VLBI measurement of the vector baseline between geodetic antennas at Kokee Park Geophysical Observatory, Hawaii.

We measured the components of the 31-m-long vector between the two very-long-baseline interferometry (VLBI) antennas at the Kokee Park Geophysical Observatory (KPGO), Hawaii, with approximately 1 mm precision using phase delay observables from dedicated VLBI observations in 2016 and 2018. The two KPGO antennas are the 20 m legacy VLBI antenna and the 12 m VLBI Global Observing System (VGOS) antenna. Independent estimates of the vector between the two antennas were obtained by the National Geodetic Survey (NGS) using standard optical surveys in 2015 and 2018. The uncertainties of the latter survey were 0.3 and 0.7 mm in the horizontal and vertical components of the baseline, respectively. We applied corrections to the measured positions for the varying thermal deformation of the antennas on the different days of the VLBI and survey measurements, which can amount to 1 mm, bringing all results to a common reference temperature. The difference between the VLBI and survey results are 0.2 ± 0.4 mm, -1.3 ± 0.4 mm, and 0.8 ± 0.8 mm in the East, North, and Up topocentric components, respectively. We also estimate that the Up component of the baseline may suffer from systematic errors due to gravitational deformation and uncalibrated instrumental delay variations at the 20 m antenna that may reach ± 10 and -2 mm, respectively, resulting in an accuracy uncertainty on the order of 10 mm for the relative heights of the antennas. Furthermore, possible tilting of the 12 m antenna increases the uncertainties in the differences in the horizontal components to 1.0 mm. These results bring into focus the importance of (1) correcting to a common reference temperature the measurements of the reference points of all geodetic instruments within a site, (2) obtaining measurements of the gravitational deformation of all antennas, and (3) monitoring local motions of the geodetic instruments. These results have significant implications for the accuracy of global reference frames that require accurate local ties between geodetic instruments, such as the International Terrestrial Reference Frame (ITRF).

Modernizing and Expanding the NASA Space Geodesy Network to Meet Future Geodetic Requirements.

NASA maintains and operates a global network of Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), and Global Navigation Satellite System (GNSS) ground stations as part of the NASA Space Geodesy Program. The NASA Space Geodesy Network (NSGN) provides the geodetic products that support Earth observations and the related science requirements as outlined by the US National Research Council (NRC 2010, 2018). The Global Geodetic Observing System (GGOS) and the NRC have set an ambitious goal of improving the Terrestrial Reference Frame (TRF) to have an accuracy of 1 millimeter and stability of 0.1 millimeters per year, an order of magnitude beyond current capabilities. NASA and its partners within GGOS are addressing this challenge by planning and implementing modern geodetic stations co-located at existing and new sites around the world. In 2013, NASA demonstrated the performance of its next-generation systems at the prototype next-generation core site at NASA's Goddard Geophysical and Astronomical Observatory in Greenbelt, Maryland. Implementation of a new broadband VLBI station in Hawaii was completed in 2016. NASA is currently implementing new VLBI and SLR stations in Texas and is planning the replacement of its other aging domestic and international legacy stations. In this article, we describe critical gaps in the current global network and discuss how the new NSGN will expand the global geodetic coverage and ultimately improve the geodetic products. We also describe the characteristics of a modern NSGN site and the capabilities of the next-generation NASA SLR and VLBI systems. Finally, we outline the plans for efficiently operating the NSGN by centralizing and automating the operations of the new geodetic stations.

Impacto de una intervención educativa sobre asma en los profesores / Impact of an asthma educational intervention programme on teachers

Objetivo: Determinar el impacto de una intervención educativa en el nivel de conocimientos de los profesores sobre el asma y su manejo. Material y método: Estudio cuasiexperimental, de tipo antes y después, con grupo control, de una intervención educativa (IE) dirigida a mejorar el grado de conocimientos sobre el asma infantil y su manejo en profesores de centros escolares de San Sebastián (Gipuzkoa). Se utilizó como elemento de medida el cuestionario de conocimientos Newcastle Asthma Knowledge Questionnaire (NAKQ) y como intervención educativa, una adaptación del programa Asma, Deporte y Salud. Se utilizó el test de los rangos con signo de Wilcoxon para comparar la puntuación total en el cuestionario antes y después de la intervención, el test de McNemar para comparar el porcentaje de respuestas correctas a cada ítem y el test U de Mann-Whitney para la comparación en la puntuación basal y a los 3 meses entre el grupo de intervención y el grupo control. Se estudiaron el tamaño del efecto y la respuesta media estandarizada. Resultados: Participaron 138 docentes de 6 centros elegidos aleatoriamente (grupo estudio) y 43 en el grupo control. En el grupo estudiado la puntuación media del cuestionario de conocimientos de asma NAKQ antes de la realización de la intervención educativa fue de 16,1±3,4 puntos, con una mediana de 16 (rango 7-23). Tras la intervención educativa, la puntuación ascendió a 22,3±4,1 con una mediana de 23 (rango 6-29), siendo la diferencia media en la puntuación global de conocimientos de 7,0±4,2 puntos, con una mediana de 8 (rango -2; 17), tamaño del efecto de 2,0(>0,8) siendo la respuesta media estandarizada de 1,7. A los 3 meses de la intervención, la puntuación media del cuestionario fue de 21,4±3,0 puntos, con una mediana de 22 (rango 12-29), significativamente superior al momento previo a la intervención (p<0,001) y algo menor que el inmediatamente posterior a la misma, suponiendo un tamaño del efecto de 1,6 y una respuesta media estandarizada de 1,2. En el grupo control no se modificó el nivel de conocimientos, permaneciendo más bajo que el grupo intervenido (p<0,001). Conclusiones: Una intervención educativa dirigida a los profesores aumenta significativamente el nivel de conocimientos sobre el asma. Además, el incremento disminuye algo pero se mantiene elevado durante al menos 3 meses. Algunos aspectos del conocimiento, aunque mejoran con la intervención educativa, no son óptimos (AU)

Objective: Our objective was to measure the impact of an educational intervention program on teacher's knowledge about asthma and its management. Material and method: Before and after quasi-experimental study, with control group, of an educational intervention, which had as its aim to improve the teacher's knowledge of asthma and its management, was conducted in some schools of San Sebastian (Gipuzkoa), Spain. The Newcastle Asthma knowledge Questionnaire (NAKQ) was used as a measuring tool, and an adaptation of the asthma, sport and health program was used as an educational intervention. The Wilcoxon signed rank test was used to compare the total score of the questionnaire before and after the intervention, and the McNemar test was performed to compare the percentages of correct answers to each item. The Mann-Whitney U test was also performed to compare the baseline score and the score at three months between the intervention group and control group. The size of the effect and the standardised mean response were studied. Results: A total of 138 teachers from 6 schools, which were chosen at random (study group), and 43 teachers in the control group participated in the study. In the study group, the mean score of the NAKQ before the educational intervention was 16.1±3.4 points, with a median of 16 (range 7 to 23). After the intervention the mean score increased to 22.3±4.1, with a median of 23 (range, 6 to 29). The mean difference in the overall score of the NAKQ was 7.0±4.2 points, with a median of 8 (range, -2 to17). Furthermore, the size of the effect was 2.0 (> 0.8) and the standardised mean response was 1.7. After 3 months of the intervention the mean score of the NAKQ was 21.4±3.0 points, with a median of 22 (range, 12 to 29) which was significantly higher than the score obtained before the intervention (P<0.001) and slightly lower than the score obtained immediately after the intervention, assuming a size of the effect of 1.6 and a standardised mean response of 1.2. In the control group, the level of knowledge did not change modified and was lower than the level of the intervention group (P<0.001). Conclusions: An educational intervention program conducted among teachers significantly increases their knowledge of asthma. Moreover, the increase reduces slightly but maintains its higher level for at least 3 months. In spite of the fact that some aspects of knowledge improved with the educational intervention, they were not optimal (AU)

[Impact of an asthma educational intervention programme on teachers]. / Impacto de una intervención educativa sobre asma en los profesores.

OBJECTIVE: Our objective was to measure the impact of an educational intervention program on teacher's knowledge about asthma and its management. MATERIAL AND METHOD: Before and after quasi-experimental study, with control group, of an educational intervention, which had as its aim to improve the teacher's knowledge of asthma and its management, was conducted in some schools of San Sebastian (Gipuzkoa), Spain. The Newcastle Asthma knowledge Questionnaire (NAKQ) was used as a measuring tool, and an adaptation of the asthma, sport and health program was used as an educational intervention. The Wilcoxon signed rank test was used to compare the total score of the questionnaire before and after the intervention, and the McNemar test was performed to compare the percentages of correct answers to each item. The Mann-Whitney U test was also performed to compare the baseline score and the score at three months between the intervention group and control group. The size of the effect and the standardised mean response were studied. RESULTS: A total of 138 teachers from 6 schools, which were chosen at random (study group), and 43 teachers in the control group participated in the study. In the study group, the mean score of the NAKQ before the educational intervention was 16.1±3.4 points, with a median of 16 (range 7 to 23). After the intervention the mean score increased to 22.3±4.1, with a median of 23 (range, 6 to 29). The mean difference in the overall score of the NAKQ was 7.0±4.2 points, with a median of 8 (range, -2 to17). Furthermore, the size of the effect was 2.0 (> 0.8) and the standardised mean response was 1.7. After 3 months of the intervention the mean score of the NAKQ was 21.4±3.0 points, with a median of 22 (range, 12 to 29) which was significantly higher than the score obtained before the intervention (P<.001) and slightly lower than the score obtained immediately after the intervention, assuming a size of the effect of 1.6 and a standardised mean response of 1.2. In the control group, the level of knowledge did not change modified and was lower than the level of the intervention group (P<.001). CONCLUSIONS: An educational intervention program conducted among teachers significantly increases their knowledge of asthma. Moreover, the increase reduces slightly but maintains its higher level for at least 3 months. In spite of the fact that some aspects of knowledge improved with the educational intervention, they were not optimal.

Association among lung function, exhaled nitric oxide, and the CAN questionnaire to assess asthma control in children.

BACKGROUND: The aim of this study was to investigate the association among a validated symptom-based questionnaire for asthma control in children (CAN), forced expiratory volume in 1 sec (FEV(1)), and fractional exhaled nitric oxide (FE(NO)). METHODS: Observational cross-sectional study was performed in a consecutive sample of asthmatic children aged between 7 and 14 years old from December 2007 to February 2008. FE(NO) was measured with a portable electrochemical analyzer and forced spirometry was performed according to American Thoracic Society/European Respiratory Society. The CAN questionnaire was completed by the parents (aged <9 years old) or by the children (> or = 9 years old). The strength of the association among FEV(1), FE(NO), and CAN questionnaire was studied using Spearman's rho, and the degree of agreement for asthma control among FEV(1), FE(NO), and CAN questionnaire, with classification of these variables according to values of normality, was studied using Pearson's chi(2) test and Cohen's kappa (KC). RESULTS: We studied 268 children, mean age 9.7 +/- 2.1 years. Significant correlations were found between FE(NO) and CAN (r = 0.2), between FEV(1) and CAN (r = -0.3), and between FE(NO) and FEV(1) (r = -0.12). On classifying the variables according to values of normality, no agreement was found to establish the degree of asthma control between FE(NO) and CAN (KC = 0.18, chi(2) Pearson = 9.63); between FEV(1) and CAN (KC = 0.29, chi(2) = 38.5); or between FE(NO) and FEV(1) (KC = 0.07, chi(2) = 4.9). CONCLUSIONS: The association among the three measurement instruments used to assess asthma control (FEV(1), FE(NO), and CAN) was weak. These are instruments that quantify variables that influence asthma in different ways, in this sense, none can be used instead of another in asthma management although they are complementary.

Subcontinental-scale crustal velocity changes along the Pacific-North America plate boundary.

Transient tectonic deformation has long been noted within approximately 100 km of plate boundary fault zones and within active volcanic regions, but it is unknown whether transient motions also occur at larger scales within plates. Relatively localized transients are known to occur as both seismic and episodic aseismic events, and are generally ascribed to motions of magma bodies, aseismic creep on faults, or elastic or viscoelastic effects associated with earthquakes. However, triggering phenomena and systematic patterns of seismic strain release at subcontinental (approximately 1,000 km) scale along diffuse plate boundaries have long suggested that energy transfer occurs at larger scale. Such transfer appears to occur by the interaction of stresses induced by surface wave propagation and magma or groundwater in the crust, or from large-scale stress diffusion within the oceanic mantle in the decades following clusters of great earthquakes. Here we report geodetic evidence for a coherent, subcontinental-scale change in tectonic velocity along a diffuse approximately 1,000-km-wide deformation zone. Our observations are derived from continuous GPS (Global Positioning System) data collected over the past decade across the Basin and Range province, which absorbs approximately 25 per cent of Pacific-North America relative plate motion. The observed changes in site velocity define a sharp boundary near the centre of the province oriented roughly parallel to the north-northwest relative plate motion vector. We show that sites to the west of this boundary slowed relative to sites east of it by approximately 1 mm yr(-1) starting in late 1999.

Anomalous strain accumulation in the yucca mountain area, nevada

Global Positioning System (GPS) surveys from 1991 to 1997 near Yucca Mountain, Nevada, indicate west-northwest crustal elongation at a rate of 1.7 +/- 0.3 millimeters per year (1final sigma) over 34 kilometers, or 50 +/- 9 nanostrain per year. Global Positioning System and trilateration surveys from 1983 to 1997 on a 14-kilometer baseline across the proposed repository site for high-level radioactive waste indicate that the crust extended by 0.7 to 0.9 +/- 0.2 millimeter per year (50 to 64 +/- 14 nanostrain per year), depending on the coseismic effect of the Ms 5.4 1992 Little Skull Mountain earthquake. These strain rates are at least an order of magnitude higher than would be predicted from the Quaternary volcanic and tectonic history of the area.