A five-level static cache architecture for web search engines

Caching is a crucial performance component of large-scale web search engines, as it greatly helps reducing average query response times and query processing workloads on backend search clusters. In this paper, we describe a multi-level static cache architecture that stores five different item types: query results, precomputed scores, posting lists, precomputed intersections of posting lists, and documents. Moreover, we propose a greedy heuristic to prioritize items for caching, based on gains computed by using items' past access frequencies, estimated computational costs, and storage overheads. This heuristic takes into account the inter-dependency between individual items when making its caching decisions, i.e.; after a particular item is cached, gains of all items that are affected by this decision are updated. Our simulations under realistic assumptions reveal that the proposed heuristic performs better than dividing the entire cache space among particular item types at fixed proportions. © 2010 Elsevier Ltd. All rights reserved

Scalable data management in distributed information systems

[EN] In the era of cloud computing and huge information systems, distributed applications should manage dynamic workloads; i.e., the amount of client requests per time unit may vary frequently and servers should rapidly adapt their computing efforts to those workloads. Cloud systems provide a solid basis for this kind of applications but most of the traditional relational database systems are unprepared to scale up with this kind of distributed systems. This paper surveys different techniques being used in modern SQL, NoSQL and NewSQL systems in order to increase the scalability and adaptability in the management of persistent data. © 2011 Springer-Verlag.This work has been supported by EU FEDER and Spanish MICINN under research grants TIN2009-14460-C03-01 and TIN2010-17193Pallardó Lozoya, MR.; Esparza Peidro, J.; García Escriva, JR.; Decker, H.; Muñoz Escoí, FD. (2011). Scalable data management in distributed information systems. 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Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications 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, 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

Efeito da ausência de trato dos bezerros de rebanhos leiteiros aos domingos sobre seus desempenhos até os seis meses de idade Effect of the absence of dairy calves management on sundays on theirs performance up to six months of age

Vinte quatro bezerros mestiços Holandês x Zebu foram usados para comparar os seguintes tratamentos experimentais: 1) presença do tratador todos os dias da semana; 2) ausência do tratador aos domingos, com compensação na quantidade de leite oferecida (seis litros de leite integral aos sábados e às segundas-feiras); e 3) ausência do tratador aos domingos, sem compensação na quantidade de leite oferecida. Os bezerros receberam quatro litros de leite integral/animal/dia até as oito semanas de idade, quando foram abruptamente desaleitados. A partir da segunda semana de vida, receberam concentrado limitado em 2 kg/animal/dia. Conclui-se que: a ausência do tratador aos domingos não afetou o peso vivo (72,3 vs 71,7 kg) e o ganho de peso médio diário (479 vs 451 g/animal/dia) aos seis meses de idade e o consumo médio de concentrado durante as dez primeiras semanas de vida (784 vs 732 g/animal/dia); a compensação na quantidade oferecida de leite resultou em animais mais pesados ao desaleitamento (63,0 vs 58,2 kg), mas não aos seis meses de idade (114,3 vs 113,8 kg).<br>Twenty-four Holstein x Zebu crossbred calves were used to compare the following experimental treatments: 1) calves management every day of the week, 2) absence of calves management on Sundays, with the compensation of the amount of milk fed (6 kg of whole milk given on Saturdays and on Mondays), and 3) absence of calves management on Sundays without the compensation of the amount of milk fed. Calves were fed 4 kg of whole milk/animal/day (except for treatment 2) up to 8 weeks of age when they were abruptly weaned. Starter was available to calves since the second week of age and limited to 2 kg/animal/day. It was concluded that: (a) the absence of calves management on Sundays did not affect body weight (72.3 vs 71.7 kg) and average daily weight gains (479 vs 451 g/animal/day) at six months of age, and average starter intake during the first ten weeks of age (784 vs 732 g/animal/day); (b) the compensation of the amount of milk fed resulted in heavier calves at weaning (63.0 vs 58.2 kg), but not at six month of age (114.3 vs 113.8 kg

Caracterização de frutos e sementes em acessos de maracujá silvestre (Passiflora foetida L.) Characterization of fruits and seeds of wild passion fruit (Passiflora foetida L.).

A espécie Passiflora foetida L.é uma trepadeira exótica cujas folhas e frutos possuem propriedades medicinais. No Brasil, a erva é utilizada na forma de extratos ou emplastros para erisipelas e doenças de pele com inflamação. O objetivo deste trabalho foi caracterizar cinco acessos de Passiflora foetida L. baseados em 17 descritores morfológicos O experimento foi conduzido em casa de vegetação em delineamento inteiramente ao acaso, com 15 repetições por genótipo. As variáveis analisadas foram cor da casca do fruto, formato do fruto, comprimento do fruto, diâmetro do fruto, massa fresca do fruto, comprimento do pedicelo, cor da polpa do fruto, espessura da casca, acidez titulável, sólidos solúveis, potencial hidrogeniônico, razão sólidos solúveis/ acidez titulável, comprimento da semente, diâmetro da semente, espessura da semente, massa fresca das sementes e o número de sementes por fruto. Os dados foram submetidos à análise de variância e teste de médias pelo teste Tukey a 5% de probabilidade. Houve diferença significativa pelo teste F a 5% de probabilidade, entre os genótipos para quase todas as características com exceção da espessura da casca, massa fresca do fruto, comprimento da semente e massa fresca das sementes. A característica que apresentou maior variação foi o teor de sólidos solúveis. E entre os genótipos, o acesso 5 foi o que apresentou as maiores médias pelo teste de Tukey a 5% de probabilidade, em todas as características analisadas, podendo ser utilizado em programas de melhoramento da espécie.<br>The species Passiflora foetida L. é an exotic vine, which leaves and fruit have medicinal properties. In Brazil, the herbis used in the form of extracts or poultices for erysipelas and skin diseases with inflammation. The aim of this study was to characterize five Passiflora foetida L. accessions based on 17 morphological descriptors The experiment was conducted in a greenhouse in a completely randomized design with 15 replicates per genotype. The variables were the fruit skin color, fruit shape, fruit length, fruit diameter, fresh fruit, length of pedicel, flesh color of the fruit, skin thickness, acidity, soluble solids, hydrogen potential ratio soluble solids / acidity, seed length, seed diameter, thickness of seed, fresh seed and seed number per fruit. The data were submitted to analysis of variance and the means were compared by Tukey test at 5% of probability. There was a significant difference by F test at 5%,of probability among the genotypes for nearly all traits, except the thickness of the shell, fresh fruit mass, seed length and fresh weight of seed. The variable that most variation was the soluble solids. The genotype 5 had the highest means by Tukey test at 5% of probability on all characteristics that can be used in breeding programs of the species

Implante de biomateriais e a consolidação óssea em cadelas submetidas à ovariossalpingo-histerectomia Influence of biomaterials on the bony consolidation in spayed female dogs

Avaliou-se a hidroxiapatita com alandronato e hidroxiapatita com colágeno na aceleração da consolidação óssea do rádio de cadelas adultas submetidas à ovariossalpingo-histerectomia (OSH). Utilizaram-se 14 cadelas adultas, distribuídas aleatoriamente em dois grupos: grupo-controle e grupo OSH (submetidas à OSH). Quatro meses após a OSH, as cadelas dos dois grupos foram submetidas à cirurgia para produção de uma falha óssea de 4mm de diâmetro nos terços distal e proximal do rádio. No terço distal do membro direito, foi utilizada a hidroxiapatita com alandronato e, no membro esquerdo, a hidroxiapatita com colágeno; no terço proximal, não se utilizou nenhum biomaterial. Houve retardo na consolidação das falhas ósseas nas cadelas submetidas à OSH comparadas com as não submetidas. A hidroxiapatita com alandronato acelerou o processo de reparação e, em todos os animais dos dois grupos, a densidade óssea foi significativamente maior no terço distal onde foi implantada. Os dois biomateriais apresentaram biocompatibilidade, constatada pela ausência de reação inflamatória ou outra reação indesejável.<br>The hydroxyapatite with alendronate and hydroxyapatite with collagen were evaluated in the acceleration of the bony consolidation of adult spayed bitch radius. For that, 14 adult bitches were distributed in two groups (control and spayed). Four months after ovariohysterectomy, the groups were submitted to the surgery for production of a 4mm diameter bony flaw in the distal and proximal third regions of the radius. In the distal region of the right thoracic limb, hydroxyapatite with alendronate was used. In the distal region of the left thoracic limb, hydroxyapatite with collagen was used. Any biomaterial was used in proximal part of the limb. There was a retard in bony flaws consolidation in the spayed bitches. Hydroxyapatite with alendronate showed better result, since the place it was implanted considerably increased the bony formation. Both biomaterials presented biocompatibility, verified by the absence of inflammatory reaction or other undesirable reaction