Publications by authors named "L F Quezada"

This work introduces a quantum subroutine for computing the distance between two patterns and integrates it into two quantum versions of the kNN classifier algorithm: one proposed by Schuld et al. and the other proposed by Quezada et al. Notably, our proposed subroutine is tailored to be memory-efficient, requiring fewer qubits for data encoding, while maintaining the overall complexity for both QkNN versions.

View Article and Find Full Text PDF

Background: In April 2022, after a year of COVID-19 vaccination, there were large differences in coverage between urban and rural areas in Guatemala. To address barriers in rural communities, the "Health on Wheels" (HoW) strategy was implemented. The strategy deployed mobile brigades with a dedicated team of health workers and a culturally sensitive health promotion plan in selected communities in 15 districts in Alta Verapaz, a health area with low COVID-19 vaccination uptake and a high-level of COVID-19 vaccine hesitancy.

View Article and Find Full Text PDF

Objective: To estimate the early impact of coronavirus disease 2019 (COVID-19) vaccination on cases in older populations in four countries (Chile, Colombia, Guatemala, and the United States of America), and on deaths in Chile and Guatemala.

Methods: Data were obtained from national databases of confirmed COVID-19 cases and deaths and vaccinations between 1 July 2020 and 31 August 2021. In each country, pre- and post-vaccination incidence ratios were calculated for COVID-19 cases and deaths in prioritized groups (50-59, 60-69, and ≥70 years) compared with those in the reference group (<50 years).

View Article and Find Full Text PDF

During a microbial infection, responding CD8+ T cells give rise to effector cells that provide acute host defense and memory cells that provide sustained protection. An alternative outcome is exhaustion, a state of T cell dysfunction that occurs in the context of chronic infections and cancer. Although it is evident that exhausted CD8+ T (TEX) cells are phenotypically and molecularly distinct from effector and memory CD8+ T cells, the factors regulating the earliest events in the differentiation process of TEX cells remain incompletely understood.

View Article and Find Full Text PDF

Background: The Indigenous Kichwa Saraguro people of southern Ecuador have long relied on traditional burning to manage their environment. However, their traditional use of fire in one of the most important ecosystems in southern Ecuador, the herbaceous paramo, is not well known. This lack of knowledge does not allow for the improvement of local regulations related to integrated fire management, which is a shortcoming compared to other regulations applied in South America.

View Article and Find Full Text PDF