The pyrethrins and related compounds. Part XXXVII. synthesis and insecticidal properties of new 1-aryl-1-(3-arylpropyl and -propenyl)cyclopropanes (non-ester pyrethroids)     

Andrew W. Farnham  Anderson Ifill  Norman F. Janes  Tariq Javed  Bhupinder P. S. Khambay 《Pest management science》1990,28(1):25-34

New routes to the title compounds, involving improved conditions for the cyclopropanation, and a new method of constructing the central three-carbon unit (based on the coupling of a Grignard reagent with an allylic acetate) give access to products for which the previously reported route was not satisfactory. For the new route, a synthesis of 5-bromo-2-fluoro-diphenyl ether was developed. Previously deduced relationships between structure and insecticidal activity apply for the new compounds: alkenes are generally more active than corresponding alkanes; substitution at the 3- or 4-position (but not the 2-) of the 1-aryl group can enhance activity. In addition, some fluorine-containing substituents lead to high activity.  相似文献   

Conformational and intramolecular hydrogen bonding effects on post-emergence and pre-emergence selectivities of herbicidal pyrrole dicarboxylates     

Tariq A. Andrea  David D. Stranz  Alex Yang  Daniel A. Kleier  Kanu M. Patel  James E. Powell  Thomas P. Price  Dennis S. Marynick 《Pest management science》1990,28(1):49-68

Dimethyl 2-methyl-5-(chloropyridin-2-yl)pyrrole-3,4-dicarboxylates in which the chlorine atom is substituted at different positions of the pyridine ring have widely varying biological properties. The 3-chloro analog (I) is a post-emergence and pre-emergence herbicide, the 4- and 5-chloro analogs (II, III) are post-emergence herbicides but not pre-emergence, and the 6-chloro analog (IV) is inactive. Computer graphic and molecular mechanics analyses of their molecular conformations showed that the 4- and 5-chloro analogs adopt a coplanar, intramolecularly hydrogen bonded conformation whereas the 3-chloro analog does not. High-level quantum mechanical calculations of the conformational preferences of related model systems were in agreement with these results. Based on this, II and III were predicted to have higher octanol/water partition coefficients relative to I, leading to higher soil binding and weaker xylem transport, hence their observed weaker pre-emergence activities. Experimental measurements of octanol/water partition coefficients, soil binding, and infrared hydrogen bonding studies verified these predictions. Molecular modeling techniques are usually used for designing compounds to fit enzyme active sites and designing putative receptor models. This study demonstrates the usefulness of these techniques for dealing with transport problems.  相似文献   

Factors affecting reproductive performance in dromedary camel herds in Saudi Arabia     

Ali  Ahmed  Derar  Derar  Alsharari  Abdulhadi  Alsharari  Assaf  Khalil  Rashid  Almundarij  Tariq I.  Alboti  Yaser  Al-Sobayil  Fahd 《Tropical animal health and production》2018,50(5):1155-1160

A survey of 7122 dromedary camels in 115 herds in Saudi Arabia was used to estimate the effects of herd size (HZ; <?25 vs. 25–49 vs. 50–100 vs. >?100 camels), herder/camels ratio (H/C; 1:<?25 vs. 1:25–50 vs. 1:>?50), manager experience (ME; <?5 vs. 5–10 vs. >?10 years), male/females ratio (M/F), housing system (HS; free vs. closed vs. mixed), length of the breeding season (winter vs. winter and spring vs. fall, winter and spring), age at first mating (3 vs. >?3 years), and time of mating after parturition (≤?3 vs. >?3 months) and their interactions on the overall pregnancy rate. Barren females of these herds (n?=?886) were examined for the causes of infertility. Results showed that herds with H/C of 1:<?25 had higher overall pregnancy rate (95.29%) than herds with H/C of 1:25–50 (79.84%) and those with H/C of 1:>?50 (72.79%) (p?=?0.003). Herds having ME of >?10 years revealed greater overall pregnancy rate (94.89%) than herds with ME of 5–10 years (80.54%) and those with ME of <?5 years (72.5%) (p?=?0.001). There were significant interactions between H/C × HZ (p?=?0.003), H/C × HS (p?=?0.006), and ME × HS (p?=?0.02). The overall pregnancy rate did not significantly differ between herds bred females by age of 3 years and those bred females by age >?3 years and in females bred within 3 months after parturition and in those bred after 3 months. The mean calving interval was shorter (p?=?0.008) in camels mated within 3 months of parturition (15.25?±?2.8 months) than in those mated after that time (24.33?±?6.5 months). Clinical endometritis, ovarian hydrobursitis, and vaginal adhesions were the common clinical findings in barren females. Thus, efforts to reduce the age at first mating and the interval after calving, increase the number of herders/camels, and control reproductive disorders could improve the reproductive performance and quality of camel herds in Saudi Arabia.

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Allelic variation and composition of HMW-GS in advanced lines derived from d-genome synthetic hexaploid / bread wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)     

Awais Rasheed  Tariq Mahmood  Alvina Gul Kazi  Abdul Ghafoor  Abdul Mujeeb-Kazi 《Journal of Crop Science and Biotechnology》2012,15(1):1-7

The objective of this study was to identify allelic variations at Glu-1 loci of wheat (Triticum aestivum L.) advanced lines derived from hybridization of bread wheat and synthetic hexaploid wheats (2n = 6x = 42; AABBDD). Locally adapted wheat genotypes were crossed with synthetic hexaploid wheats. From the 134 different cross combinations made, 202 F₈ advanced lines were selected and their HMW-GS composition was studied using SDS-PAGE. In total, 24 allelic variants and 68 HMW-GS combinations were observed at Glu-A1, Glu-B1, and Glu-D1 loci. In bread wheat, the Glu-D1 locus is usually characterized by subunits 1Dx2+1Dy12 and 1Dx5+1Dy10 with the latter having a stronger effect on bread-making quality. The subunit 1Dx5+1Dy10 was predominantly observed in these advanced lines. The inferior subunit 1Dx2+1Dy12, predominant in adapted wheat germplasm showed a comparative low frequency in the derived advanced breeding lines. Its successful replacement is due to the other better allelic variants at the Glu-D1 locus inherited in these synthetic hexaploid wheats from Aegilops tauschii (2n = 2x = 14; DD).  相似文献   

The development of faba bean expressed sequence tag–simple sequence repeats (EST‐SSRs) and their validity in diversity analysis     

Muhanad W. Akash  Gerald O. Myers 《Plant Breeding》2012,131(4):522-530

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The epidemiology of paramphistomosis of sheep (<Emphasis Type="Italic">Ovis aries</Emphasis> L.) in the north west temperate Himalayan region of India     

Tariq KA  Chishti MZ  Ahmad F  Shawl AS 《Veterinary research communications》2008,32(5):383-391

An epidemiological study with the objective to assess the prevalence of paramphistomosis in association with season, age, sex and breed was carried out in naturally infected sheep over a period of two years from February 2005 to January 2007. Gastrointestinal tract (GIT) and faecal examination were conducted monthly to monitor the seasonal occurrence of paramphistomosis. 793 sheep were examined in the first year, out of which 7.06% were positive for Paramphistomum infection. In the second year, 740 animals were investigated and 7.7% were infected. The overall prevalence of paramphistomosis was 7.3% with a mean of 56.50 ± 0.50 and 95% confidence interval (CI) (lower bound: 50.1469; upper bound: 62.8531). The prevalence of paramphistomosis through GIT examination (P = 0.593) was 7.6% at 95% CI (lower bound: −19.1186; upper bound: 57.1186) and the prevalence through faecal examination (P = 0.884) was 7.2% at 95% CI (lower bound: 5.7345; upper bound: 69.2655). Generally, season and age were the factors found to have a significant influence on the risk of paramphistomosis in sheep. The highest infection was found in the summer season (P < 0.005); lower age groups (P < 0.005) in males and in migratory (Bhakarwal) breed (P ≥ 0.005). Winter, adult animals, females and local breed reported low infection. The present study will be of great significance to understand the epidemiology of gastrointestinal helminthes of sheep initially in the resource poor communities of Himalayan region and will definitely be helpful to devise appropriate control strategies for paramphistomosis.  相似文献   

Can irrigation be sustainable?     

Shahbaz Khan  Rana Tariq  Cui Yuanlai  J. Blackwell 《Agricultural Water Management》2006,80(1-3):87-99

Globally, about 10 Mha of agricultural land is lost annually due to salinisation, of which about 1.5 Mha is in irrigated areas. While some climate and management aspects are common to semi-arid regions, the detailed mechanisms and options to secure ecological sustainability and economic viability may vary considerably from case to case. This paper applies a whole of system-water balance to compare irrigation in three semi-arid regions suffering from similar sustainability issues: Rechna Doab (RD), Pakistan; the Liuyuankou irrigation system (LIS), China; and Murrumbidgee irrigation area (MIA), Australia. Soil salinity, lack of adequate water resources and groundwater management are major issues in these areas. The MIA and LIS irrigation systems also suffer from soil salinity and low water-use efficiency issues. These similarities occur in spite of very different climatic and underlying hydrogeological conditions. The key data used to compare these different regions are climate and soils, available water resources and their use, as well as components of the water balance. In addition, the history of water resource development in these areas is examined to understand how salinity problems emerge in semi-arid regions and the consequences for production. Based on the efficiency parameters and the definitions of sustainability, approaches are explored to solve common environmental problems while maintaining economic viability and environmental sustainability for irrigation systems.  相似文献   

RESEARCN OF MODEL OF AUTOMATIC CHECWEIGHER     

Song Shouxiang  M. Tariq  W.Balachandran 《保鲜与加工》1994,(4):35-39

Generally,a second order spring-damper system is used to represent the model ofweighing sensor in checkweigher. It only represents one part of checkweigher.In this paper,accord-ing to the relationships of individual parts of checkweigher and main disturbance source,a model isproposed for whole checkweigher.It is proved by simulatlon that this model is in a good approxima-tion.  相似文献   

Haploidy breeding and mutagenesis for drought tolerance in wheat   总被引：4，自引：0，他引：4  

A.J. Khan  S. Hassan  M. Tariq  T. Khan 《Euphytica》2001,120(3):409-414

Several intraspecific crosses between known drought tolerant wheat varieties and stable high yielding recombinants were made with the objective to develop improved cultivars for the moisture stressed rainfed areas of Pakistan. Five of these crosses were selected for further creation of useful mutations through the application of low doses of gamma rays and development of doubled haploids through anther culture. Anther culture response of the selected irradiated F₁ generations was studied on liquid and solid induction media. The highest number of calli among almost all crosses was produced on Potato-2induction medium. All the crosses varied greatly in response to callus induction and maximum calli (75%) were obtained from Lyl-73/vee’s’ cross. Similarly, genotypic differences were found for green vs. albino regenerants. The highest number of green plantlets (12.1%) was recorded for Lu-26/3062. From the developed doubled haploid population 25 DH-mutants were initially selected and nine lines were finally included in multi-locational field tests. Two DH-mutants (i.e. DHML-50 and DHML-9) have potential for better grain yield, earliness, disease resistance and moisture stress tolerance. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

QTL mapping for yield and yield-contributing traits in sorghum (Sorghum bicolor (L.) Moench) with genome-based SSR markers     

Tariq Shehzad  Kazutoshi Okuno 《Euphytica》2015,203(1):17-31

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