2,254 research outputs found

    Comparative biology and fertility parameters of two spotted spider mite, Tetranychus urticae Koch. on different grapevine varieties

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    The influence of the four grapevine varieties 'Thompson Seedless', 'Manjri Naveen', 'Gulabi' and 'Bangalore Blue' on fitness, development and reproductive characteristics of the two spotted spider mite, Tetranychus urticae was studied. The biology of two spotted spider mites consisted of egg, larvae, protonymph, deutonymph and adult stages. The total duration from egg to adult was found to be the least in 'Thompson Seedless' (16.2 days) followed by ''Manjri Naveen' (17.2 days), 'Gulabi' (17.2 days) and maximum in 'Bangalore Blue' (32.2 days). The survival rate of life stages of mites was found to be lower in 'Bangalore Blue'. The higher values of net reproductive rate, intrinsic rate of increase, finite rate of increase the shortest mean generation time was observed in 'Thompson Seedless' followed by 'Gulabi', 'Manjri Naveen' and 'Bangalore Blue'. The results suggested that 'Thompson Seedless' was the most suitable cultivar with higher survival rate of life stages of mites, shortest development period, higher value intrinsic rate of increase and fecundity whereas 'Bangalore Blue' was the least suitable cultivar because of the lowest intrinsic rate of increase, longest development period, lower survival rate of life stages of mites

    Heteroaromatic annulation studies on 2-[bis(methylthio)methylene]- 1-methyl-3-oxoindole: synthesis of novel heterocyclo[b] fused indoles

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    Heteroannulation of 2-[Bis(methylthio)methylene]-1-methyl-3-oxoindole with Ī²- substituted Ī²-lithioaminoacrylonitrile, malononitrile and guanidine has been reported to yield novel substituted pyrido[3,2-b]indoles and pyrimido[5,4-b]indole derivatives in varying yields

    An indigenous cluster beam apparatus with a reflectron time-of-flight mass spectrometer

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    The design and fabrication of a Smalley-type cluster source in combination with a reflectron based time-of-flight (TOF) mass spectrometer are reported. The generation of clusters is based on supersonic jet expansion of the sampling plume. Sample cells for both liquid and solid targets developed for this purpose are described. Two pulsed Nd-YAG lasers are used in tandem, one (532 nm) for target vapourization and the other (355 nm) for cluster ionization. Methanol clusters of nuclearity up to 14 (mass 500 amu) were produced from liquid methanol as the test sample. The clusters were detected with a mass resolution of ~2500 in the R-TOF geometry. Carbon clusters up to a nuclearity of 28 were obtained using a polyimide target. The utility of the instrument is demonstrated by carrying out experiments to generate mixed clusters from alcohol mixtures

    Lack of clustering in low-redshift 21-cm intensity maps cross-correlated with 2dF galaxy densities

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    We report results from 21-cm intensity maps acquired from the Parkes radio telescope and cross-correlated with galaxy maps from the 2dF galaxy survey. The data span the redshift range 0.057<z<0.0980.057<z<0.098 and cover approximately 1,300 square degrees over two long fields. Cross correlation is detected at a significance of 5.18Ļƒ5.18\sigma. The amplitude of the cross-power spectrum is low relative to the expected dark matter power spectrum, assuming a neutral hydrogen (HI) bias and mass density equal to measurements from the ALFALFA survey. The decrement is pronounced and statistically significant at small scales. At kāˆ¼1.5k\sim1.5 hMpcāˆ’1 h \mathrm{Mpc^{-1}}, the cross power spectrum is more than a factor of 6 lower than expected, with a significance of 14.8ā€‰Ļƒ14.8\,\sigma. This decrement indicates either a lack of clustering of neutral hydrogen (HI), a small correlation coefficient between optical galaxies and HI, or some combination of the two. Separating 2dF into red and blue galaxies, we find that red galaxies are much more weakly correlated with HI on kāˆ¼1.5k\sim1.5 hMpcāˆ’1h \mathrm{Mpc^{-1}} scales, suggesting that HI is more associated with blue star-forming galaxies and tends to avoid red galaxies.Comment: 12 pages, 3 figures; fixed typo in meta-data title and paper author

    Erasing the Milky Way: new cleaning technique applied to GBT intensity mapping data

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    We present the first application of a new foreground removal pipeline to the current leading H I intensity mapping data set, obtained by the Green Bank Telescope (GBT). We study the 15- and 1-h-field data of the GBT observations previously presented in Mausui et al. and Switzer et al., covering about 41 deg2 at 0.6 < z < 1.0, for which cross-correlations may be measured with the galaxy distribution of the WiggleZ Dark Energy Survey. In the presented pipeline, we subtract the Galactic foreground continuum and the point-source contamination using an independent component analysis technique (FASTICA), and develop a Fourier-based optimal estimator to compute the temperature power spectrum of the intensity maps and cross-correlation with the galaxy survey data. We show that FASTICA is a reliable tool to subtract diffuse and point-source emission through the non-Gaussian nature of their probability distributions. The temperature power spectra of the intensity maps are dominated by instrumental noise on small scales which FASTICA, as a conservative subtraction technique of non-Gaussian signals, cannot mitigate. However, we determine similar GBT-WiggleZ cross-correlation measurements to those obtained by the singular value decomposition (SVD) method, and confirm that foreground subtraction with FASTICA is robust against 21 cm signal loss, as seen by the converged amplitude of these cross-correlation measurements. We conclude that SVD and FASTICA are complementary methods to investigate the foregrounds and noise systematics present in intensity mapping data sets

    Climate Smart agricultural practices improve soil quality through organic carbon enrichment and lower greenhouse gas emissions in farms of bread bowl of India

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    Acknowledgements The authors are thankful to NEWS India-UK for providing the first author Fellowship during the study. We are also grateful to CCAFS-CIMMYT for allowing us to collect soil samples from climate smart villages of Karnal, Haryana. The help received from Kartar Singh during soil analysis, and Kapil, Rakesh, Rajinder and Anil during field survey and sample collection is gratefully acknowledged. We are grateful to two anonymous reviewers for their insightful comments which significantly improved the quality of the manuscript.Peer reviewedPostprin

    Truncated Access to Institutional Agricultural Credit as a Major Constraint for Rural Transformation: Insights from Longitudinal Village Studies

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    The study has examined the trend of formal credit growth and its influence on rural transformation in terms of accelerating growth in household income levels. It has also identified the factors influencing the access to formal agricultural credit in the study regions, viz. eastern and semi-arid tropics (SAT) of India. The longitudinal household level data of about 1200 households in three states each in these two regions have been analysed for the period 2010 to 2013. The study has observed that the poor access to formal credit has compelled these households to take loan from informal sources who sometimes charge interest @ 60 to 120 per cent per annum, threatening the livelihoods of these smallholders and poor households. During the study period of three years (2010 - 2013), no change in situation was visible in these villages and the access to formal sources of agricultural credit seems to remain truncated. The main reasons for this disturbing trend is the lack of institutional framework to provide cheap and subsidized credit to these marginal and landless households, who take land on lease for cultivation. The Tobit model has been fitted to determine the accessibility to formal agricultural credit in these regions. The study has highlighted the need of building a strong and inclusive financial infrastructure to provide necessary credit support to the smallholder farmers in the eastern and SAT regions for bringing a rapid rural transformation

    Thermodynamic studies of the two dimensional Falicov-Kimball model on a triangular lattice

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    Thermodynamic properties of the spinless Falicov-Kimball model are studied on a triangular lattice using numerical diagonalization technique with Monte-Carlo simulation algorithm. Discontinuous metal-insulator transition is observed at finite temperature. Unlike the case of square lattice, here we observe that the finite temperature effect is not able to smear out the discontinuous metal-insulator transition seen in the ground state. Calculation of specific heat (C_v) shows single and double peak structures for different values of parameters like on-site correlation strength (U), f-electron energy (E_f) and temperature.Comment: 6 pages, 7 figure

    Non-Gaussianity from isocurvature perturbations

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    We develop a formalism to study non-Gaussianity in both curvature and isocurvature perturbations. It is shown that non-Gaussianity in the isocurvature perturbation between dark matter and photons leaves distinct signatures in the CMB temperature fluctuations, which may be confirmed in future experiments, or possibly, even in the currently available observational data. As an explicit example, we consider the QCD axion and show that it can actually induce sizable non-Gaussianity for the inflationary scale, H_{inf} = O(10^9 - 10^{11})GeV.Comment: 24 pages, 6 figures; references added; version to appear in JCA

    Elemental composition of ambient aerosols measured with high temporal resolution using an online XRF spectrometer

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    The Xact 625 Ambient Metals Monitor was tested during a 3-week field campaign at the rural, traffic-influenced site HƤrkingen in Switzerland during the summer of 2015. The field campaign encompassed the Swiss National Day fireworks event, providing increased concentrations and unique chemical signatures compared to non-fireworks (or background) periods. The objective was to evaluate the data quality by intercomparison with other independent measurements and test its applicability for aerosol source quantification. The Xact was configured to measure 24 elements in PM10 with 1ā€Æh time resolution. Data quality was evaluated for 10 24ā€Æh averages of Xact data by intercomparison with 24ā€Æh PM10 filter data analysed with ICP-OES for major elements, ICP-MS for trace elements, and gold amalgamation atomic absorption spectrometry for Hg. Ten elements (S, K, Ca, Ti, Mn, Fe, Cu, Zn, Ba, Pb) showed excellent correlation between the compared methods, with r2 values ā€‰ā‰„ā€‰ā€Æ0.95. However, the slopes of the regressions between Xact 625 and ICP data varied from 0.97 to 1.8 (average 1.28) and thus indicated generally higher Xact elemental concentrations than ICP for these elements. Possible reasons for these differences are discussed, but further investigations are needed. For the remaining elements no conclusions could be drawn about their quantification for various reasons, mainly detection limit issues. An indirect intercomparison of hourly values was performed for the fireworks peak, which brought good agreement of total masses when the Xact data were corrected with the regressions from the 24ā€Æh value intercomparison. The results demonstrate that multi-metal characterization at high-time-resolution capability of Xact is a valuable and practical tool for ambient monitoring
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