Variation in guideline implementation and adherence regarding severe traumatic brain injury treatment: a CENTER-TBI survey study in Europe

Guidelines may reduce practice variation and optimize patient care. We aimed to study differences in guideline use in the management of traumatic brain injury (TBI) patients and analyze reasons for guideline non-adherence. As part of a prospective, observational, multi-center European cohort study, participants from 68 centers in 20 countries were asked to complete 72-item questionnaires regarding their management of severe TBI. Six questions with multiple sub-questions focused on guideline use and implementation. Questionnaires were completed by 65 centers. Of these, 49 (75%) reported use of the Brain Trauma Foundation Guidelines for the medical management of TBI or related institutional protocols, 11 (17%) used no guidelines and 5 used other guidelines (8%). Of 54 centers reporting use of any guidelines, 41 (75%) relied on written guidelines. Four centers of the 54 (7%) reported no formal implementation efforts. Structural attention to the guidelines during daily clinical rounds was reported by 21 centers (38%). The most often reported reasons for non-adherence were ‘every patient is unique’ and the presence of extracranial injuries, both for centers that did and did not report the use of guidelines. There is substantial variability in the use and implementation of guidelines in neurotrauma centers in Europe. Further research is needed to strengthen the evidence underlying guidelines and to overcome implementation barriers

The NANOGrav 15 yr Data Set: Chromatic Gaussian Process Noise Models for Six Pulsars

\ua9 2024. The Author(s). Published by the American Astronomical Society.Pulsar timing arrays (PTAs) are designed to detect low-frequency gravitational waves (GWs). GWs induce achromatic signals in PTA data, meaning that the timing delays do not depend on radio frequency. However, pulse arrival times are also affected by radio-frequency-dependent “chromatic” noise from sources such as dispersion measure (DM) and scattering delay variations. Furthermore, the characterization of GW signals may be influenced by the choice of chromatic noise model for each pulsar. To better understand this effect, we assess if and how different chromatic noise models affect the achromatic noise properties in each pulsar. The models we compare include existing DM models used by the North American Nanohertz Observatory for Gravitational waves (NANOGrav) and noise models used for the European PTA Data Release 2 (EPTA DR2). We perform this comparison using a subsample of six pulsars from the NANOGrav 15 yr data set, selecting the same six pulsars as from the EPTA DR2 six-pulsar data set. We find that the choice of chromatic noise model noticeably affects the achromatic noise properties of several pulsars. This is most dramatic for PSR J1713+0747, where the amplitude of its achromatic red noise lowers from log 10 A RN = − 14.1 − 0.1 + 0.1 to − 14.7 − 0.5 + 0.3 , and the spectral index broadens from γ RN = 2.6 − 0.4 + 0.5 to γ RN = 3.5 − 0.9 + 1.2 . We also compare each pulsar\u27s noise properties with those inferred from the EPTA DR2, using the same models. From the discrepancies, we identify potential areas where the noise models could be improved. These results highlight the potential for custom chromatic noise models to improve PTA sensitivity to GWs

The NANOGrav 15 yr Data Set: Running of the Spectral Index

\ua9 2025. The Author(s)The NANOGrav 15 yr data provide compelling evidence for a stochastic gravitational-wave (GW) background at nanohertz frequencies. The simplest model-independent approach to characterizing the frequency spectrum of this signal consists of a simple power-law fit involving two parameters: an amplitude A and a spectral index γ. In this Letter, we consider the next logical step beyond this minimal spectral model, allowing for a running (i.e., logarithmic frequency dependence) of the spectral index, grun (f ) = g + b ln (f /fref ). We fit this running-power-law (RPL) model to the NANOGrav 15 yr data and perform a Bayesian model comparison with the minimal constant-power-law (CPL) model, which results in a 95% credible interval for the parameter β consistent with no running, b \uce [-0.80, 2.96], and an inconclusive Bayes factor, B(RPL versus CPL) = 0.69 \ub1 0.01. We thus conclude that, at present, the minimal CPL model still suffices to adequately describe the NANOGrav signal; however, future data sets may well lead to a measurement of nonzero β. Finally, we interpret the RPL model as a description of primordial GWs generated during cosmic inflation, which allows us to combine our results with upper limits from Big Bang nucleosynthesis, the cosmic microwave background, and LIGO–Virgo–KAGRA

The NANOGrav 15 yr Data Set: Search for Transverse Polarization Modes in the Gravitational-wave Background

\ua9 2024. The Author(s). Published by the American Astronomical Society.Recently we found compelling evidence for a gravitational-wave background with Hellings and Downs (HD) correlations in our 15 yr data set. These correlations describe gravitational waves as predicted by general relativity, which has two transverse polarization modes. However, more general metric theories of gravity can have additional polarization modes, which produce different interpulsar correlations. In this work, we search the NANOGrav 15 yr data set for evidence of a gravitational-wave background with quadrupolar HD and scalar-transverse (ST) correlations. We find that HD correlations are the best fit to the data and no significant evidence in favor of ST correlations. While Bayes factors show strong evidence for a correlated signal, the data does not strongly prefer either correlation signature, with Bayes factors ∼2 when comparing HD to ST correlations, and ∼1 for HD plus ST correlations to HD correlations alone. However, when modeled alongside HD correlations, the amplitude and spectral index posteriors for ST correlations are uninformative, with the HD process accounting for the vast majority of the total signal. Using the optimal statistic, a frequentist technique that focuses on the pulsar-pair cross-correlations, we find median signal-to-noise ratios of 5.0 for HD and 4.6 for ST correlations when fit for separately, and median signal-to-noise ratios of 3.5 for HD and 3.0 for ST correlations when fit for simultaneously. While the signal-to-noise ratios for each of the correlations are comparable, the estimated amplitude and spectral index for HD are a significantly better fit to the total signal, in agreement with our Bayesian analysis

The NANOGrav 15 yr Data Set: Search for Gravitational-wave Memory

\ua9 2025. The Author(s). Published by the American Astronomical Society.We present the results of a search for nonlinear gravitational-wave (GW) memory in the NANOGrav 15 yr data set. We find no significant evidence for memory signals in the data set, with a maximum Bayes factor of 3.1 in favor of a model including memory. We therefore place upper limits on the strain of potential GW memory events as a function of sky location and observing epoch. We find upper limits that are not always more constraining than previous NANOGrav results. We show that it is likely due to the increase in common red noise between the 12.5 and 15 yr NANOGrav data sets

The NANOGrav 15 Yr Data Set: Removing Pulsars One by One from the Pulsar Timing Array

\ua9 2025. The Author(s). Published by the American Astronomical Society. Evidence has emerged for a stochastic signal correlated among 67 pulsars within the 15 yr pulsar-timing data set compiled by the NANOGrav collaboration. Similar signals have been found in data from the European, Indian, Parkes, and Chinese pulsar timing arrays. This signal has been interpreted as indicative of the presence of a nanohertz stochastic gravitational-wave background (GWB). To explore the internal consistency of this result, we investigate how the recovered signal strength changes as we remove the pulsars one by one from the data set. We calculate the signal strength using the (noise-marginalized) optimal statistic, a frequentist metric designed to measure the correlated excess power in the residuals of the arrival times of the radio pulses. We identify several features emerging from this analysis that were initially unexpected. The significance of these features, however, can only be assessed by comparing the real data to synthetic data sets. After conducting identical analyses on simulated data sets, we do not find anything inconsistent with the presence of a stochastic GWB in the NANOGrav 15 yr data. The methodologies developed here can offer additional tools for application to future, more sensitive data sets. While this analysis provides an internal consistency check of the NANOGrav results, it does not eliminate the necessity for additional investigations that could identify potential systematics or uncover unmodeled physical phenomena in the data

A ambientalização curricular de programas de Educação Física em universidades federais do Brasil

ResumoO objetivo do artigo foi analisar evidências de ambientalização curricular em programas de educação física no contexto do ensino superior brasileiro. De acordo com esse objetivo, o "corpus" de análise foi composto pelos planos de ensino de disciplinas que abordam questões ambientais em programas de educação física de Universidades Federais do Brasil. O "corpus" foi analisado a partir da Análise Textual Discursiva, metodologia que compreende: a) desmontagem dos textos (unitarização); b) estabelecimento de relações (categorização); c) captação de um novo emergente (metatexto original). As unidades de significado destacadas na etapa de unitarização foram organizadas em categorias pré-definidas a partir das características da Rede ACES para um estudo ambientalizado. A escolha desse referencial ("benchmark") se justifica por sua representatividade diante das produções científicas no campo ambiental, constituindo-se como significativo (con)texto social atual, trazendo em suas definições o resultado de embates históricos em torno da emergência/legitimação de elementos que constituem os atuais conceitos sobre o "ambiental". Esperar-se-ia, assim, que pelo menos os conceitos chaves de cada categoria fossem contemplados pelas propostas presentes em planos de ensino de disciplinas que propõem um diálogo entre o campo ambiental e o campo da educação física. No entanto, os resultados da pesquisa mostram uma realidade bem diferente, colocando em evidência as práticas esportivas e recreativas na natureza como foco quase que exclusivo das disciplinas que abordam questões ambientais em programas de educação física de Universidades Federais do Brasil. Nos argumentos conclusivos são apresentadas significativas evidências sobre as dimensões dos discursos ambientais que estão sendo incorporados pelos currículos de educação física no âmbito do ensino (superior), assim como novas/"alternativas" perspectivas que emergem nos encontros entre o campo ambiental e o campo da educação física