The Impact of Rate-of-Return Regulation on Electricity Generation from Renewable Energy

Traditional electric utility companies face a trade-off between building generation facilities that utilize renewable energy (RE) and non-renewable energy (non-RE). The firm’s input decision to build capacity for either source depends on several constraining factors, including input prices, policies that promote or discourage RE use, and the type of regulation faced by the firm. This paper models the utility company’s decision between RE and non-RE capital types. From the model, two main results are derived. First, rate-of-return (ROR) regulation decreases the investment in RE capital relative to the unregulated firm. These findings suggest restructuring electricity generation markets, which removes the ROR on generating assets, can increase the relative use of RE. Second, the renewable portfolio standard (RPS) increases the investment in capital and labor that requires RE as a source of electricity, as expected. The model shows that the impact of an RPS depends on the amount of ROR regulation.renewable portfolio standard, renewable energy, rate-of-return regulation

Who Searches for Low Prices? Population Characteristics and Price Dispersion in the Market for Prescription Drugs

We examine the relationship between population characteristics and price dispersion for 75 prescription drugs in five markets. Based on models of price dispersion, we consider that search costs are likely lower for the elderly, who are repeat purchasers. Expected benefits from search are likely higher for low income households, who lack insurance. Our results are consistent with the hypothesis that for communities with a large percentage of elderly and poor population, search effort is greater for pharmaceutical drugs, causing lower price dispersion. By understanding the characteristics of who searches for low drug prices, we begin to identify the motives of consumers that might also lead to search for the lowest cost healthcare provider or lowest cost insurance. The results suggest that the 2004 Medicare legislation that closed the pharmaceutical donut hole may have reduced search by the elderly, increased price dispersion, and potentially increased the average price of prescription drugs.search cost; price dispersion; prescription drugs

Interst Group Incentives for Post-lottery Trade Restrictions

The rights to use publicly-managed natural resources are sometimes distributed by lottery,and typically these rights are non-transferable. Prohibition of post-lottery permit transfers discourages applicants from entering the lottery solely for protable permit sale, so only those who personally value the use of the resource apply. However, because permits are distributed randomly and trade is restricted, permits may not be used by those who value them most. We examine a possible rationale for restrictions on permit transfers based on the distribution of welfare across interest groups, and characterize the economic conditions under which post-lottery prohibitions on trade are likely to arise. We develop our model using the specic case of the Four Rivers Lottery used to allocate rafting permits on four river sections in Idaho and Oregon.lottery, trade prohibition, interest groups

Sustained-input switches for transcription factors and microRNAs are central building blocks of eukaryotic gene circuits

WaRSwap is a randomization algorithm that for the first time provides a practical network motif discovery method for large multi-layer networks, for example those that include transcription factors, microRNAs, and non-regulatory protein coding genes. The algorithm is applicable to systems with tens of thousands of genes, while accounting for critical aspects of biological networks, including self-loops, large hubs, and target rearrangements. We validate WaRSwap on a newly inferred regulatory network from Arabidopsis thaliana, and compare outcomes on published Drosophila and human networks. Specifically, sustained input switches are among the few over-represented circuits across this diverse set of eukaryotes

Zur Bekämpfung von Phytophthora cryptogea an Gerbera

In Versuchen zur Bekämpfung von Phytophthora cryptogea bei Gerbera-Jungpflanzen wurde festgestellt, daß Prothiocarb (Previcur) dem Wirkstoff Fenaminosulf (Bayer 5072) überlegen ist. Dabei war die Gießbehandlung unmittelbar nach dem Pflanzen wirksamer als die Tauchbehandlung der Wurzelballen vor dem Pflanzen. Die in Gefäßen durchgeführten Infektionsversuche zeigten, daß die Jungpflanzen bei geringerer Substratverseuchung mit einer einmaligen Previcur-Behandlung über ca. 3 Monate gesund erhalten werden konnten. Stärkere Substratverseuchung machte Folgebehandlungen notwendig. Auf die Schwierigkeiten einer erfolgreichen Bekämpfung des Pilzes bei älteren Kulturen in Grundbeeten wird hingewiesen. Control of Phytophthora cryptogea on Gerbera Experiments to control Phytophthora cryptogea on young Gerbera plants indicated that Prothiocarb (Previcur) had a better effect than Fenaminosulf (Bayer 5072). The application of the fungicide by watering immediately after planting was more effective than dipping the roots before planting. The inoculation tests made in pots showed that it was possible by one treatment to keep the young plants healthy for about 3 months, when the planting mix had a low infection rate. A higher infection rate demanded additional treatments. It was suggested that the control of the fungus on elder plants grown in soil benches will be difficult

Large-Scale Discovery of Promoter Motifs in Drosophila melanogaster

A key step in understanding gene regulation is to identify the repertoire of transcription factor binding motifs (TFBMs) that form the building blocks of promoters and other regulatory elements. Identifying these experimentally is very laborious, and the number of TFBMs discovered remains relatively small, especially when compared with the hundreds of transcription factor genes predicted in metazoan genomes. We have used a recently developed statistical motif discovery approach, NestedMICA, to detect candidate TFBMs from a large set of Drosophila melanogaster promoter regions. Of the 120 motifs inferred in our initial analysis, 25 were statistically significant matches to previously reported motifs, while 87 appeared to be novel. Analysis of sequence conservation and motif positioning suggested that the great majority of these discovered motifs are predictive of functional elements in the genome. Many motifs showed associations with specific patterns of gene expression in the D. melanogaster embryo, and we were able to obtain confident annotation of expression patterns for 25 of our motifs, including eight of the novel motifs. The motifs are available through Tiffin, a new database of DNA sequence motifs. We have discovered many new motifs that are overrepresented in D. melanogaster promoter regions, and offer several independent lines of evidence that these are novel TFBMs. Our motif dictionary provides a solid foundation for further investigation of regulatory elements in Drosophila, and demonstrates techniques that should be applicable in other species. We suggest that further improvements in computational motif discovery should narrow the gap between the set of known motifs and the total number of transcription factors in metazoan genomes

The mRNA-bound proteome of the early fly embryo

Early embryogenesis is characterized by the maternal to zygotic transition (MZT), in which maternally deposited messenger RNAs are degraded while zygotic transcription begins. Before the MZT, post-transcriptional gene regulation by RNA-binding proteins (RBPs) is the dominant force in embryo patterning. We used two mRNA interactome capture methods to identify RBPs bound to polyadenylated transcripts within the first two hours of D. melanogaster embryogenesis. We identified a high-confidence set of 476 putative RBPs and confirmed RNA-binding activities for most of 24 tested candidates. Most proteins in the interactome are known RBPs or harbor canonical RBP features, but 99 exhibited previously uncharacterized RNA-binding activity. mRNA-bound RBPs and TFs exhibit distinct expression dynamics, in which the newly identified RBPs dominate the first two hours of embryonic development. Integrating our resource with in situ hybridization data from existing databases showed that mRNAs encoding RBPs are enriched in posterior regions of the early embryo, suggesting their general importance in posterior patterning and germ cell maturation

Genome-wide identification of regulatory elements in Sertoli cells

A current goal of molecular biology is to identify transcriptional networks that regulate cell differentiation. However, identifying functional gene regulatory elements has been challenging in the context of developing tissues where material is limited and cell types are mixed. To identify regulatory sites during sex determination, we subjected Sertoli cells from mouse fetal testes to DNaseI-seq and ChIP-seq for H3K27ac. DNaseI-seq identified putative regulatory sites around genes enriched in Sertoli and pregranulosa cells; however, active enhancers marked by H3K27ac were enriched proximal to only Sertoli-enriched genes. Sequence analysis identified putative binding sites of known and novel transcription factors likely controlling Sertoli cell differentiation. As a validation of this approach, we identified a novel Sertoli cell enhancer upstream of Wt1, and used it to drive expression of a transgenic reporter in Sertoli cells. This work furthers our understanding of the complex genetic network that underlies sex determination and identifies regions that potentially harbor non-coding mutations underlying disorders of sexual development

Global target mRNA specification and regulation by the RNA-binding protein ZFP36

BACKGROUND: ZFP36, also known as tristetraprolin or TTP, and ELAVL1, also known as HuR, are two disease-relevant RNA-binding proteins (RBPs) that both interact with AU-rich sequences but have antagonistic roles. While ELAVL1 binding has been profiled in several studies, the precise in vivo binding specificity of ZFP36 has not been investigated on a global scale. We determined ZFP36 binding preferences using cross-linking and immunoprecipitation in human embryonic kidney cells, and examined the combinatorial regulation of AU-rich elements by ZFP36 and ELAVL1. RESULTS: Targets bound and negatively regulated by ZFP36 include transcripts encoding proteins necessary for immune function and cancer, and transcripts encoding other RBPs. Using partial correlation analysis, we were able to quantify the association between ZFP36 binding sites and differential target RNA abundance upon ZFP36 overexpression independent of effects from confounding features. Genes with increased mRNA half-lives in ZFP36 knockout versus wild-type mouse cells were significantly enriched for our human ZFP36 targets. We identified thousands of overlapping ZFP36 and ELAVL1 binding sites, in 1,313 genes, and found that ZFP36 degrades transcripts through specific AU-rich sequences, representing a subset of the U-rich sequences ELAVL1 interacts with to stabilize transcripts. CONCLUSIONS: ZFP36-RNA target specificities in vivo are quantitatively similar to previously reported in vitro binding affinities. ZFP36 and ELAVL1 bind an overlapping spectrum of RNA sequences, yet with differential relative preferences that dictate combinatorial regulatory potential. Our findings and methodology delineate an approach to unravel in vivo combinatorial regulation by RNA-binding proteins