Static versus dynamic fluctuations in the one-dimensional extended Hubbard model

The extended Hubbard Hamiltonian is a widely accepted model for uncovering the effects of strong correlations on the phase diagram of low-dimensional systems, and a variety of theoretical techniques have been applied to it. In this paper the world-line quantum Monte Carlo method is used to study spin, charge, and bond order correlations of the one-dimensional extended Hubbard model in the presence of coupling to the lattice. A static alternating lattice distortion (the ionic Hubbard model) leads to enhanced charge density wave correlations at the expense of antiferromagnetic order. When the lattice degrees of freedom are dynamic (the Hubbard-Holstein model), we show that a similar effect occurs even though the charge asymmetry must arise spontaneously. Although the evolution of the total energy with lattice coupling is smooth, the individual components exhibit sharp crossovers at the phase boundaries. Finally, we observe a tendency for bond order in the region between the charge and spin density wave phases.Comment: Corrected typos. (10 pages, 9 figures

Remotely Controlled Radiation Detection Laboratory for Online Education

This paper is meant to show readers how a remote radiation detection laboratory can be created using commercial-off-the-shelf equipment and "normal" radiation detection software.Remote education capabilities make up an important component of an institution’s services. A challenge in improving remote education capabilities has been developing experiments for remote laboratory education that mimic the experience found in the traditional laboratory setting. To meet this challenge, a remote laboratory for radiation detection education has been developed for the nuclear engineering and health physics disciplines. The laboratory makes use of robotics for linear and rotational movements that imitate the hands-on motion found in an in-person laboratory setting. Once logged into the system, students have access to industry-standard software and can view the experiment apparatus through a live-time camera feed. The experiments developed for this remote laboratory include counting statistics and dead time, inverse square law, Compton scattering, gamma spectroscopy with scintillation detectors, gamma attenuation, and uranium enrichment determination

Usability and Psychosocial Impact of Decision Support to Increase Sexual Health Education in American Indian and Alaska Native Communities

Despite sexual and reproductive health disparities, few evidence-based sexual health education programs exist for American Indian/Alaska Native (AI/AN) youth, with even fewer tools available to assist AI/AN communities in adopting, implementing, and maintaining such programs. iCHAMPSS (Choosing And Maintaining effective Programs for Sex education in Schools) is a theory- and web-based decision-support-system designed to address dissemination barriers and increase the reach and fidelity of evidence-based programs (EBPs), specifically sexual health education programs. To investigate the potential of iCHAMPSS in AI/AN communities, we pilot-tested iCHAMPSS with adult stakeholders (N = 36) from agencies across the country that serve AI/AN communities. Stakeholders were recruited to review selected iCHAMPSS tools over two weeks in spring 2016. Pre- and post-surveys were administered to assess usability constructs, short-term psychosocial outcomes, and perceived feasibility. Data were analyzed using descriptive and non-parametric statistics. iCHAMPSS was perceived as acceptable, easy to use, credible, appealing, more helpful than current resources, and impactful of EBP adoption, implementation, and maintenance. Conversely, using iCHAMPSS significantly increased participants’ perceived barriers to adopting an EBP (p = 0.01). Overall, AI/AN stakeholders responded positively to iCHAMPSS, indicating the potential for adaptation to support the dissemination and implementation of evidence-based sexual health education in AI/AN communities

Canadian high school rugby coaches readiness for an injury prevention strategy implementation: Evaluating a Train-the-Coach workshop

Background: Canadian rugby coach injury prevention beliefs and attitudes have not been studied, yet are key to informing injury prevention strategy implementation. Despite neuromuscular training (NMT) warm-up success in reducing injury, adoption of these programs is variable. Therefore, objectives of this study included (1) describing Canadian youth rugby coach injury prevention beliefs and attitudes and current warm-up practices and (2) evaluating intention to use a rugby-specific NMT warm-up. Methods: High school rugby coaches completed a questionnaire before and after a rugby-specific NMT warm-up workshop. The pre-workshop questionnaire captured demographics, current warm-up practice, and NMT warm-up knowledge and use. Both questionnaires captured injury prevention beliefs, attitudes and behavioral intention. Results: Forty-eight coaches participated in the workshops. Pre-workshop, 27% of coaches were aware of NMT warm-ups. Coaches primarily included aerobic and stretching components, while balance components were not common in their warm-ups over the past year. Additionally, 92% of coaches agreed to some extent they would “complete a rugby-specific warm-up program prior to every game and training session this season.” Post-workshop, 86% of coaches agreed to some extent that they would use the program in every rugby session. No differences were observed between pre- and post-workshop intention to implement the warm-up (p = 0.10). Interpretation: This is the first study to examine current Canadian youth rugby coach warm-up practices and intention to use NMT warm-ups. Canadian rugby coach intention to use a rugby-specific NMT warm-up is high, providing ample opportunity to investigate the efficacy of a NMT warm-up in youth rugby

A multi-resolution, non-parametric, Bayesian framework for identification of spatially-varying model parameters

This paper proposes a hierarchical, multi-resolution framework for the identification of model parameters and their spatially variability from noisy measurements of the response or output. Such parameters are frequently encountered in PDE-based models and correspond to quantities such as density or pressure fields, elasto-plastic moduli and internal variables in solid mechanics, conductivity fields in heat diffusion problems, permeability fields in fluid flow through porous media etc. The proposed model has all the advantages of traditional Bayesian formulations such as the ability to produce measures of confidence for the inferences made and providing not only predictive estimates but also quantitative measures of the predictive uncertainty. In contrast to existing approaches it utilizes a parsimonious, non-parametric formulation that favors sparse representations and whose complexity can be determined from the data. The proposed framework in non-intrusive and makes use of a sequence of forward solvers operating at various resolutions. As a result, inexpensive, coarse solvers are used to identify the most salient features of the unknown field(s) which are subsequently enriched by invoking solvers operating at finer resolutions. This leads to significant computational savings particularly in problems involving computationally demanding forward models but also improvements in accuracy. It is based on a novel, adaptive scheme based on Sequential Monte Carlo sampling which is embarrassingly parallelizable and circumvents issues with slow mixing encountered in Markov Chain Monte Carlo schemes

Dataset of oxygen, carbon, and strontium isotope values from the Imperial Roman site of Velia (ca. 1st-2nd c. CE), Italy

The oxygen (δ18Ocarbonate), strontium (87Sr/86Sr), and previously unpublished carbon (δ13Ccarbonate) isotope data presented herein from the Imperial Roman site of Velia (ca. 1st to 2nd c. CE) were obtained from the dental enamel of human permanent second molars (M2). In total, the permanent M2s of 20 individuals (10 male and 10 female) were sampled at the Museo delle Civiltà in Rome (formerly the Museo Nazionale Preistorico Etnografico "L. Pigorini") and were subsequently processed and analysed at McMaster University. A subsample of teeth (n=5) was initially subjected to Fourier transform infrared spectroscopy (FTIR) analysis to assess for diagenetic alteration through calculation of crystallinity index (CI) values. Subsequently, tooth enamel was analysed for δ13Ccarbonate and δ18Ocarbonate (VPDB) using a VG OPTIMA Isocarb isotope ratio mass spectrometer (IRMS) at McMaster Research for Stable Isotopologues (MRSI), and 87Sr/86Sr was measured by dynamic multi-collection using a thermal ionization mass spectrometer (TIMS) in the School of Geography and Earth Sciences. The dental enamel isotope data presented represent the first δ18O, δ13Ccarbonate, and 87Sr/86Sr values analysed from Imperial Roman Campania to date, providing data of use for comparative analyses of δ18O, δ13C, and 87Sr/86Sr values within the region and for assisting in documenting human mobility in archaeological contexts. Full interpretation of the δ18O and 87Sr/86Sr data presented here is provided in "Imperial Roman mobility and migration at Velia (1st to 2nd c. CE) in southern Italy" [1]

The Improving Rural Cancer Outcomes (IRCO) Trial: A factorial clusterrandomised controlled trial of a complex intervention to reduce time to diagnosis in rural patients with cancer in Western Australia: A study protocol

Introduction: While overall survival for most common cancers in Australia is improving, the rural-urban differential has been widening, with significant excess deaths due to lung, colorectal, breast and prostate cancer in regional Australia. Internationally a major focus on understanding variations in cancer outcomes has been later presentation to healthcare and later diagnosis. Approaches to reducing time to diagnosis of symptomatic cancer include public symptom awareness campaigns and interventions in primary care to improve early cancer detection. This paper reports the protocol of a factorial cluster-randomised trial of community and general practice (GP) level interventions to reduce the time to diagnosis of cancer in rural Western Australia (WA). Methods and analysis: The community intervention is a symptom awareness campaign tailored for rural Australians delivered through a community engagement model. The GP intervention includes a resource card with symptom risk assessment charts and local referral pathways implemented through multiple academic detailing visits and case studies. Participants are eligible if recently diagnosed with breast, colorectal, lung or prostate cancer who reside in specific regions of rural WA with a planned sample size of 1350. The primary outcome is the Total Diagnostic Interval, defined as the duration from first symptom (or date of cancer screening test) to cancer diagnosis. Secondary outcomes include cancer stage, healthcare utilisation, disease-free status, survival at 2 and 5 years and cost-effectiveness. Ethics and dissemination: Ethics approval has been granted by the University of Western Australia and from all relevant hospital recruitment sites in WA. Results: Results of this trial will be reported in peerreviewed publications and in conference presentations. Trial registration number: Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN12610000872033

Birds of a feather eat plastic together: high levels of plastic ingestion in Great Shearwater adults and juveniles across their annual migratory cycle

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Robuck, A. R., Hudak, C. A., Agvent, L., Emery, G., Ryan, P. G., Perold, V., Powers, K. D., Pedersen, J., Thompson, M. A., Suca, J. J., Moore, M. J., Harms, C. A., Bugoni, L., Shield, G., Glass, T., Wiley, D. N., & Lohmann, R. Birds of a feather eat plastic together: high levels of plastic ingestion in Great Shearwater adults and juveniles across their annual migratory cycle. Frontiers in Marine Science, 8, (2022): 719721, https://doi.org/10.3389/fmars.2021.719721.Limited work to date has examined plastic ingestion in highly migratory seabirds like Great Shearwaters (Ardenna gravis) across their entire migratory range. We examined 217 Great Shearwaters obtained from 2008–2019 at multiple locations spanning their yearly migration cycle across the Northwest and South Atlantic to assess accumulation of ingested plastic as well as trends over time and between locations. A total of 2328 plastic fragments were documented in the ventriculus portion of the gastrointestinal tract, with an average of 9 plastic fragments per bird. The mass, count, and frequency of plastic occurrence (FO) varied by location, with higher plastic burdens but lower FO in South Atlantic adults and chicks from the breeding colonies. No fragments of the same size or morphology were found in the primary forage fish prey, the Sand Lance (Ammodytes spp., n = 202) that supports Great Shearwaters in Massachusetts Bay, United States, suggesting the birds directly ingest the bulk of their plastic loads rather than accumulating via trophic transfer. Fourier-transform infrared spectroscopy indicated that low- and high-density polyethylene were the most common polymers ingested, within all years and locations. Individuals from the South Atlantic contained a higher proportion of larger plastic items and fragments compared to analogous life stages in the NW Atlantic, possibly due to increased use of remote, pelagic areas subject to reduced inputs of smaller, more diverse, and potentially less buoyant plastics found adjacent to coastal margins. Different signatures of polymer type, size, and category between similar life stages at different locations suggests rapid turnover of ingested plastics commensurate with migratory stage and location, though more empirical evidence is needed to ground-truth this hypothesis. This work is the first to comprehensively measure the accumulation of ingested plastics by Great Shearwaters over the last decade and across multiple locations spanning their yearly trans-equatorial migration cycle and underscores their utility as sentinels of plastic pollution in Atlantic ecosystems.This project was supported by the NOAA Fisheries National Seabird Program and the Volgenau Foundation. AR acknowledges support from the National Oceanic and Atmospheric Administration Dr. Nancy Foster Scholarship Program (NOAA Award Number NA17NOS4290028), the Robert and Patricia Switzer Foundation, the STEEP Superfund Research Program (NIEHS Award Number P42ES027706), and the Oak Ridge Institute for Science and Education (ORISE) program. LB was funded by INCT-Mar COI and PQ Grant No. 311409/2018-0, both by the Brazilian National Research Council (CNPq). JS was funded by the National Science Foundation Graduate Research Fellowship program

Birds of a Feather Eat Plastic Together: High Levels of Plastic Ingestion in Great Shearwater Adults and Juveniles Across Their Annual Migratory Cycle

Limited work to date has examined plastic ingestion in highly migratory seabirds like Great Shearwaters (Ardenna gravis) across their entire migratory range. We examined 217 Great Shearwaters obtained from 2008–2019 at multiple locations spanning their yearly migration cycle across the Northwest and South Atlantic to assess accumulation of ingested plastic as well as trends over time and between locations. A total of 2328 plastic fragments were documented in the ventriculus portion of the gastrointestinal tract, with an average of 9 plastic fragments per bird. The mass, count, and frequency of plastic occurrence (FO) varied by location, with higher plastic burdens but lower FO in South Atlantic adults and chicks from the breeding colonies. No fragments of the same size or morphology were found in the primary forage fish prey, the Sand Lance (Ammodytes spp., n = 202) that supports Great Shearwaters in Massachusetts Bay, United States, suggesting the birds directly ingest the bulk of their plastic loads rather than accumulating via trophic transfer. Fourier-transform infrared spectroscopy indicated that low- and high-density polyethylene were the most common polymers ingested, within all years and locations. Individuals from the South Atlantic contained a higher proportion of larger plastic items and fragments compared to analogous life stages in the NW Atlantic, possibly due to increased use of remote, pelagic areas subject to reduced inputs of smaller, more diverse, and potentially less buoyant plastics found adjacent to coastal margins. Different signatures of polymer type, size, and category between similar life stages at different locations suggests rapid turnover of ingested plastics commensurate with migratory stage and location, though more empirical evidence is needed to ground-truth this hypothesis. This work is the first to comprehensively measure the accumulation of ingested plastics by Great Shearwaters over the last decade and across multiple locations spanning their yearly trans-equatorial migration cycle and underscores their utility as sentinels of plastic pollution in Atlantic ecosystems

Gaze sensitivity: function and mechanisms from sensory and cognitive perspectives

Sensitivity to the gaze of other individuals has long been a primary focus in sociocognitive research on humans and other animals. Information about where others are looking may often be of adaptive value in social interactions and predator avoidance, but studies across a range of taxa indicate there are substantial differences in the extent to which animals obtain and use information about other individuals' gaze direction. As the literature expands, it is becoming increasingly difficult to make comparisons across taxa as experiments adopt and adjust different methodologies to account for differences between species in their socioecology, sensory systems and possibly also their underlying cognitive mechanisms. Furthermore, as more species are found to exhibit gaze sensitivity, more terminology arises to describe the behaviours. To clarify the field, we propose a restricted nomenclature that defines gaze sensitivity in terms of observable behaviour, independent of the underlying mechanisms. This is particularly useful in nonhuman animal studies where cognitive interpretations are ambiguous. We then describe how socioecological factors may influence whether species will attend to gaze cues, and suggest links between ultimate factors and proximate mechanisms such as cognition and perception. In particular, we argue that variation in sensory systems, such as retinal specializations and the position of the eyes, will determine whether gaze cues (e.g. head movement) are perceivable during visual fixation. We end by making methodological recommendations on how to apply these variations in socioecology and visual systems to advance the field of gaze research