2,462 research outputs found
Die Bedeutung einer Ausfallbedrohtheit von Versicherungskontrakten - ein Beitrag zur Behavioral Insurance
Kahneman/Tversky 1979 haben das theoretische Konstrukt der Probabilistic Insurance Kontrakte in die Literatur eingefĂŒhrt. Hiermit werden VersicherungsvertrĂ€ge bezeichnet, deren ErfĂŒllung im Leistungsfalle aufgrund einer möglichen Insolvenz des Versicherungsunternehmens nicht gewĂ€hrleistet ist. In Ausweitung einer Studie von Wakker/Thaler/Tversky 1997 wird in der vorliegenden Arbeit eine experimentelle Untersuchung durchgefĂŒhrt, wobei die Zahlungsbereitschaft potentieller Versicherungsnehmer in AbhĂ€ngigkeit des Ratings des den Versicherungskontrakt anbietenden Unternehmens festgestellt wird. Dabei zeigt sich, daĂ diese ausfallbedrohte Versicherungsprodukte relativ zu ausfallfreien VertrĂ€gen mit erheblichen PrĂ€mienabschlĂ€gen sanktionieren. Der Preisabschlag nimmt dabei mit sinkender UnternehmensbonitĂ€t (erhöhter Ausfallgefahr) zu. Die Befragungsergebnisse zeigen zudem das neuartige PhĂ€nomen, daĂ mit zunehmender Ausfallbedrohtheit immer weniger Personen bereit sind, ausfallbedrohte Versicherungsprodukte ĂŒberhaupt zu akzeptieren. SchlieĂlich werden SchluĂfolgerungen fĂŒr die Steuerung von Versicherungsunternehmen diskutiert
The Path of Internet Law: An Annotated Guide to Legal Landmarks
The evolution of the Internet has forever changed the legal landscape. The Internet is the worldâs largest marketplace, copy machine, and instrumentality for committing crimes, torts, and infringing intellectual property. Justice Holmesâs classic essay on the path of the law drew upon six centuries of case reports and statutes. In less than twenty-five years, Internet law has created new legal dilemmas and challenges in accommodating new information technologies. Part I is a brief timeline of Internet case law and statutory developments for Internet-related intellectual property (IP) law. Part II describes some of the ways in which the Internet is redirecting the path of IP in a globalized information-based economy. Our broader point is that every branch of substantive and procedural law is adapting to the digital world. Part III is the functional equivalent of a GPS for locating the latest U.S. and foreign law resources to help lawyers, policymakers, academics and law students lost in cyberspace
Detection Limits for Super-Hubble Suppression of Causal Fluctuations
We investigate to what extent future microwave background experiments might
be able to detect a suppression of fluctuation power on large scales in flat
and open universe models. Such suppression would arise if fluctuations are
generated by causal processes, and a measurement of a small suppression scale
would be problematic for inflation models, but consistent with many defect
models. More speculatively, a measurement of a suppression scale of the order
of the present Hubble radius could provide independent evidence for a
fine-tuned inflation model leading to a low-density universe. We find that,
depending on the primordial power spectrum, a suppression scale modestly larger
than the visible Horizon can be detected, but that the detectability drops very
rapidly with increasing scale. For models with two periods of inflation, there
is essentially no possibility of detecting a causal suppression scale.Comment: 8 pages, 4 figures, revtex, In Press Physical Review D 200
Neurotropic Lineage III Strains of \u3cem\u3eListeria monocytogenes\u3c/em\u3e Disseminate to the Brain without Reaching High Titer in the Blood
Listeria monocytogenes is thought to colonize the brain using one of three mechanisms: direct invasion of the blood-brain barrier, transportation across the barrier by infected monocytes, and axonal migration to the brain stem. The first two pathways seem to occur following unrestricted bacterial growth in the blood and thus have been linked to immunocompromise. In contrast, cell-to-cell spread within nerves is thought to be mediated by a particular subset of neurotropic L. monocytogenes strains. In this study, we used a mouse model of foodborne transmission to evaluate the neurotropism of several L. monocytogenes isolates. Two strains preferentially colonized the brain stems of BALB/cByJ mice 5âdays postinfection and were not detectable in blood at that time point. In contrast, infection with other strains resulted in robust systemic infection of the viscera but no dissemination to the brain. Both neurotropic strains (L2010-2198, a human rhombencephalitis isolate, and UKVDL9, a sheep brain isolate) typed as phylogenetic lineage III, the least characterized group of L. monocytogenes. Neither of these strains encodes InlF, an internalin-like protein that was recently shown to promote invasion of the blood-brain barrier. Acute neurologic deficits were observed in mice infected with the neurotropic strains, and milder symptoms persisted for up to 16âdays in some animals. These results demonstrate that neurotropic L. monocytogenes strains are not restricted to any one particular lineage and suggest that the foodborne mouse model of listeriosis can be used to investigate the pathogenic mechanisms that allow L. monocytogenes to invade the brain stem. IMPORTANCE Progress in understanding the two naturally occurring central nervous system (CNS) manifestations of listeriosis (meningitis/meningoencephalitis and rhombencephalitis) has been limited by the lack of small animal models that can readily distinguish between these distinct infections. We report here that certain neurotropic strains of Listeria monocytogenes can spread to the brains of young otherwise healthy mice and cause neurological deficits without causing a fatal bacteremia. The novel strains described here fall within phylogenetic lineage III, a small collection of L. monocytogenes isolates that have not been well characterized to date. The animal model reported here mimics many features of human rhombencephalitis and will be useful for studying the mechanisms that allow L. monocytogenes to disseminate to the brain stem following natural foodborne transmission
Free-Flow Zone Electrophoresis of Peptides and Proteins in PDMS Microchip for Narrow pI Range Sample Prefractionation Coupled with Mass Spectrometry
In this paper, we are evaluating the strategy of sorting peptides/proteins based on the charge to mass without resorting to ampholytes and/or isoelectric focusing, using a single- and two-step free-flow zone electrophoresis. We developed a simple fabrication method to create a salt bridge for free-flow zone electrophoresis in PDMS chips by surface printing a hydrophobic layer on a glass substrate. Since the surface-printed hydrophobic layer prevents plasma bonding between the PDMS chip and the substrate, an electrical junction gap can be created for free-flow zone electrophoresis. With this device, we demonstrated a separation of positive and negative peptides and proteins at a given pH in standard buffer systems and validated the sorting result with LC/MS. Furthermore, we coupled two sorting steps via off-chip titration and isolated peptides within specific pI ranges from sample mixtures, where the pI range was simply set by the pH values of the buffer solutions. This free-flow zone electrophoresis sorting device, with its simplicity of fabrication, and a sorting resolution of 0.5 pH unit, can potentially be a high-throughput sample fractionation tool for targeted proteomics using LC/MS.Korea Institute of Science and Technology. Intelligent Microsystems CenterMassachusetts Institute of Technology. Center for Environmental Health SciencesNational Institute of Environmental Health Sciences (Grant No. P30-ES002109)United States. National Institutes of Health (grant R21 EB008177
Identfication and quantfication of giant bioaerosol particles over the Amazon rainforest
Eukarya dominate the coarse primary biological aerosol (PBA) above the Amazon rainforest canopy, but their vertical profile and seasonality is currently unknown. In this study, the stratification of coarse and giant PBA >5â”m were analyzed from the canopy to 300âm height at the Amazon Tall Tower Observatory in Brazil during the wet and dry seasons. We show that >2/3 of the coarse PBA were canopy debris, fungal spores commonly found on decaying matter were second most abundant (ranging from 15 to 41%), followed by pollens (up to 5%). The atmospheric roughness layer right above the canopy had the greatest giant PBA abundance. Measurements over 5âyears showed an increased abundance of PBA during a low-rainfall period. Giant particles, such as pollen, are reduced at 300âm, suggesting their limited dispersal. These results give insights into the giant PBA emissions of this tropical rainforest, and present a major step in understanding the type of emitted particles and their vertical distribution
Loop-Generated Bounds on Changes to the Graviton Dispersion Relation
We identify the effective theory appropriate to the propagation of massless
bulk fields in brane-world scenarios, to show that the dominant low-energy
effect of asymmetric warping in the bulk is to modify the dispersion relation
of the effective 4-dimensional modes. We show how such changes to the graviton
dispersion relation may be bounded through the effects they imply, through
loops, for the propagation of standard model particles. We compute these bounds
and show that they provide, in some cases, the strongest constraints on
nonstandard gravitational dispersions. The bounds obtained in this way are the
strongest for the fewest extra dimensions and when the extra-dimensional Planck
mass is the smallest. Although the best bounds come for warped 5-D scenarios,
for which the 5D Planck Mass is O(TeV), even in 4 dimensions the graviton loop
can lead to a bound on the graviton speed which is comparable with other
constraints.Comment: 18 pages, LaTeX, 4 figures, uses revte
Cosmological Implications of Dynamical Supersymmetry Breaking
We provide a taxonomy of dynamical supersymmetry breaking theories, and
discuss the cosmological implications of the various types of models. Models in
which supersymmetry breaking is produced by chiral superfields which only have
interactions of gravitational strength (\eg\ string theory moduli) are
inconsistent with standard big bang nucleosynthesis unless the gravitino mass
is greater than \CO(3) \times 10^4 GeV. This problem cannot be solved by
inflation. Models in which supersymmetry is dynamically broken by
renormalizable interactions in flat space have no such cosmological problems.
Supersymmetry can be broken either in a hidden or the visible sector. However
hidden sector models suffer from several naturalness problems and have
difficulties in producing an acceptably large gluino mass.Comment: 24 pages (uses harvmac) UCSD/PTH 93-26, RU-3
Probing dark energy with cluster counts and cosmic shear power spectra: including the full covariance
(Abridged) Combining cosmic shear power spectra and cluster counts is
powerful to improve cosmological parameter constraints and/or test inherent
systematics. However they probe the same cosmic mass density field, if the two
are drawn from the same survey region, and therefore the combination may be
less powerful than first thought. We investigate the cross-covariance between
the cosmic shear power spectra and the cluster counts based on the halo model
approach, where the cross-covariance arises from the three-point correlations
of the underlying mass density field. Fully taking into account the
cross-covariance as well as non-Gaussian errors on the lensing power spectrum
covariance, we find a significant cross-correlation between the lensing power
spectrum signals at multipoles l~10^3 and the cluster counts containing halos
with masses M>10^{14}Msun. Including the cross-covariance for the combined
measurement degrades and in some cases improves the total signal-to-noise
ratios up to plus or minus 20% relative to when the two are independent. For
cosmological parameter determination, the cross-covariance has a smaller effect
as a result of working in a multi-dimensional parameter space, implying that
the two observables can be considered independent to a good approximation. We
also discuss that cluster count experiments using lensing-selected mass peaks
could be more complementary to cosmic shear tomography than mass-selected
cluster counts of the corresponding mass threshold. Using lensing selected
clusters with a realistic usable detection threshold (S/N~6 for a ground-based
survey), the uncertainty on each dark energy parameter may be roughly halved by
the combined experiments, relative to using the power spectra alone.Comment: 32 pages, 15 figures. Revised version, invited original contribution
to gravitational lensing focus issue, New Journal of Physic
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