Effect of rate of application on degradation of imazethapyr in groundnut and soil under tropical Indian condition

Pesticides though formulated to be biologically degradable, few herbicides reported to cause surface and groundwater contamination which needs the monitoring of herbicide residues in environment continuously. Thus, to monitor the persistence and residues in crops, imazethapyr degradation studies were conducted in soil with groundnut cropping under Indian tropical condition. A groundnut field was treated with different doses of imazethapyr as early post emergence. Results showed that the degradation of imazethapyr in soil and groundnut plant followed first order reaction kinetics irrespective of the dose. The residue of imazethapyr persists in soil up to 60 days at higher rates of application while it persists up to 30 days in plant with the calculated half life of 2.8 to 7.4 days in soil and 5.1 to 5.9 days in plant. At the time of harvest, the residue of imazethapyr in soil, groundnut haulm or pods were below the detectable limit of 0.008 mg/kg across different doses of application. However, the continuous and inappropriate use in light textured soils may cause groundwater contamination and bioaccumulation in plant system. Hence, a pre harvest interval of 75 days must be allowed after the application of imazethapyr for the weed control in groundnut

Field dissipation of pendimethalin and alachlor in sandy clay loam soil and its terminal residues in sunflower (Helianthus annus L.)

Field experiments were conducted with sunflower as a test crop during 2010-11 to study the dissipation kinetics and the persistence of pendimethalin and alachlor in sandy clay loam soil and its terminal residues in sunflower. Herbicides were applied at recommended and double the recommended dose along with control and the treatments were replicated thrice in randomized block design. The soil and plant samples collected at periodical intervals for herbicides residue determination using GC equipped with ECD detector. Results shows that the degradation of both the herbicides in soil was faster at higher dose of application than at the lower dose and the concentration decreased with the advancement in crop growth. While pendimethalin persisted in soil for 60 – 90 days, the alachlor persisted in soil for 30 - 45 days depending on the quantity of application. Degradation of both the herbicides in soil followed first order kinetics with the mean half life of 14.6 and 9.8 days respectively for pendimethalin and alachlor. Residues of these herbicides were below 0.001 mg/kg at the time of harvest in soil, sunflower seeds and stalks showed that these herbicides a can be safely used for the control of weeds in sunflower cultivation

Persistence at the onset of spatiotemporal intermittency in coupled map lattices

We study persistence in coupled circle map lattices at the onset of spatiotemporal intermittency, an onset which marks a continuous transition, in the universality class of directed percolation, to a unique absorbing state. We obtain a local persistence exponent of theta_l = 1.49 +- 0.02 at this transition, a value which closely matches values for theta_l obtained in stochastic models of directed percolation. This result constitutes suggestive evidence for the universality of persistence exponents at the directed percolation transition. Given that many experimental systems are modelled accurately by coupled map lattices, experimental measurements of this persistence exponent may be feasible.Comment: 7 pages, Latex, 6 Postscript figures, Europhysics Letters (to appear

Mechanisms by which sialylated milk oligosaccharides impact bone biology in a gnotobiotic mouse model of infant undernutrition

Undernutrition in children is a pressing global health problem, manifested in part by impaired linear growth (stunting). Current nutritional interventions have been largely ineffective in overcoming stunting, emphasizing the need to obtain better understanding of its underlying causes. Treating Bangladeshi children with severe acute malnutrition with therapeutic foods reduced plasma levels of a biomarker of osteoclastic activity without affecting biomarkers of osteoblastic activity or improving their severe stunting. To characterize interactions among the gut microbiota, human milk oligosaccharides (HMOs), and osteoclast and osteoblast biology, young germ-free mice were colonized with cultured bacterial strains from a 6-mo-old stunted infant and fed a diet mimicking that consumed by the donor population. Adding purified bovine sialylated milk oligosaccharides (S-BMO) with structures similar to those in human milk to this diet increased femoral trabecular bone volume and cortical thickness, reduced osteoclasts and their bone marrow progenitors, and altered regulators of osteoclastogenesis and mediators of Th2 responses. Comparisons of germ-free and colonized mice revealed S-BMO-dependent and microbiota-dependent increases in cecal levels of succinate, increased numbers of small intestinal tuft cells, and evidence for activation of a succinate-induced tuft cell signaling pathway linked to Th2 immune responses. A prominent fucosylated HMO, 2'-fucosyllactose, failed to elicit these changes in bone biology, highlighting the structural specificity of the S-BMO effects. These results underscore the need to further characterize the balance between, and determinants of, osteoclastic and osteoblastic activity in stunted infants/children, and suggest that certain milk oligosaccharides may have therapeutic utility in this setting

Evidence for directed percolation universality at the onset of spatiotemporal intermittency in coupled circle maps

We consider a lattice of coupled circle maps, a model arising naturally in descriptions of solid state phenomena such as Josephson junction arrays. We find that the onset of spatiotemporal intermittency (STI) in this system is analogous to directed percolation (DP), with the transition being to an unique absorbing state for low nonlinearities, and to weakly chaotic absorbing states for high nonlinearities. We find that the complete set of static exponents and spreading exponents at all critical points match those of DP very convincingly. Further, hyperscaling relations are fulfilled, leading to independent controls and consistency checks of the values of all the critical exponents. These results lend strong support to the conjecture that the onset of STI in deterministic models belongs to the DP universality class.Comment: Submitted to Physical Review

An improved effective potential for electroweak phase transitions

It is shown that improved potentials and corrected mass terms can be introduced by using a quadratic source term in the path integral construction for the effective action. The advantage of doing things this way is that we avoid ever having to deal with complex propagators in the loop expansion. The resulting effective action for electroweak phase transitions is similar to the usual results.Comment: 16 pages, NCL93-TP16, (REVTEX

Determination of active ingredients in commercial insecticides using spectral characteristics of Fourier transform infrared spectroscopy (FTIR)

Pesticides have become a basic necessity for yield development. This might be credited to the quickly expanding population, which has presented weight on the food creation industry.Fourier Transform Infra-red Spectroscopy utilizes sample with less course of action, less time consuming, simple, fast, non-destructive and environmental friendly infrared-based method. It makes use of Smart iTR window and pellets use on omnic transmission window. In FTIR the peaks formed for the representative sample are from 800 cm-1 to 4000 cm-1 of wavenumbers against the % transmittance. The FTIR spectra obtained for pesticide formulations were on par with the NIST (National Institute of Standards and Technology) spectra library. Comparing the commercial-grade spectra with the Spectrabase, NIST library and Bio-rad software showed the peak ranges for different functional groups of the compound and can be examined with KnowItAll software’s ProcessItIR and AnalyseItIR. We can obtain the active principle of the peak, peak intensities. This method can be viewed as genuine choices to long and tedious chromatographic strategies as a rule suggested for quality control of commercially accessible pesticide formulations and check for adultered formulations that harm agricultural produce.