ebnm: An R Package for Solving the Empirical Bayes Normal Means Problem Using a Variety of Prior Families

The empirical Bayes normal means (EBNM) model is important to many areas of statistics, including (but not limited to) multiple testing, wavelet denoising, multiple linear regression, and matrix factorization. There are several existing software packages that can fit EBNM models under different prior assumptions and using different algorithms; however, the differences across interfaces complicate direct comparisons. Further, a number of important prior assumptions do not yet have implementations. Motivated by these issues, we developed the R package ebnm, which provides a unified interface for efficiently fitting EBNM models using a variety of prior assumptions, including nonparametric approaches. In some cases, we incorporated existing implementations into ebnm; in others, we implemented new fitting procedures with a focus on speed and numerical stability. To demonstrate the capabilities of the unified interface, we compare results using different prior assumptions in two extended examples: the shrinkage estimation of baseball statistics; and the matrix factorization of genetics data (via the new R package flashier). In summary, ebnm is a convenient and comprehensive package for performing EBNM analyses under a wide range of prior assumptions.Comment: 43 pages, 19 figure

Nondiffusive spin dynamics in a two-dimensional electron gas

We describe measurements of spin dynamics in the two-dimensional electron gas in GaAs=GaAlAs quantum wells. Optical techniques, including transient spin-grating spectroscopy, are used to probe the relaxation rates of spin polarization waves in the wave vector range from zero to 6 x 104 cm-1. We find that the spin polarization lifetime is maximal at a nonzero wave vector, in contrast with expectations based on ordinary spin diffusion, but in quantitative agreement with recent theories that treat diffusion in the presence of spin-orbit couplin

Alkaline phosphatase binds tenaciously to titanium; implications for biological surface evaluation following bone implant retrieval

© 2017 Elsevier B.V. Enhancing the performance and longevity of titanium (Ti) implants continues to be a significant developmental theme in contemporary biomaterials design. Our specific focus pertains to the surface functionalisation of Ti using the bioactive lipid, lysophosphatidic acid (LPA) and certain phosphatase-resistant analogues of LPA. Coating survivorship to a plethora of testing regimens is required to align with due regulatory process before novel biomaterials can enter clinical trials. One of the key acceptance criteria is coating retention to the physical stresses experienced during implantation. In assessing coating stability to insertion into porcine bone we found that a subsequent in vitro assessment to confirm coating persistence was masked by abundant alkaline phosphatase (ALP) contamination adsorbed to the metal surface. Herein we report that ALP can bind to Ti in a matter of minutes by simply immersing Ti samples in aqueous solutions of the enzyme. We strongly discourage the in vitro monitoring of osteoblast and stromal cell ALP expression when assessing bioactive coating survivorship following Ti implant retrieval form native bone tissue

Tectonic and depositional history of an active forearc basin, Sandino basin, offshore Nicaragua

textHigh-resolution (20-250 Hz) multichannel seismic (MCS) reflection data with record lengths of 4-8 s TWT, totaling approximately 4620 line km on the shelf and slope of the Sandino forearc basin of offshore western Nicaragua, were acquired in November-December 2004 (cruise EW04-12) and subsequently processed at the University of Texas Institute for Geophysics. Seismic sequence interpretation was conducted using these MCS data in conjunction with deeper penetration (16-20. s TWT) MCS profiles from a previous survey (cruise EW00-05). Age estimates were based on cuttings from intersecting industry wells. Structure and isochron maps were created for 16 sequences and used to identify structural and depositional trends within the Sandino basin. The Tectonostratigraphic evolution of the basin varies considerably along-strike and is divided into five general stages from Late Cretaceous to recent. Evidence for multiple episodes of terrane accretion is observed from Late Eocene to Late Oligocene and potentially during Mid- to Late Miocene as well. Stratal stacking patterns suggest the Nicaraguan margin has not been dominated by subduction erosion during its history and extensional features beneath the slope are interpreted to have originated as a result of processes related to collision of allochthonous terrane of the downgoing plate, sediment underplating, and slab roll-back. With more precise age control, the stable northwestern region of the Sandino basin, where sediment is relatively undeformed since Late Oligocene and measures ≥ 16 km thick, offers a unique convergent margin setting for investigations of forcings on sequence development.Geological Science

Synthetic Cannabinoid Usage among College Students: The Example of K2 and Spice

The primary goal of this study was to investigate the awareness and prevalence of Spice and K2 usage among a population of college students, as well as the demographics of such users. The study also sought to determine whether or not students prefer these products over natural cannabis, in addition to examining the most popular methods of obtainment and the most commonly reported side effects of K2 and Spice usage. Participants consisted of 643 undergraduate students enrolled at the University of North Texas during the fall 2011 semester. Findings indicate that while students exhibit a relatively high awareness of K2 and Spice, usage of these products is not a prevalent occurrence. Implications of the findings are discussed

Tagalong Trail

The Cal Poly mechanical engineering team working on the Path of Lights and Sounds for the Girl Scouts of California’s Central Coast has now completed their project. In the last quarter of their project, they were able to finalize their tile’s structural design while iterating through several electronics board designs. Through this iteration, they were able to create a final electronics board and designed a water-resistant enclosure to house the board. A new team member was added, allowing them to manufacture 28 tile structures and 30 electronics assemblies over the course of two and a half weeks. This proved to be an illconsidered decision, as the manufacturing and assembly of all tiles completely consumed their time, even with a Girl Scout event held to help with assembly. Despite this, they were still able to follow through on most testing planned to determine the quality of their design. Though lacking in some specifications, the team evaluated and tested their final design and all 28 tiles to the Girl Scouts with newly guided recommendations for use (based on their testing results). After delivery, the tiles sustained minor damage from an unanticipated electrical condition, but the team was able to diagnose possible causes and provide a solution to the problem as well as updated usage recommendations to avoid future issues. The tiles now reside solely with the Girl Scouts and the team has provided them with guidance for future use and upkeep as well as how to completely reproduce more tiles if desired for future events

Prevalence and amount of feral swine damage to three row crops at planting

Feral swine damage to corn, cotton and peanut crops at planting was assessed for 46 fields in Alabama. Damage was assessed on the basis of prevalence among fields and the quantity lost within each damaged field. Feral swine control by professionals dedicated to that task appeared to greatly reduce the prevalence of damage among fields, as the 14 fields which were within the areas where professional swine control operations took place were not damaged. For the 32 fields not receiving such protection, seven (21.9%) received some level of damage. Of those, 40% (four of 10) peanut fields, 15.4% (two of 13) cotton fields, and 11.1% (one of nine) corn fields were damaged. Damage levels were highly variable, both between and within crops. Losses were typically low \u3c1.3%, but there were very notable exceptions where more substantial losses were incurred. One peanut field experienced a loss of 54.2% representing 32,401 kg of crop lost, valued at $15,779. Feral swine damage to freshly planted row crops has previously received little, if any, in-field quantification in the literature, with this study possibly being the first of its kind

Prevalence and amount of feral swine damage to three row crops at planting

Feral swine damage to corn, cotton and peanut crops at planting was assessed for 46 fields in Alabama. Damage was assessed on the basis of prevalence among fields and the quantity lost within each damaged field. Feral swine control by professionals dedicated to that task appeared to greatly reduce the prevalence of damage among fields, as the 14 fields which were within the areas where professional swine control operations took place were not damaged. For the 32 fields not receiving such protection, seven (21.9%) received some level of damage. Of those, 40% (four of 10) peanut fields, 15.4% (two of 13) cotton fields, and 11.1% (one of nine) corn fields were damaged. Damage levels were highly variable, both between and within crops. Losses were typically low \u3c1.3%, but there were very notable exceptions where more substantial losses were incurred. One peanut field experienced a loss of 54.2% representing 32,401 kg of crop lost, valued at $15,779. Feral swine damage to freshly planted row crops has previously received little, if any, in-field quantification in the literature, with this study possibly being the first of its kind