59 research outputs found
Morphological characteristics and linear body measurements of Doyogena sheep in Doyogena district of SNNPR, Ethiopia
No full textDescription of the physical characteristics of livestock breeds is very important for developing a breeding strategy in a particular production system. Doyogena sheep are among the potential breeds of Ethiopia reared in the mixed perennial crop and livestock production system of Southern Ethiopia. This research was conducted to characterise the morphological features of Doyogena sheep in an attempt to develop a breeding strategy that suits the production system of the area. A total of 512 sheep were characterized for different morphological features. Most (74.6%) of the sheep in the flock were females and 34.4% were old sheep of four and above dentition classes. Light red and red coat colours were abundant (71.5%) and 74% of the colour pattern was plain. Doyogena sheep are long fat-tailed (100%) and short haired (93.4%). The overall least square mean body weight was 31.64±0.43 kg and was affected by sex and age of sheep. The mean heart girth (74.08±0.39 cm), body length (58.84±0.30 cm), and height at rump (69.71±0.29 cm) were also affected by sex and dentition. Positive and significant correlations were obtained between body weight and other linear body measurements. The highest correlation coefficient was between body weight and heart girth. The positive and significant correlation of weight with linear body measurements indicate that linear body measurements can be used as a marker to estimate weight for different purposes. Different models can be used for different purposes. For simplicity, models with one variable can be used for marketing and by farmers. For breeding and selection purposes, since there is a need to be more precise, use of models involving more number of variables is important
Taguchi Method Optimization of Water Absorption Behavior by Wheat Straw-Basalt Hybrid Brake Pad Composite
No full textThe application of biomass-derived composite material is in high demand worldwide in various commercial sectors, including automotive, due to its durable, cost-effective, and environment-friendly characteristics. However, one of the limiting factors of biomass-based composites is its higher water absorption capacity compared to commercial synthetic composites. Therefore, this study aimed to optimize the water absorption capacity of biomass-based, wheat straw fiber-basalt hybrid composite brake pad using the Taguchi method by considering the particle size and volume % of the composite compositions. The composite synthesized in this study carried two variations of particle sizes of basalt, wheat straw, steel, river sand, and graphite, as well as two-volume percentages of epoxy resin for optimization. All composites were molded using a compression molding process at compressive pressure of 6 MPa for 2 h curing in a forced convection oven at 100 °C. Water absorption capacity has been determined according to ASTM D570. The wheat straw fiber has been chemically treated with 5 wt.% of sodium hydroxide (NaOH) to remove the impurities, lignin, and hemicellulose and increase the surface area of the fiber, resulting in a larger area of contact between the fiber and the matrix. Elemental analysis, crystallinity, morphology, and mechanical strength of wheat straw fiber-based composites have been determined by XRD, SEM, and compression tests, respectively. The statistical method, analysis of variance (ANOVA), was implemented for Taguchi optimization of the composite compositions. The maximum compressive strength and minimum and maximum water absorption capacity of composites were obtained as 77 MPa, 3.55%, and 26.86%, respectively. From the optimum setting of the confirmation experiment, the optimal water absorption value of 5.718% has been obtained. The optimum particle size of the composite compositions was 1 mm basalt particle, 0.5 mm wheat straw fiber, 1 mm steel particle, 1 mm river sand, 0.5 mm graphite dust particle, and 30 vol% epoxy resin by Taguchi method. The parameter impact of Taguchi ranking on water absorption capacity presented the maximum improvement of water absorption, 10.47%, with river sand particle size
Attentive Self-supervised Contrastive Learning (ASCL) for plant disease classification
No full textDeep-learning plays a crucial role in large-scale health monitoring of agricultural plants. One of the challenges in plant disease classification is the limited availability of annotated training data, where supervised deep feature learning typically excels. However, traditional deep learning backbones often produce representations that are not sufficiently discriminative or interpretable for detailed plant disease analysis. We propose an Attentive Self-supervised Contrastive Learning (ASCL) framework that leverages transferable representations as supervision signals. The ASCL framework enhances interpretability by incorporating attention mechanisms, such as squeeze-excitation and convolutional block attention module, which highlight key regions in plant images, aiding in transparent decision-making. In the present work, a pre-trained squeeze-excitation ResNet50 Siamese backbone network on the unlabeled PlantVillage dataset was used to validate the generalizability of the learned representations. The pre-trained weights were then fine-tuned on small-scale unseen datasets extracted from the 17-class PlantVillage Taiwan Tomato and Apple datasets. Despite involving fewer than 17 classes, the high variability within each class, such as the disease progression stages, underscores the fine-grained nature of the classification task. Extensive experiments demonstrated that the ASCL framework achieved 89 % accuracy, outperforming a baseline supervised model that scored 88.9 %. Moreover, when the ASCL learned, weights were transferred to an unseen dataset, and the model achieved 93.5 % accuracy, compared to 91.66 % with supervised ResNet50. The framework is scalable to larger datasets with more classes, making it applicable to broader fine-grained classification tasks. Therefore, the proposed ASCL framework demonstrates the generalizability and transferability of the downstream plant disease classification tasks
Intertextuality in Ethiopian Gǝ’ǝz Literature: The Lexical Relationships between the Hagiography and the Chronicle of King Iyasu I
No full textThis paper demonstrates the intertextual aspects of the hagiography and chronicle of an Ethiopian king, aṣe Iyasu I (r.1682–1706). To achieve this, lexical features of both texts are examined. These texts were written in the late seventeenth century. The chronicle of aṣe Iyasu I was written during the king’s reign by his own three chroniclers (Hawarya Krəstos, Zäwäldä Maryam, and Sinoda), while the hagiography of aṣe Iyasu I was written two years after the king’s death by azaž Sinoda. This study is based on textual methods of analysis, in particular content analysis. This method makes it possible to distinguish the lexical relationships between the two texts. For this purpose, the words and phrases that describe the royal courage and sacred personality of the king are identified. Although both the hagiography and the chronicle of aṣe Iyasu I are composed to the same king and address the subject of the same historical milieu, there is no remarkable lexical parallel between the two texts in the area of words and phrases. Unlike the chronicle of aṣe Iyasu I, the hagiography of aṣe Iyasu I uses carefully selected metaphoric words and phrases to describe the king’s bravery and sacred personality. It is thus reasonable to conclude that each author composed their text in a different literary setting rather than that one influenced the other. In other words, the two texts are interconnected but each developed its own textual features as a response to the method and approach of Ethiopian Gǝʿǝz literature
Child labor, agricultural shocks and labor sharing in rural Ethiopia
No full textThe author studies the effect of an agricultural shock and a labor sharing arrangement (informal social network) on child labor. Albeit bad parental preference to child labor (as the strand of literature claims), poor households face compelling situations to send their child to work. This is, especially, true when they are hit by an income shock and face a binding adult labor constraint.
The author used panel data from the ERHS and employed a fixed effects model to pin down causal relation between shocks, membership in a labor sharing arrangement and child labor. It was found that child labor is, indeed, a buffer stock. Though a labor sharing arrangement doesn't affect child labor at normal times, it helps households to lessen the pressure to rely on it when hit by idiosyncratic shocks. While almost the whole effect of these shocks is offset by participation in a labor sharing arrangement, the covariate shock is not. Even if this may well affect a child's academic performance, school attendance doesn't decrease. This differential effect of shocks on child labor in participant households might be because of the extra adult labor made available or due to mutual support that comes with these social networks.
This paper is indicative of the importance of considering social networks in smoothing out consumption. Further, it highlights the difficulty to cope up with covariate shocks and hence, calls for development interventions that are particularly meant to address their impact
The Agricultural Technology--Market Linkage under Liberalisation in Ghana: Evidence from Micro Data
No full textCombinations of factors, including inappropriate economic policies, have contributed to the poor economic performance of sub-Saharan Africa (SSA). The impacts of some corrective policy measures, both on the macro economy and on the rural economy, are not very clear because they have led to unintended consequences, such as increasing poverty and inequality. This paper examines the effect of the removal of subsidised agricultural credit for irrigation farmers in Ghana, a country of pioneering reforms in SSA. A theoretical model of this scenario is constructed, in which it is shown that under multiple-market imperfections farmers resort to alternative income sources to finance irrigation. Particularly in the presence of off-farm alternatives, multiple-market imperfections can induce both on- and off-farm income-generating activities during the same season. This model is subsequently tested and validated with household data collected from northern Ghana. The empirical analysis shows that there is a strong complementarity between irrigation farming and off-farm employment, two activities that depend heavily on labour endowment. The observed complementarity suggests that in weak credit markets irrigation farmers generate liquidity from off-farm activities, which could lead to a demand for larger family size in the long run. Copyright 2008 The author 2007. Published by Oxford University Press on behalf of the Centre for the Study of African Economies. All rights reserved. For permissions, please email: [email protected], Oxford University Press.
Use of a Recombinant Vaccinia Virus Expressing Interferon Gamma for Post-Exposure Protection against Vaccinia and Ectromelia Viruses
No full textabstract: Post-exposure vaccination with vaccinia virus (VACV) has been suggested to be effective in minimizing death if administered within four days of smallpox exposure. While there is anecdotal evidence for efficacy of post-exposure vaccination this has not been definitively studied in humans. In this study, we analyzed post-exposure prophylaxis using several attenuated recombinant VACV in a mouse model. A recombinant VACV expressing murine interferon gamma (IFN-γ) was most effective for post-exposure protection of mice infected with VACV and ectromelia virus (ECTV). Untreated animals infected with VACV exhibited severe weight loss and morbidity leading to 100% mortality by 8 to 10 days post-infection. Animals treated one day post-infection had milder symptoms, decreased weight loss and morbidity, and 100% survival. Treatment on days 2 or 3 post-infection resulted in 40% and 20% survival, respectively. Similar results were seen in ECTV-infected mice. Despite the differences in survival rates in the VACV model, the viral load was similar in both treated and untreated mice while treated mice displayed a high level of IFN-γ in the serum. These results suggest that protection provided by IFN-γ expressed by VACV may be mediated by its immunoregulatory activities rather than its antiviral effects. These results highlight the importance of IFN-γ as a modulator of the immune response for post-exposure prophylaxis and could be used potentially as another post-exposure prophylaxis tool to prevent morbidity following infection with smallpox and other orthopoxviruses.The article is published at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.007787
Phylogeography of influenza A H5N1 clade 2.2.1.1 in Egypt
No full textabstract: Background
Influenza A H5N1 has killed millions of birds and raises serious public health concern because of its potential to spread to humans and cause a global pandemic. While the early focus was in Asia, recent evidence suggests that Egypt is a new epicenter for the disease. This includes characterization of a variant clade 2.2.1.1, which has been found almost exclusively in Egypt.
We analyzed 226 HA and 92 NA sequences with an emphasis on the H5N1 2.2.1.1 strains in Egypt using a Bayesian discrete phylogeography approach. This allowed modeling of virus dispersion between Egyptian governorates including the most likely origin.
Results
Phylogeography models of hemagglutinin (HA) and neuraminidase (NA) suggest Ash Sharqiyah as the origin of virus spread, however the support is weak based on Kullback–Leibler values of 0.09 for HA and 0.01 for NA. Association Index (AI) values and Parsimony Scores (PS) were significant (p-value < 0.05), indicating that dispersion of H5N1 in Egypt was geographically structured. In addition, the Ash Sharqiyah to Al Gharbiyah and Al Fayyum to Al Qalyubiyah routes had the strongest statistical support.
Conclusion
We found that the majority of routes with strong statistical support were in the heavily populated Delta region. In particular, the Al Qalyubiyah governorate appears to represent a popular location for virus transition as it represented a large portion of branches in both trees. However, there remains uncertainty about virus dispersion to and from this location and thus more research needs to be conducted in order to examine this.
Phylogeography can highlight the drivers of H5N1 emergence and spread. This knowledge can be used to target public health efforts to reduce morbidity and mortality. For Egypt, future work should focus on using data about vaccination and live bird markets in phylogeography models to study their impact on H5N1 diffusion within the country.The electronic version of this article is the complete one and can be found online at: http://bmcgenomics.biomedcentral.com/articles/10.1186/1471-2164-14-87
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