An adaptive Metropolis-Hastings scheme: sampling and optimization

We propose an adaptive Metropolis-Hastings algorithm in which sampled data are used to update the proposal distribution. We use the samples found by the algorithm at a particular step to form the information-theoretically optimal mean-field approximation to the target distribution, and update the proposal distribution to be that approximatio. We employ our algorithm to sample the energy distribution for several spin-glasses and we demonstrate the superiority of our algorithm to the conventional MH algorithm in sampling and in annealing optimization.Comment: To appear in Europhysics Letter

Cold acclimation of Concord grapevines III. Relationship between cold hardiness, tissue water content, and shoot maturation

Cold acclimation of Concord grapevines in Michigan begins as early as late August in tissues at the base of current season's growth.Increases in cold hardiness are closely related to decreases in tissue water content as stems achieve vegetative maturity.Greatest differences in hardiness and water content are found in tissues which vary the most in extent of maturation on both primary shoots and summer laterals.Increases in cold resistance are not related to water saturation deficit (WSD) of shoots

A low-energy solar cosmic ray experiment for OGO-F

Instrumentation data for low energy solar cosmic ray measurements using OGO-F satellit

Collective Intelligence for Control of Distributed Dynamical Systems

We consider the El Farol bar problem, also known as the minority game (W. B. Arthur, ``The American Economic Review'', 84(2): 406--411 (1994), D. Challet and Y.C. Zhang, ``Physica A'', 256:514 (1998)). We view it as an instance of the general problem of how to configure the nodal elements of a distributed dynamical system so that they do not ``work at cross purposes'', in that their collective dynamics avoids frustration and thereby achieves a provided global goal. We summarize a mathematical theory for such configuration applicable when (as in the bar problem) the global goal can be expressed as minimizing a global energy function and the nodes can be expressed as minimizers of local free energy functions. We show that a system designed with that theory performs nearly optimally for the bar problem.Comment: 8 page

Algebraic-geometrical formulation of two-dimensional quantum gravity

We find a volume form on moduli space of double punctured Riemann surfaces whose integral satisfies the Painlev\'e I recursion relations of the genus expansion of the specific heat of 2D gravity. This allows us to express the asymptotic expansion of the specific heat as an integral on an infinite dimensional moduli space in the spirit of Friedan-Shenker approach. We outline a conjectural derivation of such recursion relations using the Duistermaat-Heckman theorem.Comment: 10 pages, Latex fil

Viticultural characteristics of VR hybrid rootstocks in a vineyard site infected with grapevine fanleaf virus

Two Vitis vinifera x Muscadinia rotundifolia hybrids (VR hybrids), 039-16 and 043-43, were tested for resistance to fanleaf degeneration over a 12-year period in the Napa Valley, California. Data comparing the vegetative growth and crop yields of these two VR hybrids to the fanleaf susceptible rootstocks AXR#1, Harmony, St. George and L171-6 (a LIDER selection) are presented for the last 8 years of the trial. Certified virus-tested Cabernet Sauvignon was used as the scion variety. Both VR hybrids became highly infected with grapevine fanleaf virus (GFLV) over the course of the trial, but neither showed the reduced crop yields associated with fanleaf degeneration. Information on the resistance of these two rootstocks to other soil-borne pests is also presented. Preliminary studies indicate that O43-43 may be susceptible to phylloxera, therefore, in sites infected with fanleaf degeneration and with potential for infestation with phylloxera, O39-16 is the only suitable choice

Positional Information – a concept underpinning our understanding of developmental biology

© 2019 Wiley Periodicals, Inc.Peer reviewedPostprin

Bibliografía

Sustainable vineyard fertilization can lead to cost savings while protecting the environment. However, appropriate fertilization conditions depend on the rootstocks, which differ in their uptake of macro- and micronutrients, as well as on the vineyard soils’ physical and chemical characteristics, which affect the soil nutrient reservoir. We studied identical sets of 14 rootstocks on three different soils. Rootstocks had a significant impact on petiole levels of nitrogen and potassium throughout the growing season. Pruning weight and fruit yield also varied considerably by rootstock and site. However, rootstock performance was not consistent among sites, nor was the seasonal pattern of change in nitrogen and potassium consistent among sites. The observed differences emphasize the impact of soil texture and nutrient availability on plant growth. Further studies will help guide the development of site-specific sustainable fertilization regimens

Thurston's pullback map on the augmented Teichm\"uller space and applications

Let $f$ be a postcritically finite branched self-cover of a 2-dimensional topological sphere. Such a map induces an analytic self-map $\sigma_f$ of a finite-dimensional Teichm\"uller space. We prove that this map extends continuously to the augmented Teichm\"uller space and give an explicit construction for this extension. This allows us to characterize the dynamics of Thurston's pullback map near invariant strata of the boundary of the augmented Teichm\"uller space. The resulting classification of invariant boundary strata is used to prove a conjecture by Pilgrim and to infer further properties of Thurston's pullback map. Our approach also yields new proofs of Thurston's theorem and Pilgrim's Canonical Obstruction theorem.Comment: revised version, 28 page

Systematic review of approaches to using patient experience data for quality improvement in healthcare settings

Objectives: Explore how patient-reported experience measures (PREMs) are collected, communicated and used to inform quality improvement (QI) across healthcare settings. Design: Systematic review. Setting: Various primary and secondary care settings, including general practice, and acute and chronic care hospitals. Participants: A full range of patient populations from (children through to the elderly) and staff (from healthcare practitioners to senior managers). Methods: Scientific databases were searched (CINAHL, PsycINFO, MEDLINE and Cochrane Libraries) as was grey literature. Qualitative and quantitative studies describing collection of PREM data and subsequent QI actions in any healthcare setting were included. Risk of bias was assessed using established criteria. Of 5312 initial hits, 32 full texts were screened, and 11 were included. Results: Patient experience data were most commonly collected through surveys and used to identify small areas of incremental change to services that do not require a change to clinician behaviour (eg, changes to admission processes and producing educational materials). While staff in most studies reported having made effective improvements, authors struggled to identify what those changes were or the impact they had. Conclusions: Findings suggest there is no single best way to collect or use PREM data for QI, but they do suggest some key points to consider when planning such an approach. For instance, formal training is recommended, as a lack of expertise in QI and confidence in interpreting patient experience data effectively may continue to be a barrier to a successful shift towards a more patient-centred healthcare service. In the context of QI, more attention is required on how patient experience data will be used to inform changes to practice and, in turn, measure any impact these changes may have on patient experience