657 research outputs found
The Use of Psychological State Terms By Late Talkers at Age 3
The use of psychological state words during mother-child play sessions at age 3 was examined in 31 children diagnosed with delayed expressive language at 24-31 months and 21 age-matched typically developing comparison children. Children and mothers in the late talker group made more references to physiological states and fewer references to cognitive states than the children and mothers in the typically developing comparison group. The children\u27s use of cognitive terms correlated significantly with measures of language ability, including mean length of utterance, Index of Productive Syntax score, and use of propositional complements, as well as with their mothers\u27 use of cognitive terms. The delay in the emergence of psychological state words, particularly cognitive terms such as think and know, may affect other aspects of late talkers\u27 cognitive and social development
The Use of Psychological State Words By Late Talkers at Ages 3, 4 and 5 Years
The use of four types of psychological state words (physiological, emotional, desire, and cognitive) during mother-child play sessions at ages 3, 4, and 5 years was examined in 30 children diagnosed with delayed expressive language at 24-31 months and 15 age-matched comparison children with typical development. The children\u27s mean length of utterance, total words uttered, lexical diversity, and use of propositional complements were assessed. The late talkers used significantly more physiological state words at ages 3 and 4, but the two groups did not differ in their use of physiological state terms at age 5. The late talkers used significantly fewer cognitive words than the comparison children at each age. The mothers of the late talkers made significantly fewer references to cognitive states than the mothers of the comparison children at each age. The delay in the emergence of cognitive state words in the preschool years may affect other aspects of late talkers\u27 cognitive and social development
Non-detection of Helium in the Upper Atmospheres of Three Sub-Neptune Exoplanets
We present a search for helium in the upper atmospheres of three sub-Neptune
size planets to investigate the origins of these ubiquitous objects. The
detection of helium for a low density planet would be strong evidence for the
presence of a primary atmosphere accreted from the protoplanetary nebula
because large amounts of helium are not expected in the secondary atmospheres
of rocky planets. We used Keck+NIRSPEC to obtain high-resolution transit
spectroscopy of the planets GJ1214b, GJ9827d, and HD97658b around the 10,833
Ang He triplet feature. We did not detect helium absorption for any of the
planets despite achieving a high level of sensitivity. We used the
non-detections to set limits on the planets' thermosphere temperatures and
atmospheric loss rates by comparing grids of 1D models to the data. We also
performed coupled interior structure and atmospheric loss calculations, which
suggest that the bulk atmospheres (winds) of the planets would be at most
modestly enhanced (depleted) in helium relative to their primordial
composition. Our lack of detections of the helium triplet for GJ1214b and
GJ9827d are highly inconsistent with the predictions of models for the present
day mass loss on these planets. Higher signal-to-noise data would be needed to
detect the helium feature predicted for HD97658b. We identify uncertainties in
the EUV fluxes of the host stars and the lack of detailed mass loss models
specifically for cool and metal-enhanced atmospheres as the main limitations to
the interpretation of our results. Ultimately, our results suggest that the
upper atmospheres of sub-Neptune planets are fundamentally different than those
of gas giant planets.Comment: AJ in pres
The alternatively-included 11a sequence modifies the effects of Mena on actin cytoskeletal organization and cell behavior
During tumor progression, alternative splicing gives rise to different Mena protein isoforms. We analyzed how Mena11a, an isoform enriched in epithelia and epithelial-like cells, affects Mena-dependent regulation of actin dynamics and cell behavior. While other Mena isoforms promote actin polymerization and drive membrane protrusion, we find that Mena11a decreases actin polymerization and growth factor-stimulated membrane protrusion at lamellipodia. Ectopic Mena11a expression slows mesenchymal-like cell motility, while isoform-specific depletion of endogenous Mena11a in epithelial-like tumor cells perturbs cell:cell junctions and increases membrane protrusion and overall cell motility. Mena11a can dampen membrane protrusion and reduce actin polymerization in the absence of other Mena isoforms, indicating that it is not simply an inactive Mena isoform. We identify a phosphorylation site within 11a that is required for some Mena11a-specific functions. RNA-seq data analysis from patient cohorts demonstrates that the difference between mRNAs encoding constitutive Mena sequences and those containing the 11a exon correlates with metastasis in colorectal cancer, suggesting that 11a exon exclusion contributes to invasive phenotypes and leads to poor clinical outcomes.Virginia and D.K. Ludwig Fund for Cancer Research (Graduate Student Fellowship)National Institutes of Health (U.S.) (GM58801)Massachusetts Institute of Technology. Ludwig Center for Molecular OncologyDavid H. Koch Institute for Integrative Cancer Research at MIT (NCI Core Grant P30-CA14051
The K2-3 system revisited: testing photoevaporation and core-powered mass loss with three small planets spanning the radius valley
Multi-planet systems orbiting M dwarfs provide valuable tests of theories of
small planet formation and evolution. K2-3 is an early M dwarf hosting three
small exoplanets (1.5-2.0 Earth radii) at distances of 0.07-0.20 AU. We measure
the high-energy spectrum of K2-3 with HST/COS and XMM-Newton, and use
empirically-driven estimates of Ly-alpha and extreme ultraviolet flux. We use
EXOFASTv2 to jointly fit radial velocity, transit, and SED data. This
constrains the K2-3 planet radii to 4% uncertainty and the masses of K2-3b and
c to 13% and 30%, respectively; K2-3d is not detected in RV measurements. K2-3b
and c are consistent with rocky cores surrounded by solar composition envelopes
(mass fractions of 0.36% and 0.07%), H2O envelopes (55% and 16%), or a mixture
of both. However, based on the high-energy output and estimated age of K2-3, it
is unlikely that K2-3b and c retain solar composition atmospheres. We pass the
planet parameters and high-energy stellar spectrum to atmospheric models.
Dialing the high-energy spectrum up and down by a factor of 10 produces
significant changes in trace molecule abundances, but not at a level detectable
with transmission spectroscopy. Though the K2-3 planets span the small planet
radius valley, the observed system architecture cannot be readily explained by
photoevaporation or core-powered mass loss. We instead propose 1) the K2-3
planets are all volatile-rich, with K2-3d having a lower density than typical
of super-Earths, and/or 2) the K2-3 planet architecture results from more
stochastic processes such as planet formation, planet migration, and impact
erosion.Comment: 15 pages, 7 figure, published in AJ, HLSPs at
https://archive.stsci.edu/hlsp/mstarpanspe
The Need for Laboratory Measurements and Ab Initio Studies to Aid Understanding of Exoplanetary Atmospheres
We are now on a clear trajectory for improvements in exoplanet observations
that will revolutionize our ability to characterize their atmospheric
structure, composition, and circulation, from gas giants to rocky planets.
However, exoplanet atmospheric models capable of interpreting the upcoming
observations are often limited by insufficiencies in the laboratory and
theoretical data that serve as critical inputs to atmospheric physical and
chemical tools. Here we provide an up-to-date and condensed description of
areas where laboratory and/or ab initio investigations could fill critical gaps
in our ability to model exoplanet atmospheric opacities, clouds, and chemistry,
building off a larger 2016 white paper, and endorsed by the NAS Exoplanet
Science Strategy report. Now is the ideal time for progress in these areas, but
this progress requires better access to, understanding of, and training in the
production of spectroscopic data as well as a better insight into chemical
reaction kinetics both thermal and radiation-induced at a broad range of
temperatures. Given that most published efforts have emphasized relatively
Earth-like conditions, we can expect significant and enlightening discoveries
as emphasis moves to the exotic atmospheres of exoplanets.Comment: Submitted as an Astro2020 Science White Pape
Iconic dishes, culture and identity: the Christmas pudding and its hundred years’ journey in the USA, Australia, New Zealand and India
Asserting that recipes are textual evidences reflecting the society that produced them, this article explores the evolution of the recipes of the iconic Christmas pudding in the United States, Australia, New Zealand and India between the mid-nineteenth and the mid-twentieth centuries. Combining a micro-analysis of the recipes and the cookbook that provided them with contemporary testimonies, the article observes the dynamics revealed by the preparation and consumption of the pudding in these different societies. The findings demonstrate the relevance of national iconic dishes to the study of notions of home, migration and colonization, as well as the development of a new society and identity. They reveal how the preservation, transformation and even rejection of a traditional dish can be representative of the complex and sometimes conflicting relationships between colonists, migrants or new citizens and the places they live in
Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV
Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
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