Hypothetical Distribution Research Articles

Association of Alzheimer Disease With Life Expectancy in People With Down Syndrome

People with Down syndrome have a high risk of developing Alzheimer disease dementia. However, penetrance and age at onset are considered variable, and the association of this disease with life expectancy remains unclear because of underreporting in death certificates. To assess whether the variability in symptom onset of Alzheimer disease in Down syndrome is similar to autosomal dominant Alzheimer disease and to assess its association with mortality. This study combines a meta-analysis with the assessment of mortality data from US death certificates (n = 77 347 case records with a International Classification of Diseases code for Down syndrome between 1968 to 2019; 37 900 [49%] female) and from a longitudinal cohort study (n = 889 individuals; 46% female; 3.2 [2.1] years of follow-up) from the Down Alzheimer Barcelona Neuroimaging Initiative (DABNI). A meta-analysis was conducted to investigate the age at onset, age at death, and duration of Alzheimer disease dementia in Down syndrome. PubMed/Medline, Embase, Web of Science, and CINAHL were searched for research reports, and OpenGray was used for gray literature. Studies with data about the age at onset or diagnosis, age at death, and disease duration were included. Pooled estimates with corresponding 95% CIs were calculated using random-effects meta-analysis. The variability in disease onset was compared with that of autosomal dominant Alzheimer disease. Based on these estimates, a hypothetical distribution of age at death was constructed, assuming fully penetrant Alzheimer disease. These results were compared with real-world mortality data. In this meta-analysis, the estimate of age at onset was 53.8 years (95% CI, 53.1-54.5 years; n = 2695); the estimate of age at death, 58.4 years (95% CI, 57.2-59.7 years; n = 324); and the estimate of disease duration, 4.6 years (95% CI, 3.7-5.5 years; n = 226). Coefficients of variation and 95% prediction intervals of age at onset were comparable with those reported in autosomal dominant Alzheimer disease. US mortality data revealed an increase in life expectancy in Down syndrome (median [IQR], 1 [0.3-16] years in 1968 to 57 [49-61] years in 2019), but with clear ceiling effects in the highest percentiles of age at death in the last decades (90th percentile: 1990, age 63 years; 2019, age 65 years). The mortality data matched the limits projected by a distribution assuming fully penetrant Alzheimer disease in up to 80% of deaths (corresponding to the highest percentiles). This contrasts with dementia mentioned in 30% of death certificates but is in agreement with the mortality data in DABNI (78.9%). Important racial disparities persisted in 2019, being more pronounced in the lower percentiles (10th percentile: Black individuals, 1 year; White individuals, 30 years) than in the higher percentiles (90th percentile: Black individuals, 64 years; White individuals, 66 years). These findings suggest that the mortality data and the consistent age at onset were compatible with fully penetrant Alzheimer disease. Lifespan in persons with Down syndrome will not increase until disease-modifying treatments for Alzheimer disease are available.

Analysis of the solvent strength parameter (linear solvent strength model) for isocratic separations in reversed-phase liquid chromatography

The solvent strength parameter (slope) and intercept (log kw) of the linear solvent strength model are determined for methanol-water (17 columns), acetonitrile-water (15 columns), acetone-water (7 columns), tetrahydrofuran-water (6 columns), and 2-propanol-water (4 columns) for varied compounds. It is shown that the linear region of the plots of the retention factor (log k) against the volume fraction of organic solvent (ϕ) is largely a system property independent of solute type for compounds with accessible retention factors. Solvent strength parameters for methanol (3.12 ± 0.12), acetonitrile (2.78 ± 0.18), acetone (2.71 ± 0.11), and tetrahydrofuran (2.95 ± 0.24) are assigned for siloxane-bonded silica and porous graphitic carbon columns as an average of the compound-specific experimental values. Statistical analysis indicates that the compound-specific solvent strength parameters are column dependent and limited as a general solvent property. Evaluation of the column-specific solvent strength parameters provides further evidence that the average solvent strength parameter is column dependent. The column-specific solvent strength values are compared with the hypothetical water-organic solvent distribution systems using the system constants of the solvation parameter models as variables confirming the column dependence of the solvent strength parameter. The column-specific solvent strength parameters can be predicted by the solvation parameter model with a typical deviation of about 0.12 over a range of 1.69 to 6.33 for the experimentally determined values. The intercept of the linear solvent strength model is shown to be both column and organic solvent dependent. Compound column-specific values are adequately described by the solvation parameter model. Log kw cannot be recommended as a descriptor of solute properties since it has no clear connection to a real distribution system.

Hydraulic and Water Quality Modelling of Water Distribution Networks Using EPANET Software

In this study, hydraulic analysis of two water distribution networks was carried out using EPANET 2.0 software developed by the US Environmental Protection Agency. The study networks are: a hypothetical 65-pipe water distribution network that had been solved by the Linear Theory method; and an existing water distribution network serving the University of Benin Ekehuan campus, for which hydraulic analysis and study for the system improvement had been previously carried out using WaterCAD software. This present study was therefore undertaken to investigate EPANET’s capability in executing hydraulic analysis and deploying it for water quality simulation studies of the campus’ water distribution system, which was not part of the scope of the previous study. The hydraulic analysis results showed that the average of deviations from solved values for total head, pressure head, and flow are 4.23%, 7.69%, and 7.15% respectively, which falls within an acceptable range. Results from the water quality analysis study in which water age and optimum residual chlorine dosage required were used as surrogates for water quality indicate that the existing water distribution network of the campus has a water age and optimum residual chlorine of 1.68 hours and 0.220mg/L respectively, while same for the proposed improved water distribution network of the campus are 5.56 hours and 0.255mg/L respectively. Expectedly, the water age and optimum residual chlorine of the improved network are higher than those of the existing network, as the pipe sizes and storage capacity in the improved network are larger to serve the increased future population of the ultimate design period. Even at that, the obtained values are within acceptable limits prescribed by the Nigerian Standard for Drinking Water Quality (NSDWQ) guidelines. Hence, it is concluded that EPANET and WaterCAD are efficient piped-water network simulation software and can be relied on for use in developing countries.

Understanding income-related differences in distribution of child growth, behaviour and development using a cross-sectional sample of a clinical cohort study

ObjectivesChildren from low-income households are at an increased risk of social, behavioural and physical health problems. Prior studies have generally relied on dichotomous outcome measures. However, inequities may exist along...

Ecological Constraints on Sexual Selection in a Human-Modified Landscape

Anthropogenic activities are changing the sensory landscape, interfering with transmission and reception of sexual signals. These changes are leading to alterations in mating behaviour with consequences to fitness. In systems where mate-finding involves long-distance signalling by one sex and approach by the other sex, the spatial distribution of signallers can have implications for male and female fitness. Spatial distribution of signallers is typically determined by an interplay of multiple factors, both ecological and evolutionary, including male competition, female choice and resources, such as calling and oviposition sites. We investigated the possible influence of resource distribution (signalling sites) on the strength and direction of sexual selection acting on false-leaf katydid Onomarchus uninotatus males, signalling in a human-modified landscape in the Western Ghats, India, a biodiversity hotspot. The landscape has changed from evergreen forests to plantations owing to human settlements. We first determined the spatial distribution of calling males and of available calling sites, which are trees of the genus Artocarpus, in the landscape. Using the information on male spacing, call transmission and hearing thresholds, the perceptual spaces of male signals were computed to understand the acoustic environment of calling males and females. It was found that both calling males and females could hear calls of males from neighbouring trees with a probability of 0.76 and 0.59, respectively. Although calling males were found to be spaced apart more than predicted by chance, significant overlap was seen in their acoustic ranges. Clustering of males enables females to easily sample multiple males, facilitating mate choice, but is detrimental to males as it increases competition for females. Using simulations, we determined the optimal spatial distributions of O. uninotatus males for female choice, and for reduction of male competition, given the signalling site distribution. The observed distribution of signallers was then compared with the hypothetical optimal distributions to examine the drivers of signaller spacing. Spacing of calling males in the field was found to be not optimal for either males or females. Resource distribution was found to limit the effectiveness of sexual selection drivers in pushing male spacing toward fitness optima of males or females.

Policy Diffusion Speed: A Replication Study Using the State Policy Innovation and Diffusion Database

Data accumulation efforts are pushing the study of policy innovation diffusion in new directions. This replication study uses one such effort, the State Policy Innovation and Diffusion database, to interrogate the claim that policy attributes like salience and complexity condition the speed of innovation adoption. The study finds that policy complexity does push the effect of policy salience in a negative direction. However, it also finds substantial heterogeneity in these conditional effects across State Policy Innovation and Diffusion’s major constituent datasets. In addition, while not completely answering questions about convenience sampling bias, the study shows that the fundamental results do not change with one re-weighting of the results to capture a hypothetical distribution of the population of state policy innovations. The article concludes with future directions for the study of both policy diffusion within American federalism and cross-national diffusion.

Eye movement as a biomarker of impaired organizational strategies during visual memory encoding in obsessive\u2013compulsive disorder

The symptoms of obsessive–compulsive disorder (OCD) are largely related to impaired executive functioning due to frontostriatal dysfunction. To better treat OCD, the development of biomarkers to bridge the gap between the symptomatic-cognitive phenotype and brain abnormalities is warranted. Therefore, we aimed to identify biomarkers of impaired organizational strategies during visual encoding processes in OCD patients by developing an eye tracking-based Rey–Osterrieth complex figure test (RCFT). In 104 OCD patients and 114 healthy controls (HCs), eye movements were recorded during memorization of the RCFT figure, and organizational scores were evaluated. Kullback–Leibler divergence (KLD) scores were calculated to evaluate the distance between a participant’s eye gaze distribution and a hypothetical uniform distribution within the RCFT figure. Narrower gaze distributions within the RCFT figure, which yielded higher KLD scores, indicated that the participant was more obsessed with detail and had less organizational strategy. The OCD patients showed lower organizational scores than the HCs. Although no group differences in KLD scores were noted, KLD scores were significantly associated with organization T scores in the OCD group. The current study findings suggest that eye tracking biomarkers of visual memory encoding provide a rapidly determined index of executive functioning, such as organizational strategies, in OCD patients.

Solvent and temperature effects on the solubility of some new adamantane/memantine sulfonamide derivatives

The dissolution processes of five new adamantane/memantine sulfonamide derivatives with different substituents in the phenyl ring were examined in the pharmaceutically relevant solvents: aqueous buffer pH 7.4, 1-octanol and n-hexane by the shake-flask method in the temperature range of 293.15–313.15 K. Compounds revealed low equilibrium solubility in water and n-hexane, and essentially better solubility in 1-octanol. Experimental solubility was correlated with the melting properties (measure of crystal lattice energy) and hypothetic distribution coefficient (measure of solvation). Neuroprotective potential of the investigated derivatives was accessed with the help of ΔlogD parameter. The solubility evaluation using the Hansen solubility parameters showed the consistency with the experimental data and revealed the trends in the structure modification within the studied class in order to achieve good potential adsorption. The activity coefficients at infinite dilution, ideal solubility of the compounds in the solvents and molar excess thermodynamic functions have been calculated. Ideal solubility was recorded much higher than the experimental one at each temperature. It has been estimated that in most cases the entropy term of the excess Gibbs energy is responsible for the deviation from ideality in the investigated drug-solvent systems. The solubility data and thermodynamic properties obtained would be useful in the process of purification, recrystallization and dosage form design of adamantane/memantine sulfonamide derivatives in pharmaceutical industry.

On the improvement of paired ranked set sampling to estimate population mean

Abstract In ecological and environmental sampling the quantification of units is either difficult or overly demanding in terms of the time, money, workload, it requires. For this reason efficient and cost-effective sampling methods need to be devised for data collecting. The most commonly used method for this purpose is the Ranked Set Sampling (RSS). In this paper, a sampling scheme called Improved Paired Ranked Set Sampling (IPRSS) is proposed to estimate the population mean. The performance of the proposed IPRSS is evaluated under perfect and imperfect rankings. A simulation study based on selected hypothetical distributions and a real-life data set showed that IPRSS is more precise than RSS, Paired RSS (PRSS) or Extreme RSS (ERSS).

Modification of the Exterior and Interior Solution of Einstein’s G22 Field Equation for a Homogeneous Spherical Massive Bodies whose Fields Differ in Radial Size, Polar Angle, and Time.

In general theory of relativity, Einstein’s field equations relate the geometry of space-time with the distribution of matter within it. These equations were first published by Einstein in the form of a tensor equation which related the local space-time curvature with the local energy and momentum within this space-time. In this article, Einstein’s geometrical field equations interior and exterior to astrophysically real or hypothetical distribution of mass within a spherical geometry were constructed and solved for field whose gravitational potential varies with time, radial distance and polar angle. The exterior solution was obtained using power series. The metric tensors and the solution of the Einstein’s exterior field equations used in this work has only one arbitrary function f(t,r,θ) , and thus put the Einstein’s geometrical theory of gravitation on the same bases with the Newton’s dynamical theory of gravitation. The gravitational scalar potential f(t,r,θ) obtained in this research work to the order of co, c-2 , contains Newton dynamical gravitational scalar potential and post Newtonian additional terms much importance as it can be applied to the study of rotating bodies such as stars. The interior solution was obtained using weak field and slow-motion approximation. The obtained result converges to Newton’s dynamical scalar potential with additional time factor not found in the well-known Newton’s dynamical theory of gravitation which is a profound discovery with the dependency on three arbitrary functions. Our result obeyed the equivalence principle of Physics.

Vitiligo – Study In view of familial occurence

Vitiligo – Study In view of familial occurence

Einstein’s Equation of motion for exterior test particles with spherical mass distribution having varied field, time and radial distance; Golden metric tensors approach.

Golden metric tensors exterior to hypothetical distribution of mass whose field varies with time and radial distance have been used to construct the coefficient of affine connections that invariably was used to obtained the Einstein’s equations of motion for test particles of non-zero rest masses. The expression for the variation of time on a clock moving in this gravitational field was derived using the time equation of motion. The test particles in this field under the condition of pure polar motion have an inverse square dependence velocity which depends on radial distance. Our result indicates that despite using the golden metric tensor, the inverse square dependence of the velocity on radial distance has not been changed.

Model Predictive Control for the Energy Management in a District of Buildings Equipped with Building Integrated Photovoltaic Systems and Batteries

This paper introduces a Model Predictive Control (MPC) strategy for the optimal energy management of a district whose buildings are equipped with vertically placed Building Integrated Photovoltaic (BIPV) systems and Battery Energy Storage Systems (BESS). The vertically placed BIPV systems are able to cover larger areas of buildings’ surfaces, as compared with conventional rooftop PV systems, and reach their peak of production during winter and spring, which renders them suitable for energy harvesting especially in urban areas. Driven by both these relative advantages, the proposed strategy aims to maximize the district’s autonomy from the external grid, which is achieved through the cooperation of interactive buildings. Therefore, the major contribution of this study is the management and optimal cooperation of a group of buildings, each of which is equipped with its own system of vertical BIPV panels and BESS, carried out by an MPC strategy. The proposed control scheme consists of three main components, i.e., the forecaster, the optimizer and the district, which interact periodically with each other. In order to quantitatively evaluate the benefits of the proposed MPC strategy and the implementation of vertical BIPV and BESS, a hypothetical five-node distribution network located in Greece for four representative days of the year was examined, followed by a sensitivity analysis to examine the effect of the system configuration on its performance.

Olbert’s Kappa Fermi and Bose Distributions

The quantum version of Olbert’s kappa distribution applicable to fermions is obtained. Its construction is straightforward but requires recognition of the differences in the nature of states separated by Fermi momenta. Its complement, the bosonic version of the kappa distribution is also given, as is the procedure of how to construct a hypothetical kappa-anyon distribution. At very low temperature the degenerate kappa Fermi distribution yields a kappa-modified version of the ordinary degenerate Fermi energy and momentum. We provide the Olbert-generalized expressions of the Olbert-Fermi partition function and entropy which may serve determining all relevant statistical mechanical quantities. Possible applications are envisaged to condensed matter physics, possibly quantum plasmas, and dense astrophysical objects like the interior state of terrestrial planets, neutron stars, magnetars where quantum effects come into play and dominate the microscopic scale but may have macroscopic consequences.

Preventive chemotherapy for the control of strongyloidiasis in school-age children: Estimating the ivermectin need.

BackgroundStrongyloides stercoralis is a soil-transmitted helminth (STH) that affects approximately 600 million people worldwide. Interventions targeting S. stercoralis have not been implemented yet. Specific treatment (ivermectin) could be included in already ongoing preventive chemotherapy (PC) campaigns targeting other STHs. The aim of this study was to estimate the quantity of ivermectin needed for an integrated STH/S. stercoralis control program.Methododology/Principal findingsOur study estimates the number of school- age children (SAC) (the main focus of STH deworming campaigns) in need of PC with ivermectin. The normal approximation of the binomial distribution was adopted to calculate the hypothetical prevalence distribution in each endemic country. Considering prevalence thresholds for PC equal to 10%, 15%, and 20%, we estimated the number of SAC in need of treatment. We adjusted the estimates accounting for ivermectin distributed in lymphatic filariasis and onchocerciasis elimination programs and excluded from our calculation areas where Loa loa is endemic.The global number of SAC that should be targeted in PC campaigns was estimated at 283.9 M (95% CI: 163.4–368.8), 207.2 M (95% CI: 160.9–380.7), and 160.7 M (95% CI: 86.6–225.7) when the threshold for intervention was set to 10%, 15%, and 20%, respectively. India, China, Indonesia, Bangladesh, and Nigeria accounted for about 50% of the global SAC would have to be covered by PC intervention.Conclusions/SignificanceOur analysis may support endemic countries to evaluate the ivermectin quantity needed for integrating strongyloidiasis in the existing STH programs. These estimates might also show to generic drug manufacturers the size of the potential market for ivermectin and encourage its production.

Bayesian Approach to Lorenz Curve Using Time Series Grouped Data

This study is concerned with estimating the inequality measures associated with the underlying hypothetical income distribution from the times series grouped data on the income proportions. We adopt the Dirichlet likelihood approach where the parameters of the Dirichlet likelihood are set to the differences between the Lorenz curve of the hypothetical income distribution for the consecutive income classes and propose a state-space model which combines the transformed parameters of the Lorenz curve through a time series structure. The present article also studies the possibility of extending the likelihood model by considering a generalized version of the Dirichlet distribution where the mean is modeled based on the Lorenz curve with an additional hierarchical structure. The simulated data and real data on the Japanese monthly income survey confirmed that the proposed approach produces more efficient estimates on the inequality measures than the existing method that estimates the model independently without time series structures.

Salience and social choice

The axioms of expected utility and discounted utility theory have been tested extensively. In contrast, the axioms of social welfare functions have only been tested in a few questionnaire studies involving choices between hypothetical income distributions. In a controlled experiment with 100 subjects placed in the role of social planners, we test five fundamental properties of social welfare functions to determine the efficacy of traditional social choice models in predicting social planner allocations when presented with choice sets designed to test the axioms of the theory. We find that three properties of the standard social welfare functions tested are systematically violated, producing an Allais paradox, a common ratio effect, and a framing effect in social choice. We find support for scale invariance and a preference for tail-increasing transfers. Our experiment also enables us to test a model of salience-based social choice which predicts the systematic deviations and highlights the close relationship between these anomalies and the classical paradoxes for risk and time.

Does a Wealth Tax Improve Equality of Opportunity?

Does parental wealth inequality impact next generation labor income inequality? And does a tax on parental wealth affect the labor income distribution of the next generation? We tackle both questions empirically using detailed intergenerational data from Norway, focusing on effects on wages rather than capital income. Results suggest that a net wealth of NOK 1 million increases wages of the children by NOK 14,000. Children of wealthy parents also have a higher labor income mobility. The estimated hypothetical wage distribution without the wealth tax is more unequal. Moreover, suggestive evidence indicates parental wealth is associated with higher labor risk taking.

Using individual stated-preferences to optimize HIV self-testing service delivery among men who have sex with men (MSM) in Malaysia: results from a conjoint-based analysis

BackgroundHIV self-testing (HIVST) has the potential to improve HIV testing uptake and frequency for key populations like MSM who experience multiple barriers accessing clinic-based HIV testing. In the absence of HIVST in Malaysia, there is no guidance to inform HIVST delivery. This study investigated the acceptability of HIVST and preferences about the HIVST service delivery approaches using a standardized stated preference method.MethodsA cross-sectional online survey conducted between January and April 2019 assessed the interest in HIVST in 544 MSM in Malaysia. Participants ranked eight hypothetical HIVST service delivery program elements with varied combinations of six, two-level HIVST service delivery program attributes (cost, privacy, accuracy, kit collection site, kit type, and testing support). SPSS conjoint procedure was used to estimate the relative importance of each attribute and preference across eight possible HIVST service delivery programs.ResultsOverall, 70.4% had previously tested for HIV, and of those, 64.0% had done so in the past 6 months (45.0% of all participants). Of all the participants, 25.2% reported having used HIVST previously. The acceptability for HIVST service delivery models ranged from 44.9 to 77.1%, with mean acceptability of 56.2% across the eight hypothetical HIVST distribution scenarios. The HIVST service delivery scenario with the highest acceptability had the following attributes: no cost (free), anonymity (name not required), 99–100% accuracy, home-delivered, fingerstick, and testing support using telephone hotline or texting. HIVST cost was the most important attribute (relative importance score: RIS = 19.30) associated with acceptability, followed by anonymity (RIS = 18.41), accuracy (RIS = 17.33), kit delivery (RIS = 16.99), fingerstick kit (RIS = 15.86), and support (RIS = 12.08).ConclusionsAcceptability for HIVST in Malaysian MSM was high but differed markedly by a number of HIVST delivery scenarios and attributes. These findings could be relevant as the Malaysian Ministry of Health is in the process of developing a regulatory framework for ensuring the quality of kits, as well as policies supporting safe use while broader implementation under national AIDS programs.

StratifyR: An R Package for optimal stratification and sample allocation for univariate populations

SummaryThis R package determines optimal stratification of univariate populations under stratified sampling designs using a parametric‐based method. It determines the optimum strata boundaries (OSB), optimum sample sizes (OSS) and multiple other quantities for the study variable, y, using the best‐fit probability density function of a study variable available from survey data. The method requires the parameters and other characteristics of the distribution of the study variable to be known, either from available data or from a hypothetical distribution if the data are not available. In the implementation, the problem of determining the OSB is formulated as a mathematical programming problem and solved by using a dynamic programming technique. If the data of the population (i.e. the study variable) are available to the surveyor, the method estimates its best‐fit distribution and determines the OSB and OSS under Neyman allocation, directly. When the dataset is not available, stratification is made based on the assumption that the values of the study variable, y, are available as hypothetical realisations of proxy values of y from past/recent surveys. Thus, it requires certain distributional assumptions about the study variable. At present, the package handles stratification for the populations where the study variable follows a continuous distribution: namely, Pareto, Triangular, Right‐triangular, Weibull, Gamma, Exponential, Uniform, Normal, Lognormal and Cauchy distributions. In this paper, applications of major functionalities in the package are illustrated with a number of real/simulated as well as some hypothetical populations.