Wetland sediments are valuable archives of environmental change but can be challenging to date. Terrestrial macrofossils are often sparse, resulting in radiocarbon (14C) dating of less desirable organic fractions. An alternative approach for capturing changes in atmospheric 14C is the use of terrestrial microfossils. We 14C date pollen microfossils from two Australian wetland sediment sequences and compare these to ages from other sediment fractions (n = 56). For the Holocene Lake Werri Berri record, pollen 14C ages are consistent with 14C ages on bulk sediment and humic acids (n = 14), whilst Stable Polycyclic Aromatic Carbon (SPAC) 14C ages (n = 4) are significantly younger. For Welsby Lagoon, pollen concentrate 14C ages (n = 21) provide a stratigraphically coherent sequence back to 50 ka BP. 14C ages from humic acid and >100 µm fractions (n = 13) are inconsistent, and often substantially younger than pollen ages. Our comparison of Bayesian age-depth models, developed in Oxcal, Bacon and Undatable, highlight the strengths and weaknesses of the different programs for straightforward and more complex chrono-stratigraphic records. All models display broad similarities but differences in modeled age-uncertainty, particularly when age constraints are sparse. Intensive dating of wetland sequences improves the identification of outliers and generation of robust age models, regardless of program used.

A new scaling is derived that yields a Reynolds-number-independent profile for all components of the Reynolds stress in the near-wall region of wall-bounded flows, including channel, pipe and boundary layer flows. The scaling demonstrates the important role played by the wall shear stress fluctuations and how the large eddies determine the Reynolds number dependence of the near-wall turbulence behaviour.

The COVID-19 pandemic has had a major impact on clinical practice. Safe standards of practice are essential to protect health care workers while still allowing them to provide good care. The Canadian Society of Clinical Neurophysiologists, the Canadian Association of Electroneurophysiology Technologists, the Association of Electromyography Technologists of Canada, the Board of Registration of Electromyography Technologists of Canada, and the Canadian Board of Registration of Electroencephalograph Technologists have combined to review current published literature about safe practices for neurophysiology laboratories. Herein, we present the results of our review and provide our expert opinion regarding the safe practice of neurophysiology during the COVID-19 pandemic in Canada.

Magnetic field-assisted freeze-casting of porous alumina structures is reported. Different freeze-casting parameters were investigated and include the composition of the original slurry (Fe3O4 and PVA content) and the control of temperature during the free casting process. The optimum content of the additives in the slurry were 3 and 6 wt% for PVA and Fe3O4, respectively. These conditions provided the most unidirectional porous structures throughout the length of the sample. The sintering temperature was maintained at 1500 °C for 3 h. The application of a vertical magnetic field (parallel to ice growth direction) with using a cooling rate mode technique was found to enhance the homogeneity of the porous structure across the sample. The current study suggests that magnetic field-assisted freeze-casting is a viable method to create highly anisotropic porous ceramic structures.

When prolonged social withdrawal was first described in Japan as ‘hikikomori’, many studies examining its etiology suggested it to be related to factors unique to Japan and thus a culture-bound syndrome. However, existing research has suffered from a lack of standardised definitions, impeding comparability between studies. We summarise existing research and discuss its relevance to psychiatric practice today.

Since the killing of Trayvon Martin, the Stand Your Ground law has come to emblematize contemporary racial injustice. Yet, the legitimacy of the statute endures, as more than thirty-three states maintain and enforce some version of Stand Your Ground. This article probes the legitimacy basis for Stand Your Ground by excavating and reconstructing its formative logic. Drawing on archival records of the Florida state legislature’s 2005 pioneering of the statute, I examine how lawmakers justified its introduction, design, and enactment. I find that proponents of Stand Your Ground framed it as a response to the cost impositions of criminal prosecution and civil action. In introducing Stand Your Ground, they sought to protect self-defensive actors against the burdens of administrative and judicial proceedings by granting them civil immunity. During the mark-up process, legislators held an extensive debate over the intended beneficiaries and victims of Stand Your Ground. Racial codes animated this debate: “drug dealers,” “gangs,” and “cop killers” represented the types of criminal subjects whom the legal protections of Stand Your Ground should exclude, while “violent criminals” in the “bad part of town” represented the intended objects of the statute’s authorization of deadly force. Ultimately, legislators translated the concerns raised during this debate into statutory design choices that baked race into Stand Your Ground.

Laboratory experiments were performed on a geometrically scaled vertical-axis wind turbine model over an unprecedented range of Reynolds numbers, including and exceeding those of the full-scale turbine. The study was performed in the high-pressure environment of the Princeton High Reynolds number Test Facility (HRTF). Utilizing highly compressed air as the working fluid enabled extremely high Reynolds numbers while still maintaining dynamic similarity by matching the tip speed ratio (defined as the ratio of tip velocity to free stream, $\unicode[STIX]{x1D706}=\unicode[STIX]{x1D714}R/U$) and Mach number (defined at the turbine tip, $Ma=\unicode[STIX]{x1D714}R/a$). Preliminary comparisons are made with measurements from the full-scale field turbine. Peak power for both the field data and experiments resides around $\unicode[STIX]{x1D706}=1$. In addition, a systematic investigation of trends with Reynolds number was performed in the laboratory, which revealed details about the asymptotic behaviour. It was shown that the parameter that characterizes invariance in the power coefficient was the Reynolds number based on blade chord conditions ($Re_{c}$). The power coefficient reaches its asymptotic value when $Re_{c}>1.5\times 10^{6}$, which is higher than what the field turbine experiences. The asymptotic power curve is found, which is invariant to further increases in Reynolds number.

Inertial lift forces are exploited within inertial microfluidic devices to position, segregate and sort particles or droplets. However, the forces and their focusing positions can currently only be predicted by numerical simulations, making rational device design very difficult. Here we develop theory for the forces on particles in microchannel geometries. We use numerical experiments to dissect the dominant balances within the Navier–Stokes equations and derive an asymptotic model to predict the lateral force on the particle as a function of particle size. Our asymptotic model is valid for a wide array of particle sizes and Reynolds numbers, and allows us to predict how focusing position depends on particle size.

This brief report investigated coping strategies and their perceived effectiveness in response to a social stressor for 7–12 year olds with high-functioning autism spectrum disorders (HFASDs). Ninety-eight participants completed a self-report coping scale in response to a self-identified socially stressful situation. Responses yielded three categories of use and perceived effectiveness: (1) strategies used frequently and viewed as effective, (2) strategies not used frequently and not perceived as effective, and (3) strategies used frequently but not perceived as effective. Respondents reported high frequency use and high perceived effectiveness of six strategies that are generally considered as positive/engagement oriented coping. They also indicated low frequency use and low perceived effectiveness of five strategies broadly regarded as negative and avoidant/disengagement coping. The last cluster of four strategies, identified as frequently used but not effective, consisted of strategies less clearly categorised as positive/engaged vs. negative/disengaged. Implications for future research and clinical considerations are proposed.

This study investigated the relationships among stress, intrapersonal resiliency factors (self-esteem, locus of control, and optimism) and quality of life [QOL] (physical health and mental health) among caregivers of children with high functioning autism spectrum disorders (HFASDs). Participants consisted of 113 caregivers of children with HFASDs (males = 38.1%, females = 61.9%; age range = 27–62; 93.6% Caucasians) and 47 caregivers of typically developing children (males = 29.8%; females = 70.2%; age range = 30–56; 93.3% Caucasians). They completed a set of self-rating surveys on perceived locus of control, self-esteem, optimism, and QOL. Within-group inferential statistical analyses were applied. For the HFASD group analyses, two simultaneous regression analyses were used to study the independent effects of the three intrapersonal variables on the physical health and mental health QOL of the caregivers. Intrapersonal factors predicted self-reported mental health QOL but not physical health QOL in caregivers of children with HFASDs.