UN OPERADOR DISCRETO PARA LA ECUACION ADVECCION-REACCION-DIFUSION EN UN ESPACIO DE DIMENSION INFINITA

La ecuación diferencial advección – reacción - difusión (ADR) modela la dinámica del transporte de un soluto en un fluido considerando los efectos de reacción dentro del mismo. La solución de dicha ecuac

Quality and time of biosolid compost when varying ratios and weight of substrates

Introduction: Biosolids generated in the treatment of wastewater are an environmental problem due to their inadequate handling and disposal. Objective: To know the effects when varying substrate ratios and pile weight on quality and time of biosolid compost. Materials and Methods: The mixture of biosolids (BS) with clay soil (CS) and equine degraded manure (DM) was evaluated in the following ratios: 70:30:00, 65:30:05, 60:30:10 and 50:30:20 to determine the optimum ratio in piles of 250 kg and evaluate it in 500 and 2 000 kg. The parameters of quality were temperature, Ph, humidity, organic matter (OM), total Kjeldahl nitrogen (TKN), C/N ratio, K/Na ratio and phosphorus (P). Results and Discussion: the ratio 65:30:05 had higher temperature (63.8 °C) and lower composting time (21 days). Significant differences ( P < 0.05) were found in the parameters of quality with respect to the substrates and pile weight. The treatments of 250 kg had the shortest processing time (28 days) with higher OM, TKN, C/N and P. Conclusion: The DM and CS favor BS composting by reducing the process to a maximum of 32 days. The ratio 65:30:05 in 250 kg increases the agronomic quality of the compost

a cross-sectional study

Objectives We determined the seroprevalence and correlates of Toxoplasma gondii infection in pregnant women in Aguascalientes City, Mexico. Design A cross-sectional survey. Setting Pregnant women were enrolled in the central Mexican city of Aguascalientes. Participants We studied 338 pregnant women who attended prenatal care in 3 public health centres. Primary and secondary outcome measures Women were examined for IgG/IgM antibodies to T. gondii by using commercially available enzyme immunoassays, and an avidity test. Multiple analyses were used to determine the association of T. gondii seropositivity with the characteristics of the pregnant women. Results Of the 338 pregnant women studied, 21 (6.2%) had IgG antibodies to T. gondii, and 1 (4.8%) of them was also positive for IgM antibodies to T. gondii. Avidity of IgG antibodies to T. gondii was high in the IgM-positive sample. Logistic regression analysis of sociodemographic, behavioural and housing variables showed that T. gondii seropositivity was associated with white ethnicity (OR=149.4; 95% CI 10.8 to 2054.1; p<0.01), not washing hands before eating (OR=6.41; 95% CI 1.73 to 23.6; p=0.005) and use of latrine (OR=37.6; 95% CI 4.63 to 306.31; p=0.001). Conclusions Results demonstrate that pregnant women in Aguascalientes City have a low seroprevalence of T. gondii infection. However, this low prevalence indicates that most pregnant women are at risk for a primary infection. Factors associated with T. gondii exposure found in this study, including food hygiene, may be useful to determine preventive measures against T. gondii infection and its sequelae

Associations Between Older Adult Physical Activity Levels, Self-Efficacy for Exercise and Sleep Habits

Motivation for exercise and engagement in healthy lifestyle behaviors (physically active, quality sleep, etc.) may help reduce the risk of non-communicable diseases, especially in older adults. Self-efficacy for exercise (SEE), performing regular physical activity (PA) and maintaining healthy sleep habits, often lead to positive health benefits. PURPOSE: To assess the relationships between SEE, PA levels and sleep quality/quantity in older adults. METHODS: Older adults (N = 60, age; 71.2 土 8.8 years, female; n = 42 and male; n = 18), were recruited for an IRB-approved cross-sectional research study conducted in spring, 2024. The survey (Qualtrics) consisted of demographic (age, gender, ethnicity, etc.) and lifestyle behavior questions. Total minutes spent weekly in PA and at various levels (vigorous, moderate, or at low/walking levels) were measured using the International Physical Activity Questionnaire (IPAQ), by Craig et al. (2003). A 9-item motivation/SEE measure using a 10-point Likert scale (90 point scale total, Resnick et al. 2000) and two questions for sleep habits (quality; excellent = 0, very good = 1, good = 2, fair = 3 and poor = 4 and quantity; total hours per night) were included. The data was analyzed using a Spearman Rank Order Correlation analysis in SPSS, version 28 and a p = 0.05 was considered significant. RESULTS: In those that indicated they were engaging in PA (IPAQ), a significant correlation between SEE and total (rho = 0.670, p = 0.000, n=42) and vigorous (rho = 0.372, p = 0.028, n=35) PA minutes per week was found with a trend towards significance in those that engaged in moderate PA minutes per week (rho = 0.265, p = 0.090, n=42). Sleep quality correlated with low/walking (rho = -0.484, p = 0.001, n=42), moderate (rho = -0.315, p = 0.042), and total PA minutes per week (rho = -0.557, p = 0.000, n=42). Number of hours sleeping per night and sleep quality were significantly related to age (rho = 0.303, p = 0.020 and rho = 0.315, p = 0.014, n=60; respectively). CONCLUSION: Significant relationships between time spent in PA, their motivation for exercise and the quality of their sleep were noted in older adults. Programs to support an older individual\u27s motivation to exercise and to promote regular physical activity may lead to healthier sleep habits and overall positive health benefits in an aging population

Understanding the limits of rapid charging using instrumented commercial 18650 high-energy Li-ion cells

The charging rates of commercial high-energy Li-ion cells are limited by the manufacturer's specifications leading to lengthy charging times. However, these cells are typically capable of much faster charging, if one ensures that the thermal and electrode-specific voltage profiles do not exceed safety limits. Unfortunately, precise and in-situ measurements of these parameters have not been achieved to date without altering the operation of these cells. Here we present a method to assess the maximum current for commercial 18650s, using novel instrumentation methods enabling in operando measurements. We found the maximum charging current that could be safely applied to the evaluated high-energy cells is 6.7 times higher than the manufacturer-stated maximum. Subsequently a rapid-charging protocol was developed that leads to over five-fold reduction in charging times without compromising the safety limits of the cells. We anticipate our work to be a starting point for a more sophisticated understanding of commercial Li-ion cells through deployment of diverse in-situ sensor systems. This understanding will enable advances in battery materials science, thermal engineering and electrical engineering of battery technology. Furthermore, this work has the potential to help the design of energy storage systems for high performance applications such as motor racing and grid balancing

Conocimiento sobre cáncer oral en estudiantes de una escuela de odontología de una universidad privada, Chiclayo 2022

La presente investigación tuvo como propósito principal, identificar el conocimiento sobre cáncer oral en alumnos de una escuela de estomatología de una universidad privada, se trató de un estudio de enfoque cuantitativo, de diseño nos experimental – transversal y de nivel descriptivo, teniendo como población a 181 estudiantes de los últimos ciclos de estomatología de una universidad privada de Chiclayo. La recolección de datos se realizó mediante la técnica de la encuesta y con un cuestionario tipo test de preguntas cerradas, las cuales fueron analizadas en una escala dicotómica de Correcta e Incorrecta; dicho instrumento fue validado por juicio de expertos y con confiabilidad estadística, aceptable. Los datos fueron analizados por métodos de la estadística descriptiva. Finalmente, los resultados del estudio demostraron que el 59.1% de los alumnos participantes pudo reconocer cual fue el tipo de cáncer oral más frecuente; por otra parte, el 50.8% reconoció el factor de riesgo más importante para la aparición de dichas neoplasias; por otra parte, el 75.7% no conocía el rango de edad donde es más prevalente la aparición de la enfermedad. Concluyendo que existe una necesidad real de implementar medidas para mejorar las nociones sobre el cáncer oral, de esta manera buscar un diagnóstico oportuno y temprano para los paciente

Hematology of Liolaemus pacha (Iguania: Liolaemidae) and its relationship with mite infestation, reproductive period and body condition

Variations in hematological profile in reptiles can be caused by multiple factors, including parasites presence. Our goals were to identify and morphologically describe blood cells of Liolaemus pacha and analyze their relationship with sex, body condition, individual reproductive/post-reproductive period and mite infestation. Blood smear analyses do not indicate the presence of hemoparasites, suggesting that the mites Neopterygosoma do not serve as vectors for these organisms, as has been proposed for other genera of ectoparasitic mites. In post-reproductive period, there was a reduction in specimens’ body condition and a higher leukocyte count in uninfected lizards. This could be a consequence of the testosterone effects, in higher concentration during the reproductive season, which can increase the metabolic rate, decreasing feeding rate. Infested and non-infested lizards showed no differences in body condition, as well as in leukocyte count, hence the host’s immune system could be developing infestation tolerance. Infested specimens had a higher count of monocytes, thrombocytes, heterophils and lymphocytes. Based on cells function, mites’ effect could be associated with inflammatory processes, allergic reactions or infectious diseases. These results suggested a complex interaction between lizards’ hematological parameters and factors associated to ectoparasites or body conditions. We consider this work as a diagnostic tool for genus Liolaemus, to evaluate health quality, with relevance to the conservation or management of this lizard’s genus.Fil: Juarez Heredia, Viviana Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundacion Miguel Lillo. Instituto de Comportamiento Animal.; ArgentinaFil: Pérez, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Miguel Lillo; ArgentinaFil: Salva, Ana Gabriela. Fundacion Miguel Lillo. Instituto de Comportamiento Animal.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Robles, Cecilia Ines. Fundacion Miguel Lillo. Instituto de Comportamiento Animal.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hernandez, Marcela Beatriz. Fundación Miguel Lillo; ArgentinaFil: Halloy, Monique. Fundación Miguel Lillo; Argentin

Pruebas in vitro de andamios 3D de biomaterial compuesto, formado por hiroxiapatita y ácido poliláctico

El interés de este estudio, es el desarrollo del ensayo biomimético de un andamio de material compuesto, con base en HAP-PLA conformado por impresión 3D, inmerso en un fluido corporal simulado (FCS), como indicador de su bioactividad, en función del tiempo. El FCS se preparó para someter a la muestra, al proceso biomimético diferencial. El seguimiento de los experimentos, se realizó, por el análisis del FCS residual, con espectroscopía FTIR y, el análisis textural superficial, por MEB. Los resultados, del FCS, después de 48 y 72 h, indicaron la descomposición del PLA al ácido láctico; a tiempos mayores, no hubo cambios significativos. Con la degradación superficial del andamio, por la formación de poros y porosidad. La prueba biomiméticas es indicativa de la bioactividad del andamio de HAP-PLA; su comportamiento resultó satisfactorio, el FCS, emuló el fluido del cuerpo, necesario para la incorporación de la HAP, con la degradación polimérica.The aim of this study is to develop a biomimetic method for a scaffold ofbiomaterial based on HAP-PLA formed by 3D printing, immersed in a simulated body fluid (SBF), as an indicator of its bioactivity, in function of time. The method was the differential biomimetic with preparing the SBF in where the sample was immersed. The FTIR spectroscopy was used to analyze the residual SBF and SEM, the superficial textural of scaffold was analyzed. The SBF results indicated the PLA decomposition to lactic acid, after 48 and 72 h; at longer times, the changes were insignificant. And the formation of pares and porosity showed the superficial degradation of the scaffolding. The biomimetic test is indicator of the bioactivity of the HAP-PLA scaffold; with a satisfactory behavior, because the SBF, emulate the body fluid needed to incorporate the hap, with polymer degradation