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The evolution of glaciers and ice sheets depends on processes in the subglacial environment. Shear seismicity along the ice–bed interface provides a window into these processes. Such seismicity requires a rapid loss of strength that is typically ascribed to rate-weakening friction, i.e., decreasing friction with sliding or sliding rate. Many friction experiments have investigated glacial materials at the temperate conditions typical of fast flowing glacier beds. To our knowledge, however, these studies have all found rate-strengthening friction. Here, we investigate the possibility that rate-weakening rock-on-rock friction between sediments frozen to the bottom of the glacier and the underlying water-saturated sediments or bedrock may be responsible for subglacial shear seismicity along temperate glacier beds. We test this ‘entrainment-seismicity hypothesis’ using targeted laboratory experiments and simple models of glacier sliding, seismicity and sediment entrainment. These models suggest that sediment entrainment may be a necessary but not sufficient condition for the occurrence of basal shear seismicity. We propose that stagnation at the Whillans Ice Stream, West Antarctica may be caused by the growth of a frozen fringe of entrained sediment in the ice stream margins. Our results suggest that basal shear seismicity may indicate geomorphic activity.
Cognitive–behavioural therapy (CBT) is the treatment of choice for generalised anxiety disorder (GAD), yielding significant improvements in approximately 50% of patients. There is significant room for improvement in the outcomes of treatment, especially in recovery.
We aimed to compare metacognitive therapy (MCT) with the gold standard treatment, CBT, in patients with GAD (clinicaltrials.gov identifier: NCT00426426).
A total of 246 patients with long-term GAD were assessed and 81 were randomised into three conditions: CBT (n = 28), MCT (n = 32) and a wait-list control (n = 21). Assessments were made at pre-treatment, post-treatment and at 2 year follow-up.
Both CBT and MCT were effective treatments, but MCT was more effective (mean difference 9.762, 95% CI 2.679–16.845, P = 0.004) and led to significantly higher recovery rates (65% v. 38%). These differences were maintained at 2 year follow-up.
MCT seems to produce recovery rates that exceed those of CBT. These results demonstrate that the effects of treatment cannot be attributed to non-specific therapy factors.
Declaration of interest
A.W. wrote the treatment protocol in MCT and several books on CBT and MCT, and receives royalties from these. T.D.B. wrote the protocol in CBT and has published several articles and chapters on CBT and receives royalties from these. All other authors declare no competing interests.
Introduction: Interest groups have become increasingly popular as students explore potential career paths earlier in their undergraduate experience. Emergency medicine (EM) has grown as a specialty and the match has become quite competitive. Attractive features of EM cited by learners (diversity, procedural skills and flexible schedule) appeal broadly to the undergraduate population. Learners at Memorial University recognized this leadership opportunity and worked with faculty to reach this wide target audience through a streamlined iterative evaluation of their EM Interest Group (EMIG). Methods: The local EMIG was formed in 2010. Yearly, EMIG executive work with outgoing members using prior experiences, contacts and best practices to facilitate handover and progress. From 2015 to present, 305 surveys were collected, giving an 81.9% response rate. 59.7% of respondents were first year students, and 40.3% were second year. The survey consisted of Likert scale and open-response questions. The Likert scale questions yielded favorable responses. 304 students (99.6%) felt presenters were knowledgeable, 301 (98.6%) would recommend the sessions to others and 301 (98.6%) were satisfied they attended. Surprisingly, 133 students (43.6%) said they were not interested in Emergency Medicine, likely attending due to the appeal of session topics and transferrable of EM skills. 232 (76.0%) stated that attendance did increase their interest in EM. Top responses for aspects of EM most interesting to them included: ability to find a work/life balance, ability to work urban or rural, variety of cases seen, and the non-routine shifts. Results: Survey feedback is used to inform refinement of the content, delivery and format of EMIG activities, delivered by EM faculty. Hands-on sessions (eg. suturing & airway management) have been popular. Informational sessions, on specific medical topics (ECG, resuscitation cases) or broader topics (EM streams) have also been very well received. Inclusion of all interested students, particularly large numbers for hands-on sessions, has presented challenges. Beyond current survey results, it will be interesting to consider if EMIG participation translates to learning or behavioral changes relevant to later clinical encounters; a question that will be difficult to quantify. Conclusion: The EM interest group is one of the most active at Memorial University. Survey results indicate that participants enjoy the EMIG session content and the structured iterative approach used by the group has been successful in maintaining an effective student led organization.
Introduction: Despite clear health benefits, and Public Health Agency of Canada recommendations, vaccination rates among Canadian adults are low. Frequent patient contacts, wait times, and the availability of trained staff make the emergency department (ED) a potential location to target specific populations and administer vaccinations. We evaluated the feasibility of two strategies to administer the Tdap vaccine to adult patients presenting to a single referral ED. Methods: Two immunization strategies and a control group were randomly ordered from one to three. Data collection for group one started on study day one with data collection for groups two and three on study days two and three respectively. This sequence was repeated over 15 consecutive weekdays (Monday-Friday, 0730-1530), evenly assigning each group to 5 different days. On intervention days, adult patients were screened during the triage process for eligibility to receive the Tdap vaccine. An ED based (EDB) strategy offered patients vaccination during that visit. The second strategy offered eligible patients a public health referral (PHR) to receive the vaccine at a later date. On all study days, patient triage times (TT), as well as markers of ED efficiency (number of patient registrations, time to physician, length of stay, left without being seen, number of admissions, number of boarded patients) were recorded. Results: The primary outcome, the proportion of eligible adults immunized, was significantly higher at 66% (n=81) for the EDB strategy (228 screened, 122 eligible), compared with 21% (n=20) for the PHR strategy (217 screened, 94 eligible; x2 (2, n=216)=43.41, p<0.00001). In addition, 10 participants in the PHR group received a second vaccine (Pneumococcal (7), Influenza (2), Human Papillomavirus (1)). Reasons for vaccine ineligibility included having an up-to-date Tdap (EDB n=47 (21%), PHR n=46 (21%)) and being considered in too much distress by the triage nurse (EDB n=26 (11%), PHR n=19 (9%)). Triage time was less for the control group (M=5:55 [mins:secs], SD=2:48) than for the EDB (M=6:47, SD=3:12) and PHR (M=7:25, SD=2:45) strategies. Conclusion: An ED based screening and immunization strategy was highly effective in providing eligible adult patients with the Tdap vaccine. A resulting small increase in triage time was not clinically significant. Further studies are required to generalize these results.
Coinfection with human immunodeficiency virus (HIV) and viral hepatitis is associated with high morbidity and mortality in the absence of clinical management, making identification of these cases crucial. We examined characteristics of HIV and viral hepatitis coinfections by using surveillance data from 15 US states and two cities. Each jurisdiction used an automated deterministic matching method to link surveillance data for persons with reported acute and chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections, to persons reported with HIV infection. Of the 504 398 persons living with diagnosed HIV infection at the end of 2014, 2.0% were coinfected with HBV and 6.7% were coinfected with HCV. Of the 269 884 persons ever reported with HBV, 5.2% were reported with HIV. Of the 1 093 050 persons ever reported with HCV, 4.3% were reported with HIV. A greater proportion of persons coinfected with HIV and HBV were males and blacks/African Americans, compared with those with HIV monoinfection. Persons who inject drugs represented a greater proportion of those coinfected with HIV and HCV, compared with those with HIV monoinfection. Matching HIV and viral hepatitis surveillance data highlights epidemiological characteristics of persons coinfected and can be used to routinely monitor health status and guide state and national public health interventions.
Employing a comparative experimental design drawing on over 18,000 interviews across eleven countries on four continents, this article revisits the discussion about the economic and cultural drivers of attitudes towards immigrants in advanced democracies. Experiments manipulate the occupational status, skin tone and national origin of immigrants in short vignettes. The results are most consistent with a Sociotropic Economic Threat thesis: In all countries, higher-skilled immigrants are preferred to their lower-skilled counterparts at all levels of native socio-economic status (SES). There is little support for the Labor Market Competition hypothesis, since respondents are not more opposed to immigrants in their own SES stratum. While skin tone itself has little effect in any country, immigrants from Muslim-majority countries do elicit significantly lower levels of support, and racial animus remains a powerful force.
We report on the EPICA Dronning Maud Land (East Antarctica) deep drilling operation. Starting with the scientific questions that led to the outline of the EPICA project, we introduce the setting of sister drillings at NorthGRIP and EPICA Dome C within the European ice-coring community. The progress of the drilling operation is described within the context of three parallel, deep-drilling operations, the problems that occurred and the solutions we developed. Modified procedures are described, such as the monitoring of penetration rate via cable weight rather than motor torque, and modifications to the system (e.g. closing the openings at the lower end of the outer barrel to reduce the risk of immersing the drill in highly concentrated chip suspension). Parameters of the drilling (e.g. core-break force, cutter pitch, chips balance, liquid level, core production rate and piece number) are discussed. We also review the operational mode, particularly in the context of achieved core length and piece length, which have to be optimized for drilling efficiency and core quality respectively. We conclude with recommendations addressing the design of the chip-collection openings and strictly limiting the cable-load drop with respect to the load at the start of the run.
There are roughly 25 very metal-poor (VMP; [Fe/H] < -2.0), highly r-process-enhanced (‘r-II’; [Eu/Fe] > + 1.0) stars currently known, discovered over the past 20+ years. These stars provide nearly pure signatures of r-process events early in the Galactic history. We are conducting a high-resolution follow-up survey of RAVE and other bright targets to identify a total of > 100 r-II stars. Our pilot runs on the du Pont 2.5-m at Las Campanas Observatory and the ARC 3.5-m at Apache Point Observatory have already identified up to fourteen new r-II stars. We are continuing our high-resolution follow-up efforts to constrain the astrophysical site(s) and nature of the r-process.
This study presents estimates of snow creep pressures from the centre section of an avalanche defence structure in western Norway. The structure is 15 in long and is erected on a 25° slope characterized by deep snow covers. Two methods of measurement are described: (1) direct estimates from earth pressure cells, and (2) construction of force, shear and moment diagrams from strains measured using vibrating wire strain gauges mounted on the steel beams of the structure.
In addition to the estimates of pressure, relevant snowpack data were measured, including snow depth, density, temperature and rammsonde hardness profiles as well as snow crystal stratigraphy. Snow gliding was also measured, and was found to be negligible. The snowpack measurements were made at approximately monthly intervals during each of the four winters which yielded useable data for the study.
Analysis of the pressure distributions along with the snowpack data yielded the following results: (1) the average pressure on the structure is linearly proportional to the product of average density times snow depth, (2) the average pressures are predicted fairly accurately by a linear, viscous creep model, (3) the maximum pressure depends strongly on the snowpack stiffness and decreases rapidly when warming and melt soften the snowpack, and (4) the maximum pressures are of the order of 254 higher than predicted by a linear, viscous creep model.
Red meat has been suggested to be adversely associated with risk of myocardial infarction (MI), whereas vegetable consumption has been found to be protective. The aim of this study was to investigate substitutions of red meat, poultry and fish with vegetables or potatoes for MI prevention. We followed up 29 142 women and 26 029 men in the Danish Diet, Cancer and Health study aged 50–64 years with no known history of MI at baseline. Diet was assessed by a validated 192-item FFQ at baseline. Adjusted Cox proportional hazard models were used to calculate hazard ratios (HR) and 95 % CI for MI associated with specified food substitutions of 150 g/week. During a median follow-up of 13·6 years, we identified 656 female and 1694 male cases. Among women, the HR for MI when replacing red meat with vegetables was 0·94 (95 % CI 0·90, 0·98). Replacing fatty fish with vegetables was associated with a higher risk of MI (HR 1·23; 95 % CI 1·05, 1·45), whereas an inverse, statistically non-significant association was found for lean fish (HR 0·93; 95 % CI 0·83, 1·05). Substituting poultry with vegetables was not associated with risk of MI (HR 1·00; 95 % CI 0·90, 1·11). Findings for substitution with potatoes were similar to findings for vegetables. Among men, a similar pattern was observed, but the associations were weak and mostly statistically non-significant. This study suggests that replacing red meat with vegetables or potatoes is associated with a lower risk of MI, whereas replacing fatty fish with vegetables or potatoes is associated with a higher risk of MI.
To characterize meal patterns across ten European countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study.
Cross-sectional study utilizing dietary data collected through a standardized 24 h diet recall during 1995–2000. Eleven predefined intake occasions across a 24 h period were assessed during the interview. In the present descriptive report, meal patterns were analysed in terms of daily number of intake occasions, the proportion reporting each intake occasion and the energy contributions from each intake occasion.
Twenty-seven centres across ten European countries.
Women (64 %) and men (36 %) aged 35–74 years (n 36 020).
Pronounced differences in meal patterns emerged both across centres within the same country and across different countries, with a trend for fewer intake occasions per day in Mediterranean countries compared with central and northern Europe. Differences were also found for daily energy intake provided by lunch, with 38–43 % for women and 41–45 % for men within Mediterranean countries compared with 16–27 % for women and 20–26 % for men in central and northern European countries. Likewise, a south–north gradient was found for daily energy intake from snacks, with 13–20 % (women) and 10–17 % (men) in Mediterranean countries compared with 24–34 % (women) and 23–35 % (men) in central/northern Europe.
We found distinct differences in meal patterns with marked diversity for intake frequency and lunch and snack consumption between Mediterranean and central/northern European countries. Monitoring of meal patterns across various cultures and populations could provide critical context to the research efforts to characterize relationships between dietary intake and health.
Introduction: In order to achieve the best possible outcomes for patients requiring resuscitation (PRRs) in the emergency department (ED), health care providers (HCPs) must provide an efficient, multi-disciplinary and coordinated response. A quality improvement (QI) project was undertaken to improve HCP response to PRRs at two tertiary care hospital EDs in Toronto. Methods: We conducted a before-and-after mixed-method survey to evaluate the perception of the adequacy of HCP response and clarity of HCP role when responding to PRRs. The results were compared using the Chi-square test. Qualitative responses to the first survey were also used to inform the development of the QI project. Through interviews of key stakeholders and with continuous input from front-line ED HCPs, a multi-disciplinary team modified the ED resuscitation protocol. This included standardized pre-hospital communication form with paramedics, ED-wide overhead announcement of ‘Code Resus’, dedicated HCPs assigned to respond to PRRs, and specific duties assigned to each responder. Change initiatives were reinforced through education and posters in the ED. Six months after implementation, a second survey was conducted to evaluate the sustained effects of the intervention. Results: Baseline measures indicated that 16 of 52 (30.8%) nurses surveyed believed their role was often or always apparent to themselves and others when they attended to a PRR (on a 5-point rating scale). This proportion increased to 35 of 55 (63.6%) nurses in the post-implementation survey (p < 0.001). Regarding adequacy of the number of HCPs responding to PRRs, 17 of 39 (43.6%) physicians and 23 of 53 (43.4%) nurses surveyed thought the appropriate number of HCPs responded to PRRs; the remainder thought that there were too few or too many HCPs. In the post-implementation survey, 34 of 41 (82.9%) physicians (p < 0.001) and 36 of 56 (64.3%) nurses (p = 0.029) surveyed felt that the appropriate number of HCPs attended to PRRs. Conclusion: Using a quality improvement approach, we identified and quantified perceived deficiencies in HCP response to PRRs in the ED. Through feedback-based modifications of the ED resuscitation protocol and by engaging HCP stakeholders, change initiatives were implemented to improve HCP response. As a result, this project achieved significant and sustained improvements in HCPs’ perceived response to PRRs.
We report the analysis of 154 hours of nearly continuous high-speed photometric data on the pulsating DB white dwarf (DBV) GD 358 obtained during the Whole Earth Telescope (WET) run of May 1990. The Fourier transform (FT) of the light curve is dominated by power in the range from 1200 – 1700μHz with more than 180 significant peaks in the total transform. We also see significant power at the sums and differences of the dominant frequencies, indicating the importance of nonlinear behavior. We can use this data to obtain an accurate total stellar mass, and surface He layer mass. The implied surface He layer mass, if correct, provides a significant and surprising challenge to stellar evolution theory, as well as the theory of chemical mixing.
The variable white dwarfs repeatedly force theory to conform to their observed properties so that further progress can be made in understanding the structure and evolution of all white dwarfs. We use the term “understanding” in a loose sense here because, as we will show, both observational constraints and interpretation of the observations vis-à-vis theory contribute to uncertainties in our understanding at this time. In any case, recent progress in this field (sometimes called white dwarf seismology) has provided some fascinating insights into the evolutionary and structural properties of white dwarfs and their progenitors. This short review is our attempt to describe recent progress made in the interaction of theory with observations.
Red meat has been suggested to be adversely associated with risk of myocardial infarction (MI), but previous studies have rarely taken replacement foods into consideration. We aimed to investigate optimal substitutions between and within the food groups of red meat, poultry and fish for MI prevention. We followed up 55 171 women and men aged 50–64 years with no known history of MI at recruitment. Diet was assessed by a validated 192-item FFQ at baseline. Adjusted Cox proportional hazard models were used to calculate hazard ratios (HR) and 95 % CI for specified food substitutions of 150 g/week. During a median follow-up time of 13·6 years, we identified 656 female and 1694 male cases. Among women, the HR for replacing red meat with fatty fish was 0·76 (95 % CI 0·64, 0·89), whereas the HR for replacing red meat with lean fish was 1·00 (95 % CI 0·89, 1·14). Similarly, replacing poultry with fatty but not lean fish was inversely associated with MI: the HR was 0·81 (95 % CI 0·67, 0·98) for fatty fish and was 1·08 (95 % CI 0·92, 1·27) for lean fish. The HR for replacing lean with fatty fish was 0·75 (95 % CI 0·60, 0·94). Replacing processed with unprocessed red meat was not associated with MI. Among men, a similar pattern was found, although the associations were not statistically significant. This study suggests that replacing red meat, poultry or lean fish with fatty fish is associated with a lower risk of MI.