The Grizzly, October 2, 2008

Lighting Up Laws: New Smoking Policies on College Campuses • Sexual Perversity Comes to Ursinus • Water, Water Everywhere • Users to Delete Profiles? Student Reactions to New Facebook • U.S. Credit Crisis Hits Home for Some Ursinus Students • College Students Hurt by Economic Woes • Banned Books Week • Lethal Filler Found in Chinese Dairy • Texting Responsible for Train Crash? • Hispania Dances Their Hearts Out for an Ursinus Audience • Tribute to Sub Connection Employee Patro • A Look Into the Past with the Sophomore Class President • Women in Science: Progress in the Scientific Community • Kabuki Dancer to Choreograph at UC • College Students Targets for ID Theft • Opinions: Presidential Debate 2008: The Battle in Mississippi; Open Your Eyes to the Truth About Senator Barack Obama; Political Messages Overtake Television More Than Ever • Cross Country Senior Spotlight: Christa Johnson • Cosmic Sucker Punch: UC Ultimate Frisbee Scores • Could New Turf Field be the Key to Football\u27s Future Success?https://digitalcommons.ursinus.edu/grizzlynews/1770/thumbnail.jp

The Grizzly, November 6, 2008

Diversity ... What\u27s That? GSA Sponsors Dessert Discussion • Falling Gas Prices Spell Relief for Drivers, Oil Profits Drop • Philly Fans Celebrate World Series Victory at Parade • Gallup: Public Interest and Early Voting • Health Insurers to Pay Therapy Bills for Autistic Children? • TV Responsible for Teen Pregnancy? Rand Corp Says Yes • Holly Gains Attention for the UC Jazz Band • Rise Against: Third Time Around Turns Out to be a Charm • Trick-or-Treat Reaches a New Height at Ursinus • City Council Member Andrea Baptiste Speaks to Students • Opinions: Election Rewind; Escape Velocity: Eternalmotion • Women\u27s Basketball Looking for Another Championship • Men\u27s and Women\u27s Swimming Splash into New Season • In Times of Test, Family is Best: UC Men\u27s Basketballhttps://digitalcommons.ursinus.edu/grizzlynews/1774/thumbnail.jp

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Neurophysiological modification of CA1 pyramidal neurons in a transgenic mouse expressing a truncated form of disrupted-in-schizophrenia 1

A t(1;11) balanced chromosomal translocation transects the Disc1 gene in a large Scottish family and produces genome-wide linkage to schizophrenia and recurrent major depressive disorder. This study describes our in vitro investigations into neurophysiological function in hippocampal area CA1 of a transgenic mouse (DISC1(tr)) that expresses a truncated version of DISC1 designed to reproduce aspects of the genetic situation in the Scottish t(1;11) pedigree. We employed both patch-clamp and extracellular recording methods in vitro to compare intrinsic properties and synaptic function and plasticity between DISC1(tr) animals and wild-type littermates. Patch-clamp analysis of CA1 pyramidal neurons (CA1-PNs) revealed no genotype dependence in multiple subthreshold parameters, including resting potential, input resistance, hyperpolarization-activated ‘sag’ and resonance properties. Suprathreshold stimuli revealed no alteration to action potential (AP) waveform, although the initial rate of AP production was higher in DISC1(tr) mice. No difference was observed in afterhyperpolarizing potentials following trains of 5–25 APs at 50 Hz. Patch-clamp analysis of synaptic responses in the Schaffer collateral commissural (SC) pathway indicated no genotype-dependence of paired pulse facilitation, excitatory postsynaptic potential summation or AMPA/NMDA ratio. Extracellular recordings also revealed an absence of changes to SC synaptic responses and indicated input–output and short-term plasticity were also unaltered in the temporoammonic (TA) input. However, in DISC1(tr) mice theta burst-induced long-term potentiation was enhanced in the SC pathway but completely lost in the TA pathway. These data demonstrate that expressing a truncated form of DISC1 affects intrinsic properties of CA1-PNs and produces pathway-specific effects on long-term synaptic plasticity