Positioning the Root Elongation Zone Is Saltatory and Receives Input from the Shoot

In the root, meristem and elongation zone lengths remain stable, despite growth and division of cells. To gain insight into zone stability, we imaged individual Arabidopsis thaliana roots through a horizontal microscope, and used image analysis to obtain velocity profiles. For a root, velocity profiles obtained every 5 min over 3 h coincided closely, implying that zonation is regulated tightly. However, the position of the elongation zone saltated, by on average 17 μm every 5 min. Saltation was apparently driven by material elements growing faster and then slower, while moving through the growth zone. When the shoot was excised, after about 90 minutes, growth zone dynamics resembled those of intact roots, except that the position of the elongation zone moved, on average, rootward, by several hundred microns in 24 h. We hypothesize that mechanisms determining elongation zone position receive input from the shoot

Single-crossover dynamics: finite versus infinite populations

Populations evolving under the joint influence of recombination and resampling (traditionally known as genetic drift) are investigated. First, we summarise and adapt a deterministic approach, as valid for infinite populations, which assumes continuous time and single crossover events. The corresponding nonlinear system of differential equations permits a closed solution, both in terms of the type frequencies and via linkage disequilibria of all orders. To include stochastic effects, we then consider the corresponding finite-population model, the Moran model with single crossovers, and examine it both analytically and by means of simulations. Particular emphasis is on the connection with the deterministic solution. If there is only recombination and every pair of recombined offspring replaces their pair of parents (i.e., there is no resampling), then the {\em expected} type frequencies in the finite population, of arbitrary size, equal the type frequencies in the infinite population. If resampling is included, the stochastic process converges, in the infinite-population limit, to the deterministic dynamics, which turns out to be a good approximation already for populations of moderate size.Comment: 21 pages, 4 figure

The 2014 Ontario Child Health Study Emotional Behavioural Scales (OCHS-EBS) Part II: Psychometric Adequacy for Categorical Measurement of Selected DSM-5 Disorders

Objectives: To compare the reliability and convergent validity of parent assessments from the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID—a structured diagnostic interview) and the Ontario Child Health Study Emotional Behavioural Scales (OCHS-EBS) symptom checklist for classifying conduct disorder (CD), conduct disorder or oppositional defiant disorder (CD-ODD), attention-deficit hyperactivity disorder (ADHD), major depressive disorder (MDD), generalized anxiety disorder (GAD), and separation anxiety disorder (SAD) based on DSM-5 criteria. Methods: Data came from 283 parent-youth dyads aged 9 to 18 years. Parents and youth completed the assessments separately on 2 different occasions 7 to 14 days apart. After converting the OCHS-EBS scale scores to binary disorder classifications, we compare test-retest reliability estimates and use structural equation modelling (SEM) to compare estimates of convergent validity for the same disorders assessed by each instrument. Results: Average test-retest reliabilities based on κ were 0.71 (MINI-KID) and 0.67 (OCHS-EBS). The average β coefficients for 3 latent measures comprising the following indicators—parent perceptions of youth mental health need and impairment, diagnosis of specific disorders based on health professional communications and youth taking prescribed medication, and youth classifications of disorder based on the MINI-KID—were 0.67 (MINI-KID) and 0.69 (OCHS-EBS). Conclusion: The OCHS-EBS and MINI-KID achieve comparable levels of reliability and convergent validity for classifying child psychiatric disorder. The flexibility, low cost, and minimal respondent burden of checklists for classifying disorder make them well suited for studying disorder in the general population and screening in clinical settings

The 2014 Ontario Child Health Study Emotional Behavioural Scales (OCHS-EBS) Part I: A Checklist for Dimensional Measurement of Selected DSM-5 Disorders

Objectives: To describe the development and psychometric properties of the 2014 Ontario Child Health Study Emotional Behavioural Scales (OCHS-EBS) for dimensional measurement of 7 disorders based on criteria from the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Methods: Scale items were selected by agreement among 19 child psychologists and psychiatrists rating the correspondence between item descriptions and DSM-5 symptoms. Psychometric evaluation of the item properties and parent/caregiver and youth scales came from a general population study of 10,802 children and youth aged 4 to 17 years in 6537 families. Test-retest reliability data were collected from a subsample of 280 children and their caregivers who independently completed the OCHS-EBS checklist on 2 occasions 7 to 14 days apart. Structural equation modelling was used to assess internal and external convergent and discriminant validity—the latter tested against the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID). Results: Confirmatory factor analyses exhibited adequate item fit to all scales. Except for conduct disorder and youth-assessed separation anxiety disorder, internal (Cronbach’s α) and test-retest reliability (Pearson’s r) for scale scores were 0.70 or above. Except for youth-assessed conduct disorder, the OCHS-EBS met criteria for internal and convergent and discriminant validity. Compared with the MINI-KID, the OCHS-EBS met criteria for external convergent and discriminant validity. Conclusions: The OCHS-EBS provide reliable and valid dimensional measurement of 7 DSM-5 disorders assessed by caregivers and youth in the general population. Part II describes use of the OCHS-EBS as a categorical (present/absent) measure of disorder

A crossover randomised controlled trial of oral mandibular advancement devices for obstructive sleep apnoea-hypopnoea (TOMADO)

Rationale Mandibular advancement devices (MADs) are used to treat obstructive sleep apnoea-hypopnoea syndrome (OSAHS) but evidence is lacking regarding their clinical and cost-effectiveness in less severe disease. Objectives To compare clinical- and cost-effectiveness of a range of MADs against no treatment in mild to moderate OSAHS. Measurements and methods This open-label, randomised, controlled, crossover trial was undertaken at a UK sleep centre. Adults with Apnoea-Hypopnoea Index (AHI) 5–<30/h and Epworth Sleepiness Scale (ESS) score ≥9 underwent 6 weeks of treatment with three nonadjustable MADs: self-moulded (SleepPro 1; SP1); semi-bespoke (SleepPro 2; SP2); fully-bespoke MAD (bMAD); and 4 weeks no treatment. Primary outcome was AHI scored by a polysomnographer blinded to treatment. Secondary outcomes included ESS, quality of life, resource use and cost. Main results 90 patients were randomised and 83 were analysed. All devices reduced AHI compared with no treatment by 26% (95% CI 11% to 38%, p=0.001) for SP1, 33% (95% CI 24% to 41%) for SP2 and 36% (95% CI 24% to 45%, p<0.001) for bMAD. ESS was 1.51 (95% CI 0.73 to 2.29, p<0.001, SP1) to 2.37 (95% CI 1.53 to 3.22, p<0.001, bMAD) lower than no treatment (p<0.001 for all). Compliance was lower for SP1, which was the least preferred treatment at trial exit. All devices were cost-effective compared with no treatment at a £20 000/quality-adjusted life year (QALY) threshold. SP2 was the most cost-effective up to £39 800/QALY. Conclusions Non-adjustable MADs achieve clinically important improvements in mild to moderate OSAHS and are cost-effective

The Recognizability and Localizability of Auditory Alarms: Setting Global Medical Device Standards.

Objective Four sets of eight audible alarms matching the functions specified in IEC 60601-1-8 were designed using known principles from auditory cognition with the intention that they would be more recognizable and localizable than those currently specified in the standard. Background The audible alarms associated with IEC 60601-1-8, a global medical device standard, are known to be difficult to learn and retain, and there have been many calls to update them. There are known principles of design and cognition that might form the basis of more readily recognizable alarms. There is also scope for improvement in the localizability of the existing alarms. Method Four alternative sets of alarms matched to the functions specified in IEC 60601-1-8 were tested for recognizability and localizability and compared with the alarms currently specified in the standard. Results With a single exception, all prototype sets of alarms outperformed the current IEC set on both recognizability and localizability. Within the prototype sets, auditory icons were the most easily recognized, but the other sets, using word rhythms and simple acoustic metaphors, were also more easily recognized than the current alarms. With the exception of one set, all prototype sets were also easier to localize. Conclusion Known auditory cognition and perception principles were successfully applied to an existing audible alarm problem. Application This work constitutes the first (benchmarking) phase of replacing the alarms currently specified in the standard. The design principles used for each set demonstrate the relative ease with which different alarm types can be recognized and localized

The contribution of geogenic particulate matter to lung disease in indigenous children

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Indigenous children have much higher rates of ear and lung disease than non-Indigenous children, which may be related to exposure to high levels of geogenic (earth-derived) particulate matter (PM). The aim of this study was to assess the relationship between dust levels and health in Indigenous children in Western Australia (W.A.). Data were from a population-based sample of 1077 Indigenous children living in 66 remote communities of W.A. (>2,000,000 km2), with information on health outcomes derived from carer reports and hospitalisation records. Associations between dust levels and health outcomes were assessed by multivariate logistic regression in a multi-level framework. We assessed the effect of exposure to community sampled PM on epithelial cell (NuLi-1) responses to non-typeable Haemophilus influenzae (NTHi) in vitro. High dust levels were associated with increased odds of hospitalisation for upper (OR 1.77 95% CI [1.02–3.06]) and lower (OR 1.99 95% CI [1.08–3.68]) respiratory tract infections and ear disease (OR 3.06 95% CI [1.20–7.80]). Exposure to PM enhanced NTHi adhesion and invasion of epithelial cells and impaired IL-8 production. Exposure to geogenic PM may be contributing to the poor respiratory health of disadvantaged communities in arid environments where geogenic PM levels are high