INFLUENCE OF AGING ON THE DYNAMICS OF LATERAL STABILIZATION IN WALKING, IN DIFFERENT EXPERIHENTAL CONDITIONS RELATED TO SHOE WEARING AND FLOOR HARDNESS

Review of biomechanics literature on the influence of aging on the locomotor system indicates that safe load bearing as well as deformation sustaining capabilities of biological tissues decrease with age. Postural studies of older populations have di8closed more body sway than in younger age groups and have often associated loss of balance with locomotion problems of old age people. On the other hand, biomechanical studies of walking and running have already demonstrated t h a t wearing shoes and shoe characteristics can play an important r o l e in shock absorption. However the influence of aging on the dynamic of lateral stabilization in walking in relationship with shoe wearing and floor hardness has received very little attention. Such a biomechanical approach t o locomotion is becoming more important since more and more older people are involved in sport and fitness activities including some form of locomotion. The present study has been undertaken in order to investigate the influence of aging together with shoe wearing and floor hardness on some of the main components, of lateral stabilization in walking, namely the lateral forces, the lateral impulse and the lateral deviation o f the center of pressure. Three groups of 15 physically active male subjects (17-22, 40-45 and 65-70 years old) were instructed to walk on a tri-dimensional force platform a t a predetermined pace set with a metronome;. Experimental conditions included walking barefoot and with regular shoes, on a hard and a softer surfaces. Kinetic data were recorded on the 5th, 25th, 50th, 100th and 500th steps for each condition, with the use of the computerized . Ariel Performance Analysis System. Analysis of the results disclosed important differences between the age groups in all three experimental parameters. Lower lateral forces exerted by the older age group lead t o the hypothesis of a different stabilization strategy based on energy saving. Findings were also discussed in relationship with the lateral stabilization process and applications were made to sport and fitness activities a s well a s the daily living situations

Spin-guides and spin-splitters: Waveguide analogies in one-dimensional spin chains

Here we show a direct mapping between waveguide theory and spin chain transport, opening an alternative approach to quantum information transport in the solid-state. By applying temporally varying control profiles to a spin chain, we design a virtual waveguide or 'spin-guide' to conduct individual spin excitations along defined space-time trajectories of the chain. We explicitly show that the concepts of confinement, adiabatic bend loss and beamsplitting can be mapped from optical waveguide theory to spin-guides (and hence 'spin-splitters'). Importantly, the spatial scale of applied control pulses is required to be large compared to the inter-spin spacing, and thereby allowing the design of scalable control architectures.Comment: 5 figure

Evaluation of knowledge level of adolescents and adults with congenital heart disease: Effectiveness of a structured CHD education program in adolescents

BackgroundAdolescents with congenital heart disease (CHD) constitute a growing population of individuals for whom a well-planned and well-executed “transition process” is essential. Transition program should include education about medical conditions and promote skills in decision-making and self-care. To improve their level of health related knowledge, a structured education program was implemented in a transition CHD program. This study aimed 1/to evaluate level of knowledge of adolescents who received structured CHD education as compared to adults who did not, 2/to evaluate whether patients who received structured education improve their knowledge.Methods and results42 adolescents (16±2years old, 21 girls) were included in a structured CHD education program and were compared to 22 adults (33±7, 6 women) with CHD who have never followed education program. Knowledge in adolescents was assessed before and after the educational program using questionnaire exploring specific issues related to CHD. A same questionnaire was used in non-educated adult patients. The mean total knowledge score in the educated adolescent group was significantly higher as compared to the non-educated adult with CHD (score=15.6/20±3.6 vs. 12.5±4.5, P<0.01). Provision of structured CHD education and female sex were determinant of higher levels of knowledge. A significant improvement of knowledge was observed in adolescents group after CHD education program (range of increase was 23 to 44%). This result was not influenced by age, sex, education level, socio-economic status of parents and disease complexity, and persists at 10months mean follow-up.ConclusionA structured education program was associated with a higher level of knowledge, above all in male CHD patients. Education at transition period has a significant impact on the adolescent knowledge. Structured education program should improve adult CHD understanding of their heart condition, and could prevent potential complications

Transition from Diffusive to Localized Regimes in Surface Corrugated Optical Waveguides

Exact calculations of the transmittance of surface corrugated optical waveguides are presented. The elastic scattering of diffuse light or other electromagnetic waves from a rough surface induces a diffusive transport along the waveguide axis. As the length of the corrugated part of the waveguide increases, a transition from the diffusive to the localized regime is observed. This involves an analogy with electron conduction in nanowires, and hence, a concept analogous to that of ``resistance'' can be introduced. We show an oscillatory behavior of both the elastic mean free path and the localization length versus the wavelength.Comment: 3 pages, REVTEX, 3 PS figure

Mitotic chromosome length scales in response to both cell and nuclear size

Multicellular development requires that cells reduce in size as a result of consecutive cell divisions without increase in embryo volume. To maintain cellular integrity, organelle size adapts to cell size throughout development. During mitosis, the longest chromosome arm must be shorter than half of the mitotic spindle for proper chromosome segregation. Using high-resolution time-lapse microscopy of living Caenorhabditis elegans embryos, we have quantified the relation between cell size and chromosome length. In control embryos, chromosome length scaled to cell size. Artificial reduction of cell size resulted in a shortening of chromosome length, following a trend predicted by measurements from control embryos. Disturbing the RAN (Ras-related nuclear protein)-GTP gradient decoupled nuclear size from cell size and resulted in chromosome scaling to nuclear size rather than cell size; smaller nuclei contained shorter chromosomes independent of cell size. In sum, quantitative analysis relating cell, nuclear, and chromosome size predicts two levels of chromosome length regulation: one through cell size and a second in response to nuclear size

Pediatric functional magnetic resonance neuroimaging: tactics for encouraging task compliance

<p>Abstract</p> <p>Background</p> <p>Neuroimaging technology has afforded advances in our understanding of normal and pathological brain function and development in children and adolescents. However, noncompliance involving the inability to remain in the magnetic resonance imaging (MRI) scanner to complete tasks is one common and significant problem. Task noncompliance is an especially significant problem in pediatric functional magnetic resonance imaging (fMRI) research because increases in noncompliance produces a greater risk that a study sample will not be representative of the study population.</p> <p>Method</p> <p>In this preliminary investigation, we describe the development and application of an approach for increasing the number of fMRI tasks children complete during neuroimaging. Twenty-eight healthy children ages 9-13 years participated. Generalization of the approach was examined in additional fMRI and event-related potential investigations with children at risk for depression, children with anxiety and children with depression (N = 120). Essential features of the approach include a preference assessment for identifying multiple individualized rewards, increasing reinforcement rates during imaging by pairing tasks with chosen rewards and presenting a visual 'road map' listing tasks, rewards and current progress.</p> <p>Results</p> <p>Our results showing a higher percentage of fMRI task completion by healthy children provides proof of concept data for the recommended tactics. Additional support was provided by results showing our approach generalized to several additional fMRI and event-related potential investigations and clinical populations.</p> <p>Discussion</p> <p>We proposed that some forms of task noncompliance may emerge from less than optimal reward protocols. While our findings may not directly support the effectiveness of the multiple reward compliance protocol, increased attention to how rewards are selected and delivered may aid cooperation with completing fMRI tasks</p> <p>Conclusion</p> <p>The proposed approach contributes to the pediatric neuroimaging literature by providing a useful way to conceptualize and measure task noncompliance and by providing simple cost effective tactics for improving the effectiveness of common reward-based protocols.</p

Reflection and transmission of waves in surface-disordered waveguides

The reflection and transmission amplitudes of waves in disordered multimode waveguides are studied by means of numerical simulations based on the invariant embedding equations. In particular, we analyze the influence of surface-type disorder on the behavior of the ensemble average and fluctuations of the reflection and transmission coefficients, reflectance, transmittance, and conductance. Our results show anomalous effects stemming from the combination of mode dispersion and rough surface scattering: For a given waveguide length, the larger the mode transverse momentum is, the more strongly is the mode scattered. These effects manifest themselves in the mode selectivity of the transmission coefficients, anomalous backscattering enhancement, and speckle pattern both in reflection and transmission, reflectance and transmittance, and also in the conductance and its universal fluctuations. It is shown that, in contrast to volume impurities, surface scattering in quasi-one-dimensional structures (waveguides) gives rise to the coexistence of the ballistic, diffusive, and localized regimes within the same sample.Comment: LaTeX (REVTeX), 12 pages with 14 EPS figures (epsf macro), minor change

An analysis of consumer protection for gamblers across different online gambling operators in Ireland: a descriptive study

The aim of the present study was to evaluate the responsible gambling tools which are available to online gamblers at Irish online gambling websites. The present study used a similar methodology to a recent study carried out on the world’s most popular websites (Bonello and Griffiths Gaming Law Review and Economics, 21, 278–285, 2017), where 50 of the most advertised online gambling websites were evaluated in relation to their responsible gambling (RG) practices. The present study evaluated 39 gambling websites with either a “.ie” or “.com/ie” domain. Each website was evaluated by checking for a number of RG practices, including presence of a dedicated RG page; age verification; access to gambling account history; the availability of RG tools, such as limit setting facilities and exclusion settings; and links to limit-setting options on the deposit page. Descriptive statistics were then performed on the results from each website. Of the 39 online gambling operators identified, 22 redirected gamblers to a “.com” domain, while 17 operators remained as a “.ie” domain. Thirty-five websites (89.7%) visited had a dedicated RG page. Responsible gambling features were evaluated and demonstrated to be available in an inconsistent manner across online gambling websites. Irish websites were shown to perform poorly in comparison with non-Irish counterparts in the provision of RG tools. The researchers of the present study are not aware of any similar studies conducted to date in Ireland

Bidirectional Transmission in an Optical Network on Chip With Bus and Ring Topologies

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Intensity Distribution of Modes in Surface Corrugated Waveguides

Exact calculations of transmission and reflection coefficients in surface randomly corrugated optical waveguides are presented. As the length of the corrugated part of the waveguide increases, there is a strong preference to forward coupling through the lowest mode. An oscillating behavior of the enhanced backscattering as a function of the wavelength is predicted. Although the transport is strongly non isotropic, the analysis of the probability distributions of the transmitted waves confirms in this configuration distributions predicted by Random Matrix Theory for volume disorder