Day surgery in a teaching hospital: identifying barriers to productivity.

Introduction: Ambulatory surgery is a standard of care for many surgical procedures due to cost-effectiveness and benefits to patients including the reduced risk of contracting hospital infection by reducing the hospital stay. However, late cancellations can be costly. We examined the utilisation of the surgical day ward in our institution over a four-year period. Methods: A retrospective study of surgical day ward records from September 2007 to September 2011 in one institution. Parameters investigated included the number of planned admissions. Reasons for cancellations were also collected. Results: A total of 17,461 procedures were intended as a day ward admission during the study interval. There were 3,539 procedures that were cancelled (20.3%). The prevalent proportion of cancellations (n = 1,367) (38.6%) were due to patients not showing up for their procedures (7.8% of planned admissions); 1,188 (33.6%) patients were cancelled by the admissions office due to bed shortages, accounting for 6.8 % of planned admissions and 650 (18.4%) of cases were due to last minute cancellations by patients, accounting for 3.7% of all planned admission. The remaining 334 (9.4%) of cases were cancelled on medical grounds including patients who were considered unfit for the intended procedure, or anti-coagulations not appropriately ceased prior to surgery, accounting for 1.9% of all planned admissions. Conclusion: The cancellation rate in this study was high, mainly due to failure of patients to attend or signal their intentions, inadequate bed capacity and bed closure strategies. The ring fencing and protection of day beds and a more active patient management interaction would have had the greatest impact on increased efficiency

Substellar and low-mass dwarf identification with near-infrared imaging space observatories

AIMS: We aim to evaluate the near-infrared colors of brown dwarfs as observed with four major infrared imaging space observatories: the Hubble Space Telescope (HST), the James Webb Space Telescope (JWST), the Euclid mission, and the WFIRST telescope. METHODS: We used the SPLAT SPEX/ISPEX spectroscopic library to map out the colors of the M-, L-, and T-type dwarfs. We have identified which color-color combination is optimal for identifying broad type and which single color is optimal to then identify the subtype (e.g., T0-9). We evaluated each observatory separately as well as the narrow-field (HST and JWST) and wide-field (Euclid and WFIRST) combinations. RESULTS: The Euclid filters perform poorly typing brown dwarfs and WFIRST performs only marginally better, despite a wider selection of filters. WFIRST's W146 and F062 combined with Euclid's Y-band discriminates somewhat better between broad brown dwarf categories. However, subtyping with any combination of Euclid and WFIRST observations remains uncertain due to the lack of medium or narrow-band filters. We argue that a medium band added to the WFIRST filter selection would greatly improve its ability to preselect brown dwarfs its imaging surveys. CONCLUSIONS: The HST filters used in high-redshift searches are close to optimal to identify broad stellar type. However, the addition of F127M to the commonly used broad filter sets would allow for unambiguous subtyping. An improvement over HST is one of two broad and medium filter combinations on JWST: pairing F140M with either F150W or F162M discriminates very well between subtypes

Substellar and low-mass dwarf identification with near-infrared imaging space observatories

Aims. We aim to evaluate the near-infrared colors of brown dwarfs as observed with four major infrared imaging space observatories: the Hubble Space Telescope (HST), the James Webb Space Telescope (JWST), the Euclid mission, and the WFIRST telescope. Methods. We used the SPLAT SPEX/ISPEX spectroscopic library to map out the colors of the M-, L-, and T-type dwarfs. We have identified which color-color combination is optimal for identifying broad type and which single color is optimal to then identify the subtype (e.g., T0-9). We evaluated each observatory separately as well as the narrow-field (HST and JWST) and wide-field (Euclid and WFIRST) combinations. Results. The Euclid filters perform equally well as HST wide filters in discriminating between broad types of brown dwarfs. WFIRST performs similarly well, despite a wider selection of filters. However, subtyping with any combination of Euclid and WFIRST observations remains uncertain due to the lack of medium, or narrow-band filters. We argue that a medium band added to the WFIRST filter selection would greatly improve its ability to preselect brown dwarfs its imaging surveys. Conclusions. The HST filters used in high-redshift searches are close to optimal to identify broad stellar type. However, the addition of F127M to the commonly used broad filter sets would allow for unambiguous subtyping. An improvement over HST is one of two broad and medium filter combinations on JWST: pairing F140M with either F150W or F162M discriminates very well between subtypes

Structural identifiability of dynamic systems biology models

22 páginas, 5 figuras, 2 tablas.-- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.A powerful way of gaining insight into biological systems is by creating a nonlinear differential equation model, which usually contains many unknown parameters. Such a model is called structurally identifiable if it is possible to determine the values of its parameters from measurements of the model outputs. Structural identifiability is a prerequisite for parameter estimation, and should be assessed before exploiting a model. However, this analysis is seldom performed due to the high computational cost involved in the necessary symbolic calculations, which quickly becomes prohibitive as the problem size increases. In this paper we show how to analyse the structural identifiability of a very general class of nonlinear models by extending methods originally developed for studying observability. We present results about models whose identifiability had not been previously determined, report unidentifiabilities that had not been found before, and show how to modify those unidentifiable models to make them identifiable. This method helps prevent problems caused by lack of identifiability analysis, which can compromise the success of tasks such as experiment design, parameter estimation, and model-based optimization. The procedure is called STRIKE-GOLDD (STRuctural Identifiability taKen as Extended-Generalized Observability with Lie Derivatives and Decomposition), and it is implemented in a MATLAB toolbox which is available as open source software. The broad applicability of this approach facilitates the analysis of the increasingly complex models used in systems biology and other areasAFV acknowledges funding from the Galician government (Xunta de Galiza, Consellería de Cultura, Educación e Ordenación Universitaria http://www.edu.xunta.es/portal/taxonomy/term/206) through the I2C postdoctoral program, fellowship ED481B2014/133-0. AB and AFV were partially supported by grant DPI2013-47100-C2-2-P from the Spanish Ministry of Economy and Competitiveness (MINECO). AFV acknowledges additional funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 686282 (CanPathPro). AP was partially supported through EPSRC projects EP/M002454/1 and EP/J012041/1.Peer reviewe

Cadernos escolares: problemas aritméticos no ensino de matemática em um diário escolar dos anos 1950

Disponível em: http://histemat.com.br/index.php/HISTEMAT/article/view/140/96Este artigo aborda problemas aritméticos encontrados em um caderno escolar do quarto ano do curso primário, dos anos de 1950. O caderno utilizado como fonte de pesquisa pertenceu a um estudante do Grupo Escolar Ramiz Galvão, localizado em Rio Pardo, Rio Grande do Sul. Nessa época estava em vigor, no Estado, o Decreto nº 8.020, de 1939, que estabelecia os programas mínimos do curso primário, guiando os professores até o final dos anos 1950. O autor do caderno, Juvenal Rosa Nunes, concedeu uma entrevista que contribuiu para os resultados desta pesquisa. A partir de análise do caderno, da entrevista e do Decreto, o artigo conclui que os problemas eram uma das principais atividades das aulas de Matemática e que, por meio deles, a professora buscava retratar o cotidiano dos alunos e atingir os objetivos estabelecidos pelos programas. Também são identificadas semelhanças entre os temas e as redações dos enunciados dos problemas com enunciados encontrados em edição contemporânea do livro “Primeira Aritmética para meninos” de Souza Lobo

Paving the Way to Future Missions: the Roman Space Telescope Coronagraph Technology Demonstration

This document summarizes how far the Nancy Grace Roman Space Telescope Coronagraph Instrument (Roman CGI) will go toward demonstrating high-contrast imaging and spectroscopic requirements for potential future exoplanet direct imaging missions, illustrated by the HabEx and LUVOIR concepts. The assessment is made for two levels of assumed CGI performance: (i) current best estimate (CBE) as of August 2020, based on laboratory results and realistic end-to-end simulations with JPL-standard Model Uncertainty Factors (MUFs); (ii) CGI design specifications inherited from Phase B requirements. We find that the predicted performance (CBE) of many CGI subsystems compares favorably with the needs of future missions, despite providing more modest point source detection limits than future missions. This is essentially due to the challenging pupil of the Roman Space Telescope; this pupil pushes the coronagraph masks sensitivities to misalignments to be commensurate with future missions. In particular, CGI will demonstrate active low-order wavefront control and photon counting capabilities at levels of performance either higher than, or comparable to, the needs of future missions.Comment: 10 pages, 3 tables. Revised version v2: added some co-author