Characterization of the variable cow's age at last calving as a measurement of longevity by using the Kaplan-Meier estimator and the Cox model

In most studies on beef cattle longevity, only the cows reaching a given number of calvings by a specific age are considered in the analyses. With the aim of evaluating all cows with productive life in herds, taking into consideration the different forms of management on each farm, it was proposed to measure cow longevity from age at last calving (ALC), that is, the most recent calving registered in the files. The objective was to characterize this trait in order to study the longevity of Nellore cattle, using the Kaplan-Meier estimators and the Cox model. The covariables and class effects considered in the models were age at first calving (AFC), year and season of birth of the cow and farm. The variable studied (ALC) was classified as presenting complete information (uncensored = 1) or incomplete information (censored = 0), using the criterion of the difference between the date of each cow's last calving and the date of the latest calving at each farm. If this difference was >36 months, the cow was considered to have failed. If not, this cow was censored, thus indicating that future calving remained possible for this cow. The records of 11 791 animals from 22 farms within the Nellore Breed Genetic Improvement Program ('Nellore Brazil') were used. In the estimation process using the Kaplan-Meier model, the variable of AFC was classified into three age groups. In individual analyses, the log-rank test and the Wilcoxon test in the Kaplan-Meier model showed that all covariables and class effects had significant effects (P < 0.05) on ALC. In the analysis considering all covariables and class effects, using the Wald test in the Cox model, only the season of birth of the cow was not significant for ALC (P > 0.05). This analysis indicated that each month added to AFC diminished the risk of the cow's failure in the herd by 2%. Nonetheless, this does not imply that animals with younger AFC had less profitability. Cows with greater numbers of calvings were more precocious than those with fewer calvings. Copyright © The Animal Consortium 2012.

Functional Magnetic Resonance Imaging Data Analysis by Autoregressive Estimator

The autoregressive (AR) estimator, a non-parametric method, is used to analyze functional magnetic resonance imaging (fMRI) data. The same method has been used, with success, in several other time series data analysis. It uses exclusively the available experimental data points to estimate the most plausible power spectra compatible with the experimental data and there is no need to make any assumption about non-measured points. The time series, obtained from fMRI block paradigm data, is analyzed by the AR method to determine the brain active regions involved in the processing of a given stimulus. This method is considerably more reliable than the fast Fourier transform or the parametric methods. The time series corresponding to each image pixel is analyzed using the AR estimator and the corresponding poles are obtained. The pole distribution gives the shape of power spectra, and the pixels with poles at the stimulation frequency are considered as the active regions. The method was applied in simulated and real data, its superiority is shown by the receiver operating characteristic curves which were obtained using the simulated data.

Speed Neuro-fuzzy Estimator Applied To Sensorless Induction Motor Control

This work proposes the development of an Adaptive Neuro-fuzzy Inference System (ANFIS) estimator applied to speed control in a three-phase induction motor sensorless drive. Usually, ANFIS is used to replace the traditional PI controller in induction motor drives. The evaluation of the estimation capability of the ANFIS in a sensorless drive is one of the contributions of this work. The ANFIS speed estimator is validated in a magnetizing flux oriented control scheme, consisting in one more contribution. As an open-loop estimator, it is applied to moderate performance drives and it is not the proposal of this work to solve the low and zero speed estimation problems. Simulations to evaluate the performance of the estimator considering the vector drive system were done from the Matlab/Simulink(R) software. To determine the benefits of the proposed model, a practical system was implemented using a voltage source inverter (VSI) to drive the motor and the vector control including the ANFIS estimator, which is carried out by the Real Time Toolbox from Matlab/Simulink(R) software and a data acquisition card from National Instruments.

An optimal estimator for the correlation of CMB anisotropies with Large Scale Structures and its application to WMAP-7year and NVSS

In the thesis we present the implementation of the quadratic maximum likelihood (QML) method, ideal to estimate the angular power spectrum of the cross-correlation between cosmic microwave background (CMB) and large scale structure (LSS) maps as well as their individual auto-spectra. Such a tool is an optimal method (unbiased and with minimum variance) in pixel space and goes beyond all the previous harmonic analysis present in the literature. We describe the implementation of the QML method in the {\it BolISW} code and demonstrate its accuracy on simulated maps throughout a Monte Carlo. We apply this optimal estimator to WMAP 7-year and NRAO VLA Sky Survey (NVSS) data and explore the robustness of the angular power spectrum estimates obtained by the QML method. Taking into account the shot noise and one of the systematics (declination correction) in NVSS, we can safely use most of the information contained in this survey. On the contrary we neglect the noise in temperature since WMAP is already cosmic variance dominated on the large scales. Because of a discrepancy in the galaxy auto spectrum between the estimates and the theoretical model, we use two different galaxy distributions: the first one with a constant bias $b$ and the second one with a redshift dependent bias $b(z)$. Finally, we make use of the angular power spectrum estimates obtained by the QML method to derive constraints on the dark energy critical density in a flat $\Lambda$CDM model by different likelihood prescriptions. When using just the cross-correlation between WMAP7 and NVSS maps with 1.8° resolution, we show that $\Omega_\Lambda$ is about the 70\% of the total energy density, disfavouring an Einstein-de Sitter Universe at more than 2 $\sigma$ CL (confidence level).

A real-time video quality estimator for emerging wireless multimedia systems

Wireless Mesh Networks (WMNs) are increasingly deployed to enable thousands of users to share, create, and access live video streaming with different characteristics and content, such as video surveillance and football matches. In this context, there is a need for new mechanisms for assessing the quality level of videos because operators are seeking to control their delivery process and optimize their network resources, while increasing the user’s satisfaction. However, the development of in-service and non-intrusive Quality of Experience assessment schemes for real-time Internet videos with different complexity and motion levels, Group of Picture lengths, and characteristics, remains a significant challenge. To address this issue, this article proposes a non-intrusive parametric real-time video quality estimator, called MultiQoE that correlates wireless networks’ impairments, videos’ characteristics, and users’ perception into a predicted Mean Opinion Score. An instance of MultiQoE was implemented in WMNs and performance evaluation results demonstrate the efficiency and accuracy of MultiQoE in predicting the user’s perception of live video streaming services when compared to subjective, objective, and well-known parametric solutions.

A logarithmic efficient estimator of the probability of ruin with recuperation for spectrally negative Lévy risk processes

This article provides an importance sampling algorithm for computing the probability of ruin with recuperation of a spectrally negative Lévy risk process with light-tailed downwards jumps. Ruin with recuperation corresponds to the following double passage event: for some t∈(0,∞)t∈(0,∞), the risk process starting at level x∈[0,∞)x∈[0,∞) falls below the null level during the period [0,t][0,t] and returns above the null level at the end of the period tt. The proposed Monte Carlo estimator is logarithmic efficient, as t,x→∞t,x→∞, when y=t/xy=t/x is constant and below a certain bound.

De ate a furor : la secularización de la intervención divina en el Hercvles fvrens de Séneca

La presente comunicación tiene como objeto indagar en la secularización del concepto de ate, entendido como la exaltación divina del héroe trágico, y su conversión en furor, en la tragedia Hercules furens, del filósofo latino Lucio Anneo Seneca. Para entender la especificidad de la intervención divina en el Hercules, se analiza la expresión de este fenómeno en el Áyax sofocleo y la vecindad que este último héroe demuestra en relación con los personajes homéricos, para, finalmente, concluir las diferencias funcionales que la emergencia de los dioses -y, en particular, el mandato divino- tiene en la estructuración dramática de la tragedia senecana. Con la remisión tanto a Homero como a Sófocles y Eurípides se pretende dar somera cuenta del tránsito que convierte un problema formal y divino, en uno eventual y humano.

La trama compleja de la acción sindical : Los casos de ATE y UPCN

En el presente trabajo se analizan comparativamente las dinámicas internas que conforman la acción sindical en las dos organizaciones gremiales nacionales del sector público: ATE y UPCN. Los ejes centrales a abordar son: en primer lugar las relaciones que se establecen al interior de cada sindicato, tanto en términos horizontales como verticales; en segundo lugar, analizamos los tipos de vinculación que se generan entre organización y militantes; en tercer termino trataremos sobre las formas de lucha; para finalmente observar el modo en que interactúan y se superponen las dinámicas de la acción propia y la de la disputa entre sindicatos. El abordaje metodológico es eminentemente cualitativo, a través de entrevistas en profundidad a dirigentes y delegados sindicales, así como a trabajadores y funcionarios

Estrategias de lucha de ATE y el astillero Río Santiago frente a la embestida privatista y reformadora del primer gobierno de Menem

Fil: Piovani, María de las Nieves. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Estrategias de lucha de ATE y el astillero Río Santiago frente a la embestida privatista y reformadora del primer gobierno de Menem

Fil: Piovani, María de las Nieves. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

De ate a furor : la secularización de la intervención divina en el Hercvles fvrens de Séneca

La presente comunicación tiene como objeto indagar en la secularización del concepto de ate, entendido como la exaltación divina del héroe trágico, y su conversión en furor, en la tragedia Hercules furens, del filósofo latino Lucio Anneo Seneca. Para entender la especificidad de la intervención divina en el Hercules, se analiza la expresión de este fenómeno en el Áyax sofocleo y la vecindad que este último héroe demuestra en relación con los personajes homéricos, para, finalmente, concluir las diferencias funcionales que la emergencia de los dioses -y, en particular, el mandato divino- tiene en la estructuración dramática de la tragedia senecana. Con la remisión tanto a Homero como a Sófocles y Eurípides se pretende dar somera cuenta del tránsito que convierte un problema formal y divino, en uno eventual y humano.

La trama compleja de la acción sindical : Los casos de ATE y UPCN

En el presente trabajo se analizan comparativamente las dinámicas internas que conforman la acción sindical en las dos organizaciones gremiales nacionales del sector público: ATE y UPCN. Los ejes centrales a abordar son: en primer lugar las relaciones que se establecen al interior de cada sindicato, tanto en términos horizontales como verticales; en segundo lugar, analizamos los tipos de vinculación que se generan entre organización y militantes; en tercer termino trataremos sobre las formas de lucha; para finalmente observar el modo en que interactúan y se superponen las dinámicas de la acción propia y la de la disputa entre sindicatos. El abordaje metodológico es eminentemente cualitativo, a través de entrevistas en profundidad a dirigentes y delegados sindicales, así como a trabajadores y funcionarios

Estrategias de lucha de ATE y el astillero Río Santiago frente a la embestida privatista y reformadora del primer gobierno de Menem

Fil: Piovani, María de las Nieves. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.