106 research outputs found
Method development of a semi-field study using micro-tunnels with the solitary bee species Osmia bicornis
Pesticide Risk Assessment: Comparing sensitivities of ‘non-Apis’ bees with the honeybee (Apis mellifera L.)
1081-61 Arterial retroperfusion by a percutaneous stent-based ventricle to coronary vein bypass (VVPASSâ„¢)
Effects of Olive Mill Wastewater on Soil Microarthropods and Soil Chemistry in Two Different Cultivation Scenarios in Israel and Palestinian Territories
Although olive mill wastewater (OMW) is often applied onto soil and is known
to be phytotoxic, its impact on soil fauna is still unknown. The objective of this study was
to investigate how OMW spreading in olive orchards affects Oribatida and Collembola
communities, physicochemical soil properties and their interdependency. For this, we
treated plots in two study sites (Gilat, Bait Reema) with OMW. Among others, the sites
differed in irrigation practice, soil type and climate. We observed that soil acidity and
water repellency developed to a lower extent in Gilat than in Bait Reema. This may be
explained by irrigation-induced dilution and leaching of OMW compounds in Gilat. In Bait
Reema, OMW application suppressed emergence of Oribatida and induced a community
shift, but the abundance of Collembola increased in OMW and water-treated plots. In
Gilat, Oribatida abundance increased after OMW application. The effects of OMW
application on soil biota result from an interaction between stimulation of biological activity and suppression of sensitive species by toxic compounds. Environmental and
management conditions are relevant for the degree and persistence of the effects.
Moreover, this study underlines the need for detailed research on the ecotoxicological
effects of OMW at different application rates
Stratospheric aerosol radiative forcing simulated by the chemistry climate model EMAC using Aerosol CCI satellite data
This paper presents decadal simulations of stratospheric and tropospheric aerosol and its radiative effects by the chemistry general circulation model EMAC constrained with satellite observations in the framework of the ESA Aerosol CCI project such as GOMOS (Global Ozone Monitoring by Occultation of Stars) and (A)ATSR ((Advanced) Along Track Scanning Radiometer) on the ENVISAT (European Environmental Satellite), IASI (Infrared Atmospheric Sounding Interferometer) on MetOp (Meteorological Operational Satellite), and, additionally, OSIRIS (Optical Spectrograph and InfraRed Imaging System). In contrast to most other studies, the extinctions and optical depths from the model are compared to the observations at the original wavelengths of the satellite instruments covering the range from the UV (ultraviolet) to terrestrial IR (infrared). This avoids conversion artifacts and provides additional constraints for model aerosol and interpretation of the observations. MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) SO2 limb measurements are used to identify plumes of more than 200 volcanic eruptions. These three-dimensional SO2 plumes are added to the model SO2 at the eruption times. The interannual variability in aerosol extinction in the lower stratosphere, and of stratospheric aerosol radiative forcing at the tropopause, is dominated by the volcanoes. To explain the seasonal cycle of the GOMOS and OSIRIS observations, desert dust simulated by a new approach and transported to the lowermost stratosphere by the Asian summer monsoon and tropical convection turns out to be essential. This also applies to the radiative heating by aerosol in the lowermost stratosphere. The existence of wet dust aerosol in the lowermost stratosphere is indicated by the patterns of the wavelength dependence of extinction in observations and simulations. Additional comparison with (A)ATSR total aerosol optical depth at different wavelengths and IASI dust optical depth demonstrates that the model is able to represent stratospheric as well as tropospheric aerosol consistently.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Intercomparison of stratospheric chemistry models under polar vortex conditions
Several stratospheric chemistry modules from box, 2-D or 3-D models, have been intercompared. The intercomparison was focused on the ozone loss and associated reactive species under the conditions found in the cold, wintertime Arctic and Antarctic vortices. Comparisons of both gas phase and heterogeneous chemistry modules show excellent agreement between the models under constrained conditions for photolysis and the microphysics of polar stratospheric clouds. While the mean integral ozone loss ranges from 4-80% for different 30-50 days long air parcel trajectories, the mean scatter of model results around these values is only about +/-1.5%. In a case study, where the models employed their standard photolysis and microphysical schemes, the variation around the mean percentage ozone loss increases to about +/-7%. This increased scatter of model results is mainly due to the different treatment of the PSC microphysics and heterogeneous chemistry in the models, whereby the most unrealistic assumptions about PSC processes consequently lead to the least representative ozone chemistry. Furthermore, for this case study the model results for the ozone mixing ratios at different altitudes were compared with a measured ozone profile to investigate the extent to which models reproduce the stratospheric ozone losses. It was found that mainly in the height range of strong ozone depletion all models underestimate the ozone loss by about a factor of two. This finding corroborates earlier studies and implies a general deficiency in our understanding of the stratospheric ozone loss chemistry rather than a specific problem related to a particular model simulation
Visualizing Ultrafast Kinetic Instabilities in Laser-Driven Solids using X-ray Scattering
Ultra-intense lasers that ionize and accelerate electrons in solids to near
the speed of light can lead to kinetic instabilities that alter the laser
absorption and subsequent electron transport, isochoric heating, and ion
acceleration. These instabilities can be difficult to characterize, but a novel
approach using X-ray scattering at keV energies allows for their visualization
with femtosecond temporal resolution on the few nanometer mesoscale. Our
experiments on laser-driven flat silicon membranes show the development of
structure with a dominant scale of ~60\unit{nm} in the plane of the laser
axis and laser polarization, and ~95\unit{nm} in the vertical direction with
a growth rate faster than . Combining the XFEL experiments
with simulations provides a complete picture of the structural evolution of
ultra-fast laser-induced instability development, indicating the excitation of
surface plasmons and the growth of a new type of filamentation instability.
These findings provide new insight into the ultra-fast instability processes in
solids under extreme conditions at the nanometer level with important
implications for inertial confinement fusion and laboratory astrophysics
A Whole Virus Pandemic Influenza H1N1 Vaccine Is Highly Immunogenic and Protective in Active Immunization and Passive Protection Mouse Models
The recent emergence and rapid spread of a novel swine-derived H1N1 influenza virus has resulted in the first influenza pandemic of this century. Monovalent vaccines have undergone preclinical and clinical development prior to initiation of mass immunization campaigns. We have carried out a series of immunogenicity and protection studies following active immunization of mice, which indicate that a whole virus, nonadjuvanted vaccine is immunogenic at low doses and protects against live virus challenge. The immunogenicity in this model was comparable to that of a whole virus H5N1 vaccine, which had previously been demonstrated to induce high levels of seroprotection in clinical studies. The efficacy of the H1N1 pandemic vaccine in protecting against live virus challenge was also seen to be equivalent to that of the H5N1 vaccine. The protective efficacy of the H1N1 vaccine was also confirmed using a severe combined immunodeficient (SCID) mouse model. It was demonstrated that mouse and guinea pig immune sera elicited following active H1N1 vaccination resulted in 100% protection of SCID mice following passive transfer of immune sera and lethal challenge. The immune responses to a whole virus pandemic H1N1 and a split seasonal H1N1 vaccine were also compared in this study. It was demonstrated that the whole virus vaccine induced a balanced Th-1 and Th-2 response in mice, whereas the split vaccine induced mainly a Th-2 response and only minimal levels of Th-1 responses. These data supported the initiation of clinical studies with the same low doses of whole virus vaccine that had previously been demonstrated to be immunogenic in clinical studies with a whole virus H5N1 vaccine
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