557 research outputs found
On the theory of Gordan-Noether on homogeneous forms with zero Hessian (Improved version)
We give a detailed proof for Gordan-Noether's results in "Ueber die
algebraischen Formen, deren Hesse'sche Determinante identisch verschwindet"
published in 1876 in Mathematische Annahlen. C. Lossen has written a paper in a
similar direction as the present paper, but did not provide a proof for every
result. In our paper, every result is proved. Furthermore, our paper is
independent of Lossen's paper and includes a considerable number of new
observations.
An earlier version of this paper has been printed in Proceedings of the
School of Science of Tokai University, Vol.49, Mar. 2014. In this version, a
serious error has been corrected and some new results have been added
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A single H/ACA small nucleolar RNA mediates tumor suppression downstream of oncogenic RAS.
Small nucleolar RNAs (snoRNAs) are a diverse group of non-coding RNAs that direct chemical modifications at specific residues on other RNA molecules, primarily on ribosomal RNA (rRNA). SnoRNAs are altered in several cancers; however, their role in cell homeostasis as well as in cellular transformation remains poorly explored. Here, we show that specific subsets of snoRNAs are differentially regulated during the earliest cellular response to oncogenic RASG12V expression. We describe a novel function for one H/ACA snoRNA, SNORA24, which guides two pseudouridine modifications within the small ribosomal subunit, in RAS-induced senescence in vivo. We find that in mouse models, loss of Snora24 cooperates with RASG12V to promote the development of liver cancer that closely resembles human steatohepatitic hepatocellular carcinoma (HCC). From a clinical perspective, we further show that human HCCs with low SNORA24 expression display increased lipid content and are associated with poor patient survival. We next asked whether ribosomes lacking SNORA24-guided pseudouridine modifications on 18S rRNA have alterations in their biophysical properties. Single-molecule Fluorescence Resonance Energy Transfer (FRET) analyses revealed that these ribosomes exhibit perturbations in aminoacyl-transfer RNA (aa-tRNA) selection and altered pre-translocation ribosome complex dynamics. Furthermore, we find that HCC cells lacking SNORA24-guided pseudouridine modifications have increased translational miscoding and stop codon readthrough frequencies. These findings highlight a role for specific snoRNAs in safeguarding against oncogenic insult and demonstrate a functional link between H/ACA snoRNAs regulated by RAS and the biophysical properties of ribosomes in cancer
The Influence of E - Stim on Posture and Respiratory Function to Improve Aerobic Capacity: A Pilot
poste
Skilful seasonal predictions of Summer European rainfal
This is the author accepted manuscript. The final version is available from American Geophysical Union (AGU) via the DOI in this record.Year-to-year variability in Northern European summer rainfall has profound societal and economic impacts; however current seasonal forecast systems show no significant forecast skill. Here we show skilful predictions are possible (r~0.5, p80 members) are required for skilful predictions. This work is promising for the development of European summer rainfall climate services.This work was supported by the Joint DECC/Defra Met Office Hadley Centre Climate
Programme (GA01101), the EU FP7 SPECS project. We acknowledge the E-OBS dataset
from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data
providers in the ECA&D project (http://www.ecad.eu). We also would like to thank Gerard
van der Schrier and Else Van Den Besselaar for kindly providing us the pre-release E-OBS
dataset version 'v16e' and further support. Model data used to create the figures are available
from the authors upon request for academic use
How Does Cryotherapy Effect Ankle Proprioception in Healthy Individuals?
Objectives: To investigate how a 15 minute Cryotherapy intervention effects proprioception by measuring Joint positional Sense (JPS) and static single legged balance. Design: Repeated measures design. Setting: Laboratory. Participants: Eighteen healthy university sports team students (11 males, 7 females) aged between 20-21 years. Main Outcome Measures: Participants were treated with 15 minutes Aircast Cryo-cuff. The subject’s skin temperature was measured before and immediately after 15 minutes Cryotherapy treatment. Ankle active joint positional sense (A-JPS) and passive joint positional sense (P-JPS) was measured at pre-test, immediately post-test and 5 minutes post-test. Static balance was measured by Centre of Pressure (CoP) mean path length, medial-lateral (ML) CoP mean Deviation and anterior-posterior (AP) CoP mean Deviation and mean time-to-boundary (TtB) Minima for AP and ML directions. Results: No significant differences found for the variables of JPS and static single balance testing after 15 minutes Cryotherapy treatment. However, mean differences for CoP mean path length and ML mean deviation were shown to improve following Cryotherapy treatment, results not previously found in the literature. Conclusion: Results suggest that 15 minute Cryo-cuff treatment doesn’t significantly affect proprioception. Although the effect of Cryotherapy on proprioception depends on cooling modality used, time frame applied and joint applied to
Process for Making Single-Domain Magnetite Crystals
A process for making chemically pure, single-domain magnetite crystals substantially free of structural defects has been invented as a byproduct of research into the origin of globules in a meteorite found in Antarctica and believed to have originated on Mars. The globules in the meteorite comprise layers of mixed (Mg, Fe, and Ca) carbonates, magnetite, and iron sulfides. Since the discovery of the meteorite was announced in August 1996, scientists have debated whether the globules are of biological origin or were formed from inorganic materials by processes that could have taken place on Mars. While the research that led to the present invention has not provided a definitive conclusion concerning the origin of the globules, it has shown that globules of a different but related chemically layered structure can be grown from inorganic ingredients in a multistep precipitation process. As described in more detail below, the present invention comprises the multistep precipitation process plus a subsequent heat treatment. The multistep precipitation process was demonstrated in a laboratory experiment on the growth of submicron ankerite crystals, overgrown by submicron siderite and pyrite crystals, overgrown by submicron magnesite crystals, overgrown by submicron siderite and pyrite. In each step, chloride salts of appropriate cations (Ca, Fe, and Mg) were dissolved in deoxygenated, CO2- saturated water. NaHCO3 was added as a pH buffer while CO2 was passed continuously through the solution. A 15-mL aliquot of the resulting solution was transferred into each of several 20 mL, poly(tetrafluoroethylene)-lined hydrothermal pressure vessels. The vessels were closed in a CO2 atmosphere, then transferred into an oven at a temperature of 150 C. After a predetermined time, the hydrothermal vessels were removed from the oven and quenched in a freezer. Supernatant solutions were decanted, and carbonate precipitates were washed free of soluble salts by repeated decantations with deionized water
IgG N-glycans are associated with prevalent and incident complications of type 2 diabetes
Aims/Hypothesis:Inflammation is important in the development of type 2 diabetes complications. The N-glycosylation of IgG influences its role in inflammation. To date, the association of plasma IgG N-glycosylation with type 2 diabetes complications has not been extensively investigated. We hypothesised that N-glycosylation of IgG may be related to the development of complications of type 2 diabetes. Methods: In three independent type 2 diabetes cohorts, plasma IgG N-glycosylation was measured using ultra performance liquid chromatography (DiaGene n = 1815, GenodiabMar n = 640) and mass spectrometry (Hoorn Diabetes Care Study n = 1266). We investigated the associations of IgG N-glycosylation (fucosylation, galactosylation, sialylation and bisection) with incident and prevalent nephropathy, retinopathy and macrovascular disease using Cox- and logistic regression, followed by meta-analyses. The models were adjusted for age and sex and additionally for clinical risk factors. Results: IgG galactosylation was negatively associated with prevalent and incident nephropathy and macrovascular disease after adjustment for clinical risk factors. Sialylation was negatively associated with incident diabetic nephropathy after adjustment for clinical risk factors. For incident retinopathy, similar associations were found for galactosylation, adjusted for age and sex. Conclusions: We showed that IgG N-glycosylation, particularly galactosylation and to a lesser extent sialylation, is associated with a higher prevalence and future development of macro- and microvascular complications of diabetes. These findings indicate the predictive potential of IgG N-glycosylation in diabetes complications and should be analysed further in additional large cohorts to obtain the power to solidify these conclusions.</p
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SEeking AnsweRs for Care Homes during the COVID-19 pandemic (COVID SEARCH)
The care and support of older people residing in long-term care facilities during the COVID-19 pandemic has created new and unanticipated uncertainties for staff. In this short report, we present our analyses of the uncertainties of care home managers and staff expressed in a self-formed closed WhatsAppTM discussion group during the first stages of the pandemic in the UK. We categorised their wide-ranging questions to understand what information would address these uncertainties and provide support. We have been able to demonstrate that almost one-third of these uncertainties could have been tackled immediately through timely, responsive and unambiguous fact-based guidance. The other uncertainties require appraisal, synthesis and summary of existing evidence, commissioning or provision of a sector- informed research agenda for the medium- to longer-term. The questions represent wider internationally relevant care home pandemic related uncertainties
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