The coarsening of folds in hanging drapes

We consider the elastic energy of a hanging drape -- a thin elastic sheet, pulled down by the force of gravity, with fine-scale folding at the top that achieves approximately uniform confinement. This example of energy-driven pattern formation in a thin elastic sheet is of particular interest because the length scale of folding varies with height. We focus on how the minimum elastic energy depends on the physical parameters. As the sheet thickness vanishes, the limiting energy is due to the gravitational force and is relatively easy to understand. Our main accomplishment is to identify the "scaling law" of the correction due to positive thickness. We do this by (i) proving an upper bound, by considering the energies of several constructions and taking the best; (ii) proving an ansatz-free lower bound, which agrees with the upper bound up to a parameter-independent prefactor. The coarsening of folds in hanging drapes has also been considered in the recent physics literature, using a self-similar construction whose basic cell has been called a "wrinklon." Our results complement and extend that work, by showing that self-similar coarsening achieves the optimal scaling law in a certain parameter regime, and by showing that other constructions (involving lateral spreading of the sheet) do better in other regions of parameter space. Our analysis uses a geometrically linear F\"{o}ppl-von K\'{a}rm\'{a}n model for the elastic energy, and is restricted to the case when Poisson's ratio is zero.Comment: 34 page

Understanding the Mood of Social Media Messages

Social Media is a valuable source of information when seeking to understand community opinion and sentiment about issues of public interest. Such analysis is usually based on sentiment or emotion processing using machine learning techniques or references a curated lexicon of words to measure the emotive intensity being expressed. The lexicon approach can be limited by the sparsity problem, where the lexicon words are not present in the text being processed, and context issues, where the lexicon words have different meanings in the domain under investigation. We have developed a novel technique based on word embeddings to mitigate these issues and present a case study showing its application, where the mood expressed by the community on social media about the Centenary of Armistice in Australia was determined in near real-time

Ventricular fibrillation in six adults without overt heart disease

AbstractFindings are described in six patients with no clinical evidence of heart disease who had documented ventricular fibrillation (five patients) or ventricular flutter (one patient). The mean age of the six patients, all men, was 34 years (range 26 to 43). Cardiovascular collapse occurred in all and was followed by successful cardioversion. No patient had electrolyte or QT abnormalities. One patient had slight right ventricular enlargement on M-mode echocardiography, and another had a left ventricular pressure gradient at rest of 30 mm Hg with a normal two-dimensional echocardiogram. Holter electrocardiographic monitoring revealed incessant ventricular tachycardia in one patient and nonsustained ventricular tachycardia in three others. Exercise testing revealed nonsustained ventricular tachycardia in one patient.Ventricular fibrillation was induced at the time of programmed electrical stimulation in four of the six patients. Documented recurrence of ventricular fibrillation or ventricular flutter occurred in three patients, but in only one patient receiving antiarrhythmic drugs. Four patients were treated with amiodarone and one received an automatic implantable cardioverter-defibrillator. All patients are alive after a mean follow-up period of 78 months after the first documentation of their arrhythmia and 37 months after programmed electrical stimulation.Ventricular fibrillation can occur in the apparently structurally normal human heart. Antiarrhythmic treatment can provide effective control of this malignant arrhythmia

The impact of an operation and management intervention on toilet usability in schools in the Philippines: a cluster randomised controlled trial.

BACKGROUND: Access to usable water, sanitation and hygiene provision in schools is included within indicators in the Sustainable Development Goals. Progress towards these indicators is dependent on developing an understanding of which intervention components are most effective to operate and maintain usable services. This study aimed to determine the impact of a school toilet operation and management intervention in the Philippines on toilet usability and student and teacher satisfaction, adjusted for clustering at school level. METHODS: In a non-blinded cluster randomised controlled trial, we compared improvements in usability and cleanliness of school toilets among those schools receiving a low-cost, replicable intervention. Toilet usability was measured based on Sustainable Development Goal indicators related to school sanitation defined by the UNICEF/WHO Joint Monitoring Programme for Water, Sanitation and Hygiene. Intervention schools received consumables, support kits, and structured tools designed to facilitate operation and maintenance of sanitation facilities. The primary outcome, toilet usability and cleanliness, was compared through a difference-in-difference analysis of toilet usability. Secondary outcomes of student and teacher satisfaction were measured through a survey at endline. All outcomes were adjusted for clustering at school level. RESULTS: 20 eligible schools in the Batangas region of the Philippines were randomly selected and allocated to either control or intervention group. We found that non-classroom toilets were 48% more likely to meet quality benchmarks in intervention schools, but this was not statistically significant. When including in-classroom toilets in the analysis, there were no significant differences in toilet usability - defined as accessible, functional, private and of high quality - between intervention and control schools. When stratified by toilet location, children in the intervention group clusters expressed a minor, but statistically significant increase in overall satisfaction with sanitation facilities (p = 0.035). CONCLUSION: Water, sanitation and hygiene interventions in schools focusing on operation and maintenance showed potential to improve toilet usability, but universal achievement of SDG targets may require additional efforts addressing toilet infrastructure. TRIAL REGISTRATION: ClinicalTrials.gov NCT03204175, June 2017 prior to participant enrolment

Chlamydia trachomatis infection and maternal outcomes in Southern Ghana

Background: Despite the fact that Chlamydia trachomatis (CT) infection in pregnancy is known to have grave impact on maternal and neonatal health, routine CT screening in pregnancy is not available in Ghana The main aim of this study was to determine the prevalence and adverse maternal outcomes of CT infection among pregnant women attending antennal clinic at the Cape Coast Teaching Hospital.Methods: Two hundred and thirty two (232) pregnant women screened for CT infection by PCR were purposively selected and enrolled into the study after informed consent had been obtained. They included one hundred and twelve (112) participants with positive CT (cases) and 120 participants without CT infections (control). A structured questionnaire was used to collect their socio demographic, obstetric and medical history. They were monitored thereafter and data on maternal outcomes were collected.Results: The prevalence of CT infection was 5.6% (112/2014). A history of STI/UTI (p<0.001) spontaneous abortion (p=0.02), preterm labour (p<0.001) and intrapartum or postpartum fever (p<0.001) were found to be associated with CT infection. However a history of Stillbirth, PID and having been treated for infertility were not associated with CT infection. Participants with CT infection were more likely to have PROM (p<0.001) and FSL (p<0.001) than those who were not infected. Parity and mode of delivery on the other hand were not associated with CT infection.Conclusions: To alleviate the adverse maternal outcomes, screening for CT infection in pregnancy should be offered routinely to pregnant women to promote early detection and treatment.  

Neurturin enhances the recovery of erectile function following bilateral cavernous nerve crush injury in the rat

BACKGROUND: The molecular mechanisms responsible for the survival and preservation of function for adult parasympathetic ganglion neurons following injury remain incompletely understood. However, advances in the neurobiology of growth factors, neural development, and prevention of cell death have led to a surge of clinical interest for protective and regenerative neuromodulatory strategies, as surgical therapies for prostate, bladder, and colorectal cancers often result in neuronal axotomy and debilitating loss of sexual function or continence. In vitro studies have identified neurturin, a glial cell line-derived neurotrophic factor, as a neuromodulator for pelvic cholinergic neurons. We present the first in vivo report of the effects of neurturin upon the recovery of erectile function following bilateral cavernous nerve crush injury in the rat. METHODS: In these experiments, groups (n = 8 each) consisted of uninjured controls and animals treated with injection of albumin (blinded crush control group), extended release neurotrophin-4 or neurturin to the site of cavernous nerve crush injury (100 μg per animal). After 5 weeks, recovery of erectile function (treatment effect) was assessed by cavernous nerve electrostimulation and peak aortic pressures were measured. Investigators were unblinded to specific treatments after statistical analyses were completed. RESULTS: Erectile dysfunction was not observed in the sham group (mean maximal intracavernous pressure [ICP] increase of 117.5 ± 7.3 cmH(2)O), whereas nerve injury and albumin treatment (control) produced a significant reduction in ICP elevation of 40.0 ± 6.3 cmH(2)O. Neurturin facilitated the preservation of erectile function, with an ICP increase of 55% at 62.0 ± 9.2 cmH(2)O (p < 0.05 vs control). Extended release neurotrophin-4 did not significantly enhance recovery of erectile function with an ICP change of 46.9 ± 9.6. Peak aortic blood pressures did not differ between groups. No significant pre- and post-treatment weight differences were observed between control, neurotrophin-4 and neurturin cohorts. All animals tolerated the five-week treatment course. CONCLUSION: Treatment with neurturin at the site of cavernous nerve crush injury facilitates recovery of erectile function. Results support further investigation of neurturin as a neuroprotective and/or neuroregenerative agent facilitating functional recovery after cavernous or other pelvic autonomic nerve injuries

Structural basis for cell surface patterning through NetrinG-NGL interactions

Brain wiring depends on cells making highly localized and selective connections through surface protein-protein interactions, including those between NetrinGs and NetrinG ligands (NGLs). The NetrinGs are members of the structurally uncharacterized netrin family. We present a comprehensive crystallographic analysis comprising NetrinG1-NGL1 and NetrinG2-NGL2 complexes, unliganded NetrinG2 and NGL3. Cognate NetrinG-NGL interactions depend on three specificity-conferring NetrinG loops, clasped tightly by matching NGL surfaces. We engineered these NGL surfaces to implant custom-made affinities for NetrinG1 and NetrinG2. In a cellular patterning assay, we demonstrate that NetrinG-binding selectivity can direct the sorting of a mixed population of NGLs into discrete cell surface subdomains. These results provide a molecular model for selectivity-based patterning in a neuronal recognition system, dysregulation of which is associated with severe neuropsychological disorders

Lutter contre les carences en micronutriments au Cameroun par la biofortification du haricot commun

La biofortification est un processus par lequel la valeur nutritionnelle (vitamines et/ou minéraux) d’une culture vivrière est améliorée par le processus de sélection conventionnelle. L’amélioration de nouvelles variétés biofortifiées repose sur la sélection génétique pour développer une plante avec des teneurs plus élevées en protéines, vitamines et les minéraux, notamment le fer, le zinc, la provitamine A, etc,. Onze haricots améliorés riches en fer et en zinc ont été introduits sur le marché au Cameroun à la suite d’une récente analyse nutritionnelle portant sur plus de 30 variétés de haricots communs (variétés locales et variétés introduites). L’adoption et la diffusion de ces variétés nouvellement identifiées avec une grande concentration en fer et en zinc contribuera à lutter contre les carences en fer et en zinc chez les femmes et les enfants de moins de cinq ans. La culture et la vente du haricot amélioré permettront également d’améliorer les revenus et la sécurité alimentaire des ménages. Le haricot commun est la légumineuse la plus cultivée et la plus consommée, et une des sources de protéine plus accessible au Cameroun. La promulgation de ces nouvelles variétés de haricot riche en fer et en zinc et leur adoption ultérieure dans les régimes alimentaires des ménages constitue une intervention peu coûteuse pour lutter contre les problèmes de santé publique liés aux carences en fer et en zinc au sein de la population

Addressing micronutrient deficiency in Cameroon through common bean biofortification

Biofortification is a process through which the nutritional value – vitamins or minerals of a food crop is enhanced through conventional breeding. Through biofortification, vitamins and minerals such as iron, zinc, provitamin A etc. are enhanced. Eleven high iron and zinc beans have been released in Cameroon after a recent nutritional screening of more than 30 common bean varieties (local landraces and improved bean varieties). The adoption and dissemination of these newly identified high iron and zinc varieties will contribute to addressing iron and zinc deficiency among women and children under five. Growing and selling beans will also ensure income and food security for the household. Common beans are the most grown and consumed legume and affordable source of protein in Cameroon. The release of high iron and zinc beans and subsequent incorporation into the household diets is a cost-effective intervention in addressing health disorders related to inadequate intake of iron and zinc

Handheld Co-Axial Bioprinting: Application to in situ surgical cartilage repair

Three-dimensional (3D) bioprinting is driving major innovations in the area of cartilage tissue engineering. Extrusion-based 3D bioprinting necessitates a phase change from a liquid bioink to a semi-solid crosslinked network achieved by a photo-initiated free radical polymerization reaction that is known to be cytotoxic. Therefore, the choice of the photocuring conditions has to be carefully addressed to generate a structure stiff enough to withstand the forces phisiologically applied on articular cartilage, while ensuring adequate cell survival for functional chondral repair. We recently developed a handheld 3D printer called Biopen . To progress towards translating this freeform biofabrication tool into clinical practice, we aimed to define the ideal bioprinting conditions that would deliver a scaffold with high cell viability and structural stiffness relevant for chondral repair. To fulfill those criteria, free radical cytotoxicity was confined by a co-axial Core/Shell separation. This system allowed the generation of Core/Shell GelMa/HAMa bioscaffolds with stiffness of 200KPa, achieved after only 10seconds of exposure to 700mW/cm2 of 365nm UV-A, containing \u3e90% viable stem cells that retained proliferative capacity. Overall, the Core/Shell handheld 3D bioprinting strategy enabled rapid generation of high modulus bioscaffolds with high cell viability, with potential for in situ surgical cartilage engineering