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Macroeconomic announcements and foreign exchange risk: Working paper series--14-05
Get PDFSavor and Wilson (2013a, 2013b) suggest that the tradeoff between state variable risk and asset returns underlying standard asset-pricing theories should be particularly strong on prescheduled macroeconomic announcement days, because important information about the state of the economy is revealed at such times. We apply this insight to foreign-exchange risk, and find robust evidence that foreign-exchange risk is priced on prescheduled macroeconomic announcement days. Our results make important contributions to both international finance and empirical asset-pricing literature
Resolving antagonistic interactions among clinical isolates of Acinetobacter baumannii with phylogenetic analysis
Get PDFAcinetobacter baumannii is a nosocomial species frequently isolated from the traumatic wounds of injured military personnel and increasingly detected in civilian healthcare facilities. Many clinical isolates of A. baumannii are drug resistant, so new treatments are needed for infections. Recently, the ability of strains of conspecific bacteria to inhibit the growth of other strains has been observed in increasing numbers of species. We previously reported on intraspecific semisolid-phase growth inhibition (antagonism) among 94 clinical isolates of A. baumannii. These antagonistic interactions may be the result of genetically-encoded molecules, so more closely related isolates would be expected to produce similar patterns of interactions caused by identically active gene products. However, the phylogeny of clinical A. baumannii below the species level has not been established for this set of isolates.In this study, we used Phylomark to identify three genetic loci that recapitulated a whole-genome phylogeny of published A. baumannii genomes and we created a parsimony-based phylogeny from the 1.2 kilobase concatenated sequences. One clade appeared to exhibit the highest incidence of antagonistic interactions against all other isolates screened, except for itself and one relatively distant clade. This clade's nearest neighbor was susceptible to the most consistent antagonistic activity by the first clade; both of these clades appear to belong to MLST ST1 with reference strain AYE. Other isolates with high rates of antagonistic activity fall outside of ST1. Future studies aim to elucidate the genetic basis of the antagonism phenotype in clinical Acinetobacter, particularly in the most antagonistic isolates. The next step will be to mine these interactions to identify expressed antimicrobial molecules with potential for drug therapy
The large-scale blast score ratio (LS-BSR) pipeline: a method to rapidly compare genetic content between bacterial genomes
Get PDFBackground. As whole genome sequence data from bacterial isolates becomes cheaper to generate, computational methods are needed to correlate sequence data with biological observations. Here we present the large-scale BLAST score ratio (LS-BSR) pipeline, which rapidly compares the genetic content of hundreds to thousands of bacterial genomes, and returns a matrix that describes the relatedness of all coding sequences (CDSs) in all genomes surveyed. This matrix can be easily parsed in order to identify genetic relationships between bacterial genomes. Although pipelines have been published that group peptides by sequence similarity, no other software performs the rapid, large-scale, full-genome comparative analyses carried out by LS-BSR. Results. To demonstrate the utility of the method, the LS-BSR pipeline was tested on 96 Escherichia coli and Shigella genomes; the pipeline ran in 163 min using 16 processors, which is a greater than 7-fold speedup compared to using a single processor. The BSR values for each CDS, which indicate a relative level of relatedness, were then mapped to each genome on an independent core genome single nucleotide polymorphism (SNP) based phylogeny. Comparisons were then used to identify clade specific CDS markers and validate the LS-BSR pipeline based on molecular markers that delineate between classical E. coli pathogenic variant (pathovar) designations. Scalability tests demonstrated that the LS-BSR pipeline can process 1,000 E. coli genomes in 27-57 h, depending upon the alignment method, using 16 processors. Conclusions. LS-BSR is an open-source, parallel implementation of the BSR algorithm, enabling rapid comparison of the genetic content of large numbers of genomes. The results of the pipeline can be used to identify specific markers between user-defined phylogenetic groups, and to identify the loss and/or acquisition of genetic information between bacterial isolates. Taxa-specific genetic markers can then be translated into clinical diagnostics, or can be used to identify broadly conserved putative therapeutic candidates
"TNOs are Cool": A survey of the trans-Neptunian region: X. analysis of classical Kuiper belt objects from Herschel and Spitzer observations
Get PDFContext. The Kuiper belt is formed of planetesimals which failed to grow to planets and its dynamical structure has been affected by Neptune. The classical Kuiper belt contains objects both from a low-inclination, presumably primordial, distribution and from a high-inclination dynamically excited population. Aims. Based on a sample of classical trans-Neptunian objects (TNOs) with observations at thermal wavelengths we determine radiometric sizes, geometric albedos and thermal beaming factors for each object as well as study sample properties of dynamically hot and cold classicals. Methods. Observations near the thermal peak of TNOs using infrared space telescopes are combined with optical magnitudes using the radiometric technique with near-Earth asteroid thermal model (NEATM). We have determined three-band flux densities from Herschel/PACS observations at 70.0, 100.0 and 160.0 m and Spitzer/MIPS at 23.68 and 71.42 m when available. We use reexamined absolute visual magnitudes from the literature and ground based programs in support of Herschel observations. Results. We have analysed 18 classical TNOs with previously unpublished data and re-analysed previously published targets with updated data reduction to determine their sizes and geometric albedos as well as beaming factors when data quality allows. We have combined these samples with classical TNOs with radiometric results in the literature for the analysis of sample properties of a total of 44 objects. We find a median geometric albedo for cold classical TNOs of 0.14-0.07+0.09 and for dynamically hot classical TNOs, excluding the Haumea family and dwarf planets, 0.085 -0.045+0.084. We have determined the bulk densities of Borasisi-Pabu (2.1-1.2+2.6 g cm-3), Varda-Ilmare (1.25-0.43+0.40 g cm-3) and 2001 QC298 (1.14-0.30+0.34 g cm-3) as well as updated previous density estimates of four targets. We have determined the slope parameter of the debiased cumulative size distribution of dynamically hot classical TNOs as q = 2.3 0.1 in the diameter range 100 < D < 500 km. For dynamically cold classical TNOs we determine q = 5.1 1.1 in the diameter range 160 < D < 280 km as the cold classical TNOs have a smaller maximum size. 2014 ESO
More than pretty pictures? How illustrations affect parent-child story reading and children's story recall
Get PDFPrevious research showed that story illustrations fail to enhance young preschoolers' memories when they accompany a pre-recorded story (e.g., Greenhoot & Semb, 2008). In this study we tested whether young children might benefit from illustrations in a more interactive story-reading context. For instance, illustrations might influence parent-child reading interactions, and thus children's story comprehension and recall. Twenty-six 3.5- to 4.5-year-olds and their primary caregivers were randomly assigned to an Illustrated or Non-Illustrated story-reading condition, and parents were instructed to "read or tell the story" as they normally would read with their child. Children recalled the story after a distracter and again after one week. Analyses of the story-reading interactions showed that the illustrations prompted more interactive story reading and more parent and child behaviors known to predict improved literacy outcomes. Furthermore,in the first memory interview, children in the Illustrated condition recalled more story events than those in the Non-Illustrated condition. Story reading measures predicted recall, but did not completely account for picture effects. These results suggest that illustrations enhance young preschoolers' story recall in an interactive story reading context, perhaps because the joint attention established in this context supports children's processing of the illustrations
The North American carbon program multi-scale synthesis and terrestrial model intercomparison project – Part 2: Environmental driver data
Get PDFEcosystems are important and dynamic components of the global carbon cycle, and terrestrial biospheric models (TBMs) are crucial tools in further understanding of how terrestrial carbon is stored and exchanged with the atmosphere across a variety of spatial and temporal scales. Improving TBM model skills, and quantifying and reducing their estimation uncertainties, pose significant challenges. The Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) is a formal multi-scale and multi-model intercomparison effort set up to tackle these challenges. The MsTMIP protocol prescribes standardized environmental driver data that are shared among model teams to facilitate model-model and model-observation comparisons. This paper describes the global and North American environmental driver data sets prepared for the MsTMIP activity to both support their use in MsTMIP and make these data, along with the processes used in selecting/processing these data, accessible to a broader audience. Based on project needs, we compiled climate, atmospheric CO2 concentrations, nitrogen deposition, land-use and land-cover change (LULCC), C3/C4 grasses fractions, major crops, phenology, and soil data into a standard format for global (0.5° x 0.5° resolution) and regional (North American, 0.25° x 0.25° resolution) simulations. In order to meet the needs of MsTMIP, improvements were made to several of the original environmental data sets, by changing the quality, the spatial and temporal coverage, resolution, or a combination of these. The resulting standardized model driver data sets are being used by over 20 different models participating MsTMIP. The data are archived at the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC, http://daac.ornl.gov) to provide long-term data management and distribution
Whole-genome analysis of Exserohilum rostratum from an outbreak of fungal meningitis and other infections
Get PDFExserohilum rostratum was the cause of most cases of fungal meningitis and other infections associated with the injection of contaminated methylprednisolone acetate produced by the New England Compounding Center (NECC). Until this outbreak, very few human cases of Exserohilum infection had been reported, and very little was known about this dematiaceous fungus, which usually infects plants. Here, we report using whole-genome sequencing (WGS) for the detection of single nucleotide polymorphisms (SNPs) and phylogenetic analysis to investigate the molecular origin of the outbreak using 22 isolates of E. rostratum retrieved from 19 case patients with meningitis or epidural/spinal abscesses, 6 isolates from contaminated NECC vials, and 7 isolates unrelated to the outbreak. Our analysis indicates that all 28 isolates associated with the outbreak had nearly identical genomes of 33.8 Mb. A total of 8 SNPs were detected among the outbreak genomes, with no more than 2 SNPs separating any 2 of the 28 genomes. The outbreak genomes were separated from the next most closely related control strain by ∼136,000 SNPs. We also observed significant genomic variability among strains unrelated to the outbreak, which may suggest the possibility of cryptic speciation in E. rostratum
Mincer-zarnovitz quantile and expectile regressions for forecast evaluations under asymmetric loss functions: Working paper series--14-01
Get PDFForecast is pervasive in all areas of applications in business and daily life and, hence, evaluating the accuracy of a forecast is important for both the generators and consumers of forecasts. There are two aspects in forecast evaluation: (1) measuring the accuracy of past forecasts using some summary statistics and (2) testing the optimality properties of the forecasts through some diagnostic tests. On measuring the accuracy of a past forecast, we illustrate that the summary statistics used should match the loss function that was used to generate the forecasts. If there is strong evidence that an asymmetric loss function has been used in the generation of a forecast, then a summary statistic that corresponds to that asymmetric loss function should be used in assessing the accuracy of the forecast instead of the popular RMSE or MAE. On testing the optimality of the forecasts, we demonstrate how the quantile regressions and expectile regressions set in the prediction-realization framework of Mincer and Zarnowitz (1969) can be used to recover the unknown parameter that controls the potentially asymmetric loss function used in generating the past forecasts. Finally, we apply the prediction-realization framework to the Federal Reserve's economic growth forecast and forecast sharing in a PC manufacturing supply chain. We find that the Federal Reserves values over prediction approximately 1.5 times more costly than under prediction. We also find that the PC manufacturer weighs positive forecast errors (under forecasts) about four times as costly as negative forecast errors (over forecasts)
The 2010 cholera outbreak in Haiti: How science solved a controversy
Get PDFThe article focuses on the genetic basis of the spread of cholera in Haiti which clarifies both the climatic and human transmission hypotheses explaining the origin of the disease after the January 12, 2010 earthquake. Topics include the role of the nonpathogenic Vibrio cholerae in cholera, studies supporting the human transmission hypothesis, and molecular study on the origin of Vibrio cholerae in the country. The use of genome sequencing as a tool for molecular epidemiology is considered
Effects of climate variability and accelerated forest thinning on watershed-scale runoff in southwestern USA ponderosa pine forests
Get PDFThe recent mortality of up to 20% of forests and woodlands in the southwestern United States, along with declining stream flows and projected future water shortages, heightens the need to understand how management practices can enhance forest resilience and functioning under unprecedented scales of drought and wildfire. To address this challenge, a combination of mechanical thinning and fire treatments are planned for 238,000 hectares (588,000 acres) of ponderosa pine (Pinus ponderosa) forests across central Arizona, USA. Mechanical thinning can increase runoff at fine scales, as well as reduce fire risk and tree water stress during drought, but the effects of this practice have not been studied at scales commensurate with recent forest disturbances or under a highly variable climate. Modifying a historical runoff model, we constructed scenarios to estimate increases in runoff from thinning ponderosa pine at the landscape and watershed scales based on driving variables: pace, extent and intensity of forest treatments and variability in winter precipitation. We found that runoff on thinned forests was about 20% greater than unthinned forests, regardless of whether treatments occurred in a drought or pluvial period. The magnitude of this increase is similar to observed declines in snowpack for the region, suggesting that accelerated thinning may lessen runoff losses due to warming effects. Gains in runoff were temporary (six years after treatment) and modest when compared to mean annual runoff from the study watersheds (0–3%). Nonetheless gains observed during drought periods could play a role in augmenting river flows on a seasonal basis, improving conditions for water-dependent natural resources, as well as benefit water supplies for downstream communities. Results of this study and others suggest that accelerated forest thinning at large scales could improve the water balance and resilience of forests and sustain the ecosystem services they provide