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The <0.1-μm size fraction of an Ordovician K-bentonite from northern Kentucky was characterized by X-ray powder diffraction (XRD). Using A.I.P.E. A. criteria for interstratification nomenclature and Reynolds’ computer algorithm the dominant clay mineral proved to be an R2 ordered illite/smectite. The best fit of observed and calculated XRD tracings was obtained using 12 > N > 5, where N is the number of layers within a diffracting domain.
Sections of the K-bentonite were prepared by ion-beam milling and examined in an analytical transmission electron microscope (ATEM). One-dimensional lattice images observed parallel to the a-b plane showed subparallel packets, about 50–100 Å thick, each of which consisted of about 10-Â thick unit layers. Somewhat thicker unit layers (as much as 14.5 Å) were also seen. The former are presumed to be illite, whereas the latter may be partially collapsed smectite. Selected-area electron diffraction patterns suggested simultaneous diffraction from several packets, each containing at least five layers. Both h0l and 0kl spacings were usually present, indicating that the stacking of the subparallel packets was random. Quantitative analysis by AEM and electron microprobe show the clay to be low in tetrahedral Al but high in octahedral Mg, the latter presumably contributing largely to the interlayer charge responsible for K fixation. The TEM data are broadly reconcilable with the accepted XRD interpretation of a two-component, mixed-layer clay. Alternatively, the TEM images may be interpreted as a single phase having numerous packet boundaries, the latter being responsible for swelling behavior. These two interpretations will not be fully reconciled until greater analytical precision and resolution permit individual packets to be studied. This work suggests that mineral definitions based purely on XRD interpretations may have to be reconsidered as more electron microscope data become available.
Female fertility is a complex trait with age-specific changes in spontaneous dizygotic (DZ) twinning and fertility. To elucidate factors regulating female fertility and infertility, we conducted a genome-wide association study (GWAS) on mothers of spontaneous DZ twins (MoDZT) versus controls (3273 cases, 24,009 controls). This is a follow-up study to the Australia/New Zealand (ANZ) component of that previously reported (Mbarek et al., 2016), with a sample size almost twice that of the entire discovery sample meta-analysed in the previous article (and five times the ANZ contribution to that), resulting from newly available additional genotyping and representing a significant increase in power. We compare analyses with and without male controls and show unequivocally that it is better to include male controls who have been screened for recent family history, than to use only female controls. Results from the SNP based GWAS identified four genomewide significant signals, including one novel region, ZFPM1 (Zinc Finger Protein, FOG Family Member 1), on chromosome 16. Previous signals near FSHB (Follicle Stimulating Hormone beta subunit) and SMAD3 (SMAD Family Member 3) were also replicated (Mbarek et al., 2016). We also ran the GWAS with a dominance model that identified a further locus ADRB2 on chr 5. These results have been contributed to the International Twinning Genetics Consortium for inclusion in the next GWAS meta-analysis (Mbarek et al., in press).
Observational studies suggest that 25-hydroxy vitamin D (25(OH)D) concentration is inversely associated with pain. However, findings from intervention trials are inconsistent. We assessed the effect of vitamin D supplementation on pain using data from a large, double-blind, population-based, placebo-controlled trial (the D-Health Trial). 21 315 participants (aged 60–84 years) were randomly assigned to a monthly dose of 60 000 IU vitamin D3 or matching placebo. Pain was measured using the six-item Pain Impact Questionnaire (PIQ-6), administered 1, 2 and 5 years after enrolment. We used regression models (linear for continuous PIQ-6 score and log-binomial for binary categorisations of the score, namely ‘some or more pain impact’ and ‘presence of any bodily pain’) to estimate the effect of vitamin D on pain. We included 20 423 participants who completed ≥1 PIQ-6. In blood samples collected from 3943 randomly selected participants (∼800 per year), the mean (sd) 25(OH)D concentrations were 77 (sd 25) and 115 (sd 30) nmol/l in the placebo and vitamin D groups, respectively. Most (76 %) participants were predicted to have 25(OH)D concentration >50 nmol/l at baseline. The mean PIQ-6 was similar in all surveys (∼50·4). The adjusted mean difference in PIQ-6 score (vitamin D cf placebo) was 0·02 (95 % CI (−0·20, 0·25)). The proportion of participants with some or more pain impact and with the presence of bodily pain was also similar between groups (both prevalence ratios 1·01, 95 % CI (0·99, 1·03)). In conclusion, supplementation with 60 000 IU of vitamin D3/month had negligible effect on bodily pain.
We investigated the impact of regionally imposed social and healthcare restrictions due to coronavirus disease 2019 (COVID-19) to the time metrics in the management of acute ischemic stroke patients admitted at the regional stroke referral site for Central South Ontario, Canada.
Methods:
We compared relevant time metrics between patients with acute ischemic stroke receiving intravenous tissue plasminogen activator (tPA) and/or endovascular thrombectomy (EVT) before and after the declared restrictions and state of emergency imposed in our region (March 17, 2020).
Results:
We identified a significant increase in the median door-to-CT times for patients receiving intravenous tPA (19 min, interquartile range (IQR): 14–27 min vs. 13 min, IQR: 9–17 min, p = 0.008) and/or EVT (20 min, IQR: 15–33 min vs. 11 min, IQR: 5–20 min, p = 0.035) after the start of social and healthcare restrictions in our region compared to the previous 12 months. For patients receiving intravenous tPA treatment, we also found a significant increase (p = 0.005) in the median door-to-needle time (61 min, IQR: 46–72 min vs. 37 min, IQR: 30–50 min). No delays in the time from symptom onset to hospital presentation were uncovered for patients receiving tPA and/or endovascular reperfusion treatments in the first 1.5 months after the establishment of regional and institutional restrictions due to the COVID-19 pandemic.
Conclusion:
We detected an increase in our institutional time to treatment metrics for acute ischemic stroke patients receiving tPA and/or endovascular reperfusion therapies, related to delays from hospital presentation to the acquisition of cranial CT imaging for both tPA- and EVT-treated patients, and an added delay to treatment with tPA.
Discrete episodes of overconsumption may induce a positive energy balance and impair metabolic control. However, the effects of an ecologically relevant, single day of balanced macronutrient overfeeding are unknown. Twelve healthy men (of age 22 (sd 2) years, BMI 26·1 (sd 4·2) kg/m2) completed two 28 h, single-blind experimental trials. In a counterbalanced repeated measures design, participants either consumed their calculated daily energy requirements (energy balance trial (EB): 10 755 (sd 593) kJ) or were overfed by 50 % (overfeed trial (OF): 16 132 (sd 889) kJ) under laboratory supervision. Participants returned to the laboratory the next day, after an overnight fast, to complete a mixed-meal tolerance test (MTT). Appetite was not different between trials during day 1 (P>0·211) or during the MTT in the fasted or postprandial state (P>0·507). Accordingly, plasma acylated ghrelin, total glucagon-like peptide-1 and total peptide YY concentrations did not differ between trials during the MTT (all P>0·335). Ad libitum energy intake, assessed upon completion of the MTT, did not differ between trials (EB 6081 (sd 2260) kJ; OF 6182 (sd 1960) kJ; P=0·781). Plasma glucose and insulin concentrations were not different between trials (P>0·715). Fasted NEFA concentrations were lower in OF compared with EB (P=0·005), and TAG concentrations increased to a greater extent on OF than on EB during the MTT (P=0·009). The absence of compensatory changes in appetite-related variables after 1 d of mixed macronutrient overfeeding highlights the limited physiological response to defend against excess energy intake. This supports the concept that repeated discrete episodes of overconsumption may promote weight gain, while elevations in postprandial lipaemia may increase CVD risk.
Analytical transmission electron microscopy was applied to some authigenic chlorites occurring as grain coatings in sandstones. Compositional variation proved to be relatively slight: all were magnesian chamosites. The coating chlorites were often intimately mixed with extremely fine-grained (0·01–0·2 µm) hematite but analytical ‘contamination’ was avoided because of the very high resolution of both observation (spot location) and analysis. One example of a water-sensitive (‘swelling chlorite’) coating was also studied. This proved to have a very much more variable composition even within a single section. The coating appeared to include both chloritic and vermiculitic components. The effect of this on structural formulae is discussed and a model proposed in which the ‘talc’ layer may be common to both components.
A range of authigenic sedimentary chlorites from sandstones has been studied by analytical transmission electron microscopy. Selected area (single crystal) electron diffraction patterns are of the Ib (β = 90°) polytype confirming the earlier observations of Hayes (1970).
TEM analyses show all samples to be relatively rich in both Al and Fe. In the general formula (Mg,Fe,Al)n [Si8−xAlxO20](OH)16, x varies between 1.5 and 2.6; Fe/(Fe + Mg) between 0.47 and 0.83 and n between 10.80 and 11.54. Octahedral Al is close to 3 in this formulation and Fe2+ predominates over Fe3+. Swelling chlorites have significantly different compositions which are consistent with smectite/chlorite interstratifications.
The Ib (β = 90°) polytype appears to be stable under conditions of moderate to deep burial. It replaces berthierine and swelling chlorites formed at lower temperatures. As commonly seen in grain coatings, however, it precipitates from porewater; solutes probably being contributed from several mineral decomposition reactions.
Observational studies have suggested that 25-hydroxyvitamin D (25(OH)D) levels are associated with inflammatory markers. Most trials reporting significant associations between vitamin D intake and inflammatory markers used specific patient groups. Thus, we aimed to determine the effect of supplementary vitamin D using secondary data from a population-based, randomised, placebo-controlled, double-blind trial (Pilot D-Health trial 2010/0423). Participants were 60- to 84-year-old residents of one of the four eastern states of Australia. They were randomly selected from the electoral roll and were randomised to one of three trial arms: placebo (n 214), 750 μg (n 215) or 1500 μg (n 215) vitamin D3, each taken once per month for 12 months. Post-intervention blood samples for the analysis of C-reactive protein (CRP), IL-6, IL-10, leptin and adiponectin levels were available for 613 participants. Associations between intervention group and biomarker levels were evaluated using quantile regression. There were no statistically significant differences in distributions of CRP, leptin, adiponectin, leptin:adiponectin ratio or IL-10 levels between the placebo group and either supplemented group. The 75th percentile IL-6 level was 2·8 pg/ml higher (95 % CI 0·4, 5·8 pg/ml) in the 1500 μg group than in the placebo group (75th percentiles:11·0 v. 8·2 pg/ml), with a somewhat smaller, non-significant difference in 75th percentiles between the 750 μg and placebo groups. Despite large differences in serum 25(OH)D levels between the three groups after 12 months of supplementation, we found little evidence of an effect of vitamin D supplementation on cytokine or adipokine levels, with the possible exception of IL-6.
Micromorphology is used to examine and compare a Late Jurassic diamictite from northeast Scotland with a Pleistocene diamict from southern Ontario, Canada in order to test if a statistical difference between diamicts can be recognized and used to separate differing types of diamicts/diamictites. The diamictites from Scotland have been ascribed to various depositional agencies occurring in several distinctly differing terrestrial and marine palaeoenvironments. In contrast, the Pleistocene diamicton is regarded as a subglacial till. Both diamicts appear remarkably similar visually and contain many corresponding features such as macrostructures, and exotic and fractured subangular to subrounded clasts. Micromorphology is used to re-examine these diamicts/diamictites at the microscopic level to detect if the palaeoenvironments within which they were deposited can be ascertained. In this paper a quantitative assessment of microstructures using micromorphology is developed. Comparative statistical analyses of these diamicts, using micromorphological features, reveals that the Jurassic diamictites are non-glacigenic, non-terrestrial and most likely deposited within a marine environment as a result of subaquatic debris mass movement, while, in contrast, the Pleistocene diamicts were most likely subglacial tectomicts deposited beneath the active base of the Laurentide Ice Sheet.
Now in its third edition, this dynamic textbook analyses the traits fundamental to human personality: what they are, why they matter, their biological and social foundations, how they play out in human life and their consequences for cognition, stress and physical and mental health. The text also considers the applications of personality assessment in clinical, educational and occupational settings, providing the reader with a detailed understanding of the whole field of personality traits. This edition, now with improved student features, includes the latest research from behavioural genetics, neuroscience, social psychology and cognitive science, assesses the impact of new research techniques like brain imagery, and provides additional content on positive aspects of traits and practical uses of personality assessment. This is an essential textbook for students taking courses in personality and individual differences and also provides researchers and practitioners with a coherent, up-to-date survey of this significant area.
This second edition of the bestselling textbook Personality Traits is an essential text for students doing courses in personality psychology and individual differences. The authors have updated the volume throughout, incorporating the latest research in the field, and added three new chapters on personality across the lifespan, health and applications of personality assessment. Personality research has been transformed by recent advances in our understanding of personality traits. This book reviews the origins of traits in biological and social processes, and their consequences for cognition, stress, and physical and mental health. Contrary to the traditional view of personality research as a collection of disconnected theories, Personality Traits provides an integrated account, linking theory-driven research with applications in clinical and occupational psychology. The new format of the book, including many additional features, makes it even more accessible and reader friendly.
Cutaneous malignant melanoma (CMM) is a major health issue in Queensland, Australia, which has the world's highest incidence. Recent molecular and epidemiologic studies suggest that CMM arises through multiple etiological pathways involving gene–environment interactions. Understanding the potential mechanisms leading to CMM requires larger studies than those previously conducted. This article describes the design and baseline characteristics of Q-MEGA, the Queensland Study of Melanoma: Environmental and Genetic Associations, which followed up 4 population-based samples of CMM patients in Queensland, including children, adolescents, men aged over 50, and a large sample of adult cases and their families, including twins. Q-MEGA aims to investigate the roles of genetic and environmental factors, and their interaction, in the etiology of melanoma. Three thousand, four hundred and seventy-one participants took part in the follow-up study and were administered a computer-assisted telephone interview in 2002–2005. Updated data on environmental and phenotypic risk factors, and 2777 blood samples were collected from interviewed participants as well as a subset of relatives. This study provides a large and well-described population-based sample of CMM cases with follow-up data. Characteristics of the cases and repeatability of sun exposure and phenotype measures between the baseline and the follow-up surveys, from 6 to 17 years later, are also described.
Introduction: neuropsychological approaches to personality
In this chapter we discuss the hypothesis that personality is an expression of individual differences in brain function. There are several reasons for linking personality traits to neural systems. First, there is the evidence from behaviour genetics discussed in the previous chapter. If personality traits are partially caused by genetic factors, then there must necessarily be a biological influence on traits, encoded within the person's DNA. Of course, the influence of the genotype on brain structure and function is likely to be influenced by interaction with the environment. Second, there is striking evidence for radical personality change resulting from brain damage (see Powell, 1981, and Zuckerman, 1999, 2005, for reviews). Damage to the frontal lobes of the cerebral cortex is notorious for disruption of personality; the person may become unstable, impulsive and even aggressive (depending on the exact region damaged). Third, there is some, though not unequivocal, evidence that traits correlate with biological indicators of brain functioning, such as the responses gathered from functional magnetic resonance imaging and electroencephalographic studies. Correlations between brain and trait parameters suggest that we might develop psychobiological theories of personality traits. Such theories should describe how individual differences in the functioning of specific brain systems influence long-standing individual differences in behaviour.
However, there are various difficulties involved in building a psychobiological theory of personality traits. First, the complexity of the task is daunting.
Social-psychological approaches have played a major role in personality psychology. In the modern era, the two most influential theorists are Albert Bandura (e.g., 1997) and Walter Mischel (e.g., 1999). Bandura's studies of modelling (e.g., Bandura and Walter, 1963) showed how social learning processes could generate dispositions, such as tendencies towards aggression. However, such dispositions were seen as dynamic rather than static, in that they undergo ongoing modification as a consequence of interaction with the environment. Mischel also emphasised social learning and dynamic person–environment interaction. His personality theory is also known for its emphasis on the situation: individuals may display consistent behaviours in specific situations, consistencies that are not related to conventional traits. The relationship between these approaches and trait theory has often been thorny: as discussed in chapter 2, Mischel's (1968) critique of trait theory was seen, in his words (Mischel, 1999, p. 39), ‘as a glove hurled to the ground’. As Mischel (1999) also points out, the two disciplines of personality psychology had previously been unified in constructive collaboration. At the present time, there is increased interest in whether – and if so, how – a new unity between the two disciplines may be forged.
From the trait perspective, there is renewed interest in social learning approaches because of evidence that links traits to the explanatory constructs of social learning theorists.
The idea of personality traits may be as old as human language itself. Aristotle (384–322 BC), writing the Ethics in the fourth century BC, saw dispositions such as vanity, modesty and cowardice as key determinants of moral and immoral behaviour. He also described individual differences in these dispositions, often referring to excess, defect and intermediate levels of each. His student Theophrastus (371–287 BC) wrote a book describing 30 ‘characters’ or personality types, of which a translator remarked that Theophrastus' title might better be rendered ‘traits’ (Rusten, 1993). Basic to his whole enterprise was the notion that individual good or bad traits of character may be isolated and studied separately.
Contemporary English is replete with terms used to describe personal qualities. Table 1.1 shows some examples: the five words rated by American college students as the most and least favourable words in Anderson's (1968) survey of 555 personality terms, together with five words given a neutral rating. Allport and Odbert (1936) identified almost 18,000 English personality-relevant terms; more words than Shakespeare used! Nouns, sentences and even actions may also have personality connotations (Hofstede, 1990). The language of personality description permeates our everyday conversation and discourse.
Everyday conceptions of personality traits make two key assumptions. First, traits are stable over time. Most people would accept that an individual's behaviour naturally varies somewhat from occasion to occasion, but would maintain also that there is a core of consistency which defines the individual's ‘true nature’: the unchangeable spots of the leopard.