162 research outputs found
Seasons Fall 2018 Volume 47 Number 3
Highlights : Thompson-Morris Plot Restoration Complete Botany for Beginners Preserving Our Tree Canopy Three Great Native Trees ArbNet Accreditationhttps://repository.upenn.edu/morrisarboretum_seasons/1000/thumbnail.jp
Hemisphere-scale differences in conifer evolutionary dynamics
Fundamental differences in the distribution of oceans and landmasses in the Northern and Southern Hemispheres potentially impact patterns of biological diversity in the two areas. The evolutionary history of conifers provides an opportunity to explore these dynamics, because the majority of extant conifer species belong to lineages that have been broadly confined to the Northern or Southern Hemisphere during the Cenozoic. Incorporating genetic information with a critical review of fossil evidence, we developed an age-calibrated phylogeny sampling âŒ80% of living conifer species. Most extant conifer species diverged recently during the Neogene within clades that generally were established during the later Mesozoic, but lineages that diversified mainly in the Southern Hemisphere show a significantly older distribution of divergence ages than their counterparts in the Northern Hemisphere. Our tree topology and divergence times also are best fit by diversification models in which Northern Hemisphere conifer lineages have higher rates of species turnover than Southern Hemisphere lineages. The abundance of recent divergences in northern clades may reflect complex patterns of migration and range shifts during climatic cycles over the later Neogene leading to elevated rates of speciation and extinction, whereas the scattered persistence of mild, wetter habitats in the Southern Hemisphere may have favored the survival of older lineages
Engaging Clinical Nurses in Research: Nursesâ Experiences Delivering a Communication Intervention in a Behavioral Oncology Clinical Trial
Despite the recognized need for clinical nurses to engage in the conduct of research, little is known about their research experiences. This article describes the experiences of nurses who delivered the communication intervention in a behavioral oncology clinical trial for parents of adolescents and young adults (AYAs) with cancer. A qualitative thematic analysis was conducted of nurse intervenersâ (NIsâ) reflections on their experiences delivering the communication intervention. Ten data-generating questions were developed to guide NIsâ reflections. Twelve NIs responded via verbal discussions. Six of these also provided written responses. Overall, nursesâ experiences as interveners were powerful and positive, and included time and space to be fully present with patients and families. NIs identified barriers to their involvement in research related to time constraints, administrative support, physical space to privately conduct the intervention, and difficulties maintaining expertise with the intervention. The importance of ongoing collaboration between nurses, unit staff, leaders, and study teams was corroborated. An unexpected finding was the importance of Reflective Clinical Research
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The association between past and future oriented thinking: Evidence from autism spectrum disorder
A number of recently developed theories (e.g., the constructive episodic simulation, self-projection, and scene construction hypotheses) propose that the ability to simulate possible future events (sometimes referred to as episodic future thinking, prospection, or foresight) depends on the same neurocognitive system that is implicated in the recall of past events (episodic memory). In this paper, we argue that autism spectrum disorder (ASD) offers an ideal test of such theories, given that it is a developmental disorder that is characterized by impairments in episodic memory. Each of these theories would predict concomitant impairments in episodic future thinking among individuals with ASD. We review evidence concerning episodic future thinking in ASD, as well as studies of prospective memory (remembering to do something in the future), planning, navigation, and theory of mind, which some theories suggest also rely on the same mechanism as episodic future thinking
THE K2-ESPRINT PROJECT. V. A SHORT-PERIOD GIANT PLANET ORBITING A SUBGIANT STAR
We report on the discovery and characterization of the transiting planet K2-39b (EPIC 206247743b). With an orbital period of 4.6 days, it is the shortest-period planet orbiting a subgiant star known to date. Such planets are rare, with only a handful of known cases. The reason for this is poorly understood but may reflect differences in planet occurrence around the relatively high-mass stars that have been surveyed, or may be the result of tidal destruction of such planets. K2-39 (EPIC 206247743) is an evolved star with a spectroscopically derived stellar radius and mass of 3.88 [subscript -0.42] [superscript +0.48] R [subscript â] and 1.53[subscript-0.12] [superscript +0.13] M[subscript â], respectively, and a very close-in transiting planet, with a/R [subscript asterisk]= 3.4 Radial velocity (RV) follow-up using the HARPS, FIES, and PFS instruments leads to a planetary mass of 50.3 [subscript -9.4] [superscript +9.7] M [subscript â]. In combination with a radius measurement of 8.3 ± 1.1 R [subscript oplus], this results in a mean planetary density of 0.50 [subscript -0.17] [superscript +0.29] g cm [superscript -3]. We furthermore discover a long-term RV trend, which may be caused by a long-period planet or stellar companion. Because K2-39b has a short orbital period, its existence makes it seem unlikely that tidal destruction is wholly responsible for the differences in planet populations around subgiant and main-sequence stars. Future monitoring of the transits of this system may enable the detection of period decay and constrain the tidal dissipation rates of subgiant stars
The multiplicity of self: neuropsychological evidence and its implications for the self as a construct in psychological research
This paper examines the issue ofwhat the self is by reviewing neuropsychological research,which converges on the idea
that the selfmay be more complex and differentiated than previous treatments of the topic have suggested. Although some aspects of self-knowledge such as episodic recollection may be compromised in individuals, other aspectsâfor instance, semantic trait summariesâappear largely intact. Taken together, these findings support the idea that the self is not a single, unified entity. Rather, it is a set of interrelated, functionally independent systems. Implications for understanding the self in various areas of psychological researchâe.g., neuroimaging, autism, amnesia, Alzheimerâs disease, and mirror self-recognitionâare discussed in brief
Doppler monitoring of five k2 transiting planetary systems
In an effort to measure the masses of planets discovered by the NASA K2 mission, we have conducted precise Doppler observations of five stars with transiting planets. We present the results of a joint analysis of these new data and previously published Doppler data. The first star, an M dwarf known as K2-3 or EPIC 201367065, has three transiting planets (âb,â with radius 2.1 Râ; âc,â 1.7 Râ; and âd,â 1.5 Râ). Our analysis leads to the mass constraints:
Mb = 8.1 -1.9 to +2.0 Mâ
and Mc < 4.2 Mâ (95% confidence).
The mass of planet d is poorly constrained because its orbital period is close to the stellar rotation period, making it difficult to disentangle the planetary signal
from spurious Doppler shifts due to stellar activity. The second star, a G dwarf known as K2-19 or EPIC 201505350, has two planets (âb,â 7.7 Râ; and âc,â 4.9 Râ) in a 3:2 mean-motion resonance, as well as a shorter period
planet (âd,â 1.1 Râ). We find
Mb = 28.5 -5.0 to +5.4 Mâ,
Mc = 25.6 -7.1 to + 7.1 Mâ
and Md < 14.0Mâ (95% conf.).
The third star, a G dwarf known as K2-24 or EPIC 203771098, hosts two transiting planets (âb,â 5.7 Râ; and âc,â 7.8 Râ) with orbital periods in a nearly 2:1 ratio. We find
Mb = 19.8 -4.4 to +4.5 Mâ and
Mc = 26.0 -6.1 to +5.8 Mâ.
The fourth star, a G dwarf known as EPIC 204129699, hosts a hot Jupiter for which we measured the mass to be
1.857 +0.081 to -0.081 MJup.
The fifth star, a G dwarf known as EPIC 205071984, contains three transiting planets (âb,â 5.4 Râ; âc,â 3.5 Râ; and âd,â 3.8 Râ), the outer two of which have a nearly 2:1 period ratio. We find
Mb = 21.1 -5.9 to +5.9 Mâ,
Mc < 8.1 Mâ (95% conf.) and
Md < 35Mâ (95% conf.)
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