To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Photonic crystal surfaces represent a class of resonant optical structures that are capable of supporting high intensity electromagnetic standing waves with near-field and far-field properties that can be exploited for high sensitivity detection of biomolecules and cells. While modulation of the resonant wavelength of a photonic crystal by the dielectric permittivity of adsorbed biomaterials enables label-free detection, the resonance can also be tuned to coincide with the excitation wavelength of common fluorescent tags - including organic molecules and semiconductor quantum dots. Photonic crystals are also capable of efficiently channeling fluorescent emission into a preferred direction for enhanced extraction efficiency. Photonic crystals can be designed to support multiple resonant modes that can perform label free detection, enhanced fluorescence excitation, and enhanced fluorescence extraction simultaneously on the same device. Because photonic crystal surfaces may be inexpensively produced over large surface areas by nanoreplica molding processes, they can be incorporated into disposable labware for applications such as pharmaceutical high throughput screening. In this talk, the optical properties of surface photonic crystals will be reviewed and several applications will be described, including results from screening a 200,000-member chemical compound library for inhibitors of protein-DNA interactions, gene expression microarrays, and high sensitivity of protein biomarkers.
This study assessed the in vitro anthelmintic (AH) activity of methanol and acetone:water leaf extracts from Annona squamosa, A. muricata and A. reticulata against Haemonchus contortus eggs. The egg hatch test was used to determine the effective concentrations required to inhibit 50% of eggs hatching (EC50). The role of polyphenols on AH activity was measured through bioassays with and without polyvinylpolypyrrolidone (PVPP). Methanolic extracts mainly caused the death of eggs at the morula stage (ovicidal activity). Meanwhile, acetone:water extracts caused egg-hatching failure of developed larvae (larvae failing eclosion (LFE) activity). The lowest EC50 values against H. contortus eggs were observed for the methanolic extracts from A. reticulata and A. muricata (274.2 and 382.9 µg/ml, respectively). From the six extracts evaluated, the methanolic extracts of A. muricata, A. reticulata and A. squamosa showed the highest ovicidal activity, resulting in 98.9%, 92.8% and 95.1% egg mortality, respectively. When the methanolic extract of A. squamosa was incubated with PVPP, its AH activity increased. Similarly, when acetone:water extracts of A. muriata and A. reticulata were incubated with PVPP, their LFE activity increased. Alkaloids were only evident in methanolic extracts, irrespective of PVPP incubation. The presence of acetogenins was not observed. In conclusion, methanolic extracts obtained from leaves of A. muricata, A. reticulata and A. squamosa showed ovicidal activity affecting the morula of H. contortus eggs, with minor LFE activity. Meanwhile, acetone:water extracts showed mostly LFE activity, with a lower proportion of ovicidal activity.
Bayesian Econometric Methods examines principles of Bayesian inference by posing a series of theoretical and applied questions and providing detailed solutions to those questions. This second edition adds extensive coverage of models popular in finance and macroeconomics, including state space and unobserved components models, stochastic volatility models, ARCH, GARCH, and vector autoregressive models. The authors have also added many new exercises related to Gibbs sampling and Markov Chain Monte Carlo (MCMC) methods. The text includes regression-based and hierarchical specifications, models based upon latent variable representations, and mixture and time series specifications. MCMC methods are discussed and illustrated in detail - from introductory applications to those at the current research frontier - and MATLAB® computer programs are provided on the website accompanying the text. Suitable for graduate study in economics, the text should also be of interest to students studying statistics, finance, marketing, and agricultural economics.
Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.
Agents that block the renin–angiotensin system (RAS) improve glucoregulation in the metabolic syndrome disorder. We evaluated the effects of egg white hydrolysate (EWH), previously shown to modulate the protein abundance of RAS component in vivo, on glucose homeostasis in diet-induced insulin-resistant rats. Sprague–Dawley rats were fed a high-fat diet (HFD) for 6 weeks to induce insulin resistance. They were then randomly divided into four groups receiving HFD or HFD supplemented with different concentrations of EWH (1, 2 and 4 %) for another 6 weeks in the first trial. In the second trial, insulin-resistant rats were divided into two groups receiving only HFD or HFD+4 % EWH for 6 weeks. Glucose homeostasis was assessed by oral glucose tolerance and insulin tolerance tests. Insulin signalling and protein abundance of RAS components, gluconeogenesis enzymes and PPARγ were evaluated in muscle, fat and liver. Adipocyte morphology and inflammatory markers were evaluated. In vivo administration of EWH increased insulin sensitivity, improved oral glucose tolerance (P < 0·0001) and reduced systemic inflammation (P < 0·05). EWH potentiated insulin-induced Akt phosphorylation in muscle (P = 0·0341) and adipose tissue (P = 0·0276), but minimal differences in the protein abundance of tissue RAS components between the EWH and control groups were observed. EWH treatment also reduced adipocyte size (P = 0·0383) and increased PPARγ2 protein abundance (P = 0·0237). EWH treatment yielded positive effects on the inflammatory profile, glucose tolerance, insulin sensitivity and adipocyte differentiation in HFD-induced insulin resistance rats. The involvement of local RAS activity requires further investigation.
Applying artificial intelligence to materials research requires abundant curated experimental data and the ability for algorithms to request new experiments. ESCALATE (Experiment Specification, Capture and Laboratory Automation Technology)—an ontological framework and open-source software package—solves this problem by providing an abstraction layer for human- and machine-readable experiment specification, comprehensive and extensible (meta-) data capture, and structured data reporting. ESCALATE simplifies the initial data collection process, and its reporting and experiment generation mechanisms simplify machine learning integration. An initial ESCALATE implementation for metal halide perovskite crystallization was used to perform 55 rounds of algorithmically-controlled experiment plans, capturing 4336 individual experiments.
Introduction: In July 2018, Emergency Medicine (EM) transitioned to the Royal College of Physicians and Surgeons of Canada's (RCPSC) Competence by Design (CBD) training framework. In anticipation of CBD implementation, we conducted a nation-wide needs assessment of EM faculty and senior residents to understand their attitudes towards CBD, workplace-based assessments (WBA) and overall educational needs. Methods: A multi-site, cross-sectional digital survey was conducted in winter 2018 with a sample of EM faculty and senior residents across RCPSC EM programs in Canada. Recruitment was via program director nomination. Survey domains included baseline perceptions about CBD, attitudes toward implementation, perceived/prompted and unperceived faculty development needs. Microsoft Excel was used to calculate descriptive statistics. This study was reviewed by the Hamilton Integrated Research Ethics Board.A multi-site, cross-sectional digital survey was conducted in winter 2018 with a sample of EM faculty and senior residents across RCPSC EM programs in Canada. Recruitment was via program director nomination. Survey domains included baseline perceptions about CBD, attitudes toward implementation, perceived/prompted and unperceived faculty development needs. Microsoft Excel was used to calculate descriptive statistics. This study was reviewed by the Hamilton Integrated Research Ethics Board. Results: Between February-April 2018, 47 participants (40 faculty, 7 residents) completed the survey (58.8% response rate). Most respondents (89.4%) thought learner feedback should be provided on each shift; 55.3% believed they provided adequate feedback. Time constraints, learner disinterest and fear of assessment repercussions were the top three barriers to providing good feedback. A majority of respondents (78.7%) thought that the ED provided above average opportunities for direct observation and 91.5% were confident of incorporating WBAs into their practice. 44.7% reported that CBD will not impact patient care; 17.0% perceived it may have a negative impact. 55.3% felt that CBD will lead to improved feedback for trainees. The top areas for faculty development were: feedback delivery, completing WBAs, resident promotion decisions, and receiving feedback on teaching. Only 25.5% were interested in learning about CBD, although the average of correct responses on the CBD knowledge test was 44.6%. Conclusion: EM is well-situated to transition to CBD given clinicians’ positive attitudes towards feedback, direct observation, WBAs, and opportunities for direct observation. Threats to CBD implementation are concerns about effects on patient care and trainee education, and skepticism regarding effects on feedback quality. Faculty development should concentrate on further developing clinical teaching and supervision skills, focusing on feedback and WBAs.
Introduction: Many drugs, including cannabis and alcohol, cause impairment and contribute to motor vehicle collisions (MVCs). Policy makers require knowledge of the prevalence of drug use in crash-involved drivers, and types of drugs used in order to develop effective prevention programs. This issue is particularly relevant with the recent legalization of cannabis. We aim to study the prevalence of alcohol, cannabis, sedating medications, and other drugs in injured drivers from 4 Canadian Provinces. Methods: This prospective cohort study obtained excess clinical blood samples from consecutive injured drivers who attended a participating Canadian trauma centre following a MVC. Blood samples were analyzed using a broad spectrum toxicology screen capable of detecting cannabinoids, cocaine, amphetamines (including their major analogues), and opioids as well as psychotropic pharmaceuticals (including antihistamines, benzodiazepines, other hypnotics, and sedating antidepressants). Alcohol and cannabinoids were quantified. Health records were reviewed to extract demographic, medical, and MVC information using a standardized data collection tool. Results: This study has been collecting data in 4 trauma centres in British Columbia (BC) since 2011 and was launched in 2 trauma centres in Alberta (AB), 1 in Saskatchewan (SK), and 2 in Ontario (ON) in 2018. In preliminary results from BC (n = 2412), 8% of injured drivers tested positive for THC and 13% for alcohol. Preliminary results from other provinces (n = 301) suggest a regional variation in prevalence of drivers testing positive for THC (10% - 27%), alcohol (17% - 29%), and other drugs. By May 2018, an estimated 4500 cases from BC, 600 from AB, 150 from SK, and 650 from ON will have been analyzed. We will report the prevalence of positive tests for alcohol, THC, other recreational drugs, and sedating medications, pre and post cannabis legalization. The number of cases with alcohol and/or THC levels above Canadian per se limits will also be reported. Results will be reported according to province, driver sex, age, single vs. multi vehicle crashes, and requirement for hospital admission. Conclusion: This will be among the largest international datasets on drug use by injured drivers. Our findings will provide patterns of drug and alcohol impairment in 4 Canadian provinces pre and post cannabis legalization. The significance of these findings and implication for impaired driving policy and prevention programs in Canada will be discussed.
The present study evaluates the use of multiple correspondence analysis (MCA), a type of exploratory factor analysis designed to reduce the dimensionality of large categorical data sets, in identifying behaviours associated with measures of overweight/obesity in Vanuatu, a rapidly modernizing Pacific Island country.
Starting with seventy-three true/false questions regarding a variety of behaviours, MCA identified twelve most significantly associated with modernization status and transformed the aggregate binary responses of participants to these twelve questions into a linear scale. Using this scale, individuals were separated into three modernization groups (tertiles) among which measures of body fat were compared and OR for overweight/obesity were computed.
Ni-Vanuatu adults (n 810) aged 20–85 years.
Among individuals in the tertile characterized by positive responses to most of or all the twelve modernization questions, weight and measures of body fat and the likelihood that measures of body fat were above the US 75th percentile were significantly greater compared with individuals in the tertiles characterized by mostly or partly negative responses.
The study indicates that MCA can be used to identify individuals or groups at risk for overweight/obesity, based on answers to simply-put questions. MCA therefore may be useful in areas where obtaining detailed information about modernization status is constrained by time, money or manpower.
OBJECTIVES/SPECIFIC AIMS: Patients with undiagnosed obstructive sleep apnea (OSA) will often present to an otolaryngologist with symptoms of chronic rhinosinusitis (CRS). Differentiating CRS from OSA may help obviate unnecessary and costly work-up for CRS. This study analyzes symptom profiles of such patients to help identify which require polysomnography. METHODS/STUDY POPULATION: This is a three-year retrospective analysis of adult patients seen in an academic practice with a rhinologic chief complaint. The 22-Item Sinonasal Outcomes Test (SNOT-22) survey, which is a validated patient-reported outcome measure widely adopted for CRS featuring a symptom scale of 1 (least severe) to 5 (most severe), was completed by patients with untreated OSA confirmed on polysomnography without CRS (OSA group) and a control group of CRS patients (CRS group). Results were compared using Chi-square test (categorical) and Wilcoxon rank-sum test (continuous) with Bonferroni correction, and multiple logistic regression. RESULTS/ANTICIPATED RESULTS: 43 patients were included in the OSA group [mean apnea-hypopnea index: 27.9 (SD: 21.2)] and 124 patients were included in the CRS group. The CRS group demonstrated significantly higher scores in nasal (p < 0.001), extra-nasal (p < 0.001) and ear/facial symptom domains (p = 0.001) while the OSA group reported higher psychological (p = 0.028) and sleep symptom domain scores (p = 0.052). As for the cardinal symptoms of CRS, nasal discharge and loss of smell were significantly higher in the CRS group (both p < 0.001), whereas facial pain (p = 0.117) and nasal obstruction (p = 0.198) were not significantly different between the two groups. After adjustment, for every 1-point increase in a patient’s score for ear pain, thick nasal discharge and loss of smell or taste, their odds of having CRS increased by a factor of 3.18 [(95% CI 1.61-6.29), p = 0.001], 1.60 [(95% CI 1.22-2.10], p = 0.001] and 1.36 [(95% CI 1.04-1.78), p = 0.025], respectively, compared to having OSA. OSA patients were more likely to choose a sleep-related symptom as a “most important complaint” (MIC) (p < 0.001). Facial pain and nasal obstruction were the most common MIC in the rhinologic domain for OSA patients, whereas thick nasal discharge and post-nasal discharge were the most common MIC for CRS patients. DISCUSSION/SIGNIFICANCE OF IMPACT: For patients presenting with rhinologic symptoms, the SNOT-22 can help identify those with undiagnosed OSA. OSA should be suspected in patients with sleep and psychological dysfunction as their primary complaints without the significant nasal drainage and anosmia that characterizes CRS.
Transnational migrant populations face critical barriers to mental health service utilization that perpetuate mental health disparities globally. Overseas Filipino workers (OFWs) number over 2 million globally and 25% are female domestic workers. Structural barriers prevent equitable access to mental health services for this population. Electronic mental health (eMental Health) intervention is a scalable alternative to face-to-face treatment. The current study sought to identify key correlates of intention to use eMental Health within a community of female Filipino domestic workers living and working in Macao (SAR), China.
Respondent-driven sampling implemented at a community field site was used to reach a sample of 1364 female domestic workers. A multivariable adjusted partial proportional-odds (PPO) model was used to assess relevant correlates of intent to use eMental Health.
The majority (62.8%) reported being likely to utilize eMental Health. The adjusted PPO model showed that younger age (18–25, 26–35, 36–45 v. over 55), longer time as an OFW, being likely (v. neutral and unlikely) to seek professional services, willingness to pay for services (v. not), belief that mental health services are a priority (v. low priority), having access to Wi-Fi outside the employer's home (v. not), and higher levels of social support were associated with increased odds of intent to use eMental Health.
eMental Health is a promising intervention with high potential for uptake among OFWs. The majority of the study population owned a smartphone and were able to connect to the Internet or Wi-Fi. Future work will rigorously evaluate eMental Health programs for use among OFWs.
Journals use social media to increase the awareness of their publications. Infographics show research findings in a concise and visually appealing manner, well suited for dissemination on social media platforms. We hypothesized that infographic abstracts promoted on social media would increase the dissemination and online readership of the parent research articles.
Twenty-four articles were chosen from the six issues of CJEM published between July 2016 and June 2017 and randomized to infographic or control groups. All articles were disseminated through the journal’s social media accounts (Twitter and Facebook). Control articles were promoted using a screen capture image of each article’s abstract on the journal’s social media accounts. Infographic articles were promoted similarly using a visual infographic. Infographics were also published and promoted on the CanadiEM.org’s website and social media channels. Abstract views, full-text views, and the change in Altmetric score were compared between groups using unpaired two-tailed t-tests.
There were no significant differences in the groups at baseline. Abstract views (mean, 95% CI) were higher in the infographics (379, 287-471) than the control group (176, 136-215, p<0.001). Mean change in Altmetric scores was higher in the infographics (26, 18-34) than in the control group (3, 2-4, p<0.0001). There was no difference in full-text views between the infographics (50, 0-101) and control groups (25, 18-32).
The promotion of CJEM articles using infographics on social media and the CanadiEM.org website increased Altmetric scores and abstract views. Infographics may have a role in increasing awareness of medical literature.
We present Phantom, a fast, parallel, modular, and low-memory smoothed particle hydrodynamics and magnetohydrodynamics code developed over the last decade for astrophysical applications in three dimensions. The code has been developed with a focus on stellar, galactic, planetary, and high energy astrophysics, and has already been used widely for studies of accretion discs and turbulence, from the birth of planets to how black holes accrete. Here we describe and test the core algorithms as well as modules for magnetohydrodynamics, self-gravity, sink particles, dust–gas mixtures, H2 chemistry, physical viscosity, external forces including numerous galactic potentials, Lense–Thirring precession, Poynting–Robertson drag, and stochastic turbulent driving. Phantom is hereby made publicly available.
We evaluated the utility of vancomycin-resistant Enterococcus (VRE) surveillance by varying 2 parameters: admission versus weekly surveillance and perirectal swabbing versus stool sampling.
Prospective, patient-level surveillance program of incident VRE colonization.
Liver transplant surgical intensive care unit (SICU) of a tertiary-care referral medical center with a high prevalence of VRE.
All patients admitted to the SICU from June to August 2015.
We conducted a point-prevalence estimate followed by admission and weekly surveillance by perirectal swabbing and/or stool sampling. Incident colonization was defined as a negative screen followed by positive surveillance. VRE was detected by culture on Remel Spectra VRE chromogenic agar. Microbiologically-confirmed VRE bloodstream infections (BSIs) were tracked for 2 months. Statistical analyses were calculated using the McNemar test, the Fisher exact test, the t test, and the χ2 test.
In total, 91 patients underwent VRE surveillance testing. The point prevalence of VRE colonization was 60.9%; VRE prevalence on admission was 30.1%. Weekly surveillance identified an additional 7 of 28 patients (25.0%) with incident colonization. VRE BSIs were more common in VRE-colonized patients than in noncolonized patients (8 of 43 vs 2 of 48; P=.028). In a direct comparison, perirectal swabs were more sensitive than stool samples in detecting VRE (64 of 67 vs 56 of 67; P=.023). Compliance with perirectal swabbing was 89% (201 of 226) compared to 56% (127 of 226) for stool collection (P≤0.001).
We recommend weekly VRE surveillance over admission-only screening in high-burden units such as liver transplant SICUs. Perirectal swabs had greater collection compliance and sensitivity than stool samples, making them the preferred methodology. Further work may have implications for antimicrobial stewardship and infection control.