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.

Perception of three-dimensional shape specified by optic flow by 8-week-old infants.

Abstract: Sensitivity of 8-week-old infants to optical flow specifying the shape of a three-dimensional object was assessed. Infants viewed kinetic random-dot displays that specified three-dimensional cubes. The cubes were identical except for the presence or absence of an interior corner. Half of the infants viewed the full display. The other half viewed the central region of the displays, where the flow specifying the presence or absence of the corner differed. Infants in the full-view condition looked significantly longer to a novel cube than to the familiar cube following habituation. In contrast, infants in the partial-view condition looked equally to the novel and familiar cubes, ruling out the possibility that infants who viewed the full displays merely discriminated differences in motion in the central region of the two displays. These findings suggest that infants as young as 8 weeks perceive three-dimensional object shape from optic flow.

Recovery from a cycling time trial is enhanced with carbohydrate-protein supplementation vs. isoenergetic carbohydrate supplementation

Abstract: In this study we assessed whether a liquid carbohydrate-protein (C+P) supplement (0.8 g/kg C; 0.4 g/kg P) ingested early during recovery from a cycling time trial could enhance a subsequent 60 min effort on the same day vs. an isoenergetic liquid carbohydrate (CHO) supplement (1.2 g/kg). Two hours after a standardized breakfast, 15 trained male cyclists completed a time trial in which they cycled as far as they could in 60 min (AMex) using a Computrainer indoor trainer. Following AMex, subjects ingested either C+P, or CHO at 10, 60 and 120 min, followed by a standardized meal at 4 h post exercise. At 6 h post AMex subjects repeated the time trial (PMex). There was a significant reduction in performance for both groups in PMex versus AMex. However, performance and power decreases between PMex and AMex were significantly greater (p ≤ 0.05) with CHO (-1.05 ± 0.44 km and -16.50 ± 6.74 W) vs C+P (-0.30 ± 0.50 km and -3.86 ± 6.47 W). Fat oxidation estimated from RER values was significantly greater (p ≤ 0.05) in the C+P vs CHO during the PMex, despite a higher average workload in the C+P group. Under these experimental conditions, liquid C+P ingestion immediately after exercise increases fat oxidation, increases recovery, and improves subsequent same day, 60 min efforts relative to isoenergetic CHO ingestion.

Germline Transgenic Methods for Tracking Cells and Testing Gene Function during Regeneration in the Axolotl

Abstract: The salamander is the only tetrapod that regenerates complex body structures throughout life. Deciphering the underlying molecular processes of regeneration is fundamental for regenerative medicine and developmental biology, but the model organism had limited tools for molecular analysis. We describe a comprehensive set of germline transgenic strains in the laboratory-bred salamander Ambystoma mexicanum (axolotl) that open up the cellular and molecular genetic dissection of regeneration. We demonstrate tissue-dependent control of gene expression in nerve, Schwann cells, oligodendrocytes, muscle, epidermis, and cartilage. Furthermore, we demonstrate the use of tamoxifen-induced Cre/loxP-mediated recombination to indelibly mark different cell types. Finally, we inducibly overexpress the cell-cycle inhibitor p16INK4a, which negatively regulates spinal cord regeneration. These tissue-specific germline axolotl lines and tightly inducible Cre drivers and LoxP reporter lines render this classical regeneration model molecularly accessible.

Work sample tests in personnel selection: a meta-analysis of black–white differences in overall and exercise scores

Abstract: Work sample exams are generally thought to have either low or comparatively low levels of ethnic group differences when used for personnel selection. Such exams are sometimes called “simulation exercises” and involve having applicants perform a set of tasks that are similar to those performed on the job. The nearly ubiquitous meta-analytic value of Black–White subgroup differences in the literature is d= .38. Unfortunately, this estimate is plagued by a variety of problems (e.g., range restriction, inclusion of nonwork sample tests). Further, there are virtually no analyses that examine how the saturation of different constructs influence work sample tests. We gathered available data for Black–White ethnic group differences and found that overall work sample differences were markedly larger for samples of job applicants (d= .73) than previously thought. We also examined how different exercises and saturation of different constructs influenced work sample ds. For example, work sample test ratings of cognitive and job knowledge skills were associated with a mean observed d= .80, whereas ratings of various social skills were associated with mean observed ds that varied from .21 to .27. We urge scientists and practitioners to consider both the method and the constructs that are targeted when forecasting predictor ds.