415 research outputs found
Antimicrobial and antioxidant properties of byproduct extracts of mango fruit
Byproducts of fruit processing could have higher content of phenolic compounds that can act as antimicrobial and antioxidant agents. In this context, the main objective of this study was to obtain extracts from peel, seed, and unused flesh of Haden, Ataulfo and Tommy Atkins mango varieties, in order to measure their antioxidant and antimicrobial properties. The extraction was performed using different methods, such as methanolic-polar, methanolic-non-polar, ethanolic-polar, ethanolic-non-polar and water infusion. The total phenolic content of the ethanolic-non-polar extract from seed of mango Haden showed 875.06 mg/g, DPPH EC50: 0.04 mg/mL, cau-sing a 100 % inhibition of bacteria pathogens applying 25 mg/mL and inhibition of 89.78 % against Alternaria applying 6.25 mg/mL. The flesh always showed the lowest content and bioactivity of the tested parameters. These results demonstrate the antimicrobial and antioxidant potential uses of fruit byproducts as sources of bioactive compounds
Dissipational versus Dissipationless Galaxy Formation and the Dark Matter Content of Galaxies
We examine two extreme models for the build-up of the stellar component of
luminous elliptical galaxies. In one case, we assume the build-up of stars is
dissipational, with centrally accreted gas radiating away its orbital and
thermal energy; the dark matter halo will undergo adiabatic contraction and the
central dark matter density profile will steepen. For the second model, we
assume the central galaxy is assembled by a series of dissipationless mergers
of stellar clumps that have formed far from the nascent galaxy. In order to be
accreted, these clumps lose their orbital energy to the dark matter halo via
dynamical friction, thereby heating the central dark matter and smoothing the
dark matter density cusp. The central dark matter density profiles differ
drastically between these models. For the isolated elliptical galaxy, NGC 4494,
the central dark matter densities follow the power-laws r^(-0.2) and r^(-1.7)
for the dissipational and dissipationless models, respectively. By matching the
dissipational and dissipationless models to observations of the stellar
component of elliptical galaxies, we examine the relative contributions of
dissipational and dissipationless mergers to the formation of elliptical
galaxies and look for observational tests that will distinguish between these
models. Comparisons to strong lensing brightest cluster galaxies yield median
M*/L_B ratios of 2.1+/-0.8 and 5.2+/-1.7 at z=0.39 for the dissipational and
dissipationless models, respectively. For NGC 4494, the best-fit dissipational
and dissipationless models have M*/L_B=2.97 and 3.96. Comparisons to expected
stellar mass-to-light ratios from passive evolution and population syntheses
appear to rule out a purely dissipational formation mechanism for the central
stellar regions of giant elliptical galaxies.Comment: 15 pages, 9 figures, accepted to Ap
Modulation of KV4.3-KChIP2 Channels by IQM-266: Role of DPP6 and KCNE2
The transient outward potassium current (Itof) is generated by the activation of KV4 channels assembled with KChIP2 and other accessory subunits (DPP6 and KCNE2). To test the hypothesis that these subunits modify the channel pharmacology, we analyzed the electrophysiological effects of (3-(2-(3-phenoxyphenyl)acetamido)-2-naphthoic acid) (IQM-266), a new KChIP2 ligand, on the currents generated by KV4.3/KChIP2, KV4.3/KChIP2/DPP6 and KV4.3/KChIP2/KCNE2 channels. CHO cells were transiently transfected with cDNAs codifying for different proteins (KV4.3/KChIP2, KV4.3/KChIP2/DPP6 or KV4.3/KChIP2/KCNE2), and the potassium currents were recorded using the whole-cell patch-clamp technique. IQM-266 decreased the maximum peak of KV4.3/KChIP2, KV4.3/KChIP2/DPP6 and KV4.3/KChIP2/KCNE2 currents, slowing their time course of inactivation in a concentration-, voltage-, time- and use-dependent manner. IQM-266 produced an increase in the charge in KV4.3/KChIP2 channels that was intensified when DPP6 was present and abolished in the presence of KCNE2. IQM-266 induced an activation unblocking effect during the application of trains of pulses to cells expressing KV4.3/KChIP2 and KV4.3/KChIP2/KCNE2, but not in KV4.3/KChIP2/DPP6 channels. Overall, all these results are consistent with a preferential IQM-266 binding to an active closed state of Kv4.3/KChIP2 and Kv4.3/KChIP2/KCNE2 channels, whereas in the presence of DPP6, IQM-266 binds preferentially to an inactivated state. In conclusion, DPP6 and KCNE2 modify the pharmacological response of KV4.3/KChIP2 channels to IQM-266
Feedback and the Formation of Dwarf Galaxy Stellar Halos
Stellar population studies show that low mass galaxies in all environments
exhibit stellar halos that are older and more spherically distributed than the
main body of the galaxy. In some cases, there is a significant intermediate age
component that extends beyond the young disk. We examine a suite of Smoothed
Particle Hydrodynamic (SPH) simulations and find that elevated early star
formation activity combined with supernova feedback can produce an extended
stellar distribution that resembles these halos for model galaxies ranging from
= 15 km s to 35 km s, without the need for accretion of
subhalos.Comment: 15 pages, 15 figures, accepted MNRA
Oceanographic processes and products around the Iberian margin: a new multidisciplinary approach
Our understanding of the role of bottom currents and associated oceanographic processes (e.g, overflows, barotropic tidal currents) including intermittent processes (e.g, vertical eddies, deep sea storms, horizontal vortices, internal waves and tsunamis) is rapidly evolving. Many deep-water processes remain poorly understood due to limited direct observations, but may generate significant depositional and erosional features on both short-and long-term time scales. This paper describes these oceanographic processes and examines their potential role in the sedimentary features around the Iberian margin. The paper explores the implications of the processes studied, given their secondary role relative to other factors such as mass-transport and turbiditic processes. An integrated interpretation of these oceanographic processes requires an understanding of contourites, sea-floor features, their spatial and temporal evolution, and the near-bottom flows that form them. Given their complex, three-dimensional and temporally-variable nature, integration of these processes into sedimentary, oceanographic and climatological frameworks will require a multidisciplinary approach that includes Geology, Physical Oceanography, Paleoceanography and Benthic Biology. This approach will synthesize oceanographic data, seafloor morphology, sediments and seismic images to improve our knowledge of permanent and intermittent processes around Iberia, and evaluate their conceptual and regional role in the sedimentary evolution of the margin. © 2015, Instituto Geologico y Minero de Espana. All rights reservedEl conocimiento del papel de las corrientes de fondo y los procesos oceanográficos asociados (overflows, corrientes de marea barotrópicas, etc), incluyendo procesos intermitentes (eddies, tormentas profundas, ondas internas, tsunamis, etc), está evolucionando rápidamente. Muchos de estos procesos son poco conocidos, en parte debido a que las observaciones directas son limitadas, si bien pueden generar importantes rasgos deposicionales y/o erosivos a escalas temporales de corto o largo periodo. Este artículo describe dichos procesos oceanográficos y examina su influencia en la presencia de rasgos sedimentarios alrededor del margen Ibérico. El trabajo discute las implicaciones de dichos procesos y el papel secundario que juegan en relación a otros factores tales como los procesos de transporte gravitacionales en masa y los turbidíticos. Para un mejor conocimiento de la sedimentación marina profunda, y en concreto de los sistemas contorníticos, se requiere de una interpretación de estos procesos oceanográficos, cuál es su evolución espacial y temporal, cómo afectan a las corrientes de fondo y cómo se ven afectados por la topografía submarina. Sin embargo, dada su complejidad y su variable naturaleza tridimensional y temporal, es necesario que estos procesos se integren en un marco sedimentológico, oceanográfico y climatológico con un enfoque multidisciplinar que incluyan la Geología, la Oceanografía Física, la Paleoceanografía y la Biología bentónica. Esta integración requiere de una mayor compilación de datos oceanográficos, de un mejor conocimiento de la morfología del fondo marino, y de una mejor caracterización de los sedimentos en ambientes profundos. Todo ello permitirá mejorar nuestro conocimiento de los procesos permanentes e intermitentes alrededor de Iberia y evaluar su verdadero efecto en la evolución sedimentaria delos márgenes continentales que le rodeanPostprint0,000
Mitochondrial angiotensin receptors in dopaminergic neurons. Role in cell protection and aging-related vulnerability to neurodegeneration
The renin-angiotensin system (RAS) was initially considered as a circulating humoral system controlling blood pressure, being kidney the key control organ. In addition to the \u27classical\u27 humoral RAS, a second level in RAS, local or tissular RAS, has been identified in a variety of tissues, in which local RAS play a key role in degenerative and aging-related diseases. The local brain RAS plays a major role in brain function and neurodegeneration. It is normally assumed that the effects are mediated by the cell-surface-specific G-protein-coupled angiotensin type 1 and 2 receptors (AT1 and AT2). A combination of in vivo (rats, wild-type mice and knockout mice) and in vitro (primary mesencephalic cultures, dopaminergic neuron cell line cultures) experimental approaches (confocal microscopy, electron microscopy, laser capture microdissection, transfection of fluorescent-tagged receptors, treatments with fluorescent angiotensin, western blot, polymerase chain reaction, HPLC, mitochondrial respirometry and other functional assays) were used in the present study. We report the discovery of AT1 and AT2 receptors in brain mitochondria, particularly mitochondria of dopaminergic neurons. Activation of AT1 receptors in mitochondria regulates superoxide production, via Nox4, and increases respiration. Mitochondrial AT2 receptors are much more abundant and increase after treatment of cells with oxidative stress inducers, and produce, via nitric oxide, a decrease in mitochondrial respiration. Mitochondria from the nigral region of aged rats displayed altered expression of AT1 and AT2 receptors. AT2-mediated regulation of mitochondrial respiration represents an unrecognized primary line of defence against oxidative stress, which may be particularly important in neurons with increased levels of oxidative stress such as dopaminergic neurons. Altered expression of AT1 and AT2 receptors with aging may induce mitochondrial dysfunction, the main risk factor for neurodegeneratio
Un análisis exploratorio de la relación entre pobreza multidimensional y conflicto armado : el caso de Antioquia en Colombia
RESUMEN: Este artículo analiza la relación entre pobreza y conflicto armado en Antioquia, Colombia. El análisis de la pobreza está enmarcado en el enfoque de las capacidades de Sen, el cual conforma la base conceptual del índice de pobreza multidimensional (IPM) desarrollado por Alkire y Foster. El IPM es calculado con información derivada de la base de datos Sisbén, la cual se utiliza para seleccionar la población atendida por los programas de asistencia social del Gobierno colombiano. Este artículo consideró tres dimensiones de pobreza: estándares de vida, salud, y educación. El conflicto armado fue medido por medio de datos de conteo acerca de la ocurrencia de eventos de violencia registrados entre 1996 y 2010 en cada municipalidad de Antioquia. Luego, la relación entre la pobreza y el conflicto armado se analizó mediante métodos exploratorios y no paramétricos como las distribuciones kernel. Los resultados sugieren que el IPM es robusto con respecto a la elección del umbral de pobreza multidimensional. Los mapas de caja y bigotes sugieren que los pobres están localizados en las regiones periféricas de Antioquia. Las distribuciones kernel muestran que las áreas más afectadas por el conflicto, usualmente, tienen altos niveles de pobreza multidimensional.ABSTRACT: This paper analyses the relationship between poverty and armed conflict in Antioquia, Colombia. The poverty analysis it uses is framed according to Sen’s capability approach, which constitutes the conceptual basis for the Multidimensional Poverty Index (MPI) subsequently developed by Alkire and Foster. The MPI is measured employing data from the government database SISBEN, which is used by the Colombian authorities to identify beneficiaries of social assistance programmes. The paper considers three poverty dimensions: living standards, health, and education. Armed conflict is measured using count data on violent events recorded for every municipality in the Department of Antioquia between 1996 and 2010. The relationship between poverty and armed conflict is then analysed using exploratory and non-parametric methods such as kernel distributions. Results suggest that the MPI is robust when compared multidimensional cutoffs. The MPI box-plot maps suggest that poor people are located in Antioquia’s peripheral areas. Kernel distributions show that areas most affected by conflict tend to show higher levels of multidimensional poverty
Antioxidant and Antimicrobial Capacity of Phenolic Compounds of Mango (Mangifera indica L.) Seed depending upon the Extraction Process
The extraction method is critical for the recovery of phenolic compounds. The main goal was to evaluate the effect of an extraction process from mango seed on their phenolic profile, antioxidant and antimicrobial capacities. Phenolic extraction was performed in different steps: maceration, alkaline hydrolysis, acid/alkaline hydrolysis, polar and non-polar fraction of an ethyl acetate separation.The macerated extract showed a higher variety of polyphenols from mango seed:gallic (138.36 µg/g dry weight), coumaric (65.36 µg/g), ferulic (1376.67 µg/g) , chlorogenic (57.75 µg/g) anddicaffeoylquinic (219.29 µg/g) acids, catechin (16.78 µg/g) and rutin (6678.62µg/g). In alkaline hydrolyzed extract most of these compounds were lost, ferulic acid decreased 1356.77 µg/g dw and gallic acid increased 1383.89 µg/g dw. Gallic and chlorogenic acids increased 165 and 969. 45 µg/g dw respectively in acid/alkaline hydrolyzed, 109.57 and 841.38 µg/g dw respectively in non-polar and 277.15 and 77.88 µg/g dw respectively in polar extracts related to the macerated extract. Rutin was found only in acid/hydrolyzed and non-polar extract in lesser amount (87.62 and 78.51 µg/g dw) compared to macerated extract. The content of phenolic compounds was higher for the macerated extract (phenols=484.42 mg GAE/g and flavonoids=86.59 mg QE/g) than for the other steps. Acid/alkaline hydrolysis increased the antioxidant activity (1787.67 μmol TE/g for DPPH and 3692.86 μmol TE/g for TEAC); while the alkaline hydrolysis increased the antimicrobial effectivity (MIC=2.5 mg/mL for bacteria and 0.5 mg/mL for yeast). Results indicate that the acid or alkaline hydrolysis yields a stronger antioxidant and antimicrobial extract
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