| 61. |
- Aboshady, Hadeer Moursy
(författare)
-
Genomic variation and molecular mechanisms of the host response to gastrointestinal nematodes in small ruminants
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Gastrointestinal nematode (GIN) infections are one of the major constrains for sheep and goat production worldwide. One of the promising control strategies is the genetic selection for resistant animals as there are no issues due to anthelmintic resistance and it aligns to demands for chemical-free food. Exploring possible phenotypic and genomic markers that could be used in breeding scheme besides understanding the mechanisms responsible for resistance were the main goals of this thesis. Thesis consists of General introduction, a brief description of GIN biology and methods to control GIN with focus on phenotypic and genomic markers, four papers and General discussion. In paper Ⅰ, a systematic review and meta-analysis were conducted to re-analyse and summarize the findings on immunoglobulins response to GIN in the literature and discuss the potential to use immunoglobulins as biomarkers of the host resistance. A conceptual model summarizing the role of immunoglobulins in resistance to GIN is proposed. In paper Ⅱ, transcriptome profiling of the abomasal mucosa and lymph node tissues were compared between non-infected, resistant and susceptible Creole goats experimentally infected with Haemonchus contortus. Results indicated that the maintenance of the integrity of the mucosa has probably the priority for the host at late infection stage. In paper Ⅲ, the dynamics of the response of the abomasal mucosa of resistant and susceptible Creole goats experimentally infected with H. contortus were compared. The immune response was activated through many relevant pathways including the Th1 immune response at different time post-infection. Interestingly, the results showed a simultaneous time series activation of Th2 related genes in resistant compared to susceptible kids. In paper Ⅳ, the genomic variants of Creole goats resistant and susceptible to H. contortus were discovered from RNAsequencing data at four different times post-infection. Single nucleotide polymorphisms, insertions and deletions that distinguish the resistant and the susceptible groups were identified and characterized through functional analysis. The T cell receptor signalling pathway was one of the top significant pathways that distinguish the resistant from the susceptible group with genomic variants in 78% of genes in this pathway.
|
|
| 62. |
- Aboshady, Hadeer Moursy, et al.
(författare)
-
Immunoglobulins as Biomarkers for Gastrointestinal Nematodes Resistance in Small Ruminants: A systematic review
- 2020
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10
-
Forskningsöversikt (refereegranskat)abstract
- The rise of anthelmintic resistance worldwide has led to the development of alternative control strategies for gastrointestinal nematodes (GIN) infections, which are one of the main constraints on the health of grazing small ruminants. Presently, breeding schemes rely mainly on fecal egg count (FEC) measurements on infected animals which are time-consuming and requires expertise in parasitology. Identifying and understanding the role of immunoglobulins in the mechanisms of resistance could provide a more efficient and sustainable method of identifying nematode-resistant animals for selection. In this study we review the findings on immunoglobulin response to GIN in the literature published to date (june 2019) and discuss the potential to use immunoglobulins as biomarkers. The literature review revealed 41 studies which measured at least one immunoglobulin: 35 focused on lamb immune response (18 used non-naive lambs) and 7 on yearlings. In this review we propose a conceptual model summarizing the role of immunoglobulins in resistance to GIN. We highlight the need for more carefully designed and documented studies to allow comparisons across different populations on the immunoglobulin response to GIN infection.
|
|
| 63. |
|
|
| 64. |
- Aboshady, Hadeer Moursy, et al.
(författare)
-
Transcriptome variation in response to gastrointestinal nematode infection in goats
- 2019
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14, s. 20-
-
Tidskriftsartikel (refereegranskat)abstract
- Gastrointestinal nematodes (GIN) are a major constraint for small ruminant production. Due to the rise of anthelmintic resistance throughout the world, alternative control strategies are needed. The development of GIN resistance breeding programs is a promising strategy. However, a better understanding of the mechanisms underlying genetic resistance might lead to more effective breeding programmes. In this study, we compare transcriptome profiling of abomasal mucosa and lymph node tissues from non-infected, resistant and susceptible infected Creole goats using RNA-sequencing. A total of 24 kids, 12 susceptible and 12 GIN resistant based on the estimated breeding value, were infected twice with 10,000 L3 Haemonchus contortus. Physiological and parasitological parameters were monitored during infection. Seven weeks after the second infection, extreme kids (n = 6 resistant and 6 susceptible), chosen on the basis of the fecal egg counts (FEC), and 3 uninfected control animals were slaughtered. Susceptible kids had significantly higher FEC compared with resistant kids during the second infection with no differences in worm burden, male and female worm count or establishment rate. A higher number of differentially expressed genes (DEG) were identified in infected compared with non-infected animals in both abomasal mucosa (792 DEG) and lymph nodes (1726 DEG). There were fewer DEG in resistant versus susceptible groups (342 and 450 DEG, in abomasal mucosa and lymph nodes respectively). 'Cell cycle' and 'cell death and survival' were the main identified networks in mucosal tissue when comparing infected versus non-infected kids. Antigen processing and presentation of peptide antigen via major histocompatibility complex class I were in the top biological functions for the DEG identified in lymph nodes. The TGF beta 1 gene was one of the top 5 upstream DEG in mucosal tissue. Our results are one of the fist investigating differences in the expression profile induced by GIN infection in goats.
|
|
| 65. |
|
|
| 66. |
- Abouhatab, Assem
(författare)
-
China
- 2015
-
Ingår i: Employability of Erasmus Mundus Graduates in Agriculture on the Chinese Professional Market. - 9788021325791 ; , s. 31-31
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 67. |
- Abouhatab, Assem, et al.
(författare)
-
COVID-19, Livestock Systems and Food Security in Developing Countries: A Systematic Review of an Emerging Literature
- 2021
-
Ingår i: Pathogens. - : MDPI AG. - 2076-0817. ; 10
-
Forskningsöversikt (refereegranskat)abstract
- In this paper, we carried out a systematic literature review to document the emerging scientific knowledge about COVID-19 impact on livestock systems and food security in developing countries to identify gaps and possible avenues for future research undertakings. Specifically, we systematically reviewed 68 peer-reviewed articles extracted based on rigorous selection criteria from Scopus, PubMed and ISI Web of Science databases and published between December 2019 and February 2021. Our results reveal that livestock supply chains presented an important 'intermediary' pathway through which the pandemic affected various dimensions of food security in developing countries. Although the research response has been rapid in terms of both quantity and temporal succession, we find a highly suggestive disjunction in studies analyzing the interconnections between COVID-19 pandemic, livestock systems and food security in developing countries. With respect to the livestock supply chain, the bulk of the reviewed evidence focuses on production and consumption, whereas considerably less focus is given to the pandemic's impact on intermediaries within livestock chains, including traders, intermediaries and processors. The analysis of livestock supply chain resilience revolves predominantly around the 'absorbance' and 'recovery' phases of resilience, whereas only a small subset of the literature investigates actions taken by supply chain actors to 'plan' or to 'adapt' livestock systems in order to reduce their vulnerability and enhance their overall resilience. Furthermore, food security has often been narrowly defined, with the majority of articles focusing on 'availability' and 'accessibility' to food due to the pandemic, and other dimensions of food security, including utilization, stability and sustainability, have been widely neglected. Based on our findings, we recommend future research to examine the dynamics of propagation of COVID-19 impact through livestock supply chains in order to develop more targeted interventions that enhance the capacity of developing countries to cope with this and future disruptions and mitigate their food insecurity outcomes. To this end, more holistic, integrated and resilience-based approaches are much recommended to recognize the complex nature of livestock systems in developing countries and to address the multifaceted and widespread effects of COVID-19 on food security channeled through livestock chains.
|
|
| 68. |
- Abouhatab, Assem
(författare)
-
Demand relationships in orange exports to Russia: a differential demand system approach focusing on Egypt
- 2016
-
Ingår i: Agricultural and Food Economics. - : Springer Science and Business Media LLC. - 2193-7532. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- Recent years have witnessed closer diplomatic relations between Egypt and Russia, which have led to significant growth in the countries’ bilateral agricultural trade. As a world-leading producer and exporter of oranges, these developments represent an opportunity for Egypt to promote its orange exports to Russia. Another emerging opportunity for Egypt to increase its share in the Russian market for imported oranges has been provided by import embargos imposed by Russia in recent years on agricultural and food commodities from several countries, creating a supply gap of around 25% in the Russian orange market. To assess the competitiveness of Egyptian oranges and explore the potential export opportunities presented by the Russian market, this paper uses a Rotterdam import allocation model to analyse demand relationships among major orange suppliers to Russia during the period 1996–2014. The results show that in comparison with other orange suppliers, Egypt enjoys a strong comparative advantage in the export of oranges to Russia. The econometric results suggest that both Morocco and Egypt would benefit the most if Russia were to allocate a larger budget to the import of oranges. The expenditure elasticity estimates indicate that an increase in Russia’s demand for imported oranges would lead to increases in the quantity of Egypt’s orange exports, as well as in its share of the Russian orange market. Furthermore, cross-price elasticity estimates reveal that Egyptian oranges are substitutes for Turkish and South African oranges, implying that Russia has a tendency to switch to these two suppliers when Egyptian oranges become relatively expensive. In light of these results, the adoption of strategies to produce oranges sustainably and cost-effectively, upgrade the orange value chain, acquire processing technologies and enhance the technical and organisational capacity of farmers and exporters could be useful means for promoting exports and boosting the competitiveness of Egyptian oranges on the Russian market.
|
|
| 69. |
- Abouhatab, Assem, et al.
(författare)
-
Determinants of import demand for Egyptian potatoes in Germany and the United Kingdom
- 2016
-
Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 1132, s. 39-48
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The European Union (EU) is the major import market for Egyptian fresh potatoes. Germany and the United Kingdom (UK) jointly imported about 44% of Egyptian potato exports to the EU during the period 1994-2012. This study sought to identify the determinants of import demand for Egyptian potatoes in these two countries. A general differentiated demand system approach was used to estimate conditional potato import demand per country. For each country, it was assumed that the system of conditional import demand equations for potatoes is specified according to the sources of origin and also depends on all imported potato prices and total import potato expenditure. When estimated econometrically, this import demand model allows conditional price and expenditure elasticities to be derived. The econometric results indicated that with an estimated elasticity of 1.95, Egyptian potato exports responded significantly to total expenditure on imported potatoes by Germany. On the other hand, Egyptian potato exports to Germany did not exhibit significant price responses. In all cases but one, estimated conditional uncompensated price elasticities were not statistically different from zero. However, more interesting results were obtained concerning the price responses of Egyptian potato exports to the UK, whereby the conditional (uncompensated) direct elasticity of potato imports from Egypt to the UK (-0.71) showed an inelastic response to its own price. Furthermore, Egyptian potato exports seemed to compete on the UK market with potatoes originating from Israel and France, while they displayed complementarity with Dutch imports.
|
|
| 70. |
- Abouhatab, Assem
(författare)
-
Determinants of SARS-CoV-2 Impacts on Small-Scale Commercial Broiler Production Systems in Egypt: Implications for Mitigation Strategies
- 2021
-
Ingår i: Animals. - : MDPI AG. - 2076-2615. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- Simple SummaryThe COVID-19 pandemic has exerted a substantial impact on small-scale broiler production systems in developing countries and put their supply chains at risk of disruption. Drawing on a survey of 205 small-scale commercial broiler farms (SCBFs) in Egypt, this study identifies the primary pathways through which the pandemic has affected these farms and investigates the determinants of their perception of COVID-19 effects. The empirical results revealed that the pandemic affected SCBFs heterogeneously based on their management and production systems and resource endowment. In particular, individually owned farms and those with membership of poultry producer organizations and larger total asset values perceived significantly fewer effects. In addition, SCBFs operating in both local and provincial markets were less likely to perceive negative effects from the pandemic. Despite that the adoption of strict containment measures was essential for protecting public health, our results indicate that policy responses to COVID-19 must consider the likely effects on small businesses such as SCBFs since disruptions to such socioeconomically important supply chains will intensify human suffering from the pandemic. These findings of our study provide important implications for enhancing the preparedness and resilience of small-scale broiler production systems in developing countries to future pandemics and natural hazards.As in many other countries, the outbreak of the COVID-19 pandemic, together with subsequent government containment measures, posed significant challenges to small-scale broiler production systems in Egypt. Based on a survey of 205 specialist small-scale commercial broiler farms (SCBFs) consisting of both farm-based and household-based production systems, this study identifies the primary pathways through which COVID-19 has affected SCBFs and investigates the determinants of farm perception of these effects. A polychoric principal component analysis sorted the effects of the pandemic on the SCBFs surveyed into five categories, namely, input availability, production and operational costs, labor and human resources, consumer demand and sales, and farm finances. Next, five ordered logit models were constructed to examine the determinants of the SCBFs' perception of each category of these effects. Generally, the empirical results revealed that COVID-19 affected SCBFs heterogeneously based on their management and production systems and resource endowment. Female-led and household-based SCBFs perceived significantly greater COVID-19 effects. In contrast, individually owned farms and those with membership of poultry producer organizations and larger total asset values perceived fewer effects. In addition, SCBFs operating in both local and provincial markets were less likely to perceive negative effects from the pandemic on their broiler farming activities. Although the adoption of strict and immediate containment measures was essential for controlling the virus and protecting public health, our results indicate that policy responses to COVID-19 must consider the likely effects on small businesses such as SCBFs since disruptions to such socioeconomically important supply chains will intensify human suffering from the pandemic.Overall, our findings provide important implications for the formulation of effective strategies for mitigating the impact of COVID-19 on small-scale broiler production systems in Egypt and enhancing their preparedness and resilience to future pandemics, natural hazard risks, and market shocks.
|
|
