1,473 research outputs found
Examination of the ocean as a source for atmospheric microplastics
Global plastic litter pollution has been increasing alongside demand since plastic products gained commercial popularity in the 1930’s. Current plastic pollutant research has generally assumed that once plastics enter the ocean they are there to stay, retained permanently within the ocean currents, biota or sediment until eventual deposition on the sea floor or become washed up onto the beach. In contrast to this, we suggest it appears that some plastic particles could be leaving the sea and entering the atmosphere along with sea salt, bacteria, virus’ and algae. This occurs via the process of bubble burst ejection and wave action, for example from strong wind or sea state turbulence. In this manuscript we review evidence from the existing literature which is relevant to this theory and follow this with a pilot study which analyses microplastics (MP) in sea spray. Here we show first evidence of MP particles, analysed by μRaman, in marine boundary layer air samples on the French Atlantic coast during both onshore (average of 2.9MP/m3) and offshore (average of 9.6MP/m3) winds. Notably, during sampling, the convergence of sea breeze meant our samples were dominated by sea spray, increasing our capacity to sample MPs if they were released from the sea. Our results indicate a potential for MPs to be released from the marine environment into the atmosphere by sea-spray giving a globally extrapolated figure of 136000 ton/yr blowing on shore
Frequency of sublethal injury in a deepwater ophiuroid, Ophiacantha bidentata, an important component of western Atlantic Lophelia reef communities
The occurrence and relative abundance of tissue (arm) regeneration in the ophiuroid, Ophiacantha bidentata (Retzius), was examined in individuals collected primarily among colonies of the deep-water coral Lophelia pertusa off the southeastern United States. Seven deep-water coral sites (384–756 m), located between Cape Lookout, NC, and Cape Canaveral, FL, were sampled in June 2004 using a manned submersible. The presence of regenerative tissue was evaluated by visual inspection of each individual ophiuroid, and the proportion of regenerating arms per individual was examined relative to size of individual, geographic location, and depth of collection. Ophiacantha bidentata, the dominant brittle star collected, commonly displayed signs of sublethal injury with over 60% of individuals displaying some evidence of regeneration. These levels of regeneration rival those reported for shallow-water ophiuroids. Larger individuals (\u3e6.5 mm disc size) had a higher incidence of regeneration than smaller individuals. Size of individual and percent of regeneration were negatively correlated with depth. Although O. bidentata was significantly less abundant in southern versus northern sites, ophiuroid abundance did not appear to be influenced by amount or density of coral substratum. Presence of dense aggregations of O. bidentata indicates that they are an important component of the invertebrate assemblage associated with deep-water coral habitat especially in the northern part of the study area. Assuming that observed frequencies of injury and subsequent regeneration represent predation events then dense ophiuroid aggregations in deepwater coral habitats represent an important renewable trophic resource within these communities
Proceedings of the 35th Annual Meeting, Southern Soybean Disease Workers (March 12-13, 2008, Pensacola, Florida)
Contents
Southern United States Soybean Disease Loss Estimate for 2007. Compiled by SR Koenning
Contributed papers (Clayton Hollier, moderator)
Effects of Row Spacing and Leaf Wetness on the Temporal and Spatial Spread of Soybean Rust within Soybean Canopies. DF Narváez, JJ Marois, DL Wright, and S Isard
Effects of Potassium, Chloride, and Minor Elements Nutrition on Asian Soybean Rust. RW Schneider, EP Mumma, CL Clark, and CG Giles
The Impact of Selected Fungicide Treatments on Disease Progress of Asian Soybean Rust and Other Diseases of Soybean. GB Padgett, MA Purvis, A Hogan, and S Martin
Soybean Sudden Death Syndrome Variety Testing at Southern Illinois University. C Herzog, C Schmidt, and M Schmidt
Soybean Yield Suppression Due to Diseases for the Top Eight Soybean-Producing Countries in 2006. A Wrather, S Koenning, R Balardin, LH Carregal, R Escobar, GK Gupta, Z Ma, W Morel, LD Ploper, and A Tenuta
Impact of Frogeye Leaf Spot on Soybean Yield in the Lower Midwest. CM Vick, AK Vick, JP Bond, and JA Wrather
Graduate student papers (Alemu Mengistu, moderator)
Laboratory Evaluation of Soybean Resistance to Pod Blight Caused by Cercospora kikuchii. BC Wells and GL Sciumbato
Temporal Dynamics of Root and Foliar Symptoms of Soybean Sudden Death Syndrome at Different Inoculum Densities. C Gongora-Canul, FW Nutter, Jr, and LFS Leandro
Discussion session (Allen Wrather, moderator)
Soybean Rust Sentinal Survey discussion. Don Hershman
Proceedings of the Southern Soybean Disease Workers are published annually by the Southern Soybean Disease Workers.
Text, references, figures, and tables are reproduced as they were submitted by authors. The opinions expressed by the participants at this conference are their own and do not necessarily represent those of the Southern Soybean Disease Workers.
Mention of a trademark or proprietary products in this publication does not constitute a guarantee, warranty, or endorsement of that product by the Southern Soybean Disease Workers
Transport and deposition of ocean-sourced microplastic particles by a North Atlantic hurricane
The atmosphere can transport large quantities of microplastics and disperse them throughout the globe to locations inaccessible by many other transport mechanisms. Meteorological events have been proven to pick up and transport particulate matter, however, how they influence the transport and deposition of atmospheric microplastics is still poorly understood. Here we present samples of atmospheric fallout collected during Hurricane Larry as it passed over Newfoundland, Canada in September 2021. During the storm peak, 1.13 × 105 particles m−2 day−1 were deposited, with a decline in deposition after the storm passed. Back-trajectory modelling and polymer type analysis indicate that those microplastics may have been ocean-sourced as the hurricane traversed the garbage patch of the North Atlantic Gyre. This study identifies the influence of North Atlantic hurricanes on the atmospheric transport and deposition of ocean-sourced microplastics and the possible consequences of increased exposure to microplastics in remote areas
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Large-scale and synoptic meteorology in the south-east Pacific during the observations campaign VOCALS-REx in austral Spring 2008
We present a descriptive overview of the meteorology in the south eastern subtropical Pacific (SEP) during the VOCALS-REx intensive observations campaign which was carried out between October and November 2008. Mainly based on data from operational analyses, forecasts, reanalysis, and satellite observations, we focus on spatio-temporal scales from synoptic to planetary. A climatological context is given within which the specific conditions observed during the campaign are placed, with particular reference to the relationships between the large-scale and the regional circulations. The mean circulations associated with the diurnal breeze systems are also discussed. We then provide a summary of the day-to-day synoptic-scale circulation, air-parcel trajectories, and cloud cover in the SEP during VOCALS-REx. Three meteorologically distinct periods of time are identified and the large-scale causes for their different character are discussed. The first period was characterised by significant variability associated with synoptic-scale systems interesting the SEP; while the two subsequent phases were affected by planetary-scale disturbances with a slower evolution. The changes between initial and later periods can be partly explained from the regular march of the annual cycle, but contributions from subseasonal variability and its teleconnections were important. Across the whole of the two months under consideration we find a significant correlation between the depth of the inversion-capped marine boundary layer (MBL) and the amount of low cloud in the area of study. We discuss this correlation and argue that at least as a crude approximation a typical scaling may be applied relating MBL and cloud properties with the large-scale parameters of SSTs and tropospheric temperatures. These results are consistent with previously found empirical relationships involving lower-tropospheric stability
Micro(nano)plastics sources, fate, and effects : what we know after ten years of research
The last decade has been transformative for micro(nano)plastic (MnP) research with recent discoveries revealing the extent and magnitude of MnP pollution, even in the world's most remote places. Historically, while researchers recognized that most plastic pollution was derived from land-based sources, it was generally believed that microplastic particles (i.e., plastic fragments <5 mm) was only a marine pollution issue with effects largely impacting marine biota. However, over the last decade MnP research has progressed rapidly with recent discoveries of MnPs in freshwater, snow, ice, soil, terrestrial biota, air and even found in ocean spray. MnPs have now been found in every environmental compartment on earth, within tissues and gastrointestinal tracts of thousands of species, including humans, resulting in harmful effects. The last 10 years has also seen the development of new techniques for MnP analysis, and re-purposing of old technologies allowing us to determine the extent and magnitude of plastic pollution down to the nano size range (<1 µm). This short review summarizes what key milestones and major advances have been made in microplastic and nanoplastic research in the environment, including their sources, fate, and effects over the last decade
Detection methods for non-Gaussian gravitational wave stochastic backgrounds
We address the issue of finding an optimal detection method for a
discontinuous or intermittent gravitational wave stochastic background. Such a
signal might sound something like popcorn popping. We derive an appropriate
version of the maximum likelihood detection statistic, and compare its
performance to that of the standard cross-correlation statistic both
analytically and with Monte Carlo simulations. The maximum likelihood statistic
performs better than the cross-correlation statistic when the background is
sufficiently non-Gaussian. For both ground and space based detectors, this
results in a gain factor, ranging roughly from 1 to 3, in the minimum
gravitational-wave energy density necessary for detection, depending on the
duty cycle of the background. Our analysis is exploratory, as we assume that
the time structure of the events cannot be resolved, and we assume white,
Gaussian noise in two collocated, aligned detectors. Before this detection
method can be used in practice with real detector data, further work is
required to generalize our analysis to accommodate separated, misaligned
detectors with realistic, colored, non-Gaussian noise.Comment: 25 pages, 12 figures, submitted to physical review D, added revisions
in response to reviewers comment
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TYPE B RADIOACTIVE MATERIAL PACKAGE FAILURE MODES AND CONTENTS COMPLIANCE
Type B radioactive material package failures can occur due to any one of the following: inadequate design, manufacture, and maintenance of packages, load conditions beyond those anticipated in the regulations, and improper package loading and operation. The rigorous package design evaluations performed in the certification process, robust package manufacture quality assurance programs, and demanding load conditions prescribed in the regulations are all well established. This paper focuses on the operational aspects of Type B package loading with respect to an overbatch which may cause a package failure
Low State, Phase-Resolved IR Spectroscopy of VV Puppis
We present phase-resolved low resolution and higher resolution -band
spectroscopy of the polar VV Pup. All observations were obtained when VV Pup
was in a low accretion state having a K magnitude near 15. The low resolution
observations reveal cyclotron emission in the band during some phases,
consistent with an origin near the active 30.5 MG pole on the white dwarf. The
secondary in VV Pup appears to be a normal M7V star and we find that the
and band fluxes are entirely due to this star at all orbital phases during
the low accretion state. We use our higher resolution Keck spectroscopy to
produce the first -band radial velocity curve for VV Pup. Our orbital
solution yields =414 km sec and leads to mass estimates of
M=0.730.05 M and M=0.100.02 M. We find
that the mass accretion rates during the normal low states of the polars VV
Pup, EF Eri, and EQ Cet are near 10 M yr. The fact
that \.M is not zero in low state polars indicates active secondary stars in
these binary systems, including the sub-stellar donor star present in EF Eri.Comment: Accepted in Astronomical Journal 5 figure
A tri-dimensional approach for auditing brand loyalty
Over the past twenty years brand loyalty has been an important topic for both marketing practitioners and academics. While practitioners have produced proprietary brand loyalty audit models, there has been little academic research to make transparent the methodology that underpins these audits and to enable practitioners to understand, develop and conduct their own audits. In this paper, we propose a framework for a brand loyalty audit that uses a tri-dimensional approach to brand loyalty, which includes behavioural loyalty and the two components of attitudinal loyalty: emotional and cognitive loyalty. In allowing for different levels and intensity of brand loyalty, this tri-dimensional approach is important from a managerial perspective. It means that loyalty strategies that arise from a brand audit can be made more effective by targeting the market segments that demonstrate the most appropriate combination of brand loyalty components. We propose a matrix with three dimensions (emotional, cognitive and behavioural loyalty) and two levels (high and low loyalty) to facilitate a brand loyalty audit. To demonstrate this matrix, we use the example of financial services, in particular a rewards-based credit card
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