bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Health System Performance at District Level: A Study Protocol
Authors: Sharma Atul , Prinja Shankar , Aggarwal Arun Kumar
Published: January 2018

Background

Limited efforts have been observed in low and middle income countries to undertake health system performance assessment at district level. Absence of a comprehensive data collection tool and lack of a standardised single summary measure defining overall performance are some of the main problems. Present study has been undertaken to develop a summary composite health system performance index at district level.

Methods

A broad range of indicators covering all six domains as per building block framework were finalized by an expert panel. The domains were classified into twenty sub-domains, with 70 input and process indicators to measure performance. Seven sub-domains for assessing health system outputs and outcomes were identified, with a total of 28 indicators. Districts in Haryana state from north India were selected for the study. Primary and secondary data will be collected from 378 health facilities, district and state health directorate headquarters. Indicators will be normalized, aggregated to generate composite performance index at district level. Domain specific scores will present the quality of individual building block domains in the public health system. Robustness of the results will be checked using sensitivity analysis.

Expected impact for public health

The study presents a methodology for comprehensive assessment of all health system domains on basis of input, process, output and outcome indicators which has never been reported from India. Generation of this index will help identify policy and implementation areas of concern and point towards potential solutions. Results may also help understand relationships between individual building blocks and their sub-components.
Set Theory
Authors: Farah Ilijas , Friedman Sy-David , Schindler Ralf-Dieter , Woodin W. Hugh
Published: January 2018

This workshop included selected talks on pure set theory and its applications, simultaneously showing diversity and coherence of the subject.
Representation Theory of Quivers and Finite Dimensional Algebras
Authors: Crawley-Boevey William , Iyama Osamu , Krause Henning
Published: January 2018

Methods and results from the representation theory of quivers and finite dimensional algebras have led to many interactions with other areas of mathematics. Such areas include the theory of Lie algebras and quantum groups, commutative algebra, algebraic geometry and topology, and in particular the theory of cluster algebras. The aim of this workshop was to further develop such interactions and to stimulate progress in the representation theory of algebras.
Mini-Workshop: Spaces and Moduli Spaces of Riemannian Metrics
Authors: Farrell F. Thomas , Tuschmann Wilderich
Published: January 2018

The mini-workshop focused on central questions and new results concerning spaces and moduli spaces of Riemannian metrics with lower or upper curvature bounds on open and closed manifolds and, moreover, related themes from Anosov geometry. These are all described in detail below. The event brought together young and senior researchers working about (moduli) spaces of negative and nonnegative sectional, nonnegative Ricci and positive scalar curvature as well as Anosov metrics, and the talks and discussions brought about many new and inspiring research problems to pursue.
Mini-Workshop: Stochastic Differential Equations: Regularity and Numerical Analysis in Finite and Infinite Dimensions
Authors: Hutzenthaler Martin , Lang Annika , Szpruch Lukasz , Yaroslavtseva Larisa
Published: January 2018

This Mini-Workshop is devoted to regularity and numerical analysis of stochastic ordinary and partial differential equations (SDEs for both). The standard assumption in the literature on SDEs is global Lipschitz continuity of the coefficient functions. However, many SDEs arising from applications fail to have globally Lipschitz continuous coefficients. Recent years have seen a prosper growth of the literature on regularity and numerical approximations for SDEs with non-globally Lipschitz coefficients. Some surprising results have been obtained – e.g., the Euler–Maruyama method diverges for a large class of SDEs with super-linearly growing coefficients, and the limiting equation of a spatial discretization of the stochastic Burgers equation depends on whether the discretization is symmetric or not. Several positive results have been obtained. However the regularity of numerous important SDEs and the closely related question of convergence and convergence rates of numerical approximations remain open. The aim of this workshop is to bring together the main contributers in this direction and to foster significant progress.
Traducción didáctica, subtitulado y TIC: proyectos en colaboración en el aula de L2
Authors: Reig Gascon Aina
Published: January 2018

Este artículo pretende contribuir al debate sobre la importancia de la traducción didáctica en el aula de lengua extranjera mediante la ilustración de su uso como recurso didáctico y herramienta de aprendizaje. Se presentan las bases metodológicas que fundamentan una propuesta materializada en tres proyectos de traducción colaborativa llevados a cabo en la educación superior, concretamente en un aula de catalán como lengua extranjera (CLE) de la Université de Picardie Jules Verne (Francia), en entornos de naturaleza presencial y virtual. Estas prácticas se agrupan en tres secuencias didácticas distintas que giran alrededor de un género discursivo determinado –un videoclip, un anuncio publicitario y una receta– y se organizan a través del trabajo en equipo.
Desarrollo de una secuencia didáctica basada en el programa Leer para Aprender:propuesta deaproximación al género narración en la educación primaria en Chile
Authors: Westhoff Ingrid
Published: January 2018

Este trabajo describe un modelo de secuencia didáctica para el desarrollo de la lectura y la escritura del género narración en alumnos de 6º Grado de Educación Primaria en el contexto chileno. La organización y fundamentación teórica de la secuencia didáctica está basada, en la pedagogía de los géneros (Genre Pedagogy) y en el programa pedagógico Reading to Learn, Leer para Aprender desarrollado por el profesor David Rose (2014). La propuesta presentada forma parte de un proyecto de creación de un corpus de plani-ficaciones didácticas organizadas según las tres familias de géneros descritas en Rose y Martin (2012), con el fin posterior de implementarlas y evaluar sus resultados en las aula de un colegio de alta vulnerabilidad social localizado en Viña del Mar, Chile.
¿Qué piensan los estudiantes universitarios frente a la formación investigativa??
Authors: Pinto Santos Alba Ruth , Cortés Peña Omar Fernando
Published: January 2018

Este artículo de investigación presenta un análisis del aporte e impacto que tiene el proceso de formación sobre el desarrollo de competencias investigativas en estudiantes universitarios. Metodológicamente se asumió una investigación holística, operacionalizada a partir de un diseño mixto triangulado. La muestra se seleccionó aleatoriamente, contando con la participación de 104 estudiantes de últimos semestres de la Universidad de la Guajira. Las técnicas e instrumentos empleados fueron los foros de discusión y análisis de contenidos a nivel cualitativo, mientras que a nivel cuantitativo se aplicó una Escala de Actitudes frente a la Formación Investigativa, con un nivel de Confiabilidad Alfa de Cronbach de (α: ,849) e indicadores de consistencia interna (correlación ítem – escala) positivos y superiores a (r: ,30). El procesamiento estadístico de los datos se realizó en el programa SPSS versión 21. A partir de los resultados de orden cualitativo, se resalta que la existencia de contenidos curriculares en el campo de formación en investigación, no es garantía de desarrollo de competencias investigativas. En el orden cuantitativo, se destaca que el 90% de los estudiantes considera que el programa al que pertenece debe revaluar la forma como orienta la formación investigativa. La contrastación de los hallazgos permitió identificar la necesidad de generar espacios de reflexión para el desarrollo de estrategias de innovación educativa que permita enriquecer los modelos curriculares, así como la promoción de los escenarios extracurriculares para el desarrollo de las competencias investigativas.
Los sentidos otorgados por el alumnado universitario a una experiencia de innovación basada en el construccionismo social
Authors: Muñoz de Bustillo Díaz Mª del Carmen , García Hernández Maria Dolores , Romero Evelyn , Peláez Amador Yexuanj , Rodríguez Alonso Silvia
Published: January 2018

El trabajo visibiliza cómo es significada por el alumnado una experiencia de innovación docente en la universidad que despliega el proceso enseñanza-aprendizaje desde las ideas del construccionismo social (Gergen, 2015). Sus valoraciones fueron abordadas desde una perspectiva emic (San Martín, 2014), empleando el software de análisis cualitativo ATLAS.ti7.  El alumnado (26) expresa que ha vivido una experiencia educativa inusual, siendo la flexibilidad la cualidad que reconocen como clave de la misma, en consonancia con propuestas pedagógicas comprometidas con la co-construcción del conocimiento. Los significados dados por el alumnado revalorizan la educación presencial, el aula es el lugar en el que se produce un aprendizaje inusual y un boom de ideas, subrayando su utilidad como espacio relacional que nutre la creatividad colaborativa.  Emergen desafíos que invitan a la reflexión acerca de cómo seguir diseñando propuestas de innovación educativa en la universidad desde la generación relacional del conocimiento.
¿Es interactiva la enseñanza en la Educación Superior? La perspectiva del alumnado
Authors: Álvarez Álvarez Carmen
Published: January 2018

La investigación ha puesto de manifiesto las ventajas que tiene la docencia basada en la interacción y el diálogo entre el alumnado y entre este y el profesorado en las aulas. Sin embargo, en España, la interacción como método de enseñanza-aprendizaje es aún empleada minoritariamente. En este artículo nos preguntamos por el estado de esta cuestión en el ámbito de la Educación Superior.  Para dar respuesta a este interrogante se recoge una investigación exploratoria basada en la realización de cincuenta entrevistas en profundidad con estudiantes de todos los campos de conocimiento en dos universidades españolas.  Los resultados muestran que los métodos didácticos de docencia universitaria habituales en la universidad española responden a un paradigma educativo de corte expositivo en el que los casos de enseñanza-aprendizaje por interacción constituyen episodios aislados.  Asimismo, fuera del marco espacio-temporal de las aulas tampoco se producen numerosos encuentros interactivos para la enseñanza-aprendizaje entre el alumnado y entre el alumnado y el profesorado. Los resultados también muestran qué aspectos facilitan la interacción y qué aspectos la entorpecen. Es posible concluir la necesidad y urgencia de introducir prácticas de enseñanza-aprendizaje por interacción en la universidad española: el alumnado demanda un cambio metodológico y quienes han tenido algunas experiencias interactivas aseguran haberse implicado más en el estudio, haber profundizado más en el contenido, haber disfrutado con la materia y haber obtenido mejores resultados académicos. Las prácticas de enseñanza-aprendizaje por interacción son imprescindibles en la mejora de la calidad docente en el ámbito de la educación superior.
Wild rabbit restocking: Suitable acclimation conditions foster adaptive behaviour and improve survival of captive reared rabbits
Authors: Machado R. D. , Magalhães P. , Godinho S. , Santos P.
Published: January 2018

Wild rabbit is a very important species in the Mediterranean region. Its relevance is both ecological, being a keystone species —prey for several predators— and economic, as it is the most important and the most managed small game species among mammals in the Iberian Peninsula. Although both researchers and game managers claim restocking operations have moderate to low success, it is still one of the management measures often used by conservationists and hunters to recover or boost wild rabbit populations. The high mortality usually verified in the first days after release is the main limiting factor in rabbit restocking. Based on practical research, protocols have improved, pointing out good practices and suggestions to increase success. Adopting soft instead of hard-release protocols has been proven to increase short-term survival after liberation. Aware that purchased rabbits seldom display a quick adaptation to the field, we performed two restocking experiments with different conditions (acclimation period and park size) in order to compare the outcomes in terms of survival rate. The rabbit batch that experienced a longer acclimation period in a larger park showed higher survival rates, as well as more frequent and much larger spatial movements. These results suggest that proper conditions during acclimation may contribute to the success of wild rabbit restocking operations.
Clinical chemistry, haematology, immune response and histological evaluation of rabbits after immunisation and challenge with rabbit haemorrhagic disease (RHD) virus
Authors: Stancu C. A. , Cărpinișan L. , Ghișe A. , Marcu A. , Pentea M. C. , Dumitrescu E. , Muselin F. , Militaru D. , Cristina R. T.
Published: January 2018

Following their immunisation and infection with a VSHI-CN-6 viral strain, a group of 15 rabbits were examined in a study of Rabbit Haemorrhagic Disease (RHD). Serum samples were collected from the external ear vein at 0, 15, 30 and 60 days post-immunisation. The recorded platelet numbers were closer to the lower physiological limit, indicating a mild thrombocytopenia, with values ranging from 26.6 to 30.43×104/mm3. The phagocytic index revealed significant differences (P<0.001) between the mean values obtained before vaccination (day 0) and the 3 post-vaccination measurements, confirming the increase in phagocytic capacity after immunisation. Additionally, the serum lysozyme average value equalled 9.14 mg/mL post-vaccination. The analysis of variance revealed significant statistical differences (P<0.05) between the average values obtained before vaccination (0) and the post-vaccination values, measured on day 14 and 30, respectively. The morphology of the samples collected from the main organs involved in immune protection, spleen and gastric and portal lymph nodes highlighted changes corresponding to the post-vaccination immunological response. The white pulp of the spleen appeared as a diffuse lymphoid tissue, presenting with primary and secondary lymphoid follicles. The ratio of white/red pulp was in favour of the white pulp and multiple lymphoid follicles were present, indicating their reactivation. In the medullary area of gastric and portal lymph nodes, narrow lymphoid cords, circumscribed by relatively large lymphatic sinuses, and well defined lymphocytolysis were observed. Moreover, the exudate and lymphoid follicles during activation were noted in the cortical area. Furthermore, the inflammatory processes were identified, morphologically manifested by the thickening of connective tissue in the lymph node capsule, dilacerations of the connective fibres and the presence of light acidophilic serous exudate with rare inflammatory cells (serous lymphoreticulitis).
Surgical Outcome of Thyroid Nodules with Atypia of Undetermined Significance and Follicular Lesion of Undetermined Significance in Fine Needle Aspiration Biopsy
Authors: Alqahtani Saad , Alsobhi Saif , Alsalloum Riyadh I , Najjar Saleh N , Al-Hindi Hindi N
Published: January 2018

Aim

To correlate selected clinical and ultrasonographic (US) characteristics with the final histopathological diagnosis in patients with atypia of undetermined significance (AUS) and follicular lesion of undetermined significance (FLUS), and whether this information can be used in planning the surgical approach.

Materials and methods

It is a retrospective study including the operated cases of AUS/FLUS from 2011 to 2014 treated at one center.

Results

This cohort included 87 women and 28 men. To test for independence between categorical variables, the chi-square test was used. There was no significant correlation between age or US variables and final pathological diagnosis. However, final diagnosis of malignancy was higher in men compared with women (64.3 and 41.4% respectively; p = 0.035). Furthermore, a significant association between the diagnosis of repeated fine needle aspiration biopsy (FNAB) and the final pathological diagnosis was noted (benign vs malignant, p = 0.005).

Conclusion

The FNAB has a significant role in the assessment of thyroid nodules. Our results showed no correlation between age, US variables, and the risk of malignancy. Male gender is associated with higher risk of malignancy.

Clinical significance

Determining the risk of malignancy and prediction of surgical outcome may help triaging cases for repeat FNA or proceeding to surgery.

How to cite this article

Alqahtani S, Alsobhi S, Alsalloum RI, Najjar SN, Al-Hindi HN. Surgical Outcome of Thyroid Nodules with Atypia of Undetermined Significance and Follicular Lesion of Undetermined Significance in Fine Needle Aspiration Biopsy. World J Endoc Surg 2017;9(3):100-103.
Ship-based MAX-DOAS measurements of tropospheric NO2, SO2, and HCHO distribution along the Yangtze River
Authors: Hong Qianqian , Liu Cheng , Chan Ka Lok , Hu Qihou , Xie Zhouqing , Liu Haoran , Si Fuqi , Liu Jianguo
Published: January 2018

Abstract. In this paper, we present ship-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements of tropospheric trace gases distribution along Yangtze River during winter 2015. The measurements were performed along Yangtze River between Shanghai and Wuhan covering major industrial areas in eastern China. Tropospheric vertical column densities (VCDs) of nitrogen dioxide (NO2), sulfur dioxide (SO2), and formaldehyde (HCHO) were retrieved using air mass factor calculated by radiative transfer model. Enhanced tropospheric NO2 and SO2 VCDs were detected over downwind areas of industrial zones over Yangtze River. In addition, spatial distributions of atmospheric pollutants are strongly affected by meteorological conditions, i.e., positive correlations were found between concentration of pollutants and wind speed over these areas indicating strong influence of transportation of pollutants from high-emission upwind areas along Yangtze River. Comparison of tropospheric NO2 VCDs between ship-based MAX-DOAS and OMI satellite observations shows good agreement with each other with Pearson correlation coefficient (R) of 0.82. In this study, NO2/SO2 ratio was used to estimate the relative contributions of industrial sources and vehicle emissions to ambient NO2 levels. Analysis results of NO2/SO2 ratio shows that higher contribution of industrial NO2 emissions in Jiangsu province, while NO2 levels in Jiangxi and Hubei provinces are mainly related to vehicle emissions. These results indicate that different pollution control strategies should be applied in different provinces. In addition, multiple linear regression analysis of ambient carbon monoxide (CO) and odd oxygen (Ox) indicated that the primary emission and secondary formation of HCHO contribute 54.4 ± 3.7 % and 39.3 ± 4.3 % to the ambient HCHO, respectively. The largest contribution from primary emissions in winter suggested that photochemically induced secondary formation of HCHO is reduced due to lower solar irradiance in winter. Our findings provide an improved understanding of major pollution sources along the eastern part of Yangtze River which are useful for designing specific air pollution control policies.
Reconstructing volcanic plume evolution integrating satellite and
ground-based data: Application to the 23rd November 2013 Etna
eruption
Authors: Poret Matthieu , Corradini Stefano , Merucci Luca , Costa Antonio , Andronico Daniele , Montopoli Mario , Vulpiani Gianfranco , Freret-Lorgeril Valentin
Published: January 2018

Abstract. Recent explosive eruptions recorded from different volcanoes worldwide (e.g. Hekla in 2000, Eyjafjallajökull in 2010, Cordón-Caulle in 2011) demonstrated the necessity of a better assessment of the eruption source parameters (e.g. column height, mass eruption rate and especially the Total Grain-Size Distribution – TGSD) to reduce the uncertainties associated with the far-travelling airborne ash mass. To do so, volcanological studies started to integrate observations in order to use more realistic numerical inputs, crucial for taking robust volcanic risk mitigation actions. On 23rd November 2013, Etna volcano (Italy) erupted producing a 10-km height plume, from which two volcanic clouds were observed at two different altitudes from satellite (MSG-SEVIRI, MODIS). One was described as mainly composed by very fine ash (i.e. PM20), whereas the second one as made of ice/SO2 droplets (i.e. not measurable in terms of ash mass). Atypical north-easterly winds transported the tephra from Etna towards the Puglia region (southern Italy), permitting tephra sampling in proximal (i.e. ~ 5–25–km from source) and medial areas (i.e. Calabria region, ~ 160 km). Based on the field data analysis, we estimated the TGSD but the paucity of data (especially related to the fine ash fraction) prevented it from being entirely representative of the initial magma fragmentation. To better estimate the TGSD covering the entire grain-size spectrum, we integrated the available field data with X-band weather radar and satellite retrievals. The resulting TGSD is used as input for the FALL3D tephra dispersal numerical model to reconstruct the tephra loading and the far-travelling airborne ash mass. The optimal TGSD is selected by solving an inverse problem through a best-fit with the field, ground-based and satellite-based measurements. The results suggest a total erupted mass of 1.2 × 109 kg, which is very similar to the field-derived value of 1.3 × 109 kg, and a TGSD with a PM20 fraction between 3.6 and 9.0 wt%.
Nitrate-driven haze pollution during summertime over the North China
Plain
Authors: Li Haiyan , Zhang Qiang , Zheng Bo , Chen Chunrong , Wu Nana , Guo Hongyu , Zhang Yuxuan , Zheng Yixuan , Li Xin , He Kebin
Published: January 2018

Abstract. Compared to the severe winter haze episodes in the North China Plain (NCP), haze pollution during summertime has drawn little public attention. In this study, we present the highly time-resolved chemical composition of submicron particles (PM1) measured in Beijing and Xinxiang in the NCP region during summertime to evaluate the driving factors of aerosol pollution. During the campaign periods (30 June to 27 July, 2015, for Beijing and 8 to 25 June, 2017, for Xinxiang), the average PM1 concentrations were 35.0 μg m−3 and 64.2 μg m−3 in Beijing and Xinxiang, respectively. Pollution episodes characterized with largely enhanced nitrate concentrations were observed at both sites. In contrast to the slightly decreased mass fractions of sulfate, semi-volatile oxygenated organic aerosol (SV-OOA), and low-volatile oxygenated organic aerosol (LV-OOA) in PM1, nitrate displayed an almost linearly increased contribution with the aggravation of aerosol pollution in both Beijing and Xinxiang, highlighting the importance of nitrate formation as the driving force of haze evolution in summer. Rapid nitrate production mainly occurred after midnight, with a higher formation rate than that of sulfate, SV-OOA, or LV-OOA. Detailed investigation of nitrate behaviors revealed several factors influencing the rapid nitrate formation in summer: high ammonia emissions in the NCP region, the gas-to-particle equilibrium of ammonium nitrate closely related to variations in temperature and relative humidity, nighttime nitrate production through heterogeneous hydrolysis of dinitrogen pentoxide (N2O5), and regional transport from different air mass origins. Finally, atmospheric particulate nitrate data acquired by mass spectrometric techniques from various field campaigns in Asia, Europe, and North America uncovered a higher concentration and higher fraction of nitrate present in China. Although measurements in Beijing during different years demonstrate a decline in the nitrate concentration in recent years, the nitrate contribution in PM1 still remains high. To effectively alleviate particulate matter pollution in summer, our results call for the urgent need to initiate ammonia emission control measures and further reduce nitrogen oxide emissions over the NCP region.
Observation of Kelvin-Helmholtz Instabilities and gravity waves in the summer mesopause above Andenes in Northern Norway
Authors: Stober Gunter , Sommer Svenja , Schult Carsten , Latteck Ralph , Chau Jorge L.
Published: January 2018

Abstract. We present observations obtained with the Middle Atmosphere Alomar Radar System (MAARSY) to investigate short period wave-like features using polar mesospheric summer echoes (PMSE) as tracer for the neutral dynamics. We conducted a multi-beam experiment including 67 different beam directions during a 9-day campaign in June 2013. We identified two Kelvin Helmholtz Instability (KHI) events from the signal morphology of PMSE. The MAARSY observations are complemented by collocated meteor radar wind data to determine the mesoscale gravity wave activity and the vertical structure of the wind field above the PMSE. The KHIs occurred in a strong shear flow with Richardson numbers Ri
High resolution modeling of gaseous methylamines over a polluted region in China: Source-dependent emissions and implications to spatial variations
Authors: Mao Jingbo , Yu Fangqun , Zhang Yan , An Jingyu , Wang Lin , Zheng Jun , Yao Lei , Luo Gan , Ma Weichun , Yu Qi , Huang Cheng , Li Li , Chen Limin
Published: January 2018

Abstract. Amines have received increasing attention in recent years because of their potential role in new particle formation in the atmosphere and their impact on aerosol chemistry. High concentrations of amines are expected to be limited to the vicinity of source regions due to their short lifetime, highlighting the necessity of having a better understanding of contributions of emissions from different source types. This study presents the first high-resolution model simulation of methylamines concentrations on a regional scale over the Yangtze River Delta region in east China. The WRF-Chem with nested grids is used in model simulations. In contrast to the very limited existing modeling studies that assumed a fixed ratio (FR) of amines to total ammonia emission, we derive source-dependent ratios (SDR) that distinguish C1-amine (CH3NH2), C2-amines (C2H7N), C3-amines (C3H9N) emissions from five different source types (agriculture, residential, transportation, chemical industry, and other industry). The amines-to-ammonia mass emission ratios, estimated from previous measurements, are 0.026, 0.0015, 0.0011, 0.0011, and 0.0011 for C1-amine, 0.007, 0.0018, 0.0015, 0.01, and 0.0009 for C2-amines, and 0.0004, 0.0005, 0.00043, 0.0006, and 0.0004 for C3-amines for chemical-industrial, other industrial, agricultural, residential, and transportational sources, respectively. The simulated concentrations of C1-, C2-, and C3-amines, based on both FR and SDR, have been compared with field measurements at a suburban site in Nanjing and at an urban site in Shanghai, China. SDR substantially improves the model’s ability in capturing the observed concentrations of methylamines. C1-, C2-, and C3-amines concentrations in the surface layer in the Yangtze River Delta region are generally in the range of 2–20 pptv, 5–50 pptv, and 0.5–4 pptv. Vertically, the concentrations of C1-, C2-, and C3-amines decrease quickly with altitude, dropping by a factor of ~ 10 from the surface to ~ 900 hPa. Results from the present study are critical to evaluating potential roles of amines in nucleation and chemical processes in polluted air.
Source apportionment of organic aerosol from two-year highly time-resolved measurements by an aerosol chemical speciation monitor in Beijing, China
Authors: Sun Yele , Xu Weiqi , Zhang Qi , Jiang Qi , Canonaco Francesco , Prévôt André S. H. , Fu Pingqing , Li Jie , Jayne John , Worsnop Douglas R. , Wang Zifa
Published: January 2018

Abstract. Organic aerosol (OA) represents a large fraction of submicron aerosols in the megacity of Beijing, yet long-term characterization of its sources and variations is very limited. Here we present analysis of in situ measurements of OA in submicrometer particles with an aerosol chemical speciation monitor (ACSM) for two years from July 2011 to May 2013. The sources of OA are analyzed with multilinear engine (ME-2) by constraining three primary OA factors including fossil fuel related OA (FFOA), cooking OA (COA), and biomass burning OA (BBOA). Two secondary OA (SOA), representing a less oxidized oxygenated OA (LO-OOA) and a more oxidized (MO-OOA) are identified during all seasons. The monthly average concentration OA varied from 13.6 to 46.7 µg m−3 with a strong seasonal pattern that is usually highest in winter and lowest in summer. FFOA and BBOA show similarly pronounced seasonal variations with much higher concentrations and contributions in winter due to enhanced coal combustion and biomass burning emissions. The contribution of COA to OA, however, is relatively stable (10–15 %) across different seasons, yet presents significantly higher values at low relative humidity levels (RH < 30 %), highlighting the important role of COA during clean periods. The two SOA factors present very different seasonal variations. The pronounced enhancement of LO-OOA concentrations in winter indicates that emissions form combustion-related primary emissions could be a considerable source of SOA under low temperature (T) conditions. Comparatively, MO-OOA shows high concentrations consistently at high RH levels across different T levels, and the contribution of MO-OOA to OA is different seasonally with lower values occurring more in winter (30–34 %) than other seasons (47–64 %). Overall, SOA (= LO-OOA + MO-OOA) dominates OA composition during all seasons by contributing 52–64 % of the total OA mass in heating season, and 65–75 % in non-heating seasons. The variations of OA composition as a function of OA mass loading further illustrates the dominant role of SOA in OA across different mass loading scenarios during all seasons. However, we also observed a large increase in FFOA associated with a corresponding decrease in MO-OOA during periods with high OA mass loadings in heating season, illustrating an enhanced role of coal combustion emissions during highly polluted episodes. Potential source contribution function analysis further shows that the transport from the regions located to the south and southwest of Beijing within ~200 km can contribute substantially to high FFOA and BBOA concentrations in heating season.
Evaluation of Himawari-8 surface downwelling solar radiation by SKYNET observations
Authors: Damiani Alessandro , Irie Hitoshi , Horio Takashi , Takamura Tamio , Khatri Pradeep , Takenaka Hideki , Nagao Takashi , Nakajima Takashi Y. , Cordero Raul R.
Published: January 2018

Abstract. Observations from the new Japanese geostationary satellite Himawari-8 permit quasi-real-time estimation of global shortwave radiation at an unprecedented temporal resolution. However, accurate comparisons with ground truthing observations are essential to assess their uncertainty. In this study, we evaluated the Himawari-8 global radiation product AMATERASS using observations recorded at four SKYNET stations in Japan and, for certain analyses, from the surface network of the Japanese Meteorological Agency in 2016. We found that the spatiotemporal variability of the satellite estimates was smaller than that of the ground observations; variability decreased with increases in the time step and spatial domain. Cloud variability was the main source of uncertainty in the satellite radiation estimates, followed by direct effects caused by aerosols and bright albedo. Under all-sky conditions, good agreement was found between satellite and ground-based data, with a mean bias in the range of 20–30 W/m2 (i.e., AMATERASS overestimated ground observations) and a root mean square error of approximately 80 W/m2. However, results depended on the time step used in the validation exercise and on the spatial domain. We also detected a limited overestimation in the number of clear-sky episodes, particularly at the pixel level. Overall, satellite-based estimates were higher under overcast conditions, whereas frequent episodes of cloud-induced enhanced surface radiation (i.e., measured radiation was greater than expected clear-sky radiation) tended to reduce this difference. Finally, the total mean bias was reduced to approximately 10–15 W/m2 under clear-sky conditions, mainly because of overall instantaneous direct aerosol forcing efficiency in the range of 120–150 W/m2 per unit of aerosol optical depth (AOD). A seasonal anti-correlation between AOD and global radiation differences was evident at all stations and was also observed within the diurnal cycle.
Production of highly oxygenated organic molecules (HOMs) from trace contaminants during isoprene oxidation
Authors: Bernhammer Anne-Kathrin , Fischer Lukas , Mentler Bernhard , Heinritzi Martin , Simon Mario , Hansel Armin
Published: January 2018

Abstract. During nucleation studies from pure isoprene oxidation in the CLOUD chamber at CERN we observed unexpected ion signals at m/z = 137.133 (C10H17+) and m/z = 81.070 (C6H9+) with the recently developed proton transfer reaction time-of-flight mass spectrometer (PTR3‑TOF) instrument. The mass-to-charge ratios of these ion signals typically correspond to protonated monoterpenes and their main fragment. We identified two origins of these signals: First secondary association reactions of protonated isoprene with isoprene within the PTR3 reaction chamber and secondly [4+2] cycloaddition (Diels-Alder) of isoprene inside the gas bottle which presumably forms the favoured monoterpenes limonene and sylvestrene, as known from literature. Under our PTR3 conditions used in 2016 an amount (relative to isoprene) of 2 % is formed within the PTR3 reaction chamber and 1 % is already present in the gas bottle. The presence of unwanted cycloaddition products in the CLOUD chamber impacts the nucleation studies by creating ozonolysis products as corresponding monoterpenes, and is responsible for the majority of the observed highly oxygenated organic molecules (HOMs). In order to study NPF from pure isoprene oxidation under atmospheric relevant conditions, it is important to improve and assure the quality and purity of the precursor isoprene. This was successfully achieved by cryogenically trapping lower volatility compounds such as monoterpenes before isoprene was introduced into the CLOUD chamber.
Upside-down fluxes Down Under: CO2 net sink in winter and net source in summer in a temperate evergreen broadleaf forest
Authors: Renchon Alexandre A. , Griebel Anne , Williams Christopher A. , Medlyn Belinda , Duursma Remko A. , Barton Craig V. M. , Maier Chelsea , Boer Matthias M. , Isaac Peter , Tissue David , Resco de Dios Victor , Pendall Elise
Published: January 2018

Abstract. Predicting the seasonal dynamics of ecosystem carbon fluxes is challenging in broadleaved evergreen forests because of their moderate climates and subtle changes in canopy phenology. We assessed the climatic and biotic drivers of the seasonality of net ecosystem-atmosphere CO2 exchange (NEE) of a eucalyptus-dominated forest near Sydney, Australia, using the eddy covariance method. The climate is characterized by a mean annual precipitation of 800 mm and a mean annual temperature of 18 °C, hot summers and mild winters, with highly variable precipitation. In the three-year study, the ecosystem was a small sink in 2014 (54 g C m−2 y−1), a stronger sink in 2015 (183 g C m−2 y−1) and even stronger sink in 2016 (337 g C m−2 y−1), but these variations were not related to precipitation. Daily net C uptake was always detected during the cooler, drier winter months (June through August), while net C loss occurred during the warmer, wetter summer months (December through February). Gross primary productivity (GPP) seasonality was low, despite longer days with higher light intensity in summer, because vapour pressure deficit (D) and air temperature (Ta) restricted surface conductance during summer while winter temperatures were still high enough to support photosynthesis. Maximum GPP during ideal environmental conditions was correlated with canopy leaf area index (LAI) (r2 = 0.24), which increased rapidly after mid-summer rainfall events. Ecosystem respiration (ER) was highest during summer in wet soils and lowest during winter months. ER had larger seasonal amplitude compared to GPP, and therefore drove the seasonal variation of NEE. Because summer carbon uptake may become increasingly limited by atmospheric drought and high temperature, and ecosystem respiration could be enhanced by rising temperature, our results suggest the potential for large-scale seasonal shifts in NEE in sclerophyll vegetation under climate change.
Carbon accumulation in a drained boreal bog was decreased but not stopped by seasonal drought
Authors: Minkkinen Kari , Ojanen Paavo , Penttilä Timo , Aurela Mika , Laurila Tuomas , Tuovinen Juha-Pekka , Lohila Annalea
Published: January 2018

Abstract. Drainage of peatlands is expected to turn these ecosystems to carbon sources to the atmosphere. We measured carbon dynamics of a drained forested peatland in southern Finland over four years, including one with severe drought during growing season. Net ecosystem exchange (NEE) of carbon dioxide (CO2) was measured with eddy covariance method from a mast above the forest. Soil and forest floor CO2 and methane (CH4) fluxes were measured from the strips and from ditches with closed chambers. Biomasses and litter production were sampled, and soil subsidence was measured by repeated levellings of the soil surface. The drained peatland ecosystem was a strong sink of carbon dioxide in all studied years. Soil CO2 balance was estimated by subtracting the carbon sink of the growing tree stand from NEE, and it showed that also the soil was a sink of carbon. A drought period in one summer significantly decreased the sink through decreased gross primary production. Drought also decreased ecosystem respiration. The site was a small sink for CH4, even when emissions from ditches were taken into account. Despite the continuous carbon sink, peat surface subsided slightly during the 10-year measurement period, which was probably mainly due to compaction of peat. It is concluded that even fifty years after drainage this peatland site acted as a soil C sink due to relatively small changes in water table and in plant community structure compared to similar undrained sites, and the significantly increased tree stand growth and litter production. Although the site is currently a soil C sink, simulation studies with process models are needed to test whether such sites could remain C sinks when managed for forestry over several tree-stand rotations.
A Database of 10 min Average Measurements of Solar Radiation and
Meteorological Variables in Ostrava, Czech Republic
Authors: Opálková Marie , Navrátil Martin , Špunda Vladimír , Blanc Philippe , Wald Lucien
Published: January 2018

Abstract. A database containing 10 min means of downward surface solar irradiance measured on a horizontal plane in several ultraviolet and visible bands from July 2014 to December 2016 at three stations in the area of the city of Ostrava (Czech Republic) is presented. The database contains time series of 10 min average irradiances or photosynthetic photon flux densities measured in the following spectral bands: [280, 315] nm (UVB); [315, 380]  nm (UVA); [400, 700] nm (photosynthetically active radiation, PAR); [510, 700] nm; [600, 700] nm; [610, 680] nm; [690, 780] nm; [400, 1100] nm. A series of meteorological variables including relative air humidity and air temperature at surface is also provided at the same 10 min time step at all three stations, and in addition air pressure, wind speed and wind direction at two stations. These two stations offer additional data: PM10, SO2, NOx, NO, NO2 concentrations. The details of the experimental sites and instruments used for the measurements are given. Special attention is given to the data quality, and the process applied to label suspicious or erroneous measurements is described in detail. About 130 000 records for all three stations are available in the database. This database offers a unique ensemble of variables having a high temporal resolution and it is a reliable source on radiation in relation with environment and vegetation in highly polluted areas of industrial cities in the middle of Europe. The database has been placed on the PANGAEA repository (https://doi.pangaea.de/10.1594/PANGAEA.879722) and contains individual data files of the three stations.
Seismic signature of turbulence during the 2017 Oroville Dam spillway erosion crisis
Authors: Goodling Phillip J. , Lekic Vedran , Prestegaard Karen
Published: January 2018

Abstract. Knowing the location of large-scale turbulent eddies during catastrophic flooding events improves predictions of erosive scour. The erosion damage to the Oroville Dam flood control spillway in early 2017 is an example of the erosive power of turbulent flow. During this event, a defect in the simple concrete channel quickly eroded into a chasm 47 meters deep. Erosion by turbulent flow is difficult to evaluate in real time, but near-channel seismic monitoring provides a tool to evaluate flow dynamics from a safe distance. Previous studies have had limited ability to identify source location or the type of surface wave (i.e. Love or Rayleigh wave) excited by different river processes. Here we use a single three-component seismometer method (Frequency-Dependent Polarization Analysis) to characterize the dominant seismic source location and seismic surface waves produced by the Oroville dam flood control spillway, using the abrupt change in spillway geometry as a natural experiment. We find that the scaling exponent between seismic power and release discharge is greater following damage to the spillway, suggesting larger turbulent eddies excite more seismic energy. The mean azimuth in the 5–10 Hz frequency band was used to resolve the location of spillway damage. Observed polarization attributes deviate from those expected for a Rayleigh wave, though numerical modelling indicates these deviations are explained by propagation up the hillside topography. Our results suggest Frequency-Dependent Polarization Analysis is a promising approach for locating areas of increased flow turbulence. This method could be applied to other erosion problems near engineered structures and to understanding energy dissipation, erosion, and channel morphology development in natural rivers, particularly at high discharges.
The effect of climate on timescales of drought propagation in an ensemble of global hydrological models
Authors: Gevaert Anouk I. , Veldkamp Ted I. E. , Ward Philip J.
Published: January 2018

Abstract. Drought is a natural hazard that occurs at many temporal and spatial scales and has severe environmental and socio-economic impacts across the globe. The impacts of drought change as drought evolves from precipitation deficits to deficits in soil moisture or streamflow. Here, we quantified the time taken for drought to propagate from meteorological drought to soil moisture drought, and from meteorological drought to hydrological drought. We did this by cross-correlating the Standardized Precipitation Index (SPI) against standardized indices of soil moisture, runoff, and streamflow from an ensemble of global hydrological models forced by a consistent meteorological dataset. Drought propagation is strongly related to climate, occurring at sub-seasonal timescales in tropical climates and at up to multi-annual timescales in continental and arid climates. Winter droughts are usually related to longer SPI accumulation periods than summer droughts, especially in continental and tropical savanna climates. The difference between the seasons is likely due to winter snow cover in the former and distinct wet and dry seasons in the latter. Model structure appears to play an important role in model variability, as drought propagation to soil moisture drought is slower in land surface models than in global hydrological models, but propagation to hydrological drought is faster in land surface models than in global hydrological models. The propagation time from SPI to hydrological drought in the models was evaluated against observed data at 297 in-situ streamflow stations. On average, errors between observed and modeled drought propagation timescales are small and the model ensemble mean is preferred over the use of a single model. Nevertheless, there is ample opportunity for improvement as substantial differences in drought propagation are found at 20 % of the study sites. A better understanding and representation of drought propagation in models may help improve seasonal drought forecasting as well as constrain drought variability under future climate scenarios.
Data Assimilation with An Improved Particle Filter and Its Application in TRIGRS Landslide Model
Authors: Xue Changhu , Nie Guigen , Li Haiyang , Wang Jing
Published: January 2018

Abstract. Particle filter has become a popular algorithm in data assimilation for its capability to handle non-linear or non-Gaussian state-space models, while it still be seriously influenced by its disadvantages. In this work, the particle filter algorithm is improved, proposed two methods to overcome the particle degeneration and improve particles’ efficiency. In this algorithm particle-propagating and resample method are ameliorated. The new particle filter is applied to Lorenz-63 model, verified its feasibility and effectiveness using only 20 particles. The root mean square difference(RMSD) of estimations converge to stable when there are more than 20 particles. Finally, we choose a 10 * 10 grid slope model of TRIGRS and carry out an assimilation experiment. Results show that the estimations of states can effectively correct the running-offset of the model and the RMSD is convergent after 3 days assimilation.
Seasonal and interannual (ENSO) climate variabilities and trends in the South China Sea over the last three decades
Authors: Piton Violaine , Delcroix Thierry
Published: January 2018

Abstract. We present a short overview of the long-term mean and variability of five Essential Climate Variables observed in the South China Sea over the last 3 decades, including sea surface temperature (SST), sea level anomaly (SLA), precipitation (P), surface wind and water discharge (WD) from the Mekong and Red Rivers. At the seasonal time scale, SST and SLAs increase in the summer (up to 4.2 °C and 14 cm, respectively), and P increases in the north. The summer zonal and meridional winds reverse and intensify (mostly over the ocean), and the WD shows positive anomalies. At the interannual time scale, each variable appears to be correlated with El Niño Southern Oscillation (ENSO) indices. Eastern Pacific El Niño events produce basin-wide SST warming (up to 1.4 °C) with a 6-month lag. The SLAs fall basin-wide (by up to 9 cm) during an El Niño event (all types), with a 3-month lag. The zonal and meridional winds strengthen (up to 4 m/s) in the north (weaken in the south) during all types of El Niño events, with a 3–5-month lag. A rainfall deficit of approximately 30 % of the mean occurs during all types of El Niño phases. The Mekong River WD is reduced by 1/3 of the mean 7–8 months after all types of El Niño events. We also show increasing trends of SST as high as 0.24 °C/decade and SLAs by 41 mm/decade. Increasing trends are observed for zonal wind, which is possibly linked to the phase of the Pacific Decadal Oscillation, and decreasing trends are observed for P in the north and both WD stations that were analyzed. The likely driving mechanisms and some of the relationships between all observed anomalies are discussed