A microscope for the data center

Nowadays, data centers are large energy consumers and the trend for next years is expected to increase further, considering the growth in the order of cloud services. A large portion of this power consumption is due to the control of physical parameters of the data center (such as temperature and humidity). However, these physical parameters are tightly coupled with computations, and even more so in upcoming data centers, where the location of workloads can vary substantially due, for example, to workloads being moved in the cloud infrastructure hosted in the data center. Therefore, managing the physical and compute infrastructure of a large data center is an embodiment of a Cyber-Physical System (CPS). In this paper, we describe a data collection and distribution architecture that enables gathering physical parameters of a large data center at a very high temporal and spatial resolution of the sensor measurements. We think this is an important characteristic to enable more accurate heat-flow models of the data center and with them, find opportunities to optimize energy consumptions. Having a high-resolution picture of the data center conditions, also enables minimizing local hot-spots, perform more accurate predictive maintenance (failures in all infrastructure equipments can be more promptly detected) and more accurate billing. We detail this architecture and define the structure of the underlying messaging system that is used to collect and distribute the data. Finally, we show the results of a preliminary study of a typical data center radio environment.

In Vitro Methods for Specific IgE Detection on Cow’s Milk Allergy

Background: A new method for determining serum specific IgE (IMMULITE“ 2000 3gAllergy) has recently become available. Objective: To evaluate the clinical performance of IMMULITE 2000 in the diagnosis of cow’s milk allergy compared with that of UniCAP“. Additionally, we verified the behavior of both methods at two diagnostic decision points proposed by other authors. Methods: The study population consisted of 31 children with cow’s milk allergy (group A) and a control group of 19 atopic children without food allergy(group B). A blood sample from each child was tested using both methods and the results were compared. Results: In group A, the values for cow’s milk IgE ranged from 0.35 kU/L (the lowest common detection limit) to above 100 kU/L. In group B, the values were less than 1.1 kU/L for IMMULITE 2000 and less than 1.6 kU/L for UniCAP. An agreement of 90 % in IgE classes was obtained. Both methods demonstrated exactly the same diagnostic performance(sensitivity: 100 %; specificity: 78.9 %; negative predictive value: 100%; positive predictive value: 84.6%;efficiency: 90.2 %). The evaluation of the two methods at the two different decision points proposed in the literature showed a better positive predictive value with UniCAP, but we obtained equivalent performance with IMMULITE 2000 by choosing higher cutoff values. Conclusions: We conclude that IMMULITE 2000 is as effective as UniCAP in the diagnosis of cow’s milk allergy. Both methods can be used to obtain site-specific decision points that are population, age and disease dependent.

Variáveis Ecocardiográficas Predizentes de Terapêuticas Apropriadas de Taquidisritmias Ventriculares em Doentes Submetidos a Terapêutica de Ressincronização Cardíaca Combinada

INTRODUCTION: The significant risk of sudden arrhythmic death in patients with congestive heart failure and electromechanical ventricular dyssynchrony has led to increased use of combined cardiac resynchronization therapy defibrillator (CRT-D) devices. OBJECTIVES: To evaluate the echocardiographic variables in patients undergoing CRT-D that predict the occurrence of appropriate therapies (AT) for ventricular tachyarrhythmia. METHODS: We analyzed 38 consecutive patients (mean age 60 +/- 12 years, 63% male) with echocardiographic evaluation before and 6 months after CRT-D implantation. Patients with AT were identified in a mean follow-up of 471 +/- 323 days. A standard echocardiographic study was performed including tissue Doppler imaging (TDI). Responders were defined as patients with improvement in NYHA class of < or = 1 in the first six months, and reverse remodeling as a decrease in left ventricular end-systolic volume of < or = 15% and/or an increase in left ventricular ejection fraction of > 25%. RESULTS: The responder rate was 74%, and the reverse remodeling rate was 55%. AT occurred in 21% of patients, who presented with greater left ventricular end-diastolic internal diameter (LVEDD) before implantation (86 +/- 8 vs. 76 +/- 11 mm, p = 0.03) and at 6 months (81 +/- 8 vs. 72 +/- 14 mm, p = 0.08), and increased left ventricular end-systolic internal diameter (66 +/- 14 vs. 56 +/- 14 mm, p = 0.03) and lower ejection fraction (24 +/- 6 vs. 34 +/- 14%, p = 0.08) at 6 months. In the group with AT, the responder rate was lower (38 vs. 83%, p = 0.03), without significant differences in reverse remodeling (38% for the AT group vs. 60%, p = 0.426) or in the other variables. By univariate analysis, predictors of AT were LVEDD before implantation and E' after implantation. Age, gender, ischemic etiology, use of antiarrhythmic drugs, reverse remodeling and the other echocardiographic parameters did not predict AT. In multivariate logistic regression analysis, both LVEDD before implantation (OR 1.24, 95% CI 1.04-1.48, p = 0.019) and postimplantation E' (OR 0.27, 95% CI 0.09-0.76, p = 0.014) remained as independent predictors of AT. CONCLUSIONS: In patients undergoing CRT-D, episodes of ventricular tachyarrhythmia occur with high incidence, independently of echocardiographic response, with LVEDD before implantation and E' after implantation as the only independent predictors of AT in the medium-term. These results highlight the importance of combined devices with defibrillation capability.

Valor Prognóstico da Normalização da Resposta Ventilatória ao Exercício para o Consumo Máximo de Oxigénio na Insuficiência Cardíaca

Cardiopulmonary exercise testing (CPET) is an objective method for assessment of functional capacity and for prognostic stratification of patients with chronic heart failure (CHF). In this study, we analyzed the prognostic value of a recently described CPET-derived parameter, the minute ventilation to carbon dioxide production slope normalized for peak oxygen consumption (VE/VCO2 slope/pVO2). METHODS: We prospectively studied 157 patients with stable CHF and dilated cardiomyopathy who performed maximal CPET using the modified Bruce protocol. The prognostic value of VE/VCO2 slope/pVO2 was determined and compared with traditional CPET parameters. RESULTS: During follow-up 37 patients died and 12 were transplanted. Mean follow-up in surviving patients was 29.7 months (12-36). Cox multivariate analysis revealed that VE/VCO2 slope/pVO2 had the greatest prognostic power of all the parameters studied. A VE/VCO2 slope/pVO2 of > or = 2.2 signaled cases at higher risk. CONCLUSION: Normalization of the ventilatory response to exercise for peak oxygen consumption appears to increase the prognostic value of CPET in patients with CHF.

Predictive Variables Affecting Transfusion Requirements in Orthotopic Liver Transplantation

INTRODUCTION AND AIMS: Adult orthotopic liver transplantation (OLT) is associated with considerable blood product requirements. The aim of this study was to assess the ability of preoperative information to predict intraoperative red blood cell (RBC) transfusion requirements among adult liver recipients. METHODS: Preoperative variables with previously demonstrated relationships to intraoperative RBC transfusion were identified from the literature: sex, age, pathology, prothrombin time (PT), factor V, hemoglobin (Hb), and platelet count (plt). These variables were then retrospectively collected from 758 consecutive adult patients undergoing OLT from 1997 to 2007. Relationships between these variables and intraoperative blood transfusion requirements were examined by both univariate analysis and multiple linear regression analysis. RESULTS: Univariate analysis confirmed significant associations between RBC transfusion and PT, factor V, Hb, Plt, pathology, and age (P values all < .001). However, stepwise backward multivariate analysis excluded variables Plt and factor V from the multiple regression linear model. The variables included in the final predictive model were PT, Hb, age, and pathology. Patients suffering from liver carcinoma required more blood products than those suffering from other pathologies. Yet, the overall predictive power of the final model was limited (R(2) = .308; adjusted R(2) = .30). CONCLUSION: Preoperative variables have limited predictive power for intraoperative RBC transfusion requirements even when significant statistical associations exist, identifying only a small portion of the observed total transfusion variability. Preoperative PT, Hb, age, and liver pathology seem to be the most significant predictive factors but other factors like severity of liver disease, surgical technique, medical experience in liver transplantation, and other noncontrollable human variables may play important roles to determine the final transfusion requirements.

Predictive factors of mortality in burn patients

Burn mortality statistics may be misleading unless they account properly for the many factors that can influence outcome. Such estimates are useful for patients and others making medical and financial decisions concerning their care. This study aimed to define the clinical, microbiological and laboratorial predictors of mortality with a view to focus on better burn care. Data were collected using independent variables, which were analyzed sequentially and cumulatively, employing univariate statistics and a pooled, cross-sectional, multivariate logistic regression to establish which variables better predict the probability of mortality. Survivors and non-survivors among burn patients were compared to define the predictive factors of mortality. Mortality rate was 5.0%. Higher age, larger burn area, presence of fungi in the wound, shorter length of stay and the presence of multi-resistant bacteria in the wound significantly predicted increased mortality. The authors conclude that those patients who are most apt to die are those with age > 50 years, with limited skin donor sites and those with multi-resistant bacteria and fungi in the wound.

Chronic hepatitis C: hepatic iron content does not correlate with response to antiviral therapy

The complex interaction between hepatitis C virus infection, iron homeostasis and the response to antiviral treatment remains controversial. The aim of this study was to evaluate the influence of hepatic iron concentration (HIC) on the sustained virological response (SVR) to antiviral therapy in patients with chronic hepatitis C. A total of 50 patients who underwent pretreatment liver biopsy with assessment of HIC by graphite furnace atomic absorption spectroscopy and were subsequently submitted to antiviral treatment with interferon/peginterferon and ribavirin were included in the study. Patients with alcoholism, history of multiple blood transfusion, chronic kidney disease, hemolytic anemia and parenteral iron therapy were excluded. The iron related markers and HIC were compared between those who achieved an SVR and non-responders (NR) patients. The mean age was 45.7 years and the proportion of patients' gender was not different between SVR and NR patients. The median serum iron was 138 and 134 µg/dL (p = 0.9), the median serum ferritin was 152.5 and 179.5 ng/mL (p = 0.87) and the median HIC was 9.9 and 8.2 µmol/g dry tissue (p = 0.51), for SVR and NR patients, respectively. Thus, hepatic iron concentration, determined by a reliable quantitative method, was not a negative predictive factor of SVR in patients with chronic hepatitis C presenting mild to moderate hepatic iron accumulation.

High diagnostic efficiency of IgM-ELISA with the use of multiple antigen peptides (MAP1) from T. gondii ESA (SAG-1, GRA-1 and GRA-7), in acute toxoplasmosis

The main serological marker for the diagnosis of recent toxoplasmosis is the specific IgM antibody, along with IgG antibodies of low avidity. However, in some patients these antibodies may persist long after the acute/recent phase, contributing to misdiagnosis in suspected cases of toxoplasmosis. In the present study, the diagnostic efficiency of ELISA was evaluated, with the use of peptides derived from T. gondii ESA antigens, named SAG-1, GRA-1 and GRA-7. In the assay referred to, we studied each of these peptides individually, as well as in four different combinations, as Multiple Antigen Peptides (MAP), aiming to establish a reliable profile for the acute/recent toxoplasmosis with only one patient serum sample. The diagnostic performance of the assay using MAP1, with the combination of SAG-1, GRA-1 and GRA-7 peptides, demonstrated better discrimination of the acute/recent phase from non acute/recent phase of toxoplasmosis. Our results show that IgM antibodies to MAP1 may be useful as a serological marker, enhancing the diagnostic efficiency of the assay for acute/recent phase of toxoplasmosis.

Efficiency of strengthening techniques assessed for existing masonry buildings

The Azores archipelago is a zone with a vast cultural heritage, presenting a building stock mainly constructed in traditional stone masonry. It is known that this type of construction exhibits poor behaviour under seismic excitations; however it is extensively used in seismic prone areas, such as this case. The 9th of July of 1998 earthquake was the last seismic event in the islands, leaving many traditional stone constructions severely damaged or totally destroyed. This scenario led to an effort by the local government of improving the seismic resistance of these constructions, with the application of several reinforcement techniques. This work aims to study some of the most used reinforcement schemes after the 1998 earthquake, and to assess their effectiveness in the mitigation of the construction’s seismic vulnerability. A brief evaluation of the cost versus benefit of these retrofitting techniques is also made, seeking to identify those that are most suitable for each building typology. Thus, it was sought to analyze the case of real structures with different geometrical and physical characteristics, by establishing a comparison between the seismic performance of reinforced and non-reinforced structures. The first section contains the analysis of a total of six reinforcement scenarios for each building chosen. Using the recorded 1998 earthquake accelerograms, a linear time-history analysis was performed for each reinforcement scenario. A comparison was then established between the maximum displacements, inter-storey drift and maximum stress obtained, in order to evaluate the global seismic response of each reinforced structure. In the second part of the work, the examination of the performance obtained in the previous section, in relation to the cost of implementing each reinforcement technique, allowed to draw conclusions concerning the viability of implementing each reinforcement method, based on the book value of the buildings in study.

Escleroterapia do Varicocelo da Veia Ovárica: Resultados a Curto e Longo Prazo

Purpose: To evaluate the safety and efficiency of sclerotherapy in ovarian vein varicocele. Study population: During 6 years, 36 women with the clinical diagnosis of ovarian vein varicocele were evaluated. Methods: The diagnosis was confirmed by flebography of the ovarian vein in 35 of the patients. In these patients sclerotherapy of the ovarian vein was performed with success by selective retrograde catheterization of the ovarian vein by femoral approach in 31 patients and by brachial approach in 4 patients. Four to eight ml of polidocanol l3% was used in each vein. Results: There was clinical improvement with complete resolution of all symptoms in 29 patients(82.9%) and partial symptomatic relief in 6 (17.1%). Long term results, evaluated between 1 and 6 years (mean 37.3 months), showed complete resolution of symptoms in 27 (77.1%) and recurrence in 8 (22.9%). Four patients with recurrence, improved following repeated sclerotherapy. Thus, there was long term improvement in 31 patients (88.6%). Conclusion: Sclerotherapy of ovarian vein appears to be a safe and efficient treatment of ovarian vein varicocele.

Can red cell distribution width be used as a marker of Crohn's disease activity?

Introduction: Recently, it has been suggested an association between red cell distribution width (RDW) and Crohn’s disease activity index (CDAI), but its use is not yet performed in daily clinical practice. Objectives: To determine whether RDW can be used as a marker of Crohn’s disease (CD) activity. Methods: This was a cross-sectional study including patients with CD, observed consecutively in an outpatient setting between January 1st and September 30th 2013. Blood cell indices, erythrocyte sedimentation rate (ESR), and C-reactive protein were measured. CD activity was determined by CDAI (active disease if CDAI ≥ 150). Associations were analyzed using logistic regression (SPSS version 20). Results: 119 patients (56% female) were included in the study with a mean age of 47 years (SD 15.2). Twenty patients (17%) had active disease. The median RDW was 14.0 (13---15). There was an association between RDW and disease activity (p = 0.044). After adjustment for age and gender, this association remained consistent (OR 1.20, 95% CI 1.03---1.39, p = 0.016). It was also found that the association between RDW and disease activity was independent of hemoglobin and ESR (OR 1.36, 95% CI 1.08---1.72, p = 0.01) and of biologic therapy (OR 1.19, 95% CI 1.03---1.37, p = 0.017). A RDW cutoff of 16% had a specificity and negative predictive value for CDAI ≥ 150 of 88% and 86%, respectively. Conclusion: In this study, RDW proved to be an independent and relatively specific marker of CD activity. These results may contribute to the implementation of this simple parameter, in clinical practice, aiming to help therapeutic decisions.

Algorithms for information extraction and signal annotation on long-term biosignals using clustering techniques

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Estratégias de Comercialização de Potência como Medida de Eficiência Energética

A presente dissertação insere-se no âmbito da unidade curricular “ Dissertação” do 2º ano do mestrado em Engenharia Eletrotécnica – Sistemas Elétricos de Energia. Com o aumento crescente do número de consumidores de energia, é cada vez mais imperioso a adoção de medidas de racionalização e gestão dos consumos da energia elétrica. Existem diferentes tipos de dificuldades no planeamento e implementação de novas centrais produtoras de energia renovável, pelo que também por este motivo é cada vez mais importante adoção de medidas de gestão de consumos, quer ao nível dos clientes alimentados em média tensão como de baixa tensão. Desta forma será mais acessível a criação de padrões de eficiência energética elevados em toda a rede de distribuição de energia elétrica. Também a economia é afetada por uma fraca gestão dos consumos por parte dos clientes. Elevados desperdícios energéticos levam a que mais energia tenha que ser produzida, energia essa que contribui ainda mais para a elevada taxa de dependência energética em Portugal, e para o degradar da economia nacional. Coloca-se assim a necessidade de implementar planos e métodos que promovam a eficiência energética e a gestão racional de consumos de energia elétrica. Apresenta-se nesta dissertação várias propostas, algumas na forma de projetos já em execução, que visam sensibilizar o consumidor para a importância da utilização eficiente de energia e, ao mesmo tempo, disponibilizam as ferramentas tecnológicas adequadas para auxiliar a implementação dos métodos propostos. Embora os planos apresentados, sobejamente conhecidos, tenham imensa importância, a implementação nos vários consumidores de sistemas capazes de efetivamente reduzir consumos tem um papel fundamental. Equipamentos de gestão de consumos, que são apresentados nesta dissertação, permitem ao consumidor aceder diretamente ao seu consumo. Podem aceder não apenas ao consumo global da instalação mas também ao consumo específico por equipamento, permitindo perceber onde se verifica a situação mais desfavorável. Funcionalidades de programação de perfis tipo, com limitações de potência em vários períodos horários, bem como possibilidades de controlo remoto com recurso a aplicações para Smartphones permitem a redução de consumos ao nível da rede de distribuição e, desta forma, contribuir para a redução dos desperdícios e da dependência energética em Portugal. No âmbito do trabalho de dissertação é desenvolvida uma metodologia de comercialização de potência, que é apresentada nesta tese. Esta metodologia propõem que o consumidor, em função dos seus consumos, pague apenas a quantidade de potência que efetivamente necessita num certo período de tempo. Assim, o consumidor deixa de pagar uma tarifa mensal fixa associada á sua potência contratada, e passará a pagar um valor correspondente apenas à potência que efetivamente solicitou em todas as horas durante o mês. Nesta metodologia que é apresentada, o consumidor poderá também fazer uma análise do seu diagrama de cargas e simular uma alteração da sua tarifa, tarifa esta que varia entre tarifa simples, bi-horária semanal, bi-horária diária, tri-horária semanal ou tri-horária diária, de forma a perceber em qual destas pagará um menor valor pela mesma energia. De forma a que o consumidor possa perceber se haverá vantagem de uma alteração para uma potência contratada flexível, ou para uma outra tarifa associada á energia, tem ao seu dispor uma ferramenta, que em função dos seus consumos, permite retirar conclusões sobre o preço final a pagar na fatura, após cada tipo de alteração. Esta ferramenta foi validada com recurso a várias simulações, para diferentes perfis de consumidores. Desta forma, o utilizador fica a perceber que realmente pode poupar com uma potência contratada flexível, ao mesmo tempo que pode identificar-se com um perfil de simulação e, mais facilmente, perceber para que alteração tarifária pode usufruir de uma maior poupança.

Providing energy efficiency location-based strategies for buildings using linked open data

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

A Prospective Assessment of Renal Transplantation Versus Haemodialysis: Which Therapeutic Modality Is Good Value for Society?

Background: Economic evaluations help health authorities facing budget constraints. This study compares the health-related quality of life (HRQOL) and costs in patient subgroups on haemodialysis (HD) and renal transplantation (KT). Methods: In a prospective study with follow-up of 1-3 years, we performed a costutility analysis of KT vs. HD, adopting a lifetime horizon. A societal perspective was taken. Costs for organ procurement, KT eligibility, transplant surgery and follow-up of living donors were included. Key clinical events were recorded. HRQOL was assessed using the EuroQol instrument. Results: The HRQOL remained stable on HD patients. After KT, mean utility score improved at 3 months while mean EQ-VAS scores showed a sustained improvement. Mean annual cost for HD was 32,567.57€. Mean annual costs for KT in the year-1 and in subsequent years were, 60,210.09€ and 12,956.77€ respectively. Cost for initial hospitalization averaged 18,740.74€. HLA-mismatches increased costs by 75% for initial hospitalization (p < 0.001) and 41% in the year-1 (p < 0.05), and duplicate the risk of readmission in the year-1 (p < 0.05). The incremental costutility ratio was 5,534.46€/QALY, increasing 35% when costs for organ procurement were added. KT costs were 41,541.63€ more but provided additional 7.51 QALY. Conclusions: The KT is cost-effective compared with HD. Public funding should reflect the value created by the intervention and adapt to the organ demand.