2,171 research outputs found
Friedmann limits of rotating hypersurface-homogeneous dust models
The existence of Friedmann limits is systematically investigated for all the
hypersurface-homogeneous rotating dust models, presented in previous papers by
this author. Limiting transitions that involve a change of the Bianchi type are
included. Except for stationary models that obviously do not allow it, the
Friedmann limit expected for a given Bianchi type exists in all cases. Each of
the 3 Friedmann models has parents in the rotating class; the k = +1 model has
just one parent class, the other two each have several parent classes. The type
IX class is the one investigated in 1951 by Goedel. For each model, the
consecutive limits of zero rotation, zero tilt, zero shear and spatial isotropy
are explicitly calculated.Comment: 39 pages, LaTeX, 1 postscript figure. Subjects: General relativity,
exact solutions, cosmolog
Treatment and secondary prevention of venous thromboembolism in cancer
Patients with cancer who develop venous thromboembolism (VTE) are at elevated
risk for recurrent thrombotic events, even during anticoagulant therapy. The
clinical picture is further complicated because these patients are also at
increased risk of bleeding while on anticoagulants. In general, there are four
key goals of treatment for VTE: preventing fatal pulmonary embolism (PE);
reducing short-term morbidities associated with acute leg or lung thrombus;
preventing recurrent VTE; and preventing the long-term sequelae of VTE (e.g.,
post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension). A
fifth goal – minimising the risk for bleeding while on anticoagulation
– is particularly warranted in patients with cancer. Traditionally,
pharmacological treatment of VTE has two phases, with the transition between
phases marked by a switch from a rapid-acting, parenterally administered
anticoagulant (such as unfractionated heparin (UFH), low-molecular-weight
heparin (LMWH), or fondaparinux) to an oral vitamin K antagonist (e.g.,
warfarin). Recent clinical trials of established agents and the advent of new
pharmacological options are changing this paradigm. Low-molecular-weight heparin
continued for 6 months is more effective than warfarin in the secondary
prevention of VTE in cancer patients without increasing the risk of bleeding and
is now the preferred treatment option. Given the impact of VTE on short-term and
long-term outcomes in patients with cancer, a group of health-care providers
based in the United Kingdom gathered in London in 2009 to discuss recent data on
cancer-associated thrombosis and to evaluate how these recommendations can be
integrated or translated into UK clinical practice. This article, which is the
third of four articles covering key topics in cancer thrombosis, focuses on
treatment and secondary prevention of VTE in cancer patients
Dvali-Gabadadze-Porrati Cosmology in Bianchi I brane
The dynamics of Dvali-Gabadadze-Porrati Cosmology (DGP) braneworld with an
anisotropic brane is studied. The Friedmann equations and their solutions are
obtained for two branches of anisotropic DGP model. The late time behavior in
DGP cosmology is examined in the presence of anisotropy which shows that
universe enters a self-accelerating phase much later compared to the isotropic
case. The acceleration conditions and slow-roll conditions for inflation are
obtained
Early-expressed chemokines predict kidney immunopathology in experimental disseminated Candida albicans infections
Available under the Creative Commons Attribution License (CCAL)Peer reviewedPublisher PD
Cosmology, cohomology, and compactification
Ashtekar and Samuel have shown that Bianchi cosmological models with compact
spatial sections must be of Bianchi class A. Motivated by general results on
the symmetry reduction of variational principles, we show how to extend the
Ashtekar-Samuel results to the setting of weakly locally homogeneous spaces as
defined, e.g., by Singer and Thurston. In particular, it is shown that any
m-dimensional homogeneous space G/K admitting a G-invariant volume form will
allow a compact discrete quotient only if the Lie algebra cohomology of G
relative to K is non-vanishing at degree m.Comment: 6 pages, LaTe
British digital game studies
This paper provides a short and potted recent history of digital games research in Great Britain. We begin this story in 2001. Though a substantial amount of research and writing on digital games was taking in Britain since at least the 1980s, for us the turn of the new millennium makes a logical starting point for our recent history. This is because this was not only the year that Aarseth (2001) marked as 'year one' for 'computer game research', but it was also the year that the first major international conference on digital games took place in the UK (in Bristol), and the first time a major British government grant was awarded to undertake research on digital gaming. The paper then charts the significant role Britain played in hosting major early international gatherings of (now leading) games researchers, such as those in Bristol and also Manchester. As well as the important crop of early British authored (text)books that helped shape the direction of this new emerging discipline. What we then see is a significant growth in British digital games studies focused around a number of key events, research clusters, and publications, and the development of a particular framing of digital games within a wider social, cultural, and political context. It is this, we would suggest, which has given British digital game studies its particular flavour and also its important global role in pushing forward research, theory, and key debates
Stress-induced nuclear accumulation is dispensable for Hog1-dependent gene expression and virulence in a fungal pathogen
The authors thank E. Veal for intellectual input. This work was funded by the UK Biotechnology and Biological Research Council [J.Q. BB/K016393/1; A.J.P.B. BB/K017365/1], the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) [D.M.M. NC/N002482/1] and the Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology [097377]). D.M.M. and A.J.P.B. are also supported by the MRC Centre for Medical Mycology at the University of Aberdeen (MR/N006364/1).Peer reviewedPublisher PD
Riemann-Cartan Space-times of G\"odel Type
A class of Riemann-Cartan G\"odel-type space-times are examined in the light
of the equivalence problem techniques. The conditions for local space-time
homogeneity are derived, generalizing previous works on Riemannian G\"odel-type
space-times. The equivalence of Riemann-Cartan G\"odel-type space-times of this
class is studied. It is shown that they admit a five-dimensional group of
affine-isometries and are characterized by three essential parameters : identical triads () correspond to locally
equivalent manifolds. The algebraic types of the irreducible parts of the
curvature and torsion tensors are also presented.Comment: 24 pages, LaTeX fil
Automated measurement of coagulation and fibrinolytic activation markers: Outcomes in coronavirus disease 2019 (COVID-19) patients
BACKGROUND: Severe coronavirus disease 2019 (COVID‐19) is characterized by marked hypoxaemia and lung oedema, often accompanied by disordered blood coagulation and fibrinolytic systems, endothelial damage and intravascular fibrin deposition. PATIENTS/METHODS: We present a retrospective observational study of 104 patients admitted to hospital with COVID‐19. Plasma samples were collected within 72 h of admission. In addition to routine coagulation and haematology testing, soluble thrombomodulin (sTM), thrombin‐antithrombin (TAT), tissue plasminogen activator‐plasminogen activator inhibitor 1 complex (tPAI‐C) and plasmin‐α2 antiplasmin complex (PIC) were performed by automated chemiluminescent enzyme immunoassays. RESULTS: Significantly higher levels of D‐dimer, TAT, sTM and tPAI‐C were observed in non‐survivors compared to survivors. To confirm which parameters were independent risk factors for mortality, multiple logistic regression was performed on D‐dimer, TAT. sTM, tPAI‐C and PIC data. Only increasing sTM was significantly associated with mortality, with an odds ratio of 1.065 for each 1.0 TU/mL increment (95% CI 1.025–1.115). CONCLUSIONS: Of the haemostatic variables measured, sTM, which can be rapidly assayed, is the best independent predictor of mortality in patients hospitalized with COVID‐19, and this suggests that endothelial dysfunction plays an important role in disease progression
- …