Effectiveness of an implementation strategy for a breastfeeding guideline in Primary Care: cluster randomised trial

<p>Abstract</p> <p>Background</p> <p>The protection and promotion of breastfeeding is considered a priority in Europe where only 22% of infants less than 6 months old are exclusively breastfed. In Spain this percentage reaches 24.8% but in our city it falls to 18.26%. Various studies emphasise that the improvement of these results should be based upon the training of health professionals. Following the recommendations of a breastfeeding guide can modify the practice of health professionals and improve results with respect to exclusively or predominatly breastfed children at 6 months of age.</p> <p>Method/Design</p> <p>This study involves a community based cluster randomized trial in primary healthcare centres in Leganés (Madrid, Spain). The project aims to determine whether the use of an implementation strategy (including training session, information distribution, opinion leader) of a breastfeeding guideline in primary care is more effective than usual diffusion.</p> <p>The number of patients required will be 240 (120 in each arm). It will be included all the mothers of infants born during the study period (6 months) who come to the health centre on the first visit of the child care programme and who give their consent to participate. The main outcome variable is the exclusive o predominant breastfeeding at 6 moths of age..</p> <p>Main effectiveness will be analyzed by comparing the percentage of infants with exclusive or predominant breastfeeding at 6 months between the intervention group and the control group. All statistical tests will be performed with intention to treat. Logistic regression with random effects will be used to adjust for prognostic factors. Confounding factors or factors that might alter the effect recorded will be taken into account in this analysis.</p> <p>Discussion</p> <p>Strategies need to be found which facilitate the giving of effective advice on breastfeeding by professionals and which provide support to women during the breastfeeding period. By applying the guide's recommendations, clinical variability can be reduced and the care received by patients can be improved.</p> <p>Trial registration</p> <p>The trial was registered with ClinicalTrials.gov, number <a href="http://www.clinicaltrials.gov/ct2/show/NCT01474096">NCT01474096</a></p

ELISA versus PCR for diagnosis of chronic Chagas disease: systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Most current guidelines recommend two serological tests to diagnose chronic Chagas disease. When serological tests are persistently inconclusive, some guidelines recommend molecular tests. The aim of this investigation was to review chronic Chagas disease diagnosis literature and to summarize results of ELISA and PCR performance.</p> <p>Methods</p> <p>A systematic review was conducted searching remote databases (MEDLINE, LILACS, EMBASE, SCOPUS and ISIWeb) and full texts bibliography for relevant abstracts. In addition, manufacturers of commercial tests were contacted. Original investigations were eligible if they estimated sensitivity and specificity, or reliability -or if their calculation was possible - of ELISA or PCR tests, for chronic Chagas disease.</p> <p>Results</p> <p>Heterogeneity was high within each test (ELISA and PCR) and threshold effect was detected only in a particular subgroup. Reference standard blinding partially explained heterogeneity in ELISA studies, and pooled sensitivity and specificity were 97.7% [96.7%-98.5%] and 96.3% [94.6%-97.6%] respectively. Commercial ELISA with recombinant antigens studied in phase three investigations partially explained heterogeneity, and pooled sensitivity and specificity were 99.3% [97.9%-99.9%] and 97.5% [88.5%-99.5%] respectively. ELISA's reliability was seldom studied but was considered acceptable. PCR heterogeneity was not explained, but a threshold effect was detected in three groups created by using guanidine and boiling the sample before DNA extraction. PCR sensitivity is likely to be between 50% and 90%, while its specificity is close to 100%. PCR reliability was never studied.</p> <p>Conclusions</p> <p>Both conventional and recombinant based ELISA give useful information, however there are commercial tests without technical reports and therefore were not included in this review. Physicians need to have access to technical reports to understand if these serological tests are similar to those included in this review and therefore correctly order and interpret test results. Currently, PCR should not be used in clinical practice for chronic Chagas disease diagnosis and there is no PCR test commercially available for this purpose. Tests limitations and directions for future research are discussed.</p

Haze and cloud structure of Saturn's North Pole and Hexagon Wave from Cassini/ISS imaging

In this paper we present a study of the vertical haze and cloud structure in the upper two bars of Saturn's Northern Polar atmosphere using the Imaging Science Subsystem (ISS) instrument onboard the Cassini spacecraft. We focus on the characterization of latitudes from 53° to 90° N. The observations were taken during June 2013 with five different filters (VIO, BL1, MT2, CB2 and MT3) covering spectral range from the 420 nm to 890 nm (in a deep methane absorption band). Absolute reflectivity measurements of seven selected regions at all wavelengths and several illumination and observation geometries are compared with the values produced by a radiative transfer model. The changes in reflectivity at these latitudes are mostly attributed to changes in the tropospheric haze. This includes the haze base height (from 600 ± 200 mbar at the lowest latitudes to 1000 ± 300 mbar in the pole), its particle number density (from 20 ± 2 particles/cm3 to 2 ± 0.5 particles/cm3 at the haze base) and its scale height (from 18 ± 0.1 km to 50 ± 0.1 km). We also report variability in the retrieved particle size distribution and refractive indices. We find that the Hexagonal Wave dichotomizes the studied stratospheric and tropospheric hazes between the outer, equatorward regions and the inner, Polar Regions. This suggests that the wave or the jet isolates the particle distribution at least at tropospheric levels

Saturn's tropospheric particles phase function and spatial distribution from Cassini ISS 2010-11 observations

The phase function describes the way particles scatter the incoming radiation. This is a fundamental piece of knowledge in order to understand how a planetary atmosphere scatters sunlight and so it has a profound influence in the retrieved atmospheric properties such as cloud height, particle density distribution and radiative forcing by aerosols. In this work we analyze data from the Imaging Science Subsystem (ISS) instrument onboard Cassini spacecraft to determine the particle phase function at blue (451 nm) and near infrared wavelengths (727-890 nm) of particles in the upper troposphere, where most of the incoming visible sunlight is scattered. In order to do so, we use observations taken in later 2010 and 2011 covering a broad range of phase angles from ~10° to ~160° in the blue (BL1) and near infrared filters associated with intermediate and deep methane absorption bands (MT2, CB2, MT3). Particles at all latitudes are found to be strongly forward scattering. The equatorial particles are in good agreement with laboratory measurements of 10 μm ammonia ice crystals, while mid- and sub-polar latitude particles may be similar to the equatorial particles, but they may also be consistent with 1 μm ellipsoids with moderate aspect ratios. Uncertainties due to limited phase coverage and parameter degeneracy prevent strong constraints of the particle shapes and sizes at these locations. Results for the particle phase function are also used to describe the spatial distribution of tropospheric particles both vertically and latitudinally in the Northern hemisphere

Haze and cloud structure of Saturn's North Pole and Hexagon Wave from Cassini/ISS imaging

In this paper we present a study of the vertical haze and cloud structure in the upper two bars of Saturn's Northern Polar atmosphere using the Imaging Science Subsystem (ISS) instrument onboard the Cassini spacecraft. We focus on the characterization of latitudes from 53° to 90° N. The observations were taken during June 2013 with five different filters (VIO, BL1, MT2, CB2 and MT3) covering spectral range from the 420 nm to 890 nm (in a deep methane absorption band). Absolute reflectivity measurements of seven selected regions at all wavelengths and several illumination and observation geometries are compared with the values produced by a radiative transfer model. The changes in reflectivity at these latitudes are mostly attributed to changes in the tropospheric haze. This includes the haze base height (from 600 ± 200 mbar at the lowest latitudes to 1000 ± 300 mbar in the pole), its particle number density (from 20 ± 2 particles/cm3 to 2 ± 0.5 particles/cm3 at the haze base) and its scale height (from 18 ± 0.1 km to 50 ± 0.1 km). We also report variability in the retrieved particle size distribution and refractive indices. We find that the Hexagonal Wave dichotomizes the studied stratospheric and tropospheric hazes between the outer, equatorward regions and the inner, Polar Regions. This suggests that the wave or the jet isolates the particle distribution at least at tropospheric levels

Vertical distribution of aerosols and hazes over Jupiter's great red spot and its surroundings in 2016 from HST/WFC3 imaging

In this work, we have analyzed images provided by the Hubble Space Telescope's Wide Field Camera 3 (HST/WFC3) in December 2016, with a spectral coverage from the ultraviolet to the near infrared. We have obtained the spectral reflectivity of the GRS and its surroundings, with particular emphasis on selected, dynamically interesting regions. A spectral characterization of the GRS area is performed following two different procedures: (a) in terms of Altitude/Opacity and Color Indices (AOI and CI); (b) by means of automatic spectral classification. We used the NEMESIS radiative transfer suite to retrieve the main atmospheric parameters (e.g., particle vertical and size distributions, refractive indices) that are able to explain the observed spectral reflectivity. The optimal a priori model atmosphere used for the retrievals is obtained from a grid of about 12,000 different atmospheric models, and choosing the one that best fits South Tropical Zone (STrZ) spectra and its observed limb-darkening. We conclude that the spectral reflectivity of the GRS area is well reproduced with the following layout: (a) a stratospheric haze with its base near the 100 mbar level, with optical depths at 900 nm of the order of unity and particles with a size of 0.3 μm; (b) a more vertically extended tropospheric haze, with τ (900 nm) ∼10 down to 500 mbar and micron sized particles. Both haze layers show a stronger short wavelength absorption, and thus both act as chromophores. The altitude difference between clouds tops in the GRS and surrounding areas is ∼10 km

Venus upper clouds and the UV absorber From MESSENGER/MASCS observations

One of the most intriguing, long-standing questions regarding Venus's atmosphere is the origin and distribution of the unknown UV absorber, responsible for the absorption band detected at the near-UV and blue range of Venus's spectrum. In this work, we use data collected by Mercury Atmospheric and Surface Composition Spectrometer (MASCS) spectrograph on board the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission during its second Venus flyby in June 2007 to address this issue. Spectra range from 0.3 μm to 1.5 μm including some gaseous H 2 O and CO 2 bands, as well as part of the SO 2 absorption band and the core of the UV absorption. We used the NEMESIS radiative transfer code and retrieval suite to investigate the vertical distribution of particles in the equatorial atmosphere and to retrieve the imaginary refractive indices of the UV absorber, assumed to be well mixed with Venus's small mode 1 particles. The results show a homogeneous equatorial atmosphere, with cloud tops (height for unity optical depth) at 75 ± 2 km above surface. The UV absorption is found to be centered at 0.34 ± 0.03 μm with a full width at half maximum of 0.14 ± 0.01 μm. Our values are compared with previous candidates for the UV aerosol absorber, among which disulfur oxide (S 2 O) and dioxide disulfur (S 2 O 2 ) provide the best agreement with our results

Color and aerosol changes in Jupiter after a North Temperate Belt disturbance

The banded appearance of Jupiter’s atmosphere shows significant changes over time, sometimes even transforming the reflectivity of a whole latitudinal band in a few weeks, and staying for years with an aspect different from the usual one. The origin of some of these disturbances may be associated with the creation and destruction of the chromophore species that provides Jovian clouds their reddish coloration. In this work, we have focused on the North Temperate Belt (NTB) disturbance detected during the second flyby of Juno mission (NASA) on October 2016, as a series of convective storms interacted with the fastest zonal jet on Jupiter at 24N over months and left a quiet belt characterized by an intense red coloration Sánchez-Lavega et al. (2017). In order to determine the corresponding changes in the upper clouds and hazes we have used images taken in 2016 and 2017 with the Hubble Space Telescope Wide Field Camera 3. Such images were acquired before and after the outbreak, showing an intense color change in a narrow latitude band. The images cover the wavelength range from 250 nm up to the methane absorption band at 890 nm, thus sensitive to a number of atmospheric levels from the lower stratosphere to the upper troposphere where the ammonia condensation cloud is expected to be located. Here we use the radiative transfer suite NEMESIS Irwin et al. (2008) to determine the vertical distribution and properties of the upper hazes that best match the observed dependence of reflectivity with wavelength and geometry. We use two models for the Jovian chromophore: (A) an extended layer whose imaginary refractive index is left as a free parameter; and (B) a concentrated chromophore as in Sromovsky et al. (2017) using the optical properties by Carlson et al. (2016). Both scenarios show an increase in the number of particles responsible for the blue absorption approximately by a factor of 2, and require only small changes in the rest of the atmospheric parameters. We find that, even though results provided by scenario B are also compatible with observations, the limb-darkening is better described by scenario A, where there is also an increase of the particle absorption at the shortest wavelengths. In this work, we also provide an extension of the expected imaginary refractive indices to wavelengths beyond those covered in previous laboratory works, which will be useful for future studies

Deep winds beneath Saturn's upper clouds from a seasonal long-lived planetary-scale storm.

Convective storms occur regularly in Saturn's atmosphere. Huge storms known as Great White Spots, which are ten times larger than the regular storms, are rarer and occur about once per Saturnian year (29.5 Earth years). Current models propose that the outbreak of a Great White Spot is due to moist convection induced by water. However, the generation of the global disturbance and its effect on Saturn's permanent winds have hitherto been unconstrained by data, because there was insufficient spatial resolution and temporal sampling to infer the dynamics of Saturn's weather layer (the layer in the troposphere where the cloud forms). Theoretically, it has been suggested that this phenomenon is seasonally controlled. Here we report observations of a storm at northern latitudes in the peak of a weak westward jet during the beginning of northern springtime, in accord with the seasonal cycle but earlier than expected. The storm head moved faster than the jet, was active during the two-month observation period, and triggered a planetary-scale disturbance that circled Saturn but did not significantly alter the ambient zonal winds. Numerical simulations of the phenomenon show that, as on Jupiter, Saturn's winds extend without decay deep down into the weather layer, at least to the water-cloud base at pressures of 10-12 bar, which is much deeper than solar radiation penetrates