Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
33,261
result(s) for
"Thomas, Peter"
Sort by:
Membrane Progesterone Receptors (mPRs, PAQRs): Review of Structural and Signaling Characteristics
The role of membrane progesterone receptors (mPRs), which belong to the progestin and adipoQ receptor (PAQR) family, in mediating rapid, nongenomic (non-classical) progestogen actions has been extensively studied since their identification 20 years ago. Although the mPRs have been implicated in progestogen regulation of numerous reproductive and non-reproductive functions in vertebrates, several critical aspects of their structure and signaling functions have been unresolved until recently and remain the subject of considerable debate. This paper briefly reviews recent developments in our understanding of the structure and functional characteristics of mPRs. The proposed membrane topology of mPRα, the structure of its ligand-binding site, and the binding affinities of steroids were predicted from homology modeling based on the structures of other PAQRs, adiponectin receptors, and confirmed by mutational analysis and ligand-binding assays. Extensive data demonstrating that mPR-dependent progestogen regulation of intracellular signaling through mPRs is mediated by activation of G proteins are reviewed. Close association of mPRα with progesterone membrane receptor component 1 (PGRMC1), its role as an adaptor protein to mediate cell-surface expression of mPRα and mPRα-dependent progestogen signaling has been demonstrated in several vertebrate models. In addition, evidence is presented that mPRs can regulate the activity of other hormone receptors.
Journal Article
Biological Flora of the British Isles: Fraxinus excelsior
This account presents information on all aspects of the biology of Fraxinus excelsior L. (Ash) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, and conservation. Fraxinus excelsior is a large forest tree, native throughout the main islands of Britain and much of mainland Europe. Seedlings are shade tolerant, but adults are not so it tends to be an intermediate successional species, invading gaps in mixed stands rather than forming extensive pure stands. Ash grows on a wide range of soils but is commonest on nutrientârich soils with a high base status and pHÂ >Â 4.2, and is at its best on dry calcareous screes and fertile alluvial soils. Fraxinus excelsior is trioecious or subdioecious with male, hermaphrodite and female flowers and trees. Seed production is prolific with periodic higher producing mast years. Seeds are primarily windâdispersed, but they can float and be moved considerable distances along waterways. Germination is delayed by dormancy until usually the second spring after being shed. Ash is tolerant of drought, but intolerant of spring frosts and so is predicted to fare well under current climate change scenarios, and indeed has recently been expanding in range in Europe. However, ash health and survival is currently seriously compromised by ash dieback caused by the fungus Hymenoscyphus fraxineus (Chalara fraxinea) that has the potential to kill all but a very few resistant trees. Moreover, the emerald ash borer beetle Agrilus planipennis, a serious pest of ash species in N. America, has reached Europe (though not yet the British Isles) and poses an equally if not more serious longâterm threat to ash.
Journal Article
Fire in the forest
\"How destructive or beneficial are forest fires to wildlife? Should we be trying to reduce or increase the amount of fire in forests? How are forest fires controlled, and why does this sometimes fail? What effect will climate change have? These and many other questions are answered in this richly illustrated book, written in non-technical language. The journey starts in the long geological history of fire leading up to our present love-hate relationship with it. Exploring the physics of how a single flame burns, the journey continues through how whole forests burn and the anatomy of firestorms. The positive and negative ecological effects of fires are explored, from plants and wildlife to whole landscapes. The journey ends with how fires are controlled, and a look to the future. This book will be of interest to ecologists, biogeographers and anyone with an interest in forest fires and the role they play\"-- Provided by publisher.
Book
Feasibility study of an automated Strabismus screening Test using Augmented Reality and Eye-tracking (STARE)
BackgroundNew digital technologies (augmented reality headsets, eye-tracking) may potentially allow for automated assessments of ocular misalignment. Here, we evaluate the feasibility of a novel, open-source strabismus test (“STARE”) as an automated screening tool.MethodsWork progressed in 2 phases. In phase 1 (“development”), we used Fresnel prisms to elicit horizontal misalignments of known magnitude (1–40 prism dioptres) in orthotropic controls. In phase 2 (“validation”), we applied the system to adults with an established diagnosis of strabismus, and quantified the ability of the test to distinguish between those with horizontal misalignment and those without. Agreement between the alternate prism cover test measurements and STARE measurements was computed using Bland–Altman plots and product-moment correlation coefficients.ResultsSeven orthotropic controls and nineteen patients with strabismus were recruited (mean age 58.7 ± 22.4 years). STARE was able to identify the presence of horizontal strabismus with an area under the curve of 1.00 (100% sensitivity and 100% specificity). The mean difference (bias) {95% CI} was 2.1 {−1.8, 9.9} prism dioptres, and the 95% coefficient of repeatability {95% CI} was ±27.9 {14.8, 50.8} prism dioptres. The Pearson correlation between APCT and STARE was r24 = 0.62, P < 0.001.ConclusionsSTARE shows promise as a simple, automated tool for performing a screening assessment of strabismus. It is a rapid (60 s) test that can be performed using a consumer augmented reality headset with integrated eye-tracking, and might conceivably be used remotely by non-specialists in future as a means of highlighting individuals needing face-to-face specialist care.
Journal Article
Photolytic radical persistence due to anoxia in viscous aerosol particles
In viscous, organic-rich aerosol particles containing iron, sunlight may induce anoxic conditions that stabilize reactive oxygen species (ROS) and carbon-centered radicals (CCRs). In laboratory experiments, we show mass loss, iron oxidation and radical formation and release from photoactive organic particles containing iron. Our results reveal a range of temperature and relative humidity, including ambient conditions, that control ROS build up and CCR persistence in photochemically active, viscous organic particles. We find that radicals can attain high concentrations, altering aerosol chemistry and exacerbating health hazards of aerosol exposure. Our physicochemical kinetic model confirmed these results, implying that oxygen does not penetrate such particles due to the combined effects of fast reaction and slow diffusion near the particle surface, allowing photochemically-produced radicals to be effectively trapped in an anoxic organic matrix.
Sunlight can change the composition of atmospheric aerosol particles, but the mechanisms through which this happens are not well known. Here, the authors show that fast radical reaction and slow diffusion near viscous organic particle surfaces can cause oxygen depletion, radical trapping and humidity dependent oxidation.
Journal Article