539 research outputs found
Symmetries,Singularities and the De-Emergence of Space
Recent work has revealed intriguing connections between a
Belinsky-Khalatnikov-Lifshitz-type analysis of spacelike singularities in
General Relativity and certain infinite dimensional Lie algebras, and in
particular the `maximally extended' hyperbolic Kac--Moody algebra E10. In this
essay we argue that these results may lead to an entirely new understanding of
the (quantum) nature of space(-time) at the Planck scale, and hence -- via an
effective `de-emergence' of space near a singularity -- to a novel mechanism
for achieving background independence in quantum gravity.Comment: 10 page
Mind the Relationship: A Multi-Layered Ethical Framework for Citizen Science in Health
There is a heated debate about what citizen science is and is not. We argue that instead of aiming at a definition of citizen science, we should reflect upon its ethical starting points. Based on our practical experiences with citizen science initiatives, we come up with an ethical framework that consists of two core values (respect and justice), five ethical desiderata (relationship between equals; recognition of each other's capacities, knowledge, and agency; reciprocity; openness for different goals; and openness for different research methods and paradigms) and two fundamental qualities (symmetry and transparency). The desiderata reflect ethically problematic practices, such as the use of citizens by academic scientists as mere sensors, and biases in the existing literature, such as labelling the projects that are initiated and led by citizens as “extreme”. The desiderata are supported by two ethical theories: care ethics and the capabilities approach. The aim of our ethical framework is to stimulate and facilitate reflection upon what needs to be considered when co-creating or assessing a citizen science initiative. Fundamentally, citizen science ought to be a humanizing endeavour unlocking the investigative capacities of humans. The ethical framework is meant to help reflect on this endeavour.</p
A Multicenter Screening Study
Background In cystic fibrosis, highly variable glucose tolerance is suspected.
However, no study provided within-patient coefficients of variation. The main
objective of this short report was to evaluate within-patient variability of
oral glucose tolerance. Methods In total, 4,643 standardized oral glucose
tolerance tests of 1,128 cystic fibrosis patients (median age at first test:
15.5 [11.5; 21.5] years, 48.8% females) were studied. Patients included were
clinically stable, non-pregnant, and had at least two oral glucose tolerance
tests, with no prior lung transplantation or systemic steroid therapy.
Transition frequency from any one test to the subsequent test was analyzed and
within-patient coefficients of variation were calculated for fasting and two
hour blood glucose values. All statistical analysis was implemented with SAS
9.4. Results A diabetic glucose tolerance was confirmed in 41.2% by the
subsequent test. A regression to normal glucose tolerance at the subsequent
test was observed in 21.7% and to impaired fasting glucose, impaired glucose
tolerance or both in 15.2%, 12.0% or 9.9%. The average within-patient
coefficient of variation for fasting blood glucose was 11.1% and for two hour
blood glucose 25.3%. Conclusion In the cystic fibrosis patients studied, a
highly variable glucose tolerance was observed. Compared to the general
population, variability of two hour blood glucose was 1.5 to 1.8-fold higher
Mind the Relationship: A Multi-Layered Ethical Framework for Citizen Science in Health
There is a heated debate about what citizen science is and is not. We argue that instead of aiming at a definition of citizen science, we should reflect upon its ethical starting points. Based on our practical experiences with citizen science initiatives, we come up with an ethical framework that consists of two core values (respect and justice), five ethical desiderata (relationship between equals; recognition of each other's capacities, knowledge, and agency; reciprocity; openness for different goals; and openness for different research methods and paradigms) and two fundamental qualities (symmetry and transparency). The desiderata reflect ethically problematic practices, such as the use of citizens by academic scientists as mere sensors, and biases in the existing literature, such as labelling the projects that are initiated and led by citizens as “extreme”. The desiderata are supported by two ethical theories: care ethics and the capabilities approach. The aim of our ethical framework is to stimulate and facilitate reflection upon what needs to be considered when co-creating or assessing a citizen science initiative. Fundamentally, citizen science ought to be a humanizing endeavour unlocking the investigative capacities of humans. The ethical framework is meant to help reflect on this endeavour
E10 and SO(9,9) invariant supergravity
We show that (massive) D=10 type IIA supergravity possesses a hidden rigid
SO(9,9) symmetry and a hidden local SO(9) x SO(9) symmetry upon dimensional
reduction to one (time-like) dimension. We explicitly construct the associated
locally supersymmetric Lagrangian in one dimension, and show that its bosonic
sector, including the mass term, can be equivalently described by a truncation
of an E10/K(E10) non-linear sigma-model to the level \ell<=2 sector in a
decomposition of E10 under its so(9,9) subalgebra. This decomposition is
presented up to level 10, and the even and odd level sectors are identified
tentatively with the Neveu--Schwarz and Ramond sectors, respectively. Further
truncation to the level \ell=0 sector yields a model related to the reduction
of D=10 type I supergravity. The hyperbolic Kac--Moody algebra DE10, associated
to the latter, is shown to be a proper subalgebra of E10, in accord with the
embedding of type I into type IIA supergravity. The corresponding decomposition
of DE10 under so(9,9) is presented up to level 5.Comment: 1+39 pages LaTeX2e, 2 figures, 2 tables, extended tables obtainable
by downloading sourc
Neurology
Contains reports on five research projects.United States Navy, Office of Naval Research (Nonr-609(39))United States Public Health Service (B-3055, B-3090)Unites States Air Force (Contract AF33(616)-7282)Unites States Air Force (Contract AF-33(616)-7588, Project: 61(8-7232); Task 71784))United States Army Chemical Corps (DA-18-108-405-Cml-942
Gradient Representations and Affine Structures in AE(n)
We study the indefinite Kac-Moody algebras AE(n), arising in the reduction of
Einstein's theory from (n+1) space-time dimensions to one (time) dimension, and
their distinguished maximal regular subalgebras sl(n) and affine A_{n-2}^{(1)}.
The interplay between these two subalgebras is used, for n=3, to determine the
commutation relations of the `gradient generators' within AE(3). The low level
truncation of the geodesic sigma-model over the coset space AE(n)/K(AE(n)) is
shown to map to a suitably truncated version of the SL(n)/SO(n) non-linear
sigma-model resulting from the reduction Einstein's equations in (n+1)
dimensions to (1+1) dimensions. A further truncation to diagonal solutions can
be exploited to define a one-to-one correspondence between such solutions, and
null geodesic trajectories on the infinite-dimensional coset space H/K(H),
where H is the (extended) Heisenberg group, and K(H) its maximal compact
subgroup. We clarify the relation between H and the corresponding subgroup of
the Geroch group.Comment: 43 page
Neurology
Contains reports on six research projects.Public Health Service (B-3055, B-3090)United States Air Force (AF33(616)-7282, AF49(638)-1130)United States Navy, Office of Naval Research (Nonr-609(39))United States Army Chemical Corps (DA-18-108-405-Cml-942)National Science Foundation (Grant G-16526
- …