Primary sulfates in atmospheric sulfates: estimation by oxygen isotope ratio measurements

The relative amounts of primary and secondary sulfates in atmospheric aerosols and precipitation can be estimated from measurements of the stable oxygen isotope ratios. The oxygen-18 content of sulfates formed in power plant stack gases before emission into the atmosphere is significantly higher than that of sulfates formed from sulfur dioxide after emission. Results show that 20 to 30 percent of the sulfates in rain and snow at Argonne, Illinois, are of primary origin.     

RAPD and ISSR fingerprinting in cultivated chickpea (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) and its wild progenitor <Emphasis Type="Italic">Cicer reticulatum</Emphasis> Ladizinsky

Detection of genetic relationships between 19 chickpea cultivars and five accessions of its wild progenitor Cicer reticulatum Ladizinsky were investigated by using RAPD and ISSR markers. On an average, six bands per primer were observed in RAPD analysis and 11 bands per primer in ISSR analysis. In RAPD, the wild accessions shared 77.8% polymorphic bands with chickpea cultivars, whereas they shared 79.6% polymorphic bands in ISSR analysis. In RAPD analysis 51.7% and 50.5% polymorphic bands were observed among wild accessions and chickpea cultivars, respectively. Similarly, 65.63% and 56.25% polymorphic bands were found in ISSR analysis. The dendrogram developed by pooling the data of RAPD and ISSR analysis revealed that the wild accessions and the ICCV lines showed similar pattern with the dendrogram of RAPD analysis. The ISSR analysis clearly indicated that even with six polymorphic primers, reliable estimation of genetic diversity could be obtained, while nearly 30 primers are required for RAPD. Moreover, RAPD can cause genotyping errors due to competition in the amplification of all RAPD fragments. The markers generated by ISSR and RAPD assays can provide practical information for the management of genetic resources. For the selection of good parental material in breeding programs the genetic data produced through ISSR can be used to correlate with the relationship measures based on pedigree data and morphological traits to minimize the individual inaccuracies in chickpea.     

Accumulation of bioactive compounds during growth and development of mango ginger (Curcuma amada Roxb.) rhizomes

Accumulation of bioactive compounds and storage components during developmental stages of mango ginger ( Curcuma amada Roxb.) rhizome was investigated from 60 to 240 days, as a function of physiological maturity. Four distinct developmental phases were defined, namely, vegetative phase (up to 60 days from planting), initiation and development phase (60-150 days), maturation phase (150-180 days), and senescence phase (180 days). Difurocumenonol, a bioactive terpenoid compound and phenolics were identified as biomarkers, to determine the optimum physiological maturity to harvest mango ginger rhizome. Accumulation of phenolics was observed in newly initiated rhizomes (after 60 days from planting). The phenolic content was high in mango ginger pulp compared to its juice. Newly initiated rhizome contained no difurocumenonol, and it was observed after 120 days after planting. Peak accumulation of phenolics, difurocumenonol, and total protein were noticed in 180 day old rhizome. Accordingly, the abundance of these components on 180 days was set as an optimum maturity standard for harvest of mango ginger rhizome, compared with a conventional harvest period that ranges from 200 to 240 days.     

Differentiation of chloride and sulphate salinity on the basis of ionic distribution in genetically diverse cultivars of wheat

Sulphate (SO₄) salinity, in general, was found to be more injurious than chloride (Cl) salinity in all the four genetically diverse wheat cultivars—Triticum monococcum (Cl), T. aestivum cv. Chinese spring (C2), T. turgidum cv. langdon (C3) and amphidiploid (C4) obtained by a cross between T. aestivum cv. Chinese spring x Thinopyrum bessarabicum grown in hydroponic cultures containing iso‐osmotic saline treatments T1 (90 mM NaCl), T2 (45 mM NaCl+22.5 mM Na₂SO₄), T3 (15 mM NaCl + 37.5 mM Na₂SO₄), and T4 (45 mM Na₂SO₄). Among the cultivars, C4 followed by C2 and C3 appeared to be more salt resistant and Cl the most salt sensitive as far as various observations on osmotic potential and internal ion accumulation were concerned. Salt resistance could be ascribed to more exclusion of Na and Cl ions. Sulphate injury might be due to less effective sequestration or mobility of this ion towards some innocuous centres of plant tissues. Most of the interactive effects of cultivar versus salinity were prominently higher in cultivar C4 in treatment T1.     

Yield components,light interception and marker compound accumulation of stevia (Stevia rebaudiana Bertoni) affected by planting material and plant density under western Himalayan conditions

A field experiment was conducted to study the effect of planting material and plant density on stevia (Stevia rebaudiana Bertoni) under western Himalayan conditions during 2011 and 2012. The experiment conducted in a split plot design consisted of two types of planting material (rooted slips and fresh seedlings) in the main plot and five inter- and intra-row spacing in subplots with three replications. Yield attributes and dry leaf biomass yield of stevia were not affected by the type of planting material; however, plant density significantly influenced the yield attributes and leaf and stem dry biomass. Although the wider spacing (60 × 45 cm) gave more leaves, higher leaf area index, higher leaf dry mass per plant as compared to closer spacing, it resulted in lower values of these attributes per unit area. Plants spaced in 30 × 30 cm accumulated 41.2% and 42.8% more total biomass than 60 × 45 cm. Steviol glycoside content did not change due to different planting materials and plant densities; however, closer plant spacing (30 × 30 cm) recorded 114.8% and 70.0% higher steviol glycoside accumulation compared to wider row spacing (60 × 45 cm) in 2011 and 2012, respectively.     

Effects of surface fire on litter decomposition and occurrence of microfungi in a Cymbopogon polyneuros dominated grassland

Abstract

Litter decomposition rate, changes in macronutrients such as nitrogen (N), phosphorus (P) and potassium (K) from different grades of litter decomposition and occurrence of soil microfungi were investigated in a Cymbopogon polyneuros-dominated tall grass ecosystem from a burned and an unburned site in southern India. The litter decomposition rate was higher at the burned site than at the unburned site. This rate was also higher when the litter was mixed with the mineral soil material than leaving the litter unaffected on the soil surface. The concentrations of N, P, and K in the litter decreased as a result of progressed litter decomposition. Occurrence of microfungi identified from the different decomposition grades of the Cymbopogon polyneuros litter was higher at the burned site compared to the unburned site. Microfungal species present at both sites showed only minor differences.     

Curcumin nanoparticles: preparation, characterization, and antimicrobial study

Curcumin is a highly potent, nontoxic, bioactive agent found in turmeric and has been known for centuries as a household remedy to many ailments. The only disadvantage that it suffers is of low aqueous solubility and poor bioavailability. The aim of the present study was to develop a method for the preparation of nanoparticles of curcumin with a view to improve its aqueous-phase solubility and examine the effect on its antimicrobial properties. Nanoparticles of curcumin (nanocurcumin) were prepared by a process based on a wet-milling technique and were found to have a narrow particle size distribution in the range of 2-40 nm. Unlike curcumin, nanocurcumin was found to be freely dispersible in water in the absence of any surfactants. The chemical structure of nanocurcumin was the same as that of curcumin, and there was no modification during nanoparticle preparation. A minimum inhibitory concentration of nanocurcumin was determined for a variety of bacterial and fungal strains and was compared to that of curcumin. It was found that the aqueous dispersion of nanocurcumin was much more effective than curcumin against Staphylococcus aureus , Bacillus subtilis , Escherichia coli , Pseudomonas aeruginosa , Penicillium notatum , and Aspergillus niger . The results demonstrated that the water solubility and antimicrobial activity of curcumin markedly improved by particle size reduction up to the nano range. For the selected microorganisms, the activity of nanocurcumin was more pronounced against Gram-positive bacteria than Gram-negative bacteria. Furthermore, its antibacterial activity was much better than antifungal activity. The mechanism of antibacterial action of curcumin nanoparticles was investigated by transmission electron micrograph (TEM) analysis, which revealed that these particles entered inside the bacterial cell by completely breaking the cell wall, leading to cell death.     

Pharmacokinetics of cefpodoxime in plasma and subcutaneous fluid following oral administration of cefpodoxime proxetil in male beagle dogs

Kumar, V., Madabushi, R., Lucchesi, M. B. B., Derendorf, H. Pharmacokinetics of cefpodoxime in plasma and subcutaneous fluid following oral administration of cefpodoxime proxetil in male beagle dogs. J. vet. Pharmacol. Therap. 34 , 130–135. Pharmacokinetics of cefpodoxime in plasma (total concentration) and subcutaneous fluid (free concentration using microdialysis) was investigated in dogs following single oral administration of prodrug cefpodoxime proxetil (equivalent to 5 and 10 mg/kg of cefpodoxime). In a cross over study design, six dogs per dose were utilized after a 1 week washout period. Plasma, microdialysate, and urine samples were collected upto 24 h and analyzed using high performance liquid chromatography. The average maximum concentration (C_max) of cefpodoxime in plasma was 13.66 (±6.30) and 27.14 (±4.56) μg/mL with elimination half‐life (t_1/2) of 3.01 (±0.49) and 4.72 (±1.46) h following 5 and 10 mg/kg dose, respectively. The respective average area under the curve (AUC_0–∞) was 82.94 (±30.17) and 107.71 (±30.79) μg·h/mL. Cefpodoxime was readily distributed to skin and average free C_max in subcutaneous fluid was 1.70 (±0.55) and 3.06 (±0.93) μg/mL at the two doses. Urinary excretion (unchanged cefpodoxime) was the major elimination route. Comparison of subcutaneous fluid concentrations using pharmacokinetic/pharmacodynamic indices of fT_>MIC indicated that at 10 mg/kg dose; cefpodoxime would yield good therapeutic outcome in skin infections for bacteria with MIC₅₀ upto 0.5 μg/mL while higher doses (or more frequent dosing) may be needed for bacteria with higher MICs. High urine concentrations suggested cefpodoxime use for urinary infections in dogs.     

Biological response of chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), to various regimes of chemical and biorational insecticides

The chilli thrips Scirtothrips dorsalis (Hood) (Thysanoptera: Thripidae), a new invasive pest in the USA, is an economically important pest of certain vegetable, ornamental and fruit crops in southern and eastern Asia, Oceania and parts of Africa. These crops cannot be protected from the pest without resorting to the use of chemical insecticides. In order to forestall or delay the development of insecticide resistance in S. dorsalis, we continued our focus on the discovery of insecticides with different modes of action for rotational use. In this study we evaluated candidate insecticides to control S. dorsalis on ‘Jalapeno’ pepper, Capsicum annuum L.; these materials belong to different IRAC mode of action classes as follows: (i) 4A – neonicotinoids, i.e., imidacloprid, thiamethoxam and dinotefuran, (ii) 5 – spinosyns, i.e., spinosad and spinetoram, (iii) 3A – pyrethroids, i.e., β-cyfluthrin, esfenvalerate, ζ-cypermethrin and λ-cyhalothrin and (iv) 8D – borax mixed together with orange oil and detergents in the TriCon^® formulation. In addition we evaluated the entomopathogenic fungus, Beauveria bassiana (Botanigard^®) alone and in combination with the borax formulation at ½ of their usual rates of application. Each of the 3 neonicotinoid insecticides when applied either as a single foliar spray or as a soil drench significantly suppressed both adults and larvae for at least 10 days; indeed imidacloprid did so for 15 days. Dinotefuran was more effective as a foliar spray than as a soil drench. Spinosyns applied as a single foliar spray, significantly suppressed both adults and larvae through 15 days after treatment (DAT). None of the 4 pyrethroids provided significant suppression of either adults or larvae. The borax formulation suppressed adults and larvae through 10 DAT. B. bassiana significantly suppressed only the larvae at 5 DAT and not at 10 DAT. This study brings the number of insecticides known to be effective against S. dorsalis to 10 and these belong to 7 different modes of action classes. The use of such insecticides in rotation belonging to different classes will help delay the development of insecticide resistance in S. dorsalis.     

Water use in rice crop through different methods of irrigation in a sodic soil

Sodic soils are characterized by high exchangeable sodium on exchange sites, soil pH greater than 8.5, relatively low electrical conductivity, low infiltration rate and dispersed clay. These characteristics restrict the capacity of soil to absorb water, resulting in poor infiltration. Evidently, these soils require application of irrigation water at shorter intervals for crop production. Thus, irrigation strategy for sodic soils differs from that of normal soils. An experiment to determine the suitable irrigation strategy along with methods of application namely: surface (farmer’s practice), sprinkler (double nozzle impact sprinkler), and low-energy water application device (LEWA) were initiated in the year 2012 for rice crop. Irrigation depths of 6 cm in case of surface method and 4 cm in case of sprinkler and LEWA methods were applied at each irrigation event. The irrigation events for rice were scheduled at 2-DAD (days after the disappearance of the ponded water), 3-DAD, and 4-DAD through surface method, and at daily, 1- and 2-day intervals (after initial ponding disappeared) by sprinkler and LEWA methods. Sprinkler and LEWA methods resulted in highest rice yield of 4.4 t ha^?1 in irrigated plots at the 2-day interval which was at par with the highest yielding surface-irrigated plot scheduled at 2-DAD. At the same time, irrigation strategy of 2-day interval through sprinkler and LEWA methods registered water saving to the extent of 30–40% over 2-DAD under surface irrigation method. Results revealed that there could be substantial saving of water and energy (electricity and diesel) through the use of sprinkling devices for irrigating rice under sodic soil environments.