182 research outputs found
Concentration Curves and Have-Statistics for Ecological Analysis of Diversity: Part 1: Dominance and Evenness in Reproductive Success
Concentration curves and a set of summary statistics called have-statistics are useful in ecological analyses of dominance and evenness among individuals in reproductive success. This approach complements, but does not replace, approaches based on frequency distributions and standard summary statistics. Examples are drawn from studies of bullfrogs, red deer, elephant seals, sculpins, fruit flies, and rice weevils, as well as from some theoretical models similar to the Wright-Fisher model of evolutionary genetics
Concentration Curves and Have-Statistics for Ecological Analysis of Diversity: Part II: Species and Other Diversity
The application of concentration curves and have-statistics to studies of dominance and evenness in reproductive success was discussed in Part I of this series of three papers. Concentration curves and have-statistics can also aid ecologists in studies of species diversity and community structure; a start in this direction was made by Patil and Taillie (1979) and Taillie (1979). Essentially, the method is the same as before except that now the "haves" are species rather than individuals and the "hads" are individuals, biomass, caloric intake, etc., rather than an individual's offspring. In addition, concentration curves and have-statistics can be applied to other ecological topics pertaining to variation and inequality, including the temporal or spatial distribution of some resource, such as food supply or rainfall. Various examples, from studies of diatoms, a community of herbaceous plants, a tropical forest, a model of niche preemption, and temporal variation in the breeding of tropical and temperate bird species illustrate this approach
Education at IIASA
This report is a product of a study of current and potential education programs at IIASA conducted by Dianne Goodwin and James Vaupel with the assistance of Olivia Carydias. The study was begun in July 1982 and completed on January 5, 1983.
The first section of this report focuses on the Young Scientists Summer Program: the current program is evaluated, several recommendations for incremental improvements are suggested, and a "Summer Roundtable" program that could either supplement or replace the current program is proposed.
The second section of this report considers opportunities for offering short courses (of one to three weeks' duration) at IIASA. Two broad options are described. IIASA could initiate a modest program of short courses based on IIASA research projects. In addition, IIASA might launch a program of East/West Colloquia.
We considered a long list of options for education at IIASA. Most were easily ruled out based on the criteria we developed or the consensus of opinion we received. This report describes the relatively few remaining options worth further consideration
Concentration Curves and Have-Statistics for Ecological Analysis of Diversity: Part III: Comparisons of Measures of Diversity
Given the central importance of diversity in ecology and the life sciences more generally, it is not surprising that a variety of methods and measures have been developed to describe and summarize diversity. In the two previous parts of this series of papers, comparisons were drawn between concentration curves and frequency distributions, the most widely used graphical display of variation, and between concentration curves and dominance-diversity curves. This final part of the three paper series compares various statistics that might be used to summarize diversity, with a focus on the usefulness of have-statistics as a supplement to more traditional measures. The first section of our discussion lays out some reasonable criteria and principles that good measures of diversity should satisfy: some traditional measures violate at least one of the criteria; the have-statistics pass the hurdles and have some desirable properties in addition. We then illustrate the use of different measures by way of examples drawn from Howard's studies of bullfrogs (discussed in Part I), the study of species diversity among diatoms (discussed in Part II), an analysis of mating systems of various birds, and a survey of human fertility in 41 countries
The Coyote Predation Issue: A Survey of Policy and Perspectives with a Focus on Southern Idaho
This paper is a compilation of an amorphous mass of information on the coyote predation issue in the U.S.A. with a focus on southern Idaho. It covers the period from the origins of the federal animal damage control program in the late 1800's up to 1981. Its aim is to survey the key factors involved in this issue relative to a backdrop of different and changing perspectives and the federal policy responses to these differences and changes
Chemical separations by bubble-assisted interphase mass-transfer
We show that when a small amount of heat is added close to a liquid-vapor interface of a captive gas bubble in a microchannel, interphase mass-transfer through the bubble can occur in a controlled manner with only a slight change in the temperature of the fluid. We demonstrate that this method, which we refer to as bubble-assisted interphase mass-transfer (BAIM), can be applied to interphase chemical separations, e.g., simple distillation, without the need for high temperatures, vacuum, or active cooling. Although any source of localized heating could be used, we illustrate BAIM with an all-optical technique that makes use of the plasmon resonance in an array of nanoscale metal structures that are incorporated into the channel to produce localized heating of the fluid when illuminated by a stationary low-power laser. © 2008 American Chemical Society
Heterogenous catalysis mediated by plasmon heating
We introduce a new method for performing and miniaturizing many types of heterogeneous catalysis involving nanoparticles. The method makes use of the plasmon resonance present in nanoscale metal catalysts to provide the necessary heat of reaction when illuminated with a low-power laser. We demonstrate our approach by reforming a flowing, liquid mixture of ethanol and water over gold nanoparticle catalysts in a microfluidic channel. Plasmon heating of the nanoparticles provides not only the heat of reaction but the means to generate both water and ethanol vapor locally over the catalysts, which in turn allows the chip and the fluid lines to remain at room temperature. The measured products of the reaction, CO2, CO, and H2, are consistent with catalytic steam reforming of ethanol. The approach, which we refer to as plasmon-assisted catalysis, is general and can be used with a variety of endothermic catalytic processes involving nanoparticles. © 2009 American Chemical Society
Block bond-order potential as a convergent moments-based method
The theory of a novel bond-order potential, which is based on the block
Lanczos algorithm, is presented within an orthogonal tight-binding
representation. The block scheme handles automatically the very different
character of sigma and pi bonds by introducing block elements, which produces
rapid convergence of the energies and forces within insulators, semiconductors,
metals, and molecules. The method gives the first convergent results for
vacancies in semiconductors using a moments-based method with a low number of
moments. Our use of the Lanczos basis simplifies the calculations of the band
energy and forces, which allows the application of the method to the molecular
dynamics simulations of large systems. As an illustration of this convergent
O(N) method we apply the block bond-order potential to the large scale
simulation of the deformation of a carbon nanotube.Comment: revtex, 43 pages, 11 figures, submitted to Phys. Rev.
A circle RNA regulatory axis promotes lung squamous metastasis via CDR1-mediated regulation of golgi trafficking
Lung squamous carcinoma (LUSC) is a highly metastatic disease with a poor prognosis. Using an integrated screening approach, we found that miR-671-5p reduces LUSC metastasis by inhibiting a circular RNA (circRNA), CDR1as. Although the putative function of circRNA is through miRNA sponging, we found that miR-671-5pmore potently silenced an axis of CDR1as and its antisense transcript, cerebellar degeneration related protein 1 (CDR1). Silencing of CDR1as or CDR1 significantly inhibited LUSC metastases and CDR1 was sufficient to promote migration and metastases. CDR1, which directly interacted with adaptor protein 1 (AP1) complex subunits and coatomer protein I (COPI) proteins, no longer promoted migration upon blockade of Golgi trafficking. Therapeutic inhibition of the CDR1as/CDR1 axis with miR-671-5p mimics reduced metastasis in vivo. This report demonstrates a novel role for CDR1 in promoting metastasis and Golgi trafficking. These findings reveal an miRNA/ circRNA axis that regulates LUSC metastases through a previously unstudied protein, CDR1. Significance: This study shows that circRNA, CDR1as, promotes lung squamous migration, metastasis, and Golgi trafficking through its complimentary transcript, CDR1. Significance: This study shows that circRNA, CDR1as, promotes lung squamous migration, metastasis, and Golgi trafficking through its complimentary transcript, CDR1
- …