750 research outputs found
Early and Late Complications Associated with Busulfan, Cyclophosphamide, and Etoposide (Bu/Cy/VP-16) Conditioning Followed by Allogeneic or Autologous Stem Cell Transplantation in Relapsed/Refractory Non-Hodgkin'S Lymphoma
Infinitesimal and local convexity of a hypersurface in a semi-Riemannian manifold
Given a Riemannian manifold M and a hypersurface H in M, it is well known
that infinitesimal convexity on a neighborhood of a point in H implies local
convexity. We show in this note that the same result holds in a semi-Riemannian
manifold. We make some remarks for the case when only timelike, null or
spacelike geodesics are involved. The notion of geometric convexity is also
reviewed and some applications to geodesic connectedness of an open subset of a
Lorentzian manifold are given.Comment: 14 pages, AMSLaTex, 2 figures. v2: typos fixed, added one reference
and several comments, statement of last proposition correcte
Closing the UK care home data gap - methodological challenges and solutions
UK care home residents are invisible in national datasets. The COVID-19 pandemic has exposed data failings that have hindered service development and research for years. Fundamental gaps, in terms of population and service demographics coupled with difficulties identifying the population in routine data are a significant limitation. These challenges are a key factor underpinning the failure to provide timely and responsive policy decisions to support care homes.
In this commentary we propose changes that could address this data gap, priorities include: (1) Reliable identification of care home residents and their tenure; (2) Common identifiers to facilitate linkage between data sources from different sectors; (3) Individual-level, anonymised data inclusive of mortality irrespective of where death occurs; (4) Investment in capacity for large-scale, anonymised linked data analysis within social care working in partnership with academics; (5) Recognition of the need for collaborative working to use novel data sources, working to understand their meaning and ensure correct interpretation; (6) Better integration of information governance, enabling safe access for legitimate analyses from all relevant sectors; (7) A core national dataset for care homes developed in collaboration with key stakeholders to support integrated care delivery, service planning, commissioning, policy and research.
Our suggestions are immediately actionable with political will and investment. We should seize this opportunity to capitalise on the spotlight the pandemic has thrown on the vulnerable populations living in care homes to invest in data-informed approaches to support care, evidence-based policy making and research
Experimental characterization of a graded-index ring-core fiber supporting 7 LP mode groups
We design and characterize a graded-index-ring-core fiber supporting 7 LP modegroups (13 spatial modes) for mode multiplexed transmission with low MIMO processing complexity. Spatial and temporal modal properties are analyzed using an SLM-based mode multiplexer/demultiplexer
New Parton Distribution Functions for the Photon
We present new improved parton distributions for the photon. We fit {\bf all}
available data on the photon structure function, , with
GeV, in order to determine the quark distributions. We also pay
particular attention to the gluon distribution in the photon,
, which has been poorly constrained in earlier analyses
which only include structure function data. We use large jet production
in collisions from TRISTAN to constrain . We also
see what information can be gleaned from collisions at HERA on
and on the quark distributions at large , where there are no
structure function data. We review future prospects of elucidating the parton
distributions of the photon.Comment: 33 pages, 8 figures, uses eps
How does the electromagnetic field couple to gravity, in particular to metric, nonmetricity, torsion, and curvature?
The coupling of the electromagnetic field to gravity is an age-old problem.
Presently, there is a resurgence of interest in it, mainly for two reasons: (i)
Experimental investigations are under way with ever increasing precision, be it
in the laboratory or by observing outer space. (ii) One desires to test out
alternatives to Einstein's gravitational theory, in particular those of a
gauge-theoretical nature, like Einstein-Cartan theory or metric-affine gravity.
A clean discussion requires a reflection on the foundations of electrodynamics.
If one bases electrodynamics on the conservation laws of electric charge and
magnetic flux, one finds Maxwell's equations expressed in terms of the
excitation H=(D,H) and the field strength F=(E,B) without any intervention of
the metric or the linear connection of spacetime. In other words, there is
still no coupling to gravity. Only the constitutive law H= functional(F)
mediates such a coupling. We discuss the different ways of how metric,
nonmetricity, torsion, and curvature can come into play here. Along the way, we
touch on non-local laws (Mashhoon), non-linear ones (Born-Infeld,
Heisenberg-Euler, Plebanski), linear ones, including the Abelian axion (Ni),
and find a method for deriving the metric from linear electrodynamics (Toupin,
Schoenberg). Finally, we discuss possible non-minimal coupling schemes.Comment: Latex2e, 26 pages. Contribution to "Testing Relativistic Gravity in
Space: Gyroscopes, Clocks, Interferometers ...", Proceedings of the 220th
Heraeus-Seminar, 22 - 27 August 1999 in Bad Honnef, C. Laemmerzahl et al.
(eds.). Springer, Berlin (2000) to be published (Revised version uses
Springer Latex macros; Sec. 6 substantially rewritten; appendices removed;
the list of references updated
The superstring Hagedorn temperature in a pp-wave background
The thermodynamics of type IIB superstring theory in the maximally
supersymmetric plane wave background is studied. We compute the thermodynamic
partition function for non-interacting strings exactly and the result differs
slightly from previous computations. We clarify some of the issues related to
the Hagedorn temperature in the limits of small and large constant RR 5-form.
We study the thermodynamic behavior of strings in the case of geometries in the presence of NS-NS and RR 3-form backgrounds. We
also comment on the relationship of string thermodynamics and the thermodynamic
behavior of the sector of Yang-Mills theory which is the holographic dual of
the string theory.Comment: 22 pages, JHEP style, minor misprints corrected, some comments adde
Uncovering precision phenotype-biomarker associations in traumatic brain injury using topological data analysis
Background: Traumatic brain injury (TBI) is a complex disorder that is traditionally stratified based on clinical signs and symptoms. Recent imaging and molecular biomarker innovations provide unprecedented opportunities for improved TBI precision medicine, incorporating patho-anatomical and molecular mechanisms. Complete integration of these diverse data for TBI diagnosis and patient stratification remains an unmet challenge.
Methods and findings: The Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Pilot multicenter study enrolled 586 acute TBI patients and collected diverse common data elements (TBI-CDEs) across the study population, including imaging, genetics, and clinical outcomes. We then applied topology-based data-driven discovery to identify natural subgroups of patients, based on the TBI-CDEs collected. Our hypothesis was two-fold: 1) A machine learning tool known as topological data analysis (TDA) would reveal data-driven patterns in patient outcomes to identify candidate biomarkers of recovery, and 2) TDA-identified biomarkers would significantly predict patient outcome recovery after TBI using more traditional methods of univariate statistical tests. TDA algorithms organized and mapped the data of TBI patients in multidimensional space, identifying a subset of mild TBI patients with a specific multivariate phenotype associated with unfavorable outcome at 3 and 6 months after injury. Further analyses revealed that this patient subset had high rates of post-traumatic stress disorder (PTSD), and enrichment in several distinct genetic polymorphisms associated with cellular responses to stress and DNA damage (PARP1), and in striatal dopamine processing (ANKK1, COMT, DRD2).
Conclusions: TDA identified a unique diagnostic subgroup of patients with unfavorable outcome after mild TBI that were significantly predicted by the presence of specific genetic polymorphisms. Machine learning methods such as TDA may provide a robust method for patient stratification and treatment planning targeting identified biomarkers in future clinical trials in TBI patients
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