121 research outputs found
Conformal proper times according to the Woodhouse causal axiomatics of relativistic spacetimes
On the basis of the Woodhouse causal axiomatics, we show that conformal
proper times and an extra variable in addition to those of space and time,
precisely and physically identified from experimental examples, together give a
physical justification for the `chronometric hypothesis' of general relativity.
Indeed, we show that, with a lack of these latter two ingredients, no clock
paradox solution exists in which the clock and message functions are solely at
the origin of the asymmetry. These proper times originate from a given
conformal structure of the spacetime when ascribing different compatible
projective structures to each Woodhouse particle, and then, each defines a
specific Weylian sheaf structure. In addition, the proper time
parameterizations, as two point functions, cannot be defined irrespective of
the processes in the relative changes of physical characteristics. These
processes are included via path-dependent conformal scale factors, which act
like sockets for any kind of physical interaction and also represent the values
of the variable associated with the extra dimension. As such, the differential
aging differs far beyond the first and second clock effects in Weyl geometries,
with the latter finally appearing to not be suitable.Comment: 25 pages, 2 figure
Abel-Jacobi maps for hypersurfaces and non commutative Calabi-Yau's
It is well known that the Fano scheme of lines on a cubic 4-fold is a
symplectic variety. We generalize this fact by constructing a closed p-form
with p=2n-4 on the Fano scheme of lines on a (2n-2)-dimensional hypersurface Y
of degree n. We provide several definitions of this form - via the Abel-Jacobi
map, via Hochschild homology, and via the linkage class, and compute it
explicitly for n = 4. In the special case of a Pfaffian hypersurface Y we show
that the Fano scheme is birational to a certain moduli space of sheaves on a
p-dimensional Calabi--Yau variety X arising naturally in the context of
homological projective duality, and that the constructed form is induced by the
holomorphic volume form on X. This remains true for a general non Pfaffian
hypersurface but the dual Calabi-Yau becomes non commutative.Comment: 34 pages; exposition of Hochschild homology expanded; references
added; introduction re-written; some imrecisions, typos and the orbit diagram
in the last section correcte
The ethical desirability of moral bioenhancement: A review of reasons
Background: The debate on the ethical aspects of moral bioenhancement focuses on the desirability of using biomedical as opposed to traditional means to achieve moral betterment. The aim of this paper is to systematically review the ethical reasons presented in the literature for and against moral bioenhancement. Discussion: A review was performed and resulted in the inclusion of 85 articles. We classified the arguments used in those articles in the following six clusters: (1) why we (don't) need moral bioenhancement, (2) it will (not) be possible to reach consensus on what moral bioenhancement should involve, (3) the feasibility of moral bioenhancement and the status of current scientific research, (4) means and processes of arriving at moral improvement matter ethically, (5) arguments related to the freedom, identity and autonomy of the individual, and (6) arguments related to social/group effects and dynamics. We discuss each argument separately, and assess the debate as a whole. First, there is little discussion on what distinguishes moral bioenhancement from treatment of pathological deficiencies in morality. Furthermore, remarkably little attention has been paid so far to the safety, risks and side-effects of moral enhancement, including the risk of identity changes. Finally, many authors overestimate the scientific as well as the practical feasibility of the interventions they discuss, rendering the debate too speculative. Summary: Based on our discussion of the arguments used in the debate on moral enhancement, and our assessment of this debate, we advocate a shift in focus. Instead of speculating about non-realistic hypothetical scenarios such as the genetic engineering of morality, or morally enhancing 'the whole of humanity', we call for a more focused debate on realistic options of biomedical treatment of moral pathologies and the concrete moral questions these treatments raise
Model Theory for Sheaves of Modules
We describe how the model theory of modules is adapted to deal with sheaves of modules
Changes in Patterns of Referral for Inpatient Rehabilitation Cancer Patients Due to COVID-19: A Retrospective Study
There is a paucity of literature on the effect of COVID-19 on hospital processes. We hypothesized that COVID-19 was associated with decreased cancer physiatry referrals in 2020. This is a retrospective cohort study of consecutive patients from April to July 2019 and 2020 admitted at an academic quaternary cancer center. The main outcomes were number of hospital admissions, rate, and characteristics of inpatient rehabilitation admissions and change in percentage of physiatry referrals as the primary endpoint. Results showed that in 2019, there were 387 referrals from 10,274 inpatient admissions (3.8%; 95% confidence interval, 2.4-4.2), compared with 337 referrals from 7051 admissions in 2020 (4.8%; 95% confidence interval, 4.3-5.3, P = 0.001). Hematology services referred more patients than neurosurgery in 2020 (20.4% vs. 31.4%; 48.2% vs. 26.5%, P = 0.01). Discharge disposition reflected an increased frequency of return to acute care service in 2020 (10.2% vs. 21.8%, P = 0.03). In conclusion, there was an increase in the rate of physiatry referrals despite a decrease in hospital admissions. There was an increase in referrals by hematology, likely due to emphasis on safe discharge and the populations hospitalized
Motivating Persons with Schizophrenia to Exercise: Rationale and Design
Persons with schizophrenia spectrum disorders (SSDs) are not only at risk because of disabling disease symptoms but because necessary medications create health risks associated with high rates of obesity. Despite the well-known benefits of exercise, persons with SSDs rarely adhere to such regimens; few interventions to motivate exercise behavior have been tested in this group.
The purpose of this study is to examine effects of the Walk, Address sensations, Learn about exercise, Cue exercise behavior for persons with SSDs (WALC-S) motivational intervention upon exercise behavior. We will recruit a total of eighty outpatients 18–68 years, meeting these criteria: 1) chart diagnosis of schizophrenia, any subtype, schizoaffective disorder or schizophreniform disorder, according to the criteria described in the Diagnostic and Statistical Manual for Mental Disorders, 2) English speaking, 3) Stable medication regimen (defined as no medication changes within the last month), and 4) medical clearance for moderate exercise in writing from primary care provider. Participants will be randomly assigned to the experimental (4-week WALC-S motivational intervention), or the control group (4-week time and attention control). After the first 4 weeks, all participants will attend a 16-week walking group.
The primary measures of the effectiveness of the WALC-S are attendance, persistence and compliance to the 16-week walking group. The study will be completed in approximately January 2010. In addition to hypothesis testing, this study will provide information to estimate effect sizes to calculate power and determine appropriate sample sizes for future inquiries. This paper describes the rationale and design of the study
Health care's response to climate change: a carbon footprint assessment of the NHS in England
Background: Climate change threatens to undermine the past 50 years of gains in public health. In response, the National Health Service (NHS) in England has been working since 2008 to quantify and reduce its carbon footprint. This Article presents the latest update to its greenhouse gas accounting, identifying interventions for mitigation efforts and describing an approach applicable to other health systems across the world. Methods: A hybrid model was used to quantify emissions within Scopes 1, 2, and 3 of the Greenhouse Gas Protocol, as well as patient and visitor travel emissions, from 1990 to 2019. This approach complements the broad coverage of top-down economic modelling with the high accuracy of bottom-up data wherever available. Available data were backcasted or forecasted to cover all years. To enable the identification of measures to reduce carbon emissions, results were disaggregated by organisation type. Findings: In 2019, the health service's emissions totalled 25 megatonnes of carbon dioxide equivalent, a reduction of 26% since 1990, and a decrease of 64% in the emissions per inpatient finished admission episode. Of the 2019 footprint, 62% came from the supply chain, 24% from the direct delivery of care, 10% from staff commute and patient and visitor travel, and 4% from private health and care services commissioned by the NHS. Interpretation: This work represents the longest and most comprehensive accounting of national health-care emissions globally, and underscores the importance of incorporating bottom-up data to improve the accuracy of top-down modelling and enabling detailed monitoring of progress as health systems act to reduce emissions. Funding: Wellcome Trust
Massive expansion of SCA2 with autonomic dysfunction, retinitis pigmentosa, and infantile spasms
OBJECTIVE: To provide clinical data on a cohort of 6 patients with massive expansion (>200 CAG repeats) of spinocerebellar ataxia type 2 (SCA2) and investigate possible pathways of pathogenesis using bioinformatics analysis of ATXN2 networks.
METHODS: We present data on 6 patients with massive expansion of SCA2 who presented in infancy with variable combinations of hypotonia, global developmental delay, infantile spasms, and retinitis pigmentosa. ATXN2 is known to interact with a network of synaptic proteins. To investigate pathways of pathogenesis, we performed bioinformatics analysis on ATXN2 combined with known genes associated with infantile spasms, retinitis pigmentosa, and synaptic function.
RESULTS: All patients had a progressive encephalopathy with autonomic dysfunction, 4 had retinitis pigmentosa, and 3 had infantile spasms. The bioinformatics analysis led to several interesting findings. First, an interaction between ATXN2 and SYNJ1 may account for the development of retinitis pigmentosa. Second, dysfunction of postsynaptic vesicle endocytosis may be important in children with this progressive encephalopathy. Infantile spasms may be associated with interactions between ATXN2 and the postsynaptic structural proteins MAGI2 and SPTAN1.
CONCLUSIONS: Severe phenotype in children with massive expansion of SCA2 may be due to a functional deficit in protein networks in the postsynapse, specifically involving vesicle endocytosis
Health care's response to climate change: a carbon footprint assessment of the NHS in England
Background
Climate change threatens to undermine the past 50 years of gains in public health. In response, the National Health Service (NHS) in England has been working since 2008 to quantify and reduce its carbon footprint. This Article presents the latest update to its greenhouse gas accounting, identifying interventions for mitigation efforts and describing an approach applicable to other health systems across the world.
Methods
A hybrid model was used to quantify emissions within Scopes 1, 2, and 3 of the Greenhouse Gas Protocol, as well as patient and visitor travel emissions, from 1990 to 2019. This approach complements the broad coverage of top-down economic modelling with the high accuracy of bottom-up data wherever available. Available data were backcasted or forecasted to cover all years. To enable the identification of measures to reduce carbon emissions, results were disaggregated by organisation type.
Findings
In 2019, the health service's emissions totalled 25 megatonnes of carbon dioxide equivalent, a reduction of 26% since 1990, and a decrease of 64% in the emissions per inpatient finished admission episode. Of the 2019 footprint, 62% came from the supply chain, 24% from the direct delivery of care, 10% from staff commute and patient and visitor travel, and 4% from private health and care services commissioned by the NHS.
Interpretation
This work represents the longest and most comprehensive accounting of national health-care emissions globally, and underscores the importance of incorporating bottom-up data to improve the accuracy of top-down modelling and enabling detailed monitoring of progress as health systems act to reduce emissions.
Funding
Wellcome Trust
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