2,444 research outputs found
Form and function of the mantle edge in Protobranchia (Mollusca: Bivalvia)
We analyzed, by optical and transmission electron microscopy, the morphology and function of the mantle edge,
including the formation of the periostracum, of ten species of protobranchs. Five species from the order Nuculida,
four species from the order Nuculanida and one species from the order Solemyida were studied. A second outer
fold, which seems to function as a template for the internal marginal crenulations of the valves, is present in the
crenulated species of Nucula. The minute non-crenulated Ennucula aegeensis shows the glandular basal cells
displaced toward the periostracal groove, resembling a minute additional fold between the outer and middle
folds. Intense secretion of glycocalyx, together with active uptake of particles, have been observed in the inner
epithelium of the middle mantle fold and the whole epithelium of the inner mantle fold in all the studied species.
Contrary to the rest of the bivalves, all the protobranchs analyzed have two basal cells involved in the formation
of the external nanometric pellicle of the periostracum, a character that would support the monophyly of protobranchs.
A three-layered pattern is the general rule for the periostracum in protobranchs, like for other bivalves.
The presence of pouches of translucent layer inside the tanned dark layer under periostracal folds is
characteristic of the species with a folded periostracum; its function is unclear but could give flexibility to the
periostracum. The non-nacreous internal shell layer and the presence of translucent pouches under periostracal
folds in Sarepta speciosa resemble those found in nuculanids. However, the free periostracum is rather similar to
those of N. hanleyi and E. aegeensis, with a continuous vesicular layer. All the latter supports the inclusion of
Sarepta in the order Nuculanida but could indicate either a basal lineage or that the translucent vesicular layer is
an adaptive trait.Málaga/CBU
Current and historical factors drive variation of reproductive traits in unisexual mosses in Europe: A case study
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiereUnisexual bryophytes provide excellent models to study the mechanisms that regulate the frequency of sexual versus asexual reproduction in plants, and their ecological and evolutionary implications. Here, we determined sex expression, phenotypic sex ratio, and individual shoot traits in 242 populations of the cosmopolitan moss Pseudoscleropodium purum spanning its whole distributional range. We tested whether niche differentiation, sex‐specific differences in shoot size, and biogeographical history explained the spatial variation of reproductive traits. We observed high levels of sex expression and predominantly female‐biased populations, although both traits showed high intraspecific variation among populations. Sex expression and sex ratio were partly explained by current macroscale environmental variation, with male shoots being less frequent at the higher end of the environmental gradients defined by the current distribution of the species. Female bias in population sex ratio was significantly lower in areas recolonized after the last glacial maximum (recent populations) than in glacial refugia (long‐term persistent populations). We demonstrated that reproductive trait variation in perennial unisexual mosses is partially driven by macroscale and historical environmental variation. Based on our results, we hypothesize that sexual dimorphism in environmental tolerance and vegetative growth contribute to sex ratio bias over time, constraining the chances of sexual reproduction, especially in long‐term persistent populations. Further studies combining genetic analyses and population monitoring should improve our understanding of the implications of the intraspecific variation in the frequency of sexual versus asexual reproduction in bryophyte population fitness and eco‐evolutionary dynamic
Temporal activity in particular segments and transitions in the Olympic Triathlon
P. 87-95El triatlón olímpico es un deporte de resistencia combinada. Incluye natación espalda con espalda, ciclismo, carrera y la transición entre eventos (T1 y T2). El objetivo del presente estudio fue analizar la posible relación entre el Tiempo perdido T1 y T2 y el rendimiento general. Los resultados mostraron que los porcentajes de tiempo total correspondientes a cada parte de la carrera fueron: 16.2% para natación, 0.74% para la transición de natación y ciclismo (T1), 53.07% para ciclismo, 0.47% para la transición de ciclismo y carrera (T2 ) y el 29,5% para correr. Las correlaciones entre cada parte de la carrera y la ubicación final fueron: r = 0.36 para nadar, r = 0.25 para T1, r = 0.62 para el ciclismo, r = 0.33 para T2 y r = 0.83 para la carrera. Además, los valores de r = 0.34 & r = 0.43 se obtuvieron para Tiempo perdido T1 y Tiempo perdido T2, respectivamente. En conclusión, se ha demostrado que perder menos tiempo durante T2 está relacionado con la obtención de un mejor resultado finalS
Gender differences in elite Olympic distance triathlon performances
P. 434-445Para el análisis de las actuaciones generales de triatlón de distancia olímpica en masculino y femenino de élite del Campeonato del Mundo y Juegos Olímpicos eventos 2000-2008. Tiempo, tiempo perdido y la posición parcial para cada segmento y de transición, las diferencias de género en el desempeño de las tres disciplinas, y los tiempos totales de los machos y las hembras se analizaron. La única diferencia significativa entre los sexos en relación con el porcentaje de tiempo utilizado en el segmento de natación (16,3 ± 0,6 M frente a 15,6 ± leq 0,6 F). La diferencia de género (SD) en la producción de energía para los ganadores en la natación, el ciclismo, la carrera fue 13,7 ± 16,1%, 67,1 ± 4,3%, 29,8 ± 8,4%, respectivamente. La coeficientes de correlación entre la pérdida de tiempo para cada segmento y de transición, y la clasificación general final fueron (0,4 M frente a 0,48 F) para nadar, (0,28 M frente a 0,3) para T1, (0,34 M frente a 0,31 F) por tiempo perdido T1, (0,63 M frente a 0,77 F) para el ciclismo, r = 0,33 (0,33 M frente a 0,34 F) para T2, (0,43 M frente a 0,29 F) por tiempo perdido y T2 (0,83 M frente a 0,84 F) para correr. El segmento de ejecución es la más decisiva, teniendo una correlación más evidente para los hombres porque hay menos escapadas o segmentos de colinas que rompen el pelotón principal, mientras que el nivel de rendimiento es similar para la mayoría de los competidores. Con las mujeres, el rendimiento es más variada y hay otras variables que conforman el segmento de marcha, menos decisivo. Sin embargo, las pequeñas diferencias en el segundo que se produjeron en el segmento de natación y las transiciones pueden tener un impacto significativo en el resultado de la competiciónS
A group decision making support system for the Web: how to work in environments with a high number of participants and alternatives
One of the main challenges that the appearance of Web 2.0 and the overall
spreading of the Internet have generated is how to tackle with the high
number of users and information available. This problem is also inherited by
the group decision making problems that can be carried out over the Web.
In this article, to solve this issue, a group decision making support system
that allows the use of a high number of participants and alternatives is presented.
This method allows any number of participants to join the decision
making process at any time. Furthermore, they let them provide information
only about a certain subset of alternatives. The high participation rate can
provide enough information for the decision process to be carried out even
if the participants do not provide information about all the high number of
available alternatives.This paper has been developed with the financing of FEDER funds in the
project TIN2016-75850-R
Evaluation of toxic effect of monoterpene compounds on anaerobic digestion
Monoterpenes are antimicrobial compounds widely distributed in vegetable biomass, whose inhibitory potential for anaerobic digestion is underestimated. In this research, the toxic effect of limonene and fenchone, two of the main monoterpenes present in vegetable biomasses, and those of 4-terpineol, α-terpineol, and p-cymene, compounds described as main metabolites of limonene degradation, have been assessed. Methane production was totally inhibited at dosed of 1000 mg L-1 of fenchone and limonene and at 600 mg L-1 of p-cymene and 4-terpineol. Based on the methane production rate, the inhibition followed the next trend: α-terpineol 85%), except p-cymene at 600 mg L-1. Therefore, monoterpenes could entail a high risk of inhibition that can be aggravated by the difficulty to accurately follow their concentration and by the scarce information on their effect on anaerobic process.Pablo de Olavide
University and the Santander Bank for mobility grantNext Generation European Funds and the Ministry
of Universities of Spain for funding the Recualificaci´on del Profesorado
Universitario systemEconomic Transformation, Industry, Knowledge, and Universities
Department of the Andalucia Autonomous Government for Emergia
fellowship (EMERGIA20_00114)CRHIAM centre (ANID/FONDAP/15130015)Funding for open access charge: Universidad de Granada / CBUA
A 800 kW wind-diesel test bench based on the MADE AE-52 variable speed wind turbine
A field work have been made about the practical installation of a wind-diesel autonomous power system. A remarkable innovation on the control of the latter wind-diesel system is the ability of taking advantage of the kinetic energy available from the wind turbine. With such an extra energy, a power quality improvement can be achieved in the presence of load commutations. Besides of that, a convenient power sharing out can be obtained, allowing a high renewable energy penetration and fuel savings. Several results show the behaviour of the whole system, apart of the power quality improvement. Index Terms—Renewable hybrid system, isolated power system, power quality, diesel generator, wind turbine
Hillings as a tillage practice in maize (Zea mays L.) in monoculture and in relay intercropped with climbing beans (Phaseolus vulgaris L.)
La práctica cultural del aporque en el cultivo del maíz está ampliamente generalizada en zonas frías del país, especialmente en las de vientos fuertes, cuando se cultivan variedades muy altas, o cuando se siembra asociado o en relevo con fríjol voluble. Para estudiar el efecto de esta práctica sobre el rendimiento y el volcamiento de maíz en monocultivo y en relevo con fríjol voluble, durante 1981 y 1982 se sembraron ensayos con tres genotipos de maíz, sin y con aporque a los 45, 60, 75, 90, 105 y 120 días después de la siembra. Los resultados indican que el aporque no produce efecto sobre los rendimientos de los maíces estudiados, pero sí en el volcamiento, tanto en monocultivo como en relevo con fríjol voluble y que para disminuirlo, dicha práctica debe ralizarse a partir de los 75 días después de la siembra. El aporque hecho al maíz no tuvo incidencia sobre el rendimiento del fríjol voluble tipo IVb, sembrado en relevo.Hilling is a generalized tillage practice in the maize crop in Colombia, mainly in the cold high altitudes where strong winds are common, or when very tall maize varieties are planted in association with or as relay intercrop with climbing beans. Research was conducted at "La Selva" ICA's Experimental Station near Medellin, during 1981 and 1982, using one bean cultivar with three maize genotypes without hilling and hilling at 45, 60, 75, 90, 105 and 120 days after planting. The objectives were to find the not hilling and hilling effect on lodging and on yield of maize and beans. The results showed not effect of hilling on the yields of corn and climbing type lVb beans planted in relay intercrop. However, maize stalk lodging was mostly increased in monoculture and in relay intercropping. 75 days after planting was the optimum time for hill tillage in the particular experiment with the three maize genotypes used.
Additional.Fríjol-Phaseolus vulgarisMaíz-Zea may
Paleoenvironment and age of Los Monos Formation (Devonian), Tarija Basin, Argentina and Bolivia
The objective of this work is to discuss the paleoenvironment and age of the Los Monos Formation, in outcrop and subsurface, along a regional transect (west-east) in the southern sector of the Tarija basin. The lithofacies and ichnofacies of the Alarache, Angosto del Pescado and Balapuca outcrops and core-intervals of the Aguas Blancas xp-13, Ramos x-12, Tartagal x-1 and Tonono x-1 boreholes were analyzed. The definition of lithofacies and ichnofacies allowed us to interpret a shallow to deep marine paleoenvironment (from the offshore-transition, offshore and shelf). Towards the top of the Tonono Formation, the equivalent of the Los Monos Formation in the Chaco-Salteño was defined as a brackish-waters marginal-marine paleoenvironment. The mineralogy of the mentioned sections plus the Vespucio x-1 borehole was analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), thus the majority elements in clay minerals were also determined from EDAX. Authigenic and detrital clays from SEM-EDAX were recognized. Four clay mineral assemblages were defined (I+Ch; Ch+I; I+K; K+I), where I+K and K+I assemblages characterize the transgressive events within the basin. The palynofacies of the Balapuca, Alarache and Angosto del Pescado outcrops and samples from the Ramos xp-1002, Ramos xp-1011 and Ramos xp-1012 boreholes were defined, the dominance of terrestrial palynomorphs was recognized with variable participation of marine palynomorphs, according to a shallow marine paleoenvironment with shoreline shifts. Two transgressive events were identified during the late Eifelian-early Givetian and the late Givetian-early Frasnian, which are characterized by an increase in marine components and clay assemblages of I+K and K+I. The palynological associations pont to a late Eifelian-early to middle Givetian age for the Los Monos Formation in the study area. The analysis of illite crystallinity and expansive layers in the mixed-layer IS determined advanced diagenesis for the unit, from late mesodiagenesis (Tonono x-1 and Vespucio x-1) to telodiagenesis (Balapuca and Ramos), according to the final stage of oil generation window to gas generation window, respectively. Finally, based on the mineral composition with a predominance of quartz (>70% in average) and low content of clays (100 km2), the unit has some of the attributes to be considered as a shale-type unconventional reservoir.Fil: Veizaga Saavedra, Juan Gonzalo. Universidad Nacional de Salta. Facultad de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Poiré, Daniel G.. Comision de Investigaciones Cientificas de la Provincia de Buenos Aires. Centro de Geologia Aplicada, Agua y Medio Ambiente.; ArgentinaFil: Vergani, Gustavo Dardo. No especifíca;Fil: Salfity, Jose Antonio. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto del Cenozoico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rubinstein, Claudia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Pérez Leytón, Miguel A.. No especifíca
Acta Horticulturae
While the molecular response of model plants to salt stress in the short-medium term (hours-days) has been broadly studied, the knowledge about the nature of genes involved in maintaining homeostatic conditions in the long term (months-years) in woody perennial trees has not been addressed yet. We have analyzed physiological parameters and the transcriptome profiles of photosynthetically active leaves from citrus trees acclimatized to moderate salinity (NaCl 30 mM) after 2 years treatment. Through functional genomics, global gene expression in response to NaCl treatment in mature (8 months-old) and young (2 months-old) leaves has been analyzed and compared. Although young leaves (YL) accumulated low levels of chloride (0.51%+/- 0.06), they exhibited a much stronger response to salinity in term of the number of differentially expressed genes (1,211 genes) compared with mature leaves (ML), which accumulated higher chloride levels (1.05%+/- 0.01), and exhibited a much lower number of differentially-responsive genes (100 genes). In this work, a number of responses have been observed that differ from those described in previous studies of citrus plants non-acclimatized to salt stress (Brumos et al., 2009), whose principal manifestation was the lack of repression of primary metabolism in leaves at the molecular and physiological levels. Results describing enriched functional categories of differentially expressed genes are presented and discussed highlighting how the long-term acclimation to NaCl stress involves drastically different molecular strategies depending on the developmental stage of plant leaves
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