On-Offer and Residual Forage in a Massai-\u3cem\u3eLeucaena\u3c/em\u3e Pasture at Different Leucaena Density

Mexican livestock producers in tropical areas are increasingly interested on the establishment of silvopastoral systems based on Leucaena (Leucaena leucocephala (Lam.) de Wit) and different tropical grasses as the Massai grass (Panicum maximum cv Massai); among questions raised on this is the importance of Leucaena density in relation to forage available. Then the objective of the study was to determine total and by species on-offer and residual forage in a grazed MassaiLeucaena pasture with different Leucaena density

Xylan-binding xylanase Xyl30 from Streptomyces avermitilis: cloning, characterization, and overproduction in solid-state fermentation

A DNA fragment from the lignocellulolytic actinomycete Streptomyces avermitilis CECT 3339 was cloned using a DNA probe from the xylanase gene xysA of Streptomyces halstedii. The nucleotide sequence analysis revealed two potential ORFs, xyl30 and hd30, encoding a deduced multimodular F/10 xylanase with a binding domain and a secreted glycoxyl hydrolase, respectively. In Streptomyces lividans carrying the subcloned DNA fragment, two xylanase activity bands with estimated molecular masses of 42.8 and 35 kDa (named Xyl30 forms "h" and "l", respectively), were detected by zymograms and SDS-PAGE. The two xylanases had identical N-terminal sequences, suggesting that Xyl30 "l" derived from Xyl30 "h" by C-terminal processing in the culture supernatant. No transcripts of hd30 were detected by RT-PCR. Characterization of the partially purified Xyl30 "h" confirmed the presence of a modular endoxylanase containing a xylan-binding domain, which after processing in the culture supernatant loses the aforementioned domain and thus its capacity to bind xylan (Xyl30 "l"). Xyl30 "h" achieved maximal activity at pH 7.5 and 60 degrees C, retaining more than 50% of its activity from pH 3 to 9 and more than 40% after a 1-h incubation at 70 masculineC. Moreover, in the recombinant host strain up to 400 U xylanase/g medium (dry weight) was produced in solid-state fermentation (SSF) using cereal bran as substrate. The high production yields of this enzyme and its biochemical features make it a good candidate for use in industrial applications

Evaluación de la capacidad reproductiva de sementales bovinos mantenidos en clima tropical húmedo

El objetivo de este estudio fue evaluar la capacidad reproductiva de sementales bovinos y determinar el efecto de factores tales como raza, edad y anormalidad anatómicas dcl aparato reproductor

Deuda viva municipal en un contexto de crisis económica: análisis de los factores determinantes y de las formas de gestión

ResumenLa especial situación de crisis económica, junto con las restricciones al endeudamiento impuestas a los ayuntamientos y el control del déficit público, han reducido los recursos de las administraciones locales. En este contexto, los gestores encuentran en la creación de entes instrumentales una herramienta que permite al ayuntamiento no computar en su presupuesto determinados niveles de deuda. El objetivo del presente trabajo es determinar si la cooperación intermunicipal, la colaboración público-privada y la descentralización, junto con los aspectos políticos y financieros de la entidad, son factores que condicionan que el ayuntamiento presente un determinado nivel de deuda en período de crisis económica. Para ello, utilizando diferentes bases de datos, se estudia sobre una muestra de 1.238 municipios, para el período 2008-2011, cuáles de estos factores influyen sobre la deuda de los municipios españoles. Los resultados muestran, tras la aplicación de un modelo de regresión agrupada, que las variables financieras influyen sobre el nivel de deuda del municipio, así como la tasa de inmigración y la presencia o no de fragmentación política en el gobierno local. Igualmente, se ha obtenido evidencia de que tanto los ayuntamientos con mayor cooperación intermunicipal como aquellos con un mayor grado de descentralización presentan un mayor nivel de deuda.AbstractAs a result of the current economic crisis, with the consequent borrowing constraints imposed on municipalities and curbs on public deficit, the resources of local governments have been severely reduced. In this context, the creation of devolved organizations provides municipalities with a means of eliminating certain forms of debt from their budget items. The aim of this study is to determine whether inter-municipal cooperation, public-private collaboration and decentralization, together with the political and financial characteristics of the local authority in question, are factors constraining it to present a particular level of debt in times of economic crisis. To achieve these goals, various databases were used to study a sample of 1,238 local authorities for the period 2008-2011, to determine which of these factors influence municipal debt in Spain. Application of a pooled regression model showed that financial variables are factors that influence the level of municipal debt, as does the political orientation of the governing local party. We also found that local councils presenting higher levels of inter-municipal cooperation and those with a higher degree of decentralization have higher levels of debt

Use of Aerial Laser Scanning to Assess the Effect on C Sequestration of Oak (Quercus ilex L. subsp. ballota [Desf.]Samp-Q. suber L.) Afforestation on Agricultural Land

Conversion of agricultural lands to forest plantations to mitigate rising atmospheric carbon dioxide (CO2) has been proposed, but it depends on accurate estimation of the on-site carbon (C) stocks distribution. The use of aerial laser scanning (ALS) data is a rapidly evolving technology for the quantification of C stocks. We evaluated the use of allometric models together with high-density ALS data for the quantification of biomass and soil C stocks in a 14-year-old Quercus ilex and Q. suber plantation in Southwestern Spain. In 2010, a field survey was performed and tree dasometric and biomass variables were measured. Forty-five soil profiles (N = 180 soil samples) were taken systematically and the soil organic C content (SOC) was determined. Biomass and soil organic C values were regressed against individual dasometric variables and total tree height was used as a predictor variable. Aerial laser scanning data were acquired with a point density of 12 points m−2. Relationships among ALS metrics and tree height were determined using stepwise regression models and used in the allometric models to estimate biomass and SOC C stocks. Finally, a C stock map of the holm-cork oak cover in the study area was generated. We found a tree total biomass of 27.9 kg tree−1 for holm oak and 41.1 kg tree−1 for cork oak. In the holm oak plantation, the SOC content was 36.90 Mg ha−1 for the layer 0–40 cm (SOC40) under the tree crown and 29.26 Mg ha−1 for the inter-planted area, with significant differences from the reference agricultural land (33.35 Mg ha−1). Linear regression models were developed to predict the biomass and SOC at the tree scale, based on tree height (R2 >0.72 for biomass, and R2 >0.62 for SOC). The overall on-site C stock in the holm-cork oak plantation was 35.11 Mg ha−1, representing a net C stock rise of 0.47 Mg ha−1 yr−1. The ALS data allows a reliable estimation of C stocks in holm and cork oak plantations and high-resolution maps of on-site C stocks are useful for silvicultural planning. The cost of ALS data acquisition has decreased and this method can be generalised to plantations of other Mediterranean species established on agricultural lands at regional scales. However, an increase of filed data and the availability of local biomass and, in particular, SOC will improve accurate quantification of the C stocks from allometric equations, and extrapolation to large planted areas

Winter Forage Yield of Signal Grass (\u3cem\u3eBrachiaria brizantha \u3c/em\u3e(Hochst. Ex. A. Rich) R.D. Webster) at Different Cutting Frequency and N Fertilization

Signal grass (Brachiaria brizantha (Hochst. Ex. A. Rich) R.D. Webster) is widely grown in sub-humid tropical environments. In winter, shorter photoperiod and lower rainfall and temperatures reduce grass forage yield. Cutting frequency and N fertilization might reduce this negative effect (Whitehead, 1995; Pereira et al., 2014). The objective of the study was to determine winter forage yield total and by components of Signal grass under different cutting frequency and N fertilization

Nuevos datos sobre la estratigrafía de subsuelo del acuífero de Torrevieja (Alicante): implicaciones en el modelo conceptual de funcionamiento.

El análisis estratigráfico de sondeos de investigación realizados en el acuifera de Torrevieja pone de manifiesto la coincidencia de las unidades hidrogeológicas con las estratigráficas y permite una mayor precisión en la definición de las primeras al poder constatar que las variaciones internas dentro de las unidades estratigráficas tienen reflejo en la geometria de los acuiferos y los parámetros hidrogeológicos. Asi mismo, la interpretación genética de los sedimentos y la caracterización de las discontinuidades que los limitan permiten realizar una extrapolación predictiva de las caracteristicas geológicas de subsuelo que pueden ser aplicadas a la modelización de las unidades hidrogeológicas

Epizoochory in Parrots as an Overlooked Yet Widespread Plant–Animal Mutualism

Plant–animal interactions are key to sustaining whole communities and ecosystem function. However, their complexity may limit our understanding of the underlying mechanisms and the species involved. The ecological effects of epizoochory remain little known compared to other seed dispersal mechanisms given the few vectors identified. In addition, epizoochory is mostly considered non-mutualistic since dispersers do not obtain nutritional rewards. Here, we show a widespread but unknown mutualistic interaction between parrots and plants through epizoochory. Combining our observations with photos from web-sources, we recorded nearly 2000 epizoochory events in 48 countries across five continents, involving 116 parrot species and nearly 100 plant species from 35 families, including both native and non-native species. The viscid pulp of fleshy fruits and anemochorous structures facilitate the adherence of tiny seeds (mean 3.7 × 2.56 mm) on the surface of parrots while feeding, allowing the dispersion of these seeds over long distances (mean = 118.5 m). This parrot–plant mutualism could be important in ecosystem functioning across a wide diversity of environments, also facilitating the spread of exotic plants. Future studies should include parrots for a better understanding of plant dispersal processes and for developing effective conservation actions against habitat loss and biological invasions.This research was funded by Severo Ochoa Program (SVP-2014-068732), Action COST “ParrotNet” (ES1304), and Loro Parque Fundación (PP-146-2018-1). E.S.-G. is funded by a Ramón y Cajal contract (RYC-2019-027216I) from the Spanish Ministry of Science and Innovation

Seismotectonic and geologic characterization of the february 1999 Mb: 4,8 Mula earthquake using geological data, seismological data and RADAR interferometry (INSAR)

La secuencia sísmica de Mula (Murcia) iniciada el 2 de Febrero de 1999 con un terremoto máximo de Mb: 4,8 alcanzó una intensidad MSK máxima de VI-VII causando numerosos daños materiales. Los datos sismológicos existentes hasta la fecha, y concretamente la profundidad hipocentral y los mecanismos focales difieren de forma significativa en función del método de cálculo usado. En este trabajo se ha utilizado una técnica novedosa como es la interferometría de RADAR (INSAR) con el fin de identificar posibles deformaciones superficiales asociadas el terremoto que ayuden a identificar la fuente sismogenética. La combinación de los resultados obtenidos con esta técnica unidos a los datos geológicos de superficie apunta, como fuente más probable, a la reactivación de la falla de Crevillente con una componente de desgarre importante y con un epicentro somero (profundidad inferior a 10 km).The 1999 Mula (Murcia) seismic sequence started in February 2nd with a Mb: 4.8 mainshock, that reached a MSK intensity VI-VII. This earthquake produced significant economic losses in the region. The seismological data available to date give different focal mechanisms and different focal depths depending on the applied method. In this work we used a modern technique as RADAR interferometry (INSAR) with the aim to identify coseismic surface displacements linked with the Mula earthquake. The correlation of the results from RADAR interferometry with geological data support a reactivation of the Crevillente fault, with a high strike-slip component and a shallow hipocenter (less than 10 km), as the more likely seismic source.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEEspaña. Comisión Interministerial de Ciencia y Tecnologíapu