Historical perspective of heavy metals contamination (Cd, Cr, Cu, Hg, Pb, Zn) in the Seine River basin (France) following a DPSIR approach (1950-2005)

The Driver-Pressures-State-Impact-Response approach is applied to heavy metals in the Seine River catchment (65,000 km(2); 14 million people of which 10 million are aggregated within Paris megacity; 30% of French industrial and agricultural production). The contamination pattern at river mouth is established on the particulate material at different time scales: 1930-2000 for floodplain cores, 1980-2003 for suspended particulate matter (SPM) and bed-sediments, 1994-2003 for atmospheric fallout and annual flood deposits. The Seine has been among the most contaminated catchments with maximum contents recorded at 130 mg kg(-1) for Cd, 24 for Hg, 558 for Pb, 1620 for Zn, 347 for Cu, 275 for Cr and 150 for Ni. Today, the average levels for Cd (1.8 mg kg(-1)), Hg (1.08), Pb (108), Zn (370), Cu (99), Cr (123) and Ni (31) are much lower but still in the upper 90% of the global scale distribution (Cr and Ni excepted) and well above the natural background values determined on pre-historical deposits. All metal contents have decreased at least since 1955/65, well before metal emission regulations that started in the mid 1970's and the metal monitoring in the catchment that started in the early 1980's. In the last 20 y, major criteria changes for the management of contaminated particulates (treated urban sludge, agricultural soils, dredged sediments) have occurred. In the mid 1990's, there was a complete shift in the contamination assessment scales, from sediment management and water usage criteria to the good ecological state, now required by the 2000 European Directive. When comparing excess metal outputs, associated to river SPM, to the average metal demand within the catchment from 1950 to 2000, the leakage ratios decrease exponentially from 1950 to 2000 for Cd, Cr, Cu, Pb and Zn, meanwhile, a general increase of the demand is observed: the rate of recycling and/or treatment of metals within the anthroposphere has been improved ten-fold. Hg environmental trajectory is very specific: there is a marked decontamination from 1970 to 2000, but the leakage ratio remains very high (10 to 20%) during this period. Drivers and Pressures are poorly known prior to 1985; State evolution since 1935 has been reconstructed from flood plain cores analysis; Impacts were maximum between 1950 and 1970 but remained unknown due to analytical limitation and lack of awareness. Some Responses are lagging 10 y behind monitoring and have much evolved in the past 10 y.     

An equation by any other name is still the same: on spatial econometrics and spatial statistics

Statistics is a branch of mathematics concerned with the collection, quantification, analysis, interpretation, and presentation of real-world data, and the use of probability theory to estimate population parameters with these data. Spatial statistics is a subset of statistics that is concerned with handling the special problems associated with geographically distributed data, which include spatial point patterns, regional and lattice measurement aggregations, irregularly spaced site-specific measurements on a surface, and image analysis. Meanwhile, econometrics is concerned with the application of statistical methods to the study of economic data and problems. When coining the term spatial econometrics in 1979, Paelinck and Klaassen characterized it as a subset of econometrics that is concerned with the role of spatial dependence in regional economic model response and explanatory variables, asymmetries in spatial relationships, the specification of geographic structure governing spatial interactions, and the explicit modeling of space. We outline and discuss principal similarities (e.g., testing for the presence of spatial autocorrelation) and differences (e.g., map generalization) between spatial statistics and spatial econometrics. In doing so, our goal is to help clarify past, present, and future relationships between these two subfields.     

A simple Hessian-based 3D mesh adaptation technique with applications to the multigroup diffusion equations

A simple error estimation and mesh adaptation procedure is proposed for the multigroup multi-dimensional diffusion equations. The procedure estimates the values of the second-order derivatives of the current numerical solution to drive the mesh refinement. Different spatial meshes are obtained for each component of the multigroup flux in order to follow the physics appropriately. This requires the proper handling of the group coupling terms arising in the multigroup diffusion equations. Results are presented in 2D and 3D.     

冠带层新平台技术

子午线轮胎出现不久,就采用钢丝带束层代替了纤维带束层,这对于实现子午线轮胎提高使用寿命和改善操纵性能的潜能是必要的。     

Use of analogies in therapeutic situations: An analogue study.

141 participants read vignettes that described stressors encountered by college students. Each vignettes also included information about the students' hobby and therapeutic advice the students might follow to deal with their stressors. This advice was expressed in either a literal or an analogical form. Ss were asked to read the vignettes from the perspective of a therapist, a patient, or an observer, and to rate the advice component of each vignette for helpfulness. Analogical advice was rated as significantly more helpful than literal advice on a variety of questions. A surprise cued-recall memory test showed that Ss in the analogical condition but not in the literal condition remembered information according to their assigned role. In the role of patients, Ss showed greatest recall for the therapeutic advice, but in the role of therapists, they showed greatest recall for the students' stressors. In line with a growing literature in cognitive psychology, these results show that the impact of analogies in therapeutic interactions is a combined is a combined function of the material to be processed and the role of the person processing it. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Constraint-induced movement therapy: A new approach to treatment in physical rehabilitation.

Constraint-Induced (CI) Movement Therapy is a new approach to the rehabilitation of movement, based on research in neuroscience and behavioral psychology, that has been shown in controlled experiments to greatly increase the amount of use of an impaired upper extremity in chronic stroke patients in both the laboratory and the real world. CI Therapy consists of a family of techniques that induce stroke patients to greatly increase their use of an affected upper extremity for many hours a day over 10 to 14 consecutive days. The signature technique involves restricting the contralateral arm in a sling and training the affected arm. This commentary reviews the animal and human research and the theoretical formulation on which CI Therapy is based. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A generalized galerkin method for steady convection-diffusion problems with application to quadratic shape function elements

A generalization of the standard Galerkin finite element method is considered to enable it to deal successfully with steady convection-diffusion problems. The proposed method employs a generalized governing equation which is obtained by subtracting from the original differential equation the scalar product of its gradient by a vector of free parameters associated with each of the coordinate directions. The generalized equation is successively discretized by the standard Bubnov-Galerkin finite element method. The effectiveness of the method is illustrated for the case of quadratic local interpolations in one and two space dimensions.     

A recognition network model-based approach to dynamic image understanding

In this paper, we present definitions for a dynamic knowledge-based image understanding system. From a sequence of grey level images, the system produces a flow of image interpretations. We use a semantic network to represent the knowledge embodied in the system. Dynamic representation is achieved by ahypotheses network. This network is a graph in which nodes represent information and arcs relations. A control strategy performs a continuous update of this network. The originality of our work lies in the control strategy: it includes astructure tracking phase, using the representation structure obtained from previous images to reduce the computational complexity of understanding processes. We demonstrate that in our case the computational complexity, which is exponential if we only use a purely data-driven bottom-up scheme, is polynomial when using the hypotheses tracking mechanism. This is to say that gain improvement in computation time is a major reason for dynamic understanding. The proposed system is implemented; experimental results of road mark detection and tracking are given.