Asymptotics for incidence matrix classes

We define {\em incidence matrices} to be zero-one matrices with no zero rows or columns. A classification of incidence matrices is considered for which conditions of symmetry by transposition, having no repeated rows/columns, or identification by permutation of rows/columns are imposed. We find asymptotics and relationships for the number of matrices with $n$ ones in these classes as $n\to\infty$.Comment: updated and slightly expanded versio

Asymptotic enumeration of 2-covers and line graphs

In this paper we find asymptotic enumerations for the number of line graphs on $n$-labelled vertices and for different types of related combinatorial objects called 2-covers. We find that the number of 2-covers, $s_n$, and proper 2-covers, $t_n$, on $[n]$ both have asymptotic growth $$s_n\sim t_n\sim B_{2n}2^{-n}\exp(-\frac12\log(2n/\log n))= B_{2n}2^{-n}\sqrt{\frac{\log n}{2n}},$$ where $B_{2n}$ is the $2n$th Bell number, while the number of restricted 2-covers, $u_n$, restricted, proper 2-covers on $[n]$, $v_n$, and line graphs $l_n$, all have growth $$u_n\sim v_n\sim l_n\sim B_{2n}2^{-n}n^{-1/2}\exp(-[\frac12\log(2n/\log n)]^2).$$ In our proofs we use probabilistic arguments for the unrestricted types of 2-covers and and generating function methods for the restricted types of 2-covers and line graphs

El desarrollo de Lesson Study en Inglaterra en el siglo XXI 2000-2015 y el potencial de una Red Europea

En: Revista Interuniversitaria de Formación del Profesorado, Vol. 29, No. 3Las Lesson Study (LS) se han venido desarrollando en el Reino Unido desde 2001. En este artículo se ofrece una explicación de cómo las LS han crecido en popularidad en el Reino Unido -en particular en Inglaterra- a pesar de los cambios radicales regresivos de las políticas gubernamentales en las escuelas, el currículo y el desarrollo profesional de los docentes. Desde la perspectiva del autor del artículo, la cronología se divide en tres fases: un primer periodo exploratorio, ampliado a nivel nacional en un segundo y, ahora, una fase de desarrollo dentro del "libre mercado", que ha visto los cambios más importantes en el sistema educativo de todo el siglo. La última parte del artículo considera los pasos que se deben dar para introducir las LS en el contexto actual europeo

Lesson Study : a Handbook

This booklet is a guide on how to use Lesson Study to develop and refine teaching, learning and teacher practice knowledge. The booklet will help you in: Getting Lesson Study going in school; Planning, teaching and analyzing the research lesson; Involving pupils in the process; Passing on to others the new practice knowledge you have gained in your Lesson Study; Leading Lesson Study. Lesson Study (LS) is a highly specified form of classroom action research focusing on the development of teacher practice knowledge. It has been in use in Japan since the 1870s. LS therefore pre-dates action research as we know it in the West, by some 70 years

Satellite observations of chlorophyll, phytoplankton biomass, and Ekman pumping in nonlinear mesoscale eddies

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 118 (2013): 6349–6370, doi:10.1002/2013JC009027.Nonlinear mesoscale eddies can influence biogeochemical cycles in the upper ocean through vertical and horizontal advection of nutrients and marine organisms. The relative importance of these two processes depends on the polarity of an eddy (cyclones versus anticyclones) and the initial biological conditions of the fluid trapped in the core of the eddy at the time of formation. Eddies originating in the eastern South Indian Ocean are unique in that anticyclones, typically associated with downwelling, contain elevated levels of chlorophyll-a, enhanced primary production and phytoplankton communities generally associated with nutrient-replete environments. From analysis of 9 years of concurrent satellite measurements of sea surface height, chlorophyll, phytoplankton carbon, and surface stress, we present observations that suggest eddy-induced Ekman upwelling as a mechanism that is at least partly responsible for sustaining positive phytoplankton anomalies in anticyclones of the South Indian Ocean. The biological response to this eddy-induced Ekman upwelling is evident only during the Austral winter. During the Austral summer, the biological response to eddy-induced Ekman pumping occurs deep in the euphotic zone, beyond the reach of satellite observations of ocean color.This work was funded by NASA grants NNX08AI80G, NNX08AR37G, NNX10AO98G, and NNX13AD78G.2014-06-0

Perineal resuturing versus expectant management following vaginal delivery complicated by a dehisced wound (PREVIEW): A pilot and feasibility randomised controlled trial

Objective: To establish the feasibility of conducting a definitive randomised controlled trial (RCT) comparing the effectiveness of resuturing versus expectant management for dehisced perineal wounds. Design: A multicentre pilot and feasibility RCT. Setting Ten UK maternity units from July 2011 to July 2013. Population: Eligible women with a dehisced perineal wound within 2 weeks of childbirth. Methods: The interventions were resuturing or expectancy. Randomisation was via web or telephone, stratified by participating centre. Blinding was not possible due to the nature of the interventions. Analysis was by intention-to-treat. Outcome: The primary outcome measure was wound healing at 6-8 weeks. Results: The study revealed a number of feasibility issues, particularly strong patient and clinician preference for treatment options at recruiting centres and the timing of the primary outcome measure. Thirty-four women were randomised (17 in each arm). Data from 33 women were analysed on an intention-to-treat analysis to obtain preliminary estimates of effect size. There was a difference in wound healing at 2 weeks favouring resuturing (OR 20.00, 95% CI 2.04 to 196.37, p=0.004). However, by 6-8 weeks all but one wound in both groups had healed. Conclusions: PREVIEW revealed a number of feasibility issues, which impacted on recruitment rate. These will have to be taken into account in the design of any future definitive study. In this feasibility study, resuturing was associated with quicker wound healing and women reported higher satisfaction rates with the outcome at 3 months

Fuller\u27s First Fifty - No. 03

A monthly historical newsletter published for the Fuller community during the fiftieth anniversary year. The School of World Mission: a new school for a new movement -- Donald A. McGavran: beginning again at 67 -- George Eldon Ladd: an appreciatio

Regional variations in the influence of mesoscale eddies on near-surface chlorophyll

Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 119 (2014): 8195–8220, doi:10.1002/2014JC010111.Eddies can influence biogeochemical cycles through a variety of mechanisms, including the excitation of vertical velocities and the horizontal advection of nutrients and ecosystems, both around the eddy periphery by rotational currents and by the trapping of fluid and subsequent transport by the eddy. In this study, we present an analysis of the influence of mesoscale ocean eddies on near-surface chlorophyll (CHL) estimated from satellite measurements of ocean color. The influences of horizontal advection, trapping, and upwelling/downwelling on CHL are analyzed in an eddy-centric frame of reference by collocating satellite observations to eddy interiors, as defined by their sea surface height signatures. The influence of mesoscale eddies on CHL varies regionally. In most boundary current regions, cyclonic eddies exhibit positive CHL anomalies and anticyclonic eddies contain negative CHL anomalies. In the interior of the South Indian Ocean, however, the opposite occurs. The various mechanisms by which eddies can influence phytoplankton communities are summarized and regions where the observed CHL response to eddies is consistent with one or more of the mechanisms are discussed. This study does not attempt to link the observed regional variability definitively to any particular mechanism but provides a global overview of how eddies influence CHL anomalies.This work was funded by NASA grants NNX08AI80G, NNX08AR37G, and NNX10AO98G. DJM gratefully acknowledges NASA grant NNX13AE47G and NSF grant OCE-1048897.2015-06-0

Does bladder wall thickness decrease when obstruction is resolved?

Introduction and hypothesis: The aim of the current study was to determine if sonographic bladder wall thickness diminishes after symptomatic obstruction is resolved in female patients after stress incontinence surgery. Methods: Between December 2008 and December 2010, 62 female patients with symptomatic bladder outlet obstruction, as defined by Blaivas, who had undergone prior surgery for urinary stress incontinence were included in the study. The patients' history was taken and symptoms were noted. Patients underwent gynaecological examination, and multichannel urodynamic assessment was performed. Vaginal sonographic assessment of the bladder wall thickness (BWT) was performed before and after urethrolysis. Results: 62 patients were included in this study, 55 of whom had undergone suburethral sling insertion and seven had Burch colposuspension. Postoperatively, BWT decreased significantly from 9.1mm ± 2.1 to 7.6mm ± 2.2 (p < 0.0001). In seven patients, obstruction was still unresolved postoperatively; of these, two had undergone a retropubic sling insertion and two had a Burch colposuspension. An ROC curve analysis showed a significant positive association between residual urine and persistent obstruction before surgery (AUC 0.76, 95%CI 0.58-0.94; p < 0.05). Conclusions: If obstruction is resolved, bladder wall thickness decreases. Preoperatively elevated residual urine may increase the risk of persistent obstruction after urethrolysi