Long‐term site productivity effects of different Rhododendron control methods in eastern beech (Fagus orientalis Lipsky) ecosystems in the Western Black Sea region of Turkey

The study area is located in an eastern beech stand on a fertile and mesic upland site in the western Black Sea region of Turkey. During natural regeneration of the beech stand, rhododendron was differentially controlled. The experiment used a randomized block design with four replicates and two different site preparation practices. The manual treatment was hand grubbing. The whole plant was uprooted and left on the site. The mechanical treatment scarified the surface soil to 5–10 cm depth with a bulldozer equipped with a brush rake. After 17 years following site preparation, the number of trees on the grubbing site (GS) was 60% more than that of mechanical treatment sites (MTS). Total tree biomass per hectare was 39% greater on GS than that of MTS. Beech trees on the grubbing sites had 18, 115, 29, 17 and 78% more N, P, K, Ca and Mg than MTS, respectively. Forest floor N content on GS was 50% more than that of MTS. On the GS, Ca content also was three times more than that of MTS. At 0–20 cm depth, cation exchange capacity on GS was 48% higher than that of MTS. At the same depth, GS had 50, 100, 78, 23, 8, 10 and 49% more C, N, P, Ca, K, Mg and S concentrations than those of MTS, respectively. Removing of organic layer and upper soil with mechanical site preparation depletes ecosystem nutrient pools compared with manual grubbing. This difference is sustained in the long‐term. Grubbing is both effective and by leaving organic layer on the sites, grubbing preserves the long‐term productivity of the ecosystem.     

Preliminary observations on effects of tillage systems on soil physical properties, cotton root growth and yield in Gezira Scheme, Sudan

The decline in cotton yields in the Gezira Scheme, Sudan, has been partially attributed to deterioration in soil physical properties and the formation of a plough pan 20 cm deep as a result of the repeated use of the disc plough for land preparation. This field study was conducted during the 1990/91 season at the Gezira Research Station Farm to evaluate the effect of tillage on some soil physical properties of Vertisols, root growth and yield of cotton (Gossypium barbadense L.). Three tillage systems were used: disc harrowing (DH), three bottom disc plough (DP) and subsoiling (SS). Infiltration rates, bulk densities, soil penetration resistance, moisture depletion and root and shoot growth were measured. The results indicated that infiltration rate was not increased significantly by SS. Plant height and shoot dry matter were significantly higher with SS at later growth stages. Bulk density of the plough pan at 135 days after sowing accounted for 90% of the observed variation in subsoil root dry weight while soil penetration resistance accounted for 59% of the variation. Subsoiling increased water use efficiency 25 and 13% over DH and DP respectively. Subsoiling increased cotton yields over DH but the increase over DP was not significant.     

Removal of Trichloroethylene by Activated Carbon in the Presence and Absence of TiO2 Nanoparticles

Nanoparticles (NPs) are emerging as a new type of contaminant in water and wastewater. The fate of titanium dioxide nanoparticles (TiO₂NPs) in a granular activated carbon (GAC) adsorber and their impact on the removal of trichloroethylene (TCE) was investigated. Key parameters governing the TiO₂NP?CGAC interaction such as specific surface area (SSA), zeta potential, and the TiO₂NP particle size distribution (PSD) were determined. The impact of TiO₂NPs on TCE adsorption on GAC was tested by conducting TCE adsorption isotherm, kinetic, and column breakthrough studies in the presence and absence of TiO₂NPs. SSA and pore size distribution of the virgin and spent GAC were obtained. The fate and transport of the TiO₂NPs in the GAC fixed bed and their impact on TCE adsorption were found to be a function of their zeta potential, concentration, PSD, and the nature of their aggregation. The TiO₂NPs under investigation are not stable in water and rapidly form larger aggregates. Due to the fast adsorption kinetics of TCE, the isotherm and kinetic studies found no effect from TiO₂NPs. However, TiO₂NPs attached to GAC and led to a reduction in the amount of TCE adsorbed during the breakthrough experiments suggesting a preloading pore blockage phenomenon. The analysis of the used GAC confirmed the pore blockage and SSA reduction.     

Chemically Modified Silica Gel with N-(2-aminoethyl)-Salicylaldimine for Simultaneous Solid Phase Extraction and Preconcentration of Cu(II), Ni(II), Cd(II) and Zn(II) in waters

In this study, N-(2-aminoethyl)salicylaldimine bonded silica gel was synthesized and characterized using Fourier transform infrared and C, H, N elemental analysis. The analytical conditions such as the pH and volume of the solution, flow rates of the sample solution and the type of eluent to achieve the simultaneous preconcentration of Cu(II), Ni(II), Cd(II) and Zn(II) were optimised using the modified silica gel loaded column using a solid phase extraction technique. Samples (50?C500?ml) containing metal ions at optimal pH of 8 were passed through the column filled with the modified silica gel at 7?ml min^?1 and then elution was achieved using 5?ml of 0.25?M HCl. The concentrations of metal ions in the eluates were determined using flame atomic absorption spectrometry (FAAS). The effects of matrix ions were also studied and none of the major ions interfered to the proposed method. The accuracy of the developed method was validated using a certified reference water sample (Ontario Lake water, NWTMDA-54.4). The method was successfully applied to the analysis of various natural water samples. The adsorption capacities of the modified silica gel for Cu(II), Ni(II), Cd(II) and Zn(II) ions were determined and found to be 0.332, 0.261, 0.130 and 0.375?mmol g^?1, respectively.     

Peroxidase gene-based estimation of genetic relationships and population structure among Citrus spp. and their relatives

Many stress-related interactions such as pathogen infection, insect tolerance, salt tolerance, auxin degradation, cell wall lignification, tissue suberization, and plant senescence involve various isoforms of peroxidases. Peroxidase gene polymorphism (POGP) markers have been used to estimate diversity, relationships and population structure among 80 Citrus and their relatives in Aurantioideae by using unweighted pair group method arithmetic average (UPGMA) and bayesian substructuring analysis. Fourteen primers produced a total of 148 fragments and 147 of them were polymorphic. The UPGMA analysis demonstrated that the accessions had a similarity range from 0.27 to 0.98 and were distinguished. The results of this study were mostly consistent with previous reports of different marker systems, but few different findings were also detected. The subtribe Clauseninae (tribe Clauseneae) did not clearly separate from the subtribes of the tribe Citreae. Substructuring analysis indicated that there were six subpopulations among the accessions studied. This study revealed that the POGP markers can be utilized to estimate genetic diversity, relationships and population structure in Citrus and related species in the Aurantioideae subfamily.     

Chemical composition and antifungal activity of Salvia macrochlamys and Salvia recognita essential oils

Essential oils of Salvia macrochlamys and Salvia recognita were obtained by hydrodistillation of dried aerial parts and characterized by gas chromatography and gas chromatography-mass spectrometry. One hundred and twenty identified constituents representing 97.7% in S. macrochlamys and 96.4% in S. recognita were characterized, and 1,8-cineole, borneol, and camphor were identified as major components of the essential oils. The oils were evaluated for their antimalarial, antimicrobial, and antifungal activities. Antifungal activity of the essential oils from both Salvia species was nonselective at inhibiting growth and development of reproductive stroma of the plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides. S. macrochlamys oil had good antimycobacterial activity against Mycobacterium intracellulare; however, the oils showed no antimicrobial activity against human pathogenic bacteria or fungi up to a concentration of 200 microg/mL. S. recognita oil exhibited a weak antimalarial activity against Plasmodium falciparum.     

茎段外植体白化处理促进“皇家嘎拉”苹果不定芽再生

研究比较了来自正常和白化处理的皇家嘎拉（Royal Gala)苹果（Malus domestic Borkh)新梢节段外植体不定芽的离体再生，。结果表明，白化处理的新梢顶部第一节段外植体所产生的不定芽数比第二、第三、第四节段分别高2、8、73倍；白化新梢的外植体不定芽再生数目比同一部位正常新梢高7倍。培养基添加较低浓度的TDZ有利于不定芽再生，对白化外植体来说，1μmol/L比10μmol/L高2．5倍，非白化外植体则高7倍,平均每个外植体的不定芽再生数高达68．8个。白化第一节段外植体的不定芽再生能力比常用的叶片外植体高4倍，表明该类外植体可用于苹果的转基因和染色体组工程育种。     

Exploiting the potential of indigenous fruit trees: <Emphasis Type="Italic">Grewia tenax</Emphasis> (Forssk.) Fiori in Sudan

The small leaved white cross berry (Grewia tenax [Forssk.] Fiori) is a fruit-producing deciduous shrub or small tree of widespread occurrence in semi-arid and sub-humid tropical climates. Despite its well-recognized potential and high prices on local markets, there are no commercial plantations in Sudan. Wild plants have continuously been used to meet the growing commercial demand for their fruits. Recently, there has been an increased interest in finding alternative, potentially high-value cash crops to improve the income of small farmers who are currently depending upon growing and selling millet (Pennisetum glaucum [L.] R. Br.), sorghum (Sorghum bicolor [L.] Moench), sesame (Sesamum indicum L.), and groundnut (Arachis hypogaea L.). G. tenax has often been cited as a prime candidate for domestication as a useful horticultural plant. One major factor hampering this development is the limited and scattered knowledge available on this species. The purpose of this paper is to highlight the importance of G. tenax by providing information on its botanical and horticultural characteristics in the effort to promote its domestication and commercialization for regional and global markets.     

Intravenous pharmacokinetics of moxifloxacin following simultaneous administration with flunixin meglumine or diclofenac in sheep

In this study, the pharmacokinetics of moxifloxacin (5 mg/kg) was determined following a single intravenous administration of moxifloxacin alone and co-administration with diclofenac (2.5 mg/kg) or flunixin meglumine (2.2 mg/kg) in sheep. Six healthy Akkaraman sheep (2 ± 0.3 years and 53.5 ± 5 kg of body weight) were used. A longitudinal design with a 15-day washout period was used in three periods. In the first period, moxifloxacin was administered by an intravenous (IV) injection. In the second and third periods, moxifloxacin was co-administered with IV administration of diclofenac and flunixin meglumine, respectively. The plasma concentration of moxifloxacin was assayed by high-performance liquid chromatography. The pharmacokinetic parameters were calculated using a two-compartment open pharmacokinetic model. Following IV administration of moxifloxacin alone, the mean elimination half-life (t_1/2β), total body clearance (Cl_T), volume of distribution at steady state (V_dss) and area under the curve (AUC) of moxifloxacin were 2.27 hr, 0.56 L h⁻¹ kg⁻¹, 1.66 L/kg and 8.91 hr*µg/ml, respectively. While diclofenac and flunixin meglumine significantly increased the t_1/2β and AUC of moxifloxacin, they significantly reduced the Cl_T and V_dss. These results suggest that anti-inflammatory drugs could increase the therapeutic efficacy of moxifloxacin by altering its pharmacokinetics.