Objectives: To describe multivariate base rates (MBRs) of low scores and reliable change (decline) scores on Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) in college athletes at baseline, as well as to assess MBR differences among demographic and medical history subpopulations. Methods: Data were reported on 15,909 participants (46.5% female) from the NCAA/DoD CARE Consortium. MBRs of ImPACT composite scores were derived using published CARE normative data and reliability metrics. MBRs of sex-corrected low scores were reported at <25th percentile (Low Average), <10th percentile (Borderline), and ≤2nd percentile (Impaired). MBRs of reliable decline scores were reported at the 75%, 90%, 95%, and 99% confidence intervals. We analyzed subgroups by sex, race, attention-deficit/hyperactivity disorder and/or learning disability (ADHD/LD), anxiety/depression, and concussion history using chi-square analyses. Results: Base rates of low scores and reliable decline scores on individual composites approximated the normative distribution. Athletes obtained ≥1 low score with frequencies of 63.4% (Low Average), 32.0% (Borderline), and 9.1% (Impaired). Athletes obtained ≥1 reliable decline score with frequencies of 66.8%, 32.2%, 18%, and 3.8%, respectively. Comparatively few athletes had low scores or reliable decline on ≥2 composite scores. Black/African American athletes and athletes with ADHD/LD had higher rates of low scores, while greater concussion history was associated with lower MBRs (p < .01). MBRs of reliable decline were not associated with demographic or medical factors. Conclusions: Clinical interpretation of low scores and reliable decline on ImPACT depends on the strictness of the low score cutoff, the reliable change criterion, and the number of scores exceeding these cutoffs. Race and ADHD influence the frequency of low scores at all cutoffs cross-sectionally.

We evaluated the impact of an electronic health record based 72-hour antimicrobial time-out (ATO) on antimicrobial utilization. We observed that 6 hours after the ATO, 21% of empiric antimicrobials were discontinued or de-escalated. There was a significant reduction in the duration of antimicrobial therapy but no impact on overall antimicrobial usage metrics.

The low demand for immediate annuities at retirement has been a long-standing puzzle. We show that a hyperbolic discount model can explain this behaviour and results in the attractiveness of long-term deferred annuities. With a set of benchmark assumptions, we find that retirees would be willing to pay a much higher price than the actuarial fair price for annuities with longer deferred periods. Moreover, if governments were to introduce a pre-commitment device which requires pensioners to make annuitisation decisions around 10 years before retirement, the take up rate of annuities could become higher.

We present Phantom, a fast, parallel, modular, and low-memory smoothed particle hydrodynamics and magnetohydrodynamics code developed over the last decade for astrophysical applications in three dimensions. The code has been developed with a focus on stellar, galactic, planetary, and high energy astrophysics, and has already been used widely for studies of accretion discs and turbulence, from the birth of planets to how black holes accrete. Here we describe and test the core algorithms as well as modules for magnetohydrodynamics, self-gravity, sink particles, dust–gas mixtures, H2 chemistry, physical viscosity, external forces including numerous galactic potentials, Lense–Thirring precession, Poynting–Robertson drag, and stochastic turbulent driving. Phantom is hereby made publicly available.

In September 2016, the annual meeting of the International Union for Quaternary Research’s Loess and Pedostratigraphy Focus Group, traditionally referred to as a LoessFest, met in Eau Claire, Wisconsin, USA. The 2016 LoessFest focused on “thin” loess deposits and loess transportation surfaces. This LoessFest included 75 registered participants from 10 countries. Almost half of the participants were from outside the United States, and 18 of the participants were students. This review is the introduction to the special issue for Quaternary Research that originated from presentations and discussions at the 2016 LoessFest. This introduction highlights current understanding and ongoing work on loess in various regions of the world and provides brief summaries of some of the current approaches/strategies used to study loess deposits.

The Chinese Loess Plateau, the world’s largest and oldest loess record, preserves evidence of Asia’s long-term dust source dynamics, but there is uncertainty over the source of the deposits. Recent single-grain detrital zircon U-Pb age analysis has progressed this issue, but debates remain about source changes, and the generation and interpretation of zircon data. To address this, we analyze different groupings of new and existing datasets from the Loess Plateau and potential sources. We also present the results of a first high resolution sampling, multi-proxy provenance analysis of Beiguoyuan loess using U-Pb dating of detrital zircons and detrital garnet geochemistry. The data shows that some small source differences seem to exist between different areas on the Loess Plateau. However, sediment source appears to be unchanging between loess and palaeosols, supporting a recent material recycling hypothesis. Our zircon and garnet data demonstrates, however, that Beiguoyuan experienced a temporary, abrupt source shift during the last glacial maximum, implying that local dust sources became periodically active during the Quaternary. Our results highlight that grouping data to achieve bigger datasets could cause identification of misleading trends. Additionally, we suggest that multi-proxy single-grain approaches are required to gain further insight into Chinese Loess Plateau dust sources.

Small skeletal sediment particles, by virtue of their size, experience physical sedimentological conditions different from those affecting large (i.e., > 4 mm) particles. In shallow, high-energy marine carbonate environments with an overall fine-grained (< 4 mm) sediment composition, grain-to-grain impacts are probably of insufficient magnitude to overcome the cushioning effect of water and cause abrasive wear. Very large skeletal grains within such a setting will promote physical degradation, but biological activity (microboring, bioerosion) is more effective in modifying particle surfaces and diminishing grain size. Only in eolian environments are collisions between small grains effective in causing abrasion. Quartz sand, a particularly important abrasive agent in the destruction of large skeletal parts under even moderate energy regimes, also appears to be appreciably important for the degradation of small skeletons only under eolian conditions.

Conodonts are small (0.2–2.0 mm), phosphatic teeth, which may have belonged to an extinct (Cambrian-Triassic) group of jawless fish. They occur principally in marine and marginal marine sedimentary rocks; most specimens probably were deposited as discrete particles or as components of fecal masses. Because the extent and nature of degradation of a skeleton reflects its taphonomic history, evaluation of the susceptibility of conodonts to physical abrasion is important. Bioerosion, probably the principal cause of degradation of calcareous skeletons, was probably insignificant in alteration of conodonts. Their mineralogical composition made conodonts unlikely substrates for endoliths, and they were insufficiently abundant to serve as a recyclable source of phosphate for larger metazoans. Chemical breakdown of skeletal apatite would not have occurred, although atmospheric exposure may have promoted degradation of organic laminae, causing exfoliation.

Experimental studies of abrasion (elements of Palmatolepis sp., Polygnathus sp. - U. Devonian, Iowa) plus petrographic examination of conodont bearing marine, marginal marine, and eolian facies of the Morgan Formation (M. Pennsylvanian, Utah and Colorado) suggests that abrasion of conodonts is insignificant in aqueous environments, and likely to occur to a major degree only under eolian conditions. High-energy (25.6 cm/sec) conditions were simulated in a tumbler containing quartz sand (4Φ − 2Φ), artificial sea water and moderate conodont abundances (50 specimens/kg). Abrasion produced under these artificially extreme conditions (e.g., continuous motion for up to 20 km travel distance) was at a scale detectable only with SEM. “Dry” tumbling experiments were ineffective, as noted by other authors simulating conditions for abrasion of mineral grains. Eolian conditions were simulated in a glass “wind tube” (see Kuenen, 1960, Journal of Geology) using a similar range of quartz sand sizes. Air velocity of approximately 100 cm/sec produced subtle visually detectable abrasion following 5 hours of exposure/transport in 2Φ quartz sand (1667 specimens/kg), but exhibited no visual evidence of abrasion under similar conditions with 3Φ sand.

The Morgan Formation is a mixed carbonate/siliciclastic sequence that reflects repeated episodes of submergence and exposure of a carbonate shelf and laterally adjacent siliciclastic eolian “sand sea.” It represents a virtually ideal ancient example for the interpretation of the effects of natural sedimentary processes because of its well-documented environmental heterogeneity and contains both abraded and unabraded conodonts. Conodonts sampled from high-energy subtidal carbonate facies of the Morgan are unabraded, irrespective of the presence of quartz sand; platform and delicate ramiform elements are all represented. Conodonts sampled from mixed siliciclastic/carbonate eolian facies are extremely abraded; only the most durable Pa elements of Adetognathus sp. and Idiognathodus sp. are preserved, although fine surface details and denticles are worn and anterior blades are missing. Laboratory simulations confirm the interpretation that marine processes are generally insufficient to physically abrade small phosphatic skeletal grains and that highly abraded Morgan conodonts experienced extremely long residence times in the eolian environment where they were transported, repeatedly buried, and exposed to bombardment and abrasion by quartz sand.

Supported by NSF EAR9004300

Chemotherapy is often administered in openly designed hospital wards, where the possibility of patient–patient social influence on health exists. Previous research found that social relationships influence cancer patient's health; however, we have yet to understand social influence among patients receiving chemotherapy in the hospital. We investigate the influence of co-presence in a chemotherapy ward. We use data on 4,691 cancer patients undergoing chemotherapy in Oxfordshire, United Kingdom who average 59.8 years of age, and 44% are Male. We construct a network of patients where edges exist when patients are co-present in the ward, weighted by both patients' time in the ward. Social influence is based on total weighted co-presence with focal patients' immediate neighbors, considering neighbors' 5-year mortality. Generalized estimating equations evaluated the effect of neighbors' 5-year mortality on focal patient's 5-year mortality. Each 1,000-unit increase in weighted co-presence with a patient who dies within 5 years increases a patient's mortality odds by 42% (β = 0.357, CI:0.204,0.510). Each 1,000-unit increase in co-presence with a patient surviving 5 years reduces a patient's odds of dying by 30% (β =−0.344, CI:−0.538,0.149). Our results suggest that social influence occurs in chemotherapy wards, and thus may need to be considered in chemotherapy delivery.

This article describes a formal proof of the Kepler conjecture on dense sphere packings in a combination of the HOL Light and Isabelle proof assistants. This paper constitutes the official published account of the now completed Flyspeck project.