975 resultados para Mixed integer nonlinear program
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The ability to identify the species origin of an unknown biological sample is relevant in the fields of human and wildlife forensics. However, the detection of several species mixed in the same sample still remains a challenge. We developed and tested a new approach for mammal DNA identification in mixtures of two or three species, based on the analysis of mitochondrial DNA control region interspecific length polymorphism followed by direct sequencing. Contrary to other published methods dealing with species mixtures, our protocol requires a single universal primer pair and is not based on a pre-defined panel of species. Amplicons can be separated either on agarose gels or using CE. The advantages and limitations of the assay are discussed under different conditions, such as variable template concentration, amplicon sizes and size difference among the amplicons present in the mixture. For the first time, this protocol provides a simple, reliable and flexible method for simultaneous identification of multiple mammalian species from mixtures, without any prior knowledge of the species involved.
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We replicate Shaw (1996) who found that individual wage growth is higher for individuals with greater preference for risk taking. Expanding her dataset with more American observations and data for Germany, Spain and Italy, we find mixed support for the earlier results. We present and estimate a new model and find that in particular the wage level is sensitive to attitudes towards risk taking. Comments given at the Labour Economics Conference in honour of Niels Westergaard (Nyborg, August 2008) and EALE 2008 (Amsterdam) and at seminars in Maastricht,Reus and Essen (RWI) are gratefully acknowledged. The authors also acknowledge financial support from the Spanish Ministry of Science and Innovation (grant number SEJ2007-66318) and from the Barcelona Economics Program of CREA. JEL code: J24; J30. Key words: wage growth, risk, post-school investment.
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BACKGROUND AND STUDY AIMS: Various screening methods for colorectal cancer (CRC) are promoted by professional societies; however, few data are available about the factors that determine patient participation in screening, which is crucial to the success of population-based programs. This study aimed (i) to identify factors that determine acceptance of screening and preference of screening method, and (ii) to evaluate procedure success, detection of colorectal neoplasia, and patient satisfaction with screening colonoscopy. PATIENTS AND METHODS: Following a public awareness campaign, the population aged 50 - 80 years was offered CRC screening in the form of annual fecal occult blood tests, flexible sigmoidoscopy, a combination of both, or colonoscopy. RESULTS: 2731 asymptomatic persons (12.0 % of the target population) registered with and were eligible to take part in the screening program. Access to information and a positive attitude to screening were major determinants of participation. Colonoscopy was the method preferred by 74.8 % of participants. Advanced colorectal neoplasia was present in 8.5 %; its prevalence was higher in males and increased with age. Significant complications occurred in 0.5 % of those undergoing colonoscopy and were associated with polypectomy or sedation. Most patients were satisfied with colonoscopy and over 90 % would choose it again for CRC screening. CONCLUSIONS: In this population-based study, only a small proportion of the target population underwent CRC screening despite an extensive information campaign. Colonoscopy was the preferred method and was safe. The determinants of participation in screening and preference of screening method, together with the distribution of colorectal neoplasia in different demographic categories, provide a rationale for improving screening procedures.
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Weak solutions of the spatially inhomogeneous (diffusive) Aizenmann-Bak model of coagulation-breakup within a bounded domain with homogeneous Neumann boundary conditions are shown to converge, in the fast reaction limit, towards local equilibria determined by their mass. Moreover, this mass is the solution of a nonlinear diffusion equation whose nonlinearity depends on the (size-dependent) diffusion coefficient. Initial data are assumed to have integrable zero order moment and square integrable first order moment in size, and finite entropy. In contrast to our previous result [CDF2], we are able to show the convergence without assuming uniform bounds from above and below on the number density of clusters.
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This note develops a flexible methodology for splicing economic time series that avoids the extreme assumptions implicit in the procedures most commonly used in the literature. It allows the user to split the required correction to the older of the series being linked between its levels and growth rates on the basis what he knows or conjectures about the persistence of the factors that account for the discrepancy between the two series that emerges at their linking point. The time profile of the correction is derived from the assumption that the error in the older series reflects the inadequate coverage of emerging sectors or activities that grow faster than the aggregate.
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To describe the collective behavior of large ensembles of neurons in neuronal network, a kinetic theory description was developed in [13, 12], where a macroscopic representation of the network dynamics was directly derived from the microscopic dynamics of individual neurons, which are modeled by conductance-based, linear, integrate-and-fire point neurons. A diffusion approximation then led to a nonlinear Fokker-Planck equation for the probability density function of neuronal membrane potentials and synaptic conductances. In this work, we propose a deterministic numerical scheme for a Fokker-Planck model of an excitatory-only network. Our numerical solver allows us to obtain the time evolution of probability distribution functions, and thus, the evolution of all possible macroscopic quantities that are given by suitable moments of the probability density function. We show that this deterministic scheme is capable of capturing the bistability of stationary states observed in Monte Carlo simulations. Moreover, the transient behavior of the firing rates computed from the Fokker-Planck equation is analyzed in this bistable situation, where a bifurcation scenario, of asynchronous convergence towards stationary states, periodic synchronous solutions or damped oscillatory convergence towards stationary states, can be uncovered by increasing the strength of the excitatory coupling. Finally, the computation of moments of the probability distribution allows us to validate the applicability of a moment closure assumption used in [13] to further simplify the kinetic theory.
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The control methods used in Brazil for both cutaneous and visceral leishmaniasis by the Ministry of Health's National Health Foundation (Fundação Nacional de Saúde) are presented. Data referring to the programme between 1980 and 1991 is presented. There was an increase in the total number of notified cases of cutaneous leishmaniasis until 1987 and from this date onwards the number has remained between 23,000 and 26,000 per year. There were significantly fewer cases of visceral leishmaniasis during the same period and until 1991 the greatest number of cases reported in one year was 2,511 in 1985. The overall picture is that it is difficult to evaluate to what extent the control methods employed have reduced the number of cases of either form of the disease. It is suggested that there is an urgent need for a closer approximation of research and health workers to review the actual control strategies and to define procedures capable of assessing accurately their impact.
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In Brazil, the use of biological vector-control methods has been largely confined to experimental research, with little or no application of such techniques by public institutions responsible for implementing control programs. The notable exceptions have been the black fly control program carried out by the Health Secretariat in the State of São Paulo. Since the 1980s, São Paulo's "Superintendência de Controle de Endemias" has been conducting studies on the viability of using Bacillus thuringiensis (H-14) for simuliid control, and the results have been so encouraging that the agency has now incorporated this method into its Simuliid Control Program.
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Background and objective: Therapeutic Drug Monitoring (TDM) has been introduced early 1970 in our hospital (CHUV). It represents nowadays an important routine activity of the Division of Clinical Pharmacology and Toxicology (PCL), and its impact and utility for clinicians required assessment. This study thus evaluated the impact of TDM recommendations in terms of dosage regimen adaptation. Design: A prospective observational study was conducted over 5 weeks. The primary objective was to evaluate the application of our TDM recommendations and to identify potential factors associated to variations in their implementation. The secondary objective was to identify pre-analytical problems linked to the collection and processing of blood samples. Setting: Four representative clinical units at CHUV. Main outcome measure: Clinical data, drug related data (intake, collection and processing) and all information regarding the implementation of clinical recommendations were collected and analyzed by descriptive statistics. Results: A total of 241 blood measurement requests were collected, among which 105 triggered a recommendation. 37% of the recommendations delivered were applied, 25 % partially applied and 34% not applied. In 4% it was not applicable. The factors determinant for implementation were the clinical unit and the mode of transmission of the recommendation (written vs oral). No clear difference between types of drugs could be detected. Pre-analytical problems were not uncommon, mostly related to completion of request forms and delays in blood sampling (equilibration or steady-state not reached). We have identified 6% of inappropriate and unusable drug level measurements that could cause a substantial cost for the hospital. Conclusion: This survey highlighted a better implementation of TDM recommendations in clinical units where this routine is well integrated and understood by the medical staff. Our results emphasize the importance of communication with the nurse or the physician in charge, either to transmit clinical recommendations or to establish consensual therapeutic targets in specific conditions. Development of strong partnerships between clinical pharmacists or pharmacologists and clinical units would be beneficial to improve the impact of this clinical activity.
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OBJECTIVE: Although the maximal quetiapine doses in the published studies were restricted to 800 mg/day, higher quetiapine doses are not unusual in clinical practice. The aim of the present study was to evaluate the effectiveness, tolerability and clinical reasons associated to the use of high dosage of quetiapine (>800 mg), when used under routine clinical conditions, in a sample of bipolar disorder and schizoaffective bipolar inpatients. METHODS: Charts of all bipolar and schizoaffective adult inpatients, who had received quetiapine for a mood episode between 1999 and 2005 were retrospectively reviewed. These charts also included the assessment of manic and depressive symptoms on admission and at discharge using the Beck-Rafaelsen Mania Scale (MAS) and the Montgomery Asberg depression rating scale (MADRS), respectively. RESULTS: Data of 50 patients were analyzed. The overall F in repeated measures ANOVA revealed a significant MAS scores reduction between admission and discharge. MAS scores reduction did not differ between the high and low quetiapine groups. Similarly, a significant MADRS reduction was found. Again, no differences between the high and the low dose group were found. Logistic regression analysis of the 50 patients revealed only mixed episodes predicted high quetiapine dosage. CONCLUSIONS: The present study confirms quetiapine efficiency and tolerability in the treatment of bipolar episodes, even in doses > to 800 mg and found a link between quetiapine doses and mixed episodes
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Nonlinear Noisy Leaky Integrate and Fire (NNLIF) models for neurons networks can be written as Fokker-Planck-Kolmogorov equations on the probability density of neurons, the main parameters in the model being the connectivity of the network and the noise. We analyse several aspects of the NNLIF model: the number of steady states, a priori estimates, blow-up issues and convergence toward equilibrium in the linear case. In particular, for excitatory networks, blow-up always occurs for initial data concentrated close to the firing potential. These results show how critical is the balance between noise and excitatory/inhibitory interactions to the connectivity parameter.
Update of the Gene Discovery Program in Schistosoma mansoni with the Expressed Sequence Tag Approach
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Continuing the Schistosoma mansoni Genome Project 363 new templates were sequenced generating 205 more ESTs corresponding to 91 genes. Seventy four of these genes (81%) had not previously been described in S. mansoni. Among the newly discovered genes there are several of significant biological interest such as synaptophysin, NIFs-like and rho-GDP dissociation inhibitor
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This paper studies endogenous mergers of complements with mixed bundling, by allowing both for joint and separate consumption. After merger, partner fi rms decrease the price of the bundled system. Besides, when markets for individual components are suffi ciently important, partner firms raise prices of stand-alone products, exploiting their monopoly power in local markets and making substitute 'mix-and-match' composite products less attractive to consumers. Even though these effects favor the pro fitability of mergers, merging is not always an equilibrium outcome. The reason is that outsiders respond by cutting their prices to retain their market share, and mergers can be unprofitable when competition is intense. From a welfare analysis, we observe that the number of mergers observed in equilibrium may be either excessive (when markets for individual components are important) or suboptimal (when markets for individual components are less important). Keywords: complements; merger; mixed bundling; separate consumption JEL classi fication: L13; L41; D43