bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maize Pollen Dispersal under Convective Conditions
Authors: Boehm Matthew T. , Aylor Donald E. , Shields Elson J. 
Published: February 2008

Abstract
The widespread adoption of genetically modified (GM) crops has led to a need to better understand the atmospheric transport of pollen because of concerns over potential cross-pollination between GM and non-GM crops. Maize pollen concentrations were modeled by a modified Lagrangian stochastic (LS) model of the convective boundary layer (CBL) and were compared with concentrations measured by airborne remotely piloted vehicles (RPVs) flown from directly above to 2 km from source fields. The turbulence parameterization in an existing CBL LS model was modified to incorporate the effects of shear-driven turbulence, which has an especially large impact near the surface, where maize pollen is released. The modified model was used to calculate concentrations corresponding to the RPV flight tracks. For the most convective cases, when at least 95% of the pollen came from sources near the RPV flight track for which source strength measurements are available and the results are less sensitive to uncertainty in wind direction since most of the pollen came from directly beneath the flight track, the geometric mean of the ratio between the modeled and measured concentrations was 0.94. When cases with larger contributions from more distant fields were included, the overall geometric mean decreased to 0.43. The scatter of the measured concentrations about the modeled values followed a lognormal distribution. These results indicate that the modified model presented herein can substantially improve the description of the near-source dispersion of heavy particles released near the surface during convective conditions.
Comparison of Gridded Multisatellite Rainfall Estimates with Gridded Gauge Rainfall over West Africa
Authors: Lamptey Benjamin L. 
Published: February 2008

Abstract
Two monthly gridded precipitation datasets of the Global Precipitation Climatology Project (GPCP; the multisatellite product) and the Global Precipitation Climatology Centre (GPCC) Variability Analysis of Surface Climate Observations (VASClimO; rain gauge data) are compared for a 22-yr period, from January 1979 to December 2000, over land areas (i.e., latitudes 4°–20°N and longitudes 18°W–15°E). The two datasets are consistent with respect to the spatial distribution of the annual and seasonal rainfall climatology over the domain and along latitudinal bands. However, the satellite generally overestimates rainfall. The inability of the GPCC data to capture the bimodal rainfall pattern along the Guinea coast (i.e., south of latitude 8°N) is an artifact of the interpolation of the rain gauge data. For interannual variability, the gridded multisatellite and gridded gauge datasets agree on the sign of the anomaly 15 out of the 22 yr (68% of the time) for region 1 (between longitude 5° and 18°W and north of latitude 8°N) and 18 out of the 22 yr (82% of the time) for region 2 (between longitude 5°W and 15°E and north of latitude 8°N). The datasets agreed on the sign of the anomaly 14 out of the 22 yr (64% of the time) over the Guinea Coast. The magnitudes of the anomaly are very different in all years. Most of the years during which the two datasets did not agree on the sign of the anomaly were years with El Niño events. The ratio of the seasonal root-mean-square differences to the seasonal mean rainfall range between 0.24 and 2.60. The Kendall’s tau statistic indicated statistically significant trends in both datasets, separately.
Development of a Global Infrared Land Surface Emissivity Database for Application to Clear Sky Sounding Retrievals from Multispectral Satellite Radiance Measurements
Authors: Seemann Suzanne W. , Borbas Eva E. , Knuteson Robert O. , Stephenson Gordon R. , Huang Hung-Lung 
Published: February 2008

AbstractA global database of infrared (IR) land surface emissivity is introduced to support more accurate retrievals of atmospheric properties such as temperature and moisture profiles from multispectral satellite radiance measurements. Emissivity is derived using input from the Moderate Resolution Imaging Spectroradiometer (MODIS) operational land surface emissivity product (MOD11). The baseline fit method, based on a conceptual model developed from laboratory measurements of surface emissivity, is applied to fill in the spectral gaps between the six emissivity wavelengths available in MOD11. The six available MOD11 wavelengths span only three spectral regions (3.8–4, 8.6, and 11–12 μm), while the retrievals of atmospheric temperature and moisture from satellite IR sounder radiances require surface emissivity at higher spectral resolution. Emissivity in the database presented here is available globally at 10 wavelengths (3.6, 4.3, 5.0, 5.8, 7.6, 8.3, 9.3, 10.8, 12.1, and 14.3 μm) with 0.05° spatial resolution. The wavelengths in the database were chosen as hinge points to capture as much of the shape of the higher-resolution emissivity spectra as possible between 3.6 and 14.3 μm. The surface emissivity from this database is applied to the IR regression retrieval of atmospheric moisture profiles using radiances from MODIS, and improvement is shown over retrievals made with the typical assumption of constant emissivity.
Analysis of Near-Surface Atmospheric Variables: Validation of the SAFRAN Analysis over France
Authors: Quintana-Seguí P. , Le Moigne P. , Durand Y. , Martin E. , Habets F. , Baillon M. , Canellas C. , Franchisteguy L. , Morel S. 
Published: February 2008

Abstract
Système d’analyse fournissant des renseignements atmosphériques à la neige (SAFRAN) is a mesoscale atmospheric analysis system for surface variables. It produces an analysis at the hourly time step using ground data observations. One of SAFRAN’s main features is that it is based on climatically homogeneous zones and is able to take vertical variations into account. Originally intended for mountainous areas, it was later extended to cover France. This paper focuses on the validation of the extended version. The principle of the analysis is described and its quality was tested for five parameters (air temperature, humidity, wind speed, rainfall, and incoming radiation), using Météo-France’s observation network and data of some well-instrumented stations. Moreover, SAFRAN’s rainfall was compared with another analysis, known as analyse utilisant le relief pour l’hydrométéorologie (Aurelhy). Last, two different versions of SAFRAN were compared for mountain conditions. Temperature and relative humidity were well reproduced, presenting no bias. Wind speed was also well reproduced; however, its bias was −0.3 m s–1. The interpolation from the 6-h time step of the analysis to the 1-h time step was one of the sources of error. The precipitation analysis was robust and not biased; its root-mean-square error was 2.4 mm day−1. This error was mainly due to the spatial heterogeneity of the precipitation within the geographical zones of analysis (1000 km2). The analysis of incoming solar radiation presented some biases, especially in coastal areas. The results of the comparison with some well-instrumented sites were encouraging. SAFRAN is being run operationally at Météo-France on a real-time basis for various applications.
Organizational Learning Mechanisms: The Meaning, Measure, and Implications for School Improvement
Authors: Schechter Chen 
Published: February 2008

Purpose: In light of the excessively broad conceptions and nonobservable terms generally characterizing discussions of organizational learning, this study explores the notion of organizational learning in schools through the conceptual framework of organizational learning mechanisms (OLM) and develops a measure of OLM at the elementary school level. Research Design: Exploratory and confirmatory factor analyses of items are conducted to examine factorial validity. To test the criterion-related validity, the OLM scale is correlated to other established constructs. Findings: Based on information processing (management science perspective), the four-factor model of OLM in elementary schools is the best fit between the empirical results and the conceptual formulation. The four-factor model includes the following subscales: analyzing information, storing—retrieving—putting to use of information, receiving—disseminating information, and seeking information. Implications: This study strengthens the feasibility of the OLM framework, based on information processing, to provide a concrete description of organizational learning processes in schools. Using this instrument, schools can assess their own learning cycle, gauging their readiness and increasing their preparation for becoming learning organizations. This study may encourage researchers to explore whether OLM can serve as mediating variable between the system level and the classroom level.
Leadership for Teacher Learning: A Community of Practice Perspective
Authors: Printy Susan M. 
Published: February 2008

Purpose: The study is a two-stage inquiry into the influence of high school principals and department chairpersons on the nature of science and mathematics teachers' community of practice participation. Of particular interest is the extent to which formal leaders influence the formation of productive communities of practice and the extent to which leaders affect teachers' professional beliefs and their instructional skills. Research Design: Using the National Educational Longitudinal Study of 1988 (NELS:88) Second Follow-up Teacher File, measures for the analysis are constructed with the Rasch model. Analysis proceeds in two stages using hierarchical linear modeling. The first stage investigates the importance of school leaders to mathematics and science teachers' participation in productive communities of practice. The second stage looks at the relationship between school leadership and teachers' competence and pedagogical skills, net of the influence of communities of practice. Findings: Results suggest that both principals and department chairpersons are instrumental in shaping opportunities for teachers to learn in communities of practice. Furthermore, results show that principals are well removed from the instructional concerns of teachers and that department chairpersons might serve to slow down the rate of instructional change. Conclusions: The connections between school-level leadership and teachers' social learning in their communities of practice have drawn the recent attention of those writing about and conducting research on teacher communities. Researchers, practitioners, and policy makers want to know if school leaders can make a difference in how teachers think about their work and the quality of their instruction in classrooms. Findings offer insight into important links in the causal chain between leadership and student achievement.
Recovery of the Menisci and Articular Cartilage of Runners after Cessation of Exercise
Authors: Kessler Markus A. , Glaser Christian , Tittel Sylvia , Reiser Maximilian , Imhoff Andreas B. 
Published: February 2008

Background It is still unclear whether long-distance running has a deleterious effect on joint health; therefore, this study was undertaken to examine the rate of recovery from alterations occurring at the knee joint in marathon runners due to loading. Hypothesis Tibial, patellar, and meniscal cartilaginous volumes are able to recover adequately from changes due to repeated loading immediately after cessation. Study Design Controlled laboratory study. Methods Twenty knees of male athletes were studied (mean age, 38 ± 14 years). The participants ran 20 km around a predetermined and precisely measured course. Cartilaginous volume was measured by magnetic resonance imaging before the run (60-min rest before exercise), immediately after the run (3-min delay), and after a recovery period of 1 hour. Results After the 20-km run, there was a significant transient decrease in cartilage volume. After 1 hour of rest, no significant reduction of cartilage volume was measured for the patella (−2.1 %), the tibia (−1.2%), the lateral meniscus (−3.2%), or the medial meniscus (−5.9%). However, the values recorded for the menisci were borderline, which indicates that recovery of meniscus volume lags behind that of articular cartilage. Conclusion Our data indicate a clear tendency toward rapid recovery of the cartilaginous and meniscal volumes at the knee. The results of this study lead to the assumption that the cartilage and the menisci are well able to adapt to the loads caused by running. Investigation of more subtle changes would require more specific magnetic resonance imaging techniques, including T2-weighted mapping and T1-weighted rho sequences, to assess cartilage biochemistry. Clinical Relevance The articular structures were investigated on a general magnetic resonance imaging level and were found to recover rapidly so that exercise could be continued after a short time without reservation.
Ciclesonide improves measures of small airway involvement in asthma
Authors: Cohen J. , Douma W. R. , ten Hacken N. H. T. , Vonk J. M. , Oudkerk M. , Postma D. S. 
Published: February 2008

Ciclesonide is delivered as a small-particle inhaled corticosteroid and improves lung function and airway hyperresponsiveness. The objective of the present study was to assess whether ciclesonide can specifically improve small airway function in asthma.A total of 16 mild-to-moderate asthma patients (seven males; median (range) age 39 (19–56) yrs and forced expiratory volume in one second (FEV1) 89 (62–120)% predicted) were randomised to 5 weeks’ treatment with placebo or 320 μg ciclesonide once daily. The following small airway parameters were assessed: mean forced expiratory flow between 25 and 75% of forced vital capacity (FVC), percentage fall in FVC at provocative dose of adenosine-5′-monophosphate and of methacholine (MCh) causing a 20% fall in FEV1, expiratory lung volume on computed tomography (CT) scan after MCh challenge, single-breath nitrogen closing volume and alveolar exhaled nitric oxide (eNO).Seven subjects received placebo and nine received ciclesonide. Both alveolar eNO and CT measurements of expiratory lung volume after MCh challenge decreased significantly with ciclesonide (median (range) decrease 4.4 (54.8–1.4) ppb and 59 (1,569– -117) mL, respectively), and compared with placebo (-0.4 (7.3– -3.4) ppb and -121 (20– -236) mL respectively). Ciclesonide did not significantly improve other small airways parameters.Inflammation and patency of small airways, reflected by alveolar exhaled nitric oxide and air trapping on computed tomography scan, both improve with ciclesonide even in this small number of patients. This indicates that ciclesonide exerts anti-inflammatory effects on small airways.
Outcome of community-acquired pneumonia: influence of age, residence status and antimicrobial treatment
Authors: Kothe H. , Bauer T. , Marre R. , Suttorp N. , Welte T. , Dalhoff K. ,   the Competence Network for Community-Acquired Pneumonia study group
Published: February 2008

Community-acquired pneumonia remains a major cause of mortality in developed countries. There is much discrepancy in the literature regarding factors influencing the outcome in the elderly population.Data were derived from a multicentre prospective study initiated by the German Competence Network for Community-Acquired Pneumonia. Patients with community-acquired pneumonia (n = 2,647; 1,298 aged <65 yrs and 1,349 aged ≥65 yrs) were evaluated, of whom 72.3% were hospitalised and 27.7% treated in the community. Clinical history, residence status, course of disease and antimicrobial treatment were prospectively documented. Microbiological investigations included cultures and PCR of respiratory samples and blood cultures. Factors related to mortality were included in multivariate analyses.The overall 30-day mortality was 6.3%. Elderly patients exhibited a significantly higher mortality rate that was independently associated with the following: age; residence status; confusion, urea, respiratory frequency and blood pressure (CURB) score; comorbid conditions; and failure of initial therapy. Increasing age remained predictive of death in the elderly. Nursing home residents showed a four-fold increased mortality rate and an increased rate of Gram-negative bacillary infections compared with patients dwelling in the community. The CURB score and cerebrovascular disease were confirmed as independent predictors of death in this subgroup.Age and residence status are independent risk factors for mortality after controlling for comorbid conditions and disease severity. Failure of initial therapy was the only modifiable prognostic factor.
High levels of Epstein–Barr virus in COPD
Authors: McManus T. E. , Marley A-M. , Baxter N. , Christie S. N. , Elborn J. S. , O'Neill H. J. , Coyle P. V. , Kidney J. C. 
Published: February 2008

Latent viral infection has been implicated in the pathophysiology of chronic obstructive pulmonary disease (COPD). Epstein–Barr virus (EBV) is known to be important in pulmonary fibrosis. The current authors hypothesised that EBV is associated with the pathogenesis of COPD.Sputum samples were collected from patients both during exacerbations of COPD and when stable. A control group of smokers who did not have airways obstruction also had their sputum examined. The presence of EBV DNA was established and quantified using a real-time nucleic acid amplification assay.A total of 136 patients with COPD were recruited during an acute exacerbation and a total of 68 when stable. EBV was detected in 65 (48%) exacerbation cases and 31 (46%) stable patients. In the comparison group of 16 nonobstructed smokers, EBV was demonstrated in only one (6%) case. Risk of COPD in patients with EBV and who are smokers confers an odds ratio of 12.6.Epstein–Barr virus DNA is more frequently identified in the respiratory tract of chronic obstructive pulmonary disease patients in comparison with unaffected smokers. It is present both during exacerbation and when stable, suggesting that infection is persistent. Smokers who do not develop chronic obstructive pulmonary disease rarely have Epstein–Barr virus in their sputum. This finding may be of importance in the pathogenesis of chronic obstructive pulmonary disease.
Children at high altitude have less nocturnal periodic breathing than adults
Authors: Kohler M. , Kriemler S. , Wilhelm E. M. , Brunner-LaRocca H. , Zehnder M. , Bloch K. E. 
Published: February 2008

Although children commonly travel to high altitudes, their respiratory adaptation to hypoxia remains elusive. Therefore, in the present study respiratory inductive plethysmography, pulse oximetry (Sp,O2) and end-tidal CO2tension (PET,CO2) were recorded in 20 pre-pubertal children (aged 9–12 yrs) and their fathers during 1 night in Zurich (490 m) and 2 nights at the Swiss Jungfrau-Joch research station (3,450 m) following ascent by train within <3 h.In children, mean±sdnocturnalSp,O2fell from 98±1% at 490 m to 85±4 and 86±4% at 3,450 m (nights 1 and 2, respectively);PET,CO2decreased significantly from 37±6 to 32±3 and 33±4 mmHg (3,450versus490 m). In adults, changes in nocturnalSp,O2andPET,CO2at 3,450 m were similar to those in children.Children spent less time in periodic breathing at 3,450 m during night 1 and 2 (8±11 and 9±13%, respectively) than adults (34±24 and 22±17%, respectively), and their apnoea threshold for CO2was lower compared with adults (27±2 and 30±2 mmHg, respectively, both nights).Sp,O2,PET,CO2and time in periodic breathing at altitude were not correlated between children and their fathers.In conclusion, children revealed a similarly reduced nocturnal O2saturation and associated hyperventilation at high altitude as adults but their breathing pattern was more stable, possibly related to a lower apnoea threshold for CO2.
Adrenal function in patients with community-acquired pneumonia
Authors: Gotoh S. , Nishimura N. , Takahashi O. , Shiratsuka H. , Horinouchi H. , Ono H. , Uchiyama N. , Chohnabayashi N. 
Published: February 2008

Adrenal insufficiency is believed to occur frequently in severe sepsis and septic shock. The aim of the present study was to determine whether adrenal function is also related to the severity of community-acquired pneumonia (CAP).In total, 64 Japanese patients with CAP were consecutively enrolled in the present study, which was carried out during 2005–2006. Serum adrenocorticotropic hormone (ACTH) and cortisol were measured in each subject, as was the response of cortisol secretion when 250 μg of cosyntropin was administered. Analyses were performed comparing these values with the score calculated according to the Pneumonia Patient Outcomes Research Team (PORT) cohort study, the number of in-hospital deaths and the length of hospital stay.As the PORT score increased, serum ACTH and cortisol also increased, while the response of cortisol secretion to the administration of cosyntropin decreased. In the analysis by receiver operating characteristic curves, adrenal dysfunction was related significantly to both the number of in-hospital deaths and the length of hospital stay.Adrenal dysfunction was shown to correlate with the Pneumonia Patient Outcomes Research Team score and the clinical outcomes, while adrenal insufficiency defined by the cosyntropin stimulation test was rare in the present study.
Coverage and yield of entry and follow-up screening for tuberculosis among new immigrants
Authors: Erkens C. , Slump E. , Kamphorst M. , Keizer S. , van Gerven P. J. H. J. , Bwire R. , Berkel M. , Borgdorff M. W. , Verver S. 
Published: February 2008

The aim of the present study was to determine the effectiveness of entry screening for tuberculosis and biannual follow-up screening among new immigrants in the Netherlands.To achieve this, the present authors analysed screening, prevalence and incidence data of 68,122 immigrants, who were followed for 29 months. Patients diagnosed within 5 months and 6–29 months after entry screening were considered to be detected at entry and during the follow-up period, respectively.Coverage of the second to fifth screening rounds was 59, 46, 36 and 34%, respectively. Yield of entry screening was 119 per 100,000 individuals, and prevalence at entry was 131 per 100,000. Average yield of follow-up screening was highest among immigrants with abnormalities on chest radiography (CXR) at entry (902 per 100,000 individuals). When excluding these, yield of follow-up screening was 9, 37 and 97 per 100,000 screenings for immigrants from countries with tuberculosis incidences of <100, 100–200 and >200 per 100,000, respectively. The incidence during follow-up in individuals with a normal CXR was 11, 58 and 145 per 100,000 person-yrs follow-up in these groups. The proportion of cases detected through screening declined per screening round from 91 to 31%.Yield of entry screening was high. Overall coverage and yield of follow-up screening was low. Follow-up screening of immigrants with a normal chest radiograph from countries with an incidence of <200 per 100,000 individuals was therefore discontinued.