A5002233749- Bayesian Methods and Mixture Models
- Statistical Methods and Inference
- Statistical Methods and Bayesian Inference
- SARS-CoV-2 and COVID-19 Research
- Vaccine Coverage and Hesitancy
- Genetic and phenotypic traits in livestock
- COVID-19 Clinical Research Studies
- Dental Health and Care Utilization
- Advanced Statistical Methods and Models
- Financial Risk and Volatility Modeling
- Stochastic processes and statistical mechanics
- Muscle Physiology and Disorders
- Global Cancer Incidence and Screening
- Colorectal Cancer Screening and Detection
- Gene expression and cancer classification
- Clostridium difficile and Clostridium perfringens research
- Oral microbiology and periodontitis research
- Control Systems and Identification
- Algorithms and Data Compression
- Pediatric health and respiratory diseases
- COVID-19 epidemiological studies
- SARS-CoV-2 detection and testing
- Antibiotic Use and Resistance
- Gut microbiota and health
- Gaussian Processes and Bayesian Inference
Pontificia Universidad Católica de Chile
2015-2025
Ministry of Health
2022-2023
Research Center for Integrated Disaster Risk Management
2021-2023
Millennium Science Initiative
2021-2022
Advanced Center for Chronic Diseases
2021
The University of Texas at Austin
2020
University of Chile
2002-2015
University of Minnesota
2008-2011
University of Concepción
2008-2011
Universidad Pontificia de México
2011
Mass vaccination campaigns to prevent coronavirus disease 2019 (Covid-19) are occurring in many countries; estimates of vaccine effectiveness urgently needed support decision making. A countrywide mass campaign with the use an inactivated severe acute respiratory syndrome 2 (SARS-CoV-2) (CoronaVac) was conducted Chile starting on February 2, 2021. We used a prospective national cohort, including participants 16 years age or older who were affiliated public health care system, assess...
Several countries have authorised or begun using a booster vaccine dose against COVID-19. Policy makers urgently need evidence of the effectiveness additional doses and its clinical spectrum for individuals with complete primary immunisation schedules, particularly in where schedule used inactivated SARS-CoV-2 vaccines.Using individual-level data, we evaluated prospective, observational, national-level cohort (aged ≥16 years) affiliated Fondo Nacional de Salud insurance programme Chile, to...
The outbreak of the B.1.1.529 lineage severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Omicron) has caused an unprecedented number Coronavirus Disease 2019 (COVID-19) cases, including pediatric hospital admissions. Policymakers urgently need evidence vaccine effectiveness in children to balance costs and benefits vaccination campaigns, but, date, is sparse. Leveraging a population-based cohort Chile 490,694 aged 3-5 years, we estimated administering two-dose schedule, 28 days...
Data analysis sometimes requires the relaxation of parametric assumptions in order to gain modeling flexibility and robustness against mis-specification probability model. In Bayesian context, this is accomplished by placing a prior distribution on function space, such as space all distributions or regression functions. Unfortunately, posterior ranging over spaces are highly complex hence sampling methods play key role. This paper provides an introduction simple, yet comprehensive, set...
Standard regression approaches assume that some finite number of the response distribution characteristics, such as location and scale, change a (parametric or nonparametric) function predictors. However, it is not always appropriate to location/scale representation, where error has unchanging shape over predictor space. In fact, often happens in applied research responses under study changes with predictors ways cannot be reasonably represented by dimensional functional form. This can...
More than 18 types of human papillomavirus (HPV) are associated with cervical cancer, the relative importance HPV may vary in different populations.To investigate HPV, age distribution, and risk factors for infection women from Santiago, Chile.We interviewed obtained two specimens a population-based random sample 1,038 sexually active (age range, 15-69 years). Specimens were tested presence DNA using GP5+/6+ primer-mediated PCR cytologic abnormalities by Papanicolaou smears.122 positive DNA,...
Policymakers urgently need evidence to adequately balance the costs and benefits of mass vaccination against COVID-19 across all age groups, including children adolescents. In this study, we aim assess effectiveness CoronaVac's primary series among adolescents in Chile.We used a large prospective national cohort about two million 6-16 years estimate an inactivated SARS-CoV-2 vaccine (CoronaVac) preventing laboratory-confirmed symptomatic infection (COVID-19), hospitalisation, admission...
Duchenne muscular dystrophy (DMD) is a severe and still incurable disease, with heart failure as leading cause of death. The identification disease-modifying therapy may require early-initiated long-term administration, but such type therapeutic trial not evident in humans. We have performed SNT-MC17/idebenone the mdx mouse model DMD, based on drug's potential to improve mitochondrial respiratory chain function reduce oxidative stress.In this study, 200 mg/kg bodyweight either or placebo was...
Abstract Background and Aims: Chile ranks fifth in the world among countries with highest incidence of gastric cancer. The aim was to quantify association between Helicobacter pylori infection cancer mortality at county residence. Methods: A cross-sectional household survey, a probability sample Chilean adult population, provided 2,615 participants whom serum H. IgG antibodies were measured (ELISA). spatial pattern 48,367 deaths due which occurred from 1985 2002 analyzed using hierarchical...
We study the support properties of Dirichlet process–based models for sets predictor–dependent probability distributions. Exploiting connection between copulas and stochastic processes, we provide an alternative definition MacEachern's dependent processes. Based on this definition, sufficient conditions full weak different versions process. In particular, show that under mild copula functions, version where only points or weights are predictors have support. addition, also characterize...
We propose a class of dependent processes in which density shape is regressed on one or more predictors through conditional tail-free probabilities by using transformed Gaussian processes. A particular linear version the process developed detail. The resulting flexible and easy to fit standard algorithms for generalized models. method applied growth curve analysis, evolving univariate random effects distributions mixed models, median survival modelling with censored data covariate-dependent errors.
The receiver operating characteristic (ROC) curve is the most widely used measure for evaluating discriminatory performance of a continuous biomarker. Incorporating covariates in analysis can potentially enhance information gathered from biomarker, as its ability may depend on these. In this paper we propose dependent Bayesian nonparametric model conditional ROC estimation. Our based Dirichlet processes, where covariate-dependent curves are indirectly modeled using probability models related...
Based on a data set obtained in dental longitudinal study, conducted Flanders (Belgium), the joint time to caries distribution of permanent first molars was modeled as function covariates. This involves an analysis multivariate continuous doubly-interval-censored since: (i) emergence tooth and it experiences were recorded yearly, (ii) events teeth same child are dependent. To model times caries, we propose dependent Bayesian semiparametric model. A major feature proposed approach is that...
Incorporating temporal and spatial variation could potentially enhance information gathered from survival data. This paper proposes a Bayesian semi-parametric model for capturing spatio-temporal heterogeneity within the proportional hazards framework. The correlation is introduced in form of county-level frailties. effect by considering stratification model, where time{dependent are indirectly modeled using probability related distributions. With this aim, an autoregressive dependent...
Abstract – Objectives: The study aimed to explore the association between parental smoking behavior and caries experience in young children, taking into account socioeconomic status oral health‐related behavior. Methods: Cross‐sectional data from 1250 3‐year‐old 1283 5‐year‐old children four geographical areas Flanders (Belgium) were analyzed. Children examined at school by trained dentist‐examiners, using standard criteria calibrated examination methodology. Data on hygiene dietary habits,...
We propose a novel class of probability models for sets predictor-dependent distributions with bounded domain. The proposal extends the Dirichlet–Bernstein prior single density estimation, by using dependent stick-breaking processes. A general model and two simplified versions are discussed in detail. Appealing theoretical properties such as continuity, association structure, marginal distribution, large support, consistency posterior distribution established all models. behavior is...
Abstract Background Intestinal colonization due to antibiotic-resistant bacteria (ARB) often precedes episodes of infection and fosters the spread antibiotic resistance. This study explores clinical, epidemiological, microbiome factors associated with ARB in Chilean adults. Methods A cross-sectional 357 community-dwelling individuals from a community central Chile was conducted between December 2018 - May 2019, using stool samples health questionnaires. Stool were cultured on selective...
Abstract Background In low- and middle-income countries, the community burden of antibiotic-resistant Gram-negative bacteria (AR-GNB) colonization is high. Understanding factors influencing AR-GNB crucial for controlling antimicrobial resistance. Methods We conducted a cohort study from December 2019 to November 2020 with community-dwelling adults in Molina, an agricultural town Central Chile. collected questionnaires fecal samples every two weeks six months identify by extended-spectrum...
In applied sciences, generalized linear mixed models have become one of the preferred tools to analyze a variety longitudinal and clustered data. Due software limitations, analyses are often restricted setting in which random effects terms follow multivariate normal distribution. However, this assumption may be unrealistic, obscuring important features among-unit variation. This work describes widely applicable semiparametric Bayesian approach that relaxes normality by using novel mixture...
Antimicrobial resistance is a global threat, heavily impacting low- and middle-income countries. This study estimated antimicrobial-resistant gram-negative bacteria (GNB) fecal colonization prevalence in hospitalized community-dwelling adults Chile before the coronavirus disease 2019 pandemic. From December 2018 to May 2019, we enrolled 4 public hospitals community dwellers from central Chile, who provided specimens epidemiological information. Samples were plated onto MacConkey agar with...
In light of the ongoing COVID-19 pandemic and emergence new SARS-CoV-2 variants, understanding effectiveness various booster vaccination regimens is pivotal. Chile, using a prospective national cohort 3.75 million individuals aged 20 or older, we evaluate against COVID-19-related intensive care unit (ICU) admissions death mRNA-based second vaccine boosters for four different three-dose background regimes: BNT162b2 primary series followed by homologous booster, CoronaVac an mRNA ChAdOx-1...