187 research outputs found
Declared Maternal Death And The Linkage Between Health Information Systems
Objective: To describe the characteristics of maternal mortality according to the Mortality Information System in relation to the data corresponding to these records that are in other systems. Methods: This was a descriptive study using two information systems on vital data and another on the hospital system, for the 26 state capitals and the Federal District of Brazil, in 2002. Initially, the maternal mortality ratios were calculated and information on declared maternal deaths were obtained. From these data, the Mortality Information System was probabilistically linked with the Live Birth Information System and the Hospital Information System, using the "Reclink II" software, with a multiple-step blocking strategy. For paired records, the diagnoses and hospital procedures brought together by the best-known criteria for severe maternal morbidity were detailed. Results: A total of 339 maternal deaths were recorded in 2002. The official and adjusted maternal mortality ratios were, respectively, 46.4 and 64.9 (deaths per 100,000 live births). By correlating with data from the live birth system, 46.5% of the maternal deaths could be located; and from the hospital information, 55.2%. The most frequent admission diagnosis was infection (13.9%) and the most frequent procedure was intensive care unit admission (39.0%). Conclusions: There were low percentage linkages between the records from the three sources studied. However, the possible failures and/or impossibilities in the linkages indicated may separately or jointly explain these low percentages.412181189AbouZahr, C., Wardlaw, T., (2003) Maternal mortality in 2000: Estimates developed by WHO, , Unicef and UNFPA. Geneva: WHO;Camargo Jr, K.R., Coeli, C.M., Reclink: Aplicativo para o relacionamento de bases de dados, implementando o método probabilistic record linkage (2000) Cad Saúde Pública, 16 (2), pp. 439-447Cecatti, J.G., Faúndes, A., Surita, F.C.C., Maternal mortality in Campinas: Evolution, under-registration and avoidance (1999) São Paulo Med J, 117 (1), pp. 5-12Coeli, C.M., Camargo Jr, K.R., Avaliação de diferentes estratégias de blocagem no relacionamento probabilÃstico de registros (2002) Rev Bras Epidemiol, 5 (2), pp. 185-196Coeli, C.M., Costa, M.C.E., Almeida, L.M., Probabilistic linkage in household survey on hospital care usage (2003) Rev Saúde Pública, 37 (1), pp. 91-99Fleiss, J.L., (1981) Statistical methods for rates and proportions, , 2nd ed. New York: John Wiley and Sons;Jaro, M.A., Advances in record-linkage methodology as applied to matching the 1985 Census of Tampa, Florida (1989) J Am Stat Assoc, 84, pp. 414-420Laurenti, R., Mello-Jorge, M.H.P., Gotlieb, S.L.D., Reflexões sobre a mensuração da mortalidade materna (2000) Cad Saúde Pública, 16 (1), pp. 23-30Laurenti, R., Mello-Jorge, M.H.P., Gotlieb, S.L.D., A mortalidade materna nas capitais brasileiras: Algumas caracterÃsticas e estimativa de um fator de ajuste (2004) Rev Bras Epidemiol, 7 (4), pp. 449-460Machado, C.J., Hill, K., Probabilistic record linkage and an automated procedure to minimize the undecided-matched pair problem (2004) Cad Saúde Pública, 20 (4), pp. 915-925Mantel, G.D., Buchmann, E., Rees, H., Pattinson, R.C., Severe acute maternal morbidity: A pilot study of a definition for a near-miss (1998) Br J Obstet Gynaecol, 105 (9), pp. 985-990Royston, E., AbouZahr, C., Measuring maternal mortality (1992) Br J Obstet Gynaecol, 99, pp. 540-542Sousa, M.H., Cecatti, J.G., Hardy, H.E., Amaral, E., Souza, J.P.D., Serruya, S., Sistemas de informação em saúde e o monitoramento de morbidade materna grave e mortalidade materna (2006) Rev Bras Saúde Matern Infant, 6 (2), pp. 161-168Souza, J.P.D., Cecatti, J.G., Parpinelli, M.A., Sousa, M.H., Serruya, S., Revisão sistemática sobre morbidade materna near miss (2006) Cad Saúde Pública, 22 (2), pp. 255-264Theme Filha, M.M., Silva, R.I., Noronha, C.P., Mortalidade materna no municÃpio do Rio de Janeiro, 1993-1996 (1999) Cad Saúde Pública, 15 (2), pp. 397-403Waterstone, M., Bewley, S., Wolfe, C., Incidence and predictors of severe obstetric morbidity: Case-control study (2001) BMJ, 322 (7294), pp. 1089-1093(1999) Reduction of maternal mortality: A joint WHO/UNFPA/Unicef World Bank Statement, , World Health Organization, Geneva;(2004) Beyond the numbers: Reviewing maternal deaths and complications to make pregnancy safer, , World Health Organization, Geneva
The Origin of Magnetic Interactions in Ca3Co2O6
We investigate the microscopic origin of the ferromagnetic and
antiferromagnetic spin exchange couplings in the quasi one-dimensional cobalt
compound Ca3Co2O6. In particular, we establish a local model which stabilizes a
ferromagnetic alignment of the S=2 spins on the cobalt sites with trigonal
prismatic symmetry, for a sufficiently strong Hund's rule coupling on the
cobalt ions. The exchange is mediated through a S=0 cobalt ion at the
octahedral sites of the chain structure. We present a strong coupling
evaluation of the Heisenberg coupling between the S=2 Co spins on a separate
chain. The chains are coupled antiferromagnetically through super-superexchange
via short O-O bonds.Comment: 5 Pages, 3 Figures; added anisotropy term in eq. 9; extended
discussion of phase transitio
Unitarity as preservation of entropy and entanglement in quantum systems
The logical structure of Quantum Mechanics (QM) and its relation to other
fundamental principles of Nature has been for decades a subject of intensive
research. In particular, the question whether the dynamical axiom of QM can be
derived from other principles has been often considered. In this contribution,
we show that unitary evolutions arise as a consequences of demanding
preservation of entropy in the evolution of a single pure quantum system, and
preservation of entanglement in the evolution of composite quantum systems.Comment: To be submitted to the special issue of Foundations of Physics on the
occassion of the seventieth birthday of Emilio Santos. v2: 10 pages, no
figures, RevTeX4; Corrected and extended version, containing new results on
consequences of entanglement preservatio
Weak Transitions in A=6 and 7 Nuclei
The He beta decay and Be electron capture processes are studied using
variational Monte Carlo wave functions, derived from a realistic Hamiltonian
consisting of the Argonne two-nucleon and Urbana-IX three-nucleon
interactions. The model for the nuclear weak axial current includes one- and
two-body operators with the strength of the leading two-body term--associated
with -isobar excitation of the nucleon--adjusted to reproduce the
Gamow-Teller matrix element in tritium -decay. The measured half-life of
. He is under-predicted by theory by 8%, while that of Be for
decay into the ground and first excited states of Li is over-predicted by
9%. However, the experimentally known branching ratio for these latter
processes is in good agreement with the calculated value. Two-body axial
current contributions lead to a 1.7% (4.4%) increase in the value of
the Gamow-Teller matrix element of He (Be), obtained with one-body
currents only, and slightly worsen (appreciably improve) the agreement between
the calculated and measured half-life. Corrections due to retardation effects
associated with the finite lepton momentum transfers involved in the decays, as
well as contributions of suppressed transitions induced by the weak vector
charge and axial current operators, have also been calculated and found to be
negligible.Comment: 23 pages 8 tables. submitted to Phys. Rev.
Impacts of Climate Change on indirect human exposure to pathogens and chemicals from agriculture
Objective: Climate change is likely to affect the nature of pathogens and chemicals in the environment and their fate and transport. Future risks of pathogens and chemicals could therefore be very different from those of today. In this review, we assess the implications of climate change for changes in human exposures to pathogens and chemicals in agricultural systems in the United Kingdom and discuss the subsequent effects on health impacts.
Data sources: In this review, we used expert input and considered literature on climate change ; health effects resulting from exposure to pathogens and chemicals arising from agriculture ; inputs of chemicals and pathogens to agricultural systems ; and human exposure pathways for pathogens and chemicals in agricultural systems.
Data synthesis: We established the current evidence base for health effects of chemicals and pathogens in the agricultural environment ; determined the potential implications of climate change on chemical and pathogen inputs in agricultural systems ; and explored the effects of climate change on environmental transport and fate of different contaminant types. We combined these data to assess the implications of climate change in terms of indirect human exposure to pathogens and chemicals in agricultural systems. We then developed recommendations on future research and policy changes to manage any adverse increases in risks.
Conclusions: Overall, climate change is likely to increase human exposures to agricultural contaminants. The magnitude of the increases will be highly dependent on the contaminant type. Risks from many pathogens and particulate and particle-associated contaminants could increase significantly. These increases in exposure can, however, be managed for the most part through targeted research and policy changes
Entangled-Photon Generation from Parametric Down-Conversion in Media with Inhomogeneous Nonlinearity
We develop and experimentally verify a theory of Type-II spontaneous
parametric down-conversion (SPDC) in media with inhomogeneous distributions of
second-order nonlinearity. As a special case, we explore interference effects
from SPDC generated in a cascade of two bulk crystals separated by an air gap.
The polarization quantum-interference pattern is found to vary strongly with
the spacing between the two crystals. This is found to be a cooperative effect
due to two mechanisms: the chromatic dispersion of the medium separating the
crystals and spatiotemporal effects which arise from the inclusion of
transverse wave vectors. These effects provide two concomitant avenues for
controlling the quantum state generated in SPDC. We expect these results to be
of interest for the development of quantum technologies and the generation of
SPDC in periodically varying nonlinear materials.Comment: submitted to Physical Review
Physical properties of FeSeTe single crystals grown under different conditions
We report on structural, magnetic, conductivity, and thermodynamic studies of
FeSeTe single crystals grown by self-flux and Bridgman methods.
The samples were prepared from starting materials of different purity at
various temperatures and cooling rates. The lowest values of the susceptibility
in the normal state, the highest transition temperature of 14.5 K, and
the largest heat-capacity anomaly at were obtained for pure (oxygen-free)
samples. The critical current density of A/cm (at 2
K) achieved in pure samples is attributed to intrinsic inhomogeneity due to
disorder at the cation and anion sites. The impure samples show increased
up to A/cm due to additional pinning centers of
FeO. The upper critical field of kOe is estimated
from the resistivity study in magnetic fields parallel to the \emph{c}-axis.
The anisotropy of the upper critical field reaches a value at . Extremely low values of the residual Sommerfeld coefficient for pure
samples indicate a high volume fraction of the superconducting phase (up to
97%). The electronic contribution to the specific heat in the superconducting
state is well described within a single-band BCS model with a temperature
dependent gap K. A broad cusp-like anomaly in the electronic
specific heat of samples with suppressed bulk superconductivity is ascribed to
a splitting of the ground state of the interstitial Fe ions. This
contribution is fully suppressed in the ordered state in samples with bulk
superconductivity.Comment: 11 pages, 11 figures, 3 table
A Real Space Description of Field Induced Melting in the Charge Ordered Manganites: II. the Disordered Case
We study the effect of A site disorder on magnetic field induced melting of
charge order (CO) in half doped manganites using a Monte-Carlo technique.
Strong A-site disorder destroys CO even without an applied field. At moderate
disorder, the zero field CO state survives but has several intriguing features
in its field response. Our spatially resolved results track the broadening of
the field melting transition due to disorder and explain the unusual dependence
of the melting scales on bandwidth and disorder. In combination with our
companion paper on field melting of charge order in clean systems we provide an
unified understanding of CO melting across all half doped manganites.Comment: 9 pages, pdflatex, 10 embedded png fig
A bootstrap method for sum-of-poles approximations
A bootstrap method is presented for finding efficient sum-of-poles approximations of causal functions. The method is based on a recursive application of the nonlinear least squares optimization scheme developed in (Alpert et al. in SIAM J. Numer. Anal. 37:1138–1164, 2000), followed by the balanced truncation method for model reduction in computational control theory as a final optimization step. The method is expected to be useful for a fairly large class of causal functions encountered in engineering and applied physics. The performance of the method and its application to computational physics are illustrated via several numerical examples
Quantum Locality
It is argued that while quantum mechanics contains nonlocal or entangled
states, the instantaneous or nonlocal influences sometimes thought to be
present due to violations of Bell inequalities in fact arise from mistaken
attempts to apply classical concepts and introduce probabilities in a manner
inconsistent with the Hilbert space structure of standard quantum mechanics.
Instead, Einstein locality is a valid quantum principle: objective properties
of individual quantum systems do not change when something is done to another
noninteracting system. There is no reason to suspect any conflict between
quantum theory and special relativity.Comment: Introduction has been revised, references added, minor corrections
elsewhere. To appear in Foundations of Physic
- …