1,782 research outputs found
Selección de clones de pino piñonero sobresalientes en la producción de piña
Though stone pine is currently a genuine forest tree of Mediterranean ecosystems, its use as grafted orchards crop for its edible pine nuts is potentially feasible. Therefore, genetic improvement of the species has been undertaken by several Spanish forest administrations, establishing in the Nineties experimental clonal orchards by grafting scions from plus trees, selected for their outstanding cone yield in pine forests of the main Spanish provenance regions. This paper analyses the coming into production of four clonal trials located at the National Forest Breeding Centre «Puerta de Hierro», Madrid. The four different-aged orchards showed a strong, synchronized masting habit. Estimations are given for the degree of genetic determination of cone production and for clonal improvement values. Due to the presence of strong size-yield correlations and spatial autocorrelations, genetic parameters were estimated by an individual tree cone-yield model adjusted for environmental tree size differences and for correlations between nearest neighbours (NN). The degree of genetic determination H2, estimated in less than 20% without adjustments, reached 30-38% adjusting for environmental size variation and 45-73% after spatial adjustment, with parallel increments in clonal improvement values and expected genetic gain. The results allow rogueing the four clone banks, progressing in the domestication of the stone pine as nut crop.El potencial uso del pino piñonero como cultivo frutal injertado para la producción de piñón justifica su mejora genética clonal (selección varietal), estableciéndose en los años noventa diversos bancos clonales partiendo de la prospección de árboles sobresalientes en las principales regiones de procedencia españolas. Este trabajo estudia y compara la entrada en producción de cuatro bancos clonales situados en Madrid. Aunque de diferentes edades, muestran un carácter vecero sincronizado entre ellos. Para evitar sesgos ambientales en la estimación del grado de determinación genética de la productividad individual de piña y de los valores de mejora clonales, se ajustaron como covariables las diferencias ambientales de tamaño de árbol y las autocorrelaciones espaciales entre árboles vecinos, que juntos aportaron un coeficiente de determinación mucho mayor que las diferencias entre clones. El grado de determinación genética H2 de la producción individual de piña, estimado en menos de 20% sin ajustar por estas variables ambientales, subió hasta un 30-38% al incluir en el modelo la variación ambiental del tamaño de árbol, hasta un 45-73% tras el ajuste espacial iterativo, incrementándose en paralelo la estimación de los valores de mejora clonal y de la ganancia genética esperada. Estos resultados permiten depurar las colecciones para avanzar en la domesticación de la especie
The dependence of oxygen and nitrogen abundances on stellar mass from the CALIFA survey
We analysed the optical spectra of HII regions extracted from a sample of 350
galaxies of the CALIFA survey. We calculated total O/H abundances and, for the
first time, N/O ratios using the semi-empirical routine HII-CHI-mistry, which,
according to P\'erez-Montero (2014), is consistent with the direct method and
reduces the uncertainty in the O/H derivation using [NII] lines owing to the
dispersion in the O/H-N/O relation. Then we performed linear fittings to the
abundances as a function of the de-projected galactocentric distances. The
analysis of the radial distribution both for O/H and N/O in the non-interacting
galaxies reveals that both average slopes are negative, but a non-negligible
fraction of objects have a flat or even a positive gradient (at least 10\% for
O/H and 4\% for N/O). The slopes normalised to the effective radius appear to
have a slight dependence on the total stellar mass and the morphological type,
as late low-mass objects tend to have flatter slopes. No clear relation is
found, however, to explain the presence of inverted gradients in this sample,
and there is no dependence between the average slopes and the presence of a
bar. The relation between the resulting O/H and N/O linear fittings at the
effective radius is much tighter (correlation coefficient = 0.80) than
between O/H and N/O slopes ( = 0.39) or for O/H and N/O in the
individual \hii\ regions ( = 0.37). These O/H and N/O values at the
effective radius also correlate very tightly (less than 0.03 dex of dispersion)
with total luminosity and stellar mass. The relation with other integrated
properties, such as star formation rate, colour, or morphology, can be
understood only in light of the found relation with mass.Comment: Accepted for publication in A&A. 20 pages, 19 figure
Thalassiosira pseudonana and Skeletonema costatum biomass optimization: cultivation, harvesting, extraction of oils and biodiesel and pelletization of the residue
Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGMicroalgae are one of the most promising feedstocks for biofuel production that can solve the energy crisis, climate change, and the depletion of fossil fuels. Biorefineries have production capacity bottlenecks that prevent them from being economically profitable, without leaving aside the environmental safety of by-products. This research aims to analyze critical stages such as harvesting or lipid extraction from two microalgae species currently unknown, such as Thalassiosira pseudonana and Skeletonema costatum. Inorganic flocculation with a low concentration of iron or aluminum salts (FeCl3 and Al2(SO4)3) was achieved to recover >60% biomass in just 20 min in both cases. Lipids extractions through chloroform: methanol (solvent ratio 2:1) obtained low performance due to the ionic strength medium. The fatty acid composition of the algae extracts showed that stearic acid (C18:0) and palmitoleic acid (C16:1) were predominant in both species. In addition, residues from the lipid extraction process were used for the manufacture of pellets. The data collected showed that these solid biofuels should be combined with other biomass typologies if the end-use are biomass boilers. The development of these studies provides new information on different microalgae species and their potential to use their biomass through an integrated utilization
Design of Pumping Stations Using a Multicriteria Analysis and the Application of the AHP Method
[EN] The pumping station are very important hydraulic system in urban water supply be-cause the pumps raise the water head ensuring the minimum pressure required in drinking water systems. In the design of a pumping station, one of the most important criteria is the number of pumps. However, in the traditional design this criterion is de-fined arbitrarily. The other criteria are defined from the number of pumps and can be produce a design not optimal. In addition, the traditional design does not consider the environment importance to choose the pumps.
The objective of this paper is defining a new design methodology for pumping sta-tions. It has been developed using a multicriteria analysis in which nine criteria are evaluated. The application of the analytic hierarchy process (AHP) allows finding an optimal solution. These design criteria have been associated in three cluster factors: technical factors, environmental factors, and economic factors. The results obtained allow not only to validate the methodology, but also to offer a solution to the problem of determining the most suitable model and the number of pumps of a pumping sta-tion.Sánchez-Ferrer, DS.; Briceño-León, CX.; Iglesias Rey, PL.; Martínez-Solano, FJ.; Fuertes-Miquel, VS. (2021). Design of Pumping Stations Using a Multicriteria Analysis and the Application of the AHP Method. Sustainability. 13(11):1-22. https://doi.org/10.3390/su13115876S122131
The economic value of drought information for water management under climate change: a case study in the Ebro basin
Drought events in the Mediterranean are likely to increase in frequency, duration and intensity due to climate change, thereby affecting crop production. Information about drought is valuable for river basin authorities and the farmers affected by their decisions. The economic value of this information and the resulting decisions are of interest to these two stakeholder groups and to the information providers. Understanding the dynamics of extreme events, including droughts, in future climate scenarios for the Mediterranean is being improved continuously. This paper analyses the economic value of information on drought events taking into account the risk aversion of water managers. We consider the effects of drought management plans on rice production in the Ebro river basin. This enables us to compute the willingness to compensate the river basin authority for more accurate information allowing for better decision-making. If runoff is reduced, river basin planners can consider the reduction of water allocation for irrigation in order to eliminate the risk of water scarcity. Alternately, river basin planners may decide to maintain water allocation and accept a reduction of water supply reliability, leaving farmers exposed to drought events. These two alternatives offer different risk levels for crop production and farmers' incomes which determine the value of this information to the river basin authority. The information is relevant for the revision of River Basin Management Plans of the Water Framework Directive (WFD) within the context of climate change
Maniobra de fiabilidad para el Músculo Peroneo Lateral Largo: Hipermobilidad del Primer Radio
The muscle Peroneus Longus is a major stabilizer of the first metatarsal bone in dynamics, since by its plantarflexor action stabilizes the bone segment to anchor the the floor and allow in this way, the correct mobility of the first metatarsophalangeal joint in the phase of toe off. But the evaluation of this muscle has not been revised in recent years and this article therefore proposes other ways of evaluating its functional integrity and to identify any functional abnormalities that resulted in a hypermobility of the first ray.El músculo Peroneo Lateral Largo es uno de los principales estabilizadores del primer Metatarsiano en la dinámica, ya que por su acción plantarflexora estabiliza dicho segmento óseo para anclarlo al suelo y permitir de esta manera la correcta movilidad de la primera Articulación Metatarso-Falángica en la fase de despegue. Pero la evaluación de este músculo no ha sido revisada en los últimos años y en este artículo por tanto se proponen otras maneras diferentes de valorar su integridad funcional y detectar las posibles anomalías funcionales que se traducen en una hipermovilidad del primer radio
Central star formation and metallicity in CALIFA interacting galaxies
We use optical integral-field spectroscopic (IFS) data from 103 nearby
galaxies at different stages of the merging event, from close pairs to merger
remnants provided by the CALIFA survey, to study the impact of the interaction
in the specific star formation and oxygen abundance on different galactic
scales. To disentangle the effect of the interaction and merger from internal
processes, we compared our results with a control sample of 80 non-interacting
galaxies. We confirm the moderate enhancement (2-3 times) of specific star
formation for interacting galaxies in central regions as reported by previous
studies; however, the specific star formation is comparable when observed in
extended regions. We find that control and interacting star-forming galaxies
have similar oxygen abundances in their central regions, when normalized to
their stellar masses. Oxygen abundances of these interacting galaxies seem to
decrease compared to the control objects at the large aperture sizes measured
in effective radius. Although the enhancement in central star formation and
lower metallicities for interacting galaxies have been attributed to tidally
induced inflows, our results suggest that other processes such as stellar
feedback can contribute to the metal enrichment in interacting galaxies.Comment: 9 pages, 9 figures. Accepted for publication in Astronomy &
Astrophysic
First survey of Wolf-Rayet star populations over the full extension of nearby galaxies observed with CALIFA
The search of extragalactic regions with conspicuous presence of Wolf-Rayet
(WR) stars outside the Local Group is challenging task due to the difficulties
in detecting their faint spectral features. In this exploratory work, we
develop a methodology to perform an automated search of WR signatures through a
pixel-by-pixel analysis of integral field spectroscopy (IFS) data belonging to
the Calar Alto Legacy Integral Field Area survey, CALIFA. This technique
allowed us to build the first catalogue of Wolf-Rayet rich regions with
spatially-resolved information, allowing to study the properties of these
complexes in a 2D context. The detection technique is based on the
identification of the blue WR bump (around He II 4686 {\AA}, mainly associated
to nitrogen-rich WR stars, WN) and the red WR bump (around C IV 5808 {\AA} and
associated to carbon-rich WR stars, WC) using a pixel-by-pixel analysis. We
identified 44 WR-rich regions with blue bumps distributed in 25 galaxies of a
total of 558. The red WR bump was identified only in 5 of those regions. We
found that the majority of the galaxies hosting WR populations in our sample
are involved in some kind of interaction process. Half of the host galaxies
share some properties with gamma-ray burst (GRB) hosts where WR stars, as
potential candidates to being the progenitors of GRBs, are found. We also
compared the WR properties derived from the CALIFA data with stellar population
synthesis models, and confirm that simple star models are generally not able to
reproduce the observations. We conclude that other effects, such as the binary
star channel (which could extend the WR phase up to 10 Myr), fast rotation or
other physical processes that causes the loss of observed Lyman continuum
photons, are very likely affecting the derived WR properties, and hence should
be considered when modelling the evolution of massive stars.Comment: 33 pages, accepted for publication in A&
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