El consumo de energía en las labores agrícolas: un aspecto que merece ser estudiado a fondo

Tradicionalmente, un aspecto muy poco analizado en la mecanización agraria ha venido siendo el del consumo energético que representa. Diversos factores, como el del ahorro de esfuerzo humano que aporta, el precio bajo de los combustibles hasta 1973 y la escasa consideración que merecían hasta ese momento la posible escasez futura de los carburantes empleados han hecho que este tema haya sido generalmente poco considerado por los investigadores. La crisis energética desatada en la última década ha conseguido traer este tema a un primer plano de interés, realizándose diversos estudios con el fin de disminuir este consumo en la agricultura. Sin embargo, se sigue careciendo de una información clara y fiable de cuál es el consumo de energía que requiere cada una de las operaciones agrícolas mecanizadas. Los diferentes enfoques escogidos para su cálculo, la diversidad de condiciones en que se han realizado y, en algunos casos, incluso la confusión en que vienen expresados hacen que no se pueda por menos que desconfiar de la información que se puede obtener.

El Ilmo. y Rvmo. Señor Don Francisco de Navarra, de la Orden de San Agustín : estudio histórico-crítico / por Mariano Arigita y Lasa.

Catálogo Fondo Urquijo 491

Proyecto de correccion y repoblacion forestal de las cuencas de las ramblas de Santomera, Cañada Ancha, el Carmen y Churra

1.545, 1.615, 1651, 1.733, 1.739, 1.774, 1.763, 1.797; son años que la tradición ha marcado con piedra negra, en la historia del valle del Segura. De ayer se recuerda que desde 1.645 a 1.650 la población y huerta de Murcia han sufrido más de 50 inundaciones; en la de 1.679 pasaron por la huerta en 10 horas cerca de 110 millones de metros cúbicos y es conocida con el nombre de Santa Teresa. Si examinamos estos datos vemos el continuo aumento del número de inundaciones a través de los siglos.

As mudanças constitucionais no Brasil e na Alemanha em virtude da adaptação ao direito da integração

Inclui notas explicativas, bibliográficas e bibliografia

Proprotein convertases in amphioxus: predicted structure and expression of proteases SPC2 and SPC3.

SPC2 and SPC3 are two members of a family of subtilisin-related proteases which play essential roles in the processing of prohormones into their mature forms in the pancreatic B cell and many other neuroendocrine cells. To investigate the phylogenetic origins and evolutionary functions of SPC2 and SPC3 we have identified and cloned cDNAs encoding these enzymes from amphioxus (Branchiostoma californiensis), a primitive chordate. The amino acid sequence of preproSPC2 contains 689 aa and is 71% identical to human SPC2. In contrast, amphioxus prproSPC3 consists of 774 aa and exhibits 55% identity to human SPC3. These results suggest that the primary structure of SPC2 has been more highly conserved during evolution than that of SPC3. To further investigate the function(s) of SPC2 and SPC3 in amphioxus, we have determined the regional expression of these genes by using a reverse transcriptase-linked polymerase chain reaction (RT-PCR) assay. Whole amphioxus was dissected longitudinally into four equal-length segments and RNA was extracted. Using RT-PCR to simultaneously amplify SPC2 and SPC3 DNA fragments, we found that the cranial region (section 1) expressed equal amounts of SPC2 and SPC3 mRNAs, whereas in the caudal region (section 4) the SPC2-to-SPC3 ratio was 5:1. In the mid-body sections 2 and 3 the SPC2-to-SPC3 ratio was 1:5. By RT-PCR we also determined that amphioxus ILP, a homologue of mammalian insulin/insulin-like growth factor, was expressed predominately in section 3. These results suggest that the relative levels of SPC2 and SPC3 mRNAs are specifically regulated in various amphioxus tissues. Furthermore, the ubiquitous expression of these mRNAs in the organism indicates that they are involved in the processing of other precursor proteins in addition to proILP.

La medición del tiempo de trabajo reproductivo a través de la Encuesta de Empleo del Tiempo y la Encuesta Nacional de Salud: un análisis comparativo

Comunicación presentada en el XI Congreso Español de Sociología, Madrid, 10-12 julio 2013.

Comparison among monitoring strategies to assess water flow dynamic and soil hydraulic properties in agricultural soils

Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, θ, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control θ and h in the vadose zone: i) non-automatic and more time-consuming; ii) automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic). Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of θ and h, but with slight differences in computed annual drainage (711 mm and 774 mm). Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, θs, and the n and α van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher.

Tārīḵẖ-yi Ḵẖvurshīdjāhī

History of Indian Muslim kings and rulers, 12th to 19th century.

Kitāb Shams ṣughrá : manuscript, 1372 or 3

Written in one column, 17 lines per page, in black ink. Text includes tables. Comments in the margins.

The changing landscape of financial markets in Europe, the United States and Japan. Bruegel Working Paper 2013/02, 18 March 2013

We compare the structure of the financial sectors of the EU27, Japan and the United States, looking at a set of 23 indicators. We find a large variation within the European Union in the structure of the financial sector. Using principal components analysis, we identify robust groups of EU countries. One group consists of the eastern European members that entered the EU more recently.These have substantially smaller financial sectors than the old member states. A second group can be classified as market-based (MBEU) and the third group is more bank-based (BBEU). We compare US, MBEU, BBEU, Eastern EU and Japan with the following main results. First, the groups within Europe are geographically related. Second, in many indicators, MBEU countries are closer to the (market-based) US, while BBEU countries more closely resemble Japan. Paradoxically, however, market-based EU countries also have large banking sectors. Banks in market-based countries have larger cross-border assets and liabilities, and derive a larger fraction of their income from fees, rather than interest income, than banks in bank-based countries. Finally, for most indicators, the ordering of groups of countries is quite stable over time, but while the crisis has had no impact on the relative ordering of the groups, it has slightly widened the gap between the US and all EU regions insome respects. We also find that during the crisis, substitution between market-based and bank-based sources of finance occurred in the US, and to a lesser extent in MBEU and BBEU countries.