Regulation of elongating RNA polymerase II by forkhead transcription factors in yeast     

Morillon A  O'Sullivan J  Azad A  Proudfoot N  Mellor J 《Science (New York, N.Y.)》2003,300(5618):492-495

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Mineralization and microbial biomass formation in upland soil amended with some tropical plant residues at different temperatures     

Abul Kalam Mohammad Azmal  Takuya Marumoto  Haruo Shindo  Masaya Nishiyama 《Soil Science and Plant Nutrition》2013,59(3):463-473

A model experiment was carried out at 15, 25, and 35°C to investigate the changes in microbial biomass and the pattern of mineralization in upland soil during 8 weeks following the addition of 8 organic materials including 6 tropical plant residues, ipil ipil (Leucaena leucocephala), azolla (Azolla pinnata), water hyacinth (Eichhornia crassipes), dhaincha (Sesbania rostrata), cowpea (Vigna unguiculata), and sunhemp (Crotalaria juncea). The amounts of CO₂-C evolved and inorganic N produced at 35°C were about 2 times larger than those at 15°C. At any temperature, the flush decomposition of C was observed within the first week and thereafter the rate of mineralization became relatively slow. A negative correlation was observed between inorganic N and C/N ratios of the added organic materials. The relationships between the amounts of cellulose or cellulose plus hemicellulose and the amount of mineralized N of the added organic materials were also negative.

The changes in the microbial biomass were affected by temperatures. The amount of biomass C and N was maximum after 42 d of incubation at 15°C, and after 7 d at 25 and 35°C, and thereafter decreased. The rate of biomass decline was slower at 15°C and faster at 35°C than at 25°C. Regardless of the temperatures, the addition of organic materials enhanced microbial biomass formation throughout the incubation periods.  相似文献   

COVID-19 impacts on the Bangladesh shrimp industry: A sequential survey-based case study from southwestern Bangladesh     

Bashar  Abul  Heal  Richard D.  Hasan  Neaz A.  Salam  Md. Abdus  Haque  Mohammad Mahfujul 《Fisheries Science》2022,88(6):767-786

Shrimp farming is fundamental to the national economy of Bangladesh, particularly through earning foreign currency. The nationwide lockdown and international cargo restriction jeopardized the sector and breaking its marketing chain. Assessing the degree of farming socio-economic peril from COVID-19 and suggesting early coping strategies and long-term mitigation measures are pressing to build resilience for this food production sector. To collect survey data, two key-informant face-to-face surveys with 51 shrimp farmers and 62 consumers in southwest Bangladesh were accomplished. As national lockdowns restricted access to export markets and movements within the country, farm incomes decreased against rising production costs. To compensate, farmers reduced their workforce (29.4%), but even with the sale of co-cultured finfish still suffered from large drops in revenue (42.8% average profit reduction). Furthermore, we present evidence that shrimp farmers should consider diversification of aquaculture product type as co-culture of additional shrimp species was a poor mitigation strategy against large market price fluctuations. Product price reductions were passed on to the consumer, who enjoyed falling product prices including more expensive shrimp products, but the markup for nearly all aquaculture products increased. The current jeopardy and consequences of shrimp farming future are discussed, including coping strategies to help policymakers in building resilience against future uncertainties.

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我国47份主要玉米自交系耐旱性分析   总被引：6，自引：2，他引：4  

王业建  郗浩江  李铭东  梁晓玲  韩登旭  杨杰  阿布来提  雷志刚  郝转芳  李明顺  刘文欣  陈绍江 《玉米科学》2018,26(4):10-16

利用耐旱系数法对我国47份主要玉米自交系农艺性状、产量与耐旱性进行相关性分析,对自交系耐旱性进行综合评价。结果表明,穗粗、行粒数、轴径与单株子粒产量耐旱系数呈极显著正相关;株高、雄穗长、穗行数、百粒重与单株子粒产量耐旱系数呈显著正相关;ASI与单株产量耐旱系数呈极显著负相关。各性状耐旱性对单株产量的相对重要性依次为穗粗行粒数轴径株高雄穗长穗行数百粒重穗位高穗长ASI。按照综合耐旱系数将自交系耐旱性分为3个级别,耐旱性较强自交系有混517、郑58、掖52106、英64、38-11等19份,占40.4%;耐旱性中等自交系有525、C103、Mo17Ht、黄早四、昌7-2等18份,占38.3%;耐旱性较弱自交系有吉853、综31、L317、Os420、WF9等10份,占21.3%。  相似文献   

Genetic screening of FecB,FecXG and FecXI mutations and their linkage with litter size in Barki and Rahmani sheep breeds          下载免费PDF全文

AS El‐Seedy  NM Hashem  KM El‐Azrak  ANM Nour El‐Din  TA Ramadan  TA Taha  MH Salem 《Reproduction in domestic animals》2017,52(6):1133-1137

Characterization of fecundity genes offers the opportunity to improve production efficiency, and the consequent increase in litter size in livestock industry, through utilizing them in breeding programs. The main objective of this study was to detect the BMPR‐IB, BMP15 and GDF9 gene mutations and to investigate whether these mutations are associated with litter size in Egyptian sheep breeds. To achieve this goal, 73 adult ewes representing Barki (n = 33) and Rahmani (n = 40) breeds were used. Polymerase chain reaction–restriction fragment length polymorphism (PCR‐RFLP) screening approach was used to detect the presence of FecB, FecX^G and FecX^I mutations in the two selected breeds. Results of this study showed that the three different candidate gene mutations, namely FecB, FecX^G and FecX^I are not present among these selected populations of the Egyptian breeds. Further studies regarding other mutations and/or other genes, which may influence ovulation rate, should be carried out to determine the type and mode of inheritance of such genes in Egyptian sheep breeds.  相似文献   

Semen supplementation with palmitoleic acid promotes kinematics,microscopic and antioxidative parameters of ram spermatozoa during liquid storage          下载免费PDF全文

M Eslami  H Ghasemiyan  E Zadeh Hashem 《Reproduction in domestic animals》2017,52(1):49-59

The purpose of the present experiment was to investigate the protective effects of palmitoleate on the quality of ram semen during low temperature liquid storage. Ejaculates were collected using the artificial vagina from four Qezel rams twice a week. Ejaculates were pooled, diluted with Tris–egg yolk extender without palmitoleate (control) or supplemented with 0.125 (P 0.125), 0.25 (P 0.25), 0.5 (P 0.5) and 1 (P 1) mM palmitoleate at a final concentration of 500 × 10⁶ spermatozoa/ml. Total motility and forward progressive motility (FPM) as well as other spermatozoa kinematics were evaluated by computer‐assisted sperm analysis. Moreover, viability and membrane functionality were determined in the spermatozoa. Additionally, amounts of malondialdehyde (MDA), total antioxidant activity (AOA), nitric oxide (NO) and superoxide dismutase (SOD) activities were evaluated in the medium and spermatozoa at 0, 24, 48 and 72 hr of storage. The palmitoleate supplementation resulted in a significant (p < .05) increase in total motility and FPM with the highest increase at 0.5 mM concentration for 72 hr. P 0.5 group also resulted in the highest percentage of membrane‐intact spermatozoa (76.60 ± 1.95%) and viability (75.81 ± 1.34%) at 72 hr (p < .05). The amounts of MDA and NO were lower in P 0.125, P 0.25 and P 0.5 groups compared to control at 48 hr and 72 hr (p < .05). Higher amounts of AOA were obtained in palmitoleate‐treated groups in medium and spermatozoa during storage time (p < .05). Furthermore, palmitoleate supplementation increased the SOD activities in spermatozoa compared to the control (p < .05). The results of the present experiment reveal that supplementation with 0.5 mM palmitoleate improves ram spermatozoa motion characteristics, AOA levels and SOD activities during liquid storage. Then, palmitoleate could be used as an antioxidant source during liquid storage of ram semen.  相似文献   

Kinetic characterization of O-phospho-L-tyrosine phosphohydrolase activity of two fungal phytases     

Ullah AH  Sethumadhavan K  Mullaney EJ 《Journal of agricultural and food chemistry》2008,56(16):7467-7471

Fungal phytases belonging to "histidine acid phosphatase" or HAP class of phosphohydrolases that catalyze the hydrolysis of phytic acid could also hydrolyze O-phospho-L-tyrosine, which is also called phosphotyrosine. Two phytases from Aspergillus niger and Aspergillus awamori with pH optima 2.5 were tested for phosphotyrosine hydrolase activity; both enzymes cleaved the phosphomonoester bond of phosphotyrosine efficiently at acidic pH. The Km for phosphotyrosine ranged from 465 to 590 microM as opposed to 135 to 160 microM for phytate. The Vmax, however, is 2-4 times higher for phosphotyrosine than it is for phytate. The catalytic efficiency of phytase for phosphotyrosine is on the same order as it is for phytate (3.5 x 10(6) to 1.6 x 10(7) M(-1) s(-1)); the pH versus activity profile for phosphotyrosine is, however, different from what it is for phytate. The temperature optima shifted 5 degrees C higher to 70 degrees C when phosphotyrosine was used as the substrate. Taken together, the kinetic data show that fungal HAPs that are known as PhyB are capable of cleaving the phosphomonoester bond in phosphotyrosine. This is the first time that phosphotyrosine phosphatase (PTPase) activity has been reported for the subgroup of HAP known as phytase.  相似文献   

Seed mycoflora ofLens esculenta and their biocontrol by chitosan     

E. F. Abd-Allah  Abeer Hashem 《Phytoparasitica》2006,34(2):213-218

Thirty-two fungal species belonging to 17 genera were recorded on 45 seed samples of lentil (Lens esculenta) collected from different governorates in Egypt. The prevalent genera wereAlternaria, Aspergillus, Cladosporium, Fusarium andPenicillium. Chitosan enhanced suppression of seedborne mycoflora, as estimated using either agar plates or a blotter test of lentil seed samples. These results suggested an alternative non-toxic means for controlling seedborne fungi. Furthermore, pretreatment of lentil seeds with chitosan significantly reduced the natural contamination with mycotoxins — aflatoxins, ochratoxin A, citrinin and zearalenone — under storage conditions for 6 months.  相似文献   

Isolation of (+)-catechin and a new polyphenolic compound in Bengal catechu     

Abul Kalam Azad  Koichi Ogiyama  Takeshi Sassa 《Journal of Wood Science》2001,47(5):406-409

Methanol extractives from the red heartwood of Bengal catechu (Acacia catechu) contained (+)-catechin as a major component making up 0.3% of the wood. A new polyphenolic compound with a (+)-homo-iso-catechin structure and having catechol and phloroglucinol moieties constituted 0.005% of the wood, and probably its epimeric compound in trace amounts, were also found.This report was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999 and the 44th Lignin Symposium, Gifu, October 1999  相似文献   

Histological studies of shoot regeneration system in hypocotyl-derived callus of Phellodendron amurense Rupr.     

Mustafa Abul Kalam Azad  Shinso Yokota  Futoshi Ishiguri  Shoji Yahara  Nobuo Yoshizawa 《Journal of Forest Research》2005,10(5):377-384

An efficient in vitro plant regeneration was achieved from hypocotyl-derived callus of a medicinal tree Phellodendron amurense. The expected morphogenic response was obtained on the media containing 0.89 µM 6-benzyl aminopurine (BAP) plus 4.52 µM 2.4-dichlorophenoxyacetic acid (2,4-D), 4.44 µM BAP plus 5.37 µM α-naphthaleneacetic acid (NAA), or 2.22 µM BAP plus 4.92 µM indole-3-butyric acid (IBA). A detailed histological study was undertaken to gain a better understanding of cellular changes that take place during the plant regeneration process from callus tissue. This study led to the identification of the cellular origin of shoot regeneration. Histological studies revealed that the new vegetative buds originated from callus that completely altered the morphology of the callus tissues by the 60th day of culture. It also revealed that BAP with NAA or IBA induces plant regeneration through organogenesis whereas BAP with 2,4-D induces embryo-like-structure (ELS) through hypocotyl-derived callus. The presence of ELS lacking root poles was also observed.  相似文献