501 research outputs found
“Johnny Came to College to get an Education – He Found Romance Anyway”: The Unconventional Wartime Story of John and Marie Teigue Renza
“Johnny Came to College to get an Education – He Found Romance Anyway”: The Unconventional Wartime Story of John and Marie Renza
Among the long list of economic, social, and political changes that American society experienced during the World War II era was a trend toward whirlwind romances, courtships, and marriages. The pressures of war, namely the conscription of most able-bodied American men, placed many young couples in precarious positions as they faced a long-term separation, names a “courtship by mail,” or a hasty marriage. Marie Teigue and John Renza, both wartime graduates of Bryant College, bucked the trends of their age. The Renzas were a couple that fell in love, grew apart, grew up, and found each other again on their own terms, against the backdrop of World War II, and not because of it
Consistent within-individual plasticity is sufficient to explain temperature responses in red deer reproductive traits
Warming global temperatures are affecting a range of aspects of wild populations, but the exact mechanisms driving associations between temperature and phenotypic traits may be difficult to identify. Here, we use a 36-year data-set on a wild population of red deer to investigate the causes of associations between temperature and two important components of female reproduction: timing of breeding and offspring size. By separating within- versus between-individual associations with temperature for each trait, we show that within-individual phenotypic plasticity (changes within a female’s lifetime) was entirely sufficient to generate the observed population-level association with temperature at key times of year. However, despite apparently adequate statistical power, we found no evidence of any variation between females in their responses (i.e. no ‘IxE’ interactions). Our results suggest that female deer show plasticity in reproductive traits in response to temperatures in the year leading up to calving, and that this response is consistent across individuals, implying no potential for either selection or heritability of plasticity. We estimate that the plastic response to rising temperatures explained 24% of the observed advance in mean calving date over the study period. We highlight the need for comparable analyses of other systems to determine the contribution of within-individual plasticity to population-level responses to climate change
Direct Imaging in Reflected Light: Characterization of Older, Temperate Exoplanets With 30-m Telescopes
Direct detection, also known as direct imaging, is a method for discovering
and characterizing the atmospheres of planets at intermediate and wide
separations. It is the only means of obtaining spectra of non-transiting
exoplanets. Characterizing the atmospheres of planets in the <5 AU regime,
where RV surveys have revealed an abundance of other worlds, requires a
30-m-class aperture in combination with an advanced adaptive optics system,
coronagraph, and suite of spectrometers and imagers - this concept underlies
planned instruments for both TMT (the Planetary Systems Imager, or PSI) and the
GMT (GMagAO-X). These instruments could provide astrometry, photometry, and
spectroscopy of an unprecedented sample of rocky planets, ice giants, and gas
giants. For the first time habitable zone exoplanets will become accessible to
direct imaging, and these instruments have the potential to detect and
characterize the innermost regions of nearby M-dwarf planetary systems in
reflected light. High-resolution spectroscopy will not only illuminate the
physics and chemistry of exo-atmospheres, but may also probe rocky, temperate
worlds for signs of life in the form of atmospheric biomarkers (combinations of
water, oxygen and other molecular species). By completing the census of
non-transiting worlds at a range of separations from their host stars, these
instruments will provide the final pieces to the puzzle of planetary
demographics. This whitepaper explores the science goals of direct imaging on
30-m telescopes and the technology development needed to achieve them.Comment: (March 2018) Submitted to the Exoplanet Science Strategy committee of
the NA
Constraints on the architecture of the HD 95086 planetary system with the Gemini Planet Imager
We present astrometric monitoring of the young exoplanet HD 95086 b obtained
with the Gemini Planet Imager between 2013 and 2016. A small but significant
position angle change is detected at constant separation; the orbital motion is
confirmed with literature measurements. Efficient Monte Carlo techniques place
preliminary constraints on the orbital parameters of HD 95086 b. With 68%
confidence, a semimajor axis of 61.7^{+20.7}_{-8.4} au and an inclination of
153.0^{+9.7}_{-13.5} deg are favored, with eccentricity less than 0.21. Under
the assumption of a co-planar planet-disk system, the periastron of HD 95086 b
is beyond 51 au with 68% confidence. Therefore HD 95086 b cannot carve the
entire gap inferred from the measured infrared excess in the SED of HD 95086.
We use our sensitivity to additional planets to discuss specific scenarios
presented in the literature to explain the geometry of the debris belts. We
suggest that either two planets on moderately eccentric orbits or three to four
planets with inhomogeneous masses and orbital properties are possible. The
sensitivity to additional planetary companions within the observations
presented in this study can be used to help further constrain future dynamical
simulations of the planet-disk system.Comment: Accepted for publication in ApJ
Improving and Assessing Planet Sensitivity of the GPI Exoplanet Survey with a Forward Model Matched Filter
We present a new matched filter algorithm for direct detection of point
sources in the immediate vicinity of bright stars. The stellar Point Spread
Function (PSF) is first subtracted using a Karhunen-Lo\'eve Image Processing
(KLIP) algorithm with Angular and Spectral Differential Imaging (ADI and SDI).
The KLIP-induced distortion of the astrophysical signal is included in the
matched filter template by computing a forward model of the PSF at every
position in the image. To optimize the performance of the algorithm, we conduct
extensive planet injection and recovery tests and tune the exoplanet spectra
template and KLIP reduction aggressiveness to maximize the Signal-to-Noise
Ratio (SNR) of the recovered planets. We show that only two spectral templates
are necessary to recover any young Jovian exoplanets with minimal SNR loss. We
also developed a complete pipeline for the automated detection of point source
candidates, the calculation of Receiver Operating Characteristics (ROC), false
positives based contrast curves, and completeness contours. We process in a
uniform manner more than 330 datasets from the Gemini Planet Imager Exoplanet
Survey (GPIES) and assess GPI typical sensitivity as a function of the star and
the hypothetical companion spectral type. This work allows for the first time a
comparison of different detection algorithms at a survey scale accounting for
both planet completeness and false positive rate. We show that the new forward
model matched filter allows the detection of fainter objects than a
conventional cross-correlation technique with a Gaussian PSF template for the
same false positive rate.Comment: ApJ accepte
Coexpression of Normally Incompatible Developmental Pathways in Retinoblastoma Genesis
It is widely believed that the molecular and cellular features of a tumor reflect its cell of origin and can thus provide clues about treatment targets. The retinoblastoma cell of origin has been debated for over a century. Here, we report that human and mouse retinoblastomas have molecular, cellular, and neurochemical features of multiple cell classes, principally amacrine/horizontal interneurons, retinal progenitor cells, and photoreceptors. Importantly, single-cell gene expression array analysis showed that these multiple cell type-specific developmental programs are coexpressed in individual retinoblastoma cells, which creates a progenitor/neuronal hybrid cell. Furthermore, neurotransmitter receptors, transporters, and biosynthetic enzymes are expressed in human retinoblastoma, and targeted disruption of these pathways reduces retinoblastoma growth in vivo and in vitro
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