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.
We investigate the spatial distribution, spectral properties and temporal variability of primary producers (e.g. communities of microbial mats and mosses) throughout the Fryxell basin of Taylor Valley, Antarctica, using high-resolution multispectral remote-sensing data. Our results suggest that photosynthetic communities can be readily detected throughout the Fryxell basin based on their unique near-infrared spectral signatures. Observed intra- and inter-annual variability in spectral signatures are consistent with short-term variations in mat distribution, hydration and photosynthetic activity. Spectral unmixing is also implemented in order to estimate mat abundance, with the most densely vegetated regions observed from orbit correlating spatially with some of the most productive regions of the Fryxell basin. Our work establishes remote sensing as a valuable tool in the study of these ecological communities in the McMurdo Dry Valleys and demonstrates how future scientific investigations and the management of specially protected areas could benefit from these tools and techniques.
This paper is a revised and updated edition of a previous description of the Quebec Newborn Twin Study (QNTS), an ongoing prospective longitudinal follow-up of a birth cohort of twins born between 1995 and 1998 in the greater Montreal area, Québec, Canada. The goal of QNTS is to document individual differences in the cognitive, behavioral, and social-emotional aspects of developmental health across childhood, their early genetic and environmental determinants, as well as their putative role in later social-emotional adjustment, school, health, and occupational outcomes. A total of 662 families of twins were initially assessed when the twins were aged 6 months. These twins and their family were then followed regularly. QNTS now has 16 waves of data collected or planned, including 5 in preschool. Over the last 24 years, a broad range of physiological, cognitive, behavioral, school, and health phenotypes were documented longitudinally through multi-informant and multimethod measurements. QNTS also entails extended and detailed multilevel assessments of proximal (e.g., parenting behaviors, peer relationships) and distal (e.g., family income) features of the child’s environment. QNTS children and a subset of their parents have been genotyped, allowing for the computation of a variety of polygenic scores. This detailed longitudinal information makes QNTS uniquely suited for the study of the role of the early years and gene–environment transactions in development.
Introduction: While negative consequences of incident delirium on functional and cognitive decline have been widely studied, very limited data is available regarding functional and cognitive outcomes in Emergency Department (ED) patients. The aim of this study was therefore to evaluate the impact of ED stay-associated delirium on older patient's functional and cognitive status at 60 days post-ED visit. Methods: This study is a planned sub-analysis of a large multicentre prospective cohort study (the INDEED study). This project took place between March and July of the years 2015 and 2016 within 5 participating EDs across the province of Quebec. Independent non-delirious patients aged □65, with an ED stay at least 8hrs were monitored until 24hrs post-ward admission. A 60-day follow-up phone assessment was also conducted. Participants were screened for delirium using the validated Confusion Assessment Method (CAM) and the severity of its symptoms was measured using the Delirium Index. Functional and cognitive status were assessed at baseline as well as at the 60-day follow-up using the validated OARS and TICS-m. Results: A total of 608 patients were recruited, 393 of which completed the 60-day follow-up. Sixty-nine patients obtained a positive CAM during ED-stay or within the first 24 hours following ward admission. At 60-days, those patients experienced a loss of 3.1 (S.D. 4.0) points on the OARS scale compared to non-delirious patients who lost 1.6 (S.D. 3.0) (p = 0.03). A significant difference in cognitive function was also noted at 60-days, as delirious patients’ TICS-m score decreased by 2.1 (S.D. 6.2) compared to non-delirious patients, who showed a minor improvement of 0.5 (S.D. 5.8) (p = 0.01). Conclusion: People who developed ED stay-associated delirium have lower baseline functional and cognitive status than non-delirious patients and they will experience a more significant decline at 60 days post-ED visit.
Introduction: Delirium is a frequent pathology in the elderly presenting to the emergency department (ED) and is seldom recognised. This condition is associated with many medical complications and has been shown to increase the hospital length-of-stay. The objective of this study was to identify the predictor factors of developing delirium in this high-risk population. Methods: Design: This study was part of the multicenter prospective cohort INDEED study. Participants: Patients aged 65 and older, initially free of delirium and with an ED stay of 8h or longer, were followed up to 24h after ward admission. Measures: Clinical and demographic variables were collected by interview and chart review. A research professional assessed their delirium status twice daily using the Confusion Assessment Method (CAM). Analyses: A classification tree was used to select predictors and cut-points that minimized classification error of patients with incident delirium. After literature review, nineteen predictors were considered for inclusion in the model (eight non-modifiable and eleven modifiable factors). Results: Among the 605 patients included in this study, incident delirium was detected by the CAM in 69 patients (11.4%). In total, fourteen variables were included in a preliminary model, of which six were intrinsic to the patient and eight were modifiable in the ED. Variables with the greatest impact in the prediction of delirium includes age, cognitive status, ED length of stay, autonomy in daily activities, fragility and mobility during their hospital stay. The diagnostic performance of the model applied to the study sample gave a sensitivity of 78.3% (95% CI: 66.7 to 87.3), a specificity of 100.0% (95% CI: 99.3 to 100.0), a PPV of 100.0% (95% CI: 93.4 to 100.0) and a NPV of 97.3% (95% CI: 95.6 to 98.5). Conclusion: The delirium risk model developed in this study shows promising results with elevated sensitivity and specificity values. Considering the limited ability to predict and detect delirium among physicians, the potential increase in sensitivity provided by this tool could be beneficial to patients. This model will ultimately serve to identify high-risk patients with the goal of developing strategies to alter modifiable risk factors and subsequently decrease the incidence of delirium in this population.
Heritability of antisocial behaviour is estimated at approximately 50% and involves multiple genes.
To investigate the cumulative genetic effects of 116 single nucleotide polymorphisms mapping to 11 candidate serotonergic genes and antisocial behaviours, in adolescence and in early adulthood.
Participants were 410 male members of the Quebec Longitudinal Study of Kindergarten Children, a population-based cohort followed up prospectively from age 6 to age 23. The serotonergic genes were selected based on known physiological processes and prior associations with antisocial behaviours. Antisocial behaviours were self-reported and assessed by using semi-structured interviews in adolescence and in adulthood.
Cumulative, haplotype-based contributions of serotonergic genes conferring risk and protection for antisocial behaviours were detected by using multilocus genetic profile risk scores (MGPRSs) and multilocus genetic profile protection scores (MGPPSs). Cumulatively, haplotype-based MGPRSs and MGPPSs contributed to 9.6, 8.5 and 15.2% of the variance in general delinquency in adolescence, property/violent crimes in early adulthood and physical partner violence in early adulthood, respectively.
This study extends previous research by showing a cumulative effect of multiple haplotypes conferring risk and protection to antisocial behaviours in adolescence and early adulthood. The findings further support the relevance of concomitantly considering multiple serotonergic polymorphisms to better understand the genetic aetiology of antisocial behaviours. Future studies should investigate the interplay between risk and protective haplotype-based multilocus genetic profile scores with the environment.
Declaration of interest:
I.O.-M. holds a Canada Research Chair in the developmental origins of vulnerability and resilience.
The Sahara was wetter and greener during multiple interglacial periods of the Quaternary, when some have suggested it featured very large (mega) lakes, ranging in surface area from 30,000 to 350,000 km2. In this paper, we review the physical and biological evidence for these large lakes, especially during the African Humid Period (AHP) 11–5 ka. Megalake systems from around the world provide a checklist of diagnostic features, such as multiple well-defined shoreline benches, wave-rounded beach gravels where coarse material is present, landscape smoothing by lacustrine sediment, large-scale deltaic deposits, and in places, tufas encrusting shorelines. Our survey reveals no clear evidence of these features in the Sahara, except in the Chad basin. Hydrologic modeling of the proposed megalakes requires mean annual rainfall ≥1.2 m/yr and a northward displacement of tropical rainfall belts by ≥1000 km. Such a profound displacement is not supported by other paleo-climate proxies and comprehensive climate models, challenging the existence of megalakes in the Sahara. Rather than megalakes, isolated wetlands and small lakes are more consistent with the Sahelo-Sudanian paleoenvironment that prevailed in the Sahara during the AHP. A pale-green and discontinuously wet Sahara is the likelier context for human migrations out of Africa during the late Quaternary.
Introduction: Prevalence and incidence of delirium in older patients admitted to acute and long-term care facilities ranges between 9.6% and 89% but little is known in the context of emergency department (ED) incident delirium. Literature regarding the incidence of delirium in the ED and its potential impacts on hospital length of stay (LOS), functional status and unplanned ED readmissions is scant, its consequences have yet to be clearly identified in order to orient modern acute medical care. Methods: This study is part of the multicenter prospective cohort INDEED study. Three Canadian EDs completed the two years prospective study (March-July 2015 and Feb-May 2016). Patients aged 65 years old, initially free of delirium with an ED stay 8hours were followed up to 24h after ward admission. Patients were assessed 2x/day during their entire ED stay and up to 24 hours on hospital ward by research assistants (RA). The primary outcome of this study was incident delirium in the ED or within 24 h of ward admission. Functional and cognitive status were assessed using validated Older Americans’ Resources and Services and the Telephone Interview for Cognitive Status- modified tools. The Confusion Assessment Method (CAM) was used to detect incident delirium. ED and hospital administrative data were collected. Inter-observer agreement was realized among RA. Results: Incident delirium was not different between sites, nor between phases, nor between times from one site to another. All phases confounded, there is between 7 to 11% of ED related incident delirious episodes. Differences were seen in ED LOS between sites in non-delirious patients, but also between some sites for delirious participants (p<0.05). Only one site had a difference in ED LOS between their delirious and non-delirious patients, respectively of 52.1 and 40.1 hours (p<0.05). There is also a difference between sites in the time between arrival to the ED and the incidence of delirium (p=0.003). Kappa statistics were computed to measure inter-rater reliability of the CAM. Based on an alpha of 5%, 138 patients would allow 80% power for an estimated overall incidence proportion of 15 % with 5% precision.. Other predictive delirium variables, such as cognitive status, environmental factors, functional status, comorbidities, physiological status, and ED and hospital length of stay were similar between sites and phases. Conclusion: The fact that incidence of delirium was the same for all sites, despite the differences of ED LOS and different time periods suggest that many other modifiable and non-modifiable factors along LOS influenced the incidence of ED induced delirium. Emergency physician should concentrate on improving senior-friendly environment for the ED.
Introduction: It is documented that physicians and nurses fail to detect delirium in more than half of cases from various clinical settings, which could have serious consequences for seniors and for our health care system. The present study aimed to describe the rate of documented incident delirium in 5 Canadian Emergency departments (ED) by health professionals (HP). Methods: This study is part of the multicenter prospective cohort INDEED study. Patients aged 65 years old, initially free of delirium with an ED stay 8hours were followed up to 24h after ward admission. Delirium status was assessed twice daily using the Confusion Assessment Method (CAM) by trained research assistants (RA). HP reviewed patient charts to assess detection of delirium. HP had no specific routine detection of delirious ED patients. Inter-observer agreement was realized among RA. Comparison of detection between RA and HP was realized with univariate analyses. Results: Among the 652 included patients, 66 developed a delirium as evaluated with the CAM by the RA. Among those 66 patients, only 10 deliriums (15.2%) were documented in the patients medical file by the HP. 54 (81.8%) patients with a CAM positive for delirium by the RA were not recorded by the HP, 2 had incomplete charts. The delirium index was significantly higher in the HP reported group compared to the HP not reported, respectively 7.1 and 4.5 (p<0.05). Other predictive delirium variables, such as cognitive status, functional status, comorbidities, physiological status, and ED and hospital length of stay were similar between groups. Conclusion: It seems that health professionals missed 81.8% of the potential delirious ED patients in comparison to routine structured screening of delirium. HP could identify patients with a greater severity of symptoms. Our study points out the need to better identify elders at risk to develop delirium and the need for fast and reliable tools to improve the screening of this disorder.
The American public's beliefs about the causes of social inequality vary greatly, with debates over the causes of racial inequality tending to be the most salient and divisive. Among whites in particular, liberals tend to see inequality as rooted in society's ills, whereas conservatives tend to see inequality as rooted in individuals’ shortcomings. Given this, many infer that white conservatives are more likely than white liberals to adopt the controversial view that racial inequality is “natural,” i.e., due to genetically inherited characteristics. We argue that genetic explanations for racial inequality, in and of themselves, offer little appeal to white conservatives. However, when white citizens are exposed to media messages that emphasize the egalitarian implications of genetic similarity between racial groups, those on the left and right engage in biased assimilation, resulting in a “nature” (conservative) versus “nurture” (liberal) divide. Data from two studies of white Americans—one representative survey and one experiment—support this theoretical framework.
Among the solar proxies, κ1 Cet, stands out as potentially having a mass very close to solar and a young age. We report magnetic field measurements and planetary habitability consequences around this star, a proxy of the young Sun when life arose on Earth. Magnetic strength was determined from spectropolarimetric observations and we reconstruct the large-scale surface magnetic field to derive the magnetic environment, stellar winds, and particle flux permeating the interplanetary medium around κ1 Cet. Our results show a closer magnetosphere and mass-loss rate 50 times larger than the current solar wind mass-loss rate when Life arose on Earth, resulting in a larger interaction via space weather disturbances between the stellar wind and a hypothetical young-Earth analogue, potentially affecting the habitability. Interaction of the wind from the young Sun with the planetary ancient magnetic field may have affected the young Earth and its life conditions.
The monoamine oxidase A (MAOA) gene has been shown to
moderate the impact of maltreatment on antisocial behaviour. Replication
efforts have, however, yielded inconsistent results.
To investigate whether the interaction between the MAOA
gene and violence is present across the full distribution of violence or
emerges at higher levels of exposure.
Participants were 327 male members of the Québec Longitudinal Study of
Kindergarten Children. Exposure to violence comprised retrospective
reports of mother's and father's maltreatment, sexual and physical abuse.
Conduct disorder and antisocial personality symptoms were assessed in
semi-structured interviews and partner violence, property-violent crimes
and arrest were self-reported.
Non-linear interactions between the MAOA gene and
violence were detected, suggesting that the genetic moderation may come
about once a certain level of violence is experienced.
Future studies should investigate the mechanisms translating substantial
violence exposure, which could, subsequently, trigger the expression of
genetically based differences in antisocial behaviour.
This is the first report of Bactra bactrana (Kennel, 1901) (Lepidoptera: Tortricidae) attacking a major solanaceous crop, sweet pepper Capsicum annuum L. The infestation was detected in two greenhouses at the area of Tympaki (Southern Crete, Greece). The moth larvae caused typical symptoms of a fruit borer with numerous small holes on the surface of the peppers and extensive damage on the inside of the fruit as a result of the feeding activity. Unknown factors facilitated this major shift in host range since B. bactrana is typically a stem borer of sedges. In addition, the pest status of B. bactrana is currently under question, as in both cases the infestations by the moth were associated with significant yield losses. B. bactrana was moderately controlled with chemicals registered for Lepidoptera management in sweet pepper due to the boring nature of the infestation. Some comparative taxonomic notes are provided to facilitate accurate pest discrimination of related Bactra species. Finally, biological attributes of the species are summarized and are discussed from pest control and ecological perspectives. Because Bactra species have been used in augmentative releases for the control of sage, the implications of our findings on the release of biocontrol agents are placed in perspective.
Physical aggression (PA) tends to have its onset in infancy and to increase rapidly in frequency. Very little is known about the genetic and environmental etiology of PA development during early childhood. We investigated the temporal pattern of genetic and environmental etiology of PA during this crucial developmental period.
Participants were 667 twin pairs, including 254 monozygotic and 413 dizygotic pairs, from the ongoing longitudinal Quebec Newborn Twin Study. Maternal reports of PA were obtained from three waves of data at 20, 32 and 50 months. These reports were analysed using a biometric Cholesky decomposition and linear latent growth curve model.
The best-fitting Cholesky model revealed developmentally dynamic effects, mostly genetic attenuation and innovation. The contribution of genetic factors at 20 months substantially decreased over time, while new genetic effects appeared later on. The linear latent growth curve model revealed a significant moderate increase in PA from 20 to 50 months. Two separate sets of uncorrelated genetic factors accounted for the variation in initial level and growth rate. Non-shared and shared environments had no effect on the stability, initial status and growth rate in PA.
Genetic factors underlie PA frequency and stability during early childhood; they are also responsible for initial status and growth rate in PA. The contribution of shared environment is modest, and perhaps limited, as it appears only at 50 months. Future research should investigate the complex nature of these dynamic genetic factors through genetic–environment correlation (rGE) and interaction (G × E) analyses.
To examine the use of vitamin D supplements during infancy among the participants in an international infant feeding trial.
Information about vitamin D supplementation was collected through a validated FFQ at the age of 2 weeks and monthly between the ages of 1 month and 6 months.
Infants (n 2159) with a biological family member affected by type 1 diabetes and with increased human leucocyte antigen-conferred susceptibility to type 1 diabetes from twelve European countries, the USA, Canada and Australia.
Daily use of vitamin D supplements was common during the first 6 months of life in Northern and Central Europe (>80 % of the infants), with somewhat lower rates observed in Southern Europe (>60 %). In Canada, vitamin D supplementation was more common among exclusively breast-fed than other infants (e.g. 71 % v. 44 % at 6 months of age). Less than 2 % of infants in the USA and Australia received any vitamin D supplementation. Higher gestational age, older maternal age and longer maternal education were study-wide associated with greater use of vitamin D supplements.
Most of the infants received vitamin D supplements during the first 6 months of life in the European countries, whereas in Canada only half and in the USA and Australia very few were given supplementation.
We investigated the antecedents and consequences of chronic victimization by bullies across a school transition using a genetically sensitive longitudinal design. Data were from the Environmental Risk Longitudinal Twin Study (E-Risk), an epidemiological cohort of 2,232 children. We used mothers' and children's reports of bullying victimization during primary school and early secondary school. Children who experienced frequent victimization at both time points were classed as “chronic victims” and were found to have an increased risk for mental health problems and academic difficulties compared to children who were bullied only in primary school, children bullied for the first time in secondary school, and never-bullied children. Biometric analyses revealed that stability in victimization over this period was influenced primarily by genetic and shared environmental factors. Regression analyses showed that children's early characteristics such as preexistent adjustment difficulties and IQ predicted chronic versus transitory victimization. Family risk factors for chronic victimization included socioeconomic disadvantage, low maternal warmth, and maltreatment. Our results suggest that bullying intervention programs should consider the role of the victims' behaviors and family background in increasing vulnerability to chronic victimization. Our study highlights the importance of widening antibullying interventions to include families to reduce the likelihood of children entering a pathway toward chronic victimization.
This paper presents a novel, compact, single-sideband (SSB) subharmonically-pumped (SHP) direct upconverter developed in a uniplanar 0.18 μm GaAs technology. A total of 100 MHz in-phase and quadrature signals directly modulate the second harmonic of a 30 GHz carrier signal, producing a 60.1 GHz output. Two pairs of antiparallel diodes reduce feed-through of the 30 GHz local oscillator (LO) signal to the mixer's RF output. Novel structures patterned in the center conductor of a coplanar waveguide (CPW) provide matching and size-reduction simultaneously. The 2.1mm2 circuit also uses a miniaturized Wilkinson divider based on asymmetric coplanar stripline and a standard CPW 90° coupler. The SSB SHP direct upconverter exhibits a conversion loss of 10 dB, a lower-sideband rejection of 15 dB and 2fLO suppression of approximately 25 dB over a wide frequency range from 52–61 GHz.