Available Moisture in Relation to Water-stable Aggregates of Two Forest Soils

Available moisture release characteristics for two well aggregated clayey forest soils of West Bengal (INDIA) were determined with respect to different-sized water-stable aggregates. In situ determination of higher range of available moisture differed appreciably from classic 1/3 bar moisture retention, for the soils. Release of moisture at lower tensions (0.33 > bar) were mainly governed by the inter-aggregate pore size distribution while that at higher tension chiefly attributed to the texture of aggregates i.e. the intra-aggregate pore size distribution. The difference in moisture releasing capacity particularly in the range 0.33—15.0 bar amongst different sized aggregates, was due mainly to varying amount of clay and organic carbon in different-sized aggregates.     

Structure—activity relationships for some organotin molluscicides

Bioassay data are reported for 12 organotin compounds, R₃SnX, against the adult snail, Biomphalaria glabrata, an intermediate host of schistosomiasis. The relationship between the molluscicidal activity and the nature of the R and X groups in the organotin compounds is discussed, as well as the possible mode of toxic action of these compounds.     

Density and nitrogen effects on interference and economic threshold of common lambsquarters in wheat

Common lambsquarters (CL) constitutes about 50 % of the total weed population in many wheat fields of the northern and central India. It causes considerable wheat yield losses. Its interference is highly influenced by nitrogen (N). Information on its density effect in response to N, and economic threshold (ET) will be useful for its effective management. This experiment was designed to evaluate and compare the interference of CL in response to N with that of natural weed infestations; and to determine its ET in wheat. It was observed that the natural weed infestation including CL, and a pure stand of 128 CL plants/m² were more competitive, causing greater reductions in wheat growth and yield than other CL densities. In the absence of CL, the natural weed infestation was less competitive. The natural weed infestation including CL, and the pure stand densities of 128 and 64 CL/m² inflicted more yield losses at 120 than 60 kg N/ha. But, at lower densities up to 32 CL/m², increasing N levels favoured wheat more, resulting in greater crop-weed balance at 120 than at 60 kg N/ha. The ET, 6–7 CL/m², would help in making decisions for CL management and fitting models. It can be approximated for other similar locations. This ET takes several production factors into account and would be more economical than what was determined based on only yield losses. The ET-based control would reduce future CL/weed populations by preventing seed bank build-up in soil, and rationalize herbicide use through tailoring of doses.     

Studies on bacteriological quality of nainital lake water in different seasons

The total coliform and E. coli load of Nainital lake water in different seasons has been studied. The variation of these organisms with season, rainfall and human activities in the catchment area were observed.     

Effect of efficient pectinolytic bacterial isolates on retting and fibre quality of jute

Four bacterial strains with high balanced polygalacturonase (PG) and pectin lyase (PNL), and xylanase with minimal cellulase activity were used in jute retting. The 16S rDNA analysis revealed that the organisms were: Bacillus sp. L6 (GQ891097), Bacillus pumilus strain EK-17 (GQ891098), B. pumilus strain Geo-03-422 (GQ891103) and B. pumilus strain IK-MB12-518F (GQ891105). The microorganisms in different combinations of consortia showed synergistic effect resulting in increased PG (35.52-46.61 IU/g cell wet weight), PNL (39.79-72.12 U/ml), xylanase (0.705-0.840 μmol/ml/min) and little cellulase (0-0.153 μmol/ml/min) activities. The organisms in different combinations of consortia reduced the retting period from 11 to 13 days as compared to 19 days in the control. Microbial inoculation produced remarkable improvement in jute fibre strength (26.62-28.91 g/tex) and fineness (2.76-2.92 tex) over control. The pH of the post-retting water samples became acidic, and the electrical conductivity (Ec), chemical oxygen demand (COD) and hardness increased. The organisms could be adopted in industrial application for extraction of jute fibre.     

Engineering design of woven fabrics using non-traditional optimization methods: A comparative study

This work aims to design woven fabrics with desired quality at optimum manufacturing cost by choice of suitable weaving parameters such as count, crimp and thread spacing of warp and weft yarns. To fulfill this goal, we endeavor to devise search based non-traditional optimization methods such as genetic algorithm, particle swarm optimization and simulated annealing for efficiently finding the appropriate combination of weave parameters. The quick response capability of the non-traditional optimization methods would benefit the fabric manufacturers for efficient determination of the required weaving parameters to produce the engineered fabrics. The experimental validation confirms that the particle swarm optimization is most suitable technique for engineering design of woven fabrics.     

Long-term feeding ecology and habitat use in harbour porpoises Phocoena phocoena from Scandinavian waters inferred from trace elements and stable isotopes

Background  

We investigated the feeding ecology and habitat use of 32 harbour porpoises by-caught in 4 localities along the Scandinavian coast from the North Sea to the Barents Sea using time-integrative markers: stable isotopes (δ¹³C, δ¹⁵N) and trace elements (Zn, Cu, Fe, Se, total Hg and Cd), in relation to habitat characteristics (bathymetry) and geographic position (latitude).     

Seasonal speedup along the western flank of the Greenland Ice Sheet

It has been widely hypothesized that a warmer climate in Greenland would increase the volume of lubricating surface meltwater reaching the ice-bedrock interface, accelerating ice flow and increasing mass loss. We have assembled a data set that provides a synoptic-scale view, spanning ice-sheet to outlet-glacier flow, with which to evaluate this hypothesis. On the ice sheet, these data reveal summer speedups (50 to 100%) consistent with, but somewhat larger than, earlier observations. The relative speedup of outlet glaciers, however, is far smaller (<15%). Furthermore, the dominant seasonal influence on Jakobshavn Isbrae's flow is the calving front's annual advance and retreat. With other effects producing outlet-glacier speedups an order of magnitude larger, seasonal melt's influence on ice flow is likely confined to those regions dominated by ice-sheet flow.     

Fluorometric detection of enzyme activity with synthetic supramolecular pores

The reversible blockage of synthetic pores formed by rigid-rod beta barrels, either by substrates or products, was used to sense a variety of enzymatic reactions in high-throughput format with "naked-eye" fluorescent detection. Improvement of sensor sensitivity beyond three orders of magnitude by straightforward internal mutations underscores the functional plasticity of rigid-rod beta barrels. Such detectors of enzyme activity with the aforementioned characteristics are needed in areas as diverse as proteomics and environmentally benign organic synthesis.     

Suppression of Botryosphaeria canker of apple by arbuscular mycorrhizal fungi

Stem brown canker or Botryosphaeria canker disease impairs the growth and kills the shoots, limbs and even trunks of infected apple trees. Apple roots are usually colonized by arbuscular mycorrhizal fungi, which may have a positive influence on plant growth and suppression of diseases. In order to assess the efficacy of AM to suppress the disease severity and plant growth enhancement, nine AMF inoculation treatments (Sclerocystis dussi, Glomus intraradices, G. fasciculatum, G. bagyaraji, G. leptotichum, G. monosporum, Gigaspora margarita, a mixed AM culture and a non-mycorrhizal control treatment) were used in this present study. Two-year-old potted apple plants, maintained under glasshouse conditions, were either pre-inoculated with AMF followed by stem inoculation with Botryosphaeria ribis or simultaneously inoculated with Botryosphaeria ribis and AM. The results indicated that the incidence of canker was less severe in plants inoculated with AMF in comparison to non-mycorrhizal control. Timing of inoculation also had a significant effect on disease development and plant survival. Plants pre-inoculated with mycorrhiza performed better over those inoculated simultaneously with Botryosphaeria ribis and AM fungi. Furthermore, AM inoculation resulted in improved survival and growth of AMF-colonized plants; though, it varied by species of AM fungi utilized.