Controls on the composition and lability of dissolved organic matter in Siberia's Kolyma River basin

High-latitude northern rivers export globally significant quantities of dissolved organic carbon (DOC) to the Arctic Ocean. Climate change, and its associated impacts on hydrology and potential mobilization of ancient organic matter from permafrost, is likely to modify the flux, composition, and thus biogeochemical cycling and fate of exported DOC in the Arctic. This study examined DOC concentration and the composition of dissolved organic matter (DOM) across the hydrograph in Siberia's Kolyma River, with a particular focus on the spring freshet period when the majority of the annual DOC load is exported. The composition of DOM within the Kolyma basin was characterized using absorbance-derived measurements (absorbance coefficienta330, specific UV absorbance (SUVA254), and spectral slope ratio SR) and fluorescence spectroscopy (fluorescence index and excitation-emission matrices (EEMs)), including parallel factor analyses of EEMs. Increased surface runoff during the spring freshet led to DOM optical properties indicative of terrestrial soil inputs with high humic-like fluorescence, SUVA254, and low SRand fluorescence index (FI). Under-ice waters, in contrast, displayed opposing trends in optical properties representing less aromatic, lower molecular weight DOM. We demonstrate that substantial losses of DOC can occur via biological (∼30% over 28 days) and photochemical pathways (>29% over 14 days), particularly in samples collected during the spring freshet. The emerging view is therefore that of a more dynamic and labile carbon pool than previously thought, where DOM composition plays a fundamental role in controlling the fate and removal of DOC at a pan-Arctic scale

The Ursinus Weekly, March 17, 1952

MSGA reveals penalty plan for cheating • Campus presidential election by ballot planned Thursday • Seminar concludes with talk on philosophy of marriage • Sarah Canan named \u27Weekly editor; Richard Richter to be managing editor • Fireside chat planned by Y • Thespians to act in Penn Olympics • Chinese diplomat to speak at Forum Wednesday, April 2 • Courses listed for Summer term by Dean • Phila. Story leaders named • Dr. Carleton Coon tells Forum of cave explorations in Iran • Editorials: Heart of the matter; Some last words; Ike strengthened in N. H. • Letters to the editor • Y delegates attend meeting at U. of P. • Four Ursinus students visit United Nations meeting Friday • Juniors make final plans for variety show, Spring prom • Mr. Wilcox to read translations • Talk postponed • Students visit Vienna art display at museum • Whistler finally locates his trunk • Belles remain undefeated with victory over Temple • Huge crowd expected for intramural night • Swarthmore wins over tank team • Curtain falls over winter sports as wrestling ends • Veterans bolster track prospects • Baseballers begin Spring practice • Badminton team loses game to Swarthmore, 5-0, Thursday • Girls drop first game by one point to Penn • Brodbeck wins intramural title • Tennis team sets up player-ladder • Chemistry students plan conference • Eight men receive alternate bids by campus fraternitieshttps://digitalcommons.ursinus.edu/weekly/1538/thumbnail.jp

The Ursinus Weekly, May 14, 1951

Robert Herber chosen for study abroad • Dramatic fraternity takes in new members • Debating Club elects • Mary MacPherson crowned May Queen before large crowd; Arsenic run registers success • Senior announcements available; Meeting set • Tom Davis elected MSGA president; Feulner is V. P. • Y doggie roast planned • Jay Ely chosen head of musical organizations • Classes vote for officers; Council named • Women\u27s dorms elect new representatives • Editorials: Oaths of loyalty? • Great debate continues • Ye olde cricket game • MSGA history shows how present system developed • Sizzling, simpering sunbathers seek solar solace! • Curtis teams vie for championships • Swarthmore jayvees defeat Ursinus girls\u27 net team, 3-2 • Bearettes trounce weak Beaver ten; Spencer fans 11 • Three records broken, another tied as Swarthmore wins triangular meet • Tennis men extend streak to five; Delaware beaten • Snell\u27s Belles continue undefeated as they roll over Chestnut Hill, 31-2 • LaSalle pounds three U hurlers in 15-4 landslide • Muhlenberg diamond squad scores shutout victory over Ursinus nine • Netmen down Dragon squad • Ursinus Women\u27s Club invited to lecture • Newman Club holds Communion, breakfast • Chi Alpha to electhttps://digitalcommons.ursinus.edu/weekly/1569/thumbnail.jp

From canopy to consumer: what makes and modifes terrestrial DOM in a temperate forest

To investigate how source and processing control the composition of “terrestrial” dissolved organic matter (DOM), we combine soil and tree leachates, tree DOM, laboratory bioincubations, and ultrahigh resolution Fourier-transform ion cyclotron resonance mass spectrometry in three common landscape types (upland forest, forested wetland, and poor fen) of Southeast Alaska’s temperate rainforest. Tree (Tsuga heterophylla and Picea sitchensis) needles and bark and soil layers from each site were leached, and tree stemflow and throughfall collected to examine DOM sources. Dissolved organic carbon concentrations were as high as 167 mg CL−1 for tree DOM, suggesting tree DOM fluxes may be substantial given the hypermaritime climate of the region. Condensed aromatics contributed as much as 38% relative abundance of spruce and hemlock bark leachates suggesting coniferous trees are potential sources of condensed aromatics to surface waters. Soil leachates showed soil wetness dictates DOM composition and processing, with wetland soils producing more aromatic formulae and allowing the preservation of traditionally biolabile, aliphatic formulae. Biodegradation impacted soil and tree DOM differently, and though the majority of source-specific marker formulae were consumed for all sources, some marker formulae persisted. Tree DOM was highly biolabile (> 50%) and showed compositional convergence where processing homogenized DOM from different tree sources. In contrast, wetland and upland soil leachate DOM composition diverged and processing diversified DOM from different soil sources during bioincubations. Increasing precipitation intensity predicted with climate change in Southeast Alaska will increase tree leaching and soil DOM flushing, tightening linkages between terrestrial sources and DOM export to the coastal ocean.The authors thank Emily Whitney for her invaluable feld, laboratory, and logistical assistance and Molly Tankersley for creating Fig. 1. They are also grateful to all the helpful researchers at the National High Magnetic Field Laboratory who enabled data acquisition and processing. This work took place on the lands of the Aak’w Kwáan Tlingit. This work was supported by the National Science Foundation through an NSF Graduate Research Fellowship to MIB. A portion of this work was performed at the National High Magnetic Field Laboratory ICR User Facility, which is supported by the National Science Foundation Division of Chemistry and Division of Materials Research through DMR-1644779 and the State of Florida. Conficts of interest/ Competing interests: The authors have no conficts of interests to declare.Ye

From canopy to consumer: what makes and modifies terrestrial DOM in a temperate forest

To investigate how source and processing control the composition of “terrestrial” dissolved organic matter (DOM), we combine soil and tree leachates, tree DOM, laboratory bioincubations, and ultrahigh resolution Fourier-transform ion cyclotron resonance mass spectrometry in three common landscape types (upland forest, forested wetland, and poor fen) of Southeast Alaska’s temperate rainforest. Tree (Tsuga heterophylla and Picea sitchensis) needles and bark and soil layers from each site were leached, and tree stemflow and throughfall collected to examine DOM sources. Dissolved organic carbon concentrations were as high as 167 mg CL−1 for tree DOM, suggesting tree DOM fluxes may be substantial given the hypermaritime climate of the region. Condensed aromatics contributed as much as 38% relative abundance of spruce and hemlock bark leachates suggesting coniferous trees are potential sources of condensed aromatics to surface waters. Soil leachates showed soil wetness dictates DOM composition and processing, with wetland soils producing more aromatic formulae and allowing the preservation of traditionally biolabile, aliphatic formulae. Biodegradation impacted soil and tree DOM differently, and though the majority of source-specific marker formulae were consumed for all sources, some marker formulae persisted. Tree DOM was highly biolabile (> 50%) and showed compositional convergence where processing homogenized DOM from different tree sources. In contrast, wetland and upland soil leachate DOM composition diverged and processing diversified DOM from different soil sources during bioincubations. Increasing precipitation intensity predicted with climate change in Southeast Alaska will increase tree leaching and soil DOM flushing, tightening linkages between terrestrial sources and DOM export to the coastal ocean.The authors thank Emily Whitney for her invaluable feld, laboratory, and logistical assistance and Molly Tankersley for creating Fig. 1. They are also grateful to all the helpful researchers at the National High Magnetic Field Laboratory who enabled data acquisition and processing. This work took place on the lands of the Aak’w Kwáan Tlingit. This work was supported by the National Science Foundation through an NSF Graduate Research Fellowship to MIB. A portion of this work was performed at the National High Magnetic Field Laboratory ICR User Facility, which is supported by the National Science Foundation Division of Chemistry and Division of Materials Research through DMR-1644779 and the State of Florida. Conficts of interest/ Competing interests: The authors have no conficts of interests to declare.Ye

The Ursinus Weekly, February 18, 1952

1952 Selective Service test set for April • Violinist, pianist schedule program Thursday night • Tryouts held for Meistersingers; Cast is chosen • Egyptian to speak here Wednesday • Communist youth festival described by U.S. delegate • Elections Wednesday as four vie for May Queen • Anne Hughes tells of her college life • Spring play selected by Curtain Club • Drs. Garrett, Miller to address first professors\u27 panel • Mr. Dolman to read Twain at English lit meeting • Sophomores plan eventful weekend for March 7-8 • Summer term students asked to select courses • Tea planned • Editorials: Where there\u27s life; W. Europe forms new army • Whistler Donahue tells of day\u27s activities in Morocco • Operation Lorelei gets underway February 29 • Washington bust given to college by Mr. Lachman • Library is not only for bookworms • Ursinus girls basketball squad overpowers Albright team, 51-23 • Spencer scores 22 as Belles triumph • Off-campus teams lead League II • University of Delaware registers an 81-55 league win over Bears • Girls win in opening meet • Frosh outstanding in winter sports • Grizzlies weak in offense as Dragons win, 82-56 • Grapplers beaten by Delaware team • New accessions to Library include many best-sellers • Teaching is profession, FTA speaker asserts • English Club reads Hamlet • Chess team loses • Couples enjoy Western dance • Chemist addresses Beardwood Society • IRC discusses conferences • MSGA discusses Student Union, parking rules • Students attend NATO conference • WAA card party benefits fundhttps://digitalcommons.ursinus.edu/weekly/1534/thumbnail.jp

The Ursinus Weekly, March 10, 1952

Cast chosen for Curtain Club play • New method used to contact students in Campus Chest drive • Operetta leads picked as Sari gets underway • Newman Club hears about new society • Sororities pledge 25 after week of rushing • Professors give various last minute admonitions at Y panel • Audrey Harte writes winning May Day pageant; Chairmen begin work: Stolen Princess of Fantasy is tale told in verse • Spirit group reorganizes • Noted archaeologist to give illustrated lecture at Forum • Juniors pick out theme for prom • Movie rescheduled • Two group plays to be staged Tuesday evening in T-G gym • Seniors plan dance, party at country club March 15 • German student to speak • Editorials: 25 want spirit; U.S. plays colonialist role • Whistler runs into customs snag getting trunk to Africa • Long evolutionary process results in Junior variety show planned for April • Engagement • One day in Duryea is almost too much, chronicler asserts • Students visit Vienna art exhibit at Philadelphia museum • Baker vs. Miller in great debate over Senator Taft • Students praised for aid to former sophomore here • Ed Dawkins, 123 pound grappler, hailed as outstanding athlete • Jayvees triumph over Drexel team • Ursinus mermaids flood Temple tank team 32-22 • Scribe chooses all-star squad • Snell\u27s Belles win to extend streak • Blue Hens defeat PMC for title • Ursinus grapplers place fifth in Middle Atlantics • Chestnut Hill wins over swimmers • League I playoff dated for tonight • Varsity places sixth; Jayvees take fourth • Hobson victorious • Alumni • Letter to the editor • Research chemist to address group • Library adds records • KDK gives card party • Sophomore dance attracts crowd • Jones reads Dickens\u27 works • Freshmen list orchestra for Celestial Fantasyhttps://digitalcommons.ursinus.edu/weekly/1537/thumbnail.jp

210Po Log-normal distribution in human urines: Survey from Central Italy people

The death in London of the former secret service agent Alexander Livtinenko on 23 November 2006 generally attracted the attention of the public to the rather unknown radionuclide 210Po. This paper presents the results of a monitoring programme of 210Po background levels in the urines of noncontaminated people living in Central Italy (near the Republic of S. Marino). The relationship between age, sex, years of smoking, number of cigarettes per day, and 210Po concentration was also studied. The results indicated that the urinary 210Po concentration follows a surprisingly perfect Log-normal distribution. Log 210Po concentrations were positively correlated to age (p < 0.0001), number of daily smoked cigarettes (p = 0.006), and years of smoking (p = 0.021), and associated to sex (p = 0.019). Consequently, this study provides upper reference limits for each sub-group identified by significantly predictive variables