7,160 research outputs found
An Analytic Hierarchy Process for The Evaluation of Transport Policies to Reduce Climate Change Impacts
Transport is the sector with the fastest growth of greenhouse gases emissions, both in developed and in developing countries, leading to adverse climate change impacts. As the experts disagree on the occurrence of these impacts, by applying the analytic hierarchy process (AHP), we have faced the question on how to form transport policies when the experts have different opinions and beliefs. The opinions of experts have been investigated by a means of a survey questionnaire. The results show that tax schemes aiming at promoting environmental-friendly transport mode are the best policy. This incentives public and environmental-friendly transport modes, such as car sharing and car pooling.Analytic Hierarchy Process, Transport Policies, Climate Change
What Are Pediatric Antidepressant Meta-Analyses Telling Clinical Practitioners? It Depends…
Finding Large Independent Sets in Line of Sight Networks
Line of Sight (LoS) networks provide a model of wireless communication which incorporates visibility constraints. Vertices of such networks can be embedded in finite d-dimensional grids of size n, and two vertices are adjacent if they share a line of sight and are at distance less tha
Role of a Conserved Glutamate Residue in the \u3cem\u3eEscherichia coli\u3c/em\u3e SecA ATPase Mechanism
Escherichia coli SecA uses ATP to drive the transport of proteins across cell membranes. Glutamate 210 in the “DEVD” Walker B motif of the SecA ATP-binding site has been proposed as the catalytic base for ATP hydrolysis (Hunt, J. F., Weinkauf, S., Henry, L., Fak, J. J., McNicholas, P., Oliver, D. B., and Deisenhofer, J. (2002) Science 297, 2018–2026). Consistent with this hypothesis, we find that mutation of glutamate 210 to aspartate results in a 90-fold reduction of the ATP hydrolysis rate compared with wild type SecA, 0.3 s–1versus 27 s–1, respectively. SecA-E210D also releases ADP at a slower rate compared with wild type SecA, suggesting that in addition to serving as the catalytic base, glutamate 210 might aid turnover as well. Our results contradict an earlier report that proposed aspartate 133 as the catalytic base (Sato, K., Mori, H., Yoshida, M., and Mizushima, S. (1996) J. Biol. Chem. 271, 17439–17444). Re-evaluation of the SecA-D133N mutant used in that study confirms its loss of ATPase and membrane translocation activities, but surprisingly, the analogous SecA-D133A mutant retains full activity, revealing that this residue does not play a key role in catalysis
Frictionless contact formulation by mathematical programming technique
The object of the paper concerns a consistent formulation of the classical Signorini's theory
regarding the frictionless unilateral contact problem between two elastic bodies in the hypothesis of
small displacements and strains. A variational approach, employed within the symmetric Boundary
Element Method, leads to an algebraic formulation based on nodal quantities. The contact problem
is decomposed into two sub-problems: one is purely elastic, and the other pertains to the unilateral
contact condition alone. Following this methodology, the contact problem, faced with symmetric
BEM, is characterized by symmetry and sign definiteness of the coefficient matrix, thus admitting a
unique solution.
The solution of the frictionless unilateral contact problem can be obtained
- through a step-by-step analysis utilizing generalized quantities as check elements in the zones of
potential contact or detachment. Indeed, the detachment or the contact phenomenon may happen
when the weighted traction or the weighted displacement is greater than the weighted cohesion
or weighted minimum reference gap, respectively;
- through a quadratic programming problem based on the minimum of the total potential energy.
In the example, given in the paper, the detachment phenomenon is considered and some
comparisons of the solution between the step-by-step analysis and the direct approach which utilizes
the quadratic programming will be shown
Immunity, Inflammation and Heart Failure: Their Role on Cardiac Function and Iron Status
Aims: Heart failure is a clinical syndrome characterized by subclinical systemic inflammation and immune system activation associated with iron deficiency. No data exist on the various activations of immune-mediated mechanisms of inflammation in heart failure patients with reduced/preserved ejection fraction. We aimed to (1) investigate possible differences in inflammatory parameters and oxidative stress, and (2) detect a different iron status between groups. Materials and Methods: We enrolled 50 consecutive Caucasian outpatients with heart failure. All patients underwent echocardiographic measurements, laboratory determinations, evaluation of iron status and Toll-like receptors, and NF-κB expression in peripheral blood mononuclear cells, as well as pro-inflammatory cytokines. All statistical calculations were made using SPSS for Mac version 21.0. Results: Patients with reduced ejection fraction showed significantly lower hemoglobin levels (12.3 ± 1.4 vs. 13.6 ± 1.4 g/dl), serum iron (61.4 ± 18.3 vs. 93.7 ± 33.7 mcg/dl), transferrin iron binding capacity (20.7 ± 8.4 vs. 31.1 ± 15.6 %), and e-GFR values (78.1 ± 36.1 vs. 118.1 ± 33.9 ml/min/1.73 m2) in comparison to patients with preserved ejection fraction, while unsaturated iron binding capacity (272.6 ± 74.9 vs. 221.7 ± 61.4 mcg/dl), hepcidin (4.61 ± 0.89 vs. 3.28 ± 0.69 ng/ml), and creatinine (1.34 ± 0.55 vs. 1.03 ± 0.25 mg/dl) were significantly higher in the same group. When considering inflammatory parameters, patients with reduced ejection fraction showed significantly higher expression of both Toll-like receptors-2 (1.90 ± 0.97 vs. 1.25 ± 0.76 MFI) and Toll-like receptors-4 (4.54 ± 1.32 vs. 3.38 ± 1.62 MFI), respectively, as well as a significantly higher activity of NF-κB (2.67 ± 0.60 vs. 1.07 ± 0.30). Furthermore, pro-inflammatory cytokines, interleukin-1, and interleukin-6, was significantly higher in patients with reduced ejection fraction, while the protective cytokine interleukin-10 was significantly lower in the same group. Correlational analyses demonstrated a significant and inverse relationship between left ventricular function and inflammatory parameters in patients with reduced ejection fraction, as well as a direct correlation between ferritin and inflammatory parameters. Conclusions: Our data demonstrate a different immune-mediated inflammatory burden in heart failure patients with reduced or preserved ejection fraction, as well as significant differences in iron status. These data contribute to further elucidate pathophysiologic mechanisms leading to cardiac dysfunction
Frictionless contact-detachment analysis: iterative linear complementarity and quadratic programming approaches
The object of the paper concerns a consistent formulation
of the classical Signorini\u2019s theory regarding the frictionless
contact problem between two elastic bodies in the
hypothesis of small displacements and strains. The employment
of the symmetric Galerkin boundary element method,
based on boundary discrete quantities, makes it possible to
distinguish two different boundary types, one in contact as
the zone of potential detachment, called the real boundary,
the other detached as the zone of potential contact, called
the virtual boundary. The contact-detachment problem is
decomposed into two sub-problems: one is purely elastic,
the other regards the contact condition. Following this methodology,
the contact problem, dealtwith using the symmetric
boundary element method, is characterized by symmetry and
in sign definiteness of the matrix coefficients, thus admitting
a unique solution. The solution of the frictionless contact-
detachment problem can be obtained: (i) through an
iterative analysis by a strategy based on a linear complementarity
problem by using boundary nodal quantities as check
quantities in the zones of potential contact or detachment;
(ii) through a quadratic programming problem, based on a
boundary min-max principle for elastic solids, expressed in
terms of nodal relative displacements of the virtual boundary
and nodal forces of the real one
A predicative and decidable characterization of the polynomial classes of languages
Characterizations of PTIME, PSPACE, the polynomial hierarchy and its elements are given, which are decidable (membership can be decided by syntactic inspection to the constructions), predicative (according to points of view by Leivant and others), and are obtained by means of increasing restrictions to course-of-values recursion on trees (represented in a dialect of Lisp). (C) 2001 Elsevier Science B.V. All rights reserved
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