Copper, zinc, iron and manganese in sediments and in the rock oyster Saccostrea cucullata in Mumbai coast

Sediment and oyster (Saccostrea cucullata) samples were collected at Dhanda, a fishing village in Mumbai, Maharashtra. The samples were analysed for copper, zinc, iron and manganese contents. Metal concentrations in the sediments and bioaccumulated levels in oysters were correlated. There is no positive correlation between the total sedimentary levels of metals analysed and the bioaccumulated levels of respective metals in oyster. A positive correlation between the bioavailable fractions of zinc, iron and manganese, and the bioaccumulated levels exists. Copper, however, shows a negative correlation with respect to the bioaccumulated levels.

Acute toxicity of copper, zinc and mercury on intertidal gastropods of Mumbai coast

The acute toxicity test conducted by static bioassay techniques have revealed that among selected heavy metals, copper is more toxic than zinc and mercury to Planaxis sulcatus and Trochus radiatus. The natural availability of heavy metals in the surrounding environment of these organisms is found to be deciding factor for their toxicity. Natural habitat of the animal also contributes to the sensitivity of a particular animal to the heavy metals tested. In addition the tendency of the animal to overcome the adverse conditions in their surrounding also plays a significant role in toxicity of pollutants.

Erratum: "Zinc oxide nanostructures and high electron mobility nanocomposite thin film transistors" (IEEE Transactions on Electron Devices (2009))

In the above entitled paper (ibid., vol. 55, no. 11, pp. 3001-3011), two errors were noticed after the paper went to press. The errors are corrected here.

Effects of dietary phosphorus and zinc levels on growth artd bone mineralization in fingerlings of rainbow trout, Oncorhynchus mykiss

A laboratory based 2 x 2 factorial experiment was conducted to investigate the influences of dietary phosphorus and zinc levels on growth and bone mineralization in fingerlings of rainbow trout for 21 weeks. Two levels of phosphorus (19 and 30 mg/g) and two levels of zinc (55 and 103 Ag/g) in the dry diets were tested. Duplicate tanks of 30 rainbow trout (average weight 1.56 ± 0.24 g) per 60L glass tank were fed experimental diets three times a day to apparent satiation level at 15 to 24°C water temperature. The results of the present study demonstrated that dietary phosphorus supplementation influenced the growth and bone mineralization whereas zinc levels significantly (p<0.05) influenced bone mineralization in rainbow trout. Further investigations in this area with different size and age groups of this fish are broadly needed.

Flexible array sensors based on zinc oxide nanowires for touch displays

Recent efforts towards the fabrication of touch sensing systems are presented, in which zinc oxide nanowire arrays are embedded in a polymer matrix to produce an engineered composite material. In the future, these sensor systems will be fully flexible and multi-touch as intended for Nokia's 'Morph' concept device.

Distribution of mercury in a tropical estuary (India) situated near a chloro-alkali plant

The distribution of mercury in water, sediment and some biological samples of the Rushikulya estuary, east coast of India were assessed during Jan-Dec. 1989. Both the dissolved plus acid leachable mercury contents in water and the sediment mercury discerned conspicuous spatial and seasonal fluctuations. Adsorption on to the suspended particulates was found to be the most likely mechanism for removal of mercury from the water column. Exchange of mercury from sediments to water was observed at high salinities (20-30x10-3). The residual mercury contents in the biological samples revealed that bio-accumulation by bottom-dwelling organisms are higher than the pelagic components.

Concentration and distribution of heavy metals (lead, cadmium, chromium, copper, nickel, zinc) in Karachi shore and offshore sediments

A study to measure the heavy metal pollution level in the sediment of coastal and offshore area indicates that high concentration of heavy metals were found around Manora channel and eastern coast of Karachi. In comparison with coastal areas, relatively low concentration of heavy metals was recorded in the offshore area. The result shows that sewage and industrial wastes are the main source of heavy metal pollution in the coastal area. The concentration of heavy metals in the sediments is as follows: Chromium 10.4-33.69, nickel 13.3-47.6, lead 10.0-39.04, cadmium 0.08-0.21, zinc 7.4-73.2 and copper 9.44-18.56 mg/kg. In the offshore areas strong correlation was observed between copper and organic carbon, and calcium carbonate and cadmium. In the shore area such correlation has been recorded among nickel, chromium, zinc, and chromium and copper. The Karachi. coast is viewed as moderately polluted when compared to other continental coastal areas.

Effect of zinc and manganese supplementation to tricalcium phosphate rich diet for tiger puffer (Takifugu rubripes)

Effects of zinc (Zn) and manganese (Mn) supplementation to a tricalcium phosphate (TCP) rich diet for tiger puffer have been investigated. A TCP supplement to the diet decreased the growth of fish compared to the control diet with a Ca supplementation from Ca-lactate. However, addition of either Zn or Mn to the TCP supplemented diet could not improve the growth of tiger puffer. Addition of both zinc and manganese to the TCP supplemented diet improved the growth of tiger puffer.

Genotoxic effect of nickel chloride and zinc sulphate on fish Hypophthalmichthys molitrix

The present investigation is to assess the genotoxic potential of nickel chloride and zinc sulphate on gill cells of silver carp Hypophthalmichthys molitrix. Fishes were exposed in sublethal concentration of nickel chloride 5. 7 mg/1 and zinc sulphate 6.8 mg/1, and sampled at 10, 20 and 30 days. Nickel chloride and zinc sulphate treated fishes exhibited an apparent increase in the aberration frequency and a decrease in the mitotic index as compared to control. Acentric fragment, chromatid break, endoreduplication, chromatid gap, centromeric fusion, ploidy, sticky plate, dicentric chromosome, clumping and partial sticky plates were some of the abnormalities observed. The chromosomal aberrations in the treated fishes were significant compared to control.

A Plant Needs Ants like a Dog Needs Fleas: Myrmelachista schumanni Ants Gall Many Tree Species to Create Housing

Hundreds of tropical plant species house ant colonies in specialized chambers called domatia. When, in 1873, Richard Spruce likened plant-ants to fleas and asserted that domatia are ant-created galls, he incited a debate that lasted almost a century. Alth

Role of RNA polymerase IV in plant small RNA metabolism.

In addition to the three RNA polymerases (RNAP I-III) shared by all eukaryotic organisms, plant genomes encode a fourth RNAP (RNAP IV) that appears to be specialized in the production of siRNAs. Available data support a model in which dsRNAs are generated by RNAP IV and RNA-dependent RNAP 2 (RDR2) and processed by DICER (DCL) enzymes into 21- to 24-nt siRNAs, which are associated with different ARGONAUTE (AGO) proteins for transcriptional or posttranscriptional gene silencing. However, it is not yet clear what fraction of genomic siRNA production is RNAP IV-dependent, and to what extent these siRNAs are preferentially processed by certain DCL(s) or associated with specific AGOs for distinct downstream functions. To address these questions on a genome-wide scale, we sequenced approximately 335,000 siRNAs from wild-type and RNAP IV mutant Arabidopsis plants by using 454 technology. The results show that RNAP IV is required for the production of >90% of all siRNAs, which are faithfully produced from a discrete set of genomic loci. Comparisons of these siRNAs with those accumulated in rdr2 and dcl2 dcl3 dcl4 and those associated with AGO1 and AGO4 provide important information regarding the processing, channeling, and functions of plant siRNAs. We also describe a class of RNAP IV-independent siRNAs produced from endogenous single-stranded hairpin RNA precursors.

An allelic series reveals essential roles for FY in plant development in addition to flowering-time control

The autonomous pathway functions to promote flowering in Arabidopsis by limiting the accumulation of the floral repressor FLOWERING LOCUS C (FLC). Within this pathway FCA is a plant-specific, nuclear RNA-binding protein, which interacts with FY, a highly conserved eukaryotic polyadenylation factor. FCA and FY function to control polyadenylation site choice during processing of the FCA transcript. Null mutations in the yeast FY homologue Pfs2p are lethal. This raises the question as to whether these essential RNA processing functions are conserved in plants. Characterisation of an allelic series of fy mutations reveals that null alleles are embryo lethal. Furthermore, silencing of FY, but not FCA, is deleterious to growth in Nicotiana. The late-flowering fy alleles are hypomorphic and indicate a requirement for both intact FY WD repeats and the C-terminal domain in repression of FLC. The FY C-terminal domain binds FCA and in vitro assays demonstrate a requirement for both C-terminal FY-PPLPP repeats during this interaction. The expression domain of FY supports its roles in essential and flowering-time functions. Hence, FY may mediate both regulated and constitutive RNA 3'-end processing.

Catalyst-free synthesis of zinc oxide nanostructures by microheaters in the ambient environment

This paper demonstrates a catalyst-free synthesis of ZnO nanostructures using platinum microheaters under ambient environmental conditions. Different morphologies of ZnO nanostructures are synthesized from the oxidization of Zn thin film by local heating. The synthesized ZnO structures are characterized by the SEM, EDX and Raman spectra. The characterization of two shapes of Pt microheaters is investigated and the relationship between the applied heating power and ZnO nanostructures synthesis is investigated under ambient conditions. We observe that the density and morphology of ZnO nanostructures can be controlled through applied heating voltages. Furthermore, a connected composite structural (Zn-ZnO-Zn) layer is synthesized using combinative microheaters. © 2011 IEEE.

Design of refrigerated sea water plant for preservation of fish

To study the feasibility of employing refrigerated sea water on board fishing vessels for the preservation of fish, a pilot model has been designed, the details of which are presented in this paper.

A pilot plant for fish protein concentrate

This communication deals with the design aspect and functions of individual pieces of equipment of a pilot plant of fifty kg capacity for the production of fish protein concentrate (FPC) per day. Design is based on a solvent extraction process of wet pressed cake with an azeotropic mixture of hexane and ethyl alcohol. A flow sheet for the process and equipment layout has been indicated.