Cannabis Legalization and Detection of Tetrahydrocannabinol in Injured Drivers.

BACKGROUND: The effect of cannabis legalization in Canada (in October 2018) on the prevalence of injured drivers testing positive for tetrahydrocannabinol (THC) is unclear. METHODS: We studied drivers treated after a motor vehicle collision in four British Columbia trauma centers, with data from January 2013 through March 2020. We included moderately injured drivers (those whose condition warranted blood tests as part of clinical assessment) for whom excess blood remained after clinical testing was complete. Blood was analyzed at the provincial toxicology center. The primary outcomes were a THC level greater than 0, a THC level of at least 2 ng per milliliter (Canadian legal limit), and a THC level of at least 5 ng per milliliter. The secondary outcomes were a THC level of at least 2.5 ng per milliliter plus a blood alcohol level of at least 0.05%; a blood alcohol level greater than 0; and a blood alcohol level of at least 0.08%. We calculated the prevalence of all outcomes before and after legalization. We obtained adjusted prevalence ratios using log-binomial regression to model the association between substance prevalence and legalization after adjustment for relevant covariates. RESULTS: During the study period, 4339 drivers (3550 before legalization and 789 after legalization) met the inclusion criteria. Before legalization, a THC level greater than 0 was detected in 9.2% of drivers, a THC level of at least 2 ng per milliliter in 3.8%, and a THC level of at least 5 ng per milliliter in 1.1%. After legalization, the values were 17.9%, 8.6%, and 3.5%, respectively. After legalization, there was an increased prevalence of drivers with a THC level greater than 0 (adjusted prevalence ratio, 1.33; 95% confidence interval [CI], 1.05 to 1.68), a THC level of at least 2 ng per milliliter (adjusted prevalence ratio, 2.29; 95% CI, 1.52 to 3.45), and a THC level of at least 5 ng per milliliter (adjusted prevalence ratio, 2.05; 95% CI, 1.00 to 4.18). The largest increases in a THC level of at least 2 ng per milliliter were among drivers 50 years of age or older (adjusted prevalence ratio, 5.18; 95% CI, 2.49 to 10.78) and among male drivers (adjusted prevalence ratio, 2.44; 95% CI, 1.60 to 3.74). There were no significant changes in the prevalence of drivers testing positive for alcohol. CONCLUSIONS: After cannabis legalization, the prevalence of moderately injured drivers with a THC level of at least 2 ng per milliliter in participating British Columbia trauma centers more than doubled. The increase was largest among older drivers and male drivers. (Funded by the Canadian Institutes of Health Research.).

One-Dimensional Relativistic Self-Gravitating Systems.

One of the oldest problems in physics is that of calculating the motion of N particles under a specified mutual force: the N-body problem. Much is known about this problem if the specified force is non-relativistic gravity, and considerable progress has been made by considering the problem in one spatial dimension. Here, I review what is known about the relativistic gravitational N-body problem. Reduction to one spatial dimension has the feature of the absence of gravitational radiation, thereby allowing for a clear comparison between the physics of one-dimensional relativistic and non-relativistic self-gravitating systems. After describing how to obtain a relativistic theory of gravity coupled to N point particles, I discuss in turn the two-body, three-body, four-body, and N-body problems. Quite general exact solutions can be obtained for the two-body problem, unlike the situation in general relativity in three spatial dimensions for which only highly specified solutions exist. The three-body problem exhibits mild forms of chaos, and provides one of the first theoretical settings in which relativistic chaos can be studied. For N≥4, other interesting features emerge. Relativistic self-gravitating systems have a number of interesting problems awaiting further investigation, providing us with a new frontier for exploring relativistic many-body systems.

Lagrangian Partition Functions Subject to a Fixed Spatial Volume Constraint in the Lovelock Theory.

We evaluate here the quantum gravity partition function that counts the dimension of the Hilbert space of a simply connected spatial region of a fixed proper volume in the context of Lovelock gravity, generalizing the results for Einstein gravity. It is found that there are sphere saddle metrics for a partition function at a fixed spatial volume in Lovelock theory. Those stationary points take exactly the same forms as in Einstein gravity. The logarithm of Z corresponding to a zero effective cosmological constant indicates that the Bekenstein-Hawking entropy of the boundary area and that corresponding to a positive effective cosmological constant points to the Wald entropy of the boundary area. We also show the existence of zeroth-order phase transitions between different vacua, a phenomenon distinct from Einstein gravity.

Holographic Dual of Extended Black Hole Thermodynamics.

By respecting the conformal symmetry of the dual conformal field theory, and treating the conformal factor of the Anti-de Sitter boundary as a thermodynamic parameter, we formulate the holographic first law that is exactly dual to the first law of extended black hole thermodynamics with variable cosmological constant but fixed Newton's constant.

Anatomical and Physiological Changes Following Primary Palatoplasty Using "The Buccal Flap Approach".

OBJECTIVE: The purpose of this study was to determine the anatomical differences among selected individuals with a cleft palate repaired using "The Buccal Flap Approach" during primary palatoplasty compared to aged-matched participants without cleft palate. DESIGN: Observational, prospective. SETTING: Two regional hospitals. PARTICIPANTS: A total of 30 adult males consisting of 15 adults born with cleft palate who received the Double Opposing Z-Plasty plus Buccal Flaps (DOZP + BF) repair at the time of primary palatoplasty and no history of secondary speech surgery or orthognathic surgery and 15 adults without a history of cleft palate. INTERVENTIONS: All participants underwent MRI to visualize anatomy. MAIN OUTCOME MEASURES: Ten velopharyngeal and craniofacial anatomical measures. RESULTS: No statistically significant differences between groups were observed for velar thickness, velar length, pharyngeal depth, NSBa angle, SNB angle, or levator veli palatini length. Individuals with the DOZP + BF presented with a greater effective velar length (p < .001), greater effective VP ratio (p < .001), smaller SNA angle (p < .001), and smaller maximal velar stretch (p < .001) compared to the control participants. CONCLUSIONS: This study suggests that adult males who received the DOZP + BF repair at the time of primary palatoplasty and no history of secondary speech surgery or orthognathic surgery present with a longer effective velar length and larger effective VP ratio in comparison to the non-cleft group. Future research is needed to compare patients with and without favorable outcomes from multiple surgical types to fully understand how surgical techniques alter the anatomy.

The First Hybrid International Educational Comprehensive Cleft Care Workshop.

OBJECTIVE: Describe the first hybrid global simulation-based comprehensive cleft care workshop, evaluate impact on participants, and compare experiences based on in-person versus virtual attendance. DESIGN: Cross-sectional survey-based evaluation. SETTING: International comprehensive cleft care workshop. PARTICIPANTS: Total of 489 participants. INTERVENTIONS: Three-day simulation-based hybrid comprehensive cleft care workshop. MAIN OUTCOME MEASURES: Participant demographic data, perceived barriers and interventions needed for global comprehensive cleft care delivery, participant workshop satisfaction, and perceived short-term impact on practice stratified by in-person versus virtual attendance. RESULTS: The workshop included 489 participants from 5 continents. The response rate was 39.9%. Participants perceived financial factors (30.3%) the most significant barrier and improvement in training (39.8%) as the most important intervention to overcome barriers facing cleft care delivery in low to middle-income countries. All participants reported a high level of satisfaction with the workshop and a strong positive perceived short-term impact on their practice. Importantly, while this was true for both in-person and virtual attendees, in-person attendees reported a significantly higher satisfaction with the workshop (28.63 ± 3.08 vs 27.63 ± 3.93; P = .04) and perceived impact on their clinical practice (22.37 ± 3.42 vs 21.02 ± 3.45 P = .01). CONCLUSION: Hybrid simulation-based educational comprehensive cleft care workshops are overall well received by participants and have a positive perceived impact on their clinical practices. In-person attendance is associated with significantly higher satisfaction and perceived impact on practice. Considering that financial and health constraints may limit live meeting attendance, future efforts will focus on making in-person and virtual attendance more comparable.

Quantum Signatures of Black Hole Mass Superpositions.

We present a new operational framework for studying "superpositions of spacetimes," which are of fundamental interest in the development of a theory of quantum gravity. Our approach capitalizes on nonlocal correlations in curved spacetime quantum field theory, allowing us to formulate a metric for spacetime superpositions as well as characterizing the coupling of particle detectors to a quantum field. We apply our approach to analyze the dynamics of a detector (using the Unruh-deWitt model) in a spacetime generated by a Banados-Teitelboim-Zanelli black hole in a superposition of masses. We find that the detector exhibits signatures of quantum-gravitational effects corroborating and extending Bekenstein's seminal conjecture concerning the quantized mass spectrum of black holes in quantum gravity. Crucially, this result follows directly from our approach, without any additional assumptions about the black hole mass properties.

Black Hole Solutions as Topological Thermodynamic Defects.

In this Letter, employing the generalized off-shell free energy, we treat black hole solutions as defects in the thermodynamic parameter space. The results show that the positive and negative winding numbers corresponding to the defects indicate the local thermodynamical stable and unstable black hole solutions, respectively. The topological number defined as the sum of the winding numbers for all the black hole branches at an arbitrary given temperature is found to be a universal number independent of the black hole parameters. Moreover, this topological number only depends on the thermodynamic asymptotic behaviors of the black hole temperature at small and large black hole limits. Different black hole systems are characterized by three classes via this topological number. This number could help us in better understanding the black hole thermodynamics and, further, shed new light on the fundamental nature of quantum gravity.

Distinguishing a Slowly Accelerating Black Hole by Differential Time Delays of Images.

Accelerating supermassive black holes, connected to cosmic strings, could contribute to structure formation and get captured by galaxies if their velocities are small. This would mean that the acceleration of these black holes is small, too. Such a slow acceleration has no significant effect on the shadow of such supermassive black holes. We also show that, for slowly accelerating black holes, the angular position of images in the gravitational lensing effects does not change significantly. We propose a method to observe the acceleration of these black holes through gravitational lensing. The method is based on the observation that differential time delays associated with the images are substantially different with respect to the case of nonaccelerating black holes.

Thermodynamics of AdS Black Holes: Critical Behavior of the Central Charge.

We reconsider the thermodynamics of anti-de Sitter black holes in the context of gauge-gravity duality. In this new setting, where both the cosmological constant Λ and the gravitational Newton's constant G are varied in the bulk, we rewrite the first law in a new form containing both Λ (associated with thermodynamic pressure) and the central charge C of the dual conformal field theory and their conjugate variables. We obtain a novel thermodynamic volume, in turn leading to a new understanding of the Van der Waals behavior of charged anti-de Sitter black holes in which phase changes are governed by the degrees of freedom in the conformal field theory. Compared to the "old" P-V criticality, this new criticality is "universal" (independent of the bulk pressure) and directly relates to the thermodynamics of the dual field theory and its central charge.

Holographic Complexity and Thermodynamic Volume.

We study the holographic complexity conjectures for rotating black holes, uncovering a relationship between the complexity of formation and the thermodynamic volume of the black hole. We suggest that it is the thermodynamic volume and not the entropy that controls the complexity of formation of large black holes in both the complexity equals action and complexity equals volume proposals in general. Our proposal reduces to known results involving the entropy in settings where the thermodynamic volume and entropy are not independent, but has broader scope. Assuming a conjectured inequality is obeyed by the thermodynamic volume, we establish that the complexity of formation is bounded from below by the entropy for large black holes.

Driving under the influence of cannabis risk perceptions and behaviour: A population-based study in Ontario, Canada.

Driving under the influence of cannabis (DUIC) is detrimental to road safety. Risk perception is a strong determinant of DUIC behaviour, yet little is known about the factors influencing DUIC risk perception in the general population. The objective of this study was to identify factors associated with risk perceptions of motor vehicle collision and legal consequences due to DUIC and examine whether these perceptions were associated with DUIC behaviour. Data were derived from the 2017 CAMH Monitor, a cross-sectional telephone survey of adults aged 18+ years in Ontario, Canada (n = 1813). Multivariable logistic regression analyses were performed. Approximately 90% of adults overall agreed that DUIC increases motor vehicle collision risk compared to 55% of those reporting past-year DUIC. Being male, less educated, and using cannabis at least monthly were associated with disagreeing that DUIC increases motor vehicle collision risk. Being male, young, and using cannabis at least monthly were associated with agreeing that DUIC is safer than driving under the influence of alcohol (DUIA). Being male and using cannabis less than monthly were associated with agreeing that the chances of getting caught for DUIC are higher than DUIA. Safety but not legal risk perceptions were associated with DUIC behaviour among cannabis-using drivers. Cannabis legalization provides a timely opportunity for DUIC prevention strategies. This study suggests that policymakers should target male cannabis users and highlight the safety risks of DUIC. Further research is needed to assess the effectiveness of prevention measures and the impact of cannabis legalization on DUIC perceptions and behaviour.

Increases in Serious Psychological Distress among Ontario Students between 2013 and 2017: Assessing the Impact of Time Spent on Social Media.

OBJECTIVE: The objective of the current research was to examine the association between time spent on social media and serious psychological distress between 2013 and 2017, a period when the rates of both were trending upward. METHODS: The current study analyzed population-based data from 3 waves of the Ontario Student Drug Use and Health Survey (N = 15,398). Multivariate logistic regression models were used to examine the association between time spent on social media and serious psychological distress controlling for theoretically relevant covariates. Interactions were tested to assess whether the association changed over time. RESULTS: The prevalence of serious psychological distress increased from 10.9% in 2013 to 16.8% in 2017 concomitantly with substantial increases in social media usage, especially at the highest levels. In the multivariate context, we found a significant interaction between social media use and the survey year which indicates that the association between time spent on social media and psychological distress has decreased from 2013 to 2017. CONCLUSION: Although both social media use and psychological distress increased between 2013 and 2017, the interaction between these variables indicates that the strength of this association has decreased over time. This finding suggests that the higher rate of heavy social media use in 2017 compared to 2013 is not actually associated with the higher rate of serious psychological distress during the same time period. From a diffusion of innovation perspective, it is possible that more recent adopters of social media may be less prone to psychological distress. More research is needed to understand the complex and evolving association between social media use and psychological distress. Researchers attempting to isolate the factors associated with the recent increases in psychological distress could benefit from broadening their investigation to factors beyond time spent on social media.

Prevalence and burden of health problems in competitive adolescent distance runners: A 6-month prospective cohort study.

To describe all health problems (injuries and illnesses) in relation to type, location, incidence, prevalence, time loss, severity, and burden, in competitive adolescent distance runners in England. Prospective observational study: 136 competitive adolescent distance runners (73 female athletes) self-reported all health problems for 24-weeks between May and October 2019. Athletes self-reported health problems using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems. The incidence of running-related injury per 1,000 hours of exposure was markedly higher, compared to previous research. At any time, 24% [95% Confidence Intervals (CI): 21-26%] of athletes reported a health problem, with 11% [95% CI: 9-12%] having experienced a health problem that had substantial negative impact on training and performance. Female athletes reported noticeably more illnesses, compared to male athletes, including higher prevalence, incidence, time loss, and severity. The most burdensome health problems, irrespective of sex, included lower leg, knee, and foot/toes injuries, alongside upper respiratory illnesses. The mean weekly prevalence of time loss was relatively low, regardless of health problem type or sex. Competitive adolescent distance runners are likely to be training and competing whilst concurrently experiencing health problems. These findings will support the development of injury and illness prevention measures.

Influence of Cannabinoid Receptor 1 Genetic Variants on the Subjective Effects of Smoked Cannabis.

As many jurisdictions consider relaxing cannabis legislation and usage is increasing in North America and other parts of the world, there is a need to explore the possible genetic differences underlying the subjective effects of cannabis. This pilot study investigated specific genetic variations within the cannabinoid receptor 1 (CNR1) gene for association with the subjective effects of smoked cannabis. Data were obtained from a double-blinded, placebo-controlled clinical trial studying the impact of cannabis intoxication on driving performance. Participants randomized to the active cannabis group who consented to secondary genetic analysis (n = 52) were genotyped at the CNR1 rs1049353 and rs2023239 polymorphic areas. Maximum value and area under the curve (AUC) analyses were performed on subjective measures data. Analysis of subjective effects by genotype uncovered a global trend towards greater subjective effects for rs1049353 T-allele- and rs2023239 C-allele-carrying subjects. However, significant differences attributed to allelic identity were only documented for a subset of subjective effects. Our findings suggest that rs1049353 and rs2023239 minor allele carriers experience augmented subjective effects during acute cannabis intoxication.

Ethnicity, Immigration Status, And Driving Under The Influence Of Alcohol.

BACKGROUND: Understanding risk factors for driving under the influence of alcohol (DUIA) informs development of effective interventions. This study examined the association between ethnicity, immigration status, and DUIA, exploring psychological distress and hazardous drinking as additional contributors. METHOD: Data were derived from the 2003-2011 cycles of the Centre for Addiction and Mental Health (CAMH) Monitor of 16,101 adults from Ontario, Canada. Hierarchical binary logistic regression analysis assessed self-identified ethnicity and immigration status as predictors of DUIA, adjusting for sociodemographics and driving exposure (Model 1), psychological distress (Model 2), and hazardous drinking (Model 3). RESULTS: In Model 1, respondents born outside of Canada had reduced odds of engaging in DUIA compared to those born in Canada (AOR = 0.72, 95%CI = 0.56 - 0.92). Relative to those identifying as Canadian, the odds of DUIA were significantly reduced for those identifying as East Asian (AOR = 0.28, 95%CI = 0.13 - 0.61) and South Asian (AOR = 0.52, 95%CI = 0.27 - 0.98). In Model 3, individuals who reported psychological distress (AOR = 1.69, 95%CI = 1.33 - 2.16) and those who reported hazardous drinking (AOR = 6.28, 95%CI= 5.13 - 7.69) were more likely to DUIA. Those identifying as East Asian continued to have reduced odds of DUIA compared to those identifying as Canadian (AOR = 0.38, 95%CI = 0.17 - 0.85). CONCLUSION: Individuals born outside of Canada were less likely to engage in DUIA than individuals born in Canada. Drivers who self-identified as East Asian were less likely to DUIA than those who self-identified as Canadian. Understanding ethnic differences underlying divergent risks for DUIA will improve prevention initiatives and remedial measures programming.

Quantum Temporal Superposition: The Case of Quantum Field Theory.

Quantum field theory is completely characterized by the field correlations between spacetime points. In turn, some of these can be accessed by locally coupling to the field simple quantum systems, also known as particle detectors. In this letter we consider what happens when a quantum-controlled superposition of detectors at different space-time points is used to probe the correlations of the field. We show that, due to quantum interference effects, two detectors can gain information on field correlations that would not be accessible, otherwise. This has relevant consequences for information theoretic quantities, like entanglement and mutual information harvested from the field. In particular, the quantum control allows for extraction of entanglement in scenarios where this is, otherwise, provably impossible.

Simulation-Based Comprehensive Cleft Care Workshops: A Reproducible Model for Sustainable Education.

OBJECTIVE: Evaluate simulation-based comprehensive cleft care workshops as a reproducible model for education with sustained impact. DESIGN: Cross-sectional survey-based evaluation. SETTING: Simulation-based comprehensive cleft care workshop. PARTICIPANTS: Total of 180 participants. INTERVENTIONS: Three-day simulation-based comprehensive cleft care workshop. MAIN OUTCOME MEASURES: Number of workshop participants stratified by specialty, satisfaction with the workshop, satisfaction with simulation-based workshops as educational tools, impact on cleft surgery procedural confidence, short-term impact on clinical practice, medium-term impact on clinical practice. RESULTS: The workshop included 180 participants from 5 continents. The response rate was 54.5%, with participants reporting high satisfaction with all aspects of the workshop and with simulation-based workshops as educational tools. Participants reported a significant improvement in cleft lip (33.3 ± 5.7 vs 25.7 ± 7.6; P < .001) and palate (32.4 ± 7.1 vs 23.7 ± 6.6; P < .001) surgery procedural confidence following the simulation sessions. Participants also reported a positive short-term and medium-term impact on their clinical practices. CONCLUSION: Simulation-based comprehensive cleft care workshops are well received by participants, lead to improved cleft surgery procedural confidence, and have a sustained positive impact on participants' clinical practices. Future efforts should focus on evaluating and quantifying this perceived positive impact, as well reproducing these efforts in other areas of need.

Bioprospecting of Native Efflux Pumps To Enhance Furfural Tolerance in Ethanologenic Escherichia coli.

Efficient microbial conversion of lignocellulose into valuable products is often hindered by the presence of furfural, a dehydration product of pentoses in hemicellulose sugar syrups derived from woody biomass. For a cost-effective lignocellulose microbial conversion, robust biocatalysts are needed that can tolerate toxic inhibitors while maintaining optimal metabolic activities. A comprehensive plasmid-based library encoding native multidrug resistance (MDR) efflux pumps, porins, and select exporters from Escherichia coli was screened for furfural tolerance in an ethanologenic E. coli strain. Small multidrug resistance (SMR) pumps, such as SugE and MdtJI, as well as a lactate/glycolate:H+ symporter, LldP, conferred furfural tolerance in liquid culture tests. Expression of the SMR pump potentially increased furfural efflux and cellular viability upon furfural assault, suggesting novel activities for SMR pumps as furfural efflux proteins. Furthermore, induced expression of mdtJI enhanced ethanol fermentative production of LY180 in the presence of furfural or 5-hydroxymethylfurfural, further demonstrating the applications of SMR pumps. This work describes an effective approach to identify useful efflux systems with desired activities for nonnative toxic chemicals and provides a platform to further enhance furfural efflux by protein engineering and mutagenesis.IMPORTANCE Lignocellulosic biomass, especially agricultural residues, represents an important potential feedstock for microbial production of renewable fuels and chemicals. During the deconstruction of hemicellulose by thermochemical processes, side products that inhibit cell growth and production, such as furan aldehydes, are generated, limiting cost-effective lignocellulose conversion. Here, we developed a new approach to increase cellular tolerance by expressing multidrug resistance (MDR) pumps with putative efflux activities for furan aldehydes. The developed plasmid library and screening methods may facilitate new discoveries of MDR pumps for diverse toxic chemicals important for microbial conversion.

Repulsive Interactions and Universal Properties of Charged Anti-de Sitter Black Hole Microstructures.

The Ruppeiner geometry of thermodynamic fluctuations provides a powerful diagnostic of black hole microstructures. We investigate this for charged anti-de Sitter black holes and find that, while an attractive microstructure interaction dominates for most parameter ranges, a weak repulsive interaction dominates for small black holes of high temperature. This unique property distinguishes the black hole system from that of a van der Waals fluid, where only attractive microstructure interactions are found. We also find two other novel universal properties for charged black holes. One is that the repulsive interaction is independent of the black hole charge and temperature. The other is that the behavior of the Ruppeiner curvature scalar near criticality is characterized by a dimensionless constant that is identical to that for a van der Waals fluid, providing us with new insight into black hole microstructures.