Arterial hypertension is one of the most prevalent chronic, non-communicable diseases and the leading preventable risk factor for cardiovascular disease (CVD) and all-cause mortality worldwide. ...Although its primary causes and consequences are preventable, it often remains undiagnosed. Consequently, this study aims to determine the prevalence and factors associated with normotensive, diagnosed, and undiagnosed hypertension in adults. A cross-sectional, population-based study was conducted in Sabaneta, Colombia, between 2021 and 2022, with 286 adults aged 18 and older. Stratified and systematic random sampling methods were employed. The World Health Organization STEP survey and the Perez Rojas test were utilized to assess behavioral risk factors and sedentary lifestyles. Body mass index, waist circumference, and arterial tension were measured using standardized instruments. The prevalence of hypertension was then estimated. Risk factors influencing normotensive, diagnosed, and undiagnosed hypertension were analyzed using multinomial regression. The outcome variable comprised three categories: normotensive (reference category), diagnosed hypertension, and undiagnosed hypertension. The multinomial regression coefficients were exponentiated and are presented as relative risk ratios (RRR) with 95% confidence intervals (CI). The model was adjusted for sex and sample weight per neighborhood. The study revealed a hypertension prevalence of 38.5% and an undiagnosed hypertension rate of 50.9%. Those with undiagnosed hypertension were predominantly adults over 60 years (RRR = 0.68; 95% CI: 0.53-0.86), individuals with an elementary school education (RRR = 1.75; 95% CI: 1.27-2.42), those physically active (RRR = 1.52; 95% CI: 1.22-1.89), without prior diagnoses of chronic comorbidities (RRR = 1.42; 95% CI: 1.12-1.82), and with obesity (RRR = 2.25; 95% CI: 1.63-3.11) or overweight conditions (RRR = 1.70; 95% CI: 1.334-2.15). Undiagnosed hypertension was significant among populations without risk conditions. There is an urgent need for community-based early detection and education strategies to mitigate this issue.
School violence and bullying are current and problematic events during adolescence. They are likely to have a marked presence in places highly exposed to armed conflict and violent environments, ...representing a double public health problem. The study aims to estimate the prevalence of different types of school violence perpetrated and experienced by school adolescents in a community with a history of exposure to armed conflict. Two thousand one hundred eighty-five school adolescents from a municipality in Colombia (males = 54.1%, 14–16 years = 38.6%) participated in the study. Nine educational institutions were included. A systematic random sampling was designed, with a proportional allocation of 35% within each school year from sixth to eleventh grade. The School Coexistence and Circumstances Affecting it—ECECA survey was applied. The prevalence and risks of bully and bullying were estimated. RRa were calculated with the 95% confidence interval adjusted for the other confounding variables. Analyses were constructed from generalized linear models, under the Poisson family and a logarithmic link function. We found a 9.3% of bullying victimization and a 3.5% prevalence of bully. A higher risk of bully was found among males, persons between 10 and 14 years of age, residents of rural or urban dispersed areas, residents of violent neighborhoods, alcohol consumers at school, and victims of aggression in childhood (RRa > 1.0, p-values <.05). The risk of victimization of bullying was higher in students younger than 15 years old, as residents of urban areas, having a history of childhood aggression, suffering abuse by a close person, and as alcohol users at school. This study provides evidence of risk factors for aggression and bullying that have implications for possible prevention measures in multiple social domains, including the individual, the family, and the school environment.
Zika, a viral disease transmitted to humans by Aedes mosquitoes, emerged in the Americas in 2015, causing large-scale epidemics. Colombia alone reported over 72,000 Zika cases between 2015 and 2016. ...Using national surveillance data from 1121 municipalities over 70 weeks, we identified sociodemographic and environmental factors associated with Zika's emergence, re-emergence, persistence, and transmission intensity in Colombia. We fitted a zero-state Markov-switching model under the Bayesian framework, assuming Zika switched between periods of presence and absence according to spatially and temporally varying probabilities of emergence/re-emergence (from absence to presence) and persistence (from presence to presence). These probabilities were assumed to follow a series of mixed multiple logistic regressions. When Zika was present, assuming that the cases follow a negative binomial distribution, we estimated the transmission intensity rate. Our results indicate that Zika emerged/re-emerged sooner and that transmission was intensified in municipalities that were more densely populated, at lower altitudes and/or with less vegetation cover. Warmer temperatures and less weekly-accumulated rain were also associated with Zika emergence. Zika cases persisted for longer in more densely populated areas with more cases reported in the previous week. Overall, population density, elevation, and temperature were identified as the main contributors to the first Zika epidemic in Colombia. We also estimated the probability of Zika presence by municipality and week, and the results suggest that the disease circulated undetected by the surveillance system on many occasions. Our results offer insights into priority areas for public health interventions against emerging and re-emerging Aedes-borne diseases.
In this paper we investigate the Kummer pairing associated to an arbitrary (one-dimensional) formal group. In particular, we obtain formulae describing the values of the pairing in terms of ...multidimensional p-adic differentiation, the logarithm of the formal group, the generalized trace and the norm on Milnor K-groups. The results are a generalization to higher-dimensional local fields of Kolyvagin's explicit reciprocity laws. In particular, they constitute a generalization of the reciprocity laws of Artin-Hasse, Iwasawa and Wiles.
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•We investigate the formation and migration of sand ripples in closed conduits.•Turbulent water flows were imposed over a granular bed in a transparent channel.•The growth and ...migration of ripples were filmed by a high-definition camera.•The length and celerity of ripples were determined by post-processing the images.
The transport of solid particles by a fluid flow is frequently found in nature and industry. Some examples are the transport of sand in rivers and hydrocarbon pipelines. When the shear stresses exerted by a fluid flow on a granular bed remain moderate, some grains are set in motion without fluidizing the bed; the moving grains form a layer, known as bed load, that moves while maintaining contact with the fixed part of the bed. Under bed load conditions, the granular bed may become unstable, generating ripples and dunes. Sand ripples are commonly observed in closed conduits and pipes such as in petroleum pipelines, sewer systems, and dredging lines. Although of importance for many scientific domains and industrial applications, the formation of ripples in closed conduits is not well understood, and the problem is still open. This paper presents an experimental study on the formation and migration of sand ripples under a turbulent closed-conduit flow and bed-load conditions. In our experiments, fully-developed turbulent water flows were imposed over a granular bed of known granulometry in a transparent channel, and bed load took place. For different water flow rates and grain diameters, the growth and migration of bedforms were filmed by a high-definition camera, and a numerical code was developed to determine the wavelength and celerity of the bedforms from the acquired images. The obtained results are compared with published stability analyses.
To estimate the risk factors for SARS-CoV-2 transmission in close contacts of adults at high risk of infection due to occupation, participants of the CoVIDA study, in Bogotá D.C., Colombia.
The ...CoVIDA study was the largest COVID-19 intensified sentinel epidemiological surveillance study in Colombia thus far, performing over 60 000 RT-PCR tests for SARS-CoV-2 infection. The study implemented a contact tracing strategy (via telephone call) to support traditional surveillance actions performed by the local health authority.
Close contacts of participants from the CoVIDA study.
SARS-CoV-2 testing results were obtained (RT-PCR with CoVIDA or self-reported results). The secondary attack rate (SAR) was calculated using contacts and primary cases features.
The CoVIDA study performed 1257 contact tracing procedures on primary cases. A total of 5551 close contacts were identified and 1050 secondary cases (21.1%) were found. The highest SAR was found in close contacts: (1) who were spouses (SAR=32.7%; 95% CI 29.1% to 36.4%), (2) of informally employed or unemployed primary cases (SAR=29.1%; 95% CI 25.5% to 32.8%), (3) of symptomatic primary cases (SAR of 25.9%; 95% CI 24.0% to 27.9%) and (4) living in households with more than three people (SAR=22.2%; 95% CI 20.7% to 23.8%). The spouses (OR 3.85; 95% CI 2.60 to 5.70), relatives (OR 1.89; 95% CI 1.33 to 2.70) and close contacts of a symptomatic primary case (OR 1.48; 95% CI 1.24 to 1.77) had an increased risk of being secondary cases compared with non-relatives and close contacts of an asymptomatic index case, respectively.
Contact tracing strategies must focus on households with socioeconomic vulnerabilities to guarantee isolation and testing to stop the spread of the disease.
Abstract
Background
The use of respiratory devices can mitigate the spread of diseases such as COVID-19 in community settings. We aimed to determine the effectiveness of closed face shields with ...surgical face masks to prevent SARS-CoV-2 transmission in working adults during the COVID-19 pandemic in Bogotá, Colombia.
Methods
An open-label non-inferiority randomized controlled trial that randomly assigned participants to one of two groups: the intervention group was instructed to wear closed face shields with surgical face masks, and the active control group was instructed to wear only surgical face masks. The primary outcome was a positive reverse transcription polymerase chain reaction test, IgG/IgM antibody test for SARS-CoV-2 detection, or both during and at the end of the follow-up period of 21 days. The non-inferiority limit was established at − 5%.
Results
A total of 316 participants were randomized, 160 participants were assigned to the intervention group and 156 to the active control group. In total, 141 (88.1%) participants in the intervention group and 142 (91.0%) in the active control group completed the follow-up. Primary outcome: a positive SARS-CoV-2 test result was identified in one (0.71%) participant in the intervention group and three (2.1%) in the active control group. In the intention-to-treat analysis, the absolute risk difference was − 1.40% (95% CI − 4.14%, 1.33%), and in the per-protocol analysis, the risk difference was − 1.40% (95% CI − 4.20, 1.40), indicating non-inferiority of the closed face shield plus face mask (did not cross the non-inferiority limit).
Conclusions
The use of closed face shields and surgical face masks was non-inferior to the surgical face mask alone in the prevention of SARS-CoV-2 infection in highly exposed groups. Settings with highly active viral transmission and conditions such as poor ventilation, crowding, and high mobility due to occupation may benefit from the combined use of masks and closed face shields to mitigate SARS-CoV-2 transmission.
Trial registration
ClinicalTrials.gov
NCT04647305
. Registered on November 30, 2020
Using previously constructed reciprocity laws for the generalized Kummer pairing of an arbitrary (one-dimensional) formal group, in this article a special consideration is given to Lubin-Tate formal ...groups. In particular, this allows for a completely explicit description of the Kummer pairing in terms of multidimensional p-adic differentiation. The results obtained here constitute a generalization, to higher local fields, of the formulas of Artin-Hasse, Iwasawa, Kolyvagin and Wiles.
•This paper examines the effects of supermarket loyalty programs on the demand for private labels.•I find a significant effect of loyalty programs on consumer preferences for PLs.•Membership reduces ...consumers’ price sensitivity for the products sold by the supermarket they are members of.•Membership increases consumers’ price sensitivity for products sold by supermarkets they are not members of.•These effects are weaker for households that are members of the loyalty programs of multiple supermarkets.
This paper examines the effects of supermarket loyalty programs (LPs) on the demand for private labels (PLs). Using transaction level data on grocery purchases and individual level information on the membership of loyalty programs, I estimate a model of demand in which membership may affect the consumers’ valuation for PLs, their sensitivity to price changes and have spillover effects on both named brands (NBs) and rivals’ PLs. My identification strategy of the membership effect exploits observed variation in shopping patterns at the consumer level over time and includes a control function using LP characteristics as instrumental variables to account for a potential selection bias related to unobserved factors of the membership decision. I find a significant effect of LPs on consumer preferences for PLs. Compared to non-members, membership reduces consumers’ price sensitivity for the products sold by the supermarket they are members of, but increases it for products sold by supermarkets they are not members of. These effects are weaker for households that are members of the LPS of multiple supermarkets. Further, I use my demand model along with a supply model to simulate counterfactual scenarios in which supermarkets unilaterally modify their LPs to make it more difficult for customers to benefit from them. I find a considerable decrease in the demand for PLs and an increase in the demand for NBs. In response, supermakets decrease PLs’ prices and increase NBs prices in order to partially offset the impact on PLs’ demand.
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