1,920 research outputs found
An integrated study of earth resources in the State of California based on Skylab and supporting aircraft data
There are no author-identified significant results in this report
Use of LANDSAT data to assess waterfowl habitat quality
The author has identified the following significant results. The capability of mapping ponds over a very large area was demonstrated, with multidate, multiframe LANDSAT imagery. A small double sample of aircraft data made it possible to adjust a LANDSAT large area census. Terrain classification was improved by using multitemporal LANDSAT data. Waterfowl production was estimated, using remotely determined pond data, in conjunction with FWS estimates of breeding population. Relative waterfowl habitat quality was characterized on a section by section basis
Disentangling the exchange coupling of entangled donors in the Si quantum computer architecture
We develop a theory for micro-Raman scattering by single and coupled
two-donor states in silicon. We find the Raman spectra to have significant
dependence on the donor exchange splitting and the relative spatial positions
of the two donor sites. In particular, we establish a strong correlation
between the temperature dependence of the Raman peak intensity and the
interdonor exchange coupling. Micro-Raman scattering can therefore potentially
become a powerful tool to measure interqubit coupling in the development of a
Si quantum computer architecture.Comment: Title changed. Other minor change
Remote sensing research for agricultural applications
Materials and methods used to characterize selected soil properties and agricultural crops in San Joaquin County, California are described. Results show that: (1) the location and widths of TM bands are suitable for detecting differences in selected soil properties; (2) the number of TM spectral bands allows the quantification of soil spectral curve form and magnitude; and (3) the spatial and geometric quality of TM data allows for the discrimination and quantification of within field variability of soil properties. The design of the LANDSAT based multiple crop acreage estimation experiment for the Idaho Department of Water Resources is described including the use of U.C. Berkeley's Survey Modeling Planning Model. Progress made on Peditor software development on MIDAS, and cooperative computing using local and remote systems is reported as well as development of MIDAS microcomputer systems
Strongly Annular Tsuji Functions
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135351/1/jlms0079.pd
An integrated study of earth resources in the State of California based on ERTS-1 and supporting aircraft data
There are no author-identified significant results in this report
Use of ERTS-1 data to access and monitor change in the west side of the San Joaquin Valley and central coastal zone of California
There are no author-identified significant results in this report
Cassini Uvis Stellar Occultation Observations of Saturn\u27s Rings
The Cassini spacecraft\u27s Ultraviolet Imaging Spectrograph (UVIS) includes a high-speed photometer (HSP) that has observed more than 100 stellar occultations by Saturn\u27s rings. Here, we document a standardized technique applied to the UVIS-HSP ring occultation datasets delivered to the Planetary Data System as higher level data products. These observations provide measurements of ring structure that approaches the scale of the largest common ring particles (similar to 5 m). The combination of multiple occultations at different viewing geometries enables reconstruction of the three-dimensional structure of the rings. This inversion of the occultation data depends on accurate calibration of the data so that occultations of different stars taken at different times and under different viewing conditions can be combined to retrieve ring structure. We provide examples of the structure of the rings as seen from several occultations at different incidence angles to the rings, illustrating changes in the apparent structure with viewing geometry
Unveiling the species-rank abundance distribution by generalizing the Good-Turing sample coverage theory
Based on a sample of individuals, we focus on inferring the vector of species relative abundance of an entire assemblage and propose a novel estimator of the complete species-rank abundance distribution (RAD). Nearly all previous estimators of the RAD use the conventional plug-in estimator pi(sample relative abundance) of the true relative abundance piof species i. Because most biodiversity samples are incomplete, the plug-in estimators are applied only to the subset of species that are detected in the sample. Using the concept of sample coverage and its generalization, we propose a new statistical framework to estimate the complete RAD by separately adjusting the sample relative abundances for the set of species detected in the sample and estimating the relative abundances for the set of species undetected in the sample but inferred to be present in the assemblage. We first show that piis a positively biased estimator of pifor species detected in the sample, and that the degree of bias increases with increasing relative rarity of each species. We next derive a method to adjust the sample relative abundance to reduce the positive bias inherent in pi. The adjustment method provides a nonparametric resolution to the longstanding challenge of characterizing the relationship between the true relative abundance in the entire assemblage and the observed relative abundance in a sample. Finally, we propose a method to estimate the true relative abundances of the undetected species based on a lower bound of the number of undetected species. We then combine the adjusted RAD for the detected species and the estimated RAD for the undetected species to obtain the complete RAD estimator. Simulation results show that the proposed RAD curve can unveil the true RAD and is more accurate than the empirical RAD. We also extend our method to incidence data. Our formulas and estimators are illustrated using empirical data sets from surveys of forest spiders (for abundance data) and soil ciliates (for incidence data). The proposed RAD estimator is also applicable to estimating various diversity measures and should be widely useful to analyses of biodiversity and community structure
Disentangling the influence of urbanization and invasion on endemic geckos in tropical biodiversity hot spots : a case study of Phyllodactylus martini (Squamata: Phyllodactylidae) along an Urban Gradient in Curaçao
Author Posting. © Peabody Museum of Natural History, 2016. This article is posted here by permission of Peabody Museum of Natural History for personal use, not for redistribution. The definitive version was published in Bulletin of the Peabody Museum of Natural History 57(2016): 147–164, doi:10.3374/014.057.0209.Predicting the response of endemic species to urbanization has emerged as a fundamental challenge
in 21st century conservation biology. The factors that underlie population declines of reptiles
are particularly nebulous, as these are often the least understood class of vertebrates in a given
community. In this study, we assess correlations between feeding ecology and phenotypic traits of
the Lesser Antillean endemic Dutch leaf-toed gecko, Phyllodactylus martini, along an urban gradient
in the Caribbean island of Curaçao. There has been a marked decline of this species in developed
habitats associated with the invasive tropical house gecko Hemidactylus mabouia. We find
a correlation between aspects of locomotor morphology and prey in undeveloped habitats that is
absent in developed habitats. Analyses of stomach contents further suggest that Phyllodactylus
martini alters primary prey items in developed areas. However, changes in prey promote the overlap
in foraging niches between Phyllodactylus martini and Hemidactylus mabouia, suggesting that
direct resource competition is contributing to the decline of Phyllodactylus martini. In addition to
competitive exclusion, we suggest that the urban extirpation of Phyllodactylus martini could also
be attributed to a top-down control on population growth by Hemidactylus mabouia. Colonizations
of walls put Phyllodactylus martini in direct contact with Hemidactylus mabouia increasing
the chances for predation events, as evidenced by our observation of a predation event on a Phyllodactylus
martini juvenile by an adult Hemidactylus mabuoia. In total, our results add to a growing
body of literature demonstrating the threat that invasive synanthropic reptiles pose to
endemics that might otherwise be able to cope with increased urbanization pressures
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