Effects of anthropogenic activities on the Lower Sakarya River

We investigate the effects of anthropogenic activities on the Lower Sakarya River. The impacts of dam, levee, and bridge constructions, sand-gravel mining activities and water withdrawals during the industrialization period of the Sakarya River Basin have been explored by analyzing flow, sediment and channel cross section data from different periods in time by comparing pre- and post-1975 periods. The year 1975 is roughly determined to be commencement of heavy human activities. Assessment of data shows that average annual flow is reduced by almost 20% after 1975. Due to increased regulations after 1975 flow became less variable, i.e. low-flows are increased and high-flows are reduced. Flow showed less variation with seasons during the post-1975 period compared to the pre-1975 period. Close inspection of precipitation and temperature patterns over the course of this period indicates that these changes in the flow regime cannot be attributed to natural causes and must be instigated by anthropogenic activities. Analyses of sediment data point toward a consistent reduction in sediment concentration and loadings with years in the Lower Sakarya River. Sediment rating curves developed for pre- and post-1975 exhibit a similar pattern. The impact of the anthropogenic activities on the river cross section is also examined by employing data from 1965, 2003 and 2006 at various points along the river profile. We found as much as 1 m aggradation at the thalweg elevation along the river profile starting from the river mouth up to the 12th km. Degradation in thalweg elevation is observed upstream of the 12th km, as much as 7 m at some locations. This research clearly undermines how human activities can alter the river hydrology and morphology. The adverse impacts of these modifications on the stream ecology in the Lower Sakarya River unfortunately remain unresolved.     

Phytosynthesis of Silver Nanoparticles using Leaf Extracts from <Emphasis Type="Italic">Ocimum basilicum</Emphasis> and <Emphasis Type="Italic">Mangifira indica </Emphasis>and their Effect on some Biochemical Attributes of <Emphasis Type="Italic">Triticum aestivum</Emphasis>

In this investigation, leaf extracts of Ocimum basilicum and Mangifira indica were used as reducing agents for biosynthesis of silver nanoparticles (AgNPs). The biosynthesized AgNPs were authorized by UV-vis spectrophotometry and X?ray diffraction (XRD) analysis. AgNPs were obtained after 5?min of reaction at 80^oC. The formation of AgNPs was confirmed by the presence of absorption peaks at 439?nm using extract from O. basilicum and at 442.5?nm from M. indica. X?ray spectra showed strong peaks for the crystalline Ag. Shape and size of the biosynthesized AgNPs were studied using high resolution transmission electron microscope (HR-TEM). Size of the produced AgNPs was found to be 9–35?nm. Effect of the synthesized nanosilver was then investigated on some biochemical attributes of wheat plant (Triticum aestivum cultivar saka 92). The growth parameters such as shoot lengths, fresh and dry weight of shoot, chlorophyll, carbohydrate and protein contents in shoot of wheat plant were investigated. Application of AgNPs synthesized from Ocimum basilicum and from Mangifira indica at the concentrations of 20,40?ppm showed an increase in shoot length, fresh and dry weight of shoot, chlorophyll, total carbohydrate and protein content in shoot of wheat plants, beyond these concentrations an inhibitory effects were shown.     

High infection rates of the tick Hyalomma anatolicum anatolicum with Trypanosoma theileri

A crossbred calf (3 months old) obtained from a farm where regular control of ticks was practised and found to be free of blood parasites was inoculated with 20 ml pooled blood collected from four field cattle which had very low Trypanosoma theileri parasitaemias (one parasite per 70 microl blood as determined by the haematocrit centrifugation technique). Trypanosoma theileri was present in the blood 6 days after injection and a peak parasitaemia of 42 parasites per 70 microl blood was recorded by day 12. Hyalomma anatolicum anatolicum nymphs were applied on the ears of the calf on day 8 and they dropped engorged by days 13 and 14. The resulting adult ticks were examined for the presence of T. theileri by severing a leg and making a smear of the clear haemolymph which exuded from the wound. The smear was fixed in methanol and stained with Giemsa stain. The infection rate with T. theileri in the ticks was 43.3% (26 out of 60). The intensity of infection was very high and various developmental stages of the flagellates were observed (epimastigotes, sphaeromastigotes, trypomastigotes and other intermediate stages). The haemolymph from 12 ticks was also collected in tissue culture medium and the trypanosomes survived for 25 weeks before eventually dying. The results demonstrated unequivocally the high vectorial capacity of the tick H. a. anatolicum for T. theileri.     

Inhibition of aflatoxin production in Aspergillus flavus by pyrazolines and pyrazoles

A new series of 1,3,5-triarylpyrazolines, obtained from 3, 4-dichloroacetophenone, were readily dehydrogenated by tetrachloro-o-benzoquinone at room temperature to the pyrazoles. The spectra and fluorescence of the compounds are discussed. The pyrazolines and pyrazoles did not significantly affect the mycelial growth of 19 fungal isolates, but at low concentrations, they inhibited aflatoxin production by Aspergillus flavus.     

Regulation of some biochemical attributes in drought-stressed cauliflower (Brassica oleracea L.) by seed pre-treatment with ascorbic acid

Cauliflower (Brassica oleracea L. var. botrytis) is widely used as a vegetable in many countries; however, productivity is adversely affected in areas affected by drought. To investigate the role of exogenously applied ascorbic acid (AsA) in mitigating the negative effects of drought on cauliflower, a pot experiment was performed using two cultivars of cauliflower ‘Local’ and ‘S-78’. Seeds of both cultivars were soaked in 75 mg l^–1, or in 150 mg l^–1 AsA, or in water (control) for 16 h. Water-deficit stress suppressed plant growth, reduced leaf chlorophyll concentrations, relative water contents (RWC), shoot and root P and K⁺ ion concentrations, and total soluble protein concentrations, significantly. However, significant drought-induced increases were observed in relative membrane permeability (RMP), the accumulation of total phenolic compounds, leaf free proline, glycinebetaine (GB), endogenous AsA, and hydrogen peroxide concentrations, and in the activity of superoxide dismutase (SOD). Seed treatment with 75 or 150 mg l^–1 AsA resulted in lower accumulations of H₂O₂, while increasing shoot and root fresh weights and dry weights, RWC, total phenolic compound, free proline, GB, and endogenous AsA concentrations, and the activities of SOD and catalase (CAT). No changes were observed in leaf chlorophyll concentrations or in peroxidase (POD) activities, RMP, shoot and root P and K⁺ ion accumulation, or in total soluble protein concentrations under water stress or non-stress conditions following seed treatment with AsA. ‘Local’ had higher proline concentrations and SOD activities; however, ‘S-78’ had higher RWC values, GB, and AsA concentrations. Overall, a pre-sowing treatment of cauliflower seed with 75 or 150 mg l^–1 AsA improved seedling tolerance to drought stress in both cultivars, which could be attributed to AsA-induced decreases in RMP and H₂O₂ concentrations, increases in the activities of CAT and SOD, increased RWC, and higher total phenolic compound, proline, GB, and AsA concentrations. The exogenous application of AsA therefore offers an effective strategy to minimise the adverse effects of drought stress on vegetable crops, including cauliflower.     

New α-Glucosidase Inhibitory Triterpenic Acid from Marine Macro Green Alga Codium dwarkense Boergs

The marine ecosystem has been a key resource for secondary metabolites with promising biological roles. In the current study, bioassay-guided phytochemical investigations were carried out to assess the presence of enzyme inhibitory chemical constituents from the methanolic extract of marine green alga—Codium dwarkense. The bioactive fractions were further subjected to chromatographic separations, which resulted in the isolation of a new triterpenic acid; dwarkenoic acid (1) and the known sterols; androst-5-en-3β-ol (2), stigmasta-5,25-dien-3β,7α-diol (3), ergosta-5,25-dien-3β-ol (4), 7-hydroxystigmasta-4,25-dien-3-one-7-O-β-d-fucopyranoside (5), 7-hydroxystigmasta-4,25-dien-3-one (6), and stigmasta-5,25-dien-3β-ol (7). The structure elucidation of the new compound was carried out by combined mass spectrometry and 1D (¹H and ¹³C) and 2D (HSQC, HMBC, COSY, and NOESY) NMR spectroscopic data. The sub-fractions and pure constituents were assayed for enzymatic inhibition of alpha-glucosidase. Compound 1 showed significant inhibition at all concentrations. Compounds 2, 3, 5, and 7 exhibited a dose-dependent response, whereas compounds 4–6 showed moderate inhibition. Utilizing such marine-derived biological resources could lead to drug discoveries related to anti-diabetics.     

Population dynamics of citrus leaf miner on different varieties of citrus in correlation with abiotic environmental factors in Sargodha District,Punjab, Pakistan

From January 2010 to December 2011, samples of leaves from citrus varieties Kinnow, Musambi and Feutral were taken from the five tehsils (administrative subdivisions) of Sargodha District in Pakistan including Sargodha, Bahalwal, Silanwalli, Sahiwal and Kotmomin, to study the population trends in citrus leaf miner (CLM), Phyllocnistis citrella (Stainton) (Lepidoptera: Gracillariidae), and its correlation with various environmental factors: (temperature, humidity and rainfall); plant morphological factors: moisture contents of leaves, leaf thickness, surface area (cm ² ), and biochemical percentage of calcium, potassium and magnesium in leaves. The maximum population of CLM was observed on Kinnow and Feutral, followed by Musambi. The effect of these factors on the larval population was 8.39- 2.30(Mg)+2.73(K)-0.398(Ca)-0.100(Temp)0.038(Humidity)+0.567(Rain)+0.07(Moist) 1.01 (Thickness)-0.022(Surface area). This equation revealed that magnesium, calcium, temperature, humidity, leaf thickness and leaf surface area are negatively correlated with larvae population, whereas potassium, rainfall and moisture are positively correlated with larvae population.     

Flexibility analysis of irrigation outlet structures using simulation of irrigation canal hydrodynamic model

The Upper Swat Canal (USC) System became operational in 1917–1918 in North West Frontier Province (NWFP) of Pakistan. The rehabilitation and modernization of the USC was undertaken with a view to overcoming the shortage of water supplies for irrigation. The water allowance was enhanced from 0.39 to 0.77 Ls⁻¹ ha⁻¹ in the study area. Recently, the operation and management of a secondary canal or ‘distributary’ was transferred to the Farmers Organization (FO). This distributary named ‘Chowki’ offtakes from the Maira Branch of the USC. The cultivable command area (CCA) of this distributary is 4,306 ha and it serves 1,485 beneficiaries. A management committee on Chowki Distributary was formed in 2003. This distributary consists of one main and two minor channels having twenty-eight direct outlets. The Simulation of Irrigation Canal (SIC) hydrodynamic model was used to evaluate the flexibility of Chowki Distributary. The model was calibrated at 100, 80 and 70% of the design discharge (Q _d) and it was validated at 90, 85 and 60% of the design discharge. The observed and simulated water levels were in close agreement with each other for the calibration and validation periods. The statistical analysis and paired t-test indicate that the model results are not statistically different from the measured values at 1% significance level. The simulated results of the SIC model were applied to studying flexibility of the outlet structures along the Chowki Distributary. The flexibility analysis demonstrates that poor performance is inbuilt into the system due to inadequate control over the accuracy of the crest setting during the construction of the outlets.