Age-related Renovascular Changes consequences in late life

This thesis provides new insights in underlying patterns that may be involved in the (accelerated) aging process, in particular in the area of renovascular changes. It hopes to unravel new targets for better diagnostic and therapeutic strategies in an attempt to maintain or even improve quality of late life

Clamping and interlocking effects on IBS block house system in comparison with conventional house system

Industrialised Building System (IBS) is a unique construction technique that has been implemented in many construction fields all around the world. However, its implementation in Malaysia is still slow and not effective. Through the research on IBS, some elements are found to be important and need to be improved in order to produce better quality components. One of the important elements is the design and innovation of IBS components by applying new interlocking configuration between blocks and by using a clamping bolted connection to the system. The main objective of this research is to determine the structural behavior of IBS block works sub-system under push over cyclic loading in comparison with conventional sub-system and to verify that the IBS interlocking geometry sub-system perform better than other sub-systems via laboratory tests. In this research, a block work assembly to form building sub-frame that integrated by two beams, two columns and infill system were built and tested to failure. Two types of IBS block work sub-systems with original geometry and interlocking geometry with scaled of 1:5 were tested with Push Over Cyclic Load Test. In comparison, a control model of Conventional Sub-System was also tested and analysed using the same methods. The results showed that the IBS geometry model with interlocking configuration performed better in terms of stiffness, ductility and flexibility of the models. The IBS original geometry model is ductile but lack structural stiffness while the conventional model is stiff but not ductile

Semi-parametric of sample selection model using fuzzy concepts

The sample selection model has been studied in the context of semi-parametric methods. With the deficiencies of the parametric model, such as inconsistent estimators, semi-parametric estimation methods provide better alternatives. This article focuses on the context of fuzzy concepts as a hybrid to the semiparametric sample selection model. The better approach when confronted with uncertainty and ambiguity is to use the tools provided by the theory of fuzzy sets, which are appropriate for modeling vague concepts. A fuzzy membership function for solving uncertainty data of a semi-parametric sample selection model is introduced as a solution to the problem

Abundance analysis of a nitrogen-rich extreme-helium hot subdwarf from the SALT survey

We have performed a detailed spectral analysis of the helium-rich hot subdwarf EC 20187-4939 using data obtained in the SALT survey of helium-rich hot subdwarfs. We have measured its effective temperature, surface gravity and chemical abundances from the spectrum. Its radius has also been determined by fitting the spectral energy distribution using photometric data, from which a mass of 0.44 Msun has been inferred using the measurement of surface gravity. This star is particularly abundant in helium and nitrogen, whilst being both carbon and oxygen-weak. The surface abundances and mass have been found to be consistent with a helium white dwarf merger product. The abundance effects of alpha captures on nitrogen during the merger process and possible connections between EC 20187-4939 and other carbon-weak related objects are discussed.Comment: 10 pages, 5 figures, 5 tables, accepted for publication in MNRA

The possible impact of aortic stiffness on quality of late life: An exploratory study

Purpose: Aortic stiffness (AS) is associated with cardiovascular events and all-cause mortality in the older population. AS might also influence the health-related quality of life (HRQOL) as a result of the negative effects of AS on cognitive and physical morbidity. We aimed to investigate the possible association between AS and HRQOL in people aged 75 years and over. Patients and Methods: This cross-sectional study was part of the SCOPE study, an international multicenter cohort observational study. The indicators for AS were aortic pulse wave velocity (aPWV) and central pulse pressure (cPP). HRQOL was assessed using the EQ-5D index and the EQ-5D visual analog scale (VAS). ANCOVA and multivariate regression models were used to investigate possible associations. Results: We included 280 Dutch participants of the SCOPE study. Median age was 79 years (IQR 76–83) and 42.1% were women. Participants reporting any problem on the EQ-5D index (n=214) had higher values of aPWV (12.6 vs 12.2 m/s, p = 0.024) than participants not experiencing any problem (n=66) and comparable values of cPP (44.4 vs 42.0 mmHg, p = 0.119). Estimates only slightly changed after adjustments. No association was found between indicators of AS and EQ-5D VAS. Conclusion: Aortic stiffness was associated with impaired quality of late life. This association could be mediated by subclinical vascular pathology affecting mental and physical health

Differential Adaptation of Human Gut Microbiota to Bariatric Surgery–Induced Weight Loss: Links With Metabolic and Low-Grade Inflammation Markers

International audienceOBJECTIVE Obesity alters gut microbiota ecology and associates with low-grade inflammation in humans. Roux-en-Y gastric bypass (RYGB) surgery is one of the most efficient procedures for the treatment of morbid obesity resulting in drastic weight loss and improvement of metabolic and inflammatory status. We analyzed the impact of RYGB on the modifications of gut microbiota and examined links with adaptations associated with this procedure. RESEARCH DESIGN AND METHODS Gut microbiota was profiled from fecal samples by real-time quantitative PCR in 13 lean control subjects and in 30 obese individuals (with seven type 2 diabetics) explored before (M0), 3 months (M3), and 6 months (M6) after RYGB. RESULTS Four major findings are highlighted: 1) Bacteroides/Prevotella group was lower in obese subjects than in control subjects at MO and increased at M3. It was negatively correlated with corpulence, but the correlation depended highly on caloric intake; 2) Escherichia coli species increased at M3 and inversely correlated with fat mass and leptin levels independently of changes in food intake; 3) lactic acid bacteria including Lacto-bacillus/Leuconostoc/Pediococcus group and Bifidobacterium genus decreased at M3; and 4) Faecalibacterium prausnitzii species was lower in subjects with diabetes and associated negatively with inflammatory markers at MO and throughout the follow-up after surgery independently of changes in food intake. CONCLUSIONS These results suggest that components of the dominant gut microbiota rapidly adapt in a starvation-like situation induced by RYGB while the F. prausnitzii species is directly linked to the reduction in low-grade inflammation state in obesity and diabetes independently of calorie intake. Diabetes 59:3049-3057, 201

Generalized Huygens principle with pulsed-beam wavelets

Huygens' principle has a well-known problem with back-propagation due to the spherical nature of the secondary wavelets. We solve this by analytically continuing the surface of integration. If the surface is a sphere of radius $R$, this is done by complexifying $R$ to $R+ia$. The resulting complex sphere is shown to be a real bundle of disks with radius $a$ tangent to the sphere. Huygens' "secondary source points" are thus replaced by disks, and his spherical wavelets by well-focused pulsed beams propagating outward. This solves the back-propagation problem. The extended Huygens principle is a completeness relation for pulsed beams, giving a representation of a general radiation field as a superposition of such beams. Furthermore, it naturally yields a very efficient way to compute radiation fields because all pulsed beams missing a given observer can be ignored. Increasing $a$ sharpens the focus of the pulsed beams, which in turn raises the compression of the representation.Comment: 49 pages, 14 figure

FDG-PET/CT Imaging Predicts Histopathologic Treatment Responses after Neoadjuvant Therapy in Adult Primary Bone Sarcomas

Purpose. The aim of this study was to prospectively evaluate whether FDG-PET allows an accurate assessment of histopathologic response to neoadjuvant treatment in adult patients with primary bone sarcomas. Methods. Twelve consecutive patients with resectable, primary high grade bone sarcomas were enrolled prospectively. FDG-PET/CT imaging was performed prior to the initiation and after completion of neoadjuvant treatment. Imaging findings were correlated with histopathologic response. Results. Histopathologic responders showed significantly more pronounced decreases in tumor FDG-SUVmax from baseline to late follow up than non-responders (64 ± 19% versus 29 ± 30 %, resp.; P = .03). Using a 60% decrease in tumor FDG-uptake as a threshold for metabolic response correctly classified 3 of 4 histopathologic responders and 7 of 8 histopathologic non-responders as metabolic responders and non-responders, respectively (sensitivity, 75%; specificity, 88%). Conclusion. These results suggest that changes in FDG-SUVmax at the end of neoadjuvant treatment can identify histopathologic responders and non-responders in adult primary bone sarcoma patients