Cracking KD-Tree: The first multidimensional adaptive indexing

Workload-aware physical data access structures are crucial to achieve short response time with (exploratory) data analysis tasks as commonly required for Big Data and Data Science applications. Recently proposed techniques such as automatic index advisers (for a priori known static workloads) and query-driven adaptive incremental indexing (for a priori unknown dynamic workloads) form the state-of-the-art to build single-dimensional indexes for single-attribute query predicates. However, similar techniques for more demanding multi-attribute query predicates, which are vital for any data analysis task, have not been proposed, yet. In this paper, we present our on-going work on a new set of workload-adaptive indexing techniques that focus on creating multidimensional indexes. We present our proof-of-concept, the Cracking KD-Tree, an adaptive indexing approach that generates a KD-Tree based on multidimensional range query predicates. It works by incrementally creating partial multidimensional indexes as a by-product of query processing. The indexes are produced only on those parts of the data that are accessed, and their creation cost is effectively distributed across a stream of queries. Experimental results show that the Cracking KD-Tree is three times faster than creating a full KD-Tree, one order of magnitude faster than executing full scans and two orders of magnitude faster than using uni-dimensional full or adaptive indexes on multiple columns

HIPE: HMC Instruction Predication Extension Applied on Database Processing

The recent Hybrid Memory Cube (HMC) is a smart memory which includes functional units inside one logic layer of the 3D stacked memory design. In order to execute instructions inside the Hybrid Memory Cube (HMC), the processor needs to send instructions to be executed near data, keeping most of the pipeline complexity inside the processor. Thus, control-flow and data-flow dependencies are all managed inside the processor, in such way that only update instructions are supported by the HMC. In order to solve data-flow dependencies inside the memory, previous work proposed HMC Instruction Vector Extensions (HIVE), which embeds a high number of functional units with a interlock register bank. In this work we propose HMC Instruction Prediction Extensions (HIPE), that supports predicated execution inside the memory, in order to transform control-flow dependencies into data-flow dependencies. Our mechanism focus on removing the high latency iteration between the processor and the smart memory during the execution of branches that depends on data processed inside the memory. In this paper we evaluate a balanced design of HIVE comparing to x86 and HMC executions. After we show the HIPE mechanism results when executing a database workload, which is a strong candidate to use smart memories. We show interesting trade-offs of performance when comparing our mechanism to previous work

Multidimensional adaptive & progressive indexes

Exploratory data analysis is the primary technique used by data scientists to extract knowledge from new data sets. This type of workload is composed of trial-and-error hypothesis-driven queries with a human in the loop. To keep up with the data scientist's productivity, the system must be capable of answering queries in interactive times. Given that these queries are highly selective multidimensional queries, multidimensional indexes are necessary to ensure low latency. However, creating the appropriate indexes is not a given due to the highly exploratory and interactive nature of such human-in-the-loop scenarios.In this paper, we identify four main objectives that are desirable for exploratory data analysis workloads: (1) low overhead over the initial queries, (2) low query variance (i.e., high robustness), (3) predictable index convergence, and (4) low total workload time. Given that not all of them can be achieved at the same time, we present three novel incremental multidimensional indexing techniques that represent three sample points on a Pareto front for this multi-objective optimization problem. (a) The Adaptive KD-Tree is designed to achieve the lowest total workload time at the expense of a higher indexing penalty for the initial queries, lack of robustness, and unpredictable convergence. (b) The Progressive KD-Tree has predictable convergence and a user-defined indexing cost for the initial queries. However, total workload time can be higher than with Adaptive KD-Trees, and per-query time still varies. (c) The Greedy Progressive KD-Tree aims at full robustness at the expense of only improving the per-query cost after full index convergence.Our extensive experimental evaluation using both synthetic and real-life data sets and workloads shows that (a) the Adaptive KD-Tree reduc

Avaliações qualitativas e quantitativas de plantas daninhas na cultura da soja submetida aos sistemas de plantio direto e convencional Quantitative and qualitative weed evaluation of soybean crop in no-tillage and conventional tillage systems

Com o objetivo de avaliar os efeitos do método de preparo do solo e do controle de plantas daninhas em resteva de aveia preta (Avena strigosa), na cultura da soja (Glycine max cv. 'IAC 14'), foi conduzido um experimento de campo na Fazenda Experimental Lageado - UNESP Botucatu - SP, em 1993/94. Os tratamentos de manejo do solo foram Plantio Direto e Plantio Convencional (preparado com uma aração e três gradagens). As formas de controle de plantas daninhas estudadas corresponderam a uma testemunha sem controle do mato; controle com uso exclusivo de herbicidas aplicados em préemergência (0,28 kg/ha de metribuzim + 1,29 kg/ha de orizalin); controle com uso exclusivo de herbicidas aplicados em pósemergência (0,25 kg/ha de fluazifop-p-butil + 0,25 kg/ha de fomesafen); controle com o uso conjunto dos tratamentos em pré e pós-emergência mencionados. Tanto no plantio direto quanto no convencional, utilizou-se glyphosate para a eliminação da aveia preta e das plantas daninhas antes da implantação da cultura. O delineamento experimental adotado foi de blocos ao acaso em parcelas subdivididas, com quatro repetições. Os tipos de manejo do solo foram aplicados às parcelas e os métodos de controle das plantas daninhas às sub-parcelas. Deve ser ressaltado que durante a fase inicial do ensaio, as chuvas foram escassas, limitando tanto o crescimento da cultura quanto a atuação dos herbicidas de pré-emergência e pósemergência. As avaliações baseadas na contagem do número de plantas/m2, realizadas aos 14, 28 e 35 dias após a emergência da cultura da soja, indicaram diferenças entre os métodos de preparo do solo e os métodos de controle. Entre as espécies daninhas mais freqüentes, Brachiaria plantaginea e Amaranthus viridis foram as predominantes no sistema de plantio convencional; estas espécies apresentaram pequena importância no plantio direto, no qual predominou Euphorbia heterophylla. No plantio convencional, os herbicidas de pré-emergência proporcionaram melhor controle de A. viridis do que de B. plantaginea; o controle com herbicidas pós-emergentes foi insatisfatório para ambas espécies. No plantio direto, o controle de E. heterophylla foi insatisfatório em todos os sistemas de controle testados. O plantio direto apresentou sempre menor número total de plantas daninhas, sobretudo de gramineas. A germinação de plantas daninhas limitou-se ao período de até 15 dias após a emergência da cultura, nos dois sistemas de cultivo.<br>With the objective to evaluate the effects of different tillage systems and different methods of control on mulch of black oat (Avena strigosa) on evolution and control of weeds in soybean crop (cultivar 'IAC 14'), a field experiment was carried out in Fazenda Experimental Lageado - UNESP Botucatu - SP, in 1993/94. The different cultivation systems were no tillage and conventional tillage, and the last cultivation system was made with disk harrow and three tandem disk harrow. The weed control methods were: control (weedy check), pre-emergence herbicides (0,28 kg/ha of metribuzim + 1,29 kg/ha of oryzalin), post-emergence herbicides (0,25 kg/ha of Fluacifop-p-butil +0,25 kg/ha of fomesafen) and pre and post-emergence treatments (with the four herbicides in the same rates). Glyphosate was applied for weed and black oat elimination before the crop establishment. The experimental design used was a randomized block arranged in split-plots scheme with four replications. The different cultivation systems were applied on plots and the different weed control on sub-plots. In the early stages of crop development, the rain was scarce, limiting crop growth and performance of the preemergence herbicides. The number the weeds/m2 was evaluated at 14, 28 and 35 days after soybean emergency, showing differences between cultivation systems and among different control systems. Brachiaria plantaginea and Amaranthus viridis were predominant on conventional tillage, and less important on no-tillage system; the most important species in this system was Euphorbia heterophylla. On the conventional system, preemergence herbicides were the best control for A. viridis than to B. plantaginea; the control with post-emergence herbicides was unsatisfactory in both tillage systems. On the no-tillage systems the control of E. heterophylla was unsatisfactory in all studied situations. No-tillage systems showed a smaller number of weeds than conventional systems. The germination of weeds was restricted until 15 days after crop emergency in both tillage systems

Bem comum e normas costumeiras: a ética das águas em comunidades rurais de Minas Gerais

É na tensão entre o "costume de repartir a água comum" e a idéia de que a água pode ser privatizada que se definem os objetivos desse artigo. Ele analisa a noção da água como bem comum construída por populações rurais de Minas Gerais, investigando em que bases se fundamenta essa concepção e, por fim, analisa a plasticidade de culturas locais ao gerir comunitariamente recursos hídricos.<br>It is in the tension among the habit of distributing the water in common and the idea that the water can be privatized that the objectives of this article are defined. It analyzes the notion of the water as common good built by rural populations of Minas Gerais, investigating in which bases that conception is based on, and finally, analyzes the plasticity of local cultures when managing the water resources in community

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

Association between administration of IL-6 antagonists and mortality among patients hospitalized for COVID-19 : a meta-analysis

IMPORTANCE Clinical trials assessing the efficacy of IL-6 antagonists in patients hospitalized for COVID-19 have variously reported benefit, no effect, and harm. OBJECTIVE To estimate the association between administration of IL-6 antagonists compared with usual care or placebo and 28-day all-cause mortality and other outcomes. DATA SOURCES Trials were identified through systematic searches of electronic databases between October 2020 and January 2021. Searches were not restricted by trial status or language. Additional trials were identified through contact with experts. STUDY SELECTION Eligible trials randomly assigned patients hospitalized for COVID-19 to a group in whom IL-6 antagonists were administered and to a group in whom neither IL-6 antagonists nor any other immunomodulators except corticosteroids were administered. Among 72 potentially eligible trials, 27 (37.5%) met study selection criteria. DATA EXTRACTION AND SYNTHESIS In this prospectivemeta-analysis, risk of biaswas assessed using the Cochrane Risk of Bias Assessment Tool. Inconsistency among trial results was assessed using the I-2 statistic. The primary analysis was an inverse variance-weighted fixed-effects meta-analysis of odds ratios (ORs) for 28-day all-cause mortality. MAIN OUTCOMES AND MEASURES The primary outcome measurewas all-cause mortality at 28 days after randomization. There were 9 secondary outcomes including progression to invasive mechanical ventilation or death and risk of secondary infection by 28 days. RESULTS A total of 10 930 patients (median age, 61 years [range of medians, 52-68 years]; 3560 [33%] were women) participating in 27 trials were included. By 28 days, there were 1407 deaths among 6449 patients randomized to IL-6 antagonists and 1158 deaths among 4481 patients randomized to usual care or placebo (summary OR, 0.86 [95% CI, 0.79-0.95]; P =.003 based on a fixed-effects meta-analysis). This corresponds to an absolute mortality risk of 22% for IL-6 antagonists compared with an assumed mortality risk of 25% for usual care or placebo. The corresponding summary ORs were 0.83 (95% CI, 0.74-0.92; P <.001) for tocilizumab and 1.08 (95% CI, 0.86-1.36; P =.52) for sarilumab. The summary ORs for the association with mortality compared with usual care or placebo in those receiving corticosteroids were 0.77 (95% CI, 0.68-0.87) for tocilizumab and 0.92 (95% CI, 0.61-1.38) for sarilumab. The ORs for the association with progression to invasive mechanical ventilation or death, compared with usual care or placebo, were 0.77 (95% CI, 0.70-0.85) for all IL-6 antagonists, 0.74 (95% CI, 0.66-0.82) for tocilizumab, and 1.00 (95% CI, 0.74-1.34) for sarilumab. Secondary infections by 28 days occurred in 21.9% of patients treated with IL-6 antagonists vs 17.6% of patients treated with usual care or placebo (OR accounting for trial sample sizes, 0.99; 95% CI, 0.85-1.16). CONCLUSIONS AND RELEVANCE In this prospectivemeta-analysis of clinical trials of patients hospitalized for COVID-19, administration of IL-6 antagonists, compared with usual care or placebo, was associated with lower 28-day all-cause mortality