143 research outputs found
TINU syndrome : two case reports and review of literature
Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2018A inflamação do interstĂcio renal, juntamente com o atingimento da Ășvea, estabelece os dois componentes da sĂndrome de nefrite tubulointersticial e uveĂte (TINU). Embora classicamente descrita como ocorrendo em mulheres jovens, a sĂndrome pode afetar um amplo espectro de doentes. Tanto a doença renal como a ocular podem ser assintomĂĄticas e/ou aparecer com um atraso importante. A doença renal dĂĄ origem a sintomas constitucionais inespecĂficos semelhantes a uma sĂndrome gripal, muitas vezes autolimitados e com bom prognĂłstico. A doença ocular surge principalmente como uma uveĂte anterior bilateral de inĂcio sĂșbito e tem uma tendĂȘncia para um curso crĂłnico, mesmo sob tratamento. Os dados clĂĄssicos indicam que a sĂndrome afeta 2% dos doentes com uveĂte. Atualmente, reconhecem-se as caracterĂsticas clĂnicas complexas da doença, acreditando-se que seja subdiagnosticada. Ă, portanto, imperativo ter uma alta suspeita clĂnica para TINU. Neste trabalho sĂŁo descritos e analisados dois casos clĂnicos da sĂndrome TINU com diferentes manifestaçÔes clĂnicas iniciais e com mais de um ano de acompanhamento.Inflammation of renal interstitium along with uvea involvement sets out the two components of tubulointerstitial nephritis and uveitis (TINU) syndrome. Though classically described as occurring in young females, it can affect a broad spectrum of patients. Both renal and eye disease could be asymptomatic and/or appear with an important delay. Renal disease gives rise to non-specific flu-like symptoms, often self-limited with therapeutic and with good prognosis. Eye-disease emerge mainly as a sudden-onset bilateral anterior uveitis and has a tendency for a chronic course, even under treatment. The syndrome was firstly thought to affect 2% of uveitis patients. Today, the challenging clinical features and the limited recognition are enlightened, and it is believed to be an underdiagnosed illness. It is thus imperative to have a high clinical suspicion for TINU. We describe and analyze two clinical cases of TINU syndrome with different initial clinical manifestations and over one-year of follow-up
PACE: Simple Multi-hop Scheduling for Single-radio 802.11-based Stub Wireless Mesh Networks
IEEE 802.11-based Stub Wireless Mesh Networks (WMNs) are a cost-effective and flexible solution to extend wired network infrastructures. Yet, they suffer from two major problems: inefficiency and unfairness. A number of approaches have been proposed to tackle these problems, but they are too restrictive, highly complex, or require time synchronization and modifications to the IEEE 802.11 MAC.
PACE is a simple multi-hop scheduling mechanism for Stub WMNs overlaid on the IEEE 802.11 MAC that jointly addresses the inefficiency and unfairness problems. It limits transmissions to a single mesh node at each time and ensures that each node has the opportunity to transmit a packet in each network-wide transmission round. Simulation results demonstrate that PACE can achieve optimal network capacity utilization and greatly outperforms state of the art CSMA/CA-based solutions as far as goodput, delay, and fairness are concerned
A peer-to-peer service architecture for the Smart Grid
Short paperThe Smart Grid vision needs to address hard challenges such as interoperability, reliability and scalability before it can become fulfilled. The need to provide full interoperability between current and future energy and non-energy systems and its disparate technologies along with the problem of seamless discovery, configuration, and communication of a large variety of networked devices ranging from the resource constrained sensing devices to the large machines inside a data center requires an agnostic Service Oriented Architecture. Moreover, the sheer scale of the Smart Grid and the criticality of the communication among its subsystems for proper management, demands a scalable and reliable communication framework able to work in an heterogeneous and dynamic environment. In this position paper, we propose a generic framework, based on Web Services for interoperability, and epidemic or gossip based communication protocols for reliability and scalability, that can serve a general management substrate where several Smart Grid problems can be solved. We illustrate the flexibility of the proposed framework by showing how it can be used in two specific scenarios.Important challenges in interoperability, reliability, and scalability need to be addressed before the Smart Grid vision can be fulfilled. The sheer scale of the electric grid and the criticality of the communication among its subsystems for proper management, demands a scalable and reliable communication framework able to work in an heterogeneous and dynamic environment. Moreover, the need to provide full interoperability between diverse current and future energy and non-energy systems, along with seamless discovery and configuration of a large variety of networked devices, ranging from the resource constrained sensing devices to servers in data centers, requires an implementation-agnostic Service Oriented Architecture. In this position paper we propose that this challenge can be addressed with a generic framework that reconciles the reliability and scalability of Peer-to-Peer systems, with the industrial standard interoperability of Web Services. We illustrate the flexibility of the proposed framework by showing how it can be used in two specific scenarios
AnĂ lisis simplificat de la mecĂ nica dâimpacte de blocs i de la seva influĂšncia en la fragmentaciĂł
Els despreniments rocosos sĂłn un gran problema per les infraestructures, els bĂ©ns i la prĂČpia vida de les persones. Aquest fenomen ha sigut estudiat en gran mesura, perĂČ les seves particularitats el fan ser una de les inestabilitats de masses mĂ©s difĂcils de preveure. Sâha arribat a crear diversitat de models per trobar les trajectĂČries i lâabast dâun despreniment, perĂČ no Ă©s habitual que en aquests models es tingui present la fragmentaciĂł que molt sovint pateixen els blocs despresos a lâimpactar amb el terreny.
En el marc del projecte de recerca RockModels, sâha dut a terme un assaig de llançament de maons al laboratori per analitzar el procĂ©s de fragmentaciĂł. Dâaquest assaig es coneixien totes les propietats dels maons, el grau de fragmentaciĂł i es van enregistrar vĂdeos a alta velocitat dels impactes.
En aquest treball, en primer lloc, sâha fet un anĂ lisi qualitatiu dels vĂdeos enregistrats, on sâha pogut observar les morfologies dâimpacte (de cara, de vĂšrtex o dâaresta). En segon lloc, sâha fet un anĂ lisi quantitatiu dels impactes per determinar lâenergia cinĂštica, lâĂ rea dâimpacte, la força normal i la pressiĂł generades de cada impacte amb models analĂtics basats en condicions elĂ stiques. Finalment, sâha comparat la força dâimpacte amb el grau de fragmentaciĂł i sâha analitzat la influĂšncia de la morfologia dâimpacte a la fragmentaciĂł.
Els resultats obtinguts de lâanĂ lisi dels vĂdeos ens mostren la importĂ ncia que tĂ© la morfologia de lâimpacte en la fragmentaciĂł. Sâobserva com els llançaments on lâimpacte es produeix amb una aresta del maĂł, acostumen a fragmentar en el primer impacte, en canvi aquells maons on lâimpacte es produeix amb el vĂšrtex, acostumen a no patir fragmentaciĂł en primera instĂ ncia.
Els resultats obtinguts del cĂ lcul numĂšric mostren que als impactes amb una Ă rea dâimpacte major, la força normal generada tambĂ© Ă©s major. A contrapartida, quan lâĂ rea dâimpacte era mĂ©s petita, la pressiĂł i la indentaciĂł eren mĂ©s grans.
De la influĂšncia en la fragmentaciĂł, els resultats mostren que aquesta es donarĂ amb mĂ©s freqĂŒĂšncia com mĂ©s gran sigui lâangle dâimpacte del centre de masses. En quant a la relaciĂł entre les forces i les pressions generades amb la fragmentaciĂł, no sâha obtingut els resultats esperats, doncs no sâha pogut analitzar de forma complerta els segons impactes, tal com sâha fet amb els primers, considerant totes les variables que intervenen i varien respecte el primer impacte
A Função Consumo em Portugal: Uma Abordagem Macroeconométrica
Este artigo propĂ”e uma função consumo agregado para o contexto portuguĂȘs. Perante a existĂȘncia de cointegração entre as variĂĄveis em estudo, foi estimado um modelo uni-equacional para tentar modelar o comportamento da função consumo agregado. Foi possĂvel concluir pela existĂȘncia de uma relação positiva entre o consumo e o rendimento disponĂvel (elasticidade unitĂĄria) e uma relação negativa entre o consumo e a taxa de juro real e a taxa de inflação.N/
An Empirical Analysis of Dynamic Multiscale Hedging using Wavelet Decomposition
This paper investigates the hedging effectiveness of a dynamic moving window
OLS hedging model, formed using wavelet decomposed time-series. The wavelet
transform is applied to calculate the appropriate dynamic minimum-variance
hedge ratio for various hedging horizons for a number of assets. The
effectiveness of the dynamic multiscale hedging strategy is then tested, both
in- and out-of-sample, using standard variance reduction and expanded to
include a downside risk metric, the time horizon dependent Value-at-Risk.
Measured using variance reduction, the effectiveness converges to one at longer
scales, while a measure of VaR reduction indicates a portion of residual risk
remains at all scales. Analysis of the hedge portfolio distributions indicate
that this unhedged tail risk is related to excess portfolio kurtosis found at
all scales.Comment: To Appear: Journal of Futures Market
AplicaciĂłn del SGSST para disminuir los accidentes laborales en la empresa Spartan Chemical PerĂș SAC, Callao 2021
La presente investigación se planteó como objetivo general determinar en qué
medida la aplicaciĂłn del Sistema de GestiĂłn de la Seguridad y Salud en el Trabajo
disminuirĂĄ los accidentes laborales en la empresa Spartan Chemical PerĂș SAC,
Callao 2021. El estudio se realizĂł en el ĂĄrea de producciĂłn en donde se observĂł la
ocurrencia de accidentes laborales, por lo cual en base al diagrama de Ishikawa y
Pareto se identificĂł que los accidentes sucedĂan prioritariamente debido al
incumplimiento de reglamentos de seguridad (14,58%). Respecto a la metodologĂa
la investigaciĂłn fue de enfoque cuantitativo, de tipo aplicada y de nivel
preexperimental. La muestra de estudio estuvo conformada por 24 trabajadores del
ĂĄrea de producciĂłn en el periodo enero-abril del 2021. En tal sentido, como
resultado de la investigaciĂłn se concluye que los accidentes laborales disminuyeron
en 66,67%. AsĂ pues, mediante la prueba Z Wilcoxon se tuvo una significancia de
0,034 por lo cual al ser menor que 0,05 existiĂł evidencia significativa para afirmar
que la aplicaciĂłn del SGSST disminuyĂł los accidentes laborales en la empresa
Spartan Chemical PerĂș SAC. Siendo asĂ, para futuras investigaciones se
recomienda realizar un programa de auditorĂas externas para mantener vigente la
supervisiĂłn del cumplimiento del SGSST
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