Ahmad K Hegazy | Cairo University (original) (raw)
Papers by Ahmad K Hegazy
Plants, Mar 10, 2023
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International Journal of Environmental Science and Technology, Mar 1, 2009
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Applied Water Science, Dec 11, 2013
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Egyptian Journal of Biology, Jul 9, 2012
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Community Ecology, Dec 1, 2007
ABSTRACT The distribution of plant communities and the pattern of species diversity were studied ... more ABSTRACT The distribution of plant communities and the pattern of species diversity were studied along an altitudinal gradient in the northwestern Red Sea region. A total of 58 stands were studied, using ten quadrats (10 m x 10 m) per stand. The classification of vegetation using the Two Way Indicator Species Analysis (TWINSPAN) identified five groups representing different altitudinal ranges. Detrended Correspondence Analysis (DCA) clearly distinguished these groups by the first two DCA axes. Edaphic factors such as soil texture, CaCO(3), organic carbon, and electrical conductivity contribute to the distribution of plant communities. Species richness, Shannon-index of diversity and evenness show a hump-shaped curve along the altitudinal gradient, whereas beta diversity decreases with elevation. Variation in the diversity and the distributional behaviour of plant species and plant communities in the study area may be attributed to the change of water resources, climatic factors, edaphic variables and anthropogenic pressures along the elevation gradient. The implications of the results are discussed and recommendations are suggested for conservation and sustainable utilization of vegetation.
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Folia geobotanica et phytotaxonomica, Sep 1, 1991
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Candollea, 1996
Kew Gardens 250th - Plants, people, possibilities Skip to content: ...
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Biologia Plantarum, 2015
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World Journal of Agricultural Sciences, 2007
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Evidence-based Complementary and Alternative Medicine, May 21, 2019
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Chemistry and Ecology, Apr 1, 2013
ABSTRACT The key point of food plant agriculture is how to regulate the harmonious relationship b... more ABSTRACT The key point of food plant agriculture is how to regulate the harmonious relationship between the soil and the plant environment. This study deals with radionuclide uptake by two food plant and two fruit tree species in relation to the geochemical characteristics of the soil. Uranium and thorium content was determined in coastal black sand and inland cultivated soils. Four commonly cultivated species Eruca sativa, Lycopersicon esculentum, Psidium guajava and Mangifera indica were investigated. Physical and chemical properties of the soil were analysed in relation to uranium and thorium uptake by plants. The results revealed the ability of plants to accumulate uranium and thorium in their edible portions. The absorbed radionuclides were positively correlated with their concentrations in the soil and the geochemical characteristics of the soil. The transfer of radioactive elements from soil to plant is a complex process that can be regulated by controlling the geochemical characteristics of the soil, including pH, clay, silt and organic matter content that reduce the bioavailability of soil radionuclides to plants, and in turn reduce the risks of biota and human exposure to radionuclide contamination.
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Security Studies
نتيجةً لظروف البيئة الطبيعيَّة الجافَّة والأنشطة التنمويَّة في الإقليم العربي وانعكاسها السلبي عل... more نتيجةً لظروف البيئة الطبيعيَّة الجافَّة والأنشطة التنمويَّة في الإقليم العربي وانعكاسها السلبي على البيئة والحياة، فإن المنطقة تعاني تدهور البيئة ومواردها الطبيعيَّة، ويتطلب الوضع القائم تقييم السِّياسات البيئيَّة ودورها في تحقيق الأمن البيئي ضمانًا للاستقرار والسلام بين دول المنطقة والعالم. وبعد أن تجاوز العالم التفكير التقليدي حول المفاهيم الأمنيَّة التقليديَّة ودمجها في البعد البيئي، لم يعُد الحفاظ على الأمن الوطني والإقليمي يتمحور حول القوة العسكريَّة أو الأمن التقليدي بقدر ما يتعلَّق بالحفاظ على البيئة والموارد الطبيعيَّة واستخدامها وتنميتها المستدامة. والشاهد على ذلك ما حدث في بعض الدول العربيَّة بعد مرحلة ما أطلق عليه «الربيع العربي» وفيما بعد وباء «كورونا» (كوفيد 19) المستجد. لم تعُد القضايا البيئيَّة قضايا تقنية بحتة يجري التعامُل معها أكاديميًّا فقط، بل أصبحت جزءًا من المفهوم العام للأمن الوطني والإقليمي، كونها تشكِّل تهديدات للأمن الوطني ومبررًا لتدخُّل الدول الكبرى في الشؤون الداخليَّة للدول العربيَّة. تتناول هذه الدراسة السِّياسات البيئيَّة العربيَّة ودورها في تحقيق الأ...
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Animals, 2022
The petroleum industry can impact the environment and human health. Heavy metals (HMs), including... more The petroleum industry can impact the environment and human health. Heavy metals (HMs), including lead (Pb), cadmium (Cd), nickel (Ni), and vanadium (V), are toxic pollutants found in petroleum that can cause several severe diseases. This study investigated the impact of the oil industry on the Arabian camel (Camelus dromedarius) in the eastern region of Saudi Arabia, pointing to HMs accumulation, tissue injury, redox imbalance, inflammation, and apoptosis. Soil and camel samples (milk, blood, muscle, liver, and kidney) were collected from a site near an oil industry field and another two sites to analyze HMs. Pb, Cd, Ni, and V were increased in the soil and in the camel’s milk, blood, muscle, liver, and kidney at the polluted site. Serum aminotransferases, urea, and creatinine were elevated, and histopathological alterations were observed in the liver and kidney of camels at the oil industry site. Hepatic and renal lipid peroxidation, pro-inflammatory cytokines, Bax, and caspase-3 ...
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Handbook of Climate Change Management, 2021
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Saudi Journal of Biological Sciences, 2018
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Environmental pollution (Barking, Essex : 1987), Jan 22, 2018
The phenylurea herbicide, linuron (LIN), is used to control various types of weeds. Despite its e... more The phenylurea herbicide, linuron (LIN), is used to control various types of weeds. Despite its efficient role in controlling weeds, it presents a persistent problem to the environment. In the current study, phytoremediation properties of transgenic CYP1A2 Arabidopsis thaliana plants to LIN were assessed. CYP1A2 gene was firstly cloned and expressed in bacteria before proceeding to plants. In presence of LIN, The growth of CYP1A2 expressing bacteria was superior compared to control bacteria transformed with the empty bacterial expression vector pET22b(+). No clear morphological changes were detected on CYP1A2 transgenic plants. However, significant resistance to LIN herbicide application either via spraying the foliar parts of the plant or via supplementation of the herbicide in the growth medium was observed for CYP1A2 transformants. Plant growth assays under LIN stress provide strong evidence for the enhanced capacity of transgenic lines to grow and to tolerate high concentrations...
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Plants, Mar 10, 2023
Bookmarks Related papers MentionsView impact
International Journal of Environmental Science and Technology, Mar 1, 2009
Bookmarks Related papers MentionsView impact
Applied Water Science, Dec 11, 2013
Bookmarks Related papers MentionsView impact
Egyptian Journal of Biology, Jul 9, 2012
Bookmarks Related papers MentionsView impact
Community Ecology, Dec 1, 2007
ABSTRACT The distribution of plant communities and the pattern of species diversity were studied ... more ABSTRACT The distribution of plant communities and the pattern of species diversity were studied along an altitudinal gradient in the northwestern Red Sea region. A total of 58 stands were studied, using ten quadrats (10 m x 10 m) per stand. The classification of vegetation using the Two Way Indicator Species Analysis (TWINSPAN) identified five groups representing different altitudinal ranges. Detrended Correspondence Analysis (DCA) clearly distinguished these groups by the first two DCA axes. Edaphic factors such as soil texture, CaCO(3), organic carbon, and electrical conductivity contribute to the distribution of plant communities. Species richness, Shannon-index of diversity and evenness show a hump-shaped curve along the altitudinal gradient, whereas beta diversity decreases with elevation. Variation in the diversity and the distributional behaviour of plant species and plant communities in the study area may be attributed to the change of water resources, climatic factors, edaphic variables and anthropogenic pressures along the elevation gradient. The implications of the results are discussed and recommendations are suggested for conservation and sustainable utilization of vegetation.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Folia geobotanica et phytotaxonomica, Sep 1, 1991
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Candollea, 1996
Kew Gardens 250th - Plants, people, possibilities Skip to content: ...
Bookmarks Related papers MentionsView impact
Biologia Plantarum, 2015
Bookmarks Related papers MentionsView impact
World Journal of Agricultural Sciences, 2007
Bookmarks Related papers MentionsView impact
Evidence-based Complementary and Alternative Medicine, May 21, 2019
Bookmarks Related papers MentionsView impact
Chemistry and Ecology, Apr 1, 2013
ABSTRACT The key point of food plant agriculture is how to regulate the harmonious relationship b... more ABSTRACT The key point of food plant agriculture is how to regulate the harmonious relationship between the soil and the plant environment. This study deals with radionuclide uptake by two food plant and two fruit tree species in relation to the geochemical characteristics of the soil. Uranium and thorium content was determined in coastal black sand and inland cultivated soils. Four commonly cultivated species Eruca sativa, Lycopersicon esculentum, Psidium guajava and Mangifera indica were investigated. Physical and chemical properties of the soil were analysed in relation to uranium and thorium uptake by plants. The results revealed the ability of plants to accumulate uranium and thorium in their edible portions. The absorbed radionuclides were positively correlated with their concentrations in the soil and the geochemical characteristics of the soil. The transfer of radioactive elements from soil to plant is a complex process that can be regulated by controlling the geochemical characteristics of the soil, including pH, clay, silt and organic matter content that reduce the bioavailability of soil radionuclides to plants, and in turn reduce the risks of biota and human exposure to radionuclide contamination.
Bookmarks Related papers MentionsView impact
Security Studies
نتيجةً لظروف البيئة الطبيعيَّة الجافَّة والأنشطة التنمويَّة في الإقليم العربي وانعكاسها السلبي عل... more نتيجةً لظروف البيئة الطبيعيَّة الجافَّة والأنشطة التنمويَّة في الإقليم العربي وانعكاسها السلبي على البيئة والحياة، فإن المنطقة تعاني تدهور البيئة ومواردها الطبيعيَّة، ويتطلب الوضع القائم تقييم السِّياسات البيئيَّة ودورها في تحقيق الأمن البيئي ضمانًا للاستقرار والسلام بين دول المنطقة والعالم. وبعد أن تجاوز العالم التفكير التقليدي حول المفاهيم الأمنيَّة التقليديَّة ودمجها في البعد البيئي، لم يعُد الحفاظ على الأمن الوطني والإقليمي يتمحور حول القوة العسكريَّة أو الأمن التقليدي بقدر ما يتعلَّق بالحفاظ على البيئة والموارد الطبيعيَّة واستخدامها وتنميتها المستدامة. والشاهد على ذلك ما حدث في بعض الدول العربيَّة بعد مرحلة ما أطلق عليه «الربيع العربي» وفيما بعد وباء «كورونا» (كوفيد 19) المستجد. لم تعُد القضايا البيئيَّة قضايا تقنية بحتة يجري التعامُل معها أكاديميًّا فقط، بل أصبحت جزءًا من المفهوم العام للأمن الوطني والإقليمي، كونها تشكِّل تهديدات للأمن الوطني ومبررًا لتدخُّل الدول الكبرى في الشؤون الداخليَّة للدول العربيَّة. تتناول هذه الدراسة السِّياسات البيئيَّة العربيَّة ودورها في تحقيق الأ...
Bookmarks Related papers MentionsView impact
Animals, 2022
The petroleum industry can impact the environment and human health. Heavy metals (HMs), including... more The petroleum industry can impact the environment and human health. Heavy metals (HMs), including lead (Pb), cadmium (Cd), nickel (Ni), and vanadium (V), are toxic pollutants found in petroleum that can cause several severe diseases. This study investigated the impact of the oil industry on the Arabian camel (Camelus dromedarius) in the eastern region of Saudi Arabia, pointing to HMs accumulation, tissue injury, redox imbalance, inflammation, and apoptosis. Soil and camel samples (milk, blood, muscle, liver, and kidney) were collected from a site near an oil industry field and another two sites to analyze HMs. Pb, Cd, Ni, and V were increased in the soil and in the camel’s milk, blood, muscle, liver, and kidney at the polluted site. Serum aminotransferases, urea, and creatinine were elevated, and histopathological alterations were observed in the liver and kidney of camels at the oil industry site. Hepatic and renal lipid peroxidation, pro-inflammatory cytokines, Bax, and caspase-3 ...
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
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Handbook of Climate Change Management, 2021
Bookmarks Related papers MentionsView impact
Saudi Journal of Biological Sciences, 2018
Bookmarks Related papers MentionsView impact
Environmental pollution (Barking, Essex : 1987), Jan 22, 2018
The phenylurea herbicide, linuron (LIN), is used to control various types of weeds. Despite its e... more The phenylurea herbicide, linuron (LIN), is used to control various types of weeds. Despite its efficient role in controlling weeds, it presents a persistent problem to the environment. In the current study, phytoremediation properties of transgenic CYP1A2 Arabidopsis thaliana plants to LIN were assessed. CYP1A2 gene was firstly cloned and expressed in bacteria before proceeding to plants. In presence of LIN, The growth of CYP1A2 expressing bacteria was superior compared to control bacteria transformed with the empty bacterial expression vector pET22b(+). No clear morphological changes were detected on CYP1A2 transgenic plants. However, significant resistance to LIN herbicide application either via spraying the foliar parts of the plant or via supplementation of the herbicide in the growth medium was observed for CYP1A2 transformants. Plant growth assays under LIN stress provide strong evidence for the enhanced capacity of transgenic lines to grow and to tolerate high concentrations...
Bookmarks Related papers MentionsView impact