Keyword Search on RDF Graphs - A Query Graph Assembly Approach

Keyword search provides ordinary users an easy-to-use interface for querying RDF data. Given the input keywords, in this paper, we study how to assemble a query graph that is to represent user's query intention accurately and efficiently. Based on the input keywords, we first obtain the elementary query graph building blocks, such as entity/class vertices and predicate edges. Then, we formally define the query graph assembly (QGA) problem. Unfortunately, we prove theoretically that QGA is a NP-complete problem. In order to solve that, we design some heuristic lower bounds and propose a bipartite graph matching-based best-first search algorithm. The algorithm's time complexity is $O(k^{2l} \cdot l^{3l})$, where $l$ is the number of the keywords and $k$ is a tunable parameter, i.e., the maximum number of candidate entity/class vertices and predicate edges allowed to match each keyword. Although QGA is intractable, both $l$ and $k$ are small in practice. Furthermore, the algorithm's time complexity does not depend on the RDF graph size, which guarantees the good scalability of our system in large RDF graphs. Experiments on DBpedia and Freebase confirm the superiority of our system on both effectiveness and efficiency

Predictors for Nonaccidental Trauma in a Child With a Fracture-A National Inpatient Database Study.

BackgroundDespite heightened awareness and multidisciplinary efforts, a predictive model to help the clinician quantify the likelihood of nonaccidental trauma (NAT) in a child presenting with a fracture does not exist. The purpose of this study was to develop an evidence-based likelihood of NAT in a child presenting with a fracture.MethodsUsing the 2012 Kids' Inpatient Database, we identified all available pediatric inpatients admitted with an extremity or spine fracture. Children with a fracture were subcategorized based on the diagnosis of NAT. Multivariate analysis using multiple logistic regression was used to generate odds ratios and create a predictive model for the probability of NAT in a child with a fracture.ResultsOf the 57,183 pediatric fracture cases, 881 (1.54%) had a concurrent diagnosis of NAT. Of these children, those presenting with multiple fractures had the highest rate of NAT (2.8%). The overall mortality rate in patients presenting with fractures and abuse was 1.8%, which was twice as high as patients without abuse (odds ratio [OR] = 2.0). Based on multivariate analysis, younger age (OR = 0.5), black race (OR = 1.7), intracranial injury (OR = 3.7), concomitant rib fracture (OR = 7.2), and burns (OR = 8.3) were positive predictors of NAT in a child with a fracture. A weighted equation using regression coefficients was generated and plotted on a receiver operative characteristic curve, demonstrating excellent correlation and probability of NAT (area under curve = 0.962). (Equation - ln (P/(1 - P)) = -1.79 - 0.65 (age in years) + 0.51 (black race) + 1.97 (rib fracture) + 1.31 (intracranial injury) + 2.12 (burn)).ConclusionUsing a large, national inpatient database, we identified an overall prevalence of 1.54% of NAT in children admitted to the hospital with a fracture. Based on five independent predictors of NAT, we generated an estimated probability chart that can be used in the clinical workup of a child with a fracture and possible NAT. This evidence-based algorithm needs to be validated in clinical practice.Level of evidencePrognostic study, Level III (case-control study)

Observations of the X-ray Nova GRO~J0422+32: II: Optical Spectra Approaching Quiescence

We present results obtained from a series of 5~\AA\ resolution spectra of the X-ray Nova GRO~J0422+32 obtained in 1993~October, when the system was approximately 2 magnitudes above quiescence, with ${\rm R \sim 19}$. The data were obtained in an effort to measure the orbital radial velocity curve of the secondary, but detection of the narrow photospheric absorption lines needed to do this proved elusive. Instead we found wide absorption bands reminiscent of M~star photospheric features. The parameters determined by fitting accretion disk line profiles (Smak profiles) to the H$\alpha$ line are similar to those found in several strong black-hole candidates. Measurements of the velocity of the H$\alpha$ line are consistent with an orbital period of 5.1~hours and a velocity semi-amplitude of the primary of $34 \pm 6$~\kms. These measurements, when combined with measurements of the velocity semi-amplitude of the secondary made by others, indicate that the mass ratio $q \sim 0.09$. If the secondary follows the empirical mass-radius relation found for CVs, the low $q$ implies a primary mass of $M_x \sim 5.6$\mo, and a rather low (face-on) inclination. The H$\alpha$ EW is found to be modulated on the orbital period with a phasing that implies a partial eclipse of the disk by the secondary, but simultaneous R~band photometry shows no evidence for such an eclipse.Comment: Accepted for ApJ, plain latex, 5 figures available as self-extracting uuendoced, compressed, tarfiles (from uufiles

Condom use and incident sexually transmitted infection after initiation of long-acting reversible contraception

Background Use of more effective contraception may lead to less condom use and increased incidence of sexually transmitted infection. Objective The objective of this study was to compare changes in condom use and incidence of sexually transmitted infection acquisition among new initiators of long-acting reversible contraceptives to those initiating non-long-acting reversible contraceptive methods. Study Design This is a secondary analysis of the Contraceptive CHOICE Project. We included 2 sample populations of 12-month continuous contraceptive users. The first included users with complete condom data (baseline, and 3, 6, and 12 months) (long-acting reversible contraceptive users: N = 2371; other methods: N = 575). The second included users with 12-month sexually transmitted infection data (long-acting reversible contraceptive users: N = 2102; other methods: N = 592). Self-reported condom use was assessed at baseline and at 3, 6, and 12 months following enrollment. Changes in condom use and incident sexually transmitted infection rates were compared using χ2 tests. Risk factors for sexually transmitted infection acquisition were identified using multivariable logistic regression. Results Few participants in either group reported consistent condom use across all survey time points and with all partners (long-acting reversible contraceptive users: 5.2%; other methods: 11.3%; P < .001). There was no difference in change of condom use at 3, 6, and 12 months compared to baseline condom use regardless of method type (P = .65). A total of 94 incident sexually transmitted infections were documented, with long-acting reversible contraceptive users accounting for a higher proportion (3.9% vs 2.0%; P = .03). Initiation of a long-acting reversible contraceptive method was associated with increased sexually transmitted infection incidence (odds ratio, 2.0; 95% confidence ratio, 1.07–3.72). Conclusion Long-acting reversible contraceptive initiators reported lower rates of consistent condom use, but did not demonstrate a change in condom use when compared to preinitiation behaviors. Long-acting reversible contraceptive users were more likely to acquire a sexually transmitted infection in the 12 months following initiation

Long-acting reversible contraception use among residents in obstetrics/gynecology training programs

Background: The objective of the study was to estimate the personal usage of long-acting reversible contraception (LARC) among obstetrics and gynecology (Ob/Gyn) residents in the United States and compare usage between programs with and without a Ryan Residency Training Program (Ryan Program), an educational program implemented to enhance resident training in family planning. Materials and methods: We performed a web-based, cross-sectional survey to explore contraceptive use among Ob/Gyn residents between November and December 2014. Thirty-two Ob/Gyn programs were invited to participate, and 24 programs (75%) agreed to participate. We divided respondents into two groups based on whether or not their program had a Ryan Program. We excluded male residents without a current female partner as well as residents who were currently pregnant or trying to conceive. We evaluated predictors of LARC use using bivariate analysis and multivariable Poisson regression. Results: Of the 638 residents surveyed, 384 (60.2%) responded to our survey and 351 were eligible for analysis. Of those analyzed, 49.3% (95% confidence interval [CI]: 44.1%, 54.5%) reported current LARC use: 70.0% of residents in Ryan Programs compared to 26.8% in non-Ryan Programs (RRadj 2.14, 95% CI 1.63-2.80). Residents reporting a religious affiliation were less likely to use LARC than those who described themselves as non-religious (RRadj 0.76, 95% CI 0.64-0.92). Of residents reporting LARC use, 91% were using the levonorgestrel intrauterine device. Conclusion: LARC use in this population of women's health specialists is substantially higher than in the general population (49% vs. 12%). Ob/Gyn residents in programs affiliated with the Ryan Program were more likely to use LARC

Global Existence and Optimal Temporal Decay Estimates for Systems of Parabolic Conservation Laws. II. The Multidimensional Case

AbstractThis paper is a continuation of our previous paper. It is concerned with the global existence and the optimal temporal decay estimates for the Cauchy problem of the following multidimensional parabolic conservation laws[formula] Hereu(t,x)=(u1(t,x),…,un(t,x))tis the unknown vector,fj(u)=(fj1(u),…,fjn(u))t(j=1,2,…,N) are arbitraryn×1 smooth vector-valued flux functions defined inBr(u), a closed ball of radiusrcentered at some fixed vectoru∈Rn, andDis a constant, diagonalizable matrix with positive eigenvalues. Our results show that if the flux functionfj(u) satisfiesfj(u)/|u−u|s∈L∞(Br(u),Rn),j=1,2,…,Nfor somes>2+1/N,u∈Rn, then foru0(x)−u∈L∞∩L1(RN,Rn) with ‖u0(x)−u‖L1(RN,Rn)sufficiently small, the above Cauchy problem (*) admits a unique globally smooth solutionu(t,x) andu(t,x) satisfies the following temporal decay estimates. For eachk=0,1,2,… [formula]HereDk=∑|α|=k(∂|α|/∂xα11···∂xαNN). The above decay estimates are optimal in the sense that they coincide with the corresponding decay estimates for the solution to the linear part of the corresponding Cauchy problem

Validation of a consumer-grade activity monitor for continuous daily activity monitoring in individuals with multiple sclerosis.

Background:Technological advancements of remote-monitoring used in clinical-care and research require validation of model updates. Objectives:To compare the output of a newer consumer-grade accelerometer to a previous model in people with multiple sclerosis (MS) and to the ActiGraph, a waist-worn device widely used in MS research. Methods:Thirty-one individuals with MS participated in a 7-day validation by the Fitbit Flex (Flex), Fitbit Flex-2 (Flex2) and ActiGraph GT3X. Primary outcome was step count. Valid epochs of 5-min block increments, where there was overlap of ≥1 step/min for both devices were compared and summed to give a daily total for analysis. Results:Bland-Altman plots showed no systematic difference between the Flex and Flex2; mean step-count difference of 25 more steps-per-day more recorded by Flex2 (95% confidence intervals (CI) = 2, 48; p = 0.04),interclass correlation coefficient (ICC) = 1.00. Compared to the ActiGraph, Flex2 (and Flex) tended to record more steps (808 steps-per-day more than the ActiGraph (95% CI= -2380, 765; p &lt; 0.01), although the ICC was high (0.98) indicating that the devices were likely measuring the same kind of activity. Conclusions:Steps from Flex and Flex2 can be used interchangeably. Differences in total step count between ActiGraph and Flex devices can make cross-device comparisons of numerical step-counts challenging particularly for faster walkers