Proactive software rejuvenation solution for web enviroments on virtualized platforms

The availability of the Information Technologies for everything, from everywhere, at all times is a growing requirement. We use information Technologies from common and social tasks to critical tasks like managing nuclear power plants or even the International Space Station (ISS). However, the availability of IT infrastructures is still a huge challenge nowadays. In a quick look around news, we can find reports of corporate outage, affecting millions of users and impacting on the revenue and image of the companies. It is well known that, currently, computer system outages are more often due to software faults, than hardware faults. Several studies have reported that one of the causes of unplanned software outages is the software aging phenomenon. This term refers to the accumulation of errors, usually causing resource contention, during long running application executions, like web applications, which normally cause applications/systems to hang or crash. Gradual performance degradation could also accompany software aging phenomena. The software aging phenomena are often related to memory bloating/ leaks, unterminated threads, data corruption, unreleased file-locks or overruns. We can find several examples of software aging in the industry. The work presented in this thesis aims to offer a proactive and predictive software rejuvenation solution for Internet Services against software aging caused by resource exhaustion. To this end, we first present a threshold based proactive rejuvenation to avoid the consequences of software aging. This first approach has some limitations, but the most important of them it is the need to know a priori the resource or resources involved in the crash and the critical condition values. Moreover, we need some expertise to fix the threshold value to trigger the rejuvenation action. Due to these limitations, we have evaluated the use of Machine Learning to overcome the weaknesses of our first approach to obtain a proactive and predictive solution. Finally, the current and increasing tendency to use virtualization technologies to improve the resource utilization has made traditional data centers turn into virtualized data centers or platforms. We have used a Mathematical Programming approach to virtual machine allocation and migration to optimize the resources, accepting as many services as possible on the platform while at the same time, guaranteeing the availability (via our software rejuvenation proposal) of the services deployed against the software aging phenomena. The thesis is supported by an exhaustive experimental evaluation that proves the effectiveness and feasibility of our proposals for current systems

Migration Patterns in Male Great Bustards (Otis tarda)

5 paginas, 1 figura y 1 tableThe Great Bustard (Otis tarda) is distributed from Iberia and Morocco in the west to China in the east and has been considered sedentary in all but the northern and eastern parts of its range (Gewalt 1959, Glutz et al. 1973, Cramp and Simmons 1980). However, some studies have reported seasonal changes in population numbers in different areas in the Iberian Peninsula (Hidalgo and Carranza 1990, Alonso et al. 1995), suggesting that the species is a partial migrant (sensu Terrill and Able 1988) in this region. We describe seasonal movements of marked adult male Great Bustards and discuss observed patterns in relation to the following questions: (1) Do migratory males display interannual fidelity to breeding and postbreeding areas? (2) Do males travel significantly farther than females in their seasonal movements? We also suggest several hypotheses that could explain patterns of partial and differential migration in male Great Bustards.This study is a contribution to DGICYT-project PB94–0068.Peer reviewe

Evaluation of captive breeding as a method to conserve threatened Great Bustard populations.

6 paginas y 1 tableThe recent Great Bustard Action Plan summarizes de main recommended lines of action to preserve current populations and their habitats in Europe. Among others, captive breeding is mentioned as a method to save clutches found in the field whose hatching success probability is suspected to be low for any reason. Birds hatched from these clutches have been used to either build up small captive-breeding flocks that ensure preservation of the genetic pool of seriously threatened populations once these may be extinct, or to be released into the natural populations as juveniles. In this paper we evaluate the viability of captive breeding in the light of new results of a recent study of juvenile Great Bustards during their maternal dependence period, family break-up and dispersal. The few data available on survival of captive-bred young after being released suggest that they suffer a high mortality, probably due to the lack of the experience acquired in natural conditions from their mothers. The negative effects of imprinting by their human keepers, particularly in relation with display and mating, has not been sufficiently investigated. These and other aspects make captive breeding questionable as an effective method, as compared with habitat protection measures.PB94-0068 of the Dirección General de Investigacion Cientifica y TecnicaPeer reviewe

Long-Term Analysis of Aerosol Concentrations Using a Low-Cost Sensor: Monitoring African Dust Outbreaks in a Suburban Environment in the Canary Islands

This study presents the results of the long-term monitoring of PM10 and PM2.5 concentrations using a low-cost particle sensor installed in a suburban environment in the Canary Islands. A laser-scattering Nova Fitness SDS011 sensor was operated continuously for approximately three and a half years, which is longer than most other studies using this type of sensor. The impact of African dust outbreaks on the aerosol concentrations was assessed, showing a significant increase in both PM10 and PM2.5 concentrations during the outbreaks. Additionally, a good correlation was found with a nearby reference instrument of the air quality network of the Canary Islands’ government. The correlation between the PM10 and PM2.5 concentrations, the effect of relative humidity, and the stability of the sensor were also investigated. This study highlights the potential of this kind of sensor for long-term air quality monitoring with a view to developing extensive and dense low-cost air quality networks that are complementary to official air quality networks

Migration Patterns in Male Great Bustards (Otis tarda)

5 paginas, 1 figura y 1 tableThe Great Bustard (Otis tarda) is distributed from Iberia and Morocco in the west to China in the east and has been considered sedentary in all but the northern and eastern parts of its range (Gewalt 1959, Glutz et al. 1973, Cramp and Simmons 1980). However, some studies have reported seasonal changes in population numbers in different areas in the Iberian Peninsula (Hidalgo and Carranza 1990, Alonso et al. 1995), suggesting that the species is a partial migrant (sensu Terrill and Able 1988) in this region. We describe seasonal movements of marked adult male Great Bustards and discuss observed patterns in relation to the following questions: (1) Do migratory males display interannual fidelity to breeding and postbreeding areas? (2) Do males travel significantly farther than females in their seasonal movements? We also suggest several hypotheses that could explain patterns of partial and differential migration in male Great Bustards.This study is a contribution to DGICYT-project PB94–0068.Peer reviewe

Supporting End-User Development through a New Composition Model: An Empirical Study

End-user development (EUD) is much hyped, and its impact has outstripped even the most optimistic forecasts. Even so, the vision of end users programming their own solutions has not yet materialized. This will continue to be so unless we in both industry and the research community set ourselves the ambitious challenge of devising end to end an end-user application development model for developing a new age of EUD tools. We have embarked on this venture, and this paper presents the main insights and outcomes of our research and development efforts as part of a number of successful EU research projects. Our proposal not only aims to reshape software engineering to meet the needs of EUD but also to refashion its components as solution building blocks instead of programs and software developments. This way, end users will really be empowered to build solutions based on artefacts akin to their expertise and understanding of ideal solution

Cloud Cover Forecasting from METEOSAT Data

AbstractSolar thermoelectric energy has a great potential as an energy supplier in many countries around the world. Since clouds are the main cause to solar radiation blocking, short term cloud forecasting can help power plant operation and therefore improve benefits. Therefore, cloud detection, classification and motion vector determination are key to forecast sun obstruction by clouds. Geostationary satellites provide cloud information covering wide areas, allowing cloud forecast to be performed for several hours in advance. Herein, the methodology developed and tested in this study is based on multispectral tests and binary cross correlations followed by coherence and quality control tests over resulting motion vectors. The following methodology utilizes Meteosat Second Generation imagery. In addition, pyrheliometric data and a whole-sky camera have also been used to test the methodology results. Cloud classification in terms of opacity and height of cloud top is also performed. Results show an agreement above 90% between satellite detected and observed cloud cover for cloudless and overcast situations and over 75% for partially cloudy skies, whereas around the 86% of the motion vectors are well determined. This work represents the starting point for addressing the prediction of solar radiation to short time using satellite imagery

Review and Proposal of Alternative Technologies for Comprehensive and Reliable Newborn Screening Using Paper Borne Urine Samples for Lysosomal Storage Disorders: Glycosphingolipid Disorders

Few current methods are efficient to detect a high number of lysosomal storage disorders (LSDs) in newborn screening. Therefore, we propose a stepwise procedure that starts with the use of paper borne urine samples (Berry-Woolf specimen) for the inexpensive detection of elevated lysosomal content and the identification of which of the three majors biochemical groups -mucopolysaccharides, oligosaccharides, and glycosphingolipids- is detected. Urine samples are preferable to blood samples because of their higher concentrations of the relevant analytes. Subsequent steps would precisely determine which enzyme deficiency is involved. As a summary, following our previous papers on the detection of elevated oligosaccharides and mucopolysaccharides, here we describe how elevated urinary glycosphingolipids (GSLs) could be fluorometrically detected using the reagent 5-hydroxy-1-tetralone (HOT) and subsequently identified with precision by continuous thin layer chromatography or other techniques. We also outline the steps required for the validation of this procedure for its introduction in newborn screening programsS

Effect of ß-cyclodextrin on phospholipids and cholesterol of the milk fat globule membrane

The aim of this study was to evaluate the effect of ß-cyclodextrin (ß-CD) on phospholipids and cholesterol in raw pasteurized milk with the purpuse on removal cholesterol from the milk fat. Total phospholipids decrease slightly in ß-CD treated milk but were not signinificantly affected by the effect of the ß-CD. ß-CD is an effective oligosacharide for cholesterol removal from milk with more than 97% of reduction and does not affect significantly the individual phospholipids (phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, phosphatidylinositol and phosphatidylserina) of the milk fat globule membrane.The authors thanks to the Ministry of Economy and Competitiveness from Spain (grant number AGL-2011-26713).Peer Reviewe