Depression: an individual-level early warning indicator of virologic failure in HIV patients in South Africa.

OBJECTIVE: To identify individual-level early warning indicators of virologic failure in HIV patients receiving antiretroviral therapy (ART) in South Africa. DESIGN: A matched case-control study of individuals with and without virologic failure (VF) (>5 months on ART and HIV-1 plasma viral load >1,000 copies/mL) was conducted between June 2014 and June 2018. Of the 1,000 participants enrolled in the parent cohort, 96 experienced VF, and 199 additional controls were identified from the parent cohort and matched 1:2 (some matched 1:3) for sex, age, ART duration, and site. Participants were interviewed while clinical, pharmacy refill, laboratory, and objective pharmacological data were obtained. Multivariate conditional logistic regression models were constructed using model selection to identify factors associated with VF. Significant determinants of VF were identified using an alpha level of 0.05. RESULTS: In a full conditional model, higher cumulative ART adherence, quantified using tenofovir-diphosphate concentrations in dried blood spots (OR 0.26) and medication possession ratio (OR 0.98) were protective against VF, whereas an increase in total depression score (OR 1.20) was predictive of VF. CONCLUSION: This analysis demonstrates the importance of depression as a key individual-level early warning indicator of VF. Efforts to address mental health concerns among patients with people living with HIV could improve virologic suppression.

OBJECTIF: Identifier les indicateurs d'alerte précoce au niveau individuel de l'échec virologique chez les patients séropositifs recevant un traitement antirétroviral (TAR) en Afrique du Sud. MÉTHODE: Une étude cas-témoins appariée de personnes avec et sans échec virologique (FV, pour l'anglais « virologic failure ¼) (>5 mois sous ART et charge virale plasmatique du VIH-1 >1 000 copies/ml) a été menée entre juin 2014 et juin 2018. Sur les 1 000 participants inscrits dans la cohorte parente, 96 ont présenté une FV et 199 témoins supplémentaires ont été identifiés dans la cohorte parentale et appariés 1:2 (certains appariés 1:3) pour le sexe, l'âge, la durée du TAR et le site. Les participants ont été interrogés pendant que des données cliniques, de renouvellement de pharmacie, de laboratoire et pharmacologiques objectives ont été obtenues. Des modèles de régression logistique conditionnelle multivariée ont été construits à l'aide d'une sélection de modèles pour identifier les facteurs associés à la FV. Les déterminants significatifs de la FV ont été identifiés à l'aide d'un niveau alpha de 0,05. RÉSULTATS: Dans un modèle conditionnel complet, une observance cumulative plus élevée du TAR, quantifiée à l'aide des concentrations de ténofovir-diphosphate dans les gouttes de sang séché (OR 0,26) et du ratio de possession de médicaments (OR 0,98) protégeait contre la FV, tandis qu'une augmentation du score de dépression totale (OR 1,20) était prédictive de la FV. CONCLUSION: Cette analyse démontre l'importance de la dépression en tant qu'indicateur précoce clé au niveau individuel de la FV. Les efforts visant à résoudre les problèmes de santé mentale chez les personnes vivant avec le VIH pourraient améliorer la suppression virologique.

Application of Levenberg-Marquardt technique for electrical conducting fluid subjected to variable viscosity.

In the present study, design of intelligent numerical computing through backpropagated neural networks (BNNs) is presented for numerical treatment of the fluid mechanics problems governing the dynamics of magnetohydrodynamic fluidic model (MHD-NFM) past a stretching surface embedded in porous medium along with imposed heat source/sink and variable viscosity. The original system model MHD-NFM in terms of PDEs is converted to nonlinear ODEs by introducing the similarity transformations. A reference dataset for BNNs approach is generated with Adams numerical solver for different scenarios of MHD-NFM by variation of parameter of viscosity, parameter of heat source and sink, parameter of permeability, magnetic field parameter, and Prandtl number. To calculate the approximate solution for MHD-NFM for different scenarios, the training, testing, and validation processes are conducted in parallel to adapt neural networks by reducing the mean square error (MSE) function through Levenberg-Marquardt backpropagation. The comparative studies and performance analyses through outcomes of MSE, error histograms, correlation and regression demonstrate the effectiveness of proposed BNNs methodology.

Evaluating the characteristics of magnetic dipole for shear-thinning Williamson nanofluid with thermal radiation.

Objective A recent evolution in fluid dynamics has been the consideration of nanoliquids which retains exceptional thermal conductivity characteristics and upsurge heat transportation in fluids. Inspired by this, the current attempt develops a nonlinear mathematical model (Williamson fluid) towards moving surface heated convectively. Formulated problem further encompasses thermophoresis, magnetic dipole, heat source, Brownian diffusion, thermal radiation and thermo-solutal convective conditions. Upshots are simulated and unveiled graphically. Drag force along with heat/mass transportation rates is addressed numerically. Method The dimensionless expressions are highly non-linear and exact/analytic computations for such expressions are not possible. Thus we employed numeric (bvp4c) scheme for solution development. Conclusions Temperature of Williamson nanofluid intesifies through larger Nb (Brownian movement) factor and Nt (thermophoretic variable). Moreover, Buongiorno relation has reverse behavior for concentration ϕ(η) of Williamson nanofluid regarding Nt and Nt. Transportation rate of heat dwindles against both Nt and Nb.

A shear-rate-dependent flow generated via magnetically controlled metachronal motion of artificial cilia.

Cilia beating is a naturally occurring phenomenon that can be utilized in fluid transport in designing several biomechanical devices. Inspired by the ubiquity of bio-fluids (which are non-Newtonian), we report the characteristics of shear-rate-dependent viscosities on fluid flow generated by the wavy propulsion of magnetic cilia. We assume that the metachronal waves of these cilia form a two-dimensional wavy channel, which is filled with generalized Newtonian Carreau liquid. Galilean transformation is employed to relate fixed and moving frames. The constitutive equations are reduced under the classical lubrication assumption. The resulting fourth-order nonlinear differential equations are solved via a perturbation approach using the stream function. The effects of four dominant fluid parameters (shear thinning/thickening, power-law index, and zero- and infinite-shear-rate viscosity), magnetic parameter (Hartmann number), and metachronal wave parameters on fluid velocity, pressure rise per wavelength, and trapping phenomenon are shown in graphical results and explained thoroughly. This study could play an advisory role in designing a magnetic micro-bot useful in the biomedical industry.

On the evaluation of stratification based entropy optimized hydromagnetic flow featuring dissipation aspect and Robin conditions.

BACKGROUND AND OBJECTIVE: The scrutiny of nonlinear convected flow aspect has continuously appealed researchers attention because of its ample demands in processes like heat exchangers, building insulation, crystal growth, insulation of nuclear reactor, food processing, solar energy and electronic element chilling etc. Taking into consideration the aforesaid utilizations, we modeled differential type (second-grade) nanoliquid considering non-linear mixed convection. The considered differential type nonlinear model elaborates viscoelasticity (elastic and viscous) characteristics. Furthermore the thermal systems emphases on transportation of heat and irreversibility reduction. Especially, evaluating the systems via thermodynamic second relation is essential with the purpose of finding a standard communication between power input prerequisite and heat transference augmentation. METHOD: Formulated non-dimensional problem is non-linear subject to the assumptions (i.e., Non-linear mixed convection, magnetic field, viscous dissipation, double stratification, Joule heating and convective conditions). Analytic simulations for modeled non-linear systems is not possible. Hence we considered bvp4c scheme for non-linear analysis. CONCLUSIONS: Velocity [Formula: see text] of second grade (non-Newtonian) fluid intensifies for larger estimations of R* and λ* whereas it dwindles for M. Temperature of nanoliquid deteriorates with S1 while (θ(η)) rises against Ec. Entropy generation (EG) and (BN) (Bejan number) significantly affected by physical parameters M, α2 and Br.

Magnetic field influence in three-dimensional rotating micropolar nanoliquid with convective conditions.

BACKGROUND: Hybrid nanoliquids have several benefits in comparison to orthodox type liquids because of their revised attributes. The enhanced rheological along with thermo-physical attributes, create them additionally apposite for systems featuring solar energy. Thus, in the current analysis, the focus retained to pursue the diversity behave by hybrid nanofluid in comparison with traditional nanofluid considering the scheme of micropolar fluid in the environment of MHD, with rotating porous channel on the exponentially stretched surface. METHODS: For the solution of the generated differential model, a numerical technique BVP-4C is applied. The information extraction is done by the graphical representations of these solutions. RESULTS: The velocity, temperature, and micro-rotation are analyzed deeply under graphical representation. For nanofluid and hybrid nanofluid, we investigated a comprehensive behavior by the variation of skin friction and Nusselt number. As a result of these explorations, we found in depth the higher rate of heat transferring in the scenario of hybrid nanofluid in comparison with nanofluid in the manifestation of porosity and rotation.

Exploring the features for flow of Oldroyd-B liquid film subjected to rotating disk with homogeneous/heterogeneous processes.

BACKGROUND AND OBJECTIVE: In the working principle of magnetic devices, the thin film substances are the verified efficient ingredients. Several fields of physics and chemistry has taken advanced studies for the features and utilization of thin film for various aspects. Here, we extracted the features of thin film analysis for time-dependent Oldroyd-B liquid. More specifically, our emphasis is to explore transportation rate of mass/heat by considering mass/energy fluxes. Furthermore, space/temperature dependent heat source/sink are considered. Radiation aspects are taken into account for mathematical modeling of Oldroyd-B liquid. Additionally, Oldroyd-B liquid features are elaborated considering Dufour/Soret aspects. Moreover, the heated surface by convection and chemical aspects remained under consideration while designing the physical model. METHOD: Feasible variables are employed to achieve nonlinear structure. Computational analysis of such a nonlinear structure is too easy. Therefore, we have engaged numerical technique (bvp4c technique) to solve nonlinear system. RESULTS: Thickness of liquid film boosts for larger rotation whereas it dwindles against magnetic parameter. Liquid concentration intensifies for Soret number. Transportation rate of mass for larger rotation parameter. CONCLUSION: Velocity components (Radial, axial, azimuthal) rises via higher ω. Velocity of liquid increase for greater (ß2) while reverse trend is detected for (ß1). Temperature of liquid dwindles for heat sink (A* < 0, B* < 0) parameters while (θ(η)) rises for (A* > 0, B* > 0).

Entropy optimized stretching flow based on non-Newtonian radiative nanoliquid under binary chemical reaction.

BACKGROUND AND OBJECTIVE: Developed electronic mechanisms frequently deal with defies about thermal management from developed phase of heat diminution or generation of available surface area regarding heat exclusion. Such promising defy can be subjugated either by introducing an optimal geometry for chilling equipments or intensifying heat transportation attributes. Nanoliquid in this perspective executes an extraordinary function to address all such matters. Having such usefulness of entropy in view, we formulated the hydromagnetic non-Newtonian nanoliquid in frames of mixed convection. Nanoliquid model comprises Brownian movement and thermophoretic mechanisms. In addition, the novel mass transportation approach featuring binary chemically reacting species is introduced. Energy expression formulation is developed through dissipation phenomenon. Besides, new conditions for Buongiorno model along with radiating flux are considered. METHOD: We obtained highly nonlinear structure. The computations of such structure are not easy. Thus we employed bvp4c scheme to tackle the nonlinear structure. RESULTS: Heat transportation rate boosts subject to higher chemical reaction parameter in comparison to thermophoretic factor and Eckert number. The considered rheological model yields viscous nanoliquid situation when material factors are assumed zero. Entropy owing to habituation of respiring air is more in comparison to its frictional factor and during hefty physical action. Entropy subject to respiring air friction under respiratory region is much higher in comparison to air habituation factor. CONCLUSION: Velocity rises via higher material parameter for thickening situation while opposing trend is witnessed for thinning nature of liquid. Entropy is meaningfully higher owing to breathing air condition rather than frictional impact towards tract. No doubt, entropy have a feasible association with respiratory thermoplasty which assists to handle asthma.

Saving bones without risking brain-bisphosphonates and risk of stroke: matched case-control study.

We investigated the association between bisphosphonate treatment and the risk of stroke using a large routine clinical dataset. We found no association between bisphosphonate treatment and risk of stroke, after adjusting for large number of clinical and demographic confounders. INTRODUCTION: There is conflicting evidence on the link between bisphosphonates and stroke with studies variously showing increased, decreased or unchanged risk. We investigated the association between bisphosphonate treatment and the risk of stroke using a large routine clinical dataset. METHODS: We used a matched nested case-control study design analysing routinely collected electronic data from patients registered at primary care practices in England participating in the Royal College of General Practitioners Research and Surveillance Centre. Cases were patients aged 18 years or over, either living or dead, recorded as having had a stroke in the period 1 January 2005 to 31 March 2016. Each case was matched to one control according to age, sex, general practice attended and calendar time. Data were analysed using Stata, version 14.2. and RStudio, version 1.1.463. Conditional logistic regression was used to determine odds ratios for stroke according to bisphosphonate treatment and duration in cases compared with controls. We adjusted for disease risk groups, cardiovascular risk factors, treatments, smoking status, alcohol consumption, ethnicity, bisphosphonate types, fracture and socioeconomic status using IMD (Index of Multiple Deprivation). RESULTS: We included 31,414 cases of stroke with an equal number of matched controls. Overall, 83.2% of cases and controls were aged 65 years or older, and there were similar proportions of females (51.5%) and males (48.5%). Bisphosphonate treatment was not associated with stroke after adjusting for the wide range of confounders considered (OR 0.86, 95% CI 0.62-1.19). CONCLUSIONS: We found no association between bisphosphonate treatment and risk of stroke, after adjusting for other confounders.

Impact of Docosahexaenoic Acid Therapy on Subgingival Plaque Microbiota.

BACKGROUND: Oral docosahexaenoic acid (DHA) + aspirin therapy has been shown to reduce periodontal probing depth (PD) and local inflammatory mediators in gingival crevicular fluid (GCF) among patients with untreated chronic periodontal disease. Whether DHA + aspirin therapy influences specific bacterial burden in this setting is unknown. Thus, the aim of this study is to evaluate the impact of DHA with low-dose aspirin therapy on periodontal bacterial profile in patients with periodontitis. METHODS: Fifty-five adults with moderate-to-severe periodontitis were enrolled in a randomized, 3-month double-masked, placebo-controlled trial of daily 2 g DHA or placebo capsules enriched with 81 mg aspirin; 46 enrollees completed the trial. In addition to clinical measurements and GCF sampling, subgingival plaque samples were collected from four posterior sites in all participants and analyzed by the checkerboard DNA-DNA hybridization technique. Presence of 40 periodontal bacterial species at baseline and 3 months was semiquantitatively estimated. RESULTS: Despite broad improvements in clinical parameters, total bacteria and individual species counts in dental plaque did not differ significantly between baseline and 3 months in either group (P >0.1 for all). A modest effect of DHA + aspirin on Porphyromonas gingivalis counts was associated with 14% (95% confidence interval: 3% to 35%) of the observed benefit of DHA on PD. DHA + aspirin had no significant effect on individual plaque bacterial counts in unadjusted models or those adjusted for age, sex, and race (P >0.1 for all). CONCLUSIONS: This pilot randomized, controlled trial suggests that DHA + aspirin therapy improves periodontitis largely by modulating host inflammatory response. Changes in individual species levels in subgingival plaque microbiota were not detectable; however, a small portion of the benefit appears to stem from changes in P. gingivalis levels in the DHA + aspirin treatment group. Whether this change in P. gingivalis levels leads to biofilm alteration with reversal of dysbiosis requires further longitudinal and more specific investigations.

Interaction of gliding motion of bacteria with rheological properties of the slime.

Bacteria which do not have organelles of motility, such as flagella, adopt gliding as a mode of locomotion. In gliding motility bacterium moves under its own power by secreting a layer of slime on the substrate. The exact mechanism by which a glider achieves motility is yet in controversy but there are evidences which support the wave-like undulation on the surface of the organism, as a possible mechanism of motility. Based on this observation, a model of undulating sheet over a layer of slime is examined as a possible model of the gliding motion of a bacterium. Three different non-Newtonian constitutive equations namely, finite extendable nonlinear elastic-peterline (FENE-P), Simplified Phan-Thien-Tanner (SPTT) and Rabinowitsch equations are used to capture the rheological properties of the slime. It is found that the governing equation describing the fluid mechanics of the model under lubrication approximation is same for all the considered three constitutive equations. In fact, it involves a single non-Newtonian parameter which assumes different values for each of the considered constitutive relations. This differential equation is solved using both perturbation and semi-analytic procedure. The perturbation solution is exploited to get an estimate of the speed of the glider for different values of the non-Newtonian parameter. The solution obtained via semi-analytic procedure is used to investigate the important features of the flow field in the layer of the slime beneath the glider when the glider is held fixed. The expression of forces generated by the organism and power required for propulsion are also derived based on the perturbation analysis.

Bacterial gliding fluid dynamics on a layer of non-Newtonian slime: Perturbation and numerical study.

Gliding bacteria are an assorted group of rod-shaped prokaryotes that adhere to and glide on certain layers of ooze slime attached to a substratum. Due to the absence of organelles of motility, such as flagella, the gliding motion is caused by the waves moving down the outer surface of these rod-shaped cells. In the present study we employ an undulating surface model to investigate the motility of bacteria on a layer of non-Newtonian slime. The rheological behavior of the slime is characterized by an appropriate constitutive equation, namely the Carreau model. Employing the balances of mass and momentum conservation, the hydrodynamic undulating surface model is transformed into a fourth-order nonlinear differential equation in terms of a stream function under the long wavelength assumption. A perturbation approach is adopted to obtain closed form expressions for stream function, pressure rise per wavelength, forces generated by the organism and power required for propulsion. A numerical technique based on an implicit finite difference scheme is also employed to investigate various features of the model for large values of the rheological parameters of the slime. Verification of the numerical solutions is achieved with a variational finite element method (FEM). The computations demonstrate that the speed of the glider decreases as the rheology of the slime changes from shear-thinning (pseudo-plastic) to shear-thickening (dilatant). Moreover, the viscoelastic nature of the slime tends to increase the swimming speed for the shear-thinning case. The fluid flow in the pumping (generated where the organism is not free to move but instead generates a net fluid flow beneath it) is also investigated in detail. The study is relevant to marine anti-bacterial fouling and medical hygiene biophysics.

Multiscale tomographic analysis of heterogeneous cast Al-Si-X alloys.

The three-dimensional microstructure of cast AlSi12Ni and AlSi10Cu5Ni2 alloys is investigated by laboratory X-ray computed tomography, synchrotron X-ray computed microtomography, light optical tomography and synchrotron X-ray computed microtomography with submicrometre resolution. The results obtained with each technique are correlated with the size of the scanned volumes and resolved microstructural features. Laboratory X-ray computed tomography is sufficient to resolve highly absorbing aluminides but eutectic and primary Si remain unrevealed. Synchrotron X-ray computed microtomography at ID15/ESRF gives better spatial resolution and reveals primary Si in addition to aluminides. Synchrotron X-ray computed microtomography at ID19/ESRF reveals all the phases ≥ ∼1 µm in volumes about 80 times smaller than laboratory X-ray computed tomography. The volumes investigated by light optical tomography and submicrometre synchrotron X-ray computed microtomography are much smaller than laboratory X-ray computed tomography but both techniques provide local chemical information on the types of aluminides. The complementary techniques applied enable a full three-dimensional characterization of the microstructure of the alloys at length scales ranging over six orders of magnitude.

Erythrocyte saturated fatty acids and systemic inflammation in adults.

OBJECTIVE: The role of saturated fatty acids (SFAs) in chronic disease remains controversial; inflammation is one pathway by which SFAs influence the risk for chronic disease. The aim of this study was to investigate the associations between red blood cell (RBC) phospholipid SFAs and systemic inflammation. METHODS: As part of a randomized controlled trial, we measured RBC phospholipid FA composition in 55 generally healthy adults twice at 3-mo intervals. We estimated associations of RBC total SFAs and two major SFA subtypes, palmitic and stearic acids, with C-reactive protein (CRP), interleukin (IL)-6, white blood count (WBC), and a composite inflammation measure using generalized estimating equations in multivariable FA substitution models. RESULTS: Mean (±SD) SFA level across both visits was 45% ± 3% of the total RBC FAs, mainly palmitic (21% ± 1%) and stearic (17% ± 3%) acids. In models adjusted for age, sex, race, smoking, body mass index, statin use, aspirin use, transunsaturated FAs, and ω-3 FAs, SFAs were significantly associated with IL-6 (20% increase per 1 SD increment; 95% confidence interval [CI], 0.03%-43%; P = 0.05) and the composite inflammation measure (P = 0.05) and marginally associated with CRP (34% increase; 95% CI, -1% to 81%; P = 0.06), but not associated with WBC. Stearic acid was positively associated with CRP (35% increase; 95% CI, 2%-79%; P = 0.04). Palmitic acid was marginally associated with the composite inflammation measure (P = 0.06) and, upon additional ω-6 FA adjustment, significantly associated with IL-6 (15% increase; 95% CI, 0.4%-27%; P = 0.006). CONCLUSIONS: RBC SFAs, which represent longer-term dietary intake, are positively associated with inflammation. In particular, palmitic acid was associated with IL-6, and stearic acid was associated with CRP after multivariable adjustment.

Nutrient intake and peripheral artery disease in adults: key considerations in cross-sectional studies.

BACKGROUND & AIMS: There are limited studies of nutrient intake and peripheral artery disease (PAD). Some studies have not accounted for the functional consequences of PAD, potentially leading to biased results. To determine the associations between intakes of dietary fiber, folate, vitamins A, C, E, and B6 and PAD. METHODS: Cross-sectional analysis of 6534 adults aged 40 years and older in the U.S. National Health and Nutrition Examination Survey between 1999 and 2004, including measurement of ankle-brachial index (ABI) and nutrient intake by 24-h dietary recall. Weighted multivariable logistic regression models to determine odds ratios and 95% confidence intervals. RESULTS: The prevalence of PAD (ABI < 0.9) was 5.3% (4.7-5.9). Inverse associations between PAD and intakes of fiber, folate, and vitamins A, B6, C, and E were statistically significant when adjusting for age, sex, hypertension, diabetes and smoking. In models further adjusted for energy intake and physical activity, these odds ratios all became null (p ≥ 0.1). CONCLUSIONS: In this sample, dietary fiber, folate, and vitamins B6, C, and E were not associated with PAD after accounting for energy intake and activity. Adjustment for energy and physical activity are essential to avoid bias due to reverse causation in cross-sectional studies of diet and PAD.

Dietary fatty acids and peripheral artery disease in adults.

BACKGROUND: Peripheral artery disease (PAD) is a debilitating condition involving atherosclerosis. Although saturated, monounsaturated and polyunsaturated fatty acids have strong associations with atherosclerosis, it is unclear if diets high in these fatty acids affect PAD. METHODS: We studied 6352 adults aged 40 years and older who participated in the U.S. National Health and Nutrition Examination Survey between 1999 and 2004. Ankle brachial index (ABI) was assessed by standardized blood pressure measurements, and we defined PAD as an ABI<0.9. Fatty acid intake was assessed by validated 24-h dietary recall. We used multivariable linear and logistic regression to estimate associations between intakes of dietary saturated fatty acids (SFAs), monounsaturated fatty acids (MFAs), marine omega-3 fatty acids (N-3), linolenic acid (LNA), and omega-6 fatty acids (N-6) and ABI/PAD. RESULTS: The prevalence and 95% confidence interval (CI) of PAD was 5.2% (95% CI 4.6-5.8). There were no associations between ABI and intakes of marine N-3 (p=0.83) or N-6 (p=0.19) in adjusted models. In contrast, LNA was associated with higher ABI (p=0.04) and SFA tended to be associated with lower ABI (p=0.06) in adjusted models. In addition, higher SFA was associated with a higher prevalence of PAD: adjusted odds ratio 1.30 (95% CI 1.01-1.67; p=0.04) and a trend toward slower gait speed (p=0.08). CONCLUSION: In this nationally representative sample, higher dietary intakes of LNA and SFAs were associated with higher and lower ABI, respectively. Prospective studies are needed to confirm the potential protective effects of dietary LNA and detrimental effects of dietary SFAs on PAD.

Three-dimensional rigid multiphase networks providing high-temperature strength to cast AlSi10Cu5Ni1-2 piston alloys.

The three-dimensional (3-D) architecture of rigid multiphase networks present in AlSi10Cu5Ni1 and AlSi10Cu5Ni2 piston alloys in as-cast condition and after 4 h spheroidization treatment is characterized by synchrotron tomography in terms of the volume fraction of rigid phases, interconnectivity, contiguity and morphology. The architecture of both alloys consists of α-Al matrix and a rigid long-range 3-D network of Al(7)Cu(4)Ni, Al(4)Cu(2)Mg(8)Si(7), Al(2)Cu, Al(15)Si(2)(FeMn)(3) and AlSiFeNiCu aluminides and Si. The investigated architectural parameters of both alloys studied are correlated with room-temperature and high-temperature (300 °C) strengths as a function of solution treatment time. The AlSi10Cu5Ni1 and AlSi10Cu5Ni2 alloys behave like metal matrix composites with 16 and 20 vol.% reinforcement, respectively. Both alloys have similar strengths in the as-cast condition, but the AlSi10Cu5Ni2 is able to retain ∼15% higher high temperature strength than the AlSi10Cu5Ni1 alloy after more than 4 h of spheroidization treatment. This is due to the preservation of the 3-D interconnectivity and the morphology of the rigid network, which is governed by the higher degree of contiguity between aluminides and Si.

IMPACT: a generic tool for modelling and simulating public health policy.

BACKGROUND: Populations are under-served by local health policies and management of resources. This partly reflects a lack of realistically complex models to enable appraisal of a wide range of potential options. Rising computing power coupled with advances in machine learning and healthcare information now enables such models to be constructed and executed. However, such models are not generally accessible to public health practitioners who often lack the requisite technical knowledge or skills. OBJECTIVES: To design and develop a system for creating, executing and analysing the results of simulated public health and healthcare policy interventions, in ways that are accessible and usable by modellers and policy-makers. METHODS: The system requirements were captured and analysed in parallel with the statistical method development for the simulation engine. From the resulting software requirement specification the system architecture was designed, implemented and tested. A model for Coronary Heart Disease (CHD) was created and validated against empirical data. RESULTS: The system was successfully used to create and validate the CHD model. The initial validation results show concordance between the simulation results and the empirical data. CONCLUSIONS: We have demonstrated the ability to connect health policy-modellers and policy-makers in a unified system, thereby making population health models easier to share, maintain, reuse and deploy.

Monounsaturated, trans, and saturated Fatty acids and cognitive decline in women.

OBJECTIVES: To prospectively assess effects of select dietary fats on cognitive decline. DESIGN: Prospective observational; 3-year follow-up. SETTING: Northwestern University. PARTICIPANTS: Four hundred eighty-two women aged 60 and older who participated in the Women's Health Initiative (WHI) Observational Study or in the control group of the WHI Diet Modification arm. MEASUREMENTS: Dietary intake from a validated food frequency questionnaire (FFQ) administered twice (mean 2.7 years apart) before baseline cognitive assessment (mean 2.9 years after second FFQ) was averaged. Testing of memory, vision, executive function, language, and attention was performed twice, 3 years apart. A global Z-score was created for both time points by averaging all Z-scores for each participant, and global cognitive change was defined as the difference between follow-up and baseline Z-scores. RESULTS: Median intake of saturated fat (SFA), trans-fat, (TFA), dietary cholesterol (DC), and monounsaturated fat (MUFA) was 18.53, 3.45, 0.201, and 19.39 g/d, respectively. There were no associations between degree of cognitive decline and intake of SFA (P=.69), TFA (P=.54), or DC (P=.64) after adjusting for baseline cognition, total energy intake, age, education, reading ability, apolipoprotein E ɛ4 allele, body mass index, estrogen and beta-blocker use, and intake of caffeine and other fatty acids. In contrast, MUFA intake was associated with lower cognitive decline in fully adjusted linear regression models, with mean decline (standard error) of 0.21 (0.05) in the lowest and 0.05 (0.05) in the highest quartiles (P=.02). This effect of MUFA intake was primarily in the visual and memory domains (P=.03 for both). CONCLUSION: Greater intake of SFA, TFA, and DC was not associated with cognitive decline, whereas greater MUFA intake was associated with less cognitive decline.

n-3 fatty acids and periodontitis in US adults.

BACKGROUND: Periodontitis is a common, chronic inflammatory disease. Although n-3 fatty acids have anti-inflammatory properties, it is unclear whether n-3 fatty acids can treat or prevent periodontitis. METHOD: We studied 9,182 adults aged 20 years and older who participated in the National Health and Nutrition Examination Survey between 1999 and 2004. Periodontitis was assessed by dental exam and was defined as >4 mm pocket depth and >3 mm attachment loss in any one tooth. Intake of n-3 fatty acids was assessed by 24-hour dietary recall. We used multivariable logistic regression to estimate the associations between periodontitis and intakes of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and linolenic acid (LNA). RESULTS: The weighted prevalence and 95% confidence interval (CI) of periodontitis was 8.2% (95% CI 7.0 to 9.4). Compared with the lowest tertiles, the adjusted odds ratios for periodontitis associated with the highest tertiles of dietary n-3 intake were 0.78 (95% CI 0.61 to 1.00; P=0.009) for DHA, 0.85 (95% CI 0.67 to 1.08; P=0.10) for EPA, and 0.86 (95% CI 0.60 to 1.23; P=0.28) for LNA. The associations were little changed by multivariable adjustment or exclusion of individuals reporting use of dietary supplements containing DHA, EPA, or LNA. CONCLUSIONS: In this nationally representative sample, higher dietary intakes of DHA and, to a lesser degree, EPA, were associated with lower prevalence of periodontitis. Interventional studies are needed to confirm the potential protective effects of n-3 fatty acids on periodontitis.