A5028668027- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Ecology and Vegetation Dynamics Studies
- Astrophysics and Star Formation Studies
- Species Distribution and Climate Change
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Forest Ecology and Biodiversity Studies
- Plant and animal studies
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Gamma-ray bursts and supernovae
- CCD and CMOS Imaging Sensors
- Astronomical Observations and Instrumentation
- Forest ecology and management
- Atmospheric Ozone and Climate
- Fire effects on ecosystems
- Plant Pathogens and Fungal Diseases
- Plant Water Relations and Carbon Dynamics
- Forest Insect Ecology and Management
- History and Developments in Astronomy
- Yeasts and Rust Fungi Studies
- Invertebrate Taxonomy and Ecology
- Enzyme Production and Characterization
- Plant Diversity and Evolution
Manaaki Whenua – Landcare Research
2019-2025
Scripps Institution of Oceanography
2007-2022
University of California, San Diego
2005-2022
The University of Queensland
2016-2020
Commonwealth Scientific and Industrial Research Organisation
2017-2019
ACT Government
2019
Nestlé (France)
2007-2017
Stellar Solutions (United States)
2013-2017
University of Virginia
2017
Université Gustave Eiffel
2007-2017
Abstract Atmospheric rivers (ARs) generate most of the economic losses associated with flooding in western United States and are projected to increase intensity climate change. This is concern as flood damages have been shown exponentially AR intensity. To assess how AR-related likely respond change, we constructed county-level damage models for 11 conterminous states using 40 years insurance data linked characteristics ARs at landfall. Damage functions were applied 14 CMIP5 global under...
We describe the design, construction, and performance of an efficient new flexure-compensated Cassegrain echelle spectrograph for 2.1 m (82-inch) Struve reflector at McDonald Observatory. The instrument has a resolving power R = lambda/Delta-lambda 60,000 two CCD pixels (for reciprocal velocity dispersion 2.5 km s-1 per pixel) provides continuous wavelength coverage lambda < 8000 A using thinned backside illuminated Reticon 1200 X 400 detector. Total in single exposure varies from roughly...
We have obtained the first high-resolution spectra of individual stars in dwarf irregular galaxy NGC 6822. The two A-type supergiants were at Very Large Telescope and Keck Observatories, using Ultraviolet-Visual Echelle Spectrograph High Resolution Spectrometer, respectively. A detailed model atmospheres analysis has been used to determine their atmospheric parameters elemental abundances. mean iron abundance from these is = -0.49 ± 0.22 (±0.21), with Cr yielding a similar underabundance,...
view Abstract Citations (117) References (44) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Search for Solar-Like Oscillations in the Stars of M67 With CCD Ensemble Photometry on a Network 4m Telescopes Gilliland, R. L. ; Brown, T. M. Kjeldsen, H. McCarthy, J. K. Peri, Belmonte, A. Vidal, I. Cram, E. Palmer, Frandsen, S. Parthasarathy, Petro, Schneider, Stetson, P. B. Weiss, W. Results are presented from large observational project directed toward...
Evolutionary radiations of woody taxa within arid environments were made possible by multiple trait innovations including deep roots and embolism-resistant xylem, but little is known about how these traits have coevolved across the phylogeny plants or they jointly influence distribution species. We synthesized global vegetation plot datasets to examine rooting depth xylem vulnerability 188 plant species interact with aridity, precipitation seasonality, water table occurrence probabilities...
High-resolution optical spectra of 13 blue horizontal-branch stars in the globular cluster M13 show enormous deviations element abundances from expected metallicity. In hotter (Teff > 12,000 K), helium is depleted by factors 10-100 below solar, while iron enhanced to 3 times solar abundance, 2 orders magnitude above canonical metallicity [Fe/H]≃-1.5 dex for this cluster. Nitrogen, phosphorus, and chromium exhibit even more pronounced enhancements, other metals are also mildly overabundant,...
This paper summarizes the optical, mechanical, electrical, and software design of LRIS-B, blue channel Keck Low Resolution Imaging Spectrograph. The LRIS-B project will shortly be completing existing LRIS instrument through addition dichroic beamsplitters, grisms to disperse light on channel, broad-band u, B, V photometric filters, a near-UV transmitting camera lens, large format blue-sensitive CCD detector. also introduce piezoelectric xy-actuation detector inside its Dewar, in order...
High-resolution optical spectra of 18 blue horizontal-branch stars in the globular cluster M15 indicate that their stellar rotation rates and photospheric compositions vary strongly as a function effective temperature. Among cooler sample, at Teff approximately 8500 K, metal abundances are rough agreement with canonical metallicity, vsini rotations appear to have bimodal distribution, eight vsini<15 km s-1 two 35 s-1. Most Teff>/=10,000 however, slowly rotating, vsini<7 s-1, iron titanium...
We have determined the projected rotational velocities of 13 blue horizontal-branch (BHB) stars in globular cluster M13 via broadening metal absorption lines. Our sample spans photometric gap observed distribution at Teff ≃ 11,000 K and reveals a pronounced difference stellar rotation on either side this feature—blueward gap, all show modest rotations, v sin i < 10 km s-1, while to red we confirm more rapidly rotating population (v 40 s-1) previously by R. C. Peterson coworkers. Taken...
We used moderately high-resolution, high S/N spectra to study the chemical composition of 10 field ab-type RR Lyrae stars. A new temperature scale was determined from literature Infrared Flux Method measures subdwarfs and Kurucz (1992) model atmospheres, calibrate colors for both dwarfs Lyraes. The applicability atmospheres in analysis Lyraes at minimum light analyzed: we found that they are able reproduce colors, excitation ionization equilibria as well wings Halpha. derived abundances 21...
Ground-based counts and colors of faint galaxies in the U R bands one field at high Galactic latitude are presented. Integrated over flux, a total 1.2x10^5 sources per square degree found to U=25.5 mag 6.3x10^5 R=27 mag, with d log N/dm ~ 0.5 band 0.3 band. Consistent these number-magnitude curves, become bluer increasing magnitude median U-R=0.6 24<U<25 U-R=1.2 25 < 26 mag. Because Lyman break redshifts into z~3, least must be z<3. Measurable U-band fluxes 73 percent suggest that majority...
Understanding the spatial variation of soil pH is critical for many different stakeholders across fields science, because it a master variable that plays central role in processes. This study documents first attempt to map (1:5 H2O) at high resolution (100 m) New Zealand. The regression framework used follows paradigm digital mapping, and limited number environmental covariates were selected using selection, before calibration quantile forest model. In order adapt outcomes this work wide...
Summary paragraph To meet the ambitious objectives of biodiversity and climate conventions, countries international community require clarity on how these can be operationalized spatially, multiple targets pursued concurrently 1 . support governments political spatial guidance is needed to identify which areas should managed for conservation generate greatest synergies between nature’s contribution people (NCP). Here we present results from a joint optimization that maximizes improvements in...
Biodiversity analyses across continental extents are important in providing comprehensive information on patterns and likely drivers of diversity. For vascular plants Australia, community‐level diversity have been restricted by the lack a consistent plot‐based survey dataset continent. To overcome these challenges, we collated harmonised vegetation data from major sources Australia used them as basis for modelling species richness (α‐diversity) community compositional dissimilarity...
Abstract Although disturbance is considered a major driver of plant invasions across many systems, our understanding the mechanisms by which mediates understorey in natural forests limited. We used national forest inventory dataset spanning New Zealand's wide climatic and soil fertility gradients to disentangle disturbance‐mediated community characteristics driving abundance, species richness functional composition invasions. Disturbance‐mediated declines canopy tree abundance increases pH...
ABSTRACT Aim Woody ecosystems provide critical ecosystem functions and services but are increasingly threatened as invasive pathogens spread globally. Myrtle rust, caused by Austropuccinia psidii , arrived in New Zealand 2017 infects at least 12 of 18 species the susceptible Myrtaceae plant family. Among these structural, successional cultural importance. We aim to assess whether functional consequences loss could be mitigated if co‐occurring with shared attributes able replace them....
We have monitored FG Sge's spectroscopic changes since the time just prior to its dramatic fading in 1992 August. The most significant qualitative spectrum include large variations strength of C2 molecular bands and gradual appearance broad blueshifted high-velocity (~200 km s-1 relative photosphere) absorption components Na I D lines. During deep minima 1994 May 1996 June, an emission-line temporarily appeared superimposed on a weak continuum; addition previously reported nebular emission...
We present internal velocity dispersion measurements for a set of 21 globular clusters in the Andromeda galaxy (M31). combine them with structural and photometric cluster parameters measured earlier Hubble Space Telescope from ground to explore correlations properties compare equivalent Galactic clusters. find that M31 globulars follow same between luminosity, central, average surface brightness, as do their counterparts. This suggests common physical origin these correlations. They may be...
ABSTRACT Characterization in Thermotoga neapolitana of a catabolic gene cluster encoding two glycosyl hydrolases, 1,4-β- d -glucan glucohydrolase (GghA) and cellobiose phosphorylase (CbpA), the apparent absence cellobiohydrolase (Cbh) suggest nonconventional pathway for glucan utilization Thermotogales . GghA purified from T. is 52.5-kDa family 1 hydrolase with optimal activity at pH 6.5 95°C. releases glucose soluble glucooligomers, preference longer oligomers: k cat / K m values are 155.2,...
We report detailed analysis of high-resolution spectra nine high velocity metal-rich dwarfs in the solar neighborhood, selected from proper motion samples Grenon. The stars are super metal-rich, and 5 them have fe >= +0.4, making most currently known. find that alpha -elements decrease with increasing metallicity; s-elements underabundant by about [s-elements/Fe] ~ -0.3; ion{Eu}{2} line was measurable for 6 stars, showing [Eu/Fe] 0.0, except G161-29 where = +0.50. All calculations followed...