Three-dimensional jamming and flows of soft glassy materials

Various disordered dense systems such as foams, gels, emulsions and colloidal suspensions, exhibit a jamming transition from a liquid state (they flow) to a solid state below a yield stress. Their structure, thoroughly studied with powerful means of 3D characterization, exhibits some analogy with that of glasses which led to call them soft glassy materials. However, despite its importance for geophysical and industrial applications, their rheological behavior, and its microscopic origin, is still poorly known, in particular because of its nonlinear nature. Here we show from two original experiments that a simple 3D continuum description of the behaviour of soft glassy materials can be built. We first show that when a flow is imposed in some direction there is no yield resistance to a secondary flow: these systems are always unjammed simultaneously in all directions of space. The 3D jamming criterion appears to be the plasticity criterion encountered in most solids. We also find that they behave as simple liquids in the direction orthogonal to that of the main flow; their viscosity is inversely proportional to the main flow shear rate, as a signature of shear-induced structural relaxation, in close similarity with the structural relaxations driven by temperature and density in other glassy systems.Comment: http://www.nature.com/nmat/journal/v9/n2/abs/nmat2615.htm

Mental Toughness in South African Youth: Relationships With Forgivingness and Attitudes Towards Risk

Young people are particularly vulnerable to health risk behaviors and interpersonal violence, stimulating scholars’ attention towards identifying factors that may reduce the likelihood that these actions will occur. Associated with positive outcomes in a variety of domains, mental toughness in young people might protect them from engaging in potentially deleterious interpersonal or health-risk behaviors, while potentially promoting positive psychological behaviors. Within this framework, the present study investigated the relationships between mental toughness, attitudes towards physical and psychological risk-taking, and trait forgiveness in a sample of 123 (males = 54, females = 69) South African youth (M age = 23.97 years, SD = 4.46). Univariate and multivariate analyses indicated higher levels of mental toughness were associated with being more forgiving, (η2pηp2 = .036), perceiving physical risk-taking more positively (η2pηp2 = .062), but having more negative attitudes towards psychological risk-taking (η2pηp2 = .036). These findings give credence to mental toughness as a psychological characteristic involved in youth risk-taking perceptions and interpersonal functioning. Future research might explore the integration of mental toughness into the development of future youth risk behavior interventions

Genetic Diversity of Wild Rice (Oryza longistaminata) in Ghana

Oryza longistaminata is a wild rice taxon and an excellent source of genetic variation that remains largely unexploited. This study was conducted to understand the genetic diversity between and within O. longistaminata populations, collected from different geographic locations in Ghana. In this study, SSR markers were used to determine the intra-specific variability in O. longistaminata, and how the variation is partitioned within and between different populations. Analysis of molecular variance revealed high levels of polymorphism (95.9%) within the populations. The overall genetic diversity for all the loci in the six populations was high (Shannon's Information Index I = 0.579, Nei's unbiased expected heterozygosity, He = 0.405). Hierarchical partitioning also indicated a high genetic diversity between and within populations, with some level of relatedness between samples taken from the Savannah agroecological area. The high genetic diversity observed in this study offer a great opportunity for screening useful traits among the populations of O. longistaminata in Ghana for rice breeding programs

Fungal Growth on Wetblue: Methods to Measure Impact on Leather Quality

Wild and known fungal species were selected to inoculate a standardized wetblue leather and various methods were then employed to quantify the concomitant damage associated with mold growth. Fungi were isolated from commercially tanned samples of contaminated wetblue and pure strains were sourced from ATCC cultures. Test cuttings of wetblue leather were inoculated with the selected cultures and incubated along with matched control cuttings for a period of 90 days. Unknown wild strains were later identified using DNA sequencing techniques. Microscopic observations of all treated versus control samples did not show any difference in grain structure or skin morphology, indicating little or no breakdown of intact and tanned collagen structures. Various staining and analytical assay techniques indicated significant reduction in fatty material content in the treated samples compared with the untreated controls. RESUMENEspecies de hongos silvestres y conocidos fueron seleccionadas para inocular un cuero wet-blue estandarizado y varios métodos fueron luego empleados para cuantificar el daño concomitante asociado con el crecimiento del moho. Los hongos fueron aislados de muestras comerciales contaminadas de wetblue curtido y de cepas puras procedentes de cultivos ATCC. Muestras de cuero wetblue fueron inoculados con los cultivos seleccionados e incubados junto con idénticas muestras de control por un período de 90 días. Cepas silvestres desconocidas fueron identificadas posteriormente mediante técnicas de secuenciación de ADN. Observaciones microscópicas de todas las muestras tratadas en comparación con las muestras de control no mostraron ninguna diferencia en la estructura de la flor o en la morfología de la piel, lo que indica poca o ninguna interrupción de las estructuras de colágeno curtido. Varias técnicas de tinción y ensayos analíticos indican una reducción significativa en el contenido de materia grasa en las muestras tratadas en comparación con los controles no tratados

Combining quantitative and qualitative survey work. Methodological framework, practical issues, and case studies

This document is an output of the DFID funded research project R7033 "Methodological Framework for Integrating Qualitative and Quantitative Approaches for Socio-Economic Survey Work". The project's main objective was to improve survey methodologies used in the natural resources sector, leading in turn to improved quality of information required for decision-making at the various stages of natural resources programmes and projects. The project, which was jointly implemented by the Natural Resources Institute and the Statistical Services Centre, attempted to bridge the gap between informal I qualitative methods on the one hand and formal I quantitative ones on the other. The document is presented in the form of a manual, allowing the user to read each of its parts and sections independently of each other. Nevertheless, cross references indicate links to other parts of the document where appropriate. Part I provides a methodological framework, which will also be available as a Best-Practice Guideline published by the Natural Resources Systems Programme of DFID. Part 11, which contains six theme papers, looks into a number of practical issues encountered when combining quantitative and qualitative survey techniques. And finally, in Part III case studies are used to demonstrate how the two approaches can be integrated in survey work and experiments related to the natural resources sector. The framework document, theme papers and case studies have been produced between 1998 and 2000

Serous cystic neoplasm of the pancreas: A multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

OBJECTIVES: Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality. DESIGN: Retrospective multinational study including SCN diagnosed between 1990 and 2014. RESULTS: 2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58\u2005years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40\u2005mm (2-200)), 9% had resection beyond 1\u2005year of follow-up (3\u2005years (1-20), size at diagnosis: 25\u2005mm (4-140)) and 39% had no surgery (3.6\u2005years (1-23), 25.5\u2005mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1\u2005year (n=1271), size increased in 37% (growth rate: 4\u2005mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1). CONCLUSIONS: After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN

Induction of Isochromanones by Co-Cultivation of the Marine Fungus Cosmospora sp. and the Phytopathogen Magnaporthe oryzae

Microbial co-cultivation is a promising approach for the activation of biosynthetic gene clusters (BGCs) that remain transcriptionally silent under artificial culture conditions. As part of our project aiming at the discovery of marine-derived fungal agrochemicals, we previously used four phytopathogens as model competitors in the co-cultivation of 21 marine fungal strains. Based on comparative untargeted metabolomics analyses and anti-phytopathogenic activities of the co-cultures, we selected the co-culture of marine Cosmospora sp. with the phytopathogen Magnaporthe oryzae for in-depth chemical studies. UPLC-MS/MS-based molecular networking (MN) of the co-culture extract revealed an enhanced diversity of compounds in several molecular families, including isochromanones, specifically induced in the co-culture. Large scale co-cultivation of Cosmospora sp. and M. oryzae resulted in the isolation of five isochromanones from the whole co-culture extract, namely the known soudanones A, E, D (1-3) and their two new derivatives, soudanones H-I (4-5), the known isochromans, pseudoanguillosporins A and B (6, 7), naphtho-γ-pyrones, cephalochromin and ustilaginoidin G (8, 9), and ergosterol (10). Their structures were established by NMR, HR-ESIMS, FT-IR, electronic circular dichroism (ECD) spectroscopy, polarimetry ([α]D), and Mosher’s ester reaction. Bioactivity assays revealed antimicrobial activity of compounds 2 and 3 against the phytopathogens M. oryzae and Phytophthora infestans, while pseudoanguillosporin A (6) showed the broadest and strongest anti-phytopathogenic activity against Pseudomonas syringae, Xanthomonas campestris, M. oryzae and P. infestans. This is the first study assessing the anti-phytopathogenic activities of soudanones

Evaluation of Credit Risk Management Practices in Societe Generale Ghana

The study evaluated the credit risk management strategies of SG-SSB Ghana. The research was an attempt to assess the extent to which the implementation of various credit risk management strategies by the bank has reduced the amount of non-performing loans. In order to answer the research objectives, the case study approach was employed where face-to face interview was conducted to collate the views of a senior credit officer at SG-SSB Ghana Ltd on credit risk management strategies. Besides, information on non-performing loans was obtained from administered questionnaires. The results from the study showed that SG-SSB has a clear, written guideline on credit risk management with the board of directors having an oversight responsibility for implementation. SG-SSB realigns the amount of credit within various sectors grouped into a credit portfolio depending on environmental factors such as political regime, macroeconomic strategy of political regimes, new and existing regulations and legislation, social concerns of operating markets and technological developments within the banking industry in Ghana.  The study recommends that SG-SSB should work in collaboration with credit reference bureau in the country to thoroughly investigate the past credit records of loan applicants so as to reduce the high rate of default

Examination of The Problems Associated with Revenue Collection at Electricity Company of Ghana. A Case Study of Afienya District

Revenue refers to the amount in a monetary unit received during a period of time. These monetary units are generated from different sources such as taxes, fines, borrowings, fees and bills. Revenue is important to an organization because an increase in revenue could mean an increase in profit, however if revenue increases, expenses will also (usually) increase and so on the percentage change in profit will not shift as much as one might think. The study examined the problems associated with revenue collection at Electricity Company of Ghana using Afienya District as a case study. Both primary and secondary data were sourced for the study. The data collected were analysed qualitatively using descriptive analysis like charts, graphs and tables. The major findings of the study were that though Afienya District of Electricity Company of Ghana applies guidelines like disconnections, taking action against illegal connectors, monitoring of consumption patterns of customers and billing customers. These guidelines are not effectively followed to enable it meet annual targets. The recommendations are that the company intensifies its monitoring, bill customers promptly, and take prompt and stringent action against illegal connectors and overdue accounts to maximize revenue