Inferring mixed-culture growth from total biomass data in a wavelet approach

It is shown that the presence of mixed-culture growth in batch fermentation processes can be very accurately inferred from total biomass data by means of the wavelet analysis for singularity detection. This is accomplished by considering simple phenomenological models for the mixed growth and the more complicated case of mixed growth on a mixture of substrates. The main quantity provided by the wavelet analysis is the Holder exponent of the singularity that we determine for our illustrative examples. The numerical results point to the possibility that Holder exponents can be used to characterize the nature of the mixed-culture growth in batch fermentation processes with potential industrial applications. Moreover, the analysis of the same data affected by the common additive Gaussian noise still lead to the wavelet detection of the singularities although the Holder exponent is no longer a useful parameterComment: 17 pages and 10 (png) figure

Load Index Metrics for an Optimized Management of Web Services: A Systematic Evaluation

The lack of precision to predict service performance through load indices may lead to wrong decisions regarding the use of web services, compromising service performance and raising platform cost unnecessarily. This paper presents experimental studies to qualify the behaviour of load indices in the web service context. The experiments consider three services that generate controlled and significant server demands, four levels of workload for each service and six distinct execution scenarios. The evaluation considers three relevant perspectives: the capability for representing recent workloads, the capability for predicting near-future performance and finally stability. Eight different load indices were analysed, including the JMX Average Time index (proposed in this paper) specifically designed to address the limitations of the other indices. A systematic approach is applied to evaluate the different load indices, considering a multiple linear regression model based on the stepwise-AIC method. The results show that the load indices studied represent the workload to some extent; however, in contrast to expectations, most of them do not exhibit a coherent correlation with service performance and this can result in stability problems. The JMX Average Time index is an exception, showing a stable behaviour which is tightly-coupled to the service runtime for all executions. Load indices are used to predict the service runtime and therefore their inappropriate use can lead to decisions that will impact negatively on both service performance and execution cost

Gathering patients and rheumatologists' perceptions to improve outcomes in idiopathic inflammatory myopathies

Objective: Therapeutic targets in Idiopathic Inflammatory Myopathies (IIM) are based on the opinions of physicians/specialists, which may not reflect the main concerns of patients. The authors, therefore, assessed the outcome concerns of patients with IIM and compared them with the concerns of rheumatologists in order to develop an IIM outcome standard set. Methods: Ninety-three IIM patients, 51 rheumatologists, and one physiotherapist were invited to participate. An open questionnaire was initially applied. The top 10 answers were selected and applied in a multiple-choice questionnaire, inquiring about the top 3 major concerns. Answers were compared, and the agreement rate was calculated. Concerns were gathered in an IIM outcome standard set with validated measures. Results: The top three outcome concerns raised by patients were medication side effects/muscle weakness/prevention functionality loss. The top three concerns among rheumatologists were to prevent loss of functionality/to ensure the quality of life/to achieve disease remission. Other's outcomes concerns only pointed out by patients were muscle pain/diffuse pain/skin lesions/fatigue. The agreement rate between both groups was 41%. Assessment of these parameters guided the development of an IIM standard set which included Myositis Disease Activity Assessment Visual Analogue Scale/Manual Muscle Testing/fatigue and pain Global Visual Analogue Scale/Health Assessment Questionnaire/level of physical activity. Conclusion: The authors propose a novel standard set to be pursued in IIM routine follow-up, which includes not only the main patients/rheumatologist outcome concerns but also additional important outcomes only indicated by patients. Future studies are necessary to confirm if this comprehensive approach will result in improved adherence and ultimately in better assistance

Evaluation of mitochondrial activity in spermatozoids after collecting and posthawing in Boer and Alpine goats in autumn and spring

Caprine spermatozoa undergo glycolisis and mitocondrial respiration to keep the necessary energy balance to their transportation and other cellular functions. An objective test to evaluate quantitatively and qualitatively mitochondrial activity in caprine spermatozoa was applied in the analysis of semen samples of 9 bucks from Boer (n=5) and Alpine (n=4) breeds. Samples were collected and frozen in TRIS medium in two different year seasons. Semen collection was performed using artificial vagina to obtain 135 ejaculates, which were used to post-collection and post-frozen extended in sildes. To determine mitochondrial activity, a citochemical procedure developed and validated for HRUDKA (1987) was used. The technique is based on the enzymatic 3,3-diaminobenzidine (DAB) oxidation, where the reagent is polymerized and attached to the mitochondrial membrane throughout the spermatic intermediary piece. A medium level of citochemical activity (IAC) was determined as being 74,37%, 74,37% during Autumn and 77% e 77,75% during Spring for Boer and Alpine breeds, respectively. For post-collection IAC levels were 85,62% and 85,93 and for post-frozen 66% and 67,25% for Boer and Alpine breeds, respectively. ANOVA test was used to evaluate breed, post-collection, post-frozen, IAC rates and year season parameters. Differences were not noticed for breed, IAC rates and year season. Nonetheless, there was a significant effect among samples for post-collection and post-frozen analysis (POs espermatozóides caprinos realizam a respiração mitocondrial, mantendo um balanço energético necessário para o transporte e as demais funções celulares. Um teste objetivo de avaliação quantitativa e qualitativa da atividade mitocondrial em espermatozóides caprinos foi aplicado no sêmen de nove reprodutores das raças Boer (n=5) e Alpina (n=4) colhidos e congelados em diluidor TRIS em duas estações. A colheita do sêmen foi realizada com auxílio da vagina artificial, totalizando 135 ejaculados e foram confeccionados esfregaços com sêmen pós-colheita e pós-descongelação. Para a determinação da atividade mitocondrial foi utilizado o procedimento citoquímico desenvolvido e validado por HRUDKA (1987). Esta técnica é baseada na oxidação da 3,3-diaminobenzidine (DAB) pela enzima em reação em cadeia, onde o reagente é polimerizado e depositado na bainha mitocondrial ao longo da peça intermediária dos espermatozóides. Foi determinado um índice médio de atividade citoquímica (IAC) de 74,37%, 74,37% no outono, 77% e 77,75% na primavera. E 85,62% e 85,93 no pós-colheita, 66% e 67,25% pós-descongelação para as raças Boer e Alpina, respectivamente. As variáveis raças, pós-colheita e pós-descongelação, classes (IAC), e estação foram estudadas por meio de ANOVA. Não foram observadas diferenças estatísticas para raças, classes, bem como para as estações. Entretanto, efeito significativo entre as amostras pós-colheita e pós-descongelação (

A Novel Hybrid Feature Selection Algorithm for Hierarchical Classification

Feature selection is a widespread preprocessing step in the data mining field. One of its purposes is to reduce the number of original dataset features to improve a predictive model’s performance. Despite the benefits of feature selection for the classification task, to the best of our knowledge, few studies in the literature address feature selection for the hierarchical classification context. This paper proposes a novel feature selection method based on the general variable neighborhood search metaheuristic, combining a filter and a wrapper step, wherein a global model hierarchical classifier evaluates feature subsets. We used twelve datasets from the proteins and images domains to perform computational experiments to validate the effect of the proposed algorithm on classification performance when using two global hierarchical classifiers proposed in the literature. Statistical tests showed that using our method for feature selection led to predictive performances that were consistently better than or equivalent to that obtained by using all features with the benefit of reducing the number of features needed, which justifies its efficiency for the hierarchical classification scenario

Are the magnetic fields of millisecond pulsars ~ 10^8 G?

It is generally assumed that the magnetic fields of millisecond pulsars (MSPs) are $\sim 10^{8}$G. We argue that this may not be true and the fields may be appreciably greater. We present six evidences for this: (1) The $\sim 10^{8}$ G field estimate is based on magnetic dipole emission losses which is shown to be questionable; (2) The MSPs in low mass X-ray binaries (LMXBs) are claimed to have $< 10^{11}$ G on the basis of a Rayleygh-Taylor instability accretion argument. We show that the accretion argument is questionable and the upper limit $10^{11}$ G may be much higher; (3) Low magnetic field neutron stars have difficulty being produced in LMXBs; (4) MSPs may still be accreting indicating a much higher magnetic field; (5) The data that predict $\sim 10^{8}$ G for MSPs also predict ages on the order of, and greater than, ten billion years, which is much greater than normal pulsars. If the predicted ages are wrong, most likely the predicted $\sim 10^{8}$ G fields of MSPs are wrong; (6) When magnetic fields are measured directly with cyclotron lines in X-ray binaries, fields $\gg 10^{8}$ G are indicated. Other scenarios should be investigated. One such scenario is the following. Over 85% of MSPs are confirmed members of a binary. It is possible that all MSPs are in large separation binaries having magnetic fields $> 10^{8}$ G with their magnetic dipole emission being balanced by low level accretion from their companions.Comment: 16 pages, accept for publication in Astrophysics and Space Scienc

Multiobjective optimization of MPLS-IP networks with a variable neighborhood genetic algorithm

This paper presents a Genetic Algorithm for the optimization of multiple indices of Quality of Service of Multi Protocol Label Switching (MPLS) IP networks. The proposed algorithm, the Variable Neighborhood Multiobjective Genetic Algorithm (VN-MGA), is a Genetic Algorithm based on the NSGA-II, with the particular feature that solutions are encoded defining two different kinds of neighborhoods. The first neighborhood is defined by considering as decision variables the edges that form the routes to be followed by each request, whilst the second part of solution is kept constant. The second neighborhood is defined by considering the request sequence as decision variable, with the first part kept constant. Comparisons are performed with: (i) a VNS algorithm that performs a switch between the same two neighborhoods that are used in VN-MGA; and (ii) the results obtained with an integer linear programming solver, running a scalarized version of the multiobjective problem. The results indicate that the proposed VN-MGA outperforms the pure VNS algorithm, and provides a good approximation of the exact Pareto fronts obtained with Integer Linear Programming (ILP) approach, at a much smaller computational cost. Besides potential benefits of the application of the proposed approach to the optimization of packet routing in MPLS networks, this work raises the theoretical issue of the systematic application of variable encodings, which allow variable neighborhood searches, as generic operators inside general evolutionary computation algorithms. Codice rivista: E013138 Titolo rivista: APPLIED SOFT COMPUTING Issn: 1568-4946 Cordiali saluti CINECA - Servizio Gestione Rivist