Isolation and characterization of the elusive cyanoformate ion and the dependence of its stability on solvent dielectric constant

xvi, 164 leaves : ill. (some col.) ; 29 cm.Includes abstract.Includes bibliographical references (leaves 144-164).The cyanoformate ion, speculated to be an intermediate by-product in the biosynthesis of ethylene in plants for decades but never observed, was successfully isolated for the first time as its tetraphenylphosphonium salt ([PPh[subscript 4]][NCCO[subscript 2]]). Full spectroscopic and crystallographic characterization of [PPh[subscript 4]][NCCO[subscript 2]] is provided, including characterization of [superscript 13]C-labelled isotopologues. In situ infrared spectroscopic analysis of the decomposition of cyanoformate in various solvents has revealed that cyanoformate will dissociate into CN- and CO[subscript 2] in higher dielectric media. The active site of 1-aminocyclopropane-1-carboxylic acid oxidase (ACC oxidase) bears an iron atom which may be protected from produced cyanide by its complexation with CO[subscript 2] as cyanoformate. When cyanoformate migrates out of the active site of the enzyme to the higher dielectric cytosol, it then dissociates, producing CN[superscript -] or HCN, which is subsequently metabolized

The Grizzly, February 20, 2020

UC Hosts The Vagina Monologues • Spend a Semester in Philadelphia • College Launches First Mobile App • Slavery in the Age of Memory Talk • Q&A with the Creator of High Education • Get to Know New Tech with a DLA Fellow • Opinions: The Good Place Ends in a Good Place; Marriage Story Isn\u27t Divorced from Humanity • Gymnastics Aims for First Nationals Appearance Since 2017 • Men\u27s Hoops on the Brink of Clinching CC Playoff Berthhttps://digitalcommons.ursinus.edu/grizzlynews/1599/thumbnail.jp

Live, Attenuated Influenza A H5N1 Candidate Vaccines Provide Broad Cross-Protection in Mice and Ferrets

BACKGROUND: Recent outbreaks of highly pathogenic influenza A H5N1 viruses in humans and avian species that began in Asia and have spread to other continents underscore an urgent need to develop vaccines that would protect the human population in the event of a pandemic. METHODS AND FINDINGS: Live, attenuated candidate vaccines possessing genes encoding a modified H5 hemagglutinin (HA) and a wild-type (wt) N1 neuraminidase from influenza A H5N1 viruses isolated in Hong Kong and Vietnam in 1997, 2003, and 2004, and remaining gene segments derived from the cold-adapted (ca) influenza A vaccine donor strain, influenza A/Ann Arbor/6/60 ca (H2N2), were generated by reverse genetics. The H5N1 ca vaccine viruses required trypsin for efficient growth in vitro, as predicted by the modification engineered in the gene encoding the HA, and possessed the temperature-sensitive and attenuation phenotypes specified by the internal protein genes of the ca vaccine donor strain. More importantly, the candidate vaccines were immunogenic in mice. Four weeks after receiving a single dose of 10(6) 50% tissue culture infectious doses of intranasally administered vaccines, mice were fully protected from lethality following challenge with homologous and antigenically distinct heterologous wt H5N1 viruses from different genetic sublineages (clades 1, 2, and 3) that were isolated in Asia between 1997 and 2005. Four weeks after receiving two doses of the vaccines, mice and ferrets were fully protected against pulmonary replication of homologous and heterologous wt H5N1 viruses. CONCLUSIONS: The promising findings in these preclinical studies of safety, immunogenicity, and efficacy of the H5N1 ca vaccines against antigenically diverse H5N1 vaccines provide support for their careful evaluation in Phase 1 clinical trials in humans

Overfitting Affects the Reliability of Radial Velocity Mass Estimates of the V1298 Tau Planets

Mass, radius, and age measurements of young (<100 Myr) planets have the power to shape our understanding of planet formation. However, young stars tend to be extremely variable in both photometry and radial velocity, which makes constraining these properties challenging. The V1298 Tau system of four ~0.5 Rjup planets transiting a pre-main sequence star presents an important, if stress-inducing, opportunity to directly observe and measure the properties of infant planets. Su\'arez-Mascare\~no et al. (2021) published radial-velocity-derived masses for two of the V1298 Tau planets using a state-of-the-art Gaussian Process regression framework. The planetary densities computed from these masses were surprisingly high, implying extremely rapid contraction after formation in tension with most existing planet formation theories. In an effort to further constrain the masses of the V1298 Tau planets, we obtained 36 RVs using Keck/HIRES, and analyzed them in concert with published RVs and photometry. Through performing a suite of cross validation tests, we found evidence that the preferred model of SM21 suffers from overfitting, defined as the inability to predict unseen data, rendering the masses unreliable. We detail several potential causes of this overfitting, many of which may be important for other RV analyses of other active stars, and recommend that additional time and resources be allocated to understanding and mitigating activity in active young stars such as V1298 Tau.Comment: 26 pages, 12 figures; published in A

Devotions for Lent 2023 Hymns of Lent

This Lent, we will continue reflecting on hymns of faith, namely, some of our most beloved Lenten hymns. 10 such hymns have been chosen to fill the 40(+) days of Lent. Therefore, this devotional, different from previous editions, does not proceed on a weekly basis, but merely flows from one hymn to the next. Also different from previous editions, the devotional reflections are specifically based on the stanzas of the selected hymns. Therefore, each day’s reflection features the text of the hymn stanza, a devotion based on that stanza, a prayer, and then a Scripture passage or passages for further meditation. I pray these reflections may be of edification for you during this Lenten season.https://scholar.csl.edu/osp/1022/thumbnail.jp