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51.
Sadaf Kayani Manzoor Hussain Mushtaq Ahmad Mir Ajab Khan Maryam Akram Butt Sidra N. Ahmed Sofia Rashid Zafar Jamal Hafiza Mamona Nazir 《Microscopy research and technique》2022,85(4):1465-1482
The pollen morphology, with special reference to exine sculpture, of some species of the gymnosperms was assessed for the first time from the subalpine and alpine zones of western Himalayas northern Pakistan. The pollen of all these species is airborne and allergenic, so pollen morphology helps for identification of this allergenic pollen at specific level. Different morpho-palynological characteristics were analyzed including size range of pollen, polar and equatorial diameter ratio, exine ornamentation, sculpturing, exine thickness, pollen type, and shape. For accurate and quick identification of species, taxonomic key was made based on different morpho-palynological characteristics. The quantitative data were processed using SPSS software. Gymnospermal pollen includes inaperturate, rarely 1-colpate observed in (Cupressaceae), hexazonocolpate in (Ephedraceae), vesiculate, bissacate in (Pinaceae), and inaperturate in (Taxaceae). Different pollen shapes observed were prolate (4 spp), sub-spheroidal (7 spp), and oblate (1 spp). Variation was observed in exine sculpturing granular (4 spp), reticulate (1 spp), areolate-punctate (3 spp), and psilate (2 spp). This is based on the analysis of 10 plants belonging to four families of gymnosperms. Distinct pollen shape has emerged as the most diagnostic feature to separate some genera such as spheroidal in (Cupressaceae, Taxaceae), prolate and radiosymmetrical in (Ephedraceae), and bilateral in (Pinaceae). Exine thickness and sculpturing proved to be helpful at generic and specific levels. The results reinforced the significance of gymnospermal pollen morphological features which were used as aid for valuable taxonomic tool in plant systematics. 相似文献
52.
Aflatoxin B1 (AFB1) levels were evaluated in betel nuts (Areca catechu L.) being imported to Pakistan during 2010–2011. In total, 278 betel nut samples (India = 21, Indonesia = 51, Sri-Lanka = 34 and Thailand = 172) were received from the Department of Customs and were analysed by thin layer chromatography (TLC). All Indian origin betel nuts showed AFB1 contamination ranging from 11.7–262.0 µg kg?1 with a mean of 92.5 µg kg?1. Among Indonesian and Sri Lankan shipments, 80.4% and 73.5% betel nuts were contaminated with AFB1 ranging between 3.3–39.2 and 6.5–103.4 µg kg?1 with a mean of 11.6 and 35.0 µg kg?1, respectively. However, only 30.2% of Thailand origin samples showed AFB1 contamination ranging 3.3–77.0 µg kg?1 with a mean of 6.6 µg kg?1. The widespread occurrence of AFB1 increases the hazard associated with betel nuts. Thus, strict control is a pre-requisite for the production and import/export of psychoactive substances as betel nuts. 相似文献
53.
54.
How to do structural validity of a system dynamics type simulation model: The case of an energy policy model 总被引:2,自引:0,他引:2
System dynamics based simulation models are becoming increasingly popular in the analysis of important energy policy issues including global warming, deregulation, conservation and efficiency. The usefulness of these models is predicated on their ability to link observable patterns of behavior of a system to micro-level structures. This paper argues that the structural validity of the simulation model—right behavior for the right reasons—is a stringent measure to build confidence in a simulation model regardless of how well the model passes behavior validity tests. That leads to an outline of formal structural validity procedures available but less explored in system dynamics modeling ‘repertoire’. An illustration of a set of six tests for structural validity of a system dynamics model for energy policy analysis follows. Then using Theil inequality statistics, the behavior validity of the model is also tested. Finally, some conclusions on the increased appeal for simulation models for energy policy analysis and design are presented. 相似文献
55.
Ahsan Abdullah 《Color research and application》2019,44(3):433-445
The world has undergone a techno‐cultural revolution during the last decades with the materialization of the “global village” and more; all having a profound impact on our culture. Quantitative analysis of these profound multidimensional changes needs cross‐cultural data, and scalable tools/techniques that can discover interesting nontrivial hidden relationships in large data sets. Subsequently, presenting these discovered relationships in an intuitive visual form to non‐IT domain experts. In this article, using proven data mining techniques, we perform cross‐cultural clustering of word‐color associations for 344 respondents from three cultures, that is, the United States, Pakistan, and Kingdom of Saudi Arabia. We consider the concept words cheap, reliable, and high quality along with colors liked and disliked for 10 colors. After statistical data validation one‐way cross‐cultural clustering was performed. High similarity of word‐based cluster association was discovered across the three cultures for negative and positive connotation words, and clear dissimilarity in clustering was discovered within each culture for color‐based cluster association; with possible explanations given. The universal consistent similarities in cross‐culture associations and the dissimilarities in local or intra‐culture associations could be useful for global brand decision making. In this article, we also do a technical comparison of the proposed technique with three traditional techniques used for such analysis, that is, hierarchical clustering, k‐means clustering and factor analysis; along with related comparison with principal component analysis and multidimensional scaling. 相似文献
56.
巴基斯坦塔尔地区某燃煤电站冷却水计划回灌至煤层下部承压含水层,为了确保回灌的可行性,开展了一系列的抽水、注水试验。根据非稳定流抽水试验,计算了含水层的导水系数和渗透系数;根据非稳定流抽水试验的s~lgt曲线形态以及三段降深稳定流抽水试验结果判断出煤层下部含水层为稳定分布的承压含水层;采用补给影响半径的概念,基于三段降深稳定流抽水试验结果,计算了合理的回灌井距;结合短周期回灌试验和设计要求确定了单井回灌量;通过对比稳定流抽水试验数据和短周期回灌试验数据,分析了回灌阻力,并确定了回灌阻力曲线;将长期回灌试验曲线划分为回灌阻力阶段和阻塞效应阶段,分析了阻塞效应。通过试验观测数据以及试验曲线的一阶导数,认为阻塞效应并不明显。研究成果可为未来回灌工程建设提供一定的理论基础和技术依据。 相似文献
57.
Sehrosh Mir Mushtaq Ahmad Mir Ajab Khan Muhammad Zafar Sarwat Jahan Shazia Sultana Munazza Jabeen Salman Majeed 《Microscopy research and technique》2019,82(9):1401-1409
The research was performed to investigate pollen morphology of endangered species of Capparidaceae in subtropical regions of Pakistan. The distinguishing characters were investigated by using light microscope and scanning electron microscope. Palynological study is comprised of pollen shape, pollen type, exine sculpturing, polar and equatorial diameter, length and width of colpi, mesocolpium, and exine thickness. In polar view, Cleome viscosa exhibited the highest pollen size 26.4 (32.7–24.5 μm) ±0.776 whereas Capparis spinosa appeared to be the lowest 12.6 (14.5?10.7 μm) ±0.400. In equatorial view, Cleome viscosa had the largest pollen size 17.1 (20.0–15.0 μm) ±0.606 and Capparis spinosa had the smallest pollen size 9.7 (12.50–8.00 μm) ±0.394. The maximum fertility percentage has been observed in Capparis spinosa, that is, 98.96% and minimum in Cleome viscosa, that is, 82.93%. Diagnostic key has been constructed to state the essential diagnostic features by means of which the taxa can be identified. Remarkable variations have been observed in pollen size, shape, and exine sculpturing. All the selected species were tricolporate. Prolate to subprolate pollen were observed. There is a great variation existed in exine sculpturing such as in Capparis decidua and C. sp. nova sculpturing is reticulate, in Capparis himalayensis sculpturing is Scabrate granulate, in Capparis spinosa sculpturing is Psilate, in Cleome viscosa sculpturing is regulate‐reticulate, in Dipterygium glaucum sculpturing is regulate and in Gynandropsis gynandra sculpturing is striate‐regulate. On the basis of overall characteristics of pollen it seems that palynology of this family is helpful at the generic and specific level. 相似文献
58.
The objectives of this confirmatory study were to investigate the association of socio-economic demographics (age, education of respondent, gender, monthly family income, parentage education), motives (communication and information, self-actualization and outward looking) of using Social Networking Sites (SNSs) and attitudinal and behavior variable (intensity of using SNS, self-esteem, gratification with university life, duration of use, and number of ties) with the formation of bonding and bridging social capital. Total 461 students, aged 18–35 years filled the questionnaire, from randomly selected departments of University of the Punjab, Lahore, Pakistan. Regression analysis was used to assess the association among variables. The study indicated that Facebook is the most popular SNS among university students in Pakistan. Intensity of using SNS, duration of using SNSs, and motives of using SNSs were found to be positively associated with formation of bonding and bridging social capital. Self-esteem and gratifications with university life were found to be significant predictors in formation of bonding social capital only. The demographics variables (education, parentage education, monthly family income) had no influence on formation of both bonding and bridging social capital. 相似文献
59.
Here, more than 100 years of incumbency reports on officers of the irrigation bureaucracy of Punjab, Pakistan, are presented and analyzed. The data highlight how representation changed before and after partition within the irrigation bureaucracy. The data show that the irrigation bureaucracy increased through staffing its representation of local communities and is in its appointments responsive to elected representatives. Therefore, it is argued that empowerment of the local community can be achieved without irrigation management transfer but through the irrigation bureaucracy itself. 相似文献
60.
Nauman Khalid Anwaar Ahmed Muhammad Shahbaz Bhatti Muhammad Atif Randhawa Asif Ahmad Rabab Rafaqat 《Critical reviews in food science and nutrition》2014,54(9):1222-1240
This paper reviews research published in recent years concerning the effects of zinc deficiency, its consequences, and possible solutions. Zinc is an essential trace element necessary for over 300 zinc metalloenzymes and required for normal nucleic acid, protein, and membrane metabolism. Zinc deficiency is one of the ten biggest factors contributing to burden of disease in developing countries. Populations in South Asia, South East Asia, and sub-Saharan Africa are at greatest risk of zinc deficiency. Zinc intakes are inadequate for about a third of the population and stunting affects 40% of preschool children. In Pakistan, zinc deficiency is an emerging health problem as about 20.6% children are found in the levels of zinc, below 60 μg/dL. Signs and symptoms caused by zinc deficiency are poor appetite, weight loss, and poor growth in childhood, delayed healing of wounds, taste abnormalities, and mental lethargy. As body stores of zinc decline, these symptoms worsen and are accompanied by diarrhea, recurrent infection, and dermatitis. Daily zinc requirements for an adult are 12–16 mg/day. Iron, calcium and phytates inhibit the absorption of zinc therefore simultaneous administration should not be prescribed. Zinc deficiency and its effects are well known but the ways it can help in treatment of different diseases is yet to be discovered. Improving zinc intakes through dietary improvements is a complex task that requires considerable time and effort. The use of zinc supplements, dietary modification, and fortifying foods with zinc are the best techniques to combat its deficiency. 相似文献