Electrophysiological Correlates of Visual Object Category Formation in a Prototype-Distortion Task

In perceptual learning studies, participants engage in extensive training in the discrimination of visual stimuli in order to modulate perceptual performance. Much of the literature in perceptual learning has looked at the induction of the reorganization of low-level representations in V1. However, much remains to be understood about the mechanisms behind how the adult brain (an expert in visual object categorization) extracts high-level visual objects from the environment and categorically represents them in the cortical visual hierarchy. Here, I used event-related potentials (ERPs) to investigate the neural mechanisms involved in object representation formation during a hybrid visual search and prototype distortion category learning task. EEG was continuously recorded while participants performed the hybrid task, in which a peripheral array of four dot patterns was briefly flashed on a computer screen. In half of the trials, one of the four dot patterns of the array contained the target, a distorted prototype pattern. The remaining trials contained only randomly generated patterns. After hundreds of trials, participants learned to discriminate the target pattern through corrective feedback. A multilevel modeling approach was used to examine the predictive relationship between behavioral performance over time and two ERP components, the N1 and the N250. The N1 is an early sensory component related to changes in visual attention and discrimination (Hopf et al., 2002; Vogel & Luck, 2000). The N250 is a component related to category learning and expertise (Krigolson et al., 2009; Scott et al., 2008; Tanaka et al., 2006). Results indicated that while N1 amplitudes did not change with improved performance, increasingly negative N250 amplitudes did develop over time and were predictive of improvements in pattern detection accuracy

Absence of synaptic regulation by phosducin in retinal slices.

Phosducin is an abundant photoreceptor protein that binds G-protein βγ subunits and plays a role in modulating synaptic transmission at photoreceptor synapses under both dark-adapted and light-adapted conditions in vivo. To examine the role of phosducin at the rod-to-rod bipolar cell (RBC) synapse, we used whole-cell voltage clamp recordings to measure the light-evoked currents from both wild-type (WT) and phosducin knockout (Pd(-/-)) RBCs, in dark- and light-adapted retinal slices. Pd(-/-) RBCs showed smaller dim flash responses and steeper intensity-response relationships than WT RBCs, consistent with the smaller rod responses being selectively filtered out by the non-linear threshold at the rod-to-rod bipolar synapse. In addition, Pd(-/-) RBCs showed a marked delay in the onset of the light-evoked currents, similar to that of a WT response to an effectively dimmer flash. Comparison of the changes in flash sensitivity in the presence of steady adapting light revealed that Pd(-/-) RBCs desensitized less than WT RBCs to the same intensity. These results are quantitatively consistent with the smaller single photon responses of Pd(-/-) rods, owing to the known reduction in rod G-protein expression levels in this line. The absence of an additional synaptic phenotype in these experiments suggests that the function of phosducin at the photoreceptor synapse is abolished by the conditions of retinal slice recordings

The impact of minimum wages on adult female employment and labor force participation

This study attempts to theoretically and empirically examine if minimum wage legislation alters the employment and labor force participation of women age twenty and older. The theoretical and empirical analyses are based on a combination of the labor force participation and minimum wage literatures;The previous minimum wage literature is not consistent in the empirical measurement of the impact on adult women. This study attempts to reconcile the empirical results of the Mincer (2) and Gramlich (1) minimum wage studies by re-estimating their quarterly time series models. To extend this analysis, the model constructed for this study, while regressing the minimum wage on the aggregate employment, full time and part time employment, and labor force participation of adult women, controls for the unemployment rate and the presence of children, as do Mincer (2) and Gramlich (1), and also controls for female earnings, the husband\u27s income and welfare supplements. To test for a discriminant impact, the dependent labor force variable is also categorized by race, marital status, and marital status and age, and the dependent employment variable is categorized by race, full time and part time and marital status. Due to data limitations on the dependent variables by marital status and age, these equations use annual data. All other models use quarterly data;The re-estimation of the Mincer (2) and Gramlich (1) models suggest that minimum wage legislation does not adversely affect the aggregate employment and labor force participation of adult women but that it does augment the part time employment of these women. The extended time series analysis tends to support this conclusion and also suggests that the labor force participation of women age 20 to 24, especially single women, tends to be adversely affected by the legislation. Older women, regardless of marital status, do not appear to be adversely affected;(1) Gramlich, Edward. The Impact of Minimum Wages on Other Wages, Employment, and Family Income. Brookings Papers on Economic Activity (1976):409-451;(2) Mincer, Jacob. Unemployment Effects of Minimum Wages. Journal of Political Economy 84 (August 1976):s87-s104

The Influence of Tree Species Composition on Songbird Abundance and Productivity

Most avian habitat selection studies are conducted within small spatial and temporal scales and fail to link habitat selection decisions to reproductive success. This limits our understanding of avian demographic patterns across the full continuum of ecological conditions a species inhabits and may result in the application of inappropriate conservation strategies. The golden-cheeked warbler (Setophaga chrysoparia; hereafter warbler) is a federally endangered songbird that breeds in oak-juniper woodland of central Texas. Management guidelines indicate that mature, dense Ashe juniper cover is an attribute of high quality warbler breeding habitat, but few studies have examined warbler responses to Ashe juniper across the continuum of vegetation types they inhabit. I used data collected from 899 territories on 90 study sites (2009–2013) located across the warbler’s breeding range to investigate the influence of year, geographic location, various Ashe juniper metrics, and dominant oak species on warbler abundance and productivity. My results reiterate that vegetation utilized by warblers is highly variable and that warblers successfully breed in areas with vegetation characteristics outside current descriptions of warbler breeding habitat. Warbler territory density remained constant across the full range of percent Ashe juniper cover in woodland dominated by Lacey (Quercus laceyi), live (Q. fusiformis), and Texas oak (Q. buckleyi). Warbler territory density increased with increasing percent Ashe juniper cover in woodland dominated by post oak (Q. stellata) and in mixed oak woodland and warbler territory density decreased with increasing percent Ashe juniper cover in woodland stands dominated by shin oak (Q. sinuata). Territories were larger in oak-juniper woodland stands dominated by live oak than oak-juniper woodland stands dominated by all other species but post oak. Results regarding relationships between territory-scale metrics and territory size and pairing and fledging success varied, but indicate that prioritizing sites based on qualitative Ashe juniper metrics or managing sites to promote single-aged stands of mature Ashe juniper cover may not be the most effective strategy for warblers. Management and restoration efforts may be more effective if tailored to local vegetation characteristics associated with tree species composition

Urban/rural differences in food security in America’s East North Central Region

The literature on food insecurity in America is extensive, but there is still a lack of understanding of urban/rural differences. Food insecure populations in urban communities undoubtedly experience different and unique challenges to food access than food insecure populations in rural areas. While urban households may face a lack of options for fresh produce, rural households may find that they live an inaccessible distance from the nearest grocer. Through analysis of the Census Bureau’s Current Population Survey and Food Security Supplement, this project seeks to discover common, underlying variables in food-insecure communities in metropolitan and nonmetropolitan areas in America’s East North Central Region (Wisconsin, Michigan, Illinois, Indiana, and Ohio) to better understand the policy environment surrounding food security in America

Alien Registration- Long, Marie C. (Fort Kent, Aroostook County)

https://digitalmaine.com/alien_docs/36304/thumbnail.jp

Marie Olivieri Russell and Sarah Sundborg Long

Marie Olivieri Russell Dr. Russell attended Jefferson Medical College where she graduated top of her class in 1970. In addition to being the first woman to receive the Alumni Prize for highest cumulative GPA, in 1971 she became the first student to serve as a full voting member of the Board of Trustees at Jefferson. After graduation she completed both a residency in Pediatrics and a fellowship in Pediatric Hematology Oncology at Children’s Hospital of Philadelphia before continuing on as a part of their academic staff until 1981 and managing the Comprehensive Sickle Cell Program. After leaving Children’s and academic medicine Dr. Russell transitioned into Primary Care, eventually co-founding a pediatric practice for Crozer-Keystone Health System in Media, Pennsylvania. The practice later moved to Springfield, Pennsylvania, grew to include six physicians, and became part of Children’s Hospital of Philadelphia’s Primary Care Network. Over the years she also held faculty appointments at University of Pennsylvania, Hahnemann Medical College, and Drexel University. Dr. Russell retired in 2005 to spend more time with her family. Sarah Sundborg Long Dr. Long graduated from St. Francis College with a Bachelor’s of Science in Biology before entering Jefferson Medical College. Upon her graduation in 1970 she completed an Infectious Disease residency and fellowship at St. Christopher’s Hospital for Children in Philadelphia. She is currently the Chief for the Section of Infectious Diseases at St Christopher’s and a Professor of Pediatrics at Drexel University College of Medicine. Throughout her teaching career she has held more than seventy-five visiting professorships and earned a number of honors and awards, including most recently the Lindback Award. Dr. Long is the founding editor of Principles and Practice of Pediatric Infectious Disease as well as an associate editor of The Journal of Pediatrics and the Red Book Report of the Committee on Infectious Diseases of the American Academy of Pediatrics. Her main research areas are common infectious diseases and vaccine-preventable diseases in children.https://jdc.jefferson.edu/oral_histories/1010/thumbnail.jp

Alamance County Archaeological Survey Project, Alamance County, North Carolina

Research Report No. 5, Research Laboratories of Archaeology, University of North Carolina at Chapel Hill. Reports in this series discuss the findings of archaeological excavations and research projects undertaken by the RLA between 1984 and present