18,334 research outputs found
An Ecological Study of Timberline and Alpine Areas, Mount Lincoln, Park County, Colorado
During the short alpine growing season of 1945 the authors had the opportunity of studying conditions and biota on Mount Lincoln, Park County, Colorado, in an attempt to evaluate the ecological conditions and animal communities of the area. Of the large amount of taxonomic and ecological zoology published on the state, most has been in the field of autecology, and, except in the province of aquatic studies, little has appeared bearing on synecological relations, especially among invertebrates. The marked differences between the physiography, climatology, and biology of timberline, alpine, and other stations seemed to offer a field well worthy of investigation. Since the work was done, other factors have been introduced which have greatly altered the nearly primitive conditions encountered at the time of the investigation. One of the areas has been entirely destroyed by the formation of a water storage lake, and others have been affected through heavy summer grazing by bands of sheep.
The material published on the Mount Lincoln area is very limited. Cary (1911) was concerned with similar areas in other parts of the state, but apparently he did not work around the mountains at the head of the South Platte. The most detailed paper on the region is that of Patton and his collaborators (1912) which covers the physiography very completely. There are scattered references to the animal life of the vicinity in Coues (1874), Sclater (1912), Warren (1942), and elsewhere. The most complete published reports on the animal life of the region are those of Brewer (1871) and Allen (1872, 1876a, 1876b); the first of Allen\u27s papers is the source of most of Coues\u27 references to the Mount Lincoln avifauna. None of these papers deals with the invertebrates, save for comments by Brewer on the relative abundance of certain orders of insects
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On the Projection of Mortality Rates to Extreme Old Age
This article shows how cohort mortality rate projections of mortality models that involve age effects can be improved and extended to extreme old ages. The proposed approach allows insurers to use such mortality models to obtain valuations of financial instruments such as annuities that depend on projections of extreme old age mortality rates
Berkeleyâs Arguments on Realism and Idealism
We analyse Berkeley's argument that realism cannot be defined, and show that his epistemological assumptions lead to the inevitable conclusion that solipsism is the only definable metaphysics. We conclude with a discussion of what this means for the realism/idealism debate, and also with a discussion of the possibility for apodictic evidence in this matter
Divisibility, Logic, Radical Empiricism, and Metaphysics
We will explore the problem of the manner in which the world may be divided into parts, and how this affects the application of logic. We will also consider how this affects the problem of knowing the world. Such considerations bring us to discuss how the divisibility of the world relates to idealism, realism, and the radical empiricist program of James. The epistemological difficulties sometimes associated with realism will in particular be shown to be in principle the result of misunderstanding the nature of the divisibility of the world. When such divisibility is properly understood, we claim that there is no epistemological dilemma, at least in principle, although of course in practice there may be other difficulties. We conclude by tentatively analyzing these practical difficulties
MINIMIZING FARM-TO-MILL COTTON CLEANING COST
This study focuses on least-cost farm-to-mill cotton cleaning configurations employing survey, regression, and simulation techniques. The resulting least-cost cotton cleaning configurations, employing standard textile technology, included the use of one lint cleaning in the ginning stage. The use of a field cleaner in the harvesting stage was also found to be optimal with some variation based on the desired yarn quality. Results of the study indicated that the optimal cleaning configurations were distinctly different from currently used practices, such that appropriate changes could save the cotton industry between 0.60 per bale of cotton, depending on the desired yarn quality.Cotton cleaning, Least-cost configuration, Yarn quality, Crop Production/Industries,
Acetone in the Atmosphere of Hong Kong, Abundance, Sources and Photochemical Precursors
Intensive field measurements were carried out at a mountain site and an urban site at the foot of the mountain from September to November 2010 in Hong Kong. Acetone was monitored using both canister air samples and 2,4-dinitrophenylhydrazine cartridges. The spatiotemporal patterns of acetone showed no difference between the two sites (p > 0.05), and the mean acetone mixing ratios on O3 episode days were higher than those on non-O3 episode days at both sites (p < 0.05). The source contributions to ambient acetone at both sites were estimated using a receptor model i.e. Positive Matrix Factorization (PMF). The PMF results showed that vehicular emission and secondary formation made the most important contribution to ambient acetone, followed by the solvent use at both sites. However, the contribution of biogenic emission at the mountain site was significantly higher than that at the urban site, whereas biomass burning made more remarkable contribution at the urban site than that at the mountain site. The mechanism of oxidation formation of acetone was investigated using a photochemical box model. The results indicated that i-butene was the main precursor of secondary acetone at the mountain site, while the oxidation of i-butane was the major source of secondary acetone at the urban site.Department of Civil and Environmental Engineerin
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A Simple Approach to Project Extreme Old Age Mortality Rates and Value Mortality-Related Financial Instruments
This article shows how mortality models that involve age effects can be fitted to ages beyond the sample range using projections of age effects as replacements for age effects that might not be in the sample. This âprojected age effectâ approach allows insurers to use age-effect mortality models to obtain valuations of financial instruments such as annuities that depend on projections of extreme old ag
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SO<sub>2</sub> emissions from basaltic eruptions, and the excess sulfur issue
Volcanic SO2 can affect the Earth's environment. Where no direct measurements of SO2 in the atmosphere are available, a petrologic method of assessing sulfur release from the magma must be used. However, in studies of arc-derived eruptions, satellite-based measurements of SO2 emissions using Total Ozone Mapping Spectrometer (TOMS) data are orders of magnitude greater than those calculated petrologically, implying that a separate S-rich gas phase in the magma chamber may be responsible for the excess sulfur. We test whether this applies in other settings. For Icelandic and Hawaiian basalts we find that petrologic SO2 values are comparable to measurements of SO2 by TOMS. Thus, for non-arc basalts, the petrologic method gives reliable estimates of SO2 released. The implied absence of excess sulfur in non-arc basaltic magmas is a reflection of source magma conditions, notably lower fO2 and volatile contents than arc magmas, inhibiting the exsolution of a S-rich gas prior to eruption
Methane Abundance Variations toward the Massive Protostar NGC 7538 : IRS9
Absorption and emission lines originating from the nu3 C-H stretching
manifold of gas phase CH4 were discovered in the high resolution (R=25,000)
infrared L band spectrum along the line of sight toward NGC 7538 : IRS9. These
observations provide a diagnostic of the complex dynamics and chemistry in a
massive star forming region. The line shapes resemble P Cygni profiles with the
absorption and emission components shifted by ~7 km/s with respect to the
systemic velocity. Similar velocity components were observed in CO at 4.7 um,
but in contrast to CH4, the CO shows deep absorption due to a high velocity
outflow as well as absorption at the systemic velocity due to the cold outer
envelope. It is concluded that the gas phase CH4 abundance varies by an order
of magnitude in this line of sight: it is low in the envelope and the outflow
(X[CH4]<0.4e-6), and at least a factor of 10 larger in the central core. The
discovery of solid CH4 in independent ground and space based data sets shows
that methane is nearly entirely frozen onto grains in the envelope. It thus
appears that CH4 is formed by grain surface reactions, evaporates into the gas
phase in the warm inner regions of protostellar cores and is efficiently
destroyed in shocks related to outflows.Comment: Scheduled for publication in ApJ 615, 01 Nov. 2004. 11 page
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