134 research outputs found

    B¨acklund transformations for Cosgrove’s equation F-XVIII

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    In this paper we study B¨acklund transformations (BTs) for Cosgrove’s equation F-XVIII.We use the generalization of Fokas and Ablowitz method to derive BTs between F-XVIII and new fourth-order ordinary differential equations (ODEs) of Painlev´e-type. Moreover we derive auto-BT and give special solutions for F-XVIII.In this paper we study B¨acklund transformations (BTs) for Cosgrove’s equation F-XVIII.We use the generalization of Fokas and Ablowitz method to derive BTs between F-XVIII and new fourth-order ordinary differential equations (ODEs) of Painlev´e-type. Moreover we derive auto-BT and give special solutions for F-XVII

    Improving irrigation efficiency will be insufficient to meet future water demand in the Nile Basin

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    The Nile River Basin covers an area of approximately 3.2 million km2 and is shared by 11 countries. Rapid population growth is expected in the region. The irrigation requirements of Nile riparian countries of existing (6.4 million ha) and additional planned (3.8 million ha, 2050) irrigation schemes were calculated, and the likely water savings through improved irrigation efficiency were evaluated. We applied SPARE:WATER to calculate irrigation demands on the basis of the well-known FAO56 Crop Irrigation Guidelines. Egypt (67 km3 yr-1) and Sudan (19 km3 yr-1) consume the highest share of the 84 km3 yr-1 total (2011). Assuming today’s poor irrigation infrastructure, the total consumption was predicted to increase to 123 km3 yr-1 (2050), an amount far exceeding the total annual yield of the Nile Basin. Therefore, a key challenge for water resources management in the Nile Basin is balancing the increasing irrigation water demand basin-wide with the available water supply. We found that water savings from improved irrigation technology will not be able to meet the additional needs of planned areas. Under a theoretical scenario of maximum possible efficiency, the deficit would still be 5 km3 yr-1. For more likely efficiency improvement scenarios, the deficit ranged between 23 and 29 km3 yr-1. Our results suggest that that improving irrigation efficiency may substantially contribute to decreasing water stress on the Nile system but would not completely meet the demand. Study Region: The Nile River Basin covers an area of approximately 3.2 million km2 and is shared by 11 countries. Rapid population growth is expected in the region. Study Focus: Record population growth is expected for the study region. Therefore, the irrigation requirements of Nile riparian countries of existing (6.4 million ha) and additional planned (3.8 million ha, 2050) irrigation schemes were calculated, and likely water savings through improved irrigation efficiency were evaluated. We applied a spatial decision support system (SPARE:WATER) to calculate the irrigation demands on the basis of the well-known FAO56 Crop Irrigation Guidelines. New Hydrological Insights for the Region: Egypt (67 km3yr-1) and Sudan (19 km3yr-1) consume the highest share of 84 km3yr-1 (2011). Assuming today’s poor irrigation infrastructure, the total demand were predicted to increase to 123 km3yr-1 (2050), an amount far exceeding the total annual yield of the Nile Basin. Therefore, a key challenge for water resources management in the Nile Basin is balancing the increasing irrigation water demand and available water supply. We found that water savings from improved irrigation technology will not be able to meet the additional needs of planned areas. Under a theoretical scenario of maximum possible efficiency, the deficit would still be 5 km3yr-1. For more likely efficiency improvement scenarios, the deficit ranges between 23 and 29 km3yr-1. Our results suggest that improving irrigation efficiency may substantially contribute to decreasing water stress on the Nile system but would not completely meet the demand

    Chemical Profiling of Significant Antioxidant and Phytotoxic Microwave-Extracted Essential Oil from Araucaria heterophylla Resin

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    Due to the various hazards of using synthetic chemical compounds in pharmaceutics, agriculture, and industry, scientists and researchers do their best to explore and assess new green natural compounds from natural resources with potent activity. The essential oil (EO) from the resin collected from Araucaria heterophylla Salisb. was extracted by the microwave technique and chemically characterized via GC-MS analysis. Furthermore, the extract EO was assessed for its antioxidant and phytotoxic activities. The EO has 33 compounds, mainly terpenes (98.23%), and the major compounds were α-pinene (62.57%), β-pinene (6.60%), germacrene D (5.88%), and β-caryophyllene (3.56%). The extracted EO showed substantial antioxidant activity, where it showed IC50 values of 142.42 and 118.03 mg L−1 for DPPH and ABTS, respectively. On the other hand, the EO revealed considerable phytotoxicity against the weed Chenopodium murale, where the EO showed IC50 values of 304.0, 230.1, and 147.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. Moreover, the EO showed the same pattern of allelopathic inhibition against the weed Sonchus oleraceus, where it showed IC50 values of 295.7, 224.5, and 106.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. The present study showed that the extraction technique affects the constituents of the EO, particularly the quantitative composition. The EO of A. heterophylla resin also revealed considerable antioxidant and phytotoxic activity against weeds. Therefore, it can be considered a promising natural resource that could be integrated into the weed management approach. However, further study is recommended for deep characterization of their authentic compounds and evaluation of their mode of action(s) on a wide spectrum of weeds

    In vitro anti-inflammatory and acetylcholinesterase inhibition efficiency of plant extracts from Sinai-Egypt

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    635-641Ten plant extracts were prepared and tested in in vitro assays against COX-2, COX-1 and acetylcholinesterase with evaluation of their antioxidant properties. The tested extracts exhibited varied anti COX-2 effect and they were superior to celecoxibe (inhibition percentage was 42.67% at 50 µg/mL), reference drug. Lavandula coronopifolia and Scrophularia Libanotica extracts were the efficient inhibitors (100% and 91% at 50 µg/mL respectively). Launaeaspinosa and Pulicaria undulata were the powerful AChE inhibitor (IC50 values were 16.69 and 29.06 µg/mL, respectively) followed with L. coronopifolia and S.libanotica extracts (IC50 values were 61.89 and 49.83 µg/mL, respectively) and they were efficient in scavenging superoxide radicals and metal ions, nitric oxide formation inhibition, as well as, lipid peroxide production suppression. L. coronopifolia and S. Libanotica extracts can be introduced as natural cyclooxygenase-2 inhibitors without affecting cyclooxygenase-1 whereas L. spinosa and P. undulata extracts were potent suppressor for AChE with robust antioxidant properties which suggest the possibility of using the four extracts, L. coronopifolia, S. libanotica, L. spinosa and P. undulata as natural agent in treating neurodegenerative disorder

    In vitro anti-inflammatory and acetylcholinesterase inhibition efficiency of plant extracts from Sinai-Egypt

    Get PDF
    Ten plant extracts were prepared and tested in in vitro assays against COX-2, COX-1 and acetylcholinesterase with evaluation of their antioxidant properties. The tested extracts exhibited varied anti COX-2 effect and they were superior to celecoxibe (inhibition percentage was 42.67% at 50 µg/mL), reference drug. Lavandula coronopifolia and Scrophularia Libanotica extracts were the efficient inhibitors (100% and 91% at 50 µg/mL respectively). Launaeaspinosa and Pulicaria undulata were the powerful AChE inhibitor (IC50 values were 16.69 and 29.06 µg/mL, respectively) followed with L. coronopifolia and S.libanotica extracts (IC50 values were 61.89 and 49.83 µg/mL, respectively) and they were efficient in scavenging superoxide radicals and metal ions, nitric oxide formation inhibition, as well as, lipid peroxide production suppression. L. coronopifolia and S. Libanotica extracts can be introduced as natural cyclooxygenase-2 inhibitors without affecting cyclooxygenase-1 whereas L. spinosa and P. undulata extracts were potent suppressor for AChE with robust antioxidant properties which suggest the possibility of using the four extracts, L. coronopifolia, S. libanotica, L. spinosa and P. undulata as natural agent in treating neurodegenerative disorder

    Preclinical mouse models for BRCA1-associated breast cancer

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    A substantial part of all hereditary breast cancer cases is caused by BRCA1 germline mutations. In this review, we will discuss the insights into BRCA1 functions that we obtained from mouse models with conventional and conditional mutations in Brca1. The most advanced models closely resemble human BRCA1-related breast cancer and may therefore be useful for addressing clinically relevant questions

    Large-Scale Controls of the Surface Water Balance Over Land-Insights From a Systematic Review and Meta-Analysis

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    The long-term surface water balance over land is described by the partitioning of precipitation (P) into runoff and evapotranspiration (ET), and is commonly characterized by the ratio ET/P. The ratio between potential evapotranspiration (PET) and P is explicitly considered to be the primary control of ET/P within the Budyko framework, whereas all other controls are often integrated into a single parameter, ω. Although the joint effect of these additional controlling factors of ET/P can be significant, a detailed understanding of them is yet to be achieved. This study therefore introduces a new global dataset for the long-term mean partitioning of P into ET and runoff in 2733 catchments, which is based on in-situ observations and assembled from a systematic examination of peer-reviewed studies. A total of 26 controls of ET/P that are proposed in the literature are assessed using the new dataset. Results reveal that: (i) factors controlling ET/P vary between regions with different climate types; (ii) controls other than PET/P explain at least 35% of the ET/P variance in all regions, and up to ∼90% in arid climates; (iii) among these, climate factors and catchment slope dominate over other landscape characteristics; and (iv) despite the high attention that vegetation-related indices receive as controls of ET/P, they are found to play a minor and often non-significant role. Overall, this study provides a comprehensive picture on factors controlling the partitioning of P, with valuable insights for model development, watershed management, and the assessment of water resources around the globe

    Small molecule activators of the Trk receptors for neuroprotection

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    The neurotophin signaling network is critical to the development and survival of many neuronal populations. Especially sensitive to imbalances in the neurotrophin system, cholinergic neurons in the basal forebrain are progressively lost in Alzheimer's disease. Therapeutic use of neurotrophins to prevent this loss is hampered, however, by a number of pharmacological challenges. These include a lack of transport across the blood-brain barrier, rapid degradation in the circulation, and difficulty in production. In this review we discuss the evidence supporting the neurotrophin system's role in preventing neurodegeneration and survey some of the pharmacological strategies being pursued to develop effective therapeutics targeting neurotrophin function
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