204 research outputs found
Logics of Finite Hankel Rank
We discuss the Feferman-Vaught Theorem in the setting of abstract model
theory for finite structures. We look at sum-like and product-like binary
operations on finite structures and their Hankel matrices. We show the
connection between Hankel matrices and the Feferman-Vaught Theorem. The largest
logic known to satisfy a Feferman-Vaught Theorem for product-like operations is
CFOL, first order logic with modular counting quantifiers. For sum-like
operations it is CMSOL, the corresponding monadic second order logic. We
discuss whether there are maximal logics satisfying Feferman-Vaught Theorems
for finite structures.Comment: Appeared in YuriFest 2015, held in honor of Yuri Gurevich's 75th
birthday. The final publication is available at Springer via
http://dx.doi.org/10.1007/978-3-319-23534-9_1
On the Parameterized Intractability of Monadic Second-Order Logic
One of Courcelle's celebrated results states that if C is a class of graphs
of bounded tree-width, then model-checking for monadic second order logic
(MSO_2) is fixed-parameter tractable (fpt) on C by linear time parameterized
algorithms, where the parameter is the tree-width plus the size of the formula.
An immediate question is whether this is best possible or whether the result
can be extended to classes of unbounded tree-width. In this paper we show that
in terms of tree-width, the theorem cannot be extended much further. More
specifically, we show that if C is a class of graphs which is closed under
colourings and satisfies certain constructibility conditions and is such that
the tree-width of C is not bounded by \log^{84} n then MSO_2-model checking is
not fpt unless SAT can be solved in sub-exponential time. If the tree-width of
C is not poly-logarithmically bounded, then MSO_2-model checking is not fpt
unless all problems in the polynomial-time hierarchy can be solved in
sub-exponential time
Dependence Logic with Generalized Quantifiers: Axiomatizations
We prove two completeness results, one for the extension of dependence logic
by a monotone generalized quantifier Q with weak interpretation, weak in the
meaning that the interpretation of Q varies with the structures. The second
result considers the extension of dependence logic where Q is interpreted as
"there exists uncountable many." Both of the axiomatizations are shown to be
sound and complete for FO(Q) consequences.Comment: 17 page
Pharmacy led medicine reconciliation at hospital: a systematic review of effects and costs
Background: Transition of patients care between settings presents an increased opportunity for errors and preventable morbidity. A number of studies outlined that pharmacy-led medication reconciliation (MR) might facilitate safer information transfer and medication use. MR practice is not well standardised and often delivered in combination with other healthcare activities. The question regarding the effects and costs of pharmacy-led MR and the optimum MR practice is warranted of value. Objectives: To review the evidence for the effects and costs/ cost-effectiveness of complete pharmacy-led MR in hospital settings. Methods: A systematic review searching the following database was conducted up to the 13th December 2015; EMBASE & MEDLINE Ovid, CINAHL and the Cochrane library. Studies evaluating pharmacy-led MR performed fully from admission till discharges were included. Studies evaluated non-pharmacy-led MR at only one end of patient care or transfer were not included. Articles were screened and extracted independently by two investigators. Studies were divided into those in which: MR was the primary element of the intervention and labelled as “primarily MR” studies, or MR combined with non-MR care activities and labelled as “supplemented MR” studies. Quality assessment of studies was performed by independent reviewers using a pre-defined and validated tool. Results: The literature search identified 4,065 citations, of which 13 implemented complete MR. The lack of evidence precluded addressing the effects and costs of MR. Conclusions: The composite of optimum MR practice is not widely standardised and requires discussion among health professions and key organisations. Research focused on evaluating cost-effectiveness of pharmacy-led MR is lacking
- …