Preservation and decomposition theorems for bounded degree structures

We provide elementary algorithms for two preservation theorems for first-order sentences (FO) on the class \^ad of all finite structures of degree at most d: For each FO-sentence that is preserved under extensions (homomorphisms) on \^ad, a \^ad-equivalent existential (existential-positive) FO-sentence can be constructed in 5-fold (4-fold) exponential time. This is complemented by lower bounds showing that a 3-fold exponential blow-up of the computed existential (existential-positive) sentence is unavoidable. Both algorithms can be extended (while maintaining the upper and lower bounds on their time complexity) to input first-order sentences with modulo m counting quantifiers (FO+MODm). Furthermore, we show that for an input FO-formula, a \^ad-equivalent Feferman-Vaught decomposition can be computed in 3-fold exponential time. We also provide a matching lower bound.Comment: 42 pages and 3 figures. This is the full version of: Frederik Harwath, Lucas Heimberg, and Nicole Schweikardt. Preservation and decomposition theorems for bounded degree structures. In Joint Meeting of the 23rd EACSL Annual Conference on Computer Science Logic (CSL) and the 29th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS), CSL-LICS'14, pages 49:1-49:10. ACM, 201

Ridesharing as an Alternative to Ambulance Transport for Voluntary Psychiatric Patients in the Emergency Department

Introduction: Emergency department (ED) crowding is a growing problem. Psychiatric patients have long ED lengths of stay awaiting placement and transportation to a psychiatric facility after disposition.Methods: Retrospective analysis of length of ED stay after disposition for voluntary psychiatric patients before and after the use of Lyft ridesharing services for inter-facility transport.Results: Using Lyft transport to an outside crisis center shortens time to discharge both statistically and clinically from 113 minutes to 91 minutes (p = 0.028) for voluntary psychiatric patients. Discharge time also decreased for involuntary patients from 146 minutes to 127 minutes (p = 0.0053).Conclusion: Ridesharing services may be a useful alternative to medical transportation for voluntary psychiatric patients

Mediating the Relation Between Parent-Child Attachment Relationships and Peer Acceptance With Preschoolers’ Self-Regulation

Peer acceptance represents the degree to which a child is well liked by peers, and it is a crucial component of the early childhood years (Ladd & Sechler, 2013). Being accepted among peers impacts multiple areas of child development, including academics, behavior, and social-emotional domains. A child who is highly accepted by their peers is viewed as a preferred playmate and can be observed playing with various peers. Young children’s earliest peer relationships begin forming during the preschool years. One predicting factor of peer acceptance is the attachment relationship between the parent and child. The security experiences within parent-child attachment relationships help foster the growth of children’s social competence, which in turn allows children to begin forming relationships with other children (Raikes, Virmani, Thompson, & Hatton, 2013; Thompson, 2016). Another important predictor of peer acceptance is children’s self-regulation, which includes several cognitive and behavioral processes that allow children to manage their emotions, behavior, and thoughts to better acclimate to their environment (Liew, 2012). Self-regulation is linked to both the parent-child attachment relationship and children’s peer acceptance (Contreras, Kerns, Weimer, Gentzler, & Tomich, 2000; Gottman & Mettetal, 1986). The purpose of this study was to test the mediating role of preschoolers’ self-regulation on the association between parent-child attachment relationship qualities and preschoolers’ peer acceptance. Three mediation models were tested via a structural equation modeling approach using path analysis. In the first mediation model, it was predicted that the model will represent the best fit for the data collected, supporting that children’s (girls and boys combined) self-regulation mediates the relation between the parent-child attachment relationship qualities and preschoolers’ peer acceptance. Results from the first mediation model indicated that preschoolers’ self-regulation mediates the relation of parent-child attachment qualities and preschoolers’ peer acceptance. In the second mediation model, it was predicted that older preschoolers will demonstrate stronger self-regulation, compared to younger preschoolers. Results from the second mediation model indicated that children’s age significantly predicts preschoolers’ self-regulation. In the third mediation model, with sufficient statistical power, it was predicted that girls will demonstrate stronger self-regulation, compared to boys. Results from the third mediation model indicated that children’s gender significantly predicts preschoolers’ self-regulation. These results contribute to the literature regarding factors that predict peer acceptance and have important implications for children, families, early childhood education teachers, and other professionals who support young children’s overall development. KEYWORDS: preschool, attachment, self-regulation, peer acceptance

Tracking Pacific bluefin tuna (Thunnus thynnus orientalis) in the northeastern Pacific with an automated algorithm that estimates latitude by matching sea-surface-temperature data from satellites with temperature data from tags on fish

Data recovered from 11 popup satellite archival tags and 3 surgically implanted archival tags were used to analyze the movement patterns of juvenile northern bluefin tuna (Thunnus thynnus orientalis) in the eastern Pacific. The light sensors on archival and pop-up satellite transmitting archival tags (PSATs) provide data on the time of sunrise and sunset, allowing the calculation of an approximate geographic position of the animal. Light-based estimates of longitude are relatively robust but latitude estimates are prone to large degrees of error, particularly near the times of the equinoxes and when the tag is at low latitudes. Estimating latitude remains a problem for researchers using light-based geolocation algorithms and it has been suggested that sea surface temperature data from satellites may be a useful tool for refining latitude estimates. Tag data from bluefin tuna were subjected to a newly developed algorithm, called “PSAT Tracker,” which automatically matches sea surface temperature data from the tags with sea surface temperatures recorded by satellites. The results of this algorithm compared favorably to the estimates of latitude calculated with the lightbased algorithms and allowed for estimation of fish positions during times of the year when the lightbased algorithms failed. Three near one-year tracks produced by PSAT tracker showed that the fish range from the California−Oregon border to southern Baja California, Mexico, and that the majority of time is spent off the coast of central Baja Mexico. A seasonal movement pattern was evident; the fish spend winter and spring off central Baja California, and summer through fall is spent moving northward to Oregon and returning to Baja California

Policy Priorities of Municipal Candidates in the 2014 Local Ontario Elections

This paper reports the results of a survey on the policy priorities of municipal candidates in the 2014 municipal elections in Ontario. As part of a survey of municipal candidates in 47 Ontario municipalities, we asked a series of questions relating to perceived policy priorities, election issues, and electoral success to shed light on the extent to which municipal political candidates are “policy seekers,” and the extent to which their policy priorities vary across municipalities and municipal types, successful and unsuccessful candidates, and urban and rural candidates. We find that reported policy priorities tend to fall into two major categories: fiscal issues and economic development or administration and good governance. The prominence of these fiscal and procedural priorities is steady across a range of local candidate types, including successful and unsuccessful candidates, incumbent and non-incumbent candidates, and even urban and rural candidates. Only in very large municipalities, according to our findings, does the structure of candidate priorities begin to diverge from this standard emphasis on finance and procedure

SMT-Based Refutation of Spurious Bug Reports in the Clang Static Analyzer

We describe and evaluate a bug refutation extension for the Clang Static Analyzer (CSA) that addresses the limitations of the existing built-in constraint solver. In particular, we complement CSA's existing heuristics that remove spurious bug reports. We encode the path constraints produced by CSA as Satisfiability Modulo Theories (SMT) problems, use SMT solvers to precisely check them for satisfiability, and remove bug reports whose associated path constraints are unsatisfiable. Our refutation extension refutes spurious bug reports in 8 out of 12 widely used open-source applications; on average, it refutes ca. 7% of all bug reports, and never refutes any true bug report. It incurs only negligible performance overheads, and on average adds 1.2% to the runtime of the full Clang/LLVM toolchain. A demonstration is available at {\tt https://www.youtube.com/watch?v=ylW5iRYNsGA}.Comment: 4 page

Context-bounded model checking with ESBMC 1.17

ESBMC is a context-bounded symbolic model checker that allows the verification of single- and multi-threaded C code with shared variables and locks. ESBMC supports full ANSI-C, and can verify programs that make use of bit-level operations, arrays, pointers, structs, unions, memory allocation and foating-point arithmetic. It can reason about arithmetic under- and overflows, pointer safety, memory leaks, array bounds violations, atomicity and order violations, local and global deadlocks, data races, and user-specified assertions. However, as other bounded model checkers, ESBMC is in general incomplete