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Radiative absorption enhancements due to the mixing state of atmospheric black carbon 总被引：3，自引：0，他引：3
CD Cappa TB Onasch P Massoli DR Worsnop TS Bates ES Cross P Davidovits J Hakala KL Hayden BT Jobson KR Kolesar DA Lack BM Lerner SM Li D Mellon I Nuaaman JS Olfert T Petäjä PK Quinn C Song R Subramanian EJ Williams RA Zaveri 《Science (New York, N.Y.)》2012,337(6098):1078-1081
Atmospheric black carbon (BC) warms Earth's climate, and its reduction has been targeted for near-term climate change mitigation. Models that include forcing by BC assume internal mixing with non-BC aerosol components that enhance BC absorption, often by a factor of ~2; such model estimates have yet to be clearly validated through atmospheric observations. Here, direct in situ measurements of BC absorption enhancements (E(abs)) and mixing state are reported for two California regions. The observed E(abs) is small-6% on average at 532 nm-and increases weakly with photochemical aging. The E(abs) is less than predicted from observationally constrained theoretical calculations, suggesting that many climate models may overestimate warming by BC. These ambient observations stand in contrast to laboratory measurements that show substantial E(abs) for BC are possible. 相似文献
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Derar Refaat Ibraheem Mohammad Mootaz Ahmad Mohammad Abdel-Rahman 《Journal of Veterinary Behavior: Clinical Applications and Research》2013,8(1):46-50
The present study was primarily carried out to trace the behavioral, physiological, and adrenal changes during the first stage of labor in cases of dystocia, either in parturient buffalo heifers or cows, and their clinical significance. Of the 118 investigated buffalo herds, 40 cows (dystocia = 20 and eutocia = 20) and 40 heifers (dystocia = 20 and eutocia = 20) were used in this study. Cows approaching actual birth were transferred to a calving box with straw bedding. Behavior of the studied animals was recorded from the time that the animal was moved to the calving box until the emergence of the fetal limbs in the vulval lips. If no progress in parturition was observed within two hours after the rupture of fetal sacs (end of the first stage), these cases were considered as suffering dystocia. As the fetal limbs emerged from the birth canal, animals were examined clinically to determine their average pulse and respiratory rates as well as body temperature. Blood samples were collected to determine the cow/heifers cortisol level. Results of the present study indicated that dystocia was accompanied by disturbed physiological status and cortisol levels. Practical monitoring system of parturient animals, through observing behavioral, physiological, and adrenal aspects during calving, should be regarded to expect dystocia and provide help for the animal in the appropriate time. 相似文献
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Abdelhaleem Fahmy Salah Amin Ahmed Mostafa Basiouny Mohamed Elsayed Ibraheem Heba Fathy 《Journal of Soils and Sediments》2020,20(3):1742-1753
Journal of Soils and Sediments - Bedload transport discharge is important in river engineering and morphodynamics. The Meyer-Peter and Müller (MPM) equation for determining bedload transport... 相似文献
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Sawalha MN Kridli RT Jawasreh KI Meza-Herrera CA 《Tropical animal health and production》2011,43(7):1345-1350
This experiment was conducted to evaluate the effect of administering hormonal treatments (melatonin and progestagen/equine chronic gonadotropin (eCG)) on advancing puberty in Awassi ewe lambs. Fifty-one 6-month-old ewe lambs of similar body weights (around 28 kg) were randomly assigned into four treatment groups; control (CON; n?=?14), melatonin (MEL; n?=?13), melatonin plus progestagen–eCG (MELPP; n?=?11), and progestagen–eCG (PP; n?=?13). Ewe lambs in the PP and MELPP groups were fitted with intravaginal progestagen sponges containing 60 mg medroxyprogesterone acetate for 14 days; 400 IU eCG were administered to each of these ewe lambs on the day of sponge removal. Ewe lambs in the MEL and MELPP groups received subcutaneous melatonin implants (Regulin®, 18 mg melatonin) 36 days before sponge insertion. Hormonal treatment had no effect on ewe lamb body weight change. Estrous behavior was greater (p?p?p?p?相似文献
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Khalid A. Ibrahim Bassam I. El-Eswed Khaleel A. Abu-Sbeih Tawfeeq A. Arafat Mahmoud M. H. Al Omari Fouad H. Darras Adnan A. Badwan 《Marine drugs》2016,14(8)
An increasing interest has recently been shown to use chitin/chitosan oligomers (chito-oligomers) in medicine and food fields because they are not only water-soluble, nontoxic, and biocompatible materials, but they also exhibit numerous biological properties, including antibacterial, antifungal, and antitumor activities, as well as immuno-enhancing effects on animals. Conventional depolymerization methods of chitosan to chito-oligomers are either chemical by acid-hydrolysis under harsh conditions or by enzymatic degradation. In this work, hydrolysis of chitosan to chito-oligomers has been achieved by applying adsorption-separation technique using diluted HCl in the presence of different types of zeolite as adsorbents. The chito-oligomers were retrieved from adsorbents and characterized by differential scanning calorimetry (DSC), liquid chromatography/mass spectroscopy (LC/MS), and ninhydrin test. 相似文献
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Moses Adeolu Adebayo Adesike Oladoyin Kolawole Ibraheem Raji Joseph Ajayi 《Archives of Agronomy and Soil Science》2017,63(9):1292-1300
The present study aims at identifying potentially high-yielding testcross maize hybrids using different selection indices that consider agronomic traits other than grain yield alone. Forty-one (41) testcross hybrids developed from 20 elite drought-tolerant maize inbred lines and two inbred testers plus three hybrid checks were evaluated in the rainy seasons of 2013 and 2014 in Ogbomoso in the derived savanna agroecological zone of Nigeria. Hybrids were planted in each year in 11 × 4 lattices with two replications. Testcross hybrids and checks exhibited significant differences for all measured traits except ear height, husk cover and number of ears per plant. Grain yield of hybrids and checks averaged over the 2 years varied from 3117 to 8393 kg ha?1 with a mean of 5935 kg ha?1. Top 11 hybrids produced vigorous plants, each yielding >7000 kg ha?1. Base index and multivariate index methods identified EXL11 × 9071 whereas base index and Smith–Hazel selection index methods identified EXL18 × 9071 as superior hybrids at 5% selection intensity. These hybrids will be considered for advanced breeding program and release to farmers as high-yielding drought-tolerant hybrid maize varieties in the increasingly drought-prone derived savanna agroecology of Nigeria. 相似文献
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Purpose Changes in retinal glutamate distribution occur in primary glaucoma (PG) in dogs. Although the redistribution resembles that induced by ischemia, decreases in glutamine synthetase (GS) activity may also induce a similar glutamate redistribution. We examined the distribution of GS, glutamate, and glial fibrillary acidic protein (GFAP), a marker for reactive glia, in PG retinas by immunohistochemistry to determine whether decreases in GS and formation of reactive glia are associated with glutamate redistribution and neuronal damage. Animals Sections from 14 control dog eyes and 22 eyes from dogs with PG. Methods Sections from 14 control and 22 glaucomatous globes were immunohistochemically stained for GS, glial fibrillary acidic protein or glutamate. Results In semiquantitative immunogold studies, decreases in GS staining density were strongly correlated with glutamate redistribution and neuronal damage. In less quantitative immunoperoxidase staining of acute (≤ 5 days after clinical signs) and chronic PG retinas, GS immunoreactivity was decreased in focal regions of some acute PG retinas, and there were widespread decreases in chronic PG retinas. GFAP immunoreactivity was increased in Müller cells primarily in severely damaged regions of chronic PG retinas. Conclusions Decreases in GS immunoreactivity were associated with glutamate redistribution. These decreases in GS occurred even in mildly damaged regions of retina before retinal thinning. Reactive Müller cells were seen primarily in chronic PG in severely damaged regions. Decreases in GS may potentiate ischemia‐induced early glutamate redistribution and neuronal damage in canine PG. 相似文献