653 research outputs found
sj-pdf-1-smm-10.1177_09622802221122423 - Supplemental material for Optimal sampling allocation for outcome-dependent designs in cluster-correlated data settings
No full textSupplemental material, sj-pdf-1-smm-10.1177_09622802221122423 for Optimal sampling allocation for outcome-dependent designs in cluster-correlated data settings by Claudia Rivera-Rodriguez, Sebastien Haneuse and Sara Sauer in Statistical Methods in Medical Research</p
Supplemental material for Augmented pseudo-likelihood estimation for two-phase studies
No full textSupplemental Material for Augmented pseudo-likelihood estimation for two-phase studies by Claudia Rivera-Rodriguez, Sebastien Haneuse, Molin Wang and Donna Spiegelman in Statistical Methods in Medical Research</p
SAGE_SM – Supplemental material for Quantifying and reducing statistical uncertainty in sample-based health program costing studies in low- and middle-income countries
No full textSupplemental material, SAGE_SM for Quantifying and reducing statistical uncertainty in sample-based health program costing studies in low- and middle-income countries by Claudia L Rivera-Rodriguez, Stephen Resch and Sebastien Haneuse in SAGE Open Medicine</p
Interdependent Projects Selection with Preference Incorporation
No full textThe Project Portfolio Problem (PPP) has been solved through different approaches. The success of some of them is related to a proper application of the decision-maker’s preferences, and a correct identification of organization’s resource practices and conditions. However, there are still a small number of classes of PPP that have been solved using these approaches, and there is also a need for increasing them. Due to this situation, the present research develops a strategy, based on ant colony optimization that incorporates the decision-maker’s preferences into the solution of a case of PPP under conditions of synergy, cannibalization, redundancy, and with interactions between projects. The algorithm was experimentally tested, and the results show a good performance of it over a random set of instances
Estudios citogenéticos y moleculares en una población sorda institucionalizada con síndrome de Waardenburg en Colombia
No full textIP 1203-04-088-98Incluye anexos.Latting, Martalucia Tamayo. -- En: Coleccion derecho a vivirendesventaja : folleto No. 7. -- 38 p. : il. ;FOLLETO(S): Sindrome de waardenburg / Maria Claudia Latting, Martalucia Tamayo. -- En: Coleccion derecho a;vivir en desventaja : folleto No. 8. -- 33 p. : il. ; 22 cm. --Sorderas no sindromicas / Maria Claudia;22 cm. -- ARTICULO(S) EN REVISTA: Results of a screening programfor waardenburg syndrome in Colombia / M.;Tamayo, M.C. Latting, M. Rodriguez, N. Gelvez, J.C. Prieto. --En: The American Journal of Human Genetics. --;Vol. 67, no. 4. (oct. 2000); p. 534
Estudios citogenéticos y moleculares en una población sorda institucionalizada con síndrome de Waardenburg en Colombia
No full textIP 1203-04-088-98Incluye anexos.Latting, Martalucia Tamayo. -- En: Coleccion derecho a vivirendesventaja : folleto No. 7. -- 38 p. : il. ;FOLLETO(S): Sindrome de waardenburg / Maria Claudia Latting, Martalucia Tamayo. -- En: Coleccion derecho a;vivir en desventaja : folleto No. 8. -- 33 p. : il. ; 22 cm. --Sorderas no sindromicas / Maria Claudia;22 cm. -- ARTICULO(S) EN REVISTA: Results of a screening programfor waardenburg syndrome in Colombia / M.;Tamayo, M.C. Latting, M. Rodriguez, N. Gelvez, J.C. Prieto. --En: The American Journal of Human Genetics. --;Vol. 67, no. 4. (oct. 2000); p. 534
Biodegradación de espumas plásticas por larvas de insectos: ¿una estrategia sustentable?
No full textMany modern human activities rely greatly on plastic foams, whose consumption and production have considerably increased in the past decades. The use of plastic products has had positive impacts on human general welfare; however, the negative effects derived from their inappropriate disposition have become a major concern, especially during the current COVID-19 sanitary emergency, in which the utilization of single-use plastics has rapidly increased. Although some plastic polymers such as polyethylene (PE) and polystyrene (PS) can be recycled, the high demand for energy and technology, the use of potentially toxic substances and the low profitability of the process, make this option non-optimal. In this situation, biological treatment of plastic waste is emerging as a promising alternative and the use of PE and PS-eating organisms, such as mealworms and waxworms, has attracted the attention of researchers around the world. The aim of this review is to synthesize the most recent advances in the field of plastics polymers degradation by insects larvae and an analysis of the current and future trends of this developing research area.En la actualidad, la mayoría de las actividades humanas dependen en gran medida del uso de los plásticos, cuya producción y consumo han aumentado considerablemente en las últimas décadas. La utilización de productos plásticos ha tenido impactos positivos para nuestro bienestar; sin embargo, los efectos negativos derivados de su disposición inapropiada son motivo de gran preocupación, especialmente durante la actual emergencia sanitaria provocada por la COVID-19, en la que el uso de plásticos por una ocasión ha aumentado drásticamente. A pesar de que algunos polímeros plásticos como el polietileno (PE) y el poliestireno (PS) pueden reciclarse, la alta demanda energética y tecnológica, el empleo de sustancias potencialmente tóxicas y la baja rentabilidad económica del proceso, vuelven a esta opción poco viable. Ante esta situación, el tratamiento biológico de plásticos a través de organismos degradadores del PE y del PS, como las larvas de la harina y de la cera, surge como una alternativa prometedora y ha llamado la atención de investigadores alrededor del mundo. El objetivo de esta revisión es sintetizar los avances más recientes en el campo de la biodegradación de plásticos por larvas de insectos y un análisis de las tendencias actuales y futuras en esta creciente área de investigación
A comparison of methods for combining surveys
No full textAs more and more researchers start to study more complicated survey problems, a single
survey might not be sufficient to meet the analytical needs. Therefore, combining multiple
waves of repeated surveys to get larger and more diverse samples is useful in some
situations. This thesis focus on comparing different methods of combining multiple
waves of repeated surveys. A large simulation study where we investigate the properties
of different methods for combining surveys is presented in this thesis. In the
simulation, we create a series of populations that contain geographic information so
the stratified two-stage cluster sampling method can be applied when selecting
samples. Then, two methods (weight-adjust method and calibration weighting
methods) of combining surveys are applied. The analytical results of simulated data
show that the weight-adjust method can reduce the estimation bias (i.e.
underestimating or overestimating) if overlapped observations can be identified and
need to be removed in order to meet study needs when combining surveys. However, if
the variables we are interested in change over time, the estimates produced by the weightadjust
method may contain minor biases. Therefore, using the calibration method when
auxiliary variables are available is recommended since it will help reduce the standard
error and produce more accurate estimates. Especially when using re-calculated weights
to estimate the variables that change over time, using the calibration method can reduce
the bias
Constrained Maximum Likelihood Estimation Under Two-Phase Designs Using Group-Level Information in Cluster-Correlated Settings
No full textA two-phase design is a cost-efficient approach in resource-limited settings that makes optimal use of readily available auxiliary information. By using auxiliary information from the first phase sample, a sub-sample is drawn in the second phase and the covariates of interest that are exceedingly expensive to collect are measured. With appropriate
sampling schemes, two-phase designs may be as efficient as using the entire first phase data.
In some cases, auxiliary information may not be available as individual observations,
but rather in the form of model parameters, known as external models. Recent literature
has focused on incorporating external model information into second-phase models.
One such method is the constrained maximum likelihood (CML), which utilises external
models through constraints. However, the CML approach primarily assumes independence
among individual observations, while in practice, participants are often naturally
correlated. Ignoring this correlation may lead to underestimation of the true variance and
invalid conclusions. Therefore, it is essential to consider the dependencies among the
observations in estimating the variance.
To the best of our knowledge, not much research has been done to extend the CML
method when participants are cluster-correlated. We seek to fill this gap by providing
a framework for valid estimation that appropriately elucidate the correlated structure in
CML. We propose a variance correction for parameter estimates that arise from CML
under cluster-correlated data settings. Simulation studies were conducted under random
sampling designs and case-control designs to evaluate the performance of the proposed
variance correction. For both designs, our results demonstrate that the proposed variance
correction estimates the variance better than the original variance estimator, where the
correlation is ignored.
Furthermore, we compare the efficiency of the CML with existing methods such
as weighted and calibrated likelihood, for cluster-correlated data. For simple random
sampling designs and case-control designs with rare outcome, our findings show that the
CML approach outperforms other methods in terms of efficiency, particularly when an
individual-level external model is used. We also extend the method to situations where
the external model is aggregated. The proposed variance correction performs well, and
the aggregated CML approach exhibits higher efficiency for cluster-level variables
Gender, anxiety, and legitimation of violence in adolescents facing simulated physical aggression at school
No full textWe analyzed gender and anxiety differences in middle school students facing a physical peer aggression situation. The participants were 1147 adolescents aged between 12 and 18 years (male: n = 479; female: n = 668) who watched a 12 s animation representing the situation and filled out a questionnaire to analyze the legitimation of violent behaviors and anxiety levels. We registered their decisions to solve the situation using a categorical scale that included assertive, avoidant, aggressive, submissive, and supportive behaviors. Gender was not associated with the adolescent’s behaviors in facing a simulated peer aggression situation. However, male teenagers tended to perceive adults as sanctioners and neutrals; those who used the diffusion of responsibility and dehumanization to justify their behavior also showed a higher state of anxiety. Female teenagers who expected legitimation from their peers, presented higher anxiety as well. Educational interventions may use these results, helping adolescents to understand that their acts have substantial implications in the lives of others. It is essential to develop group interventions that modify how adolescents manage their conflicts and change gender stereotypes that significantly impact health. We highlight the need for linking families in educational programs facing the challenges of transforming the legitimization of violence in parental practices.Martínez-González, Marina Begoña-will be generated-orcid-0000-0002-5840-6383-600Turizo-Palencia, Yamile-will be generated-orcid-0000-0002-1071-0239-600Arenas Rivera, Claudia Patricia-will be generated-orcid-0000-0002-6004-2267-600Acuña Rodriguez, Mónica Patricia-will be generated-orcid-0000-0002-7567-2069-600Gómez-López, YefersonClemente-Suárez, Vicente Javier-will be generated-orcid-0000-0002-2397-2801-60
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