361 research outputs found
Animal behaviour: Shifting attention in order to disperse
New findings in the nematode Caenorhabditis elegans identify neuromodulation of behavioural responses to pheromones as a mechanism for regulating dispersal and foraging strategies
Payments for Pioneers? Revisiting the Role of External Rewards for Sustainable Innovation under Heterogeneous Motivations
© 2017, Elsevier Acknowledging the diversity of preferences, goals and motivations of individuals is key to promote the effectiveness of incentive-based conservation interventions. This paper analyses the heterogeneity of motivations to adopt silvopastoral practices, a social-ecological innovation for soil conservation and carbon emission reduction. We use Q methodology to identify smallholders' views with regard to these practices in a community in the forest frontier in Chiapas (Mexico). The analysis uncovers three main perspectives: self-sufficient pioneers, environmentally-conscious followers and payment-dependent conservatives. We discuss these perspectives around three topics: smallholders' predisposition to adopt silvopastoral practices, their views about needing external payments to sustain their livelihood and the diffusion of innovative sustainable practices. We relate these perspectives with livelihood characteristics and with observed adoption levels under a pilot programme to promote silvopasture. Our findings suggest that incentives other than payments may be more appropriate for those more likely to adopt, and that payments could encourage rent-seeking strategies and not necessarily promote permanent behavioural change. We suggest ways for designing more effective and adaptive environmental conservation programmes to foster adoption and continuation of social-ecological innovations
Texture perception determined by doy protein isolate and inulin addition in potato puree: links with mechanical and microstructural features
This study evaluated the effect of adding soy protein isolate (SPI) and long-chain perception, trained and untrained panel inulin (INL) blends with 10 different SPI : INL ratios on the textural, rheological and 17 microstructural properties of freshly made and frozen/thawed potato puree. All the potato puree samples were subjected to a sensory texture pro?le analysis and a 21 trained panel rated the intensity of six descriptors, while an untrained panel did the same on six selected frozen/thawed products. The main SPI : INL ratio effect remained signi?cant for all the descriptors evaluated, when the analysis of variance was applied considering the untrained assessors as random effects. However, only trained panel scores for creaminess corresponded well with untrained assessor. Rheological ?ow index values were linked with variations in perceived consistency, and geometric and surface textural attributes were explained by structural features such as the presence of INL crystallites and SPI coarse strands
O papel dos sistemas biodiversos e do acesso a terra na promoção da segurança alimentar: um estudo de caso no estado de São Paulo, Brasil.
Resumo: Dentro do enfoque agroecológico, os sistemas biodiversos visam incrementar a biodiversidade, diversificar a produção, aumentar a resiliência dos sistemas e a segurança alimentar. Por meio de pesquisa qualitativa em um assentamento de reforma agrária na região de Ribeirão Preto, estado de São Paulo, objetivou-se verificar a percepção dos agricultores sobre o papel dos sistemas agroflorestais (SAF) na segurança alimentar das famílias. Realizaram-se entrevistas semi estruturadas com oito famílias que adotam SAF há mais de cinco anos. As famílias relacionam a produção do SAF com qualidade, quantidade e regularidade, com importante papel na promoção da segurança alimentar. Preferem diversificar a produção ao invés de especializá-la, garantindo produtos para o autoconsumo e como uma estratégia de superar eventos como estiagem ou acessar novos mercados. Notou-se a importância do acesso a terra, uma vez que os entrevistados percebem uma melhoria na alimentação após serem assentados. Abstract: Within the agroecological approach, the biodiverse systems aimed to increase biodiversity, diversify production, to increase the resilience of systems and food security. Through qualitative research in a agrarian reform settlement in the region of Ribeirão Preto, state of São Paulo aimed to verify the perception of smallholders on the role of agroforestry systems (SAF) in household food security. Were realized semi structured interviews with eight families who adopt SAF for more than five years. Families relate the production of SAF with quality, quantity and regularity, with an important role in promoting food security. They prefer to diversify the production rather than specialize it, ensuring products for consumption and as a strategy to overcome events like drought or access new markets. It was noted the importance of access to land, since the interviewed perceive an improvement in food after being settled
Sistemas agroecológicos biodiversos como estratégia de segurança alimentar: um estudo de caso no Assentamento Sepé Tiaraju - São Paulo.
Frente à insustentabilidade do modelo de agricultura industrial, o qual se expressa em grandes monoculturas de exportação ocupando extensas regiões do país, o enfoque transdisciplinar da agroecologia propõe a transição para estilos de desenvolvimento rural mais sustentáveis, centrados na agricultura familiar. Nesta perspectiva, os sistemas biodiversos representam uma alternativa de incremento da biodiversidade e resiliência dos agroecossistemas, diversificando a produção e promovendo a soberania alimentar. No presente trabalho, busca-se analisar o papel dos Sistemas Agroflorestais (SAF) para a segurança alimentar de famílias assentadas da reforma agrária. Adotou-se como estudo de caso o Assentamento Sepé Tiarajú, situado em importante região canavieira no nordeste do estado de São Paulo. Por meio de pesquisa qualitativa, baseada em entrevistas semi-estruturadas e análise de discurso, buscou-se captar a percepção dos agricultores. Verificou-se que valorizam a produção agroflorestal tanto para o autoconsumo como para o mercado, enfatizando atributos como qualidade (sem agrotóxicos), quantidade, diversidade e regularidade, revelando um importante papel na promoção da segurança alimentar. Adotam a diversificação como estratégia para garantir alimentação mais saudável, amenizar riscos climáticos e acessar novos mercados, sendo observada nas entrevistas uma grande diversidade de cultivos produzidos no sistema agroflorestal, variando de 16 a mais de 100 espécies, com uma média de 20 a 30 espécies por SAF. Por fim, notou-se a importância do acesso à terra via reforma agrária, pois os entrevistados percebem uma melhoria na alimentação após serem assentados
La retirada del carné de conducir: incidencia en los ámbitos penal y laboral
Given its important implications, the withdrawal of the driving license can be considered the most significant consequence of traffic regulation.
Precisely for this reason, this paper devotes special attention to this increasingly common phenomenon in our lives from the dual perspective of labor law and criminal law. The first section discusses aspects directly related to the removal of the driving license from a criminal law perspective. The second section examines the consequences for professional life, analyzing the case of those people for whom driving is crucial for the adequate provision of the services they render.Dadas las importantes implicaciones de todo tipo que de ello se derivan (jurídicas, económicas, sociales, profesionales, etc.), la retirada del permiso de conducir supone tal vez la medida administrativa de mayor trascendencia y repercusión jurídica y social entre las numerosas que contempla la normativa de tráfico. Precisamente por ello, el presente estudio dedica una atención especial a este fenómeno cada vez más habitual en nuestras vidas desde la doble perspectiva penal y laboral. Así las cosas, en la primera parte de este trabajo se analizan los aspectos directamente relacionados con la retirada del carné de conducir desde un punto de vista estrictamente penal. En cambio, en la segunda parte del mismo se abordan las consecuencias que la retirada del carné de conducir tiene en el ámbito profesional; muy especialmente, por referencia a quienes la conducción de vehículos a motor resulta determinante para la adecuada prestación de sus servicios
Stochastic unit commitment in microgrids: Influence of the load forecasting error and the availability of energy storage
A Stochastic Model for the Unit Commitment (SUC) problem of a hybrid microgrid for a short period of 24 h is presented. The microgrid considered in the problem is composed of a wind turbine (WT), a photovoltaic plant (PV), a diesel generator (DE), a microturbine (MT) and a Battery Energy Storage System (BESS). The problem is addressed in three stages. First, based on the historical data of the demanded power in the microgrid, an ARMA model is used to obtain the demand prediction. Second, the 24-h-ahead SUC problem is solved, based on generators’ constraints, renewable generation and demand forecast and the statistical distribution of the error in the demand estimation. In this problem, a spinning reserve of the dispatchable units is considered, able to cover the uncertainties in the demand estimation. In the third stage, once the SUC problem has been solved, a case study is established in real time, in which the demand estimation error in every moment is known. Therefore, the objective of this stage is to select the spinning reserve of the units in an optimal way to minimize the cost in the microgrid operation
Influencia de la fertilización nitrogenada sobre las concentraciones de K+, Mg2+ y Ca2+ y sus bioindicadores en raíces y hojas de plantas de judía
The pyruvate kinase (PK) and ATPase activities taking part in nitrogen (N) assimilation is essential for the growth and development of plants. Studies on the kinetics of these enzymes reveal that its activities are dependent of the cofactors K+, Ca2+, and Mg2+. Therefore, the objective of the present work was to determine the effect of different doses of N on enzymatic activities of ATPase and PK as potentials biochemical indicators of the levels of K+, Mg2+, and Ca2+ in the roots and leaves of green bean plants. The N was applied to the nutrient solution as NH4NO3 at the following rates: 1.5, 3.0, 6.0, 12.0, 18.0, and 24.0 mM of N. These results indicate that deficient conditions of N (N1 and N2) were characterized by the lowest accumulation of K+, Mg2+ and Ca2+ in both total and soluble forms, and also minimum activities of PK and ATPase induced by K+, Mg2+ and Ca2+, with respect to the activity of basal PK and ATPase; this could mean near optimum conditions for these cations. On the contrary, high-N treatments (N4, N5 and N6) were characterized by presenting decreasing concentrations of total and soluble K+, Mg2+ and Ca2+ in roots and leaves of green bean plants; however, the activities of PK and ATPase induced with K+, Mg2+ and Ca2+ were increased reaching their maximum activity with respect to basal PK and ATPase, both enzymes reflecting the level of cations in roots and leaves, hence being considered as good physiological bioindicators of these cations.Las actividades piruvato kinasa (PK) y ATPasa participan en la asimilación de nitrógeno (N), la cual es esencial para el crecimiento y desarrollo de las plantas. Estudios sobre cinéticas de estas enzimas revelan que sus actividades son dependientes de los cofactores K+, Ca2+ y Mg2+. Por lo tanto, el objetivo del presente trabajo fue determinar el efecto de diferentes dosis de N sobre las actividades de la ATPasa y PK como posibles bioindicadores de los niveles de K+, Mg2+ y Ca2+ en raíces y hojas de plantas de judía (Phaseolus vulgaris L. cv. Strike). Se aplicó N a la solución nutritiva como NH4NO3 en las siguientes dosis: N1=1,5 mM, N2=3,0 mM, N3=6,0 mM, N4=12,0 mM, N5=18,0 mM y N6=24,0 mM. Los resultados indican que bajo condiciones deficientes de N (N1 y N2), las plantas presentaron menor acumulación de K+, Mg2+ y Ca2+ en su forma total y soluble, así como mínimas actividades PK y ATPasa inducidas por K+, Mg2+ y Ca2+ respecto a la actividad PK y ATPasa basal; lo cual indica condiciones cercanas a las óptimas de estos cationes. Por el contrario, en los tratamientos elevados de N (N4, N5 y N6) las plantas presentaron concentraciones decrecientes de K+, Mg2+ y Ca2+ total y soluble tanto en raíces como en hojas; sin embargo, las actividades PK y ATPasa inducidas con K+, Mg2+ y Ca2+ se incrementaron alcanzando sus máximas actividades con respecto a la PK y ATPasa basal, lo que indica una mayor necesidad fisiológica de estos cationes en los tratamientos elevados de N. Finalmente, la actividad ATPasa basal y la inducida con K+, Mg2+ y Ca2+ se comportaron de forma similar a la actividad PK, lo que refleja el nivel de cationes en raíces y en hojas, por lo que se consideran buenos bioindicadores fisiológicos de estos cationes
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