43,548 research outputs found
Decoupling of morphological disparity and taxic diversity during the adaptive radiation of anomodont therapsids
Adaptive radiations are central to macroevolutionary theory. Whether triggered by acquisition of new traits or ecological opportunities arising from mass extinctions, it is debated whether adaptive radiations are marked by initial expansion of taxic diversity or of morphological disparity (the range of anatomical form). If a group rediversifies following a mass extinction, it is said to have passed through a macroevolutionary bottleneck, and the loss of taxic or phylogenetic diversity may limit the amount of morphological novelty that it can subsequently generate. Anomodont therapsids, a diverse clade of Permian and Triassic herbivorous tetrapods, passed through a bottleneck during the end-Permian mass extinction. Their taxic diversity increased during the Permian, declined significantly at the PermoâTriassic boundary and rebounded during the Middle Triassic before the clade's final extinction at the end of the Triassic. By sharp contrast, disparity declined steadily during most of anomodont history. Our results highlight three main aspects of adaptive radiations: (i) diversity and disparity are generally decoupled; (ii) models of radiations following mass extinctions may differ from those triggered by other causes (e.g. trait acquisition); and (iii) the bottleneck caused by a mass extinction means that a clade can emerge lacking its original potential for generating morphological variety
The \u27hole\u27 in the Pantry Story: Should Penguin have Validated Belle Gibson\u27s Cancer Claims?
Pursuance: The Movement of The Common Wind
The 2018 publication of Julius S. Scottâs The Common Wind: Afro-American Currents in the Age of the Haitian Revolution inspired a renewed focus on the reverberations of the Haitian Revolution. Here, six scholars of the Atlantic World and the Age of Revolutions consider the historiographical implications of The Common Wind and remind us how the Haitian upheaval belongs at the very center of the ripples of modernity that spread across the globe from the revolutionary Atlantic
An exploratory investigation examining male and female students' initial impressions and expectancies of lecturers
The aim of this study was to examine the informational cues that male and female students perceive to be influential when developing initial impressions and expectancies of a lecturer. University students (n 752) rated the extent to which 30 informational cues influence their initial perceptions of a lecturer. Following exploratory factor analysis (EFA), a five-factor model (i.e. appearance (APP), accessories (ACC), third-party reports (TPR), communication skills (CS) and nationality/ethnicity (NE)) was extracted for male students and a five-factor model (i.e. ACC, TPR, APP, interpersonal skills (IPS) and engagement (ENG)) extracted for female students. Inspection of mean scores identified that male students rated CS (e.g. clarity of voice) and TPR (e.g. qualifications) and female students IPS (e.g. control of class), ENG (e.g. eye contact) and TPR to be influential factors in forming initial impressions and expectancies of a lecturer. The findings further identify the potential for expectancy effects within student lecturer interactions
The human salivary microbiome exhibits temporal stability in bacterial diversity
The temporal variability of the human microbiome may be an important factor in determining its relationship with health and disease. In this study, the saliva of 40 participants was collected every 2 months over a one-year period to determine the temporal variability of the human salivary microbiome. Salivary pH and 16S rRNA gene copy number were measured for all participants, with the microbiome of 10 participants assessed through 16S rRNA amplicon sequencing. In February 2013, 16S rRNA gene copy number was significantly (P < 0.001) higher, with individual changes between time points significant (P = 0.003). Salivary pH levels were significantly (P < 0.001) higher in December 2012 than in October 2012 and February 2013, with significant (P < 0.001) individual variations seen throughout. Bacterial α-diversity showed significant differences between participants (P < 0.001), but not sampling periods (P = 0.801), and a significant positive correlation with salivary pH (R(2) = 7.8%; P = 0.019). At the phylum level, significant differences were evident between participants in the Actinobacteria (P < 0.001), Bacteroidetes (P < 0.001), Firmicutes (P = 0.008), Fusobacteria (P < 0.001), Proteobacteria (P < 0.001), Synergistetes (P < 0.001) and Spirochaetes (P = 0.003) phyla. This study charted the temporal variability of the salivary microbiome, suggesting that bacterial diversity is stable, but that 16S rRNA gene copy number may be subject to seasonal flux
Employment status and health after privatisation in white collar civil servants: prospective cohort study
Objectives To determine whether employment status after job loss due to privatisation influences health and use of health services and whether financial strain, psychosocial measures, or health related behaviours can explain any findings.Design Data collected before and 18 months after privatisation.Setting One department of the civil service that was sold to the private sector,Participants 666 employees during baseline screening in the department to be privatised.Main outcome measures Health and health service outcomes associated with insecure re-employment, permanent exit from paid employment, and unemployment after privatisation compared with outcomes associated with secure re-employmentResults Insecure re-employment and unemployment were associated with relative increases in minor psychiatric morbidity (mean difference 1.56 (95% confidence intervals interval 1.0 to 2.2) and 1.25 (0.6 to 2.0) respectively) and having four or more consultations with a general practitioner in the past year (odds ratio 2.04 (1.1 to 3.8) and 2.39 (1.3 to 4.7) respectively). Health outcomes for respondents permanently out of paid employment closely resembled those in secure re-employment, except for a substantial relative increase in longstanding illness (2.25; 1.1 to 4.4), Financial strain and change in psychosocial measures and health related behaviours accounted for little of the observed associations. Adjustment for change in minor psychiatric morbidity attenuated the association between insecure re-employment or unemployment and general practitioner consultations by 26% and 27%, respectively.Conclusions Insecure re-employment and unemployment after privatisation result in increases in minor psychiatric morbidity and consultations with a general practitioner, which are possibly due to the increased minor psychiatric morbidity
Athletes' perceived use of information sources when forming initial impressions and expectancies of a coach: An explorative study
The study aimed to identify the sources of information that athletes perceive as influential during their initial evaluation of coaching ability. University athletes (N = 538) were asked to indicate the influence of 31 informational cues (e.g., gender, body language or gestures, reputation) on the initial impression formed of a coach. Following exploratory factor analysis, a 3-factor model, (i.e., static cues, dynamic cues, and third-party reports) was extracted. Mean scores revealed that although static cues (e.g., gender, race or ethnicity) were rated as relatively unimportant during impression formation, dynamic cues (e.g., facial expressions, body language or gestures) and third-party reports (e.g., coaching qualifications, reputation.) were viewed by athletes as influential factors in the formation of expectancies about coaches. Such findings have implications for the occurrence of expectancy effects in coach-athlete relationships and the way in which coaches seek to present themselves. © 2008 Human Kinetics, Inc
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