348 research outputs found
Validation of Viola wittrockiana
Der Name Viola wittrockiana GAMS (Garten-Stiefmütterchen) war bisher nicht gültig publiziert, trotz anders lautender Angabe im Index Kewensis. In der vorliegenden Veröffentlichung erfolgen Validierung und Typisierung des seit langem eingebürgerten Namens.Contrary to the information in the Index Kewensis the name Viola wittrockiana GAMS (Garden Pansy) has hitherto not been validly published. Therefore we will provide a validation and typification of this commonly used name here
Effect of canine hyperimmune plasma on TNFα and inflammatory cell levels in a lipopolysaccharide-mediated rat air pouch model of inflammation
The purpose of this study was to test the effect of canine hyperimmune frozen plasma (HFP), which is known to contain elevated levels of soluble TNFα receptor 1 (sTNFR1), on TNFα and inflammatory cell levels in a LPS-mediated rat air pouch model of inflammation.
There appears to be a correlation between elevated levels of sTNFR1 and depression of TNFα and neutrophil levels in the pouch fluid of HFP dosed rats (r = -0.73, P < 0.0001). The data suggest that canine HFP, which has been demonstrated to contain elevated levels of sTNFR1 compared with FFP, has a direct effect on depressing TNFα levels and neutrophil sequestration in the rat air pouch model of inflammation. These data suggest that HFP may be worthy of further investigation to determine whether such preparations have a therapeutic potential for treatment of acute inflammatory diseases in which TNFα is implicated
Theoretical efficient high capacity Quantum Key Distribution Scheme
A theoretical quantum key distribution scheme using EPR pairs is presented.
This scheme is efficient in that it uses all EPR pairs in distributing the key
except those chosen for checking eavesdroppers. The high capacity is achieved
because each EPR pair carries 2 bits of key code.Comment: 3 pages and 1 figure, to appear in Physical Review
Tailoring Single and Multiphoton Probabilities of a Single Photon On-Demand Source
As typically implemented, single photon sources cannot be made to produce
single photons with high probability, while simultaneously suppressing the
probability of yielding two or more photons. Because of this, single photon
sources cannot really produce single photons on demand. We describe a
multiplexed system that allows the probabilities of producing one and more
photons to be adjusted independently, enabling a much better approximation of a
source of single photons on demand.Comment: 4 pages, LaTex, 2 figures, twocolumn and RevTex Style for PR
Structure of microbial communities in Sphagnum peatlands and effect of atmospheric carbon dioxide enrichment
Little is known about the structure of microbial communities in Sphagnum peatlands, and the potential effects of the increasing atmospheric C02 concentration on these communities are not known. We analyzed the structure of microbial communities in five Sphagnum-dominated peatlands across Europe and their response to C02 enrichment using miniFACE systems. After three growing seasons, Sphagnum samples were analyzed for heterotrophic bacteria, cyanobacteria, microalgae, heterotrophic flagellates, ciliates, testate amoebae, fungi, nematodes, and rotifers. Heterotrophic organisms dominated the microbial communities and together represented 78% to 97% of the total microbial biomass. Testate amoebae dominated the protozoan biomass. A canonical correspondence analysis revealed a significant correlation between the microbial community data and four environmental variables (Na+, DOC, water table depth, and DIN), reflecting continentality, hydrology, and nitrogen deposition gradients. Carbon dioxide enrichment modified the structure of microbial communities, but total microbial biomass was unaffected. The biomass of heterotrophic bacteria increased by 48%, and the biomass of testate amoebae decreased by 13%. These results contrast with the absence of overall effect on methane production or on the vegetation, but are in line with an increased below-ground vascular plant biomass at the same sites. We interpret the increase in bacterial biomass as a response to a C02-induced enhancement of Sphagnum exudation. The causes for the decrease of testate amoebae are unclear but could indicate a top-down rather than a bottom-up control on their densit
Practical free-space quantum key distribution over 1 km
A working free-space quantum key distribution (QKD) system has been developed
and tested over an outdoor optical path of ~1 km at Los Alamos National
Laboratory under nighttime conditions. Results show that QKD can provide secure
real-time key distribution between parties who have a need to communicate
secretly. Finally, we examine the feasibility of surface to satellite QKD.Comment: 5 pages, 2 figures, 2 tables. Submitted to Physics Review Letters,
May 199
Computationally-efficient and perceptually-motivated rendering of diffuse reflections in room acoustics simulation
Geometrical acoustics is well suited for simulating room reverberation in
interactive real-time applications. While the image source model (ISM) is
exceptionally fast, the restriction to specular reflections impacts its
perceptual plausibility. To account for diffuse late reverberation, hybrid
approaches have been proposed, e.g., using a feedback delay network (FDN) in
combination with the ISM. Here, a computationally-efficient, digital-filter
approach is suggested to account for effects of non-specular reflections in the
ISM and to couple scattered sound into a diffuse reverberation model using a
spatially rendered FDN. Depending on the scattering coefficient of a room
boundary, energy of each image source is split into a specular and a scattered
part which is added to the diffuse sound field. Temporal effects as observed
for an infinite ideal diffuse (Lambertian) reflector are simulated using
cascaded all-pass filters. Effects of scattering and multiple (inter-)
reflections caused by larger geometric disturbances at walls and by objects in
the room are accounted for in a highly simplified manner. Using a single
parameter to quantify deviations from an empty shoebox room, each reflection is
temporally smeared using cascaded all-pass filters. The proposed method was
perceptually evaluated against dummy head recordings of real rooms.Comment: This work has been submitted to Forum Acusticum 2023 for publicatio
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