634 research outputs found
A study on a mixed stopping strategy for total recall tasks
How do we calculate how many relevant documents are in a collection? In this abstract, we discuss our line of research about total recall systems such as interactive system for systematic reviews based on an active learning framework [4\u20136]. In particular, we will present 1) the problem in mathematical terms, and 2) the experiments of an interactive system that continuously monitors the costs of reviewing additional documents and suggests the user whether to continue or not in the search based on the available remaining resources. We will discuss the results of this system on the ongoing CLEF 2019 eHealth task
An evaluation resource for geographic information retrieval
In this paper we present an evaluation resource for geographic information retrieval developed within the Cross Language Evaluation
Forum (CLEF). The GeoCLEF track is dedicated to the evaluation of geographic information retrieval systems. The resource
encompasses more than 600,000 documents, 75 topics so far, and more than 100,000 relevance judgments for these topics. Geographic
information retrieval requires an evaluation resource which represents realistic information needs and which is geographically
challenging. Some experimental results and analysis are reported
GeoCLEF 2007: the CLEF 2007 cross-language geographic information retrieval track overview
GeoCLEF ran as a regular track for the second time within the Cross
Language Evaluation Forum (CLEF) 2007. The purpose of GeoCLEF is to test
and evaluate cross-language geographic information retrieval (GIR): retrieval
for topics with a geographic specification. GeoCLEF 2007 consisted of two sub
tasks. A search task ran for the third time and a query classification task was
organized for the first. For the GeoCLEF 2007 search task, twenty-five search
topics were defined by the organizing groups for searching English, German,
Portuguese and Spanish document collections. All topics were translated into
English, Indonesian, Portuguese, Spanish and German. Several topics in 2007
were geographically challenging. Thirteen groups submitted 108 runs. The
groups used a variety of approaches. For the classification task, a query log
from a search engine was provided and the groups needed to identify the
queries with a geographic scope and the geographic components within the
local queries
GeoCLEF 2006: the CLEF 2006 Ccross-language geographic information retrieval track overview
After being a pilot track in 2005, GeoCLEF advanced to be a regular track within CLEF 2006. The
purpose of GeoCLEF is to test and evaluate cross-language geographic information retrieval (GIR): retrieval for
topics with a geographic specification. For GeoCLEF 2006, twenty-five search topics were defined by the
organizing groups for searching English, German, Portuguese and Spanish document collections. Topics were
translated into English, German, Portuguese, Spanish and Japanese. Several topics in 2006 were significantly
more geographically challenging than in 2005. Seventeen groups submitted 149 runs (up from eleven groups and
117 runs in GeoCLEF 2005). The groups used a variety of approaches, including geographic bounding boxes,
named entity extraction and external knowledge bases (geographic thesauri and ontologies and gazetteers)
Effects of the replacement of nitrates/nitrites in salami by plant extracts on colon microbiota
Salami is a cured sausage consisting of fermented and air-dried meat obtained from a mixture of meat and fat with spices and other ingredients. Excessive processed meat consumption is negatively considered because of its high fat and salt contents and few bioactive molecules. Notwithstanding, salami is largely consumed, and there is a strong interest to produce better and healthier products by substituting nitrites and nitrates with natural extracts. This work produced four different salami, two controls including nitrates and two alternative preparations where nitrates were substituted with plant extract and ascorbic acid. The products were in vitro digested with the INFOGEST protocol to simulate the oro-gastro-duodenal phase and in vitro fermented with MICODE model to simulate the colon phase. Samples were analyzed by microbiomics and metabolomics approaches to study the changes in bacterial populations and in metabolites production. The results showed that the clean-label formulations promote a general eubiosis of the intestinal microbiota, including favorable F/B ratio, the proliferation of beneficial microbial taxa (Bifidobacteriaceae), and reduction of negative microbial populations (Enterobacteriaceae). Volatilome analysis highlighted a marked production of beneficial molecules, including acetate, propionate and butyrate, and a reduction in host negative molecules such as phenol and p-cresol. Our results tell that the plant extracts could be used to replace nitrates, because the features obtained are comparable to those of controls. This work could represent an encouraging starting point for the processed meat industry for the development of clean-label formulations aimed at reducing the negative impact of these products on consumers
Insight on Glucose and Fructose Absorption and Relevance in the Enterocyte Milieu
Although epidemiological studies indicate a strong correlation between high sugar intake and metabolic diseases, the biological mechanisms underlying this link are still controversial. To further examine the modification and crosstalk occurring in enterocyte metabolism during sugar absorption, in this study we evaluate the diffusion and intestinal metabolism of glucose, fructose and sucrose, which were supplemented in equimolar concentration to Caco-2 cells grown on polyester membrane inserts. At different time points after supplementation, changes in metabolite concentration were evaluated in the apical and basolateral chambers by nuclear magnetic resonance (NMR) and gas-chromatography (GC). Sucrose was only minimally hydrolyzed by Caco-2 cells. Upon supplementation, we observed a faster uptake of fructose than glucose, the pentose sugar being also faster catabolized. Monosaccharide absorption was concomitant to the synthesis/transport of other metabolites, which occurred differently in glucose and fructose supplemented cells. Our results confirm the prominent role of intestinal cells in fructose metabolism and clearance after absorption, representing a further step forward in the understanding of the role of dietary sugars. Future research, including targeted analysis on specific transporters/enzymes and the use of labeled substrates, will be helpful to confirm the present results and their interpretation
Hardware prototyping and validation of a W-ΔDOR digital signal processor
Microwave tracking, usually performed by on ground processing of the signals coming from a spacecraft, represents a crucial aspect in every deep-space mission. Various noise sources, including receiver noise, affect these signals, limiting the accuracy of the radiometric measurements obtained from the radio link. There are several methods used for spacecraft tracking, including the Delta-Differential One-Way Ranging (ΔDOR) technique. In the past years, European Space Agency (ESA) missions relied on a narrowband ΔDOR system for navigation in the cruise phase. To limit the adverse effect of nonlinearities in the receiving chain, an innovative wideband approach to ΔDOR measurements has recently been proposed. This work presents the hardware implementation of a new version of the ESA X/Ka Deep Space Transponder based on the new tracking technique named Wideband ΔDOR (W-ΔDOR). The architecture of the new transponder guarantees backward compatibility with narrowband ΔDOR
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