Eggshell geochemistry reveals ancestral metabolic thermal regulation in Dinosauria

Studying the origin of avian thermoregulation is complicated by a lack of reliable methods to measure body temperatures in extinct dinosaurs. Evidence from bone histology and stable isotope analysis often relies on uncertain assumptions about the relationship between growth rate and body temperature, or the isotopic composition (δ18O) of body water. By contrast, clumped isotope (Δ47) paleothermometry, which relies on the binding of 13C to 18O, provides a robust tool for determining the body temperatures of dinosaurs, but has yet to be applied across a broad phylogenetic range while accounting for the influence of paleoenvironmental conditions. Applying this method to well-preserved fossil eggshells, we find that the three major clades of dinosaurs, Ornithischia, Sauropodomorpha, and Theropoda, were characterized by warm body temperatures. Dwarf titanosaurs may have exhibited similar body temperatures to larger sauropods, although these conclusions are provisional in light of uncertainties in the taxonomic assignment of dwarf titanosaur eggshell. Regardless, our results reveal that metabolically controlled thermoregulation was the ancestral condition for Dinosauria

Eggshell geochemistry reveals ancestral metabolic thermoregulation in Dinosauria.

Studying the origin of avian thermoregulation is complicated by a lack of reliable methods for measuring body temperatures in extinct dinosaurs. Evidence from bone histology and stableisotopes often relies on uncertain assumptions about the relationship between growth rate and body temperature, or the isotopic composition (δ18O) of body water. Clumped isotope (Δ47) paleothermometry, based on binding of 13C to 18O, provides a more robust tool, but has yet to be applied across a broad phylogenetic range of dinosaurs while accounting for paleoenvironmental conditions. Applying this method to well-preserved fossil eggshells demonstrates that the three major clades of dinosaurs, Ornithischia, Sauropodomorpha, and Theropoda, were characterized by warm body temperatures. Dwarf titanosaurs may have exhibited similar body temperatures to larger sauropods, although this conclusion isprovisional, given current uncertainties in taxonomic assignment of dwarf titanosaur eggshell. Our results nevertheless reveal that metabolically controlled thermoregulation was the ancestral condition for Dinosauria

Eggshell geochemistry reveals ancestral metabolic thermoregulation in Dinosauria

Studying the origin of avian thermoregulation is complicated by a lack of reliable methods for measuring body temperatures in extinct dinosaurs. Evidence from bone histology and stableisotopes often relies on uncertain assumptions about the relationship between growth rate and body temperature, or the isotopic composition (δ18O) of body water. Clumped isotope (Δ47) paleothermometry, based on binding of 13C to 18O, provides a more robust tool, but has yet to be applied across a broad phylogenetic range of dinosaurs while accounting for paleoenvironmental conditions. Applying this method to well-preserved fossil eggshells demonstrates that the three major clades of dinosaurs, Ornithischia, Sauropodomorpha, and Theropoda, were characterized by warm body temperatures. Dwarf titanosaurs may have exhibited similar body temperatures to larger sauropods, although this conclusion isprovisional, given current uncertainties in taxonomic assignment of dwarf titanosaur eggshell. Our results nevertheless reveal that metabolically controlled thermoregulation was the ancestral condition for Dinosauria

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Mitogen-activated protein kinase phosphatase-2 deletion modifies ventral tegmental area function and connectivity and alters reward processing

Mitogen-activated protein kinases (MAPKs) regulate normal brain functioning, and their dysfunction is implicated in a number of brain disorders. Thus, there is great interest in understanding the signalling systems that control MAPK functioning. One family of proteins that contribute to this process, the mitogen-activated protein kinase phosphatases (MKPs), directly inactivate MAPKs through dephosphorylation. Recent studies have identified novel functions of MKPs in foetal development, the immune system, cancer and synaptic plasticity and memory. In the present study, we performed an unbiased investigation using MKP-2-/- mice to assess whether MKP-2 plays a global role in modulating brain function. Local cerebral glucose utilization is significantly increased in the ventral tegmental area (VTA) of MKP-2-/- mice, with connectivity analysis revealing alterations in VTA functional connectivity, including a significant reduction in connectivity to the nucleus accumbens and hippocampus. In addition, spontaneous excitatory postsynaptic current frequency, but not amplitude, onto putative dopamine neurons in the VTA is increased in MKP-2-/- mice, which indicates that increased excitatory drive may account for the increased VTA glucose utilization. Consistent with modified VTA function and connectivity, in behavioural tests MKP-2-/- mice exhibited increased sucrose preference and impaired amphetamine-induced hyperlocomotion. Overall, these data reveal that MKP-2 plays a role in modulating VTA function and that its dysfunction may contribute to brain disorders in which altered reward processing is present

The discovery of an M4+T8.5 binary system

The original article can be found at: http://www3.interscience.wiley.com Copyright Blackwell Publishing / Royal Astronomical Society. DOI: 10.1111/j.1365-2966.2009.14620.xWe report the discovery of a T8.5 dwarf, which is a companion to the M4 dwarf Wolf 940. [Please see original online abstract for complete version with correct notation]Peer reviewe

The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr

Tuberculosis Incidence Rates during 8 Years of Follow-Up of an Antiretroviral Treatment Cohort in South Africa: Comparison with Rates in the Community

BACKGROUND: Although antiretroviral therapy (ART) is known to be associated with time-dependent reductions in tuberculosis (TB) incidence, the long-term impact of ART on incidence remains imprecisely defined due to limited duration of follow-up and incomplete CD4 cell count recovery in existing studies. We determined TB incidence in a South African ART cohort with up to 8 years of follow-up and stratified rates according to CD4 cell count recovery. We compared these rates with those of HIV-uninfected individuals living in the same community. METHODOLOGY/PRINCIPAL FINDINGS: Prospectively collected clinical data on patients receiving ART in a community-based cohort in Cape Town were analysed. 1544 patients with a median follow-up of 5.0 years (IQR 2.4-5.8) were included in the analysis. 484 episodes of incident TB (73.6% culture-confirmed) were diagnosed in 424 patients during 6506 person-years (PYs) of follow-up. The TB incidence rate during the first year of ART was 12.4 (95% CI 10.8-14.4) cases/100PYs and decreased to 4.92 (95% CI 3.64-8.62) cases/100PYs between 5 and 8 years of ART. During person-time accrued within CD4 cell strata 0-100, 101-200, 201-300, 301-400, 401-500, 501-700 and ≥700 cells/µL, TB incidence rates (95% CI) were 25.5 (21.6-30.3), 11.2 (9.4-13.5), 7.9 (6.4-9.7), 5.0 (3.9-6.6), 5.1 (3.8-6.8), 4.1 (3.1-5.4) and 2.7 (1.7-4.5) cases/100PYs, respectively. Overall, 75% (95% CI 70.9-78.8) of TB episodes were recurrent cases. Updated CD4 cell count and viral load measurements were independently associated with long-term TB risk. TB rates during person-time accrued in the highest CD4 cell count stratum (>700 cells/µL) were 4.4-fold higher that the rate in HIV uninfected individuals living in the same community (2.7 versus 0.62 cases/100PYs; 95%CI 0.58-0.65). CONCLUSIONS/SIGNIFICANCE: TB rates during long-term ART remained substantially greater than rates in the local HIV uninfected populations regardless of duration of ART or attainment of CD4 cell counts exceeding 700 cells/µL

The PhanSST global database of Phanerozoic sea surface temperature proxy data

Paleotemperature proxy data form the cornerstone of paleoclimate research and are integral to understanding the evolution of the Earth system across the Phanerozoic Eon. Here, we present PhanSST, a database containing over 150,000 data points from five proxy systems that can be used to estimate past sea surface temperature. The geochemical data have a near-global spatial distribution and temporally span most of the Phanerozoic. Each proxy value is associated with consistent and queryable metadata fields, including information about the location, age, and taxonomy of the organism from which the data derive. To promote transparency and reproducibility, we include all available published data, regardless of interpreted preservation state or vital effects. However, we also provide expert-assigned diagenetic assessments, ecological and environmental flags, and other proxy-specific fields, which facilitate informed and responsible reuse of the database. The data are quality control checked and the foraminiferal taxonomy has been updated. PhanSST will serve as a valuable resource to the paleoclimate community and has myriad applications, including evolutionary, geochemical, diagenetic, and proxy calibration studies