2,277 research outputs found
What and Who Has Determined Adoption? A Study on Improved Forage Technologies in Colombia from an Agricultural Innovation System (AIS) Perspective
The complex process behind the adoption of improved forages in Colombia remains largely unexplored. Despite governmental and scientific efforts to promote and disseminate the implementation of improved forages for the sake of sustainable livestock production, local livestock producers continue to extensively use native species and adoption rates of more efficient forages remain low. This study explores the dynamics behind the development and diffusion of improved forage technologies in Colombia, from the 1960\u27s to the present through an Agricultural Innovation Systems (AIS) perspective. Here we map the agents involved, classify the roles they exerted over time and reconstruct the historical context in which the creation and dissemination of forage technologies in the country took form. Through the use of qualitative research tools such as in-depth interviews, and extensive archival work, we were able to identify various factors determining the course of improved forage adoption processes. First, a gradual decline on public and private investment destined to agricultural research hindered national scientific agendas and affected the continuity of ongoing projects. Second, the primacy of interpersonal relationships further complicates this panorama as it can either interfere with or promote the use of improved forages, subjecting technology dissemination to a non-institutional realm. Thirdly, released technological packages remain incomplete and impede rising adoption rates, mainly due to both Colombiaâs low-latitude (and its restrictions for national seed production) and ineffective processes of training and support aimed at local livestock producers. Aside from the identification of key actors and historical trends, the study concludes by suggesting the implementation of a systematic (AIS) approach that gives account of the complex and ever-changing process of forage adoption, its agents, roles, strengths and limitations so that a comprehensive diagnosis can serve as a guideline for future adoption policies in the subject
From Theory to Practice: What Should We Have in Mind When Building Effective and Sustainable Payments for Ecosystem Services (PES) Schemes for Silvo-Pastoral Systems? Evidence from Colombia
In most Latin American countries, payment for ecosystem services (PES) can be a useful strategy for restoration and conservation of the environment, increasing productivity and promoting sustainable development in rural areas. Despite these plausible benefits, PES implementation can be challenging due to the contextual framework in which it takes place (e.g. institutional weakness in the implementation and monitoring stages, limited connectivity among stakeholders, low adoption levels of agricultural technology). This study aims at evaluating PES schemes for silvo-pastoral systems in Colombia by considering six dimensions based on an extensive literature review: policy and governance; social context; environmental context; risks and challenges; dynamics; and monitoring and evaluation approaches. A literature meta-analysis and semi-structured interviews with decision makers were carried out. The results suggest that: 1) It is necessary to restructure PES schemes given their limited scope in developing countries; 2) A new approach towards successful PES schemes should be adopted, transitioning from temporary conservation-oriented PES to schemes focused on the articulation of value chains and thus, transmitting costs to the final consumers; 3) Although policies regarding PES have been increasing, governance systems and responsibility assignments remain unclear; and 4) PES are more likely to be efficient when accompanied by complementary strategies (e.g. technical assistance, mechanisms for market inclusion) and conservation strategies that last in time. This study revealed the difficulties in monitoring territories as well as the underlying dynamics of implementing PES schemes in farms with nettle aptitude to receive them (despite the willingness of the producers). It also highlights the importance of analyzing the cultural and economic dimensions of the producers to assess the assigned importance of nature conservation. This work enriches the debate and informs the dialogue among PES experiences in order to guide public and private strategies in developing countries
Economic Benefits of Sustainable, Forage-Based Cattle Systems in Colombia and Nicaragua
Forage-based cattle systems play a key role in rural economies of developing countries in terms of food security and poverty alleviation, particularly in tropical Latin America. However, they are often related to being a major cause of negative environmental impacts by contributing to increased greenhouse gas emissions, land degradation, and the reduction of biodiversity. Significant resources have been allocated to research and development in forage material improvement, including selection and breeding. A broad range of improved materials were released by private and public sector actors showing superior characteristics in terms of productivity and environmental impacts compared to native or naturalized materials. Profitability is a fundamental attribute to incentivize or generate adoption of new systems by cattle producers, but this information is often not available to the livestock producer or the extension agents supporting decision-making processes. This research provides an overview on the economic viability of integrating different improved forage varieties in sustainably intensified cattle production systems in Colombia and Nicaragua. Our evaluations show that, despite higher establishment and management costs, integrating improved forage technologies (and management practices) in sustainably intensified cattle systems, either as monoculture, grass-legume associations, silvo-pastoral systems, or in combination with improved management strategies (e.g., intensive, or rotational grazing), not only make sense from the environmental and productive perspectives but also in terms of economic viability. In nearly all evaluated scenarios, the economic indicators improve by integrating improved forage technologies. Strong increases were observed for the following indicators: a) net income, b) unit profit margin, c) Net Present Value, d) Internal Rate of Return, and f) benefit-cost ratio. Strong decreases were observed for the following indicators: a) unit production cost, b) risk of obtaining economic loss, c) payback time, d) minimum area required for a profitable system, and e) sensitivity of the system to external shocks. This information will help cattle producers, extensionists and policymakers to make more holistic and informed land-use decisions that include productive, environmental, economic, and social benefits, and by this contributes to the broader adoption of more sustainable production systems
A convergent interaction engine: vocal communication among marmoset monkeys
To understand the primate origins of the human interaction engine, it is worthwhile to focus not only on great apes but also on callitrichid monkeys (marmosets and tamarins). Like humans, but unlike great apes, callitrichids are cooperative breeders, and thus habitually engage in coordinated joint actions, for instance when an infant is handed over from one group member to another. We first explore the hypothesis that these habitual cooperative interactions, the marmoset interactional ethology, are supported by the same key elements as found in the human interaction engine: mutual gaze (during joint action), turn-taking, volubility, as well as group-wide prosociality and trust. Marmosets show clear evidence of these features. We next examine the prediction that, if such an interaction engine can indeed give rise to more flexible communication, callitrichids may also possess elaborate communicative skills. A review of marmoset vocal communication confirms unusual abilities in these small primates: high volubility and large vocal repertoires, vocal learning and babbling in immatures, and voluntary usage and control. We end by discussing how the adoption of cooperative breeding during human evolution may have catalysed language evolution by adding these convergent consequences to the great ape-like cognitive system of our hominin ancestors.
This article is part of the theme issue âRevisiting the human âinteraction engineâ: comparative approaches to social action coordinationâ
Putting the cart before the horse? The origin of information donation
Heintz & Scott-Phillips propose that the partner choice ecology of our ancestors required Gricean cognitive pragmatics for reputation management, which caused a tendency toward showing and expecting prosociality that subsequently scaffolded language evolution. Here, we suggest a cognitively leaner explanation that is more consistent with comparative data and posits that prosociality and eventually language evolved along with cooperative breeding
Nonadjacent dependency processing in monkeys, apes and humans
The ability to track syntactic relationships between words, particularly over distances (ânonadjacent dependenciesâ), is a critical faculty underpinning human language, although its evolutionary origins remain poorly understood. While some monkey species are reported to process auditory nonadjacent dependencies, comparative data from apes are missing, complicating inferences regarding shared ancestry. Here, we examined nonadjacent dependency processing in common marmosets, chimpanzees, and humans using âartificial grammarsâ: strings of arbitrary acoustic stimuli composed of adjacent (nonhumans) or nonadjacent (all species) dependencies. Individuals from each species (i) generalized the grammars to novel stimuli and (ii) detected grammatical violations, indicating that they processed the dependencies between constituent elements. Furthermore, there was no difference between marmosets and chimpanzees in their sensitivity to nonadjacent dependencies. These notable similarities between monkeys, apes, and humans indicate that nonadjacent dependency processing, a crucial cognitive facilitator of language, is an ancestral trait that evolved at least ~40 million years before language itself
The Wnt pathway controls cell death engulfment, spindle orientation, and migration through CED-10/Rac
Wnt signalling pathways have extremely diverse functions in animals, including induction of cell fates or tumours, guidance of cell movements during gastrulation, and the induction of cell polarity. Wnt can induce polar changes in cellular morphology by a remodelling of the cytoskeleton. However, how activation of the Frizzled receptor induces cytoskeleton rearrangement is not well understood. We show, by an in depth 4-D microscopy analysis, that the Caenorhabditis elegans Wnt pathway signals to CED-10/Rac via two separate branches to regulate modulation of the cytoskeleton in different cellular situations. Apoptotic cell clearance and migration of the distal tip cell require the MOM-5/Fz receptor, GSK-3 kinase, and APC/APR-1, which activate the CED-2/5/12 branch of the engulfment machinery. MOM-5 (Frizzled) thus can function as an engulfment receptor in C. elegans. Our epistatic analyses also suggest that the two partially redundant signalling pathways defined earlier for engulfment may act in a single pathway in early embryos. By contrast, rearrangement of mitotic spindles requires the MOM-5/Fz receptor, GSK-3 kinase, and beta-catenins, but not the downstream factors LIT-1/NLK or POP-1/Tcf. Taken together, our results indicate that in multiple developmental processes, CED-10/Rac can link polar signals mediated by the Wnt pathway to rearrangements of the cytoskeleton
Meal-derived glucagon responses are related to lower hepatic phosphate concentrations in obesity and type 2 diabetes
Aim. - Type 2 diabetes (T2D) alters glucagon, glucagon-like peptide (GLP)-1, glucose-dependent insulinotropic polypeptide (GIP) and hepatic energy metabolism, yet the possible relationships remain unclear.Methods. - In this observational study, lean insulin-sensitive control subjects (BMI: 23.2 +/- 1.5 kg/m(2)), age-matched insulin-resistant obese subjects (BMI: 34.3 +/- 1.7 kg/m(2)) and similarly obese elderly T2D patients (BMI: 32.0 +/- 2.4 kg/m(2)) underwent mixed-meal tolerance tests (MMTTs), and assessment of hepatic gamma ATP, inorganic phosphate (P-i) and lipids using P-31/H-1 magnetic resonance spectroscopy. Meal-induced secretion of glucagon and incretins was calculated from incremental areas under the concentration-time curves (iAUCs). Peripheral and adipose tissue insulin sensitivity were assessed from time courses of circulating glucose, insulin and free fatty acids.Results. - MMTT-derived peripheral insulin sensitivity was lowest in T2D patients (P <0.001), while glucagon concentrations were comparable across all three groups. At 260 min, GLP-1 was lower in T2D patients than in controls, whereas GIP was lowest in obese individuals. Fasting glucagon concentrations correlated positively with fasting (r = 0.60) and postprandial hepatocellular lipid levels (160 min: r= 0.51, 240 min: r = 0.59), and negatively with adipose tissue insulin sensitivity (r = -0.73). Higher meal-induced glucagon release (iAUC(0)(-260) (min)) correlated with lower fasting (r = -0.62) and postprandial P(i )levels (160 min: r = -0.43, 240 min: r = -0.42; all P <0.05). Higher meal-induced release of GIP (iAUC(0-260) (min)) correlated positively with fasting (r = 0.54) and postprandial serum triglyceride concentrations (iAUC(0-260 min, )r = 0.54; all P <0.01).Conclusion. - Correlations between fasting glucagon and hepatic lipids and between meal-induced glucagon and hepatic P-i suggest a role for glucagon in hepatic energy metabolism. (C) 2018 Elsevier Masson SAS. All rights reserved.</p
Beneficios económicos de los sistemas ganaderos sostenibles basados en forrajes en América Latina
Beneficios econĂłmicos de los sistemas ganaderos
sostenibles basados en forrajes en América Latin
Linking Demand with Supply for Tropical Forage Genetic Resources to Reach Impact at Scale
Over the last decades a wealth of information on tropical forage genetic resources has been collated and is accessible to users ranging from farmers, development practitioners and researchers to decision makers and academia, e.g. through online tools such as Tropical Forages: An interactive selection tool (www.tropicalforages.info). However, while genetic diversity is being conserved by international gene banks, adoption of improved tropical forages is still far from reaching its full potential. Major bottlenecks in our view include lack of awareness of available forage genetic resources, confirmation of adaptation in a wide range of bio-physical, socio-economic, political and cultural contexts and functionality of financing, extension and seed supply systems. This paper discusses the potential for adoption of tropical forages in the context of new opportunities by market driven innovation, and presents early successes using as examples improved Urochloa spp., Megathyrsus maximus and other grass and legume germplasm, while describing possible pathways to go to scale with small and medium size livestock producers. We use examples of approaches from the tropical Americas, tropical Africa and tropical Asia, including partnerships with the private sector in diverse market environments (e.g. Africa and Latin America) and network approaches (Asia)
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