A Regularized Method for Selecting Nested Groups of Relevant Genes from Microarray Data

Gene expression analysis aims at identifying the genes able to accurately predict biological parameters like, for example, disease subtyping or progression. While accurate prediction can be achieved by means of many different techniques, gene identification, due to gene correlation and the limited number of available samples, is a much more elusive problem. Small changes in the expression values often produce different gene lists, and solutions which are both sparse and stable are difficult to obtain. We propose a two-stage regularization method able to learn linear models characterized by a high prediction performance. By varying a suitable parameter these linear models allow to trade sparsity for the inclusion of correlated genes and to produce gene lists which are almost perfectly nested. Experimental results on synthetic and microarray data confirm the interesting properties of the proposed method and its potential as a starting point for further biological investigationsComment: 17 pages, 8 Post-script figure

Metodi di valutazione delle proprietà naftogeniche originarie di una roccia madre.

The knowledge of the original potential is of primary importance in order to obtain a good geochemical model for the petroleum system modeling. For mature source rocks it is possible to measure in laboratory only the residual features: petroleum potential – PPR, total organic carbon content – TOCR, hydrogen index – HIR. In case of extremely mature rocks only the TOC value remains as a proof of an early naphthogenic appeal. Historically, there were at least three different methods to evaluate the original petroleum potential. After a bibliographical review on the subject, the different evaluation hypotheses introduced by Claypool (in Hunt, 1995), Scotti (1998, Agip internal report) and Jarvie (2012) have been verified and compared. The common base is the utilization of the residual features, which can be measured in laboratory, and the analysis of the original quality of the organic matter, or more precisely of the kerogen, its diagenetic product, in terms of one more plausible value of the hydrogen index - HI. Once the reliability of the results in different theoretical conditions has been tested, we have verified the different approaches on real sample of source rocks, considering the samples from the Hils Syncline in the Posidonia Shale (Germany). The intrusion of the laccolitic body in this region allowed different conditions of maturity within the same formation, making possible the measurement of the naphthogenic residual features, through the decrease of the HI in samples that can be considered similar. The more recently proposed method (Jarvie, 2012) is also the most accurate, even if of complex application. Claypool (1995) proposed a formula that is even more complex and of difficult application, since it needs many parameters sometimes indefinable; moreover, in particular situations, it can lead to poor quality results. Scotti's method (1998) offers results that are identical to those obtained with Jarvie's formula (2012) only in case of overmature source rocks; if the maturity of the source rocks is intermediate and the kerogen is of excellent quality, we can observe a gap in comparison to Jarvie's method (2012). Using a simpler version of this formula, the calculation often converge towards the more precise formula proposed by Jarvie (2012). This seems to be of easier use, since it does not consider a really critical parameter that is the quantity of free hydrocarbon present in the sample, which can be sometimes hard to identify due to the presence of migrated hydrocarbons, in addition to indigenous ones. The study allowed to define the limits and the peculiarities of each proposed method and to establish which is the more correct work flow in order to evaluate the original potential of a source rock.ope

Ozonation of Human Blood Induces a Remarkable Upregulation of Heme Oxygenase-1 and Heat Stress Protein-70

Heme oxygenase-I (HO-1) has emerged as one of the most protective enzymes and its pleiotropic activities have been demonstrated in a variety of human pathologies. Unpublished observations have shown that HO-1 is induced after the infusion of ozonated blood into the respective donors, and many other experimental observations have demonstrated the efficacy of oxidizing agents. It appeared worthwhile to evaluate whether we could better define the activity of potential inducers such as hydrogen peroxide and ozonated human plasma. Human vascular endothelial cells at confluence were challenged with different concentrations of these inducers and the simultaneous production of nitric oxide (NO); and HO-1 was measured by either measuring nitrite, or bilirubin formation, or/and the immune reactivity of the protein by Western blot using a rabbit antihuman HO-1 and Hsp-70. The results show that production of both NO and HO-1 is fairly dose dependent but is particularly elevated using human plasma after transient exposure to a medium ozone concentration. At this concentration, there is also induction of Hsp-70. The results clarify another positive effect achievable by the use of ozone therapy

Nonparametric Sparsity and Regularization

In this work we are interested in the problems of supervised learning and variable selection when the input-output dependence is described by a nonlinear function depending on a few variables. Our goal is to consider a sparse nonparametric model, hence avoiding linear or additive models. The key idea is to measure the importance of each variable in the model by making use of partial derivatives. Based on this intuition we propose and study a new regularizer and a corresponding least squares regularization scheme. Using concepts and results from the theory of reproducing kernel Hilbert spaces and proximal methods, we show that the proposed learning algorithm corresponds to a minimization problem which can be provably solved by an iterative procedure. The consistency properties of the obtained estimator are studied both in terms of prediction and selection performance. An extensive empirical analysis shows that the proposed method performs favorably with respect to the state-of-the-art

Iterative Projection Methods for Structured Sparsity Regularization

In this paper we propose a general framework to characterize and solve the optimization problems underlying a large class of sparsity based regularization algorithms. More precisely, we study the minimization of learning functionals that are sums of a differentiable data term and a convex non differentiable penalty. These latter penalties have recently become popular in machine learning since they allow to enforce various kinds of sparsity properties in the solution. Leveraging on the theory of Fenchel duality and subdifferential calculus, we derive explicit optimality conditions for the regularized solution and propose a general iterative projection algorithm whose convergence to the optimal solution can be proved. The generality of the framework is illustrated, considering several examples of regularization schemes, including l1 regularization (and several variants), multiple kernel learning and multi-task learning. Finally, some features of the proposed framework are empirically studied

Camparison of estimated glomerular filtration rate with serum creatinie and 51Cr-EDTA method in head and neck cancer patients treated with cisplatin

Orientador: Celso Dario RamosDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: Objetivos: A avaliação da função renal, em particular da taxa de filtração glomerular (TFG), é extremamente importante em pacientes submetidos à quimioterapia com cisplatina, um fármaco nefrotóxico. Os objetivos deste trabalho foram comparar a estimativa da TFG pela fórmula Crockcroft-Gault (TFGe), que se baseia na creatinina sérica, com a TFG medida pelo método do EDTA-51Cr (TFG-EDTA), considerado "padrão-ouro", em pacientes com diagnóstico de carcinoma de cabeça e pescoço (CCP) antes e 30 dias após quimioterapia com cisplatina e acompanhar a evolução da função renal desses pacientes após 6 meses. Pacientes e Métodos: Foram avaliados 69 pacientes com diagnóstico de CCP submetidos à quimioterapia com cisplatina, sendo 6 mulheres e 63 homens. Esses pacientes foram submetidos ao exame com EDTA-51Cr e coleta de sangue para cálculo da TFGe antes e 30 dias após a quimioterapia. A função renal de 40 destes pacientes também foi analisada através da TFG-EDTA 6 meses após a quimioterapia. Resultados: A média da TFGe e TFG-EDTA pré-quimioterapia foi de 91,21 ml/min/1.73m2 e 84,33 ml/min/1.73m2, respectivamente. Trinta dias após a quimioterapia com cisplatina esta média foi de 78,79 ml/min/1.73m2 para a TFGe e 64,97 ml/min/1.73 m2 para a TFG-EDTA. A diferença entre os valores encontrados tanto pré-quimioterapia quanto pós-quimioterapia foi estatisticamente significante (p<0,0001). Nos 40 pacientes que tiveram a TFG acompanhada com EDTA-51Cr, foi encontrada média de 79,3, 60,9 e 64,9 ml/min/1.73m2, antes, 30 dias e 6 meses, respectivamente, após o tratamento com cisplatina. Conclusão: A medida da TFGe apresenta baixa acurácia para a avaliação da função renal em pacientes com CCP, tanto antes como imediatamente após o tratamento com cisplatina, e não pode ser recomendada como substituta do método com EDTA-51Cr. Há queda significativa da função renal após quimioterapia com cisplatina nestes pacientes e não ocorre recuperação completa da função renal 6 meses após o tratamento na maioria dos casosAbstract: Purpose: Renal function analysis, primarily glomerular filtration rate (GFR), is extremely important in patients undergoing chemotherapy with cisplatin, a nephrotoxic drug. The aim of this current study was to compare estimated TGF using the Crockcroft-Gault formula (eGFR) and the 51Cr-EDTA method EDTA-GFR), which is consider the "gold standard", in head and neck cancer (HNC) patients before and 30 days after chemotherapy with cisplatin. EDTA-GFR was also analysed 6 months after chemotheraphy. Materials and Methods: We evaluated 69 HNC patients who underwent chemotherapy with cisplatin (6 women and 63 men). These patients were submitted to 51Cr-EDTA plasma clearance and blood collection for eGFR calculation before and 30 days after chemotherapy. Forty of these patients had GFR examined by 51Cr-EDTA 6 months after chemotherapy. Results: The mean of eGFR and EDTA-GFR pre-chemotherapy was 91.21ml/min/1.73m2 and 84.33ml/min/1.73m2, respectively. Thirty days after chemotherapy with cisplatin the mean was 78.79ml/min/1.73 m2 for eGFR and 64.97ml/min/1.73m2 for EDTA-GFR. The difference between the values found pre and post-chemotherapy are statistically significant (p <0.0001). In the 40 patients who had GFR followed by 51Cr-EDTA, it was found a mean of 79.3, 60.9 and 64.9 mL/min/1.73m2, before, 30 days and 6 months after treatment with cisplatin, respectively. Conclusions: eGFR showed low accuracy in the assessment of renal function in patients with HNC, both before and immediately after cisplatin treatment, and cannot be recommended as a substitute to the method 51Cr-EDTA. There was a significant decrease in renal function after cisplatin chemotherapy in these patients and in the majority of the cases no recovery of renal function was observed 6 months after treatmentMestradoClinica MedicaMestra em Clínica Médic

Corrupção, Ética e Direito no Brasil

En Brasil la corrupción es una realidad incontestable, fácilmente observable en la vida cotidiana de las personas, en las empresas y en el Estado. En el alcance del derecho, la corrupción es un hecho jurídico ilegal. Desde un punto de vista sociológico, la corrupción es un hecho social, pues es una forma de actuar y de pensar determinada principalmente por circunstancias externas a los individuos. La corrupción tiene como telón de fondo una dimensión ética, que establece el ordenamiento jurídico no sólo a través de normas legales, pero sobre todo, por medio del principio de la buena fe.No Brasil a corrupção é uma realidade factual incontestável, de fácil observação na vida cotidiana das pessoas, das empresas e do Estado. No âmbito do direito a corrupção é um fato jurídico, da espécie ato ilícito. Do ponto de vista sociológico, a corrupção é um fato social, pois constitui um modo de agir e de pensar determinado preponderantemente por circunstâncias exteriores aos indivíduos. A corrupção tem como pano de fundo uma dimensão ética, que se estabelece no ordenamento jurídico não apenas por intermédio de regras legais, mas, principalmente, por meio do princípio da boa-fé

Rendimiento académico en la asignatura "Álgebra y Geometría Analítica" de FACENA-UNNE EN 2018

La asignatura Algebra y Geometría Analítica de la Facultad de Ciencias Exactas y Naturales y Agrimensura de la Universidad Nacional del Nordeste, pertenece al plan de estudios de ocho de las carreras que conforman la oferta curricular de la mencionada Casa de Altos Estudios, a saber: Bioquímica, Licenciatura en Ciencias Físicas, Licenciatura en Ciencias Químicas, Ingeniería Eléctrica, Ingeniería en Agrimensura, Ingeniería en Electrónica, Profesorado en Ciencias Químicas y del Ambiente y Profesorado en Física. La variedad de perfiles de formación que atraviesan a la asignatura, así como también el elevado número de alumnos que la cursan (ya que corresponde al primer cuatrimestre del primer año de estudios de las ocho carreras mencionadas), obligan a trabajar en numerosas comisiones de clases, tanto teóricas como prácticas, lo cual complejiza el proceso de seguimiento y evaluación de los procesos de enseñanza y aprendizaje durante el cursado de la asignatura. De ahí que el presente trabajo, tiene como objetivo realizar una detallada descripción de los resultados de dicho cursado en el año lectivo 2018, en las evaluaciones parciales que se realizan a fin de regularizar la asignatura, discriminados según la comisión de clases prácticas a la que cada estudiante asistió. Para realizar el análisis mencionado se utilizó la técnica de análisis de datos composicionales, presentándose los resultados obtenidos mediante gráficos ternarios. Asimismo, se determinó el porcentaje de desgranamiento de alumnos durante el cursado de la asignatura, llegando a la conclusión que sólo un 49% de los alumnos inscriptos completan el curso y de éstos casi el 51% la regulariza. Mediante las envolventes convexas de las comisiones correspondientes a alumnos de Ingeniería y a las de estudiantes de otras carreras, se comparó el rendimiento académico de la cursada de los dos grupos de comisiones, observándose que las Ingenierías ostentan un rendimiento académico ligeramente superior al resto de las carreras. Finalmente, se concluye que el elevado número de fracasos de los alumnos en el cursado de la asignatura está, principalmente, explicado por el desgrana- miento y, a fin de paliar esta problemática y de favorecer la retención de los estudiantes, se proponen algunas modificaciones a las currículas de las carreras de Ingeniería.