Golden Mouse (Ochrotomys nuttalli) and White-Footed Mouse (Peromyscus leucopus) Dietary Resource Partitioning Under Experimental Field Conditions

Ochrotomys nuttalli and Peromyscus leucopus are two small-mammal species that have similar life histories. This results in a relationship with a high degree of sociality between the two species, including extreme niche overlap. We investigated differences in diet preference and daily caloric intake under experimental field conditions in order to clarify this close relationship. Diets were based on reported food preferences in their natural environment. Five food resources were provided to 20 adult individuals (10 male, 10 female) of each species for three consecutive days. Individuals were contained in separate covered mesocosm tanks located in a riparian forest ecosystem. White-footed mice consumed more energy per day than golden mice (0.89 and 0.70 kcal • g live wt-1, respectively), which is considerably less (2.38 and 1.48 kcal • g live wt-1, respectively) than those reported by Gibbes and Barrett (1) when fed identical diets under controlled, laboratory conditions (22°C). This study also suggests that nest cavities and soundscape assist in mitigating environmental perturbations, such as food scarcity and predation, in their natural habitat

Deserts and pile-ups in the distribution of exoplanets due to photoevaporative disc clearing

We present models of giant planet migration in evolving protoplanetary discs. We show that disc clearing by EUV photoevaporation can have a strong effect on the distribution of giant planet semi-major axes. During disc clearing planet migration is slowed or accelerated in the region where photoevaporation opens a gap in the disc, resulting in "deserts" where few giant planets are found and corresponding "pile-ups" at smaller and larger radii. However, the precise locations and sizes of these features are strong functions of the efficiency of planetary accretion, and therefore also strongly dependent on planet mass. We suggest that photoevaporative disc clearing may be responsible for the pile-up of ~Jupiter-mass planets at ~1AU seen in exoplanet surveys, and show that observations of the distribution of exoplanet semi-major axes can be used to test models of both planet migration and disc clearing.Comment: 5 pages, 3 figures. Accepted for publication in MNRAS Letter

Cerebral Autoregulation Is Disrupted Following a Season of Contact Sports Participation

Repetitive subconcussive head impacts across a season of contact sports participation are associated with a number of deficits in brain function. To date, no research has investigated the effect of such head impact exposure on dynamic cerebral autoregulation (dCA). To address this issue, 179 elite, junior-level (age 19.6 ± 1.5 years) contact sport (ice hockey, American football) athletes were recruited for pre-season testing. Fifty-two non-concussed athletes returned for post-season testing. Fifteen non-contact sport athletes (age 20.4 ± 2.2) also completed pre- and postseason testing. dCA was assessed via recordings of beat-by-beat mean arterial pressure (MAP) and middle cerebral artery blood velocity (MCAv) using finger photoplethysmography and transcranial Doppler ultrasound, respectively, during repetitive squat-stand maneuvers at 0.05 and 0.10 Hz. Transfer function analysis was used to determine Coherence (correlation), Gain (response amplitude), and Phase (response latency) of the MAP-MCAv relationship. Results showed that in contact sport athletes, Phase was reduced (p = 0.027) and Gain increased (p < 0.001) at post-season compared to pre-season during the 0.10 Hz squat-stand maneuvers, indicating cerebral autoregulatory impairment in both the latency and magnitude of the response. Changes in Phase were greater in athletes experiencing higher numbers and severity of head impacts. By contrast, no changes in dCA were observed in non-contact sport controls. Taken together, these results demonstrate that repetitive subconcussive head impacts occurring across a season of contact sports participation are associated with exposure-dependent impairments in the cerebrovascular pressure-buffering system capacity. It is unknown how long these deficits persist or if they accumulate year-over-year

Mining Markov Network Surrogates for Value-Added Optimisation

Surrogate fitness functions are a popular technique for speeding up metaheuristics, replacing calls to a costly fitness function with calls to a cheap model. However, surrogates also represent an explicit model of the fitness function, which can be exploited beyond approximating the fitness of solutions. This paper proposes that mining surrogate fitness models can yield useful additional information on the problem to the decision maker, adding value to the optimisation process. An existing fitness model based on Markov networks is presented and applied to the optimisation of glazing on a building facade. Analysis of the model reveals how its parameters point towards the global optima of the problem after only part of the optimisation run, and reveals useful properties like the relative sensitivities of the problem variables

Highly selective CO2 vs. N2 adsorption in the cavity of a molecular coordination cage

Two M8L12 cubic coordination cages, as desolvated crystalline powders, preferentially adsorb CO2 over N2 with ideal selectivity CO2/N2 constants of 49 and 30 at 298 K. A binding site for CO2 is suggested by crystallographic location of CS2 within the cage cavity at an electropositive hydrogen-bond donor site, potentially explaining the high CO2/N2 selectivity compared to other materials with this level of porosity

DBD plasma microbubble reactor for pre-treatment of lignocellulosic biomass [poster]

DBD plasma microbubble reactor for pre-treatment of lignocellulosic biomass [poster

DBD plasma microbubble reactor for pre-treatment of lignocellulosic biomass [poster]

DBD plasma microbubble reactor for pre-treatment of lignocellulosic biomass [poster

The performance of ensemble-based free energy protocols in computing binding affinities to ROS1 kinase

Optimization of binding affinities for compounds to their target protein is a primary objective in drug discovery. Herein we report on a collaborative study that evaluates a set of compounds binding to ROS1 kinase. We use ESMACS (enhanced sampling of molecular dynamics with approximation of continuum solvent) and TIES (thermodynamic integration with enhanced sampling) protocols to rank the binding free energies. The predicted binding free energies from ESMACS simulations show good correlations with experimental data for subsets of the compounds. Consistent binding free energy differences are generated for TIES and ESMACS. Although an unexplained overestimation exists, we obtain excellent statistical rankings across the set of compounds from the TIES protocol, with a Pearson correlation coefficient of 0.90 between calculated and experimental activities

Integration of Crop-Livestock Systems: An Opportunity toProtect Grasslands from Conversion to Cropland in the US Great Plains

The Great Plains is a mixture of cropland and grassland mainly used for agricultural purposes, with grasslands under continual threat of conversion to cropland. Agriculturists are advocating for the integration of crop-livestock systems (ICLS) to recouple nutrient cycles, improve biodiversity, and increase resilience of agricultural operations. We address the benefits of ICLS in the Great Plains, contending that focus on improving soil health and financial stability of agricultural operations should reduce the conversion of grasslands to cropland. Using US Department of Agriculture National Agricultural Statistics Service Census of Agriculture survey data from the 1925 to 2017 category “cropland used only for pasture or grazing,” which represents land that had been cropped but converted to annual/perennial pasture and grazed, we showcase that the number of farms and the land area in this category is a reasonable proxy of ICLS. As expected, ICLS dramatically decreased in the entire United States from 1925 to 1945, but from 1945 to 2002 in the Great Plains ICLS remained relatively constant, providing evidence of sustained crop-livestock integration. Consistent high numbers of beef cows during this period and the wide availability of forages and crop residues for ruminants facilitated opportunities for producers to use ICLS on their individual operations (within farm) or among operations where row crop farmers and forage-based producers integrated beef cattle use across the landscape (among farms). This integration, however, was decoupled from 2006 to 2013, a period of high grain prices. As a result, economic value of grasslands was decreased and conversion to cropland was increased. Thus, conservation efforts in the Great Plains for grasslands should focus on keeping grasslands intact for provision of multiple ecosystem goods and services by emphasizing incorporation of ICLS within and among farms to reduce the risk of converting grassland to cropland

Estimated South Dakota Land Use Change from 2006 to 2012

Grasslands play a key role in providing wildlife habitat and recreation, as well as in range and pasture livestock production systems by producing high quality animal protein for human consumption. Croplands provide high quality grains for human consumption, coarse grains for ethanol production, and along with forages, feed for confined livestock production systems. These livestock systems also produce high quality animal protein for human consumption. Both land use systems play important roles in a wide range of societal issues facing South Dakota including economic productivity and development, water quality and quantity, health of rural communities, urban development, and additional aspects of quality-of-life long associated with the state. The purpose of this study was to estimate land use changes in South Dakota from 2006 to 2012. Estimates of land use changes were calculated based on proportions of visually observed land use using high resolution imagery (\u3c 2-m resolution) at the same 14,400 sampling points in the years 2006 and 2012. Between 2006 and 2012, the estimated grassland losses were 1,837,100 acres (±21,100). Grassland losses resulted in increased acres devoted to cropland (1,439,500 acres ±15,600), roads + buildings (nonagricultural purposes, 27,400 acres ±110), wetlands + forest (habitat, 126,800 acres ±690), and open water (243,300 acres ±860). The consequences of changes in land use in South Dakota may impact a wide range of stakeholder and interest groups, as well as society in general