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How and why do predators sometimes fuel disease outbreaks but other times thwart them? Answering this could help explain spatial and temporal variation in disease and could explain why attempts to control disease by manipulating predators sometimes fail. We give eight mechanisms by which predators can suppress/spread disease in prey populations, exploring each generally and reviewing evidence from the study system that has been the focus of much of our research. This system focuses on Daphnia dentifera, a dominant herbivore in lake food webs in the Midwestern United States. D. dentifera is prey to bluegill sunfish and phantom midge larvae, as well as host to a virulent fungal pathogen. We review evidence for bluegill sunfish as ‘healthy herds’ predators that reduce disease, and for midge larvae as ‘predator spreaders’ that fuel disease outbreaks. We find that both predators can impact disease via multiple mechanisms. Bluegill feed selectively on infected hosts and also depress disease in Daphnia by reducing the density of midge larvae which spread disease. They also increase the abundance of Ceriodaphnia, which reduce disease. Midge larvae increase disease in their hosts, in part by releasing spores into the water column where they can be consumed by additional hosts.
Mexican Americans suffer from a disproportionate burden of modifiable risk factors, which may contribute to the health disparities in mild cognitive impairment (MCI) and Alzheimer’s disease (AD).
The purpose of this study was to elucidate the impact of comorbid depression and diabetes on proteomic outcomes among community-dwelling Mexican American adults and elders.
Data from participants enrolled in the Health and Aging Brain among Latino Elders study was utilized. Participants were 50 or older and identified as Mexican American (N = 514). Cognition was assessed via neuropsychological test battery and diagnoses of MCI and AD adjudicated by consensus review. The sample was stratified into four groups: Depression only, Neither depression nor diabetes, Diabetes only, and Comorbid depression and diabetes. Proteomic profiles were created via support vector machine analyses.
In Mexican Americans, the proteomic profile of MCI may change based upon the presence of diabetes. The profile has a strong inflammatory component and diabetes increases metabolic markers in the profile.
Medical comorbidities may impact the proteomics of MCI and AD, which lend support for a precision medicine approach to treating this disease.
Floriculture value exceeds $5.8 billion in the United States. Environmental challenges, market trends, and diseases complicate breeding priorities. To inform breeders’ and geneticists’ research efforts, we set out to gather consumers’ preferences in the form of willingness to pay (WTP) for different rose attributes in a discrete choice experiment. The responses are modeled in WTP space, using polynomials to account for heterogeneity. Consumer preferences indicate that heat and disease tolerance were the most important aspects for subjects in the sample, followed by drought resistance. To the best of our knowledge, this is the first study to identify breeding priorities in rosaceous plants from a consumer perspective.
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.
Background: Focal cortical dysplasias (FCDs) are congenital structural abnormalities of the brain, and represent the most common cause of medication-resistant focal epilepsy in children and adults. Recent studies have shown that somatic mutations (i.e. mutations arising in the embryo) in mTOR pathway genes underlie some FCD cases. Specific therapies targeting the mTOR pathway are available. However, testing for somatic mTOR pathway mutations in FCD tissue is not performed on a clinical basis, and the contribution of such mutations to the pathogenesis of FCD remains unknown. Aim: To investigate the feasibility of screening for somatic mutations in resected FCD tissue and determine the proportion and spatial distribution of FCDs which are due to low-level somatic mTOR pathway mutations. Methods: We performed ultra-deep sequencing of 13 mTOR pathway genes using a custom HaloPlexHS target enrichment kit (Agilent Technologies) in 16 resected histologically-confirmed FCD specimens. Results: We identified causal variants in 62.5% (10/16) of patients at an alternate allele frequency of 0.75–33.7%. The spatial mutation frequency correlated with the FCD lesion’s size and severity. Conclusions: Screening FCD tissue using a custom panel results in a high yield, and should be considered clinically given the important potential implications regarding surgical resection, medical management and genetic counselling.
Young people with 22q11.2 deletion syndrome (22q11.2DS) are at high risk for neurodevelopmental disorders. Sleep problems may play a role in this risk but their prevalence, nature and links to psychopathology and cognitive function remain undescribed in this population.
Sleep problems, psychopathology, developmental coordination and cognitive function were assessed in 140 young people with 22q11.2DS (mean age = 10.1, s.d. = 2.46) and 65 unaffected sibling controls (mean age = 10.8, s.d.SD = 2.26). Primary carers completed questionnaires screening for the children's developmental coordination and autism spectrum disorder.
Sleep problems were identified in 60% of young people with 22q11.2DS compared to 23% of sibling controls (OR 5.00, p < 0.001). Two patterns best-described sleep problems in 22q11.2DS: restless sleep and insomnia. Restless sleep was linked to increased ADHD symptoms (OR 1.16, p < 0.001) and impaired executive function (OR 0.975, p = 0.013). Both patterns were associated with elevated symptoms of anxiety disorder (restless sleep: OR 1.10, p = 0.006 and insomnia: OR 1.07, p = 0.045) and developmental coordination disorder (OR 0.968, p = 0.0023, and OR 0.955, p = 0.009). The insomnia pattern was also linked to elevated conduct disorder symptoms (OR 1.53, p = 0.020).
Clinicians and carers should be aware that sleep problems are common in 22q11.2DS and index psychiatric risk, cognitive deficits and motor coordination problems. Future studies should explore the physiology of sleep and the links with the neurodevelopment in these young people.
Introduction: Quality improvement and patient safety (QIPS) are increasingly recognized as integral to the provision and advancement of emergency medicine (EM) care. In 2015, QIPS were added to the Canadian Medical Education Directives for Specialists (CanMEDS) framework. However, the level of QIPS education and support that Canadian EM residents receive is unknown. In order to better plan national QIPS efforts aimed at enabling EM residents to improve their local care settings, we sought to assess the current state of QIPS education and support in Canadian EM residency programs. Methods: This was a descriptive, cross-sectional electronic survey that was disseminated to all current Canadian EM residents from both Royal College (RC) and Family Medicine - EM training streams. Residents were recruited either directly or through their program's administrative assistant. The survey consisted of multiple-choice, Likert and free-text entry questions. Themes included a) familiarity with QIPS; b) local opportunities for QIPS projects and mentorship; and c) desire for further QIPS education and involvement. The survey was open for a five-week period, with formal reminders after the first and third weeks. Descriptive statistics are reported. Results: 189 (35%) of 535 current EM residents completed the survey, representing all 17 medical schools. 77% of respondents were from the RC stream. 54.7% of respondents reported being “somewhat” or “very” familiar with QIPS. 47.2% of respondents reported “not knowing” or “not having readily available” QIPS projects to participate in their local environment, and 51.5% had equivalent responses with respect to QIPS mentorship opportunities. Only 17.5% of respondents reported that QIPS methodologies were already formally taught in their residency program, and 66.9% indicated a desire for increased QIPS teaching. The majority of respondents were “slightly” (35.9%), “moderately” (23.2%) or “very” (11.3%) interested in becoming involved with QIPS training and initiatives. Conclusion: Responding Canadian EM residents are interested in obtaining greater QIPS education as well as project and mentorship opportunities, but many perceive that they do not have adequate access to these at the current time. As the importance of QIPS increases in the EM community, supporting residents with more robust educational infrastructures may be necessary. Future efforts may include the standardizing of QIPS postgraduate curricula and improving access to QIPS opportunities across the country.
Introduction: Capitalizing on the success of Simulation-Based Education (SBE) in residency-training programs, simulation has been gradually integrated into Continued Professional Development (CPD) programs for Emergency Physicians (EPs) in Canada. This study sought to characterize how Canadian academic emergency medicine (EM) departments have implemented SBE for CPD. Methods: We conducted two national surveys: 1) the National Faculty Simulation Status Assessment Survey, administered by telephone to the simulation directors (or equivalent) at 20 Canadian academic EM sites and 2) the Faculty Simulation Needs Assessment Survey administered online to all full-time EPs across 9 Canadian academic EM sites. Results: The response rates for the National Status and Needs Assessment Surveys were 100% (20/20), and 40% (252/635), respectively. The majority (60%) of Canadian academic EM sites reported utilizing SBE for CPD, though only 30% reported dedicated funding support. EPs reported participating in a median of 3 hours per year of SBE (IQR 1-6 hours). Reported incentivization offered in the form of continued medical education credits varied between simulation directors (67%) and EPs (44%). Simulation directors identified several significant barriers to SBE including a lack of faculty time, fear of peer judgment, and faculty inexperience. In contrast, EP-identified barriers included time commitments outside of shift, lack of opportunities, and lack of departmental. The three most common topics of interest for SBE by EPs were performance of rare procedures, pediatric resuscitation, and neonatal resuscitation. Interprofessional involvement in SBE CPD was valued by both simulation directors and EPs, with most EPs (79%) indicating it is useful. Conclusion: Most Canadian EPs and simulation directors recognize the value of SBE for CPD, yet it is only utilized, infrequently, by 67% of Canadian academic EM departments for this purpose. This may be explained, in part, by poor incentivization for participation. Simulation directors and EPs noted different barriers to SBE implementation for CPD suggesting the need for dialogue to improve utilization. As SBE for CPD is incorporated more frequently, and at more sites, content should be guided by local needs assessments with an emphasis on interprofessional participation.
Introduction: Simulation has assumed an integral role in the Canadian healthcare system with applications in quality improvement, systems development, and medical education. High quality simulation-based research (SBR) is required to ensure the effective and efficient use of this tool. This study sought to establish national SBR priorities and describe the barriers and facilitators of SBR in Emergency Medicine (EM) in Canada. Methods: Simulation leads (SLs) from all fourteen Canadian Departments or Divisions of EM associated with an adult FRCP-EM training program were invited to participate in three surveys and a final consensus meeting. The first survey documented active EM SBR projects. Rounds two and three established and ranked priorities for SBR and identified the perceived barriers and facilitators to SBR at each site. Surveys were completed by SLs at each participating institution, and priority research themes were reviewed by senior faculty for broad input and review. Results: Twenty SLs representing all 14 invited institutions participated in all three rounds of the study. 60 active SBR projects were identified, an average of 4.3 per institution (range 0-17). 49 priorities for SBR in Canada were defined and summarized into seven priority research themes. An additional theme was identified by the senior reviewing faculty. 41 barriers and 34 facilitators of SBR were identified and grouped by theme. Fourteen SLs representing 12 institutions attended the consensus meeting and vetted the final list of eight priority research themes for SBR in Canada: simulation in CBME, simulation for interdisciplinary and inter-professional learning, simulation for summative assessment, simulation for continuing professional development, national curricular development, best practices in simulation-based education, simulation-based education outcomes, and simulation as an investigative methodology. Conclusion: Conclusion: This study has summarized the current SBR activity in EM in Canada, as well as its perceived barriers and facilitators. We also provide a consensus on priority research themes in SBR in EM from the perspective of Canadian simulation leaders. This group of SLs has formed a national simulation-based research group which aims to address these identified priorities with multicenter collaborative studies.
Shiga-toxin producing Escherichia coli (STEC) is a pathogen that can cause bloody diarrhoea and severe complications. Cases occur sporadically but outbreaks are also common. Understanding the incubation period distribution and factors influencing it will help in the investigation of exposures and consequent disease control. We extracted individual patient data for STEC cases associated with outbreaks with a known source of exposure in England and Wales. The incubation period was derived and cases were described according to patient and outbreak characteristics. We tested for heterogeneity in reported incubation period between outbreaks and described the pattern of heterogeneity. We employed a multi-level regression model to examine the relationship between patient characteristics such as age, gender and reported symptoms; and outbreak characteristics such as mode of transmission with the incubation period. A total of 205 cases from 41 outbreaks were included in the study, of which 64 cases (31%) were from a single outbreak. The median incubation period was 4 days. Cases reporting bloody diarrhoea reported shorter incubation periods compared with cases without bloody diarrhoea, and likewise, cases aged between 40 and 59 years reported shorter incubation period compared with other age groups. It is recommended that public health officials consider the characteristics of cases involved in an outbreak in order to inform the outbreak investigation and the period of exposure to be investigated.
The back reflection x-ray divergent beam technique is examined as a tool for studying elastic strains. In particular, a method of calculating interplanar spacings using a least squares fit of experimental "conic" coordinates to Newman's general equation for back reflection (J. Appl. Cryst. 3 (1970) 191) is described. Using this technique, interplanar spacings can be obtained from partial conies. To determine the precision of this method an unstrained silicon single crystal is studied, and the errors associated with determining its interplanar spacings are discussed. The technique is then applied to elastically strained silicon and the results compared to theoretical predictions. It is shown that strains down to 2 × 10−5 are readily measured on high angle planes in silicon.
Lithostratigraphical studies coupled with the development of new dating methods has led to significant progress in understanding the Late Pleistocene terrestrial record in Scotland. Systematic analysis and re-evaluation of key localities have provided new insights into the complexity of the event stratigraphy in some regions and the timing of Late Pleistocene environmental changes, but few additional critical sites have been described in the past 25 years. The terrestrial stratigraphic record remains important for understanding the timing, sequence and patterns of glaciation and deglaciation during the last glacial/interglacial cycle. Former interpretations of ice-free areas in peripheral areas during the Last Glacial Maximum (LGM) are inconsistent with current stratigraphic and dating evidence. Significant challenges remain to determine events and patterns of glaciation during the Early and Middle Devensian, particularly in the context of offshore evidence and ice sheet modelling that indicate significant build-up of ice throughout much of the period. The terrestrial evidence broadly supports recent reconstructions of a highly dynamic and climate-sensitive British–Irish Ice Sheet (BIIS), which apparently reached its greatest thickness in Scotland between 30 and 27ka, before the global LGM. A thick (relative to topography) integrated ice sheet reaching the shelf edge with a simple ice-divide structure was replaced after the LGM by a much thinner one comprising multiple dispersion centres and a more complex flow structure.
A fine-grained, up to 3-m-thick tephra bed in southwestern Saskatchewan, herein named Duncairn tephra (Dt), is derived from an early Pleistocene eruption in the Jemez Mountains volcanic field of New Mexico, requiring a trajectory of northward tephra dispersal of ~1500 km. An unusually low CaO content in its glass shards denies a source in the closer Yellowstone and Heise volcanic fields, whereas a Pleistocene tephra bed (LSMt) in the La Sal Mountains of Utah has a very similar glass chemistry to that of the Dt, supporting a more southerly source. Comprehensive characterization of these two distal tephra beds along with samples collected near the Valles caldera in New Mexico, including grain size, mineral assemblage, major- and trace-element composition of glass and minerals, paleomagnetism, and fission-track dating, justify this correlation. Two glass populations each exist in the Dt and LSMt. The proximal correlative of Dt1 is the plinian Tsankawi Pumice and co-ignimbritic ash of the first ignimbrite (Qbt1g) of the 1.24 Ma Tshirege Member of the Bandelier Tuff. The correlative of Dt2 and LSMt is the co-ignimbritic ash of Qbt2. Mixing of Dt1 and Dt2 probably occurred during northward transport in a jet stream.
Many recent studies of “regime politics” argue that judicial review is ultimately used to promote the interests of the dominant governing regime. I explore this claim by evaluating whether the invalidation of federal laws by the US Supreme Court fits the empirical expectations of the regime politics approach. I find that the Court frequently invalidates statutes when (1) the ideology of the Court diverges from that of the sitting elected branches (suggesting that the Court does not fear sanctions or nonimplementation), and (2) the ideology of the sitting elected branches converges with that of the elected branches that enacted the statute (suggesting that the Court is defying the sitting elected branches). My findings suggest that the Court does not primarily use judicial review to promote the interests of the dominant governing regime.
This paper reviews the changing environments, developing landforms and terrestrial stratigraphy during the Early and Middle Pleistocene stages in Scotland. Cold stages after 2.7 Ma brought mountain ice caps and lowland permafrost, but larger ice sheets were short-lived. The late Early and Middle Pleistocene sedimentary record found offshore indicates more than 10 advances of ice sheets from Scotland into the North Sea but only 4–5 advances have been identified from the terrestrial stratigraphy. Two primary modes of glaciation, mountain ice cap and full ice sheet modes, can be recognised. Different zones of glacial erosion in Scotland reflect this bimodal glaciation and the spatially and temporally variable dynamics at glacier beds. Depths of glacial erosion vary from almost zero in Buchan to hundreds of metres in glens in the western Highlands and in basins both onshore and offshore. The presence of tors and blockfields indicates repeated development of patches of cold-based, non-erosive glacier ice on summits and plateaux. In lowlands, chemical weathering continued to operate during interglacials, but gruss-type saprolites are mainly of Pliocene to Early Pleistocene age. The Middle Pleistocene terrestrial stratigraphic record in Scotland, whilst fragmentary and poorly dated, provides important and accessible evidence of changing glacial, periglacial and interglacial environments over at least three stadial–interstadial–interglacial cycles. The distributions of blockfields and tors and the erratic contents of glacial sediments indicate that the configuration, thermal regime and pattern of ice flow during MIS 6 were broadly comparable to those of the last ice sheet. Improved control over the ages of Early and Middle Pleistocene sediments, soils and saprolites and on long-term rates of weathering and erosion, combined with information on palaeoenvironments, ice extent and sea level, will in future allow development and testing of new models of Pleistocene tectonics, isostasy, sea-level change and ice sheet dynamics in Scotland.
In 1947, the US Supreme Court considered a challenge to a New York tax on transportation utilities in Central Greyhound Lines v. Mealey. The State of New York had levied a two percent tax on the gross income of all utilities operating in the state, including common carriers such as Central Greyhound Lines. Because the Constitution delegates to Congress the power to tax interstate commerce, the tax applied only to buses moving within the state of New York; transportation between New York and other states was not subject to the tax. However, the State Tax Commission held that the utilities tax applied to the transportation of passengers between two points in New York even if substantial portions of the transportation utilized highways in other states. Central Greyhound Lines challenged the constitutionality of the tax as applied to a route between two points in New York because 43.53 percent of the route passed through New Jersey and Pennsylvania and therefore might be considered interstate commerce.
In the Court's conference discussion, a majority of justices supported upholding the New York tax, and the opinion of the Court was assigned to Justice Frank Murphy. Majority opinion assignments were rare for Justice Murphy. “Neither [Chief Justice Harlan Fiske] Stone nor [Chief Justice Fred M.] Vinson had much confidence in his work. Accordingly, he received few opinions in important cases from either chief justice”; in fact, the opinion in Central Greyhound had been his “sole assignment to date” during the 1947 term. The other justices viewed him as “lazy and unsophisticated in the law” (Justice Felix Frankfurter once wrote to another justice, “[T]he short of the matter is that today you would no more heed Murphy's tripe than you would be seen naked at Dupont Circle at high noon tomorrow”). Murphy “lacked the intellectual drive and the patience to structure the central juridical options of his time,” and he even doubted his own technical competence. Most importantly,Murphy was deficient in the social and leadership skills necessary to persuade his colleagues and marshal the Court: He “seldom spoke in public,”his assets were “all highly personal rather than ‘lawyerly,”’ and “he lacked the charisma, and perhaps the cunning, to build a political coalition capable of sustaining reform movements and of surviving himself.”