Glacial environments exhibit temporally variable microseismicity. To investigate how microseismicity influences event detection, we implement two noise-adaptive digital power detectors to process seismic data from Taylor Glacier, Antarctica. We add scaled icequake waveforms to the original data stream, run detectors on the hybrid data stream to estimate reliable detection magnitudes and compare analytical magnitudes predicted from an ice crack source model. We find that detection capability is influenced by environmental microseismicity for seismic events with source size comparable to thermal penetration depths. When event counts and minimum detectable event sizes change in the same direction (i.e. increase in event counts and minimum detectable event size), we interpret measured seismicity changes as ‘true’ seismicity changes rather than as changes in detection. Generally, one detector (two degree of freedom (2dof)) outperforms the other: it identifies more events, a more prominent summertime diurnal signal and maintains a higher detection capability. We conclude that real physical processes are responsible for the summertime diurnal inter-detector difference. One detector (3dof) identifies this process as environmental microseismicity; the other detector (2dof) identifies it as elevated waveform activity. Our analysis provides an example for minimizing detection biases and estimating source sizes when interpreting temporal seismicity patterns to better infer glacial seismogenic processes.

Introduction: The Canadian C-Spine rule (CCR) was validated for use by paramedics to selectively immobilize stable trauma patients. However, the CCR “Dangerous Mechanism” is highly prevalent in sports. Our objective was to compare the CCR performance in sport-related vs. non-sport-related injuries and describe sport-related mechanisms of injury. Methods: We reviewed data from the prospective paramedic CCR validation and implementation studies in 7 Canadian cities, which already included identification of sport-related injuries. A single trained reviewer further categorized mechanisms of injury using a pilot-tested standardized form, with the aid of a sport medicine physician in 15 ambiguous cases. We compared the CCR's recommendation to immobilize sport-injured versus non-sport-injured patients using chi-square and relative risk statistics with 95% confidence intervals. Results: There were 201 amateur sport-injuries among the 5,978 patients. Sport-injured patients were younger (mean age 36.2 vs. 42.4) and more predominantly male (60.5% vs 46.8%) than non-sport-injured patients. Paramedics did not miss any c-spine injuries when using the CCR. Although cervical spine injury rates were similar between sport (2/201; 1.0%) and non-sport injured patients (47/5,777; 0.8%), the absolute number of sport-related injuries was very small. Although CCR recommended immobilization equally between the two groups (46.4% vs 42.5% p = 0.29; RR 1.17 95%CI 0.87-1.57), the reason for immobilization was more likely to be a dangerous mechanism in sport injuries (68.6% vs 54.5%, p = 0.012). Although we observed a wide range of mechanisms, the most common dangerous mechanism responsible for immobilization in sport was axial load. Conclusion: The CCR identified all significant c-spine injuries in a cohort of patients assessed and transported by paramedics. Although an equal proportion of sport and non-sports related injuries were immobilized, a dangerous mechanism was most often responsible for immobilization in sport-related cases. These findings do not address the potential impact of using the CCR to evaluate all sport-related injuries in collegiate or pro athletes evaluated by sport medicine therapists and physicians, as these patients are rarely assessed by paramedics or transported to a hospital. It does support the safety and benefit of using the CCR in sport-injured patients for which paramedics are called.

Introduction: Mild traumatic brain injury (mTBI) with intracranial hemorrhage (ICH) is a common cause of Emergency Department (ED) visits. Over the past years, several authors have debated the relevance of radiological and clinical follow-up of these patients, as the main challenge is to identify patients at risk of clinical deterioration. Objectives: To determine whether demographic, clinical or radiological variables can predict patient deterioration. Methods: Design: An historical cohort was constituted in two level-1 trauma centers (Chu de Quebec - Hôpital de l'Enfant-Jésus (Québec City) and Hôpital du Sacré-Coeur (Montréal)). Participants: Medical records of mTBI patients aged ⩾16 with an ICH were reviewed using a standardized data collection tool. Consecutive medical records were reviewed from the end of 2017 backwards until sample saturation. Measures: Deterioration was defined as either death, deterioration of the control CT scan according to the radiologist, clinical deterioration or neurosurgical intervention. Analyses: Logistic regression analyses were performed to ascertain predictors of deterioration. Interobserver agreement was calculated. Results: A total of 274 patients were included in our analyses. Mean age was 60.8 and 68.9% (n = 188) were men. Four variables were found to be associated with all outcomes: radiological deterioration, clinical deterioration, death, and neurosurgical intervention. Diabetes (odds ratio (OR) = 2.6, 95% CI [0.97-6.94]), confusion as an initial symptom (OR = 2.8, 95% CI [1.42-5.61]), anticoagulation (OR = 2.8, 95% CI [1.01-7.84]) and significant subdural hemorrhage (≥4 mm) (OR = 3.4, 95% CI [1.42-5.61]) seen on the first computed tomography scan were strongly associated with these outcomes. Age had a neutral effect (OR = 1.01, 95% CI [0.99-1.03]) while high initial Glasgow Coma score seemed to have a protective effect (OR = 0.4, 95% CI [0.24-0.69]). Radiological deterioration was not systematically associated with clinical deterioration. As for the 46 patients with a deterioration of CT scan, only 30.4% vs. 69.5% without deterioration (p = 0.0035) showed a clinical deterioration. Conclusion: Diabetes, anticoagulation, significant subdural hemorrhage and confusion as an initial symptom seem to be predictors of deterioration following a mild traumatic brain injury with positive CT scan.

Introduction: The radiological and clinical follow-up of patients with a mild traumatic brain injury (mTBI) and an intracranial hemorrhage (ICH) is often heterogeneous, as there is no official guideline for CT scan control. Furthermore, public sector health expenditure has increased significantly as the number of MRI and CT scan almost doubled in Canada in the last decade. Therefore, the main objective of this study was to describe the current management practices of mTBI patients with intracranial hemorrhage at two level-1 trauma centers. Methods: Design: An historical cohort was created at the CHU de Québec – Hôpital de l'Enfant-Jésus (Québec City) and Hôpital du Sacré-Coeur (Montréal). Consecutive medical records were reviewed from the end of 2017 backwards until sample saturation using a standardized checklist. Participants: mTBI patients aged ⩾16 with an ICH were included. Measures: The main and secondary outcomes were the presence of a control CT scan and neurosurgical consultation/admission. Analyses: Univariate descriptive analyses were performed. Inter-observer measures were calculated. Results: Two hundred seventy-four patients were included, of which 51.1% (n = 140) came from a transfer. Mean age was 60.8 and 68.9% (n = 188) were men. Repeat CT scan was performed in 73.6% (n = 201) of our patients as 12.5% showed a clinical deterioration. The following factors might have influenced clinician decision to proceed to a repeat scan: anticoagulation (association of 87.1% with scanning; n = 27), antiplatelet (84.1%; 58), GCS of 13 (94.1%; 16), GCS of 14 (75%; 72) and GCS of 15 (70.2%; 111). 93.0% (n = 254) of patients had a neurosurgical consultation and only 6.7% (17) underwent a neurosurgical intervention. Conclusion: The management of mild traumatic brain injury with hemorrhage uses a lot of resources that might be disproportionate with regards to risks. Further research to identify predictive factors of deterioration is needed.

We assessed clinicians’ continuing professional development (CPD) needs at family practice teaching clinics in the province of Quebec. Our mixed methodology design comprised an environmental scan of training programs at four family medicine departments, an expert panel to determine priority clinical situations for senior care, a supervisors survey to assess their perceived CPD needs, and interviews to help understand the rationale behind their needs. From the environmental scan, the expert panel selected 13 priority situations. Key needs expressed by the 352 survey respondents (36% response rate) included behavioral and psychological symptoms of dementia, polypharmacy, depression, and cognitive disorders. Supervisors explained that these situations were sometimes complex to diagnose and manage because of psychosocial aspects, challenges of communicating with patients and families, and coordination of interprofessional teams. Supervisors also reported more CPD needs in long-term and home care, given the presence of caregivers and complexity of senior care in these settings.

This article is a critique of C. B. Macpherson's interpretation of Hobbes's Leviathan. In reading possessive individualism into Hobbes's work, Macpherson assumes two basic theses: a logical claim, that a specific model of society is required to derive a universal opposition among men's powers; and a textual claim, that this universal opposition is implied by Hobbes as an unstated postulate in chapters 10–11 of Leviathan. These basic claims are both unfounded. Logically, the postulated universal opposition of powers does not require Macpherson's model of society for its derivation. Indeed, on premisses preferred by Macpherson, the two are logically inconsistent. Textually, the postulated universal opposition of powers does not occur in Leviathan: a careful sifting of the text indicates that there is no direct evidence at all for this postulate. Notwithstanding the brilliance of possessive individualism as a contribution to modern political understanding, this theory cannot properly be ascribed to Hobbes.

As C. B. Macpherson allows in his comment, my critique of his interpretation is based upon “minute” reasoning and textual analysis. It would not be appropriate (or even possible) to reproduce that analysis here, or to defend it in detail against Macpherson's rebuttal. The best response to his remarks, therefore, is the critique itself, as originally stated: I can only hope that those who are interested in these issues will read it with care. Here, I will confine myself to a few general observations.

This article examines Hobbes' conception of natural right in society as presented in Part Two of Leviathan (primarily chapters 21 and 26 through 28). In contrast to Hobbes' earlier works, this section contains an implicit but important account of natural rights (called “true liberties”) in society and a corresponding set of restrictions on the proper use of law and punishment. Authority is thus absolute, but its proper use is limited. I argue that these limits are significant, that they represent an important revision in Hobbes' theory and that the resulting conception of natural right provides a useful basis for understanding rights today.