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Selected Works

1997

Articles 1 - 14 of 14

Full-Text Articles in Physical Sciences and Mathematics

Cloning And Conservation Of Biological Diversity: Paradox, Panacea, Or Pandora's Box?, Shaily Menon, Kamaljit Bawa, Leah Gorman Jul 1997

Cloning And Conservation Of Biological Diversity: Paradox, Panacea, Or Pandora's Box?, Shaily Menon, Kamaljit Bawa, Leah Gorman

Shaily Menon

The success of a Scottish team in cloning a mammal from an adult tissue cell has generated considerable speculation in the popular press about potential applications to conservation biology. Possibilities that have been mentioned include cloning endangered species and creating gene banks for the germplasm of rare species. Sensational or inaccurate reports might encourage the mistaken notion that cloning technology is more advanced or reliable than it actually is. More important, such reports might foster the myth that there is no longer an urgency to conserve endangered species or their habitats as long as we have frozen germplasm and cloning …

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Synthesis Of [15n,15n‘]-N,N,N‘,N‘-Tetramethyl- Ethylenediamine And Its Use In Solvation Studies Of [6li]-N-Butyllithium., Delia Waldmüller, Barbara Kotsatos, Michael Nichols, Paul Williard Jun 1997

Synthesis Of [15n,15n‘]-N,N,N‘,N‘-Tetramethyl- Ethylenediamine And Its Use In Solvation Studies Of [6li]-N-Butyllithium., Delia Waldmüller, Barbara Kotsatos, Michael Nichols, Paul Williard

Michael A Nichols

No abstract provided.

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Timing And Extent Of Late Quaternary Paleolakes In The Trans-Pecos Closed Basin, West Texas And South-Central New Mexico, David Wilkins, Donald Currey Apr 1997

Timing And Extent Of Late Quaternary Paleolakes In The Trans-Pecos Closed Basin, West Texas And South-Central New Mexico, David Wilkins, Donald Currey

David E. Wilkins

The Trans-Pecos Closed Basin is a hydrographically closed region covering 20,000 km centered on Salt Basin, 160 km east of El Paso, Texas. Geomorphic and limnetic evidence have been used to identify four major highstands for Lake King during the last glacial maximum (LGM). Additional geomorphic features from a second, recently identified, paleolake, Lake Sacramento, have been found in the Beargrass subbasin, a nested subbasin approximately 75 km northwest of Salt Basin. Radiocarbon ages of the organic material in Lake King sediments date four abrupt climate changes and rapid lacustrine transgressions during the LGM with a quasi-periodicity of 2000 yr. …

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Two-Photon Optogalvanic Spectra Of Argon: Odd Parity Rydberg States, Naveed Piracha, M. Baig, S. Khan, B. Suleman Mar 1997

Two-Photon Optogalvanic Spectra Of Argon: Odd Parity Rydberg States, Naveed Piracha, M. Baig, S. Khan, B. Suleman

Naveed K. Piracha

Extensive new data on the odd-parity, single-colour, two-photon optogalvanic spectra of argon in the visible region is reported using an excimer-pumped dye laser in conjunction with an argon discharge cell. The experimental technique enables us to record a pure two-photon spectrum in a region which is dominated by one-photon transitions. A large number of two-photon transitions, originating from the two metastable states [...] and [...] to the excited states of configurations [...] (J=0, 2) and [...] (J = 0 - 4) of argon, has been recorded and arranged into 10 Rydberg series. The interchannel interactions among the [...] and the …

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Small Scale Electronic Transport In Diamond Microcrystals., M. Jaeger, S. Hyun, Anthony Day, M. Thorpe, B. Golding Feb 1997

Small Scale Electronic Transport In Diamond Microcrystals., M. Jaeger, S. Hyun, Anthony Day, M. Thorpe, B. Golding

Anthony Roy Day

The interpretation of electronic transport in polycrystalline diamond has proven difficult as a result of the disorder arising from physical and chemical inhomogeneities. We describe experimental methods, based on electron beam lithography, for studying transport in single crystallites grown by CVD on Si substrates. The electrical contacting process utilizes the flexibility of the scanning electron microscope to write metallic contacts to individual crystallites with lateral dimensions of a few μm. A detailed analysis of the current distribution in the crystals allows us to extract the electronic conductivity from arbitrarily shaped, faceted crystals.

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The Voltammetry Of Sc3@C82, Mark Anderson, Harry Dorn, Paul Burbank, Steven Stevenson, James Gibson Jan 1997

The Voltammetry Of Sc3@C82, Mark Anderson, Harry Dorn, Paul Burbank, Steven Stevenson, James Gibson

Mark R. Anderson

Many endohedral metallofullerenes have a C82 cage surrounding the metals, even though the normal arc-vaporization method of fullerene preparation does not generate C82 in significant abundance.1-10Manolopous et al.11-13attribute the low abundance of empty-cage C82 to the unfavorable electron configuration of this species. Consequently, the prevalence of C82 in metallofullerenes may be the result of an electron transfer from the encapsulated metal atoms to the fullerene cage.10-13 The extent of this charge transfer also contributes to the properties (e.g. catalytic, superconductive, nonlinear optical, and ferromagnetic) that are attributed to the endohedral metallofullerenes.14,15Because of the importance of the charge transfer reaction, characterization …

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Constraint Satisfaction Methods For Generating Valid Cuts, John Hooker Dec 1996

Constraint Satisfaction Methods For Generating Valid Cuts, John Hooker

John Hooker

No abstract provided.

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A Niobium(V) Complex With Mixed O,S-Donor Ligands. Synthesis, Structure And Properties Of The Anion Tris(2-Mercapto-4-Methylphenolato)Niobate(V), Paul Challen, Diane Peapus, Karen Magnes Dec 1996

A Niobium(V) Complex With Mixed O,S-Donor Ligands. Synthesis, Structure And Properties Of The Anion Tris(2-Mercapto-4-Methylphenolato)Niobate(V), Paul Challen, Diane Peapus, Karen Magnes

Paul R. Challen

Reaction of Nb(OEt)5 with 2-mercapto-4-methylphenol (mmpH2) in the presence of triethylamine gave the mononuclear tris complex (Et3NH)[Nb(mmp)3] which was structurally characterized. The coordination geometry around the niobium is between octahedral and trigonal prismatic, with a twist angle of 41.5°. The mercaptophenolate ligands are arranged around the metal in a “propeller” fashion. (Et3NH)[Nb(mmp)3] was characterized by IR, 1H NMR and UV-vis spectroscopies, and cyclic voltammetry. A reversible reduction wave found at −1.03 V is for reduction to the NbIV complex.

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Effectiveness Of The Protected Area Network In Biodiversity Conservation: A Case-Study Of Meghalaya State, M. Latif Khan, Shaily Menon, Kamaljit Bawa Dec 1996

Effectiveness Of The Protected Area Network In Biodiversity Conservation: A Case-Study Of Meghalaya State, M. Latif Khan, Shaily Menon, Kamaljit Bawa

Shaily Menon

The North-Eastern region of India is significant for biodiversity conservation because of its floristic richness and high levels of endemism. Deforestation levels are high in the region due to anthropogenic pressures. We accessed various literature sources to create a database for Meghalaya state containing information on plant species, habit, altitudinal distribution, endemism, and endangered status. Information on the existing protected area network (type, extent, and altitudinal representation) was added to the database. The database was used to assess the effectiveness of the existing protected area network in conserving the floristic biodiversity of the state. Of a total of 3331 plant …

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Biodiversity Monitoring: The Missing Ingredient, Kamaljit Bawa, Shaily Menon Dec 1996

Biodiversity Monitoring: The Missing Ingredient, Kamaljit Bawa, Shaily Menon

Shaily Menon

With mounting losses in biological diversity, inventorying and monitoring of biodiversity to assess the magnitude and rate of losses are emerging as dominant themes in conservation biology. Inventorying has been defined as the surveying, sorting, cataloging, quantifying and mapping of entities ranging from genes to landscapes1 and monitoring has been defined as the surveillance of the compliance with or deviation from a predetermined standard2. Renner and Ricklefs3 argued that rushed inventories will compromise scientific rigor and have little influence on decision making. More recently, Stork et al.4 argued that losses in biological diversity are so severe that inventorying and monitoring …

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The Elastic Moduli Of Random Networks: Calculations, Anthony Day Dec 1996

The Elastic Moduli Of Random Networks: Calculations, Anthony Day

Anthony Roy Day

No abstract provided.

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Mathematica In Action., Stan Wagon Dec 1996

Mathematica In Action., Stan Wagon

Stan Wagon, Retired

No abstract provided.

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Constructing Essential Laminations In 2-Bridge Knot Surgered 3-Manifolds, Ramin Naimi Dec 1996

Constructing Essential Laminations In 2-Bridge Knot Surgered 3-Manifolds, Ramin Naimi

Ramin Naimi

A nontrivial knot that can be drawn with only two relative maxima in the vertical direction is called a 2-bridge knot, and one that can be drawn on a torus is called a torus knot. Loosely speaking, a lamination in a manifold M is a foliation of M, except that it can have a nonempty open complement in M, and very loosely speaking, the lamination is essential if each leaf of it L is incompressible, i.e. inclusion of L into M induces an injective homomorphism from π1(L) into π1(M). Our main result is: Theorem 2. Every 3-manifold obtained by surgery …

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Is There Environmental Racism? The Demographics Of Hazardous Waste In Los Angeles County, J. Boer, Manuel Pastor, James Sadd, Lori Snyder Dec 1996

Is There Environmental Racism? The Demographics Of Hazardous Waste In Los Angeles County, J. Boer, Manuel Pastor, James Sadd, Lori Snyder

James Sadd

The article assesses the location of treatment, storage and disposal facilities (TSDF) in Los Angeles County, California, with focus on racism. The study shows that a simple comparison of tracts with and without TSDF reveals statistically significant differences by race and economic status along the lines suggested by the environmental justice proponents. There are also significant differences by industrial land use and manufacturing employment along the lines suggested by critics of the environmental justice concept. In this multivariate model race, along with industrial land use and employment in manufacturing, remains a factor, rising income that has a positive then a …

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