17 research outputs found
Recommended from our members
Review and assessment of latent and sensible heat flux accuracy over the global oceans
For over a decade, several research groups have been developing air-sea heat flux information over the global ocean, including latent (LHF) and sensible (SHF) heat fluxes over the global ocean. This paper aims to provide new insight into the quality and error characteristics of turbulent heat flux estimates at various spatial and temporal scales (from daily upwards). The study is performed within the European Space Agency (ESA) Ocean Heat Flux (OHF) project. One of the main objectives of the OHF project is to meet the recommendations and requirements expressed by various international programs such as the World Research Climate Program (WCRP) and Climate and Ocean Variability, Predictability, and Change (CLIVAR), recognizing the need for better characterization of existing flux errors with respect to the input bulk variables (e.g. surface wind, air and sea surface temperatures, air and surface specific humidities), and to the atmospheric and oceanic conditions (e.g. wind conditions and sea state). The analysis is based on the use of daily averaged LHF and SHF and the asso- ciated bulk variables derived from major satellite-based and atmospheric reanalysis products. Inter-comparisons of heat flux products indicate that all of them exhibit similar space and time patterns. However, they also reveal significant differences in magnitude in some specific regions such as the western ocean boundaries during the Northern Hemisphere winter season, and the high southern latitudes. The differences tend to be closely related to large differences in surface wind speed and/or specific air humidity (for LHF) and to air and sea temperature differences (for SHF). Further quality investigations are performed through comprehensive comparisons with daily-averaged LHF and SHF estimated from moorings. The resulting statistics are used to assess the error of each OHF product. Consideration of error correlation between products and observations (e.g., by their assimilation) is also given. This reveals generally high noise variance in all products and a weak signal in common with in situ observations, with some products only slightly better than others. The OHF LHF and SHF products, and their associated error characteristics, are used to compute daily OHF multiproduct-ensemble (OHF/MPE) estimates of LHF and SHF over the ice-free global ocean on a 0.25° × 0.25° grid. The accuracy of this heat multiproduct, determined from comparisons with mooring data, is greater than for any individual product. It is used as a reference for the anomaly characterization of each individual OHF product
Changing cause of death profile in Morocco : The impact of child-survival programmes
This study was carried out to evaluate the trends in cause-specific mortality and the impact of child-survival programmes in Morocco. Two national surveys on causes and circumstances of child deaths were conducted in Morocco in 1988 and 1998 (ECCD-1 and ECCD-2 respectively). These surveys were based on a representative sample of deaths of children aged less than five years (432 and 866 respectively). Causes of death were assessed by verbal autopsy and were validated on a subsample of 94 cases. Data on causes of deaths were matched with death rates from demographic surveys (Enquete Nationale Demographique a Passages Repetes and Demographic and Health Survey) to compute cause-specific death rates. Morocco underwent a dramatic mortality decline since independence, and the decline in mortality among children aged less than five years was particularly rapid over the 1988-1997 period, at an average rate of -6% a year, and faster for children (aged 1-4 year(s)) than for infants. The decline in mortality varied markedly by causes of death and was most pronounced for causes due to vaccine-preventable diseases, such as neonatal tetanus, measles, whooping cough, tuberculosis, for diarrhoeal diseases and malnutrition, and for selected infectious diseases. However, mortality due to acute lower respiratory infection (ALRI) outside the neonatal period did not change significantly as was the case for some neonatal conditions (birth trauma and prematurity) and for accidents. The decline in cause-specific mortality could be attributed to the success of public-health programmes: the Expanded Programme on Immunization, the management of diarrhoeal diseases and malnutrition, and the use of antibiotics for selected infectious diseases. It is likely that improvements in living conditions, child-feeding practices, hygiene, and sanitation also contributed to the decline in mortality, although these could not explain the magnitude of the changes for target diseases. In contrast, the ALRI programme, which started after 1997, could not have any effect yet, and conditions of delivery and care of the newborn improved only marginally over the study period
Parabolic inequalities in L1 as limits of renormalized equations
The paper deals with the existence of solutions of some parabolic
bilateral problems approximated by the renormalized solutions of
some parabolic equations
Selection effects of source of contraceptive supply in an analysis of discontinuation of contraception: multilevel modelling when random effects are correlated with an explanatory variable
Conventional multilevel models assume that the explanatory variables are uncorrelated with the random effects. In some situations, this assumption may be invalid. One such example is the evaluation of a health or social programme that is non-randomly placed and/or in which participation is voluntary. In this case, there may be unobserved factors influencing the placement of the programme and the decision to participate that are correlated with the unobserved factors that influence the outcome of interest. The paper presents an application of a multiprocess multilevel model to assess the difference in rates of discontinuation of contraception between private and Government family planning providers, while accounting for the possibility that there may be unobserved individual and community level factors that influence both a couple's choice of provider and their probability of discontinuation. Copyright 2003 Royal Statistical Society.
Selection effects of source of contraceptive supply in an analysis of discontinuation of contraception: multilevel modelling when random effects are correlated with an explanatory variable
Conventional multilevel models assume that the explanatory variables are uncorrelated with the random effects. In some situations, this assumption may be invalid. One such example is the evaluation of a health or social programme that is non-randomly placed and/or in which participation is voluntary. In this case, there may be unobserved factors influencing the placement of the programme and the decision to participate that are correlated with the unobserved factors that influence the outcome of interest. The paper presents an application of a multiprocess multilevel model to assess the difference in rates of discontinuation of contraception between private and Government family planning providers, while accounting for the possibility that there may be unobserved individual and community level factors that influence both a couple's choice of provider and their probability of discontinuation
Pyrano-isoflavans from <i>Glycyrrhiza uralensis</i> with Antibacterial Activity against <i>Streptococcus mutans</i> and <i>Porphyromonas gingivalis</i>
Continuing investigation of fractions
from a supercritical fluid
extract of Chinese licorice (<i>Glycyrrhiza uralensis</i>) roots has led to the isolation of 12 phenolic compounds, of which
seven were described previously from this extract. In addition to
these seven metabolites, four known components,
1-methoxyerythrabyssin II (<b>4</b>), 6,8-diprenylgenistein,
gancaonin G (<b>5</b>), and isoglycyrol (<b>6</b>), and
one new isoflavan, licorisoflavan C (<b>7</b>), were characterized
from this material for the first time. Treatment of licoricidin (<b>1</b>) with palladium chloride afforded larger amounts of <b>7</b> and also yielded two new isoflavans, licorisoflavan D (<b>8</b>), which was subsequently detected in the licorice extract,
and licorisoflavan E (<b>9</b>). Compounds <b>1</b>–<b>9</b> were evaluated for their antibacterial activities against
the cariogenic <i>Streptococcus mutans</i> and the periodontopathogenic <i>Porphyromonas gingivalis</i>. Licoricidin (<b>1</b>),
licorisoflavan A (<b>2</b>), and <b>7</b>–<b>9</b> showed antibacterial activity against <i>P. gingivalis</i> (MICs of 1.56–12.5 μg/mL). The most potent activity
against <i>S. mutans</i> was obtained with <b>7</b> (MIC of 6.25 ÎĽg/mL), followed by <b>1</b> and <b>9</b> (MIC of 12.5 ÎĽg/mL). This study provides further evidence
for the therapeutic potential of licorice extracts for the treatment
and prevention of oral infections