266,971 research outputs found
A Tutorial on Evolutionary Multi-Objective Optimization (EMO)
No full textMany real-world search and optimization problems are naturally posed
as non-linear programming problems having multiple objectives.
Due to lack of suitable solution techniques, such problems are
artificially converted into a single-objective problem and solved.
The difficulty arises because such problems give rise to a set
of Pareto-optimal solutions, instead of a single optimum solution.
It then becomes important to find not just one Pareto-optimal
solution but as many of them as possible. Classical methods are
not quite efficient in solving these problems because they require
repetitive applications to find multiple Pareto-optimal solutions
and in some occasions repetitive applications do not guarantee
finding distinct Pareto-optimal solutions. The population approach
of evolutionary algorithms (EAs) allows an efficient way to find
multiple Pareto-optimal solutions simultaneously in a single
simulation run.
In this tutorial, we discussed the following aspects related to
EMO:
1. The basic differences in principle of EMO with classical methods.
2. A gentle introduction to evolutionary algorithms with simple
examples. A simple method of handling constraints was also
discussed.
3. The concept of domination and methods of finding non-dominated
solutions in a population of solutions were discussed.
4. A brief history of the development of EMO is highlighted.
5. A number of main EMO methods (NSGA-II, SPEA and PAES) were
discussed.
6. The advantage of EMO methodologies was discussed by presenting
a number of case studies. They clearly showed the advantage of
finding a number of Pareto-optimal solutions simultaneously.
7. Three advantages of using an EMO methodology were stressed:
(i) For a better decision making (in terms of choosing a
compromised solution) in the presence of multiple solutions
(ii) For finding important relationships among decision variables
(useful in design optimization). Some case studies from engineering
demonstrated the importance of such studies.
(iii) For solving other optimization problems efficiently. For
example, in solving genetic programming problems, the so-called
`bloating problem of increased program size can be solved by using
a second objective of minimizing the size of the programs.
8. A number of salient research topics were highlighted. Some of
them are as follows:
(i) Development of scalable test problems
(ii) Development of computationally fast EMO methods
(iii) Performance metrics for evaluating EMO methods
(iv) Interactive EMO methodologies
(v) Robust multi-objective optimization procedures
(vi) Finding knee or other important solutions including partial
Pareto-optimal set
(vii) Multi-objective scheduling and other optimization problems.
It was clear from the discussions that
evolutionary search methods offers an alternate means of solving
multi-objective optimization problems compared to classical
approaches. This is why multi-objective optimization using EAs is
getting a growing attention in the recent years.
The motivated readers may explore
current research issues and other important studies from various
texts (Coello et al, 2003; Deb, 2001), conference proceedings
(EMO-01 and EMO-03 Proceedings) and numerous research papers
(http://www.lania.mx/~ccoello/EMOO/).
References:
----------
C. A. C. Coello, D. A. VanVeldhuizen, and G. Lamont.
Evolutionary Algorithms for Solving Multi-Objective Problems.
Boston, MA: Kluwer Academic Publishers, 2002.
K.Deb. Multi-objective optimization using evolutionary algorithms.
Chichester, UK: Wiley, 2001.
C. Fonseca, P. Fleming, E. Zitzler, K. Deb, and L. Thiele, editors.
Proceedings of the Second Evolutionary Multi-Criterion
Optimization (EMO-03) Conference
(Lecture Notes in Computer Science (LNCS) 2632).
Heidelberg: Springer, 2003.
E. Zitzler, K. Deb, L. Thiele, C. A. C. Coello, and D. Corne,
editors. Proceedings of the First Evolutionary Multi-Criterion
Optimization (EMO-01) Conference
(Lecture Notes in Computer Science (LNCS) 1993).
Heidelberg: Springer, 2001
Indotrachytes Deb & Raychaudhuri 1965
No full textIndotrachytes Deb & Raychaudhuri, 1965 Indotrachytes Deb & Raychaudhuri, 1965: 122. Type species Indotrachytes longisetus Deb & Raychaudhuri, 1965: 122, by original designation. Notes. Deb & Raychaudhuri (1965) spelled the name of this genus as Indrotrachytes (twice) and Indotrachytes (three times). I interpret Indotrachytes as the correct spelling, since it appears to be based on the country of origin of the type species (India).Published as part of Halliday, R. B., 2015, Catalogue of genera and their type species in the mite Suborder Uropodina (Acari: Mesostigmata), pp. 101-147 in Zootaxa 3972 (2) on page 116, DOI: 10.11646/zootaxa.3972.2.1, http://zenodo.org/record/23277
DEB parameters estimation for <i>Mytilus edulis</i>
No full textThe potential of DEB theory to simulate an organism life-cycle has been demonstrated at numerous occasions. However, its applicability requires parameter estimates that are not easily obtained by direct observations. During the last years various attempts were made to estimate the main DEB parameters for bivalve species. The estimation procedure was by then, however, rather ad-hoc and based on additional assumptions that were not always consistent with the DEB theory principles. A new approach has now been developed - the covariation method - based on simultaneous minimization of the weighted sum of squared deviations between data sets and model predictions in one single procedure. This paper presents the implementation of this method to estimate the DEB parameters for the blue mussel Mytilus edulis, using several data sets from the literature. After comparison with previous trials we conclude that the parameter set obtained by the covariation method leads to a better fit between model and observations, with potentially more consistency and robustness
Fibroblasts as Target Cells for DEB Gene Therapy
No full textDystrophic epidermolysis bullosa (DEB) is due to mutations in the type VII collagen (C7) gene. Potential therapies for DEB include (i) ex vivo gene therapy and (ii) intradermal injection of gene-corrected DEB fibroblasts, lentiviral vectors expressing C7 or recombinant C7 itself. With regard to molecular engineering, the dermal fibroblast has advantages over epidermal keratinocytes for delivering C7 to DEB patients
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Pairing of homologous chromosomes in <i>C. elegans</i> meiosis requires DEB-1 - an orthologue of mammalian vinculin
No full textDuring meiosis, homologous chromosomes undergo a dramatic movement in order to correctly align. This is a critical meiotic event but the molecular properties of this ‘chromosomal dance’ still remainunclear. We identified DEB-1 – an orthologue of mammalian vinculin – as a new component of the mechanistic modules responsible for attaching the chromosomes to the nuclear envelope as apart of the LINC complex. In early meiotic nuclei of C. elegans, DEB-1 is localized to the nuclear periphery and alongside the synaptonemal complex of paired homologues. Upon DEB-1 depletion, chromosomes attached to SUN-1 foci remain highly motile until late pachytene. Although the initiation of homologue pairing started normally, irregularities in the formation of the synaptonemal complex occur, and these results in meiotic defects such as increased number of univalents at diakinesis and high embryonic lethality. Our data identify DEB-1 as a new player regulating chromosome dynamics and pairing during meiotic prophase I.</p
Role of haemoglobin in the protection of cultured lymphocytes against diepoxybutane (DEB), assessed by in vitro induced chromosome breakage.
No full textMutat Res. 2003 Apr 20;536(1-2):61-7.
Role of haemoglobin in the protection of cultured lymphocytes against diepoxybutane (DEB), assessed by in vitro induced chromosome breakage.
Porto B, Chiecchio L, Gaspar J, Faber A, Pinho L, Rueff J, Malheiro I.
Laboratory of Cytogenetics, Instituto Ciências Biomédicas Abel Salazar (ICBAS), Largo do Prof. Abel Salazar, No. 2, 4099-003, Porto, Portugal.
Abstract
Diepoxybutane (DEB) is an alkylating agent that can be used to assess chromosome instability in repair-deficient subjects. Previous authors investigated the role of red blood cells (RBC) in determining individual susceptibility to DEB in normal healthy donors, and demonstrated that a polymorphic enzyme in RBC, Glutathione S-transferase T1 (GSTT1), is involved in DEB detoxification. In the present work we studied the influence of individual GSTM1 and GSTT1 genotypes and the presence of RBC on the frequency of DEB-induced chromosome breakage in lymphocyte cultures from normal individuals and, in particular, the influence of isolated components of RBC: RBC membranes, RBC lysate, and haemoglobin. Our results confirm that individual GSTT1 genotypes modulate the level of genetic lesions induced by DEB; however, this effect was not sufficient to explain the highly significant variation in chromosome breakage between whole blood and RBC-depleted cultures. We showed that RBC can protect cultured lymphocytes against chromosome breakage induced by DEB and we demonstrated the particular role of haemoglobin in the protective effect.
PMID: 12694746 [PubMed - indexed for MEDLINE
Use of drug eluting balloons (DEB) in the treatment of coronary artery disease (CAD)
No full textKoronarna arterijska bolest vodeći je uzrok smrti u svijetu i najčešća kardiovaskularna bolest današnjeg svijeta. Intervencijska kardiologija mnogo je napredovala u liječenju koronarne bolesti srca. Baloni koji luče lijekove su jedni od aduta u lepezi terapijskih rješenja za koronarnu arterijsku bolest. Priprema lezija ključan je preduvjet za uspješnu isporuku lijeka. Baloni koji luče lijekove su se pokazali djelotvornima u intervencijama pojedinih lezija poput in-stent restenoze, de novo lezija, bolesti malih krvnih žila, itd. Istraživanja su pokazala kako su baloni koji luče lijekove jednako uspješni kao i DES ili BMS, ako ne i bolji u određenim slučajevima. Kada je riječ o novcu, DEB se pokazao isplativom opcijom u liječenju koronarne bolesti srca. Buduće studije su potrebne kako bi se utvrdila primjenjivost DEB-a koji luči lijek sirolimus.Coronary artery disease (CAD) is the leading cause of death in the world and the most common cardiovascular disease nowadays. Interventional cardiology has come a long way in treating CAD. Drug eluting balloons (DEB) represent a trump card in a fan of treating options for CAD. Lesion preparation is mandatory in order for drug delivery to be successful. DEB has shown effectiveness in several lesion types such as in-stent restenosis, de novo, small vessels, etc. Research have shown that DEB is non inferior to DES or BMS, if not even better in some cases. Money matters, DEB has proven to be a cost effective option in the treatment of CAD. Future studies should address applicability of sirolimus based DEB
<i>Pisaster ochraceus</i> DEB parameter values, and results of sensitivity analysis.
No full text1<p>Estimated directly from data.</p>2<p>Estimated using covariation method (DEBtool).</p>3<p>Estimated using grid-search.</p>4<p>Kept fixed.</p><p>Sensitivity is the percent change in arm length at age 2 y divided by the percent change in a single parameter value (10%). Analyses were carried out using <i>ad libitum</i> food, at a temperature of 13°C. Parameters with a negative relation to growth are printed in bold type. Sensitivity of parameters not estimated is NaN.</p><p><i>Pisaster ochraceus</i> DEB parameter values, and results of sensitivity analysis.</p
The thin blue line
No full text12 unnumbered leaves : illustrations ; 13 x 33 cm, in box 15 x 37 x 6 cm
Artist's statement: "To get at the book you have to break the surface of the water by sliding back the lid of the box, which becomes a diving board . . . On the surface the book is about my enjoyment of swimming in the calm, blue water; beneath the surface it's about taking risks in life; being willing to jump in when I don't know if I will swim, and finding that I can make my way and stay afloat in increasingly deep waters."
Number 17 of 40 copies in the edition.
Call number: SPL OVERSZ N7433.4.R56 T4 199
- …
