Bayesian Neural Networks for Geothermal Resource Assessment: Prediction with Uncertainty

We consider the application of machine learning to the evaluation of geothermal resource potential. A supervised learning problem is defined where maps of 10 geological and geophysical features within the state of Nevada, USA are used to define geothermal potential across a broad region. We have available a relatively small set of positive training sites (known resources or active power plants) and negative training sites (known drill sites with unsuitable geothermal conditions) and use these to constrain and optimize artificial neural networks for this classification task. The main objective is to predict the geothermal resource potential at unknown sites within a large geographic area where the defining features are known. These predictions could be used to target promising areas for further detailed investigations. We describe the evolution of our work from defining a specific neural network architecture to training and optimization trials. Upon analysis we expose the inevitable problems of model variability and resulting prediction uncertainty. Finally, to address these problems we apply the concept of Bayesian neural networks, a heuristic approach to regularization in network training, and make use of the practical interpretation of the formal uncertainty measures they provide.Comment: 27 pages, 12 figure

To be or not to be an auctioneer: Some thoughts on the legal nature of online eBay auctions and the protection of consumers

This paper discusses the legal classification of online “eBay” auctions. The discussion has key implications on the scope of consumer protection law as sale by auctions are, for example, excluded from the scope of the Consumer Protection (Distance Selling) Regulations 2000. The paper uncovers that online “eBay” auctions cannot always be considered as traditional auctions and that eBay, as an intermediary, is not to be considered as an auctioneer. This creates difficulties associated with a distributive application of consumer protection laws such as the Consumer Protection (Distance Selling) Regulations 2000. Another set of difficulties is associated with a lenient legal regime applicable to the liability of eBay under the Electronic Commerce (EC Directive) Regulations 2002 . The paper concludes that there is an urgent need to clarify the legal classification of online auctions and to rethink the liability of online auction sites to better protect consumers

The Stress Response Factors Yap6, Cin5, Phd1, and Skn7 Direct Targeting of the Conserved Co-Repressor Tup1-Ssn6 in S. cerevisiae

Maintaining the proper expression of the transcriptome during development or in response to a changing environment requires a delicate balance between transcriptional regulators with activating and repressing functions. The budding yeast transcriptional co-repressor Tup1-Ssn6 is a model for studying similar repressor complexes in multicellular eukaryotes. Tup1-Ssn6 does not bind DNA directly, but is directed to individual promoters by one or more DNA-binding proteins, referred to as Tup1 recruiters. This functional architecture allows the Tup1-Ssn6 to modulate the expression of genes required for the response to a variety of cellular stresses. To understand the targeting or the Tup1-Ssn6 complex, we determined the genomic distribution of Tup1 and Ssn6 by ChIP-chip. We found that most loci bound by Tup1-Ssn6 could not be explained by co-occupancy with a known recruiting cofactor and that deletion of individual known Tup1 recruiters did not significantly alter the Tup1 binding profile. These observations suggest that new Tup1 recruiting proteins remain to be discovered and that Tup1 recruitment typically depends on multiple recruiting cofactors. To identify new recruiting proteins, we computationally screened for factors with binding patterns similar to the observed Tup1-Ssn6 genomic distribution. Four top candidates, Cin5, Skn7, Phd1, and Yap6, all known to be associated with stress response gene regulation, were experimentally confirmed to physically interact with Tup1 and/or Ssn6. Incorporating these new recruitment cofactors with previously characterized cofactors now explains the majority of Tup1 targeting across the genome, and expands our understanding of the mechanism by which Tup1-Ssn6 is directed to its targets

Towards a fairer trading system for micro and small businesses post-Brexit? Comparative aspects with other common law systems

This chapter explores the position that the English legislature and courts would have on the issue of imposing unfair contract terms on Micro and Small Businesses (MSBs) in the post-Brexit era. The chapter looks into the extent that current applicable law and developments in English contract law offer protections for contractual trading with MSBs. In the presence of current legal gaps with regards to such protections that often lead to abuse by larger corporations there might be some solutions available in the current law to deal with the invalidation of unfair contract terms in Business to Business (B2B) transactions involving MSBs, however these still do not deal with the issue in its entirety and are also met with limitations. Given the uncertain developments on this matter after Brexit the chapter considers a brief comparative analysis with other common law jurisdictions on the issue as they might influence possible future reforms. The comparative analysis consists of examining the protections available on imposing unfair contract terms on small businesses in the Australian and the US legal systems. This chapter thereby analyses what possible solutions can be raised in dealing with this pressing issue after Brexit by considering these comparative results

The Transcriptional Repressor TupA in Aspergillus niger Is Involved in Controlling Gene Expression Related to Cell Wall Biosynthesis, Development, and Nitrogen Source Availability.

The Tup1-Cyc8 (Ssn6) complex is a well characterized and conserved general transcriptional repressor complex in eukaryotic cells. Here, we report the identification of the Tup1 (TupA) homolog in the filamentous fungus Aspergillus niger in a genetic screen for mutants with a constitutive expression of the agsA gene. The agsA gene encodes a putative alpha-glucan synthase, which is induced in response to cell wall stress in A. niger. Apart from the constitutive expression of agsA, the selected mutant was also found to produce an unknown pigment at high temperatures. Complementation analysis with a genomic library showed that the tupA gene could complement the phenotypes of the mutant. Screening of a collection of 240 mutants with constitutive expression of agsA identified sixteen additional pigment-secreting mutants, which were all mutated in the tupA gene. The phenotypes of the tupA mutants were very similar to the phenotypes of a tupA deletion strain. Further analysis of the tupA-17 mutant and the DeltatupA mutant revealed that TupA is also required for normal growth and morphogenesis. The production of the pigment at 37 degrees C is nitrogen source-dependent and repressed by ammonium. Genome-wide expression analysis of the tupA mutant during exponential growth revealed derepression of a large group of diverse genes, including genes related to development and cell wall biosynthesis, and also protease-encoding genes that are normally repressed by ammonium. Comparison of the transcriptome of up-regulated genes in the tupA mutant showed limited overlap with the transcriptome of caspofungin-induced cell wall stress-related genes, suggesting that TupA is not a general suppressor of cell wall stress-induced genes. We propose that TupA is an important repressor of genes related to development and nitrogen metabolism