1,994 research outputs found
p63 is a key regulator of iRHOM2 signalling in the keratinocyte stress response.
Hyperproliferative keratinocytes induced by trauma, hyperkeratosis and/or inflammation display molecular signatures similar to those of palmoplantar epidermis. Inherited gain-of-function mutations in RHBDF2 (encoding iRHOM2) are associated with a hyperproliferative palmoplantar keratoderma and squamous oesophageal cancer syndrome (termed TOC). In contrast, genetic ablation of rhbdf2 in mice leads to a thinning of the mammalian footpad, and reduces keratinocyte hyperproliferation and migration. Here, we report that iRHOM2 is a novel target gene of p63 and that both p63 and iRHOM2 differentially regulate cellular stress-associated signalling pathways in normal and hyperproliferative keratinocytes. We demonstrate that p63-iRHOM2 regulates cell survival and response to oxidative stress via modulation of SURVIVIN and Cytoglobin, respectively. Furthermore, the antioxidant compound Sulforaphane downregulates p63-iRHOM2 expression, leading to reduced proliferation, inflammation, survival and ROS production. These findings elucidate a novel p63-associated pathway that identifies iRHOM2 modulation as a potential therapeutic target to treat hyperproliferative skin disease and neoplasia
Phylogenetic Resolution and Quantifying the Phylogenetic Diversity and Dispersion of Communities
Conservation biologists and community ecologists have increasingly begun to quantify the phylogenetic diversity and phylogenetic dispersion in species assemblages. In some instances, the phylogenetic trees used for such analyses are fully bifurcating, but in many cases the phylogenies being used contain unresolved nodes (i.e. polytomies). The lack of phylogenetic resolution in such studies, while certainly not preferred, is likely to continue particularly for those analyzing diverse communities and datasets with hundreds to thousands of taxa. Thus it is imperative that we quantify potential biases and losses of statistical power in studies that use phylogenetic trees that are not completely resolved. The present study is designed to meet both of these goals by quantifying the phylogenetic diversity and dispersion of simulated communities using resolved and gradually ‘unresolved’ phylogenies. The results show that: (i) measures of community phylogenetic diversity and dispersion are generally more sensitive to loss of resolution basally in the phylogeny and less sensitive to loss of resolution terminally; and (ii) the loss of phylogenetic resolution generally causes false negative results rather than false positives
Photoinduced Dehydrogenation of Defects in Undoped a-Si:H Using Positron Annihilation Spectroscopy
We report changes in variable-energy positron annihilation spectroscopy measurements on undoped hydrogenated amorphous silicon films after light soaking. The change, seen predominantly in the high momentum band of the annihilation radiation, is not reversed by thermal annealing. We suggest, following recent models of the Staebler-Wronski effect, that light exposure induces hydrogen trapped in vacancylikc detects to become mobile in the Si network. The observations place constraints on models of hydrogen motion fitting macroscopic Staebler-Wronski effect kinetics and may help to achieve a definitive description of metastability in a-Si:H.published_or_final_versio
In silico-guided optimisation of oxygen gradients in hepatic spheroids
One of the key advantages of assessing the hepatotoxic potential of xenobiotics in spheroids rather than monolayer cell culture is the existence of a more physiologically relevant testing environment. Three-dimensional cultures support spatial gradients in nutrients such as oxygen that can be exploited to better represent in vivo gradients that exist along a fundamental sub-unit of liver microarchitecture, the liver sinusoid. The physical and physiological processes that result in the establishment of such gradients can be described mathematically. Quantification of the rates governing these processes and optimisation of cell culture conditions can be performed in silico to better inform experimental design. In this study, we take into account cell line-specific physiological properties, spheroid size and the impact of experimental equipment geometries in order to demonstrate how mathematical models can be optimised to achieve specific in vivo-like features in different scenarios. Furthermore, the sensitivity of such optimised gradients is analysed with respect to culture conditions and considerations are given to prevent the emergence of hypoxic regions in the spheroid. The methodology presented provides an enhanced understanding of the mechanisms of the system within this simulated in vitro framework such that experimental design can be more carefully calibrated when conducting experiments using hepatic spheroids. © 2019 Elsevier B.V
On the Thermal Activation of Turin Metro Line 2 Tunnels
The Turin metro Line 2 will extend for nearly 28 km and include 26 stations. It will connect the SW suburbs of the city to the NE ones. The excavation will be performed by means of TBM and Cut & Cover techniques and, once concluded, will host a fully automated driverless light metro. This paper will describe the feasibility study carried out to assess the energy potential of the thermal activation of the line by using an innovative tunnel lining segment (ENERTUN) recently patented and tested in real operating conditions. A novel methodology was adopted, involving thermo-hydraulic 3D FE numerical anal- yses to identify the geothermal potential for the different sections of the line. A study of the possible collectors for the thermal energy produced was also performed considering the planned stations, the existing buildings and the future urban developments
Study of microvoids in high-rate a-Si:H using positron annihilation
Theme: Amorphous and microcrystalline silicon technologyIn this paper, we have carried out the positron annihilation measurement on high-rate and low-rate a-Si;H thin films deposited by PECVD. By means of the slow positron beam Doppler-broadening technique, the depth profiles of microvoids in a-Si:H have been determined. We have also studied the vacancy-type defect in the surface region in high-rate grown a-Si:H, making comparison between high-rate and low-rate a-Si:H. By plotting S and W parameters in the (S, W) plane, we have shown that the vacancies in all of the high-rate and low-rate deposited intrinsic samples, and in differently doped low-rate samples are of the same nature.published_or_final_versio
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Cleavage of the pseudoprotease iRhom2 by the signal peptidase complex reveals an ER-to-nucleus signaling pathway.
iRhoms are pseudoprotease members of the rhomboid-like superfamily and are cardinal regulators of inflammatory and growth factor signaling; they function primarily by recognizing transmembrane domains of their clients. Here, we report a mechanistically distinct nuclear function of iRhoms, showing that both human and mouse iRhom2 are non-canonical substrates of signal peptidase complex (SPC), the protease that removes signal peptides from secreted proteins. Cleavage of iRhom2 generates an N-terminal fragment that enters the nucleus and modifies the transcriptome, in part by binding C-terminal binding proteins (CtBPs). The biological significance of nuclear iRhom2 is indicated by elevated levels in skin biopsies of patients with psoriasis, tylosis with oesophageal cancer (TOC), and non-epidermolytic palmoplantar keratoderma (NEPPK); increased iRhom2 cleavage in a keratinocyte model of psoriasis; and nuclear iRhom2 promoting proliferation of keratinocytes. Overall, this work identifies an unexpected SPC-dependent ER-to-nucleus signaling pathway and demonstrates that iRhoms can mediate nuclear signaling
Interface characterisation and internal electric field evaluation of a-Si:H pin solar cell by variable energy positron annhilation spectroscopy
Symposium Theme: Amorphous and microcrystalline silicon technologyBy means of the slow positron beam Doppler-broadening technique, the depth profile of microvoids across a p-i-n double junction solar cell has been resolved. VEPFIT fitting results indicate an approximately uniform density of the defects throughout the solar cell, but with an enhanced concentration at all of the interfaces possibly due to network mismatch. In order to evaluate the internal electric field, Variable Energy Positron Annihilation Spectroscopy (VEPAS) measurements have been performed on a single junction pin solar cell at different biases. The internal electric field effect on positrons has also been examined in terms of the bias dependence of positron drift in a-Si:H single junction pin solar cell.published_or_final_versio
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The convective storm initiation project
Copyright @ 2007 AMSThe Convective Storm Initiation Project (CSIP) is an international project to understand precisely where, when, and how convective clouds form and develop into showers in the mainly maritime environment of southern England. A major aim of CSIP is to compare the results of the very high resolution Met Office weather forecasting model with detailed observations of the early stages of convective clouds and to use the newly gained understanding to improve the predictions of the model. A large array of ground-based instruments plus two instrumented aircraft, from the U.K. National Centre for Atmospheric Science (NCAS) and the German Institute for Meteorology and Climate Research (IMK), Karlsruhe, were deployed in southern England, over an area centered on the meteorological radars at Chilbolton, during the summers of 2004 and 2005. In addition to a variety of ground-based remote-sensing instruments, numerous rawin-sondes were released at one- to two-hourly intervals from six closely spaced sites. The Met Office weather radar network and Meteosat satellite imagery were used to provide context for the observations made by the instruments deployed during CSIP. This article presents an overview of the CSIP field campaign and examples from CSIP of the types of convective initiation phenomena that are typical in the United Kingdom. It shows the way in which certain kinds of observational data are able to reveal these phenomena and gives an explanation of how the analyses of data from the field campaign will be used in the development of an improved very high resolution NWP model for operational use.This work is funded by the National Environment Research Council following an initial award from the HEFCE Joint Infrastructure Fund
Angiographic outcome of coronary artery bypass grafts: Radial Artery Database International Alliance
BACKGROUND: We used a large patient-level dataset including six angiographic randomized trials (RCTs) on coronary artery bypass conduits to explore incidence and determinants of coronary graft failure. METHODS: Patient-level angiographic data of six RCTs comparing long-term outcomes of the radial artery and other conduits were joined. Primary outcome was graft occlusion at maximum follow-up. The analysis was divided as follows: 1) left anterior descending coronary (LAD) distribution, 2) non-LAD distribution (circumflex and right coronary artery). To identify predictors of graft occlusion, mixed model multivariable Cox regression including all baseline characteristics with stratification by individual trials was used. RESULTS: 1091 patients and 2281 grafts were included (921 left internal mammary arteries, 74 right internal mammary arteries, 710 radial artery and 576 saphenous veins; all left internal mammary arteries were used on the LAD, the other conduits were used on the non-LAD distribution; mean angiographic follow up: 65±29 months). Occlusion rate was 2.3%, 13.5%, 9.4%, 17.5% for the left internal mammary arteries, right internal mammary arteries, radial artery and saphenous veins, respectively. At multivariable analysis type of conduit used, age, female gender, left ventricular ejection fraction<50% and use of the Y graft were significantly associated with graft occlusion in the non-LAD distribution. CONCLUSIONS: Our analyses showed that failure of the left internal mammary arteries to LAD bypass is a very uncommon event. For the non-LAD distribution, the non-use of radial artery, age, female gender, left ventricular ejection fraction<50% and use of the Y graft configuration were significantly associated with mid-term graft failure
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