421 research outputs found

    Caracterización de endemismos mediterráneos en la flora egipcia

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    The Mediterranean Basin is the world’s second richest hotspot, and one of the most important locations on the planet for endemic taxa. However, there is no available up-to-date list of Mediterranean endemics. Available data are frequently insufficient or outdated. Therefore, this study aimed at delimiting the Mediterranean floristic region in Egypt, screening its Mediterranean endemics, and determining their habitats, life forms, flowering periods, dispersal types and phyto-geographical distribution. From a list of 275 Mediterranean endemic taxa in Egypt compiled from literature, this study reduced it to 57 taxa (including species, subspecies and varieties; 20.7%) belonging to 46 genera and 22 families. Fifteen major habitats harbored Mediterranean endemics in Egypt, with coastal dunes (17 taxa = 29.8%) and non-saline depressions (16 taxa = 28.1%) being the most represented. Moreover, the Mareotis (west) subsector was the richest (46 taxa = 80.7%). The largest number of taxa was recorded in North African sub-region (52 taxa = 91.2%), followed by Eastern (levant) sub-region (36 taxa = 63.2%). Therophytes were the most recorded life form, while ballochory was the most represented dispersal type. In conclusion, it is crucial to shed the light on Mediterranean endemics and provide an up-to-date documented database to help future management plan that support their conservation and sustainable use.La cuenca Mediterránea es el segundo hotspot más rico del mundo y uno de los lugares más importantes del planeta en taxones endémicos. Sin embargo, no existe una lista actualizada de taxones endémicos mediterráneos. Los datos disponibles son frecuentemente insuficientes o están desactualizados. Por tanto, nuestro objetivo fue delimitar la región florística mediterránea en Egipto, seleccionar sus plantas endémicas mediterráneas y determinar sus hábitats, formas de vida, periodos de floración, tipos de dispersión y distribución fitogeográfica. Partiendo de una lista preliminar de 275 taxones endémicos del Mediterráneo presentes en Egipto recopilada de la bibliografía, este estudio redujo ese número a 57 taxones (incluyendo especies, subespecies y variedades; 20.7%) pertenecientes a 46 géneros y 22 familias. Las plantas endémicas mediterráneas de Egipto viven en quince hábitats principales, siendo los más representativos las dunas costeras (17 taxones = 29.8%) y las depresiones no salinas (16 taxones = 28.1%). El subsector Mareotis (al oeste) fue el más rico (46 taxones = 80.7%), mientras que el mayor número de taxones se registró en la subregión del norte de África (52 taxones = 91.2%), seguida de la subregión del este (levante) (36 taxones = 63.2%). Los terófitos fueron la forma vital más registrada y la balocoria el tipo de dispersión más común. En conclusión, es crucial arrojar luz sobre las plantas endémicas del Mediterráneo y proporcionar una base de datos documentada y actualizada que ayude a planificar una gestión futura que promueva su conservación y uso sostenible

    Characterization of Mediterranean endemics in the Egyptian flora

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    The Mediterranean Basin is the world’s second richest hotspot, and one of the most important locations on the planet for endemic taxa. However, there is no available up-to-date list of Mediterranean endemics. Available data are frequently insufficient or outdated. Therefore, this study aimed at delimiting the Mediterranean floristic region in Egypt, screening its Mediterranean endemics, and determining their habitats, life forms, flowering periods, dispersal types and phyto-geographical distribution. From a list of 275 Mediterranean endemic taxa in Egypt compiled from literature, this study reduced it to 57 taxa (including species, subspecies and varieties; 20.7%) belonging to 46 genera and 22 families. Fifteen major habitats harbored Mediterranean endemics in Egypt, with coastal dunes (17 taxa = 29.8%) and non-saline depressions (16 taxa = 28.1%) being the most represented. Moreover, the Mareotis (west) subsector was the richest (46 taxa = 80.7%). The largest number of taxa was recorded in North African sub-region (52 taxa = 91.2%), followed by Eastern (levant) sub-region (36 taxa = 63.2%). Therophytes were the most recorded life form, while ballochory was the most represented dispersal type. In conclusion, it is crucial to shed the light on Mediterranean endemics and provide an up-to-date documented database to help future management plan that support their conservation and sustainable use

    Homogeneous Bubble Nucleation driven by local hot spots: a Molecular Dynamics Study

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    We report a Molecular Dynamics study of homogenous bubble nucleation in a Lennard-Jones fluid. The rate of bubble nucleation is estimated using forward-flux sampling (FFS). We find that cavitation starts with compact bubbles rather than with ramified structures as had been suggested by Shen and Debenedetti (J. Chem. Phys. 111:3581, 1999). Our estimate of the bubble-nucleation rate is higher than predicted on the basis of Classical Nucleation Theory (CNT). Our simulations show that local temperature fluctuations correlate strongly with subsequent bubble formation - this mechanism is not taken into account in CNT

    Biocontrol of Damping-Off Disease Caused by Rhizoctonia Solani in Some Medicinal Plants Using Local Strain of Streptomyces Pactum

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    Abstract: A number of 187 Streptomyces isolates were isolated from different Egyptian soil samples and screened for their antifungal activities (mm inhibition zone) by agar diffusion method, only 5 isolates representing 2.67% produced antifungal metabolites. Starch nitrate agar was the most suitable medium for growth and production of antifungal metabolites by different Streptomyces isolates. In addition, Streptomyces isolate S131 was the most efficient isolate in antifungal activities (mm) which was identified as a strain of Streptomyces pactum. S131 .Furthermore, the most sensitive test organism for antifungal metabolites produced by S. pactum strain S131was Aspergillus niger followed by Fusarium oxysporum, Candida albicans, Aspergillus flavus, Fusarium moniliforme, Rhizoctonia solani and Pythium sp which resulted 20, 17, 16, 15,15, 14 and 13 mm of inhibition zone around agar (6 mm) culture disks of Streptomyces pactum-S131, respectively. Application of cultural filtrate in biocontrol against damping-off caused by Rhizoctonia solani in fennel and coriander seedlings were studied, the results revealed that there were significantly differences among all soil treatments in the percentage of total survival fennel plants from damping-off disease. The maximum percentage of total survival fennel plants from damping-off disease was recorded at uninfested soil treatment followed by soil infested with R. solani + rhizolex, soil infested with R. solani + culture filtrate and soil infested with R. solani, which resulted 82.35, 69.41, 55.50 and 22.28%, respectively. In addition, there were no significantly differences between uninfested soil and soil infested with R. solani + rhizolex in the percentage of total survival coriander plants from damping-off disease, which gave 91.67 and 90.67%, respectively. But there were significantly differences between soil infested with R. solani + culture filtrate of Streptomyces pactum strain S131 and soil infested with R. solani only in the percentage of total survival coriander plants from damping-off disease, which gave 58.34 and 11.09%, respectively

    The prognostic value of p53 mutation in pediatric marrow hypoplasia

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    <p>Abstract</p> <p>Background</p> <p>The tumor suppressor gene p53 is involved in the control of cell proliferation, particularly in stressed cells. p 53 gene mutations are the most frequent genetic event found in human cancers. Fanconi Anemia (FA) is the most common representative of inherited bone marrow failure syndromes (IBMFS) with a leukemic propensity. P 53 DNA alteration has not been studied before in Egyptian children with FA.</p> <p>Patients and methods</p> <p>we investigated p53 mutation in the bone marrow and peripheral blood of forty children, FA (n = 10), acquired aplastic anemia (AAA) (n = 10), and immune thrombocytopenia (ITP) as a control (n = 20), using real-time PCR by TaqMan probe assay</p> <p>Results</p> <p>Mutation of p53 gene was demonstrated in the BM of 90% (9/10) of children with FA, compared to 10% (1/10) in AAA (p < 0.001), while, no p53 DNA mutation was seen in the control group. A positive correlation between DNA breakage and presence of p53 mutation was seen in FA (p < 0.02, r0.81).</p> <p>Conclusion</p> <p>mutation of p53 gene in hypoplastic marrow especially FA may represent an early indicator of significant DNA genetic alteration with cancer propensity.</p

    Validated stability indicating liquid chromatographic determination of ebastine in pharmaceuticals after pre column derivatization: Application to tablets and content uniformity testing

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    An accurate, simple, sensitive and selective reversed phase liquid chromatographic method has been developed for the determination of ebastine in its pharmaceutical preparations. The proposed method depends on the complexation ability of the studied drug with Zn2+ ions. Reversed phase chromatography was conducted using an ODS C18 (150 × 4.6 mm id) stainless steel column at ambient temperature with UV-detection at 260 nm. A mobile phase containing 0.025%w/v Zn2+ in a mixture of (acetonitril/methanol; 1/4) and Britton Robinson buffer (65:35, v/v) adjusted to pH 4.2, has been used for the determination of ebastine at a flow rate of 1 ml/min. The calibration curve was rectilinear over the concentration range of 0.3 - 6.0 μg/ml with a detection limit (LOD) of 0.13 μg/ml, and quantification limit (LOQ) of 0.26 μg/ml. The proposed method was successfully applied for the analysis of ebastine in its dosage forms, the obtained results were favorably compared with those obtained by a comparison method. Furthermore, content uniformity testing of the studied pharmaceutical formulations was also conducted. The composition of the complex as well as its stability constant was also investigated. Moreover, the proposed method was found to be a stability indicating one and was utilized to investigate the kinetics of alkaline and ultraviolet induced degradation of the drug. The first-order rate constant and half life of the degradation products were calculated

    Bio-informatics assessment schema (BIAS) to improve myocardial perfusion image diagnostic and prognostic value: the NHLBI-sponsored women's ischemia syndrome evaluation (WISE) study

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    Introduction: When assessing myocardial perfusion image (MPI) data for diagnosis or prediction of prognosis it is common to evaluate the technology using a Receiver-Operator Characteristic (ROC) curve. The diagonal response represents the knowledge prior to conducting the test (i.e. the diagonal represents random chance). We present an approach termed Bio-Informatics Assessment Schema (BIAS) that provides an elevated baseline from which to evaluate the MPI reading, i.e. indicating that at baseline, more data is available than random chance. Here we describe how the BIAS formulae are generated for cardiovascular magnetic resonance image (CMRI) data applied to the Women's Ischemia Syndrome Evaluation (WISE) Study

    Validated stability-indicating spectrofluorimetric methods for the determination of ebastine in pharmaceutical preparations

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    Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS) in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides) producing a product with intense fluorescence, which was measured at 496 nm after excitation at 388 nm
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