Stefania evansi

Number of Pages: 3Integrative BiologyGeological Science

Improving and Assessing Information Literacy Skills through Faculty-Librarian Collaboration

This article addresses ways to assess the effectiveness of integrating information literacy into college courses by taking a close look at a partnership developed between Dr. Amy Dailey and the reference librarians at Gettysburg College

Uncertainty in phylogenetic tree estimates

Estimating phylogenetic trees is an important problem in evolutionary biology, environmental policy and medicine. Although trees are estimated, their uncertainties are discarded by mathematicians working in tree space. Here we explicitly model the multivariate uncertainty of tree estimates. We consider both the cases where uncertainty information arises extrinsically (through covariate information) and intrinsically (through the tree estimates themselves). The importance of accounting for tree uncertainty in tree space is demonstrated in two case studies. In the first instance, differences between gene trees are small relative to their uncertainties, while in the second, the differences are relatively large. Our main goal is visualization of tree uncertainty, and we demonstrate advantages of our method with respect to reproducibility, speed and preservation of topological differences compared to visualization based on multidimensional scaling. The proposal highlights that phylogenetic trees are estimated in an extremely high-dimensional space, resulting in uncertainty information that cannot be discarded. Most importantly, it is a method that allows biologists to diagnose whether differences between gene trees are biologically meaningful, or due to uncertainty in estimation.Comment: Final version accepted to Journal of Computational and Graphical Statistic

Geospatial Analysis of Rickettsial Species in Arkansas

Rickettsia species are obligate intracellular, arthropod-borne bacteria with a potential to cause multiple diseases including Rocky Mountain spotted fever (RMSF). Fleas, mites, and ticks serve as vectors for Rickettsia, but ticks are the primary vector of interest. RMSF and other rickettsial diseases have continued to gain importance in both human and veterinary medicine as RMSF is the most common tick-borne disease within the United States according to the Lyme and Tick-Borne Disease Research Center. A statewide citizen science project was utilized to determine the prevalence of Spotted Fever Group (SFG) Rickettsia in Arkansas. This project yielded results in 64 of Arkansas’s 75 counties. Results were utilized to determine prevalence in each of the represented counties, and then compiled into a geospatial representation of the data. It was determined that 34.32% of the ticks sampled were carriers of one or more rickettsial species. As the samples were divided by county, multiple counties were shown to have concerningly high exposure risk for SFG Rickettsia. There were six species of ticks represented throughout this study with Amblyomma americanum being the most common. There were also six species of Spotted Fever Group Rickettsia found within the samples. The small portion of ticks that underwent further analysis to determine the specific rickettsial species present, indicated that Rickettsia amblyommatis is likely the most common SFG Rickettsia in Arkansas

I’m Doing Better on My Own: Social Inhibition in Vocabulary Learning in Adults

Published: 05 June 2019Vocabulary learning is better achieved by children facing a teacher than when presented to the same teacher through video (so-called “video deficit” effect), which has significant implications for toddlers’ education. Since millions of adults also learn new vocabulary when acquiring a second language (L2), it is important to explore whether adults suffer from “video deficit” effects, as children do. In the present study, we report two experiments in which Spanish native late learners of English were involved in a vocabulary learning task. In Experiment 1, participants had to learn English (L2) labels associated to real objects. In Experiment 2, participants had to learn English (L2) and Spanish (L1) labels associated to novel objects. In both experiments, vocabulary learning was divided into three conditions: In the NoFace condition, participants were presented with the objects and their auditory labels, through video. In the Video condition, a teacher was showing the objects and uttering their names, through video. The Live condition was equivalent, except that the teacher was facing the participants in the room. Each condition was followed by a recall test. Better learning in Video compared to NoFace condition revealed that adults benefit from the teacher’s display with direct gaze, confirming the fundamental role of face display with direct gaze in social communication in adults. Interestingly, adults learned better through Video than in the Live condition. Those results were obtained in L2 vocabulary learning in both Experiments 1 and 2, and also generalized to native language in Experiment 2. We argue that adults suffer from social inhibition, meaning that they perform worse when in the presence of another person during task performance. In sum, we show that video-mediated teaching might not be detrimental for adults learning new vocabulary lists, as it is the case for young children. These results might have important implications for pedagogical programs targeting adults’ second language vocabulary learning, since proper acquisition of vocabulary list can be achieved through video including a teacher’s display.This research was funded by a grant from the FP7/2007–2013 Cooperation grant agreement 613465-AThEME, an ERC grant from the European Research Council (ERC-2011-ADG-295362), grants from the Spanish Government (PSI2014-54500, PSI2015-65694, and PSI2017-82941-P), and from the Basque Government (PI_2015_1_25 and PIBA18_29)

Influence of interface structure on electronic properties and Schottky barriers in Fe/GaAs magnetic junctions

The electronic and magnetic properties of Fe/GaAs(001) magnetic junctions are investigated using first-principles density-functional calculations. Abrupt and intermixed interfaces are considered, and the dependence of charge transfer, magnetization profiles, Schottky barrier heights, and spin polarization of densities of states on interface structure is studied. With As-termination, an abrupt interface with Fe is favored, while Ga-terminated GaAs favors the formation of an intermixed layer with Fe. The Schottky barrier heights are particularly sensitive to the abruptness of the interface. A significant density of states in the semiconducting gap arises from metal interface states. These spin-dependent interface states lead to a significant minority spin polarization of the density of states at the Fermi level that persists well into the semiconductor, providing a channel for the tunneling of minority spins through the Schottky barrier. These interface-induced gap states and their dependence on atomic structure at the interface are discussed in connection with potential spin-injection applications.Comment: 9 pages, 9 figures, to appear in PR

Getting the message: The adaptive potential of interpersonal judgments

According to the Social Message Model, interpersonal judgments are transactions in which judges convey important social messages to the individuals they evaluate (the targets); targets can then respond to the judgments in more or less adaptive ways. We argue that judges’ opinions emerge from their current concerns, be it to promote their own well-being, or to foster group cohesion. Targets of judgments can best interpret the meaning of a judgment they receive by understanding the judge’s concerns, competence of the judge, and other qualities of the transaction. We suggest that judges and targets who are better able to reason about the judgment process are likely to change their behaviors more adaptively than people less able to reason in this area