The contrasting physiological and subjective effects of chewing gum on social stress

Uncertainty exists with respect to the extent to which chewing gum may attenuate stress-induced rises in cortisol secretion (Scholey et al., 2009; Smith, 2010; Johnson et al., 2011). The present study used the Trier Social Stress Task (TSST: Kirschbaum et al., 1993), a task known to elevate cortisol secretion (Kudielka et al., 2004), in order to examine the moderating physiological and subjective effects of chewing gum on social stress. Forty participants completed the TSST either with or without chewing gum. As expected, completion of the TSST elevated both cortisol and subjective stress levels, whilst impairing mood. Although gum moderated the perception of stress, cortisol concentrations were higher following the chewing of gum. The findings are consistent with Smith (2010) who argued that elevations in cortisol following the chewing of gum reflect heightened arousal. The findings suggest that chewing gum only benefits subjective measures of stress. The mechanism remains unclear; however, this may reflect increased cerebral blood flow, cognitive distraction, and/or effects secondary to task facilitation

Antipredatory Defense of Neonatal Pronghorn (Antilocapra americana) by Yearling Male Pronghorn in Southwestern South Dakota

Antipredatory defense of pronghorn (Antilocapra americana) neonates (≤1 month old) by adult females (\u3e18 months old) is well documented throughout the geographic range of this species. However, reports of male pronghorn defending neonates against predators are limited to a single study in northwestern Wyoming where occurrences were documented of adult males assisting female pronghorn in defending neonates against coyotes (Canis latrans). To our knowledge, defense of neonatal pronghorn by yearling males (12–18 months old) has not been reported previously for this species. We report occurrences of antipredatory defense of neonatal pronghorn by yearling males in southwestern South Dakot

The Prairie Naturalist Manuscript Submission Guidelines

These guidelines present The Prairie Naturalist (PNAT) policies and procedures for submitting scientific manuscripts for consideration for publication. In January 2009, a change in Editorial staff occurred and these guidelines address the ongoing transition and update the online Suggestions for Contributors guidelines provided on the PNAT website (http://www.fhsu.edu/biology/pn/prairienat.htm); these instructions supersede all previous guidelines. Tables and appendices are included for common word expressions with superfluous wording, examples of correct format and style guidelines for tables accompanying manuscripts, guidance in properly preparing Research Articles and Notes, citing literature, and mandatory abbreviations for tables, figures and parenthetical expressions

Vegetative Characteristics of Pronghorn Bed Sites in Wind Cave National Park, South Dakota

Much of the previous literature on pronghorn (Antilocapra americana) fawns has focused on fawn mortality (Beale 1978, Barrett 1984, Gregg et al. 2001) and social behavior (Kitchen 1974, Autenrieth and Fichter 1975, Bromley 1977). Selection of bed sites by pronghorn fawns is a major factor affecting fawn survival (Bromley 1978, Barrett 1981, O\u27Gara et al. 1986, VanSchmus 1990) because adequate cover is a crucial component of fawn bed site selection (Autenrieth 1984). Alldredge et al. (1991) reported that fawns selected dense shrub cover but avoided the most-dense cover in sagebrush-steppe communities in southcentral Wyoming while Tucker and Gamer (1983) noted that height and density of vegetation provided concealment cover to hiding fawns. Canon and Bryant (1997) also found density and height of vegetation to be factors affecting survival of fawns and suggested that increased grass and forb production provided necessary hiding cover for fawns. Bromley (1978) and Smith and Beale (1980) noted that fawns selected bed sites that offered the greatest opportunity for visual detection of predators rather than concealment The pronghorn was reintroduced into Wind Cave National Park, South Dakota, i 1914 and thus, has been maintained within its boundaries for nearly a century However, no information is available on fawning habitat within Wind Cave National Park. The objective of our study was to quantity vegetative characteris tics of fawn bed sites throughout Wind Cave National Park

Vegetative Characteristics of Pronghorn Bed Sites in Wind Cave National Park, South Dakota

Much of the previous literature on pronghorn (Antilocapra americana) fawns has focused on fawn mortality (Beale 1978, Barrett 1984, Gregg et al. 2001) and social behavior (Kitchen 1974, Autenrieth and Fichter 1975, Bromley 1977). Selection of bed sites by pronghorn fawns is a major factor affecting fawn survival (Bromley 1978, Barrett 1981, O\u27Gara et al. 1986, VanSchmus 1990) because adequate cover is a crucial component of fawn bed site selection (Autenrieth 1984). Alldredge et al. (1991) reported that fawns selected dense shrub cover but avoided the most-dense cover in sagebrush-steppe communities in southcentral Wyoming while Tucker and Gamer (1983) noted that height and density of vegetation provided concealment cover to hiding fawns. Canon and Bryant (1997) also found density and height of vegetation to be factors affecting survival of fawns and suggested that increased grass and forb production provided necessary hiding cover for fawns. Bromley (1978) and Smith and Beale (1980) noted that fawns selected bed sites that offered the greatest opportunity for visual detection of predators rather than concealment The pronghorn was reintroduced into Wind Cave National Park, South Dakota, i 1914 and thus, has been maintained within its boundaries for nearly a century However, no information is available on fawning habitat within Wind Cave National Park. The objective of our study was to quantity vegetative characteris tics of fawn bed sites throughout Wind Cave National Park

Electron-Polarization Coupling in Superconductor-Ferroelectric Superlattices

We present a phenomenological model of periodic ferroelectric-superconductor (FE-S) heterostructures containing two alternating ferroelectric and superconducting layers. The interaction at the FE-S contacts is described as a coupling of the local carrier density of the superconductor with the spontaneous ferroelectric polarization near the FE-S interface. We obtain a stable symmetric domain-type phase exhibiting a contact-induced polarization and the ferroelectric domain structure at temperatures above the bulk ferroelectric transition temperature. With an increasing coupling energy, we find the appearance of the ferroelectric phase coexisting with the suppressed superconductivity in the S-film. The system is analyzed for different thicknesses of the FE- and S-films demonstrating the dramatic change of the topology of the phase diagrams with a variation of the layers thickness. The results are expected to shed light on the processes occurring in high-temperature superconducting films grown on perovskite alloy-substrates exhibiting ferroelectric properties at lower temperatures.Comment: 12 pages, 8 figure

Work function of a quasicrystal surface: Icosahedral Al–Pd–Mn

The work function of a surface is one of its most basic and influential features. It has long been recognized that work function controls thermionic and field emission. The work function of a solid surface affects charge transfer to or from an adsorbate. It influences the electron tunneling probability between surfaces. It plays a role in quantization of electron states parallel to the surface in metal-supported metallic nanoislands. There is also evidence linking the work function of a metal surface to its friction coefficient

Evaluating Diet Composition of Pronghorn in Wind Cave National Park, South Dakota

The pronghorn (Antilocapra americana) was reintroduced into Wind Cave National Park (WCNP), South Dakota, in 1914, and thus, has inhabited the Park for nearly a century. During the 1990\u27s, a decline in the population raised concern for the continued existence of pronghorn inside WCNP; an investigation into the observed decline was initiated. Primary objectives of our study were to evaluate diet composition and forage selection by pronghorn in WCNP. Microhistological analysis was conducted on 58 fecal samples collected opportunistically from pronghorn during 2002. Blue grama (Bouteloua gracilis), common juniper (Juniperus communis), and northern bedstraw (Galium boreale) were identified as major seasonal food items, representing 14.6, l 0.6, and 6.5 % of the annual diet, respectively. Annual diets of pronghorn in WCNP included 41.5% grasses, 31.1% shrubs, and 27.4% forbs. Total forage production in WCNP was 2% grass, 4% shrubs, and 23% forbs. Results indicated strong dietary selection by pronghorn for shrubs

Evaluating Genetic Viability of Pronghorn in Wind Cave National Park

The pronghorn (Antilocapra americana) was reintroduced into Wind Cave National Park, South Dakota, in 1914 and thus, has inhabited the Park for almost a century. A decline in the population has raised concern for the continued existence of pronghorn inside Wind Cave National Park. Historically, pronghorn numbers reached greater than 300 individuals in the 1960\u27s but declined to about 30 individuals by 2002. The primary objective of our study was to evaluate genetic characteristics of pronghorn to determine if reduced heterozygosity contributed to the decline of pronghorn in Wind Cave National Park. Microsatellite DNA was collected from 75 pronghorn inhabiting Wind Cave National Park in western South Dakota (n = 11), northwestern South Dakota (n = 33), and southwestern South Dakota (n = 31). Pronghorn in Wind Cave National Park had similar levels of observed heterozygosity (0.473 to 0.594) and low inbreeding coefficients (-0.168 to 0.037) when compared with other populations in western South Dakota. Furthermore, indices of population structure indicated no differentiation occurred among pronghorn populations. Results indicated that genetic variability was not a primary factor in the decline of pronghorn in Wind Cave National Park