20,220 research outputs found
The influence of tobacco smoking on adhesion molecule profiles
Sequential interactions between several adhesion molecules and their ligands regulate lymphocyte circulation and leukocyte recruitment to inflammatory foci. Adhesion molecules are, therefore, central and critical components of the immune and inflammatory system. We review the evidence that tobacco smoking dysregulates specific components of the adhesion cascade, which may be a common factor in several smoking-induced diseases. Smoking causes inappropriate leukocyte activation, leukocyte-endothelial adhesion, and neutrophil entrapment in the microvasculature, which may help initiate local tissue destruction. Appropriate inflammatory reactions may thus be compromised. In addition to smoke-induced alterations to membrane bound endothelial and leukocyte adhesion molecule expression, which may help explain the above phenomena, smoking has a profound influence on circulating adhesion molecule profiles, most notably sICAM-1 and specific sCD44 variants. Elevated concentrations of soluble adhesion molecules may simply reflect ongoing inflammatory processes. However, increasing evidence suggests that specific soluble adhesion molecules are immunomodulatory, and that alterations to soluble adhesion molecule profiles may represent a significant risk factor for several diverse diseases. This evidence is discussed herein
Clinical presentation, diagnostic findings and outcome of dogs with presumptive spinal-only meningoencephalomyelitis of unknown origin
Objectives: To summarise clinical presentation, diagnostic findings and long-term outcome for dogs clinically diagnosed with meningoencephalomyelitis of unknown origin affecting the spinal cord alone.
Methods: Medical records were reviewed for dogs diagnosed with presumptive spinal-only meningoencephalomyelitis of unknown origin between 2006 and 2015.
Results: 21 dogs were included; the majority presented with an acute (43%) or chronic (52%) onset of neurological signs. Ambulatory paresis was the most common neurological presentation (67%). Neurological examination most commonly revealed a T3-L3 myelopathy, and spinal hyperaesthesia was a common finding (71%). A spinal cord lesion was visible in 90% of cases on magnetic resonance imaging. Eighteen lesions (86%) showed parenchymal contrast enhancement and 17 lesions (81%) showed contrast enhancement of overlying meninges. All dogs were treated with immunosuppressive doses of glucocorticosteroids, sometimes combined with cytosine arabinoside. At time of data capture, 10/21 dogs (48%) had died or been euthanased because of the condition. Overall median survival time was 669 days.
Clinical Significance: Meningoencephalomyelitis of unknown origin should be considered in the differential diagnosis of dogs presenting with a progressive myelopathy. Magnetic resonance imaging features can possibly help to distinguish presumptive meningoencephalomyelitis of unknown origin from other more common spinal diseases. Overall, long-term survival is guarded, approximately 50% of dogs will die or be euthanased despite appropriate therapy
Correlation length scalings in fusion edge plasma turbulence computations
The effect of changes in plasma parameters, that are characteristic near or
at an L-H transition in fusion edge plasmas, on fluctuation correlation lengths
are analysed by means of drift-Alfven turbulence computations. Scalings by
density gradient length, collisionality, plasma beta, and by an imposed shear
flow are considered. It is found that strongly sheared flows lead to the
appearence of long-range correlations in electrostatic potential fluctuations
parallel and perpendicular to the magnetic field.Comment: Submitted to "Plasma Physics and Controlled Fusion
Fast Community Identification by Hierarchical Growth
A new method for community identification is proposed which is founded on the
analysis of successive neighborhoods, reached through hierarchical growth from
a starting vertex, and on the definition of communities as a subgraph whose
number of inner connections is larger than outer connections. In order to
determine the precision and speed of the method, it is compared with one of the
most popular community identification approaches, namely Girvan and Newman's
algorithm. Although the hierarchical growth method is not as precise as Girvan
and Newman's method, it is potentially faster than most community finding
algorithms.Comment: 6 pages, 5 figure
Quantum electric-dipole liquid on a triangular lattice
Geometric frustrations and quantum mechanical fluctuations may prohibit the
formation of long-range ordering even at the lowest temperature, and therefore
liquid-like ground states could be expected. A good example is the quantum spin
liquid in frustrated magnets that represents an exotic phase of matter and is
attracting enormous interests. Geometric frustrations and quantum fluctuations
can happen beyond magnetic systems. Here we propose that quantum
electric-dipole liquids, analogs to quantum spin liquids, could emerge in
frustrated dielectrics where antiferroelectrically coupled small electric
dipoles reside on a triangular lattice. The quantum paraelectric hexaferrite
BaFe12O19, in which small electric dipoles originated from the off-center
displacement of Fe3+ in the FeO5 bipyramids constitute a two-dimensional
triangular lattice, represents a promising candidate to generate the
anticipated electric-dipole liquid. We present a series of experimental
evidences, including dielectric permittivity, heat capacity, and thermal
conductivity measured down to 66 mK, to reveal the existence of a nontrivial
ground state in BaFe12O19, characterized by itinerant low-energy excitations
with a small gap, to which we interpret as an exotic liquid-like quantum phase.
The quantum electric-dipole liquids in frustrated dielectrics open up a fresh
playground for fundamental physics and may find applications in quantum
information and computation as well.Comment: 13 pages, 6 figure
Analysis of circulating insulin-like growth factor-1 (IGF-1) and IGF binding protein-3 (IGFBP-3) in tobacco smokers and non-smokers
<p>Abstract</p> <p>Background</p> <p>IGF-1 and the major serum IGF-1 binding protein, IGFBP-3, are under extensive investigation as potential prognostic markers of specific malignancies and vascular diseases. However, there is conflicting evidence that tobacco smoking may influence systemic concentrations of IGF-1 and IGFBP-3.</p> <p>Subjects and methods</p> <p>Serum concentrations of IGF-1 and IGFBP-3 were measured in 20 smokers and 20 non-smokers, matched for age and gender. Serum concentrations of cotinine, the major metabolite of nicotine, and ICAM-1, known to exhibit a dose-dependent relationship with cotinine, were also assayed.</p> <p>Results</p> <p>There was no difference between the systemic concentrations of IGF-1 or IGFBP-3 found in smokers and non-smokers (IGF-1: mean [s.d]; 104 <abbrgrp><abbr bid="B29">29</abbr></abbrgrp> vs 101 <abbrgrp><abbr bid="B24">24</abbr></abbrgrp> ng ml<sup>-1</sup>, respectively; and IGFBP-3: 2562 [522] vs 2447 [570] ng ml<sup>-1</sup>, respectively). Similarly, there was no correlation between serum cotinine and IGF-1 or IGFBP-3 concentrations in smokers. Soluble ICAM-1 concentrations were significantly increased in smokers, compared to non-smokers (mean [s.d]; 258 [60] vs 194 [50] ng ml<sup>-1</sup>, respectively; p = 0.002).</p> <p>Conclusion</p> <p>There was no relationship noted between tobacco smoking and either IGF-1 or IGFBP-3. These data suggest that smoking would not appear to be a major confounder of the reported clinical associations between IGF-1, IGFBP-3, or IGF-1/IGFBP-3 ratios and specific disease entities.</p
The role of the BĂ©zier extraction operator for T-splines of arbitrary degree: linear dependencies, partition of unity property, nesting behaviour and local refinement
We determine linear dependencies and the partition of unity property of T-spline meshes of arbitrary degree
using the BĂ©zier extraction operator. Local refinement strategies for standard, semi-standard and nonstandard
T-splines – also by making use of the Bézier extraction operator – are presented for meshes of
even and odd polynomial degrees. A technique is presented to determine the nesting between two T-spline
meshes, again exploiting the BĂ©zier extraction operator. Finally, the hierarchical refinement of standard,
semi-standard and non-standard T-spline meshes is discussed. This technique utilises the reconstruction
operator, which is the inverse of the BĂ©zier extraction operator
Pregnancies and associated events in women receiving Enzyme Replacement Therapy for late onset Glycogen Storage Disease Type II (Pompe disease)
AIM:
Glycogen storage disease type II (GSD II or Pompe disease; OMIM; 232 300) is a rare autosomal recessive lysosomal storage disorder resulting from deficiency of α-glucosidase and accumulation of glycogen in muscle. Clinical symptoms include weakness of skeletal and respiratory muscles and, in infants, cardiomyopathy. Patients with GSD II receive infusions of recombinant α-glucosidase (enzyme replacement therapy; ERT), which slow the progression of the disease. ERT is given to male and female patients of all ages but as yet little is documented on the effects of continuing ERT during pregnancy. The aim of this case series was therefore to ascertain the pregnancy outcomes of women with GSD II on ERT and to describe adverse events associated with pregnancy, delivery and therapy.
METHODS:
The medical records of eight women attending the Royal Free Hospital Lysosomal Storage Disorders Unit were reviewed. Four of the eight women had seven pregnancies over a period of 8 years.
RESULTS:
In this series GSD II was associated with interventional deliveries but normal neonates. Cessation of ERT in early pregnancy resulted in deterioration of maternal symptoms and emergence of allergic reactions on restarting ERT.
CONCLUSION:
Individualized care plans are required to ensure the best neonatal and maternal outcomes. Consideration should be given to the potential benefits to mother and fetus of continuing ERT during pregnancy
Design Methodology for Unmanned Aerial Vehicle (UAV) Team Coordination
Unmanned Aerial Vehicle (UAV) systems, despite having no onboard human pilots, currently
require extensive human involvement to accomplish successful mission operations. Further,
successful operations also require extensive colalboration between mission stakeholders,
including operators, mission commanders, and information consumers (e.g. ground troops relying
on intelligence reports in their area).
Existing UAV system interfaces provide little to no support for collaboration between remote
operators or for operators to collaborate with information consumers. As reliance on UAVs
continues to increase in military and civilian operations, this lack of support for collaboration will
likely become a substantial limitation of existing UAV systems.
In order to introduce effective collaboration support to UAV system interfaces, it is essential to
understand, and be able to derive system design requirements that address, the necessary group
interactions that occur in UAV task enviroments. However, few collaborative requirements
analysis methods exist, and to our knowledge, no method exists that captures design requirements
for collaborative decision making in complex, time-critical environments.
This report describes the development of a new design requirements analysis method for deriving
information and functional requirements that address the collaboration needs of UAV (and other
complex task) operators, and the needs of stakeholders interacting with these operators. More
specifically, theis method extends a recently developed requirements analysis method, called the
Hybrid Cognitive Task Analysis (CTA) method, which enables the generation of information and
functional requirements for futuristic UAV system interfaces. The original Hybrid CTA method
focused on deriving single user system interface requirements. This work extends this method by
introducing analytic steps to identify task and decision-making dependencies between different
UAV operations collaborators.
This collaborative extension to the Hybrid CTA utilizes the notion of boundary objects, an
analytic construct commonly used in the study of group work. Boundary objects are physical or
information artifacts that cross the task boundaries between members of distinct groups.
Identifying boundary objects in complex task operations help the analyst to identify task and
decision-making dependencies between local and remote collaborators. Understanding these
dependencies helps to identify information sharing requirements that the UAV system should
support.
This report describes the analytic steps of the collaborative extension, and provides background
information on the original Hybrid CTA method and the boundary object construct. The report
also describes a project in which the new design requirements method was used to revise a
proposed set of UAV operator displays.Prepared For Boeing Phantom Work
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