Cell Size: Chromosomes Get Slapped by a Midzone Ruler

SummarySpatial and temporal coordination of mitotic events has been generally attributed to the coincidental outcome of increasing cyclin-dependent kinase activity. A recent study reports that mitotic events and structures previously considered to be independently controlled are capable of trans-regulation to ensure genomic integrity

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

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

Addressing the programming challenges of practical interferometric mesh based optical processors

We demonstrate a novel mesh of Mach-Zehnder interferometers (MZIs) for programmable optical processors. The proposed mesh, referred to as Bokun mesh, is an architecture that merges the attributes of the prior topologies Diamond and Clements. Similar to Diamond, Bokun provides diagonal paths passing through every individual MZI enabling direct phase monitoring. However, unlike Diamond and similar to Clements, Bokun maintains a minimum optical depth leading to better scalability. Providing the monitoring option, Bokun's programming is faster improving the total energy efficiency of the processor. The performance of Bokun mesh enabled by an optimal optical depth is also more resilient to the loss and fabrication imperfections compared to architectures with longer depth such as Reck and Diamond. Employing an efficient programming scheme, the proposed architecture improves energy efficiency by 83% maintaining the same computation accuracy for weight matrix changes at 2 kHz

The Empirical Power of Rare Variant Association Methods: Results from Sanger Sequencing in 1,998 Individuals

The role of rare genetic variation in the etiology of complex disease remains unclear. However, the development of next-generation sequencing technologies offers the experimental opportunity to address this question. Several novel statistical methodologies have been recently proposed to assess the contribution of rare variation to complex disease etiology. Nevertheless, no empirical estimates comparing their relative power are available. We therefore assessed the parameters that influence their statistical power in 1,998 individuals Sanger-sequenced at seven genes by modeling different distributions of effect, proportions of causal variants, and direction of the associations (deleterious, protective, or both) in simulated continuous trait and case/control phenotypes. Our results demonstrate that the power of recently proposed statistical methods depend strongly on the underlying hypotheses concerning the relationship of phenotypes with each of these three factors. No method demonstrates consistently acceptable power despite this large sample size, and the performance of each method depends upon the underlying assumption of the relationship between rare variants and complex traits. Sensitivity analyses are therefore recommended to compare the stability of the results arising from different methods, and promising results should be replicated using the same method in an independent sample. These findings provide guidance in the analysis and interpretation of the role of rare base-pair variation in the etiology of complex traits and diseases

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

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

A Randomized Clinical Trial Comparing Individual Cognitive Behavioral Therapy and Child-Centered Therapy for Child Anxiety Disorders

This study compared individual cognitive behavioral therapy (CBT) and a supportive child-centered therapy (CCT) for child anxiety disorders on rates of treatment response and recovery at posttreatment and 1-year follow-up, as well as on real-world measures of emotional functioning. Youth (N = 133; ages 9–14) with anxiety disorders (generalized, separation, and/or social anxiety) were randomized using a 2:1 ratio to CBT (n = 90) or CCT (n = 43), which served as an active comparison. Treatment response and recovery at posttreatment and 1-year follow-up were assessed by Independent Evaluators, and youth completed ecological momentary assessment of daily emotions throughout treatment. The majority of youth in both CBT and CCT were classified as treatment responders (71.1% for CBT, 55.8% for CCT), but youth treated with CBT were significantly more likely to fully recover, no longer meeting diagnostic criteria for any of the targeted anxiety disorders and no longer showing residual symptoms (66.7% for CBT vs. 46.5% for CCT). Youth treated with CBT also reported significantly lower negative emotions associated with recent negative events experienced in daily life during the latter stages of treatment relative to youth treated with CCT. Furthermore, a significantly higher percentage of youth treated with CBT compared to CCT were in recovery at 1-year follow-up (82.2% for CBT vs. 65.1% for CCT). These findings indicate potential benefits of CBT above and beyond supportive therapy on the breadth, generalizability, and durability of treatment-related gains

The interaction of gambling outcome and gambling harm-minimisation strategies for electronic gambling: the efficacy of computer generated self-appraisal messaging

It has been argued that generating pop-up messages during electronic gambling sessions, which cause a player to engage in self-appraisal of their gambling behaviour, instil greater control and awareness of behaviour (Monaghan, Computers in Human Behaviour, 25, 202–207, 2009). Consideration for the potential interaction between the messaging’s efficacy and gambling outcome (winning or losing) is lacking however. Thirty participants took part in a repeated-measures experiment where they gambled on the outcome of a computer-simulated gambling task. Outcome was manipulated by the experimenter to induce winning and losing streaks. Participants gambled at a significantly faster speed and a higher average stake size, which resulted in a greater betting intensity in the Loss condition compared to the Win condition. Computer generated self-appraisal messaging was then applied during the gambling session, which was able to significantly reduce the average speed of betting in the Loss condition only, demonstrating an interaction effect between computer generated messaging and gambling outcome

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