236 research outputs found
CALCULATION OF SOIL WATER DIFFUSIVITY USING A MODEL FOR SOIL MOISTURE PROFILE UNDER DIFFERENT SALINITY CONDITIONS
A closed formed model modified from that of van Genuchten (1980) was used to fit
the data of soil moisture profile ( θ vs. λ ) from which the slope dλ/dθ can be evaluated
and then the soil water diffusivity [D(θ)] can be calculated. Diffusivity was calculated for three soil textures under different salinity conditions.
The results showed that the model fitted the data very well with 1% confidence level (R2 > 0.93). D(θ) increased sharply with soil moisture for all soils but its values were lower when the texture got finer. At a certain sodium adsorption ratio (SAR), D(θ)
increase with the increase of salt concentration (C) of the water infiltrating. Increasing SAR of water caused a decrease in D(θ) at any level of C. Same trends were obtained for the values of weighted mean diffusivity D
Types of stigma experienced by patients with mental illness and mental health nurses in Indonesia : a qualitative content analysis
Background: Stigma refers to the discrediting, devaluing, and shaming of a person because of characteristics or attributes that they possess. Generally, stigma leads to negative social experiences such as isolation, rejection, marginalization, and discrimination. If related to a health condition such as mental illness, stigma may affect a person’s illness and treatment course, including access to appropriate and professional medical treatment. Stigma has also been reported to affect patients’ families or relatives, along with professionals who work in mental healthcare settings. Stigma is strongly influenced by cultural and contextual value systems that differ over time and across contexts. However, limited information is available on how types of stigma are experienced by patients with mental illness and mental health nurses in Indonesia. Method: We explored the stigma-related experiences of 15 nurses and 15 patients in Indonesia. The study design and analysis of interview data were guided by deductive (directed) content analysis. Results: Five themes emerged. Four themes were patient-related: personal/patients’ stigma, public/social stigma, family stigma, and employment stigma. The fifth theme related to stigma toward healthcare professionals working with patients with mental illnesses, which we categorized as professional stigma. Conclusions: This study has achieved a deep understanding of the concept of stigma in the Indonesian context. This understanding is a prerequisite for developing appropriate interventions that address this phenomenon and thereby for the development of mental health services in Indonesia. This study may also be transferable to other countries that share similar cultural backgrounds and adhere to traditional and religious value systems
Prion protein stabilizes amyloid-β (Aβ) oligomers and enhances Aβ neurotoxicity in a Drosophila model of Alzheimer's disease
The cellular prion protein (PrPC) can act as a cell-surface receptor for β-amyloid (Aβ) peptide; however, a role for PrPC in the pathogenesis of Alzheimer's disease (AD) is contested. Here, we expressed a range of Aβ isoforms and PrPC in the Drosophila brain. We found that co-expression of Aβ and PrPC significantly reduces the lifespan, disrupts circadian rhythms, and increases Aβ deposition in the fly brain. In contrast, under the same conditions, expression of Aβ or PrPC individually did not lead to these phenotypic changes. In vitro studies revealed that substoichiometric amounts of PrPC trap Aβ as oligomeric assemblies and fragment-preformed Aβ fibers. The ability of membrane-anchored PrPC to trap Aβ as cytotoxic oligomers at the membrane surface and fragment inert Aβ fibers suggests a mechanism by which PrPC exacerbates Aβ deposition and pathogenic phenotypes in the fly, supporting a role for PrPC in AD. This study provides a second animal model linking PrPC expression with Aβ toxicity and supports a role for PrPC in AD pathogenesis. Blocking the interaction of Aβ and PrPC represents a potential therapeutic strategy
PVP2005-71322 INTRODUCTION OF THE ELEMENT INTERACTION TECHNIQUE FOR WELDING ANALYSIS AND SIMULATION
ABSTRACT The residual stresses generated due to welding in pressure components may have several harmful effects such as decrease in the resistance to cycling load and corrosive environments. The analysis of the welding process has been developed extensively in 2D and 3D. The element movement technique has been shown to be very effective in simulating the filler material deposition leading to a reduction in the analysis time. However, when attempted for wider fields of applications, it had some limitations, especially when moving the elements towards the base-plate. In this paper, the element interaction technique is introduced utilizing the concepts of both the element movement and element birth techniques. The new technique is verified versus the currently developed procedures. In this technique, the elements of the weld pool are held in place in contact with the elements of the base-plate and the interaction is made to be a function of time. This gave several flexibilities in modeling the welding process. Hence, the technique is then used to analyze simple fillet welding of a plate and circumferential butt-welding of a pipe. INTRODUCTION The residual stresses generated during welding vary with the change in the welding parameters depending on the procedure of the joining process. Many researches have been done to investigate the residual stress for specific problem. Due to the complexity of the different applications, several assumptions and approximations, such as reducing the model from 3D to 2D, are made to facilitate the analysis. These approximations help mainly in reducing modeling efforts and analysis time. The element birth technique has been used in simulating metal deposition in both 3D and 2D models. Brown and Song [1] have used the technique in an axisymmetric simulation of a fillet-weld of ringstiffened cylinder. Wilkening and Snow [2] have also solved an axisymmetric simulation of a two-pass butt-weld of a cylinder using the element birth technique. Also, for a plate, they assumed that the through thickness variation of the residual stress is insignificant, so they modeled a single-pass butt-weld of plate using 2D plane model of the plate. Bouchard et a
Assessment of energy credits for the enhancement of the Egyptian Green Pyramid Rating System
Energy is one of the most important categories in the Green Building Rating Systems all over the world. Green Building is a building that meets the energy requirements of the present with low energy consumption and investment costs without infringing on the rights of forthcoming generations to find their own needs. Despite having more than a qualified rating system, it is clear that each system has different priorities and needs on the other. Accordingly, this paper proposes a methodology using the Analytic Hierarchy Process (AHP) for assessment of the energy credits through studying and comparing four of the common global rating systems, the British Building Research Establishment Environmental Assessment Method (BREEAM), the American Leadership in Energy and Environmental Design (LEED), the Australian Green Stars (GS), and the PEARL assessment system of the United Arab Emirates, in order to contribute to the enhancement of the Egyptian Green Pyramid Rating System (GPRS). The results show the mandatory and optional energy credits that should be considered with their proposed weights according to the present and future needs of green Egypt. The results are compared to data gathered through desk studies and results extracted from recent questionnaires
Racial/Ethnic Disparities in Alzheimer’s Disease Risk: Role of Exposure to Ambient Fine Particles
Background
Whether racial/ethnic disparities in Alzheimer’s disease (AD) risk may be explained by ambient fine particles (PM2.5) has not been studied.
Methods
We conducted a prospective, population-based study on a cohort of Black (n=481) and White (n=6004) older women (aged 65-79) without dementia at enrollment (1995-98). Cox models accounting for competing risk were used to estimate the hazard ratio (HR) for racial/ethnic disparities in AD (1996-2010) defined by DSM-IV and the association with time-varying annual average PM2.5 (1999-2010) estimated by spatiotemporal model.
Results
Over an average follow-up of 8.3 (±3.5) years with 158 incident cases (21 in Black women), the racial disparities in AD risk (range of adjusted HRBlack women = 1.85-2.41) observed in various models could not be explained by geographic region, age, socioeconomic characteristics, lifestyle factors, cardiovascular risk factors, and hormone therapy assignment. Estimated PM2.5 exposure was higher in Black (14.38±2.21 µg/m 3) than in White (12.55±2.76 µg/m 3) women, and further adjustment for the association between PM2.5 and AD (adjusted HRPM2.5 = 1.18-1.28) slightly reduced the racial disparities by 2-6% (HRBlack women = 1.81-2.26). The observed association between PM2.5 and AD risk was ~2 times greater in Black (HRPM2.5 = 2.10-2.60) than in White (HRPM2.5 = 1.07-1.15) women (range of interaction Ps: Conclusions
PM2.5 may contribute to racial/ethnic disparities in AD risk and its associated increase in AD risk was stronger amongst Black women
Field-applicable recombinase polymerase amplification assay for rapid detection of Mycoplasma capricolum subsp. capripneumoniae
Contagious caprine pleuropneumonia (CCPP) is a highly contagious disease caused by Mycoplasma capricolum subsp. capripneumoniae that affects goats in Africa and Asia. Current available methods for the diagnosis of Mycoplasma infection, including cultivation, serological assays, and PCR, are time-consuming and require fully equipped stationary laboratories, which make them incompatible with testing in the resource-poor settings that are most relevant to this disease. We report a rapid, specific, and sensitive assay employing isothermal DNA amplification using recombinase polymerase amplification (RPA) for the detection of M. capricolum subsp. capripneumoniae. We developed the assay using a specific target sequence in M. capricolum subsp. capripneumoniae, as found in the genome sequence of the field strain ILRI181 and the type strain F38 and that was further evidenced in 10 field strains from different geographical regions. Detection limits corresponding to 5 × 103 and 5 × 104 cells/ml were obtained using genomic DNA and bacterial culture from M. capricolum subsp. capripneumoniae strain ILRI181, while no amplification was obtained from 71 related Mycoplasma isolates or from the Acholeplasma or the Pasteurella isolates, demonstrating a high degree of specificity. The assay produces a fluorescent signal within 15 to 20 min and worked well using pleural fluid obtained directly from CCPP-positive animals without prior DNA extraction. We demonstrate that the diagnosis of CCPP can be achieved, with a short sample preparation time and a simple read-out device that can be powered by a car battery, in < 45 min in a simulated field setting
Serum Albumin's Protective Inhibition of Amyloid-beta Fiber Formation Is Suppressed by Cholesterol, Fatty Acids and Warfarin
GIP Does Not Potentiate the Antidiabetic Effects of GLP-1 in Hyperglycemic Patients With Type 2 Diabetes
The non-octarepeat copper binding site of the prion protein is a key regulator of prion conversion
The conversion of the prion protein (PrP(C)) into prions plays a key role in transmissible spongiform encephalopathies. Despite the importance for pathogenesis, the mechanism of prion formation has escaped detailed characterization due to the insoluble nature of prions. PrP(C) interacts with copper through octarepeat and non-octarepeat binding sites. Copper coordination to the non-octarepeat region has garnered interest due to the possibility that this interaction may impact prion conversion. We used X-ray absorption spectroscopy to study copper coordination at pH 5.5 and 7.0 in human PrP(C) constructs, either wild-type (WT) or carrying pathological mutations. We show that mutations and pH cause modifications of copper coordination in the non-octarepeat region. In the WT at pH 5.5, copper is anchored to His96 and His111, while at pH 7 it is coordinated by His111. Pathological point mutations alter the copper coordination at acidic conditions where the metal is anchored to His111. By using in vitro approaches, cell-based and computational techniques, we propose a model whereby PrP(C) coordinating copper with one His in the non-octarepeat region converts to prions at acidic condition. Thus, the non-octarepeat region may act as the long-sought-after prion switch, critical for disease onset and propagation
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