964 resultados para multiple objective programming


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Discussion opposing the Theory of the Firm to the Theory of Stakeholders are contemporaneous and polemical. One focal point of such debates refers to which objective-function companies, should choose, whether that of the shareholders or that of the stakeholders, and whether it is possible to opt for both simultaneously. Several empirical studies. have attempted-to test a possible correlation between both functions, and there has not been any consensus-so far. The objective of the present research is to examine a gap in such discussions: is there (or not) a subordination of the stakeholders` objective-function to that of the shareholders? The research is empirical,and analytical and employs quantitative methods. Hypotheses were tested and data analyzed by using non-parametrical (chi-square test) and parametrical procedures (frequency. correlation `coefficient). Secondary data was collected from he Economitica database and from the Brazilian Institute of Social and-Economic Analyses (IBASE) website, relative to public companies that have published their Social Balance Statements following the IBASE model from 1999 to 2006, whose sample amounted to 65 companies; In order to assess the objective-function of shareholders a proxy was created based on the following three indices: ROE (return on equity), EnterpriseValue and Tobin`s Q. In order to assess the objective-function of stakeholders a proxy was created by employing the following IBASE social balance indices: internal ones (ISI), external ones (ISE), and environmental ones (IAM). The results have shown no evidence of subordination of stakeholders` objective-function to that of the shareholders in analyzed companies, negating initial expectations and calling for deeper investigation of results. Its main conclusion, which states that the attempted subordination does not take place, is limited to the sample herein investigated and calls for ongoing research aiming at improvements which may lead to sample enlargement and, as a consequence, may make feasible the application of other statistical techniques which may yield a more thorough, analysis of the studied phenomehon.

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Quantifying mass and energy exchanges within tropical forests is essential for understanding their role in the global carbon budget and how they will respond to perturbations in climate. This study reviews ecosystem process models designed to predict the growth and productivity of temperate and tropical forest ecosystems. Temperate forest models were included because of the minimal number of tropical forest models. The review provides a multiscale assessment enabling potential users to select a model suited to the scale and type of information they require in tropical forests. Process models are reviewed in relation to their input and output parameters, minimum spatial and temporal units of operation, maximum spatial extent and time period of application for each organization level of modelling. Organizational levels included leaf-tree, plot-stand, regional and ecosystem levels, with model complexity decreasing as the time-step and spatial extent of model operation increases. All ecosystem models are simplified versions of reality and are typically aspatial. Remotely sensed data sets and derived products may be used to initialize, drive and validate ecosystem process models. At the simplest level, remotely sensed data are used to delimit location, extent and changes over time of vegetation communities. At a more advanced level, remotely sensed data products have been used to estimate key structural and biophysical properties associated with ecosystem processes in tropical and temperate forests. Combining ecological models and image data enables the development of carbon accounting systems that will contribute to understanding greenhouse gas budgets at biome and global scales.

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OBJECTIVE To determine the prevalence, intensity and associated risk factors for infection with Ascaris, hookworms and Trichuris in three tea-growing communities in Assam, India. METHODS Single faecal samples were collected from 328 individuals and subjected to centrifugal floatation and the Kato Katz quantitation technique and prevalence and intensities of infection with each parasite calculated. Associations between parasite prevalence, intensity and host and environmental factors were then made using both univariate and multivariate analysis. RESULTS The overall prevalence of Ascaris was 38% [95% confidence interval (CI): 33, 43], and the individual prevalence of hookworm and Trichuris was 43% (95% CI: 38, 49). The strongest predictors for the intensity of one or more geohelminths using multiple regression (P less than or equal to 0.10) were socioeconomic status, age, household crowding, level of education, religion, use of footwear when outdoors, defecation practices, pig ownership and water source. CONCLUSION A universal blanket treatment with broad-spectrum anthelmintics together with promotion of scholastic and health education and improvements in sanitation is recommended for helminth control in the communities under study.

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Objective: Existing evidence suggests that family interventions can be effective in reducing relapse rates in schizophrenia and related conditions. Despite this, such interventions are not routinely delivered in Australian mental health services. The objective of the current study is to investigate the incremental cost-effectiveness ratios (ICERs) of introducing three types of family interventions, namely: behavioural family management (BFM); behavioural intervention for families (BIF); and multiple family groups (MFG) into current mental health services in Australia. Method: The ICER of each of the family interventions is assessed from a health sector perspective, including the government, persons with schizophrenia and their families/carers using a standardized methodology. A two-stage approach is taken to the assessment of benefit. The first stage involves a quantitative analysis based on disability-adjusted life years (DALYs) averted. The second stage involves application of 'second filter' criteria (including equity, strength of evidence, feasibility and acceptability to stakeholders) to results. The robustness of results is tested using multivariate probabilistic sensitivity analysis. Results: The most cost-effective intervention, in order of magnitude, is BIF (A$8000 per DALY averted), followed by MFG (A$21 000 per DALY averted) and lastly BFM (A$28 000 per DALY averted). The inclusion of time costs makes BFM more cost-effective than MFG. Variation of discount rate has no effect on conclusions. Conclusions: All three interventions are considered 'value-for-money' within an Australian context. This conclusion needs to be tempered against the methodological challenge of converting clinical outcomes into a generic economic outcome measure (DALY). Issues surrounding the feasibility of routinely implementing such interventions need to be addressed.

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The Australian fossil record shows that from ca. 25 Myr ago, the aseasonal-wet biome (rainforest and wet heath) gave way to the unique Australian sclerophyll biomes dominated by eucalypts, acacias and casuarinas. This transition coincided with tectonic isolation of Australia, leading to cooler, drier, more seasonal climates. From 3 Myr ago, aridification caused rapid opening of the central Australian and zone. Molecular phylogenies with dated nodes have provided new perspectives on how these events could have affected the evolution of the Australian flora. During the Mid-Cenozoic (25-10 Myr ago) period of climatic change, there were rapid radiations in sclerophyll taxa, such as Banksia, eucalypts, pea-flowered legumes and Allocasuarina. At the same time, taxa restricted to the aseasonal-wet biome (Nothofagus, Podocarpaceae and Araucariaceae) did not radiate or were depleted by extinction. During the Pliocene aridification, two Eremean biome taxa (Lepidium and Chenopodiaceae) radiated rapidly after dispersing into Australia from overseas. It is clear that the biomes have different histories. Lineages in the aseasonal-wet biome are species poor, with sister taxa that are species rich, either outside Australia or in the sclerophyll biomes. In conjunction with the fossil record, this indicates depletion of the Australian aseasonal-wet biome from the Mid-Cenozoic. In the sclerophyll biomes, there have been multiple exchanges between the southwest and southeast, rather than single large endemic radiations after a vicariance event. There is need for rigorous molecular phylogenetic studies so that additional questions can be addressed, such as how interactions between biomes may have driven the speciation process during radiations. New studies should include the hither-to neglected monsoonal tropics.

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The habit of inducing plant galls has evolved multiple times among insects but most species diversity occurs in only a few groups, such as gall midges and gall wasps. This phylogenetic clustering may reflect adaptive radiations in insect groups in which the trait has evolved. Alternatively, multiple independent origins of galling may suggest a selective advantage to the habit. We use DNA sequence data to examine the origins of galling among the most speciose group of gall-inducing scale insects, the eriococcids. We determine that the galling habit has evolved multiple times, including four times in Australian taxa, suggesting that there has been a selective advantage to galling in Australia. Additionally, although most gall-inducing eriococcid species occur on Myrtaceae, we found that lineages feeding on Myrtaceae are no more likely to have evolved the galling habit than those feeding on other plant groups. However, most gall-inducing species-richness is clustered in only two clades (Apiomorpha and Lachnodius + Opisthoscelis), all of which occur exclusively on Eucalyptus s.s. The Eriococcidae and the large genus Eriococcus were determined to be non-monophyletic and each will require revision. (C) 2004 The Linnean Society of London.

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Objective. To analyze the association between police violence and homicide mortality rates taking into consideration the effect of contextual variables. Methods. This was an environmental, cross-sectional study that included the 96 census districts in the City of Sao Paulo. The association between the variables was analyzed using Spearman`s rank correlation and simple and multiple regression analysis. Results. Univariate analysis revealed a strong and significant association between homicide mortality coefficients and all the indicators of socioeconomic development and police violence. After controlling for potential confounding factors, the association between police violence and homicide mortality coefficients remained strong and significant. This significance was lost only after control for the size of the resident population. Conclusion. The results indicate that police action that violates basic human rights is not the right answer to urban violence. The combination of homicides from interpersonal violence and deaths from police violence results in negative socialization and promotes further violence.

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Background: The fact that some cancers and viral infections can be controlled by effector CD8 T cells led to the possibility of utilising minimal CD8 T cell epitope peptides as vaccines. However using minimal CD8 T cell epitope peptide immunisations and a tumour protection model in mice, we have previously shown that functional memory CD8 T cells are not generated unless CD4 T help is provided at the time of CD8 T cell priming. Short-lived effector cells nevertheless are generated in the absence of T help. Aim: To determine the role of CD4 T help in multiple immunisations. Method: Minimal CD8 T cell peptides of HPV16 E7 protein and Ovalbumin were used (with adjuvants Quil-A or IFA) as immunogens in C57BL mice. The presence of effector CD8 T cells were determined by tumour protection assays and was quantified by IFN-gamma ELISPOT assays. Results: In the present study we show that unless T help is provided at the time CD8 T cells are primed, no CD8 effector cells are generated when boosted with the vaccine again in the absence of T help. Our results further show that this failure could be prevented by the inclusion of a T helper peptide during the primary or booster immunisations.

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Study Design. A case report describing chronic recurrent multifocal osteomyelitis (CRMO) with initial presentation limited to spine, successfully treated by anti-TNF-alpha therapy after failure of conventional treatment methods. Objective. To describe an unusual manifestation and treatment of a rare disease. Summary of Background Data. CRMO is a rare inflammatory bone disease that should be differentiated from bacterial osteomyelitis. Rarely, it can affect the spine and in this case the most important differential diagnosis is infectious spondylodiscitis. The disease has an unpredictable course with exacerbations and spontaneous remissions. Although the majority of cases remit spontaneously (or after the use of nonsteroidal anti-inflammatory drugs [NSAIDs]), some progressive and resistant cases have been reported. Methods. We describe a case of CRMO with an unusual clinical presentation emphasizing the importance of this finding as a differential diagnosis of spondylodiscitis and comment on the available treatment alternatives. Results. A 17-year-old man presented with debilitating dorsal spine pain. Magnetic resonance imaging of the spine revealed bone lesions at multiple vertebral levels. After failure of antibiotic treatment, the diagnosis of CRMO was suggested. An initial good response to NSAIDs was followed by a recurrent course and involvement of peripheral joints besides the use of corticosteroids and other drugs. The introduction of infliximab was followed by complete remission of the disease. Conclusion. Our observation highlights the need of awareness for the differential diagnosis in suspected cases of osteomyelitis not responding to antibiotics. Anti-TNF-alpha agents should be considered in CRMO refractory cases.

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Context: Previous studies have shown that double RET mutations may be associated with unusual multiple endocrine neoplasia type 2 (MEN 2) phenotypes. Objective: Our objective was to report the clinical features of patients harboring a previously unreported double mutation of the RET gene and to characterize this mutation in vitro. Patients: Sixteen patients from four unrelated families and harboring the C634Y/Y791F double RET germline mutation were included in the study. Results: Large pheochromocytomas measuring 6.0-14 cm and weighing upto 640 g were identified in the four index cases. Three of the four tumors were bilateral. High penetrance of pheochromocytoma was also seen in the C634Y/Y791F-mutation-positive relatives (seven of nine, 77.7%). Of these, two cases had bilateral tumors, one presented with multifocal tumors, two cases had large tumors (>5 cm), and one case, which was diagnosed with a large (5.5 x 4.5 x 4.0 cm) pheochromocytoma, reported early onset of symptoms of the disease (14 yr old). The overall penetrance of pheochromocytoma was 84.6% (11 of 13). Development of medullary thyroid carcinoma in our patients seemed similar to that observed in patients with codon 634 mutations. Haplotype analysis demonstrated that the mutation did not arise from a common ancestor. In vitro studies showed the double C634Y/Y791F RET receptor was significantly more phosphorylated than either activated wild-type receptor or single C634Y and Y791F RET mutants. Conclusions: Our data suggest that the natural history of the novel C634Y/Y791F double mutation carries a codon 634-like pattern of medullary thyroid carcinoma development, is associated with increased susceptibility to unusually large bilateral pheochromocytomas, and is likely more biologically active than each individual mutation. (J Clin Endocrinol Metab 95: 1318-1327, 2010)

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Context: 21-Hydroxylase deficiency (21OHD) is caused by CYP21A2 gene mutations disrupting the adrenal 21-hydroxylase, P450c21. CYP21A2 mutations generally correlate well with the 21OHD phenotype, but some children with severe CYP21A2 mutations have residual 21-hydroxylase activity. Some hepatic P450 enzymes can 21-hydroxylate progesterone, but their physiological relevance in modifying 21OHD is not known. Objective: Wedetermined the ability of CYP2C19 and CYP3A4 to 21-hydroxylate progesterone and 17-hydroxyprogesterone (17OHP), determined the impact of the common P450 oxidoreductase (POR) variant A503V on these activities, and examined correlations between CYP2C19 variants and phenotype in patients with 21OHD. Methods: Bacterially expressed, N-terminally modified, C-His-tagged human P450c21, CYP2C19, and CYP3A4 were combined with bacterially expressed wild-type and A503V POR. The 21-hydroxylation of radiolabeled progesterone and 17OHP was assessed, and the Michaelis constant (Km) and maximum velocity (Vmax) of the reactions were measured. CYP2C19 was genotyped in 21OHD patients with genotypes predicting severe congenital adrenal hyperplasia. Results: Compared to P450c21, the Vmax/Km for 21-hydroxylation of progesterone by CYP2C19 and CYP3A4 were 17 and 10%, respectively. With both forms of POR, the Km for P450c21 was approximately 2.6 mu M, the Km for CYP2C19 was approximately 11 mu M, and the Km for CYP3A4 was approximately 110 mu M. Neither CYP2C19 nor CYP3A4 could 21-hydroxylate 17OHP. The CYP2C19 ultrametabolizer allele CYP2C19* 17 was homozygous in one of five patients with a 21OHD phenotype that was milder than predicted by the CYP21A2 genotype. Conclusions: CYP2C19 and CYP3A4 can 21-hydroxylate progesterone but not 17OHP, possibly ameliorating mineralocorticoid deficiency, but not glucocorticoid deficiency. Multiple enzymes probably contribute to extraadrenal 21-hydroxylation. (J Clin Endocrinol Metab 94: 89-95, 2009)

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The Ordos Plateau in China is covered with up to 300,000 ha of peashrub (Caragana) which is the dominant natural vegetation and ideal for fodder production. To exploit peashrub fodder, it is crucially important to optimize the culture conditions, especially culture substrate to produce pectinase complex. In this study, a new prescription process was developed. The process, based on a uniform experimental design, first optimizes the solid substrate and second, after incubation, applies two different temperature treatments (30 degrees C for the first 30 h and 23 degrees C for the second 42 h) in the fermentation process. A multivariate regression analysis is applied to a number of independent variables (water, wheat bran, rice dextrose, ammonium sulfate, and Tween 80) to develop a predictive model of pectinase activity. A second-degree polynomial model is developed which accounts for an excellent proportion of the explained variation (R-2 = 97.7%). Using unconstrained mathematical programming, an optimized substrate prescription for pectinase production is subsequently developed. The mathematical analysis revealed that the optimal formula for pectinase production from Aspergillus niger by solid fermentation under the conditions of natural aeration, natural substrate pH (about 6.5), and environmental humidity of 60% is rice dextrose 8%, wheat bran 24%, ammonium sulfate ((NH4)(2)SO4) 6%, and water 61%. Tween 80 was found to have a negative effect on the production of pectinase in solid substrate. With this substrate prescription, pectinase produced by solid fermentation of A. niger reached 36.3IU/(gDM). Goats fed on the pectinase complex obtain an incremental increase of 0.47 kg day(-1) during the initial 25 days of feeding, which is a very promising new feeding prospect for the local peashrub. It is concluded that the new formula may be very useful for the sustainable development of and and semiarid pastures such as those of the Ordos Plateau. (c) 2005 Elsevier Inc. All rights reserved.