Monitoring Replication Protein A (RPA) Dynamics in Homologous Recombination Through Site-specific Incorporation of Non-canonical Amino Acids

An essential coordinator of all DNA metabolic processes is Replication Protein A (RPA). RPA orchestrates these processes by binding to single-stranded DNA (ssDNA) and interacting with several other DNA binding proteins. Determining the real-time kinetics of single players such as RPA in the presence of multiple DNA processors to better understand the associated mechanistic events is technically challenging. To overcome this hurdle, we utilized non-canonical amino acids and bio-orthogonal chemistry to site-specifically incorporate a chemical fluorophore onto a single subunit of heterotrimeric RPA. Upon binding to ssDNA, this fluorescent RPA (RPAf) generates a quantifiable change in fluorescence, thus serving as a reporter of its dynamics on DNA in the presence of multiple other DNA binding proteins. Using RPAf, we describe the kinetics of facilitated self-exchange and exchange by Rad51 and mediator proteins during various stages in homologous recombination. RPAf is widely applicable to investigate its mechanism of action in processes such as DNA replication, repair and telomere maintenance

Diversity and Dispersal Among Eastern Continental Divide Headwater Stream Fishes in Gwinnett County, Georgia.

The eastern continental divide that bisects Georgia runs through Gwinnett County, separating headwater streams of the western Chattahoochee River watershed from headwater streams of the eastern Ocmulgee and Oconee River watersheds. This landscape feature was used to test hypotheses regarding headwater habitat, fish diversity and gene flow. Headwater habitats are dominant components of river network ecosystems delivering vital ecosystem services and biodiversity. Three headwater streams, one in the Chattahoochee watershed and two in the Oconee watershed, on Gwinnett County Park property, were sampled for differences in physical and chemical properties and fish inter- and intraspecific diversity. Our results suggest the headwater habitats are each distinguished by unique physical and temporal features. Initial hypotheses regarding expectations of fish diversity based on habitat type were not supported. However, hypotheses regarding the impact of gene flow on genetic diversity among headwater stream species were supported. Gene flow estimates and phylogenetic analyses among three well-sampled species observed in these headwater streams, Semotilus atromaculatus, Notropis lutipinnis, and Nocomis leptocephalus, suggest the Eastern Continental Divide acts as a barrier for gene flow for some species. Our findings highlight a proposed methodology for headwater stream analysis that combines habitat heterogeneity with community and species-level measures of diversity

Transformations between 2MASS, SDSS and BVI photometric systems for late-type giants

We present colour transformations from Two Micron All Sky Survey (2MASS) photometric system to Johnson-Cousins system and to Sloan Digital Sky Survey (SDSS) system for late-type giants and vice versa. The giant star sample was formed using surface gravity constraints ($2 < \log g \leq 3$) to Cayrel de Strobel et al.\rq s (2001) spectroscopic catalogue. 2MASS, SDSS and Johnson-Cousins photometric data was taken from Cutri et al. (2003), Ofek (2008) and van Leeuwen (2007), respectively. The final sample was refined applying the following steps: (1) the data were dereddened, (2) the sample stars selected are of the highest photometric quality. We give two--colour dependent transformations as a function of metallicity as well as independent of metallicity. The transformations provide absolute magnitudes and distance determinations which can be used in space density evaluations at relatively short distances where some or all of the SDSS magnitudes of late-type giants are saturated.Comment: The variables and "f" parameters in the equations 15-17 and 27-29 were change

The Grizzly, February 7, 1995

Faculty and Administrators Focus on Sophomore Concerns • Survey of Ursinus Freshmen • Voice of Ursinus Rings Clear • Border Dispute Between Ecuador and Peru • Tabby Buckingham Dies at 16 • Ursinus Students Attend March for Life • Senior Spotlight: Michelle Ryan • WVOU: No Longer Speechless!! • The Marginal Uncertainty Hour Brings Talk Radio to Ursinus • Bears Snap Two-Game Skid • West Chester Edges Gymnasts • Cauley Triple Winner in Phone Meets • Cosgrove Sets Records in Win • Put Down the Pencils, Faculty is Going to Schoolhttps://digitalcommons.ursinus.edu/grizzlynews/1352/thumbnail.jp

The Grizzly, September 12, 1995

Strassburger to Students: Be Responsible • Class of \u2799 Arrives, Survives Orientation • Seneca Falls: The Birthplace of Women\u27s Suffrage • Treasure Hunt, Anyone? • Students Dedicate Mural To Strassburger • Did You Get Your Invitation? • Reality 100 • Biology Boot Camp • Want to be a Tech-y? • WVOU: It\u27s up to You • Internet Site of the Week • A Whole New Dining Experience • Commuter Connections • Get Involved by Joining a Committee • Victory: Bears Defense Shuts Down WPI • Women\u27s soccer: The Spirit to Fight • New Look for UC Volleyball Team • Lady Bears Win Field Hockey Openerhttps://digitalcommons.ursinus.edu/grizzlynews/1361/thumbnail.jp

The Grizzly, September 27, 1994

Berry\u27s Political Future Uncertain • Violence in Haiti Will Not be Tolerated • Status of Citizenship Questioned • What is Newman Society? • On Being Reared in the U.S. • What Scares Me • Rabinor Opens Lectures on Eating Disorders • UC Volleyball Battles Floor Problems and Injuries • UC X-C Runners are New and Improved • Defense to do it for Eagles • Bears Drop Close One to Western Marylandhttps://digitalcommons.ursinus.edu/grizzlynews/1341/thumbnail.jp

Investigating harms of testing for ovarian cancer – psychological outcomes and cancer conversion rates in women with symptoms of ovarian cancer:A cohort study embedded in the multicentre ROCkeTS prospective diagnostic study

Objective: To investigate psychological correlates in women referred with suspected ovarian cancer via the fast‐track pathway, explore how anxiety and distress levels change at 12 months post‐testing, and report cancer conversion rates by age and referral pathway. Design: Single‐arm prospective cohort study. Setting: Multicentre. Secondary care including outpatient clinics and emergency admissions. Population: A cohort of 2596 newly presenting symptomatic women with a raised CA125 level, abnormal imaging or both. Methods: Women completed anxiety and distress questionnaires at recruitment and at 12 months for those who had not undergone surgery or a biopsy within 3 months of recruitment. Main outcome measures: Anxiety and distress levels measured using a six‐item short form of the State–Trait Anxiety Inventory (STAI‐6) and the Impact of Event Scale – Revised (IES‐r) questionnaire. Ovarian cancer (OC) conversion rates by age, menopausal status and referral pathway. Results: Overall, 1355/2596 (52.1%) and 1781/2596 (68.6%) experienced moderate‐to‐severe distress and anxiety, respectively, at recruitment. Younger age and emergency presentations had higher distress levels. The clinical category for anxiety and distress remained unchanged/worsened in 76% of respondents at 12 months, despite a non‐cancer diagnosis. The OC rates by age were 1.6% (95% CI 0.5%–5.9%) for ag

CD4 Depletion in SIV-Infected Macaques Results in Macrophage and Microglia Infection with Rapid Turnover of Infected Cells

In rhesus macaques (RMs), experimental depletion of CD4+ T-cells prior to SIV infection results in higher viremia and emergence of CD4-independent SIV-envelopes. In this study we used the rhesus recombinant anti-CD4 antibody CD4R1 to deplete RM CD4+ T-cells prior to SIVmac251 infection and investigate the sources of the increased viral burden and the lifespan of productively infected cells. CD4-depleted animals showed (i) set-point viral load two-logs higher than controls; (ii) macrophages constituting 80% of all SIV vRNA+ cells in lymph node and mucosal tissues; (iii) substantial expansion of pro-inflammatory monocytes; (iv) aberrant activation and infection of microglial cells; and (v) lifespan of productively infected cells significantly longer in comparison to controls, but markedly shorter than previously estimated for macrophages. The net effect of CD4+ T-cell depletion is an inability to control SIV replication and a shift in the tropism of infected cells to macrophages, microglia, and, potentially, other CD4-low cells which all appear to have a shortened in vivo lifespan. We believe these findings have important implications for HIV eradication studies

The Grizzly, September 26, 1995

Ursinus Improves in National Rankings • Racism in Everywhere • The Dawn of a New S.T.A.R. • Royersford Teachers Strike • Restaurant Night is Back! • Stories from Abroad • Help, I\u27m an E-mail Addict! • Political Parties, Presidents, and Colin Powell • Writing Off Old Men\u27s? • Way to go, Collegeville! • Letters to the Editor • Spirit of Life Ensemble to Perform • Tobin Display at Berman • Are Wismer\u27s Grades Slipping? • Hillel Trip a Success • Celebrating Hispanic Heritage • What\u27s Going on at Ursinus College? • U.S.G.A. Minutes • C.A.B. Minutes • Conserve, Conserve, Conserve! What You Can do to Save Energy and the Earth • Soccer Team Splits • Field Hockey Team Wins Fourth Straight • Runners Compete • Football Team Not Offensive in Loss • Volleyball Team Nets Third Winhttps://digitalcommons.ursinus.edu/grizzlynews/1363/thumbnail.jp

The Grizzly, October 11, 1994

The Last Pledging Season? • Homecoming \u2794 a Success • The American Sexual Landscape • Fire, Fire! • Religious Sect Linked to Murder-Suicides • Campus Artwork Encounters Vandalism • Soup Kitchen Visit Provides Eye-Opening Experience • Retired Officer Expresses Thanks to Ursinus Community • Celebrate National Coming Out Day with GALA • Red and Gold Students Storm the Campus • Security Officer Larry Kirlin Leaves Ursinus • Memories of Homecoming 1994 • A Healthy Outlook on Life • Update From Career Planning & Placement • An Open Letter to President Richter • UC Soccer Wins in Closing Minutes • Walker Memorial Winners • Golley Wins McIntyre Award • UC Wins On Homecoming, 21-20https://digitalcommons.ursinus.edu/grizzlynews/1343/thumbnail.jp