An asymptotic multipartite Kühn-Osthus theorem

In this paper we prove an asymptotic multipartite version of a well-known theorem of K¨uhn and Osthus by establishing, for any graph H with chromatic number r, the asymptotic multipartite minimum degree threshold which ensures that a large r-partite graph G admits a perfect H-tiling. We also give the threshold for an H-tiling covering all but a linear number of vertices of G, in a multipartite analogue of results of Koml´os and of Shokoufandeh and Zhao

Achieving Perfect Imaging beyond Passive and Active Obstacles by a Transformed Bilayer Lens

A bilayer lens is proposed based on transformation optics. It is shown that Pendry's perfect lens, perfect bilayer lens made of indefinite media, and the concept of compensated media are well unified under the scope of the proposed bilayer lens. Using this concept, we also demonstrate how one is able to achieve perfect imaging beyond passive objects or active sources which are present in front of the lens.Comment: 15 pages, 6 figure

Law Schools as Knowledge Centers in the Digital Age

This article explores what it would mean for law schools to be “knowledge centers” in the digital age, and to have this as a central mission. It describes the activities of legal knowledge centers as: (1) focusing on solving real legal problems in society outside of the academy; (2) evaluating the problem-solving effectiveness of the legal knowledge being developed; (3) re-conceptualizing the structures used to represent legal knowledge, the processes through which legal knowledge is created, and the methods used to apply that knowledge; and (4) disseminating legal knowledge in ways that assist its implementation. The Article uses as extended examples of knowledge centers in the digital age the research laboratories in the sciences, and in particular research laboratories in linguistics and information science. It uses numerous examples to suggest how law schools might implement the concept of a knowledge center

Law Schools as Knowledge Centers in the Digital Age

This article explores what it would mean for law schools to be “knowledge centers” in the digital age, and to have this as a central mission. It describes the activities of legal knowledge centers as: (1) focusing on solving real legal problems in society outside of the academy; (2) evaluating the problem-solving effectiveness of the legal knowledge being developed; (3) re-conceptualizing the structures used to represent legal knowledge, the processes through which legal knowledge is created, and the methods used to apply that knowledge; and (4) disseminating legal knowledge in ways that assist its implementation. The Article uses as extended examples of knowledge centers in the digital age the research laboratories in the sciences, and in particular research laboratories in linguistics and information science. It uses numerous examples to suggest how law schools might implement the concept of a knowledge center

Interventions to treat fear of childbirth in pregnancy: A systematic review and meta-analysis

Background Between 5% and 14% of women suffer from fear of childbirth (FOC) which is associated with difficulties during birth and in postnatal psychological adjustment. Therefore, effective interventions are needed to improve outcomes for women. A systematic review and meta-analysis was used to identify effective interventions for treating women with FOC. Methods Literature searches were undertaken on online databases. Hand searches of reference lists were also carried out. Studies were included in the review if they recruited women with FOC and aimed to reduce FOC and/or improve birth outcomes. Data were synthesised qualitatively and quantitatively using meta-analysis. The literature searches provided a total of 4474 citations. Results After removing duplicates and screening through abstracts, titles and full texts, 66 papers from 48 studies were identified for inclusion in the review. Methodological quality was mixed with 30 out of 48 studies having a medium risk of bias. Interventions were categorised into six broad groups: Cognitive behavioural therapy, other talking therapies, antenatal education, enhanced midwifery care, alternative interventions and interventions during labour. Results from the meta-analysis showed that most interventions reduced FOC, regardless of the approach (mean effect size =-1.27; z =-4.53, p < 0.0001) and that other talking therapies may reduce caesarean section rates (OR 0.48, 95% CI 0.48-0.90). Conclusions Poor methodological quality of studies limits conclusions that can be drawn; however, evidence suggests that most interventions investigated reduce FOC. Future high-quality randomised controlled trials are needed so that clear conclusions can be made

Exploiting Term Hiding to Reduce Run-time Checking Overhead

One of the most attractive features of untyped languages is the flexibility in term creation and manipulation. However, with such power comes the responsibility of ensuring the correctness of these operations. A solution is adding run-time checks to the program via assertions, but this can introduce overheads that are in many cases impractical. While static analysis can greatly reduce such overheads, the gains depend strongly on the quality of the information inferred. Reusable libraries, i.e., library modules that are pre-compiled independently of the client, pose special challenges in this context. We propose a technique which takes advantage of module systems which can hide a selected set of functor symbols to significantly enrich the shape information that can be inferred for reusable libraries, as well as an improved run-time checking approach that leverages the proposed mechanisms to achieve large reductions in overhead, closer to those of static languages, even in the reusable-library context. While the approach is general and system-independent, we present it for concreteness in the context of the Ciao assertion language and combined static/dynamic checking framework. Our method maintains the full expressiveness of the assertion language in this context. In contrast to other approaches it does not introduce the need to switch the language to a (static) type system, which is known to change the semantics in languages like Prolog. We also study the approach experimentally and evaluate the overhead reduction achieved in the run-time checks.Comment: 26 pages, 10 figures, 2 tables; an extension of the paper version accepted to PADL'18 (includes proofs, extra figures and examples omitted due to space reasons

Hall Effect of Spin Waves in Frustrated Magnets

We examine a possible spin Hall effect for localized spin systems with no charge degrees of freedom. In this scenario, a longitudinal magnetic field gradient induces a transverse spin current carried by spin wave excitations with an anomalous velocity which is associated with the Berry curvature raised by spin chirality, in analogy with anomalous Hall effects in itinerant electron systems. Our argument is based on a semiclassical equations of motion applicable to general spin systems. Also, a microscopic model of frustrated magnets which exhibits the anamalous spin Hall effect is presented.Comment: 5 pages, title and presentation style are changed, accepted for publication in Phys. Rev. Let