S wave velocity structure below central Mexico using high-resolution surface wave tomography

Shear wave velocity of the crust below central Mexico is estimated using surface wave dispersion measurements from regional earthquakes recorded on a dense, 500 km long linear seismic network. Vertical components of regional records from 90 well-located earthquakes were used to compute Rayleigh-wave group-velocity dispersion curves. A tomographic inversion, with high resolution in a zone close to the array, obtained for periods between 5 and 50 s reveals significant differences relative to a reference model, especially at larger periods (>30 s). A 2-D S wave velocity model is obtained from the inversion of local dispersion curves that were reconstructed from the tomographic solutions. The results show large differences, especially in the lower crust, among back-arc, volcanic arc, and fore-arc regions; they also show a well-resolved low-velocity zone just below the active part of the Trans Mexican Volcanic Belt (TMVB) suggesting the presence of a mantle wedge. Low densities in the back arc, inferred from the low shear wave velocities, can provide isostatic support for the TMVB

Impact of the Deficiency of Micronutrients on Patients with HIV/Aids

Introduction: HIV-AIDS is an infectious disease that damages the immune system, putting you at risk of serious infections and certain types of cancer. Micronutrient deficiency varies widely, depending on the population and stage of the disease. It can contribute to the weakening of the immune state and the worsening of the physical condition. Objective: To identify through the collection of nutritional information the consequences produced by the lack of micronutrients in patients with HIV-AIDS. Methodology: It was carried out through bibliographic reviews, scientific articles in order to find true and proven information on the effect that micronutrient deficiency has on people with HIV/AIDS. Results: It is shown that clinical deficiencies of some nutrients occur rapidly in response to dietary deficiencies, malabsorption, or altered metabolism, while those nutrients that have reserves in the body take longer to deplete. Discussion: The acquired immunodeficiency virus that causes AIDS; is associated with weight loss due to malnutrition. There are foods that can counteract many of the symptoms of the patient with HIV/AIDS, hence the importance of their knowledge. Conclusion: Micronutrient deficiency influences the immune system, accentuating the immunodeficiency that leads to AIDS. People living with this disease should have a balanced diet with Vitamins A, B, zinc and iron to strengthen the immune system, these offer a safe and economical treatment to slow the progression of the infection. Keywords: micronutrients, HIV, AIDS. RESUMEN Introducción: El VIH-SIDA es una enfermedad infecciosa que daña el sistema inmunitario lo que pone en riesgo de contraer infecciones graves y ciertos tipos de cáncer. La deficiencia de micronutrientes varía ampliamente, según la población y el estadio de la enfermedad; puede contribuir al debilitamiento del estado inmune y al empeoramiento de la condición física.  Objetivo: Identificar mediante la recopilación de información nutricional las consecuencias que produce la falta de micronutrientes en pacientes con VIH-SIDA. Metodología: Se realizó a través de revisiones bibliográficas, artículos científicos con el fin de encontrar información verídica y comprobada del efecto que tiene la deficiencia de micronutrientes en personas con VIH/SIDA.  Resultados: Se demuestra que las deficiencias clínicas de algunos nutrientes ocurren rápidamente en respuesta a deficiencias dietéticas, malabsorción, o metabolismo alterado, mientras que aquellos nutrientes que tienen reservas en el cuerpo tardan más en agotarse. Discusión: El virus de la inmunodeficiencia adquirida causante del SIDA; está asociada con la pérdida de peso por malnutrición. Hay muchos alimentos del grupo de los micronutrientes que minimizan manifestaciones clínicas en los enfermos el síndrome de inmunodeficiencia adquirida, siendo necesario saber cuáles son. Conclusiones: La deficiencia de micronutrientes influye en el sistema inmune, acentuando la inmunodeficiencia que lleva al SIDA. Las personas que viven con esta enfermedad deben tener una dieta balanceada con Vitaminas A, B, zinc y hierro para fortalecer el sistema inmunológico, estas ofrecen un tratamiento seguro y económico para retardar la progresión de la infección. Palabras claves: micronutrientes, VHI, SIDA

Seasonality and interannual variability of copepods in the Western English Channel, Celtic Sea, Bay of Biscay, and Cantabrian Sea with a special emphasis to Calanus helgolandicus and Acartia clausi

A total of five mesozooplankton time series data sets were assembled to compare the seasonal and interannual patterns of abundance of calanoid copepods in the Western English Channel (Station L4), Celtic Sea, Bay of Biscay (Continuous Plankton Recorder), and the Cantabrian Sea (RADIALES time series, Santander, St-4 and St-6) from January 1992 to December 1999. A strong seasonal component in taxonomic composition was detected at the locations considered. There was also a strong latitudinal effect on diversity at each location, southernmost locations being more diverse. The seasonal dynamics and year-to-year variability of two copepod species: Calanus helgolandicus and Acartia clausi were studied in detail. A latitudinal pattern in the seasonal cycles of both copepod species was observed. The peaks of both occur earlier in spring in the warmer southern region and move northwards, consistent with the temperature regimes at each location, supporting the broad concept that species occupy a thermal niche in time as well as in space. There was a strong degree of interannual variability between sites and between species. No clear trends, but some coherent events among data sets, reveal a regional response to environmental forcing factors. Correlations suggest possible connections with environmental indices like the North Atlantic Oscillation and the Gulf Stream North Wall index. There was a positive correlation between the NAO and the abundance of C. helgolandicus at station L4 off Plymouth; however, the relationship in the Celtic Sea and Bay of Biscay was opposite to that expected based on previous results. Despite the differences in the sampling techniques used within each dataset, the results are comparable and coherent in terms of taxonomic composition and the seasonal and interannual patterns detected

El trasplante de células de la glía envolvente del bulbo olfatorio tras lesión de la médula espinal: Estudio experimental en ratas.

Objetivo Evaluar el efecto a largo plazo del trasplante de células de la glía envolvente (GE) del bulbo olfatorio tras lesión de la médula espinal. Material y método Se practicó una laminectomía dorsal T8, en 16 ratas adultas Sprague-Dawley, dejando al descubierto la médula espinal subyacente, la cual se bañó con rosa de Bengala durante 10 minutos, antes de lesionarla por iluminación con una fibra óptica acoplada a una lámpara halógena, durante 2,5 minutos. A la mitad de los animales se les inyectó 180.000 células de GE, en 10 μl de medio (grupo GE), y a la otra mitad sólo 10 μl de DMEM (Dulbecco's modified Eagle's medium) (grupo DM). Los animales se sacrificaron a los 90 días de efectuar la lesión y se evaluó el área de médula espinal preservada, la recuperación locomotora y la sensibilidad nociceptiva. Resultados Los animales del grupo GE mostraron un nivel de locomoción superior y retiraron antes la pata al estímulo nociceptivo que los del grupo DM. También hubo una mayor preservación de parénquima medular y más células p75 positivas en el grupo GE que en el DM. Conclusiones El trasplante de GE favorece la preservación de parénquima medular y evita la pérdida de funciones motoras y sensoriales en la rata

Perivascular Spaces Segmentation in Brain MRI Using Optimal 3D Filtering

Perivascular Spaces (PVS) are a recently recognised feature of Small Vessel Disease (SVD), also indicating neuroinflammation, and are an important part of the brain's circulation and glymphatic drainage system. Quantitative analysis of PVS on Magnetic Resonance Images (MRI) is important for understanding their relationship with neurological diseases. In this work, we propose a segmentation technique based on the 3D Frangi filtering for extraction of PVS from MRI. Based on prior knowledge from neuroradiological ratings of PVS, we used ordered logit models to optimise Frangi filter parameters in response to the variability in the scanner's parameters and study protocols. We optimized and validated our proposed models on two independent cohorts, a dementia sample (N=20) and patients who previously had mild to moderate stroke (N=48). Results demonstrate the robustness and generalisability of our segmentation method. Segmentation-based PVS burden estimates correlated with neuroradiological assessments (Spearman's $\rho$ = 0.74, p $<$ 0.001), suggesting the great potential of our proposed metho

Cinética de crecimiento de bacterias ácido- lácticas autóctonas aisladas de “queso doble crema” con potencial para un cultivo iniciador

Currently, there is a permanent search for native Lactic Acid Bacteria (LAB) to explore and apply their biodiversity in the development and improvement of industrial processes, with studies of growth kinetics and performance factors being a fundamental tool for biotechnological use. The objective of this study was to determine the kinetic parameters of 12 autochthonous strains (Pediococcus pentosaceus (19), Leuconostoc citreum (20), Pediococcus acidilactici (21), Leuconostoc mesenteroides subsp. Mesenteroides (22, 29), Enterococcus faecium (24, 25), Enterococcus faecalis (27), Weissella viridescens (28), Lactococcus lactis (30), Lacticaseibacillus casei (31) and Limosilactobacillus fermentum (32)) isolated from a traditional Colombian cheese Double Cream Cheese to obtain information that allows establishing the ideal conditions of the inoculum, standardizing the production of metabolites and exploring their use as starter cultures. Fermentation was carried out in UHT milk at 120 rpm and 35-37 °C until stationary phase, and samples were taken over time to determine pH and titratable acidity (TTA). Exponential and logistic models were used to fit the growth kinetics data. Validation of both models was carried out with the coefficient of determination R2, obtaining good consistency for both (R2 = 0.925 - R2 = 0.932), with slight variations in the kinetic parameters in all the strains. The genera Pediococcus, Leuconostoc, Lactococcus, and E. faecium (24) had the shortest adaptation phases (0-2 h), being P. acidilactici (21), Leu. mesenteroides (22), W. viridescens (28), and E. faecium (24) presented the lowest pH values and high acidity percentages, which shows their potential to be included in the native LAB starter culture and for technology and suitability aptitude studies to produce double cream cheese using pasteurized milk without losing the qualities of the original product.Actualmente, existe una búsqueda permanente de bacterias ácido-lácticas (BAL) autóctonas para explorar y aplicar su biodiversidad en el desarrollo y mejoramiento de procesos industriales, siendo los estudios de cinética de crecimiento y los factores de rendimiento una herramienta fundamental para la utilización biotecnológica. Este trabajo tuvo como objetivo determinar los parámetros cinéticos de 12 cepas autóctonas (Pediococcus pentosaceus (19), Leuconostoc citreum (20), Pediococcus acidilactici (21), Leuconostoc mesenteroides subsp. Mesenteroides (22, 29), Enterococcus faecium (24, 25), Enterococcus faecalis (27), Weissella viridescens (28), Lactococcus lactis (30), Lacticaseibacillus casei (31) y Limosilactobacillus fermentum (32)) aisladas de un queso doble crema tradicional colombiano con el fin de obtener información para identificar su potencial en la conformación de un cultivo iniciador. Se realizó una fermentación en leche UHT a 120 rpm y 35-37 °C hasta la fase estacionaria, y se tomaron muestras para determinar el pH y la acidez titulable (TTA). Se emplearon los modelos exponencial y logístico para ajustar los datos de la cinética de crecimiento. La validación de ambos modelos se realizó empleando el coeficiente de correlación R2, presentando buena consistencia en ambos (R2 = 0.925 - R2 = 0.932) con variaciones en los parámetros cinéticos en todas las cepas. Los géneros Pediococcus, Leuconostoc, Lactococcus y E. faecium (24) tuvieron las fases de adaptación más cortas (0-2 h), siendo P. acidilactici (21), Leu. mesenteroides (22), W. viridescens (28) y E. faecium (24) quienes presentaron los menores valores de pH y altos porcentajes de acidez. Esto evidencia su potencial para ser incluidas en el cultivo iniciador de BAL autóctonos y en estudios de aptitud tecnológica e idoneidad para la elaboración del queso tipo doble crema utilizando leche pasteurizada sin perder las cualidades del producto original

Microstructure and magnetocaloric effect of melt-spun Ni52Mn26Ga22 ribbon

"Microstructural features and magnetocaloric properties of Ni52Mn26Ga22 melt-spun ribbons were studied. Results show that there are four types of differently oriented variants of seven-layered modulated (7M) martensite at room temperature, being twin-related one another and clustered in colonies. Due to the coupled magnetic and structural transformations between parent austenite and 7M martensite, the melt-spun ribbons exhibit a significant magnetocaloric effect. At an applied magnetic field of 5 T, an absolute maximum value of the isothermal magnetic entropy change of 11.4 J kg(-1) K-1 is achieved with negligible hysteresis losses.

Determinantes de la duración de la incapacidad temporal y la vuelta al trabajo en un área sanitaria de Galicia

ObjetivoDeterminar los factores asociados con la incidencia y la duración de la incapacidad temporal (IT) en un área sanitaria.DiseñoDescriptivo, retrospectivo.EmplazamientoÁrea Sanitaria Sur de la provincia de Lugo.ParticipantesUna muestra de 1.513 episodios de IT seleccionada aleatoriamente entre el total de éstos, durante un período de 3 años.Mediciones principalesSe analizaron las características sociodemográficas del paciente, el régimen de la seguridad social (SS), el diagnóstico que justifica la IT y la fecha de la prescripción; del médico prescriptor se analizaron la edad, el sexo, la formación especializada, la antigüedad en la plaza y los años de ejercicio. La comparación de medias se realizó mediante el análisis de la varianza y el test de Kruskal-Wallis. El efecto relativo de cada variable sobre la probabilidad de volver al trabajo se estimó mediante modelos de regresión de Cox.ResultadosLa duración media de los episodios de IT fue de 74 ± 103 días. Los diagnósticos más frecuentes fueron los del sistema osteomioarticular (SOMA), las lesiones y envenenamientos (LYE) y las enfermedades respiratorias (NML). Se reduce la probabilidad de volver al trabajo con el incremento de la edad, en los regímenes de seguridad social autónomos y agrarios por cuenta propia, en los diagnósticos de enfermedades mentales y del aparato circulatorio, y cuando el médico prescriptor es de mayor edad o menos antiguo en la plaza.ConclusionesLa duración media de los episodios de IT es superior a la de otros estudios españoles. Los factores que más influyen en la reincorporación al trabajo son la edad del paciente, el régimen de la seguridad social y la enfermedad diagnosticada.ObjectiveTo determine the factors associated with the incidence and duration of temporary work incapacity (TWI) in a health district.DesignDescriptive and retrospective study.SettingSouth health district of the province of Lugo, Spain.ParticipantsA random sample of 1513 cases was selected among the total of episodes of TWI, during 3 years period.Main measuresThe main factors analyzed are, on the one hand, the socio-demographic characteristics of the patient, his or her social security (SS) scheme, diagnosis that justifies the TWD, and the prescription date; and, on the other hand, the age, sex, specialised training, time in the post and years in practice of the physician who prescribes the TWI. The comparison of the means was carried out using variance analysis and the Kruskal-Wallis test. The relative effect of each variable on the probability of returning to the work was estimated through Cox regression models.ResultsThe mean duration of the episodes of TWI was of 74±103 days. The most frequent diagnoses were those of the bones-muscles and joints (BMAJ), injuries and poisonings (IAP), and respiratory diseases (RD). The probability of returning to work is reduced with the increase of the age, with agrarian and autonomous SS affiliates, with diagnoses of mental disease or diagnoses of the circulatory system, and in cases prescribed by older doctors or less time in the post.ConclusionsThe mean duration of the episodes of TWD is higher than that of other Spanish studies. The most influential factors in the return to work are the age of the patient, the SS scheme and the diagnosed illness

Enhanced refrigerant capacity in Gd-Al-Co microwires with a biphase nanocrystalline/amorphous structure

"A class of biphase nanocrystalline/amorphous Gd(50+5x)Al(30-5x)Co20 (x = 0, 1, 2) microwires fabricated directly by melt-extraction is reported. High resolution transmission electron microscopy and Fourier function transform based analysis indicate the presence of a volume fraction (similar to 20%) of similar to 10nm sized nanocrystallities uniformly embedded in an amorphous matrix. The microwires possess excellent magnetocaloric properties, with large values of the isothermal entropy change (-Delta S-M similar to 9.7 J kg(-1) K-1), the adiabatic temperature change (Delta T-ad similar to 5.2K), and the refrigerant capacity (RC similar to 654 J kg(-1)) for a field change of 5 T. The addition of Gd significantly alters T-C while preserving large values of the Delta S-M and RC. The nanocrystallites allow for enhanced RC as well as a broader operating temperature span of a magnetic bed for energy-efficient magnetic refrigeration.