Evidence of negative Poisson's ratio in wood from finite element analysis and off-axis compression experiments

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The microstructure of wood is highly anisotropic, which suggests that this material could exhibit unusual elastic properties. A few studies have suggested the possibility of auxeticity, or negative Poisson's ratio (NPR) in some wood samples. In order to conclusively confirm that wood does show NPR, we have used a combination of geometric modelling, finite element analysis (FEA) and off-axis compression testing. The geometric model indicates that idealised thin-walled wood cell structures should generate NPR of −1, FEA suggests that more realistic cell arrays can attain NPR, to −0.27, and compression tests show that some NPR – to −0.74 – remains in real wood samples. These results could help design “engineered-wood” laminates products with tailored elastic properties

Wie werden die Gesamtnährstoffgehalte des Ackerbodens durch Biomasseein- und -austräge im Agroforstsystem beeinflusst?

Der Rückgang organischer Bodensubstanz durch den kontinuierlichen Entzug von Nährstoffen und Biomasse mit dem Erntegut ist eine der Hauptursachen für die Degradierung intensiv genutzter Ackerböden. Agroforstsysteme können ein Schlüssel zu einer nachhaltigen Erhöhung der Bodenfruchtbarkeit sein, da zusätzliche Ausgangsstoffe für die Bildung organischer Bodensubstanz wie Laubstreu und Wurzelexsudate dem Agrarökosystem zugeführt werden. Im Rahmen des BonaRes-SIGNAL-(„Sustainable intensification of agriculture through agroforestry“) Projektes werden die Quantität und Qualität der oberirdischen Biomasseein- und -austräge für zwei Alley Cropping-Agroforstsysteme mit Ackerkulturen bzw. Grünland in Niedersachsen bestimmt. Es werden räumliche Ertragsanalysen der Ackerkulturen und Grünlandbestände durchgeführt und die räumliche und zeitliche Verteilung und Zersetzung der Laubstreu gemessen. Das Poster präsentiert erste Ergebnisse zur Beeinflussung der Gesamtnährstoffgehalte des Ackerbodens durch die zusätzlichen Biomasseeinträge der schnellwachsenden Bäume und die Biomasseausträge durch die Ernte der Ackerkulturen, sowie zu der Frage welche Ackerbodenbereiche neben den Kulturpflanzen auch von den Bäumen durchwurzelt und somit als Nährstoffquelle genutzt werden

Long-term effects of an inpatient weight-loss program in obese children and the role of genetic predisposition-rationale and design of the LOGIC-trial

<p>Abstract</p> <p>Background</p> <p>The prevalence of childhood obesity has increased worldwide, which is a serious concern as obesity is associated with many negative immediate and long-term health consequences. Therefore, the treatment of overweight and obesity in children and adolescents is strongly recommended. Inpatient weight-loss programs have shown to be effective particularly regarding short-term weight-loss, whilst little is known both on the long-term effects of this treatment and the determinants of successful weight-loss and subsequent weight maintenance.</p> <p>The purpose of this study is to evaluate the short, middle and long-term effects of an inpatient weight-loss program for children and adolescents and to investigate the likely determinants of weight changes, whereby the primary focus lies on the potential role of differences in polymorphisms of adiposity-relevant genes.</p> <p>Methods/Design</p> <p>The study involves overweight and obese children and adolescents aged 6 to 19 years, who participate in an inpatient weight-loss program for 4 to 6 weeks. It started in 2006 and it is planned to include 1,500 participants by 2013. The intervention focuses on diet, physical activity and behavior therapy. Measurements are taken at the start and the end of the intervention and comprise blood analyses (DNA, lipid and glucose metabolism, adipokines and inflammatory markers), anthropometry (body weight, height and waist circumference), blood pressure, pubertal stage, and exercise capacity. Physical activity, dietary habits, quality of life, and family background are assessed by questionnaires. Follow-up assessments are performed 6 months, 1, 2, 5 and 10 years after the intervention: Children will complete the same questionnaires at all time points and visit their general practitioner for examination of anthropometric parameters, blood pressure and assessment of pubertal stage. At the 5 and 10 year follow-ups, blood parameters and exercise capacity will be additionally measured.</p> <p>Discussion</p> <p>Apart from illustrating the short, middle and long-term effects of an inpatient weight-loss program, this study will contribute to a better understanding of inter-individual differences in the regulation of body weight, taking into account the role of genetic predisposition and lifestyle factors.</p> <p>Trial Registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01067157">NCT01067157</a>.</p

Sharing data for future research-engaging participants' views about data governance beyond the original project:a DIRECT Study

Purpose: Biomedical data governance strategies should ensure that data are collected, stored, and used ethically and lawfully. However, research participants' preferences for how data should be governed is least studied. The Diabetes Research on Patient Stratification (DIRECT) project collected substantial amounts of health and genetic information from patients at risk of, and with type II diabetes. We conducted a survey to understand participants' future data governance preferences. Results will inform the postproject data governance strategy.Methods: A survey was distributed in Denmark, Sweden, The Netherlands, and the United Kingdom.Results: In total 855 surveys were returned. Ninety-seven percent were supportive of sharing data postproject, and 90% were happy to share data with universities, and 56% with commercial companies. The top three priorities for data sharing were highly secure database, DIRECT researchers to monitor data used by other researchers, and researchers cannot identify participants. Respondents frequently suggested that a postproject Data Access Committee should involve a DIRECT researcher, diabetes clinician, patient representative, and a DIRECT participant.Conclusion: Preferences of how data should be governed, and what data could be shared and with whom varied between countries. Researchers are considered as key custodians of participant data. Engaging participants aids in designing governance to support their choices.</p