27 research outputs found

    iSENSE: Intelligent Sensor Monitoring Services with Integrated WSN Testbed

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    AbstractWireless sensor network (WSN) is drawing interest in various areas as they have great potential for many distributed applications in different scenarios. This paper demonstrates iSENSE, which provides a web-based sensor monitoring service and a sensor network test-bed. iSENSE uses heterogeneous wireless sensors that are capable of measuring temperature, humidity and light. Gateway nodes collect the sensed data from their respective network area and store the data in MySQL database for analysis and visualization through a portal. Through the test-bed user can remotely submit a sensor application (programs written in NesC) for compiling it using required softwares (TinyOS and NesC) and evaluating the performance of the application by downloading and executing them on dedicated sensing devices which form the test-bed

    Programmed Cell Death (PCD) in Plant: Molecular Mechanism, Regulation, and Cellular Dysfunction in Response to Development and Stress

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    Programmed cell death (PCD) or apoptosis is a genetically programmed cellular process. Though in the plant, a true caspase system is lacking, still PCD can occur throughout the life cycle at any cell type, tissue, and organ part in response to a wide range of stimuli. Here we have discussed the current understanding of plant PCD in terms of different pathways, cellular dysfunction, regulation, and signaling mechanisms. Our present study discussed how and to what extent PCD is involved in pre-zygotic and post-zygotic plant life cycle and emphasized to what extent PCD modulated in response to abiotic and biotic stress. Additionally, the expression profile of different PCD-associated genes that are modulated by developmental stage, biotic-abiotic stress, cellular metabolites are also elucidated. Hence, this study will be helpful for understanding the molecular and structural instincts of PCD in different stages of plant growth and development, response to biotic/abiotic stimuli, and cellular dysfunction

    Acaricidal activity of nishinda (Vitex negundo) leaf and garlic (Allium sativum) bulb extract against red spider mite, Oligonychus coffeae (Acari: Tetranychidae) in tea plantations of Darjeeling hill, West Bengal, India

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    The red spider mite, Oligonychus coffeae (Nietner) serves as a serious threat to the Darjeeling tea plantations affecting the quality of the leaves. Various plant extracts are currently being researched as an alternative to the chemical pesticides to control the red spider mites. In the present study, the leaves of Vitex negundo L. and the bulb of Allium sativum L. were analyzed for their acaricidal activity on the larval, nymphal and adult stages of the mite. Both the extracts were found to have potent activity against red spider mites and may prove to be potential acaricides in future

    Consequences of habitat heterogeneity for availability of nutrients in a dry tropical forest

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    1 This study evaluates the consequences of habitat heterogeneity in terms of patchy availability of nutrients in a dry tropical forest. The forest floor was characterized by the presence of topographic depressions; litter accumulation in these troughs gives rise to patchy microsites which are different in appearance from the adjoining non-patchy milieu (flats). 2 Litter mass and decomposition were significantly greater in the troughs than in the flats. Decomposition of 95% of the leaf litter needed 488 days in the troughs compared to 576 days in the flats. 3 Troughs were characterized by higher levels of microbial biomass and available nutrient pool. N-mineralization rates were also higher in the troughs. C, N and P concentrations in microbial biomass were positively correlated with N-mineralization rate when data for flats and troughs were pooled. The study indicated that immobilization and release of nutrients occurred in different parts of the year. 4 Fine roots were concentrated in the troughs with the net fine root production of 488 g m-1 compared to 218 g m-1 in the flats. Fine root biomass was positively correlated with the concentrations of mineral N and available P in the troughs. N-mineralization explained 46-63% variability in fine root biomass in the microsites. 5 The troughs supported greater herbaceous shoot biomass, particularly in the rainy season, thus preventing leaching by immobilizing excess nutrients. Herbaceous shoot biomass was positively correlated with N-mineralization and mineral N throughout the growing season and across the fertility gradient. 6 Troughs, which accumulated litter and trapped the nutrients in the dynamic microbial biomass, were characterized by higher amounts or organic C, total and mineral N, available P and nutrient supply potential. These areas attracted fine roots to support tree growth, compensated for nutrient limitation and sustained a fairly high level of net primary production in otherwise nutrient poor, leached, impoverished and shallow soil milieu

    Seasonal and spatial dynamics of plant-available N and P pool and N-mineralization in relation to fine roots in a dry tropical forest habitat

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    Seasonal dynamics of mineral N (NH4+ and NO3-), available P (NaHCO3-Pi) and N-mineralization rates in patchy and adjacent microsites Of a dry tropical forest were examined in relation to fine root biomass. Patchy microsites were richer in mineral N and P. Year-long averages indicated that NH4+ dominated over NO3- in the nutrient rich patchy microsites where fine root biomass, production and turnover were comparatively greater than in the nutrient-poor adjacent microsites which were dominated by NO3- . However, during the wet season nitrate was the dominating form of mineral-N in all the microsites. N-mineralization was higher in the patchy microsites than in the adjacent microsites. Fine root biomass was positively correlated with the N-mineralization and nitrification rates in nutrient-rich microsites indicating that fine root development was facilitated by higher amounts of mineral-N irrespective of the form in which N was prevalent

    Synthesis, structure, DNA-binding and photocleavage activity of a binuclear copper(II) complex

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    643-649A binuclear copper(II) complex [Cu(L)(NO₃)]₂ (1), where L is a NSO-donor reduced Schiff base ligand derived from salicylaldehyde and 2-mercaptoethylamine, is prepared, structurally characterized as 10.5MeCN by single crystal X-ray diffraction method and its DNA binding and photo-induced DNA cleavage activity studied. Complex 1 has a diphenoxo-bridged binuclear structure with a {Cu₂(μ-OAr)₂} core showing CuNO₃S coordination at each metal centre. The redox active complex displays two quasi-reversible cyclic voltammetric responses at 0.26 V (ΔEp = 390 mV) and at 0.078 V (ΔEp = 375 mV) versus SCE in DMF-0.1 M TBAP at scan rate of 50 mV s⁻¹. The complex exhibits a d-d band at 661 nm in DMF and shows moderate binding propensity to calf thymus DNA. It cleaves supercoiled (SC) DNA in the presence of 3-mercaptopropionic acid as a reducing agent. The complex is active in showing photo-induced cleavage of supercoiled pUC19 DNA in UV light of 365 nm and red light of 633 nm (He-Ne laser). The DNA photocleavage reaction involves formation of singlet oxygen (¹O₂) as the reactive species in a type-II pathway

    Production cost reduction through optimization of machine component

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    This thesis aiming to reduce the cost of production through analyzing and optimizing a set of weaving machine components including five legs; three main legs and two support legs. This set of legs has a reciprocating revolutionary movement around a central axis which is driven by a crank shaft. Finite element static Structural analysis, explicit and fatigue analyses been applied using Ansys workbench. The results show that some areas of legs are under small stresses far from material yield strength. This fact provides the potential for mass reduction of legs without significant effect on mechanical safety factors. Ansys Workbench parameter optimization and shape optimization been applied in this study in order to reduce mass while maintaining almost the same safety factors. Besides performing optimization on original legs, new optimized design alternatives presented for both main legs and support legs. Mass reduction of maximum 18% is obtained in new designs

    Design and Synthesis of a Functional Derivative of the Triazinium Cation and Its Rhodium Complex that Shows Photoinduced DNA Cleavage Activity and Photocytotoxicity

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    The design and synthesis of an intensely blue rhodium(III) complex 3]+ of a new N,N-donor ligand, 8-(quinolin-8-ylamino)pyrido2,1-c]1,2,4]benzotriazin-11-ium, 2]+, which contains a planar pendant triazinium arm, is described. Structural characterization for 3]+ was carried out by using various spectroscopic techniques and single-crystal X-ray crystallography. The organometallic rhodium(III) compound shows a ligand-based reversible reduction at 0.65 V. The electrochemically reduced compound displays a single-line EPR spectrum that signifies the formation of ligand-based free radicals. Compound 3]+ shows a binding propensity to calf thymus DNA to give a Kapp value of 6.05X105 M1. The parent triazinium salt, pyrido2,1-c]1,2,4]benzotriazin-11-ium 1]+ and the ligand salt 2]+ exhibit photoinduced cleavage of DNA in UV-A light, whereas the reference Rh complex 3]+ photocleaves DNA with red light (647.1 nm). The compounds show photonuclease activities under both aerobic and anaerobic conditions. Mechanistic investigations under aerobic conditions with several inhibitors indicate the formation of hydroxyl radicals by means of a photoredox pathway. Under anaerobic conditions, it is believed that a photoinduced oxidation of DNA mechanism is operative. Compound 3]+ exhibits photocytotoxicity in HeLa cervical cancer cells to give IC50 values of (12+/-0.9) mu M in UV-A light at 365 nm and (31.4+/-1.1) mu M in the dark

    Copper(II) Complexes of l-Arginine as Netropsin Mimics Showing DNA Cleavage Activity in Red Light

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    Copper(II) complexes [Cu(L-arg)(2)](NO3)(2) (1) and [Cu(L-arg)(B)Cl]Cl (2-5), where B is a heterocyclic base, namely, 2,2'-bipyridine (bpy, 2), 1,10-phenanthroline (phen, 3), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq, 4), and dipyrido[3,2-a:2',3'-c)phenazine (dppz, 5), are prepared and their DNA binding and photoinduced DNA cleavage activity studied. Ternary complex 3, structurally characterized using X-ray crystallography, shows a square-pyramidal (4 + 1) coordination geometry in which the N,O-donor L-arginine and N,N-donor 1,10-phenanthroline form the basal plane with one chloride at the elongated axial site. The complex has a pendant cationic guanidinium moiety. The one-electron paramagnetic complexes display a metal-centered d-d band in the range of 590-690 nm in aqueous DMF They show quasireversible cyclic voltammetric response due to the Cu(II)/Cu(I) couple in the range of -0.1 to -0.3 V versus a saturated calomel electrode in a DMF-Tris HCl buffer (pH 7.2). The DNA binding propensity of the complexes is studied using various techniques. Copper(II) bis-arginate 1 mimics the minor groove binder netropsin by showing preferential binding to the AT-rich sequence of double-strand (ds) DNA. DNA binding study using calf thymus DNA gives an order: 5 (L-arg-dppz) >= 1 (biS-L-arg) > 4 (L-arg-dpq) > 3 (L-arg-phen) >> 2 (L-arg-bpy). Molecular docking calculations reveal that the complexes bind through extensive hydrogen bonding and electrostatic interactions with ds-DNA. The complexes cleave supercoiled pUC19 DNA in the presence of 3-mercaptopropionic acid as a reducing agent forming hydroxyl ((OH)-O-center dot) radicals. The complexes show oxidative photoinduced DNA cleavage activity in UV-A light of 365 nm and red light of 647.1 nm (Ar-Kr mixed-gas-ion laser) in a metal-assisted photoexcitation process forming singlet oxygen (O-1(2)) species in a type-II pathway. All of the complexes, barring complex 2, show efficient DNA photocleavage activity. Complexes 4 and 5 exhibit significant double-strand breaks of DNA in red light of 647.1 nm due to the presence of two photosensitizers, namely, L-arginine and dpq or dppz in the molecules

    DNA photocleavage and anticancer activity of terpyridine copper(II) complexes having phenanthroline bases

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    Copper(II) complexes Cu(ph-tpy)(B)](ClO4) (1-3), where ph-tpy is (4'-phenyl)-2,2':6',2 `'-terpyridine and B is N,N-donor phenanthroline base, viz. 1,10-phenanthroline (phen, 1), dipyridoquinoxaline (dpq, 2), and dipyridophenazine (dppz, 3), were prepared and characterized from analytical and spectral data. Complex 1, characterized by X-ray crystallography, shows a distorted square-pyramidal (4 + 1) CuN5 coordination geometry having the tridentate ph-tpy ligand at the basal plane and bidentate phen bound to the axial-equatorial sites. The complexes display a d-d band near 650 nm in aqueous DMF. The complexes are avid binders to calf thymus DNA giving the binding order: 3 (dppz) > 2 (dpq) > 1 (phen). The dpq and dppz complexes show photo-induced DNA cleavage activity in red light via photo-redox pathway forming hydroxyl radicals. The cytotoxicity of the dppz complex 3 was studied by MTT assay in HeLa cancer cells. The IC50 values are 3.7 and 12.4 mu M in visible light of 400-700 nm and dark, respectively. (C) 2010 Elsevier Ltd. All rights reserved
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