In this retrospective cohort study of military trainees, symptomatic-only coronavirus disease 2019 (COVID-19) arrival antigen testing decreased isolation requirements without increasing secondary cases compared to universal antigen testing. Symptomatic-only arrival antigen testing is a feasible alternative for individuals entering a congregant setting with a high risk of COVID-19 transmission.

Secondary use of clinical data in research or learning activities (SeConts) has the potential to improve patient care and biomedical knowledge. Given this potential, the ethical question arises whether physicians have a professional duty to support SeConts. To investigate this question, we analyze prominent international declarations on physicians’ professional ethics to determine whether they include duties that can be considered as good reasons for a physicians’ professional duty to support SeConts. Next, we examine these documents to identify professional duties that might conflict with a potential duty of physicians to support SeConts.

In the present study, the effect of training on inter-observer reliability was studied for a 5-category lameness scoring system used for routine on-farm surveys of welfare in dairy cattle. The inter-observer agreement between an experienced and an initially inexperienced observer was determined during an initial training phase and at specific time points in the course of data collection in 46 herds. During the training phase on three farms, inter-observer reliability increased to an acceptable level for both the 5-category gait scoring system and the distinction between lame and non-lame cows.

The 4th testing after 17 on-farm visits revealed a considerable increase in inter-observer reliability which was further improved in the course of the on-farm visits.

In conclusion, acceptable inter-observer agreement for differentiating between non-lame and lame cows was achieved after only a brief introduction. In order to obtain high inter-observer repeatability with the 5-category gait scoring system used in this study, (more) intensive training procedures are required.

Waterfall Bluff is a rock shelter in eastern Pondoland, South Africa, adjacent to a narrow continental shelf that limited coastline movements across glacial/interglacial cycles. The archaeological deposits are characterized by well-preserved stratigraphy, faunal, and botanical remains alongside abundant stone artifacts and other materials. A comprehensive dating protocol consisting of 5 optically stimulated luminescence ages and 51 accelerator mass spectrometry 14C ages shows that the record of hunter-gatherer occupations at Waterfall Bluff persisted from the late Pleistocene to the Holocene, spanning the last glacial maximum and the transition from the Pleistocene to the Holocene. Here, we provide detailed descriptions about the sedimentary sequence, chronology, and characteristics of the archaeological deposits at Waterfall Bluff. Remains of marine mollusks and marine fish also show, for the first time, that coastal foraging was a component of some hunter-gatherer groups’ subsistence practices during glacial phases in the late Pleistocene. The presence of marine fish and shellfish further demonstrates that hunter-gatherers selectively targeted coastal resources from intertidal and estuarine habitats. Our results therefore underscore the idea that Pondoland's coastline remained a stable and predictable point on the landscape over the last glacial/interglacial transition being well positioned for hunter-gatherers to access resources from the nearby coastline, narrow continental shelf, and inland areas.

We have studied the structures of Al/Si disordered leucite and bicchulite with a quantum mechanical version of the virtual crystal approximation, VCA. In leucite, the average tetrahedron has a composition of (AlSi2)O4, while bicchulite represents an extreme case with (Al2Si)O4 tetrahedra. Both structures are well described with the VCA. In conjunction with an earlier study, where we have shown that the (AlSi)O4 tetrahedra in gehlenite and Al,Si-disordered octahedra are also well reproduced, we have now established that the VCA gives a reliable description of the averaged structure of disordered aluminosilicates over the whole compositional range. The current calculations confirm that Al/Si ordering is not driving the cubic to tetragonal phase transformation in leucite. In bicchulite, the model calculations are consistent with hydrogen on Wyckoff position 8c, in agreement with the result of a single crystal X-ray diffraction study, but in variance with results based on a neutron powder diffraction study.

The infrared (IR) spectra of almandine-grossular and almandine-pyrope garnet solid solutions have been measured using the powder method. Frequency shifts of a band related to internal vibrations associated with the 8-co-ordinate dodecahedral site are nonlinear in almandine-grossular garnets and mimic the form of its molar volume of mixing curve. Almandine-pyrope solid solutions have nearly ideal molar volumes of mixing and the frequency shift of this same 8-co-ordinate site-related band is linear. The IR data support the empirically based crystal chemical model of Equivalent Site (ES) behaviour (Newton and Wood, 1980). The IR spectra give no indication of long-range ordering between Ca and Fe2+ in garnet, but thermodynamic calculations involving Ca-poor garnets might be affected by small volume or short-range ordering anomalies.

Ab initio total energy calculations based on the local density approximation (LDA) and using a conjugate-gradient solver for the Kohn-Sham equations have been performed for cordierite, brucite, (Mg(OH)2) and diaspore (AlOOH). The calculated fractional coordinates of all structures are in good agreement with experimental diffraction data. The angle of the non-linear hydrogen bond in diaspore is reproduced well. The Raman active OH stretching frequency in brucite has been calculated using the frozen phonon approach and the calculated stretching frequency is in very good agreement with the observed value. The energetically most favourable calculated orientation of the proton-proton vector of an H2O molecule incorporated in the structural channels of cordierite agrees with findings deduced from spectroscopic data, and the calculated energy of hydration is in reasonable agreement with calorimetric data. It is therefore concluded that ab initio total energy calculations can confidently be used to predict properties of hydrogen bonded structures, which is difficult with conventional parameterized static lattice energy minimization calculations. An extension to the model is necessary to improve the agreement of the predicted to the observed lattice parameters for small structures.

The structure of a synthetic sample of analcime has been determined as a function of temperature between 30–300 K by high-resolution neutron powder diffraction. Although there are some reports of samples of analcime having non-cubic structures, the sample in our experiments remained cubic (space group la3d), and hence disordered, down to low temperatures. The absence of phase transitions involving ordering of the orientations of the water molecules, ordering of the sodium positions, or a displacive instability as in leucite and related materials, is discussed. We speculate that part of the reason for the absence of ordering of the water molecules or sodium cations is associated with the Al/Si disorder, which cannot order at low temperatures. We also discuss the likely distribution of the orientations of the water molecules at low temperatures, and propose that the water diads lie close to any of the crystal diads with the H-H Vectors lying close to the triads.

Background: External ventricular drain (EVD) insertion is a common neurosurgical procedure performed in patients with life-threatening conditions, but can be associated with complications. The objectives of this study are to evaluate data on national practice patterns and complications rates in order to optimize clinical care Methods: The Canadian Neurosurgery Research Collaborative conducted a prospective multi-centre registry of patients undergoing EVD insertions at Canadian residency programs Results: In this interim analysis, 4 sites had recruited 46 patients (mean age: 53.9 years, male:female 2:1). Most EVD insertions occurred outside of the operating theatre, using free-hand technique, and performed by junior neurosurgery residents (R1-R3). The catheter tip was in the ipsilateral frontal horn or body of the lateral ventricle in 76% of cases. Suboptimally placed catheters did not have higher rates of short-term occlusion. EVD-related hemorrhage occurred in 6.5% (3/45) with only 1 symptomatic patient. EVD-related infection occurred in 13% (6/46) at a mean of 6 days and was associated with longer duration of CSF drainage (P=0.039; OR: 1.13) Conclusions: Interim results indicate rates of EVD-related complications may be higher than previously thought. This study will continue to recruit patients to confirm these findings and determine specific risk factors associated with them

A recent theoretical literature highlights the role of endogenous firm entry as an internal amplification mechanism of business cycle fluctuations. The amplification mechanism works through the competition effect (CE) and the variety effect (VE). This paper tests the significance of this amplification mechanism, quantifies its importance, and disentangles the CE and VE. To this end, we estimate a medium-scale real business cycle model with firm entry for the U.S. economy. The CE and VE are estimated to be statistically significant. Together, they amplify the volatility of output by 8.5% relative to a model in which both effects are switched off. The CE accounts for most amplification, whereas the VE only plays a minor role.

Background: No standardized method of resident operative-case logging exists. Our study sought to develop a standardized form used by residents to log operative-cases. Methods: Members of the Canadian Neurosurgery Research Collaborative (CNRC), a national resident-led research organization have created a standardized document based on the current Royal College objectives for operative procedures (section 5). Modifications to structure and content will be guided via consensus from Canadian neurosurgery program-directors. Results: Program directors in each CNRC collaborative institution will be asked to modify the standardized form. The CNRC currently involves thirteen of the fourteen Canadian neurosurgery residency programs. Additional consensus, if necessary, can be reached at the Royal College meeting for program directors of neurosurgery March 20th 2017. Conclusions: A standardized operative-case log represents the first step in a prospective study towards compiling operative volume of all Canadian neurosurgical residents over one academic year. Such data will be essential to guide informed decisions with regard to Royal College requirements as Canadian neurosurgical programs transition to a competency based framework.

Background: Communicating with senior neurosurgical colleagues during residency necessitates a reliable and versatile smartphone. Smartphones and their apps are commonplace. They enhance communication with colleagues, provide the ability to access patient information and results, and allow access to medical reference applications. Patient data safety and compliance with the Personal Health Information Protection Act (PHIPA, 2004) in Canada remain a public concern that can significantly impact the way in which mobile smartphones are utilized by resident physicians Methods: Through the Canadian Neurosurgery Research Collaborative (CNRC), an online survey characterizing smartphone ownership and utilization of apps among Canadian neurosurgery residents and fellows was completed in April 2016. Results: Our study had a 47% response rate (80 surveys completed out of 171 eligible residents and fellows). Smartphone ownership was almost universal with a high rate of app utilization for learning and facilitating the care of patients. Utilization of smartphones to communicate and transfer urgent imaging with senior colleagues was common. Conclusions: Smartphone and app utilization is an essential part of neurosurgery resident workflow. In this study we characterize the smartphone and app usage within a specialized cohort of residents and suggest potential solutions to facilitate greater PHIPA adherence

Background: The Canadian Neurosurgery Research Collaborative (CNRC) was founded in November 2015 as a resident-led national network for multicentre research. We present an annual report of our activities. Methods: CNRC meetings and publications were reviewed and summarized. The status of ongoing and future studies was collected from project leaders. Results: In its first year, the CNRC produced two papers accepted for publication in the Canadian Journal of Neurological Sciences: A CNRC launch letter and a study of operative volume at Canadian neurosurgery residency programs. Three manuscripts are in preparation: 1) a study of the demographics of Canadian neurosurgery residents, 2) an assessment of mobile devices usage patterns and 3) a validation study of the most utilized neurosurgery mobile apps. In addition, protocols for two multi-centre studies are currently undergoing national Research Ethics Board review: A retrospective study of the incidence and predictors of cerebellar mutism and a prospective registry of external ventricular drain procedures and complications. The network is now a registered not-for-profit organization endorsed by the Canadian Neurosurgical Society. Conclusions: The CNRC is a feasibile, relevant and productive resident-led national research network. As the CNRC matures, we look forward to expanding the scope and impact of its projects.