Estimation of the Trend Model with Autoregressive Errors

This paper is concerned with estimation and inference in a univariate p-th order autoregressive model with a time trend and, possibly, a unit root. Econometric interest in uni variate autoregressions is partly due to the direct benefits that are attainable from a better understanding of the time series structures of individual economic variables. In addition, developments in the study of univariate time series typically lead the way to developments in the study of multivariate time series models. There are two fundamental problems that complicate estimation and inference in autoregressive models with a possible unit root (i.e., AR/UR models). First, the ordinary least squares (OLS) estimator is biased and nonnormal in finite samples. Second, the asymptotic distribution of the OLS estimator is discontinuous at the boundary of the parameter space, being normal in the interior but nonstandard at the unit root endpoint

An Investigation of the Behavior of Citellus townsendii townsendii (Bachman) in Central Washington

This study of the behavior of Citellus townsendii townsendii was based on field observations of animals at their northern most distribution. The squirrels\u27 seasonal activity and behavioral repertoire, when considered with environmental parameters, suggest important adaptations for survival. The animals were in torpor from about July to February. Activity generally occurred during the midmorning hours, allowing them to avoid temperature extremes. Quantitative analysis of behavioral observations indicated that most activities occurred in a non-random order

Theology, News and Notes - Vol. 20, No. 04

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1048/thumbnail.jp

Theology, News and Notes - Vol. 18, No. 04

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1040/thumbnail.jp

Reconstructing long-term ecological data from annual census returns: a test for observer bias in counts of bird populations on Skokholm 1928–2002

Long-term ecological data are essential for conservation and to monitor and evaluate the effects of environmental change. Bird populations have been routinely assessed on islands off the British coast for many years and here long term data for one such island, Skokholm, is evaluated for robustness in the light of some 20 changes in observers (wardens) on the island over nearly eight decades. It was found that the dataset was robust when compared to bootstrap data with no species showing significant changes in abundance in years when wardens changed. It is concluded that the breeding bird populations on Skokholm and other British offshore islands are an important scientific resource and that protocols should be enacted to ensure the archiving of records, the continuance of data collection using standardised protocols into the future, and the recognition of such long-term data for science in terms of an appropriate conservation designation

An in-silico quality assurance study of contouring target volumes in thoracic tumors within a cooperative group setting

Introduction: Target delineation variability is a significant technical impediment in multi-institutional trials which employ intensity modulated radiotherapy (IMRT), as there is a real potential for clinically meaningful variances that can impact the outcomes in clinical trials. The goal of this study is to determine the variability of target delineation among participants from different institutions as part of Southwest Oncology Group (SWOG) Radiotherapy Committee\u27s multi-institutional in-silico quality assurance study in patients with Pancoast tumors as a dry run for trial implementation. Methods: CT simulation scans were acquired from four patients with Pancoast tumor. Two patients had simulation 4D-CT and FDG-FDG PET-CT while two patients had 3D-CT and FDG-FDG PET-CT. Seventeen SWOG-affiliated physicians independently delineated target volumes defined as gross primary and nodal tumor volumes (GTV_P and GTV_N), clinical target volume (CTV), and planning target volume (PTV).Six board-certified thoracic radiation oncologists were designated as the \u27Experts\u27 for this study. Their delineations were used to create a simultaneous truth and performance level estimation (STAPLE) contours using ADMIRE software (Elekta AB, Sweden 2017). Individual participants\u27 contours were then compared with Experts\u27 STAPLE contours. Results: When compared to the Experts\u27 STAPLE, GTV_P had the best agreement among all participants, while GTV_N showed the lowest agreement among all participants. There were no statistically significant differences in all studied parameters for all TVs for cases with 4D-CT versus cases with 3D-CT simulation scans. Conclusions: High degree of inter-observer variation was noted for all target volume except for GTV_P, unveiling potentials for protocol modification for subsequent clinically meaningful improvement in target definition. Various similarity indices exist that can be used to guide multi-institutional radiotherapy delineation QA credentialing

Visual storytelling using National Capability data

UKCEH held a visualisation-training event with three aims: (i) Increasing capacity in UK-SCAPE and in HEIs for scientific staff to create engaging visualisations from their research (ii) Fostering awareness of UK-SCAPE data and knowledge (iii) Supporting collaboration between staff funded on UK-SCAPE and researchers in the Higher Education Institutions (HEIs). The training was attended by 23 UKCEH and 17 HEI staff. Attendees were invited to join a series of 5 workshops. These workshops covered design principles, using design software, designing infographics as well as how to bring data into design software. There workshops were complemented with a frameing workshop at the beginning, a practical ‘drop-in’ workshop, and an evaluation workshop at the end. Feedback from participants highlighted: (i) An increased awareness of UK-SCAPE data, particularly amongst HEI participants (ii) Self-reported increase in design skills, knowledge and confidence (iii) Lack of time is a common barrier to producing visualisations, that still needs to be addressed (iv) Lack of access/knowledge of the right tools for visualisation was no longer reported as a barrier for any of the participants at the end of the course

Bivariate least squares linear regression: towards a unified analytic formalism

Concerning bivariate least squares linear regression, the classical approach pursued for functional models in earlier attempts is reviewed using a new formalism in terms of deviation (matrix) traces. Within the framework of classical error models, the dependent variable relates to the independent variable according to the usual additive model. Linear models of regression lines are considered in the general case of correlated errors in X and in Y for heteroscedastic data. The special case of (C) generalized orthogonal regression is considered in detail together with well known subcases. In the limit of homoscedastic data, the results determined for functional models are compared with their counterparts related to extreme structural models. While regression line slope and intercept estimators for functional and structural models necessarily coincide, the contrary holds for related variance estimators even if the residuals obey a Gaussian distribution, with a single exception. An example of astronomical application is considered, concerning the [O/H]-[Fe/H] empirical relations deduced from five samples related to different stars and/or different methods of oxygen abundance determination. For selected samples and assigned methods, different regression models yield consistent results within the errors for both heteroscedastic and homoscedastic data. Conversely, samples related to different methods produce discrepant results, due to the presence of (still undetected) systematic errors, which implies no definitive statement can be made at present. A comparison is also made between different expressions of regression line slope and intercept variance estimators, where fractional discrepancies are found to be not exceeding a few percent, which grows up to about 20% in presence of large dispersion data.Comment: 56 pages, 2 tables, and 2 figures. New Astronomy, accepte

Estimation in Semiparametric Transition Measurement Error Models for Longitudinal Data

We consider semiparametric transition measurement error models for longitudinal data, where one of the covariates is measured with error in transition models, and no distributional assumption is made for the underlying unobserved covariate. An estimating equation approach based on the pseudo conditional score method is proposed. We show the resulting estimators of the regression coefficients are consistent and asymptotically normal. We also discuss the issue of efficiency loss. Simulation studies are conducted to examine the finite-sample performance of our estimators. The longitudinal AIDS Costs and Services Utilization Survey data are analyzed for illustration

Supernova Neutrino-Nucleus Astrophysics

In this brief review we explore the role of neutrino-nucleus interactions in core-collapse supernovae and discuss open questions. In addition implications of neutrino mass and mixings in such environments are summarized.Comment: Revtex 4 figure