Factors influencing the occurrence of fall armyworm parasitoids in Zambia     

Durocher-Granger  Léna  Mfune  Tibonge  Musesha  Monde  Lowry  Alyssa  Reynolds  Kathryn  Buddie  Alan  Cafà  Giovanni  Offord  Lisa  Chipabika  Gilson  Dicke  Marcel  Kenis  Marc 《Journal of pest science》2021,94(4):1133-1146

Journal of Pest Science - Invasive alien species have environmental, economic and social impacts, disproportionally threatening livelihood and food security of smallholder farmers in low- and...  相似文献   

Efficiency of local feeds for the common carp (Cyprinus carpio L.) in Saudi Arabia     

N.A. Al Asgah  R.M. Bedawi   《Aquaculture (Amsterdam, Netherlands)》1984,40(4):363-365

The effects of feeding three local feeds (53%, 43% and 33% protein) on the growth and quality of the common carp (Cyprinus carpio L.) were investigated. The 43% protein feed proved most economical, with the highest biological value and has increased the protein and amino acid contents of the flesh but resulted in poor fish growth (0.10 g/day).  相似文献   

Effect of γ (Gamma)-radiation on the physico-mechanical properties of grafted jute fabric reinforced polypropylene (PP) composites     

G. M. Shafiur Rahman  Muhammad Abdullah Al Mamun  Mubarak A. Khan 《Fibers and Polymers》2014,15(2):340-346

The bleached jute fabric (BJF) reinforced polypropylene (PP) composites with various contents of acrylic acid (AA)-treated BJF and un-AA-treated BJF were fabricated by compression moulding method at 190 °C. The AA-grafted BJF reinforced PP composites were then irradiated by γ-ray at various doses. The mechanical properties of neat PP (N-P), ungrafted-BJF and PP composites (UG-BJFPC), AA-grafted-BJF and PP composites (AA-BJFPC) and γ-ray cum AA-grafted-BJF and PP composites (γAA-BJFPC) show maximum tensile strength (TS) of 30, 46, 47 and 51 MPa, maximum flexural strength (FS) of 34, 49, 50 and 54 MPa and maximum Young’s modulus (E) of 280, 428, 436, and 680 MPa, respectively. The increase of TS, FS and E from UG-BJFPC are 2 %, 2 %, and 2 % for AA-BJFPC and 11 %, 10 % and 59 % for γAA-BJFPC. The TS, FS and E are found to increase with radiation dose up to 500Krad and then decrease. The water absorption (WA) for UG-BJFPC, AA-BJFPC and γAA-BJFPC is respectively about 14, 10 and 9 %, indicating a gradual development of hydrophobic character of the composites first by AA-treatment and then by γ-ray-treatment. AA treatment on jute fabric and gamma irradiation on composite result in significant change of morphology of the jute fabric composites surface and better mechanical bonding between fabric and polymer matrix, as a result improved mechanical properties are found.  相似文献   

Nitrogen Deep Placement Combined with Straw Mulch Cultivation Enhances Physiological Traits,Grain Yield and Nitrogen Use Efficiency in Mechanical Pot-Seedling Transplanting Rice     

Li Lin  Zhang Zheng  Tian Hua  Umair Ashraf  Yousef Alhaj Hamoud  Al Aasmi Alaa  Tang Xiangru  Duan Meiyang  Wang Zaiman  Pan Shenggang 《水稻科学》2022,29(1):89

To assess the effects of straw return coupled with deep nitrogen (N) fertilization on grain yield and N use efficiency (NUE) in mechanical pot-seedling transplanting (MPST) rice, the seedlings of two rice cultivars, i.e., Yuxiangyouzhan and Wufengyou 615 transplanted by MPST were applied with N fertilizer at 150 kg/hm² and straw return at 6 t/hm² in early seasons of 2019 and 2020. The experiment comprised of following treatments: CK (no fertilizer and no straw return), MDS (deep N fertilization and straw return), MBS (broadcasting fertilizer and straw return), MD (deep N fertilization without straw return), MB (broadcasting fertilizer without straw return). Results depicted that the MDS treatment significantly increased the rice yield by 41.69%?72.22% due to total above-ground biomass, leaf area index and photosynthesis increased by 54.70%?55.80%, 38.52%?52.17% and 17.89%?28.40%, respectively, compared to the MB treatment. In addition, the MDS treatment enhanced the total N accumulation by 37.74%?43.69%, N recovery efficiency by 141.45%?164.65%, N agronomic efficiency by 121.76%? 134.19%, nitrate reductase by 46.46%?60.86% and glutamine synthetase by 23.56%?31.02%, compared to the MB treatment. The average grain yield and NUE in both years for Yuxiangyouzhan were higher in the MDS treatment than in the MD treatment. Hence, deep N fertilization combined with straw return can be an innovative technique with improved grain yield and NUE in MPST in South China.  相似文献   

Soil Salinization in Some Irrigated Areas of the Kingdom of Bahrain     

Asma Ali Abahussain  Abdelhadi Abdelwahab Mohamed  Ahmed Ali Salih  Ahmad Al Safe  Nader Abdul Hamed Mosa  Yahya Othman 《农业科学与技术》2014,(2):112-122

Monitoring and assessment of agricultural land degradation is of vital importance for better land and water management planning and reclamation. It requires setting baseline information and basic analysis at specific time and space. About 33 geo-referenced soil sampling spots were selected in two agricultural production locations in the Kingdom of Bahrain to assess the status and preliminary causes of land degradation. Soil samples were taken from 13 sites in Diraz location while 19 samples were taken from Budayyi location. The samples were taken to 90 cm depth at 30 cm intervals. Standard procedures were followed to determine soil physiochemical properties. In addition, field observations on farm condition, distance from the sea, method of irrigation and irrigation water source were taken. Some of the soil samples were deliberately taken from outside the irrigated basins among trees compared with samples taken from inside the actively growing area for comparison. The results indicated that the salinity level was significantly （P 〈 0.001） higher at the 0-30 cm soil depth compared with 30-60 cm or 60-90 cm depths in both locations. The distance from the sea did not show clear correlation with surface soil salinity in Budayyi area compared with Diraz. Both locations showed significantly higher salinity levels on samples taken outside the actively growing areas compared with those taken from within. The effect is more prominent at the 0-30 cm depth. The observed variability on salinity levels may be attributed to farm management practices and deteriorating quality of ground water. Thus, agricultural land degradation in Bahrain cannot be attributed to ground water deterioration alone. The use of tertiary treated sewage water （TSE） may ease the pressure on ground water, but the pH of the TSE should be carefully monitored and managed with proper studies on leaching requirements to avoid further salinity complications.  相似文献   

白蔹挥发油化学成分分析   总被引：1，自引：0，他引：1  

高欢 《特产研究》2014,(1):52-54

首次采用水蒸气蒸馏法制备白蔹挥发油,通过面积归一化法测定其相对百分含量,应用气相色谱-质谱联用技术研究分析其化学成分。最终分离鉴定出14种化学成分,占挥发油总量的99.997%,主要包括:芳姜黄酮(21.465%)、2-甲基-6-对甲苯基-2-庚烯醇(17.438%)和蒽(14.224%)等,为白蔹的进一步开发利用提供了研究依据。  相似文献   

Morphological development of post hatch larval goldlined seabream Rhabdosargus sarba (Forskål, 1775)     

Fahad S Ibrahim  Krishen J Rana  James Stephen Goddard  & Issa S Al Amri 《Aquaculture Research》2006,37(12):1156-1164

Ultrastructural changes in Rhabdosargus sarba larva in early life history were investigated. At hatching, the digestive system was histologically undifferentiated. The digestive tract was a straight tube attached to the dorsal end of the yolk‐sac and was not connected to either the mouth or the anus. The layer of gut epithelium at some regions of the luminal surface was straight and microvilli were not present. These straight borders were not observed at 1 day post hatching (DPH) onwards as microvilli increased in number on the luminal surface and became more regular. At 2 DPH, the digestive system was well differentiated and the separation of the mid‐ and hindgut by the intestino‐rectal valve became more advanced. At 0 DPH, the eye was spherical and the retina had a zonation with undifferentiated cells. The eye also lacked differentiated photoreceptors (PR). The retinal PRs increased in length and in number as the yolk‐sac was absorbed. By 2 DPH, the eye was fully pigmented, suggesting that the larval vision system was functional. The larvae had a pure cone retina at the onset of exogenous feeding. Morphological and functional differentiation of the digestive tract and the eye of the larvae preceded the completion of yolk and oil globule absorption. The oil globule was exhausted at 4 DPH and at 2 DPH, the yolk‐sac was completely absorbed. Food particles were observed at 3 DPH. Food particle ingestion and absorption of the yolk‐sac were observed as vision became fully functional.  相似文献   

Historical Changes in Levels of Organic Pollutants in Sediment Cores from Brno Reservoir, Czech Republic     

E. Franců  J. Schwarzbauer  R. Lána  D. Nývlt  S. Nehyba 《Water, air, and soil pollution》2010,209(1-4):81-91

Results of a comprehensive study are presented on the spatial and depth-related distribution of persistent organic pollutants (POPs) in sediments of the Brno reservoir, Czech Republic. Based on sedimentological observations, three major historic phases were identified related to the evolution of the depositional environment, flow rate, and material input. Data on organic carbon, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides showed specific distribution patterns in a 3-m-deep core. The analysis of the depth trends of the geochemical data combined with sedimentology made it possible to distinguish between remote sources of the pollutants, early weathering alterations of POPs, transport by river associated with organic matter as sorbent on one hand, and local sources weakly related to lithology on the other hand. The integrated sedimentological and environmental geochemical archive provided an improved dynamic view of the pollution in historical terms.  相似文献   

Frost Hardiness Expression and Characterisation in Wheat at Ear Emergence     

M. Al‐Issawi  H. Z. Rihan  N. El‐Sarkassy  M. P. Fuller 《Journal of Agronomy and Crop Science》2013,199(1):66-74

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犬瘟热患犬中性粒细胞cAMP PDE活性变化及中药作用研究     

朱莉娜  陈武  侯显涛  姜代勋  陈益山  李佳  于同泉  路苹  王惠芳  穆祥 《中国畜牧兽医》2008,35(11):51-56

研究犬瘟热患犬中性粒细胞(PMN)中环磷酸腺苷-磷酸二酯酶（cAMP-PDE）的活性变化及中药对其活性的体外调节作用，为抗炎药研究和病毒性炎症的中药治疗积累资料。提取犬瘟热患犬（n=9）和正常犬(n=6)的中性粒细胞制备cAMP-PDE样品，通过高效液相色谱(HPLC)法测定其活性及中药对其活性的影响。结果显示，犬瘟热患犬组中性粒细〖JP2〗胞cAMP-PDE活性（18.55%±2.66%）显著（P<0.05）高于正常组（11.54%±5.16%）。解表药等5类114味中药中芦根（77.27%）、胡黄连（70.41%）、女贞子（65.50%）、香薷（65.16%）、贝母（61.43%）、黄芩（60.67%）、淫羊藿（60.34%）、黄芪（59.13%）、青蒿（56.93%）、秦皮（55.55%）、辛夷（55.03%）、甘草（54.67%）、牛蒡子（53.40%）、麻黄（53.32%）14味对cAMP-PDE活性具有明显抑制作用。结果表明，中性粒细胞cAMP-PDE活性在犬瘟热患犬炎症过程中具有重要作用，对cAMP-PDE活性有明显抑制作用的中药对其炎症可能具有疗效，同时，中药抑制中性粒细胞中cAMP-PDE活性可能是其抗炎作用机理之一。  相似文献