The role of differential rotation in the evolution of the r-mode instability

We discuss the role of differential rotation in the evolution of the l=2 r-mode instability of a newly born, hot, rapidly-rotating neutron star. It is shown that the amplitude of the r-mode saturates in a natural way at a value that depends on the amount of differential rotation at the time the instability becomes active. It is also shown that, independently of the saturation amplitude of the mode, the star spins down to a rotation rate that is comparable to the inferred initial rotation rates of the fastest pulsars associated with supernova remnants.Comment: 4 pages, 2 figures, in Proceedings of the 5th International Workshop "New Worlds in Astroparticle Physics", Faro, Portugal, 8-10 January 200

How Experience Can Be Useful in Veterinary Pathological Anatomy

Veterinary anatomical pathology is a medical specialty very similar to human anatomical pathology. This specialty consists in diagnosing diseases, based mostly on the gross and microscopic examination of organs and tissues, obtained by surgical procedure or necropsy It consists in the application of criteria based in the knowledge of the gross and histological lesions to obtain a final pathological diagnosis. The aim of this specific diagnosis is, generally, to find which disease affects the animal, if it is alive, or what caused its death. The main difficulties in veterinary pathological diagnosis are related to the various animal species a pathologist has to deal with, the use of exhaustive classifications of different types, the costs, the subjectivity, including disagreement between the clinical and pathologic diagnoses, and the urgency in issuing the report. So the urgent need to compile all available information to obtain a diagnosis, in a short period of time, is the constant challenge placed to the professional experts in the area concerned. This chapter proposes a framework and a software system that can be useful for making diagnosis of disease. We developed the framework based on the analysis of the bibliography of the domain. Both proposals can be useful for making better diagnosis.This work was supported by Portuguese Foundation for Science and Technology, Center for Studies in Education, Technologies and by Health and by strategic project PEst-OE/CED/UI4016/201

Nonlinear evolution of r-modes: the role of differential rotation

Recent work has shown that differential rotation, producing large scale drifts of fluid elements along stellar latitudes, is an unavoidable feature of r-modes in the nonlinear theory. We investigate the role of this differential rotation in the evolution of the l=2 r-mode instability of a newly born, hot, rapidly rotating neutron star. It is shown that the amplitude of the r-mode saturates a few hundred seconds after the mode instability sets in. The saturation amplitude depends on the amount of differential rotation at the time the instability becomes active and can take values much smaller than unity. It is also shown that, independently of the saturation amplitude of the mode, the star spins down to rotation rates that are comparable to the inferred initial rotation rates of the fastest pulsars associated with supernova remnants. Finally, it is shown that, when the drift of fluid elements at the time the instability sets in is significant, most of the initial angular momentum of the star is transferred to the r-mode and, consequently, almost none is carried away by gravitational radiation.Comment: 10 pages, 5 figure

Modelo de crescimento para árvores em povoamentos juvenis de sobreiro em Portugal

The juvenile and adult stages in cork oak are distinct because of the periodic debarking of the stem and branches that characterizes the adult stage. This fact implies the use of diameter under bark for the adult stage while diameter over bark is the natural variable for juvenile stands in growth and yield studies. Tree growth in the adult stage may also be affected by the periodic debarking. The differences between the two stages justify the development of different models for each of them. The objective of this paper is to develop an individual tree growth and yield model for juvenile cork oak stands for general application on the cork oak distribution area in Southern Portugal. The most important modules of this growth model were developed using data collected from a large number of trees in the juvenile stage, from several plots distributed around the South of Portugal. These modules were: an individual tree diameter growth model, a height-diameter model and a model for crown diameter prediction

The influence of differential rotation on the detectability of gravitational waves from the r-mode instability

Recently, it was shown that differential rotation is an unavoidable feature of nonlinear r-modes. We investigate the influence of this differential rotation on the detectability of gravitational waves emitted by a newly born, hot, rapidly-rotating neutron star, as it spins down due to the r-mode instability. We conclude that gravitational radiation may be detected by the advanced laser interferometer detector LIGO if the amount of differential rotation at the time the r-mode instability becomes active is not very high.Comment: 8 pages, 6 figures, revtex

Mapping cork caliper in Portugal using percentile regression

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Improving data modelling through the use of case-based-reasoning

Experience plays an important role in Information Systems data modelling activity. This role is justified by the fact that determining the correct and consistent information requirements is a difficult and a challenging task. Currently three types of data modelling techniques are widely used: entity-attribute-relationship, object-relationship and object-oriented. There is not a consensus about which one is the best. This article proposes a framework, supported by a software tool, that uses Case-Based-Reasoning (CBR) methodology to represent and use experience in the data modelling task. The proposed framework does not depend on the data modelling technique nor on the modelling tool.- (undefined

Re-using experience in information systems development

Information Systems Development (ISD) is an important organization activity that generally involves the development of models. This paper describes a framework, supported by Case-Based-Reasoning (CBR) method, that enables the use of experience in model development in the context of ISD process.- (undefined

A FRAMEWORK THAT ENABLES THE USE OF EXPERIENCE IN CONCEPTUAL MODELLING

Better Information Systems (IS) could be developed, if experience were used. The use of experience could be applied in any phase of the Information System Development process. This paper presents a framework that applies the Case-Based Reasoning (CBR) method to enable the use of experience in conceptual modelling. This framework could be used in several conceptual modelling types, as long as graphical modelling languages were used. Our framework was implemented in an Internet application that has a modular structure