96 research outputs found
Caveat Vendor: Sellers of Real Estate Now Need to Beware of Misrepresentations about the Condition of Property
The common law approach to disclosure of latent defects in real property was caveat emptor, which meant sellers had no duty to disclose latent defects to purchasers.2 Most modem courts have mitigated the harshness of the doctrine by adopting a system that mandates disclosure by a seller of any latent defect3 material to the purchaser\u27s decision to buy the property and whose existence is known by the seller. Droz v. Trump highlights a growing trend among a number of Missouri courts willing to further narrow the seller protections of caveat emptor in favor of protecting innocent purchasers of real property. Most significant in this case is the use of the affirmative representation doctrine to completely cancel the purchaser\u27s duty to investigate latent defects
Here\u27s Your Burrito and Watch Your Back: Does Missouri Really Want to Hold Businesses Liable for Attacks on Patrons
In the late 1980s, Missouri altered a longstanding common law rule and found that businesses sometimes owe a duty to their patrons to protect against or warn about criminal attacks by third parties.\u27 This new rule generally applies when a business has experienced prior incidents that are reasonably recent and similar to the attack in question.3 In Stroot v. Taco Bell Corp., the Missouri Court of Appeals for the Eastern District of Missouri upheld a summary judgment entered in favor of a business for an attack that occurred in the business\u27s parking lot even though the victim alleged that prior violent incidents had occurred in the parking lot and filed supporting affidavits.4 Perhaps Stroot represents a shift away from the modem trend of premises liability law and a return to a take care of yourself\u27 approach. Even more surprising is the court\u27s apparent willingness to ignore the rescue doctrine in favor of protecting businesses from potential liability
Marine biogeographic boundaries and human introduction along the European coast revealed by phylogeography of the prawn Palaemon elegans
11 páginas, 5 figuras, 6 tablas.A phylogeographic analysis is carried out for the widely distributed European littoral prawn Palaemon elegans in order to test for potential genetic differentiation and geographic structure. Mitochondrial sequences were obtained from 283 specimens from the northeastern Atlantic, the Baltic, Mediterranean, Black and Caspian Seas. Our study revealed a surprisingly complex population structure. Three main haplogroups can be separated: one from the Atlantic (Type I) and two from the Mediterranean (Types II and III). While the Mediterranean types occur in sympatry, a clear phylogeographic break was observed along the Almería-Oran Front separating Type I and giving evidence for a genetic isolation of Atlantic and Mediterranean populations. Type III represents the most distinct haplogroup with high levels of nucleotide divergence, indicating the occurrence of a cryptic species with a Messinian origin. The colonization of the southeastern Baltic Sea is most likely due to human introduction.For financial support we like to thank the European Union funding (FEDER), the Spanish “Ministerio de Educación y Ciencia, Plan Nacional I+D” (Project CGL2004-01083), the DAAD (D/03/40344) and the Spanish “Ministerio de Ciencia y Tecnología—Acciones Integradas (HA2003-078).Peer reviewe
Revisiting promyelocytic leukemia protein targeting by human cytomegalovirus immediate-early protein 1
This work was supported by a grant (MR/P022146/1) from the Medical Research Council (https://mrc.ukri.org) to MMN, a grant (T16/28) from Tenovus Scotland (https://tenovus-scotland.org.uk) to CP, a European Union Erasmus+ grant (https://www.erasmusplus.org.uk) to BW and the Wellcome Trust Institutional Strategic Support Fund (https://wellcome.ac.uk) to CP and MMN.Promyelocytic leukemia (PML) bodies are nuclear organelles implicated in intrinsic and innate antiviral defense. The eponymous PML proteins, central to the self-organization of PML bodies, and other restriction factors found in these organelles are common targets of viral antagonism. The 72-kDa immediate-early protein 1 (IE1) is the principal antagonist of PML bodies encoded by the human cytomegalovirus (hCMV). IE1 is believed to disrupt PML bodies by inhibiting PML SUMOylation, while PML was proposed to act as an E3 ligase for IE1 SUMOylation. PML targeting by IE1 is considered to be crucial for hCMV replication at low multiplicities of infection, in part via counteracting antiviral gene induction linked to the cellular interferon (IFN) response. However, current concepts of IE1-PML interaction are largely derived from mutant IE1 proteins known or predicted to be metabolically unstable and globally misfolded. We performed systematic clustered charge-to-alanine scanning mutagenesis and identified a stable IE1 mutant protein (IE1cc172-176) with wild-type characteristics except for neither interacting with PML proteins nor inhibiting PML SUMOylation. Consequently, IE1cc172-176 does not associate with PML bodies and is selectively impaired for disrupting these organelles. Surprisingly, functional analysis of IE1cc172-176 revealed that the protein is hypermodified by mixed SUMO chains and that IE1 SUMOylation depends on nucleosome rather than PML binding. Furthermore, a mutant hCMV expressing IE1cc172-176 was only slightly attenuated compared to an IE1-null virus even at low multiplicities of infection. Finally, hCMV-induced expression of cytokine and IFN-stimulated genes turned out to be reduced rather than increased in the presence of IE1cc172-176 relative to wild-type IE1. Our findings challenge present views on the relationship of IE1 with PML and the role of PML in hCMV replication. This study also provides initial evidence for the idea that disruption of PML bodies upon viral infection is linked to activation rather than inhibition of innate immunity.Publisher PDFPeer reviewe
Congested Traffic States in Empirical Observations and Microscopic Simulations
We present data from several German freeways showing different kinds of
congested traffic forming near road inhomogeneities, specifically lane
closings, intersections, or uphill gradients. The states are localized or
extended, homogeneous or oscillating. Combined states are observed as well,
like the coexistence of moving localized clusters and clusters pinned at road
inhomogeneities, or regions of oscillating congested traffic upstream of nearly
homogeneous congested traffic. The experimental findings are consistent with a
recently proposed theoretical phase diagram for traffic near on-ramps [D.
Helbing, A. Hennecke, and M. Treiber, Phys. Rev. Lett. {\bf 82}, 4360 (1999)].
We simulate these situations with a novel continuous microscopic single-lane
model, the ``intelligent driver model'' (IDM), using the empirical boundary
conditions. All observations, including the coexistence of states, are
qualitatively reproduced by describing inhomogeneities with local variations of
one model parameter.
We show that the results of the microscopic model can be understood by
formulating the theoretical phase diagram for bottlenecks in a more general
way. In particular, a local drop of the road capacity induced by parameter
variations has practically the same effect as an on-ramp.Comment: Now published in Phys. Rev. E. Minor changes suggested by a referee
are incorporated; full bibliographic info added. For related work see
http://www.mtreiber.de/ and http://www.helbing.org
Gas-kinetic derivation of Navier-Stokes-like traffic equations
Macroscopic traffic models have recently been severely criticized to base on
lax analogies only and to have a number of deficiencies. Therefore, this paper
shows how to construct a logically consistent fluid-dynamic traffic model from
basic laws for the acceleration and interaction of vehicles. These
considerations lead to the gas-kinetic traffic equation of Paveri-Fontana. Its
stationary and spatially homogeneous solution implies equilibrium relations for
the `fundamental diagram', the variance-density relation, and other quantities
which are partly difficult to determine empirically.
Paveri-Fontana's traffic equation allows the derivation of macroscopic moment
equations which build a system of non-closed equations. This system can be
closed by the well proved method of Chapman and Enskog which leads to
Euler-like traffic equations in zeroth-order approximation and to
Navier-Stokes-like traffic equations in first-order approximation. The latter
are finally corrected for the finite space requirements of vehicles. It is
shown that the resulting model is able to withstand the above mentioned
criticism.Comment: For related work see
http://www.theo2.physik.uni-stuttgart.de/helbing.htm
Feedback control algorithms for the dissipation of traffic waves with autonomous vehicles
International audienceThis article considers the problem of traffic control in which an autonomous vehicle is used to regulate human piloted traffic to dissipate stop and go traffic waves. We first investigate the controllability of well-known microscopic traffic flow models, namely i) the Bando model (also known as the optimal velocity model), ii) the follow-the-leader model, and iii) a combined optimal velocity follow the leader model. Based on the controllability results, we propose three control strategies for an autonomous vehicle to stabilize the other, human-piloted traffic. We subsequently simulate the control effects on the microscopic models of human drivers in numerical experiments to quantify the potential benefits of the controllers. Based on the simulations, finally we conduct a field experiment with 22 human drivers and a fully autonomous-capable vehicle, to assess the feasibility of autonomous vehicle based traffic control on real human piloted traffic. We show that both in simulation and in the field test that an autonomous vehicle is able to dampen waves generated by 22 cars, and that as a consequence, the total fuel consumption of all vehicles is reduced by up to 20%
Traffic and Related Self-Driven Many-Particle Systems
Since the subject of traffic dynamics has captured the interest of
physicists, many astonishing effects have been revealed and explained. Some of
the questions now understood are the following: Why are vehicles sometimes
stopped by so-called ``phantom traffic jams'', although they all like to drive
fast? What are the mechanisms behind stop-and-go traffic? Why are there several
different kinds of congestion, and how are they related? Why do most traffic
jams occur considerably before the road capacity is reached? Can a temporary
reduction of the traffic volume cause a lasting traffic jam? Under which
conditions can speed limits speed up traffic? Why do pedestrians moving in
opposite directions normally organize in lanes, while similar systems are
``freezing by heating''? Why do self-organizing systems tend to reach an
optimal state? Why do panicking pedestrians produce dangerous deadlocks? All
these questions have been answered by applying and extending methods from
statistical physics and non-linear dynamics to self-driven many-particle
systems. This review article on traffic introduces (i) empirically data, facts,
and observations, (ii) the main approaches to pedestrian, highway, and city
traffic, (iii) microscopic (particle-based), mesoscopic (gas-kinetic), and
macroscopic (fluid-dynamic) models. Attention is also paid to the formulation
of a micro-macro link, to aspects of universality, and to other unifying
concepts like a general modelling framework for self-driven many-particle
systems, including spin systems. Subjects such as the optimization of traffic
flows and relations to biological or socio-economic systems such as bacterial
colonies, flocks of birds, panics, and stock market dynamics are discussed as
well.Comment: A shortened version of this article will appear in Reviews of Modern
Physics, an extended one as a book. The 63 figures were omitted because of
storage capacity. For related work see http://www.helbing.org
- …