bluuebunny/crossref_metadata_2025 huggingface dataset:
Three Japanese Patients With Congenital Pituitary Hormone Deficiency and Ophthalmological Anomalies
Authors: Takanashi Kuniko , Suzuki Yashuto , Noro Ayumu , Sugiyama MInako , Nakanishi Masanori , Nagashima Tetsuro , Nakamura Akie , Katsura Ishizu , Tajima Toshihiro
Published: July 2011

The clinical phenotype of congenital pituitary hormone deficiency is variable and can be associated with a number of structural abnormalities of the central nervous system. We report three Japanese patients with congenital pituitary hormone deficiency and ophthalmological anomalies. Two of the patients initially showed strabismus and unilateral optic nerve hypoplasia. Thereafter, growth failure became evident, leading to the diagnosis of pituitary hormone deficiency. The other patient had severe congenital hypopituitarism with respiratory distress and hypoglycemia from the first day of life. In addition, he had prolonged jaundice and impaired liver function with bilateral optic nerve hypoplasia. Neuroimaging of the pituitary region in all three patients demonstrated a small anterior pituitary lobe and no pituitary stalk. Our findings indicate that clinical variability of congenital hypopituitarism must be considered. In a patient with ophthalmological symptoms, endocrine evaluation and neuroimaging of the CNS including the pituitary region should be considered.
Teachers’ professional development needs in data handling and probability
Authors: Wessels Helena , Nieuwoudt Hercules
Published: July 2011

Poor Trends in International Mathematics and Science Study (TIMMS) results and widespread disappointing mathematics results in South Africa necessitate research-based and more efficient professional development for in-service mathematics teachers. This article reports on the profiling of mathematics teachers’ statistical knowledge, beliefs and confidence in order to inform the development of in-service teacher education programmes in statistics for Grade 8 and Grade 9 teachers. Ninety mathematics teachers from schools with culturally diverse learner populations in an urban region in South Africa were profiled using an adapted profiling instrument (Watson, 2001). Although statistics formed part of quite a number of these teachers’ initial teacher education and about half of them were involved in professional development in statistics education, they still teach traditionally, rather than using a more data driven approach. Teachers indicated high levels of confidence in teaching most statistics topics but showed low levels of statistical thinking when they had to apply their knowledge of concepts, such as sample and average in social contexts including newspaper articles and research reports.
A review of uncommon cytopathologic diagnoses of pleural effusions from a chest diseases center in Turkey
Authors: Cakir Ebru , Demirag Funda , Aydin Mehtap , Erdogan Yurdanur
Published: July 2011

Background:

After pneumonia, cancer involving the pleura is the leading cause of exudative pleural effusion. Cytologic examination of pleural effusions is an important initial step in management of malignant effusions. The aim of this study is to evaluate the spectrum of uncommon malignant pleural effusions in a chest disease center in Turkey.

Materials and Methods:

A retrospective study of samples of pleural effusions submitted to Ataturk Chest Diseases and Chest Surgery Education and Research Hospital Department of Pathology between March 2005 and November 2008 was performed.

Results:

Out of a total of 4684 samples reviewed 364 (7.8%) were positive for cancer cells. Of the malignant pleural effusions 295 (81%) were classified as adenocarcinoma or carcinoma not otherwise specified (NOS). Pleural effusion specimens revealing a diagnosis other than adenocarcinoma/carcinoma NOS were: 32 (8.8%) malignant mesotheliomas, 14 (3.8%) small cell carcinomas, 13 (3.5%) hematolymphoid malignancies and 10 (2.7%) squamous cell carcinoma. Hematolymphoid malignancies included non- Hodgkin lymphoma (diffuse B large cell lymphoma, mantle cell lymphoma), multiple myeloma, chronic myeloid leukemia, and acute myeloid leukemia.

Conclusions:

Despite that adenocarcinoma is the most common cause of malignant pleural effusions, there is a significant number of hematological and non-hematological uncommon causes of such effusions. Cytopathologists and clinicians must keep in mind these uncommon entities in routine practice for an accurate diagnosis.
Proteomic studies of Anaplasia in Wilms Tumor
Authors: Fan Rong , Grignon David , Gulcicek Erol E. , Faught Philip , Cheng Liang
Published: July 2011

Wilms tumor is the most common malignant tumor in the pediatric kidney. Anaplasia, focal or diffuse as defined by histological criteria, is the most important parameter to guide the clinical treatment plan. We sought to identify and characterize potential useful biomarkers associated with anaplasia and provide insight into the peculiar molecular biology of Wilms tumor with unfavorable histology.

Utilizing isobaric tagging technology for relative and absolute quantitation, coupled with tandem mass spectrometry, we identified proteins that are differently regulated in different Wilms tumor histologies. Four Wilms tumor specimens were selected, including two with classic favorable histology, one with focal anaplasia, and one with diffuse anaplasia. A total of 256 proteins with a Protein Score >1.0 are identified from all samples (proteins with >90% confidence).

Compared with classic favorable morphology: in the focal anaplasia group, we identified a total of 26 proteins of which six were underexpressed and 20 were overexpressed; in the diffuse anaplasia group, we identified a total of 20 proteins of which eight were underexpressed and 12 were overexpressed. With a total of 39 involved proteins, seven were common to both the focal and diffuse anaplasia cases, and clearly seemed to have a similar regulation. The newly identified potential markers for Wilms tumor with unfavorable histology include ENO1, GAPDH, ALDOA, SLC25A6, LDHA, PGAM1, MIF, RBP1, HBA, HP, COL1A1, CFL1, and FSCN1 etc. In Wilms tumors, though there are unfavorable histology differences (focal or diffuse anaplasia), the protein expression seems to be similarly dysregulated compared with the favorable histology group. The newly identified potential markers may provide insights into the molecular biology of Wilms tumor and may have practical implications.
Corrosion Initiation Projection for Reinforced Concrete Exposed to Chlorides: Part 1—Black Bars
Authors: Hartt W.H.
Published: July 2011

A protocol is described whereby time-to-corrosion, Ti, of reinforcing steel in concrete exposed to chlorides is calculated as a distributed, rather than a discrete, parameter. The method consists of inputting distribution functions for surface Cl− concentration (Cs), the effective diffusion coefficient (D), concrete cover over the reinforcement (x), and the critical Cl− concentration threshold to initiate active corrosion (CT) into a governing, first-principles equation from which the fraction of identically exposed, electrochemically independent elements that has initiated corrosion is calculated at a specific time. By doing this for multiple times, a cumulative distribution function (CDF) plot of Ti is developed. Example analyses were performed based upon either literature or assumed distributed Cs, D, x, and CT data. The results indicate that reinforced concrete durability should be characterized not simply in terms of the time at which reinforcement corrosion occurs initially, as is normally the case, but also by the rate at which active corrosion subsequently commences for the remaining passive elements. Further, an important but often overlooked aspect of how Cs is determined or chosen for diffusion analyses in concrete is emphasized. Advantageous attributes of this methodology in which influential variables are distributed are discussed and comparisons made to the more traditional discrete parameter approach.
Publicaciones médicas procesadas en las bases de datos PubMed y CUMED: Cienfuegos 1998-2007
Authors: Hernández Lourdes Luques
Published: July 2011

Objetivo: caracterizar la producción científica de las ciencias médicas de Cienfuegos.Material y Método: estudio descriptivo bibliométrico. Se realizó una búsqueda en las bases dedatos PubMed y CUMED durante el periodo 1998 – 2007. En la estrategia de búsqueda se utilizóla palabra “Cienfuegos” en PubMed y CUMED Habana, mientras en CUMED Cienfuegos “$”.Se analizaron el número de publicaciones, tipo e idioma, nombre de la revista, país editor,institución de procedencia entre otras variables. Fueron excluidos los registros fuera del periodo,repetidos, incongruentes, capturas erróneas, solapamiento, cd-rom, resúmenes, libros.Resultados: se estudiaron un total de 288 publicaciones. En general, el número de publicacionespor años se incrementó progresivamente con una tendencia al incremento, excepto en los dosúltimos años, 2006 y 2007. En PubMed el 51.3% de las publicaciones aparecieron en RevistaNeurología y British Medical Journal, en CUMED Habana el 48.6% aparecieron en Medisur,Revista Cubana de Medicina y Revista Cubana de Pediatría y en CUMED Cienfuegos el 92.2%en Medisur y Finlay. El Hospital Provincial Dr. Gustavo Aldereguía Lima tuvo el mayor númerode publicaciones en PubMed (83.8%) y CUMED Cienfuegos (47.9%). El original fue el tipo depublicación más frecuente con 56.6%. En general predominaron los temas de Medicina Interna(18.1%) y Pediatría (16.3%).Conclusiones: se observó por primera vez, con algunos detalles, cuál ha sido la actividadinvestigadora de los profesionales de la salud en Cienfuegos.
Estratégias metodológicas adotadas nas pesquisas de iniciação científica premiadas na UFPB
Authors: Duarte Emeide Nóbrega , Ramalho Francisca Arruda , Autran Marynice Medeiros Matos , Paiva Eliane Bezerra , Araújo Milena Borges Simões
Published: July 2011

A produção científica, importante para as áreas do conhecimento, necessita adotar estratégias metodológicas e de comunicação. Nesse sentido, encontra-se em fase de conclusão uma pesquisa que tem como objetivo identificar as estratégias metodológicas adotadas nas pesquisas premiadas no âmbito do CCSA/UFPB. Trata-se de uma pesquisa documental com abordagem quantitativa e qualitativa, para a qual se delimitaram cinco categorias de análise: classificação dos temas abordados, identificação dos trabalhos quanto à natureza, identificação quanto ao nível de aprofundamento, delineamento das pesquisas, abordagem metodológica e técnicas/instrumentos adotados que fundamentaram a produção científica premiada. As tendências estratégicas metodológicas refletidas nas pesquisas analisadas indicam uma mudança de paradigma no sentido dos métodos de abordagens. No entanto, a forma de comunicar a metodologia adotada não está clara, evidenciando maior organização das informações entre as partes que compõem os textos.
Os periódicos científicos no compartilhamento da informação e do conhecimento: aspectos extrínsecos dos periódicos eletrônicos Qualis A da área de Ciência da Informação
Authors: Carelli Ana Esmeralda , Giannasi-Kaimen Maria Júlia
Published: July 2011

O periódico desempenha papel central na comunicação cientifica, tornou-se o meio de excelência para o acesso, uso e produção de conhecimento. Na sua transição para o suporte eletrônico, deve-se assegurar sua qualidade, tanto de seu conteúdo como da sua formatação. Esse estudo focaliza, especificamente, os aspectos dos periódicos científicos eletrônicos Qualis A da área de Ciência da Informação. Os dados analisados referem-se a: dados gerais dos periódicos; tempo de existência de cada título; periodicidade; presença dos títulos nos mecanismos de indexação e resumos e em repositórios digitais; seções de cada título; equipe editorial; sistema de organização; sistema de navegação; sistema de rotulagem; sistema de busca; conteúdo das informações; usabilidade do site; e tipos de documentos de comportam (html, pdf etc.). As “Instruções para autores” foi outro item de analise. Em geral, todos os títulos de periódicos desse estudo tiveram desempenho satisfatório nos aspectos analisados. Deve-se também creditar que com o aumento da visibilidade, pois todos os títulos estão disponibilizados na Web, favoreceu maior acesso e uso pela comunidade científica, provavelmente com isto, gerou-se a necessidade de estabelecimento de padrões de excelência, que garantam a qualidade da informação produzida, e também de sua formatação.
Representações profissionais de bibliotecários no Brasil: alguns resultados de pesquisa
Authors: Walter Maria Tereza Machado Teles , Baptista Sofia Galvão
Published: July 2011

As representações profissionais de bibliotecários em atuação no Brasil são apresentadas com base em parte dos resultados da pesquisa de doutorado realizada entre os anos de 2007 e 2008. Foi focalizado, especialmente, aspectos relacionados à percepção dos profissionais com relação aos próprios bibliotecários, à Biblioteconomia, à realidade do mercado de trabalho e das tecnologias de informação e comunicação e à formação profissional. Os resultados para essa pesquisa apontam para avaliações críticas dos profissionais com relação aos seus pares, indicam que a avaliação feita do curso que realizaram, assim como a idade, influenciam na percepção mais positiva ou mais negativa da carreira. Reconhecem que a profissão não é valorizada pela sociedade e associam esse fato a fatores diversos como, por exemplo, o desempenho dos próprios profissionais ou o baixo investimento em educação existente no país.
Gestão de Informação Empresarial com Portais Plone
Authors: Bax Marcello Peixoto , Barbosa Daniel Mendes
Published: July 2011

O artigo discute os requisitos necessários para a gestão adequada da informação em empresas de todos os segmentos. Para ilustrar, mostra-se como é possível implementar com o Plone um portal corporativo utilizando-se de software livre, de forma integrada com o ambiente Windows, proprietário. Por tratar-se do ambiente presente na grande maioria das empresas e organizações da atualidade, um portal que atenda a especificidades da gestão de informação neste contexto, de forma integrada, é fortemente representativo. Com efeito, a integração dos conteúdos no portal com o ambiente Windows, no cliente e não no servidor, não é trivial. O artigo mostra que implantando o portal nesse contexto a empresa avança consideravelmente com relação à gestão da informação. Para tal o artigo foca na descrição dos aspectos positivos que decorrem da implantação de um portal de intranet / extranet nesse contexto, i.e. integração com Windows e com o Office  ou outras aplicações de escritório; controle de edição compartilhada (com check-in e check-out); acesso universal ao acervo pela internet; uso de metadados e automação de processos via workflow.
A construção da memória organizacional utilizando o gerenciamento de processo nas pactuações da comissão intergestores bipartite do Sistema Único de Saúde
Authors: Remor Lourdes de Costa , Rados Gregório Jean Varvakis , Remor Carlos Augusto Monguilhott , Miranda Angélica Conceição Dias
Published: July 2011

O artigo aborda o gerenciamento de processo e a sua implicação na construção da memória organizacional. Apresenta a relevância do conhecimento em uma organização e os danos causados quando eles não são incorporados à memória da organização. O gerenciamento de processo por organizar e sistematizar os trabalhos parece permitir a disseminação do conhecimento dentro da organização, tanto para os indivíduos quanto para os repositórios. E por fim, apresenta o processo da pactuação na Comissão Intergestores Bipartite, Fórum de negociação e tomada de decisão entre os Gestores: Municipais e Estadual do SUS.
In situ measurements of isoprene and monoterpenes within a south-east Asian tropical rainforest
Authors: Jones C. E. , Hopkins J. R. , Lewis A. C.
Published: July 2011

Abstract. Biogenic volatile organic compounds (BVOCs) emitted from tropical rainforests comprise a substantial fraction of global atmospheric VOC emissions, however there are only relatively limited measurements of these species in tropical rainforest regions. We present observations of isoprene, α-pinene, camphene, Δ-3-carene, γ-terpinene and limonene, as well as oxygenated VOCs (OVOCs) of biogenic origin such as methacrolein, in ambient air above a tropical rainforest in Malaysian Borneo during the Oxidant and Particle Photochemical Processes above a south-east Asian tropical rainforest (OP3) project in 2008. Daytime composition was dominated by isoprene, with an average mixing ratio of the order of ~1 ppb. γ-terpinene, limonene and camphene were the most abundant monoterpenes, with average daytime mixing ratios of 102, 71 and 66 ppt respectively, and with an average monoterpene toisoprene ratio of 0.3 during sunlit hours, compared to 2.0 at night. Limonene and camphene abundances were seen to be related to both temperature and light conditions. In contrast, γ-terpinene emission continued into the late afternoon/evening, under relatively low temperature and light conditions. The contributions of isoprene, monoterpenes and other classes of VOC to the volatile carbon budget and OH reactivity have been summarised for this rainforest location. We observe good agreement between surface and aircraft measurements of boundary layer isoprene and methacrolein above the natural rainforest, suggesting that the ground-level observations are broadly representative of isoprene emissions from this region.
Contrasting winter and summer VOC mixing ratios at a forest site in the Western Mediterranean Basin: the effect of local biogenic emissions
Authors: Seco R. , Peñuelas J. , Filella I. , Llusià J. , Molowny-Horas R. , Schallhart S. , Metzger A. , Müller M. , Hansel A.
Published: July 2011

Abstract. Atmospheric volatile organic compounds (VOCs) are involved in ozone and aerosol generation, thus having implications for air quality and climate. VOCs and their emissions by vegetation also have important ecological roles as they can protect plants from stresses and act as communication cues between plants and between plants and animals. In spite of these key environmental and biological roles, the reports on seasonal and daily VOC mixing ratios in the literature for Mediterranean natural environments are scarce. We conducted seasonal (winter and summer) measurements of VOC mixing ratios in an elevated (720 m a.s.l.) holm oak Mediterranean forest site near the metropolitan area of Barcelona (NE Iberian peninsula). Methanol was the most abundant compound among all the VOCs measured in both seasons. While aromatic VOCs showed almost no seasonal variability, short-chain oxygenated VOCs presented higher mixing ratios in summer, presumably due to greater emission by vegetation and increased photochemistry, both enhanced by the high temperatures and solar radiation in summer. Isoprenoid VOCs showed the biggest seasonal change in mixing ratios: they increased by one order of magnitude in summer, as a result of the vegetation's greater physiological activity and emission rates. The maximum diurnal concentrations of ozone increased in summer too, most likely due to more intense photochemical activity and the higher levels of VOCs in the air. The daily variation of VOC mixing ratios was mainly governed by the wind regime of the mountain, as the majority of the VOC species analyzed followed a very similar diel cycle. Mountain and sea breezes that develop after sunrise advect polluted air masses to the mountain. These polluted air masses had previously passed over the urban and industrial areas surrounding the Barcelona metropolitan area, where they were enriched in NOx and in VOCs of biotic and abiotic origin. Moreover, these polluted air masses receive additional biogenic VOCs emitted in the local valley by the vegetation, thus enhancing O3 formation in this forested site. The only VOC species that showed a somewhat different daily pattern were monoterpenes because of their local biogenic emission. Isoprene also followed in part the daily pattern of monoterpenes, but only in summer when its biotic sources were stronger. The increase by one order of magnitude in the concentrations of these volatile isoprenoids highlights the importance of local biogenic summer emissions in these Mediterranean forested areas which also receive polluted air masses from nearby or distant anthropic sources.
Emulation of a complex global aerosol model to quantify sensitivity to uncertain parameters
Authors: Lee L. A. , Carslaw K. S. , Pringle K. , Mann G. W. , Spracklen D. V.
Published: July 2011

Abstract. Sensitivity analysis of atmospheric models is necessary to identify the processes that lead to uncertainty in model predictions, to help understand model diversity, and to prioritise research. Assessing the effect of parameter uncertainty in complex models is challenging and often limited by CPU constraints. Here we present a cost-effective application of variance-based sensitivity analysis to quantify the sensitivity of a 3-D global aerosol model to uncertain parameters. A Gaussian process emulator is used to estimate the model output across multi-dimensional parameter space using information from a small number of model runs at points chosen using a Latin hypercube space-filling design. Gaussian process emulation is a Bayesian approach that uses information from the model runs along with some prior assumptions about the model behaviour to predict model output everywhere in the uncertainty space. We use the Gaussian process emulator to calculate the percentage of expected output variance explained by uncertainty in global aerosol model parameters and their interactions. To demonstrate the technique, we show examples of cloud condensation nuclei (CCN) sensitivity to 8 model parameters in polluted and remote marine environments as a function of altitude. In the polluted environment 95 % of the variance of CCN concentration is described by uncertainty in the 8 parameters (excluding their interaction effects) and is dominated by the uncertainty in the sulphur emissions, which explains 80 % of the variance. However, in the remote region parameter interaction effects become important, accounting for up to 40 % of the total variance. Some parameters are shown to have a negligible individual effect but a substantial interaction effect. Such sensitivities would not be detected in the commonly used single parameter perturbation experiments, which would therefore underpredict total uncertainty. Gaussian process emulation is shown to be an efficient and useful technique for quantifying parameter sensitivity in complex global atmospheric model.
Ultraviolet absorption cross sections of carbonyl sulfide isotopologues OC32S, OC33S, OC34S and O13CS: isotopic fractionation in photolysis and atmospheric implications
Authors: Hattori S. , Danielache S. O. , Johnson M. S. , Schmidt J. A. , Kjaergaard H. G. , Toyoda S. , Ueno Y. , Yoshida N.
Published: July 2011

Abstract. We report measurements of the ultraviolet absorption cross sections of OC32S, OC33S, OC34S and O13CS from 195 to 260 nm. The OCS isotopologues were synthesized from isotopically-enriched elemental sulfur by reaction with carbon monoxide. The measured cross section of OC32S is consistent with literature spectra recorded using natural abundance samples. Relative to the spectrum of the most abundant isotopologue, substitution of heavier rare isotopes has two effects. First, as predicted by the reflection principle, the Gaussian-based absorption envelope becomes slightly more narrow and blue-shifted. Second, as predicted by Franck-Condon considerations, the weak vibrational structure is red-shifted. Sulfur isotopic fractionation constants (33ε, 34ε) as a function of wavelength are not highly structured, and tend to be close to zero on average on the high energy side and negative on the low energy side. Since OCS photolysis occurs in the lower stratosphere, the integrated photolysis rate of each isotopologue at 20 km was calculated. Sulfur isotopic fractionation constants at 20 km altitude are (−3.7 ± 4.5) ‰ and (1.1 ± 4.2) ‰ for 33ε and 34ε, respectively, which is inconsistent with the previously estimated large fractionation of over 73 ‰ in 34ε. This demonstrates that OCS photolysis does not produce sulfur isotopic fractionation of more than ca. 5 ‰, suggesting OCS may be the source of background stratospheric sulfate aerosols. Finally, the predicted isotopic fractionation constant for 33S excess (33E) in OCS photolysis is (−4.2 ± 6.6) ‰, and thus photolysis of OCS is not expected to be the source of the non-mass-dependent signature observed in modern and Archaean samples.
Ionic and carbonaceous compositions of PM10, PM2.5 and PM1.0 at Gosan ABC superstation and their ratios as source signature
Authors: Lim S. , Lee M. , Lee G. , Kim S. , Yoon S. , Kang K.
Published: July 2011

Abstract. PM1.0, PM2.5, and PM10 were sampled at Gosan ABC Superstation on Jeju Island from August 2007 to September 2008. The carbonaceous aerosols were quantified with the thermal/optical reflectance (TOR) method, which produced five organic carbon (OC) fractions, OC1, OC2, OC3, OC4, and pyrolyzed organic carbon (OP), and three elemental carbon (EC) fractions, EC1, EC2, and EC3. The mean mass concentrations of PM1.0, PM2.5, and PM10 were 13.72 μg m−3, 17.24 μg m−3, and 28.37 μg m−3, respectively. The averaged mass fractions of OC and EC were 23.0 % and 10.4 % for PM1.0, 22.9 % and 9.8 % for PM2.5, and 16.4 % and 6.0 % for PM10. Among the OC and EC sub-components, OC2 and EC2+3 were enriched in the fine mode, but OC3 and OC4 in the coarse mode. The filter-based PM1.0 EC agreed well with black carbon (BC) measured by an Aethalometer, and PM10 EC was higher than BC, implying less light absorption by larger particles. EC was well correlated with sulfate, resulting in good relationships of sulfate with both aerosol scattering coefficient measured by Nephelometer and BC concentration. Our measurements of EC confirmed the definition of EC1 as char-EC emitted from smoldering combustion and EC2+3 as soot-EC generated from higher-temperature combustion such as motor vehicle exhaust and coal combustion. In particular, EC1 was strongly correlated with potassium, a traditional biomass burning indicator, except during the summer, when the ratio of EC1 to EC2+3 was the lowest. We also found the ratios of major chemical species to be a useful tool to constrain the main sources of aerosols, by which the five air masses were well distinguished: Siberia, Beijing, Shanghai, Yellow Sea, and East Sea types. Except Siberian air, the continental background of the study region, Beijing plumes showed the highest EC1 (and OP) to sulfate ratio, which implies that this air mass had the highest net warming by aerosols of the four air masses. Shanghai-type air, which was heavily influenced by southern China, showed the highest sulfate enhancement. The highest EC2+3/EC1 ratio was found in aged East Sea air, demonstrating a significant influence of motor vehicle emissions from South Korea and Japan and less influence from industrial regions of China. The high ratio results from the longer residence time and less sensitivity to wet scavenging of EC2+3 compared to EC1, indicating that soot-EC could have greater consequence in regional-scale warming.
Aerosols in the CALIOPE air quality modelling system: validation and analysis of PM levels, optical depths and chemical composition over Europe
Authors: Basart S. , Pay M. T. , Jorba O. , Pérez C. , Jiménez-Guerrero P. , Schulz M. , Baldasano J. M.
Published: July 2011

Abstract. The CALIOPE high-resolution air quality modelling system is developed and applied to Europe (12 km × 12 km, 1 h). The modelled daily to seasonal aerosol variability over Europe in 2004 have been evaluated and analysed. The aerosols are estimated from two models, CMAQv4.5 (AERO4) and BSC-DREAM8b. CMAQv4.5 calculates biogenic, anthropogenic and sea salt aerosol and BSC-DREAM8b provides the natural mineral dust contribution from North African deserts. For the evaluation, we use daily PM10/PM2.5 and chemical composition data from 54 stations of the EMEP/CREATE network and coarse and fine aerosol optical depth (AOD) data from 35 stations of the AERONET sun photometer network. The model achieves daily PM10 and PM2.5 correlations of 0.57 and 0.47, respectively, and total, coarse and fine AOD correlations of 0.51, 0.63, and 0.53, respectively. The higher correlations of the PM10 and the coarse mode AOD are largely due to the accurate representation of the African dust influence in the forecasting system. Overall PM and AOD levels are underestimated. The evaluation of the chemical composition highlights underestimations of the modelled fine fractions particularly for carbonaceous matter (EC and OC) and secondary inorganic aerosols (SIA; i.e. nitrates, sulphates and ammonium). The scores of the bulk parameters are significantly improved after applying a simple model bias correction based on the chemical composition observations. SIA are dominant in the fine fractions representing up to 80 % of the aerosol budget in latitudes beyond 40° N. The highest aerosol concentrations are found over the industrialized and populated areas of the Po Valley and the Benelux regions. High values in southern Europe are linked to the transport of coarse particles from the Sahara desert which contributes up to 40 % of the total aerosol mass. Close to the surface, maxima dust seasonal concentrations (>30 μg m–3) are found between spring and early autumn. We estimate that desert dust causes daily exceedances of the PM10 European air quality threshold (50 μg m–3) in large areas south of 45° N reaching up to more than 75 days per year in the southernmost regions.
Measuring the 3-D wind vector with a weight-shift microlight aircraft
Authors: Metzger S. , Junkermann W. , Butterbach-Bahl K. , Schmid H. P. , Foken T.
Published: July 2011

Abstract. This study investigates whether the 3-D wind vector can be measured reliably from a highly transportable and low-cost weight-shift microlight aircraft. Therefore we draw up a transferable procedure to accommodate flow distortion originating from the aircraft body and -wing. This procedure consists of the analysis of aircraft dynamics and seven successive calibration steps. For our aircraft the horizontal wind components receive their greatest single amendment (14 %, relative to the initial uncertainty) from the correction of flow distortion magnitude in the dynamic pressure computation. Conversely the vertical wind component is most of all improved (31 %) by subsequent steps considering the 3-D flow distortion distribution in the flow angle computations. Therein the influences of the aircraft's trim (53 %), as well as changes in the aircraft lift (16 %) are considered by using the measured lift coefficient as explanatory variable. Three independent lines of analysis are used to evaluate the quality of the wind measurement: (a) A wind tunnel study in combination with the propagation of sensor uncertainties defines the systems input uncertainty to ≈0.6 m s−1 at the extremes of a 95 % confidence interval. (b) During severe vertical flight manoeuvres the deviation range of the vertical wind component does not exceed 0.3 m s−1. (c) The comparison with ground based wind measurements yields an overall operational uncertainty (root mean square error) of ≈0.4 m s−1 for the horizontal and ≈0.3 m s−1 for the vertical wind components. No conclusive dependence of the uncertainty on the wind magnitude (<8 m s−1) or true airspeed (ranging from 23–30 m s−1) is found. Hence our analysis provides the necessary basis to study the wind measurement precision and spectral quality, which is prerequisite for reliable Eddy-Covariance flux measurements.
A sublimation technique for high-precision measurements of δ13CO2 and mixing ratios of CO2 and N2O from air trapped in ice cores
Authors: Schmitt J. , Schneider R. , Fischer H.
Published: July 2011

Abstract. In order to provide high precision stable carbon isotope ratios (δ13CO2 or δ13C of CO2) from small bubbly, partially and fully clathrated ice core samples we developed a new method based on sublimation coupled to gas chromatography-isotope ratio mass spectrometry (GC-IRMS). In a first step the trapped air is quantitatively released from ~30 g of ice and CO2 together with N2O are separated from the bulk air components and stored in a miniature glass tube. In an off-line step, the extracted sample is introduced into a helium carrier flow using a minimised tube cracker device. Prior to measurement, N2O and organic sample contaminants are gas chromatographically separated from CO2. Pulses of a CO2/N2O mixture are admitted to the tube cracker and follow the path of the sample through the system. This allows an identical treatment and comparison of sample and standard peaks. The ability of the method to reproduce δ13C from bubble and clathrate ice is verified on different ice cores. We achieve reproducibilities for bubble ice between 0.05 ‰ and 0.07 ‰ and for clathrate ice between 0.05 ‰ and 0.09 ‰ (dependent on the ice core used). A comparison of our data with measurements on bubble ice from the same ice core but using a mechanical extraction device shows no significant systematic offset. In addition to δ13C, the CO2 and N2O mixing ratios can be volumetrically derived with a precision of 2 ppmv and 8 ppbv, respectively.
Three-dimensional factorization of size-resolved organic aerosol mass spectra from Mexico City
Authors: Ulbrich I. M. , Canagaratna M. R. , Cubison M. J. , Zhang Q. , Ng N. L. , Aiken A. C. , Jimenez J. L.
Published: July 2011

Abstract. A size-resolved submicron organic aerosol composition dataset from a high-resolution time-of-flight mass spectrometer (HR-ToF-AMS) collected in Mexico City during the MILAGRO campaign in March 2006 is analyzed using 3-dimensional (3-D) factorization models. A method for estimating the precision of the size-resolved composition data for use with the factorization models is presented here for the first time. Two 3-D models are applied to the dataset. One model is a 3-vector decomposition (PARAFAC model), which assumes that each chemical component has a constant size distribution over all time steps. The second model is a vector-matrix decomposition (Tucker 1 model) that allows a chemical component to have a size distribution that varies in time. To our knowledge, this is the first report of an application of 3-D factorization models to data from fast aerosol instrumentation; it is also the first application of this vector-matrix model to any ambient aerosol dataset. A larger number of degrees of freedom in the vector-matrix model enable fitting real variations in factor size distributions, but also make the model susceptible to fitting noise in the dataset, giving some unphysical results. For this dataset and model, more physical results were obtained by partially constraining the factor mass spectra using a priori information and a new regularization method. We find four factors with each model: hydrocarbon-like organic aerosol (HOA), biomass-burning organic aerosol (BBOA), oxidized organic aerosol (OOA), and a locally occurring organic aerosol (LOA). These four factors have previously been reported from 2-dimensional factor analysis of the high-resolution mass spectral dataset from this study. The size distributions of these four factors are consistent with previous reports for these particle types. Both 3-D models produce useful results, but the vector-matrix model captures real variability in the size distributions that cannot be captured by the 3-vector model. A tracer m/z-based method provides a useful approximation for the component size distributions in this study. Variation in the size distributions is demonstrated in a case study day with a large secondary aerosol formation event, in which there is evidence for the coating of HOA-containing particles with secondary species, shifting the HOA size distribution to larger particle sizes. These 3-D factorizations could be used to extract size-resolved aerosol composition data for correlation with aerosol hygroscopicity, cloud condensation nuclei (CCN), and other aerosol impacts. Furthermore, application of these 3-D factorization models to other fast and chemically complex 3-D datasets, including those from thermal desorption or chromatographic separation, has the potential to provide further insights into organic aerosol sources and processing.
Relativistic transformation of phase-space distributions
Authors: Treumann R. A. , Nakamura R. , Baumjohann W.
Published: July 2011

Abstract. We investigate the transformation of the distribution function in the relativistic case, a problem of interest in plasma when particles with high (relativistic) velocities come into play as for instance in radiation belt physics, in the electron-cyclotron maser radiation theory, in the vicinity of high-Mach number shocks where particles are accelerated to high speeds, and generally in solar and astrophysical plasmas. We show that the phase-space volume element is a Lorentz constant and construct the general particle distribution function from first principles. Application to thermal equilibrium lets us derive a modified version of the isotropic relativistic thermal distribution, the modified Jüttner distribution corrected for the Lorentz-invariant phase-space volume element. Finally, we discuss the relativistic modification of a number of plasma parameters.
Alpine grassland soils contain large proportion of labile carbon but indicate long turnover times
Authors: Budge K. , Leifeld J. , Hiltbrunner E. , Fuhrer J.
Published: July 2011

Abstract. Alpine soils are expected to contain large amounts of labile carbon (C) which may become a further source of atmospheric carbon dioxide (CO2) as a result of global warming. However, there is little data available on these soils, and understanding of the influence of environmental factors on soil organic matter (SOM) turnover is limited. We extracted 30 cm deep cores from five grassland sites along a small elevation gradient from 2285 to 2653 m a.s.l. in the central Swiss Alps. Our aim was to determine the quantity, allocation, degree of stabilization and mean residence time (MRT) of SOM in relation to site factors such as soil pH, vegetation, and SOM composition. Soil fractions obtained by size and density fractionation revealed a high proportion of labile C in SOM, mostly in the uppermost soil layers. Labile C in the top 20 cm across the gradient ranged from 39.6–57.6 % in comparison to 7.2–29.6 % reported in previous studies for lower elevation soils (810–1960 m a.s.l.). At the highest elevation, MRTs measured by means of radiocarbon dating and turnover modelling, increased between fractions of growing stability from 90 years in free POM (fPOM) to 534 years in the mineral associated fraction (mOM). Depending on elevation and pH, plant community data suggested considerable variation in the quantity and quality of organic matter input, and these patterns could be reflected in the dynamics of soil C. 13C NMR data confirmed a relationship of SOM composition to MRT. While low temperature in alpine environments is likely to be a major cause for the slow turnover rate observed, other factors such as residue quality and soil pH, as well as the combination of all factors, play an important role in causing small scale variability of SOM turnover. Failing to incorporate this interplay of controlling factors into models may impair the performance of models to project SOM responses to environmental change.
Bio-optical provinces in the eastern Atlantic Ocean and their biogeographical relevance
Authors: Taylor B. B. , Torrecilla E. , Bernhardt A. , Taylor M. H. , Peeken I. , Röttgers R. , Piera J. , Bracher A.
Published: July 2011

Abstract. The relationship between phytoplankton assemblages and the associated optical properties of the water body is important for the further development of algorithms for large-scale remote sensing of phytoplankton biomass and the identification of phytoplankton functional types (PFTs), which are often representative for different biogeochemical export scenarios. Optical in-situ measurements aid in the identification of phytoplankton groups with differing pigment compositions and are widely used to validate remote sensing data. In this study we present results from an interdisciplinary cruise aboard the R/V Polarstern along a north-to-south transect in the eastern Atlantic Ocean in November 2008. Phytoplankton community composition was identified using a broad set of in-situ measurements. Water samples from the surface and the depth of maximum chlorophyll concentration were analyzed by high performance liquid chromatography (HPLC), flow cytometry, spectrophotometry and microscopy. Simultaneously, the above- and underwater light field was measured by a set of high spectral resolution (hyperspectral) radiometers. An unsupervised cluster algorithm applied to the measured parameters allowed us to define bio-optical provinces, which are compared to ecological provinces proposed elsewhere in the literature. This method has the potential to become an automated approach where satellite data could be used to identify shifting boundaries of established ecological provinces or to track exceptions from the rule to improve our understanding of the biogeochemical cycles in the ocean.
A late Holocene pollen and climate record from Lake Yoa, northern Chad
Authors: Lézine A.-M. , Zheng W. , Braconnot P. , Krinner G.
Published: July 2011

Abstract. The discovery of groundwater fed Lake Yoa (19.03° N, 20.31° E) in the hyperarid desert of northern Chad by the German research team ACACIA headed by S. Kröpelin provides a unique, continuous sedimentary sequence of late Holocene age for the entire Saharan desert. Here we present pollen data and climate simulations using the LMDZ atmospheric model with a module representing the climatologically relevant thermal and hydrological processes occurring above and beneath inland water surfaces to document past environmental and climate changes during the last 6000 cal yr BP. Special attention is paid to wind strength and direction, length and amplitude of the rainy season, and on dry spell occurrence, all of which are of primary importance for plant distribution and pollen transport. In addition to climate changes and their impact on the natural environment, anthropogenic changes are also discussed. Two main features can be highlighted: (1) the shift from an earlier predominantly monsoonal climate regime to one dominated by northern Mediterranean fluxes occurred after 4000 cal yr BP. The direct consequence of this was the establishment of the modern desert environment at Yoa at 2700 cal yr BP. (2) Changes in climate parameters (simulated rainfall amount and dry spell length) between 6 and 4000 cal yr BP were comparatively minor. However, changes in the seasonal distribution of precipitation during this time dramatically affected the vegetation composition and were at the origin of the retreat of tropical plant communities from the Lake Yoa.
Spatial stochastic and analytical approaches to describe the complex hydraulic variability inherent channel geometry
Authors: Hadadin N.
Published: July 2011

Abstract. The effects of basin hydrology on channel hydraulic variability for incised streams were investigated using available field data sets and models of watershed hydrology and channel hydraulics for Yazoo River Basin, USA. The study presents the hydraulic relations of bankfull discharge, channel width, mean depth, cross- sectional area, longitudinal slope, unit stream power, and runoff production as a function of drainage area using simple linear regression. The hydraulic geometry relations were developed for sixty one streams, twenty of them are classified as channel evaluation model (CEM) Types IV and V and forty one of them are streams of CEM Types II and III. These relationships are invaluable to hydraulic and water resources engineers, hydrologists, and geomorphologists, involved in stream restoration and protection. These relations can be used to assist in field identification of bankfull stage and stream dimension in un-gauged watersheds as well as estimation of the comparative stability of a stream channel. Results of this research show good fit of hydraulic geometry relationships in the Yazoo River Basin. The relations indicate that bankfull discharge, channel width, mean depth, cross-sectional area have stronger correlation to changes in drainage area than the longitudinal slope, unit stream power, and runoff production for streams CEM Types II and III. The hydraulic geometry relations show that runoff production, bankfull discharge, cross-sectional area, and unit stream power are much more responsive to changes in drainage area than are channel width, mean depth, and slope for streams of CEM Types IV and V. Also, the relations show that bankfull discharge and cross-sectional area are more responsive to changes in drainage area than are other hydraulic variables for streams of CEM Types II and III. The greater the regression slope, the more responsive to changes in drainage area will be.
Representation of spatial and temporal variability of daily wind speed and of intense wind events over the Mediterranean Sea using dynamical downscaling: impact of the regional climate model configuration
Authors: Herrmann M. , Somot S. , Calmanti S. , Dubois C. , Sevault F.
Published: July 2011

Abstract. Atmospheric datasets coming from long term reanalyzes of low spatial resolution are used for different purposes. Wind over the sea is, for example, a major ingredient of oceanic simulations. However, the shortcomings of those datasets prevent them from being used without an adequate corrective preliminary treatment. Using a regional climate model (RCM) to perform a dynamical downscaling of those large scale reanalyzes is one of the methods used in order to produce fields that realistically reproduce atmospheric chronology and where those shortcomings are corrected. Here we assess the influence of the configuration of the RCM used in this framework on the representation of wind speed spatial and temporal variability and intense wind events on a daily timescale. Our RCM is ALADIN-Climate, the reanalysis is ERA-40, and the studied area is the Mediterranean Sea. First, the dynamical downscaling significantly reduces the underestimation of daily wind speed, in average by 9 % over the whole Mediterranean. This underestimation has been corrected both globally and locally, and for the whole wind speed spectrum. The correction is the strongest for periods and regions of strong winds. The representation of spatial variability has also been significantly improved. On the other hand, the temporal correlation between the downscaled field and the observations decreases all the more that one moves eastwards, i.e. further from the atmospheric flux entry. Nonetheless, it remains ~0.7, the downscaled dataset reproduces therefore satisfactorily the real chronology. Second, the influence of the choice of the RCM configuration has an influence one order of magnitude smaller than the improvement induced by the initial downscaling. The use of spectral nudging or of a smaller domain helps to improve the realism of the temporal chronology. Increasing the resolution very locally (both spatially and temporally) improves the representation of spatial variability, in particular in regions strongly influenced by the complex surrounding orography. The impact of the interactive air-sea coupling is negligible for the temporal scales examined here. Using two different forcing datasets induces differences on the downscaled fields that are directly related to the differences between those datasets. Our results also show that improving the physics of our RCM is still necessary to increase the realism of our simulations. Finally, the choice of the optimal configuration depends on the scientific objectives of the study for which those wind datasets are used.