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Elevated levels of organochlorines (OC) have been reported in Inuit populations in the Arctic. We hypothesized that prenatal exposure to a Canadian Arctic OC mixture adversely affects male reproductive function and health with age. Sprague–Dawley female rats (F0) were gavaged with an environmentally relevant concentration of an Arctic OC mixture or corn oil (Control) during mating with untreated males until parturition (F1 litters). After postnatal day (PND) 90, the weights of the OC F1 males differed dramatically relative to Controls (P<0.05; n=10) and they exhibited respiratory distress. Except for possible thinning of the alveolar barrier, histological observation of the lungs revealed no apparent pathology to explain the respiratory distress. At PND 365, OC F1 males had reduced relative reproductive organ weights and lower sperm quality than Controls (P<0.05). At PND 90, OC F1 males were subfertile (P<0.05), but were infertile at PND 365. In conclusion, environmentally relevant prenatal OC exposure reduced reproductive function and health in aging male rats, providing new insight into the effects of early-life exposures to these contaminants.
Atherosclerosis is a significant risk factor for ischemic stroke, and is a frequent cause for extra- and intra-cranial vessels stenosis. Here, we present an unusual case of ischemic stroke associated with intra-cranial vessel stenosis and subarachnoid hemorrhage (SAH) secondary to carotid artery atheroma. A 64-year old female known for hypertension and dyslipidemia presented with a three-day history of three transient episodes (< 30 minutes) of dysarthria and right hand weakness. An initial brain CT scan revealed left frontal SAH. She was admitted to our Stroke Unit for observation and management. CT-angiogram revealed 90% ICAs stenosis bilaterally with several short focal stenotic lesions, involving several left MCA branches. Brain MRI revealed acute infarcts in the left insula, external capsule and inferior frontal gyrus. The clinical picture was attributed to a thromboembolic left MCA ischemic stroke. She was managed with maximum medical therapy, and later underwent successful left carotid endarterectomy. The presence of SAH on our patient’s presenting CT scan lead to an initial radiological diagnosis of RCVS. However, subsequent imaging studies indicated that SAH had occurred in association with a thromboembolic ischemic stroke. Despite its rarity, this clinical association is important to recognize to avoid diagnostic confusion and guide appropriate management.
Introduction: An evidence-based care protocol to treat migraine with low-dose Propofol was implemented in May 2014 at the emergency department (ED) of the CHUL (Québec city). Given potential side effects of Propofol, we aimed to evaluate the safety and effectiveness of this protocol. Methods: We reviewed charts of all patients aged 16 years and older who received Propofol between May 2014 and August 2017 for a migraine headache with or without aura, as defined in the International Headache Society Classification. The care protocol consisted of: 1) administration of intra-venous Propofol 20 mg each 5 to 10 minutes as needed (maximum of 6 doses); 2) sets of vital signs before and after each dose; and 3) continuous cardiac and saturation monitoring. Our primary outcome measures were the incidence (95%CI) of the following side effects: low arterial pressure (< 90 systolic or < 65 mean), desaturation (SaO2<92%), excessive sedation (scores 3 or 4 on the Pasero scale), and any arrhythmia. We also compared the mean reduction (95%CI) of pain pre- and post-treatment (visual analogous scale VAS 0-10) and the proportion (95%CI) of rescue medication among patients who received Propofol as first-line medication to a matched cohort of patients who had Metoclopramide first. The two cohorts were paired for gender, age, triage priority, and month/year of ED visit. Results: Over the 3-year study period, 45 patients with migraine received Propofol through the care protocol, either as a first-line or a rescue therapy. In this cohort, hypotension, bradycardia (<60/min) and desaturation occurred in 17.8% (8.0-32.1), 13.3% (5.1-26.8) and 6.7% (1.4-18.3) of cases respectively; no excessive sedation was reported. An intervention was undertaken in 4 cases [8.9% (2.5-21.2) 3 iv fluid bolus, 1 supplemental oxygen] to palliate the side effects of Propofol. A statistically significant mean reduction of 3.6 points (2.8-4.4) on the VAS scale was observed in patients treated with Propofol as first-line therapy (n=35). However, patients managed with first-line Metoclopramide (n=100) experienced a significantly higher mean reduction of their VAS score [5.3 (4.6-6.0)] than the Propofol group (p=0.003). The proportion of patients requiring the use of rescue medication was higher among patients first treated with Propofol [77.1% (63.2-91.1) vs. 29.0% (20.1-37.9); p<0.001]. Conclusion: Our care protocol to treat migraine with low doses of Propofol appears to be safe and to cause very few side effects prompting corrective interventions. Continuous (as opposed to intermittent) heart and saturation monitoring is probably not indicated. Given the effectiveness of Propofol compared to Metoclopramide, our care protocol will be used as a second-line therapy.
Introduction: Poor physicians’ knowledge of health care costs has been identified as an important barrier to improving efficiency and reducing overuse in care delivery. Moreover, costs of tests and treatments estimated with traditional costing methods have been shown to be imprecise and unreliable. We estimated the cost of frequent care activities in the emergency department (ED) using the time-driven activity-based costing (TDABC) method. Methods: We conducted a TDABC study in the ED of the CHUL, Québec city (77000 visits/year). We estimated the cost of all potential care activities (e.g. triage) provided to adult patients with selected urgent (e.g. pulmonary sepsis) and non urgent (e.g. urinary tract infection) conditions frequently encountered in the ED. Following Lean management principles, process maps were developed by a group of ED care providers for each care activity to identify human resources, supplies and equipment involved, and to estimate the time required to complete each process. Resource unit cost (e.g. cost per minute of a nurse) and overhead rate were calculated using financial information from fiscal year 2015-16. Estimated cost of each care activity (e.g. chest X-ray) including physicians’ charges was calculated by summing overhead allocation and the cost of each process (e.g. disinfection of the X-ray machine) as obtained by multiplying the resource unit cost by the time for process completion. Results: Process maps were developed for 14 conditions and 68 ED care activities. We estimated the costs of activities (CAN$) related to nursing (e.g. urinalysis and culture triage ordering $14.70), clerk tasks (e.g. patient registration $3.40), physicians (e.g. FAST scan $20.90), laboratory testing (e.g. CBC $6.30), diagnostic imaging (e.g. abdominal CT scan $146.50), therapy (e.g. 5 mg of iv morphine $20.40), and resuscitation (rapid sequence intubation with ketamine and succinylcholine $146.40). Overall, emergency physicians’ charges, personnel salaries and overheads accounted for 38%, 22% and 16% of all ED care costs, respectively. Conclusion: Our results represent an important step toward increasing emergency physicians’ awareness on the real cost of their interventions and empowering them to adopt more cost-effective practice patterns.
We present an in-depth study of metal-poor stars, based high resolution spectra combined with newly released astrometric data from Gaia, with special attention to observational uncertainties. The results are compared to those of other studies, including Gaia benchmark stars. Chemical evolution models are discussed, highlighting few puzzles that are still affecting our understanding of stellar nucleosynthesis and of the evolution of our Galaxy.
A great many plantain varieties are cropped in West and Central Africa, and there is a lack of information about their production potential and suitability for cropping system environments. To obtain benchmark data for the production potential of plantain varieties, experimental and modelling approaches were combined to determine intrinsic growth parameters and to increase understanding of factors affecting yield. Five real plantains commonly cropped in Cameroon and representative of plantain group diversity (Batard, Big Ebanga, Essong, French clair and Mbouroukou n°3) and four plantain-like hybrids (CRBP39, D248, D535 and FHIA21) were studied. A process-based growth model (the AAB model) was developed that accounts for specific characteristics of the plantain crop that includes parameters affecting growth, development and yield. Varietal-specific parameters were determined in a field experiment conducted under nearly non-limiting production conditions while general parameters were drawn from the literature. Parameters describing the conversion of intercepted radiation into dry matter were evaluated by model fitting. Photosynthetic efficiency was significantly higher for real plantains than for plantain-like hybrids. The model realistically simulated development, growth and bunch production for five varieties. These results are the first step in developing a useful tool for assessing the suitability of plantain varieties to different environments. The current study highlights the need for greater knowledge of plantain physiology in order to better model plantain growth and develop variety-specific production approaches.
Background: There are currently no national standards for clinical electromyography (EMG) training for residents in neurology and physiatry in Canada. The purpose of this study was to obtain demographic and qualitative data pertaining to EMG residency training in Canada, with the goal of facilitating discourse that could lead to national standards for EMG training. Methods: An online survey was distributed to senior neurology and physiatry residents (post-graduate years 3-5), at seven tertiary Canadian centres. The study authors, who are trainees and consultants with a broad range of EMG expertise (junior and senior resident, clinical neuromuscular fellows, senior physiatrist and neuromuscular neurologists), developed pertinent demographic and qualitative questions. Results: Thirty-eight residents completed the survey (23 neurology, 15 physiatry). There was inter-program variation in quantity of the training experience, content of the curriculum, access to expertise (including technologists) and goals for future training and practice. Similarly, differences were identified between the training experiences of neurology and physiatry residents. Conclusions: Inter-program variability in EMG training was identified. Additionally, differences were identified between neurology and physiatry resident training. This data provides evidence of training discrepancies across the country and can be used to establish national training standards for EMG in Canada.
During 1990 we surveyed the southern sky using a multi-beam receiver at frequencies of 4850 and 843 MHz. The half-power beamwidths were 4 and 25 arcmin respectively. The finished surveys cover the declination range between +10 and −90 degrees declination, essentially complete in right ascension, an area of 7.30 steradians. Preliminary analysis of the 4850 MHz data indicates that we will achieve a five sigma flux density limit of about 30 mJy. We estimate that we will find between 80 000 and 90 000 new sources above this limit. This is a revised version of the paper presented at the Regional Meeting by the first four authors; the surveys now have been completed.
Epidemiological evidence regarding the association between carbohydrate intake, glycaemic load (GL) and glycaemic index (GI) and risk of ovarian cancer has been mixed. Little is known about their impact on ovarian cancer risk in African-American women. Associations between carbohydrate quantity and quality and ovarian cancer risk were investigated among 406 cases and 609 controls using data from the African American Cancer Epidemiology Study (AACES). AACES is an ongoing population-based case–control study of ovarian cancer in African-Americans in the USA. Cases were identified through rapid case ascertainment and age- and site-matched controls were identified by random-digit dialling. Dietary information over the year preceding diagnosis or the reference date was obtained using a FFQ. Multivariable logistic regression models were used to estimate odds ratios and 95 % CI adjusted for covariates. The OR comparing the highest quartile of total carbohydrate intake and total sugar intake v. the lowest quartile were 1·57 (95 % CI 1·08, 2·28; Ptrend=0·03) and 1·61 (95 % CI 1·12, 2·30; Ptrend<0·01), respectively. A suggestion of an inverse association was found for fibre intake. Higher GL was positively associated with the risk of ovarian cancer (OR 1·18 for each 10 units/4184 kJ (1000 kcal); 95 % CI 1·04, 1·33). No associations were observed for starch or GI. Our findings suggest that high intake of total sugars and GL are associated with greater risk of ovarian cancer in African-American women.
Antisocial personality disorder (ASPD) is characterised by elevated
impulsive aggression and increased risk for criminal behaviour and
incarceration. Deficient activity of the monoamine oxidase A
(MAOA) gene is suggested to contribute to
serotonergic system dysregulation strongly associated with impulsive
aggression and antisocial criminality.
To elucidate the role of epigenetic processes in altered
MAOA expression and serotonin regulation in a
population of incarcerated offenders with ASPD compared with a healthy
non-incarcerated control population.
Participants were 86 incarcerated participants with ASPD and 73 healthy
controls. MAOA promoter methylation was compared between
case and control groups. We explored the functional impact of
MAOA promoter methylation on gene expression
in vitro and blood 5-HT levels in a subset of the
Results suggest that MAOA promoter hypermethylation is
associated with ASPD and may contribute to downregulation of
MAOA gene expression, as indicated by functional
assays in vitro, and regression analysis with
whole-blood serotonin levels in offenders with ASPD.
These results are consistent with prior literature suggesting
MAOA and serotonergic dysregulation in antisocial
populations. Our results offer the first evidence suggesting epigenetic
mechanisms may contribute to MAOA dysregulation in
Discovery of ultra-compact dwarfs (UCDs) in the past 15 years blurs the once thought clear division between classic globular clusters (GCs) and early-type galaxies. The intermediate nature of UCDs, which are larger and more massive than typical GCs but more compact than typical dwarf galaxies, has triggered hot debate on whether UCDs should be considered galactic in origin or merely the most extreme GCs. Previous studies of various scaling relations, stellar populations and internal dynamics did not give an unambiguous answer to the primary origin of UCDs. In this contribution, we present the first ever detailed study of global dynamics of 97 UCDs (rh ≳ 10 pc) associated with the central cD galaxy of the Virgo cluster, M87. We found that UCDs follow a different radial number density profile and different rotational properties from GCs. The orbital anisotropies of UCDs are tangentially-biased within ~ 40 kpc of M87 and become radially-biased with radius further out. In contrast, the blue GCs, which have similar median colors to our sample of UCDs, become more tangentially-biased at larger radii beyond ~ 40 kpc. Our analysis suggests that most UCDs in M87 are not consistent with being merely the most luminous and extended examples of otherwise normal GCs. The radially-biased orbital structure of UCDs at large radii is in general agreement with the scenario that most UCDs originated from the tidally threshed dwarf galaxies.
Nanobiosensors have drawn significant research interest in recent years owing to the advantages of label-free, electrical detection. However, nanobiosensors fabricated by bottom-up process are limited in terms of yield and device uniformity due to the challenges in assembly. Nanobiosensors fabricated by top-down process, on the other hand, exhibit better uniformity but require time and costly processes and materials to achieve the critical dimensions required for high sensitivity. In this report, we introduce a top-down nanobiosensor based on polysilicon nanoribbon. The polysilicon nanoribbon devices can be fabricated by conventional photolithography with only materials and equipments used in the standard CMOS process, thus resulting in great time and cost efficiency, as well as scalability. The devices show great response to pH changes with a wide dynamic range and high sensitivity. Biomarker detection is also demonstrated with clinically relevant sensitivity. Such results suggest that polysilicon nanoribbon devices exhibit great potential toward a highly efficient, reliable and sensitive biosensing platform.
According to a popular scenario supported by numerical models, the mass assembly and growth of massive galaxies, in particular the Early-Type Galaxies (ETGs), is, below a redshift of 1, mainly due to the accretion of multiple gas–poor satellites. In order to get observational evidence of the role played by minor dry mergers, we are obtaining extremely deep optical images of a complete volume limited sample of nearby ETGs. These observations, done with the CFHT as part of the ATLAS3D, NGVS and MATLAS projects, reach a stunning 28.5 – 29 mag.arcsec−2 surface brightness limit in the g' band. They allow us to detect the relics of past collisions such as faint stellar tidal tails as well as the very extended stellar halos which keep the memory of the last episodes of galactic accretion. Images and preliminary results from this on-going survey are presented, in particular a possible correlation between the fine structure index (which parametrizes the amount of tidal perturbation) of the ETGs, their stellar mass, effective radius and gas content.
The Next Generation Virgo Cluster Survey (NGVS) is a CFHT Large Program that is using the wide field of view capabilities of the MegaCam camera to map the entire Virgo Cluster from its core to virial radius. The observing strategy has been optimized to detect very low surface brightness structures in the cluster, including intracluster stellar streams and faint dwarf spheroidal galaxies. We present here the current status of this ongoing survey, with an emphasis on the detection and analysis of the very low-mass galaxies in the cluster that have been revealed by the NGVS.
Ultraclean semiconductor processes were developed for ULSI technologies to significantly reduce metallics, foreign materials, and to preserve silicon surface morphology. State-of-the-art detection techniques (Elymat, TXRF, VPD, and SPV) were implemented in all critical process sectors. Acceptable levels of metallic contamination were derived from previous experience and from published work on this subject relating metallic contamination levels to gate oxide reliability and retention time.
A comprehensive diagnostic/characterization system was utilized in evaluating a wide variety of test structures emulating key device process interactions. Advanced techniques were employed for measurement of reliability and surface morphology. Also root causes for all integration problems are identified.
The mass assembly of galaxies leaves various imprints on their surroundings, such as shells, streams and tidal tails. The frequency and properties of these fine structures depend on the mechanism driving the mass assembly: e.g. a monolithic collapse, rapid cold-gas accretion followed by violent disk instabilities, minor mergers or major dry/wet mergers. Therefore, by studying the outskirts of galaxies, one can learn about their main formation mechanism. I present here our on-going work to characterize the outskirts of Early-Type Galaxies (ETGs), which are powerful probes at low redshift of the hierarchical mass assembly of galaxies. This work relies on ultra–deep optical images obtained at CFHT with the wide-field of view MegaCam camera of field and cluster ETGs obtained as part of the ATLAS3D and NGVS projects. State of the art numerical simulations are used to interpret the data. The images reveal a wealth of unknown faint structures at levels as faint as 29 mag arcsec−2 in the g-band. Initial results for two galaxies are presented here.
The cognitive profile of early onset Parkinson’s disease (EOPD) has not been clearly defined. Mutations in the parkin gene are the most common genetic risk factor for EOPD and may offer information about the neuropsychological pattern of performance in both symptomatic and asymptomatic mutation carriers. EOPD probands and their first-degree relatives who did not have Parkinson’s disease (PD) were genotyped for mutations in the parkin gene and administered a comprehensive neuropsychological battery. Performance was compared between EOPD probands with (N = 43) and without (N = 52) parkin mutations. The same neuropsychological battery was administered to 217 first-degree relatives to assess neuropsychological function in individuals who carry parkin mutations but do not have PD. No significant differences in neuropsychological test performance were found between parkin carrier and noncarrier probands. Performance also did not differ between EOPD noncarriers and carrier subgroups (i.e., heterozygotes, compound heterozygotes/homozygotes). Similarly, no differences were found among unaffected family members across genotypes. Mean neuropsychological test performance was within normal range in all probands and relatives. Carriers of parkin mutations, whether or not they have PD, do not perform differently on neuropsychological measures as compared to noncarriers. The cognitive functioning of parkin carriers over time warrants further study. (JINS, 2011, 17, 1–10)
We have measured the velocity dispersion of the Galactic globular cluster NGC 2419 to determine if a substantial amount of dark matter is present in this cluster. NGC 2419 is one of the best globular clusters to look for dark matter due to its large mass, long relaxation time and large Galactocentric distance, which makes tidal stripping of dark matter unlikely. Our results can be summarized as follows. (i) We found a global velocity dispersion of 4.14 ± 0.48 km s−1, which leads to a total cluster mass of (9.02 ± 2.22) × 105 M⊙ and implies a global mass-to-light ratio of 2.05 ± 0.50 M⊙/L⊙. (ii) Our derived mass-to-light ratio is completely consistent with the mass-to-light ratio of a standard stellar population at the metallicity and age of NGC 2419. In addition, the mass-to-light ratio of NGC 2419 does not increase towards the outer cluster parts. (iii) We can therefore rule out the presence of a dark-matter halo with a central density greater than about 0.02 M⊙ pc−3. Similar limits are found for other halo globular clusters, like Pal 14. These observations therefore indicate that NGC 2419 and other halo globular clusters did not form at the centers of dark-matter halos similar to those surrounding dwarf galaxies. Instead, an origin driven by gas-dynamical processes during mergers between galaxies or proto-galactic fragments seems to be the more likely explanation for the formation of even the lowest-metallicity globular clusters.
METHODS FOR STUDYING THE ACQUISITION AND MAINTENANCE OF EXPERTISE
Janice M. Deakin, School of Physical and Health Education, Queen's University,
Jean Côté, School of Physical and Health Education, Queen's University,
Andrew S. Harvey, Department of Economics, St. Mary's University
Time is an inescapable dimension of all human activity. What time of day, month, and year, for how long, before or after what other activity, how long before or after another given activity and how often, are questions answerable for all activities. The relevance of each question varies with one's perspective on the activity. Time-use methodology can provide rich, objective, and replicable temporal information to answer the questions posed, hence providing a basis for forming and/or collaborating empirical judgments. Coupled with other objective and subjective contextual information on each incident of an activity, time-use methodologies can generate invaluable information for understanding activities and human behavior. Time-use studies show how people use their time. Minimally, they show what activities people do, while maximally, they can show what people are doing, where they are, who they are with, and how they feel.
Time-use studies can use a variety of data-collection methods ranging from self-reported activities to observation reports. In expertise research, time spent in an activity needs to be considered at a minimum of two different levels: a macro and a micro level. These two different levels encompass different units of time and provide different information about an activity. For example, at a macro level a researcher interested in music expertise may want to assess a typical week of training by analyzing time spent on general activities, such as practice alone, practice with a teacher, playing with others, resting, and so forth.