Missing data estimation in extreme rainfall indices for the Metropolitan area of Cali - Colombia: An approach based on artificial neural networks
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ABSTRACT:
SUBMITTER: Ocampo-Marulanda C
PROVIDER: S-EPMC8626650 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The success of many projects linked to the management and planning of water resources depends mainly on the quality of the climatic and hydrological data that is provided. Nevertheless, the missing data are frequently found in hydroclimatic variables due to measuring instrument failures, observation recording errors, meteorological extremes, and the challenges associated with accessing measurement areas. Hence, it is necessary to apply an appropriate fill of missing data before any analysis. This paper is intended to present the filling of missing data of monthly rainfall of 45 gauge stations located in southwestern Colombia. The series analyzed covers 34 years of observations between 1983 and 2016, available from the Instituto de Hidrología, Meteorología y Estudios Ambientales (IDEAM). The estimation of missing data was done using Non-linear Principal Component Analysis (NLPCA); a non-linear generalization of the standard Principal Component Analysis Method via an Artificial Neural Networks (ANN) approach. The best result was obtained using a network with a [45-44-45] architecture. The estimated mean squared error in the imputation of missing data was approximately 9.8 mm. month-1, showing that the NLPCA approach constitutes a powerful methodology in the imputation of missing rainfall data. The estimated rainfall dataset helps reduce uncertainty for further studies related to homogeneity analyses, conglomerates, trends, multivariate statistics and meteorological forecasts in regions with information deficits such as southwestern Colombia.
| S-EPMC6811873 | biostudies-other
Project description:BackgroundColombia's climatological variety, added to pathogen diversity, creates local niches for infectious diseases. In Bogotá, respiratory syncytial virus causes 30%-52% of the cases of respiratory infections. In coastal or inter-Andean cities with higher temperature and longer dry seasons, frequency of this virus is 7%-13%. By 2017, increased hospitalizations due to airway infections occurred in regions whose weather is differently influenced by "El Niño Southern Oscillation" than in Bogotá, although microbial diversity might have also been involved.MethodsFor Cali, an inter-Andean city with warm tropical weather, records of respiratory syncytial virus from 2014 to 2018, in children two years old or younger, were analyzed, and genotypes transmitted during 2016-2017 were identified based on partial sequences of glycoprotein G.ResultsMost cases of respiratory syncytial virus in Cali occur in the first semesters, with peaks expressed around March-April, without a clear association with pluviosity. Unlike the biannual rotating pattern of Bogotá, co-circulation of types A and B was detected. As years pass, transmission seasons are becoming longer and frequencies of the virus augment. The viral genotypes identified follow international trends with dominance of Ontario and Buenos Aires clades. Similar to other isolates in these clades, viruses from Cali exhibit glycosylation variability that may account for their fitness.ConclusionsThe pattern of respiratory syncytial virus transmission in Cali differs from that in Bogotá. Its epidemiology is shifting and will remain so with the advent of novel respiratory diseases. This may impact the introduction of vaccination schemes for these or other respiratory viruses.
| S-EPMC8189202 | biostudies-literature
Project description:The negative effects of coronavirus disease 2019 (COVID-19) pandemic have impacted the world economy due to the absence from work because of SARS-CoV-2 infection in workers, among other reasons. However, some economic areas are essential to society and people must continue working outside the home to support economic reactivation; their serological profile could be different from that of the global population. Cross-sectional study: Workers from health, construction, public transportation, public force, bike delivery messengers, independent or informal commerce areas, and residents of Bucaramanga or its metropolitan area were invited to participate. All participants self-completed a virtual survey and a blood test was taken to assess IgG and IgM with the ARC COV2 test. Seroprevalence was estimated considering a complex survey design, correcting for a finite population effect and adjusting for test performance. A total of 7045 workers were enrolled; 59.9% were women and most were residents of Bucaramanga and working in health occupations. The global adjusted seroprevalence was 19.5% (CI: 95% 18.6-20.4), being higher for Girón (27.9%; 95% CI: 24.5-31.30). Workers with multiple contact with people during working hours or using public transportation to go to work had a higher frequency of seropositivity for SARS-CoV-2. The seroprevalence among workers living in these four municipalities from the Colombian northeast area is still low.
| S-EPMC8071134 | biostudies-literature
Project description:Venereal syphilis is a multi-stage, sexually transmitted disease caused by the spirochetal bacterium Treponema pallidum (Tp). Herein we describe a cohort of 57 patients (age 18-68 years) with secondary syphilis (SS) identified through a network of public sector primary health care providers in Cali, Colombia. To be eligible for participation, study subjects were required to have cutaneous lesions consistent with SS, a reactive Rapid Plasma Reagin test (RPR-titer > or = 1 : 4), and a confirmatory treponemal test (Fluorescent Treponemal Antibody Absorption test- FTA-ABS). Most subjects enrolled were women (64.9%), predominantly Afro-Colombian (38.6%) or mestizo (56.1%), and all were of low socio-economic status. Three (5.3%) subjects were newly diagnosed with HIV infection at study entry. The duration of signs and symptoms in most patients (53.6%) was less than 30 days; however, some patients reported being symptomatic for several months (range 5-240 days). The typical palmar and plantar exanthem of SS was the most common dermal manifestation (63%), followed by diffuse hypo- or hyperpigmented macules and papules on the trunk, abdomen and extremities. Three patients had patchy alopecia. Whole blood (WB) samples and punch biopsy material from a subset of SS patients were assayed for the presence of Tp DNA polymerase I gene (polA) target by real-time qualitative and quantitative PCR methods. Twelve (46%) of the 26 WB samples studied had quantifiable Tp DNA (ranging between 194.9 and 1954.2 Tp polA copies/ml blood) and seven (64%) were positive when WB DNA was extracted within 24 hours of collection. Tp DNA was also present in 8/12 (66%) skin biopsies available for testing. Strain typing analysis was attempted in all skin and WB samples with detectable Tp DNA. Using arp repeat size analysis and tpr RFLP patterns four different strain types were identified (14d, 16d, 13d and 22a). None of the WB samples had sufficient DNA for typing. The clinical and microbiologic observations presented herein, together with recent Cali syphilis seroprevalence data, provide additional evidence that venereal syphilis is highly endemic in this region of Colombia, thus underscoring the need for health care providers in the region to be acutely aware of the clinical manifestations of SS. This study also provides, for the first time, quantitative evidence that a significant proportion of untreated SS patients have substantial numbers of circulating spirochetes. How Tp is able to persist in the blood and skin of SS patients, despite the known presence of circulating treponemal opsonizing antibodies and the robust pro-inflammatory cellular immune responses characteristic of this stage of the disease, is not fully understood and requires further study.
| S-EPMC2872645 | biostudies-literature
Project description:This data brief describes data collected in Cali, Colombia about the economic dynamic and socioeconomic conditions of street vendors in the city. The study was conducted between 2014 and 2016 in two populated sites in terms of formal and informal commerce in the city. We present the methodology followed in the study, location of street vending sites and type of data collected to approximate to the economic dimension of street vending. Data collected contains information about sociodemographic characteristics, life satisfaction, business operation and characteristics, income and expenses, official license for operation. This information is linked to the publication (Martinez et al., 2017) [1].
| S-EPMC5537378 | biostudies-literature
Project description:IntroductionHead and neck cancer (HNC) is the seventh most common type of cancer in the world. In Latin America, data on HCN are limited by the scarcity of population-based cancer registries.ObjectiveTo describe survival and changes in the time trends of incidence and mortality rates of HCN with data from the Cali Cancer Population Registry (Colombia) during 1962-2018.MethodMales and females of any age residing in Cali were included. The trends in incidence rates (1962-2016) and mortality (1984-2018) were analysed by calculating the mean annual percentage change (APC). Five-year net survival was estimated for the four 5-year periods of 1996-2015 using the Pohar-Perme method.ResultsDuring 1962-2015, 5,110 new cases of HNC were recorded: 1,506 in the larynx, 1,377 in the oral cavity, 487 in the nose and paranasal sinuses, 643 in the oropharynx, 603 in the salivary glands and 360 in Naso-Hypopharynx region. The incidence rates of HNC decreased significantly at all subsites, except in those associated with the human papillomavirus. Between 1984 and 2018, there were 1,941 deaths attributed to HNC, and the mortality rate decreased significantly. The 5-year age-standardized net survival was 43.2% in 1996-2000, remained stable during the following decade, and for 2011-2015 it was 50.9%.ConclusionThe incidence and mortality of HNC in Cali decreased significantly during the study period in both sexes.
| S-EPMC8651828 | biostudies-literature
Project description:This data article describes two data sets about the socioeconomic conditions of recyclers in Cali, the third largest city in Colombia, South America. Data collected were aimed at understanding the social and economic conditions of this population in order to provide information for crafting policy alternatives for poverty alleviation. Information was collected in two waves in 2013 and in 2015. The first data collection (2013) was focused on a subgroup of recyclers and the second data collection (2015) was a census. In total, more than 3000 direct surveys to recyclers were conducted at individual and family level. In both data collection rounds, information about socioeconomic factors, health, working conditions, access to welfare programs and family composition was gathered. Both data rounds were financed by the local government as an input to design policy interventions to improve the recyclers' quality of life in the city. The data of this manuscript is associated with the publication (Estrada et al., 2017).
| S-EPMC6369313 | biostudies-literature
Project description:The co-occurrence of COVID-19 with endemic diseases is a public health concern that may affect patient prognosis and outcomes. The objective of this study was to describe the clinical characteristics of patients with dengue virus (DENV) and SARS-CoV-2 co-infections and compare their outcomes against those of COVID-19 patients without dengue. A cross-sectional study was conducted in patients with SARS-CoV-2 infection who attended a single center in Cali, Colombia, from March 2020 to March 2021. All patients who were tested by both real-time polymerase chain reaction for SARS-CoV-2 and IgM/NS1 for DENV were included. Dengue was diagnosed as having either an IgM- or an NS1- positive test. A total of 90 patients were included (72 with COVID-19 only and 18 with co-infection). Patients with co-infection had more dyspnea (61.1% versus 22.2%; P = 0.003) as well as higher oxygen desaturation (53.3% versus 13.4%; P = 0.002) and neutrophil-to-lymphocyte ratio (5.59 versus 3.84; P = 0.038) than patients with COVID-19 alone. The proportion of patients classified with moderate to severe COVID-19 was higher in the co-infection group (88.3% versus 47.8%; P = 0.002). Also, co-infection was associated with an increased need for mechanical ventilation (P = 0.06), intensive care unit (ICU) initial management (P = 0.02), and ICU admission during hospitalization (P = 0.04) compared with COVID-19 only. The ICU mortality rate was 66.6% in patients with co-infection versus 29.4% in patients infected with only SARS-CoV-2 (P < 0.05). The possibility of DENV and SARS-CoV2 co-infection occurred in the convergence of both epidemic waves. Co-infection was associated with worse clinical outcomes and higher mortality in ICU-admitted patients than in patients with the COVID-19 only.
| S-EPMC10484269 | biostudies-literature
Project description:BackgroundCardiovascular disease (CVD) is the leading cause of mortality worldwide and in Colombia. The analysis of CVD mortality has been mainly relied on individual factors and rates, but occurrence is also related to contextual conditions. Understanding the distribution of CVD in a region will contribute to implement more focused-preventive and care interventions.MethodsUsing the national mortality register established by the Department of National Statistics, standardized rates and spatial distribution of CVD mortality were estimated for Cali, Colombia, between 2010-2017. Global and local spatial aggregation was assessed using the Geary's C test and for each district standardized mortality ratios smoothed by the Bayesian empirical were estimated.ResultsOver the period, CVD was the main cause of mortality with 28,804 deaths accounting for 23,8% of total deaths. The global CVD mortality rate varied from 235.9 to 257.4 per 100.000 habitants, with an average increase of 9.1% in the percentage change. The main cause of mortality were hypertensive diseases following by ischemic heart diseases and stroke. The standardized mortality ratios smoothed by the Bayesian empirical method showed that the districts 7, 13, 14, 15 and 16 located at the eastern area with the lowest socio-economic strata and the district 22 at the south of the city with the highest socio-economic strata had the high risks of CVD mortality. All these areas were at the boundary of the city. The the lowest risk was observed in districts 1 and 2 at the northwest area with the upper socio-economic strata. Over the study period, a spatial autocorrelation was found in the districts 1,9 10, 11, 12, 13, 14, 15, 19, and 21 by using the Geary's C test. The highest significant spatial association was found in the districts 1 and 21.ConclusionOf 22 districts in Cali, the highest risk of CVD mortality was found in three at the lowest and one in the upper socio-economic strata between 2013 and 2017. Over the period a global spatial aggregation was identified due mainly to districts peripherical located suggesting that there could be contextual conditions influencing the risk. Therefore, there is a need for considering local conditions to prevent CVD mortality.
| S-EPMC10064751 | biostudies-literature
Project description:BackgroundThe third wave of the global health crisis attributed to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus reached Colombia in March 2021. Over the following 6 months, it was interpolated by manifestations of popular disapproval to the actual political regime-with multiple protests sprouting throughout the country. Large social gatherings seeded novel coronavirus disease 2019 (COVID-19) variants in big cities and propagated their facile spread, leading to increased rates of hospitalizations and deaths.MethodsIn this article, we evaluate the effective reproduction number (Rt) dynamics of SARS-CoV-2 in Cali, Colombia, between 4 April 2021 and 31 July 2021 based on the analysis of 228 genomes.ResultsOur results showed clear contrast in Rt values between the period of frequent protests (Rt > 1), and the preceding and following months (Rt < 1). Genomic analyses revealed 16 circulating SARS-CoV-2 lineages during the initial period-including variants of concern (VOCs) (Alpha, Gamma, and Delta) and variants of interest (VOIs) (Lambda and Mu). Furthermore, we noticed the Mu variant dominating the COVID-19 distribution schema as the months progressed. We identified four principal clusters through phylogenomic analyses-each one of potentially independent introduction to the city. Two of these were associated with the Mu variant, one associated with the Gamma variant, and one with the Lambda variant.ConclusionOur results chronicle the impact of large group assemblies on the epidemiology of COVID-19 during this intersection of political turmoil and sanitary crisis in Cali, Colombia. We emphasize upon the effects of limited biosecurity strategies (which had characterized this time period), on the spread of highly virulent strains throughout Cali and greater Colombia.
| S-EPMC9008484 | biostudies-literature