178 research outputs found
Keyword search in the Deep Web
The Deep Web is constituted by data accessible through Web
pages, but not readily indexable by search engines, as they are returned
in dynamic pages. In this paper we propose a framework for accessing
Deep Web sources, represented as relational tables with so-called ac-
cess limitations, with keyword-based queries. We formalize the notion
of optimal answer and investigate methods for query processing. To our
knowledge, this problem has never been studied in a systematic way
XWeB: the XML Warehouse Benchmark
With the emergence of XML as a standard for representing business data, new
decision support applications are being developed. These XML data warehouses
aim at supporting On-Line Analytical Processing (OLAP) operations that
manipulate irregular XML data. To ensure feasibility of these new tools,
important performance issues must be addressed. Performance is customarily
assessed with the help of benchmarks. However, decision support benchmarks do
not currently support XML features. In this paper, we introduce the XML
Warehouse Benchmark (XWeB), which aims at filling this gap. XWeB derives from
the relational decision support benchmark TPC-H. It is mainly composed of a
test data warehouse that is based on a unified reference model for XML
warehouses and that features XML-specific structures, and its associate XQuery
decision support workload. XWeB's usage is illustrated by experiments on
several XML database management systems
Study of Mex(VO3)2 vanadates, (Me = Co, Ni, Mn, 1 < x < 2) for lithium rechargeable cells
Transition metal vanadates, Mex(VO3)2.2H2O, where Me = Co, Ni and Mn and 1.0 < x < 2.0, were found to reversibly insert lithium. The efficiency of reversible insertion depended on both the transition metal present and the stoichiometric ratio of Me:V in the vanadate structure. The Ni and Co vanadates gave the highest specific capacities using lithium metal coin cells, with initial specific capacities above 0.7 A h/g (1.0 W h/g) when x is near 1.0. The operating voltage of these materials was in the range of 1.0 to 2.0 V. Lithium ion coin cells using LiCoO2 coupled with the vanadates, were also examined. These were found to deliver about 200 mA h/g, with average voltages of 2.5 to 2.0 V for values of x from 1.1 to 1.2.Peer reviewed: YesNRC publication: Ye
Composition with Target Constraints
It is known that the composition of schema mappings, each specified by
source-to-target tgds (st-tgds), can be specified by a second-order tgd (SO
tgd). We consider the question of what happens when target constraints are
allowed. Specifically, we consider the question of specifying the composition
of standard schema mappings (those specified by st-tgds, target egds, and a
weakly acyclic set of target tgds). We show that SO tgds, even with the
assistance of arbitrary source constraints and target constraints, cannot
specify in general the composition of two standard schema mappings. Therefore,
we introduce source-to-target second-order dependencies (st-SO dependencies),
which are similar to SO tgds, but allow equations in the conclusion. We show
that st-SO dependencies (along with target egds and target tgds) are sufficient
to express the composition of every finite sequence of standard schema
mappings, and further, every st-SO dependency specifies such a composition. In
addition to this expressive power, we show that st-SO dependencies enjoy other
desirable properties. In particular, they have a polynomial-time chase that
generates a universal solution. This universal solution can be used to find the
certain answers to unions of conjunctive queries in polynomial time. It is easy
to show that the composition of an arbitrary number of standard schema mappings
is equivalent to the composition of only two standard schema mappings. We show
that surprisingly, the analogous result holds also for schema mappings
specified by just st-tgds (no target constraints). This is proven by showing
that every SO tgd is equivalent to an unnested SO tgd (one where there is no
nesting of function symbols). Similarly, we prove unnesting results for st-SO
dependencies, with the same types of consequences.Comment: This paper is an extended version of: M. Arenas, R. Fagin, and A.
Nash. Composition with Target Constraints. In 13th International Conference
on Database Theory (ICDT), pages 129-142, 201
The risk stratification of adverse neonatal outcomes in women with gestational diabetes (STRONG) study
Aims: To assess the risk of adverse neonatal outcomes in women with gestational diabetes (GDM) by identifying subgroups of women at higher risk to recognize the characteristics most associated with an excess of risk. Methods: Observational, retrospective, multicenter study involving consecutive women with GDM. To identify distinct and homogeneous subgroups of women at a higher risk, the RECursive Partitioning and AMalgamation (RECPAM) method was used. Overall, 2736 pregnancies complicated by GDM were analyzed. The main outcome measure was the occurrence of adverse neonatal outcomes in pregnancies complicated by GDM. Results: Among study participants (median age 36.8 years, pre-gestational BMI 24.8Â kg/m2), six miscarriages, one neonatal death, but no maternal death was recorded. The occurrence of the cumulative adverse outcome (OR 2.48, 95% CI 1.59â3.87), large for gestational age (OR 3.99, 95% CI 2.40â6.63), fetal malformation (OR 2.66, 95% CI 1.00â7.18), and respiratory distress (OR 4.33, 95% CI 1.33â14.12) was associated with previous macrosomia. Large for gestational age was also associated with obesity (OR 1.46, 95% CI 1.00â2.15). Small for gestational age was associated with first trimester glucose levels (OR 1.96, 95% CI 1.04â3.69). Neonatal hypoglycemia was associated with overweight (OR 1.52, 95% CI 1.02â2.27) and obesity (OR 1.62, 95% CI 1.04â2.51). The RECPAM analysis identified high-risk subgroups mainly characterized by high pre-pregnancy BMI (OR 1.68, 95% CI 1.21â2.33 for obese; OR 1.38 95% CI 1.03â1.87 for overweight). Conclusions: A deep investigation on the factors associated with adverse neonatal outcomes requires a risk stratification. In particular, great attention must be paid to the prevention and treatment of obesity
Quality of life and treatment satisfaction in adults with Type 1 diabetes: A comparison between continuous subcutaneous insulin infusion and multiple daily injections
Aims: The aim of this case-control study was to compare quality of life (QoL) and treatment satisfaction in adults with Type 1 diabetes (T1DM) treated with either continuous subcutaneous insulin infusion (CSII) or multiple daily injections (MDI). Methods: Consecutive patients aged between 18 and 55 years, and attending diabetes clinics for a routine visit, completed the Diabetes-Specific Quality-of-Life Scale (DSQOLS), the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and the SF-36 Health Survey (SF-36). Case (CSII) and control subjects (MDI) were recruited in a 1 : 2 ratio. Results: Overall, 1341 individuals were enrolled by 62 diabetes clinics; 481 were cases and 860 control subjects. Cases had a longer diabetes duration and were more likely to have eye and renal complications. Age, school education, occupation and HbA1c were similar. Of control subjects, 90% followed glargine-based MDI regimens and 10% used NPH-based MDI regimens. On multivariate analysis, after adjusting for socioeconomic and clinical characteristics, scores in the following areas of the DSQOLS were higher in cases than control subjects: diet restrictions (ÎČ = 5.96; P < 0.0001), daily hassles (ÎČ = 3.57; P = 0.01) and fears about hypoglycaemia (ÎČ = 3.88; P = 0.006). Treatment with CSII was also associated with a markedly higher DTSQ score (ÎČ = 4.13; P < 0.0001) compared with MDI. Results were similar when CSII was compared separately with glargine- or NPH-based MDI regimens. Conclusions: This large, non-randomized, case-control study suggests quality of life gains deriving from greater lifestyle flexibility, less fear of hypoglycaemia, and higher treatment satisfaction, when CSII is compared with either glargine-based or NPH-based MDI regimens. © 2008 The Authors
reference architecture and framework
M. Adorni, F. Arcelli, S. Bandini, L. Baresi, C. Batini, A. Bianchi, D. Bianchini, M. Brioschi, A. Caforio, A. Cali, P. Cappellari, C. Cappiello, T. Catarci, A. Corallo, V. De Antonellis, C. Franza, G. Giunta, A. Limonta, G. Lorenzo, P. Losi, A. Maurino, M. Melideo, D. Micucci, S. Modafferi, E. Mussi, L. Negri, C. Pandolfo, B. Pernici, P. Plebani, D. Ragazzi, C. Raibulet, M. Riva, N. Simeoni, C. Simone, G. Solazzo, F. Tisato, R. Torlone, G. Vizzari, and A. Zill
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