Morphological study of the hard palate in the Egyptian goats (Capra hircus): A scanning electron microscopic study          下载免费PDF全文

Mohamed A. A. Mahdy  Kamal E. H. Abdalla  Salma A. Mohamed 《Anatomia, histologia, embryologia》2018,47(5):391-397

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Nitrous oxide fluxes and denitrification sensitivity to temperature in Irish pasture soils     

M. Abdalla  M. Jones  P. Smith  M. Williams 《Soil Use and Management》2009,25(4):376-388

Nitrous oxide (N₂O) emissions from grazed pastures constitute approximately 28% of total global anthropogenic N₂O emissions. The aims of this study were to investigate the effect of inorganic N fertilizer application on fluxes of N₂O, quantify the emission factors (EFs) for a sandy loam soil which is typical of large areas in Ireland and to investigate denitrification sensitivity to temperature. Nitrous oxide flux measurements from a cut and grazed pasture field for 1 year and denitrification laboratory incubation were carried out. The soil pH was 7.3 and had a mean organic C and N content at 0–20 cm of 44.1 and 4.4 g/kg dry weight, respectively. The highest observed peaks of N₂O fluxes of 67 and 38.7 g N₂O‐N per hectare per day were associated with times of application of inorganic N fertilizer. Annual fluxes of N₂O from control and fertilized treatments were 1 and 2.4 kg N₂O‐N per hectare, respectively. Approximately 63% of the annual flux was associated with N fertilizer application. Multiple regression analysis revealed that soil nitrate and the interaction between soil nitrate and soil water content were the main factors controlling N₂O flux from the soil. The derived EF of 0.83% was approximately 66% of the IPCC default EF value of 1.25% as used by the Irish EPA to estimate greenhouse gases (GHGs) in Ireland. The IPCC‐revised EF value is 0.9%. A highly significant exponential regression (r² = 0.98) was found between denitrification and incubation temperature. The calculated Q₁₀ ranged from 4.4 to 6.2 for a temperature range of 10–25 °C and the activation energy was 47 kJ/mol. Our results show that denitrification is very sensitive to increasing temperature, suggesting that future global warming could lead to a significant increase in soil denitrification and consequently N₂O fluxes from soils.  相似文献   

Veneer strand flanged I-beam with MDF or particleboard as web material II: effect of resin type,application rate,strand dimension,and pressing time on the basic properties     

Ashraf M.A.?Abdalla  Noboru?SekinoEmail author 《Journal of Wood Science》2004,50(5):400-406

Optimization of the manufacturing conditions of the veneer strand flanged I-beam invented in the previous study was investigated using different combinations of strand dimensions, resin types between web and flange, different pressing times, and different wood–resin moisture contents under conventional hot pressing conditions. The main results revealed that the strand dimensions have no effect on the bending properties of the flange part and the dimensional stability of the I-beam. Increasing the resin application rate between strands was found to improve the dimensional stability of the I-beams. The use of isocyanate (MDI) resin between web and flange significantly improved the bond strength between web and flange, the modulus of rupture of the I-beam, and the modulus of rupture of the flange part. Dimensional stability was also improved. Shortening the pressing time from 20 to 12min was found to be feasible. Using low wood-resin moisture content was found to interfere with the curing of the phenol–formaldehyde (PF) resin at the flange part resulting in poor quality beams. Of the three moisture content levels tested, 12% was found to be the optimal level for producing I-beams with balanced mechanical properties and dimensional stability.Part of this work was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, March 2003  相似文献   

Distribution of lipid droplets is an indicator for egg quality in brown trout, Salmo trutta fario     

Nabil Mansour  Robert A. Patzner 《Aquaculture (Amsterdam, Netherlands)》2007,273(4):744-747

In the eggs of the brown trout, Salmo trutta fario, lipid droplets are clearly visible beneath the oolemma on the surface of the protein yolk. When examining the distribution of lipid vesicles in egg batches of different quality, four categories of lipid vesicle distribution could be distinguished: In the first category, the lipid droplets were evenly distributed throughout the egg. These egg batches had a high quality (percentage of eggs developing to eyed stage embryos: 96.2 ± 5.2). Some lipid droplets had the tendency to coalesce in one pole of the egg in the second category. This coalescing of lipid droplets was accompanied with a reduction in egg quality to about 50% of the first category (% of eyed stage embryos: 40.6 ± 15.2). In the last two categories, the lipid droplets were mostly coalesced in one or two poles of the egg and the egg quality was very low (% of eyed stage embryos: 3.3 ± 2.9 and zero, respectively). In conclusion, examination of lipid droplets distribution, in brown trout, can distinguish between high and low quality eggs in an easy and reliable way.  相似文献   

Selection in Faba Bean for Tolerance to Broomrape, Orobanche crenata Forsk.     

M. S. Radwan    M. M. F. Abdalla    G. Fischbeck    A. A. Metwally  D. S. Darwish 《Plant Breeding》1988,100(4):289-298

Six populations of faba bean (Vicia faba L.) were developed through various selection schemes to examine the influence of selection In improving tolerance to Orobanche crenata (Forsk.) in local faba bean stocks. All populations trace their origin to 209 farmers’ seed lots that were collected from Egypt. The entries of each population were grown during the 1982/1983 season in the Orobanche nursery located at Giza in Egypt. Comparison among means of the selected, populations showed that more progress in improving Orobanche tolerance could be achieved from combined selection between and within lots. Between-lots selection was less efficient than single-plant selection. Results, of this study show that considerable progress could be achieved from selection for Orobanche tolerance in local faba bean germplasm. There was sufficient residual genetic variation in the selected populations to expect substantial progress from further selection for most tolerance traits.  相似文献   

Simulated mobilization of metals from sediments in response to lake acidification     

Nabil Arafat  Jerome . Nriagu 《Water, air, and soil pollution》1986,31(3-4):991-998

The regeneratable forms of pollutant metals in lake sediments were estimated using different chemical extractants and the effects of lake acidification on the mobilization of such metal fractions studied in laboratory microcosm. The release of each metal was found to increase exponentially below a threshold pH value, which was about 4.0 for Cu, Ni, Zn, Cd and Fe. The data suggest that a large percentage of pollutant metals are mobile as determined by chemical extraction techniques and long-term release experiments.  相似文献   

Sources of resistance in bread wheat to Russian wheat aphid (Diuraphis noxia) in Syria identified using the Focused Identification of Germplasm Strategy (FIGS)     

M. El Bouhssini  K. Street  A. Amri  M. Mackay  F. C. Ogbonnaya  A. Omran  O. Abdalla  M. Baum  A. Dabbous  F. Rihawi 《Plant Breeding》2011,130(1):96-97

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Influence of various phosphopeptides of caseins on iron absorption   总被引：2，自引：0，他引：2  

Bouhallab S  Cinga V  Aít-Oukhatar N  Bureau F  Neuville D  Arhan P  Maubois JL  Bouglé D 《Journal of agricultural and food chemistry》2002,50(24):7127-7130

The influence of the origin and kind of caseinophosphopeptide (CPP) on iron absorption was assessed by comparing a commercially available CPP mixture (CPPs) and derived chromatographic fractions with the purified, chemically phosphopeptide of beta-casein [beta-CN(1-25)] using a perfused rat duodenal loop system; gluconate iron was used as control. Only iron complexed to beta-CN(1-25) displayed a better bioavailability than gluconate iron. The results obtained with various chromatographic fractions indicated that phosphopeptides of different origins (alpha(s)- versus beta-caseins) display specific effects. These findings contribute to the explanation of the discrepancy about the role of caseinophosphopeptides on mineral bioavailability in vivo.  相似文献   

The Poll Glands of the Dromedary (Camelus dromedarius): Ultrastructural Characteristics     

A. A. M. Taha    E. M. Abdel-Magied  M. A. Abdalla  A. B. Abdalla  + 《Anatomia, histologia, embryologia》1994,23(3):269-274

The poll glands of the camel are tubuloalveolar glands. They consist of lobules separated by interlobular connective tissue. Adrenergic axons and blood vessels including fenestrated capillaries are present in the intralobular connective tissue in close proximity to the secretory cells. The prominent features of the secretory cell cytoplasm are many mitochondria, smooth endoplasmic reticulum, and many vesicles in various secretory stages.
It is concluded that the secretory cells have apocrine as well as merocrine modes of secretion. The glands may have the ability to uptake hormones and concentrate them. Additional work is needed before considering these glands as steroid-secreting glands.  相似文献   

Present status and vision for veterinary higher education in the Arab world     

Hailat N 《Journal of veterinary medical education》2005,32(2):151-155

The veterinary profession and veterinary education stand, in the Arab world and worldwide, in the middle of many changes resulting from rapid communication, explosion of large amounts of information, international traffic of people, animals, and animal products, flow of capital, recent political changes, and new threats to global public health. These changes have put more pressure on veterinary leaders and educators to reconsider the different programs, projects, attitudes, and methodologies of thinking in faculties and institutes of veterinary medicine.  相似文献