The Star Formation Rate-Density Relation at 0.6<z<0.9 and the Role of Star Forming Galaxies

We study the star formation rates (SFRs) of galaxies as a function of local galaxy density at 0.6<z<0.9. We used a low-dispersion prism in IMACS on the 6.5-m Baade (Magellan I) telescope to obtain spectra and measured redshifts to a precision of sigma_z/(1+z)=1% for galaxies with z<23.3 AB mag. We utilized a stellar mass-limited sample of 977 galaxies above M>1.8x10^{10} Msun to conduct our main analysis. With three different SFR indicators, (1) Spitzer MIPS 24-micron imaging, (2) SED fitting, and (3) [OII]3727 emission, we find the median specific SFR (SSFR) and SFR to decline from the low-density field to the cores of groups and a rich cluster. For the SED and [OII] based SFRs, the decline in SSFR is roughly an order of magnitude while for the MIPS based SFRs, the decline is a factor of ~4. We find approximately the same magnitude of decline in SSFR even after removing the sample of galaxies near the cluster. Galaxies in groups and a cluster at these redshifts therefore have lower star formation (SF) activity than galaxies in the field, as is the case at z~0. We investigated whether the decline in SFR with increasing density is caused by a change in the proportion of quiescent and star forming galaxies (SFGs) or by a decline in the SFRs of SFGs. Using the rest-frame U-V and V-J colors to distinguish quiescent galaxies from SFGs we find the fraction of quiescent galaxies increases from ~32% to 79% from low to high density. In addition, we find the SSFRs of SFGs, selected based on U-V and V-J colors, to decline with increasing density by factors of ~5-6 for the SED and [OII] based SFRs. The MIPS based SSFRs for SFGs decline with a shallower slope. The order of magnitude decline in the SSFR-density relation at 0.6<z<0.9 is therefore driven by both a combination of declining SFRs of SFGs as well as a changing mix of SFGs and quiescent galaxies [ABRIDGED].Comment: 21 pages, 15 figures, 2 tables, resubmitted to ApJ after addressing referee comment

The Seventh Data Release of the Sloan Digital Sky Survey

This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor correction

The 3D-HST Survey: <i>Hubble Space Telescope</i> WFC3/G141 Grism Spectra, Redshifts, and Emission Line Measurements for ~ 100,000 Galaxies

We present reduced data and data products from the 3D-HST survey, a 248-orbit $HST$ Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3 $H_{140}$ imaging, parallel ACS G800L spectroscopy, and parallel $I_{814}$ imaging. In a previous paper, we presented photometric catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we describe and present the WFC3 G141 spectroscopic data, again augmented with data from GO-1600 in GOODS-N (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (1D) spectra for all objects in the Skelton et al. (2014) photometric catalogs. The 2D spectra and the multi-band photometry were fit simultaneously to determine redshifts and emission line strengths, taking the morphology of the galaxies explicitly into account. The resulting catalog has redshifts and line strengths (where available) for 22,548 unique objects down to ${{JH}}_{\mathrm{IR}}\leq 24$ (79,609 unique objects down to ${{JH}}_{\mathrm{IR}}\leq 26$). Of these, 5459 galaxies are at $z > 1.5$ and 9621 are at $0.7< z< 1.5$, where Hα falls in the G141 wavelength coverage. The typical redshift error for ${{JH}}_{\mathrm{IR}}\leq 24$ galaxies is ${\sigma }_{z}\approx 0.003\times (1+z)$, i.e., one native WFC3 pixel. The $3\sigma$ limit for emission line fluxes of point sources is $2.1\times {10}^{-17}$ erg $s^{-1} cm^{-2}$. All 2D and 1D spectra, as well as redshifts, line fluxes, and other derived parameters, are publicly available

Novel genetic loci associated with hippocampal volume

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness

Novel genetic loci underlying human intracranial volume identified through genome-wide association

Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438 adults, we discovered five novel loci for intracranial volume and confirmed two known signals. Four of the loci are also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height. We found a high genetic correlation with child head circumference (ρgenetic=0.748), which indicated a similar genetic background and allowed for the identification of four additional loci through meta-analysis (Ncombined = 37,345). Variants for intracranial volume were also related to childhood and adult cognitive function, Parkinson’s disease, and enriched near genes involved in growth pathways including PI3K–AKT signaling. These findings identify biological underpinnings of intracranial volume and provide genetic support for theories on brain reserve and brain overgrowth

Subscribed Content Human Rights and Trade: Beyond the "Spotlight"

Human rights concerns figure prominently on the global economic agenda. Yet little empirical analysis has addressed the prospective impact of human rights for global economic interactions. To gain insight into this linkage, we assess the empirical relationship between human rights and an important facet of the global economy, dyadic trade flows. Traditional arguments posit that respect for human rights and trade are uncomfortable bedfellows at best, and that repression may provide a foundation for increased trade activity. We posit that, alternatively, respect for human rights and trade may be a pragmatic coupling. In addition to the normative value of promoting and protecting human rights, there may be a "business case" as there are ways in which respect for human rights may encourage trade. Using a cross-sectional time-series research design, we test the relationship between human rights and trade for the years 1989-2000. Our results show that human rights conditions have a significant influence on dyadic trade

Labor Rights and Foreign Direct Investment: Is There a Race to the Bottom?

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The Gendered Consequences of Financial Crises: A Cross-National Analysis

What effects do financial crises have on women\u27s well-being? While much research has addressed various socio-economic and political consequences of financial crises, the gendered impact of financial crises are empirically underexplored. Moreover, extant literature has mainly focused on specific crises or countries with little attempt at determining possible common effects and patterns across the world. To provide broader insight into the gendered consequences of financial crises, we examined the degree to which five types of financial crises-banking crises, currency crises, domestic sovereign debt crises, external sovereign debt crises, and inflation crises-affect women\u27s health and educational outcomes as well as their participation in the formal economy and politics. We also examined the persistence of these effects in the postcrisis years. The results from a panel of 68 countries for the years 1980 to 2010 indicate that financial crises undermine women\u27s participation in the formal workforce, their presence in politics, their educational attainment, and their health outcomes. We also found significant lingering effects of financial crises: the deleterious gendered effects of crises persist even seven years after the end of a crisis

Resource Wealth: A “Curse” for Labor Rights?

Though a great deal of research has examined the economic and political consequences of natural resource wealth, its implications for labor remain empirically under-examined. In this article, we contend that resource abundance undermines labor rights due to the inelastic demand for resource-intensive products, which serves to insulate these states from internal and external pressures to protect these rights. In addition to this direct linkage, we posit that resource wealth indirectly undercuts labor rights through its adverse impact on civil society and bureaucratic capacity. Examining these linkages across 148 countries for the years 1994–2010, we find that resource wealth has a negative and significant impact on labor rights practices, though not on labor rights laws. Results from a causal mediation analysis show that resource wealth also undermines labor rights through its negative impact on labor organizations and bureaucratic capacit