982 resultados para propagation properties
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Summary We have determined the full-length 14,491-nucleotide genome sequence of a new plant rhabdovirus, alfalfa dwarf virus (ADV). Seven open reading frames (ORFs) were identified in the antigenomic orientation of the negative-sense, single-stranded viral RNA, in the order 3′-N-P-P3-M-G-P6-L-5′. The ORFs are separated by conserved intergenic regions and the genome coding region is flanked by complementary 3′ leader and 5′ trailer sequences. Phylogenetic analysis of the nucleoprotein amino acid sequence indicated that this alfalfa-infecting rhabdovirus is related to viruses in the genus Cytorhabdovirus. When transiently expressed as GFP fusions in Nicotiana benthamiana leaves, most ADV proteins accumulated in the cell periphery, but unexpectedly P protein was localized exclusively in the nucleus. ADV P protein was shown to have a homotypic, and heterotypic nuclear interactions with N, P3 and M proteins by bimolecular fluorescence complementation. ADV appears unique in that it combines properties of both cytoplasmic and nuclear plant rhabdoviruses.
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Meleagrid herpesvirus 1 (MeHV-1 or turkey herpesvirus) has been widely used as a vaccine in commercial poultry. Initially, these vaccine applications were for the prevention of Marek’s disease resulting from Gallid herpesvirus 2 infections, while more recently MeHV-1 has been used as recombinant vector for other poultry infections. The construction of herpesvirus infectious clones that permit propagation and manipulation of the viral genome in bacterial hosts has advanced the studies of herpesviral genetics. The current study reports the construction of five MeHV-1 infectious clones. The in vitro properties of viruses recovered from these clones were indistinguishable from the parental MeHV-1. In contrast, the rescued MeHV-1 viruses were significantly attenuated when used in vivo. Complete sequencing of the infectious clones identified the absence of two regions of the MeHV-1 genome compared to the MeHV-1 reference sequence. These analyses determined the rescued viruses have seven genes, UL43, UL44, UL45, UL56, HVT071, sorf3 and US2 either partially or completely deleted. In addition, single nucleotide polymorphisms were identified in all clones compared with the MeHV-1 reference sequence. As a consequence of one of the polymorphisms identified in the UL13 gene, four of the rescued viruses were predicted to encode a serine/threonine protein kinase lacking two of three domains required for activity. Thus four of the recovered viruses have a total of eight missing or defective genes. The implications of these findings in the context of herpesvirus biology and infectious clone construction are discussed.
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The electrical activation energy and optical band-gap of GeSe and GeSbSe thin films prepared by flash evaporation on to glass substrates have been determined. The conductivities of the films were found to be given by Image , the activation energy Ea being 0.53 eV and 0.40 eV for GeSe and GeSbSe respectively. The optical absorption constant α near the absorption edge could be described by Image from which the optical band-gaps E0 were found to be 1.01 eV for GeSe and 0.67 eV for GeSbSe at 300°K. At 110°K the corresponding values of E0 were 1.07 eV and 0.735 eV respectively. The significance of these values is discussed in relation to those of other amorphous semiconductors.
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Simultaneous and collocated measurements of total and hemispherical backscattering coefficients (σ and β, respectively) at three wavelengths, mass size distributions, and columnar spectral aerosol optical depth (AOD) were made onboard an extensive cruise experiment covering, for the first time, the entire Bay of Bengal (BoB) and northern Indian Ocean. The results are synthesized to understand the optical properties of aerosols in the marine atmospheric boundary layer and their dependence on the size distribution. The observations revealed distinct spatial and spectral variations of all the aerosol parameters over the BoB and the presence of strong latitudinal gradients. The size distributions varied spatially, with the majority of accumulation modes decreasing from north to south. The scattering coefficient decreased from very high values (resembling those reported for continental/urban locations) in the northern BoB to very low values seen over near-pristine environments in the southeastern BoB. The average mass scattering efficiency of BoB aerosols was found to be 2.66 ± 0.1 m2 g−1 at 550 nm. The spectral dependence of columnar AOD deviated significantly from that of the scattering coefficients in the northern BoB, implying vertical heterogeneity in the aerosol type in that region. However, a more homogeneous scenario was observed in the southern BoB. Simultaneous lidar and in situ measurements onboard an aircraft over the ocean revealed the presence of elevated aerosol layers of enhanced extinction at altitudes of 1 to 3 km with an offshore extent of a few hundred kilometers. Back-trajectory analyses showed these layers to be associated with advection from west Asia and western India. The large spatial variations and vertical heterogeneity in aerosol properties, revealed by the present study, need to be included in the regional radiative forcing over the Bay of Bengal.
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Explosive driven micro blast waves are generated in the laboratory using NONEL tubes. The explosive mixture coated to the inner walls of the plastic Nonel tube comprises of HMX and Aluminum ( 18mg/m). The detonation is triggered electrically to generate micro blast waves from the open end of the tube. Flow visualization and over pressure measurements have been carried out to understand the propagation dynamics of these micro-blast waves in both confined and unconfined domains. The classical cubic root law used for large scale blast correlation appears to hold good even for these micro-blasts generated in the laboratory.
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The interfacial shear rheological properties of a continuous single-crystalline film of CuS and a 3D particulate gel of CdS nanoparticles (3−5 nm in diameter) formed at toluene−water interfaces have been studied. The ultrathin films (50 nm in thickness) are formed in situ in the shear cell through a reaction at the toluene−water interface between a metal−organic compound in the organic layer and an appropriate reagent for sulfidation in the aqueous layer. Linear viscoelastic spectra of the nanofilms reveal solid-like rheological behavior with the storage modulus higher than the loss modulus over the range of angular frequencies probed. Large strain amplitude sweep measurements on the CdS nanofilms formed at different reactant concentrations suggest that they form a weakly flocculated gel. Under steady shear, the films exhibit a yield stress, followed by a steady shear thinning at high shear rates. The viscoelastic and flow behavior of these films that are in common with those of many 3D “soft” materials like gels, foams, and concentrated colloidal suspensions can be described by the “soft” glassy rheology model.
Resumo:
Meleagrid herpesvirus 1 (MeHV-1 or turkey herpesvirus) has been widely used as a vaccine in commercial poultry. Initially, these vaccine applications were for the prevention of Marek’s disease resulting from Gallid herpesvirus 2 infections, while more recently MeHV-1 has been used as recombinant vector for other poultry infections. The construction of herpesvirus infectious clones that permit propagation and manipulation of the viral genome in bacterial hosts has advanced the studies of herpesviral genetics. The current study reports the construction of five MeHV-1 infectious clones. The in vitro properties of viruses recovered from these clones were indistinguishable from the parental MeHV-1. In contrast, the rescued MeHV-1 viruses were significantly attenuated when used in vivo. Complete sequencing of the infectious clones identified the absence of two regions of the MeHV-1 genome compared to the MeHV-1 reference sequence. These analyses determined the rescued viruses have seven genes, UL43, UL44, UL45, UL56, HVT071, sorf3 and US2 either partially or completely deleted. In addition, single nucleotide polymorphisms were identified in all clones compared with the MeHV-1 reference sequence. As a consequence of one of the polymorphisms identified in the UL13 gene, four of the rescued viruses were predicted to encode a serine/threonine protein kinase lacking two of three domains required for activity. Thus four of the recovered viruses have a total of eight missing or defective genes. The implications of these findings in the context of herpesvirus biology and infectious clone construction are discussed.
Resumo:
The crown ethers, 2,3-benzo-1,4,7,10,13-pentaoxa-cyclopentadeca-2-ene and 2,3, ll,12-dibenzo-l,4,7,10,13,16-hexaoxscyclooctadeca-2,11-diene are incorporated into H,N'-ethylenebis(acetylacetoneimino) nickel(II) and copper(II), phenol, and β-naphthol by diazo coupling reactions. The selective nature of the coupling reaction has-been demonstrated by the isolation of both asymmetric mono- and symmetric bis(glyoxalarylcrownhydrazoneimino) metal(II) complexes. An interesting binuclear complex containing two intramolecularly rearranged (glyoxal-hydrazonearylimino) metal(II) groups joined by 18-crown-6 result8 when bis(arenediazonium)-18-crown-6 is coupled with the metal(I1) Schiff bases. The substituted ethers form cationic salts with NaClO4, KCNS, NH4CNS, 14g(CNS)2 and Ca(CNS)2. All the synthesised ethers exhibit ion selectivity sequence as K+ > Na+ and Ca2+ > Mg2+.
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Serine hydroxymethyltransferase, the first enzyme in the pathway for interconversion of C1 fragments, was purified to homogeneity for the first time from any plant source. The enzyme from 72-h mung bean (Vigna radiata L.) seedlings was isolated using Blue Sepharose CL-6B and folate-AH-Sepharose-4B affinity matrices and had the highest specific activity (1.33 micromoles of HCHO formed per minute per milligram protein) reported hitherto. The enzyme preparation was extremely stable in the presence of folate or L-serine. Pyridoxal 5'-phosphate, ethylenediaminetetraacetate and 2-mercaptoethanol prevented the inactivation of the enzyme during purification. The enzyme functioned optimally at pH 8.5 and had two temperature maxima at 35 and 55°C. The Km values for serine were 1.25 and 68 millimolar, corresponding to Vmax values of 1.8 and 5.4 micromoles of HCHO formed per minute per milligram protein, respectively. The K0.5 value for L-tetrahydrofolate (H4folate) was 0.98 millimolar. Glycine, the product of the reaction and D-cycloserine, a structural analog of D-alanine, were linear competitive inhibitors with respect to L-serine with Ki values of 2.30 and 2.02 millimolar, respectively. Dichloromethotrexate, a substrate analog of H4folate was a competitive inhibitor when H4folate was the varied substrate. Results presented in this paper suggested that pyridoxal 5'-phosphate may not be essential for catalysis.The sigmoid saturation pattern of H4folate (nH = 2.0), one of the substrates, the abolition of sigmoidicity by NADH, an allosteric positive effector (nH = 1.0) and the increase in sigmoidicity by NAD+ and adenine nucleotides, negative allosteric effectors (nH = 2.4) clearly established that this key enzyme in the folate metabolism was an allosteric protein. Further support for this conclusion were the observations that (a) serine saturation exhibited an intermediary plateau region; (b) partial inhibition by methotrexate, aminopterin, O-phosphoserine, DL-{alpha}-methylserine and DL-O-methylserine; (c) subunit nature of the enzyme; and (d) decrease in the nH value from 2.0 for H4folate to 1.5 in presence of L-serine. These results highlight the regulatory nature of mung bean serine hydroxymethyltransferase and its possible involvement in the modulation of the interconversion of folate coenzymes.
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This study examined the psychometric properties of a Persian translation of the Career Adapt-Abilities Scale (CAAS—Iran Form) and its relationships with career satisfaction, business opportunity identification, and entrepreneurial intentions. It was hypothesized that career adaptability relates positively to these three outcomes, even when controlling for demographic and employment characteristics. Data were provided by 204 workers from Iran. Results showed that the overall CAAS score and sub-dimension scores (concern, control, curiosity, and confidence) were highly reliable. Moreover, confirmatory factor analyses indicated that the CAAS—Iran Form measures four distinct dimensions that can be combined into a higher-order career adaptability factor. Findings also demonstrated criterion-related validity of the scale with regard to career satisfaction and entrepreneurial intentions. In contrast, overall career adaptability was not significantly related to opportunity identification, while concern related positively, and control related negatively to opportunity identification. Overall, the CAAS—Iran Form has very good psychometric properties and predicts important career outcomes, suggesting that it can be used for career counseling and future research with Persian-speaking workers.
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Hydrazinium magnesium sulfate, (N2H5)2Mg(SO4)2, has been prepared by dissolving magnesium powder in a solution of ammonium sulfate in hydrazine hydrate, by the reaction of ammonium magnesium sulfate with hydrazine hydrate, and by the cocrystallisation of dihydrazinium sulfate and magnesium sulfate. The product has been characterized by chemical analysis and infrared spectra. Thermal analysis of (N2H5)2Mg(SO4)2 by TG and DTA show exothermic decomposition at 302°C giving Mg(N2H4)SO4 as an intermediate and an endother-mic decomposition at 504°C producing MgSO4.
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Arginine decarboxylase which makes its appearance in Lathyrus sativus seedlings after 24 h of seed germination reaches its highest level around 5–7 days, the cotyledons containing about 60% of the total activity in the seedlings at day 5. The cytosol enzyme was purified 977-fold from whole seedlings by steps involving manganese chloride treatment, ammonium sulphate and acetone fractionations, positive adsorption on alumina C-γ gel, DEAE-Sephadex chromatography followed by preparative disc gel electrophoresis. The enzyme was shown to be homogeneous by electrophoretic and immunological criteria, had a molecular weight of 220000 and appears to be a hexamer with identical subunits. The optimal pH and temperature for the enzyme activity were 8.5 and 45 °C respectively. The enzyme follows typical Michaelis-Menten kinetics with a Km value of 1.73 mM for arginine. Though Mn2+ at lower concentrations stimulated the enzyme activity, there was no dependence of the enzyme on any metal for the activity. The arginine decarboxylase of L. sativus is a sulfhydryl enzyme. The data on co-factor requirement, inhibition by carbonyl reagents, reducing agents and pyridoxal phosphate inhibitors, and a partial reversal by pyridoxal phosphate of inhibition by pyridoxal · HCl suggests that pyridoxal 5'-phosphate is involved as a co-factor for the enzyme. The enzyme activity was inhibited competitively by various amines including the product agmatine. Highest inhibition was obtained with spermine and arcain. The substrate analogue, l-canavanine, homologue l-homoarginine and other basic amino acids like l-lysine and l-ornithine inhibited the enzyme activity competitively, homoarginine being the most effective in this respect.
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The authors derive the Korteweg-de Vries equation in a multicomponent plasma that includes any number of positive and negative ions. The solitary wave solutions are also found explicitly for the case of isothermal and non-isothermal electrons.
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The antibacterial activity and total phenolic (TP) content of Agaricus bisporus stipes were assessed using solvent and water extracts to determine its bioactivity. Extraction methods included accelerated solvent extraction (ASE) and hot water followed by membrane concentration. Water extract from ASE had the highest TP of 1.08 gallic acid equivalents (GAE)/g dry weight (DW) followed by ethanol at 0.61 mg GAE/g DW and 0.11 mg GAE/g DW for acetone. Acetone extracts inhibited Escherichia coli and Staphylococcus aureus at less than 50%; ethanol inhibited E. coli at 61.9% and S. aureus at 56.6%; and ASE water inhibited E. coli at 78.6% and S. aureus at 65.4%. The TP content of membrane concentrated extract of mushroom was 17 mg GAE in 100 mL. Membrane concentrated water extracts had a higher percentage inhibition on S. aureus than E. coli. Overall, the results were promising for further application of mushroom stipe extracts as a functional food additive. Practical Applications Mushrooms are known for their health benefits and have been identified as a good source of nutrients. The highly perishable nature of mushrooms warrants further processing and preservation to minimize losses along the supply chain. This study explores the possibility of adding value to mushroom stipes, a by-product of the fresh mushroom industry. The extracts assessed indicate the antibacterial activity and phenolic content, and the potential of using these extracts as functional ingredients in the food industry. This study provides valuable information to the scientific community and to the industries developing novel ingredients to meet the market demand for natural food additives.
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The performance of optoelectronic devices critically depends on the quality of active layer. An effective way to obtain a high quality layers is by creating excess of metal atoms through various heat treatments. Recently, rapid thermal annealing (RTA) has proved a versatile technique for the post-treatment of semiconductor materials as compared to other techniques due to its precise control over the resources. Thus, we carried out a set of experiments on SnS films to explore the influence of RTA treatment on their properties. From these experiments we noticed that the films treated at 400 °C for 1 min in N2 atmosphere have a low electrical resistivity of ~5 Ωcm with relatively high Hall mobility and carrier density of 99 cm2/Vs and 1.3 × 1016 cm−3, respectively. The observed results, therefore, emphasise that it is possible to obtain good quality SnS films through RTA treatment without disturbing their crystal structure.