Gettysburg College

About: Gettysburg College is a education organization based out in Gettysburg, Pennsylvania, United States. It is known for research contribution in the topics: Population & Politics. The organization has 1223 authors who have published 2348 publications receiving 52162 citations. The organization is also known as: Pennsylvania College.

Growth Inhibition of Tadpoles Exposed to Sertraline in the Presence of Conspecifics

Abstract: Sertraline (“Zoloft”) is a selective serotonin reuptake inhibitor (SSRI) suspected of causing developmental abnormalities in some aquatic organisms at environmentally relevant concentrations. SSRIs have been detected downstream from wastewater treatment plants, but the risks associated with environmental exposure have not been well documented. We tested the effects of sertraline on development of Wood Frog (Lithobates sylvaticus) larvae. Tadpoles hatched from wild-collected egg masses were exposed to concentrations of 0, 0.1, 1.0, or 10.0 μg/L of sertraline through metamorphosis. We tracked tadpole development using image analysis (452 digital images) to estimate mass periodically during the tadpole stage, and we also recorded mass at metamorphosis. Time to metamorphosis did not differ between treatments, but sertraline-exposed tadpoles grew less when raised among conspecifics. However, this effect was not detected when the study was repeated with tadpoles raised individually. This indicates that...

Radiocarbon Date List X: Baffin Bay, Baffin Island, Iceland, Labrador Sea, and the Northern North Atlantic

Abstract: Date List X contains an annotated listing of 213 radiocarbon dates determined on samples from marine and terrestrial environments. The marine samples were collected from the East Greenland, Iceland, Spitzbergen, and Norwegian margins, Baffin Bay, and Labrador Sea. The terrestrial samples were collected from Vestfirdir, Iceland and Baffin Island. The samples were submitted by INSTAAR and researchers affiliated with INSTAAR's Micropaleontology Laboratory under the direction of Dr.’s John T. Andrews and Anne E. Jennings. All of the dates from marine sediment cores were determined from either shells or foraminifera (both benthic and planktic). All dates were obtained by the Accelerator Mass Spectrometry (AMS) method. Regions of concentrated marine research include: Baffin Bay, Baffin Island, Labrador Sea, East Greenland fjords, shelf and slope, Denmark Strait, the southwestern and northwestern Iceland shelves, and Vestfirdir, Iceland. The non-marine radiocarbon dates are from peat, wood, plant microfossils, and mollusc. The radiocarbon dates have been used to address a variety of research objectives such as: 1. determining the timing of northern hemisphere high latitude environmental changes including glacier advance and retreat, and 2. assessing the accuracy of a fluctuating reservoir correction. Thus, most of the dates constrain the timing, rate, and interaction of late Quaternary paleoenvironmental fluctuations in sea level, glacier extent, sediment input, and changes in ocean circulation patterns. Where significant, stratigraphic and sample contexts are presented for each core to document the basis for interpretations.

The stellar content of the young open cluster Trumpler 37

Abstract: With an apparent cluster diameter of 1.5° and an age of 4 Myr, Trumpler 37 is an ideal target for photometric monitoring of young stars as well as for the search of planetary transits, eclipsing binaries and other sources of variability. The YETI consortium has monitored Trumpler 37 throughout 2010 and 2011 to obtain a comprehensive view of variable phenomena in this region. In this first paper we present the cluster properties and membership determination as derived from an extensive investigation of the literature. We also compared the coordinate list to some YETI images. For 1872 stars we found literature data. Among them 774 have high probability of being member and 125 a medium probability. Based on infrared data we re-calculate a cluster extinction of 0.9–1.2 mag. We can confirm the age and distance to be 3–5 Myr and870 pc. Stellar masses are determined from theoretical models and the mass function is fitted with a power-law index of α = 1.90 (0.1–0.4 M⊙) and α = 1.12 (1–10 M⊙). (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A Behavioral Confirmation and Reduction of the Natural versus Synthetic Drug Bias.

Abstract: Research reveals a biased preference for natural v. synthetic drugs; however, this research is based on self-report and has not examined ways to reduce the bias. We examined these issues in 5 studies involving 1125 participants. In a pilot study (N = 110), participants rated the term natural to be more positive than the term synthetic, which reveals a default natural-is-better belief. In studies 1 (N = 109) and 2 (N = 100), after a supposed personality study, participants were offered a thank you "gift" of a natural or synthetic pain reliever. Approximately 86% (study 1) and 93% (study 2) of participants chose the natural v. synthetic pain reliever, which provides a behavioral choice confirmation of the natural drug bias. In studies 3 (N = 350) and 4 (N = 356), participants were randomly assigned to a control or experimental condition and were asked to consider a scenario in which they had a medical issue requiring a natural v. synthetic drug. The experimental condition included a stronger (study 3) or weaker (study 4) rational appeal about the natural drug bias and a statement suggesting that natural and synthetic drugs can be good or bad depending on the context. In both studies, the natural bias was reduced in the experimental condition, and perceived safety and effectiveness mediated this effect. Overall, these data indicate a bias for natural over synthetic drugs in preferences and behavioral choices, which might be reduced with a rational appeal.

Pigtail: A Pig Addendum

Abstract: The object of the jeopardy dice game Pig is to be the first player to reach 100 points. Each turn, a player repeatedly rolls a die until either a 1 is rolled or the player holds and scores the sum of the rolls (i.e., the turn total). At any time during a player’s turn, the player is faced with two choices: roll or hold. If the player rolls a 1, the player scores nothing and it becomes the opponent’s turn. If the player rolls a number other than 1, the number is added to the player’s turn total and the player’s turn continues. If the player instead chooses to hold, the turn total is added to the player’s score and it becomes the opponent’s turn. In our original article [Neller and Presser 2004], we described a means to compute optimal play for Pig. Since that time, we have also solved a number of Pig variants. In this addendum, we review the optimality equations for Pig, show how these equations change for several Pig variants, and show how the resulting optimal policies change accordingly. [excerpt]