bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional Classification of Pulmonary Hypertension in Children: Report from the PVRI Pediatric Taskforce, Panama 2011
Authors: Lammers Astrid E. , Adatia Ian , del Cerro Maria Jesus , Diaz Gabriel , Freudenthal Alexandra Heath , Freudenthal Franz , Harikrishnan S. , Ivy Dunbar , Lopes Antonio A. , Raj J. Usha , Sandoval Julio , Stenmark Kurt , Haworth Sheila G.
Published: August 2011

The members of the Pediatric Task Force of the Pulmonary Vascular Research Institute (PVRI) were aware of the need to develop a functional classification of pulmonary hypertension in children. The proposed classification follows the same pattern and uses the same criteria as the Dana Point pulmonary hypertension specific classification for adults. Modifications were necessary for children, since age, physical growth and maturation influences the way in which the functional effects of a disease are expressed. It is essential to encapsulate a child's clinical status, to make it possible to review progress with time as he/she grows up, as consistently and as objectively as possible. Particularly in younger children we sought to include objective indicators such as thriving, need for supplemental feeds and the record of school or nursery attendance. This helps monitor the clinical course of events and response to treatment over the years. It also facilitates the development of treatment algorithms for children. We present a consensus paper on a functional classification system for children with pulmonary hypertension, discussed at the Annual Meeting of the PVRI in Panama City, February 2011.
Diagnosis and Assessment of Pulmonary Vascular Disease by Doppler Echocardiography
Authors: Roberts Justin D. , Forfia Paul R.
Published: August 2011

Pulmonary hypertension (PH) is a relatively misunderstood disease, partly related to the fact that many perceive PH to be a singular diagnosis. An unintended consequence of this is the misapplication of the role of the Doppler‐Echocardiographic (DE) examination, as well as an underappreciation for its ability to help discern PH pathophysiology prior to right heart catheterization. Since DE often serves as the “gatekeeper” to invasive right heart catheterization, misinterpretation of the DE can lead to missed or delayed diagnosis with devastating consequences. Too often, the primary or nearly exclusive focus of the DE examination is placed on the pulmonary artery pressure estimation. Two main issues with this approach are that Doppler pressure estimations can be inaccurate and even when accurate, without integration of additional 2‐D and Doppler information, the clinician will often still not appreciate the pathophysiology of the PH nor its clinical significance. This review will focus on the 2‐D and Doppler features necessary to assess pulmonary vascular disease (PVD), discern the salient differences between PVD and pulmonary venous hypertension (PVH), and how to integrate these key DE parameters such that PH pathophysiology can be determined noninvasively and early in the patient workup. Overreliance on any single DE metric, and especially PA pressure estimation, detracts from the overall diagnostic potential of the DE examination. Integrating the relative balance of right and left heart findings, along with proper Doppler interpretation provides a wealth of clinical and pathophysiologic insight prior to invasive hemodynamic assessment. The end results are heightened awareness and improved identification of which patients should be referred for further invasive testing, as well the use of the DE information to compliment the findings from invasive testing.
Log‐Transformation Improves the Prognostic Value of Serial NT‐proBNP Levels in Apparently Stable Pulmonary Arterial Hypertension
Authors: Soon Elaine , Doughty Natalie J. , Treacy Carmen M. , Ross Robert M. , Toshner Mark , Upton Paul D. , Sheares Karen , Morrell Nicholas W. , Pepke‐Zaba Joanna
Published: August 2011

N‐terminal pro B‐type natriuretic peptide (NT‐proBNP) is a product of cleavage of the cardiac prohormone pro B‐type natriuretic peptide into its active form. It has proven to be a useful biomarker in left heart failure. However, studies examining the utility of serial measurements of NT‐proBNP in pulmonary arterial hypertension (PAH) patients have shown mixed results. We compared three methods of predicting adverse clinical outcomes in PAH patients: the change in 6 minute walk distance (6MWD), the change in absolute levels of NT‐proBNP and the change in log‐transformed levels of NT‐proBNP. All PAH patients presenting from March–June 2007 were screened. Patients who were clinically unstable, had abnormal renal function or hemoglobin levels or lacked a prior NT‐proBNP were excluded. 63 patients were followed up for adverse clinical outcomes (defined as death, transplantation, hospitalisation for right heart failure, or need for increased therapy). Three methods were used to predict adverse events, i.e.: (a) comparing a 6MWD performed in March–June 2007 and a previous 6MWD. A decrease in 6MWD of ≥30m was used to predict clinical deterioration; (b) comparing a NT‐proBNP value measured in March–June 2007 and a previous NT‐proBNP. An increase in NT‐proBNP of ≥250pg/ml was used to predict clinical deterioration (250pg/ml represented approximately 30% change from the baseline median value of NT‐proBNP for this cohort); and (c) comparing the loge equivalents of two consecutive NT‐proBNP values. We used the formula: loge(current NT‐proBNP) ‐ loge(previous NT‐proBNP)=x. A value of x≥+0.26 was used to predict adverse events. This is equivalent to a 30% change from baseline, and hence is comparable to the chosen cut‐off for absolute levels of NT‐proBNP. A loge difference of ≥+0.26 identifies patients at risk of adverse events with a specificity of 98%, a sensitivity of 60%, a positive predictive value of 89%, and a negative predictive value of 90%. A drop in 6MWD of ≥30m has a specificity of 29%, a sensitivity of 73%, a positive predictive value of 24% and a negative predictive value of 24%. It seems possible to risk‐stratify apparently stable PAH patients by following the changes in their serial log‐transformed NT‐proBNP values. In this small pilot study, this method was better than relying on changes in the actual levels of NT‐proBNP or changes in 6MWD. This needs to be validated prospectively in a larger cohort.
Computational Models of the Pulmonary Circulation: Insights and the Move towards Clinically Directed Studies
Authors: Tawhai Merryn H. , Clark Alys R. , Burrowes Kelly S.
Published: August 2011

Biophysically‐based computational models provide a tool for integrating and explaining experimental data, observations, and hypotheses. Computational models of the pulmonary circulation have evolved from minimal and efficient constructs that have been used to study individual mechanisms that contribute to lung perfusion, to sophisticated multi‐scale and ‐physics structure‐based models that predict integrated structure‐function relationships within a heterogeneous organ. This review considers the utility of computational models in providing new insights into the function of the pulmonary circulation, and their application in clinically motivated studies. We review mathematical and computational models of the pulmonary circulation based on their application; we begin with models that seek to answer questions in basic science and physiology and progress to models that aim to have clinical application. In looking forward, we discuss the relative merits and clinical relevance of computational models: what important features are still lacking; and how these models may ultimately be applied to further increasing our understanding of the mechanisms occurring in disease of the pulmonary circulation.
Pulmonary Vascular Wall Stiffness: An Important Contributor to the Increased Right Ventricular Afterload with Pulmonary Hypertension
Authors: Wang Zhijie , Chesler Naomi C.
Published: August 2011

Pulmonary hypertension (PH) is associated with structural and mechanical changes in the pulmonary vascular bed that increase right ventricular (RV) afterload. These changes, characterized by narrowing and stiffening, occur in both proximal and distal pulmonary arteries (PAs). An important consequence of arterial narrowing is increased pulmonary vascular resistance (PVR). Arterial stiffening, which can occur in both the proximal and distal pulmonary arteries, is an important index of disease progression and is a significant contributor to increased RV afterload in PH. In particular, arterial narrowing and stiffening increase the RV afterload by increasing steady and oscillatory RV work, respectively. Here we review the current state of knowledge of the causes and consequences of pulmonary arterial stiffening in PH and its impact on RV function. We review direct and indirect techniques for measuring proximal and distal pulmonary arterial stiffness, measures of arterial stiffness including elastic modulus, incremental elastic modulus, stiffness coefficient β and others, the changes in cellular function and the extracellular matrix proteins that contribute to pulmonary arterial stiffening, the consequences of PA stiffening for RV function and the clinical implications of pulmonary vascular stiffening for PH progression. Future investigation of the relationship between PA stiffening and RV dysfunction may facilitate new therapies aimed at improving RV function and thus ultimately reducing mortality in PH.
Acute Respiratory Distress Syndrome: A Clinical Review
Authors: Donahoe Michael
Published: August 2011

The acute respiratory distress syndrome (ARDS) is a complex disorder of heterogeneous etiologies characterized by a consistent, recognizable pattern of lung injury. Extensive epidemiologic studies and clinical intervention trials have been conducted to address the high mortality of this disorder and have provided significant insight into the complexity of studying new therapies for this condition. The existing clinical investigations in ARDS will be highlighted in this review. The limitations to current definitions, patient selection, and outcome assessment will be considered. While significant attention has been focused on the parenchymal injury that characterizes this disorder and the clinical support of gas exchange function, relatively limited focus has been directed to hemodynamic and pulmonary vascular dysfunction equally prominent in the disease. The limited available clinical information in this area will also be reviewed. The current standards for cardiopulmonary management of the condition will be outlined. Current gaps in our understanding of the clinical condition will be highlighted with the expectation that continued progress will contribute to a decline in disease mortality.
A Consensus Approach to the Classification of Pediatric Pulmonary Hypertensive Vascular Disease: Report from the PVRI Pediatric Taskforce, Panama 2011
Authors: del Cerro Maria Jesus , Abman Steven , Diaz Gabriel , Freudenthal Alexandra Heath , Freudenthal Franz , Harikrishnan S. , Haworth Sheila G. , Ivy Dunbar , Lopes Antonio A. , Raj J. Usha , Sandoval Julio , Stenmark Kurt , Adatia Ian
Published: August 2011

Current classifications of pulmonary hypertension have contributed a great deal to our understanding of pulmonary vascular disease, facilitated drug trials, and improved our understanding of congenital heart disease in adult survivors. However, these classifications are not applicable readily to pediatric disease. The classification system that we propose is based firmly in clinical practice. The specific aims of this new system are to improve diagnostic strategies, to promote appropriate clinical investigation, to improve our understanding of disease pathogenesis, physiology and epidemiology, and to guide the development of human disease models in laboratory and animal studies. It should be also an educational resource. We emphasize the concepts of perinatal maladaptation, maldevelopment and pulmonary hypoplasia as causative factors in pediatric pulmonary hypertension. We highlight the importance of genetic, chromosomal and multiple congenital malformation syndromes in the presentation of pediatric pulmonary hypertension. We divide pediatric pulmonary hypertensive vascular disease into 10 broad categories.
Numerical Methods for Balance Laws with Space Dependent Flux: Application to Radiotherapy Dose Calculation
Authors: Berthon Christophe , Frank Martin , Sarazin Céline , Turpault Rodolphe
Published: August 2011

The present work is concerned with the derivation of numerical methods to approximate the radiation dose in external beam radiotherapy. To address this issue, we consider a moment approximation of radiative transfer, closed by an entropy minimization principle. The model under consideration is governed by a system of hyperbolic equations in conservation form supplemented by source terms. The main difficulty coming from the numerical approximation of this system is an explicit space dependence in the flux function. Indeed, this dependence will be seen to be stiff and specific numerical strategies must be derived in order to obtain the needed accuracy. A first approach is developed considering the 1D case, where a judicious change of variables allows to eliminate the space dependence in the flux function. This is not possible in multi-D. We therefore reinterpret the 1D scheme as a scheme on two meshes, and generalize this to 2D by alternating transformations between separate meshes. We call this procedure projection method. Several numerical experiments, coming from medical physics, illustrate the potential applicability of the developed method.
Split Local Artificial Boundary Conditions for the Two-Dimensional Sine-Gordon Equation on R2
Authors: Han Houde , Zhang Zhiwen
Published: August 2011

In this paper the numerical solution of the two-dimensional sine-Gordon equation is studied. Split local artificial boundary conditions are obtained by the operator splitting method. Then the original problem is reduced to an initial boundary value problem on a bounded computational domain, which can be solved by the finite difference method. Several numerical examples are provided to demonstrate the effectiveness and accuracy of the proposed method, and some interesting propagation and collision behaviors of the solitary wave solutions are observed.
Simulation of Three-Dimensional Strained Heteroepitaxial Growth Using Kinetic Monte Carlo
Authors: Schulze Tim P. , Smereka Peter
Published: August 2011

Efficient algorithms for the simulation of strained heteroepitaxial growth with intermixing in 2+1 dimensions are presented. The first of these algorithms is an extension of the energy localization method [T. P. Schulze and P. Smereka, An energy localization principle and its application to fast kinetic Monte Carlo simulation of heteroepitaxial growth, J. Mech. Phys. Sol., 3 (2009), 521-538] from 1+1 to 2+1 dimensions. Two approximations of this basic algorithm are then introduced, one of which treats adatoms in a more efficient manner, while the other makes use of an approximation of the change in elastic energy in terms of local elastic energy density. In both cases, it is demonstrated that a reasonable level of fidelity is achieved. Results are presented showing how the film morphology is affected by misfit and deposition rate. In addition, simulations of stacked quantum dots are also presented.
Dynamical Coupling Atomistic and Continuum Simulations
Authors: Ren Guowu , Zhang Dier , Gong Xin-Gao
Published: August 2011

We propose a new multiscale method that couples molecular dynamics simulations (MD) at the atomic scale and finite element simulations (FE) at the continuum regime. By constructing the mass matrix and stiffness matrix dependent on coarsening of grids, we find a general form of the equations of motion for the atomic and continuum regions. In order to improve the simulation at finite temperatures, we propose a low-pass phonon filter near the interface between the atomic and continuum regions, which is transparent for low frequency phonons, but dampens the high frequency phonons.
Numerical Entropy and Adaptivity for Finite Volume Schemes
Authors: Puppo Gabriella , Semplice Matteo
Published: August 2011

We propose an a-posteriori error/smoothness indicator for standard semi-discrete finite volume schemes for systems of conservation laws, based on the numerical production of entropy. This idea extends previous work by the first author limited to central finite volume schemes on staggered grids. We prove that the indicator converges to zero with the same rate of the error of the underlying numerical scheme on smooth flows under grid refinement. We construct and test an adaptive scheme for systems of equations in which the mesh is driven by the entropy indicator. The adaptive scheme uses a single nonuniform grid with a variable timestep. We show how to implement a second order scheme on such a space-time non uniform grid, preserving accuracy and conservation properties. We also give an example of ap-adaptive strategy.
Informatização e organização do trabalho em bibliotecas universitárias: estudo comparado entre Brasil, Moçambique e Africa do Sul
Authors: Mangue Manuel Valente , Crivellari Helena Maria Tarchi
Published: August 2011

O artigo, baseado em estudo comparativo entre bibliotecas universitárias de alguns países em desenvolvimento (Brasil, África do Sul e Moçambique) discute o processo de informatização dessas bibliotecas a partir de um enfoque integrado, que inclui, além dos aspectos tecnológicos, os relacionados à gestão do processo, à organização do trabalho e à qualificação dos trabalhadores, tratando-os como igualmente relevantes. Embora represente uma análise parcial, os dados apontam para uma relação direta entre a adoção tecnológica nessas bibliotecas e o macro ambiente econômico, político e social em que estão inseridas. Fica também evidente que a adoção tecnológica é um processo endógeno à instituição e que cada fase deve ser acompanhada pelo correspondente aperfeiçoamento dos mecanismos administrativos, sob pena de involução, no caso, da unidade de informação como um todo, a despeito do uso da mais alta tecnologia.
Informação, memória e história: a instituição de um sistema de um sistema de informação na corte do Rio de Janeiro
Authors: Thiesen Icleia
Published: August 2011

A história da Ciência da Informação não se confunde com a Informação na História. É possível identificar as condições de formação dessa disciplina em diferentes instâncias e épocas que tornaram possível a passagem do que era ainda evanescente, para a consolidação de um conjunto de saberes que se instituem em determinada época, articulados às demandas sociais e políticas que legitimam seu nascimento. É o caso da informação na história do sistema prisional produzido na Corte do Rio de Janeiro. Quais são essas condições de possibilidade? Que elementos compõem esse cenário histórico, onde a informação produzida sobre prisioneiros constitui parte relevante das estratégias de poder? O presente trabalho tem por objetivo analisar dispositivos de controle e vigilância, desenvolvidos por um conjunto de instituições sobre os que romperam o pacto social, visando produzir sobre prisioneiros um saber e uma memória que constituem imagens da clausura, cujos fragmentos são hoje recuperados, analisados e resignificados à luz da memória social, um fato do presente.
Estudo da rede de co-autoria e da interdisciplinaridade na produção científica com base nos métodos de análise de redes sociais: avaliação do caso do programa de pós-graduação em ciência da informação - PPGCI / UFMG
Authors: Silva Antonio Braz de Oliveira e , Matheus Renato Fabiano , Parreiras Fernando Silva , Parreiras Tatiane A. Silva
Published: August 2011

Este artigo apresenta a Análise de Redes Sociais (ARS) como um método a ser aplicado em estudos na Ciência da Informação (CI). Esta é, normalmente, apresentada como uma área do conhecimento interdisciplinar, mas as diferentes linhas de pesquisa existentes nos Programas de Pós-Graduação no Brasil recebem influências de diferentes áreas do conhecimento, ou seja, possuem diferenças em suas interdisciplinaridades. A aplicação da ARS no estudo da rede de co-autoria dos professores do PPGCI/UFMG permite tanto a apresentação do método como a obtenção de resultados empíricos para alimentar a discussão sobre a CI. As redes de colaboração entre os professores refletem, em tese, a participação em programas de pesquisa da área. A colaboração entre professores das diferentes linhas se relaciona com a integração das diferentes interdisciplinaridades que elas apresentam. O texto dá uma visão geral da ARS e apresenta estudos da área, destacando-se a análise de redes de co-autoria. Em seguida, se descreve a metodologia da pesquisa e os principais resultados obtidos da ARS.
Aplicación del modelo bradford en la producción científica del área biomédica de la universidad de granada (1988-1996)
Authors: Osma Elvira Ruiz de
Published: August 2011

Introducción: Se propone con este trabajo averiguar en qué publicaciones daban a conocer sus trabajos los investigadores biomédicos granadinos durante los años 1988 a 1996. Material y Métodos: A partir de los datos obtenidos de la consulta a las bases de datos IME, Medline y SCI y mediante la aplicación del modelo Bradford se pudo averiguar las revistas en que estos autores daban a conocer sus investigaciones. Resultados: Los resultados se expresan para el conjunto global de revistas, para el conjunto de revistas extranjeras y para el conjunto de revistas nacionales. En el primer caso se determina que el núcleo está formado por revistas de procedencia española, aunque también figuran entre las más utilizadas cuatro extranjeras. Éstas y las primeras revistas españolas se encuentran incluidas en el SCI. En el conjunto de revistas extranjeras se observa un mayor incremento en la publicación en estas revistas debido a la mayor inversión en el PIB y a la presión por publicar en revistas extranjeras que surge a comienzos de los años noventa. Las áreas que más publican en este grupo de revistas son las básicas. En el conjunto de revistas de procedencia nacional se observa que la mayoría de ellas son especializadas y hay muy pocas de temática general. Son revistas en las que publican fundamentalmente las áreas clínicas. Conclusiones: La producción es muy nacional. Aumenta el número de investigaciones publicadas en revistas internacionales. Interés por las revistas internacionales en las áreas básicas. Las áreas clínicas publican en revistas nacionales, especializadas y de poca difusión internacional.
Ciência da informação e semiótica: conexão de saberes
Authors: Moura Maria Aparecida
Published: August 2011

A Ciência da Informação (CI) é um campo de conhecimento que se caracteriza pela interdisciplinaridade. Esse fato se deve em grande medida a informação, objeto de estudos compartilhado pela CI e distintas áreas de conhecimento. Nos últimos anos foram desenvolvidos inúmeros estudos nos quais ficaram evidentes as interfaces existentes entre a Ciência da Informação e a Semiótica. Tais interconexões devem-se, sobretudo ao fato de a Ciência da Informação demandar uma melhor compreensão da informação no que concerne aos processos de significação. Nesse artigo busca-se identificar os pontos de convergência existentes entre a Ciência da Informação e a Semiótica tendo em vista ampliar a compreensão do fenômeno informacional na contemporaneidade através das perspectivas teóricas e práticas decorrentes dessa interação.
Typical types and formation mechanisms of haze in an eastern Asia megacity, Shanghai
Authors: Huang K. , Zhuang G. , Lin Y. , Fu J. S. , Wang Q. , Liu T. , Zhang R. , Jiang Y. , Deng C.
Published: August 2011

Abstract. An intensive aerosol and gases campaign has been performed at Shanghai in the Yangtze River Delta region over Eastern China from late March to early June 2009. This study provided a complementary picture of typical haze types and formation mechanisms in megacities over China by using a synergy of ground-based monitoring, satellite observation and lidar inversion. During the whole study period, several extreme low visibility periods were observed with distinct characteristics, and three typical haze types were identified, i.e. secondary inorganic pollution, dust, and biomass burning. Sulfate, nitrate and ammonium accounted for a major part of PM2.5 mass during the secondary inorganic pollution, and the good correlation between SO2/NOx/CO and PM2.5 indicated that coal burning and vehicle emission were the major sources. Large-scale regions with high AOD and low Ångström exponent were detected by remote-sensing observation during the dust pollution episode, and this episode corresponded to coarse particles rich in mineral components such as Al and Ca with mineral aerosol contributing 76.8 % to TSP. The relatively low Ca/Al ratio of 0.75 combined with the air mass backward trajectory analysis suggested the dust source from Gobi Desert. Typical tracers for biomass burning from satellite observation (column CO and HCHO) and from ground measurement (CO, particulate K+, OC, and EC) were greatly enhanced during the biomass burning pollution episode. The exclusive linear correlation between CO and PM2.5 corroborated that organic aerosol dominated aerosol chemistry during biomass burning, and the high concentration and enrichment degree of arsenic (As) could be also partly derived from biomass burning. Aerosol optical profile observed by lidar demonstrated that aerosol was mainly constrained below the boundary layer and comprised of spheric aerosol (depolarization ratio <5 %) during the secondary inorganic and biomass burning episodes, while during the dust episode thick dust layer distributed at altitudes from near the ground to 1.4 km (average depolarization ratio = 0.122 ± 0.023) with dust accounting for 44–55 % of the total aerosol extinction coefficient. This study had illustrated a good picture of the typical haze types and proposed that identification of the complicated emission sources was important for the air quality improvement in megacities in China.
Variation of upper tropospheric clouds and water vapor over the Indian ocean
Authors: Bhawar R. L. , Jiang J. H. , Su H.
Published: August 2011

Abstract. The upper tropospheric (UT) ice water content (IWC) and water vapor (H2O) observed by the Microwave Limb Sounder (MLS) show dominant dipole mode variability over the Indian Ocean. This is characterized by the oscillating differences between the Western and Eastern Indian Ocean (WIO and EIO) with greater amplitude in JJA and SON than in other seasons. We denote δ X = X_WIO–X_EIO, with X being H2O and IWC at three UT levels (215 hPa, 147 hPa and 100 hPa) as well as sea surface temperature (SST), following the definition for previously identified Indian Ocean Dipole (IOD) variability. We found a strong positive correlation of δIWC at three UT levels with δSST, and a relatively weak positive correlation of δIWC with Nino 3.4 SST, suggesting that the UT clouds over the Indian Ocean are largely controlled by local thermally-driven circulation while teleconnection to ENSO plays a secondary role. The change per degree of δSST for δIWC in SON is 5.5 mg m−3 C−1 at 215 hPa, 1.6 mg m−3 C−1 at 147 hPa and 0.13 mg m−3 C−1 at 100 hPa (the 7-yr mean δIWC is −4.7 mg m−3, −1.6 mg m−3 and −0.13 mg m−3 at 215 hPa, 147 hPa and 100 hPa respectively). For δH2O, the per degree δSST change of 41.2 ppmv C−1 corresponds to a strong increase at 215 hPa and a decrease of −0.23 ppmv C−1 (−0.18 ppmv C−1) at 100 hPa (147 hPa), respectively. The Nino 3.4 SST has a relatively weak positive (negative) correlation with δ H2O at 215 hPa (100 hPa). The increase of δH2O at 215 hPa with increasing δSST is associated with the sharper contrast in convective intensity while the decrease of δH2O at 100 hPa with increasing δSST is a signature of the "convective cold top" and temperature control of 100 hPa H2O. For H2O, the 147 hPa marks a transition from the convection-controlled 215 hPa to the temperature-controlled 100 hPa.
Comparison of catchment grouping methods for flow duration curve estimation at ungauged sites in France
Authors: Sauquet E. , Catalogne C.
Published: August 2011

Abstract. The study aims at estimating flow duration curves (FDC) at ungauged sites in France and quantifying the associated uncertainties using a large dataset of 1080 FDCs. The interpolation procedure focuses here on 15 percentiles standardised by the mean annual flow, which is assumed to be known at each site. In particular, this paper discusses the impact of different catchment grouping procedures on the estimation of percentiles by regional regression models. In a first step, five parsimonious FDC parametric models are tested to approximate FDCs at gauged sites. The results show that the model based on the expansion of Empirical Orthogonal Functions (EOF) outperforms the other tested models. In the EOF model, each FDC is interpreted as a linear combination of regional amplitude functions with spatially variable weighting factors corresponding to the parameters of the model. In this approach, only one amplitude function is required to obtain a satisfactory fit with most of the observed curves. Thus, the considered model requires only two parameters to be applicable at ungauged locations. Secondly, homogeneous regions are derived according to hydrological response, on the one hand, and geological, climatic and topographic characteristics on the other hand. Hydrological similarity is assessed through two simple indicators: the concavity index (IC) representing the shape of the dimensionless FDC and the seasonality ratio (SR), which is the ratio of summer and winter median flows. These variables are used as homogeneity criteria in three different methods for grouping catchments: (i) according to an a priori classification of French Hydro-EcoRegions (HERs), (ii) by applying regression tree clustering and (iii) by using neighbourhoods obtained by canonical correlation analysis. Finally, considering all the data, and subsequently for each group obtained through the tested grouping techniques, we derive regression models between physiographic and/or climatic variables and the two parameters of the EOF model. Results on percentile estimation in cross validation show that a significant benefit is obtained by defining homogeneous regions before developing regressions, particularly when grouping methods make use of hydrogeological information.
Applying PUB to the real world: rapid data assessment
Authors: Jackisch C. , Zehe E. , Singh A. K.
Published: August 2011

Abstract. "Predictions in Ungauged Basins" are a challenging task – especially when it comes to meso-scale rural catchments. We present a rapid data assessment scheme based on a functional perspective on the landscape for a hydrological land use decision support model. A hierarchical merging of top down and bottom up approaches combines hydrology, soil physics, agronomy and meteorology in a common nomenclature. The study at hand is an example to bring PUB to real world application.
Modelling nitrogen and phosphorus loads in a Mediterranean river catchment (La Tordera, NE Spain)
Authors: Caille F. , Riera J. L. , Rosell-Melé A.
Published: August 2011

Abstract. Human activities have resulted in increased nutrient levels in many rivers all over Europe. Sustainable management of river basins demands an assessment of the causes and consequences of human alteration of nutrient flows, together with an evaluation of management options. In the context of an integrated and interdisciplinary environmental assessment (IEA) of nutrient flows, we present and discuss the application of the nutrient emission model MONERIS (MOdelling Nutrient Emissions into River Systems) to the Catalan river basin, La Tordera (North-East of Spain), for the period 1996-2002. After a successful calibration and verification process (Nash-Sutcliffe efficiencies E = 0.85 for phosphorus, and E = 0.86 for nitrogen), the application of the model MONERIS proved to be useful to estimate nutrient loads. Crucial for model calibration, in-stream retention (mainly affected by variability in precipitation) was estimated to be about 50 % of nutrient emissions on an annual basis. Through this process, we identified the importance of point sources for phosphorus emissions (about 94 % for 1996–2002), and diffuse sources, especially inputs via groundwater, for nitrogen emissions (about 31 % for 1996–2002). Despite potential hurdles related to model structure, observed loads, and input data encountered during the modelling process, MONERIS provided a good representation of the major interannual and spatial patterns in nutrient emissions. An analysis of the model uncertainty and sensitivity to input data indicates that the model MONERIS, even in data-starved Mediterranean catchments, may be profitably used for evaluating quantitative nutrient emission scenarios that may help catchment managers and planners to develop effective policy and management measures to reduce nutrient loads.
Acute Kidney Injury Due to Rhabdomyolysis in Narcotic Drug Users
Authors: Kosmadakis George , Michail Otho , Georgoulias Christodoulos , Filiopoulos Vasileios , Papadopoulou Panoraia , Michail Spiridon
Published: August 2011

Background

Regular or illegal drugs and toxins are the most frequent non-physical causes of rhabdomyolysis (RM) in peacetime. Acute Kidney Injury (AKI) is a serious and, sometimes, fatal complication of RM. It occurs in 8–20% of RM incidents.

Methods

In this prospective study we evaluated the severity of RM and AKI in narcotic drug users. From January 2001 to December 2007, 21 patients (17 males, mean age 27.8±4.8 years) with RM associated with AKI were classified into two groups: 11 heroin users (HU) and 10 non-heroin users (NHU). The severity of RM was evaluated by estimation, on admission, of serum creatine phosphokinase (CPK), serum glutamic oxaloacetic transaminase (SGOT), lactate dehydrogenase (LDH), phosphate (PO4) and calcium (Ca) and by the presence of paraplegia (PPL). The severity of AKI during hospitalization was evaluated by estimation of serum creatinine (CR), the presence of oligoanuria (OA), the days of hospitalization (DH), the total of hemodialysis treatments (THD) and the number of patients who received blood transfusions (BT).

Results

RM was much more severe in HU than in NHU. Mean SGOT, CPK, LDH, and P values on admission were higher in HU. Hypocalcemia was statistically more severe in HU. Nine HU were admitted with PPL vs. 1 NHU. Serum CR levels were higher and oligoanuria was much more common in HU. HU had a longer hospitalization period and underwent a bigger number of HT. More HU took BT.

Conclusions

The results of this study suggest that both RM and ARF are more severe in HU than in NHU possibly due to an additional myotoxic effect of heroin.
Nafamostat Mesilate as an Anticoagulant during Continuous Veno-Venous Hemodialysis: A Three-Year Retrospective Cohort Study
Authors: Maruyama Yukio , Yoshida Hiraku , Uchino Shigehiko , Yokoyama Keitaro , Yamamoto Hiroyasu , Takinami Masanori , Hosoya Tatsuo
Published: August 2011

Introduction

Although nafamostat mesilate, a synthetic serine protease inhibitor, has been commonly used in Japan as an anticoagulant during continuous renal replacement therapy (CRRT), its clinical utility has not been well determined. The aim of this study was to evaluate the efficacy (filter survival) and safety (bleeding complications) of nafamostat mesilate in CRRT for acute kidney injury (AKI) among critically ill patients.

Methods

We retrospectively studied consecutive patients with AKI treated with continuous veno-venous hemodialysis and nafamostat mesilate from April 2005 to March 2008. Demographic, clinical and laboratory data were extracted from the clinical chart.

Results

Fifty-eight patients were enrolled in this study (45 males with an average age of 66±15 years). The median filter survival was 21.8 h (range: 2.8–55.5 h), and the mean was 20.8±8.4 h. Only 38 out of 181 filters (21%) were interrupted because of filter failure within 24 hours and 89 filters (49%) were electively renewed within 24 hours. Activated partial thromboplastin time was elevated especially during the first 24 hours (46.7±13.1 s at baseline versus 73.9±24.3 s at day 1; ANOVA p<0.01). Hematocrit level was kept around 30% and did not change significantly (ANOVA p=0.69). No patients experienced major bleeding while treated with CRRT.

Conclusions

Nafamostat mesilate provided sufficient filter survival without causing major bleeding complications despite the prolongation of APTT.
Axillary Dissection in Breast Cancer Patients with Metastatic Sentinel Node: To Do or Not to Do? Suggestions from Our Series
Authors: Bortolini M. , Genta F. , Biacchiardi Chiara Perono , Zanon E. , Camanni M. , Deltetto F.
Published: August 2011

Several studies have put to question and evaluated the indication and prognosis of sentinel lymph node biopsy (SNLB) as sole treatment in human breast cancer. We reviewed 1588 patients who underwent axillary surgery. In 239 patients, axillary lymph node dissection (ALND) was performed following positive fine needle aspiration cytology (FNAC), and, in 299 cases, ALND was executed after positive SNLB. The most dramatic result from our data is that patients with either micrometastasis of the sentinel lymph node (SLN) or only metastatic SLN have, respectively, an 84.5% and a 75.0% chance of having no other nodal involvement. We believe a more refined patient selection is neccessary when considering ALND. Where the primary tumor is larger than 5 cm, where radio or adjuvant therapies are not indicated, in cases of FNAC+ nodes, and in cases presenting more than one metastatic sentinel node, we prefer to carry out ALND. Having thus said, however, our data suggests that it is wise not to perform ALND in almost all cases presenting positive SLNs.
Differentiated Thyroid Cancer in Navarra (Spain): Historic Cohort Results (1987–2003)
Authors: Salvador Egea María Pilar , Echegoyen Silanes Ana Aranzazu , Layana Echezuri Eduardo , Anda Apiñariz Emma , Puras Gil Ana , Menéndez Torre Edelmiro , Forga Llenas Lluis , Sainz de los Terreros Amaya
Published: July 2011

Introduction. Navarra has the highest incidence of differentiated thyroid cancer in Spain. The aim of this study was to review its management carried out by the Navarra's multidisciplinary Thyroid Disease Unit, from 1987 to 2003. Material and Methods. 325 patients were studied to find the incidence, prevalence, and prognostic factors. Statistical analysis comprised univariate and multivariate Cox proportional hazards regression models for survival and tumor recurrence. Results. The average annual incidence was 3.6 per 100,000 inhabitants, with a final prevalence of 82.4 per 100,000. Regarding survival and recurrence, statistical significance was observed for stage IV, follicular carcinoma, capsular and prethyroid muscles invasion, and T4 group. Only survival was related to tumour size larger than 40 mm. Only recurrence was related to lymph node metastases and radioiodine dose higher than 100 mCi. Conclusions. Attendance of patients in a functional unit setting has allowed us to classify them into three risk groups.
Channel bar dynamics on multi‐decadal timescales in an active meandering river
Authors: Hooke J. M. , Yorke L.
Published: July 2011

Occurrence and development of channel bars are major components of the morphodynamics of rivers and their relation to river meandering has been much explored through theory and experimentation. However, field and documentary data of characteristics and evolution over timescales from years to several decades are lacking. Four sets of aerial photographs in the period 1984–2007 were used to map and quantify bar numbers and areas in GIS on an active meandering reach. Bar types were classified. Additional temporal resolution was provided by annual ground photography and mapping for 1981–2010. Analysis was extended backward by use of large scale Ordnance Survey maps from 1873 onwards. As expected, point bars are the most common type but ‘free’ bars of several types are major components of bar deposition. Point bars and attached bars are significantly larger in size than mid‐channel and side bars. Spatial distribution of bars varies down the reach and over time but is related to channel sinuosity, gradient and mobility and to bend evolution. Different types of bar occur in distinctive channel locations, with point and concave‐bend bars in zones of high curvature. Bar activity shows a relation with discharge events and phases and possibly with changing riparian conditions, but superimposed on this is a common sequence of bar evolution from incipient gravel mid‐channel bars to full floodplain integration. This life‐cycle is identified as 7–9 years on average. No evidence for mobility of free bars within the course is found. The results are compared with bar and bend theory; the bars are forced and conform in general to bend theory but detailed variation relates to geomorphic factors and to autogenic sequences of bends and bars. Mid‐channel bars are width induced. Variability of bar occurrence needs to be taken into account in river management and ecological evaluation, including for the EU WFD. Copyright © 2011 John Wiley & Sons, Ltd.
Method development for aquatic ecotoxicological characterization factor calculation for hydrocarbon mixtures in life cycle assessment
Authors: Bamard Emilie , Bulle Cécile , Deschênes Louise
Published: July 2011

Most pollutants are released into the environment in the presence of other contaminants, creating complex mixtures. In life-cycle impact assessment (LCIA) methods, characterization factors (CFs) are used to obtain the potential impacts associated with each contaminant emission. Current LCIA methods do not include CFs to evaluate the potential impacts of complex organic mixtures on ecosystems. This study explores the possibility of developing new CFs for petroleum mixtures. Petroleum products are an example of mixtures whose constituents have a common toxic mode of action: the narcosis effect. Characterization factors were calculated for a series of representative constituents of a specific petroleum mixture and also for different fractions of the same mixture developed using the hydrocarbon block (HBM) and Total Petroleum Hydrocarbon Criteria Working Group (TPHWG) methods. Finally, CFs were developed for the mixture itself as a whole by using experimental property measurements and estimations. The soil-water partitioning coefficient, water solubility, degradation kinetic constant in soil, octanol-water partitioning coefficient, and vapor pressure were measured while the molar weight and the degradation kinetic constants in air, water, and sediments were estimated. The highest aquatic ecotoxicological CFs, no matter the approach chosen, were obtained for an emission to freshwater up to 2.2 × 10+07 PAF·m3·d/kg for the highest CF. CF distributions obtained using the different blocking method and experimental CFs obtained for oil as a whole are, on average, not significantly different, given the known uncertainty of ecotoxicological models in LCIA. Consequently, all the CFs obtained using the different blocking methods from the literature are considered relevant for characterizing the potential impact for aquatic ecotoxicity of petroleum substances. Environ. Toxicol. Chem. 2011;30:2342–2352. © 2011 SETAC
Performance and sensitivity of rapid sublethal sediment toxicity tests with the amphipod Melita plumulosa and copepod Nitocra spinipes
Authors: Simpson Stuart L , Spadaro David A
Published: July 2011

Sublethal whole-sediment toxicity tests are an important tool for assessing the potential effects of contaminated sediments. However, the longer duration required for evaluating potential chronic effects may increase endpoint variability and test costs compared to survival endpoints. In the present study we compare the performance and sensitivity to contaminants of 10-d sublethal sediment toxicity tests with the amphipod Melita plumulosa and harpacticoid copepod Nitocra spinipes. For both tests, sublethal effects were consistently observed when sediment contaminant concentrations exceeded sediment quality guideline (SQG) concentrations. The response of these bioassays in metal-contaminated sediments was shown to conform ideally with respect to the mean SQG quotient calculated on the basis of the Australian and New Zealand lower SQG trigger value, with toxicity being observed only in those sediments where the mean quotient exceeded one. Better predictions of nontoxicity were obtained when dilute acid-extractable rather than total metal concentrations were used. Using the upper SQG, toxicity frequently occurred at mean quotients below one. The effects were generally consistent with predictions from the acid-volatile sulfide and simultaneously extracted metal model. Effects on reproduction of M. plumulosa were detected for sediments that did not cause effects on survival and highlighted the environmental relevance and importance of using these sublethal endpoints. When using four replicates for M. plumulosa and five replicates for N. spinipes, the endpoint variability (standard error) was less than 10%. Variations in sediment particle size and organic carbon content did not affect endpoint variability. Both species are relatively easily cultured in the laboratory, and the estimated effort and cost of achieving the sublethal endpoints is 1.5 times that of the acute survival test endpoints. Environ. Toxicol. Chem. 2011;30:2326–2334. © 2011 SETAC
Oxidative stress in zebrafish embryos induced by short-term exposure to bisphenol A, nonylphenol, and their mixture
Authors: Wu Minghong , Xu Hai , Shen Yang , Qiu Wenhui , Yang Ming
Published: July 2011

Bisphenol A (BPA) and nonylphenol (NP) are well-known endocrine-disrupting chemicals (EDCs) present in the aquatic environment, but little is known about their oxidative stress effects on fish embryos. In the present study, we examined the oxidative stress indices and antioxidant parameters of zebrafish embryos after a short-term exposure to various concentrations of BPA, NP, and their mixture (BPA-NP) for 4 h postfertilization (hpf) to 168 hpf. Exposure to the chemicals was found to enhance the production of hydroxyl radicals and lipid peroxidation in a concentration-dependent manner. The content of total glutathione (TG), reduced glutathione (GSH), and oxidized glutathione (GSSH), as well as the activity of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase were all significantly inhibited after exposure to BPA, NP, and BPA-NP, indicating the occurrence of oxidative stress. Coexposure to BPA-NP resulted in an additive effect on some antioxidant parameters. In addition, the alkaline phosphatase activity was also significantly inhibited after exposure to BPA, NP, and their mixtures. Our results demonstrated that BPA, NP, and BPA-NP in aquatic systems can affect antioxidant responses in zebrafish embryos. Environ. Toxicol. Chem. 2011;30:2335–2341. © 2011 SETAC