Transformation of Tobacco with ScMTII Gene‐Enhanced Cadmium and Zinc Accumulation     

Hatice Daghan  Mehmet Arslan  Veli Uygur  Nurcan Koleli 《洁净——土壤、空气、水》2013,41(5):503-509

Genetic transformation is gaining importance for developing plant types suitable to metal accumulate and/or hyperaccumulate. In this study, the transgenic tobacco plant which transferred the ScMTII gene from Saccharomyces cerevisiae to wild type tobacco cultivar Petite Havana (SR1) was grown on soils with low and high cadmium (Cd) and zinc (Zn) concentrations in a growth chamber for 6 weeks and compared to wild type tobacco for Cd and Zn accumulation. Cadmium and Zn accumulations in the transgenic and wild type tobacco plants were increased with the increasing Cd and Zn concentrations. Unlike Zn, the transgenic plant accumulated significantly higher amount of Cd compared to the wild type control plants. Shoot Cd concentrations of transgenic tobacco in higher Cd dosages reached the above the hyperaccumulation threshold value of 100 mg Cd kg^?1 in the dry weight (DW). Transgenic tobacco accumulated 354, 400, 372, and 457 mg Cd kg^?1 DW, for 10, 20, 40, and 80 mg Cd kg^?1 soil treatments, respectively. These values are 3.5–4.5‐fold higher than that of Cd hyperaccumulation threshold value. With 10 mg kg^?1 Cd treatment, the bioconcentration factor (BCF) of transgenic tobacco plants for Cd reached up to 35 in which the threshold value for BCF should be at least 10. Our results showed that the transgenic tobacco may be used as a good Cd hyperaccumulator plant and for phytoextraction of Cd contaminated soils, but not for Zn.  相似文献   

Comparison of near-fault and far-fault ground motion effects on geometrically nonlinear earthquake behavior of suspension bridges   总被引：2，自引：1，他引：1  

Süleyman Adanur  Ahmet Can Altuni?ik  Alemdar Bayraktar  Mehmet Akk?se 《Natural Hazards》2012,64(1):593-614

This paper presents a comparison of near-fault and far-fault ground motion effects on geometrically nonlinear earthquake behavior of suspension bridges. Bo?azi?i (The First Bosporus) and Fatih Sultan Mehmet (Second Bosporus) suspension bridges built in Istanbul, Turkey, are selected as numerical examples. Both bridges have almost the same span. While Bo?azi?i Suspension Bridge has inclined hangers, Fatih Sultan Mehmet Suspension Bridge has vertical hangers. Geometric nonlinearity including P-delta effects from self-weight of the bridges is taken into account in the determination of the dynamic behavior of the suspension bridges for near-fault and far-fault ground motions. Near-fault and far-fault strong ground motion records, which have approximately identical peak ground accelerations, of 1999 Chi-Chi, 1999 Kocaeli, and 1979 Imperial Valley earthquakes are selected for the analyses. Displacements and internal forces of the bridges are determined using the finite element method including geometric nonlinearity. The displacements and internal forces obtained from the dynamic analyses of suspension bridges subjected to each fault effect are compared with each other. It is clearly seen that near-fault ground motions are more effective than far-fault ground motion on the displacements and internal forces such as bending moment, shear force and axial forces of the suspension bridges.  相似文献   

GIS-based landslide susceptibility mapping using bivariate statistical analysis in Devrek (Zonguldak-Turkey)   总被引：15，自引：10，他引：5  

Cagatay Yilmaz  Tamer Topal  Mehmet Lütfi Süzen 《Environmental Earth Sciences》2012,65(7):2161-2178

Devrek town with increasing population is located in a hillslope area where some landslides exist. Therefore, landslide susceptibility map of the area is required. The purpose of this study was to generate a landslide susceptibility map using a bivariate statistical index and evaluate and compare the results of the statistical analysis conducted with three different approaches in seed cell concept resulting in different data sets in Geographical Information Systems (GIS) based landslide susceptibility mapping applied to the Devrek region. The data sets are created from the seed cells of (a) crowns and flanks, (b) only crowns, and (c) only flanks of the landslides by using ten different causative parameters of the study area. To increase the data dependency of the analysis, all parameter maps are classified into equal frequency classes based directly on the percentile divisions of each corresponding seed cell data set. The resultant maps of the landslide susceptibility analysis indicate that all data sets produce fairly acceptable results. In each data set analysis, elevation, lithology, slope, aspect, and drainage density parameters are found to be the most contributing factors in landslide occurrences. The results of the three data sets are compared using Seed Cell Area Indexes (SCAI). This comparison shows that the crown data set produces the most accurate and successful landslide susceptibility map of the study area.  相似文献   

Removal of Organochlorine Pesticides from Aqueous Solution by Using Neutralized Red Mud     

Senar Ozcan  Ali Tor  Mehmet Emin Aydin 《洁净——土壤、空气、水》2011,39(11):972-979

This work describes the potential usability of neutralized red mud for the removal of organochlorine pesticides (OCPs) from aqueous solutions. After examination on the adsorption capability of neutralized red mud for all studied OCPs, the experiments were performed by employing aldrin as a model compound. The effect of several parameters, such as contact time, pH of the solution, initial aldrin concentration, and dosage of the adsorbent was evaluated by batch experiments. The determination of OCPs was carried out using traditional liquid–liquid extraction followed by a GC coupled with µ‐electron capture detector (GC‐µECD). The results showed that adsorption equilibrium time depended upon the initial aldrin concentration and adsorption followed the second‐order kinetic model. Kinetic study also indicated that the film diffusion mechanism was a main rate control mechanism. The removal was explained by considering the electrostatic interactions between metal oxides surface of the neutralized red mud and inductively charged centers (negative charge (d?) of chlorine atoms and positive charge (d+) of π‐cloud aromatic ring) of the aldrin molecules. In comparison to the Langmuir isotherm model, the Freundlich model better represented the adsorption data. The neutralized red mud was also succesfully employed for the removal of OCPs from real water samples, including tap water and surface (lake) water, fortified with studied OCPs.  相似文献   

The effect of the electron sound speed on wave propagation in the ionospheric plasma     

Ali Yesil  Mehmet Aydogdu 《Acta Geophysica》2011,59(2):398-406

In this study, the effect of the electron sound speed on the extraordinary wave propagation is calculated without an approximation for either collisional or collisionless cases in the ionospheric plasma by using the real geometry of the Earth’s magnetic field for the Northern Hemisphere. It is observed that there is no remarkable effect on the propagation of the extraordinary wave, especially at reflection altitudes. But it is also observed that the magnitudes of k ² (the square of the wave number) have changed every season, and the phase velocity of wave in warm ionospheric plasma has increased.  相似文献   

Wet and dry spell analysis of Global Climate Model-generated precipitation using power laws and wavelet transforms   总被引：2，自引：2，他引：0  

Ashok K. Mishra  Mehmet ?zger  Vijay P. Singh 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(4):517-535

Climate model simulations for the twenty-first century point toward changing characteristics of precipitation. This paper investigates the impact of climate change on precipitation in the Kansabati River basin in India. A downscaling method, based on Bayesian Neural Network (BNN), is applied to project precipitation generated from six Global Climate Models (GCMs) using two scenarios (A2 and B2). Wet and dry spell properties of monthly precipitation series at five meteorologic stations in the Kansabati basin are examined by plotting successive wet and dry durations (in months) against their number of occurrences on a double-logarithmic paper. Straight-line relationships on such graphs show that power laws govern the pattern of successive persistent wet and dry monthly spells. Comparison of power-law behaviors provides useful interpretation about the temporal precipitation pattern. The impact of low-frequency precipitation variability on the characteristics of wet and dry spells is also evaluated using continuous wavelet transforms. It is found that inter-annual cycles play an important role in the formation of wet and dry spells.  相似文献   

Stratigraphy and palaeoenvironment of the Lower-“middle” Oligocene units in the northern part of the Western Taurides (İncesu area,Isparta, Turkey)     

Mehmet Serkan Akkiraz  Funda Akgün  Sefer Örçen 《Journal of Asian Earth Sciences》2011,40(2):452-474

This study describes the stratigraphic and palaeoenvironmental significance of the Lower-“middle” Oligocene sediments based on the fauna from the Delikarkas? Formation and the microflora from the ?ncesu Formation of the ?ncesu area (northern part of the western Taurides, Isparta province, Turkey). In the area, the Oligocene sediments show a regressive succession, which begins with the limestones of the Delikarkas? Formation indicating marine conditions followed by conglomerates, sandstones and coaly mudstones of alluvial and fluvial (shallow marine-continental) origin. A well preserved foraminiferal assemblage including Nummulites intermedius, Nummulites vascus and Halkyardia maxima proves an Early Oligocene age for the Delikarkas? Formation. Due to palynological markers such as Boehlensipollis hohli, Slowakipollis hippophaëoides, Dicolpopollis kockelii, Magnolipollis neogenicus ssp. minor, Plicapollis pseudoexcelsus, Caryapollenites simplex and Intratriporopollenites instructus the ?ncesu Formation, which concordantly rests on the Delikarkas? Formation, may be assigned to the Early-“middle” Oligocene. From the palynomorph assemblage, three zones have been recognised according to abundance of species. Zone 1 is characterized by predominance of C. simplex and Momipites punctatus and rarely presence of tricolpate and tricolporate pollen. Zone 2 consists mainly of Inaperturopollenites dubius, Leiotriletes maxoides ssp. maximus, Verrucatosporites favus, Verrucatosporites alienus and infrequently marine dinoflagellate cysts. Zone 3 is characterized by a high percentage of ferns such as Echinatisporis?chattensis and Polypodiaceoisporites saxonicus. The presence of marine dinoflagellate cysts like Apectodinium sp. and Cleistosphaeridium sp., back-mangrove elements such as Acrostichum aureum and lepidocaryoid palms (e.g. Longapertites discordis, Longapertites punctatus and Longapertites psilatus) in the sediments of the ?ncesu Formation imply coastal or near-coastal conditions. Terrestrial palynomorphs in more inland settings were transported by running water towards the sea. Conifers are represented by poorly preserved and rare pollen grains of Pityosporites, Cathayapollis and Piceapollis which may have been transported by wind. In this study, the terrestrial climate of the ?ncesu Formation is also discussed on the basis of the Coexistence Approach method. The climate was warm at the coast (over 20 °C), as evidenced by A. aureum and lepidocaryoid palms, whereas there was a mean annual temperature of 17.2–17.4 °C must be assumed for the upland environment(s).  相似文献   

The effect of welding degree on geotechnical properties of an ignimbrite flow unit: the Bitlis castle case (eastern Turkey)   总被引：1，自引：0，他引：1  

Tamer Koralay  Mehmet ?zkul  Halil Kumsar  Sefer Beran ?elik  Kadir Pekta? 《Environmental Earth Sciences》2011,64(3):869-881

Ignimbrites are associated with nearly most of the world’s volcanoes and are defined as a deposit from pyroclastic density currents. They consist predominantly of pumiceous lapilli and blocks, and glass shards, which shows evidence of having been emplaced as a concentrated hot and dry particulate flow. These rocks are widely used as building stone especially in ancient buildings. Bitlis valley is covered by ignimbritic products, derived from Nemrut stratovolcano, one of the significant volcanic centers in Eastern Anatolia. The Bitlis ignimbrite is separated into lower level (LL), middle level (ML) and upper level (UL) according to color, welding degree and structural features. All three levels were used extensively in many parts of the Bitlis castle as masonry materials. Studies were carried out on mineralogical and geochemical composition and on physical and mechanical properties of the ignimbrites. In addition, a freeze–thaw cycle test was executed. There are no considerable differences in mineralogical composition among the levels of ignimbrite. All levels contain plagioclase, sanidine, pyroxene, and opaque mineral. In addition, anorthoclase and quartz are seen. In general, the LL of ignimbrite shows relic perlitic and eutaxitic texture, whereas eutaxitic and vesicular texture are commonly developed in the ML and UL, respectively. Lower, middle, and upper level ignimbrite samples display similar and limited compositional spread in terms of major oxide elements. They have trachyte composition. Building stones can be classified according to mineralogy, mechanical and physical properties and processing types. Mechanical and physical properties are very important with respect to stone quality/durability. The mechanical and physical properties of the ignimbrites are controlled by the welding degree. It was found that increasing welding degree from UL to LL correlates with increasing density, compressive strength and slake durability index and with decreasing porosity. The Bitlis ignimbrites have turned out as susceptible to freeze–thaw cycles.  相似文献   

Hydrochemical characterisation of ground and surface water at Dörtyol/Hatay/Turkey     

Maren Brehme  Traugott Scheytt  Mehmet Çelik  Uğur Erdem Dokuz 《Environmental Earth Sciences》2011,63(6):1395-1408

The degradation of ground water quality due to human activities is a widespread environmental problem. Furthermore, coastal aquifers are threatened by sea water intrusion as a result of increasing water exploitation. The investigation area near Dörtyol is located at the Mediterranean coast, southern Turkey, and dominated by agricultural land use. Drinking, domestic and agricultural purposes require different amounts of uncontaminated water. In this study the hydrogeological characteristics of the coastal plain were investigated. Discharge and ground water level measurements as well as geological investigations were undertaken in field in addition to anion and cation analyses of ground and surface water. The results show geological and anthropogenic influence on ground and surface water composition. In spite of a large number of wells in the coastal area sea water intrusion was not detected. With the goal of devising sustainable water use regulations, more emphasis and research needs to be directed to the long-term observation of ground and surface water quality as well as the detailed investigation of hydraulic characteristics of the local aquifer.  相似文献   

Comparative analysis of fuzzy inference systems for water consumption time series prediction   总被引：1，自引：0，他引：1  

Mahmut Firat  Mustafa Erkan Turan  Mehmet Ali Yurdusev   《Journal of Hydrology》2009,374(3-4):235-241

Two types of fuzzy inference systems (FIS) are used for predicting municipal water consumption time series. The FISs used include an adaptive neuro-fuzzy inference system (ANFIS) and a Mamdani fuzzy inference systems (MFIS). The prediction models are constructed based on the combination of the antecedent values of water consumptions. The performance of ANFIS and MFIS models in training and testing phases are compared with the observations and the best fit model is identified according to the selected performance criteria. The results demonstrated that the ANFIS model is superior to MFIS models and can be successfully applied for prediction of water consumption time series.  相似文献