Using Particle Swarm Optimization to Determine the Optimal Strata Boundaries

Stratified random sampling is a commonly used sampling methodology especially for heterogeneous populations with outliers. Stratified sampling is preferably employed due to its capability of improving statistical precision by yielding a smaller variance of the estimator, compared with simple random sampling. In order to reduce the variance of the estimator in stratified sampling, the problems of stratum boundary determination and sample allocation must be resolved initially. This paper proposes a PSO algorithm to solving the problem of stratum boundary determination in heterogeneous populations while distributing the sample size according to Neyman allocation method. The PSO algorithm is tested on two groups of populations and a comparative study with Kozak, GA and Delanius and Hodges methods have been implemented. The numerical results show the ability of the proposed algorithm to find the optimal stratified boundaries for a set of standard populations and various standard test functions compared with other algorithms

Spatial distribution, determinants and trends of full vaccination coverage in children aged 12-59 months in Peru: A subanalysis of the Peruvian Demographic and Health Survey

Objective To assess the spatial distribution, trends and determinants of crude full vaccination coverage (FVC) in children aged 12-59 months between 2010 and 2019 in Peru. Design, setting and analysis A cross-sectional study based on the secondary data analysis of the 2010 and 2019 Peruvian Demographic and Health Surveys (DHSs) was conducted. Logit based multivariate decomposition analysis was employed to identify factors contributing to differences in FVC between 2010 and 2019. The spatial distribution of FVC in 2019 was evaluated through spatial autocorrelation (Global Moran's I), ordinary kriging interpolation (Gaussian process regression) and Bernoulli-based purely spatial scan statistic. Outcome measure FVC, as crude coverage, was defined as having completely received BCG; three doses of diphtheria, pertussis, and tetanus, and polio vaccines; and measles vaccine by 12 months of age. Participants A total of 5 751 and 14 144 children aged 12-59 months from 2010 and 2019 DHSs, respectively, were included. Results FVC increased from 53.62% (95% CI 51.75% to 55.49%) in 2010 to 75.86% (95% CI 74.84% to 76.85%) in 2019. Most of the increase (70.39%) was attributable to differences in coefficients effects. Family size, visit of health workers in the last 12 months, age of the mother at first delivery, place of delivery and antenatal care follow-up were all significantly associated with the increase. The trend of FVC was non-linear and increased by 2.22% annually between 2010 and 2019. FVC distribution was heterogeneous at intradepartmental and interdepartmental level. Seven high-risk clusters of incomplete coverage were identified. Conclusions Although FVC has increased in Peru, it still remains below the recommended threshold. The increase of FVC was mainly attributed to the change in the effects of the characteristics of the population. There was high heterogeneity across Peruvian regions with the presence of high-risk clusters. Interventions must be redirected to reduce these geographical disparities.Revisión por pare

Cannabis and the Brain: Friend or Foe?

Legalization of cannabis in the US and other countries highlight the need to understand the health consequences of this substance use. Research indicates that some cannabis ingredients may play beneficial role in treating various medical conditions while other ingredients may pose health risks. This review is focused on the brain and mental health effects of cannabis use. The rationale for examining cannabis use in behavioral and neural conditions is that these conditions are highly widespread in the US and account for high level of medical healthcare and associated cost. The purpose of this review is to provide an overview of the known medicinal benefits of selected cannabis cannabinoids in conditions like pediatric epilepsy, attention deficit hyperactivity disorder, autism spectrum disorder, and the known side effects or contraindications in conditions such as addiction, cognition, and psychosis. Several recommendations are made as to studies that will help further understanding the increasing role of cannabis in neuropsychiatric health and disease

Detection of local Bacillus subtilis producing Endo-β-1,4-glucanase Of Thi Qar province

The study included  isolating  and  diagnosing of Bacillus subtilis  different soils at  Thi Qar province. The ability of bacterial isolates to produce Endo-β-1,4-glucanase was determined after growing on carboxymethyl cellulose CMC medium, Using Congo red and NaCl.  Enzyme  Endo-β-1,4-glucanase  isolates were  identified using   biochemical tests and VITEK2 as B. subtilis. Isolates were identified using  16S rRNA tests after extraction of DNA from isolates and amplified by PCR using 27F primers (Forward) and 1492R  (Reverse) . All isolates in the current study were positive for this gene and the size of the gene for all isolates was at 1500 pb. After identifying the gene sequences and comparing them with the data available in the Gen Bank, NCBI  data  showed  that they were  new  strains of B. subtilis strain m1 (MF449304) and B. subtilis strain M2 (MF449461) bacteria. Isolates were recorded in NCBI GenBank and were design for each evolutionary tree isolation by Software MEGA6. After the diagnosis of bacterial  isolates, the ideal conditions for the production of Endo-β-1,4-glucanase were changed for incubation period, temperature, pH , Incubator Shake, carbon and   nitrogen sources. Enzymatic efficacy was determined using of dinitro salicylic acid DNS detector to detect the glucose releasing  glucose molecules  Endo-β-1,4-glucanase. The enzyme was  produced  after growing of bacterial  isolates of  plant  culture containing  plant and cardboard residues as natural sources of carbon and alternative to costly industrial sources as a source of carbon  at a concentration of 1%  at  45 ° C for 48 hours and  pH (6 - 5) The highest  wheat bran and  millet bran  has superior efficacy over  other  natural and  industrial sources were used as an alternative to the  industrial  nitrogen  source of peptone with a concentration of 1%. The malt extract  as the best nitrogen source for all isolates in the present study was superior to all other nitrogen sources. Other sources came from either banana Peel that showed no growth for all isolates. The study aimed to isolate and diagnose B. subtilis producing an  Endoglucanases  using cheap natural sources as alternatives source to reduce to costly carbon  cost of and nitrogen sources and benefiting from biological treatment of agricultural and industrial waste

Detection of local Bacillus subtilis producing Endo-?-1,4-glucanase Of Thi Qar province

The study included  isolating  and  diagnosing of Bacillus subtilis  different soils at  Thi Qar province. The ability of bacterial isolates to produce Endo-?-1,4-glucanase was determined after growing on carboxymethyl cellulose CMC medium, Using Congo red and NaCl.  Enzyme  Endo-?-1,4-glucanase  isolates were  identified using   biochemical tests and VITEK2 as B. subtilis. Isolates were identified using  16S rRNA tests after extraction of DNA from isolates and amplified by PCR using 27F primers (Forward) and 1492R  (Reverse) . All isolates in the current study were positive for this gene and the size of the gene for all isolates was at 1500 pb. After identifying the gene sequences and comparing them with the data available in the Gen Bank, NCBI  data  showed  that they were  new  strains of B. subtilis strain m1 (MF449304) and B. subtilis strain M2 (MF449461) bacteria. Isolates were recorded in NCBI GenBank and were design for each evolutionary tree isolation by Software MEGA6. After the diagnosis of bacterial  isolates, the ideal conditions for the production of Endo-?-1,4-glucanase were changed for incubation period, temperature, pH , Incubator Shake, carbon and   nitrogen sources. Enzymatic efficacy was determined using of dinitro salicylic acid DNS detector to detect the glucose releasing  glucose molecules  Endo-?-1,4-glucanase. The enzyme was  produced  after growing of bacterial  isolates of  plant  culture containing  plant and cardboard residues as natural sources of carbon and alternative to costly industrial sources as a source of carbon  at a concentration of 1%  at  4

Associated factors, inequalities, and spatial distribution of the use of modern contraceptive methods among women of reproductive age in Peru: a population-based cross-sectional study

Background: The use of contraceptive methods in Peru has remarkably increased in recent decades. Nevertheless, despite the completeness and accessibility of family planning methods, modern contraceptive methods utilization in Peru remains below the South American average. Thus, this study aimed to elucidate the factors associated with modern contraceptive use, as well as the presence of inequalities and the spatial distribution in Peruvian women aged 15–49 years in 2019. Methods: A secondary data analysis was conducted using information from the 2019 Peruvian Demographic and Health Survey. We performed descriptive statistics, bivariate analysis, and Poisson multiple regression. Inequalities were estimated through concentration curves and Erreygers’ normalized concentration index. Spatial analysis included choropleth map, Global Moran’s I, Kriging interpolation and Getis-Ord-Gi* statistic. Results: The prevalence of modern contraceptive use was 39.3% among Peruvian women of reproductive age. Modern contraceptive use was directly associated with youth (aPR 1.39), women having their first sexual intercourse before the age of 18 (aPR 1.41), and being married but not together (aPR 1.87). In addition, speaking Quechua or Aymara (aPR 0.87) and having no children (aPR 0.59) were inversely associated with utilization of modern contraceptives. We found the presence of inequalities in the use of contraceptive methods (pro-rich distribution), although the magnitude was low. Spatial analysis unveiled the presence of a clustered distribution pattern (Moran’s Index = 0,009); however, there was inter-departmental and intra-departmental heterogeneity in the predicted prevalence of the use of modern contraceptives. In addition, significant hot and cold spots were found in Peru. Conclusion: Two out of five Peruvian women of reproductive age used modern contraceptives. It was associated with younger women’s age, younger age at first sexual intercourse, being married or cohabitant, among others. No substantial inequality was found in modern contraceptive use. The prevalence was heterogeneous at the intra- and inter-departmental level. Those departments located in the south, south-east, and north-east had the lowest prevalence. Therefore, nonfinancial barriers must be tackled through multi- and cross-sectoral efforts and continue to universally provide modern contraceptives.Revisión por pare

Case report: Primary cardiac lymphoma manifesting as superior vena cava syndrome

A 64-year-old man presented with symptoms indicative of superior vena cava syndrome. Imaging work-up revealed an obstructing right atrial mass, which was subsequently excised and diagnosed as primary cardiac lymphoma. Post-surgery, the patient showed significant clinical improvement and was started on a chemotherapy regimen with complete remission at 1 year

Access to HIV/STI testing among male and female Venezuelan migrants in Peru: evidence from a nationwide survey

Background: Human immunodeficiency virus (HIV) infection and sexually transmitted infections (STIs) are major global public health issues. Migrants represent a vulnerable group that faces multiple barriers to access to healthcare services, including HIV/STI testing. This study aimed to assess the factors associated with access to HIV/STI testing in male and female Venezuelan migrants in Peru. Methods: This was a cross-sectional study involving secondary data analysis of the 2022 Venezuelan Population Residing in Peru Survey. The study was conducted in the eight most populated cities inhabited by Venezuelan migrants and refugees. For each city, the sampling design was probabilistic, stratified, and independent. The outcome variable was whether participants had access to HIV or other STI testing during their stay in Peru. Statistical analysis was stratified by sex owing to potential effect modification. Crude and adjusted prevalence ratios were calculated using generalized linear models Poisson family with log link function. Confidence intervals were calculated to 95%. Results: A total of 3,723 male and 3,984 female migrants were included. Access to HIV/STI testing among male and female migrants was 19.85% and 25.16%, respectively. Among male migrants, being LGBTI, health insured, and married or cohabiting were associated with increased access to HIV/STI testing. Among females, those aged 18–44 years, those who were married or cohabiting and were health insured, and those residing for more than 1 year in Peru were significantly more likely to have access to HIV/STI testing. Moreover, physical/mental disability and unemployed status were associated with a lower probability of HIV/STI testing in females. Conclusions: Only two in ten Venezuelan migrants and refugees in Peru were screened for HIV/STI, with fewer males than females. Sex-specific sociodemographic, health-related, and migration-related variables were independently associated with access to HIV/STI testing

Altitude and excess mortality during COVID-19 pandemic in Peru

We have read with interest the short communication published by Segovia-Juarez et al., 2020 in Respiratory Physiology & Neurobiology establishing that high altitude reduces the infection rate of COVID-19 but not the case fatality rate in the Peruvian setting. We support this hypothesis, however there could be an important number of under registered deaths on account of a low rate of diagnostic tests performed per inhabitant and mostly in symptomatic patients (Pasquariello and Stranges, 2020).Revisión por pare

Rural and urban disparities in anemia among Peruvian children aged 6-59 months: a multivariate decomposition and spatial analysis

Introduction: Anemia is a global public health issue that affects mainly children aged less than 5 years. In Peru, despite the reduction in the prevalence of anemia between 2010 and 2018, anemia remains a major concern, especially in high-risk zones such as rural areas. Several sociodemographic factors have been associated with anemia in children; however, components contributing to the urban–rural gap have not been previously assessed. The purpose of this study was to evaluate the determinants of the difference in anemia prevalence between urban and rural areas, and its spatial distribution in Peruvian children aged 6–59 months. Methods: A secondary data analysis was conducted using the 2019 Peruvian Demographic Health Survey. The study population included 18 846 children aged 6–59 months. A multivariate decomposition analysis for non-linear response model was performed to identify the factors contributing to the gap in the prevalence of anemia across urban and rural areas. Global Moran's I autocorrelation, Ordinary Kriging interpolation and Bernoullibased purely spatial scan statistics were employed to assess the spatial pattern of anemia. Results: Nationwide, the prevalence of anemia in Peru was 29.47% (95%CI 28.63–30.33). In rural areas, it was 38.25%, and in urban areas 26.39%. The decomposition analysis revealed that 88.61% of the difference in the prevalence of anemia between urban and rural areas was attributed to the difference in the respondents’ characteristics. Wealth index, mother's education, mother's employment status, number of living children and mother's age were key determinants contributing to the rural–urban gap. Spatial heterogeneity of anemia prevalence in childhood was observed at both inter and intradepartmental level. The SaTScan spatial analysis identified six significant cluster areas with high prevalence of anemia in childhood. Conclusion: A considerable gap of anemia prevalence between urban and rural areas was found. Targeted interventions are necessary to reduce geographic disparities.Revisión por pare