13,824 research outputs found
Recommended from our members
A Monte Carlo model checker for probabilistic LTL with numerical constraints
We define the syntax and semantics of a new temporal logic called probabilistic LTL with numerical constraints (PLTLc).
We introduce an efficient model checker for PLTLc properties. The efficiency of the model checker is through approximation
using Monte Carlo sampling of finite paths through the modelās state space (simulation outputs) and parallel model checking
of the paths. Our model checking method can be applied to any model producing quantitative output ā continuous or
stochastic, including those with complex dynamics and those with an infinite state space. Furthermore, our offline approach
allows the analysis of observed (real-life) behaviour traces. We find in this paper that PLTLc properties with constraints
over free variables can replace full model checking experiments, resulting in a significant gain in efficiency. This overcomes
one disadvantage of model checking experiments which is that the complexity depends on system granularity and number of
variables, and quickly becomes infeasible. We focus on models of biochemical networks, and specifically in this paper on
intracellular signalling pathways; however our method can be applied to a wide range of biological as well as technical
systems and their models. Our work contributes to the emerging field of synthetic biology by proposing a rigourous approach
for the structured formal engineering of biological systems
Microminiature gas chromatographic column
Techniques commonly used for fabrication of integrated circuits are utilized to produce long capillary tubes for microminiature chromatographs. Method involves bonding of flat silicon plate to top of spirally grooved silicon chip to close groove and form capillary column
Chemiluminescence of asbestos-activated macrophages
Chemiluminescence, a measure of reactive oxygen release by phagocytes, was compared in peritoneal exudate macrophages elicited with chrysotile asbestos, Corynebacterium parvum and saline. Chrysotile asbestos- and C. parvum-activated macrophages produced significantly more chemiluminescence than saline-elicited macrophages. In a second series of experiments the ability of opsonized chrysotile asbestos to act as a trigger for the release of chemiluminescence was tested. Opsonized chrysotile asbestos produced a dose-related release of chemiluminescence from activated macrophages except at the highest dose where chemiluminescence was reduced due, possibly, to a toxic effect of chrysotile during the assay. Opsonized latex also triggered a dose-related chemiluminescent response from activated macrophages. The potential role of toxic reactive oxygen species, released from macrophages, in the development of asbestos-related pulmonary inflammation and fibrosis are discussed
Petri nets for systems and synthetic biology
We give a description of a Petri net-based framework for
modelling and analysing biochemical pathways, which uniĀÆes the qualita-
tive, stochastic and continuous paradigms. Each perspective adds its con-
tribution to the understanding of the system, thus the three approaches
do not compete, but complement each other. We illustrate our approach
by applying it to an extended model of the three stage cascade, which
forms the core of the ERK signal transduction pathway. Consequently
our focus is on transient behaviour analysis. We demonstrate how quali-
tative descriptions are abstractions over stochastic or continuous descrip-
tions, and show that the stochastic and continuous models approximate
each other. Although our framework is based on Petri nets, it can be
applied more widely to other formalisms which are used to model and
analyse biochemical networks
Recommended from our members
SOX10 commonly stains scar in Mohs sections
Sox10 immunostaining is used for the diagnosis and margin evaluation of melanocytic lesions. Sox10 was initially thought not to stain fibrohistiocytic processes. Consequently, it was believed to reliably distinguish desmoplastic melanoma from scar. However, recent data from formalin sections suggest Sox10 is less specific than previously thought. In this report, we demonstrate that Sox10-stained Mohs sections commonly show strong, fractional staining of scar. When using Sox10 with frozen section immunohistochemistry, Mohs practitioners should recognize the potential of this marker to stain scar to avoid overdiagnosis of desmoplastic melanoma
Recommended from our members
An introduction to Biomodel engineering, illustrated for signal transduction pathways
BioModel Engineering is the science of designing, constructing
and analyzing computational models of biological systems. It is inspired
by concepts from software engineering and computing science.
This paper illustrates a major theme in BioModel Engineering, namely
that identifying a quantitative model of a dynamic system means building
the structure, finding an initial state, and parameter fitting. In our
approach, the structure is obtained by piecewise construction of models
from modular parts, the initial state is obtained by analysis of the structure
and parameter fitting comprises determining the rate parameters of
the kinetic equations. We illustrate this with an example in the area of
intracellular signalling pathways
Feedback control of unsupported standing
This paper presents the results of continuing work on feedback control of unsupported standing in paraplegia. Our experimental setup considers a situation in which all joints above the ankle are braced, and stabilising torque at the ankle is generated by stimulation of the plantarflexors. A previous study showed that short periods of unsupported standing with paraplegic subjects could be achieved. In order to improve consistency and reliability of unsupported standing we are currently investigating several modifications to the control strategy. The paper reports progress towards this goal
Transgender Healthcare Teaching in the Undergraduate Medical School Curriculum
With increasing recognition of the diverse and specific needs of transgender individuals in a health care setting, lack of knowledge, poor attitudes and prejudice towards transgender patients can result in this population being afraid to access medical care. Educating medical students early in their career in a sensitive and inclusive manner could help change these attitudes. It has been shown that medical undergraduates and post-graduates often feel unprepared or uncomfortable in caring for transgender patients due to lack of training and experience2-4. The aim of this study was to address this through introduction of basic transgender healthcare education into the University of Glasgow undergraduate medical curriculum, with the goal of implementing further interactive and fully inclusive teaching
Computing dispersal of atmospheric pollutants near airports
Computing dispersal of atmospheric pollutants near airports by use of mean wind and temperature profile
- ā¦