166 research outputs found

    Spectroscopy of Isolated Prebiotic Nucleobases

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    We use multiphoton ionization and double resonance spectroscopy to study the excited state dynamics of biologically relevant molecules as well as prebiotic nucleobases, isolated in the gas phase. Molecules that are biologically relevant to life today tend to exhibit short excited state lifetimes compared to similar but non-biologically relevant analogs. The mechanism is internal conversion, which may help protect the biologically active molecules from UV damage. This process is governed by conical intersections that depend very strongly on molecular structure. Therefore we have studied purines and pyrimidines with systematic variations of structure, including substitutions, tautomeric forms, and cluster structures that represent different base pair binding motifs. These structural variations also include possible alternate base pairs that may shed light on prebiotic chemistry. With this in mind we have begun to probe the ultrafast dynamics of molecules that exhibit very short excited states and search for evidence of internal conversions

    The Grizzly, March 5, 2009

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    Memorable Performance Depicts Life of Anne Frank ‱ Batter Up! Baseball Hopes for Home Run Season ‱ Cheapest Trip to Italy ‱ Young Invincibles Shun Medical Care ‱ Black in History: Tribute to Debbie Allen ‱ Money, Sex, Faith, Health and a True Happiness Formula? ‱ Finding Inspiration on the Back of Your Dove Chocolate Wrapper ‱ Opinions: Updike\u27s Death Calls for a Greater Appreciation for His Life ‱ Senior Leatherman Hurdles Into Eighth and Final Season at UChttps://digitalcommons.ursinus.edu/grizzlynews/1782/thumbnail.jp

    The Grizzly, September 11, 2008

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    Republican National Convention Rallies Supporters ‱ Studies Show Half of College Students Contemplate Suicide ‱ Start of New Now on View Art Film Festival ‱ Science, Strife and Speculation of Hurricane Season \u2708 ‱ UC Senior Implements First Ever Bike Share Program ‱ Cinematic Guild Brings Creative Filmography to Campus ‱ Introducing Cassandra Aguilar ‱ The Grizzly Catches Up with Dean Nolan ‱ Celebrating Herencia Latina Fall Events ‱ Molly Maguire\u27s: A Bit O\u27 Irish Spirit ‱ UC Women\u27s Soccer Fights for Another Strong Season ‱ Football\u27s New Motto: No Interceptions, No Exceptionshttps://digitalcommons.ursinus.edu/grizzlynews/1767/thumbnail.jp

    The Grizzly, October 30, 2008

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    Sounds of NYC Poet Tracie Morris ‱ Plan to Vote? UC Students Take Note: Polling Location Change ‱ Business Management Students Assist Charitable Causes ‱ Colin Powell Publicly Endorses Obama ‱ Young and Engaged: Planning for Life Beyond UC Years ‱ Hingston of Philadelphia Speaks at UC ‱ Faculty Spotlight on Philosophy Professor Kelly Sorensen ‱ More from Students Studying Abroad: UC in Germany ‱ Opinions: We Will Overcome: Positive Psychology in America; Logical Reason Behind Refusal to Vote; Controversy for the Republicans ‱ Football Quarterback Nick Dye Great Leader for Young Team ‱ Kelly Hosier: Sole, Shy Senior on UC Women\u27s Volleyball Teamhttps://digitalcommons.ursinus.edu/grizzlynews/1773/thumbnail.jp

    Early Neolithic wine of Georgia in the South Caucasus

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    Chemical analyses of ancient organic compounds absorbed into the pottery fabrics from sites in Georgia in the South Caucasus region, dating to the early Neolithic period (ca. 6,000-5,000 BC), provide the earliest biomolecular archaeological evidence for grape wine and viniculture from the Near East, at ca. 6,000-5,800 BC. The chemical findings are corroborated by climatic and environmental reconstruction, together with archaeobotanical evidence, including grape pollen, starch, and epidermal remains associated with a jar of similar type and date. The very large-capacity jars, some of the earliest pottery made in the Near East, probably served as combination fermentation, aging, and serving vessels. They are the most numerous pottery type at many sites comprising the so-called "Shulaveri-Shomutepe Culture" of the Neolithic period, which extends into western Azerbaijan and northern Armenia. The discovery of early sixth millennium BC grape wine in this region is crucial to the later history of wine in Europe and the rest of the world

    Risk Factors for and Prediction of Post-Intubation Hypotension in Critically Ill Adults: A Multicenter Prospective Cohort Study

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    OBJECTIVE: Hypotension following endotracheal intubation in the ICU is associated with poor outcomes. There is no formal prediction tool to help estimate the onset of this hemodynamic compromise. Our objective was to derive and validate a prediction model for immediate hypotension following endotracheal intubation. METHODS: A multicenter, prospective, cohort study enrolling 934 adults who underwent endotracheal intubation across 16 medical/surgical ICUs in the United States from July 2015-January 2017 was conducted to derive and validate a prediction model for immediate hypotension following endotracheal intubation. We defined hypotension as: 1) mean arterial pressure \u3c 65 mmHg; 2) systolic blood pressure \u3c 80 mmHg and/or decrease in systolic blood pressure of 40% from baseline; 3) or the initiation or increase in any vasopressor in the 30 minutes following endotracheal intubation. RESULTS: Post-intubation hypotension developed in 344 (36.8%) patients. In the full cohort, 11 variables were independently associated with hypotension: increasing illness severity; increasing age; sepsis diagnosis; endotracheal intubation in the setting of cardiac arrest, mean arterial pressure \u3c 65 mmHg, and acute respiratory failure; diuretic use 24 hours preceding endotracheal intubation; decreasing systolic blood pressure from 130 mmHg; catecholamine and phenylephrine use immediately prior to endotracheal intubation; and use of etomidate during endotracheal intubation. A model excluding unstable patients’ pre-intubation (those receiving catecholamine vasopressors and/or who were intubated in the setting of cardiac arrest) was also developed and included the above variables with the exception of sepsis and etomidate. In the full cohort, the 11 variable model had a C-statistic of 0.75 (95% CI 0.72, 0.78). In the stable cohort, the 7 variable model C-statistic was 0.71 (95% CI 0.67, 0.75). In both cohorts, a clinical risk score was developed stratifying patients’ risk of hypotension. CONCLUSIONS: A novel multivariable risk score predicted post-intubation hypotension with accuracy in both unstable and stable critically ill patients. STUDY REGISTRATION: Clinicaltrials.gov identifier: NCT02508948 and Registered Report Identifier: RR2-10.2196/11101

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be ∌24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with ÎŽ<+34.5∘\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r∌27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie
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