Chemical and physical pretreatments of microalgal biomass

Non-axenic microalga Chlorella sorokiniana was cultivated in batch cultures, and its total sugar composition was determined. The microalga under study showed a total sugar concentration of 21.44 ± 0.46% (w/w). The effects of freeze-drying, oven-drying, freezing and thawing, chemical and the combination of hydrothermal and chemical pretreatments were evaluated. In the combined pretreatment different concentrations of H2SO4 and reaction times were also optimized. It was possible to determine that the sugar extraction yields more significant were 59.5% for the lyophilization, 6.2% with 6 cycles of freeze and thawing and around 100% for 2 and 4% (v/v) of H2SO4 at 121 °C for 30 min. Some of the methods that were described in this study are interesting to facilitate cost-efficient conversion of microalgal biomass into biofuels.info:eu-repo/semantics/publishedVersio

Transition to agroforestry: Current challenges and opportunities for the adoption of agroforestry as carbon sequestration strategy

The multiple benefits of agroforestry include the provision of several ecosystem services, e.g. biodiversity, food, timber, mitigation of climate change and the risk of erosion and land degradation. Carbon sequestration from agroforestry systems is an important regulating ecosystem service. Data from several studies in Europe (Northern Ireland, England, Spain, Portugal) suggest that agroforestry has a great potential to sequester carbon, in some cases more than grassland (Olave, 2016; Fornara et al., 2017). However, adoption of agroforestry is facing challenges due to several factors influencing farmers and land managers decision-making. Similar to what was found in a recent British study on livestock farmers’ attitudes to on-farm climate change mitigation strategies using a decision-support tool tailored for the sector (Burbi et al., 2016), the adoption of innovation to transition to climate friendly practices can encounter obstacles that are not always related to the evidence base to support the benefits of agroforestry. Barriers to innovation in the agroforestry sector include the uncertainty regarding carbon assessment methodologies. In particular, Land Use and Land Use Change from Forestry (LULUCF) accounting needs to better reflect the full potential for carbon sequestration from agroforestry systems using comprehensive calculations. Economic modelling is also a key aspect in promoting agroforestry, as one of the greatest barriers to innovation is the uncertainty in finance and labour required in an agroforestry system. This is particularly important for researchers to consider when engaging in the promotion of agroforestry. Clear and transparent communication on the multiple benefits of a system should also include information on the trade-offs and the possibility of integration of agroforestry within the current legislative framework. On the one hand, future work needs to address the uncertainty in LULUCF accounting and refine current methodologies used to measure the carbon balance of the system. Agroforestry-adapted legislation is also needed to better reflect the importance of these systems in terms of climate change mitigation and their delivery of multiple environmental and socio-economic ecosystem services. On the other hand, decision-support tools need to be adapted for agroforestry to highlight practices that are more suited for the landscape and the socio-economic context, helping farmers and land managers to easily identify the practices that provide greater carbon sequestration without compromising the productivity of their agri-businesses.References:1.Burbi, S., Baines, R.N., & Conway, J.S. (2016) Achieving successful farmer engagement on greenhouse gas emission mitigation. International Journal of Agricultural Sustainability, 14: 466-483. DOI: 10.1080/14735903.2016.11520622.Fornara, D., Olave, R., Burgess, P., Delmer, A., Upson, M., & McAdam, J. (2017). Land use change and soil carbon pools: evidence from a long-term silvopastoral experiment. Agroforestry Systems, AGFORWARD. Special Issue.3.Olave, R. (2016). Agroforestry as a land use option to sequester carbon in a cool temperate climate. World Congress Silvo-pastoral Systems 2016. University of Évora, Portugal. 27-30 September 2016

Nominal Wage Rigidities in Mexico: Evidence from Social Security Records

This paper analyses the existence and extent of downward nominal wage rigidities in the Mexican labor market using data from the administrative records of the Mexican Social Security Institute (IMSS). This longitudinal, firm-level dataset allows us to track workers employed with the same firm, observe their wage profiles and calculate the nominal-wage changes they experience over time. Based on the estimated density functions of nominal wage changes and other moments of the distribution, we are able to calculate several standard tests of nominal wage rigidity that have been proposed in the literature. Furthermore, we extend these tests to take into account the presence of minimum wage laws that may affect the distribution of nominal wage changes. The densities and tests calculated using these date are similar to those obtained using administrative data from other countries, and constitute a significant improvement over the measures of nominal wage rigidities obtained from household survey data. We find considerably more wage rigidity than previous estimates obtained for Mexico using data from the National Urban Employment Survey suggest. Furthermore, we find evidence that the extent of nominal wage rigidities has been falling over time. We also document the importance of minimum wages in the Mexican labor market, as evidenced by the large fraction of minimum wage earners and the widespread indexation of wage changes to the minimum wage increases.

Universal Intellectual Property Rights: Too Much of a Good Thing?

Developing countries' incentives to protect intellectual property rights (IPR) are studied in a model of vertical innovation. Enforcing IPR boosts export opportunities to advanced economies but slows down technological transfers and incentives to invest in R&D. Asymmetric protection of IPR, strict in the North and lax in the South, leads in many cases to a higher world level of innovation than universal enforcement. IPR enforcement is U-shaped in the relative size of the export market compared to the domestic one: rich countries and small/poor countries enforce IPR, the former to protect their innovations, the latter to access foreign markets, while large emerging countries free-ride on rich countries' technology to serve their internal demand

Effect of fungal endophytes on plant growth and nutrient uptake in Trifolium subterraneum and Poa pratensis as affected by plant host specificity

[EN[ The introduction of well-adapted species, such as Trifolium subterraneum (subclover) and Poa pratensis (Kentucky bluegrass), might enhance the forage yield and quality of dehesa pastures for feeding livestock. However, the climatic hardness and poor soils in these agrosystems may limit plant establishment and development. Since fungal endophytes have been found to alleviate the environmental stresses of their host, the aim of this study was to assess the effect of five isolates on forage yield, nutritive value, and plant mineral uptake after their inoculation in the two abovementioned plant species. Two experiments were established (under greenhouse and field conditions) using plants inoculated with two isolates in 2012/2013 (Epicoccum nigrum, Sporormiella intermedia) and three isolates in 2013/2014 (Mucor hiemalis, Fusarium equiseti, Byssochlamys spectabilis). Fusarium equiseti (E346) increased the herbage yield of T. subterraneum under greenhouse conditions, and B. spectabilis improved the forage quality of T. subterraneum by reducing fiber content and of P. pratensis by increasing crude protein. S. intermedia increased the mineral uptake of Ca, Cu, Mn, Pb, Tl, and Zn in subclover, and M. hiemalis increased the uptake of K and Sr in Kentucky bluegrass. These results evidence the potential of the studied fungal endophytes to enhance herbage yield and nutritional value of forage, although further studies should include all of the target forage species as certain host specificity in the effect was observed.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was funded by Project AGL2011-27454, granted by the Ministry of Economy and Competitiveness of Spain (the former Ministry of Science and Innovation) and by the European Regional Development Fund (ERDF).Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Clothes of power: comparing textiles and rock art of northwestern Argentina (13th to 15th centuries)

Proponemos que la suma de atributos visuales presentes en un conjunto de representaciones rupestres antropomorfas del Período de Desarrollos Regionales (PDR) e Inca del NO de Argentina estaría relacionada con la conformación de un lenguaje visual de poder que se vincularía: a) en el PDR, con el surgimiento y/o consolidación de grupos y/o comunidades con pretensiones territoriales e identitarias específicas y, b) durante el Período Inca, con una estrategia de intervención estatal que apeló a la apropiación de íconos vigentes, resignificándolos para la instauración de un nuevo poder y/o para la explicitación de las alianzas entabladas. Para ello, partimos de un estudio comparativo sistemático que tomó en cuenta dicho registro rupestre y la muestra de piezas textiles sincrónicas, recuperadas en la región del NO y centro de Argentina y que integró, en ambos soportes, un examen de los aspectos representativos y estructurales, entendidos como partes indivisibles de una totalidad.In this paper we suggest that a particular assemblage of visual attributes observed in a number of specific types of anthropomorphic rock-art depictions of the last moments of Regional Developments Period (RDP) in NW Argentina, could be related to the conformation of a visual language of power. This could be associated to: a) the emergence and consolidation of different groups and/or communities with specific territorial and identity claims during RDP, and b) during the Inca Period, with a state intervention strategy to appropriate and resignify existing local icons in order to establish a new power and/or explicitness of new alliances. To this end we carried out a comparative and systematic study that included the analysis of RDP rock art record and textiles recovered in NW and Central Argentina. In addition we examined representative and synchronous technical aspects, both understood as indivisible parts of the whole.Fil: Lopez Campeny, Sara Maria Luisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucuman. Instituto Superior de Estudios Sociales; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Arqueología y Museo; ArgentinaFil: Martel, Alvaro Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucuman. Instituto Superior de Estudios Sociales; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Arqueología y Museo; Argentin

Potential of fungal endophytes isolated from pasture species in Spanish dehesas to produce enzymes under salt conditions

Producción CientíficaEndophytic fungi have been found to produce a wide range of extracellular enzymes, which are increasingly in demand for their industrial applications. Different by-products from the agrifood industry could be used as fungal growth substrates for the massive production of these enzymes, specifically as a way to revalorize them. However, such by-products often present unfavorable conditions for the microorganism’s growth, such as high salt concentrations. Therefore, the objective of the present study was to evaluate the potential of eleven endophytic fungi—which were isolated from plants growing in a harsh environment, specifically, from the Spanish dehesas—for the purposes of the in vitro production of six enzymes (i.e., amylase, lipase, protease, cellulase, pectinase and laccase) under both standard and salt-amended conditions. Under standard conditions, the studied endophytes produced between two and four of the six enzymes evaluated. In most of the producer fungal species, this enzymatic activity was relatively maintained when NaCl was added to the medium. Among the isolates evaluated, Sarocladium terricola (E025), Acremonium implicatum (E178), Microdiplodia hawaiiensis (E198), and an unidentified species (E586) were the most suitable candidates for the massive production of enzymes by using growth substrates with saline properties (such as those found in the many by-products from the agrifood industry). This study should be considered an initial approach by which to further study the identification of these compounds as well as to develop the optimization of their production by directly using those residues.Junta de Extremadura y Fondo Social Europeo - (grant PD18037

El fitoplancton de Lagunas de Ruidera (Parque Natural, Ciudad Real, España)

El Parque Natural Lagunas de Ruidera es una zona húmeda catalogada como de importancia nacional situada en el valle del Alto Guadiana, en Ciudad Real. Está constituido por 15 lagunas separadas por barreras travertínicas, acabando en el embalse de Peñarroya. En este estudio se presentan los primeros datos conocidos sobre la biodiversidad, abundancia, biovolumen y dinámica del fitoplancton (incluido el picoplancton autotrófico) de este sistema. Las muestras se tomaron en mayo y septiembre de 2000 y en marzo, junio, septiembre y diciembre de 2001 en el embalse y en cada laguna, excepto en aquellas que sufrieron periodos secos. Todas las muestras fueron tomadas del epilimnion. El estudio taxonómico del fitoplancton permitió evidenciar la presencia de 215 especies pertenecientes a los grandes grupos de algas: 9 taxones a Cyanophyta, 9 a Euglenophyta, 6 a Cryptophyceae, 7 a Dinophyceae, 10 a Chrysophyceae, 58 a Chlorophyta, 103 Bacillariophyceae, 12 a Desmidiaceae, y un grupo de pequeños flagelados considerados como una única población. Las especies más comunes fueron: Cyclotella ocellata, Rhodomonas minuta, Cryptomonas erosa, Cyclotella kuetzingiana y Peridinium umbonatum. Las lagunas presentaron una alta riqueza específica propia de sitios aun no muy degradados. Los grupos funcionales de las algas dominantes (Reynolds, 1997) fueron propios de sistemas eutróficos: Y (Cryptomonas; pequeños lagos eutróficos), L (Peridinium umbonatum y Ceratium; lagos meso-eutróficos estratificados), C (Asterionella formosa y Aulacoseira; lagos eutróficos mezclados) y E (Dinobryon; lagos oligo-mesotróficos). La dinámica temporal de la abundancia y composición del fitoplancton fue diferente en cada laguna. El biovolumen calculado del fitoplancton se encontró entre 0.2 y 7.2 mm3/l, y el del picoplancton autotrófico entre 0.12 y 0.2 mm3/l. Tanto la biomasa algal como la concentración de clorofila a resultaron menores de lo esperado para la elevada concentración de nutrientes medida en las lagunas. Sin embargo, el aporte relativo del picoplancton y la composición algal indican un alarmante proceso de eutrofización.The Lagunas de Ruidera Natural Park is a humid zone classified as of national importance, located in the alto de Guadiana valley, Ciudad Real. The Park is composed of 15 lagoons separated by travertine barriers, which end in the Peñarroya reservoir. This work shows the first published data on biodiversity, density, biomass and dynamics of phytoplankton (including autotrophic picoplankton) of this system. Samples were collected in May and September 2000 and in March, June, September and December 2001 in the reservoir and in each lagoon (except in those which suffered a dry period). All samples were collected from the epilimnion. The taxonomic study revealed the presence of 215 species: 9 taxa of Cyanophyta, 9 of Euglenophyta, 6 of Cryptophyceae, 7 of Dinophyceae, 10 of Chrysophyceae, 58 of Chlorophyta, 103 of Bacillariophyceae, 12 of Desmidiaceae, and a group of small fragellates considered to be a single population. The most common species were: Cyclotella ocellata, Rhodomonas minuta, Cryptomonas erosa, Cyclotella kuetzingiana and Peridinium umbonatum. The lakes had a high species richness associated with non contaminated places. The functional groups of dominant algae (Reynolds, 1997) were indicative of eutrophic systems: Y (Cryptomonas; small eutrophic lakes), L (Peridinium umbonatum and Ceratium; stratified meso-eutrophic lakes), C (Asterionella formosa and Aulacoseira; mixed eutrophic lakes) and E (Dinobryon; oligo-mesotrophic lakes). The temporal dynamics of abundance and composition of phytoplankton was different in each lagoon. The estimated phytoplankton biomass range was between 0.2 and 7.2 mm3/l, and that of the autotrophic picoplankton was between 0.12 and 0.2 mm3/l. Both algae biomass and chlorophyll a concentration were lower than expected in relation to the high nutrient concentrations in the lagoons. However, the relative contribution of picoplankton and algal composition, indicate an alarming eutrophication process

Presentación

[ES] La violencia ha sido considerada uno de los grandes ejes que explican el devenir de la humanidad desde los comienzos de la ciencia historiográfica. Nos repele y nos atrae, deseamos olvidarla pero no debemos dejar que caiga en el olvido, aparenta estar ligada a momentos históricos concretos pero atraviesa nuestro día a día… Quizás por estas razones la violencia, en todas sus posibles manifestaciones, lejos de ser un tema obsoleto, continúa teniendo un gran potencial como cuestión historiográfica, tal y como muestran las investigaciones que conforman este libro. De la mano de diferentes especialistas, y en un recorrido que va desde la Prehistoria hasta la Edad Contemporánea, este volumen colectivo analiza las violencias históricas desde la antropología física, la historia militar, la iconografía, o la historia de la infancia entre otros puntos de vista. Guerras, conflictos políticos y religiosos y sus significados simbólicos, o la violencia como espectáculo son algunas de las cuestiones que abordan sus páginas. Si bien existen pocos temas que hayan sido más estudiados por la historiografía que la violencia, este libro, fruto del Congreso Internacional La Violencia en la Historia, celebrado en la Universidad de Salamanca en octubre de 2019, es una muestra de que las preguntas históricas nunca se agotan y de que las violencias pasadas deben seguir siendo revisitadas desde nuevos enfoques