Modelling of time-to-events in an ambispective study: illustration with the analysis of ABO blood groups on venous thrombosis recurrence

In studies of time-to-events, it is common to collect information about events that occurred before the inclusion in a prospective cohort. In an ambispective design, when the risk factors studied are independent of time, including both pre- and post-inclusion events in the analyses increases the statistical power but may lead to a selection bias. To avoid such a bias, we propose a survival analysis weighted by the inverse of the survival probability at the time of data collection about the events. This method is applied to the study of the association of ABO blood groups with the risk of venous thromboembolism (VT) recurrence in the MARTHA and MEGA cohorts. The former relying on an ambispective design and the latter on a standard prospective one. In the combined sample totalling 2,752 patients including 993 recurrences, compared with the O1 group, A1 has an increased risk (Hazard Ratio (HR) of 1.18, p=4.2x10-3), homogeneously in MARTHA and in MEGA. The same trend (HR=1.19, p=0.06) was observed for the less frequent A2 group. In conclusion, this work clarified the association of ABO blood groups with the risk of VT recurrence. Besides, the methodology proposed here to analyse time-independent risk factors of events in an ambispective design has an immediate field of application in the context of genome wide association studies.

The time-fractional kinetic equation for the non-equilibrium processes

In this study, we consider the non-Markovian dynamics of the generic non-equilibrium kinetic process. We summarize the generalized master equation, the continuous and discrete forms of the time-fractional diffusion equation. Using path integral formulation, we generalized the solutions of the Markovian system to the non-Markovian for the non-equilibrium kinetic processes. Then, we obtain the time-fractional kinetic equation for the non-equilibrium systems in terms of free energy. Finally, we introduce a time-fractional equation to analyse time evolution of the open probability for the deformed voltage-gated ion-channel system as an example.

Go with the FLOW: visualizing spatiotemporal dynamics in optical widefield calcium imaging

Widefield calcium imaging has recently emerged as a powerful experimental technique to record coordinated large-scale brain activity. These measurements present a unique opportunity to characterize spatiotemporally coherent structures that underlie neural activity across many regions of the brain. In this work, we leverage analytic techniques from fluid dynamics to develop a visualization framework that highlights features of flow across the cortex, mapping wavefronts that may be correlated with behavioural events. First, we transform the time series of widefield calcium images into time-varying vector fields using optic flow. Next, we extract concise diagrams summarizing the dynamics, which we refer to as FLOW (flow lines in optical widefield imaging) portraits . These FLOW portraits provide an intuitive map of dynamic calcium activity, including regions of initiation and termination, as well as the direction and extent of activity spread. To extract these structures, we use the finite-time Lyapunov exponent technique developed to analyse time-varying manifolds in unsteady fluids. Importantly, our approach captures coherent structures that are poorly represented by traditional modal decomposition techniques. We demonstrate the application of FLOW portraits on three simple synthetic datasets and two widefield calcium imaging datasets, including cortical waves in the developing mouse and spontaneous cortical activity in an adult mouse.

66 Cycle 1: Time for Peripherally Inserted Central Catheter (PICC) Insertion for Patients with Complex Infections in The Trauma and Orthopaedic Department at The Royal Infirmary of Edinburgh (RIE)

Introduction Bone, joint and soft tissue infections often require long term antibiotic therapy alongside operative management. Intravenous (IV) access is essential for antibiotic administration and monitoring. ‘Long-lines’ such as PICC provide reliable long-term IV access. Aim: analyse time to insertion of ‘Long-lines’ and effects on patient outcomes. Method Standard audit protocol. Data tool was developed, trialled, and tested. Data was collected retrospectively from departmental database and TRAK (Online patient record system) for patients admitted with suspected bone, joint or soft tissues infection from 01/11/19- 29/2/20. Results 91 patients admitted with presumed infection. PICC requested in 30 patients. Mean time to PICC request from admission was 8.7 days (1-33). 23 patients received PICC. Mean time to PICC following request was 6.7 days (1-15). Mean time to PICC from admission was 15.9 days (4-39). 10 of 30(33.3%) patients had documented missed antibiotics due to lack of IV access. Conclusions Large variation in time for patients receiving PICC from admission and from time of request. A significant proportion of patients are missing IV antibiotics due to poor IV access. Improvement in time to ‘longlines’ would reduce incidence of venepuncture in patients requiring IV access in addition to reducing missed IV antibiotics due to lack of access.

Pedagogical Variables and Motor Commitment in the Planning of Invasion Sports in Primary Education

Research on Sports Pedagogy necessitates studying the knowledge possessed by pre-service teachers (PSTs) and its application in the planning of sports in school. The main objectives of this study were to consider if PSTs really apply their beliefs when planning their didactic units, and to analyse time management and its influence on external load in invasion sports. Eighteen PSTs were interviewed and 899 learning tasks were coded using the Integral Analysis System of Training Tasks. Three groups of pedagogical variables (type of task, game phase and game situation), organisational variables related to time and the external load were analysed. A descriptive analysis was made of the contents of the interviews, on the use of the pedagogical variables and on those used in the learning tasks. Application exercises were set by 50.70% of the tasks and 44.30% were without opposition. This did not coincide with teachers’ beliefs, as they did not show a clear choice of ideal type of task and indicated that individual game situations with opposition were preferable. A descriptive analysis was also made of the organisational variables according to the planned sport. Inferential analysis using the Kruskal-Wallis H test and pairwise multiple comparisons showed differences in the motor commitment and external load of the task*time depending on the type of invasion sport (p < 0.05). Time management conditioned the motor commitment and task load.

Reduction of the VLF Signal Phase Noise Before Earthquakes

In this paper we analyse temporal variations of the phase of a very low frequency (VLF) signal, used for the lower ionosphere monitoring, in periods around four earthquakes (EQs) with magnitude greater than 4. We provide two analyses in time and frequency domains. First, we analyse time evolution of the phase noise. And second, we examine variations of the frequency spectrum using Fast Fourier Transform (FFT) in order to detect hydrodynamic wave excitations and attenuations. This study follows a previous investigation which indicated the noise amplitude reduction, and excitations and attenuations of the hydrodynamic waves less than one hour before the considered EQ events as a new potential ionospheric precursors of earthquakes. We analyse the phase of the ICV VLF transmitter signal emitted in Italy recorded in Serbia in time periods around four earthquakes occurred on 3, 4 and 9 November 2010 which are the most intensive earthquakes analysed in the previous study. The obtained results indicate very similar changes in the noise of phase and amplitude, and show an agreement in recorded acoustic wave excitations. However, properties in the obtained wave attenuation characteristics are different for these two signal parameters.

A pipeline to analyse time-course gene expression data

The phenotypic diversity of cells is governed by a complex equilibrium between their genetic identity and their environmental interactions: Understanding the dynamics of gene expression is a fundamental question of biology. However, analysing time-course transcriptomic data raises unique challenging statistical and computational questions, requiring the development of novel methods and software. This workflow provides a step-by-step tutorial of the methodology used to analyse time-course data: (1) quality control and normalization of the dataset; (2) differential expression analysis using functional data analysis; (3) clustering of time-course data; (4) interpreting clusters with GO term and KEGG pathway enrichment analysis. As a case study, we apply this workflow to time-course transcriptomic data from mice exposed to four strains of influenza to showcase every step of the pipeline.

The multidimensionality of poverty: Time poverty in Spain

In the last few years the concept of poverty has evolved from simply being a measure of income poverty to a multidimensional measure that takes into consideration essential aspects for the attainment of certain levels of wellbeing. This paper assesses how the incorporation of time can contribute to the measurement of poverty. To this end, we reviewed the time poverty literature and focused on the Spanish case. We use the Spanish Time-Use Survey 2009-2010 to analyse time poverty in Spain, and estimate a probit model to assess the probability of being time poor in Spain and identify key factors associated with time poverty in Spain.

Cancer Incidence Trends in the Oil Shale Industrial Region in Estonia

Large oil shale resources are found in Eastern Estonia, where the mineral resource is mined, excavated, and used for electricity generation and shale oil extraction. During industrial activities in the last 100 years, pollutants have been emitted in large amounts, some of which are toxic and carcinogenic. The current study aims to analyse time trends in cancer incidence in the oil shale industry-affected areas and compare them with overall cancer incidence rates and trends in Estonia. We analysed Estonian Cancer Registry data on selected cancer sites that have been previously indicated to have relationships with industrial activities like oil shale extraction. We included lung cancer, kidney cancer, urinary bladder cancer, leukaemia, breast cancer, and non-Hodgkin’s lymphoma. A statistically significantly higher lung cancer age-standardized incidence rate (ASIR) was found during the study period (1992—2015) only in males in the oil shale areas as compared to males in Estonia overall: 133.6 and 95.5 per 100,000, respectively. However, there appeared to be a statistically significant (p < 0.05) decrease in the lung cancer ASIR in males in the oil shale areas (overall decrease 28.9%), whereas at the same time, there was a significant increase (p < 0.05) in non-oil shale areas (13.3%) and in Estonia overall (1.5%). Other cancer sites did not show higher ASIRs in the oil shale industrial areas compared to other areas in Estonia. Possible explanations could be improved environmental quality, socio-economic factors, and other morbidities.

When the disc’s away, the stars will play: dynamical masses in the nova-like variable KR Aur with a pinch of accretion

ABSTRACT We obtained time-resolved optical photometry and spectroscopy of the nova-like variable KR Aurigae in the low state. The spectrum reveals a DAB white dwarf (WD) and a mid-M dwarf companion. Using the companion star’s i-band ellipsoidal modulation we refine the binary orbital period to be P = 3.906519 ± 0.000001 h. The light curve and the spectra show flaring activity due to episodic accretion. One of these events produced brightness oscillations at a period of 27.4 min, that we suggest to be related with the rotation period of a possibly magnetic WD at either 27.4 or 54.8 min. Spectral modelling provided a spectral type of M4–5 for the companion star and $T_{1}=27\, 148$ $\pm \, 496$ K, $\log \, g=8.90 \pm 0.07$, and $\log (\mathrm{He/H})= -0.79^{+0.07}_{-0.08}$ for the WD. By simultaneously fitting absorption- and emission-line radial velocity curves and the ellipsoidal light curve, we determined the stellar masses to be $M_1 = 0.94^{+0.15}_{-0.11}\, {\rm{M}_{\rm \odot}}$ and $M_2 = 0.37^{+0.07}_{-0.07}\,{\rm{M}_{\rm \odot}}$ for the WD and the M-dwarf companion, respectively, and an orbital inclination of $47^{+1^{\rm o}}_{-2^{\rm o}}$. Finally, we analyse time-resolved spectroscopy acquired when the system was at an i-band magnitude of 17.1, about 1.3 mag brighter than it was in the low state. In this intermediate state, the line profiles contain an emission S-wave delayed by ≃0.2 orbital cycle relative to the motion of the WD, similar to what is observed in SW Sextantis stars in the high state.