Gamma Distribution Function Research Articles

Utilization of Gamma & Weibull Distribution Functions in Validating Experimental-based Result of Ore Amenability for Coarse Gangue Rejection

Abstract The mining industry faces two-pronged challenges, that is the increasing demand for commodities and declining ore quality, resulting in higher energy consumption and operational costs but poor productivity. Multiple methods have been proposed to address this issue, including early coarse gangue rejection which requires further amenability testing by either experiments and statistical analysis. Experimental approaches, such as Gangue Rejection Amenability Tests (GRAT), have demonstrated efficacy but required substantial time and resources. Statistical methodologies utilizing lognormal distributions offered an alternative, but unable to validate statistical outcomes against experimental results. This study investigated the potential of alternative statistical methods (i.e., gamma and Weibull distributions) to validate GRAT. Through the analysis of grade and density parameters data drawn from eight ore fractions, this research constructed an accurate statistical model for predicting ore separation results. The model’s accuracy was evaluated based on coefficient of determination, heterogeneity of data, and comparison of statistical predictions of cumulative mass and metal yield with laboratory results. The results of employing two distributions did not yield accurate predictions of GRAT results. The statistical values tended to be higher than the experimental results for both parameters. We suggested that alternative functions be tested for more representative and suitable use in coarse gangue rejection applications.

Two Monotonicity Results for Beta Distribution Functions.

Write pbeta(·,α,β) for the distribution function of the Beta distribution with parameters α and β. We show that α↦pbeta(α/(α+β),α,β) is decreasing and α↦pbeta(α/(α+β),α+1,β) is increasing over the positive reals, with the common limit for α→∞ expressible in terms of the Gamma distribution functions, and discuss implications for the distribution functions of the Gamma, Poisson and Binomial distributions.

ON IMPROVED GAUSSIAN CORRELATION INEQUALITIES FOR SYMMETRICAL -RECTANGLES EXTENDED TO CERTAIN MULTIVARIATE GAMMA DISTRIBUTIONS AND SOME FURTHER PROBABILITY INEQUALITIES

The Gaussian correlation inequality (GCI) for symmetrical n-rectangles is improved if the absolute components have a joint cumulative distribution function (cdf), which is MTP2 (multivariate totally positive of order 2). Inequalities of the given type hold at least for all MTP2-cdfs on or with everywhere positive smooth densities. In particular, at least some infinitely divisible multivariate chi-square distributions (gamma distributions in the sense of Krishnamoorthy and Parthasarathy) with any positive real “degree of freedom” are shown to be MTP2. Moreover, further numerically calculable probability inequalities for a broader class of multivariate gamma distributions are derived. A different improvement for inequalities of the GCI-type, and of a similar type with three instead of two groups of components with more special correlation structures is also obtained. The main idea behind these inequalities is to find for a given correlation matrix with positive correlations, a further correlation matrix with smaller correlations whose inverse is an M-matrix and where the corresponding multivariate gamma distribution function is numerically available.

Modeling of mRNA deadenylation rates reveal a complex relationship between mRNA deadenylation and decay

Complete cytoplasmic polyadenosine tail (polyA-tail) deadenylation is thought to be essential for initiating mRNA decapping and subsequent degradation. To investigate this prevalent model, we conducted direct RNA sequencing of S. cerevisiae mRNAs derived from chase experiments under steady-state and stress condition. Subsequently, we developed a numerical model based on a modified gamma distribution function, which estimated the transcriptomic deadenylation rate at 10 A/min. A simplified independent method, based on the delineation of quantile polyA-tail values, showed a correlation between the decay and deadenylation rates of individual mRNAs, which appeared consistent within functional transcript groups and associated with codon optimality. Notably, these rates varied during the stress response. Detailed analysis of ribosomal protein-coding mRNAs (RPG mRNAs), constituting 40% of the transcriptome, singled out this transcript group. While deadenylation and decay of RPG mRNAs accelerated under heat stress, their degradation could proceed even when deadenylation was blocked, depending entirely on ongoing nuclear export. Our findings support the general primary function of deadenylation in dictating the onset of decapping, while also demonstrating complex relations between these processes.

Hypertension-Associated Expenditures Among Privately Insured US Adults in 2021.

There are no recent estimates for hypertension-associated medical expenditures. This study aims to estimate hypertension-associated incremental medical expenditures among privately insured US adults. We conducted a retrospective cohort study using IQVIA's Ambulatory Electronic Medical Records-US data set linked with PharMetrics Plus claims data. Among privately insured adults aged 18 to 64 years, hypertension was identified as having ≥1 diagnosis code or ≥2 blood pressure measurements of ≥140/90 mm Hg, or ≥1 antihypertensive medication in 2021. Annual total expenditures (in 2021 $US) were estimated using a generalized linear model with gamma distribution and log-link function adjusting for demographic characteristics and cooccurring conditions. Out-of-pocket expenditures were estimated using a 2-part model that included logistic and generalized linear model regression. Overlap propensity score weights from logistic regression were used to obtain a balanced sample on hypertension status. Among the 393 018 adults, 156 556 (40%) were identified with hypertension. Compared with individuals without hypertension, those with hypertension had $2926 (95% CI, $2681-$3170) higher total expenditures and $328 (95% CI, $300-$355) higher out-of-pocket expenditures. Adults with hypertension had higher total inpatient ($3272 [95% CI, $1458-$5086]) and outpatient ($2189 [95% CI, $2009-$2369]) expenditures when compared with those without hypertension. Hypertension-associated incremental total expenditures were higher for women ($3242 [95% CI, $2915-$3569]) than for men ($2521 [95% CI, $2139-$2904]). Among privately insured US adults, hypertension was associated with higher medical expenditures, including higher inpatient and out-of-pocket expenditures. These findings may help assess the economic value of interventions effective in preventing hypertension.

Seasonal Temperature Distributions and Variations in Salt Marshes: Field Investigation and Numerical Simulation

AbstractSoil temperature regulates biogeochemical processes and is a key environmental factor affecting salt marsh ecosystems. Previous studies on soil temperature and heat transport in intertidal marshes predominantly focused on short‐term changes, leaving seasonal variations unclear. This study conducted a yearlong field and modeling investigation to examine temporal and spatial temperature variations in a creek‐marsh section under estuarine and meteorological influences. The results showed that inundating tidal water propagated the seasonal water temperature signal to marsh soils, especially at low elevations, thereby modulating air temperature‐induced soil temperature variations and distributions. The response of soil temperature to air and tidal water temperatures exhibited a damped and delayed pattern. In contrast, tide‐induced porewater circulations near the creek facilitated the temperature responses. A regression model incorporating a Gamma distribution function was developed to quantify the delayed and cumulative thermal effects of tidal water and air on shallow soil temperatures. The model coefficients varied along the creek‐marsh section, capturing the seasonal regulation of periodic tidal inundation on soil temperature in the low‐elevation marsh and near the creek. Sensitivity analyses indicated that relative sea level rise lowered yearly‐averaged temperatures for the marsh platform by enhancing latent heat export. Surface water warming increased the marsh temperatures at lower elevations. This study demonstrates that the creek‐marsh topography, warming, and relative sea level rise jointly affect soil temperature dynamics, advancing our understanding of temperature‐dependent biogeochemical processes in marsh ecosystems.

Effectiveness of bedside staplers in bariatric robotic procedures

BackgroundFew studies have evaluated the use of laparoscopic staplers in robotic procedures (bedside stapling, BS). This study aims to evaluate the effectiveness of BS compared with robotic staplers (RS) in bariatric robotic procedures.MethodsPatients who underwent robotic sleeve gastrectomy or gastric bypass elective procedures between 1/1/2021 and 12/31/2021 were extracted from PINC AI™ Healthcare Data. The following clinical outcomes were compared: blood transfusion, bleeding, anastomotic leak, intensive care unit (ICU) visit, and 30-day readmission, operating room (OR) time, inpatient costs, and length of stay. We evaluated baseline balance in BS and RS and bivariate association between covariates and outcomes using Chi-square or Fisher exact test and t-test or ANOVA. Multivariable general linear mixed models (GLMMs) with respective gamma or binomial distribution and log-link function were used to obtain adjusted outcomes variations between BS and RS.ResultsTotal of 7268 discharges were included with 1603 (22.1%) BS and 5665 (77.9%) RS cases. RS cases consisted of a higher number of patients who were Hispanic (17.0% vs. 9.4%), had Medicaid (26.9% vs. 19.4%) and underwent sleeve gastrectomy (68.4% vs. 53.5%). Higher proportions of RS cases were done by providers in Northeast region (35.5% vs. 24.3%), smaller size (< 500 beds; 71.1% vs. 52.3%), and teaching hospitals (59.4% vs. 39%). The adjusted outcomes variations demonstrated that patients that had RS were significantly more likely to have blood transfusions, ICU stays, increased ORT (19 min) and costs ($1273). Sensitivity analysis showed similar results, except no significant differences in blood transfusion rates in both groups.ConclusionsBedside staplers significantly reduce healthcare resource utilization with equivalent effectiveness and fewer ICU stays compared to robotic staplers.Graphical abstract

Spending Analysis of Machine Learning-Based Communication Nudges in Oncology.

Serious illness conversations (SICs) in the outpatient setting may improve mood and quality of life among patients with cancer and decrease aggressive end-of-life care. Interventions informed by behavioral economics may increase rates of SICs between oncology clinicians and patients, but the impact of these interventions on end-of-life spending is unknown. This study is a secondary analysis of a stepped-wedge cluster randomized, controlled trial that involved nine medical oncology practices and their high-risk patients at a large academic institution between June 2019 and April 2020. The study included 1187 patients who were identified by a machine-learning algorithm as high risk of 180-day mortality and who died by December 2020. The patients were randomly assigned to standard of care (controls) or to a behavioral intervention designed to increase clinician-initiated SICs. We abstracted spending - defined as inflation-adjusted costs for acute care (inpatient plus emergency room), office/outpatient care, intravenous systemic therapy, other therapy (e.g., radiation), long-term care, and hospice - from the institution's accounting system, and we captured spending at inpatient, outpatient, and pharmacy settings. To evaluate intervention impacts on spending, we used a two-part model, first using logistic regression to model zero versus nonzero spending and second using generalized linear mixed models with gamma distribution and log-link function to model daily mean spending in the last 180days of life. Models were adjusted for clinic and wedge fixed effects, and they were clustered at the oncologist level. For all patients with at least one SIC within 6 months of death, we also calculated their mean daily spending before and after SIC. Median age at death was 68years (interquartile range, 15.5), 317 patients (27%) were Black or of ethnicities other than white, and 448 patients (38%) had an SIC. The intervention was associated with lower unadjusted mean daily spending in the last 6 months of life for the intervention group versus controls ($377.96 vs. $449.92; adjusted mean difference, -$75.33; 95% confidence interval, -$136.42 to -$14.23; P=0.02), translating to $13,747 total adjusted savings per decedent and $13 million in cumulative savings across all decedents in the intervention group. Compared with controls, patients in the intervention group incurred lower mean daily spending for systemic therapy (adjusted difference, -$44.59; P=0.001), office/outpatient care (-$9.62; P=0.001), and other therapy (-$8.65; P=0.04). The intervention was not associated with differences in end-of-life spending for acute care, long-term care, or hospice. Results were consistent for spending in the last 1 and 3 months of life and after adjusting for age, race, and ethnicity. For patients with SICs, mean daily spending decreased by $37.92 following the first SIC ($329.87 vs. $291.95). A machine learning-based, behaviorally informed intervention to prompt SICs led to end-of-life savings among patients with cancer, driven by decreased systemic therapy and outpatient spending. (Funded by the Penn Center for Precision Medicine and the National Institutes of Health; ClinicalTrials.gov number, NCT03984773.).

Fish Composition, Size Distribution and Fishing Gear Selectivity in Lake Malombe, Malawi

Lake Malombe is connected to Lake Malawi; the latter is an African Great Lake endowed with the World highest fish species diversity. Thus, fish species of the two lakes are commonly shared and form valuable food resource. The Lake Malombe fishery resources have been exploited to alarming levels by residents and mobile fishermen that use different types of fishing gears; the same has also affected parts of Lake Malawi. This study was conducted on 18 landing sites in eastern and western regions of Lake Malombe on 7-21th July 2017 to provide baseline information on performance and impact of seven fishing gears (Kandwindwi, Nkacha seine, Mosquito net, Gill nets, Fish traps, Handlines and Longlines) on the Lake Malombe fishery. This study: (i) updates the status of artisanal fishing gears, (ii) determines catch rates, (iii) determines the size and species composition, (iv) assesses gear selectivity, and (v) provides recommendations for the management of the fisheries. Species identification, length and weight measurements were done in collaboration with fishing gear owners. Beach name, gear owner, number of crew, craft type, gear type, fish catch, mesh size, fishing times, landing times and fishing ground were recorded using reference manuals on-site to compare morphometric and meristic characters of the fish species. Fish size and length frequency distribution were modelled using the Gamma distribution function to compensate for skewed distribution of the data from seine nets. Size- specific selectivity of the “Nkacha” seine net, being the dominant, was modelled using the logistic model. Overall total catch sample was estimated at 676 kg from 33 gears, the catch per unit effort (CPUE) was 0.1 and 40.1 Kg/trip with an average of 11.3 ±16.3 Kg/trip. Local seine nets known as Kandwindwi and Nkacha, and Gill nets recorded the highest CPUE of 40.1, 28.4 and 8.9 Kg/trip, respectively. Fish traps, Handlines, Mosquito seine nets and longlines were found less effective harvesting 1.1, 0.5, 0.3 and 0.1 Kg/trip, respectively. Fish catches comprised of 19 genera and 28 species classified into four fish families; Cichlidae, Cyprinidae, Claridae and Characidae. Cichlidae recorded highest abundance accounting for more than 77% of the catch followed by Cyprinidae (18%), Claridae (5%) and Characidae (0.003%). Nineteen (19) genera comprising of Nyassachromis (31.8%), Otopharynx (21.2%) and Engraulicypris (16.3%) constituted more than 75% of fish catches. There were over 28 taxa in landings from all fishing gears, the majority of the catches being composed of five species;Nyassachromis argyrosoma (31.8%), Otopharynx argyrosoma stripe (17.6%),Engraulicypris sardella (16.3%), Lethrinops lethrinus (6.5%) and Copadichromis chrysonotus (4.8%) making up of more than 75% of the landings. A decline of 60.7% (from 56 taxa to 28 taxa) was recorded among fish catches from Nkacha seines. The size of fish ranged from 17 to 380 mm TL with an average of 69.1±43.2 mm TL and the smallest fish sizes-at-capture observed in all seine nets ranged from 47 to 64.5 mm TL. Meanwhile, the sizes-at-capture for all fishing gears ranged from 47.0 to 124.4 mm TL and 77.3 ±28.1 mm TL was the mean value. Fish sizes-at-capture showed that most fishing gears were unselective, catching mostly juvenile forms. Naturally, this contributed to heavy declines in catches, further confirming why recorded catches were 12,000 tons in 1981-91 and only 3,820 tons in 2016. The intrusion or invasion of Usipa (Engraulicypris sardella) from Lake Malawi into Lake Malombe is a new phenomenon indicating a change in environment and species composition. Removal of illegal gears combined with a Rights-Based system should be considered while refining legal instruments. Above all, political will needs to be galvanised if the fishery is to be restored

Over 300 km Dispersion of Wild Boar during Hot Summer, from Central Poland to Ukraine.

The movement of wild boars is a complex process influenced by both internal conditions and external factors. Despite their typically sedentary lifestyle, dispersion constitutes an integral element of the wild boar's behavior. This report documents the longest observed wild boar dispersal, involving a collared two-year-old male near Warsaw, Poland. The aim of this study was to present the characteristics of movement during the "nomadic phase", drawing comparisons with the "sedentary phase". The other aim was to evaluate the influence of meteorological factors on the minimum daily travel distance of the wild boar. We collected data from two-year-old males. The first exhibited long-distance dispersal and the second only demonstrated local movements. We calculated the minimum daily distance of both wild boars based on collar locations and calculated basic statistics of movement. We used a generalized linear model with a gamma distribution and log link function to assess the potential impact of weather conditions on the minimum daily distance of wild boars. We tested maximum daily temperature, average daily temperature, and the sum of daily precipitation. The wild boar during a "nomadic phase" covered a total of 922 km with a mean minimum daily movement of 6 km. The dispersion distance was 307 km. The highest value of the minimum daily distance reached 31.8 km/day. The second wild boar (near Warsaw) covered a mean minimum daily distance of 1.4 km; the highest value of the minimum daily distance was 3.9 km. Both wild boars exhibited no dependence of minimum daily distance on weather conditions. However, when intensive and non-intensive dispersion were analyzed separately, it was demonstrated that the maximum daily temperature positively influenced the minimum daily distance. We speculate that the wild boar was forced to search for water sources after dark on hot days, which induced a longer traveling distance in an unfamiliar environment. This study highlights the significant spatial capabilities of wild boar in the transmission of genes or pathogens. We speculate that extended daily distances during the initial "nomadic phase" might suggest a panicked escape from a perceived threat. It is plausible that the wild boar found improved shelter within tall cereal crops in July and August, which resulted in lower daily distances.

Comparative Interrupted Time Series Analysis of Direct Medical Expense and Length of Stay in Elderly Patients with Femoral Neck Fractures Who Underwent Total Hip Arthroplasty and Hemiarthroplasty: A Real World Nationwide Database Study.

The objective of our study was to analyze the postoperative direct medical expenses and hospital lengths of stay (LOS) of elderly patients who had undergone either hemiarthroplasty (HA) or total hip arthroplasty (THA) for femoral neck fractures and to determine the indication of THA by comparing those variables between the 2 groups by time. In this comparative large-sample cohort study, we analyzed data from the 2011 to 2018 Korean National Health Insurance Review and Assessment Service database. The included patients were defined as elderly individuals aged 60 years or older who underwent HA or THA for a femoral neck fracture. A 1:1 risk-set matching was performed on the propensity score, using a nearest-neighbor matching algorithm with a maximum caliper of 0.01 of the hazard components. In comparative interrupted time series analysis, time series were constructed using the time unit of one-quarter before and after 3 years from time zero. For the segmented regression analysis, we utilized a generalized linear model with a gamma distribution and logarithmic link function. A total of 4,246 patients who received THA were matched and included with 4,246 control patients who underwent HA. Although there was no statistically significant difference in direct medical expense and hospital LOS for the first 6 months after surgery, direct medical expenses and hospital LOS in THA were relatively reduced compared to the HA up to 24 months after surgery (p < 0.05). In the subgroup analysis, the THA group's hospital LOS decreased significantly compared to that of the HA group during the 7 to 36 months postoperative period in the 65 ≤ age < 80 age group (p < 0.05). Direct medical expenses of the THA group significantly decreased compared to those of the HA group during the period from 7 to 24 months after surgery in the men group (p < 0.05). When performing THA in elderly patients with femoral neck fractures, the possibility of survival for at least 2 years should be considered from the perspective of medical expense and medical utilization. Additionally, in healthy and active male femoral neck fracture patients under the age of 80 years, THA may be more recommended than HA.

Modelling diameter at breast height distribution of jack pine and black spruce natural stands in eastern Canada

Individual tree diameter at breast height (DBH) distribution is an important information for forest management planning. Forest managers obtain the DBH data either by field measurements or estimations using predictive models. However, probability distribution models are still lacking or need improvement. Therefore, we aimed to construct and fit diameter distribution models that reflect forest structure and composition change. We evaluated gamma, log-normal, and Weibull probability distribution functions (PDFs) for two commercially important tree species, black spruce ( Picea mariana (Mill) B.S.P.) and jack pine ( Pinus banksiana Lamb), grown in natural stands across Ontario, Canada. We modelled the parameters of the distributions as a function of stand-level variables for these species. We used DBH data from 735 permanent sample plots. Our results showed that all three evaluated PDFs reflected observed DBH distribution. We demonstrated that the moment-based recovered parameters could represent the maximum likelihood-estimated parameters precisely, and parameters of the PDFs can be modelled as a function of stand-level dynamic covariates. The models unbiasedly predicted the PDF parameters DBH means and DBH classes. The R2 of the model fit ranged between 0.35 and 0.98 for the predicted parameters and 0.90 and 0.97 for the predicted DBH.

Menstruation-related symptoms are associated with physical activity and midpoint of sleep: a pilot study.

Menstruation-related symptoms (MRSs) significantly impact women's health and contribute to economic burdens worldwide. Current interventions, primarily pharmacological ones, have limitations and side effects that underscore the need for alternative management strategies. This study explores the association between MRSs and lifestyle factors, specifically physical activity and sleep timing across menstrual cycle phases, to inform non-pharmacological intervention development. Fourteen female students from Ritsumeikan University, Japan, with regular menstrual cycles (25-38 days), not on hormonal treatment or engaged in shift work, participated in this observational study. Using a Fitbit Inspire 2, total daily energy expenditure (TDEE) and sleep timing were monitored over a complete cycle. Menstrual cycle phases were defined based on ovulation day, predicted using home luteinizing hormone tests. Participants completed daily electronic questionnaires rating MRSs using a modified menstrual distress questionnaire. Data were analyzed using a generalized linear mixed model with a gamma distribution and logarithmic link function, examining the relationship of TDEE and the midpoint of sleep time (MS time) with MRS severity. The following observations were noted: first, MRS severity, except for behavioral change symptoms, significantly increased during the menstrual and luteal phases compared to the follicular phase. Second, delayed MS time was associated with reduced pain, concentration symptoms, water retention, and negative affect during the menstrual phase and reduced negative affect during the luteal phase. Finally, an increase in TDEE was associated with reduced concentration symptoms, autonomic reaction symptoms, and negative affect during the menstrual and luteal phases and reduced water retention only during the luteal phase. This study provides insights into the relationship between MRSs and TDEE/MS time, suggesting potential non-therapeutic approaches for symptom management, though further research is needed to substantiate these findings for practical applications.

Study of convective air turbulence based on the probability distribution function of angle of arrival fluctuations

This study investigates the probability density function (PDF) of angle of arrival (AoA) fluctuations of a laser beam propagating through convective air turbulence in two settings: indoor turbulence and atmospheric surface layer. The indoor turbulence is generated by an electric heater with a 50 cm × 100 cm surface area placed horizontally on the bottom. The atmospheric turbulence experiments are conducted over a level at 60 cm height from an asphalted area using a slightly divergent laser beam that propagates along 350 m. Image motion monitoring of four sub-apertures installed in front of the receiving telescope aperture is used to record the AoA fluctuations and their PDFs over the entrance pupil at the sub-aperture locations for both types of turbulence. The observations are made in two perpendicular directions to the propagation of the laser beam. The experimental PDFs of the AoA fluctuations are fitted with Gaussian, Lognormal, Weibull, and Gamma distribution functions. The results show that the Weibull and Gamma models are more consistent with the experimental data for the indoor convective air and atmospheric turbulence respectively. For the indoor convective turbulence, the full width at half maximum and the peak location of the measured PDFs increase with the heater temperature, as well as the goodness of fit, which saturates at high temperatures.

Utilization and costs of health care and early support services in Germany and the influence of mental health burden during the postnatal period

Limited evidence is available about health care utilization and its determinants in the vulnerable postnatal period for mothers and their children. Thus, the aim of our analyses was to assess determinants of health care and early support services utilization regarding mothers and their children and associated costs in the postnatal period in Germany. Moreover, we aimed to investigate the impact of noticeable mental health and psychosocial burdens on health care and early support services utilization and costs. Using a two-step assessment process of parents from a randomly selected sample of 30,000 recently born children in the multicenter observational population-based cohort study of the SKKIPPI project, we firstly identified mothers who were potentially at risk of mental health and psychosocial burden. These mothers were then invited to participate in an in-depth assessment, including a detailed self-developed questionnaire focusing on early support and health care services utilization. A follow-up after 6 months was conducted. Potential determinants of early support services utilization were analyzed using logistic regression. General linear models with gamma distribution and log link functions were applied to analyze potential determinants of health care costs and to estimate mean adjusted costs. Mothers with a noticeable mental health or psychosocial burden and their children caused mean early support services costs of €1073 and caused total costs of €10,849 in the postnatal period from a payer’s perspective compared to €349 (early support services) and €9136 (total costs) for mothers without a noticeable mental health or psychosocial burden and their children. The main determinants of total costs were facing a chronic disease (child), preterm delivery, bad experiences with doctors and midwives, and single parenthood. The majority of participants (69 %) utilized some kind of early support services. The most important determinants of early support service utilization in the postnatal period with respect to the children were facing a chronic disease, being the first child, and being born as a twin. Our findings highlight the importance of sufficient appreciation and treatment of mental health problems in the postnatal period from both a societal and payer’s perspective. Future research should investigate whether these and more specific interventions could be a cost-effective way to support mothers with mental health or psychosocial burden and their children.

Racial differences in healthcare expenditures for prevalent multimorbidity combinations in the USA: a cross-sectional study

BackgroundWe aimed to model total charges for the most prevalent multimorbidity combinations in the USA and assess model accuracy across Asian/Pacific Islander, African American, Biracial, Caucasian, Hispanic, and Native American populations.MethodsWe used Cerner HealthFacts data from 2016 to 2017 to model the cost of previously identified prevalent multimorbidity combinations among 38 major diagnostic categories for cohorts stratified by age (45–64 and 65 +). Examples of prevalent multimorbidity combinations include lipedema with hypertension or hypertension with diabetes. We applied generalized linear models (GLM) with gamma distribution and log link function to total charges for all cohorts and assessed model accuracy using residual analysis. In addition to 38 major diagnostic categories, our adjusted model incorporated demographic, BMI, hospital, and census division information.ResultsThe mean ages were 55 (45–64 cohort, N = 333,094) and 75 (65 + cohort, N = 327,260), respectively. We found actual total charges to be highest for African Americans (means $78,544 [45–64], $176,274 [65 +]) and lowest for Hispanics (means $29,597 [45–64], $66,911 [65 +]). African American race was strongly predictive of higher costs (p < 0.05 [45–64]; p < 0.05 [65 +]). Each total charge model had a good fit. With African American as the index race, only Asian/Pacific Islander and Biracial were non-significant in the 45–64 cohort and Biracial in the 65 + cohort. Mean residuals were lowest for Hispanics in both cohorts, highest in African Americans for the 45–64 cohort, and highest in Caucasians for the 65 + cohort. Model accuracy varied substantially by race when multimorbidity grouping was considered. For example, costs were markedly overestimated for 65 + Caucasians with multimorbidity combinations that included heart disease (e.g., hypertension + heart disease and lipidemia + hypertension + heart disease). Additionally, model residuals varied by age/obesity status. For instance, model estimates for Hispanic patients were highly underestimated for most multimorbidity combinations in the 65 + with obesity cohort compared with other age/obesity status groupings.ConclusionsOur finding demonstrates the need for more robust models to ensure the healthcare system can better serve all populations. Future cost modeling efforts will likely benefit from factoring in multimorbidity type stratified by race/ethnicity and age/obesity status.

Pricing patterns of an indigenous goat in rural and urban communities in KwaZulu-Natal, South Africa

Agro-pastoralism plays an important role in the livelihoods of rural communities in many parts of the world. In southern Africa, small-scale rural farmers keep various kinds of livestock like goats for additional income and to meet their household needs. The objective of the study was to determine whether small-scale goat farmers obtained better prices for their animals at auctions as opposed to sales taking place at their homesteads. We quantified sales of indigenous goats that took place at homesteads and auctions, and determined the number, colour, sex, age, and the prices at which the goats were sold. We did this by collecting data on sales from 27 homesteads in the Msinga area of KwaZulu-Natal Province of South Africa during 2017 and 2018. Similarly, we collected data on sales at three goat auctions that took place at a rural and peri-urban centre located near Msinga and at another auction located at an urban centre distant from Msinga. All four auctions occurred between 2019 and 2022. The data were analysed using generalised linear models with a gamma distribution and log-link function. Results showed that male and female goats were sold in about equal numbers among all sales while subadult goats were more represented (55%) in the sales than adult goats (45%). At a mean price of ZAR1484.22 ± 30.23, a male goat was substantially cheaper than a female goat (R1911.81 ± 65.71) among all sales. Overall, the urban auction provided the best price, followed by homestead sales and the rural auction, and lastly the peri-urban site. Most of the animals that were not sold were returned from the peri-urban site. Adult goats fetched a significantly higher price than subadult goats, but at the auctions, this was also influenced by site, i.e. significant site × age interaction. Brown-coloured goats fetched the highest price at homesteads (R2287.50 ± 493.15) and auctions (R1965.10 ± 81.74) while black goats fetched similarly low prices of R1239.58 ± 147.37 and R1237.50 ± 519.82, respectively. Taken together, these results suggest that prices of indigenous goats sold at homesteads compare favourably or better than those obtained at local level auctions. Auctions at major urban centres may fetch higher prices but this may be offset by transport costs. Farmers may benefit from auctions when they need to sell many animals in a short time.

The feasibility of quantitative assessment of dynamic 18F-fluorodeoxyglucose PET in Takayasu's arteritis: a pilot study.

PET has been demonstrated to be sensitive for detecting active inflammation in Takayasu's arteritis (TAK) patients, but semi-quantitative-based assessment may be susceptible to various biological and technical factors. Absolute quantification via dynamic PET (dPET) may provide a more reliable and quantitative assessment of TAK-active arteries. The purpose of this study was to investigate the feasibility and efficacy of dPET in quantifying TAK-active arteries compared to static PET. This prospective study enrolled 10 TAK-active patients (fulfilled the NIH criteria) and 5 control participants from March to October 2022. One-hour dPET scan (all TAK and control participants) and delayed static PET scan at 2-h (all TAK patients) were acquired. For 1-h static PET, summed images from 50 to 60min of the dPET were extracted. PET parameters derived from 1- and 2-h static PET including SUV (SUV1H and SUV2H), target-to-background ratio (TBR) (TBR1H and TBR2H), net influx rate (Ki), and TBRKi extracted from dPET were obtained. The detectability of TAK-active arteries was compared among different scanning methods using the generalized estimating equation (GEE) with a logistic regression with repeated measures, and the GEE with gamma distribution and log link function was used to evaluate the different study groups or scanning methods. Based on the disease states, 5 cases of TAK were classified as untreated and relapsed, respectively. The SUVmax on 2-h PET was higher than that on 1-h PET in the untreated patients (P < 0.05). However, no significant differences were observed in the median SUVmax between 1-h PET and 2-h PET in the relapsed patients (P > 0.05). The TBRKi was significantly higher than both TBR1H and TBR2H (all P < 0.001). Moreover, the detectability of TAK-active arteries by dPET-derived Ki was significantly higher than 1-h and 2-h PET (all P < 0.001). Significant differences were observed in Kimax, SUVmax-1H, TBR1H, and TBRKi among untreated, relapsed, and control groups (all P < 0.05). Absolute quantitative assessment by dPET provides an improved sensitivity and detectability in both visualization and quantification of TAK-active arteries. This elucidates the clinical significance of dPET in the early detection of active inflammation and monitoring recurrence.

Modification of standardized precipitation index in different climates of Iran

AbstractThe most popular metric for drought monitoring is the standardized precipitation index (SPI). It does have some drawbacks, though, such as using gamma probability distribution function as the default distribution and not taking into account seasonal variations. The effectiveness of SPI in monitoring droughts in various Iranian climates was examined in this study, and in order to address its limitations, it was contrasted with the modified SPI (mod‐SPI). Then, the performance of the mod‐SPI and SPI in drought monitoring was compared with nine meteorological stations throughout Iran during the period 1956–2010. The results showed that the gamma distribution function was not selected in any of the 12 timescales (TS) considered at the studied meteorological stations. Based on the Cohen's kappa index analysis, there is a clear difference between the SPI and mod‐SPI in monitoring drought classes, which is more evident at low TS (less than 6 months), but at much higher TS (above TS‐9), the two indices almost coincide. The results showed that in the arid and semiarid areas, the SPI and mod‐SPI are significantly different, so it seems that the SPI monitors aridity rather than drought. The results imply that using mod‐SPI instead of SPI provides more accurate drought monitoring by eliminating the seasonal effects of precipitation data. Considering the low efficiency of SPI in short‐term drought monitoring (less than 9 months) in arid and semiarid regions, it is recommended to use mod‐SPI instead of SPI in most parts of Iran, especially on the southern coasts of Iran.

Diffusion and incidence of helium on tungsten surface

In this study, we investigated the diffusion and incidence of helium on tungsten surfaces using first principles and molecular dynamics methods. For three common tungsten surfaces (100, 111, 110), we found that the diffusion barrier of helium is positively/negatively correlated with the interatomic spacing/surface atomic density. The diffusion barriers of helium are relatively similar on the three surfaces, ranging from 5.82 to 6.50 eV. The diffusion barrier of helium on the tungsten surface represents the lower limit of the incidence barrier for helium implantation into tungsten. In our simulation, only helium with an incidence energy greater than 7 eV has the potential to be implanted into tungsten. Generally speaking, the implantation ratio of helium increases with increasing incidence energy and decreases with increasing substrate temperature (although the effect is minor). At a constant temperature, the implantation ratio of helium exhibits an exponential relationship with the incidence energy. The depth distribution of helium can be well described by Gamma distribution function, and the shape and scale parameters of the gamma distribution function can be determined based on the mean and variance of the helium depth distribution. The proposed fitting function allows for the quantitative description of the mean and variance of the helium depth distribution based on the incidence conditions (incident energy E and substrate temperature T), thereby determining the helium depth distribution. This has important implications for the in-depth study of helium-induced tungsten surface fuzz formation.