Role of ACC-deaminase and/or nitrogen fixing rhizobacteria in growth promotion of wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) under cadmium pollution     

Waseem Hassan  Safdar Bashir  Farhan Ali  Muhammad Ijaz  Mubshar Hussain  Julie David 《Environmental Earth Sciences》2016,75(3):267

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Evaluation of various relationships of reaeration rate coefficient for modeling dissolved oxygen in a river with extreme flow variations in Pakistan     

Husnain Haider  Waris Ali  Sajjad Haydar 《水文研究》2013,27(26):3949-3963

Mathematical relationships have been developed for reaeration rate coefficient (K_a) by various researchers. These relationships have a number of variables such as depth, velocity, width, slope, Froud number, molecular diffusion coefficient, kinematic viscosity and the gas‐transfer Reynolds number. From these variables, 29 relations have been developed and divided into four groups. To evaluate their predictive capability for highly variable flow rivers receiving high pollution loads form large cities, these relationships have been used to model dissolved oxygen (DO) in the River Ravi. Such rivers are either saturated with DO during high flows or anaerobic during critical low‐flow conditions. The evaluation is based on the agreement between model DO values calculated using K_a obtained from the available equations and the measured DO concentrations in the river samples in terms of sum of square of residuals (SSR) and coefficient of determination (R²). It has been found that in general, the group of equations containing depth and velocity as the only two variables affecting K_a performed better than the equations in other groups as reflected by lower SSR and higher R² values. The study results also reveal that the turbulence‐based reaeration rate coefficient equation containing additional variables also resulted in close agreement between DO model results and the measured values. The study results identify the most important parameters affecting the reaeration rate coefficient and the suitability of various K_a relationships as well for rivers with highly variable flows. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

GIS-based high-resolution spatial interpolation of precipitation in mountain–plain areas of Upper Pakistan for regional climate change impact studies     

Muhammad Waseem Ashiq  Chuanyan Zhao  Jian Ni  Muhammad Akhtar 《Theoretical and Applied Climatology》2010,99(3-4):239-253

In this study, the baseline period (1960–1990) precipitation simulation of regional climate model PRECIS is evaluated and downscaled on a monthly basis for northwestern Himalayan mountains and upper Indus plains of Pakistan. Different interpolation models in GIS environment are used to generate fine scale (250?×?250 m²) precipitation surfaces from PRECIS precipitation data. Results show that the multivariate extension model of ordinary kriging that uses elevation as secondary data is the best model especially for monsoon months. Model results are further compared with observations from 25 meteorological stations in the study area. Modeled data show overall good correlation with observations confirming the ability of PRECIS to capture major precipitation features in the region. Results for low and erratic precipitation months, September and October, are however showing poor correlation with observations. During monsoon months (June, July, August) precipitation pattern is different from the rest of the months. It increases from south to north, but during monsoon maximum precipitation is in the southern regions of the Himalayas, and extreme northern areas receive very less precipitation. Modeled precipitation toward the end of the twenty-first century under A2 and B2 scenarios show overall decrease during winter and increase in spring and monsoon in the study area. Spatially, both scenarios show similar pattern but with varying magnitude. In monsoon, the Himalayan southern regions will have more precipitation, whereas northern areas and southern plains will face decrease in precipitation. Western and south western areas will suffer from less precipitation throughout the year except peak monsoon months. T test results also show that changes in monthly precipitation over the study area are significant except for July, August, and December. Result of this study provide reliable basis for further climate change impact studies on various resources.  相似文献   

Effect of Parthenium Extract on the Metabolism of Young Colisa Fasciatus (BL. and SCHN.) (Pisces,Perciformes)     

M. S. Prasad  Z. A. Haider 《洁净——土壤、空气、水》1986,14(6):661-666

Parthenium hysterophorus seed extract possesses the potentiality to alter the fish metabolism. Lower concentrations (sublethal) of the seed extract stimulate the respiratory muscles, resulting in an increased rate of O₂ uptake, whereas higher concentrations (lethal) exhibit a neuro-toxic effect causing paralysis of the respiratory muscles manifested by a decreased rate of O₂ uptake, cessation of the respiratory pumps and casualty by asphyxiation. The seed extract also inhibits the activity of the enzymes SDH and carbonic anhydrase at the gas exchange sites. The log/log plotting of the O₂ uptake (mg/h) and the exposure period (2, 6, 12, 24, 72 and 168 h) showed slope values of 0.0744, 0.0778, 0.0322 and 0.0164, respectively, in four concentrations (10, 20, 25 and 30 %) of Parthenium extract.  相似文献   

New age constraints on counter-clockwise rotation of NE Japan     

Ayumi K. Baba  Takaaki Matsuda  Tetsumaru Itaya  Yutaka Wada  Noriyuki Hori  Masahiko Yokoyama  Nobuaki Eto  Rieko Kamei  Haider Zaman  Tesfaye Kidane  Yo-Ichiro Otofuji 《Geophysical Journal International》2007,171(3):1325-1341

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Investigation of the weathering layer using seismic refraction and high-resolution seismic reflection methods, NE of Riyadh city     

Ghunaim T. Al-Anezi  Abdullah M. Al-Amri  Haider Zaman 《Arabian Journal of Geosciences》2012,5(6):1347-1358

Five seismic refraction and five high-resolution seismic reflection (HRSR) profiles were carried out in northeastern part of Riyadh city to investigate depth of the weathering layer. Results obtained from seismic refraction survey reveal the depths of weathering layer at 12, 25, 17, 12, and 16?m, respectively. On the other hand, HRSR stack sections illustrate the depths of weathering layer at 14, 28, 20, 13, and 18?m, respectively. The weathering layer is composed of alluvial sediments and gravel, which is underlain by a sequence of limestone and dolomite layer. Seismic results from site no. 2 have been found to be in good agreement with lithological information reported from the adjacent water well. The HRSR data generally reveal better signal-to-noise ratio and enhanced resolution compared to the refraction data. Although, the HRSR data failed in achieving high-quality common midpoint (CMP) stacking profile at site no. 3, it provide an improved image of the subsurface features than the refraction data, recognizing it as a potential seismic technique.  相似文献   

Heavy metal toxicity levels in the coastal sediments of the Arabian Sea along the urban Karachi (Pakistan) region   总被引：1，自引：0，他引：1  

Azhar Siddique  Majid Mumtaz  Nayyer A. Zaigham  Khalil A. Mallick  Sumayya Saied  Erum Zahir  Haider A. Khwaja 《Marine pollution bulletin》2009,58(9):1406-1414

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Structural Seismology: Exploring the Correspondence between Surface Geological Features and Heterogeneities in the Earth’s Crust and Mantle     

GAO StephenShangxing  LIU KellyHong  FU Xiaofei  Haider DAHM  KONG Fansheng  LIU Lin  Cory REED  SUN Muchen  YU Youqiang 《《地质学报》英文版》2019,93(Z2):3-4

The North Qaidam is an Early Paleozoic UHP metamorphic belt located at the north margin of the Tibet plateau. Eclogites in this belt contain both continental‐and oceanic‐type ones. In which, the continental‐type eclogites have protolith ages of 750–850 Ma and WPB or CFB geochemical signatures and are believed to have formed in a continental rift or an incipient oceanic basin setting related to the breakup of the Rodinia supercontinent, their metamorphic ages (421–458 Ma) and P–T paths are comparable to their host gneisses; oceanic‐type eclogites have cumulate gabbro or E‐MORB geochemical signatures, their protolith and metamorphic ages are 510–516 Ma and 425–450 Ma, respectively(Zhang et al., 2008). Therefore, the North Qaidam UHP belt was thought to record the whole Neoprotoerozoic–Paleozoic Wilson cycle (Song et al., 2014). In this study, we reported three new kinds of eclogites: kyanite‐bearing eclogite, lawsonite pseudomorph‐bearing eclogite and double mineral eclogite. They occur as big lentoid blocks in regional granitic gneiss in the western part of the belt. Phase equilibrium modelling and zircon LA‐ICPMS U‐Pb dating show that all these three eclogites experienced a clockwise P–T path with peak metamorphic conditions close to or fall in the coesite stability field, and their peak metamorphic age were around 436‐439 Ma, similar to those continental‐type eclogites in this belt. But their protolith ages are between 1273 and 1070 Ma, and some of them recorded an amphibolite facies metamorphic age of 927 Ma, and geochemical data and zircon Lu‐Hf and O isotope analysis indicate these eclogites have features of present day N‐MORB. Combined with the existing results, we propose that the North Qaidam is a polycyclic composite orogenwhich recorded tectonic evolution of Mesoproterozoic ocean floor spreading, assembly and breakup of Rodinia supercontinent, Early Paleozoic oceanic deep subduction and subsequently continental deep subduction.  相似文献   

Groundwater vulnerability mapping assessment of central West Bank catchments using PI method     

Marwan Ghanem  Waseem Ahmad  Yacoub Keilan  Farah Sawaftah 《Environmental Earth Sciences》2017,76(9):347

A groundwater vulnerability assessment was carried out in order to understand and control the pollution sources affecting vulnerable regions in two adjacent catchments (Sarida and Natuf), located in the western middle part of the West Bank. The catchments were subjected to groundwater vulnerability mapping and assessment using the modified German State Geological Surveys (GLA method) method called Protective Cover and Infiltration Conditions method (PI method) via ArcGis 2014.2 software package in February of 2016. The results showed that the study area has high effectiveness of protective cover (P-factor), which was obtained by overlying top soil, bedrock, subsoil, and recharge layers. On the other hand, the dominant flow types, land usage, slopes, and topographical classification layers were overlaid to get the infiltration conditions (I-factor). The interaction between the two main factors was carried out in order to obtain the final spatially distributed π-factor values (vulnerability map), which was classified into four vulnerability classes. Statistically, about 4% of the overall area was of extreme vulnerability and concentrated along the sinking streams, while 22% was of low vulnerability and existed outside the main watersheds, followed by high vulnerability with 26%. The largest proportion with 48% of the overall area was of moderate vulnerability to groundwater contamination.  相似文献   

Identification of the Major Allergen in Greasy-Back Shrimp （Metapenaeus ensis） by MALDI-TOF-MS     

Samee Haider 《中国海洋大学学报(英文版)》2010,9(2):178-184

In order to better understand shrimp allergen,some basic characters of the major allergen of greasy-back shrimp (Metapenaeus ensis)were investigated.The major allergen was extracted and separated,and its peptide mass fingerprint(PMF) was analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS).After screening in the NCBI database with Mascot searching engine,the results indicated that the major allergen of greasy-back shirmp was muscle tropomyosin.Database matching search showed that the top protein matched,i.e.the tropomyosin from giant tiger prawn(Penaeus monodon),had a Mowse value of 268.In addition,there were 27 queries matched with the allergen in greasy-back shirmp with an amino acid sequence coverage value of 65%.The matching scores and the sequence coverage values were also high with tropomyosins of other invertebrates,including Tyrophagus putrescentiae and Lepisma saccharina.These results indicated that the allergen of Metapenaeus ensis had high homology with other crustacean allergens,and provided molecular explanations for the high cross-reactivity of the major allergens between crustaceans and some other invertebrates.  相似文献