5,600 research outputs found
Gravitational Wave Detector Sites
Locations and orientations of current and proposed laser-interferometric
gravitational wave detectors are given in tabular form.Comment: 2 pages, revtex, no figure
A preliminary treatment of the Holomitrium complex (Musci: Dicranaceae) in Central America
The Holomitrium-complex (consisting of Holomitrium, Eucamptodontopsis, and Schliephackea) is a group of closely related genera in the Dicranaceae characterized by five features: 1. a strong single costa, 2. well developed alar cells, 3. long, sheathing perichaetial leaves, 4. erect capsules, and 5. undivided peristome teeth. Holomitrium sinuosum is newly described. Dicranoloma brittonae is transferred to Eucamptodontopsis. Holomitrium standleyi is a synonym of H. arboreum. Breedlovea chiapensis is a synonym of Holomitrium pulchellum and the genus Breedlovea is placed into the synonymy of Holomitrium
A preliminary treatment of the genus Campylopus (Musci: Dicranaceae) in Central America
There are 26 species of Campylopus in Central America. They are divided into three groups on the basis of two characters: the presence or absence in the costa of a ventral layer of enlarged, hyaline cells and the presence or absence in the stem of an outer hylodermis. Dicranum costaricensis Bartr. is transferred to Campylopus as C. valerioi nom. nov. Campylopus hoffmanii and C. standleyi are recognized as distinct species. Six new synonyms are proposed: C. straminifolius = C. densicoma; C. costaricensis = C. surinamensis; C. roellii = C. tallulensis; C. donnellii = C. zygodonticarpus; C. tuerckheimii = C. zygodonticarpus; C. sargii = C. zygodonticarpus
A revision of the genus Crossomitrium (Musci: Hookeriaceae)
Crossomitrium is a genus of neotropical, essentially epiphyllous mosses. The genus consists of six species that are distributed in two sections: section Crossomitrium (C. acuminatum, C. patrisiae, and C. scabrisetum) and section Cormophila (C. epiphyllum, C. saprophilum, and C. sintenisii). Section Crossomitrium is characterized by 1. plants nearly always on leaves or twigs, 2. lateral leaves oblongacuminate and widest below the middle, 3. leaves when dry that arch from an erect base downward to the substrate and, 4. the presence of specialized brood branches that are closely adnate to the substrate and have tightly imbricate leaves. Section Cormophila is characterized by 1. plants growing on rocks and tree trunks as well as on leaves, 2. lateral leaves oval to obovate, acute to apiculate and widest above the middle, 3. leaves when dry flattened to the substrate and, 4. the presence of erect, specialized brood branches that have leaves spreading on all sides. Crossomitrium is placed in the Hookeriaceae (sensu Whittemore & Allen, 1989) on the basis of its branched stems, ecostate leaves, straight, unbranched rhizoids that are tightly clustered just posterior to the leaf bases, 2-celled axillary hairs and weakly pigmented stem cortex. Within the Hookeriaceae Crossomitrium is considered close to the genus Lepidopilum by virtue of 1. its peristome which is hydrocastique and has a high basal membrane, 2. the spinose setae of C.acuminatum and C. scabrisetum, 3. the irregular subdivision of its stomatal guard cells (including the presence of stomates at the base of raised pustules), 4. leaves doubly serrulate by the projecting ends of contiguous marginal cells, 6. absence of a stem central strand. It differs from Lepidopilum in its 1. symmetric, ecostate leaves, 2. calyptra fimbriate by downward projecting, multicellular hairs that arise from the margins of the calyptra, 3. collenchymatous exothecial cells, 4. the presence of broodbodies on specialized brood branches as well as in clusters just below the junction of the leaf with the stem
A checklist of the mosses of Belize
A survey of the limited literature on the mosses of Belize and an examination of various taxonomic revisions has been made, together with many recent collections giving rise to a list of 250 species and 13 varieties. Extensive nomenclatural changes have been made since the older contributions came into print, so that the present list will serve as a basis for future recording
The Petition: A Global Warming Case Study
These are the teaching notes for a case study in which students consider the political, economic, and ethical issues surrounding the debate over global warming. This case was designed to strengthen their understanding of the greenhouse effect; global warming and its possible causes; how past changes in temperature and carbon dioxide concentration can be estimated; what controls weather patterns; geochemical cycles; and how to read graphs and interpret data. In addition, they will acquire a better understanding of how humans may impact the earth's environment; the politics and economics of scientific issues; how and why experts may differ; and their responsibility in dealing with ethical and political issues. Educational levels: High school, Undergraduate lower division
Closed Form Expression for the Momentum Radiated from Cosmic String Loops
We modify the recent analytic formula given by Allen and Casper for the rate
at which piecewise linear cosmic string loops lose energy to gravitational
radiation to yield the analogous analytic formula for the rate at which loops
radiate momentum. The resulting formula (which is exact when the effects of
gravitational back-reaction are neglected) is a sum of O(N^4) polynomial and
log terms where, N is the total number of segments on the piecewise linear
string loop. As illustration, we write the formula explicitly for a simple
one-parameter family of loops with N=5. For most loops the large number of
terms makes evaluation ``by hand" impractical, but, a computer or symbolic
manipulator may by used to yield accurate results. The formula has been used to
correct numerical results given in the existing literature. To assist future
work in this area, a small catalog of results for a number of simple string
loops is provided.Comment: 17 pages, RevTex 3.0, 3 postscript figures and C-language computer
code available via anonymous ftp from directory pub/pcasper at
alpha1.csd.uwm.edu, WISC-MILW-94-TH-1
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