1,622 research outputs found
Remarkable insights into the paleoecology of the Avalonian Ediacaran macrobiota
Ediacaran macrofossils from the Avalon Terrane (primarily eastern Newfoundland and the central UK) record
some of the earliest large and complex multicellular organisms on Earth. Perhaps the greatest unknown regarding
these fossils is their relevance to the early evolutionary history of the Kingdom Animalia. In recent years, new
data and discoveries have revealed insights into Ediacaran paleobiology, taxonomic relationships, paleoecology
and taphonomy, significantly refining our understanding of Avalonian ecosystems. Here, we summarise recent
observational and quantitative studies, and their bearing on the current understanding of Avalonian benthic marine
ecosystems. A review of existing knowledge of the biological composition of Avalonian marine assemblages
demonstrates that they record densely-populated ecosystems inhabited by a diverse range of organisms, likely
representing multiple biological Kingdoms. Appreciation of this diversity, and of the complexities it introduces
to paleoecological studies, is vital when considering the relationship between macroevolution and contemporaneous
climatic, tectonic and geochemical events. We then summarise current understanding of Avalonian paleoecology.
Studies into locomotion, reproduction, feeding strategies, and community structure and succession
reveal that these ecosystems were considerably different to Phanerozoic settings. Furthermore, we suggest
that Avalonian ecosystems witnessed the appearance of novel nutrient sources, offering new opportunities
and niches for benthic organisms. The suggestion that the numerically dominant rangeomorphs were
osmotrophic is reviewed and appraised in light of geochemical, morphological, and biological information. Finally,
the use of modern ecological metrics in the study of Ediacaran fossil assemblages is assessed. Concerns regarding
the interpretation of paleoecological data are outlined in light of current taphonomic and sedimentological
understanding, and these cast doubt on previous suggestions that the Avalonian assemblages were largely composed
of metazoans. Nevertheless, we emphasise that if treated with necessary caution, paleoecological data can
play a significant role in assisting efforts to determine the biological affinities of late Ediacaran macroscopic
organisms.Thanks are extended to the editors of Gondwana Research, T. Horscroft
and M. Santosh, for inviting this review, and for their patience whilst we
completed it. The Parks and Natural Areas Division, Department of Environment
and Conservation, Government of Newfoundland and Labrador
provided permits to conduct research within the Mistaken Point Ecological
Reserve between 2008–2013, whilst the Department of Tourism, Culture
and Recreation provided permits for paleontological research in
other parts of the Province from 2012–2013. The support of the
Portugal Cove South Visitor Center interpreters during our field research
was greatly appreciated. This work has been supported by the Natural
Environment Research Council [grant numbers NE/I005927/1 to CGK
and NE/G523539/1 to EGM]; a Henslow Junior Research Fellowship
from Cambridge Philosophical Society to AGL; and the National
Geographic Global Exploration Fund [GEFNE 22-11 to AGL]. Field assistance
from J. Matthews, J. Stewart, D. Collins, and T. Hearing has been
invaluable, and we have enjoyed fruitful discussions on this topic with
N. Butterfield, D. McIlroy, J. Hoyal Cuthill, M. Brasier, S. Conway Morris
and P. Wilby. The work and support of past and current workers in this
field is gratefully acknowledged. B. MacGabhann and one anonymous
reviewer are thanked for providing detailed comments that
have strengthened this manuscript, whilst S. Jensen and M. Friedman
provided helpful feedback on parts of this manuscript assessed as a
chapter of AGL's thesis.This is the final published version of an article that was originally published in Gondwana Research, Available online 4 December 2014, doi:10.1016/j.gr.2014.11.00
Creativity and the computer nerd: an exploration of attitudes
This study arises from our concern that many of our best art and design students are failing to make the most of the opportunities provided by IT because of their fear or dislike of computers. This not only deprives them of useful skills, but, even more importantly, deprives many IT based developments of their input. In this paper we investigate the relationship between attitudes to creativity and to computers among students. We quickly discard an approach based on theories of personality types as philosophically and educationally problematic. An approach based on the self-concept of artists and designers, in relation to their own creativity and to their feelings about computers, offers more hope of progress. This means that we do not try to define the attributes of "creative people". Rather, we ask what creativity means to students of art and design and relate these responses to their attitudes to computers. Self-concept depends on how the subjects see themselves within society and culture, and is liable to change as culture changes. One major instrument of cultural change at the present time is the growth of IT itself. We then describe a first attempt at using a psychological method - Kelly's Repertory Grids - to investigate the self-concept of artists and designers. It is hoped to continue with this approach in further studies over the next few years
Testing the cognitive-behavioural maintenance models across DSM-5 bulimic-type eating disorder diagnostic groups: A multi-centre study
The original cognitive-behavioural (CB) model of bulimia nervosa, which provided the basis for the widely used CB therapy, proposed that specific dysfunctional cognitions and behaviours maintain the disorder. However, amongst treatment completers, only 40–50 % have a full and lasting response. The enhanced CB model (CB-E), upon which the enhanced version of the CB treatment was based, extended the original approach by including four additional maintenance factors. This study evaluated and compared both CB models in a large clinical treatment seeking sample (N = 679), applying both DSM-IV and DSM-5 criteria for bulimic-type eating disorders. Application of the DSM-5 criteria reduced the number of cases of DSM-IV bulimic-type eating disorders not otherwise specified to 29.6 %. Structural equation modelling analysis indicated that (a) although both models provided a good fit to the data, the CB-E model accounted for a greater proportion of variance in eating-disordered behaviours than the original one, (b) interpersonal problems, clinical perfectionism and low self-esteem were indirectly associated with dietary restraint through over-evaluation of shape and weight, (c) interpersonal problems and mood intolerance were directly linked to binge eating, whereas restraint only indirectly affected binge eating through mood intolerance, suggesting that factors other than restraint may play a more critical role in the maintenance of binge eating. In terms of strength of the associations, differences across DSM-5 bulimic-type eating disorder diagnostic groups were not observed. The results are discussed with reference to theory and research, including neurobiological findings and recent hypotheses
Potential of a cyclone prototype spacer to improve in vitro dry powder delivery
Copyright The Author(s) 2013. This article is published with open access at Springerlink.com. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedPurpose: Low inspiratory force in patients with lung disease is associated with poor deagglomeration and high throat deposition when using dry powder inhalers (DPIs). The potential of two reverse flow cyclone prototypes as spacers for commercial carrierbased DPIs was investigated. Methods: Cyclohaler®, Accuhaler® and Easyhaler® were tested with and without the spacers between 30-60 Lmin-1. Deposition of particles in the next generation impactor and within the devices was determined by high performance liquid chromatography. Results: Reduced induction port deposition of the emitted particles from the cyclones was observed due to the high retention of the drug within the spacers (e.g. salbutamol sulphate (SS): 67.89 ± 6.51 % at 30 Lmin-1 in Cheng 1). Fine particle fractions of aerosol as emitted from the cyclones were substantially higher than the DPIs alone. Moreover, the aerodynamic diameters of particles emitted from the cyclones were halved compared to the DPIs alone (e.g. SS from the Cyclohaler® at 4 kPa: 1.08 ± 0.05 μm vs. 3.00 ± 0.12 μm, with and without Cheng 2, respectively) and unaltered with increased flow rates. Conclusion: This work has shown the potential of employing a cyclone spacer for commercial carrier-based DPIs to improve inhaled drug delivery.Peer reviewe
Examining a staging model for anorexia nervosa: empirical exploration of a four stage model of severity.
Background: An illness staging model for anorexia nervosa (AN) has received increasing attention, but assessing the merits of this concept is dependent on empirically examining a model in clinical samples. Building on preliminary findings regarding the reliability and validity of the Clinician Administered Staging Instrument for Anorexia Nervosa (CASIAN), the current study explores operationalising CASIAN severity scores into stages and assesses their relationship with other clinical features. Method: In women with DSM-IV-R AN and sub-threshold AN (all met AN criteria using DSM 5), receiver operating curve (ROC) analysis (n = 67) assessed the relationship between the sensitivity and specificity of each stage of the CASIAN. Thereafter chi-square and post-hoc adjusted residual analysis provided a preliminary assessment of the validity of the stages comparing the relationship between stage and treatment intensity and AN sub-types, and explored movement between stages after six months (Time 3) in a larger cohort (n = 171). Results: The CASIAN significantly distinguished between milder stages of illness (Stage 1 and 2) versus more severe stages of illness (Stages 3 and 4), and approached statistical significance in distinguishing each of the four stages from one other. CASIAN Stages were significantly associated with treatment modality and primary diagnosis, and CASIAN Stage at Time 1 was significantly associated with Stage at 6 month follow-up. Conclusions: Provisional support is provided for a staging model in AN. Larger studies with longer follow-up of cases are now needed to replicate and extend these findings and evaluate the overall utility of staging as well as optimal staging models
Phenotypic and molecular assessment of seven patients with 6p25 deletion syndrome: Relevance to ocular dysgenesis and hearing impairment
BACKGROUND: Thirty-nine patients have been described with deletions involving chromosome 6p25. However, relatively few of these deletions have had molecular characterization. Common phenotypes of 6p25 deletion syndrome patients include hydrocephalus, hearing loss, and ocular, craniofacial, skeletal, cardiac, and renal malformations. Molecular characterization of deletions can identify genes that are responsible for these phenotypes. METHODS: We report the clinical phenotype of seven patients with terminal deletions of chromosome 6p25 and compare them to previously reported patients. Molecular characterization of the deletions was performed using polymorphic marker analysis to determine the extents of the deletions in these seven 6p25 deletion syndrome patients. RESULTS: Our results, and previous data, show that ocular dysgenesis and hearing impairment are the two most highly penetrant phenotypes of the 6p25 deletion syndrome. While deletion of the forkhead box C1 gene (FOXC1) probably underlies the ocular dysgenesis, no gene in this region is known to be involved in hearing impairment. CONCLUSIONS: Ocular dysgenesis and hearing impairment are the two most common phenotypes of 6p25 deletion syndrome. We conclude that a locus for dominant hearing loss is present at 6p25 and that this locus is restricted to a region distal to D6S1617. Molecular characterization of more 6p25 deletion patients will aid in refinement of this locus and the identification of a gene involved in dominant hearing loss
Galaxies in the EAGLE hydrodynamical simulation and in the Durham and Munich semi-analytical models
We compare global predictions from the eagle hydrodynamical simulation, and two semi-analytic (SA) models of galaxy formation, l-galaxies and galform. All three models include the key physical processes for the formation and evolution of galaxies and their parameters are calibrated against a small number of observables at z ≈ 0. The two SA models have been applied to merger trees constructed from the eagle dark matter only simulation. We find that at z ≤ 2, both the galaxy stellar mass functions for stellar masses M* 109.5 M⊙ differ in some instances by an order of magnitude, while the stellar mass–size relation in eagle is a factor of ≈2 tighter than for the two SA models. Our results suggest the need for a revision of how SA models treat the effect of baryonic self-gravity on the underlying dark matter. The treatment of gas flows in the models needs to be revised based on detailed comparison with observations to understand in particular the evolution of the stellar mass–metallicity relation
Preventing recurrence of thromboembolic events through coordinated treatment in the District of Columbia
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87024/1/j.1747-4949.2011.00654.x.pd
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