There is repeated evidence that hybridization is a major contributor to the production of adaptive diversity; however, the evolutionary fate of hybrids in natural populations remains poorly understood. In Heliconius butterflies, hybridization is common and responsible for generating a variety of warning color patterns across the genus. Predator avoidance of warning colorations appears to largely be learned, which drives strong positive frequency-dependent selection. This creates a paradox for hybrid lineages: how do novel hybrid forms manage to establish and persist under such strong selection? In this dissertation, I present a series of studies centered on the selection dynamics of Heliconius hybrid zones, to elucidate how novel adaptive traits establish in nature. Clines across hybrid zones have often been analyzed to estimate selection on ecologically important loci. Here, warning color clines were characterized and compared across multiple transects along a Heliconius hybrid zone in the Guiana Shield. Furthermore, a mark-resight experiment and communal roost observations were completed near the center of this hybrid zone to determine the survival and likelihood of establishment of native and foreign forms. These studies reveal similar survivorship of hybrid and pure color patterns, and specifically demonstrate that a rare putative hybrid form can survive and establish within a hybrid zone. Both hybrids and pure color patterns showed comparable life expectancies in the mark-resight experiment and similar patterns of presence at nocturnal roosts. These results suggest that selection on warning color pattern is relatively weak within the hybrid zone. Analyses of color pattern clines uncovered strong selection bounding the hybrid zone in bi-race areas, while weaker selection was estimated for a tri-race area. In fact, the tri-race area was three times wider than the bi-race areas. Collectively, these studies suggest that the selection dynamics across hybrid zones may play an integral role in the establishment of new adaptive traits, and offers a route by which a reputed hybrid race may have arisen. The investigations within this dissertation also provide a new view of hybrid zone dynamics, and improve our understanding of how hybridization and selection shapes the evolution of biodiversity.

Insular fauna face disproportionate risks of extinction owing to direct human perturbation and intrinsic factors that are enhanced at small population sizes. Currently, our understanding of the processes that promote long-term persistence of naturally small populations and the cryptic processes that may contribute to accelerating their decline is limited by lack of empirical investigations across the range of natural conditions. Implementing effective protections for rare and understudied taxa requires the identification and examination of factors that limit recruitment at critical life stages. Predicting population health outcomes of future perturbations further necessitates an understanding a taxon’s behavioral ecology. Finally, cryptic threats to viability, such as inbreeding depression, must be investigated with an appreciation for taxon-specific life history, as these attributes can alter the context in which severe fitness reductions are expressed. In this project I enlist integrative and cross-disciplinary approaches to study the behavioral ecology and conservation genetics of a critically endangered West Indian Rock Iguana, Cyclura nubila caymanensis, on Little Cayman Island. I demonstrate how coastal communal nesting areas, a critical limiting resource on the island, serve a diverse population demographic and contribute to significantly enhanced nesting outcomes. These data emphasize the importance of expanding protections for major sites, as aggregative nesting appears to be perpetuated by both habitat suitability and adaptive fitness benefits. I next evaluate the possibility of evolved inbreeding avoidance strategies, including natal dispersal, non-assortative mate choice, and genetic bet-hedging. I conclude that the contribution of pre-reproductive dispersal to inbreeding avoidance likely outweighs that of active mate choice. Importantly, observed patterns of siring success imply constrained female choice and sexual conflict over genetic mating outcomes – a pattern that may extend to many territorial, male-driven mating systems and therefore should be an important consideration in genetic management. Finally, I investigate age-dependent inbreeding effects and the degree to which inbreeding depression may limit recruitment to the breeding population. I fail to reveal significant correlations of multi-locus heterozygosity with hatchling fitness; however, negative effects of parental inbreeding on fecundity and hatching success imply fitness consequences of inbreeding depression could be felt at other life stages.

Thesis (Ph.D. Agriculture (Plant Production)) -- University of Limpopo, 2022 / Livestock has evolved to serve as the foundation and backbone of human well-being, and it is an important component of South Africa's agricultural sector. The small stock such as sheep (Ovis aries) in Limpopo province has remained a significant and multifunctional livelihood strategy for the majority of the rural and resource-poor people. Factors such as population growth, urbanization, rising per capita income and changes in consumer tastes and preferences are all contributing to gradual increases in livestock product consumption and demand. According to the 2019 Abstract of Agricultural Statistics, South Africa is an importer of sheep and sheep products. If the sheep production industry in the province could pursue this opportunity and realize its full production potential then increased production could stimulate economic growth and development, particularly from the communal and smallholder sector. Objective one of the study seeks to describe the demographic and socio-economic characteristics of communal and smallholder sheep farmers, identify sheep feeding practices and describe the constraints that hinder the sustainable productive growth of communal and smallholder sheep systems. Data were collected from one hundred and twenty (120) sheep farmers using a structured questionnaire across three agro-ecological zones of Limpopo province. Results revealed that overall, the majority of sheep farmers were males (78%) and farmers were above 60 years old (48%). Mean sheep flock size differed significantly between communal (24.74) and smallholder (62.36) farmers. Indigenous crossbreeds were the dominant breed kept by communal (86%) and smallholder (77%) farmers. The majority of communal and smallholder farmers (90% and 96%, respectively) reared their sheep under an extensive system with rangelands as the main source of feed. As a result, they experience a critical feed gap during June and September, the mid-winter to early spring until the first rains. The findings of the study revealed that feed shortages and diseases were ranked as the first and second production constraints by sheep farmers in both the production systems. In rangeland-dependent feeding systems, insufficient feed to meet animal demands create a feed gap, which is a critical factor that limits sheep productivity and causes xxi land degradation through overgrazing. Improved forages have been widely advocated as a critical step toward resolving this challenge. However, the adoption and utilization of improved technologies such as on-farm forage legume production by these farmers have been very low, contributing to the province's low sheep productivity. An extension of objective one of this study used primary data which was collected from a sample of 120 sheep farmers to determine the factors that influence the adoption of on-farm forage legume production and the perceived barriers to adoption by communal and smallholder sheep farmers in the Limpopo province. A Probit regression model and Principal Component Analysis (PCA) were used to analyze the data. The study revealed that the adoption of on-farm forage production by communal and smallholder sheep farmers is influenced by several factors, including gender, farming experience, knowledge of forage legume production, source of income, membership in farmer associations, access to extension services and farm size. Farmer perceived barriers to adoption of on-farm forage legume production identified by this study were low institutional support, lack of resources, lack of knowledge, shortage of water and objectives of the farmer. It is therefore recommended that intensive and high-quality extension support in partnership with industry associations and stakeholders is required for communal and smallholder farmers to improve forage technology awareness, training and promote on-farm forage production to transform communal and smallholder sheep feeding practices. In the face of climate change, identifying forage species with a high potential to mitigate winter feed gap challenges under more variable climatic conditions is critical. Trifolium and Vicia species are forage legumes well known for producing high-quality forage, particularly protein, which is deficient in the majority of feed resources used for sheep feeding during the winter season. Climate change-induced stresses from rising temperatures, which these winter annual forage legumes are likely to face, necessitate agronomic and breeding approaches to improve their adaptability. Lack of knowledge on how these climate change mitigation approaches influence the productivity of winter annual forage legumes in the Pietersburg Plateau of Limpopo province prompted objective two of this study. A three-year field experiment laid in a split-split plot design with four replications was conducted to measure the effects of planting date, cultivar and harvest stage on the physiological traits associated with biomass production, forage quality, nodulation activity and xxii nutritive value of annual clover and vetch species. The results showed that the planting date and harvest stage had a significant effect on leaf gaseous exchange and biomass production. A non-significant effect of planting date on nutritive value was observed. Intercellular CO2 concentration, transpiration rate, stomatal conductance, instantaneous water use efficiency and intrinsic water use efficiency in cultivars increased with delayed planting, while a decrease in photosynthetic rate, shoot DM, root DM and nodule DM was observed. Overall among the cultivars, Resal, Alex, Elite, Laser and Dr Baumans showed more consistency in terms of leaf gaseous exchange, biomass production and quality traits under planting date 1 and varying harvest stages. Investment in the year-round fodder flow establishment with high-quality forages is important in supporting sustainable sheep production. Forage legume-grass rotation systems are important not only for green fodder production of high crude protein, mineral and vitamin content throughout the year but also for enhanced soil fertility to reduce the nitrogen (N) fertilizer requirements. Accurate estimates of forage yields on the farm are required for fodder flow planning to ensure the seasonal distribution of fodder throughout the year. Objective three of the study was a no-tillage, short-term rotation experiment conducted to determine the growth and nutritive value of forage sorghum, planted after the winter annual forage legumes in combination with nitrogen application and to validate the performance of the APSIM-grain sorghum crop model in simulating forage sorghum growth and biomass production under different N rates. The treatments were planting date (January and February) and N source from inorganic N fertilizer (0 kg N ha-1, 60 kg N ha-1, 120 kg N ha-1, 180 kg N ha-1) and forage legume N residues (Alex, Capello, Dr Baumans, Elite, Hanka, Laser, Linkarus, Opolska, Resal and Timok) arranged in a randomized complete block design with four replicates. The findings of this study showed a significant response of forage sorghum growth and nutritive value to planting date. Delayed planting reduced plant height (11%), stem diameter (18%), LAI (6.7%), chlorophyll content (18%), NDVI (2.5%), photosynthetic rate (38%) and biomass production (8%). Delayed planting further reduced crude protein, acid detergent fiber and N yield. Nitrogen source from inorganic N at 60 kg N ha-1, 120 kg N ha-1, 180 kg N ha-1 and residual N from annual clover and vetch cultivars had a significant effect on morphological, physiological, yield and nutritive value parameters of forage sorghum. xxiii Generally, legume N residue effects on all the studied parameters of forage sorghum were similar to the inorganic N fertilizer of 60 kg N ha-1. However, the effects differed widely according to the species and cultivar of the legume. Resal, Laser, Elite Capello and Dr Baumans N residue consistently showed greater effects than other legume residues. They consistently outperformed inorganic 60 kg N ha-1 on the most measured parameters. The results confirm that annual clover-forage sorghum and vetch-forage sorghum rotation have huge potential to reduce the cost and negative environmental effects associated with inorganic N use in forage prediction systems. Regarding the evaluation of the potential of the APSIM grain legume model to simulate forage legume DM and plant height, in general, the model performed well and accurately in predicting the shoot dry matter accumulation and plant height under 0 kg N ha-1, 60 kg N ha-1 and 120 kg N ha-1. However, it underestimated both these parameters at 180 kg N ha-1 implying that the application of N up to 180 kg N ha-1 is not necessary. APSIM-grain module was able to accurately predict forage biomass production under N rates up to 120 kg N ha-1 and it is therefore considered reliable to support the N nutrition in the forage sorghum fodder production systems. / University of Limpopo, research office under the UCDP program and National Research Foundation-Thuthuka

The novel The Bluest Eye highlights different modes of racism that is relevant to engage with in today’s society. From a pedagogical standpoint, novels of this nature can enable rich and fruitful discussions about the implication of racism and how to counter it. However, its pedagogical potential is juxtaposed against the risks of presenting such explicit material to a classroom, and the consequential effects of migrating an African American novel to a Swedish subtext. A solution to this is applying Critical Race Theory (CRT) as a theoretical framework which from a conceptual perspective can preserve the integrity of the novel and enable students to actively engage with the text. However, the Swedish National Agency for Education (SNAE) lacks pedagogical tools for English teachers that want to address and counter racism in their classrooms which leaves a gap for those interested in working with The Bluest Eye. This paper aims to contribute to this gap by presenting how The Bluest Eye can help English 7 students engage with questions surrounding racism by applying CRT as a pedagogical framework. In order to migrate CRT to a pedagogical context rather than an institutional one, my focus is on the tenets of the theory along with counter narrative and storytelling. Subsequently, the findings of this paper highlight two aspects of the novel that are indicative of its pedagogical potential: the narrative strategies and the thematic elements which stress different modes of racism. The results also show that with CRT as apedagogical framework, students can gain a deeper understanding in the multidimensionality of racism through engaging with this novel. This paper indicates the strengths of applying CRT as a framework when working with this text by showcasing the richness in The Bluest Eye and providing pedagogical guidelines in teaching it.

Petr Černoch - Dining together in the New Testament church from the collective memory perspective - Abstract The collective memory is a relatively new method of studying early Christianity that was taken from the humanities, especially sociology. This diploma thesis chose it as its method of studying the phenomenon of dining together, especially in the manifestation of the ritual of the Eucharist in the 1st century AD. In the first chapter, right after the introduction, this work briefly discussed the development of the study of memory from the collective memory of Mauritius Halwbachs with its social roots. He influenced contemporary memory studies through Jan Assmann, who developed his collective memory of the cultural and described its connection to New Testament research. By defining Cultural Memory, he showed strong links in religion between identity, myth and ritual. The work tried to define the terms myth and ritual with which it operates The next chapter deals with the linguistic and literary world of books, where the words of the establishment of the ritual of the Eucharist are located, discusses their structure and references to food or dining together. The work tried to show the view of the collective memory and thus shed light on some places of tradition and the origin of the ritual of the...

Thesis (M.Sc. Agriculture (Animal Production)) -- University of Limpopo, 2022 / Refer to document / National Research Foundation (NRF)

The relevance of this dissertation research is connected with insufficient development of theoretical, methodological and practical issues of accounting and control of payments for housing and communal services between the operating companies and their contractors, meanwhile, as this sphere of activity has high economic and social importance. The work examines the complex theoretical and methodological issues of accounting and analysis of payment transactions between management companies and contractors in the sphere of housing and communal services and developed recommendations for their improvement. The peculiarities of normative regulation of financial and economic activities of managing organizations that affect their methods of accounting, including tariff policy, payments to contractors, and improved methods of accounting and analytical support these processes. / Актуальность диссертационного исследования связана с недостаточной разработкой теоретических, методических и практических вопросов учета и контроля расчетов по жилищно-коммунальным услугам между управляющими компаниями и их контрагентами, между тем, как данная сфера деятельности имеет высокую экономическую и социальную значимость. В работе исследован комплекс теоретических и методических вопросов учета и анализа расчетных операций между управляющими компаниями и контрагентами в сфере жилищно-коммунального хозяйства и разработаны рекомендации по их совершенствованию. Выявлены особенности нормативного регулирования финансово-хозяйственной деятельности управляющих организаций, влияющих на методики их бухгалтерского учета, в том числе тарифной политики, расчетов с контрагентами, и совершенствование методов учетно-аналитического обеспечения данных процессов.

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Why are some areas more resilient to riots than others? The literature seems divided on whether exposure to violence affects societies to become more resilient or more vulnerable to future violence. The most supported view is that "violence begets violence", but some studies suggest that riot exposed areas could possibly develop resilience. Potential resilience would arguably be the most noticeable in times of turmoil. As India had an outbreak of riot after the 2019 national election, it constitutes a good case to study. I therefore investigate whether riot exposure makes societies more resilient to violence or not, by looking at the probability that riot exposed areas in the pre-election period, had election-related riots after the election. The current thesis tests a hypothesis suggesting that there is lower probability that areas exposed to riots in the pre-election period experience riots in the post-election period, than in areas with no riot exposure in the pre-election period. By running a Linear Probability Model, on riot data in four Indian states, containing 1099 urban observations, the results of the thesis indicate that the hypothesis is unsubstantiated. Instead, an opposite relationship appears, which gives further support to the notion that “violence”, indeed, “begets violence”.