, p<0.02).The capability of the elderly to control their CoM during stair descent can fluctuate. During the landing phase a greater posterior ‘lean’ towards the staircase occurs with increased step rise, which could reduce the eccentric muscle action necessary to control lowering of the CoM. This lean was maintained by the SS strategy during mid-stance suggesting that this approach provides a mechanism for a safer single limb support. However, this strategy resulted in a simultaneous rapid CoM acceleration (1m/s/s) and large CoP-CoM separation (10cm) prior to toe off, indicating an unstable and potentially dangerous transition into swing. Whilst the INC SbS strategy also resulted in a large peak acceleration, a smaller CoP-CoM separation (1.2cm) occurred at a slower rate (0.07m/s/s) during this transition. This INC SbS strategy could offer increased CoM control, stability and support during stair descent

The relationship between structural game characteristics and gambling behavior: a population-level study

The aim of this study was to examine the relationship between the structural characteristics and gambling behavior among video lottery terminal (VLT) gamblers. The study was ecological valid, because the data consisted of actual gambling behavior registered in the participants natural gambling environment without intrusion by researchers. Online behavioral tracking data from Multix, an eight game video lottery terminal, were supplied by Norsk-Tipping (the state owned gambling company in Norway). The sample comprised the entire population of Multix gamblers (N = 31,109) who had gambled in January 2010. The individual number of bets made across games was defined as the dependent variable, reward characteristics of a game (i.e., payback percentage, hit frequency, size of winnings and size of jackpot) and bet characteristics of a game (i.e., range of betting options and availability of advanced betting options) served as the independent variables. Control variables were age and gender. Two separate cross-classified multilevel random intercepts models were used to analyze the relationship between bets made, reward characteristics and bet characteristics, where the number of bets was nested within both individuals and within games. The results show that the number of bets is positively associated with payback percentage, hit frequency, being female and age, and negatively associated with size of wins and range of available betting options. In summary, the results show that the reward characteristics and betting options explained 27 % and 15 % of the variance in the number of bets made, respectively. It is concluded that structural game characteristics affect gambling behavior. Implications of responsible gambling are discussed

Phylodynamics of foot-and-mouth disease virus O/PanAsia in Vietnam 2010-2014

© 2017 The Author(s). Foot-and-mouth disease virus (FMDV) is endemic in Vietnam, a country that plays an important role in livestock trade within Southeast Asia. The large populations of FMDV-susceptible species in Vietnam are important components of food production and of the national livelihood. In this study, we investigated the phylogeny of FMDV O/PanAsia in Vietnam, reconstructing the virus' ancestral host species (pig, cattle or buffalo), clinical stage (subclinical carrier or clinically affected) and geographical location. Phylogenetic divergence time estimation and character state reconstruction analyses suggest that movement of viruses between species differ. While inferred transmissions from cattle to buffalo and pigs and from pigs to cattle are well supported, transmission from buffalo to other species, and from pigs to buffalo may be less frequent. Geographical movements of FMDV O/PanAsia virus appears to occur in all directions within the country, with the South Central Coast and the Northeast regions playing a more important role in FMDV O/PanAsia spread. Genetic selection of variants with changes at specific sites within FMDV VP1 coding region was different depending on host groups analyzed. The overall ratio of non-synonymous to synonymous nucleotide changes was greater in pigs compared to cattle and buffalo, whereas a higher number of individual amino acid sites under positive selection were detected in persistently infected, subclinical animals compared to viruses collected from clinically diseased animals. These results provide novel insights to understand FMDV evolution and its association with viral spread within endemic countries. These findings may support animal health organizations in their endeavor to design animal disease control strategies in response to outbreaks

Assessing Internet addiction using the parsimonious Internet addiction components model - a preliminary study [forthcoming]

Internet usage has grown exponentially over the last decade. Research indicates that excessive Internet use can lead to symptoms associated with addiction. To date, assessment of potential Internet addiction has varied regarding populations studied and instruments used, making reliable prevalence estimations difficult. To overcome the present problems a preliminary study was conducted testing a parsimonious Internet addiction components model based on Griffiths’ addiction components (2005), including salience, mood modification, tolerance, withdrawal, conflict, and relapse. Two validated measures of Internet addiction were used (Compulsive Internet Use Scale [CIUS], Meerkerk et al., 2009, and Assessment for Internet and Computer Game Addiction Scale [AICA-S], Beutel et al., 2010) in two independent samples (ns = 3,105 and 2,257). The fit of the model was analysed using Confirmatory Factor Analysis. Results indicate that the Internet addiction components model fits the data in both samples well. The two sample/two instrument approach provides converging evidence concerning the degree to which the components model can organize the self-reported behavioural components of Internet addiction. Recommendations for future research include a more detailed assessment of tolerance as addiction component

Deletion of the GABAA α2-subunit does not alter self dministration of cocaine or reinstatement of cocaine seeking

Rationale GABAA receptors containing α2-subunits are highly represented in brain areas that are involved in motivation and reward, and have been associated with addiction to several drugs, including cocaine. We have shown previously that a deletion of the α2-subunit results in an absence of sensitisation to cocaine. Objective We investigated the reinforcing properties of cocaine in GABAA α2-subunit knockout (KO) mice using an intravenous self-administration procedure. Methods α2-subunit wildtype (WT), heterozygous (HT) and KO mice were trained to lever press for a 30 % condensed milk solution. After implantation with a jugular catheter, mice were trained to lever press for cocaine (0.5 mg/kg/infusion) during ten daily sessions. Responding was extinguished and the mice tested for cue- and cocaine-primed reinstatement. Separate groups of mice were trained to respond for decreasing doses of cocaine (0.25, 0.125, 0.06 and 0.03 mg/kg). Results No differences were found in acquisition of lever pressing for milk. All genotypes acquired self-administration of cocaine and did not differ in rates of self-administration, dose dependency or reinstatement. However, whilst WT and HT mice showed a dose-dependent increase in lever pressing during the cue presentation, KO mice did not. Conclusions Despite a reported absence of sensitisation, motivation to obtain cocaine remains unchanged in KO and HT mice. Reinstatement of cocaine seeking by cocaine and cocaine-paired cues is also unaffected. We postulate that whilst not directly involved in reward perception, the α2-subunit may be involved in modulating the “energising” aspect of cocaine’s effects on reward-seeking

Do Interventions Designed to Support Shared Decision-Making Reduce Health Inequalities? : A Systematic Review and Meta-Analysis

Copyright: © 2014 Durand et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Increasing patient engagement in healthcare has become a health policy priority. However, there has been concern that promoting supported shared decision-making could increase health inequalities. Objective: To evaluate the impact of SDM interventions on disadvantaged groups and health inequalities. Design: Systematic review and meta-analysis of randomised controlled trials and observational studies.Peer reviewe

Using a logical model to predict the growth of yeast

<p>Abstract</p> <p>Background</p> <p>A logical model of the known metabolic processes in <it>S. cerevisiae </it>was constructed from iFF708, an existing Flux Balance Analysis (FBA) model, and augmented with information from the KEGG online pathway database. The use of predicate logic as the knowledge representation for modelling enables an explicit representation of the structure of the metabolic network, and enables logical inference techniques to be used for model identification/improvement.</p> <p>Results</p> <p>Compared to the FBA model, the logical model has information on an additional 263 putative genes and 247 additional reactions. The correctness of this model was evaluated by comparison with iND750 (an updated FBA model closely related to iFF708) by evaluating the performance of both models on predicting empirical minimal medium growth data/essential gene listings.</p> <p>Conclusion</p> <p>ROC analysis and other statistical studies revealed that use of the simpler logical form and larger coverage results in no significant degradation of performance compared to iND750.</p