251 research outputs found
Aloe vera Flowers, a by product with great potential and wide application, depending on maturity stage
Flowers of Aloe vera are a byproduct providing a valuable source of bioactive compounds with different functions for health benefits. The characterization in amino acids, organic acids, sugars, trigonelline, volatiles compounds, fatty acids, total phenolic, carotenoids, vitamin C content, and antioxidant capacity of Aloe flowers (Aloe barbadensis Miller) has been studied at three maturity stages (I: immature; II: mature; III: mature, with flowers buds opened). Immature flowers presented the highest content in phenyl alanine, tyrosine, citric acid, trigonelline, carotenoids, retinol activity equivalent, vitamin C, and total phenolic and antioxidant capacity. As the flower develops, the content of these compounds decreases Aloe vera flowers presented an important content in fatty acids, and the principal concentration was identified in polyunsaturated unsaturated fatty acids (PUFAs) as α-linolenic acid, and linoleic acid, with a ratio close to one. The main saturated fatty acid was palmitic acid, followed by stearic acid. Maturity stage III showed the lowest fatty acid content. The bioactive compounds found in Aloe vera flowers have potential applications in the cosmetic, pharmaceutical, nutraceutical, and food industries. Depending on the compound of interest, it could be worthwhile harvesting flowers at maturity stage I, thereby reducing the energy consumption of flowers from the plant and thus favoring plant development. This is an example of a circular economy for Aloe vera producers, generating economic and business opportunities and thus providing environmental and social benefits.This research was funded by the Fondo Europeo de Desarrollo Regional/Ministerio de Ciencia e Innovación-Agencia Estatal de Investigación (FEDER/MICINN-AEI), project RTI2018-099139-B-C21
Bio-monitoring of metal(loid)s pollution in dry riverbeds affected by mining activity
The aim of this study was to evaluate the most abundant native plants that could be used
as a bio-monitor of metal(loid) concentration in dry riverbeds affected by mining activities. Three
plants species and their respective rhizospheric soils were sampled from the El Beal (Piptatherum
miliaceum, 15 samples), La Carrasquilla (Foeniculum vulgare, 10 samples), and Ponce (Dittrichia viscosa,
12 samples) dry riverbeds from the mining district of Cartegena-La Unión (SE Spain). There is
scanty bibliography of the capacity of these species to be used as bio-monitors in the dry riverbeds.
Plants categorized as a bio-monitor were established according to the bioaccumulation factor (BF),
mobility ratio (MR), and linear correlations between metal(loid) concentrations in plants tissues (root
or stem)-rhizospheric soils. The rhizospheric soils were highly contaminated for As, Cd, Pb, and
Zn (Cf ≥ 6), and moderately contaminated for Mn (1 ≤ Cf < 3). Piptatherum miliaceum presented on
Cd similar mean concentrations on rhizospheric soil and root, BF = 1.07, with a strong correlation
soil–root (r = 0.61, p = 0.02). Therefore, of the three species with the capacity to grow in the area,
Piptatherum miliaceum showed characteristics to be considered as a bio-monitor for Cd, with a BF > 1,
and a positive–significant correlation between the rhizospheric soil and roots.This research (Proyecto PID2019-110311RB-C22) received funding from MCIN/AEI/10.13039/ 501100011033
Spatial distribution and pollution evaluation in dry riverbeds afected by mine tailings
The objective of this study was to evaluate the level of pollution, sources and potential risk
of heavy metals (Zn, Cu, Mn, Cd, Cr, Ni, Fe and
Pb) and arsenic (As) in four dry riverbeds afected
by mine tailing, which drain into one of the biggest
coastal lagoon of Europe (Mar Menor). El Beal, La
Carrasquilla, Las Matildes and Ponce dry riverbeds
sediments were sampled along its course (20, 18, 13,
19 samples were collected, respectively), and total/
soluble metal(loid)s, water soluble ions, nitrogen,
and organic/inorganic carbon contents were analyzed.
Spatial distribution, principal component analysis
(PCA), hierarchical cluster analysis (HCA), contamination factor (Cf), pollution load index (PLI) and
potential ecological risk index (RI) were used to identify the possible sources of metal(loid)s and to assess
the sediment pollution status. The results showed that
the mean total concentrations of As, Cu, Cd, Mn, Zn
and Pb exceeded the natural background levels of
the study area, with the highest values located close
to the mining areas. Correlation and cluster analysis
identifed that Cd and Zn were associated mainly
with anthropogenic activities for all riverbeds, while
Cr and Ni come from parent. PLI graded the four riverbeds as contaminated by heavy metals, while RI
manifested that 100% of samples located in El Beal,
La Carrasquilla and Las Matildes had a signifcantly
high ecological risk. Therefore, this study suggests
that mine wastes are the main source of metal(loids)
contamination in the dry riverbeds, which results can
be used to design actions and measures to reduce
the environmental impact of metal(loid)s in the Mar
Menor coastal lagoon
A new approach for teaching power electronics converter experiments
This paper presents a new methodological approach
to teaching power electronics converter experiments. This approach
is based on a reconfigurable hardware–software platform
for use in converter experiments in a basic power electronics
course. This course is an optional subject, and, therefore, the
experiments need to motivate the students. The platform is controlled
by software (made in a LabVIEW environment) run on a
PC. The student can control the fundamental parameters of the
selected converter topology through the user interface and, with a
little work, can compare the results with a real circuit. An example
of use of the methodology in an inverter experiment is included.The authors would like to thank the students whose excellent
work and whose comments have helped improve the experiments
carried out at the Power Electronics Laboratory of the
Technical University of Cartagena, Spain. The laboratory was
founded by the Spanish Ministry of Education and the Regional
Government of Murcia
Linear and circular UWB millimeter-wave and terahertz monostatic near-field synthetic aperture Iimaging
Millimeter-wave and terahertz frequencies offer unique characteristics to simultaneously obtain good spatial resolution and penetrability. In this paper, a robust near-field monostatic ocusing technique is presented and successfully applied for the internal imaging of different penetrable geometries. These geometries and environments are related to the growing need to furnish new vehicles with radar-sensing devices that can visualize their surroundings in a clear and robust way. Sub-millimeter-wave radar sensing offers enhanced capabilities in providing information with a high level of accuracy and quality, even under adverse weather conditions. The aim of this paper was to research the capability of this radar system for imaging purposes from an analytical and experimental point of view. Two sets of measurements, using reference targets, were performed in the W band at 100 GHz (75 to 110 GHz) and terahertz band at 300 GHz (220 to 330 GHz). The results show spatial resolutions of millimeters in both the range (longitudinal) and the cross-range (transversal) dimensions for the two different imaging geometries in terms of the location of the transmitter and receiver (frontal or lateral views). The imaging quality in terms of spatial accuracy and target material parameter was investigated and optimized.This research was funded by the Ministry of Education and Science, Spain (TEC2016-78028-C3-1-P and TEC2016-78028-C3-2-P) and by the European FEDER funds
Peripheral Inflammation Enhances Microglia Response and Nigral Dopaminergic Cell Death in an in vivo MPTP Model of Parkinson’s Disease
The impact of systemic inflammation in nigral dopaminergic cell loss remains unclear. Here, we have investigated the role of peripheral inflammation induced by systemic lipopolysaccharide (LPS) administration in the MPTP-based model of Parkinson’s disease. Brain inflammation, microglia and astroglia activation, disruption of the blood–brain barrier (BBB) and integrity of the nigrostriatal dopaminergic system were evaluated in response to i.p. injection of LPS, MPTP or the combination of both. Our results showed that combinative treatment exacerbates microglia activation and enhances (i) the appearance of galectin-3-positive microglia, recently identified as microglial disease-associated phenotypic marker, (ii) the up-regulation of pro-inflammatory cytokines, (iii) the occurrence of A1 neurotoxic astrocytes, (iv) the breakdown of the BBB, and (v) the loss of dopaminergic neurons in the substantia nigra. Microglia activation was triggered earlier than other degenerative events, suggesting that over-activation of microglia (including different polarization states) may induce dopaminergic neuron loss by itself, initiating the endless cycle of inflammation/degeneration. Our study revitalizes the importance of peripheral inflammation as a potential risk factor for Parkinson’s disease and raises the possibility of using new anti-inflammatory therapies to improve the course of neurodegenerative diseases, including those directly aimed at modulating the deleterious activity of disease-associated microglia.España MINECO y FEDER SAF2015-64171-
Errors and omissions in learning. Classical worlds and modern society
En esta comunicación presentaremos someramente los resultados obtenidos en
la primera fase del proyecto «Los mundos clásicos en la sociedad actual. Errores
y omisiones que dificultan el aprendizaje». El ámbito de aplicación consiste en el
alumnado de varias asignaturas del grado en Estudios clásicos y de otros grados
en los que impartimos docencia, como el grado en Estudios ingleses o un grupo
específico para el aprendizaje del latín: Latín nivel 0. El objetivo era detectar y
valorar las carencias que dificultan el aprendizaje y la adquisición de competencias
relacionadas con la influencia de los mundos clásicos (greco-latino y árabe)
en la sociedad actual, así como trazar con claridad el perfil del alumnado que
cursaba estas asignaturas. Para ello necesitábamos saber la concepción y conocimientos
que poseían sobre los mundos clásicos. El método que utilizamos fue una
encuesta doble con una parte centrada en el mundo clásico grecolatino y otra,
paralela, dedicada al mundo árabe clásico. El análisis de los resultados permitió
concluir que asocian mundo clásico a historia, mitología, cultura o cocina, pero
no a la lengua; que la mayoría conoce la mitología porque es un tema de gran
interés para los medios de entretenimiento (cine, televisión, videojuegos) que son
la fuente de su conocimiento. En el caso del árabe, su interés se centra en temas
culturales en los que se integra la religión considerada un aspecto cultural más,
pues su conocimiento procede de los medios de entretenimiento entre los que
mencionan libros de lectura como las novelasIn this paper we will briefly present the results obtained in the first phase of the
project «The Classical Worlds in Today’s Society. Errors and omissions that make
learning difficult». The scope of application consists of the students of several
subjects of the degree in Classical Studies and of other degrees in which we participate,
as the degree in English Studies or a specific group for the learning of
Latin, Latin level 0. The objective was to detect the deficiencies that make learning
difficult and to acquire competences related to the influence of the classical worlds
(Greco-Latin and Arabic) in modern society, as well as to outline the profile of
the students who studied these subjects. We needed to know the conception and
knowledge they had on the classical world. The method we used was a double
survey with one part centered on the classic Greco-Roman world and another dedicated
to the classical Arab world. The analysis of the results allowed to conclude
they associate classic world with history, mythology, culture or cuisine, but not with
language; the majority knows mythology because it is a subject of great interest
for the entertainment media (cinema, television, video games), main source of its
knowledge. In the case of Arabic world, their interest is focused on cultural issues
in which religion is considered a cultural aspect, since their knowledge comes from
the entertainment media as cinema, video games and novels
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