Synergistic Performance of Lithium Difluoro(oxalato)borate and Fluoroethylene Carbonate in Carbonate Electrolytes for Lithium Metal Anodes

There is significant interest in the development of rechargeable high-energy density batteries which utilize lithium metal anodes. Recently, fluoroethylene carbonate (FEC) and lithium difluoro(oxalato)borate (LiDFOB) have been reported to significantly improve the electrochemical performance of lithium metal anodes. This investigation focuses on exploring the synergy between LiDFOB and FEC in carbonate electrolytes for lithium metal anodes. In ethylene carbonate (EC) electrolytes, LiDFOB is optimal when used in high salt concentrations, such as 1.0 M, to improve the electrochemistry of the lithium metal anode in Cu||LiFePO4 cells. However, in FEC electrolytes, LiDFOB is optimal when used in lower concentrations, such as 0.05–0.10 M. From surface analysis, LiDFOB is observed to favorably react on the surface of lithium metal to improve the performance of the lithium metal anode, in both EC and FEC-based electrolytes. This research demonstrates progress toward developing feasible high-energy density lithium-based batteries

Investigation of the Lithium Solid Electrolyte Interphase in Vinylene Carbonate Electrolytes Using Cu||LiFePO\u3csub\u3e4\u3c/sub\u3e Cells

The influence of vinylene carbonate (VC) on the plating/stripping of lithium was investigated using Cu||LiFePO4 cells. These cells allow for easy fabrication and in-situ generation of lithium, with no excess lithium to influence performance. Addition of VC to the electrolyte improves both capacity retention and efficiency. IR and XPS spectroscopy of the surface of the plated lithium suggests the presence of a significant amount of poly(VC) when the electrolyte (1.2 M LiPF6 in ethylene carbonate (EC): ethyl methyl carbonate (EMC) (3:7, vol)) contains 5% of added VC. This suggests employing additives that generate polymeric species on the surface of lithium improves plating/stripping performance in carbonate electrolytes

Using Triethyl Phosphate to Increase the Solubility of LiNO\u3csub\u3e3\u3c/sub\u3e in Carbonate Electrolytes for Improving the Performance of the Lithium Metal Anode

The investigation of novel electrolytes for lithium metal anodes has been conducted. Incorporation of LiNO3 into lithium difluoro(oxalato) borate (LiDFOB) in ethylene carbonate (EC) and dimethyl carbonate (DMC) electrolytes results in a significant improvement in capacity retention and Coulombic efficiency. While the solubility of LiNO3 is very low in common carbonate solvents (~0.03 M), the use of triethyl phosphate (TEP) significantly increases the solubility of LiNO3 and improves the capacity retention and Coluombic efficiency of lithium metal anodes. Ex-situ surface analysis of the cycled electrodes suggests that incorporation of LiNO3 results in nitrogen containing species (NO3−, NO2−, and N3−) in the solid electrolyte interphase (SEI) which is likely responsible for the performance enhancement

Is DEET safe for children?

Reported evidence suggests that DEET use is safe for children older than 2 months, with only very rare incidence of major adverse effects (strength of recommendation [SOR]: C). Typically, a topical concentration between 10% and 30% should be used (SOR: C). Increasing DEET concentration does not improve protection, but does increase the duration of action (SOR: A)

Cortisol relates to executive functioning for children attending Head Start preschool

Background: Approximately 15 million children in the United States grow up in poverty circumstances (National Center for Children in Poverty, 2018), as 24% of all children under the age of 6 live in households with income levels classified as below the federal poverty guideline (Jiang et al., 2016). Recent research has highlighted the impact of early childhood poverty circumstances on physiological systems that respond to stress (Lupien et al., 2001), with implications for typical development in the prefrontal cortex (Hair et al., 2015) and related executive functioning (Blair & Raver, 2016). Method: The present study investigated relations among various components of teacher-reported executive functioning (BRIEF; Gioia et al., 2000) and total cortisol output of 318 young children (ages 3-5 years) across a preschool day. Salivary cortisol was sampled in duplicate at 4 times across 2 days in the beginning of the school year, resulting in a total of 16 samples per child. Results and Implications: We hypothesized that higher cortisol levels, likely attributable to poverty-stress (Blair et al., 2011) across the preschool day would relate to greater difficulties in teacher-reported EF, controlling for child age, sex, and family income. A multiple regression model that aligned with this hypothesis predicted BRIEF, General Composite Score with statistical significance. Moreover, child salivary cortisol across the preschool day predicted teacher-reported executive functioning for each domain score of the BRIEF. Implications concern understanding the impact of stress on executive functioning in the preschool classroom and promoting positive outcomes for children facing poverty risk

Distribution and Diet of Ivory Gulls (Pagophila eburnea) in the North Water

Ivory gulls (Pagophila eburnea, Phipps, 1774), one of the world’s least-known species, have declined throughout their range in recent years. This study describes the patterns of ivory gull use of the North Water polynya, a large polynya that occurs every year near ivory gull breeding sites on Ellesmere Island, Nunavut, Canada. We conducted at-sea surveys from Canadian icebreakers during the summers of 1997–99. In 1998, stomach contents of five ivory gulls were analyzed. We measured stable isotope ratios (d13C, d15N) of liver, muscle, feather and bone to determine how ivory gull diets vary during the year. We observed a total of 275 individuals, most of which were seen on the western side of the polynya. Flying was the predominant behavior (76% of individuals); other behaviors included sitting on ice, sitting on water, and feeding. Four juveniles were seen in August and September. Birds collected had arctic cod (Boreogadus saida) in their stomachs. Other food items included an otolith from an unidentified species of Liparid fish and two bones from a mole, presumed to be a star-nosed mole (Condylura cristata). Stable isotope results indicated that ivory gull trophic levels (TLs) were high (around TL 4 based on d15N) but varied over the season. From the three individuals whose feathers were analyzed, we conclude that differences among individuals in their winter diets or foraging locations are possible.Les mouettes blanches (Pagophila eburnea), soit l’une des espèces les moins connues dans le monde, ont enregistré un déclin à travers l’ensemble de leurs habitats ces dernières années. Cette étude décrit les habitudes des mouettes blanches dans la polynie des eaux du Nord, une grande polynie qui se développe chaque année près des sites de reproduction de mouettes blanches sur l’île Ellesmere, au Nunavut, Canada. Nous avons effectué des relevés depuis des brise-glace canadiens au cours des étés 1997 à 1999. En 1998, le contenu des estomacs de cinq mouettes blanches a été analysé. Nous avons également mesuré les ratios d’isotopes stables (d13C, d15N) dans les foies, les muscles, les plumages et les os afin de déterminer comment le régime alimentaire des mouettes blanches variait au cours de l’année. Nous avons observé 275 individus, provenant principalement du côté ouest de la Polynie. La majorité (76 %) étaient en vol. Parmi les autres comportements observés, notons la présence d’oiseaux sur la glace, d’oiseaux sur l’eau et d’oiseaux en train de se nourrir. Quatre oiseaux juvéniles ont été repérés en août et en septembre. Les oiseaux capturés avaient de la morue polaire (Boreogadus saida) dans l’estomac. Les autres aliments trouvés comprenaient un otolithe provenant d’une espèce non identifiée de poisson Liparidé, et deux os de taupe, probablement un condylure étoilé (Condylura cristata). L’analyse des isotopes stables indique que les niveaux trophiques (NT) des mouettes blanches étaient élevés (NT 4 environ en fonction de d15N), mais variaient au cours de la saison. À partir des trois individus dont les plumes ont été analysées, nous en avons conclu qu’il est possible qu’il existe des différences entre les régimes d’hiver ou les lieux de nourriture des individus

The Interaction between AID and CIB1 Is Nonessential for Antibody Gene Diversification by Gene Conversion or Class Switch Recombination

Activation-induced deaminase (AID) initiates somatic hypermutation, gene conversion and class switch recombination by deaminating variable and switch region DNA cytidines to uridines. AID is predominantly cytoplasmic and must enter the nuclear compartment to initiate these distinct antibody gene diversification reactions. Nuclear AID is relatively short-lived, as it is efficiently exported by a CRM1-dependent mechanism and it is susceptible to proteasome-dependent degradation. To help shed light on mechanisms of post-translational regulation, a yeast-based screen was performed to identify AID-interacting proteins. The calcium and integrin binding protein CIB1 was identified by sequencing and the interaction was confirmed by immunoprecipitation experiments. The AID/CIB1 resisted DNase and RNase treatment, and it is therefore unlikely to be mediated by nucleic acid. The requirement for CIB1 in AID-mediated antibody gene diversification reactions was assessed in CIB1-deficient DT40 cells and in knockout mice, but immunoglobulin gene conversion and class switch recombination appeared normal. The DT40 system was also used to show that CIB1 over-expression has no effect on gene conversion and that AID-EGFP subcellular localization is normal. These combined data demonstrate that CIB1 is not required for AID to mediate antibody gene diversification processes. It remains possible that CIB1 has an alternative, a redundant or a subtle non-limiting regulatory role in AID biology

The influence of winter water on phytoplankton blooms in the Chukchi Sea

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 118 (2015): 53-72, doi:10.1016/j.dsr2.2015.06.006.The flow of nutrient-rich winter water (WW) through the Chukchi Sea plays an important and previously uncharacterized role in sustaining summer phytoplankton blooms. Using hydrographic and biogeochemical data collected as part of the ICESCAPE program (June-July 2010-11), we examined phytoplankton bloom dynamics in relation to the distribution and circulation of WW (defined as water with potential temperature ≤ -1.6°C) across the Chukchi shelf. Characterized by high concentrations of nitrate (mean: 12.3 ± 5.13 μmol L-1) that typically limits primary production in this region, WW was correlated with extremely high phytoplankton biomass, with mean chlorophyll a concentrations that were three-fold higher in WW (8.64 ± 9.75 μg L-1) than in adjacent warmer water (2.79 ± 5.58 μg L-1). Maximum chlorophyll a concentrations (~30 μg L-1) were typically positioned at the interface between nutrient-rich WW and shallower, warmer water with more light availability. Comparing satellite-based calculations of open water duration to phytoplankton biomass, nutrient concentrations, and oxygen saturation revealed widespread evidence of under-ice blooms prior to our sampling, with biogeochemical properties indicating that blooms had already terminated in many places where WW was no longer present. Our results suggest that summer phytoplankton blooms are sustained for a longer duration along the pathways of nutrient-rich WW and that biological hotspots in this region (e.g. the mouth of Barrow Canyon) are largely driven by the flow and confluence of these extremely productive pathways of WW that flow across the Chukchi shelf.This material is based upon work supported by the National Aeronautic and Space Administration (NASA) under Grant No. NNX10AF42G and the National Science Foundation Graduate Research Fellowship under Grant No. DGE-0645962 to K.E. Lowry

Thermal stress induces glycolytic beige fat formation via a myogenic state.

Environmental cues profoundly affect cellular plasticity in multicellular organisms. For instance, exercise promotes a glycolytic-to-oxidative fibre-type switch in skeletal muscle, and cold acclimation induces beige adipocyte biogenesis in adipose tissue. However, the molecular mechanisms by which physiological or pathological cues evoke developmental plasticity remain incompletely understood. Here we report a type of beige adipocyte that has a critical role in chronic cold adaptation in the absence of β-adrenergic receptor signalling. This beige fat is distinct from conventional beige fat with respect to developmental origin and regulation, and displays enhanced glucose oxidation. We therefore refer to it as glycolytic beige fat. Mechanistically, we identify GA-binding protein α as a regulator of glycolytic beige adipocyte differentiation through a myogenic intermediate. Our study reveals a non-canonical adaptive mechanism by which thermal stress induces progenitor cell plasticity and recruits a distinct form of thermogenic cell that is required for energy homeostasis and survival

BET bromodomain proteins regulate enhancer function during adipogenesis

Developmental transitions are guided by master regulatory transcription factors. During adipogenesis, a transcriptional cascade culminates in the expression of PPARγ and C/EBPα, which orchestrate activation of the adipocyte gene expression program. However, the coactivators controlling PPARγ and C/EBPα expression are less well characterized. Here, we show the bromodomain-containing protein, BRD4, regulates transcription of PPARγ and C/EBPα. Analysis of BRD4 chromatin occupancy reveals that induction of adipogenesis in 3T3L1 fibroblasts provokes dynamic redistribution of BRD4 to de novo super-enhancers proximal to genes controlling adipocyte differentiation. Inhibition of the bromodomain and extraterminal domain (BET) family of bromodomain-containing proteins impedes BRD4 occupancy at these de novo enhancers and disrupts transcription of Pparg and Cebpa, thereby blocking adipogenesis. Furthermore, silencing of these BRD4-occupied distal regulatory elements at the Pparg locus by CRISPRi demonstrates a critical role for these enhancers in the control of Pparg gene expression and adipogenesis in 3T3L1s. Together, these data establish BET bromodomain proteins as time- and context-dependent coactivators of the adipocyte cell state transition