The purpose of this study was to compile practical feeding guidelines for donkeys in the UK. Current guidelines are to feed 0.75 of horse feeding recommendations on a body weight basis. However, the superior digestive efficiency of donkeys, compared to horses, may render the use of horse recommendations inappropriate. The formulation of guidelines specific to donkeys would enable owners to calculate their donkey‟s requirements with greater accuracy and prevent overfeeding. A postal survey, used to gain information on the body condition score of donkeys in the UK, and the husbandry and feeding practices used to manage them, indicated that approximately 24% of donkeys in the UK are overweight. Feeding practices indicated that although owners were aware of their donkey‟s requirement for fibrous forages, the practice of feeding unnecessary concentrates, chaffs and high energy forages, in addition to grazing, was the likely cause of donkeys becoming overweight. The finding that the majority (85 – 90%) of donkeys were kept as non-working companion animals also reduced the need for owners to feed higher energy foods to their donkeys. Results also suggested that owners were unsure of how to adjust their donkey‟s diet to account for seasonal changes in requirements and pasture availability, as most owners‟ adjusted grazing access, and not the feeding of supplementary feeds. From a study of dry matter (DM) and digestible energy (DE) intakes by 20 mature donkeys maintaining weight during each UK season, the maintenance DE requirements of donkeys were calculated. Results showed no effect of sex on DM or DE intake. Season significantly (P<0.001) affected DM and DE intakes, implying increased requirements in winter compared to spring, summer and autumn. Dry matter intakes (DMI) increased from 51g/kg BW0.75 in spring, summer and autumn to 66g/kg BW0.75 in winter. Digestible energy requirements increased from 0.32MJ/kg BW0.75 in spring, summer and autumn to 0.43MJ/kg BW0.75 in winter. Comparison of results with horse recommendations showed considerably reduced requirements by donkeys. Horse recommendations overestimated DE requirements in summer and winter by 82 and 30%, respectively, making horse recommendations unsuitable for calculating donkey energy requirements. Husbandry practices commonly used by owners to manage their donkeys grazing access (grazing time, grazing area, strip grazing), were assessed for their effect on DMI by grazing donkeys in summer and autumn, using n-alkanes. The effect of grazing time was assessed by restricting donkeys to 8, 12 or 23 hours grazing per day. Season significantly affected food intake with donkeys in the 8 and 23 hour grazing groups eating more during summer when pasture availability was greater. Donkeys responded to the poorer quality summer pasture by grazing more intensively but less selectively, increasing the rate at which food was consumed. Grazing time was only influential over grass intake in summer, when pasture was more abundant. Restricting donkeys to 12 hours or less grazing per day significantly (P<0.001) reduced their grass intake compared to that of donkeys with 23 hours access. When grazing sparse pastures (autumn), grazing time did not influence grass intake, indicating an effect of herbage mass on grazing behaviour. Herbage mass was the most influential factor over diet composition (percentage of grass and straw consumed) in a second grazing study assessing the affect of strip grazing and set stocking systems on intake by grazing donkeys during summer and autumn. Herbage mass per donkey was higher in the set stocking system during both seasons, resulting in higher grass intakes. Determining if either grazing system was more effective at regulating grass intake was prevented due to differences in pasture availability between study sites. It is concluded that donkeys have lower DMI and maintenance DE requirements than horses, requiring donkey feeding guidelines to be formulated. Excess body weight in donkeys is caused in part, by the feeding of energy dense feeds in addition to low energy forages. Most owners place little nutritional importance on pasture, despite its potential to provide a large percentage of daily DM, DE and nutrient intake. Therefore nutritional guidelines must include advice on how to manage access to grazing, and how to feed donkeys with access to pasture. Restricting grazing time to 8 hours a day did reduce grass intake by donkeys, but was only effective when grazing abundant pastures. Providing ad libitum straw to grazing donkeys allows them to satisfy their DM and dietary fibre requirements without consuming excess energy.

Philosophiae Doctor - PhD / Numerical simulations play a crucial role in testing current cosmological models of the formation and evolution of the cosmic structure observed in the modern Universe. Simulations of the collapse of both baryonic and non-baryonic matter under the influence of gravity have yielded important results in our understanding of the large scale structure of the Universe. In addition to the underlying large scale structure, simulations which include gas dynamics can give us valuable insight into, and allow us to make testable predictions on, the nature and distribution of baryonic matter on a wide range of scales. In this work we give an overview of cosmological simulations and the methods employed in the solution of many body problems. We then present three projects focusing on scales ranging from individual galaxies to the cosmic web connecting clusters of galaxies thereby demonstrating the potential and diversity of numerical simulations in the fields of cosmology and astrophysics. We firstly investigate the environmental dependance of neutral hydrogen in the intergalactic medium by utilising high resolution cosmological hydrodynamic simulations in Chapter 3. We find that the extent of the neutral hydrogen radial profile is dependant on both the environment of the galaxy and its classification within the group ie. whether it is a central or satellite galaxy. We investigate whether this effect could arise from ram pressure forces exerted on the galaxies and find good agreement between galaxies experiencing high ram pressure forces and those with a low neutral hydrogen content. In Chapter 4 we investigate the velocity–shape alignment of clusters in a dark matter only simulation and the effect of such an alignment on measurements of the kinetic Sunyaev–Zeldovich (kSZ) effect. We find an alignment not only exists but can lead to an enhancement in the kSZ signal of up to 60% when the cluster is orientated along the line-of-sight. Finally we attempt to identify shocked gas in clusters and filaments using intermediate resolution cosmological hydrodynamic simulations in Chapter 5 with a view to predicting the synchrotron emission from these areas, something that may be detectable with the Square Kilometer Array.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-09-28T11:32:42Z No. of bitstreams: 1 viniciusdasilvacarvalho.pdf: 5576805 bytes, checksum: a8650866883ad86296123cb38cf68ca8 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-09-28T14:13:15Z (GMT) No. of bitstreams: 1 viniciusdasilvacarvalho.pdf: 5576805 bytes, checksum: a8650866883ad86296123cb38cf68ca8 (MD5) / Made available in DSpace on 2017-09-28T14:13:15Z (GMT). No. of bitstreams: 1 viniciusdasilvacarvalho.pdf: 5576805 bytes, checksum: a8650866883ad86296123cb38cf68ca8 (MD5) Previous issue date: 2017-08-11 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Atualmente, observamos uma crescente preocupação por parte de educadores e pesquisadores da educação química voltada para aspectos da inclusão. Diante desse público, destacamos o surdo, usuário da Língua de Sinais Brasileira (Libras), que requer atenção por parte dos profissionais envolvidos no processo da educação científica que atente para as especificidades linguísticas. Essa acessibilidade está diretamente ligada à construção de termos químicos para a Libras, ainda escassos nos dicionários oficiais. Nessa perspectiva, buscou-se nessa pesquisa investigar a construção de sinais do campo da ciência, referentes ao conteúdo de matéria e energia. A emersão de sinais a partir da Libras, foi estimulada por recursos visuais, com dois grupos de surdos, docentes de Libras, da cidade de Juiz de Fora. Em sequência, os sinais científicos criados foram trabalhados com alunos surdos da educação pública básica, por meio de um material didático de química adaptado para realidade educacional. Para verificar a aprendizagem dos alunos surdos, utilizou-se a dinâmica do Roleplaying Game (RPG), no qual é possível observar a apropriação dos sinais científicos de ocorrência natural com uso da Libras. Nesse sentido, ao entrelaçar o uso de material didático acessível com os sinais para termos químicos, foi possível acompanhar a apropriação dos sinais criados pelos alunos, bem como os meios que levaram sua modificação durante os eventos de comunicação. Entendemos na postura de educadores da área de uma ciência inclusiva a surdos, que é possível aliar estratégias metodológicas de ensino estimuladas por recursos visuais e que não se deve subestimar o fato da ausência de sinais para termos específicos de química em Libras. Acreditamos que o docente ao subestimar esse fato, poderá estar suscetível a oferecer um ensino de química defasado, ausente de possibilidades para que o surdo discuta ativamente os aspectos sociais para questões científicas. / Currently, there is a growing concern on the part of educators and researchers of chemical education focused on aspects of inclusion. In front of this audience, we highlight the deaf, user of the Brazilian Sign Language (Libras), which requires attention from the professionals involved in the process of scientific education that attends to the linguistic specificities. This accessibility is directly linked to the construction of chemical terms for the Libras, still scarce in the official dictionaries. From this perspective, this research sought to investigate the construction of signals from the field of science, referring to the content of matter and energy. The emergence of signs from the Libras, was stimulated by visual resources, with two groups of deaf, teachers of Libras, from the city of Juiz de Fora. In sequence, the scientific signals created were worked with deaf students of basic public education, through a didactic material of chemistry adapted to educational reality. In order to verify the deaf students' learning, the dynamics of the Roleplaying Game (RPG) were used, in which it is possible to observe the appropriation of scientific signs of natural occurrence with the use of Libras. In this sense, by interweaving the use of accessible didactic material with the signs for chemical terms, it was possible to follow the appropriation of the signs created by the students, as well as the means that led to their modification during the communication events. We understand the attitude of educators in the area of an inclusive science to the deaf, that it is possible to combine methodological strategies of teaching stimulated by visual resources and that the fact of the absence of signs for specific terms of chemistry in Pounds should not be underestimated. We believe that the teacher, by underestimating this fact, may be susceptible to offer a lagged chemistry teaching, lacking in possibilities for the deaf to actively discuss social aspects for scientific questions.

Questa tesi di dottorato analizza l’utilizzo del sorgo (Sorghum bicolour (L.) Moench) al fine di produrre energia elettrica, tramite combustione diretta della biomassa. Il focus della tesi è stato quello di sottolineare i benefici ed i rischi associati all’uso di tre genotipi di sorgo caratterizzati da diversa lunghezza del ciclo culturale (precoce, medio-tardivo e tardivo). La dinamica e la durata del processo di essicazione in campo sono state simulate attraverso un modello ad hoc (“sorghum haying model”), il quale integrato a CropSyst, è stato utilizzato per realizzare un’analisi del rischio produttivo stimando le perdite di biomassa (respirazione e meccanizzazione), ed i mancati affienamenti. Nell’analisi del rischio vengono stimati il numero di ettari necessari e la probabilità di eccedere la soglia di 64.000 ton ss anno-1 necessari per l’alimentazione di una centrale nell’Oltrepò pavese . Inoltre uno studio di Life Cycle Assessment è stato condotto per la valutazione dell’impatto ambientale dell’utilizzo del sorgo integrato a quello della paglia per il completamento del fabbisogno totale della centrale 94.000 ton ss anno-1. Particolare attenzione inoltre è stata data alla variazione del contenuto di C organico del suolo dovuto alla rimozione della paglia ed all’interramento dei mancati affienamenti di sorgo. Il genotipo precoce mostra le migliori performance produttive ed energetiche oltre che la più alta probabilità di eccedere la soglia di 64.000 ton ss anno-1. Lo studio di LCA non ha mostrato differenze significative tra i genotipi anche se il minor impatto ambientale, è stato evidenziato dal genotipo tardivo conseguenza dell’interramento della più alta quantità di mancati affienamenti. / This PhD thesis explores the use of sorghum (Sorghum bicolour (L.) Moench) as a dedicated bio-energy crop and highlights the benefits and risks associated with the use of early, medium-late and late sorghum genotypes to generate electricity by direct combustion in a biomass power plant. The dynamics and duration of the field drying process were simulated through the development of a specific model ("sorghum haying model"), which integrated with CropSyst, was used to perform a production risk assessment analysis estimating the biomass losses (respiration and mechanical), the haymaking failures and consequently to quantify the amount of dry baled biomass available for the power plant. In addition, the number of hectares needed to plant sorghum and the probability to exceed the threshold of 64000 Mg DM y-1, necessary to feed a biomass power plant in Oltrepò Pavese, were estimated. A complete Life Cycle Assessment (LCA) study was carried out in order to evaluate the environmental impact of the three sorghum genotypes involved in this study. The LCA study takes into consideration the use of winter wheat straw as an additional biomass source to satisfy the total biomass power plant needs (94000 Mg DM y-1). Particular attention was given to the soil organic C change (ΔSOC) due to straw removal and haymaking failures soil incorporation. Early genotype showed the best biomass production and energy performance as well as the highest probability to exceed the threshold of 64000 Mg DM y-1. The LCA results did not show significant differences between genotypes although the lower environmental impact, has been achieved by the late genotype due to the highest amount of haymaking failures incorporated in the soil.