Deficit irrigation in fruit trees and vines in Spain

[ENG] Water has become the most precious of natural resources in many areas of Spain and, since agriculture is the major consumer of water, improvements in water use efficiency are increasingly sought. Regulated deficit irrigation (RDI) is an irrigation strategy based on applying only a fraction of the plant water requirements during certain periods of plant development. The paper reviews the available information on RDI strategies, in woody tree crops and vines based on studies by Spanish research groups. Both the promising results obtained and the drawbacks are covered. [ESP] El agua se ha convertido en el más preciado de los recursos naturales en muchas zonas de España y, dado que la agricultura es el principal consumidor, es prioritario mejorar la eficiencia de uso del agua en la agricultura de regadío. El riego deficitario controlado (RDC) es una estrategia de riego que se basa en aplicar tan sólo una fracción de los requerimientos hídricos del cultivo durante determinados períodos del ciclo vegetativo. En este trabajo se presenta la información disponible sobre diferentes estrategias de RDC aplicadas en cultivos leñosos y vid, basada en estudios realizados por grupos de investigación españoles. Se discuten las ventajas y desventajas así como los prometedores resultados obtenidos.This research was supported by Spanish Ministry of Science and Innovation MICINN (AGL2006-12914- C02-01; AGL2007-66279-C03-03/AGR; AGL2009- 06981), Séneca Foundation, Murcia (08845/PI/08; 08847/PI/08), and Rideco-Consolider CSD2006-00067 grants to the authors

Gas exchange and water relations of young apricot plants under drought conditions

Potted 1.5-year-old apricot plants (Prunus armeniaca L.), growing under polycarbonate glasshouse conditions with a cooling system, were subjected to two successive water stress/recovery periods until pre-dawn leaf water potential (Ypd) reached values between -2.0 and -2.5 MPa, during summer 1996. Control plants were irrigated daily to maintain the soil matric potential at c. -20 kPa. Water stress limited plant growth and induced a significant reduction in leaf area, caused by mature leaf abscission. The parallel behaviour of leaf turgor potential and epinasty in stressed plants indicated that these movements are turgor-dependent. Osmotic adjustments of 0.27 and 0.60 MPa were observed at the end of the first and second stress period, respectively. Relative apoplastic water content (RWCa) values were high, ranging from 27 to 42%, and were not affected by water stress. The rapid decrease in leaf conductance (gl) from the beginning of the stress periods, together with the delay in stomatal reopening after rewatering the plants, indicated that stomatal behaviour was not a simple passive response to water deficits. Net photosynthesis decreased only at the end of both stress periods and recovered quickly. These observations indicate that leaf productivity may be affected only slightly by short-term water stress. The results indicate that drought resistance in apricot is based mainly on avoidance mechanisms, such as stomatal control, epinasty and limitation of transpiration by reducing leaf area. However, some tolerance characteristics, including osmotic adjustment, high RWCa and low leaf osmotic potential at turgor loss point (Ytlp) values were observed.The authors are grateful to J. Soto-Montesinos, M.D. Velasco, M. García and E. Nicolás for their assistance. The study was supported by CICYT (AMB95- 0071) and Consejería de Medio Ambiente, Agricultura y Agua de Murcia grants to the authors

Una revisión a la formación posgradual de los profesionales de la Contaduría Pública en la ciudad de Villavicencio

This article presents partial results of an investigation that is supported in a qualitative methodological process and a type of descriptive study, the information gathered reveals the status of the offer in advanced training for professional Universidad de los Llanos 39 accountants in the city of Villavicencio, which is the purpose of the article, accompanied by a few theoretical for study and understanding elements. With the clustering of data obtained from the universities tried to interpret the current situation of public accountants in relation to its advanced training taking account of the different factors that influence it, at the end the authors posit the object of reflection on the shortcomings presented by the environment of this type of training.Este articulo plantea resultados parciales de una investigación que está soportada en un proceso metodológico de carácter cualitativo y tipo de estudio descriptivo, la información recolectada devela el estado de la oferta en formación avanzada para los profesionales contables en la ciudad de Villavicencio, que se constituye en el propósito del artículo, acompañado de unos elementos teóricos para su estudio y comprensión. Con el agrupamiento de datos obtenidos de las universidades se intentó interpretar la actual situación posgradual de los contadores públicos, atendiendo los diferentes factores que influyen en ella. Al final las autoras postulan el objeto de la reflexión con base en las falencias que presenta el entorno de este tipo de formació

Early transformation of the Mediterranean Outflow Water (MOW) in the Gulf Of Cádiz, SW Iberian Peninsula: pathways, mixing and temporal variability.

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Service-learning by PhD students to aid socially neglected people

In recent years, there have been calls for change in higher education to meet the needs of today's society. A higher education that enables our students to offer solutions to struggling areas of our society. Innovative and differentiating solutions from what we have been used to until now. In view of these needs, it is necessary to unite the society, which reveals its main needs, and the university community, which offers solutions on the knowledge acquired. One of the ways to carry out this integration is based on developing a methodology called "Service-Learning" (SL). This learning method is based on a strategy of collaboration between educational centers and society itself. At present, this methodology is spreading within higher education institutions worldwide. This learning strategy emerged as a learning methodology in America, to be later extended to Europe, from the United Kingdom to the rest of the continent, and from there, reaching a global impact. Throughout this long road, this methodology has been improving, encouraging the creation of increasingly strong links between educational institutions and universities, and society, by promoting the improvement of student training as well as the development of certain areas of society. This paper presents a SL project where two apparently disparate areas are related, such as doctoral students in the area of chemical engineering and sectors of society at risk of exclusion. Specifically, the objective is for the students to present some of the technological developments they have achieved to a neglected sector of society, which should participate not only in the developments, but also learning about the technical base of such technologies.This work has been carried out with the financial support of the SL UCM 2018/19_16 project and the Madrid City Council.Torrecilla, J.; Buitrón Ruiz, S.; Sánchez, M.; Cancilla, JC.; Pradana López, S.; Perez Calabuig, AM. (2020). Service-learning by PhD students to aid socially neglected people. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):831-837. https://doi.org/10.4995/HEAd20.2020.11153OCS83183730-05-202

The potential role of the adipokine HMGB1 in obesity and insulin resistance. Novel effects on adipose tissue biology

Discovery of the adipose tissue as a major source of signaling molecules almost three decades ago set a novel physiological paradigm that paved the way for the identification of metabolic organs as endocrine organs. Adipocytes, the main adipose tissue cell type, do not only represent the principal site of energy storage in form of triglycerides, but also produce a variety of molecules for short and long distance intercellular communication, named adipokines, which coordinate systemic responses. Although the best known adipokines identified and characterized hitherto are leptin and adiponectin, novel adipokines are continuously being described, what have significantly helped to elucidate the role of adipocyte biology in obesity and associated comorbidities. One of these novel adipokines is high-mobility group box 1 (HMGB1), a ubiquitous nuclear protein that has been recently reported to be dysregulated in obese dysfunctional adipocytes. Although the classical function of HMGB1 is related to inflammation and immunity, acting as an alarmin, novel advances evidence an active implication of HMGB1 in tissue remodeling and fibrosis. This review summarizes the current evidence on the mechanisms controlling HMGB1 release, as well as its role as a regulator of adipocyte function and extracellular matrix remodeling, with special emphasis on the potential of this novel adipokine as a target in the obesity treatment

Introducción al concepto de derivados financieros y su manejo en Colombia

The market of financial instruments dating back to the era before Christ, and despite their remote origin can be said that its boom began in the Decade of the ‘ 70s, thanks to the model of valuation of financial derivatives, known as the model of Black-Scholes-Merton, which enabled its evaluation and encouraged its use by investors in financial for whom it is a valuable tool. Around the world, have been the subject of widespread criticism, even to be designated as the cause of great financial crisis originated in the developed countries. In Latin American markets Brazil as the leader of the derivatives market, and Mexico as a duly self-regulated growth market. In the Colombian case, it should be mentioned that the derivative market is just in its initial stage, with relatively prudent use, in addition to deemed that the information emerged on the subject is scarce and concentrated in Government as theBolsa de Valores de Colombia and the FinancialSupervisory Authority. The objective of this work is to generate a document of academic type that allows you to introducing to not knowledgeable on the subject, which is extremely interesting and useful tool in the economic and commercial context of the country. This has been determined using a methodology of research of exploratory type, which is useful when there is no exact investigation on the matter.El mercado de los instrumentos financieros data de la era de antes de Cristo y pese a su remota procedencia puede decirse que su auge inició en la década de los 70, gracias al denominado modelo de valoración de derivados financieros, conocido en el ámbito financiero como el modelo de Black-Scholes-Merton,que posibilitó su evaluación y fomentó su utilización por parte de los inversionistas, para quienes es un instrumento valioso. A nivel mundial, han sido objeto de amplias críticas, llegando incluso a ser señalados como causantes de grandes crisis financieras, originadas en los países desarrollados; en tanto AméricaLatina deja ver a Brasil como el líder del mercado de derivados y a México como un mercado en expansión debidamente autoregulado. Del caso colombiano, debe mencionarse que el mercado de derivado está apenas en su etapa inicial, con uso relativamente prudente, además de considerarse que la información surgida respecto al tema es escasa y concentrada en entes gubernamentales como la Bolsa de Valores de Colombia y la Superintendencia Financiera. El objetivo de este trabajo es generar un documento de tipo académico que permita introducir a no conocedores en la temática, que es por demás interesante y de gran utilidad en el contexto económico y comercial del país. Para ello se ha determinado el uso de una metodología de investigación de tipo exploratoria, que es útil cuando no existen investigaciones exactas sobre el asunto

Metal mobility and bioaccessibility from cyanide leaching heaps in a historical mine site

Unlike acidic sulfide mine wastes, where metal/loid mobility and bioaccessibility has been widely studied, less attention has been paid to alkaline cyanide heap leaching wastes. Thus, the main goal of this study is to evaluate the mobility and bioaccessibility of metal/loids in Fe-rich (up to 55%) mine wastes resulting from historical cyanide leaching activities. Wastes are mainly composed of oxides/oxyhydroxides (i.e. goethite and hematite), oxyhydroxisulfates (i.e. jarosite), sulfates (i.e., gypsum, evaporitic sulfate salts), carbonates (i.e., calcite, siderite) and quartz, with noticeable concentrations of metal/loids (e.g., 1453–6943 mg/kg of As, 5216–15,672 mg/kg; of Pb, 308–1094 mg/kg of Sb, 181–1174 mg/kg of Cu, or 97–1517 mg/kg of Zn). The wastes displayed a high reactivity upon rainfall contact associated to the dissolution of secondary minerals such as carbonates, gypsum, and other sulfates, exceeding the threshold values for hazardous wastes in some heap levels for Se, Cu, Zn, As, and sulfate leading to potential significant risks for aquatic life. High concentrations of Fe, Pb, and Al were released during the simulation of digestive ingestion of waste particles, with average values of 4825 mg/kg of Fe, 1672 mg/kg of Pb, and 807 mg/kg of Al. Mineralogy may control the mobility and bioaccessibility of metal/loids under rainfall events. However, in the case of the bioaccessible fractions different associations may be observed: i) the dissolution of gypsum, jarosite and hematite would mainly release Fe, As, Pb, Cu, Se, Sb and Tl; ii) the dissolution of an un-identified mineral (e.g., aluminosilicate or Mn oxide) would lead to the release of Ni, Co, Al and Mn and iii) the acid attack of silicate materials and goethite would enhance the bioaccessibility of V and Cr. This study highlights the hazardousness of wastes from cyanide heap leaching, and the need to adopt restoration measures in historical mine sites.This work was supported by the Spanish Ministry of Economic and Competitiveness through the projects TRAMPA (PID2020–119196RBC21) and by H2020 European Institute of Innovation and Technology (EIT RawMaterials) through the project Modular recovery process services for hydrometallurgy and water treatment (MORECOVERY). This work was partially supported by FCT (Portugal) through contract UID/ Multi/04349/2019. C.R C´anovas thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference RYC2019–027949-I. M.D. Basallote thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference IJC 2018–035056-I. The authors would also like to thank to Prof. Edward D. Burton, Ph.D (Editor) and three anonymous reviewers for the support and comments that notably improved the quality of the original paper