918 resultados para Multiple Objective Optimization
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OBJECTIVE: To report the hemodynamic and functional responses obtained with clinical optimization guided by hemodynamic parameters in patients with severe and refractory heart failure. METHODS: Invasive hemodynamic monitoring using right heart catheterization aimed to reach low filling pressures and peripheral resistance. Frequent adjustments of intravenous diuretics and vasodilators were performed according to the hemodynamic measurements. RESULTS: We assessed 19 patients (age = 48±12 years and ejection fraction = 21±5%) with severe heart failure. The intravenous use of diuretics and vasodilators reduced by 12 mm Hg (relative reduction of 43%) pulmonary artery occlusion pressure (P<0.001), with a concomitant increment of 6 mL per beat in stroke volume (relative increment of 24%, P<0.001). We observed significant associations between pulmonary artery occlusion pressure and mean pulmonary artery pressure (r=0.76; P<0.001) and central venous pressure (r=0.63; P<0.001). After clinical optimization, improvement in functional class occurred (P< 0.001), with a tendency towards improvement in ejection fraction and no impairment to renal function. CONCLUSION: Optimization guided by hemodynamic parameters in patients with refractory heart failure provides a significant improvement in the hemodynamic profile with concomitant improvement in functional class. This study emphasizes that adjustments in blood volume result in imme-diate benefits for patients with severe heart failure.
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Lipid nanoballoons integrating multiple emulsions of the type water-in-oil-in-water enclose, at least in theory, a biomimetic aqueous-core suitable for housing hydrophilic biomolecules such as proteins, peptides and bacteriophage particles. The research effort entertained in this paper reports a full statistical 23x31 factorial design study (three variables at two levels and one variable at three levels) to optimize biomimetic aqueous-core lipid nanoballoons for housing hydrophilic protein entities. The concentrations of protein, lipophilic and hydrophilic emulsifiers, and homogenization speed were set as the four independent variables, whereas the mean particle hydrodynamic size (HS), zeta potential (ZP) and polydispersity index (PI) were set as the dependent variables. The V23x31 factorial design constructed led to optimization of the higher (+1) and lower (-1) levels, with triplicate testing for the central (0) level, thus producing thirty three experiments and leading to selection of the optimized processing parameters as 0.015% (w/w) protein entity, 0.75% (w/w) lipophilic emulsifier (soybean lecithin) and 0.50% (w/w) hydrophilic emulsifier (poloxamer 188). In the present research effort, statistical optimization and production of protein derivatives encompassing full stabilization of their three-dimensional structure, has been attempted via housing said molecular entities within biomimetic aqueous-core lipid nanoballoons integrating a multiple (W/O/W) emulsion.
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L’objectiu d’aquest projecte que consisteix a elaborar un algoritme d’optimització que permeti, mitjançant un ajust de dades per mínims quadrats, la extracció dels paràmetres del circuit equivalent que composen el model teòric d’un ressonador FBAR, a partir de les mesures dels paràmetres S. Per a dur a terme aquest treball, es desenvolupa en primer lloc tota la teoria necessària de ressonadors FBAR. Començant pel funcionament i l’estructura, i mostrant especial interès en el modelat d’aquests ressonadors mitjançant els models de Mason, Butterworth Van-Dyke i BVD Modificat. En segon terme, s’estudia la teoria sobre optimització i programació No-Lineal. Un cop s’ha exposat la teoria, es procedeix a la descripció de l’algoritme implementat. Aquest algoritme utilitza una estratègia de múltiples passos que agilitzen l'extracció dels paràmetres del ressonador.
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A statistical methodology is developed by which realised outcomes can be used to identify, for calendar years between 1974 and 2012, when policy makers in ‘advanced’ economies have successfully pursued single objectives of different kinds, or multiple objectives. A simple criterion is then used to distinguish between multiple objectives pure and simple and multiple objectives subject to a price stability constraint. The overall and individual country results which this methodology produces seem broadly plausible. Unconditional and conditional analyses of the inflation and growth associated with different types of objectives reveal that multiple objectives subject to a price stability constraint are associated with roughly as good economic performance as the single objective of inflation. A proposal is then made as to how the remit of an inflation-targeting central bank could be adjusted to allow it to pursue other objectives in extremis without losing the credibility effects associated with inflation targeting.
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The paper develops a stability theory for the optimal value and the optimal set mapping of optimization problems posed in a Banach space. The problems considered in this paper have an arbitrary number of inequality constraints involving lower semicontinuous (not necessarily convex) functions and one closed abstract constraint set. The considered perturbations lead to problems of the same type as the nominal one (with the same space of variables and the same number of constraints), where the abstract constraint set can also be perturbed. The spaces of functions involved in the problems (objective and constraints) are equipped with the metric of the uniform convergence on the bounded sets, meanwhile in the space of closed sets we consider, coherently, the Attouch-Wets topology. The paper examines, in a unified way, the lower and upper semicontinuity of the optimal value function, and the closedness, lower and upper semicontinuity (in the sense of Berge) of the optimal set mapping. This paper can be seen as a second part of the stability theory presented in [17], where we studied the stability of the feasible set mapping (completed here with the analysis of the Lipschitz-like property).
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A recently developed technique, namely multiple beam interference microscopy, has been applied to investigate the morphology of the parasite Toxoplasma gondii for the first time. The interference pattern obtained from the multiple internal reflection of a T. gondii, sandwiched between a glass plate and a cover plate, was focused on the objective of a conventional microscope. Because of the enhance contrast, several details of sub cellular structure and separating compartments are clearly visible. Details reveal the presence of a nucleus, lipid body, dense granule, rhoptry and amylopectin. The wall thickness of the membrane of the lipid body and the amylopectin is of the order of 0.02 µm and can be clearly distinguished with the help of the present technique. The same parasite has also been examined with the help of atomic force microscopy, and because of its thick membrane, the inner structural details were not observed at all. Sub cellular details of T. gondii observed with the present technique have been reported earlier only by low amplification transmission electron microscopy and not by any optical microscopic technique.
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Significant progress has been made with regard to the quantitative integration of geophysical and hydrological data at the local scale. However, extending the corresponding approaches to the scale of a field site represents a major, and as-of-yet largely unresolved, challenge. To address this problem, we have developed downscaling procedure based on a non-linear Bayesian sequential simulation approach. The main objective of this algorithm is to estimate the value of the sparsely sampled hydraulic conductivity at non-sampled locations based on its relation to the electrical conductivity logged at collocated wells and surface resistivity measurements, which are available throughout the studied site. The in situ relationship between the hydraulic and electrical conductivities is described through a non-parametric multivariatekernel density function. Then a stochastic integration of low-resolution, large-scale electrical resistivity tomography (ERT) data in combination with high-resolution, local-scale downhole measurements of the hydraulic and electrical conductivities is applied. The overall viability of this downscaling approach is tested and validated by comparing flow and transport simulation through the original and the upscaled hydraulic conductivity fields. Our results indicate that the proposed procedure allows obtaining remarkably faithful estimates of the regional-scale hydraulic conductivity structure and correspondingly reliable predictions of the transport characteristics over relatively long distances.
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Integrating and expressing stably a transgene into the cellular genome remain major challenges for gene-based therapies and for bioproduction purposes. While transposon vectors mediate efficient transgene integration, expression may be limited by epigenetic silencing, and persistent transposase expression may mediate multiple transposition cycles. Here, we evaluated the delivery of the piggyBac transposase messenger RNA combined with genetically insulated transposons to isolate the transgene from neighboring regulatory elements and stabilize expression. A comparison of piggyBac transposase expression from messenger RNA and DNA vectors was carried out in terms of expression levels, transposition efficiency, transgene expression and genotoxic effects, in order to calibrate and secure the transposition-based delivery system. Messenger RNA reduced the persistence of the transposase to a narrow window, thus decreasing side effects such as superfluous genomic DNA cleavage. Both the CTF/NF1 and the D4Z4 insulators were found to mediate more efficient expression from a few transposition events. We conclude that the use of engineered piggyBac transposase mRNA and insulated transposons offer promising ways of improving the quality of the integration process and sustaining the expression of transposon vectors.
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The objective of this study is to determine the extent of the problem of poly-drug (multiple-drug) use among patients receiving methadone. The study investigated levels and patterns of cocaine and cannabis use in opiate dependent patients receiving methadone treatment. This research also examines risks associated with injecting cocaine. A total number of 851 methadone patients receiving treatment for opiate related problems participated in the survey from a total number of 1082 patients receiving treatment in these clinics. This figure accounts for 80.1%. Participants reported the frequency and intensity of cocaine and cannabis use. Data collected showed that 42% of the methadone patients are using cannabis on a daily basis and that 77.47% had a history of cocaine use. The figure of cocaine use is an important indicator of the level and extent of cocaine use. It is valuable from a public health perspective to assess needs, and to plan and evaluate services. The survey concluded that cocaine abuse is emerging as a problem in the Irish drug sceneThis resource was contributed by The National Documentation Centre on Drug Use.
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TRAIL and TRAIL Receptor genes have been implicated in Multiple Sclerosis pathology as well as in the response to IFN beta therapy. The objective of our study was to evaluate the association of these genes in relation to the age at disease onset (AAO) and to the clinical response upon IFN beta treatment in Spanish MS patients. We carried out a candidate gene study of TRAIL, TRAILR-1, TRAILR-2, TRAILR-3 and TRAILR-4 genes. A total of 54 SNPs were analysed in 509 MS patients under IFN beta treatment, and an additional cohort of 226 MS patients was used to validate the results. Associations of rs1047275 in TRAILR-2 and rs7011559 in TRAILR-4 genes with AAO under an additive model did not withstand Bonferroni correction. In contrast, patients with the TRAILR-1 rs20576-CC genotype showed a better clinical response to IFN beta therapy compared with patients carrying the A-allele (recessive model: p = 8.88×10(-4), pc = 0.048, OR = 0.30). This SNP resulted in a non synonymous substitution of Glutamic acid to Alanine in position 228 (E228A), a change previously associated with susceptibility to different cancer types and risk of metastases, suggesting a lack of functionality of TRAILR-1. In order to unravel how this amino acid change in TRAILR-1 would affect to death signal, we performed a molecular modelling with both alleles. Neither TRAIL binding sites in the receptor nor the expression levels of TRAILR-1 in peripheral blood mononuclear cell subsets (monocytes, CD4+ and CD8+ T cells) were modified, suggesting that this SNP may be altering the death signal by some other mechanism. These findings show a role for TRAILR-1 gene variations in the clinical outcome of IFN beta therapy that might have relevance as a biomarker to predict the response to IFN beta in MS.
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In Europe, the combination of plerixafor + granulocyte colony-stimulating factor is approved for the mobilization of hematopoietic stem cells for autologous transplantation in patients with lymphoma and myeloma whose cells mobilize poorly. The purpose of this study was to further assess the safety and efficacy of plerixafor + granulocyte colony-stimulating factor for front-line mobilization in European patients with lymphoma or myeloma. In this multicenter, open label, single-arm study, patients received granulocyte colony-stimulating factor (10 μg/kg/day) subcutaneously for 4 days; on the evening of day 4 they were given plerixafor (0.24 mg/kg) subcutaneously. Patients underwent apheresis on day 5 after a morning dose of granulocyte colony-stimulating factor. The primary study objective was to confirm the safety of mobilization with plerixafor. Secondary objectives included assessment of efficacy (apheresis yield, time to engraftment). The combination of plerixafor + granulocyte colony-stimulating factor was used to mobilize hematopoietic stem cells in 118 patients (90 with myeloma, 25 with non-Hodgkin's lymphoma, 3 with Hodgkin's disease). Treatment-emergent plerixafor-related adverse events were reported in 24 patients. Most adverse events occurred within 1 hour after injection, were grade 1 or 2 in severity and included gastrointestinal disorders or injection-site reactions. The minimum cell yield (≥ 2 × 10(6) CD34(+) cells/kg) was harvested in 98% of patients with myeloma and in 80% of those with non-Hodgkin's lymphoma in a median of one apheresis. The optimum cell dose (≥ 5 × 10(6) CD34(+) cells/kg for non-Hodgkin's lymphoma or ≥ 6 × 10(6) CD34(+) cells/kg for myeloma) was harvested in 89% of myeloma patients and 48% of non-Hodgkin's lymphoma patients. In this prospective, multicenter European study, mobilization with plerixafor + granulocyte colony-stimulating factor allowed the majority of patients with myeloma or non-Hodgkin's lymphoma to undergo transplantation with minimal toxicity, providing further data supporting the safety and efficacy of plerixafor + granulocyte colony-stimulating factor for front-line mobilization of hematopoietic stem cells in patients with non-Hodgkin's lymphoma or myeloma.
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BACKGROUND Responsiveness, defined as the ability to detect a meaningful change, is a core psychometric property of an instrument measuring quality of life (QoL) rarely reported in multiple sclerosis (MS) studies. OBJECTIVE To assess the responsiveness of the Multiple Sclerosis International Quality of Life (MusiQoL) questionnaire to change in disability over 24 months, defined by change in the Expanded Disability Status Scale (EDSS) score. METHODS Patients with MS were enrolled into a multicenter, longitudinal observational study. QoL was assessed using both the MusiQoL and the 36-Item Short-Form (SF-36) instruments at baseline and every 6 months thereafter up to month 24; neurological assessments, including EDSS score, were performed at each evaluation. RESULTS The 24-month EDSS was available for 524 patients. In the 107 worsened patients, two specific dimensions of MusiQoL, the sentimental and sexual life and the relationships with health care system dimensions, and 'physical' scores of SF-36 showed responsiveness. CONCLUSIONS Whereas specific dimensions of MusiQoL identified EDSS changes, the MusiQoL index did not detect disability changes in worsened MS patients in a 24-month observational study. Future responsiveness validation studies should include longer follow-up and more representative samples.
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Argentina is among the four largest producers of soybeans, sunflower, corn, and wheat, among other agricultural products. Institutional and policy changes during the 1990s fostered the development of Argentine agriculture and the introduction of innovative process and product technologies (no-till, agrochemicals, GMO, GPS) and new investments in modern, large-scale sunflower and soybean processing plants. In addition to technological changes, a "quiet revolution" occurred in the way agricultural production was carried out and organized: from self-production or ownership agriculture to a contract-based agriculture. The objective of this paper is to explore and describe the emergence of networks in the Argentine crop production sector. The paper presents and describes four cases that currently represent about 50% of total grain and oilseed production in Argentina: "informal hybrid form", "agricultural trust fund", "investor-oriented corporate structure", and "network of networks". In all cases, hybrid forms involve a group of actors linked by common objectives, mainly to gain scale, share resources, and improve the profitability of the business. Informal contracts seem to be the most common way of organizing the agriculture process, but using short-term contracts and sequential interfirm collaboration. Networks of networks involve long-term relationships and social development, and reciprocal interfirm collaboration. Agricultural trust fund and investor-oriented corporate structures have combined interfirm collaboration and medium-term relationships. These organizational forms are highly flexible and show a great capacity to adapt to challenges; they are competitive because they enjoy aligned incentives, flexibility, and adaptability.
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OBJECTIVE To assess the effectiveness of glatiramer acetate (GA) compared to other multiple sclerosis (MS) therapies in routine clinical practice. MATERIALS AND METHODS Observational cohort study carried out in MS patients treated with GA (GA cohort) or other MS therapies -switched from GA- (non-GA cohort). Study data were obtained through review of our MS patient database. The primary endpoint was the Expanded Disability Status Scale (EDSS) scores reached at the end of treatment/last check-up. RESULTS A total of 180 patients were included: GA cohort n = 120, non-GA cohort n = 60. Patients in the GA cohort showed better EDSS scores at the end of treatment/last check-up (mean ± SD, 2.8 ± 1.8 vs. 3.9 ± 2.2; P = 0.001) and were 1.65 times more likely to show better EDSS scores compared to the non-GA cohort (odds ratio, 0.606; 95%CI, 0.436-0.843; P = 0.003). Patients in the GA cohort showed longer mean time to reach EDSS scores of 6 (209.1 [95%CI, 187.6-230.6] vs. 164.3 [95% CI, 137.0-191.6] months; P = 0.004) and slower disability progression (hazard ratio, 0.415 [95%CI, 0.286-0.603]; P < 0.001). The annualized relapse rate was lower in the GA cohort (mean ± SD, 0.5 ± 0.5 vs. 0.8 ± 0.5; P = 0.001) and patients' quality of life was improved in this study cohort compared to the non-GA cohort (mean ± SD, 0.7 ± 0.1 vs. 0.6 ± 0.2; P = 0.01). CONCLUSIONS GA may slow down the progression of EDSS scores to a greater extent than other MS therapies, as well as achieving a greater reduction in relapses and a greater improvement in patients' quality of life. Switching from GA to other MS therapies has not proved to entail a better response to treatment.
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Individual-as-maximizing agent analogies result in a simple understanding of the functioning of the biological world. Identifying the conditions under which individuals can be regarded as fitness maximizing agents is thus of considerable interest to biologists. Here, we compare different concepts of fitness maximization, and discuss within a single framework the relationship between Hamilton's (J Theor Biol 7: 1-16, 1964) model of social interactions, Grafen's (J Evol Biol 20: 1243-1254, 2007a) formal Darwinism project, and the idea of evolutionary stable strategies. We distinguish cases where phenotypic effects are additive separable or not, the latter not being covered by Grafen's analysis. In both cases it is possible to define a maximand, in the form of an objective function phi(z), whose argument is the phenotype of an individual and whose derivative is proportional to Hamilton's inclusive fitness effect. However, this maximand can be identified with the expression for fecundity or fitness only in the case of additive separable phenotypic effects, making individual-as-maximizing agent analogies unattractive (although formally correct) under general situations of social interactions. We also feel that there is an inconsistency in Grafen's characterization of the solution of his maximization program by use of inclusive fitness arguments. His results are in conflict with those on evolutionary stable strategies obtained by applying inclusive fitness theory, and can be repaired only by changing the definition of the problem.