601 research outputs found
Resuscitating the Dying Autopsy
Summary points Despite the relevant information that postmortem examinations can provide, autopsy rates have been declining worldwide in the last few decades. Autopsies are especially necessary in low-income countries, where reliable information on cause of death is much more limited and in vivo clinical diagnosis is hampered by the scarce availability of diagnostic tools. The use of the autopsy or of robust substitutes for this procedure needs to be encouraged as a mechanism for the continuous improvement of clinical diagnosis and as a complement for cause-of-death investigation and surveillance
Cohomology Groups of Deformations of Line Bundles on Complex Tori
The cohomology groups of line bundles over complex tori (or abelian
varieties) are classically studied invariants of these spaces. In this article,
we compute the cohomology groups of line bundles over various holomorphic,
non-commutative deformations of complex tori. Our analysis interpolates between
two extreme cases. The first case is a calculation of the space of
(cohomological) theta functions for line bundles over constant, commutative
deformations. The second case is a calculation of the cohomologies of
non-commutative deformations of degree-zero line bundles.Comment: 24 pages, exposition improved, typos fixe
A sigma model field theoretic realization of Hitchin's generalized complex geometry
We present a sigma model field theoretic realization of Hitchin's generalized
complex geometry, which recently has been shown to be relevant in
compactifications of superstring theory with fluxes. Hitchin sigma model is
closely related to the well known Poisson sigma model, of which it has the same
field content. The construction shows a remarkable correspondence between the
(twisted) integrability conditions of generalized almost complex structures and
the restrictions on target space geometry implied by the Batalin--Vilkovisky
classical master equation. Further, the (twisted) classical Batalin--Vilkovisky
cohomology is related non trivially to a generalized Dolbeault cohomology.Comment: 28 pages, Plain TeX, no figures, requires AMS font files AMSSYM.DEF
and amssym.tex. Typos in eq. 6.19 and some spelling correcte
Energy-Sensitive and "Classical-like" Distances Between Quantum States
We introduce the concept of the ``polarized'' distance, which distinguishes
the orthogonal states with different energies. We also give new inequalities
for the known Hilbert-Schmidt distance between neighbouring states and express
this distance in terms of the quasiprobability distributions and the normally
ordered moments. Besides, we discuss the distance problem in the framework of
the recently proposed ``classical-like'' formulation of quantum mechanics,
based on the symplectic tomography scheme. The examples of the Fock, coherent,
``Schroedinger cats,'' squeezed, phase, and thermal states are considered.Comment: 23 pages, LaTex, 2 eps figures, to appear in Physica Script
Calibrated cycles and T-duality
For Hitchin's generalised geometries we introduce and analyse the concept of
a structured submanifold which encapsulates the classical notion of a
calibrated submanifold. Under a suitable integrability condition on the ambient
geometry, these generalised calibrated cycles minimise a functional occurring
as D-brane energy in type II string theories, involving both so-called NS-NS-
and R-R-fields. Further, we investigate the behaviour of calibrated cycles
under T-duality and construct non-trivial examples.Comment: 43 pages. v4: formalism and T-duality part considerably expande
Epidemiology and clinical presentation of community-acquired Staphylococcus aureus bacteraemia in children under 5 years of age admitted to the Manhica District Hospital, Mozambique, 2001-2019
Staphylococcus aureus bacteraemia (SAB) is one of the most common bloodstream infections globally. Data on the burden and epidemiology of community-acquired SAB in low-income countries are scarce but needed to defne preventive and management strategies. Blood samples were collected from children<5 years of age with fever or severe disease admitted to the Manhiça District Hospital for bacterial isolation, including S. aureus. Between 2001 and 2019, 7.6% (3,197/41,891) of children had bacteraemia, of which 12.3% corresponded to SAB. The overall incidence of SAB was 56.1 episodes/100,000 children-years at risk (CYAR), being highest among neonates (589.8 episodes/100,000 CYAR). SAB declined signifcantly between 2001 and 2019 (322.1 to 12.5 episodes/100,000 CYAR). In-hospital mortality by SAB was 9.3% (31/332), and signifcantly associated with infections by multidrugresistant (MDR) strains (14.7%, 11/75 vs. 6.9%, 14/204 among non-MDR, p=0.043) and methicillin-resistant S. aureus (33.3%, 5/15 vs. 7.6%, 20/264 among methicillin-susceptible S. aureus, p=0.006). Despite the declining rates of SAB, this disease remains an important cause of death among children admitted to MDH, possibly in relation to the resistance to the frst line of empirical treatment in use in our setting, suggesting an urgent need to review current policy recommendationspublishersversionpublishe
Healthcare providers’ views and perceptions on post-mortem procedures for cause of death determination in Southern Mozambique
Background: The minimally invasive autopsy (MIA) is being investigated as an alternative to the complete diagnostic autopsy (CDA), gold standard for CoD determination, in settings where CDA is unfeasible and/or unacceptable. We aimed to explore healthcare providers’ views and perceptions on theoretical and factual acceptability of the CDA and the MIA.
Methods: A qualitative study, combining ethnographic and grounded-theory approaches, was conducted within a project aiming to validate the MIA tool against the CDA for CoD investigation. We present data on in-depth and semi-structured interviews of 33 healthcare providers operating within the formal and informal health services in Southern Mozambique. MIA perception was analysed through the theory of diffusion of innovations.
Results: All participants considered CDA useful for CoD determination. CDA was perceived reliable, but the unpleasant nature of the procedure and its associated infection risk were the main perceived disadvantages. Participants considered the MIA simple, easy and quick to perform; likely to meet families’ expectations to know the CoD, and able to provide evidence-based knowledge for disease management. Concerns were raised on its reliability compared to the CDA. Family's emotional status and accessibility to decision-makers were mentioned as principal barriers for MIA performance. The main jeopardizing factors for MIA implementation were the shortage of required resources and the significant proportion of people dying at home. Key facilitators for MIA acceptance included the need for the support from community and religious leaders, provision of clear information to the community, and accompaniment to bereaved families. Conclusions:
Healthcare providers consider the MIAs potentially more acceptable and feasible than CDAs in places where the latter have shown significant implementation challenges. A clear understanding of healthcare provider’s perceived barriers and facilitators for conducting post-mortem procedures in general, and MIAs in particular, will shed light on their future field implementation for more robust mortality surveillance
Mirror duality and noncommutative tori
In this paper, we study a mirror duality on a generalized complex torus and a
noncommutative complex torus. First, we derive a symplectic version of Riemann
condition using mirror duality on ordinary complex tori. Based on this we will
find a mirror correspondence on generalized complex tori and generalize the
mirror duality on complex tori to the case of noncommutative complex tori.Comment: 22pages, no figure
Precisely tracking childhood death
Little is known about the specific causes of neonatal and
under-five childhood death in high-mortality geographic regions
due to a lack of primary data and dependence on inaccurate
tools, such as verbal autopsy. To meet the ambitious new
Sustainable Development Goal 3.2 to eliminate preventable child
mortality in every country, better approaches are needed to
precisely determine specific causes of death so that prevention
and treatment interventions can be strengthened and focused.
Minimally invasive tissue sampling (MITS) is a technique that
uses needle-based postmortem sampling, followed by advanced
histopathology and microbiology to definitely determine cause of
death. The Bill & Melinda Gates Foundation is supporting a
new surveillance system called the Child Health and Mortality
Prevention Surveillance network, which will determine cause of
death using MITS in combination with other information, and
yield cause-specific population-based mortality rates,
eventually in up to 12-15 sites in sub-Saharan Africa and south
Asia. However, the Gates Foundation funding alone is not enough.
We call on governments, other funders, and international
stakeholders to expand the use of pathology-based cause of death
determination to provide the information needed to end
preventable childhood mortality
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