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Philadelphia, PA, United States

Keystone College is a small private college located in Northeastern Pennsylvania. Its official mailing address is La Plume, Pennsylvania in Lackawanna County; however, much of the campus is in Factoryville, Pennsylvania in Wyoming County. The school was founded in 1868. Wikipedia.

Tucker Serniak L.,Keystone College | Tucker Serniak L.,Oregon State University
Weed Research | Year: 2016

Summary: Fallopia japonica (Japanese Knotweed) is a prolific invader possessing several potentially allelopathic chemicals. The aim of this study was to determine whether four of these compounds inhibit the germination and growth of radish (Raphanus sativus) seedlings. Seeds were planted in potting soil and grown under glasshouse conditions for 2 weeks and the phytochemicals were gradually added to the soil over the course of the study. For all phytochemicals, there was no significant reduction in germination, plant heights, leaf widths or leaf lengths. However, plants treated with resveratrol, emodin and (-)-epicatechin had significantly shorter root lengths than the control. Seedlings were dried and extracts were prepared with methanol. Extracts were tested via fluorescence spectrophotometry for uptake of the chemicals. Polydatin was detected at the highest concentration, with resveratrol and emodin detected at much lower concentrations. (-)-Epicatechin was below the limits of detection. These results suggest that F. japonica may negatively impact the growth of other species and that multiple chemicals work together to give the plant a competitive advantage. Weed Research © 2016 European Weed Research Society. Source

Saginor I.,Keystone College | Gazel E.,Lamont Doherty Earth Observatory | Carr M.J.,Rutgers University | Swisher C.C.,Rutgers University | Turrin B.,Rutgers University
Journal of Volcanology and Geothermal Research | Year: 2011

The volcanic record of western Nicaragua documents a significant lull in volcanic activity that has persisted from the late Miocene (~. 7. Ma) to the formation of the modern volcanic front around 350 ka. This study fills this gap for the first time with samples collected in Northwest Nicaragua between Cosigüina and San Cristóbal volcanoes and with samples collected from the Nicaraguan Depression. We found two previously unknown volcanic units ranging from 3.6 to 1.3. Ma and the improved volcanic record allows us to reconstruct the geochemical evolution of the Nicaraguan arc. U/Th values increased by nearly threefold since the Miocene following the "carbonate crash" at 10. Ma, when dominantly carbonate sediment deposition shifted toward hemipelagic sediment deposition. This transition was thought to be abrupt, however our new data show that it took place gradually over the last 7. Ma. Northwest Nicaragua is a particularly interesting case study because it contains Middle Miocene volcanism on either side of the Nicaraguan Depression, the Coyol Formation (25-7. Ma) to the East and the Tamarindo Formation (14.7-11.7. Ma) to the West. The presence of Mid Miocene volcanism on either side of the Nicaraguan Depression has led to the hypothesis that the two coeval units, currently separated by ~. 100 km, were once connected and have since been separated by extension. Here, we present data suggesting that the Tamarindo and Coyol are geochemically distinct and therefore cannot be considered part of the same unit. © 2011 Elsevier B.V. Source

Phillips Y.,Keystone College
ICETC 2010 - 2010 2nd International Conference on Education Technology and Computer | Year: 2010

Technology is important in teaching and learning mathematics. This paper will discuss the use of graphing calculators, the internet and computer math software in mathematics education. Our modern world has entered the information age. Internet online teaching and learning, and online testing have become important part of faculty development and student learning. © 2010 IEEE. Source

Wentz B.,Keystone College | Lazar J.,Towson University
ACM International Conference Proceeding Series | Year: 2011

With the increasing use of web-based applications in the workplace, it is imperative that all users can equally access those applications. It has been previously reported that blind users have problems accessing Facebook, but little empirical data on the topic exists. It has also been suggested by Facebook and anecdotal user comments that the mobile interface (hereafter referred to as "Facebook Mobile") for the application is more usable than the standard, desktop interface (hereafter referred to as "Facebook Desktop") for individuals who use screen readers to access the Facebook interface from their computers. This paper presents empirical data from 15 blind users, who took part in the usability evaluation of Facebook Desktop as well as a second phase of usability testing with 15 blind users to evaluate Facebook Mobile (when accessed from a computer and web browser). This research concludes that Facebook Mobile is more usable than the Facebook Desktop interface; however, the mobile interface is missing some features and is not consistently aligned with the Facebook Desktop interface. The implications of this study raise the question of whether there is often a usability and functionality difference between different interfaces for an application when one interface is suggested to be the "accessible" version. Copyright © 2011 ACM. Source

Senavci H.V.,Ankara University | Hussain G.A.J.,ESO | O'Neal D.,Keystone College | Barnes J.R.,University of Hertfordshire
Astronomy and Astrophysics | Year: 2011

Aims. We aim to reconstruct the first detailed surface maps of the W UMa-type contact binary system, SW Lac. These maps should reveal the distributions of dark, magnetically active spot regions on the component stars and enable us to compare these with the results of similar studies of other active stars. Methods. We used the noise-reduction technique least squares deconvolution (LSD) to obtain high signal-to-noise ratio spectra of SW Lac, enabling individual starspot features to be observed in the highly rotationally broadened profiles of this rapid rotator. We performed the Doppler mapping of the system using the Doppler imaging code, DoTS. To test the reliability of our images, we assessed the performance of the code when applied to data with incomplete phase coverage. Results. We obtained surface maps of the system. The secondary (more massive) component is found to have a lower effective temperature and a slightly higher spot coverage than the primary. These may indicate that the secondary is more spotted than the primary component. Our results are consistent with theoretical assumptions as well as the photometric studies of W-type W UMa contact binary systems, indicating that the secondary component is typically more active than its primary. © 2011 ESO. Source

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