212 research outputs found
Immune monitoring of patients with septic shock by measurement of intraleukocyte cytokines
Objective: To assess the immune competence of patients presenting with septic shock by measuring on-line the production of intracellular cytokines by circulating leukocytes. Design and setting: Prospective study in a 18-bed medical intensive care unit of a university hospital. Patients and participants: 21 patients with septic shock, and 11 volunteers. Interventions: Single-step isolation of leukocytes from whole blood obtained within the first 24h after admission. Leukocytes were fixed immediately or after treatment with lipopolysaccharide (LPS) and/or heterologous plasma. Measurements and results: Leukocytes were permeabilized, and the intracellular cytokine expression of TNF-α and IL-10 was quantified by immunostaining and flow cytometry. LPS treatment significantly increased monocyte intracellular cytokine TNF-α and IL-10 as well as lymphocyte intracellular cytokine IL-10 in normal leukocytes. Septic monocytes and granulocytes had nonstimulated intracellular cytokine TNF-α concentrations lower than those measured in volunteers and were severely hyporesponsive to LPS. These phenotypic changes were correlated with disease severity and could be reproduced by treatment of normal leukocytes with plasma from patients with septic shock. Conclusions: Intracellular cytokine staining is a simple and rapid method to assess in situ and on-line the inflammatory balance and responsiveness of leukocyte subpopulations and could therefore represent a useful monitoring tool to assess the immune competence of critically ill patients. This study identifies the cellular source of cytokines in whole blood and confirms prior reports showing that septic phagocytes are characterized by a predominant anti-inflammatory phenotype, with hyporesponsiveness to LPS, depending on a plasma deactivation facto
Understanding the Shape Properties of Trihedral Polyhedra
This paper presents a framework for the computation of projective invariants of trihedral polyhedra. Invariants for such shapes, which are composed of triples of planes meeting at vertices, were first discussed by Rothwell, {\em et al.} in~\cite{rothwell-forsyth-etal:93}. However, they treated only four degree of freedom objects (dof.), and not polyhedra in general. We extend their results to arbitrary dof. figures by showing that more complex shapes can be broken down into sets of connected four dof. polyhedra. Although the more general shapes do not possess projective properties as a whole (when viewed by a single camera), each subpart does yield a projective description. Furthermore, planar projective invariants can be measured which link together the subparts. Consequently, we are able to provide local-global descriptions for general trihedral polyhedra. The original projective description also involved a difficult mathematical analysis. We demonstrate that a set of {\em butterfly invariants} can be used in equivalence to the original formulation. We also provide a novel algebraic formulation of the butterfly invariant which is simpler both to implement and to understand than previous approaches. We therefore provide a more straightforward route to the computation of polyhedral invariants. Finally, we demonstrate the recovery of polyhedral shape descriptions from images by exploiting the local-global nature of the invariants. Local measures can be extracted far more reliably in real images due to the problems of feature segmentation. Additionally, with the aid of a model base, we can extend the local descriptions to global measures and move towards the recognition of entire polyhedra
Pseudo Identities Based on Fingerprint Characteristics
This paper presents the integrated project TURBINE which is funded under the EU 7th research framework programme. This research is a multi-disciplinary effort on privacy enhancing technology, combining innovative developments in cryptography and fingerprint recognition. The objective of this project is to provide a breakthrough in electronic authentication for various applications in the physical world and on the Internet. On the one hand it will provide secure identity verification thanks to fingerprint recognition. On the other hand it will reliably protect the biometric data through advanced cryptography technology. In concrete terms, it will provide the assurance that (i) the data used for the authentication, generated from the fingerprint, cannot be used to restore the original fingerprint sample, (ii) the individual will be able to create different "pseudo-identities" for different applications with the same fingerprint, whilst ensuring that these different identities (and hence the related personal data) cannot be linked to each other, and (iii) the individual is enabled to revoke an biometric identifier (pseudo-identity) for a given application in case it should not be used anymore
Optics Testing at Planetary Scale
Each and every telescope that ships inside a Planet Dove or Superdove goes through a vigorous testing procedure. These tests are designed so that the user does not have to be an expert to run the test, or to interpret the results. All of our optics tests can be run either at the satellite level, or at the bare telescope level. This gives us maximum flexibility during the manufacturing process
On Some Incompatible Properties of Voting Schemes
In this paper, we study the problem of simultaneously achieving several security properties, for voting schemes, without non-standard assumptions. More specifically, we focus on the universal veriability of the computation of the tally, on the unconditional privacy/anonymity of the votes, and on the receipt-freeness properties, for the most classical election processes. Under usual assumptions and efficiency requirements, we show that a voting system that wants to publish the final list of the voters who actually voted, and to compute the number of times each candidate has been chosen, we cannot achieve: - universal verifiability of the tally (UV) and unconditional privacy of the votes (UP) simultaneously, unless all the registered voters actually vote; - universal verifiability of the tally (UV) and receipt- freeness (RF), unless private channels are available between the voters and/or the voting authorities
Did Saturn's rings form during the Late Heavy Bombardment ?
The origin of Saturn\' s massive ring system is still unknown. Two popular
scenarios - the tidal splitting of passing comets and the collisional
destruction of a satellite - rely on a high cometary flux in the past. In the
present paper we attempt to quantify the cometary flux during the Late Heavy
Bombardment (LHB) to assess the likelihood of both scenarios. Our analysis
relies on the so-called Nice model of the origin of the LHB (Tsiganis et al.,
2005; Morbidelli et al., 2005; Gomes et al., 2005) and on the size distribution
of the primordial trans-Neptunian planetesimals constrained in Charnoz &
Morbidelli (2007). We find that the cometary flux on Saturn during the LHB was
so high that both scenarios for the formation of Saturn rings are viable in
principle. However, a more detailed study shows that the comet tidal disruption
scenario implies that all four giant planets should have comparable ring
systems whereas the destroyed satellite scenario would work only for Saturn,
and perhaps Jupiter. This is because in Saturn\'s system, the synchronous orbit
is interior to the Roche Limit, which is a necessary condition for maintaining
a satellite in the Roche zone up to the time of the LHB. We also discuss the
apparent elimination of silicates from the ring parent body implied by the
purity of the ice in Saturn \' s rings. The LHB has also strong implications
for the survival of the Saturnian satellites: all satellites smaller than Mimas
would have been destroyed during the LHB, whereas Enceladus would have had from
40% to 70% chance of survival depending on the disruption model. In conclusion,
these results suggest that the LHB is the sweet moment for the formation of a
massive ring system around Saturn.Comment: 39 pages, 9 figures, 3 tables. Accepted for publication in ICARUS.
New version with figures included in the tex
Jet disc coupling in black hole binaries
In the last decade multi-wavelength observations have demonstrated the
importance of jets in the energy output of accreting black hole binaries. The
observed correlations between the presence of a jet and the state of the
accretion flow provide important information on the coupling between accretion
and ejection processes. After a brief review of the properties of black hole
binaries, I illustrate the connection between accretion and ejection through
two particularly interesting examples. First, an INTEGRAL observation of Cygnus
X-1 during a 'mini-' state transition reveals disc jet coupling on time scales
of orders of hours. Second, the black hole XTEJ1118+480 shows complex
correlations between the X-ray and optical emission. Those correlations are
interpreted in terms of coupling between disc and jet on time scales of seconds
or less. Those observations are discussed in the framework of current models.Comment: Invited talk at the Fifth Stromlo Symposium: Disks, Winds & Jets -
from Planets to Quasars. Accepted for publication in Astrophysics & Space
Scienc
Expansion of Nature Conservation Areas: Problems with Natura 2000 Implementation in Poland?
In spite of widespread support from most member countries’ societies for European Union policy, including support for the sustainable development idea, in many EU countries the levels of acceptance of new environmental protection programmes have been and, in particular in new member states, still are considerably low. The experience of the countries which were the first to implement union directives show that they cannot be effectively applied without widespread public participation. The goal of this study was, using the example of Poland, to assess public acceptance of the expansion of nature conservation in the context of sustainable development principles and to discover whether existing nature governance should be modified when establishing new protected areas. The increase in protected areas in Poland has become a hotbed of numerous conflicts. In spite of the generally favourable attitudes to nature which Polish people generally have, Natura 2000 is perceived as an unnecessary additional conservation tool. Both local authorities and communities residing in the Natura areas think that the programme is a hindrance, rather than a help in the economic development of municipalities or regions, as was initially supposed. This lack of acceptance results from many factors, mainly social, historic and economic. The implications of these findings for current approach to the nature governance in Poland are discussed
Phylogenomics of Unusual Histone H2A Variants in Bdelloid Rotifers
Rotifers of Class Bdelloidea are remarkable in having evolved for millions of years, apparently without males and meiosis. In addition, they are unusually resistant to desiccation and ionizing radiation and are able to repair hundreds of radiation-induced DNA double-strand breaks per genome with little effect on viability or reproduction. Because specific histone H2A variants are involved in DSB repair and certain meiotic processes in other eukaryotes, we investigated the histone H2A genes and proteins of two bdelloid species. Genomic libraries were built and probed to identify histone H2A genes in Adineta vaga and Philodina roseola, species representing two different bdelloid families. The expressed H2A proteins were visualized on SDS-PAGE gels and identified by tandem mass spectrometry. We find that neither the core histone H2A, present in nearly all other eukaryotes, nor the H2AX variant, a ubiquitous component of the eukaryotic DSB repair machinery, are present in bdelloid rotifers. Instead, they are replaced by unusual histone H2A variants of higher mass. In contrast, a species of rotifer belonging to the facultatively sexual, desiccation- and radiation-intolerant sister class of bdelloid rotifers, the monogononts, contains a canonical core histone H2A and appears to lack the bdelloid H2A variant genes. Applying phylogenetic tools, we demonstrate that the bdelloid-specific H2A variants arose as distinct lineages from canonical H2A separate from those leading to the H2AX and H2AZ variants. The replacement of core H2A and H2AX in bdelloid rotifers by previously uncharacterized H2A variants with extended carboxy-terminal tails is further evidence for evolutionary diversity within this class of histone H2A genes and may represent adaptation to unusual features specific to bdelloid rotifers
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