Small scale agriculture, marginal conditions and market access: impacts on natural resources and farmers' welfare

Keywords: small-scale farmers, food security, impact evaluation, Ecuador, Ethiopia, crop choice, social capital, crop genetic diversity, pesticides. Numerous are the obstacles and difficulties smallholder farmers from developing countries have to face to achieve food security or improve their wellbeing. Challenges and opportunities may vary dramatically from having to cope with harsh climatic and production conditions to having the option of entering the market, yet farming systems and production decisions are crucial elements to reduce poverty and improve wellbeing. This is particularly true in a time in which growing population, climate change and energy requirements pose increasing pressure on land and natural resources. In either context, the use and exploitation of natural resources is thus a key aspect to consider particularly with regard to the variety choices that can affect genetic diversity and to the use of pesticides that might be induced to achieve standards required by the market. This thesis attempts to address these elements by analysing how small-scale farmers deal with achieving food security and improving their wellbeing through crop production choices, farming technologies and strategies adopted to access the market in marginal but market-oriented conditions as opposed to manage production in harsh agro-ecological conditions. After analyzing in detail the role of agriculture, of Plant Genetic Resources for Food and Agriculture (PGRFA) and of agricultural markets and seed systems, the thesis is divided in two parts. The first part deals with analyzing how small-scale farmers from the Ecuadorian Sierra benefit from dynamic changes in the agricultural economy and what is the impact of their production choices on the use of pesticides and of potato varieties adopted. The second part examines how smallholder farmers from the Hararghe region of Ethiopia deal with frequent production difficulties and with production shocks mainly determined by drought through variety adoption choices and what are the impacts of these choices on production efficiency and genetic diversity. The importance of social capital, evident throughout the work presented, is specifically analyzed for the case of Ethiopia. By using different approaches, methodologies and data, among which rigorous impact assessment plays a key role, findings show the unequivocal importance of market access, seed sources, production technologies and social capital. The analysis undertaken demonstrates that programs and policies to be effective need to be implemented throughout the entire value chain: from input use to produce commercialization, whereas social capital might dramatically facilitate the successfulness of variety adoption, seed access and program implementation. Lastly, this work demonstrates that rigorous impact evaluation can help identify aspects of programs and policies crucial to suggest the way forward on achieving sustainable economic development. <br/

Asymmetric Construction of Low-Latency and Length-Flexible Polar Codes

Polar codes are a class of capacity-achieving error correcting codes that have been selected for use in enhanced mobile broadband in the 3GPP 5th generation (5G) wireless standard. Most polar code research examines the original Arikan polar coding scheme, which is limited in block length to powers of two. This constraint presents a considerable obstacle since practical applications call for all code lengths to be readily available. Puncturing and shortening techniques allow for flexible polar codes, while multi-kernel polar codes produce native code lengths that are powers of two and/or three. In this work, we propose a new low complexity coding scheme called asymmetric polar coding that allows for any arbitrary block length. We present details on the generator matrix, frozen set design, and decoding schedule. Our scheme offers flexible polar code lengths with decoding complexity lower than equivalent state-of-the-art length-compatible approaches under successive cancellation decoding. Further, asymmetric decoding complexity is directly dependent on the codeword length rather than the nearest valid polar code length. We compare our scheme with other length matching techniques, and simulations are presented. Results show that asymmetric polar codes present similar error correction performance to the competing schemes, while dividing the number of SC decoding operations by up to a factor of 2 using the same codeword lengthComment: To appear in IEEE International Conference on Communications 2019 (Submitted October 12, 2018), 6 page

Deglutition syncope: A manifestation of vagal hyperactivity following carotid endarterectomy

A 61-year-old man with left amaurosis fugax and bilateral >80% internal carotid artery stenoses underwent a left carotid endarterectomy. On the first postoperative day, he developed hypotension, bradycardia, and chest pain with food ingestion. He was diagnosed as having deglutition syncope and was treated with oral anticholinergics. Similar symptoms occurred when he underwent a right carotid endarterectomy. Deglutition syncope is a neurally mediated situational syncope resulting from vagus nerve over-activity. This is the first report of deglutition syncope associated with carotid endarterectomy. It is important to recognize and differentiate these symptoms from other causes of postendarterectomy hemodynamic instability

Linking food security, climate change adaptation and mitigation: the case of sustainable land management in Malawi

Climate-smart agriculture (CSA) aims at enhancing the capacity of farming systems to sustainably support food security in the context of climatic changes (CC). Questions arise about the profitability of alternative farming options and their cost-effectiveness in mitigating CC. A large dataset has been built through household surveys, key informant interviews and focus group discussions conducted in different agro ecological zones of Malawi. Farmers adopt a wide combination of sustainable land management (SLM) practices, earning often higher yields, profits and returns to labor than under conventional farming. Differences are more significant in dry areas indicating potential for CC adaptation. However, this may come at excessive costs in terms of capital and labor. Negative marginal abatement costs for most SLM options show synergies between increased farm incomes and CC mitigation. Cost- effectiveness of agriculture management practices is proposed as policy decision criterion to prioritize CSA interventions on the basis of economic efficiency in greenhouse gases abatement

Seed systems smallholder farmers use

Seed can be an important entry point for promoting productivity, nutrition and resilience among smallholder farmers. While investments have primarily focused on strengthening the formal sector, this article documents the degree to which the informal sector remains the core for seed acquisition, especially in Africa. Conclusions drawn from a uniquely comprehensive data set, 9660 observations across six countries and covering 40 crops, show that farmers access 90.2 % of their seed from informal systems with 50.9 % of that deriving from local markets. Further, 55 % of seed is paid for by cash, indicating that smallholders are already making important investments in this arena. Targeted interventions are proposed for rendering formal and informal seed sector more smallholder-responsive and for scaling up positive impacts

Behavioural science interventions within the development and environmental fields in developing countries: An evidence gap map

This evidence gap map (EGM) presents a landscape of studies on the effectiveness of behavioural science interventions in non-Annex I settings, a group of mainly developing countries within the context of the Kyoto Protocol of the United Nations Framework Convention on Climate Change. The EGM summarizes causal evidence from development and environmental interventions. Understanding what is effective in changing behaviour in these countries is important for both adaptation and mitigation purposes. Although the evidence base is thin, the EGM reveals that the most commonly evaluated interventions are reminders, feedback, micro-incentives, salience of communication, commitment devices, salience of experience design (how individuals interact with their physical or digital environment), goal setting, rules of thumb, social norms and social benchmarking. The impact evaluations are relatively skewed towards sub-Saharan Africa and East Asia and the Pacific. A limited number of impact evaluations have been conducted in Europe and Central Asia, the Middle East and North Africa. A majority of the studies included in the EGM emanate from the water, sanitation and hygiene sector, the financial sector, the energy and extractives sector and the agricultural secto

Evidence Review on Behavioural Science Interventions in Development and Environmental Fields in Developing Countries:Protocol

This evidence gap map (EGM) presents a landscape of studies on the effectiveness of behavioural science interventions in non-Annex I settings, a group of mainly developing countries within the context of the Kyoto Protocol of the United Nations Framework Convention on Climate Change. The EGM summarizes causal evidence from development and environmental interventions. Understanding what is effective in changing behaviour in these countries is important for both adaptation and mitigation purposes. Although the evidence base is thin, the EGM reveals that the most commonly evaluated interventions are reminders, feedback, micro-incentives, salience of communication, commitment devices, salience of experience design (how individuals interact with their physical or digital environment), goal setting, rules of thumb, social norms and social benchmarking. The impact evaluations are relatively skewed towards sub-Saharan Africa and East Asia and the Pacific. A limited number of impact evaluations have been conducted in Europe and Central Asia, the Middle East and North Africa. A majority of the studies included in the EGM emanate from the water, sanitation and hygiene sector, the financial sector, the energy and extractives sector and the agricultural secto