229 research outputs found
NASA's Solar System Exploration Research Virtual Institute: Science and Technology for Lunar Exploration
The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on research at the intersection of science and exploration, training the next generation of lunar scientists, and development and support of the international community. As part of its mission, SSERVI acts as a hub for opportunities that engage the larger scientific and exploration communities in order to form new interdisciplinary, research-focused collaborations. The nine domestic SSERVI teams that comprise the U.S. complement of the Institute engage with the international science and exploration communities through workshops, conferences, online seminars and classes, student exchange programs and internships. SSERVI represents a close collaboration between science, technology and exploration enabling a deeper, integrated understanding of the Moon and other airless bodies as human exploration moves beyond low Earth orbit. SSERVI centers on the scientific aspects of exploration as they pertain to the Moon, Near Earth Asteroids (NEAs) and the moons of Mars, with additional aspects of related technology development, including a major focus on human exploration-enabling efforts such as resolving Strategic Knowledge Gaps (SKGs). The Institute focuses on interdisciplinary, exploration-related science focused on airless bodies targeted as potential human destinations. Areas of study represent the broad spectrum of lunar, NEA, and Martian moon sciences encompassing investigations of the surface, interior, exosphere, and near-space environments as well as science uniquely enabled from these bodies. This research profile integrates investigations of plasma physics, geology/geochemistry, technology integration, solar system origins/evolution, regolith geotechnical properties, analogues, volatiles, ISRU and exploration potential of the target bodies. New opportunities for both domestic and international partnerships are continually generated through these research and community development efforts, and SSERVI can further serve as a model for joint international scientific efforts through its creation of bridges across disciplines and between countries. Since the inception of the NASA Lunar Science Institute (SSERVIs predecessor), it has and will continue to contribute in many ways toward the advancement of lunar science and the eventual human exploration of the Moon
Human Facial Recognition by Northern Mockingbirds
A number of studies have examined the ability of various animal species to recognize individual humans, but only a few have focused on native, non-captive birds. Previous research demonstrated that American Crows learn to recognize individual human faces. Other research indicated that Northern Mockingbirds learn to discriminate among individual humans, but did not examine the factors involved in the discrimination. Here we report on a study of Northern Mockingbirds on the University of North Georgia campus in Dahlonega, GA, to test the hypothesis that Northern Mockingbirds learn to distinguish among individual humans based on facial recognition. Our field tests involved approaching and touching mockingbird nests on successive days and recording the responses of parent birds. We used masks of human faces which we interchanged among researchers to determine if birds key on faces as a discriminating factor. The mockingbirds we tested indicated an ability to distinguish among humans based on facial recognition. Our research has received funding from the UNG Center for Undergraduate Research and Creative Activities and from the UNG Department of Biology
NASA's Solar System Exploration Research Virtual Institute: Building Collaboration Through International Partnerships
The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on research at the intersection of science and exploration, training the next generation of lunar scientists, and community development. As part of the SSERVI mission, we act as a hub for opportunities that engage the larger scientific and exploration communities in order to form new interdisciplinary, research-focused collaborations. This talk will describe the international partnership program, research efforts and how we are engaging the international science and exploration communities through workshops, conferences, online seminars and classes, student exchange programs and internships
NASA SSERVI: Merging Science and Human Exploration
The NASA Solar System Exploration Research Virtual Institute (SSERVI) is a virtual institute focused on research at the intersection of science and exploration, training the next generation of lunar scientists, and community development. As part of the SSERVI mission, we act as a hub for opportunities that engage the larger scientific and exploration communities in order to form new interdisciplinary, research-focused collaborations. This talk will describe the research efforts of the thirteen domestic teams that constitute the U.S. complement of the Institute and how we will engage the community through workshops, conferences, online seminars and classes, student exchange programs and internships
High eccentricity planets from the Anglo-Australian Planet Search
We report Doppler measurements of the stars HD187085 and HD20782 which
indicate two high eccentricity low-mass companions to the stars. We find
HD187085 has a Jupiter-mass companion with a ~1000d orbit. Our formal `best
fit' solution suggests an eccentricity of 0.47, however, it does not sample the
periastron passage of the companion and we find that orbital solutions with
eccentricities between 0.1 and 0.8 give only slightly poorer fits (based on RMS
and chi^2) and are thus plausible. Observations made during periastron passage
in 2007 June should allow for the reliable determination of the orbital
eccentricity for the companion to HD187085. Our dataset for HD20782 does sample
periastron and so the orbit for its companion can be more reliably determined.
We find the companion to HD20782 has M sin i=1.77+/-0.22M_JUP, an orbital
period of 595.86+/-0.03d and an orbit with an eccentricity of 0.92+/-0.03. The
detection of such high-eccentricity (and relatively low velocity amplitude)
exoplanets appears to be facilitated by the long-term precision of the
Anglo-Australian Planet Search. Looking at exoplanet detections as a whole, we
find that those with higher eccentricity seem to have relatively higher
velocity amplitudes indicating higher mass planets and/or an observational bias
against the detection of high eccentricity systems.Comment: to appear in MNRA
Shifts in Species Interactions Due to the Evolution of Functional Differences between Endemics and Non-Endemics: An Endemic Syndrome Hypothesis
Species ranges have been shifting since the Pleistocene, whereby fragmentation, isolation, and the subsequent reduction in gene flow have resulted in local adaptation of novel genotypes and the repeated evolution of endemic species. While there is a wide body of literature focused on understanding endemic species, very few studies empirically test whether or not the evolution of endemics results in unique function or ecological differences relative to their widespread congeners; in particular while controlling for environmental variation. Using a common garden composed of 15 Eucalyptus species within the subgenus Symphyomyrtus (9 endemic to Tasmania, 6 non-endemic), here we hypothesize and show that endemic species are functionally and ecologically different from non-endemics. Compared to non-endemics, endemic Eucalyptus species have a unique suite of functional plant traits that have extended effects on herbivores. We found that while endemics occupy many diverse habitats, they share similar functional traits potentially resulting in an endemic syndrome of traits. This study provides one of the first empirical datasets analyzing the functional differences between endemics and non-endemics in a common garden setting, and establishes a foundation for additional studies of endemic/non-endemic dynamics that will be essential for understanding global biodiversity in the midst of rapid species extinctions and range shifts as a consequence of global change
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Catalyst Editing via Post-Synthetic Functionalization by Phosphonium Generation and Anion Exchange for Nickel-Catalyzed Ethylene/Acrylate Copolymerization.
Rapid, efficient development of homogeneous catalysts featuring desired performance is critical to numerous catalytic transformations but remains a key challenge. Typically, this task relies heavily on ligand design that is often based on trial and error. Herein, we demonstrate a catalyst editing strategy in Ni-catalyzed ethylene/acrylate copolymerization. Specifically, alkylation of a pendant phosphine followed by anion exchange provides a high yield strategy for a large number of cationic Ni phosphonium catalysts with varying electronic and steric profiles. These catalysts are highly active in ethylene/acrylate copolymerization, and their behaviors are correlated with the electrophile and the anion used in late-stage functionalization
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Detection of Planetary and Stellar Companions to Neighboring Stars via a Combination of Radial Velocity and Direct Imaging Techniques
13 pages, 6 figures, 4 tables, accepted for publication in the Astronomical Journal (submitted 25 Feb 2019; accepted 28 April 2019). Machine readable tables and Posteriors from the RadVel fits are available here: http://stephenkane.net/rvfits.tarThe sensitivities of radial velocity (RV) surveys for exoplanet detection are extending to increasingly longer orbital periods, where companions with periods of several years are now being regularly discovered. Companions with orbital periods that exceed the duration of the survey manifest in the data as an incomplete orbit or linear trend, a feature that can either present as the sole detectable companion to the host star, or as an additional signal overlain on the signatures of previously discovered companion(s). A diagnostic that can confirm or constrain scenarios in which the trend is caused by an unseen stellar rather than planetary companion is the use of high-contrast imaging observations. Here, we present RV data from the Anglo-Australian Planet Search (AAPS) for 20 stars that show evidence of orbiting companions. Of these, six companions have resolved orbits, with three that lie in the planetary regime. Two of these (HD 92987b and HD 221420b) are new discoveries. Follow-up observations using the Differential Speckle Survey Instrument (DSSI) on the Gemini South telescope revealed that 5 of the 20 monitored companions are likely stellar in nature. We use the sensitivity of the AAPS and DSSI data to place constraints on the mass of the companions for the remaining systems. Our analysis shows that a planetary-mass companion provides the most likely self-consistent explanation of the data for many of the remaining systems.Peer reviewedFinal Accepted Versio
Temperature and rainfall are separate agents of selection shaping population differentiation in a forest tree
Research highlights: We present evidence indicating that covariation of functional traits
among populations of a forest tree is not due to genetic constraints, but rather selective covariance
arising from local adaptation to di erent facets of the climate, namely rainfall and temperature.
Background and Aims: Traits frequently covary among natural populations. Such covariation can
be caused by pleiotropy and/or linkage disequilibrium, but also may arise when the traits are
genetically independent as a direct consequence of natural selection, drift, mutation and/or gene flow.
Of particular interest are cases of selective covariance, where natural selection directly generates
among-population covariance in a set of genetically independent traits. We here studied the causes of
population-level covariation in two key traits in the Australian tree Eucalyptus pauciflora. Materials
and Methods: We studied covariation in seedling lignotuber size and vegetative juvenility using
37 populations sampled from throughout the geographic and ecological ranges of E. pauciflora on
the island of Tasmania. We integrated evidence from multiple sources: (i) comparison of patterns of
trait covariation within and among populations; (ii) climate-trait modelling using machine-learning
algorithms; and (iii) selection analysis linking trait variation to field growth in an arid environment.
Results: We showed strong covariation among populations compared with the weak genetic correlation
within populations for the focal traits. Population di erentiation in these genetically independent
traits was correlated with di erent home-site climate variables (lignotuber size with temperature;
vegetative juvenility with rainfall), which spatially covaried. The role of selection in shaping the
population di erentiation in lignotuber size was supported by its relationship with fitness measured
in the field. Conclusions: Our study highlights the multi-trait nature of adaptation likely to occur as
tree species respond to spatial and temporal changes in climateinfo:eu-repo/semantics/publishedVersio
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