More Like this

1. Improved high‐resolution global and regionalized isoscapes of δ18O , δ2H and d‐excess in precipitation

   https://doi.org/10.1002/hyp.14254  

   Terzer‐Wassmuth, Stefan ; Wassenaar, Leonard I. ; Welker, Jeffrey M. ; Araguás‐Araguás, Luis J. ( June 2021 , Hydrological Processes)

   Patterns ofδ¹⁸O andδ²H in Earth's precipitation provide essential scientific data for use in hydrological, climatological, ecological and forensic research. Insufficient global spatial data coverage promulgated the use of gridded datasets employing geostatistical techniques (isoscapes) for spatiotemporally coherent isotope predictions. Cluster‐based isoscape regionalization combines the advantages of local or regional prediction calibrations into a global framework. Here we present a revision of a Regionalized Cluster‐Based Water Isotope Prediction model (RCWIP2) incorporating new isotope data having extensive spatial coverage and a wider array of predictor variables combined with high‐resolution gridded climatic data. We introduced coupling ofδ¹⁸O andδ²H (e.g.,d‐excess constrained) in the model predictions to prevent runaway isoscapes when each isotope is modelled separately and cross‐checked observed versus modelledd‐excess values. We improved model error quantification by adopting full uncertainty propagation in all calculations. RCWIP2 improved the RMSE over previous isoscape models by ca. 0.3 ‰ forδ¹⁸O and 2.5 ‰ forδ²H with an uncertainty <1.0 ‰ forδ¹⁸O and < 8 ‰ forδ²H for most regions of the world. The determination of the relative importance of each predictor variable in each ecoclimatic zone is a new approach to identify previously unrecognized climatic drivers on mean annual precipitationδ¹⁸O andδ²H. The improved RCWIP2 isoscape grids and maps (season, monthly, annual, regional) are available for download athttps://isotopehydrologynetwork.iaea.org.

    

   more » « less
2. Evaluating electrochemical accessibility of 4f n 5d 1 and 4f n+1 Ln( ii ) ions in (C 5 H 4 SiMe 3 ) 3 Ln and (C 5 Me 4 H) 3 Ln complexes

   https://doi.org/10.1039/D1DT02427B  

   Trinh, Michael T. ; Wedal, Justin C. ; Evans, William J. ( October 2021 , Dalton Transactions)

   The reduction potentials (reported vs. Fc + /Fc) for a series of Cp′ 3 Ln complexes (Cp′ = C 5 H 4 SiMe 3 , Ln = lanthanide) were determined via electrochemistry in THF with [ n Bu 4 N][BPh 4 ] as the supporting electrolyte. The Ln( iii )/Ln( ii ) reduction potentials for Ln = Eu, Yb, Sm, and Tm (−1.07 to −2.83 V) follow the expected trend for stability of 4f 7 , 4f 14 , 4f 6 , and 4f 13 Ln( ii ) ions, respectively. The reduction potentials for Ln = Pr, Nd, Gd, Tb, Dy, Ho, Er, and Lu, that form 4f n 5d 1 Ln( ii ) ions ( n = 2–14), fall in a narrow range of −2.95 V to −3.14 V. Only cathodic events were observed for La and Ce at −3.36 V and −3.43 V, respectively. The reduction potentials of the Ln( ii ) compounds [K(2.2.2-cryptand)][Cp′ 3 Ln] (Ln = Pr, Sm, Eu) match those of the Cp′ 3 Ln complexes. The reduction potentials of nine (C 5 Me 4 H) 3 Ln complexes were also studied and found to be 0.05–0.24 V more negative than those of the Cp′ 3 Ln compounds. 

   more » « less
3. Direct and indirect selection on flowering time, water‐use efficiency ( WUE , δ 13 C), and WUE plasticity to drought in Arabidopsis thaliana

   https://doi.org/10.1002/ece3.1270  

   Kenney, Amanda M. ; McKay, John K. ; Richards, James H. ; Juenger, Thomas E. ( November 2014 , Ecology and Evolution)

   Flowering time and water‐use efficiency (WUE) are two ecological traits that are important for plant drought response. To understand the evolutionary significance of natural genetic variation in flowering time,WUE, andWUEplasticity to drought inArabidopsis thaliana, we addressed the following questions: (1) How are ecophysiological traits genetically correlated within and between different soil moisture environments? (2) Does terminal drought select for early flowering and drought escape? (3) IsWUEplasticity to drought adaptive and/or costly? We measured a suite of ecophysiological and reproductive traits on 234 spring flowering accessions ofA. thalianagrown in well‐watered and season‐ending soil drying treatments, and quantified patterns of genetic variation, correlation, and selection within each treatment.WUEand flowering time were consistently positively genetically correlated.WUEwas correlated withWUEplasticity, but the direction changed between treatments. Selection generally favored early flowering and lowWUE, with drought favoring earlier flowering significantly more than well‐watered conditions. Selection for lowerWUEwas marginally stronger under drought. There were no net fitness costs ofWUEplasticity.WUEplasticity (per se) was globally neutral, but locally favored under drought. Strong genetic correlation betweenWUEand flowering time may facilitate the evolution of drought escape, or constrain independent evolution of these traits. Terminal drought favored drought escape in these spring flowering accessions ofA. thaliana.WUEplasticity may be favored over completely fixed development in environments with periodic drought.

    

   more » « less
4. Combined Effects of Gametogenic Calcification and Dissolution on δ18O Measurements of the Planktic Foraminifer Trilobatus sacculifer

   https://doi.org/10.1029/2018GC007908  

   Wycech, Jody B. ; Kelly, Daniel Clay ; Kitajima, Kouki ; Kozdon, Reinhard ; Orland, Ian J. ; Valley, John W. ( November 2018 , Geochemistry, Geophysics, Geosystems)
5. 5′‐End sequencing in Saccharomyces cerevisiae offers new insights into 5′‐ends of tRNAH is and snoRNAs

   https://doi.org/10.1002/1873-3468.13364  

   Dodbele, Samantha ; Moreland, Blythe ; Gardner, Spencer M. ; Bundschuh, Ralf ; Jackman, Jane E. ( April 2019 , FEBS Letters)