2,653 research outputs found
Does a shell matter for defence? Chemical deterrence in two cephalaspidean gastropodes with calcified shells
Opisthobranch molluscs show an evolutionary trend to reduce, internalize and lose the shell. Many of them base their defensive strategies on natural deterrent products and current evolutionary theory suggests that the acquisition of chemical defences preceded shell reduction and loss, which has characterized the evolution of this group. Here we show that basal, shelled opisthobranch molluscs are defended against sympatric predators even if their protective shell is removed. The cephalaspideans Bulla striata and Haminoea orbignyana, both with distinct shell calcification, significantly deterred feeding by sympatric crab and fish predators, both in laboratory and field assays. However, our results argue against a progressive increment of chemical defences associated with shell reduction, because the cephalaspidean with the more fully calcified shell, Bulla striata, was also the more deterrent. These findings suggest that effective chemical defences might have evolved independently from shell loss, at least in basal opisthobranchs such as cephalaspideans
Contact allergy to local anaesthetics–value of patch testing with a caine mix in the baseline series
BACKGROUND:
Contact allergy to local anaesthetics is relatively common. Patch testing with benzocaine in the European baseline series is recommended for diagnosis, even though a caine mix has been previously suggested to be superior.
OBJECTIVES:
To assess the frequency and patterns of contact allergy to local anaesthetics by using a caine mix (benzocaine, tetracaine, and cinchocaine) in the baseline series, and evaluate its efficiency as compared with benzocaine alone.
METHODS:
We reviewed the results of 2736 patch tests performed between 2000 and 2010, identifying patients with positive reactions to caine mix or to one of seven local anaesthetics.
RESULTS:
One hundred and twelve patients (4.1%) had at least one allergic reaction to local anaesthetics; 86 were tested with all seven local anaesthetics, resulting in 71 reactions in 53 patients. Cinchocaine gave the most reactions (50.7%); these occurred as a single reaction in 83.3% of patients, mostly with current or past relevance (97%). Benzocaine represented 22.5% of reactions, many of which were non-relevant (44%) or resulting from cross-reactions with para-compounds.
CONCLUSIONS:
Almost 70% of allergic reactions to local anaesthetics would have been missed if benzocaine had been used as a screening allergen. This study supports a recommendation to replace benzocaine with a caine mix containing cinchocaine in the baseline patch test series
An evaluation of the replicate pool method: quick estimation of genome-wide linkage peak p -values
The calculation of empirical p -values for genome-wide non-parametric linkage tests continues to present significant computational challenges for many complex disease mapping studies. The gold standard approach is to use gene dropping to simulate null genome scans. Unfortunately, this approach is too computationally expensive for many data sets of interest. An alternative, more efficient method for sampling null genome scans is to pre-calculate pools of family-specific statistics and then resample from these replicate pools to generate “pseudo-replicate” genome scans. In this study, we use simulations to explore properties of the replicate pool p -value estimator [pcirc] RP and show that it provides an excellent approximation to the traditional gene-dropping estimator for significantly less computational effort. While the computational efficiency of the replicate pool estimator is noticeable in almost all data sets, by applying the replicate pool method to several previously characterized data sets we show that savings in computational effort can be especially significant (on the order of 10,000-fold or more) when one or more large families are analyzed. We also estimate replicate pool p -values for the schizophrenia data described by Abecasis et al. and show that [pcirc] RP closely approximates gene-drop p -values for all linkage peaks reported for this study. Lastly, we expand upon Song et al.'s previous work by deriving a conservative estimator of the variance for [pcirc] RP that can easily be computed in practical settings.We have implemented the replicate pool method along with our variance estimator in a new program called Pseudo, which is the first widely available automated implementation of the replicate pool method. Genet . Epidemiol . 30, 2006. © 2006 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50657/1/20147_ftp.pd
Hamiltonian thermodynamics of three-dimensional dilatonic black holes
The action for a class of three-dimensional dilaton-gravity theories with a
cosmological constant can be recast in a Brans-Dicke type action, with its free
parameter. These theories have static spherically symmetric black
holes. Those with well formulated asymptotics are studied through a Hamiltonian
formalism, and their thermodynamical properties are found out. The theories
studied are general relativity (), a dimensionally reduced
cylindrical four-dimensional general relativity theory (), and a
theory representing a class of theories (). The Hamiltonian
formalism is setup in three dimensions through foliations on the right region
of the Carter-Penrose diagram, with the bifurcation 1-sphere as the left
boundary, and anti-de Sitter infinity as the right boundary. The metric
functions on the foliated hypersurfaces are the canonical coordinates. The
Hamiltonian action is written, the Hamiltonian being a sum of constraints. One
finds a new action which yields an unconstrained theory with one pair of
canonical coordinates , being the mass parameter and its
conjugate momenta The resulting Hamiltonian is a sum of boundary terms only. A
quantization of the theory is performed. The Schr\"odinger evolution operator
is constructed, the trace is taken, and the partition function of the canonical
ensemble is obtained. The black hole entropies differ, in general, from the
usual quarter of the horizon area due to the dilaton.Comment: 34 pages, 3 figures, references added, minor changes in the revised
versio
An architecture for interoperability and ubiquity of medical information
In critical situations, such as decision making in healthcare, is necessary to have access to all the patient’s information, this information must be reliable, and must be accessed in an easy and fast way. These requirements make medical information systems of extreme importance. However in today’s molds and with the advent of the Internet and mobile devices, a paradigm shift, from the current isolated systems to interoperable distributed systems, that take advantage of ubiquitous computing, is needed. The present work proposes an architecture that aims to answer the needs of
interoperability between heterogeneous systems and the need of ubiquity of medical information systems
Combustion behavior of Jet-A1 single droplets and its blends with Hydroprocessed Vegetable Oil in a drop tube furnace
The aeronautical sector contributes significantly to greenhouse gases and pollutant emissions. The negative impact of these emissions in the environment has raised awareness for the introduction of alternative and greener fuels. The implementation of alternative fuels remains one of the main challenges for this sector in the near future. The aeronautical industry is characterized by the dependence on single fossil fuel and by a long service time of its assets. For these reasons, the main research drive has been around the development of “drop-in” fuels, which are alternative fuels that can be used in the already existing fleet without significant modifications.
One of the proposed solutions is the blending of biofuels with jet fuel, which would allow the use of greener fuels and a reduction in greenhouse gases and emissions without significant changes in the existing companies’ fleets. In this context, the present work evaluates the ignition and the combustion of single droplets of jet-fuel, hydroprocessed vegetable oil (NExBTL), and their mixtures in a drop tube furnace. The main research focus of this study is to evaluate the influence of the mixture composition in the fuel-burning characteristics.
Droplets with diameters of 155 ± 5 μm, produced by a commercial droplet generator, were injected into the top of the drop tube furnace. Three temperatures were investigated 900, 1000, and 1100 °C. The ignition and combustion of the droplets were evaluated through the images obtained with a high-speed camera (CR600x2) coupled with a high magnification lens (Navitar 6000 zoom lens) and treated with an edge detection algorithm. The images allowed for the observation of the burning phenomena, and the data reported the temporal evolution of the droplet sizes and burning rates. The pure fuels and mixtures followed the D2 law, except for the mixture with 75% jet-fuel/ 25% biofuel at 1100 °C that reveals disruptive burning phenomena contributing to the enhancement of the single droplet combustion. The disruptive burning phenomena are related to the appearance of “puffing” and micro-explosions at the end of the droplet lifetime.Fundação para a Ciência e a Tecnologiainfo:eu-repo/semantics/publishedVersio
Promoting ubiquity and interoperability among health information systems using an soa based architecture
Health information systems are of extreme importance and they became an intrinsic part of the healthcare sector. However, in today’s molds and with the advent of the Internet and mobile devices, a paradigm shift, from the current isolated systems to interoperable distributed systems, that take advantage of ubiquitous computing, is needed. In critical situations, such as decision making in healthcare, it is necessary to have access to all of the patient’s information; for the information must be reliable and must be accessed in an easy and fast way. The present work
proposes an architecture that aims to answer the needs of interoperability between heterogeneous health information systems and the need for ubiquity of medical information. A prototype was developed that tries to provide interoperability through a service-oriented architecture using web
services. A mobile component was also developed to enable ubiquitous access to medical information. This work is based on the authors’ knowledge about the Portuguese National Health Service
A SOA based architecture to promote ubiquity and interoperability among health information systems
In critical situations, such as decision making in healthcare, is necessary to have access to all
of the patient’s information, the information must be reliable, and must be accessed in an easy
and fast way. These requirements make medical information systems of extreme importance.
However in today’s molds and with the advent of the Internet and mobile devices, a paradigm
shift, from the current isolated systems to interoperable distributed systems, that take
advantage of ubiquitous computing, is needed. The present work proposes an architecture that
aims to answer the needs of interoperability between heterogeneous systems and the need of
ubiquity of medical information systems. A prototype was developed that tries to provide
interoperability through a service-oriented architecture using web services. A mobile
component was also developed to enable ubiquitous access to medical information. This work
was based on the author’s knowledge about the Portuguese National Health Service
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Exome Sequencing and Complex Disease: Practical Aspects of Rare Variant Association Studies
Genetic association and linkage studies can provide insights into complex disease biology, guiding the development of new diagnostic and therapeutic strategies. Over the past decade, genetic association studies have largely focused on common, easy to measure genetic variants shared between many individuals. These common variants typically have subtle functional consequence and translating the resulting association signals into biological insights can be challenging. In the last few years, exome sequencing has emerged as a cost-effective strategy for extending these studies to include rare coding variants, which often have more marked functional consequences. Here, we provide practical guidance in the design and analysis of complex trait association studies focused on rare, coding variants
Charged shells in Lovelock gravity: Hamiltonian treatment and physical implications
Using a Hamiltonian treatment, charged thin shells in spherically symmetric
spacetimes in d dimensional Lovelock-Maxwell theory are studied. The
coefficients of the theory are chosen to obtain a sensible theory, with a
negative cosmological constant appearing naturally. After writing the action
and the Lagrangian for a spacetime comprised of an interior and an exterior
regions, with a thin shell as a boundary in between, one finds the Hamiltonian
using an ADM description. For spherically symmetric spacetimes, one reduces the
relevant constraints. The dynamic and constraint equations are obtained. The
vacuum solutions yield a division of the theory into two branches, d-2k-1>0
(which includes general relativity, Born-Infeld type theories) and d-2k-1=0
(which includes Chern-Simons type theories), where k gives the highest power of
the curvature in the Lagrangian. An additional parameter, chi, gives the
character of the vacuum solutions. For chi=1 the solutions have a black hole
character. For chi=-1 the solutions have a totally naked singularity character.
The integration through the thin shell takes care of the smooth junction. The
subsequent analysis is divided into two cases: static charged thin shell
configurations, and gravitationally collapsing charged dust shells. Physical
implications are drawn: if such a large extra dimension scenario is correct,
one can extract enough information from the outcome of those collapses as to
know, not only the actual dimension of spacetime, but also which particular
Lovelock gravity, is the correct one.Comment: 25 pages, 9 figure
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