bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Visible Data in Improving Satellite Rain-Rate Estimates
Authors: King Patrick W. S. , Hogg William D. , Arkin Philip A.
Published: August 2010

Data from the first Algorithm Intercomparison Project(AIP/1) collected over Japan and surrounding waters in June, July, and August 1989 are used in this study to assess the importance of visible data in satellite rain estimation techniques. The purpose of the project was to compare different methods for estimating rainfall using satellite measurements. Radar and surface gauge data provided the validation set.

RAINSAT, an estimation technique using both visible (VIS) and infrared (IR) data, achieved the highest correlation with the validation data. In this paper rainfall estimates from RAINSAT (VIS+IR) am compared with two IR-only techniques to deduce the effectiveness of VIS data. Some estimates are also made using a VIS-only technique. Comparisons am made on both a spatial and diurnal basis.

Cloud climatologies for a subset of the AIP/1 data and the southern Ontario data on which RAINSAT was trained showed a marked similarity. It is found that the total volume of rain as a function of albedo is very similar for both Japanese and Ontario data.

The VIS data generally produced higher correlations with the validation data than did the IR data. This was especially the case when rain fell from warm, orogaphically induced rainfall. When rain fell from cold bright clouds. especially over the ocean, the correlations of the two types of data with the validation data were similar.

It is also shown that normalization of VIS data by the cosine of solar zenith data was inadequate to remove diurnal variations in apparent brightness.
Growth and Decay of Error in a Numerical Cloud Model Due to Small Initial Perturbations and Parameter Changes
Authors: Li Qihang , Bras Rafael L. , Islam Shafiqul
Published: August 2010

The behavior of a numerical cloud model is investigated in terms of its sensitivity to perturbations with two kinds of lateral boundary conditions: 1) with cyclic lateral boundary conditions, the model is sensitive to many aspects of its structure, including a very small potential temperature perturbation at only one grid point, changes in time step, and small changes in parameters such as the autoconversion rate from cloud water to rainwater and the latent heat of vaporization; 2) with prescribed lateral boundary conditions, growth and decay of perturbations are highly dependent on the flow conditions inside the domain. It is shown that under relatively uniform (unidirectional) advection across the domain, the perturbations will decay. On the other hand, convergence, divergence, or, in general, flow patterns with changing directions support error growth. This study shows that it is the flow structure inside the model domain that is important in determining whether the prescribed lateral boundary conditions will result in decaying or growing perturbations. The numerical model is inherently sensitive to initial perturbations, but errors can decay due to advection of information from lateral boundaries across the domain by uniform flow. This result provides one explanation to the reported results in earlier studies showing both error growth and decay.
Local Advection of Momentum, Heat, and Moisture during the Melt of Patchy Snow Covers
Authors: Liston Glen E.
Published: August 2010

A numerical atmospheric boundary layer model, based on higher-order turbulence closure assumptions, is developed and used to simulate the local advection of momentum, heat, and moisture during the melt of patchy snow covers over a 10-km horizontal domain. The coupled model includes solution of the mass continuity equation, the horizontal and vertical momentum equations, an E−ε turbulence model, an energy equation, and a water vapor conservation equation. Atmospheric buoyancy is accounted for, and a land surface energy balance model is implemented at the lower boundary.

Model integrations indicate that advective processes occurring at local scales produce nonlinear horizontal variations in surface fluxes. Under conditions of the numerical experiments, the energy available to melt snow-covered regions has been found to increase by as much as 30% as the area of exposed vegetation increases upwind of the snow cover. The melt increase is found to vary in a largely linear fashion with decreasing snow-covered area for snow-covered areas greater than 25% and in a strongly nonlinear fashion below that value. Decreasing the ratio of patch size to total area, or increasing the patchiness, of the snow cover also leads to nonlinear increases in the energy available to melt the snow. In the limit of a snow cover composed of small patches, melt energy is found to increase linearly as the fractional snow-covered area decreases. In addition, for the purpose of computing grid-average surface fluxes during snowmelt in regional atmospheric models, the results of this study indicate that separate energy balance computations can be performed over the snow-covered and vegetation-covered regions, and the resulting fluxes can be weighted in proportion to the fractional snow cover to allocate the total energy flux partitioning within each surface grid cell.
Disaggregative Invariance of Daily Precipitation
Authors: Krzysztofowicz Roman , Pomroy Thomas A.
Published: August 2010

Disaggregative invariance refers to stochastic independence between the total precipitation amount and its temporal disaggregation. This property is investigated herein for areal average and point precipitation amounts accumulated over a 24-h period and disaggregated into four 6-h subperiods. Statistical analyses of precipitation records from 1948 to 1993 offer convincing empirical evidence against the disaggregative invariance and in favor of the conditional disaggregative invariance, which arises when the total amount and its temporal disaggregation are conditioned on the timing of precipitation within the diurnal cycle.

The property of conditional disaggregative invariance allows the modeler or the forecaster to decompose the problem of quantitative precipitation forecasting into three tasks: (i) forecasting the precipitation timing; (ii) forecasting the total amount, conditional on timing; and (iii) forecasting the temporal disaggregation, conditional on timing. Tasks (ii) and (iii) can be performed independently of one another, and this offers a formidable advantage for applications.
Rainfall Anomaly over the Lee Side of Mount Carmel (Israel) and the Associated Wind Field
Authors: Goldreich Yair , Freundlich Ariel , Alpert Pinhas
Published: August 2010

Yagur and other rain gauge stations located on the lee side of Mount Carmel in Israel experience much higher amounts of precipitation than those measured on the windward side of the mountain at a similar altitude and more rain than stations on the mountain itself. This phenomenon is consistently observed, and in the current study it is investigated primarily by means of simultaneous rain–wind observations and by using a two-dimensional simplified orographic model. Orographic model simulations suggest the existence of a flow disturbance at the lee of Mount Carmel, which might cause local rain enhancement. Results from the anemograph placed at Yagur, along with other wind measurements in the Carmel region, support the findings of this model. Observations depict the disturbed flow that occurred at the lee of Mount Carmel and was associated with rain enhancement. The channeled flow caused horizontal convergence, which is in accordance with the second hypothesis. Observations during the rainy periods indicate that the rain enhancement in Yagur is associated with the ridge-parallel flow on the lee side of the mountain. It is hypothesized that the horizontal convergence of the leeside flow with the flow over the mountain causes the local enhancement of precipitation.
Simulation of Nocturnal Drainage Flows Enhanced by Deep Canyons: The Rocky Flats Case
Authors: Varvayanni Melpomeni , Bartzis John G. , Catsaros Nicolas , Deligiannis Panagiotis , Elderkin Chuck E.
Published: August 2010

The DELTA–ADREA (discretization with elements of triangle approach–atmospheric dispersion of pollutants over irregular terrain) numerical prediction model, developed at the National Center for Scientific Research Demokritos, is specifically designed to perform wind field calculations over terrains of high complexity. The numerical model has the capability to handle air–ground interaction processes by describing the ground-surface details while keeping the computation time at a reasonable level. The numerical model is applied here to a high-resolution topographical representation of the region surrounding the Rocky Flats Facility in Colorado, based on a digitized map consisting of approximately 4.8 × 106 points. Wind field calculations over the region are made using the atmospheric experimental data of 4 February 1991, collected by the participants within the Atmospheric Studies in Complex Terrain research program. The numerical predictions indicate strong drainage flows created at different altitudes with interaction between them, resulting in a quite complicated mesoscale wind field during nighttime. Available observations support the predicted flow features.
Variability of SO=4, Total Sulfate, NO−3, and Total Nitrate Scavenging Ratios for the Frontal Boundary Study
Authors: Davis W. E. , Thorp J. M. , Lee R. N.
Published: August 2010

Precipitation and air concentration data collected during a U.S. Department of Energy–sponsored Frontal Boundary Study (FBS) were used to calculate scavenging ratios. The precipitation data were collected on a 100 km × 100 km surface grid containing 36 sampling sites, while the air concentration data were collected by aircraft. Radar and rawinsonde data were used to position the aircraft into the air mass feeding the precipitation. The coordination of the aircraft data with surface precipitation data allows the calculation of scavenging ratios. During the study, three out of seven events sampled allowed the calculation of scavenging ratios for SO=4, total sulfate, NO−3, and total nitrate. The 36 precipitation samplers allowed calculation of multiple scavenging ratios to represent an event. From these scavenging ratios, both a geometric mean and a geometric standard deviation of the scavenging ratio were calculated for each event. The geometric mean (geometric standard deviation) scavenging ratio for total sulfate is 6 × 104 (1.1) for 10 October 1989, 10 × 104 (1.5) for 16–17 October 1989, and 4 × 104 (1.3) for 31 October 1989. For SO=4 the scavenging ratios are 10 × 105 (1.1) for 10 October 1989, 4 × 105 (1.5) for 16–17 October 1989, and 3 × 105 (1.3) for 31 October 1989. The scavenging ratio for NO−3 is 3 × 106 (1.2) for 10 October 1989, 20 × 106 (1.4) for 16–17 October 1989, and 0.4 × 106 (1.5) for 31 October 1989. The scavenging ratio for total nitrate is 2 × 106 (1.2) for 10 October 1989, 2 × 106 (1.4) for 16–17 October 1989, and 0.2 × 106 (1.5) for 31 October 1989. The most important finding is the small variation of the numbers within the events as reflected in the geometric standard deviations. These values ranged from 1.1 to 1.5. Based on these results, a single scavenging ratio can be used on a 100 km × 100 km area with a minimum of error.

Two other results were found when comparing these scavenging ratios to total precipitation in the sampler. The comparison revealed that the variation in the scavenging ratio increased with decreasing total precipitation. The increase was up to a factor of 2 for less than 5 mm when compared with greater than 5 mm of total precipitation.
Remote Sounding of Multilayer Cirrus Cloud Systems Using AVHRR Data Collected during FIRE-II-IFO
Authors: Ou S. C. , Liou K. N. , Caudill T. R.
Published: August 2010

Surface observations show that multilayer clouds frequently occur in frontal areas where cirrus clouds overlie boundary layer convective clouds or stratus clouds. In this paper, an algorithm is presented for the retrieval of cirrus cloud optical depths and ice crystal sizes in multilayer cloud systems based on the theory of radiative transfer and parameterizations. For the validation of the retrieval program, AVHRR data is analyzed for two dates during FIRE-II-IFO in which cirrus clouds overlie a layer of low stratus cloud. It is shown that the domain-averaged retrieved cloud temperatures are within the boundaries of cirrus clouds determined from the collocated replicator, radar, and lidar data. The retrieved ice crystal mean effective sizes and optical depths are also in general agreement with the values determined from the balloon-borne replicator and 2D probe data.
The Impact of Secondary Flow Systems on Air Pollution in the Area of São Paulo
Authors: Bischoff-Gauß I. , Kalthoff N. , Fiedler F.
Published: August 2010

The area between the Atlantic Ocean and São Paulo is highly polluted due to high emission rates at Cubatão, a city situated 15 km inland at a steep slope. It was expected that secondary circulations would develop caused by the land–sea contrast and strong orographic changes, which influence the transport and diffusion of air pollutants. In 1994–95, surface stations were operated and radiosonde ascents were performed to analyze the characteristic features of the land–sea-breeze circulation.

The stations make evident a land–sea-breeze system that arrived in the suburbs of São Paulo in the early afternoon. The upslope winds favor the propagation of the sea breeze at the steep slope. During the measurement period, large-scale northwesterly winds prevailed that advected warm air from the plateau to the coastal area in the afternoon and resulted in a limitation of the boundary layer growth. The data were used to initialize a three-dimensional mesoscale model for calculation of the transport and deposition of SO2 emitted at Cubatão. The boundary layer height was found to be a limitation for vertical mixing of the air pollutants. However, a step between the coastal boundary layer and the boundary layer over the plateau causes SO2 to be vented into the free atmosphere at the slope and then transported toward the Atlantic Ocean with the large-scale northwesterly winds. Thus, over the coastal area, the SO2 concentrations in the free atmosphere were even higher than within the mixed layer. The deposition, summed up over a day, was calculated and found to be strongest at the slope and over the Atlantic Ocean.
The Estimation of Hydrometeor Profiles from Wideband Microwave Observations
Authors: Skofronick-Jackson Gail M. , Wang James R.
Published: August 2010

Profiles of the microphysical properties of clouds and rain cells are essential in many areas of atmospheric research and operational meteorology. To enhance the understanding of the nonlinear and underconstrained relationships between cloud and hydrometeor microphysical profiles and passive microwave brightness temperatures, estimations of cloud profiles for an anvil region, a convective region, and an updraft region of an oceanic squall were performed. The estimations relied on comparisons between radiative transfer calculations of incrementally estimated microphysical profiles and concurrent dual-altitude wideband brightness temperatures from the 22 February 1993 flight during the Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment. The wideband observations (10–220 GHz) are necessary for estimating cloud profiles reaching up to 20 km. The low frequencies enhance the rain and cloud water profiles, and the high frequencies are required to detail the higher-altitude ice microphysics. A microphysical profile was estimated for each of the three regions of the storm. Each of the three estimated profiles produced calculated brightness temperatures within ∼10 K of the observations. A majority of the total iterative adjustments were to the estimated profile’s frozen hydrometeor characteristics and were necessary to match the high-frequency calculations with the observations. This requirement indicates a need to validate cloud-resolving models using high frequencies. Some difficulties matching the 37-GHz observation channels on the DC-8 and ER-2 aircraft with the calculations simulated at the two aircraft heights (∼11 km and 20 km, respectively) were noted, and potential causes were presented.
Three Methods to Determine Profiles of Reflectivity from Volumetric Radar Data to Correct Precipitation Estimates
Authors: Vignal Bertrand , Galli Gianmario , Joss Jürg , Germann Urs
Published: August 2010

The vertical variability of radar reflectivity reduces the reliability of precipitation estimation by radar, especially in complex orography. This important source of error can, at least partially, be corrected for, if the vertical profile of radar reflectivity (VPR) is known. This work addresses three ways to determine VPR from volumetric radar data for correcting precipitation estimates. The first way uses a climatological profile. The second method, operational in Switzerland, takes the actual weather conditions into account: a mean profile is estimated directly from volumetric radar data collected close to the radar. The third way determines the identified profile, taking the variability of the VPRs in space into account. This approach yields local estimates of the profile (on areas of about 20 km × 20 km) based on an inverse method. Two cases, a convective event and a stratiform event, are used to illustrate the three ways for determining the VPR, and the resulting improvement, verified with rain gauges. An enlarged dataset of nine cases shows that a correction based on a climatological profile already improves the accuracy of rain estimates by radar significantly: the fractional standard error (FSE) is reduced from the noncorrected 44% to 31%. By correcting with a single, mean profile (averaged over 1 h using real-time data), the FSE is further reduced from 31% to 25%. Last, the use of 70 locally identified profiles leads to best results (FSE = 23%). A higher improvement (lower FSE) is obtained for the stratiform rain event than for the convective case.
Assimilation of DMSP and TOVS Satellite Soundings in a Mesoscale Model
Authors: Powers Jordan G. , Gao Kun
Published: August 2010

A modeling investigation explores the impacts of the assimilation of satellite-retrieved soundings on forecast error in the Fifth-Generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5). Simulations of the period of the U.S. Air Force’s Contrail Experiment (18–29 September 1995) vary the initialization method and datasets assimilated, the performance of first-guess reanalysis, the imposition of quality control (QC) on the satellite data, and the frequency of the model update cycle. MM5 experiments employing four-dimensional data assimilation (FDDA) are compared with a control experiment without FDDA. In the former, combinations of conventional surface and radiosonde observations and retrieved temperature and moisture soundings from the Defense Meteorological Satellite Program (DMSP) and Television and Infrared Observation Satellite Operational Vertical Sounder (TOVS) satellite instruments are assimilated. Forecast error statistics for the experiments are computed and analyzed. It is found that for retrieved temperatures the DMSP and TOVS sounding datasets used have similar, reasonable accuracy, but for retrieved dewpoints they display significant, and more differing, errors. Overall, the TOVS retrievals obtained are of poorer quality than are the DMSP retrievals. Sensitivity tests reveal that imposing a QC filter on the satellite data prior to assimilation does improve the resultant MM5 simulations. With such QC, it is found that assimilating DMSP and TOVS soundings with the methods used can significantly improve the forecasts of both temperature and moisture variables in the MM5. Model performance, however, can still reflect the relative quality of the satellite retrievals assimilated, with the lower-error DMSP data yielding better simulations than do the TOVS data. Tests exploring the reanalysis of first-guess fields obtained from FDDA show that it does benefit the short-term (0–12 h) forecast but that significant gains diminish thereafter.
Lightning Rod Improvement Studies
Authors: Moore C. B. , Rison William , Mathis James , Aulich Graydon
Published: August 2010

Although lightning rods have long been used to limit damage from lightning, there are currently no American standards for the shape and form of these devices. Following tradition, however, sharp-tipped Franklin rods are widely installed despite evidence that, on occasion, lightning strikes objects in their vicinity. In recent tests of various tip configurations to determine which were preferentially struck by lightning, several hemispherically tipped, blunt rods were struck but none of the nearby, sharper rods were “hit” by lightning.

Measurements of the currents from the tips of lightning rods exposed to strong electric fields under negatively charged cloud bases show that the emissions consist of periodic ion charge bursts that act to reduce the strength of the local fields. After a burst of charge, no further emissions occur until that charge has moved away from the tip. Laboratory measurements of the emissions from a wide range of electrodes exposed to strong, normal-polarity thunderstorm electric fields show that positive ions are formed and move more readily over sharp-tipped electrodes than over blunter ones. From these findings, it appears that the electric field rates of intensification over sharp rods must be much greater than those over similarly exposed blunt rods for the initiation of upward-going leaders.

Calculations of the relative strengths of the electric fields above similarly exposed sharp and blunt rods show that although the fields, prior to any emissions, are much stronger at the tip of a sharp rod, they decrease more rapidly with distance. As a result, at a few centimeters above the tip of a 20-mm-diameter blunt rod, the strength of the field is greater than that over an otherwise similar, sharper rod at the same height. Since the field strength at the tip of a sharpened rod tends to be limited by the easy formation of ions in the surrounding air, the field strengths over blunt rods can be much stronger than those at distances greater than 1 cm over sharper ones.

The results of this study suggest that moderately blunt metal rods (with tip height–to–tip radius of curvature ratios of about 680:1) are better lightning strike receptors than are sharper rods or very blunt ones.
Model Calculations and Interferometer Measurements of Ice-Cloud Characteristics
Authors: Chung Sunggi , Ackerman Steven , van Delst Paul F. , Menzel W. Paul
Published: August 2010

This paper investigates the relationship between high–spectral resolution infrared (IR) radiances and the microphysical and macrophysical properties of cirrus clouds. Through use of radiosonde measurements of the atmospheric state at the Department of Energy’s Atmospheric Radiation Measurement Program site, high–spectral resolution IR radiances are calculated by combining trace gas absorption optical depths from a line-by-line radiative transfer model with the discrete ordinate radiative transfer (DISORT) method. The sensitivity of the high–spectral resolution IR radiances to particle size, ice-water path, cloud-top location, cloud thickness, and multilayered cloud conditions is estimated in a multitude of calculations.

DISORT calculations and interferometer measurements of cirrus ice cloud between 700 and 1300 cm−1 are compared for three different situations. The measurements were made with the High–Spectral Resolution Interferometer Sounder mounted on a National Aeronautics and Space Administration ER-2 aircraft flying at 20-km altitude during the Subsonic Aircraft Contrail and Cloud Effects Special Study (SUCCESS).
Near-Neutral Surface Layer Turbulence at the Boulder Atmospheric Observatory Tower: Evidence of Increasing Vertical Turbulence with Height
Authors: Bowen Brent M.
Published: August 2010

Wind and turbulence profiles were analyzed during breezy, near-neutral conditions at the Boulder Atmospheric Observatory tower to quantify the effects of an abrupt 20- to 30-m increase in terrain located 3–5 km west of the tower. Results indicate that regional roughness length z0 is greatest and local z0 is smallest in sectors downwind of a long, shallow bluff, suggesting that distant, more complex, upwind terrain enhances horizontal turbulence but has little effect on local wind speed profiles. Turbulence parameter profiles are nearly constant up to 200 m above ground level (AGL), and friction velocity u∗ is nearly constant up to 150–200 m for simple fetch with z0 equal to 4 cm and near-surface wind speed approximately equal to 7 m s−1 at 10 m AGL. Horizontal turbulence parameters, however, increase by 50% to nearly 100% at all tower levels downwind of the distant terrain bluff when compared with those with simple fetch. The effect of the bluff on vertical turbulence increases with height. Although the effect on the 10-m standard deviation of vertical wind speed σw is negligible, the 200-m σw increases by about 0.5 m s−1, or about twice the 10-m value. The u∗ also increases by 16% to nearly 100% between the 10- and 200-m heights downwind of the bluff. Primarily because of the enhanced σw downwind of the bluff, atmospheric dispersion could be underestimated by factors of about 2.5, 2.0, and 1.3 at the 200-, 100-, and 50-m levels, respectively, if the vertical and transverse standard deviations of the wind angle fluctuations are estimated from 10-m values.
Efficacy of Counseling and Psychotherapy in Schools: A Meta-Analytic Review of Treatment Outcome Studies 1Ψ7
Authors: Baskin Thomas W. , Slaten Christopher D. , Crosby Nicole R. , Pufahl Tiffany , Schneller Cali L. , Ladell Monica
Published: August 2010

This study investigated the efficacy of counseling and psychotherapy interventions for youth in schools. Data were examined for 107 studies that included 132 treatment interventions. Overall efficacy was d = 0.45 and was significantly different from zero. Interventions for adolescents outperformed those of children, treatment groups that were predominately female or male did better than mixed-gender groups, and licensed professional therapists outperformed paraprofessionals, who outperformed graduate students. Implications for supporting the mental health needs of youth in schools are discussed.
“Why Am I Out of the Loop?” Attributions Influence Responses to Information Exclusion
Authors: Jones Eric E. , Kelly Janice R.
Published: August 2010

Studies show the importance of information sharing in decision making. However, information sharing also affects intrapersonal perceptions and group dynamics. Three experiments demonstrated that out-of-the-loop individuals experienced thwarted needs (e.g., belonging) and decreased trust and liking of group members. Experiment 1 showed these deleterious effects only occurred when information exclusion appeared intentional. Experiment 2 established that constructive motives could mitigate negative effects of intentional information exclusion. Experiment 3 showed that unintentional information exclusion deflated participants only when perceived as preventable. These experiments also provided evidence for a mediating process. Information exclusion, particularly when ill intentioned or preventable, signals poor group standing, leading to deleterious psychological effects.
Characteristics and risk factors for hyperglycemia in Chinese female patients with systemic lupus erythematosus
Authors: Zeng Y-J. , Zeng F-Q. , Dai L. , Yang C. , Lin B-Z. , Zheng D-H. , Liu D. , Yan L. , Ren M. , Cheng H.
Published: August 2010

The aim of the study was to investigate the characteristics and risk factors for hyperglycemia in Chinese female patients with systemic lupus erythematosus (SLE). One hundred and forty-six female SLE patients without a history of diabetes underwent a 75 g oral glucose tolerance test to evaluate glucose tolerance, insulin sensitivity and pancreatic beta cell function. According to the 1999 World Health Organization criteria, all patients were divided into three groups: normal glucose regulation, impaired glucose tolerance and diabetes mellitus. Glucocorticoid doses, insulin sensitivity and pancreatic beta cell function were compared among these groups. Risk factors for hyperglycemia were analyzed by univariate and multi-variate regression analysis. Our results showed that 46 of the 146 female SLE patients (31.5 %) were hyperglycemic, including 21 (14.4%) diabetes mellitus patients and 25 (17.1%) impaired glucose tolerance patients. These female SLE patients with hyperglycemia were characterized by insulin resistance and reduced pancreatic beta cell function, and they were relatively young. Age ≥35 years and high glucocorticoid doses were risk factors for hyperglycemia in Chinese female SLE patients. The prevalence of diabetes mellitus and impaired glucose tolerance are quite high in Chinese female SLE patients. It is suggested that plasma glucose concentration should be monitored regularly and oral glucose tolerance test should be recommended for SLE patients who have risk factors for hyperglycemia. Lupus (2010) 19, 1344—1350.
Women’s Experience of Group Prenatal Care
Authors: Novick Gina , Sadler Lois S. , Kennedy Holly Powell , Cohen Sally S. , Groce Nora E. , Knafl Kathleen A.
Published: August 2010

Group prenatal care (GPNC) is an innovative alternative to individual prenatal care. In this longitudinal study we used ethnographic methods to explore African American and Hispanic women’s experiences of receiving GPNC in two urban clinics. Methods included individual, in-depth, semistructured interviews of women and group leaders in GPNC, participant observation of GPNC sessions, and medical record review. GPNC offered positive experiences and met many of women’s expressed preferences regarding prenatal care. Six themes were identified, which represented separate aspects of women’s experiences: investment, collaborative venture, a social gathering, relationships with boundaries, learning in the group, and changing self. Taken together, the themes conveyed the overall experience of GPNC. Women were especially enthusiastic about learning in groups, about their relationships with group leaders, and about having their pregnancy-related changes and fears normalized; however, there were also important boundaries on relationships between participants, and some women wished for greater privacy during physical examinations.
How Different is Qualitative Health Research From Qualitative Research? Do We Have a Subdiscipline?
Authors: Morse Janice M.
Published: August 2010

Here, I compare the content, characteristics of participants, and the methods used in qualitative health research with qualitative inquiry in general. Special problems that occur when conducting research in an institution, with the emotional content when participants are ill, in pain, or dying, will be discussed. What concerns for the investigator, for the researcher as a person, and methodological quandaries occur? The bottom line is: Do we have a subdiscipline? Is there a need for a special forum for those practicing qualitative health/illness research?
Advance Provision of Emergency Contraception for Adolescents
Authors: Adamji Jehan-Marie , Swartwout Kathryn
Published: August 2010

Emergency contraception is most effective at preventing unintended pregnancy when taken as early as possible following unprotected sexual intercourse. Advance provision of this medication supports more timely and effective use. In the midst of rising teen pregnancy rates, current policies often limit access to emergency contraception for adolescents. A literature search identified three recent experimental studies of advance provision for adolescents. This article reviews those studies and finds strong support for advance provision for adolescents. Usage of emergency contraception increased with advance provision and there was no increase in negative sexual behaviors or decrease in usage of other contraceptive forms. Implications of these findings for school nurses and school-based health center staff are also discussed.
Impact of current supply on LED colour
Authors: Pousset N. , Rougié B. , Razet A.
Published: August 2010

The quality of light emitted by lighting systems based on high brightness LEDs is studied using colorimetric parameters (chromaticity coordinates, correlated colour temperature and colour rendering index) when operating with different forms of electrical power supply (continuous and pulsed current). Uncertainties, calculated by Monte Carlo simulations applied to relative spectral measurements and colorimetric parameters are presented.
Photometric measurements for visibility level computations
Authors: Brémond Roland , Dumont E. , Ledoux V. , Mayeur A.
Published: August 2010

Visibility level is a standard quality index in road lighting design. Three photometric values are needed to compute the visibility level of a target: its luminance, the luminance of its near background and the adaptation luminance. We discuss the consequences of how these parameters are set on the ability to predict the performance of a driver at target detection. An experiment was designed using a closed-road circuit. Sixteen targets were presented twice to 34 subjects. Six visibility level assessment methods were compared. The background luminance was set as the luminance at the bottom of the target, as the mean luminance around the target, or as the luminance associated with the maximum target contrast. The adaptation luminance was set either to the background luminance or to the mean luminance. The best non-linear fit between computed visibility level and target detection performance was found using the maximum contrast over the four sides of the square target, and setting the adaptation luminance to a unique estimated road luminance instead of the local background luminance. Even so, the variability of the visibility level data suggests great caution when using it as an index of road visibility.
VE-cadherin expression allows identification of a new class of hematopoietic stem cells within human embryonic liver
Authors: Oberlin Estelle , Fleury Maud , Clay Denis , Petit-Cocault Laurence , Candelier Jean-Jacques , Mennesson Benoît , Jaffredo Thierry , Souyri Michèle
Published: August 2010

Edification of the human hematopoietic system during development is characterized by the production of waves of hematopoietic cells separated in time, formed in distinct embryonic sites (ie, yolk sac, truncal arteries including the aorta, and placenta). The embryonic liver is a major hematopoietic organ wherein hematopoietic stem cells (HSCs) expand, and the future, adult-type, hematopoietic cell hierarchy becomes established. We report herein the identification of a new, transient, and rare cell population in the human embryonic liver, which coexpresses VE-cadherin, an endothelial marker, CD45, a pan-hematopoietic marker, and CD34, a common endothelial and hematopoietic marker. This population displays an outstanding self-renewal, proliferation, and differentiation potential, as detected by in vitro and in vivo hematopoietic assays compared with its VE-cadherin negative counterpart. Based on VE-cadherin expression, our data demonstrate the existence of 2 phenotypically and functionally separable populations of multipotent HSCs in the human embryo, the VE-cadherin+ one being more primitive than the VE-cadherin− one, and shed a new light on the hierarchical organization of the embryonic liver HSC compartment.
Distinct clinical and biological features of de novo acute myeloid leukemia with additional sex comb-like 1 (ASXL1) mutations
Authors: Chou Wen-Chien , Huang Huai-Hsuan , Hou Hsin-An , Chen Chien-Yuan , Tang Jih-Luh , Yao Ming , Tsay Woei , Ko Bor-Sheng , Wu Shang-Ju , Huang Shang-Yi , Hsu Szu-Chun , Chen Yao-Chang , Huang Yen-Ning , Chang Yi-Chang , Lee Fen-Yu , Liu Min-Chih , Liu Chia-Wen , Tseng Mei-Hsuan , Huang Chi-Fei , Tien Hwei-Fang
Published: August 2010

Mutations in the additional sex comb-like 1 (ASXL1) gene were recently shown in various myeloid malignancies, but they have not been comprehensively investigated in acute myeloid leukemia (AML). In this study, we analyzed ASXL1 mutations in exon 12 in 501 adults with de novo AML. ASXL1 mutations were detected in 54 patients (10.8%), 8.9% among those with normal karyotype and 12.9% among those with abnormal cytogenetics. The mutation was closely associated with older age, male sex, isolated trisomy 8, RUNX1 mutation, and expression of human leukocyte antigen–DR and CD34, but inversely associated with t(15;17), complex cytogenetics, FLT3–internal tandem duplication, NPM1 mutations, WT1 mutations, and expression of CD33 and CD15. Patients with ASXL1 mutations had a shorter overall survival than patients without, but the mutation was not an independent adverse prognostic factor in multivariate analysis. Sequential analyses showed that the original ASXL1 mutations were lost at relapse and/or refractory status in 2 of the 6 relapsed ASXL1-mutated patients studied, whereas 2 of the 109 ASXL1-wild patients acquired a novel ASXL1 mutation at relapse. In conclusion, AML bearing ASXL1 mutations showed distinct clinical and biological features. The ASXL1 mutation status can change during disease evolution in a few patients.
Surfactant protein B polymorphisms, pulmonary function and COPD in 10,231 individuals
Authors: Bækvad-Hansen M. , Nordestgaard B.G. , Dahl M.
Published: August 2010

Thesurfactant protein (SP)-Bgene may influence chronic obstructive pulmonary disease (COPD) and, thus, personalised medicine. We tested whether functional polymorphisms inSP-B(rs1130866 (1580T>C), rs2077079 (-18A>C) and rs3024791 (-384G>A)) associate with reduced lung function and risk of COPD in the general population.

We genotyped 10,231 individuals from the general adult Danish population, and recorded spirometry and hospital admissions due to COPD. Because we previously found an association between the rareSP-B121ins2 mutation and COPD among smokers, we stratified the analyses for smoking status.

None of the individualSP-Bgenotypes or genotype combinations were associated with reduced forced expiratory volume in 1 s (FEV1) % predicted, forced vital capacity (FVC) % pred and FEV1/FVC overall or among smokers (p = 0.25–0.99). The odds ratio for spirometrically defined COPD did not differ from 1.0 for any of theSP-Bgenotypes or genotype combinations overall or among smokers (p = 0.17–0.78). Similar results were obtained for hospitalisation due to COPD (p = 0.07–0.93); we could exclude overall hazard ratios for heterozygotes of 1.18–1.21 and for homozygotes of 1.25–1.57 or larger for all three polymorphisms.

In conclusion, the functional rs1130866, rs2077079 and rs3024791 polymorphisms in theSP-Bgene are not associated with reduced lung function or risk of COPD, making it unlikely that these variants will be useful in personalised medicine.
The effect of dornase alfa on ventilation inhomogeneity in patients with cystic fibrosis
Authors: Amin R. , Subbarao P. , Lou W. , Jabar A. , Balkovec S. , Jensen R. , Kerrigan S. , Gustafsson P. , Ratjen F.
Published: August 2010

Outcome measures to assess therapeutic interventions in cystic fibrosis (CF) patients with mild lung disease are lacking. Our aim was to determine if the lung clearance index (LCI) can detect a treatment response to dornase alfa in paediatric CF patients with normal spirometry.

CF patients between 6–18 yrs of age with FEV1≥80% pred were eligible. In a crossover design, 17 patients received 4 weeks of dornase alfa and placebo in a randomised sequence separated by a 4-week washout period. The primary end-point was the change in LCI from dornase alfaversusplacebo. A mixed model approach incorporating period-dependent baselines was used.

The mean±sdage was 10.32±3.35 yrs. Dornase alfa improved LCIversusplacebo (0.90±1.44; p = 0.022). Forced expiratory flow at 25–75% expired volume measured by % pred and z-scores also improved in subjects on dornase alfa (6.1%±10.34%; p = 0.03 and 0.28±0.46 z-score; p = 0.03).

Dornase alfa significantly improved LCI. Therefore the LCI may be a suitable tool to assess early intervention strategies in this patient population.
Improving standards in flexible bronchoscopy for lung cancer
Authors: Slade M.G. , Rahman N.M. , Stanton A.E. , Curry L. , Slade G.C. , Clelland C.A. , Gleeson F.V.
Published: August 2010

Can the detection rate of flexible bronchoscopy for lung cancer be increased by a series of simple quality improvement measures?

Bronchoscopy-associated clinical parameters were prospectively recorded between 2001 and 2007 in patients with suspected lung malignancy. The detection rate of bronchoscopy, diagnostic yield of each biopsy modality and the possible impact of different service-improvement measures were assessed.

746 bronchoscopies were performed in 704 patients. The detection rate of bronchoscopy for malignancy was 83.6%, and increased over time (67.3% detection rate in 2001 (95% CI 52.9–79.7), 89.7% detection rate in 2007 (95% CI 81.3–95.2); p<0.001). Detection rate increased for bronchoscopically visible (75.0% in 2001 to 94.5% in 2007) and non-visible tumours (41.7% in 2001 to 81.2% in 2007; p<0.001 for both analyses). Prior computed tomography availability was associated with a higher diagnostic yield that did not reach statistical significance. Logistic regression analysis identified tumour visibility, year of study, use of transbronchial needle aspiration and pathologist identity as independent predictors of a positive diagnosis.

A significant increase in bronchoscopic detection rate for malignancy occurred in association with a number of simple improvement measures.
No increase in the prevalence of COPD in two decades
Authors: Vasankari T.M. , Impivaara O. , Heliövaara M. , Heistaro S. , Liippo K. , Puukka P. , Saarelainen S. , Kanervisto M. , Jousilahti P.
Published: August 2010

Relevant information on the prevalence of chronic obstructive pulmonary disease (COPD) and its trends is scarce. In the present study, we compare the prevalence rates and potential determinants of COPD in two national population samples that were surveyed 20 yrs apart.

In 1978–1980, a sample of 8,000 people was surveyed; subjects were representative of the Finnish population and were aged ≥30 yrs. Among those aged 30–74 yrs, acceptable spirometry was obtained from 6,364 (87%) subjects. In a similar survey conducted in 2000–2001, comparable spirometry was obtained from 5,495 (80%) participants. Airway obstruction was defined as forced expiratory volume in 1 s (FEV1)/forced vital capacity below the lower limit of normal and staged for severity on the basis of FEV1% predicted.

The age-adjusted prevalence rates of obstruction (stages I–IV) were rather similar in both surveys in males (4.7versus4.3%; p = 0.25), but were almost significantly higher in females in the later survey (2.2versus3.1%; p = 0.06). The rates of COPD stage II or higher were 3.9% in 1978–1980, and 3.6% in 2000–2001 (p = 0.36) for males, and 1.4 and 1.5% (p = 0.93), respectively, for females.

In conclusion, no significant difference was found in the prevalence of COPD stages II–IV between similar population based surveys performed 20 yrs apart. Since COPD is mostly mild or moderate there is a strong case for early prevention.
Possible use of ail and foxA polymorphisms for detecting pathogenic Yersinia enterocolitica
Authors: Huang Ying , Wang Xin , Cui Zhigang , Yang Yuhuan , Xiao Yuchun , Tang Liuying , Kan Biao , Xu Jianguo , Jing Huaiqi
Published: August 2010

Background

Yersinia enterocoliticais an enteric pathogen that invades the intestinal mucosa and proliferates within the lymphoid follicles (Peyer's patches). The attachment invasion locus (ail) mediates invasion byY. enterocoliticaand confers an invasive phenotype upon non-invasiveE. coli;ailis the primary virulence factor ofY. enterocolitica. The ferrioxamine receptor (foxA) located on theY. enterocoliticachromosome, together with its transport protein, transports a siderophore specific for ferric ion. Currently,ailis the primary target gene for nucleic acid detection of pathogenicY. enterocolitica.

Results

The genesailandfoxAin 271 pathogenic and 27 non-pathogenicY. enterocoliticastrains isolated from China and 10 reference strains were sequenced, aligned, compared to theailandfoxAsequences ofYersinia enterocolitica subsp. enterocolitica8081 (Genbank: NC_008800), and analyzed for sequence polymorphism. Theailfrom the 282 strains showed 3 sequence patterns: 277 strains of serotypes O:3, O:9 and O:5, 27 with identical nucleic acid sequences formed pattern A1; 4 strains of serotype 1B/O:8 with identical nucleic acid sequences formed pattern A2; and one Chinese isolate 2/O:9 formed pattern A3. In the primary coding region of thefoxAORF (Genebank: X60447 nt 433-1866; nt 28 to 1,461 in the ORF), the sequences formed 3 groups and were further divided into 8 sequence patterns.

Conclusion

TheailandfoxAloci of pathogenicY. enterocoliticahave been analyzed. Theailsequence was highly conserved among the same serotype strains from different sources; andfoxAwas highly conserved among the pathogenic strains, although there was some sequence diversity. Fewer strains were used from outside China, which is a limitation of the study.
The ascorbic acid content of tomato fruits is associated with the expression of genes involved in pectin degradation
Authors: Di Matteo Antonio , Sacco Adriana , Anacleria Milena , Pezzotti Mario , Delledonne Massimo , Ferrarini Alberto , Frusciante Luigi , Barone Amalia
Published: August 2010

Background

High levels of ascorbic acid (AsA) in tomato fruits provide health benefits for humans and also play an important role in several aspects of plant life. Although AsA metabolism has been characterized in detail, the genetic mechanisms controlling AsA accumulation in tomatoes are poorly understood. The transcriptional control of AsA levels in fruits can be investigated by combining the advanced genetic and genomic resources currently available for tomato. A comparative transcriptomic analysis of fruit tissues was carried out on an introgression line containing a QTL promoting AsA accumulation in the fruit, using a parental cultivar with lower AsA levels as a reference.

Results

Introgression line IL 12-4 (S. pennellii in a S. lycopersicum background) was selected for transcriptomic analysis because it maintained differences in AsA levels compared to the parental genotypes M82 and S. pennellii over three consecutive trials. Comparative microarray analysis of IL 12-4 and M82 fruits over a 2-year period allowed 253 differentially-expressed genes to be identified, suggesting that AsA accumulation in IL 12-4 may be caused by a combination of increased metabolic flux and reduced utilization of AsA. In particular, the upregulation of a pectinesterase and two polygalacturonases suggests that AsA accumulation in IL12-4 fruit is mainly achieved by increasing flux through the L-galactonic acid pathway, which is driven by pectin degradation and may be triggered by ethylene.

Conclusions

Based on functional annotation, gene ontology classification and hierarchical clustering, a subset of the 253 differentially-expressed transcripts was used to develop a model to explain the higher AsA content in IL 12-4 fruits in terms of metabolic flux, precursor availability, demand for antioxidants, abundance of reactive oxygen species and ethylene signaling.