Test code for the assessment and improvement of Reynolds stress models

An existing two-dimensional, compressible flow, Navier-Stokes computer code, containing a full Reynolds stress turbulence model, was adapted for use as a test bed for assessing and improving turbulence models based on turbulence simulation experiments. To date, the results of using the code in comparison with simulated channel flow and over an oscillating flat plate have shown that the turbulence model used in the code needs improvement for these flows. It is also shown that direct simulation of turbulent flows over a range of Reynolds numbers are needed to guide subsequent improvement of turbulence models

Heterologous expression of a recombinant lactobacillal -galactosidase in Lactobacillus plantarum: effect of different parameters on the sakacin P-based expression system

Background: Two overlapping genes lacL and lacM (lacLM) encoding for heterodimeric -galactosidase from Lactobacillus reuteri were previously cloned and over-expressed in the food-grade host strain Lactobacillus plantarum WCFS1, using the inducible lactobacillal pSIP expression system. In this study, we analyzed different factors that affect the production of recombinant L. reuteri -galactosidase. Results: Various factors related to the cultivation, i.e. culture pH, growth temperature, glucose concentration, as well as the induction conditions, including cell concentration at induction point and inducer concentration, were tested. Under optimal fermentation conditions, the maximum -galactosidase levels obtained were 130 U/mg protein and 3540 U/ml of fermentation broth corresponding to the formation of approximately 200 mg of recombinant protein per litre of fermentation medium. As calculated from the specific activity of the purified enzyme (190 U/mg), -galactosidase yield amounted to roughly 70% of the total soluble intracellular protein of the host organism. It was observed that pH and substrate (glucose) concentration are the most prominent factors affecting the production of recombinant -galactosidase. Conclusions: The over-expression of recombinant L. reuteri -galactosidase in a food-grade host strain was optimized, which is of interest for applications of this enzyme in the food industry. The results provide more detailed insight into these lactobacillal expression systems and confirm the potential of the pSIP system for efficient, tightly controlled expression of enzymes and proteins in lactobacilli.(VLID)90704

Towards a fair and transparent research participant compensation and reimbursement framework in Viet Nam

Background: Providing compensation for participants in clinical research is well established and whilst international guidelines exist, defining a context specific and fair compensation for participants in low resource settings is challenging due to ethical concerns and the lack of practical, national compensation and reimbursement frameworks. Methods: We reviewed OUCRU (Oxford University Clinical Research Unit) internal reimbursement documentation over a ten-year period and conducted a scoping literature review to expand our knowledge of compensation and reimbursement practices including ethical concerns. We developed a preliminary reimbursement framework that was presented to Community Advisory Boards (CAB) and clinical investigators to assess its applicability, fairness, and transparency. Results: The main topics discussed at the workshops centered on fairness and whether the reimbursements could be perceived as financial incentives. Other decisive factors in the decision making process were altruism and the loss of caregivers’ earnings. Investigators raised the issue of additional burdens, whereas the CAB members were focused on non-monetary elements such as the healthcare quality the patients would receive. All elements discussed were reviewed and where possible, incorporated into the final framework. Conclusion: Our new reimbursement framework provides a consistent, fair and transparent decision-making process and will be implemented across all future OUCRU clinical research in Viet Nam

CONTAMINATION BY ARSENIC AND LEAD IN RESIDENTS FROM VIETNAM

Joint Research on Environmental Science and Technology for the Eart

Security and reliability analysis of a two-way half-duplex wireless relaying network using partial relay selection and hybrid TPSR energy harvesting at relay nodes

In recent years, physical layer security has been considered as an effective method to enhance the information security beside the cryptographic techniques that are used in upper layers. In this paper, we provide the security analysis for a two-way relay network, where the two sources can only communicate through the intermediate relay nodes. In particular, we consider the scenario that there is an eavesdropper in the vicinity of one source node. Both reliability and security aspects are taken into consideration in our work. To enhance the reliability of communication, the intermediate relays are supplied with the energy harvested from the sources radio frequency (RF) signals using hybrid time-switching and power splitting (TPSR) protocol. Also, we apply the relay selection technique to select the best relay for the information exchange between two sources. Regarding security, the secrecy of information is improved with the help of friendly jammers nearby the eavesdropper. We provide the in-dept reliability and security analysis in terms of the closed-form expressions of the outage probability (OP) at the source nodes, the intercept probability (IP) at the eavesdropper, the secrecy outage probability (SOP), and the average secrecy capacity (ASC) of the system. Finally, the Monte Carlo simulations are also conducted to verify the correctness of our analysis and the effectiveness of the proposed scheme. Numerical results confirms that with the appropriate and feasible choices of involved parameters, both outage OP and IP can be kept at small values to guarantee the reliable and secure communication of the system.Web of Science818718118716

L'initiative européenne "Suivi global pour l'environnement et la sécurité'' et le protocole de Kyoto

International audienceEn 1992 la Convention Cadre des Nations Unies pour le Contrôle du Changement du Climat (UNFCCC) a montré la prise de conscience internationale des effets néfastes de l'accumulation dans l'atmosphère des gaz à effet de serre, conduisant à un réchauffement climatique, sous l'effet direct ou indirect des activités anthropiques. Le Protocole de Kyoto, adopté en 1997, a fixé des engagements quantitatifs que les parties signataires s'engageaient à respecter. Ceci suppose des moyens d'observation afin de comprendre, modéliser, mesurer l'évolution des sources et des puits de gaz à effet de serre, et tout particulièrement celles sur lesquelles l'Homme peut avoir une influence directe. Conjointement aux mesures in situ, l'observation de la Terre par satellite s'avère un moyen puissant pour répondre à cet objectif. L'Europe, comme le rappelle le "Manifeste de Baveno" adopté par un certain nombre d'agences impliquées dans les activités spatiales, dispose d'atouts majeurs pour remplir de tels objectifs. Le présent article s'efforce de donner une vue synthétique des différentes informations à rassembler pour le suivi des clauses du Protocole de Kyoto, de l'UNFCCC et de leurs conséquences globales sur le changement climatique, mettant en évidence les résultats obtenus, les moyens à entreprendre, les recherches restant à mener, pour atteindre ces buts

Blood pressure screening during the May Measurement Month 2017 programme in Vietnam-South-East Asia and Australasia.

Elevated blood pressure (BP) is a growing burden worldwide, leading to over 10 million deaths each year. May Measurement Month (MMM) is a global initiative aimed at raising awareness of high BP and to act as a temporary solution to the lack of screening programmes worldwide. Our aim was to screen for hypertension (HTN) and cardiovascular risk factors in people aged ≥18 years in the community, thereby define the proportion of subjects with elevated BP and assess the awareness and the effectiveness of its treatment. An opportunistic cross-sectional survey of volunteers aged ≥18 years was carried out in May 2017. Blood pressure measurement, the definition of HTN and statistical analysis followed the standard MMM protocol. From May 2017 to June 2017, through 10 cities/provinces in Vietnam, 10 993 individuals with mean age 49.1 ± 16.2 years were screened during MMM17. After multiple imputation, 3154 (28.7%) had HTN. Of individuals not receiving antihypertensive medication, 1509 (16.1%) were hypertensive. Of individuals receiving antihypertensive medication, 620 (37.7%) had uncontrolled BP. Raised BP was also associated with additional risk factors including smoking, alcohol, overweight-obesity, and diabetes. May Measurement Month 17 was the largest BP screening campaign ever undertaken in Vietnam. Undiagnosed and uncontrolled HTN in Vietnam remains a substantial health problem. Local campaigns applying standardized methods such as MMM17, will be highly useful to screen for the significant number of individuals with raised BP and increase the awareness of HTN

Multimorbidity and its social determinants among older people in southern provinces, Vietnam

Background: Developing countries are poorly equipped for health issues related to ageing populations making multimorbidity challenging. As in Vietnam the focus tends to be on single conditions. Hence little is known about burden of multimorbidity. This study aimed to examine the prevalence and the determinants of multimorbidity among older people in Southern Vietnam. Methods: A cross-sectional study was conducted in two provinces of Southern Vietnam with a sample of 2400 people aged 60 years and older. The presence of chronic disease was ascertained by medical examination done by physicians at commune health stations. Information on social and demographic factors was collected using structured questionnaire. Univariate and multivariable logistic regression analyses were used to examine the factors associated with multimorbidity. Results: Nearly 40 % of older people had multimorbidity. Currently not working, and healthcare utilisation were associated with higher prevalence of multimorbidity. Living in urban areas and being literate were associated with lower prevalence of multimorbidity. Conclusion: The study found a high burden of multimorbidity among illiterate, especially those living in rural areas. This highlights the need for targeted community based programs aimed at reducing the burden of chronic disease