Regiões de estabilidade no ambiente de um sistema de asteroide triplo

This work was developed from the study by Araujo, R.A.N. et al. Stability regions around the components of the triple system 2001 SN263. (Monthly Notices Of The Royal Astronomical Society, 2012, v. 423(4), 3058-3073 p.) where it was studied the stable and unstable regions system (2001 SN263), which is a triple asteroid system, and these are celestial orbiting our sun. Being close to the Earth is characterized as NEA (Near-Earth Asteroids), asteroids and which periodically approach the Earth's orbit, given that there is great interest in the study and exploitation of these objects, it is the key can carry features that contribute to better understand the process of formation of our solar system. Study the dynamics of bodies that govern those systems proves to be greatly attractive because of the mutual gravitational perturbation of bodies and also by external disturbances. Recently, NEA 2001 SN263 was chosen as a target of Aster mission where a probe is sent for this triple system, appearing therefore the need for obtaining information for characterizing stable regions internal and external to the system, with respect to the effects of radiation pressure. First, this study demonstrated that the integrator used showed satisfactory results of the orbital evolution of bodies in accordance with previous studies and also the characterization of stable and unstable regions brought similar results to the study by Araujo et al. (2012). From these results it was possible to carry out the implementation of the radiation pressure in the system in 2001 SN263, in a region close to the central body, where the simulations were carried out, which brought as a result that the regions before being characterized as stable in unstable true for small particles size from 1 to 5 micrometers. So the next orbital region to the central body and the ... ( Complete abstract click electronic access below)

Static postural balance study in patients with vestibular disorders using a three dimensional eletromagnetic sensor system

The vestibular-ocular reflex assessment is important, but not enough. Tridimensional electromagnetic sensor systems represent a new method to assess posturography. Aim: To assess body sway in healthy subjects who had positive Dix Hallpike and Epley maneuvers and with other vestibular dysfunctions by means of a three-dimensional system. Study design: Prospective. Materials and Methods: We had 23 healthy women, 15 with peripheral vestibular dysfunction found upon caloric test and 10 with positive Epley and Dix Hallpike maneuvers. All tests performed in the following positions: open and closed eyes on stable and unstable surfaces. Results: With the Eyes Open and on a stable surface, p < 0.01 between the control group and the one with peripheral vestibular dysfunction in all variables, except the a-p maximum, full speed and mediolateral trajectory velocity, which had a p < 0.01 between the group with vestibular dysfunction and controls in all positions. The group with positive Epley and Dix Hallpike maneuvers had p < 0.01 at full speed and in its components in the x and y in positions with open and eyes closed on an unstable surface. Conclusion: The tridimensional electromagnetic sensors system was able to generate reliable information about body sway in the study volunteers.

Bivalirudin versus unfractionated heparin during percutaneous coronary intervention

BACKGROUND: Whether bivalirudin is superior to unfractionated heparin in patients with stable or unstable angina who undergo percutaneous coronary intervention (PCI) after pretreatment with clopidogrel is unknown. METHODS: We enrolled 4570 patients with stable or unstable angina (with normal levels of troponin T and creatine kinase MB) who were undergoing PCI after pretreatment with a 600-mg dose of clopidogrel at least 2 hours before the procedure; 2289 patients were randomly assigned in a double-blind manner to receive bivalirudin, and 2281 to receive unfractionated heparin. The primary end point was the composite of death, myocardial infarction, urgent target-vessel revascularization due to myocardial ischemia within 30 days after randomization, or major bleeding during the index hospitalization (with a net clinical benefit defined as a reduction in the incidence of the end point). The secondary end point was the composite of death, myocardial infarction, or urgent target-vessel revascularization. RESULTS: The incidence of the primary end point was 8.3% (190 patients) in the bivalirudin group as compared with 8.7% (199 patients) in the unfractionated-heparin group (relative risk, 0.94; 95% confidence interval [CI], 0.77 to 1.15; P=0.57). The secondary end point occurred in 134 patients (5.9%) in the bivalirudin group and 115 patients (5.0%) in the unfractionated-heparin group (relative risk, 1.16; 95% CI, 0.91 to 1.49; P=0.23). The incidence of major bleeding was 3.1% (70 patients) in the bivalirudin group and 4.6% (104 patients) in the unfractionated-heparin group (relative risk, 0.66; 95% CI, 0.49 to 0.90; P=0.008). CONCLUSIONS: In patients with stable and unstable angina who underwent PCI after pretreatment with clopidogrel, bivalirudin did not provide a net clinical benefit (i.e., it did not reduce the incidence of the composite end point of death, myocardial infarction, urgent target-vessel revascularization, or major bleeding) as compared with unfractionated heparin, but it did significantly reduce the incidence of major bleeding. (ClinicalTrials.gov number, NCT00262054.)

Development of system separation strategy using synchrophasor data

In the current market system, power systems are operated at higher loads for economic reasons. Power system stability becomes a genuine concern in such operating conditions. In case of failure of any larger component, the system may become stressed. These events may start cascading failures, which may lead to blackouts. One of the main reasons of the major recorded blackout events has been the unavailability of system-wide information. Synchrophasor technology has the capability to provide system-wide real time information. Phasor Measurement Units (PMUs) are the basic building block of this technology, which provide the Global Positioning System (GPS) time-stamped voltage and current phasor values along with the frequency. It is being assumed that synchrophasor data of all the buses is available and thus the whole system is fully observable. This information can be used to initiate islanding or system separation to avoid blackouts. A system separation strategy using synchrophasor data has been developed to answer the three main aspects of system separation: (1) When to separate: One class support machines (OC-SVM) is primarily used for the anomaly detection. Here OC-SVM was used to detect wide area instability. OC-SVM has been tested on different stable and unstable cases and it is found that OC-SVM has the capability to detect the wide area instability and thus is capable to answer the question of “when the system should be separated”. (2) Where to separate: The agglomerative clustering technique was used to find the groups of coherent buses. The lines connecting different groups of coherent buses form the separation surface. The rate of change of the bus voltage phase angles has been used as the input to this technique. This technique has the potential to exactly identify the lines to be tripped for the system separation. (3) What to do after separation: Load shedding was performed approximately equal to the sum of power flows along the candidate system separation lines should be initiated before tripping these lines. Therefore it is recommended that load shedding should be initiated before tripping the lines for system separation.

Dynamic response of a monolithic master-oscillator power-amplifier at 1.5 µm

We study experimentally the dynamic properties of a fully integrated high power master-oscillator power-amplifier emitting at 1.5 μm under continuous wave and gain-switching conditions. High peak power (2.7 W) optical pulses with short duration (~ 110 ps) have been generated by gain switching the master-oscillator. We show the existence of working points at very close driving conditions with stable or unstable regimes caused by the compound cavity effects. The optical and radio-frequency spectra of stable and unstable operating points are analyzed.

Social status regulates growth rate: Consequences for life-history strategies

The life-history strategies of organisms are sculpted over evolutionary time by the relative prospects of present and future reproductive success. As a consequence, animals of many species show flexible behavioral responses to environmental and social change. Here we show that disruption of the habitat of a colony of African cichlid fish, Haplochromis burtoni (Günther) caused males to switch social status more frequently than animals kept in a stable environment. H. burtoni males can be either reproductively active, guarding a territory, or reproductively inactive (nonterritorial). Although on average 25–50% of the males are territorial in both the stable and unstable environments, during the 20-week study, nearly two-thirds of the animals became territorial for at least 1 week. Moreover, many fish changed social status several times. Surprisingly, the induced changes in social status caused changes in somatic growth. Nonterritorial males and animals ascending in social rank showed an increased growth rate whereas territorial males and animals descending in social rank slowed their growth rate or even shrank. Similar behavioral and physiological changes are caused by social change in animals kept in stable environmental conditions, although at a lower rate. This suggests that differential growth, in interaction with environmental conditions, is a central mechanism underlying the changes in social status. Such reversible phenotypic plasticity in a crucial life-history trait may have evolved to enable animals to shift resources from reproduction to growth or vice versa, depending on present and future reproductive prospects.

An n-allele model for progressive amplification in the FMR1 locus.

An n-allele model is developed for the FMR1 locus, which causes the fragile X syndrome, where n is the number of triplet repeats in the first exon. Frequencies in the general population and in index families are used to generate an n to n + delta transition matrix that predicts specific risks in satisfactory agreement with observation. However, until sequencing distinguishes between stable and unstable alleles with the same value of n, it is premature to infer whether allelic frequencies at the FMR1 locus are at equilibrium or, as some have suggested, are evolving toward higher frequencies of the pathogenic allele.

ESTUDO DOS EFEITOS DE PROGRAMA DE APOIO NA AGRESSIVIDADE REACIONAL DE POLICIAIS ENVOLVIDOS EM OCORRÊNCIAS GRAVES

O objetivo do presente trabalho é estudar os efeitos de programa de apoio na agressividade reacional de policiais envolvidos em ocorrências graves, considerando-se como tal aquelas em que há confronto armado ou acidentes de trânsito com viaturas em atividade operacional, qualquer que seja o resultado do evento. Esse estudo é composto pela verificação da modificação da resposta agressiva reacional de 77 policiais militares envolvidos em ocorrências graves, utilizando-se, para esse fim, o Psicodiagnóstico Miocinético antes e depois da execução do programa de apoio. Compõem, ainda, o estudo a caracterização sóciodemográfica da amostra e a identificação dos níveis de agressividade nela existentes no início do programa e após o seu encerramento, além da definição do perfil de cinco categorias distintas, em função do tipo de resposta apresentada após o programa: agressividade ampliada, reduzida, inalterada, estável e instável. É ainda objeto da presente pesquisa o estudo clínico de um caso de cada uma das categorias definidas, de acordo com o perfil apurado, utilizando-se, além dos dados do Psicodiagnóstico Miocinético, outros levantados por intermédio de ficha de cadastro, de entrevista individual, do Teste Palográfico e da Escala de Personalidade de Comrey. Os resultados demonstram a modificação da resposta agressiva reacional na maioria dos policiais militares envolvidos no estudo, após o programa de apoio.

Spectra of Ruelle Transfer Operators for Contact Flows

In this survey article we discuss some recent results concerning strong spectral estimates for Ruelle transfer operators for contact flows on basic sets similar to these of Dolgopyat obtained in the case of Anosov flows with C1 stable and unstable foliations. Some applications of Dolgopyat's results and the more recent ones are also described.

O Contrato Psicológico e a Influência do Tipo de Vínculo: empenhamento na carreira e commitment organizacional

As transformações nas relações contratuais e na ligação psicológica do indivíduo à organização motivaram a realização do presente estudo. Os seus objectivos centrais consistiram em, por um lado, analisar a influência do tipo de vínculo na formação do Contrato Psicológico dos indivíduos com a organização e, por outro lado, compreender a relação do Contrato Psicológico com o Empenhamento na Carreira e com o Commitment Organizacional, e o que poderá distinguir estas relações. A metodologia apoiou-se num questionário, aplicado a uma amostra de 102 profissionais com vínculos de trabalho estáveis e instáveis, de diferentes organizações, ramos profissionais e sectores de actividade. A amostra é proporcional e representativa. (a) Os resultados demonstram que os profissionais prestadores de serviço são o único caso em que o tipo de vínculo tem influência significativa sobre a formação do Contrato Psicológico, percepcionando uma ligação transaccional com a organização. (b) Em contrapartida, provam que uma maior ou menor estabilidade contratual não tem influência significativa sobre os Contratos Psicológicos relacional ou equilibrado. (c) Os resultados sugerem ainda que o Contrato Psicológico está mais directamente relacionado com o Empenhamento na Carreira do que com o Commitment Organizacional. O Contrato Psicológico apresenta correlações fortes com o Empenhamento na Carreira e a consequente utilização de comportamentos individuais de Gestão de Carreira, sendo esta mais significativa nas ligações psicológicas de tipo equilibrado e relacional. No que respeita ao Commitment Organizacional, este não apresenta relação significativa com o Contrato Psicológico mas verificamos a existência de focus de Commitment Organizacional. Os resultados comprovam que o Contrato Psicológico se correlaciona com a sua dimensão normativa. As conclusões evidenciam o incremento das relações transaccionais, motivadas pela menor durabilidade dos vínculos e o desenvolvimento de reduzidas expectativas na relação com a organização e para o carácter individual e circunstancial das ligações psicológicas, que já não obedecem a um padrão tipo. Perante cenários de grande instabilidade, independentemente do Contrato Psicológico estabelecido, a preocupação com a Carreira ganha relevância. Os profissionais actuais tendem a transferir a preocupação com o vínculo e a segurança no emprego para questões de carreira, segurança de empregabilidade e sucesso psicológico. Observa-se que a lealdade à organização é na maior parte dos casos transferida para a lealdade à carreira. / Transformations in contractual relationships and in the psychological connection of an individual to an organization have motivated the execution of the present study. The main objectives of this study were, on the one hand, to analyze the influence of the type of contractual bond in the shaping of the psychological contract of individuals with an organization, and, on the other hand, to understand the relationship between the psychological contract, the career commitment and the organizational commitment, to understand subsequently what may distinguish these relationships. The methodology was supported by a questionnaire, which was applied to a sample of 105 professionals with both stable and unstable contractual bonds in different organizations, professional lines of business and activity sectors. The sample is proportional and representative. (a) The results demonstrate that service providing professionals are the only case in which the type of contractual bond has a significant influence on the shaping of a psychological contract, perceived as a transactional connection with the organization. (b) On the other hand a higher or lower contractual stability has no significant influence or relationship with the psychological contract, relational or balanced. (c) The results also suggest that the psychological contract is more directly related to career commitment than to organizational commitment. The psychological contract shows a strong correlation with the career commitment and the consequent use of the individual behaviour of Career Management, with the latter being more significant to a balanced and relational type of psychological connection. In regard to Organizational Commitment, this presents no significant relationship with the psychological contract but the focus on the organizational commitment is verified. The results also show that the psychological contract is correlated with its normative dimension. The increase in transactional relationships are evident. This is driven by reduction of the durability of contractual bonds and the development of reduced expectations in relation to the organization and the individual character and circumstance of the psychological connections, which no longer conform to a standard type. Scenarios of great instability, regardless of the psychological contract established, cause the concern with career to gain relevance. Current professionals tend to transfer their concerns about contractual bonds and job security to career issues, job security and psychological success. It can also be seen that loyalty to the organization is, in most cases, transferred to loyalty to the career.

Abordagem do paciente com Cardiopatia Isquémica em consulta de Medicina Dentária

Nos últimos anos com a evolução dos sistemas de saúde tem-se verificado uma melhoria na qualidade dos serviços médicos prestados, conduzindo a uma esperança média de vida mais longa. Muitas patologias, apesar de patentes, são tratadas e/ou controladas de modo a permitir que a população possa adquirir um estilo de vida normal. As doenças cardiovasculares com o seu carácter multidimensional, têm consequências graves para o cidadão comum, para a sociedade e para o sistema de saúde, o que determina que sejam encaradas como um dos mais importantes problemas de saúde pública, problema este que urge minorar. Dentro das doenças cardiovasculares, a cardiopatia isquémica tem um significado relevante, uma vez que, engloba condições que necessitam de cuidados médicos especiais, em situações de emergência, como o enfarte agudo do miocárdio e a angina de peito (estável e instável). O médico dentista deve estar atento ao doente com cardiopatia isquémica, tendo em conta os cuidados especiais em consultório dentário que o mesmo necessita. A recolha de uma anamnese detalhada e história clínica atualizada, são fundamentais para o sucesso do tratamento dentário. O médico dentista deverá estar habilitado para atuar em situações de emergência e ter o consultório devidamente equipado, de forma a agir em conformidade com estes possíveis eventos.

Balancing the demands of two tasks: an investigation of cognitive-motor dual-tasking in relapsing remitting multiple sclerosis

Background: People with relapsing remitting MS (PwRRMS) suffer disproportionate decrements in gait under dual-task conditions, when walking and a cognitive task are combined. There has been much less investigation of the impact of cognitive demands on balance. This study investigated whether: (1) PwRRMS show disproportionate decrements in postural stability under dual-task conditions compared to healthy controls; (2) dual-task decrements are associated with everyday dual-tasking difficulties. In addition, the impact of mood, fatigue and disease severity on dual-tasking were also examined. Methods: 34 PwRRMS and 34 matched controls completed cognitive (digit span) and balance (movement of centre of pressure on a Biosway, on stable and unstable surfaces) tasks under single and dual-task conditions. Everyday dual-tasking was measured using the DTQ. Mood was measured by the HADS. Fatigue was measured via the MFIS. Results: No differences in age, gender, years of education, estimated pre-morbid IQ or baseline digit span between the groups. Compared to healthy controls, PwRRMS showed a significantly greater decrement in postural stability under dual-task conditions on an unstable surface (p=0.007), but not a stable surface (p=0.679). PwRRMS reported higher levels of everyday dual-tasking difficulties (p<0.001). Balance decrement scores were not correlated with everyday dual-tasking difficulties, or with fatigue. Stable surface balance decrement scores were significantly associated with levels of anxiety (rho=0.527, p=0.001) and depression (rho=0.451, p=0.007). Conclusion: RRMS causes difficulties with dual-tasking, impacting balance, particularly under challenging conditions, which may contribute to an increased risk of gait difficulties and falls. The striking relationship between anxiety/depression and dual-task decrement suggests that worry may be contributing to dual-task difficulties.

The Synthesis of Arbitrary Stable Dynamics in Non-linear Neural Networks II: Feedback and Universality

We wish to construct a realization theory of stable neural networks and use this theory to model the variety of stable dynamics apparent in natural data. Such a theory should have numerous applications to constructing specific artificial neural networks with desired dynamical behavior. The networks used in this theory should have well understood dynamics yet be as diverse as possible to capture natural diversity. In this article, I describe a parameterized family of higher order, gradient-like neural networks which have known arbitrary equilibria with unstable manifolds of known specified dimension. Moreover, any system with hyperbolic dynamics is conjugate to one of these systems in a neighborhood of the equilibrium points. Prior work on how to synthesize attractors using dynamical systems theory, optimization, or direct parametric. fits to known stable systems, is either non-constructive, lacks generality, or has unspecified attracting equilibria. More specifically, We construct a parameterized family of gradient-like neural networks with a simple feedback rule which will generate equilibrium points with a set of unstable manifolds of specified dimension. Strict Lyapunov functions and nested periodic orbits are obtained for these systems and used as a method of synthesis to generate a large family of systems with the same local dynamics. This work is applied to show how one can interpolate finite sets of data, on nested periodic orbits.

Load-Commutated SCR Current-Source-Inverter-Fed Induction Motor Drive With Sinusoidal Motor Voltage and Current

Current source inverter (CSI) is an attractive solution in high-power drives. The conventional gate turn-off thyristor (GTO) based CSI-fed induction motor drives suffer from drawbacks such as low-frequency torque pulsation, harmonic heating, and unstable operation at low-speed ranges. These drawbacks can be overcome by connecting a current-controlled voltage source inverter (VSI) across the motor terminal replacing the bulky ac capacitors. The VSI provides the harmonic currents, which results in sinusoidal motor voltage and current even with the CSI switching at fundamental frequency. This paper proposes a CSI-fed induction motor drive scheme where GTOs are replaced by thyristors in the CSI without any external circuit to assist the turning off of the thyristors. Here, the current-controlled VSI, connected in shunt, is designed to supply the volt ampere reactive requirement of the induction motor, and the CSI is made to operate in leading power factor mode such that the thyristors in the CSI are autosequentially turned off. The resulting drive will be able to feed medium-voltage, high-power induction motors directly. A sensorless vector-controlled CSI drive based on the proposed configuration is developed. The experimental results from a 5 hp prototype are presented. Experimental results show that the proposed drive has stable operation throughout the operating range of speeds.

Development of a stable isotope index to assess decadal-scale vegetation change and application to woodlands of the Burdekin catchment, Australia

Forty-four study sites were established in remnant woodland in the Burdekin River catchment in tropical north-east Queensland, Australia, to assess recent (decadal) vegetation change. The aim of this study was further to evaluate whether wide-scale vegetation 'thickening' (proliferation of woody plants in formerly more open woodlands) had occurred during the last century, coinciding with significant changes in land management. Soil samples from several depth intervals were size separated into different soil organic carbon (SOC) fractions, which differed from one another by chemical composition and turnover times. Tropical (C4) grasses dominate in the Burdekin catchment, and thus δ13C analyses of SOC fractions with different turnover times can be used to assess whether the relative proportion of trees (C3) and grasses (C4) had changed over time. However, a method was required to permit standardized assessment of the δ13C data for the individual sites within the 13 Mha catchment, which varied in soil and vegetation characteristics. Thus, an index was developed using data from three detailed study sites and global literature to standardize individual isotopic data from different soil depths and SOC fractions to reflect only the changed proportion of trees (C3) to grasses (C3) over decadal timescales. When applied to the 44 individual sites distributed throughout the Burdekin catchment, 64% of the sites were shown to have experienced decadal vegetation thickening, while 29% had remained stable and the remaining 7% had thinned. Thus, the development of this index enabled regional scale assessment and comparison of decadal vegetation patterns without having to rely on prior knowledge of vegetation changes or aerial photography.