L'CO/LFIR Relations with CO Rotational Ladders of Galaxies Across the Herschel SPIRE Archive

We present a catalog of all CO (J=4-3 through J=13-12)), [CI], [NII] lines available from extragalactic spectra from the Herschel SPIRE Fourier Transform Spectrometer (FTS) archive combined with observations of the low-J CO lines from the literature and from the Arizona Radio Observatory. This work examines the relationships between LFIR, L'CO, and LCO/LCO(1-0). We also present a new method for estimating probability distribution functions (PDFs) from marginal signal-to-noise ratio Herschel} FTS spectra, which takes into account the instrumental "ringing" and the resulting highly correlated nature of the spectra. The slopes of log(LFIR) vs. log(L'CO) are linear for all mid- to high-J CO lines and slightly sublinear if restricted to (U)LIRGs. The mid- to high-J CO luminosity relative to CO J=1-0 increases with increasing LFIR, indicating higher excitement of the molecular gas, though these ratios do not exceed ~ 180. For a given bin in LFIR, the luminosities relative to CO J=1-0 remain relatively flat from J=6-5 through J=13-12, across three orders of magnitude of LFIR. A single component theoretical photon-dominated region (PDR) model cannot match these flat SLED shapes, though combinations of PDR models with mechanical heating added qualitatively match the shapes, indicating the need for further comprehensive modeling of the excitation processes of warm molecular gas in nearby galaxies.Comment: 17 pages, 4 figures (including appendix), accepted by ApJ. Full tables will be in VizieR upon publication, email first author for tables in the meantim

Experimental constraints on the uncoupled Galileon model from SNLS3 data and other cosmological probes

The Galileon model is a modified gravity theory that may provide an explanation for the accelerated expansion of the Universe. This model does not suffer from instabilities or ghost problems (normally associated with higher-order derivative theories), restores local General Relativity -- thanks to the Vainshtein screening effect -- and predicts late time acceleration of the expansion. In this paper, we derive a new definition of the Galileon parameters that allows us to avoid having to choose initial conditions for the Galileon field, and then test this model against precise measurements of the cosmological distances and the rate of growth of cosmic structures. We observe a small tension between the constraints set by growth data and those from distances. However, we find that the Galileon model remains consistent with current observations and is still competitive with the \Lambda CDM model, contrary to what was concluded in recent publications.Comment: 19 pages, 15 figures, accepted to Astronomy and Astrophysic

Incentives and the Effects of Publication Lags on Life Cycle Research Productivity in Economics

We investigate how increases in publication delays have affected the life-cycle of publications of recent Ph.D. graduates in economics. We construct a panel dataset of 14,271 individuals who were awarded Ph.D.s between 1986 and 2000 in US and Canadian economics departments. For this population of scholars, we amass complete records of publications in peer reviewed journals listed in the JEL (a total of 368,672 observations). We find evidence of significantly diminished productivity in recent relative to earlier cohorts when productivity of an individual is measured by the number of AER equivalent publications. Diminished productivity is less evident when number of AER equivalent pages is used instead. Our findings are consistent with earlier empirical findings of increasing editorial delays, decreasing acceptance rates at journals, and a trend toward longer manuscripts. This decline in productivity is evident in both graduates of top thirty and non-top thirty ranked economics departments and may have important implications for what should constitute a tenurable record. We also find that the research rankings of the faculty do not line up with the research quality of their students in many cases.

First experimental constraints on the disformally coupled Galileon model

The Galileon model is a modified gravity model that can explain the late-time accelerated expansion of the Universe. In a previous work, we derived experimental constraints on the Galileon model with no explicit coupling to matter and showed that this model agrees with the most recent cosmological data. In the context of braneworld constructions or massive gravity, the Galileon model exhibits a disformal coupling to matter, which we study in this paper. After comparing our constraints on the uncoupled model with recent studies, we extend the analysis framework to the disformally coupled Galileon model and derive the first experimental constraints on that coupling, using precise measurements of cosmological distances and the growth rate of cosmic structures. In the uncoupled case, with updated data, we still observe a low tension between the constraints set by growth data and those from distances. In the disformally coupled Galileon model, we obtain better agreement with data and favour a non-zero disformal coupling to matter at the $2.5\sigma$ level. This gives an interesting hint of the possible braneworld origin of Galileon theory.Comment: 9 pages, 6 figures, updated versio

Measuring a Light Neutralino Mass at the ILC: Testing the MSSM Neutralino Cold Dark Matter Model

The LEP experiments give a lower bound on the neutralino mass of about 46 GeV which, however, relies on a supersymmetric grand unification relation. Dropping this assumption, the experimental lower bound on the neutralino mass vanishes completely. Recent analyses suggest, however, that in the minimal supersymmetric standard model (MSSM), a light neutralino dark matter candidate has a lower bound on its mass of about 7 GeV. In light of this, we investigate the mass sensitivity at the ILC for very light neutralinos. We study slepton pair production, followed by the decay of the sleptons to a lepton and the lightest neutralino. We find that the mass measurement accuracy for a few-GeV neutralino is around 2 GeV, or even less if the relevant slepton is sufficiently light. We thus conclude that the ILC can help verify or falsify the MSSM neutralino cold dark matter model even for very light neutralinos.Comment: 7 pages, 1 figure; references adde

Peptide Antigen Concentration Modulates Digital NFAT1 Activation in Primary Mouse Naive CD8(+) T Cells as Measured by Flow Cytometry of Isolated Cell Nuclei

Circulating naive T cells exist in a quiescent state. After TCR contact with the cognate peptide presented by APCs in secondary lymphoid structures, T cells undergo a period of rapid transcriptional changes that set the stage for fate-determining effector or memory programming. We describe a novel method to analyze TCR signaling pathway activation in nuclei isolated from primary mouse naive T cells after stimulation with natural peptide Ags. We prelabeled cells with cell tracking dye to easily distinguish CD8(+) T cell nuclei from APC nuclei by conventional flow cytometry. Using this approach, we observed clear digital activation of NFAT1 transcription factor in OT-I T cells stimulated with OVA peptide presented by bulk splenocytes. OVA concentration had discrete control over the fraction of the cells that translocated NFAT1, indicating that a distinct threshold amount of TCR signaling is required to switch on NFAT1 in naive T cells. This behavior was cell contact dependent and qualitatively more exact than the NFAT1 response in ionomycin-stimulated naive T cells. These data contribute to our understanding of the digital behavior of TCR signaling components documented in other studies and indicate how T cells might discriminate log-fold changes in Ag availability during an actual infection. Overall, these results highlight the potential of this coculture nuclei isolation protocol to address stimulation-dependent translocation of proteins in primary lymphocytes

Global surfaces of section in the planar restricted 3-body problem

The restricted planar three-body problem has a rich history, yet many unanswered questions still remain. In the present paper we prove the existence of a global surface of section near the smaller body in a new range of energies and mass ratios for which the Hill's region still has three connected components. The approach relies on recent global methods in symplectic geometry and contrasts sharply with the perturbative methods used until now.Comment: 11 pages, 1 figur

Constraining Type Ia Supernovae progenitors from three years of SNLS data

While it is generally accepted that Type Ia supernovae are the result of the explosion of a carbon-oxygen White Dwarf accreting mass in a binary system, the details of their genesis still elude us, and the nature of the binary companion is uncertain. Kasen (2010) points out that the presence of a non-degenerate companion in the progenitor system could leave an observable trace: a flux excess in the early rise portion of the lightcurve caused by the ejecta impact with the companion itself. This excess would be observable only under favorable viewing angles, and its intensity depends on the nature of the companion. We searched for the signature of a non-degenerate companion in three years of Supernova Legacy Survey data by generating synthetic lightcurves accounting for the effects of shocking and comparing true and synthetic time series with Kolmogorov-Smirnov tests. Our most constraining result comes from noting that the shocking effect is more prominent in rest-frame B than V band: we rule out a contribution from white dwarf-red giant binary systems to Type Ia supernova explosions greater than 10% at 2 sigma, and than 20% at 3 sigma level.Comment: 14 pages, 15 figures, resubmitted to ApJ, figure 15 modifie

GENOMICS OF ENDOGLIN PATHWAY IN PREECLAMPSIA

THE GENOMICS OF ENDOGLIN PATHWAY IN PREECLAMPSIA Mandy J. Bell, PhD, RN University of Pittsburgh, 2012 Preeclampsia is a pregnancy disorder that greatly impacts maternal and fetal/neonatal health and wellbeing. This case-control candidate gene association study investigated endoglin pathway genetic variation and its association with preeclampsia. Tagging single nucleotide polymorphisms (tSNPs) in ENG, TGFβ1, TGFβR1, ALK1, and TGFβR2 were genotyped with iPLEX® and TaqMan® in maternal/fetal dyads. The Prenatal Exposures and Preeclampsia Prevention study provided maternal DNA extracted from peripherally collected white blood cell pellets, along with umbilical cord serum we used for fetal DNA extraction. Data on 355 white (181 cases/174 controls) and 60 black (30 cases/30 controls) women matched on ancestry, age, and parity were analyzed. Separate subgroup allele/genotype/haplotype tests were conducted with Chi-square or Fisher’s exact tests. Binary logistic regression provided odds ratios for tSNPs with significant genotype tests. Analysis of maternal/fetal dyads was not conducted, because unlike the maternal samples, the fetal samples did not provide a quality template suitable for iPLEX® data collection. In white women, variation in ENG (rs11792480, rs10121110) and TGFβR2 (rs6550005) was associated with preeclampsia. Allelic frequency distributions in rs11792480, rs10121110, and rs6550005 were significantly different among cases and controls while genotype distributions of rs10121110 and rs6550005 were further associated with preeclampsia (p-values < .05). For rs10121110, women with the AA genotype were 2.290 times more likely to develop preeclampsia compared to the GG genotype (99% CI [1.022, 5.133], p = .008). ENG haplotype TACGA, which contains rs11792480 and rs10121110 risk alleles, was also over-represented in cases (p = .022). In black women, variation in TGFβ1 (rs4803455, rs4803457), TGFβR1 (rs10739778), and TGFβR2 (rs6550005, rs1346907, rs877572) was associated with preeclampsia. Allelic frequency distributions in rs10739778, rs6550005, rs1346907, and rs877572 were significantly different among cases and controls while genotype distributions of rs10739778, rs4803455, and rs4803457 were further associated with preeclampsia (p-values < .05). For rs4803457, women with the CT genotype were 7.437 more times likely to develop preeclampsia compared to the CC genotype (99% CI [1.192, 46.408], p = .005). These results demonstrate that variation in ENG pathway genes is associated with preeclampsia, with different genes from the same pathway contributing to preeclampsia in white compared to black women