Physicochemical characterization of the pod husk of Theobroma cacao L. of clones CCN51, FEAR5, and FSV41 and its agroindustrial application.

In cocoa production, the harvest and postharvest processes tend to generate residues that, if not properly treated or disposed of, become a source of pests or diseases for the crop and the farmer. The residues are environmental contaminants, which are equivalent to 70%-80% of the total fruit (husk, placenta, leachates). In the case of cacao pod husk (CPH), it is hollow form contributes to the accumulation of water or leachates. These residues with no apparent profitable use may have components of agroindustrial interest, such as pectins, cellulose, and starches, in products with high added value. Thus, the physicochemical characterization CPH of clones Castro Naranjal Collection 51 (CCN51), FEDECACAO Arauquita 5 (FEAR5), and FEDECACAO San Vicente 41 (FSV41) is presented to identify different applications such as biopolymers, bioremediation, and renewable energies and their potential biotechnological use in contributing to the circular economy according to the characteristics of each clone. In conclusion, it is important to continue with the research on CPHs of the different clones and to promote the sustainable development of cocoa in the Department of Risaralda, Colombia.

Circulating miRNAs as Noninvasive Biomarkers for PDAC Diagnosis and Prognosis in Mexico.

Among malignant neoplasms, pancreatic ductal adenocarcinoma (PDAC) has one of the highest fatality rates due to its late detection. Therefore, it is essential to discover a noninvasive, early, specific, and sensitive diagnostic method. MicroRNAs (miRNAs) are attractive biomarkers because they are accessible, highly specific, and sensitive. It is crucial to find miRNAs that could be used as possible biomarkers because PDAC is the eighth most common cause of cancer death in Mexico. With the help of microRNA microarrays, differentially expressed miRNAs (DEmiRNAs) were found in PDAC tissues. The presence of these DEmiRNAs in the plasma of Mexican patients with PDAC was determined using RT-qPCR. Receiver operating characteristic curve analysis was performed to determine the diagnostic capacity of these DEmiRNAs. Gene Expression Omnibus datasets (GEO) were employed to verify our results. The Prisma V8 statistical analysis program was used. Four DEmiRNAs in plasma from PDAC patients and microarray tissues were found. Serum samples from patients with PDAC were used to validate their overexpression in GEO databases. We discovered a new panel of the two miRNAs miR-222-3p and miR-221-3p that could be used to diagnose PDAC, and when miR-221-3p and miR-222-3p were overexpressed, survival rates decreased. Therefore, miR-222-3p and miR-221-3p might be employed as noninvasive indicators for the diagnosis and survival of PDAC in Mexican patients.

Thermal Sensor Allocation for Effective and Efficient Heat Transfer Measurements in Transportation Systems.

Power plants, electric generators, high-frequency controllers, battery storage, and control units are essential in current transportation and energy distribution networks. To improve the performance and guarantee the endurance of such systems, it is critical to control their operational temperature within certain regimes. Under standard working conditions, those elements become heat sources either during their entire operational envelope or during given phases of it. Consequently, in order to maintain a reasonable working temperature, active cooling is required. The refrigeration may consist of the activation of internal cooling systems relying on fluid circulation or air suction and circulation pulled from the environment. However, in both scenarios pulling surrounding air or making use of coolant pumps increases the power demand. The augmented power demand has a direct impact on the power plant or electric generator autonomy, while instigating higher power demand and substandard performance from the power electronics and batteries' compounds. In this manuscript, we present a methodology to efficiently estimate the heat flux load generated by internal heat sources. By accurately and inexpensively computing the heat flux, it is possible to identify the coolant requirements to optimize the use of the available resources. Based on local thermal measurements fed into a Kriging interpolator, we can accurately compute the heat flux minimizing the number of sensors required. Considering the need for effective thermal load description toward efficient cooling scheduling. This manuscript presents a procedure based on temperature distribution reconstruction via a Kriging interpolator to monitor the surface temperature using a minimal number of sensors. The sensors are allocated by means of a global optimization that minimizes the reconstruction error. The surface temperature distribution is then fed into a heat conduction solver that processes the heat flux of the proposed casing, providing an affordable and efficient way of controlling the thermal load. Conjugate URANS simulations are used to simulate the performance of an aluminum casing and demonstrate the effectiveness of the proposed method.

Implementing a provisional overarching intervention for COVID-19 monitoring and control in the Brazil-Colombia-Peru frontier.

Introduction: he challenge was to provide comprehensive health resources to a remote and underserved population living in the Brazil-Colombia-Peru border, amid the most disruptive global crisis of the century. Methods: In August 2021, Fundação Oswaldo Cruz Amazonia (FIOCRUZ Amazônia) and partner collaborators implemented an overarching provisional program for SARS-CoV-2 detection and lineages characterization, training of laboratory personnel and healthcare providers, donation of diagnostic supplies and personal protective equipment, and COVID-19 vaccination. The expedition was conducted at the Port of Tabatinga, a busy terminal with an intense flux of people arriving and departing in boats of all sizes, located in the Amazon River basin. Local government, non-profit organizations, private companies, and other stakeholders supported the intervention. Results: The expedition was accomplished in a convergence point, where migrant workers, traders, army personnel, people living in urban areas, and people from small villages living in riversides and indigenous territories are in close and frequent contact, with widespread cross-border movement. Using a boat as a provisional lab and storage facility, the intervention provided clinical and laboratory monitoring for 891 participants; vaccination for 536 individuals; personal protective equipment for 200 healthcare providers; diagnostic supplies for 1,000 COVID-19 rapid tests; training for 42 community health agents on personal protection, rapid test execution, and pulse oximeter management; and hands-on training for four lab technicians on molecular diagnosis. Discussion: Our experience demonstrates that multilateral initiatives can counterweigh the scarcity of health resources in underserved regions. Moreover, provisional programs can have a long-lasting effect if investments are also provided for local capacity building.

[Political will and governance: keys to Implementing HEARTS in PeruVontade política e governança, chaves na Implementação da iniciativa HEARTS no Peru]. / La voluntad política y la gobernanza: claves en la implementación de HEARTS en el Perú.

The objective of this article is to describe how governance and political will have influenced the implementation of the HEARTS Initiative for the prevention and control of hypertension in the Peruvian health system.The governance process is described and a secondary data analysis compares baseline levels at the start of HEARTS phase 1 with observed levels after the first six months of follow-up in 34 health facilities.HEARTS implementation was planned and organized at the national level through the Directorate of Noncommunicable Diseases, with political support from senior management of the Ministry of Health and technical support from the Pan American Health Organization. Governance was structured at three levels: national, regional, and local; implementation was supported by key actors from academia, scientific societies, regional health directorates, and integrated networks.Results after the initial months of follow-up showed an increase in the coverage and control of hypertension in most of the participating facilities. Analysis of the key factors related to political will and governance in the implementation of the HEARTS Initiative for the prevention and control of hypertension showed that the functions of senior management-in terms of aligning public policies and prioritizing noncommunicable diseases, in close and permanent coordination between policymakers and the Minister of Health-had a positive effect on the implementation of the HEARTS Initiative in Peru.

O objetivo do artigo é descrever como a governança e a vontade política influenciaram a implementação da Iniciativa HEARTS para a prevenção e o controle da hipertensão arterial no sistema de saúde peruano.O processo de governança é descrito e uma análise de dados secundários é realizada comparando os níveis basais no início da fase 1 do HEARTS com os primeiros 6 meses de acompanhamento em 34 estabelecimentos de saúde.O planejamento e a organização da implementação do HEARTS foi realizado no nível nacional por meio da Diretoria de Doenças Não Transmissíveis, contando com a vontade política da alta direção do Ministério da Saúde e o apoio técnico da Organização Pan-Americana da Saúde. A governança foi estruturada em três níveis ­ nacional, regional e local ­ e a implementação contou com o apoio de atores importantes do meio acadêmico, das sociedades científicas, das diretorias regionais de saúde e das redes integradas.Os resultados encontrados após os primeiros meses de acompanhamento mostraram um aumento da cobertura e do controle da hipertensão arterial na maioria dos estabelecimentos nos quais a intervenção foi implementada. A análise dos principais fatores relacionados à vontade política e à governança na implementação da Iniciativa HEARTS para a prevenção e o controle da hipertensão arterial mostrou que a atuação da alta direção para alinhar as políticas públicas e priorizar as doenças não transmissíveis, em estreita e permanente articulação entre os formuladores de políticas e o Ministério da Saúde, teve um efeito positivo na implementação da Iniciativa HEARTS no Peru.

La voluntad política y la gobernanza: claves en la implementación de HEARTS en el Perú

[RESUMEN]. El objetivo del artículo es describir cómo la gobernanza y la voluntad política han influido en la implementa- ción de la Iniciativa HEARTS para la prevención y el control de la hipertensión arterial en el sistema de salud de Perú. Se describe el proceso de gobernanza y se realiza un análisis secundario de datos que compara los niveles basales al inicio de la fase 1 de HEARTS con los primeros seis meses de seguimiento en 34 establecimientos de salud. Se realizó la planificación y organización de la implementación de HEARTS desde el nivel nacional a través de la Dirección de Enfermedades No Transmisibles, contando con la voluntad política de la Alta dirección del Ministerio de Salud y el acompañamiento técnico de la Organización Panamericana de la Salud. La gober- nanza se estructuró en 3 niveles: nacional, regional y local; la implementación se apoyó en actores claves de la academia, las sociedades científicas y las Direcciones Regionales de Salud y de las Redes Integrales. Los resultados encontrados tras los primeros meses de seguimiento evidenciaron un incremento de la cober- tura y el control de la hipertensión arterial en la mayoría de los establecimientos intervenidos. El análisis de los factores claves relacionados con la voluntad política y la gobernanza en la implementación de la Inicia- tiva HEARTS para la prevención y el control de la hipertensión arterial demostró que las funciones de la Alta dirección, para alinear las políticas públicas y priorizar las enfermedades no trasmisibles, en coordinación estrecha y permanente entre los formuladores de política y el Ministro de Salud, tuvieron un efecto positivo en la implementación de la Iniciativa HEARTS en el Perú.

[ABSTRACT]. The objective of this article is to describe how governance and political will have influenced the implementa- tion of the HEARTS Initiative for the prevention and control of hypertension in the Peruvian health system. The governance process is described and a secondary data analysis compares baseline levels at the start of HEARTS phase 1 with observed levels after the first six months of follow-up in 34 health facilities. HEARTS implementation was planned and organized at the national level through the Directorate of Noncom- municable Diseases, with political support from senior management of the Ministry of Health and technical support from the Pan American Health Organization. Governance was structured at three levels: national, regional, and local; implementation was supported by key actors from academia, scientific societies, regional health directorates, and integrated networks. Results after the initial months of follow-up showed an increase in the coverage and control of hypertension in most of the participating facilities. Analysis of the key factors related to political will and governance in the implementation of the HEARTS Initiative for the prevention and control of hypertension showed that the func- tions of senior management—in terms of aligning public policies and prioritizing noncommunicable diseases, in close and permanent coordination between policymakers and the Minister of Health—had a positive effect on the implementation of the HEARTS Initiative in Peru.

[RESUMO]. O objetivo do artigo é descrever como a governança e a vontade política influenciaram a implementação da Iniciativa HEARTS para a prevenção e o controle da hipertensão arterial no sistema de saúde peruano. O processo de governança é descrito e uma análise de dados secundários é realizada comparando os níveis basais no início da fase 1 do HEARTS com os primeiros 6 meses de acompanhamento em 34 estabelecimen- tos de saúde. O planejamento e a organização da implementação do HEARTS foi realizado no nível nacional por meio da Diretoria de Doenças Não Transmissíveis, contando com a vontade política da alta direção do Ministério da Saúde e o apoio técnico da Organização Pan-Americana da Saúde. A governança foi estruturada em três níveis – nacional, regional e local – e a implementação contou com o apoio de atores importantes do meio acadêmico, das sociedades científicas, das diretorias regionais de saúde e das redes integradas. Os resultados encontrados após os primeiros meses de acompanhamento mostraram um aumento da cobertura e do controle da hipertensão arterial na maioria dos estabelecimentos nos quais a intervenção foi implementada. A análise dos principais fatores relacionados à vontade política e à governança na imple- mentação da Iniciativa HEARTS para a prevenção e o controle da hipertensão arterial mostrou que a atuação da alta direção para alinhar as políticas públicas e priorizar as doenças não transmissíveis, em estreita e permanente articulação entre os formuladores de políticas e o Ministério da Saúde, teve um efeito positivo na implementação da Iniciativa HEARTS no Peru.

A Molecular Dynamics Simulation of Polymers' Interactions with Kaolinite (010) Surfaces in Saline Solutions.

The search for polymers that meet the demands of the water recovery process in mining is a contingent challenge. Both the presence of clays and saline waters can impair water recovery from tailings when conventional flocculants are used. In this work, the adsorption of polyacrylamide (PAM), hydrolyzed polyacrylamide (HPAM), poly(2-acrylamido-2-methyl-1-propane sulfonic acid) (PAMPS), polyacrylic acid (PAA), polyethylene oxide (PEO), and guar gum (GUAR) on a kaolinite surface (010) was investigated using classical molecular dynamics. The results show that the presence of sodium chloride modifies the affinities of the polymers with kaolinite (010). At low salt concentrations, the PAM and GUAR polymers generally show higher adsorption due to the formation of hydrogen bridges. However, the highest adsorptions occur in salt solutions in the presence of HPAM by cationic bridging with sodium ions as a mediator. This high affinity of HPAM is not efficient for flocculation because it re-disperses the particles, but it is promising for the design of new additives produced by grafting HPAM groups onto advanced polymers.

The Impact of Mild Frost Occurring at Different Harvesting Times on the Volatile and Phenolic Composition of Virgin Olive Oil.

The organoleptic characteristics of virgin olive oil (VOO), together with its nutritional and health properties, have led the olive tree to be cultivated beyond the Mediterranean basin, reaching latitudes with colder climates, with minimum temperatures below 0 °C and with a higher probability of early frosts. The freezing of olives generates destruction within the tissues and promotes degradation reactions. In this study, the impact of mild frost occurring at different harvesting times on the composition of volatiles and phenolic compounds in VOO were investigated. Arbequina variety olives were harvested at different stages of ripening. Half of the olives were subjected to oil extraction and the other half were frozen at -3 ± 1 °C for 12 h prior to oil extraction. A significant decrease of phenolic compounds with harvesting time was observed in both types of oils (fresh and frozen olives). Oils from frozen olives presented a slightly higher content of total phenols, except in the advanced ripening stage (September), and a slightly lower content of volatile compounds at all harvesting times. In addition, a higher content of 3,4-DHPEA-EDA was observed in oils from frozen olives, which is attributed to an early action of the endogenous ß-glucosidase enzyme on oleuropein in freeze-damaged olive fruits. Principal component analysis and Discriminant Partial Least Square Regression allowed the oils to be classified according to the type of fruit (fresh and frozen) and the month of harvest. This study would indicate that mild frost would have a low impact on the chemical composition of virgin olive oil, although, this depends on the ripening stage.

Species Surface Distribution and Surface Tension of Aqueous Solutions of MIBC and NaCl Using Molecular Dynamics Simulations.

Methyl isobutyl carbinol (MIBC) is a high-performance surfactant with unusual interfacial properties much appreciated in industrial applications, particularly in mineral flotation. In this study, the structure of air-liquid interfaces of aqueous solutions of MIBC-NaCl is determined by using molecular dynamics simulations employing polarizable and nonpolarizable force fields. Density profiles at the interfaces and surface tension for a wide range of MIBC concentrations reveal the key role of polarizability in determining the surface solvation of Cl- ions and the expulsion of non-polarizable Na+ ions from the interface to the liquid bulk, in agreement with spectroscopic experiments. The orientation of MIBC molecules at the water liquid-vapor interface changes as the concentration of MIBC increases, from parallel to the interface to perpendicular, leading to a well-packed monolayer. Surface tension curves of fresh water and aqueous NaCl solutions in the presence of MIBC intersect at a reproducible surfactant concentration for a wide range of salt concentrations. The simulation results for a 1 M NaCl aqueous solution with polarizable water and ions closely capture the MIBC concentration at the intercept. The increase in surface tension of the aqueous MIBC/NaCl mixture below the concentration of MIBC at the intersection seems to originate in a disturbance of the interfacial hydrogen bonding structure of the surface liquid water caused by Na+ ions acting at a distance and not by its presence on the interface.

Predictors of COVID-19 Fatality: A Worldwide Analysis of the Pandemic over Time and in Latin America.

SARS-CoV-2 has infected over one hundred million people worldwide and has affected Latin America particularly severely in terms of both cases and deaths. This study aims to determine the association between SARS-CoV-2 testing and COVID-19 fatality rate worldwide over 8 months and to examine how this relationship differs between Latin America and all other countries. This cross-sectional study used March 2021 data from 169 countries. Multivariate regressions predicted COVID-19 fatality (outcome) from the number of SARS-CoV-2 tests (exposure), while controlling for other predictors. Results for March 2021 were compared to results from June 2020. Additionally, results for Latin America were also compared to all other countries except Latin American for March 2021. SARS-CoV-2 testing was associated with a significant decrease in COVID-19 fatality rate in both June 2020 and March 2021 (RR = 0.92; 95% CI 0.87-0.96 and RR = 0.86; 95% CI 0.74-1.00, respectively). SARS-CoV-2 testing was associated with a significant decrease in COVID-19 fatality rate in Latin American countries but not in all other countries (RR = 0.45; 95% CI 0.23-0.89 and RR = 0.95; 95% CI 0.82-1.11, respectively). However, the difference between the risk ratios for June 2020 and March 2021 and between the risk ratios for Latin America and all other countries were not statistically significant. Increased SARS-CoV-2 testing may be a significant predictor of lower COVID-19 case fatality rate, specifically in Latin American countries, due to the existence of a strong association, which may have driven the worldwide results.

Modificaciones de la conducta alimentaria, actividad física y salud mental por la cuarentena COVID-19 en adultos jóvenes / Modifications of feeding behavior, physical activity and mental health due to the COVID-19 quarantine in young adults

RESUMEN En Perú, una de las primeras medidas preventivas para allanar la curva epidemiológica de la pandemia COVID-19 fue la cuarentena, que cambió de forma importante la conducta alimentaria, la actividad física y la salud mental. Objetivo : Determinar las modificaciones de la conducta alimentaria, actividad física y salud mental antes y durante la cuarentena por la pandemia COVID-19 en adultos jóvenes. Material y métodos : Estudio observacional, descriptivo, longitudinal en 384 adultos entre 18 y 24 años, mediante una encuesta virtual que incluyó: Cuestionario de frecuencia de consumo de alimentos, Cuestionario Internacional de Actividad física y Cuestionario de cambios en la salud mental, analizados mediante ji - cuadrado. Resultados : Durante la cuarentena se encontró un incremento en la distribución de frecuencia de comidas diarias [desayuno (p < 0,001), media mañana (p < 0,05), almuerzo (p < 0,001), merienda (p<0,001), cena (p < 0,05)] y de las preferencias alimentarias, con aumento en el consumo de frutas (p = 0,005) y una disminución de comidas rápidas (p < 0,05) y golosinas (p = 0,03). El nivel de actividad física bajo fue más frecuente (Varones: 28,4%; Mujeres: 25,3%) y hubo una disminución en las horas de sueño, por otro lado, la salud mental se vio severamente afectada durante la cuarentena. Conclusiones : Los resultados indican que la cuarentena ha producido variaciones en la conducta alimentaria, una disminución de la actividad física y un aumento de problemas de salud mental. Estas modificaciones representan un riesgo de sobrepeso u obesidad, incluso, desarrollo de enfermedades no transmisibles.

SUMMARY In Peru, one of the first interventions to flattened the epidemiologic curve of the pandemic was quarantine that changed eating behavior, physical activity and mental health of the population. Objective : to determine modifications in eating behavior, physical activity and mental health in young adults before and after the quarantine. Methods : cohort study involving 384 adults from 18 to 24 years of age that were subjected to a virtual interview and application of an international questionnaire to evaluate changings in eating behavior, physical activity and mental health contrasted by Chi square. Results : an increase in the distribution of daily foods [breakfast (p<0.001), morning snack (p<0.05), lunch (p<0.001), afternoon snack (p<0.001), dinner (p<0.05)] and an increase in ingestion of fruits (p=0.005) and reduction in the ingestion of fast food (p<0.05) and candies (p=0.03). Physical activity decreases specially in males vs females (28.4% vs. 25.3%) and there was a reduction in the total number of sleep hours, mental health was severely affected. Conclusions : quarantine induced variations in eating behavior, reduction in physical activity and increase in mental health disorders. These modifications put the population at risk for weight gain or obesity and eventually to non-transmissible diseases.

La voluntad política y la gobernanza: claves en la implementación de HEARTS en el Perú / Political will and governance: keys to Implementing HEARTS in Peru / Vontade política e governança, chaves na Implementação da iniciativa HEARTS no Peru

RESUMEN El objetivo del artículo es describir cómo la gobernanza y la voluntad política han influido en la implementación de la Iniciativa HEARTS para la prevención y el control de la hipertensión arterial en el sistema de salud de Perú. Se describe el proceso de gobernanza y se realiza un análisis secundario de datos que compara los niveles basales al inicio de la fase 1 de HEARTS con los primeros seis meses de seguimiento en 34 establecimientos de salud. Se realizó la planificación y organización de la implementación de HEARTS desde el nivel nacional a través de la Dirección de Enfermedades No Transmisibles, contando con la voluntad política de la Alta dirección del Ministerio de Salud y el acompañamiento técnico de la Organización Panamericana de la Salud. La gobernanza se estructuró en 3 niveles: nacional, regional y local; la implementación se apoyó en actores claves de la academia, las sociedades científicas y las Direcciones Regionales de Salud y de las Redes Integrales. Los resultados encontrados tras los primeros meses de seguimiento evidenciaron un incremento de la cobertura y el control de la hipertensión arterial en la mayoría de los establecimientos intervenidos. El análisis de los factores claves relacionados con la voluntad política y la gobernanza en la implementación de la Iniciativa HEARTS para la prevención y el control de la hipertensión arterial demostró que las funciones de la Alta dirección, para alinear las políticas públicas y priorizar las enfermedades no trasmisibles, en coordinación estrecha y permanente entre los formuladores de política y el Ministro de Salud, tuvieron un efecto positivo en la implementación de la Iniciativa HEARTS en el Perú.

ABSTRACT The objective of this article is to describe how governance and political will have influenced the implementation of the HEARTS Initiative for the prevention and control of hypertension in the Peruvian health system. The governance process is described and a secondary data analysis compares baseline levels at the start of HEARTS phase 1 with observed levels after the first six months of follow-up in 34 health facilities. HEARTS implementation was planned and organized at the national level through the Directorate of Noncommunicable Diseases, with political support from senior management of the Ministry of Health and technical support from the Pan American Health Organization. Governance was structured at three levels: national, regional, and local; implementation was supported by key actors from academia, scientific societies, regional health directorates, and integrated networks. Results after the initial months of follow-up showed an increase in the coverage and control of hypertension in most of the participating facilities. Analysis of the key factors related to political will and governance in the implementation of the HEARTS Initiative for the prevention and control of hypertension showed that the functions of senior management—in terms of aligning public policies and prioritizing noncommunicable diseases, in close and permanent coordination between policymakers and the Minister of Health—had a positive effect on the implementation of the HEARTS Initiative in Peru.

RESUMO O objetivo do artigo é descrever como a governança e a vontade política influenciaram a implementação da Iniciativa HEARTS para a prevenção e o controle da hipertensão arterial no sistema de saúde peruano. O processo de governança é descrito e uma análise de dados secundários é realizada comparando os níveis basais no início da fase 1 do HEARTS com os primeiros 6 meses de acompanhamento em 34 estabelecimentos de saúde. O planejamento e a organização da implementação do HEARTS foi realizado no nível nacional por meio da Diretoria de Doenças Não Transmissíveis, contando com a vontade política da alta direção do Ministério da Saúde e o apoio técnico da Organização Pan-Americana da Saúde. A governança foi estruturada em três níveis - nacional, regional e local - e a implementação contou com o apoio de atores importantes do meio acadêmico, das sociedades científicas, das diretorias regionais de saúde e das redes integradas. Os resultados encontrados após os primeiros meses de acompanhamento mostraram um aumento da cobertura e do controle da hipertensão arterial na maioria dos estabelecimentos nos quais a intervenção foi implementada. A análise dos principais fatores relacionados à vontade política e à governança na implementação da Iniciativa HEARTS para a prevenção e o controle da hipertensão arterial mostrou que a atuação da alta direção para alinhar as políticas públicas e priorizar as doenças não transmissíveis, em estreita e permanente articulação entre os formuladores de políticas e o Ministério da Saúde, teve um efeito positivo na implementação da Iniciativa HEARTS no Peru.

Assessment of the Occurrence of Forest Fires in Pandemic Period by COVID-19 in Chile. Preliminary Backgrounds.

The spatial and temporal behavior of the occurrence of forest fires in Chile was evaluated in the presence of COVID-19 and mobility restrictions. The fire period from 2015-2016 to 2020-2021 was considered and statistics on mobility restrictions were granted by the Government of Chile. The analysis was developed at different scales of geographic perception. At the national and regional levels, the global behavior of the occurrence was determined, and later at the communal level, the political territorial unit, to determine internal variations attributable to the mobility dynamics in the quarantine period. In the process, the meteorological background of the fire activity was also considered. The results indicate that it is possible to rule out a meteorological effect, based on the variation of the moisture content of fine fuel. There was also no statistical association between the humidity of the fuel and the variation in the occurrence of fires. It is concluded that the communes that presented the greatest mobility of people before the pandemic were those that obtained the greatest reduction in fires. The variation in mobility, the product of restriction measures, is a statistical predictor of the increase or decrease in fires.

Molecular Dynamics Study of the Conformation, Ion Adsorption, Diffusion, and Water Structure of Soluble Polymers in Saline Solutions.

Polymers have interesting physicochemical characteristics such as charge density, functionalities, and molecular weight. Such attributes are of great importance for use in industrial purposes. Understanding how these characteristics are affected is still complex, but with the help of molecular dynamics (MD) and quantum calculations (QM), it is possible to understand the behavior of polymers at the molecular level with great consistency. This study was applied to polymers derived from polyacrylamide (PAM) due to its great use in various industries. The polymers studied include hydrolyzed polyacrylamide (HPAM), poly (2-acrylamido-2-methylpropanesulfonate) (PAMPS), polyacrylic acid (PAA), polyethylene oxide polymer (PEO), and guar gum polysaccharide (GUAR). Each one has different attributes, which help in understanding the effects on the polymer and the medium in which it is applied along a broad spectrum. The results include the conformation, diffusion, ion condensation, the structure of the water around the polymer, and interatomic polymer interactions. Such characteristics are important to selecting a polymer depending on the environment in which it is found and its purpose. The effect caused by salinity is particular to each polymer, where polymers with an explicit charge or polyelectrolytes are more susceptible to changes due to salinity, increasing their coiling and reducing their mobility in solution. This naturally reduces its ability to form polymeric bridges due to having a polymer with a smaller gyration radius. In contrast, neutral polymers are less affected in their structure, making them favorable in media with high ionic charges.