7 research outputs found

    Seedling Emergence and Growth of Mangrove Avicennia marina (Forssk.) Vierh. Under Different Environmental Conditions in the United Arab Emirates

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    Seedling emergence, survival and growth of gray mangrove Avicennia marina (Forssk.) vierh. were studied in relation to different environmental factors through a series of experiments conducted at indoor low temperature, outdoor shaded and field areas at the Marine Resources Research Center, Umm Al Qaiwain. No emergence occurred when seeds were sowed in salinities equal to or higher than 60 ppt. Seedling survival rate decreased with increasing salinity at both indoor and outdoor experimental sites . Faster seedling growth rates were observed under outdoor shaded conditions than under indoor low temperatures. Results of field studies on a sloping beach indicated that the seedling survival was limited to a landward distance of about 5 meters from seawater line, whereas on a flat beach the survival of seedlings was observed up to about 19 meters from seawater line. Mangrove seedling survival growth rates decreased with distance from the seawater line in sloping and flat beaches due to the increase in salinity and depth of ground water. Higher chlorophyll content of the mangrove leaves were encountered in outdoor location than in indoor low temperature area. In the field, the leaf chlorophyll content of mangrove seedlings decreased in the outward direction from the seawater line. Roots contained more moisture than sterns or leaves. Moisture content of roots, sterns, and leaves decreased with an increase in salinity of the seedling growing media in indoor areas and with increasing distance from seawater line in the field. In all analysed soil samples, more than 93 % sand was found in the field study area; whereas sodium, potassium and calcium carbonate were the dominant chemical constituents of the sediment

    Aerodynamic Model for Tandem Flapping Wings

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    Working as teacher assistants/aides in schools: understanding experiences in an Arabian context using the wider pedagogical role model

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    AbstractDiscussions about the contributions of teacher assistants (Tas) are mainly limited to Western contexts, such as Australia, the UK, and the United States, and studies have consistently explored the role of TAs in inclusive learning environments despite their continuous deployment in special schools. This study attempted to understand the experiences of TAs working in special and inclusive schools in the United Arab Emirates. The study was guided by the wider pedagogical role model, which explains the preparations, deployment, and practices of TAs in schools. Twelve TAs working in special and inclusive schools were engaged in one-on-one interviews and focus group discussions. While there seemed to be support for TA preparation, there were issues pertaining to their deployment and practices in schools. The findings recommend the development of national guidelines explaining the recruitment and role of TAs in schools

    Evolution of mangrove research in an extreme environment: Historical trends and future opportunities in Arabia

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