Non-zero mean Gaussian process prior wind field models

This report outlines the derivation and application of a non-zero mean, polynomial-exponential covariance function based Gaussian process which forms the prior wind field model used in 'autonomous' disambiguation. It is principally used since the non-zero mean permits the computation of realistic local wind vector prior probabilities which are required when applying the scaled-likelihood trick, as the marginals of the full wind field prior. As the full prior is multi-variate normal, these marginals are very simple to compute.

Development of a neurotoxicity test-system, using human post-mitotic, astrocytic and neuronal cell lines in co-culture

Astrocytes are essential for neuronal function and survival, so both cell types were included in a human neurotoxicity test-system to assess the protective effects of astrocytes on neurons, compared with a culture of neurons alone. The human NT2.D1 cell line was differentiated to form either a co-culture of post-mitotic NT2.N neuronal (TUJ1, NF68 and NSE positive) and NT2.A astrocytic (GFAP positive) cells (∼2:1 NT2.A:NT2.N), or an NT2.N mono-culture. Cultures were exposed to human toxins, for 4 h at sub-cytotoxic concentrations, in order to compare levels of compromised cell function and thus evidence of an astrocytic protective effect. Functional endpoints examined included assays for cellular energy (ATP) and glutathione (GSH) levels, generation of hydrogen peroxide (H2O2) and caspase-3 activation. Generally, the NT2.N/A co-culture was more resistant to toxicity, maintaining superior ATP and GSH levels and sustaining smaller significant increases in H2O2 levels compared with neurons alone. However, the pure neuronal culture showed a significantly lower level of caspase activation. These data suggest that besides their support for neurons through maintenance of ATP and GSH and control of H2O2 levels, following exposure to some substances, astrocytes may promote an apoptotic mode of cell death. Thus, it appears the use of astrocytes in an in vitro predictive neurotoxicity test-system may be more relevant to human CNS structure and function than neuronal cells alone. © 2007 Elsevier Ltd. All rights reserved.

Scenario-based preparedness plan for floods

The increasing trend of disaster victims globally is posing a complex challenge for disaster management authorities. Moreover, to accomplish successful transition between preparedness and response, it is important to consider the different features inherent to each type of disaster. Floods are portrayed as one of the most frequent and harmful disasters, hence introducing the necessity to develop a tool for disaster preparedness to perform efficient and effective flood management. The purpose of the article is to introduce a method to simultaneously define the proper location of shelters and distribution centers, along with the allocation of prepositioned goods and distribution decisions required to satisfy flood victims. The tool combines the use of a raster geographical information system (GIS) and an optimization model. The GIS determines the flood hazard of the city areas aiming to assess the flood situation and to discard floodable facilities. Then, the multi-commodity multimodal optimization model is solved to obtain the Pareto frontier of two criteria: distance and cost. The methodology was applied to a case study in the flood of Villahermosa, Mexico, in 2007, and the results were compared to an optimized scenario of the guidelines followed by Mexican authorities, concluding that the value of the performance measures was improved using the developed method. Furthermore, the results exhibited the possibility to provide adequate care for people affected with less facilities than the current approach and the advantages of considering more than one distribution center for relief prepositioning.