In this thesis I inspect learning about adoption of technologies among cocoa farmers in Ghana, which are represented by non-labor inputs, particularly by fertilizer and hybrid seeds. Earlier research focused mainly on learning about returns associated with adoption of such innovative inputs. However, it is not clear whether the adopters learn about these returns or rather about what are the optimal amounts of these inputs. Therefore the focus of this thesis is to examine how do the farmers choose and learn about optimal amounts of inputs. Cocoa farming is very labor intensive, and thus this thesis concentrates on learning about both non-labor and labor inputs, which are closely connected. Similar research carried out in India suggests that heterogeneous returns among farmers might cause that the farmers rely rather on their own considerations than on observation of behavior of their village neighbors, i.e. social learning. The heterogeneous returns are also present among the Ghanaian cocoa farmers, which suggest that these farmers should similarly prefer individual learning over the social one. Using a model developed for estimation of the prevailing type of learning about the optimal amount of inputs, I show that the farmers do tend to prefer individual learning in case of the non-labor inputs but rather...

The aim of this study is twofold; To analyse and understand how well small-scale farmers seed production system from i.e Ladakh, India have been recognised in the 1966 seed policy bill and compare it with the newly released 2019 seed policy draft as well as examining potential effects if the draft is enacted. This has been done by using a post-structural policy analysis developed by Carol Bacchi and Susan Goodwin called “What is the problem represented to be”. The method has enabled for an in-depth and critical examination of the two policies in relation to the posed research questions. To be able to put the result into context and answer the questions, an analytical framework made frompost-structuralism, power relations and literature review is explained. This study concludes the problem representation to be the same for both policies, being disbelief in farmers seed production system, and that it is of disadvantage for the small-scale farmers in relation to seeds in Ladakh. This, due to its definitions and expressions of farmers and the liberal/neoliberal reasoning. Instead, the reasoning gives advantage to seed dealers and companies by favouriting Intellectual Property Rightsand a free market over farmers seed production systems and knowledges. Furthermore, this revelation resulted in a low representation for the small-scale farmers in Ladakh as they are viewed as inept of providing seeds of good quality to the market. It has also been noted that Ladakh as a remote area does not receive any special attention regarding their unique high-mountainous climate. Conclusively, the policies tend to subject all areas and farmers in India in a homogenous manner which is problematic in terms of rationality and perspectives in the policies. The lack of recognition for smallscale farmers in Ladakh and their seed production system increases the risk of further environmentaldegradation, loss heirloom seeds connected to culture and traditions and an increase of dependency onlow-land India. The author concludes that it is of relevant that small-scale farmers knowledges, not only from Ladakh, regarding seed production are incorporated in the policies. This, to eradicate on its homogeneous and inequality traits as well to minimize threatening scenarios that might result from a liberal agenda.

Radioactive seed implant brachytherapy is a common radiotherapy treatment method for prostate cancer. In current clinical practice, a seed consists of a single isotope, such as 125I or 103Pd. A seed containing a mixture of two isotopes has been proposed for prostate cancer treatment. This study investigates a method for defining a prescription dose for new seed compositions based on matching the biological equivalent dose (BED) of a reference plan. Ten prostate cancer cases previously treated using single isotope seeds (5 using 125I seeds and 5 using 103Pd seeds) were selected for this study. Verification of the method was done by calculating prescription doses for 103Pd and 125I seeds. A prescription dose for a 50/50 hybrid seed was calculated. Number and location of seeds remained invariant within each case. The BED distributions for hybrid and single isotope seed plans were generated and matched to the BED distribution generated off of the optimized plans. For the 125I isotopes, the dose necessary to cover 90% of the prostate with a BED of 110 Gy is 145 Gy. For the same BED coverage, the dose for 103Pd and 50/50 hybrid seed is 120 Gy and 137 Gy respectively. A method is introduced for obtaining prescription doses for new brachytherapy sources. The method was verified by obtaining doses for 125I and 103Pd isotopes which match clinical prescription doses. The method developed is robust enough to calculate prescription doses in any region of interest, for any seed type, and for any isotope as long as the BED coverage remains invariant with respect to the treatment plan. Numerical calculations were performed to derive analytical conversions of total dose to BED for 50/50, 75/25 and 25/75 hybrid seeds. These analytical conversions are faster than the original numerical methods employed allowing for real-time BED optimization for hybrid seeds. Varying seed distribution was seen not to influence the analytical conversions. It was observed that when total dose remained invariant while individual isotope contributions varied, the value of BED varied. The BED variance was seen to be the smaller at larger BED values (~2% at 100 Gy). Using the conversions derived in this paper, BED based optimization for hybrid seeds are now performable. However, these conversions should only be used in high dose regions due to high uncertainty in the low regime.

Made available in DSpace on 2014-08-20T13:44:37Z (GMT). No. of bitstreams: 1 tese_ademir_luiz_capelaro.pdf: 530051 bytes, checksum: 5341eb64d3d21ee5323d0a427e36b506 (MD5) Previous issue date: 2014-03-28 / The present study aimed to evaluate the effects of genetic inheritance in the physiological quality and the storage potential of some corn hybrids seeds produced in the field and stored in two different environments: cold room and common warehouse, for a period of eighteen months. To this study were produced seeds from six corn hybrids by crossing a group of three male parental lines with two female parental lines. Seeds from these hybrids were produced in the Syngenta Production Research field area, located at Tupaciguara-MG, under a high technology environment/condition with a necessary isolation in order to prevent any kind of contamination between their parents. Harvest was done in spikes and after drying and processing, 10 kg of seeds samples each hybrid and parent lines corresponding to 20R size were separated. Then these samples were divided in two sub-samples of 5 kg each one and storage in two different environments: cold room at 10 º C and 60 % RH and common warehouse in natural enviroment (25 - 35° C and 30 - 90% RH). Seeds quality for the two environment conditions was evaluated by using the germination test, acelerating aging test (EVA) and cold test, for a period of eighteen months. The statistical design was completely randomized factorial 3x5 for each hybrid and male and female parent, in five evaluation periods, performed separately for each storage condition, with four replications in case of germination and three replications for each treatment in case of accelerated aging test and cold test. According the results was possible to conclude that the physiological quality of the seeds and their longevity (shelf life) was similar for all hybrids, independent of the different combination of their respective male and female. Also the hybrids have ever presented better performance of their respective parental lines. In all situations evaluated was observed that the hybrids presented higher performance to physiological quality than their respective parent lines, indicating that the effects of the heterosis was very important. / O presente trabalho teve o objetivo de avaliar o efeito da herança genética na qualidade e no potencial de armazenamento de sementes de híbridos de milho, produzidas em condições de campo e armazenadas em dois ambientes diferentes: armazém climatizado e armazém convencional. Para tanto, foram produzidas sementes de seis híbridos simples de milho, através do cruzamento de um grupo de três linhagens parentais masculinas com duas linhagens parentais femininas. As sementes dos referidos híbridos foram produzidas no campo de Pesquisa de Produção da Syngenta Seeds, localizada no município de Tupaciguara/MG, em condições de alta tecnologia e com todos os isolamentos necessários para evitar qualquer tipo de contaminação entre os parentais. A colheita foi realizada em espigas que após a sua secagem e beneficiamento, originaram dez kg de sementes de cada um dos genótipos utilizados, híbridos e linhagens parentais, separadas em peneira 20R. Em seguida esta amostra foi dividida em duas sub-amostras de cinco kg, sendo cada uma delas armazenadas em dois diferentes ambientes: armazém climatizado com 10 ºC e 60 % UR; armazém convencional em condições de ambiente natural (25 a 35° C e 30 a 90% UR). A qualidade das sementes, para as duas condições de armazenamento, foi avaliada pelo teste de germinação, teste de envelhecimento acelerado e teste de frio. O delineamento estatístico utilizado foi inteirarmente casualizado em esquema fatorial 3x5, para cada híbrido e parental masculino e feminino, em cinco épocas de avaliação, realizadas separadamente para cada condição de armazenamento, com quatro repetições para cada tratamento no caso do teste de germinação e três repetições para cada tratamento nos testes de vigor envelhecimento acelerado e teste de frio. Quanto a significância, realizou-e análise de regressão polinimial. Concluiu-se que a qualidade e o potencial de armazenamento das sementes foram semelhantes para todos os híbridos, independentemente da combinação entre os respectivos parentais masculinos e femininos. O comportamento de cada híbrido foi independente do parental masculino utilizado no cruzamento com cada um dos parentais femininos. Em todas as situações avaliadas observou-se que os híbridos apresentaram uma qualidade fisiológica bastante superior em relação aos seus respectivos parentais, masculinos e femininos, indicando que houve um efeito da heterose na qualidade fisiológica das sementes.