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The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
Despite the global significance of the Leach’s Storm-petrel Hydrobates leucorhous colony on Baccalieu Island, Newfoundland and Labrador, Canada, the estimate of 3.36 million breeding pairs reported for 1984 by Sklepkovych and Montevecchi stands as the single published population estimate for the world’s largest colony. This study increases knowledge of this population by analysing data from additional independent surveys conducted in 1984 and 1985, and by updating the population status with a survey conducted in 2013. Population estimates were derived by extrapolating occupied burrow densities to the estimated occupied area of four main habitat types (heath, forest, grass and fern), which in turn were based on proportions of habitats observed in plots (1984 and 1985) or by using a Geographic Information System approach (2013). Based on these surveys, the Leach’s Storm-petrel breeding population size on Baccalieu Island was estimated at 5.12 ± 0.73 (SE) and 4.60 ± 0.42 (SE) million pairs in 1984 and 1985 respectively, representing estimates 37–51% greater than the original 1984 survey. While discrepancies among these estimates were largely driven by the way occupied areas were estimated, our study confirms that Baccalieu Island hosts the largest Leach’s Storm-petrel colony in the world. Results from the 2013 survey estimate the current breeding Leach’s Storm-petrel population at 1.95 ± 0.14 (SE) million pairs, representing a 42% decline over 29 years (-1.4% per year), relative to the original published estimate of 3.36 ± 0.12 (SE) million pairs. The most prominent change has occurred in the density of storm-petrel burrows found in forest habitat which dropped by 70% despite forest remaining the second most abundant habitat available to nesting storm-petrels on Baccalieu Island. The cause of this decline remains unknown and is likely multi-faceted. Future research focusing on demographic studies is required to understand what is driving the population decline of this internationally important colony.
The variability of adhesion promoter (primer) film thickness has been identified at Ford Motor Company as an important factor in maintaining the quality of paint on exterior plastic body parts. XRF offers unique advantages for non-destructive film monitoring. Monitoring of large parts for process control requires a non-contact approach using a small mobile probe. Previous attempts to implement a practical XRF gauging probe have been hampered by the choice of available x-ray detection technologies; proportional counters cannot resolve the layer's fluorescent lines properly and suffer from instability, while Si(Li) or Ge detectors need cooling to low temperatures, which makes their usage impractical for mobile probe.
The recent commercial availability of state-of-the-art Mercuric Iodide (HgI2) x-ray detectors led to the development of a lightweight XRF probe that contains an x-ray tube and a HgI2 detector. Thickness measurements of primer films on plastic substrates were characterized, and 15 sec. acquisition yielded precision of 0.225 and 0.525 pm for film thicknesses of 5 and 20 µm respectively. Ti was added to the substrate and Cr to the film as tagging elements. A ratiometric technique, taking into account absorption of the Ti signal in the film, yields excellent linearity and compensates for instrumental errors such as sampleto- probe distance variation and x-ray source fluctuations.
Droplets can be levitated by their own vapour when placed onto a superheated plate (the Leidenfrost effect). It is less known that the Leidenfrost effect can likewise be observed over a liquid pool (superheated with respect to the drop), which is the study case here. Emphasis is placed on an asymptotic analysis in the limit of small evaporation numbers, which indeed proves to be a realistic one for millimetric-sized drops (i.e. where the radius of the drop is of the order of the capillary length). The global shapes are found to resemble ‘superhydrophobic drops’ that follow from the equilibrium between capillarity and gravity. However, the morphology of the thin vapour layer between the drop and the pool is very different from that of classical Leidenfrost drops over a flat rigid substrate, and exhibits different scaling laws. We determine analytical expressions for the vapour thickness as a function of temperature and material properties, which are confirmed by numerical solutions. Surprisingly, we show that deformability of the pool suppresses the chimney instability of Leidenfrost drops.
Paludification is the most common process of peatland formation in boreal regions. In this study, we investigated the autogenic (e.g., topography) and allogenic (fire and climate) factors triggering paludification in different geomorphological contexts (glaciolacustrine silty-clayey and fluvioglacial deposits) within the Québec black spruce (Picea mariana)–moss boreal forest. Paleoecological analyses were conducted along three toposequences varying from a forest on mineral soil to forested and semi-open peatlands. Plant macrofossil and charcoal analyses were performed on basal peat sections (≤50 cm) and thick forest humus (<40 cm) to reconstruct local vegetation dynamics and fire history involved in the paludification process. Results show that primary paludification started in small topographic depressions after land emergence ca. 8000 cal yr BP within rich fens. Lateral peatland expansion and secondary paludification into adjacent forests occurred between ca. 5100 and 2300 cal yr BP and resulted from low-severity fires during a climatic deterioration. Fires that reduced or eliminated entirely the organic layer promoted the establishment of Sphagnum in microdepressions. Paludification resulted in the decline of some coniferous species such as Abies balsamea and Pinus banksiana. The paleoecological approach along toposequences allowed us to understand the spatiotemporal dynamics of paludification and its impacts on the vegetation dynamics over the Holocene.
Rhinonyssids are obligate haematophagous mites that parasitize the nasal cavity of vertebrates, and occur in a wide range of birds worldwide. Two species of nasal mites are known to occur in penguins: Rhinonyssus sphenisci, which has been recorded from Humboldt and Magellanic penguins (Spheniscus humboldti and S. magellanicus, respectively), and Rhinonyssus schelli, which has been recorded in Adélie and Gentoo penguins (Pygoscelis adeliae and P. papua, respectively). We examined the nasal cavity of African penguins (Spheniscus demersus) that died while under care at a rehabilitation centre (N = 40) or that were found dead at breeding colonies (N = 67). Nasal mites were found in the nasal cavity and/or paranasal of sinuses of 21 penguins, some of which had signs of mild-to-moderate sinusitis. Prevalence was higher in juveniles (29%) and adults (27%) than in chicks (10%). Mean intensity was 5.9 ± 12.9 mites per infected host (range 1–60). The mites presented morphological characteristics that were at times consistent with either R. sphenisci or R. schelli, and therefore we conservatively classified them as ‘R. sphenisci sensu lato’. Our morphometric results raise the question of whether the specific status of R. schelli is justified.
To make pragmatic recommendations on best practices for the engagement of patients in emergency medicine (EM) research.
We created a panel of expert Canadian EM researchers, physicians, and a patient partner to develop our recommendations. We used mixed methods consisting of 1) a literature review; 2) a survey of Canadian EM researchers; 3) qualitative interviews with key informants; and 4) feedback during the 2017 Canadian Association of Emergency Physicians (CAEP) Academic Symposium.
We synthesized our literature review into categories including identification and engagement, patients’ roles, perceived benefits, harms, and barriers to patient engagement; 40/75 (53% response rate) invited researchers completed our survey. Among respondents, 58% had engaged patients in research, and 83% intended to engage patients in future research. However, 95% stated that they need further guidance to engage patients. Our qualitative interviews revealed barriers to patient engagement, including the need for training and patient partner recruitment.
Our panel recommends 1) an overarching positive recommendation to support patient engagement in EM research; 2) seven policy-level recommendations for CAEP to support the creation of a national patient council, to develop, adopt and adapt training material, guidelines, and tools for patient engagement, and to support increased patient engagement in EM research; and 3) nine pragmatic recommendations about engaging patients in the preparatory, execution, and translational phases of EM research.
Patient engagement can improve EM research by helping researchers select meaningful outcomes, increase social acceptability of studies, and design knowledge translation strategies that target patients’ needs.
Isotopic composition of leaf carbon (δ13C) and nitrogen (δ15N) is determined by biotic and abiotic factors. In order to determine the influence of leaf habit and site on leaf δ13C and δ15N in the understorey of two Atlantic forests in Brazil that differ in annual precipitation (1200 and 1900 mm), we measured these isotopes in the shaded understorey of 38 tropical tree species (20 in the 1200-mm site and 18 in the 1900-mm site). Mean site values for δ15N were significantly lower at the 1200-mm site (−1.4‰) compared with the 1900-mm site (+3.0‰), and δ13C was significantly greater in the 1200-mm site (−30.4‰) than in the 1900-mm site (−31.6‰). Leaf C concentration was greater and leaf N concentration was lower at 1200-mm than at 1900-mm. Leaf δ15N was negatively correlated with δ13C across the two sites. Leaf δ13C and δ15N of evergreen and deciduous species were not significantly different within a site. No significant phylogenetic signal for any traits among the study species was found. Overall, site differences were the main factor distinguishing traits among species, suggesting strong functional convergence to local climate and soils within each site for individuals in the shaded understorey.
Previous work has identified associations between psychotic experiences (PEs) and general medical conditions (GMCs), but their temporal direction remains unclear as does the extent to which they are independent of comorbid mental disorders.
In total, 28 002 adults in 16 countries from the WHO World Mental Health (WMH) Surveys were assessed for PEs, GMCs and 21 Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) mental disorders. Discrete-time survival analyses were used to estimate the associations between PEs and GMCs with various adjustments.
After adjustment for comorbid mental disorders, temporally prior PEs were significantly associated with subsequent onset of 8/12 GMCs (arthritis, back or neck pain, frequent or severe headache, other chronic pain, heart disease, high blood pressure, diabetes and peptic ulcer) with odds ratios (ORs) ranging from 1.3 [95% confidence interval (CI) 1.1–1.5] to 1.9 (95% CI 1.4–2.4). In contrast, only three GMCs (frequent or severe headache, other chronic pain and asthma) were significantly associated with subsequent onset of PEs after adjustment for comorbid GMCs and mental disorders, with ORs ranging from 1.5 (95% CI 1.2–1.9) to 1.7 (95% CI 1.2–2.4).
PEs were associated with the subsequent onset of a wide range of GMCs, independent of comorbid mental disorders. There were also associations between some medical conditions (particularly those involving chronic pain) and subsequent PEs. Although these findings will need to be confirmed in prospective studies, clinicians should be aware that psychotic symptoms may be risk markers for a wide range of adverse health outcomes. Whether PEs are causal risk factors will require further research.
We assessed clinicians’ continuing professional development (CPD) needs at family practice teaching clinics in the province of Quebec. Our mixed methodology design comprised an environmental scan of training programs at four family medicine departments, an expert panel to determine priority clinical situations for senior care, a supervisors survey to assess their perceived CPD needs, and interviews to help understand the rationale behind their needs. From the environmental scan, the expert panel selected 13 priority situations. Key needs expressed by the 352 survey respondents (36% response rate) included behavioral and psychological symptoms of dementia, polypharmacy, depression, and cognitive disorders. Supervisors explained that these situations were sometimes complex to diagnose and manage because of psychosocial aspects, challenges of communicating with patients and families, and coordination of interprofessional teams. Supervisors also reported more CPD needs in long-term and home care, given the presence of caregivers and complexity of senior care in these settings.
Traumatic events are associated with increased risk of psychotic experiences, but it is unclear whether this association is explained by mental disorders prior to psychotic experience onset.
To investigate the associations between traumatic events and subsequent psychotic experience onset after adjusting for post-traumatic stress disorder and other mental disorders.
We assessed 29 traumatic event types and psychotic experiences from the World Mental Health surveys and examined the associations of traumatic events with subsequent psychotic experience onset with and without adjustments for mental disorders.
Respondents with any traumatic events had three times the odds of other respondents of subsequently developing psychotic experiences (OR=3.1, 95% CI 2.7–3.7), with variability in strength of association across traumatic event types. These associations persisted after adjustment for mental disorders.
Exposure to traumatic events predicts subsequent onset of psychotic experiences even after adjusting for comorbid mental disorders.
A selection of elements (Bi, Ca, Cd, Co, Cu, Mn, Na, Sr, U, V, Zn) were measured by high-resolution inductively coupled plasma sector-field mass spectrometry in firn- and ice-core samples from Law Dome, Antarctica, corresponding to the period 4500 BC to AD 1989. Concentrations of rock dust and sea salts were calculated for each sample and then used to determine concentrations of each element originating from crustal and marine aerosol emissions, respectively. Where calculated contributions from crustal and marine aerosol sources failed to account for the total measured concentration of an element, the remainder was apportioned to volcanic and/or anthropogenic sources and defined as an enrichment. On this basis, it was determined that Bi and Cd concentrations in Law Dome ice are overwhelmingly influenced by volcanic emissions (enrichments 150–250x crustal and marine inputs); Co, Cu, Pb and Zn concentrations in Law Dome ice are largely influenced by volcanic emissions (enrichments 16–36x crustal and marine inputs); and Mn, Sr, U and V concentrations in Law Dome ice are minimally influenced by volcanic emissions (enrichments 1.5–4x crustal and marine inputs). During the 20th century, enrichments of Pb and Cu concentrations were observed to be greater than in earlier centuries, consistent with increasing anthropogenic emissions of Pb and Cu in the Southern Hemisphere over that period.