36 research outputs found

    Gametogenesis and spawning of Spirobranchus tetraceros (Polychaeta, Serpulidae) in Abu Kir Bay, Egypt

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    The serpulid polychaete Spirobranchus tetraceros of Red Sea / Indo-pacific origin, recently has succeeded to establish a foothold in Alexandria Mediterranean waters. Worms were monthly scraped from submerged iron substrates at Abu Kir Bay during the period December 2000 – November 2001. Both light and TEM were used to study gametogenesis and time of spawning of S. tetraceros.Gametogenesis was asynchronous and oogenesis could be divided into two previtellogenic, two vitellogenic and a spawning stage. Oocyte development took about 8 months, from October to June. Spawning occurred from late May - early June until October. Thus S. tetraceros is a long period spawner. The maximum diameter of ripe oocyte is 78 mm. The spermatogenic phase could be divided into three stages: spermatogonia, spermatocytes and spermatids (including spermatozoa). The duration of sperm development took about 8 months. Spermatocytes persist from October to March. By March the sperms grew rapidly until they became spermatozoa in May. The sperm could be considered ect-aquasperm with regard to its fertilization biology

    Promising prospective effects of Withania somnifera on broiler performance and carcass characteristics: A comprehensive review

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    Poultry production contributes markedly to bridging the global food gap. Many nations have limited the use of antibiotics as growth promoters due to increasing bacterial antibiotic tolerance/resistance, as well as the presence of antibiotic residues in edible tissues of the birds. Consequently, the world is turning to use natural alternatives to improve birds' productivity and immunity. Withania somnifera, commonly known as ashwagandha or winter cherry, is abundant in many countries of the world and is considered a potent medicinal herb because of its distinct chemical, medicinal, biological, and physiological properties. This plant exhibits antioxidant, cardioprotective, immunomodulatory, anti-aging, neuroprotective, antidiabetic, antimicrobial, antistress, antitumor, hepatoprotective, and growth-promoting activities. In poultry, dietary inclusion of W. somnifera revealed promising results in improving feed intake, body weight gain, feed efficiency, and feed conversion ratio, as well as reducing mortality, increasing livability, increasing disease resistance, reducing stress impacts, and maintaining health of the birds. This review sheds light on the distribution, chemical structure, and biological effects of W. somnifera and its impacts on poultry productivity, livability, carcass characteristics, meat quality, blood parameters, immune response, and economic efficiency

    Towards a Dynamic Optimal Alphabetic Tree

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    Binary trees have a wide variety of applications in computer science and information systems. Fast algorithms for building all kinds of binary trees in O(n log n) time do exist. However, no existing algorithm makes it possible to insert in (or delete from) the tree without losing its optimality. In this paper, we propose an algorithm to insert into or delete from a weighted binary alphabetic tree in linear time keeping the tree optimal after insertion or deletion. We show that both insertion and deletion of a node can be done in O(n) time provided its weight is not bigger than the higher weight of its two neighbouring nodes. This algorithm makes it possible to have a dynamic optimal alphabetic tree with reasonable complexity. Key words : Optimal alphabetic trees,insertion and deletion ,linear time alphabetic trees. 1 Introduction Binary trees have received a considerable attention in computer science research. It saves a lot of time to search for data stored in a binary tree structur..

    Evaluation of humic substances fertigation through surface and subsurface drip irrigation systems on potato grown under Egyptian sandy soil conditions

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    The aim of this study was to evaluate the effect of humic substances application in sandy soil under surface and subsurface drip irrigation systems on potato tubers yield quantity, quality, nutrients concentration in tubers and soil fertility after harvesting. For this purpose, field experiment was carried out at the experimental farm of the Agricultural Research Station, National Research Center, El-Nubaria district, Egypt during the winter season of 2007/2008. The used experimental design was split plot design with three replicates, main treatments were presented irrigation systems, i.e. surface and subsurface drip irrigation, while subtreatments were presented rates of humic substances additives which were 0, 60 and 120kgha-1. Results showed that increasing humic substances application rates up to 120kgha-1 enhanced tubers yield quantity, starch content and total soluble solids. The increase of humic substances application rates was associated with the decrease of nutrients leaching, which was reflected on increasing macro- and micronutrients concentration in potato tubers, as well as increasing concentration of these nutrients in soil after tubers harvesting. Subsurface drip irrigation system was found to be more efficient than surface drip irrigation system on improving tubers yield quantity, quality parameters and nutrients concentration content, in addition to soil fertility after harvesting.Humic substance Fertigation Surface drip irrigation Subsurface drip irrigation Potato Sandy soil

    Banach bundles and linear operators

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    The Baby-friendly Hospital Initiative and Qatar, 2016

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    Breastfeeding instills countless benefits that extend beyond the infant and child to the entire nation. One of the global targets set by the WHO to improve maternal, infant, and young child nutrition is to increase the rate of exclusive breast-feeding “in the first 6 months” up to at least 50% by 2025.3 Thus, as a global endeavor to promote and sustain breastfeeding, the WHO and UNICEF launched the Baby-friendly Hospital Initiative (BFHI) 1 year after the Innocenti Declaration of 1990. Regarding the State of Qatar, there was a 34% rate of early initiation of breastfeeding “within the first hour of birth” and a 29% rate of exclusive breastfeeding between 2010 and 2015. In Qatar during 2016, many obstacles in achieving the aforementioned global target remained. In addition, there are still no hospitals with a BFHI accreditation. Keywords: Baby-friendly Hospital Initiative, Breastfeeding, Maternal health, Qata
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