Size and Treewidth Bounds for Conjunctive Queries

This paper provides new worst-case bounds for the size and treewith of the result Q(D) of a conjunctive query Q to a database D. We derive bounds for the result size |Q(D) | in terms of structural properties of Q, both in the absence and in the presence of keys and functional dependencies. These bounds are based on a novel “coloring ” of the query variables that associates a coloring number C(Q) to each query Q. Using this coloring number, we derive tight bounds for the size of Q(D) in case (i) no functional dependencies or keys are specified, and (ii) simple (one-attribute) keys are given. These results generalize recent size-bounds for join queries obtained by Atserias, Grohe, and Marx (FOCS 2008). An extension of our coloring technique also gives a lower bound for |Q(D) | in the general setting of a query with arbitrary functional dependencies. Our new coloring scheme also allows us to precisely characterize (both in the absence of keys and with simple keys) the treewidth-preserving queries— the queries for which the output treewidth is bounded by a function of the input treewidth. Finally we characterize the queries that preserve the sparsity of the input in the general setting with arbitrary functional dependencies

Parent employment and the use of child care subsidies

A review of research studies examining parent employment outcomes associated with the use of child care subsidie

Parent employment and the use of child care subsidies: Table of methods and findings

A table summarizing the research questions, groups studied, methods, validity and reliability issues, and findings of studies discussed in an accompanying literature review examining parent employment outcomes associated with the use of child care subsidie

Predictors of child care subsidy use: Table of methods and findings

A table of methods and findings on child care subsidy us

Predictors of child care subsidy use

A review of research on factors influencing child care subsidy use among eligible families

A combined biomarker and clinical panel for chronic graft versus host disease diagnosis.

Whilst many chronic graft versus host disease (cGVHD) biomarkers have been previously reported, few have been verified in an independent cGVHD cohort. We aimed to verify the diagnostic accuracy of previously reported markers of cGVHD in a multi-centre Chronic GVHD Consortium. A total of 42 RNA and 18 protein candidate biomarkers were assessed amongst 59 cGVHD cases and 33 matched non-GVHD controls. Total RNA was isolated from PBMC, and RNA markers were quantified using PCR. Serum protein markers were quantified using ELISA. A combined 3 RNA biomarker (IRS2, PLEKHF1 and IL1R2) and 2 clinical variables (recipient CMV serostatus and conditioning regimen intensity) panel accurately (AUC 0.81) segregated cGVHD cases from controls. Other studied RNA and protein markers were not confirmed as accurate cGVHD diagnostic biomarkers. The studied markers failed to segregate higher risk cGVHD (per overall NIH 0-3 score, and overlap versus classic cGVHD status). These data support the need for multiple independent verification studies for the ultimate clinical application of cGVHD diagnostic biomarkers

Restricted Dislocation Motion in Crystals of Colloidal Dimer Particles

At high area fractions, monolayers of colloidal dimer particles form a degenerate crystal (DC) structure in which the particle lobes occupy triangular lattice sites while the particles are oriented randomly along any of the three lattice directions. We report that dislocation glide in DCs is blocked by certain particle orientations. The mean number of lattice constants between such obstacles is 4.6 +/- 0.2 in experimentally observed DC grains and 6.18 +/- 0.01 in simulated monocrystalline DCs. Dislocation propagation beyond these obstacles is observed to proceed through dislocation reactions. We estimate that the energetic cost of dislocation pair separation via such reactions in an otherwise defect free DC grows linearly with final separation, hinting that the material properties of DCs may be dramatically different from those of 2-D crystals of spheres

Advance Care Planning in Patients Undergoing Hematopoietic Cell Transplantation

AbstractFew data are available on the prevalence of advance care planning (ACP) in patients undergoing hematopoietic cell transplantation (HCT). We surveyed adult patients pre-HCT to ascertain completion of various elements of ACP. We also reviewed medical records for documentation of discussions regarding ACP and for the presence of written advance directives. Evaluable surveys were returned by 155 of 335 patients (46%) who underwent HCT during the study period; we obtained permission for medical record review from 137 of these 155 survey respondents (88%). We found that 69% of the respondents reported having designated a health care proxy, 44% had completed a living will, 61% had prepared an estate will, and 63% had discussed their wishes regarding life support with family and friends. In contrast, only 16% had discussed their wishes regarding life support with their clinicians. Documentation of discussions between clinicians and patients regarding most elements of ACP was rare. Written advance directives were present in the charts of 54 patients (39%). ACP was more common in older, college-educated, and allogeneic transplant patients. Even though ACP was more prevalent among this sample than in the general population, its use still could be enhanced, given the high risks of decisional incapacity and death that HCT patients face

Earth-like Habitats in Planetary Systems

Understanding the concept of habitability is related to an evolutionary knowledge of the particular planet-in-question. Additional indications so-called "systemic aspects" of the planetary system as a whole governs a particular planet's claim on habitability. Here we focus on such systemic aspects and discuss their relevance to the formation of an 'Earth-like' habitable planet. We summarize our results obtained by lunar sample work and numerical models within the framework of the Research Alliance "Planetary Evolution and Life". We consider various scenarios which simulate the dynamical evolution of the Solar System and discuss the likelihood of forming an Earth-like world orbiting another star. Our model approach is constrained by observations of the modern Solar System and the knowledge of its history. Results suggest that the long-term presence of terrestrial planets is jeopardized due to gravitational interactions if giant planets are present. But habitability of inner rocky planets may be supported in those planetary systems hosting giant planets. Gravitational interactions within a complex multiple-body structure including giant planets may supply terrestrial planets with materials which formed in the colder region of the proto-planetary disk. During these processes, water, the prime requisite for habitability, is delivered to the inner system. This may occur either during the main accretion phase of terrestrial planets or via impacts during a post-accretion bombardment. Results for both processes are summarized and discussed with reference to the lunar crater record. Starting from a scenario involving migration of the giant planets this contribution discusses the delivery of water to Earth, the modification of atmospheres by impacts in a planetary system context and the likelihood of the existence of extrasolar Earth-like habitable worlds.Comment: 36 Pages, 6 figures, 2014, Special Issue in Planetary and Space Science on the Helmholtz Research Alliance on Planetary Evolution and Lif