Photosynthetic Versatility in the Genome of Geitlerinema sp. PCC 9228 (Formerly Oscillatoria limnetica ‘Solar Lake’), a Model Anoxygenic Photosynthetic Cyanobacterium

Anoxygenic cyanobacteria that use sulfide as the electron donor for photosynthesis are a potentially influential but poorly constrained force on Earth’s biogeochemistry. Their versatile metabolism may have boosted primary production and nitrogen cycling in euxinic coastal margins in the Proterozoic. In addition, they represent a biological mechanism for limiting the accumulation of atmospheric oxygen, especially before the Great Oxidation Event and in the low-oxygen conditions of the Proterozoic. In this study, we describe the draft genome sequence of Geitlerinema sp. PCC 9228, formerly Oscillatoria limnetica ‘Solar Lake’, a mat-forming diazotrophic cyanobacterium that can switch between oxygenic photosynthesis and sulfide-based anoxygenic photosynthesis. Geitlerinema possesses three variants of psbA, which encodes protein D1, a core component of the photosystem II reaction center. Phylogenetic analyses indicate that one variant is closely affiliated with cyanobacterial psbA genes that code for a D1 protein used for oxygen-sensitive processes. Another version is phylogenetically similar to cyanobacterial psbA genes that encode D1 proteins used under microaerobic conditions, and the third variant may be cued to high light and/or elevated oxygen concentrations. Geitlerinema has the canonical gene for sulfide quinone reductase (SQR) used in cyanobacterial anoxygenic photosynthesis and a putative transcriptional regulatory gene in the same operon. Another operon with a second, distinct sqr and regulatory gene is present, and is phylogenetically related to sqr genes used for high sulfide concentrations. The genome has a comprehensive nif gene suite for nitrogen fixation, supporting previous observations of nitrogenase activity. Geitlerinema possesses a bidirectional hydrogenase rather than the uptake hydrogenase typically used by cyanobacteria in diazotrophy. Overall, the genome sequence of Geitlerinema sp. PCC 9228 highlights potential cyanobacterial strategies to cope with fluctuating redox gradients and nitrogen availability that occur in benthic mats over a diel cycle. Such dynamic geochemical conditions likely also challenged Proterozoic cyanobacteria, modulating oxygen production. The genetic repertoire that underpins flexible oxygenic/anoxygenic photosynthesis in cyanobacteria provides a foundation to explore the regulation, evolutionary context, and biogeochemical implications of these co-occurring metabolisms in Earth history

The Grizzly, January 27, 1989

Constructium Ursini • Ad Hoc Hoists Honor • New GPA: 2.25 or Dive! • Letter: Green Shirt Makes Reed Red • Fair Not Just for Freshmen • Security Shacks in Reimert • Beverly Oehlert Named to Pottstown Board of Directors • Final Red and Gold Day • Hoopsters Stunning in Second • Lady Bears Go For Title • U.C. Hockey Bids Boyd Bon Voyage • A \u27bears Recover from Fla. • Dryfoos, Knauer Newest Dirs. • Bailey Bandies With Bush • Grim Gripes: Wismer Hard to Swallow • Quintet Jazzes Up First Forum • Greenstein to Performhttps://digitalcommons.ursinus.edu/grizzlynews/1226/thumbnail.jp

The Grizzly, February 3, 1989

Hoc\u27sters Hammer Out Honesty Hazards • Middleton Mitts Mega-Bucks to Make Meta-Blood • Absentees Abound: Apathy Apparent • Letter: Bussers and Shirts Ream Reed • Pinsker\u27s Pace Paralyzes Prof. Pack • Grim Groans at Rock Ignorants • Plan B Plants U.C. in Place • Lady Bears Breeze by Lehigh • Hoopsters Haul Ball • AquaBears Swim On • Seniors Snarf Steak • Cinders Casting • Durst Demonstrates Decking Deftness • U.C. Supposedly Safe and Sound • Fruit Fantasy Makes Maxi Delight • U.C. Mourns Losshttps://digitalcommons.ursinus.edu/grizzlynews/1227/thumbnail.jp

The Grizzly, April 14, 1989

Middle States: What To Look For At U.C. • Sorority Songfest Continues • Letters: Lack of MACLAS Coverage Disturbing; I.D. Hassles; We Smell a Rat! • Middle States Closing Offers Suggestions • Canterbury Corner too Costly • Lacrosse Braces for Traditional Rivalry • Outmanned, But Still Best • Tennis Turns Tables • Ursinus Sweeps • Men\u27s Lax Gets Physical • Cinders Burnin\u27 Down the House • Guess Who\u27s Coming to Dinner? • Branker Wins Jazz Fellowship • MACLAS Meeting Absolute Success • Sternal: Functional Art at U.C. • Cyclists Rolling to Victories • Pilgrim Continues U.C. Evaluation • Admissions Reception • Grant to Give Biology a Boost • The Music Scenehttps://digitalcommons.ursinus.edu/grizzlynews/1235/thumbnail.jp

Oligotyping : differentiating between closely related microbial taxa using 16S rRNA gene data

© The Authors. Methods in Ecology and Evolution © 2013 British Ecological Society.. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Methods in Ecology and Evolution 4 (2013): 1111–1119, doi:10.1111/2041-210X.12114.Bacteria comprise the most diverse domain of life on Earth, where they occupy nearly every possible ecological niche and play key roles in biological and chemical processes. Studying the composition and ecology of bacterial ecosystems and understanding their function are of prime importance. High-throughput sequencing technologies enable nearly comprehensive descriptions of bacterial diversity through 16S ribosomal RNA gene amplicons. Analyses of these communities generally rely upon taxonomic assignments through reference data bases or clustering approaches using de facto sequence similarity thresholds to identify operational taxonomic units. However, these methods often fail to resolve ecologically meaningful differences between closely related organisms in complex microbial data sets. In this paper, we describe oligotyping, a novel supervised computational method that allows researchers to investigate the diversity of closely related but distinct bacterial organisms in final operational taxonomic units identified in environmental data sets through 16S ribosomal RNA gene data by the canonical approaches. Our analysis of two data sets from two different environments demonstrates the capacity of oligotyping at discriminating distinct microbial populations of ecological importance. Oligotyping can resolve the distribution of closely related organisms across environments and unveil previously overlooked ecological patterns for microbial communities. The URL http://oligotyping.org offers an open-source software pipeline for oligotyping.This work was supported by the National Institutes of Health [1UH2DK083993 to M.L.S.] and the Alfred P. Sloan Foundation

Adapting the Communication and Teamwork Skills Assessment to Assess Pre-licensure Health Care Student Team Performance in Simulation-Enhanced Interprofessional Education

Introduction: Literature demonstrates a lack of structured reporting of interprofessional (IPE) education activities and challenges objectively measuring team performance. The purposes of this article are: to provide a structured description of a simulation-enhanced IPE project focusing on pre-licensure health care student team performance; and, to describe how the Communication and Teamwork Skills (CATS) assessment was adapted to assess teamwork and communication skills during student team simulations. Methods: Simulated case scenarios were conducted with teams consisting of nursing, respiratory therapy, and medical students. The CATS tool was adapted for use in IPE simulations by adding two statements that globally assessed frequency and quality of teamwork. Individual items from the CATS tool guided assessment of overall team performance. Faculty assessors piloted the tool by discussing tool components and assessing several sample cases together. Faculty assessors then scored each simulation individually and the adapted CATS tool was assessed for inter-rater reliability. Results: The team assessed sixty-eight cases (n=68). Thirty-four (n=34) cases were rated by three of the faculty and thirty-four (n=34) were rated by two faculty. Inter-rater reliability for frequency of communication was .808 and .789 for quality of communication. Conclusion: This project suggests that an adapted version of the CATS assessment tool can be used to reliably assess communication performance of health care student teams during a simulated acute care case. In addition, the planning team hopes that the project can be replicated to develop a model of IPE that is sustainable and feasible within other academic or health care settings

Uncovering Dangerous Cheats: How Do Avian Hosts Recognize Adult Brood Parasites?

BACKGROUND: Co-evolutionary struggles between dangerous enemies (e.g., brood parasites) and their victims (hosts) lead to the emergence of sophisticated adaptations and counter-adaptations. Salient host tricks to reduce parasitism costs include, as front line defence, adult enemy discrimination. In contrast to the well studied egg stage, investigations addressing the specific cues for adult enemy recognition are rare. Previous studies have suggested barred underparts and yellow eyes may provide cues for the recognition of cuckoos Cuculus canorus by their hosts; however, no study to date has examined the role of the two cues simultaneously under a consistent experimental paradigm. METHODOLOGY/PRINCIPAL FINDINGS: We modify and extend previous work using a novel experimental approach--custom-made dummies with various combinations of hypothesized recognition cues. The salient recognition cue turned out to be the yellow eye. Barred underparts, the only trait examined previously, had a statistically significant but small effect on host aggression highlighting the importance of effect size vs. statistical significance. CONCLUSION: Relative importance of eye vs. underpart phenotypes may reflect ecological context of host-parasite interaction: yellow eyes are conspicuous from the typical direction of host arrival (from above), whereas barred underparts are poorly visible (being visually blocked by the upper part of the cuckoo's body). This visual constraint may reduce usefulness of barred underparts as a reliable recognition cue under a typical situation near host nests. We propose a novel hypothesis that recognition cues for enemy detection can vary in a context-dependent manner (e.g., depending on whether the enemy is approached from below or from above). Further we suggest a particular cue can trigger fear reactions (escape) in some hosts/populations whereas the same cue can trigger aggression (attack) in other hosts/populations depending on presence/absence of dangerous enemies that are phenotypically similar to brood parasites and costs and benefits associated with particular host responses

The Grizzly, April 21, 1989

Spring Weekend a Whopper! • Ours Nouveau • Sunday\u27s Reception Huge Success • Letter: Shed Miniskirts for Spandex • Heritage Day • Berman Roofing Top Hat Affair • \u27Packers Hike Hick Hills • Ground Round: Super Service • Running\u27s More Than Just Winning • Spring Sports: Hot and Cold • Mr. Ursinus a Whomping Good Time!https://digitalcommons.ursinus.edu/grizzlynews/1236/thumbnail.jp

The Grizzly, February 10, 1989

Ursinus Seeks Mid-States Reaccreditation • Heck Beats Traffic Blahs • Letter: Doughty Expresses Doubts • U.C. Salutes French Bicentennial • Medieval Fest Needs You • Ginsberg to Give Revolutionary Forum • Casa Maria: Muy Bien • de la Hoya Happy • Ursinus Slays F & M • U.C. Aims for Title • O\u27Malley Leaps to Nationals • Women\u27s Indoor Inspiring • U.C. Fields Strong Squad • A\u27Bears Peaking at Right Time • Scholarships to Scotland • Guess Who\u27s Coming for Dinner? • His Cheating Makes Twice the Test for You • Hallinger Argues for Proposal 42: Academics Before Athlete • Greenstein Grabs Grim \u27Just Right\u27 • Valentine No-No\u27s • From America With Love: Students Flock to U.C.https://digitalcommons.ursinus.edu/grizzlynews/1228/thumbnail.jp

Sedimentary pyrite sulfur isotope compositions preserve signatures of the surface microbial mat environment in sediments underlying low-oxygen cyanobacterial mats

The sedimentary pyrite sulfur isotope (delta S-34) record is an archive of ancient microbial sulfur cycling and environmental conditions. Interpretations of pyrite delta S-34 signatures in sediments deposited in microbial mat ecosystems are based on studies of modern microbial mat porewater sulfide delta S-34 geochemistry. Pyrite delta S-34 values often capture delta S-34 signatures of porewater sulfide at the location of pyrite formation. However, microbial mats are dynamic environments in which biogeochemical cycling shifts vertically on diurnal cycles. Therefore, there is a need to study how the location of pyrite formation impacts pyrite delta S-34 patterns in these dynamic systems. Here, we present diurnal porewater sulfide delta S-34 trends and delta S-34 values of pyrite and iron monosulfides from Middle Island Sinkhole, Lake Huron. The sediment-water interface of this sinkhole hosts a low-oxygen cyanobacterial mat ecosystem, which serves as a useful location to explore preservation of sedimentary pyrite delta S-34 signatures in early Earth environments. Porewater sulfide delta S-34 values vary by up to similar to 25 parts per thousand throughout the day due to light-driven changes in surface microbial community activity that propagate downwards, affecting porewater geochemistry as deep as 7.5 cm in the sediment. Progressive consumption of the sulfate reservoir drives delta S-34 variability, instead of variations in average cell-specific sulfate reduction rates and/or sulfide oxidation at different depths in the sediment. The delta S-34 values of pyrite are similar to porewater sulfide delta S-34 values near the mat surface. We suggest that oxidative sulfur cycling and other microbial activity promote pyrite formation in and immediately adjacent to the microbial mat and that iron geochemistry limits further pyrite formation with depth in the sediment. These results imply that primary delta S-34 signatures of pyrite deposited in organic-rich, iron-poor microbial mat environments capture information about microbial sulfur cycling and environmental conditions at the mat surface and are only minimally affected by deeper sedimentary processes during early diagenesis