Query scheduling techniques and power/latency trade-off model for large-scale search engines

[Resumen] Los motores de búsqueda actuales deben enfrentarse a un veloz incremento de información y a un enorme tráfico de consultas. Las grandes compa˜nías se han visto obligadas a construir centros de datos geográficamente distribuidos y compuestos por miles de servidores. El suministro eléctrico supone un enorme gasto energético, por lo que una peque˜na mejora a nivel de eficiencia puede suponer grandes ventajas económicas. Esta tesis permitirá a grandes compa˜nías de Recuperación de Información la construcción de motores de búsqueda dotados de mayor eficiencia. Por una parte, esta tesis propone nuevas técnicas de distribución de consultas a los servidores que las procesan para disminuir su tiempo de respuesta, estimando cuál será el primer servidor disponible. Por otra parte, esta tesis define un modelo matemático que establece un balance entre el tiempo de respuesta de un motor de búsqueda y su consumo energético. Basándonos en datos históricos y actuales, el modelo estima el tráfico de consultas entrante y, de modo automático, aumenta/disminuye los servidores necesarios para procesar las consultas. Se consigue así un gran porcentaje de ahorro energético sin degradar la latencia del sistema. Nuestros experimentos atestiguan las grandes mejoras alcanzadas en cuanto a eficiencia y ahorro energético.[Resumo] Os motores de busca actuais deben enfrontarse a un grande incremento de información e a un enorme tráfico de consultas. As grandes compa˜nías víronse obrigadas a construír centros de datos xeograficamente distribuídos e compostos por milleiros de servidores. A subministración eléctrica supón un enorme gasto enerxético, polo que una pequena mellora a nivel de eficiencia pode supo˜ner grandes vantaxes económicas. Esta tese permitir´a a grandes compa˜n´ıas de Recuperaci´on de Información a construción de motores de busca dotados de maior eficiencia. Por una parte, esta tese propón novas técnicas de distribución de consultas aos servidores que as procesan para diminuír su tempo de resposta, estimando cál será o primeiro servidor dispo˜nible. Por outra parte, esta tese define un modelo matemático que establece un balance entre o tempo de resposta dun motor de busca e o seu consumo enerxético. A partir de datos históricos e actuais, o modelo estima o tráfico de consultas entrantes e automaticamente aumenta/diminúe os servidores necesarios para procesar as consultas. Conséguese así unha grande porcentaxe de aforro enerxético sen degradar a latencia do sistema. Os nosos experimentos testemu˜nan as grandes melloras alcanzadas en canto a eficiencia e aforro enerxético.[Abstract] Web search engines have to deal with a rapid increase of information, demanded by high incoming query traffic. This situation has driven companies to build geographically distributed data centres housing thousands of computers, consuming enormous amounts of electricity and requiring a huge infrastructure around. At this scale, even minor efficiency improvements result in large financial savings. This thesis represents a novel contribution to query scheduling and power consumption state-of-the-art, by assisting large-scale data centres to build more efficient search engines. On the one hand, this thesis proposes new scheduling techniques to decrease the response time of queries, by estimating the server that will be idle soonest. On the other hand, this thesis defines a simple mathematical model that establishes a threshold between the power and latency of a search engine. Using historical and current data, the model estimates the incoming query traffic and automatically increases/decreases the necessary number of active machines in the system. We achieve high energy savings during the whole day, without degrading the latency. Our experiments have attested the power of both scheduling methods and the power/latency trade-off model in improving the efficiency and achieving high energy savings

Relevance of gastrointestinal manifestations in a large Spanish cohort of patients with systemic lupus erythematosus: what do we know?

SLE can affect any part of the gastrointestinal (GI) tract. GI symptoms are reported to occur in >50% of SLE patients. To describe the GI manifestations of SLE in the RELESSER (Registry of SLE Patients of the Spanish Society of Rheumatology) cohort and to determine whether these are associated with a more severe disease, damage accrual and a worse prognosis. METHODS: We conducted a nationwide, retrospective, multicentre, cross-sectional cohort study of 3658 SLE patients who fulfil =4 ACR-97 criteria. Data on demographics, disease characteristics, activity (SLEDAI-2K or BILAG), damage (SLICC/ACR/DI) and therapies were collected. Demographic and clinical characteristics were compared between lupus patients with and without GI damage to establish whether GI damage is associated with a more severe disease. RESULTS: From 3654 lupus patients, 3.7% developed GI damage. Patients in this group (group 1) were older, they had longer disease duration, and were more likely to have vasculitis, renal disease and serositis than patients without GI damage (group 2). Hospitalizations and mortality were significantly higher in group 1. Patients in group 1 had higher modified SDI (SLICC Damage Index). The presence of oral ulcers reduced the risk of developing damage in 33% of patients. CONCLUSION: Having GI damage is associated with a worse prognosis. Patients on a high dose of glucocorticoids are at higher risk of developing GI damage which reinforces the strategy of minimizing glucocorticoids. Oral ulcers appear to decrease the risk of GI damage. © The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

ATLANTIC-PRIMATES: a dataset of communities and occurrences of primates in the Atlantic Forests of South America

Primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. There are 26 primate species in the Atlantic Forests of South America, 19 of them endemic. We compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera Callithrix and Alouatta. The dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates of primate population sizes, covering most natural forest types of the tropical and subtropical Atlantic Forest of Brazil, Paraguay and Argentina and some other biomes. On average, primate communities of the Atlantic Forest harbor 2 ± 1 species (range = 1–6). However, about 40% of primate communities contain only one species. Alouatta guariba (N = 2,188 records) and Sapajus nigritus (N = 1,127) were the species with the most records. Callicebus barbarabrownae (N = 35), Leontopithecus caissara (N = 38), and Sapajus libidinosus (N = 41) were the species with the least records. Recorded primate densities varied from 0.004 individuals/km 2 (Alouatta guariba at Fragmento do Bugre, Paraná, Brazil) to 400 individuals/km 2 (Alouatta caraya in Santiago, Rio Grande do Sul, Brazil). Our dataset reflects disparity between the numerous primate census conducted in the Atlantic Forest, in contrast to the scarcity of estimates of population sizes and densities. With these data, researchers can develop different macroecological and regional level studies, focusing on communities, populations, species co-occurrence and distribution patterns. Moreover, the data can also be used to assess the consequences of fragmentation, defaunation, and disease outbreaks on different ecological processes, such as trophic cascades, species invasion or extinction, and community dynamics. There are no copyright restrictions. Please cite this Data Paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. © 2018 by the The Authors. Ecology © 2018 The Ecological Society of Americ

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Retos actuales en el acceso y la gestión de la información biomédica

Las tecnologías emergentes NBIC (Nano-Bio-Info-Cogno) ofrecen soluciones innovadoras en el ámbito de la biomedicina mediante la aplicación de nuevos conocimientos de carácter multidisciplinar. Los datos subyacentes a este nuevo conocimiento son numerosos, a veces inconexos, de carácter distribuido y heterogéneo, y plantean nuevos desafíos para su integración con el conocimiento biomédico ya existente. Dicha explosión de datos se ha visto a su vez favorecida por el descenso de precios, tanto en los dispositivos para el almacenaje de datos como en los dispositivos de carácter biomédico

Antimalarials exert a cardioprotective effect in lupus patients: Insights from the Spanish Society of Rheumatology Lupus Register (RELESSER) analysis of factors associated with heart failure.

Factors associated with chronic heart failure (CHF) in patients with systemic lupus erythematosus (SLE) have received little attention. Recent data on the use of hydroxychloroquine in the treatment of SARS-CoV-2 infection have cast doubt on its cardiac safety. The factors associated with CHF, including therapy with antimalarials, were analyzed in a large multicenter SLE cohort. Cross-sectional study including all patients with SLE (ACR-1997 criteria) included in the Spanish Society of Rheumatology Lupus Register (RELESSER), based on historically gathered data. Patients with CHF prior to diagnosis of SLE were excluded. A multivariable analysis exploring factors associated with CHF was conducted. The study population comprised 117 patients with SLE (ACR-97 criteria) and CHF and 3,506 SLE controls. Ninety percent were women. Patients with CHF were older and presented greater SLE severity, organ damage, and mortality than those without CHF. The multivariable model revealed the factors associated with CHF to be ischemic heart disease (7.96 [4.01-15.48], p  Patients with SLE and CHF experience more severe SLE. Treatment with antimalarials appears to confer a cardioprotective effect