332 research outputs found
Accumulation of pharmaceuticals, perfluorinated compounds, plasticisers and illicit drug metabolite in aquatic sediment and plants in three rivers of Greater London and SE England
Accumulation of persistent organic pollutants (POPs) in sediment (n=23) and aquatic plants (n=15) was assessed by ultrasonicationassisted extraction (UAE) followed by an in-house validated method for solid phase extraction (SPE) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Eleven POPs were selected: inter alia pharmaceuticals acetaminophen, diclofenac and ethinylestradiol, illicit drug metabolite benzoylecgonine, perfluorinated compounds perfluorooctanoic acid (PFOA), perfluorononanoic acid,
perfluorooctanesulfonic acid (PFOS) and perfluorobutane sulfonic acid (PFBS), and plasticisers bisphenol-A (BPA), 4’-hydroxyacetophenone (HAP) and bisphenol-S (BPS). Sediment samples were air dried, homogenised, sieved to 500 um then subjected to UAE for 20 m at 45°C in an extraction solution of 50:50 acetonitrile (ACN):Methanol (MeOH) with 1% acetic acid (v/v) followed by SPE and LC-MS/MS analysis. Bioaccumulation in aquatic plants was assessed using two species: Water Starwart (Callitriche sp., n=8) and Pondweed (Potamogeton sp., n=7). All plant samples were air dried, powdered, homogenised then subjected to UAE for 20 m at 40°C in an extraction solution of 25:75 ACN:MeOH with 1% acetic acid (v/v) followed by SPE and LCMS/MS analysis. Mean recoveries were 76% for sediment and 82% for plants. Ten of eleven POPs were detected in sediments with frequencies ranging from 22-83% (benzoylecgonine and BPA respectively) and mean quantifiable concentrations ranging from 0.84-11.1 ng/g (BPS and BPA respectively). Organic matter content in sediment samples was estimated using standard methods for loss on ignition and ranged from 1.2-6.4%. Seven of eleven POPs were detected in Callitriche sp. with frequencies ranging from 13% (acetaminophen) to 100% (HAP, BPS, PFBS and PFOA) and mean quantifiable concentrations ranging from 0.42-113 ng/g (diclofenac and PFOS respectively). Lastly, eight of eleven POPs were detected in Potamogeton sp. with frequencies ranging from 14-100% (acetaminophen and HAP respectively) and mean quantifiable concentrations from 0.38-71.0 ng/g (acetaminophen and HAP respectively). Overall, levels of target POPs were lowest in sediment and highest in Callitriche sp. with mean levels as much as 18.3 and 11.5 times higher (PFOS) than in sediment and Potamogeton sp. respectively. The extent to which POP bioaccumulation may affect higher trophic levels is unclear and warrants further investigation
Jet propagation and the asymmetries of CSS radio sources
As Compact Steep Spectrum radio sources have been shown to be more
asymmetrical than larger sources of similar powers, there is a high probability
that they interact with an asymmetric medium in the central regions of the host
elliptical galaxy. We consider a simple analytical model of the propagation of
radio jets through a reasonable asymmetric environment and show that they can
yield the range of arm-length and luminosity asymmetries that have been
observed. We then generalize this to allow for the effects of orientation, and
quantify the substantial enhancements of the asymmetries that can be produced
in this fashion. We present two-dimensional and three-dimensional simulations
of jets propagating through multi-phase media and note that the results from
the simulations are also broadly consistent with the observations.Comment: 11 pages, 6 figures, 1 table, accepted for publication in A&
Weak headed quasars
We use the published VLA maps of high luminosity, steep-spectrum radio quasars showing prominent kiloparsec-scale one-sided jets, but faint hot-spots (i.e., weak-headed quasars) to call into question the common perception that the mechanism leading to such unusual morphologies is the strong dissipation of the jet's power through a vigorous entrainment of thermal gas by the initially relativistic jet. Under this hypothesis nearly half of the weak-headed quasars would be predicted to exhibit two-sided jets, one of which is actually receding from us, but is made visible nonetheless due to the postulated strong dissipation. However, no example of a source with two-sided jets is found in a well mapped representative sample of 8 weak-headed quasars. Evidently, the prominent appearance of their (all one-sided) jets is still largely due to relativistic bulk flow. We therefore suggest that the anomalous weakness of the heads of the jets is probably linked to the weakening of the Mach disk, following the onset of decollimation of the jet's working surface as its forward motion slows down to nearly subsonic speed. We out-line some potentially interesting observable consequences of this scenario. Weak-headed quasars, which seem to be a substantial subset of the steep-spectrum quasar population at large redshifts, could provide important clues on the late evolutionary stages of powerful radio sources
Management of diseases and insect-pests of French bean in Northwestern Indian Himalayan region using integrated approaches
French bean (Phaseolus vulgaris L.) production is adversely affected by many pathogens and insect-pests worldwide. In the present investigation, effect of different bio-fortified composts, organic amendments, botanicals and pesticides were evaluated against diseases and insect- pests of french bean. The results showed that seed treatment and drenching with Trichoderma harzianum strain 11, followed by soil application of fortified farmyard manure resulted in the lowest root rot incidence, highest germination, vigour and yield in french bean. In another set of experiment, soil incorporation of Parthenium hysterophorus, Urtica dioicaandLantana camarawere found to reduce root rot incidence with high germination and pod yield. Among the bioproducts and botanicals tested, foliar spray of cow dung extract (50%) reduced angular leaf spot, rust and bacterial blight severity by 51, 69 and 25 per cent, respectively. Among the fungicides, foliar application of azoxystrobin 23 SC (0.1%) and difenoconazole 25EC (0.025%), also reduced angular leaf spot and rust severity by 93 and 90 per cent, respectively. Among different insect pest management strategies under field conditions, cartap hydrochloride and batain seed extract registered low sucking bug (Chauliops choprai) population. Integrated approaches including bio-agents, botanicals along with chemicals for managing these diseases and insect-pests were found appropriate options. Out of six different IPM modules evaluated, seed treatment with carbendazim along with foliar spray of 0.1% azoxystrobin and cartap hydrochloride resulted in lowest root rot, rust, angular leaf spot, bacterial blight and Chaulopsis choprai bug population in French bean
Strategic selection of white maize inbred lines for tropical adaptation and their utilization in developing stable, medium to long duration maize hybrids
White maize plays an important role in human diet, especially in traditional crop growing regions of northern hill region, north-eastern states and central-western parts of India. Breeding efforts to enhance the genetic potential of white maize was not so prominent as compared to yellow maize in the country. As a result, genetic base of the material utilized in white maize breeding program in India is very narrow and majorly contains indigenous germplasm and few introductions. Hence, efforts were made to use 365 white maize inbred lines from CIMMYT, Mexico, for breeding program. These new inbred lines were grown at winter nursery center, Indian Institute of Maize Research, New Delhi for its tropical adaptation. After preliminary evaluation, a total 47 inbred lines were selected and evaluated in randomized complete block design with two replications at Regional Maize Research and Seed Production Centre, Begusarai, Bihar, during rabi 2014. Out of this top performing 12 inbred lines viz, CML 47, CML 95, CML 314, CML 319, CML 377, CML 488, CML 494, CML 504, CML 517, CML 522, CML 531 and CML 538 were selected and were crossed in diallel manner to obtain 66 medium to long duration experimental hybrids. Stability analysis using AMMI model was done to identify adaptive hybrids with high yielding potentiality. According to the ASVi value obtained, the hybrid G38 appeared to be stable followed by G50 and G44. On the other hand, the hybrid G25 appeared as location specific hybrid suitable for high input conditions
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Driving factors of aerosol properties over the foothills of central Himalayas based on 8.5 years continuous measurements
This study presents analysis of in situ measurements conducted over the period 2005–2014 in the Indian Himalayas to give a thorough overview of the factors and causes that drive aerosol properties. Aerosol extensive properties (namely, particle number concentration, scattering coefficient, equivalent black carbon, PM2.5, and PM10) have 1.5–2 times higher values in the early to late afternoon than during the night, and a strong seasonality. The interannual variability is ±20% for both PM2.5 and total particle number concentration. Analysis of the data shows statistically significant decreasing trends of −2.3 μg m−3 year−1 and −2.7 μg m−3 year−1 for PM2.5 and PM10, respectively, over the study period. The mountainous terrain site (Mukteshwar, MUK) is primarily under the influence of air from the plains. This is due to convective transport processes that are enhanced by local and mesoscale topography, leading to pronounced valley/mountain winds and consequently to atmospheric boundary layer air lifting from the plains below. The transport from plains is evident in seasonal‐diurnal patterns observed at MUK. The timing of the patterns corresponds with changes in turbulence and water vapor (q). According to our analysis, using these as proxies is a viable method for examining boundary layer influence in the absence of direct atmospheric boundary layer height measurements. Comparing the measurements with climate models shows that even regional climate models have problems capturing the orographic influence accurately at MUK, highlighting the importance of long‐term direct measurements at multiple points to understand aerosol behavior in mountainous areas
Registration of DB 199313, Cytoplasmic Male Sterile Grain Amaranth Genetic Stock
Grain amaranth (Amaranthus spp.) seed stocks are customarily from self-pollinating plants that open pollinate and are not F1 hybrids. However, cytoplasmic male sterility (CMS) traits are available for hybrid seed production. DB 199313 (Reg. No. GS-10, PI 686465) grain amaranth (A. hypochondriacus L.) is the first publicly available CMS line in Amaranthus. It is an F1 hybrid from a cross between male sterile plants of DB 921 (PI 568125) and male fertile PI 568179. Fertility can be restored by crossing DB 199313 with K432 (PI 538323). DB 199313 is adapted for seed production in Ames, IA, from direct seeding in the field, but it has not been selected for competitive agronomic performance. It provides a new publicly available genetic resource for improved grain amaranth crossing
Correction for a measurement artifact of the Multi-Angle Absorption Photometer (MAAP) at high black carbon mass concentration levels
The Multi-Angle Absorption Photometer (MAAP) is a widely-used instrument for aerosol black carbon (BC) measurements. In this paper, we show correction methods for an artifact found to affect the instrument accuracy in environments characterized by high black carbon concentrations. The artifact occurs after a filter spot change – as BC mass is accumulated on a fresh filter spot, the attenuation of the light (raw signal) is weaker than anticipated. This causes a sudden decrease, followed by a gradual increase in measured BC concentration. The artifact is present in the data when the BC concentration exceeds ~3 μg m<sup>−3</sup> at the typical MAAP flow rate of 16.7 L min<sup>−1</sup> or 1 m<sup>3</sup> h<sup>−1</sup>. The artifact is caused by erroneous dark counts in the photodetector measuring the transmitted light, in combination with an instrument internal averaging procedure of the photodetector raw signals. It was found that, in addition to the erroneous temporal response of the data, concentrations higher than 9 μg m<sup>−3</sup> (at the flow rate of 16.7 L min<sup>−1</sup>) are underestimated by the MAAP. The underestimation increases with increasing BC accumulation rate. At a flow rate of 16.7 L min<sup>−1</sup> and concentration of about 24 μg m<sup>−3</sup> (BC accumulation rate ~0.4 μg min<sup>−1</sup>), the underestimation is about 30%. There are two ways of overcoming the MAAP artifact. One method is by logging the raw signal of the 165° photomultiplier measuring the reflected light from the filter spot. As this signal is not affected by the artifact, it can be converted to approximately correct absorption and BC values. However, as the typical print formats of the MAAP do not give the reflected signal as an output, a semi-empirical correction method was developed based on laboratory experiments to correct for the results in the post-processing phase. The correction function was applied to three MAAP datasets from Gual Pahari (India), Beijing (China), and Welgegund (South Africa). In Beijing, the results could also be compared against a photoacoustic spectrometer (PAS). The correction improved the quality of all three MAAP datasets substantially, even though the individual instruments operated at different flow rates and in different environments
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1999 Site Environmental Report
Throughout the scientific community, Brookhaven National Laboratory (BNL) is renowned for its leading-edge research in physics, medicine, chemistry, biology, materials, and the environment. BNL is committed to supporting its world-class scientific research with an internationally recognized environmental protection program. The 1999 Site Environmental Report (SER) summarizes the status of the Laboratory's environmental programs and performance, including the steady progress towards cleaning up the site and fully integrating environmental stewardship into all facets of the Laboratory's mission. BNL is located on 5,265 acres of pine barrens in Suffolk County in the center of Long Island, New York. The Laboratory is situated above a sole source aquifer at the headwaters of the Peconic River; therefore, protecting ground and surface water quality is a special concern. Approximately 3,600 acres of the site are undeveloped and serve as habitat for a wide variety of animals and plants, including one New York State endangered species, the tiger salamander, and two New York State threatened species, the banded sunfish and the stiff goldenrod. Monitoring, preserving, and restoring these ecological resources is a high priority for the Laboratory
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