4,694 research outputs found
A new parenting-based group intervention for young anxious children: results of a randomized controlled trial
Objective
Despite recent advances, there are still no interventions that have been developed for the specific treatment of young children who have anxiety disorders. This study examined the impact of a new, cognitive–behaviorally based parenting intervention on anxiety symptoms.
Method
Families of 74 anxious children (aged 9 years or less) took part in a randomized controlled trial, which compared the new 10-session, group-format intervention with a wait-list control condition. Outcome measures included blinded diagnostic interview and self-reports from parents and children.
Results
Intention-to-treat analyses indicated that children whose parent(s) received the intervention were significantly less anxious at the end of the study than those in the control condition. Specifically, 57% of those receiving the new intervention were free of their primary disorder, compared with 15% in the control condition. Moreover, 32% of treated children were free of any anxiety diagnosis at the end of the treatment period, compared with 6% of those in the control group. Treatment gains were maintained at 12-month follow-up.
Conclusions
This new parenting-based intervention may represent an advance in the treatment of this previously neglected group. Clinical trial registration information: Anxiety in Young Children: A Randomized Controlled Trial of a New Cognitive-Behaviourally Based Parenting Intervention; http://www.isrctn.org/; ISRCTN12166762
Performance of nonparametric species richness estimators in a high diversity plant community
The efficiency of four nonparametric species richness estimators - first-order Jackknife, second-order Jackknife, Chao2 and Bootstrap - was tested using simulated quadrat sampling of two field data sets (a sandy 'Dune' and adjacent 'Swale') in high diversity shrublands (kwongan) in south-western Australia. The data sets each comprised > 100 perennial plant species and < 10 000 individuals, and the explicit (x-y coordinate) location of every individual. We applied two simulated sampling strategies to these data sets based on sampling quadrats of unit sizes 1/400th and 1/100th of total plot area. For each site and sampling strategy we obtained 250 independent sample curves, of 250 quadrats each, and compared the estimators' performances by using three indices of bias and precision: MRE (mean relative error), MSRE (mean squared relative error) and OVER (percentage overestimation). The analysis presented here is unique in providing sample estimates derived from a complete, field-based population census for a high diversity plant community. In general the true reference value was approached faster for a comparable area sampled for the smaller quadrat size and for the swale field data set, which was characterized by smaller plant size and higher plant density. Nevertheless, at least 15-30% of the total area needed to be sampled before reasonable estimates of St (total species richness) were obtained. In most field surveys, typically less than 1% of the total study domain is likely to be sampled, and at this sampling intensity underestimation is a problem. Results showed that the second-order Jackknife approached the actual value of St more quickly than the other estimators. All four estimators were better than Sobs (observed number of species). However, the behaviour of the tested estimators was not as good as expected, and even with large sample size (number of quadrats sampled) all of them failed to provide reliable estimates. First- and second-order Jackknives were positively biased whereas Chao2 and Bootstrap were negatively biased. The observed limitations in the estimators' performance suggests that there is still scope for new tools to be developed by statisticians to assist in the estimation of species richness from sample data, especially in communities with high species richness
Lubricating Bacteria Model for Branching growth of Bacterial Colonies
Various bacterial strains (e.g. strains belonging to the genera Bacillus,
Paenibacillus, Serratia and Salmonella) exhibit colonial branching patterns
during growth on poor semi-solid substrates. These patterns reflect the
bacterial cooperative self-organization. Central part of the cooperation is the
collective formation of lubricant on top of the agar which enables the bacteria
to swim. Hence it provides the colony means to advance towards the food. One
method of modeling the colonial development is via coupled reaction-diffusion
equations which describe the time evolution of the bacterial density and the
concentrations of the relevant chemical fields. This idea has been pursued by a
number of groups. Here we present an additional model which specifically
includes an evolution equation for the lubricant excreted by the bacteria. We
show that when the diffusion of the fluid is governed by nonlinear diffusion
coefficient branching patterns evolves. We study the effect of the rates of
emission and decomposition of the lubricant fluid on the observed patterns. The
results are compared with experimental observations. We also include fields of
chemotactic agents and food chemotaxis and conclude that these features are
needed in order to explain the observations.Comment: 1 latex file, 16 jpeg files, submitted to Phys. Rev.
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The architecture of EMC reveals a path for membrane protein insertion.
Funder: Boehringer Ingelheim Fonds; FundRef: http://dx.doi.org/10.13039/501100001645Funder: Naito Foundation; FundRef: http://dx.doi.org/10.13039/100007428Funder: Japanese Biochemical SocietyApproximately 25% of eukaryotic genes code for integral membrane proteins that are assembled at the endoplasmic reticulum. An abundant and widely conserved multi-protein complex termed EMC has been implicated in membrane protein biogenesis, but its mechanism of action is poorly understood. Here, we define the composition and architecture of human EMC using biochemical assays, crystallography of individual subunits, site-specific photocrosslinking, and cryo-EM reconstruction. Our results suggest that EMC's cytosolic domain contains a large, moderately hydrophobic vestibule that can bind a substrate's transmembrane domain (TMD). The cytosolic vestibule leads into a lumenally-sealed, lipid-exposed intramembrane groove large enough to accommodate a single substrate TMD. A gap between the cytosolic vestibule and intramembrane groove provides a potential path for substrate egress from EMC. These findings suggest how EMC facilitates energy-independent membrane insertion of TMDs, explain why only short lumenal domains are translocated by EMC, and constrain models of EMC's proposed chaperone function
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The architecture of EMC reveals a path for membrane protein insertion
Approximately 25% of eukaryotic genes code for integral membrane proteins that are assembled at the endoplasmic reticulum. An abundant and widely conserved multi-protein complex termed EMC has been implicated in membrane protein biogenesis, but its mechanism of action is poorly understood. Here, we define the composition and architecture of human EMC using biochemical assays, crystallography of individual subunits, site-specific photocrosslinking, and cryo-EM reconstruction. Our results suggest that EMC’s cytosolic domain contains a large, moderately hydrophobic vestibule that can bind a substrate’s transmembrane domain (TMD). The cytosolic vestibule leads into a lumenally-sealed, lipid-exposed intramembrane groove large enough to accommodate a single substrate TMD. A gap between the cytosolic vestibule and intramembrane groove provides a potential path for substrate egress from EMC. These findings suggest how EMC facilitates energy-independent membrane insertion of TMDs, explain why only short lumenal domains are translocated by EMC, and constrain models of EMC’s proposed chaperone function
Protecting Offspring Against Fire: Lessons From Banksia Seed Pods
Wildfires are a natural component in many terrestrial ecosystems and often play a crucial role in maintaining biodiversity, particularly in the fire-prone regions of Australia. A prime example of plants that are able to persist in these regions is the genus Banksia. Most Banksia species that occur in fire-prone regions produce woody seed pods (follicles), which open during or soon after fire to release seeds into the post-fire environment. For population persistence, many Banksia species depend on recruitment from these canopy-stored seeds. Therefore, it is critical that their seeds are protected from heat and rapid oxidation during fire. Here, we show how different species of Banksia protect their seeds inside follicles while simultaneously opening up when experiencing fire. The ability of the follicles to protect seeds from heat is demonstrated by intense 180 s experimental burns, in which the maximum temperatures near the seeds ranged from ∼75°C for B. serrata to ∼90°C for B. prionotes and ∼95°C for B. candolleana, contrasting with the mean surface temperature of ∼450°C. Many seeds of native Australian plants, including those of Banksia, are able to survive these temperatures. Structural analysis of individual follicles from these three Banksia species demonstrates that all of them rely on a multicomponent system, consisting of two valves, a porous separator and a thin layer of air surrounding the seeds. The particular geometric arrangement of these components determines the rate of heat transfer more than the tissue properties alone, revealing that a strong embedment into the central rachis can compensate for thin follicle valves. Furthermore, we highlight the role of the separator as an important thermal insulator. Our study suggests that the genus Banksia employs a variety of combinations in terms of follicle size, valve thickness, composition and geometric arrangement to effectively protect canopy-stored seeds during fire
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Pre-emptive Quality Control of a Misfolded Membrane Protein by Ribosome-Driven Effects.
Cells possess multiple mechanisms that protect against the accumulation of toxic aggregation-prone proteins. Here, we identify a pre-emptive pathway that reduces synthesis of membrane proteins that have failed to properly assemble in the endoplasmic reticulum (ER). We show that loss of the ER membrane complex (EMC) or mutation of the Sec61 translocon causes reduced synthesis of misfolded forms of the yeast ABC transporter Yor1. Synthesis defects are rescued by various ribosomal mutations, as well as by reducing cellular ribosome abundance. Genetic and biochemical evidence point to a ribosome-associated quality-control pathway triggered by ribosome collisions when membrane domain insertion and/or folding fails. In support of this model, translation initiation also contributes to synthesis defects, likely by modulating ribosome abundance on the message. Examination of translation efficiency across the yeast membrane proteome revealed that polytopic membrane proteins have relatively low ribosome abundance, providing evidence for translational tuning to balance protein synthesis and folding. We propose that by modulating translation rates of poorly folded proteins, cells can pre-emptively protect themselves from potentially toxic aberrant transmembrane proteins
The Value of IAQ: A Review of the Scientific Evidence Supporting the Benefits of Investing in Better Indoor Air Quality
Other studies have examined how ventilation rates, combined with the presence of pollutant sources, can affect productivity. These studies provide evidence that increased ventilation, including increases above common guidance levels such as ASHRAE’s ventilation standards, improve occupant productivity. Increased occupant control over ventilation has also been shown to improve productivity. Higher indoor carbon dioxide (CO2) levels have been directly associated with impaired work performance and increased health symptoms. Historically, it was believed that these associations exist only because higher indoor CO2 concentrations, resulting from lower outdoor air ventilation rates, are also correlated with higher levels of other indoor-generated pollutants that directly cause the adverse effects. More recent studies, however, have found that CO2 itself, even at levels previously considered acceptable, may have adverse effects.
Considering the benefits and demonstrated return on investment, building owners and operators should consider proactive methods of improving IAQ. Established strategies and guidelines are readily available to help identify and implement IAQ-related improvements. These include recognizing and addressing potential and real IAQ issues during the design, construction, renovation, and ongoing maintenance of buildings. Research has found that the benefits of IAQ improvement far outweigh the costs, with estimates of 3–6 times returns for increased ventilation, 8 times returns for increased filtration, and up to 60 times returns when all improvements and related benefits are combined. Collectively, the scientific literature demonstrates that improved workplace productivity and reduced absenteeism from improved IAQ have been shown to provide substantial financial benefits, with the benefits often greatly outweighing the associated costs
Assessing cognitive dysfunction in Parkinson's disease: An online tool to detect visuo-perceptual deficits.
BackgroundPeople with Parkinson's disease (PD) who develop visuo-perceptual deficits are at higher risk of dementia, but we lack tests that detect subtle visuo-perceptual deficits and can be performed by untrained personnel. Hallucinations are associated with cognitive impairment and typically involve perception of complex objects. Changes in object perception may therefore be a sensitive marker of visuo-perceptual deficits in PD.ObjectiveWe developed an online platform to test visuo-perceptual function. We hypothesised that (1) visuo-perceptual deficits in PD could be detected using online tests, (2) object perception would be preferentially affected, and (3) these deficits would be caused by changes in perception rather than response bias.MethodsWe assessed 91 people with PD and 275 controls. Performance was compared using classical frequentist statistics. We then fitted a hierarchical Bayesian signal detection theory model to a subset of tasks.ResultsPeople with PD were worse than controls at object recognition, showing no deficits in other visuo-perceptual tests. Specifically, they were worse at identifying skewed images (P < .0001); at detecting hidden objects (P = .0039); at identifying objects in peripheral vision (P < .0001); and at detecting biological motion (P = .0065). In contrast, people with PD were not worse at mental rotation or subjective size perception. Using signal detection modelling, we found this effect was driven by change in perceptual sensitivity rather than response bias.ConclusionsOnline tests can detect visuo-perceptual deficits in people with PD, with object recognition particularly affected. Ultimately, visuo-perceptual tests may be developed to identify at-risk patients for clinical trials to slow PD dementia. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society
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