bluuebunny/crossref_metadata_2025 huggingface dataset:
Diastereoface-Differentiating Reactions in a New Type of Enzyme Bound 5-Deazaflavin Model
Authors: Kawamoto Tetsuji , Tanaka Kiyoshi , Kuroda Yoshihiro , Yoneda Fumio
Published: May 2006

In a new type of enzyme bound 5-deazaflavin model (1), hydrogen incorporation occurred exclusively at the pseudoequatorial position at C(5) in the reduced product. In hydrocyanation of 1, cyano group occupied both the equatorial and the axial positions depending on the experimental conditions employed. Consideration of bent conformations of the reduced or addition products explains these results.
Effects of Water and Water-Mimicking Solvents on the Lipase-Catalyzed Esterification in an Apolar Solvent
Authors: Kitaguchi Hiroshi , Itoh Isamu , Ono Mitsunori
Published: May 2006

The enantioselectivity, as well as the catalytic activity of Candida Cylindracea lipase was found to be affected by water and water-mimicking solvents in n-hexane. There existed a parallel relation between the reaction rate and the selectivity; the faster the former, the higher the latter.
Mechanism of Thermal Dehydrogenation of Hydrotreated Pitch Using Tritium Tracer
Authors: Kabe Toshiaki , Wang Xiangsheng , Ishihara Atsushi , Shono Hiroaki
Published: May 2006

Behavior of hydrogen during the heat treatment of the tritiated coal tar pitch for high performance carbon fiber (HPCF) was investigated under nitrogen atmosphere by using a tritium as a tracer of hydrogen atoms. It was found that the reactions of carbon–carbon bond cleavage and the evaporation of volatile components were end up at about 600 °C. The dehydrogenation of polynuclear aromatic rings are sustained up to 1000 °C.
Conductivity Change of SnO2 with CO2 Adsorption
Authors: Tamaki Jun , Akiyama Morito , Xu Chaonan , Miura Norio , Yamazoe Noboru
Published: May 2006

Evidence for the electronic interaction of CO2 with the SnO2 surface has been collected for the first time. The adsorption of CO2 at 100 °C resulted in an considerable increase in electric resistance of SnO2, holding a quantitative relation between them. Such interaction became invisible in the presence of H2O because of the interference.
Synthesis and Structure of the New Organometallic Polyoxovanadates, {[(η-C8H12)Ir]2(V4O12)}2− and [(η-C8H12)Ir(V4O12)]3−
Authors: Day Victor W , Klemperer Walter G , Yagasakl Atsushi
Published: May 2006

A 1,5-cyclooctadieneiridium complex of V4O124−, {[(η-C8H12)Ir]2(V4O12)}2− is synthesized as a tetra-n-butylammonium salt by reacting [(η-C8H12)IrCl]2 with either [(n-C4H9)4N]3V5O14 or [(n-C4H9)4N]VO3 in CH3CN. The reaction of [(η-C8H12)IrCl]2 with [(n-C4H9)4N]VO3 in CH3CN also yields [(η-C8H12)Ir(V4O12)]3− as a tetra-n-butylammonium salt. X-Ray structural analyses revealed that the [(η-C8H12)Ir(V4O12)]3− and {[(η-C8H12)Ir]2(V4O12)}2− anions contain a V4O124− ring coordinated to one or two (η-C8H12)Ir+ moieties, respectively.
Structural Characterization of the Transition-metal Imido Complex Coordinated in a Bidentate Fashion. Preparation and the Molecular Structure of Seven-Coordinate Hydrido(succinimido-N,O)bis[1,2-bis(dipehnylphosphino)ethane]molybdenum(II)
Authors: Kurishima Susumu , Ito Takashi
Published: May 2006

The photoreaction of [MoH4(dppe)2] with succinimide gave [MoH(succinimido-N,O)(dppe)2], which was characterized spectroscopically as well as X-ray crystallographically to have the imido ligand coordinated to the metal bidentately via nitrogen and oxygen atoms constructing four membered metallacycle.
Synthesis of Glufosinate via Amidocarbonylation
Authors: Takigawa Shinichiro , Shinke Shuzo , Tanaka Masato
Published: May 2006

Cobalt carbonyl-catalyzed carbonylation of methylvinylphosphinate with acetamide followed by hydrolysis gave 2-amino-4-[hydroxy(methyl)phosphinyl]butanoic acid (glufosinate) in more than 80% overall yield.
Evaluation of Complex Formation of Bis(12-crown-4)s with Sodium Picrate in Solution by 23Na NMR Spectroscopy
Authors: Tanaka Minoru , Mizufune Hideya , Shono Toshiyuki
Published: May 2006

The complex formation of malonate-type bis(12-crown-4)s with sodium picrate was studied by 23Na NMR. The dependence of the 23Na NMR signals on the molar ratio [bis(12-crown-4)]/[Na+] is quite different from that on a molar ratio [monocyclic 12-crown-4]/[Na+], indicating the stable sandwich-type complex formation for the bis(12-crown-4)s.
Axial Preference of Bulky Group- and Electron-Withdrawing Group-Substituted Oxygen Atom on the Chair-Type -Cyclohexanone, -Glutaric Anhydride, and -Glutarimide
Authors: Nagao Yoshimitsu , Goto Michimasa , Ochiai Masahito , Shiro Motoo
Published: May 2006

Axial preference (>ca. 70% at 25 °C) of alkoxy and silyloxy groups of the chair-type six-membered cyclic compounds has been clarified by the 1H-NMR bandwidth mesurement method. Based on the X-ray analysis of 4-substituted cyclohexanones, it has been disclosed that the cyclohexanone ring adopts chair form and the 4-substituent occupies the axial site in all cases.
Amorphous V–P Mixed Oxide with P/V = 2.0 as Active Phase for Butane Oxidation
Authors: Morishige Hidetaka , Tamaki Jun , Miura Norio , Yamazoe Noboru
Published: May 2006

V–P mixed oxide catalysts prepared by evaporation method was made up of a mixture of an amorphous phase with P/V = 2.0 and a crystalline phase of (VO)2P2O7. The amorphous phase, separated from the (VO)2P2O7 particles by dissolving the precursor in boiled water, was found to show essentially the same selectivity and activity per unit surface area for the maleic anhydride formation from butane as the unseparated catalyst.
Dissociation and Conduction of Alkali Metal Ion in Nafion/Crown Ether Composite Films
Authors: Takeoka Shinji , Sakai Hiromi , Tsuchida Eishun
Published: May 2006

M+-Nafiori (M = Li, Na, K)/crown ethers (15-crown-5, 18-crown-6) composite films show single ion conduction, reflecting the ion-dipole interaction between cations and crown ethers. Stable cation/crown ether complex leads to the high dissociation of M+-Nafion but results in the low ionic conductivity.
Reactions between Pentadienyltins and 1,2-Naphthoquinones, Regiocontrolled Introduction of Pentadienyl Group
Authors: Nishigaichi Yutaka , Takuwa Akio
Published: May 2006

1,2-Naphthoquinones were efficiently pentadienylated at their 4-position with usa of pentadienyltin (PDT) reagents. Regiochemistry of the introduced pentadienyl moiety, α, γ, or ε position of the PDT, was controlled by both the reaction conditions and the reactants.
1H-NMR Spectroscopic Studies on the BiruthenoceniumX+PF6− (X; Br, Cl) Salts
Authors: Watanabe Masanobu , Sano Hirotoshi , Motoyama Izumi
Published: May 2006

BiruthenoceniumX+PF6− salts expressed as [Ru(II)Cp(C5H4)(C5H4)CpRu(IV)X]+PF6− were obtained by oxidizing biruthenocene with FeX3 in HX–NH4PF6 (X; Br, Cl) solution. 1H-NMR spectroscopic studies of the salts suggest the presence of rapid intramolecular electron transfer between the Ru(II) and Ru(IV) atoms at room temperature.
Synthesis and Crystal Structure of Potassium cis-Diamminetetranitrocobaltate(III). Completion of the Nitroammine Series
Authors: Fujihara Takashi , Fuyuhiro Akira , Yamanari Kazuaki , Kaizaki Sumio
Published: May 2006

cis-K[Co(NO2)4(NH3)2] was first synthesized from hexanitrocobaltate(III) in liquid ammonia and characterized by the elemental analysis and electronic and infrared spectra. The cis structure was confirmed by the X-ray analysis. The anomalous congested contact among three oxygens of three nitro ligands was found in the crystal.
Generation, Characterization, and Reactions of Fulvene Dianions
Authors: Kawase Takeshi , Fujino Shin-ichi , Oda Masaji
Published: May 2006

The dianion of 6,6-diphenylfulvene obtained by reduction with lithium metal was first characterized spectroscopically. Reduction of 6-dimethylamino-6-phenylfulvene also generated its dianion whose reactions with electrophiles led to 6-phenylfulvene derivatives, demonstrating synthetic utility of fulvene dianions.
Syntheses and Properties of Novel Vinyl Monomers Bearing a Glycoside Residue
Authors: Kitazawa Sadaya , Okumura Masakazu , Kinomura Keisuke , Sakakibara Toshiyuki
Published: May 2006

Novel acrylic monomers bearing a monosaccharide residue were synthesized in reactions of some methyl glycosides with 2-hydroxylethyl acrylate or methacrylate in the presence of heteropoly acid. All of them were highly soluble in water and readily polymerized by radical initiators.
An Efficient and Stereocontrolled Syntheses of (±)-Methyl Epijasmonate and (±)-Cucurbic Acid
Authors: Seto Hideharu , Yoshioka Hirosuke
Published: May 2006

The total synthesis of epijasmonoids, (±)-methyl epijasmonate and (±)-cucurbic acid, starting from norbornene was described, where a key intermediate, 5β-hydroxy-2β-methoxycarbonylmethylcyclopentane 1β-acetic acid γ-lactone was efficiently prepared via a highly regioselective Baeyer–Villiger oxidation of 7-syn-substituted norbornanone based on remote substituent control.
Preparation Method and Lithium Adsorption Property of λ-MnO2-Silica Composite
Authors: Onodera Yoshio , Iwasaki Takashi , Hayashi Hiromichi , Torii Kazuo
Published: May 2006

A new composite material based on λ-MnO2 and macroporous silica was prepared by heat-treatment of the silica beads impregnated with a mixed aq. solution of lithium and manganese nitrates (Li/Mn molar ratio = 0.5), followed by acid-treatment. This composite can adsorb Li+ ion selectively and has merit of usable for column operation.
Photoinduced Electron-Transfer Reactions of Poly(4-trimethylsilylmethylstyrene) in the Presence of Polycyanobenzenes
Authors: Mizuno Kazuhiko , Kobata Toshitsugu , Maeda Ryouichi , Otsuj Yoshio
Published: May 2006

The photoreactions of poly(4-trimethylsilylmethylstyrene) (2) with o-, m-, and p-dicyanobenzenes in benzene-acetonitrile (3:2) afforded insoluble polymers in high yields. On the other hand, the photoreaction of 2 with 1,2,4,5-tetracyanobenzene gave a soluble polymer. In the latter photoreaction, the trimethylsilyl group of 2 was efficiently replaced by 2,4,5-tricyanophenyl group. The mechanistic features for the formation of insoluble polymers were also described.
A Facile Access to 3-Hydroxycephems from Penicillin G through Bi/Sn or Ti/Sn Redox-Promoted Cyclization of 4-(Phenylsulfonylthio)azetidinones
Authors: Tanaka Hideo , Taniguchi Masatoshi , Kameyama Yutaka , Monnin Marc , Sasaoka Michio , Shiroi Takashi , Nagao Shigemitsu , Torii Sigeru
Published: May 2006

Direct conversion of 1-(3-chloro-2-hydroxy-1-p-methoxybenzyloxycarbonyl-1-propenyl)-4-(phenylsulfonylthio)azetidinones derived from penicillin G into 3-hydroxycephems was performed successfully by the action with BiCl4/Sn or TiCl4/Sn bimetal redox couples in DMF containing pyridine.
High Cation Extractabilities of Acyclic Ionophores Having Quinaldate Moieties and Their Conformations in Solution
Authors: Wakita Ryuhei , Fujiwara Kazuhiko , Nakatsuji Yohji , Okahara Mitsuo
Published: May 2006

New acyclic ionophores with two quinaldate terminal moieties showed efficient extraction abilities toward alkali metal ions; one of them extracted K+ on about the same level with unsubstituted 18-crown-6. Their conformations in solution were examined by 1H NMR.
A Novel Method for the Preparation of 2-Hydroxyiminocarboxylic Acid Esters. Cobalt(II) Catalyzed α-Oximation of α,β-Unsaturated Esters with Butyl Nitrite and Phenylsilane
Authors: Kato Koji , Mukaiyama Teruaki
Published: May 2006

Various α,β-unsaturated esters are directly converted to the corresponding 2-hydroxyiminocarboxylic acid esters with butyl nitrite and phenylsilane in high yields by use of N,N′-bis(2-ethoxycarbonyl-3-oxobutylidene)ethylenediaminato cobalt(II) complex as catalyst under mild condition.
Improved Stability by Two-Dimensional Crosslinking of Langmuir–Blodgett Films of a Polyamine/Polycarboxylate Salt
Authors: Ueno Tetuo , Kunitake Toyoki
Published: May 2006

A polyion complex of a maleic acid copolymer with poly(allylamine) was transferred onto solid substrates by the Langmuir–Blodgett technique, and converted by heating at 150 °C in vacuo to a two-dimensionally crosslinked film. The pinhole-free, imidecrosslinked LB film (6 layers) on a Fluoropore membrane did not deteriorate when immersed in water or in benzene.
Wavelength-dependent Photofading of Zinc Phthalocyanin in the Presence of an Electron Donor
Authors: Nishimura Yoshinobu , Kaneko Yuji , Arai Tatsuo , Sakuragi Hirochika , Tokumaru Katsumi , Ktten Mariko , Yamamura Shigeo , Matsunaga Daisaku
Published: May 2006

Zinc(II) phthalocyanintetrasulfonate exhibits a remarkable wavelength effect in its photoreduction with triethanolamine. This compound is durable to visible light but reduced on irradiation with near-UV light.
Extracyclic Stereocontrol in Addition Reaction of Crotylsilanes with 2-Substituted 2-Cyclopentenones. Stereodivergent Synthesis of (+)-Neonepetalactone and (+)-Isoneoneptalactone
Authors: Pan Li-Rui , Tokoroyama Takashi
Published: May 2006

The addition reaction of E- and Z-crotylsilanes with 2-substituted 2-cyclopentenones showed the preference of erythro and threo products respectively. The refinement of the selectivity was investigated and the result was utilized for efficient syntheses of the title natural products.
The Absolute Stereochemistry of Salvinorins
Authors: Koreeda Masato , Brown Lindsey , Valdés III Leander J
Published: May 2006

The absolute stereostructures of the hallucinogenic diterpenes salvinorin A and B have been unambiguously determined by the use of the non-empirical exciton chirality circular dichroism method on their 1α,2α-diol dibenzoate derivative.
Solid Electrolyte CO2 Sensor Using Binary Carbonate Electrode
Authors: Yao Sheng , Shimizu Youichi , Miura Norio , Yamazoe Noboru
Published: May 2006

A simple potentiometric CO2 sensor based upon a Na+-conducting solid electrolyte (NASICON) was found to be greatly improved in response time and water vapor-resistance by using a binary carbonate electrode of BaCO3–Na2CO3. For a wide range of CO2 concentration from 4 to 400000 ppm, the electromotive force examined at 823 K followed a Nernst’s equation excellently, with a 90% response time of as short as 8 s. Water vapor hardly affected the sensor characteristics, in contrast to the case of a pure Na2CO3 electrode.
Tin(IV) Chloride Catalyzed Addition of Methyl 2-Oxo-3-alkenoates to Simple Alkenes
Authors: Sera Akira , Ohara Meguru , Yamada Hiroaki , Egashira Emiko , Ueda Naohiro , Setsune Jun-ichiro
Published: May 2006

Tin(IV) chloride catalyzed inverse electron demand hetero-Diels-Alder reaction of substituted methyl 2-oxo-3-alkenoates with simple alkenes led to methyl 3,4-dihydro-2H-pyran-6-carboxylates in satisfactory yields. The addition proceeded stereospecifically through an exo transition state.
Nucleophilic Substitutions at Olefinic Carbon Atoms. S-N and N-N Exchange Reactions of 4-Trifluoroacetyl- and 4,4-Bis(trifluoroacetyl)-1,3-butadienyl Sulfides and -Amines with Various Amines
Authors: Hojo Masaru , Masuda Ryoichi , Okada Etsuji
Published: May 2006

Nucleophilic substitutions at olefinic carbon atoms of 4-trifluoroacetyl- and 4,4-bis(trifluoroacetyl)-1,3-butadienyl sulfides and -amines with various amines proceed easily under mild conditions to give the corresponding S-N and N-N exchanged products.
Oxidative Addition of Halo(methyl)silanes to an In Situ Generated Ir(I) Complex and β-Hydride Elimination Reaction of the Resulting (Methylsilyl)iridium Complexes
Authors: Yamashita Hiroshi , Kawamoto Aparecida M , Tanaka Masato , Goto Midori
Published: May 2006

Halomethylsilanes (MeSiCl3, Me3SiI, Me2SiCl2, Me3SiCl, and Me3SiBr) undergo oxidative addition to IrH(pipr3)2 in situ generated from IrH5(pipr3)2 and two equivalent neohexene to form halo(organosilyl)iridium(III) complexes. In addition, the resulting (methylsilyl)iridium complexes undergo β-hydride elimination reactions leading to the formation of dihydroiridium species.
Ni(1,4,8,11-tetrathiaundecane). Synthesis of a Square Planar NiS2S−2 Complex in Terms of CO-dehydrogenase
Authors: Yamamura Takeshi , Arai Hiroki , Nakamura Nobuhumi , Miyamae Hiroshi
Published: May 2006

Ni(1,4,8,11-tetrathiaundecane), the mononuclear nickel complex of 1,4,8,11-tetrathiaundecane, was synthesized, and the molecular structure was studied by X-ray crystallography. The XANES spectrum of the coordination unit, a square planar NiS2S−2 geometry, was discussed in terms of the nickel in CO-dehydrogenases.
Structural Stability of Lecithin Liposomes as Improved by Adding an Artificial Boundary Lipid
Authors: Sunamoto Junzo , Goto Mitsuaki , Akiyoshi Kazunari
Published: May 2006

Enzymatic lyses of phosphatidylcholine liposomes by phospholipase A2 and D are significantly depressed by adding an artificial boundary lipid, 1,2-dimyristoylamido-1,2-deoxyphosphatidylcholine (DDPC). Most interestingly, DDPC was not the substrate even for phospholipase D and phospholipase A2 as well.
Facile Synthesis of Alkylthiophosphonium Salts of Tris(2,6-dimethoxyphenyl)phosphine and Their Reactions with Thiols
Authors: Wada Masanori , Kanzaki Mituyuki , Fujiwara Masanobu , Kajihara Kazuhisa , Erabi Tatsuo
Published: May 2006

Tris(2,6-dimethoxyphenyl)phosphine sulfide reacted with alkyl iodides or bromides under mild conditions to give stable alkylthiophosphonium salts, which reacted with thiols at room temperature in the presence of a catalytic amount of tris(2,6-dimethoxyphenyl)phosphine to give the tertiary phosphonium salt and unsymmetrical disulfides.
The Effect of Preheating Treatment on the Pyrolysis of Chlorophyll-a. Simulation of Diagenetic Processes in Kerogen Formation
Authors: Ishiwatari Mariko , Ishiwatari Ryoshi , Sakashita Haru , Tatsumi Takashi , Tominaga Hiro-o
Published: May 2006

Pyrolysis of chlorophyll-a preheated at 250 °C has been carried out to investigate the precursor of 1-pristene often observed in pyrolysis products of kerogens. The 1-pristene/(phytadienes + phytene) ratio increased with increasing preheating time, suggesting the significance of the moiety derived from chlorophyll as the precursor of 1-pristene.
Selective Hydrodechlorination of CFC-113 to 1-Chloro-1,2,2-trifluoroethylene over Supported Ni Catalysts
Authors: Ueda Wataru , Tomioka Satoshi , Morikawa Yutaka , Sudo Motonori , Ikawa Tsuneo
Published: May 2006

Various metal oxides have been examined as catalysts for the hydrodechlorination of CFC-113 to form 1-chloro-1,2,2-trifluoroethylene (CFC-1113). NiO was most effective and over silica gel- or Y zeolite-supported Ni catalyst, 100% conversion of CFC-113 and 96% selectivity to CFC-1113 were attained.
Conductometric Determination of Boric Acid by Reversed-phase High Performance Liquid Chromatography Using Sorbitol as a Complexing Agent
Authors: Zenki Michio , Ohtani Jun , Ikeda Takahiko , Tôei Kyoji
Published: May 2006

Separation and determination of boric acid by reversed-phase liquid chromatography with conductivity detection have been demonstrated. D-Sorbitol was used as a precolumn complexing agent for boric acid and water as the mobile phase. The detection limit was 20 ng ml−1.
Highly Conductive Langmuir–Blodgett Films of Pyrolytic Polyimide
Authors: Akatsuka Takahisa , Tanaka Hideaki , Toyama Jiro , Nakamura Takayoshi , Kawabata Yasujiro
Published: May 2006

Highly conductive Langmuir–Blodgett (LB) films were obtained by the pyrolysis of polyimide LB films at 1000 °C in vacuum or under nitrogen atmosphere. The films showed the conductivity of as high as 300 S/cm, depending on the thickness of the film. The highest conductivity so far obtained was 600 S/cm. The film was stable under ambient conditions over months.
Reactions of Sulfoxides Bearing ortho-Sulfur Functional Groups and Thianthrene Monooxide with Grignard Reagents
Authors: Furukawa Naomichi , Ogawa Satoshi , Matsumura Kazunori , Shibutani Tadao , Fujihara Hisashi
Published: May 2006

Diaryl sulfoxides bearing ortho-sulfur substituents react readily with Grignard reagents on the sulfur atom to produce the corresponding phenyl Grignard reagents bearing ortho-sulfur functional group. Furthermore, thianthrene monooxide was found to react with alkyl Grignard reagents affording o,o′-bis-Grignard reagent of diphenyl sulfide which was converted easily to Martin’s sulfurane.
Equitable Models for the Stochastic Ground-Holding Problem Under Collaborative Decision Making
Authors: Kotnyek Balázs , Richetta Octavio
Published: May 2006

The adoption of collaborative decision making within the ground-delay program rendered obsolete much of the published research on the ground-holding problem as the emphasis was on control of individual flights. We focus on two pertinent static-stochastic models that exercise control on groups of flights instead of individual flights. We show that the first model, developed previous to the collaborative decision-making initiative, is capable of providing the information needed for the assignment of ground holds under the current system; however, the integrality and equity of solutions is not guaranteed. We then prove that by focusing on marginally nondecreasing ground-hold cost functions, solutions to the linear programming relaxation of the first model are guaranteed to be integer and equitable. We also show that the second model, a model with linear costs developed after collaborative decision-making procedures were in place, is a simplified version of the first that offers the advantage of a smaller number of variables at the expense of modeling flexibility. Our computational results show that the size advantage does not translate into significantly faster running times and demonstrate the relevance of the modeling flexibility associated with the first model. These results suggest that implementation of the earlier model is still an attractive option.
Working in groups in an international publishing class
Authors: Phillips Angus
Published: May 2006

This article examines the attitudes of students to working in groups within a class studying for an MA in Publishing at Oxford Brookes University. The class is highly international with 20 nationalities represented. Comparative data was collected within the same cohort at different
stages of the academic year, and from a separate, more homogeneous class at undergraduate level. The findings showed more positive attitudes to group work amongst the international class alongside student concerns over language levels and free-riding. Appropriate interventions are discussed
as well as the value of group work for students' social interactions and employability.
Reviews
Authors: Arabas Jan , Cartiere Cameron
Published: May 2006

Review of the second annual International Society for the Scholarship of Teaching and Learning conference, October 2005, Vancouver, British Columbia, Canada

Tom Hunter - Living in Hell and Other Stories The National Gallery, 7 December 2005 - 12 March 2006 Jeff Wall - Photographs
19782004 Tate Modern, 21 October 2005 - 8 January 2006
Comparative evaluation of a new immunoradiometric assay for corticotropin
Authors: Wilkinson Charles W. , Raff Hershel
Published: May 2006

We have characterized the performance of a commercial two-site immunoradiometric assay for manual in vitro diagnostic measurement of plasma corticotropin from Scantibodies Laboratory. We compared the results with those of a similar commonly used assay from Nichols Institute Diagnostics that has recently been withdrawn from production. The lower detection limit, range of the standard curve, cross-reactivity, and intra-assay and inter-assay imprecision of the two assays are very similar. Measurement of clinical samples and a series of samples from an experimental subject demonstrate high correlations between the two assays. These factors, together with recent clearance by the United States Food and Drug Administration for manual in vitro diagnostic measurement, make the Scantibodies corticotropin immunoradiometric assay an appropriate replacement for the Nichols assay.
Entwicklung und Test mikroschwingungstechnischer Belastungseinrichtungen für ein optisches Messsystem zur Zuverlässigkeitsanalyse von Sensoren (Development and Test of Micro-vibration Loading Techniques for an Optical Measuring System for Sensor Reliability Analyses)
Authors: Rümmler Norbert , Schnitzer René
Published: May 2006

Für ein optisches Messsystem zur Analyse und Sicherung der Langzeitzuverlässigkeit von Mikrosystemen wurden zwei Demonstratoren mikroschwingungstechnischer Belastungseinrichtungen (Module) entwickelt. Das Akusto-Modul basiert auf einem speziellen Hochton-Lautsprecher. Mit dem Körperschall-Modul werden Sensorstrukturen berührend über einen Piezoaktuator angeregt. Zum Charakterisieren der thermo-mechanischen, insbesondere der dynamischen Sensoreigenschaften wird ein Laser-Scanning-Vibrometer eingesetzt. Die spektrale Lage der Eigenfrequenzen, die Amplitudenhöhe und die dazugehörigen Schwingformen gestatten Aussagen zum Bauteilverhalten und damit auch zur Zuverlässigkeit.
Evaluierung optischer Messmethoden am Beispiel mikromechanischer Bauelemente (Evaluation of Optical Measurement Techniques for the Characterization of Micromechanical Devices)
Authors: Kunz Ulrich , Müller-Fiedler Roland
Published: May 2006

Es wurden optische Messmethoden hinsichtlich ihrer Eignung zur Charakterisierung von mikromechanischen Bauelementen bewertet.

Ein weiterer Schwerpunkt war das Langzeitmonitoring von Materialeigenschaften mittels optischer Messtechniken. Dies wurde am Beispiel von HF-MEMS-Schaltern untersucht.
Vegetation development on the glacier forefield Morteratsch (Switzerland)
Authors: Burga Conradin A.
Published: May 2006

Abstract. Within the glacier forefield Morteratsch (1900–2100 m a.s.l.)near Pontresina, OberEngadin, Switzerland), the dominant plant species and communities of areas, deglaciated between 1857 and 1997, have been investigated. This study takes three species groups into consideration: (1) pioneer species; (2) subalpine forest and dwarf‐shrub/heath species; and (3) grassland species. On the basis of species cover‐abundance values and age data on the deglaciated areas, time‐related dynamics of selected plant species and the establishment of the Epilobietum fleischeri, Oxyrietum digynae and Larici‐Pinetum cembrae were estimated. First, invaders of the Epilobietum fleischeri appeared after ca.7yr (obtaining higher cover‐abundance values after ca. 27 yr). This community persists on the whole glacier forefield. The first plants of the Oxyrietum digynae appear after ca. 12 yr (though earlier on some sites); this community disappears after ca. 27 yr. The establishment of the Larici‐Pinetum cembrae took place after ca. 77 yr, while the climax stage was reached after ca. 97 yr since deglaciation.
Relations between the invasive Cinnamomum verum and the endemic Phoenicophorium borsigianum on Mané island, Seychelles
Authors: Fleischmann Karl
Published: May 2006

Abstract. In the Seychelles the endemic palm Phoenicophorium borsigianum and the aggressively invasive alien Cinnamomum verum are competitors in a series of habitats. The extent to which demographic variables (relative growth rates of leaf area (RGRAL) and height (RGRR) together with mortality and recruitment) were important determinants of the competitive ability of the above species was investigated.

It was studied whether competitive relations between Cinnamomum and Phoenicophorium can change with light intensity as a result of different morphological responses and to what extent native plants such as Phoenicophorium can establish, regenerate and potentially outcompete Cinnamomum in important biodiversity sites in mountain mist forest and intermediate forest habitats. The light intensity in terms of diffuse site factors (DifSF) was estimated at 32 microsites from hemispherical photographs using a computerized image analysis system. A new plant growth analysis function, the so‐called leaf area height index (ALHI), has been introduced and a principal components analysis (PCA) was carried out to evaluate the seedling performance of Cinnamomum and Phoenicophorium. Competition between Cinnamomum and Phoenicophorium was greatly influenced by the amount of available photosynthetically active radiation (PAR). For both species there was a negative correlation between mean leaf area of seedlings and light levels. Phoenicophorium responded significantly better in terms of RGRAL and ALHI to low gap light levels than Cinnamomum. Both species showed no further response to direct sunlight with levels of 98.7 % diffuse site factor. Phoenicophorium and probably other palms endemic to the Seychelles such as Deckenia nobilis and Roscheria melanochaetes act as a filter affecting the distribution and abundance of establishing Cinnamomum seedlings. Mortality of Cinnamomum was strongly negatively correlated with levels of PAR while Phoenicophorium showed no such correlation. Unlike Phoenicophorium, Cinnamomum could establish and regenerate only in light levels of >7.5 % diffuse site factor.
The remote sensing approach in broad‐scale phenological studies
Authors: Ricotta C. , Avena G.C.
Published: May 2006

Abstract. Satellite imagery provides a unique tool for monitoring seasonal dynamics of the Earth's vegetation on a global scale. The combination of the normalized difference vegetation index (NDVI) data derived from the Advanced Very High Resolution Radiometer (AVHRR) with a daily repeat cycle and 1 km spatial resolution makes weather satellites operated by the National Oceanic and Atmospheric Administration very well suited for deriving broad‐scale phenological metrics from satellite images. In this paper, similarities and differences between remotely sensed phenological studies and traditional symphenological studies conducted by ground‐based observations are summarized. Finally, major shortcomings in deriving phenological metrics from NDVI time series are discussed.
Effects of increased temperature and nitrogen availability on the displacement of Calluna vulgaris by Pteridium aquilinum
Authors: Werkman Ben R. , Callaghan Terry V.
Published: May 2006

Abstract. Atmospheric greenhouse gas concentrations will continue to rise for the foreseeable future, and, due to radiative forcing, surface temperatures will also increase. If soils warm sufficiently, this will result in increased litter decomposition rates, while nitrogen availability will also rise due to increased deposition. A field‐based experiment manipulating air temperatures using polythene tents and nitrogen availability by adding 50 kg N ha‐1 yr‐1 has shown that this will result in further encroachment of Pteridium into Calluna moorland. Although this experiment, treating plots on and around the boundary between Pteridium and Calluna, did not show any statistically significant effect on the movement of the boundary, there were clear indications of Calluna dieback at the boundary. In addition, the frequency of Pteridium fronds increased in the Calluna‐dominated areas, while Calluna became less abundant in the pure Pteridium plots. Calluna dieback was not due to litter accumulation as is frequently assumed, but the dieback is likely to be caused by shading of Calluna by the increased growth of Pteridium fronds. Botanical diversity was higher in the Pteridium plots, but considering the importance of grouse shooting for the maintenance of Calluna moorland, displacement of Calluna by Pteridium may result in a lower conservation and economic value of moorlands.
Soil seed bank and regeneration potential on eroded hill slopes in the Kondoa Irangi Hills, central Tanzania
Authors: Lyaruu H.V.M. , Backeus I.
Published: May 2006

Abstract. The soil seed bank of the severely eroded Kondoa Irangi Hills, Tanzania was studied in order to determine the seed density and composition and to establish the relationship between seed bank and standing vegetation. The area had not been grazed for 15 yr prior to the study. A recently grazed area was used for comparison. The seed bank density (at 0 ‐ 5 cm depth) ranged from 344 to 915 8 seeds/m2 in the dry season and 172 to 5107 seeds/m2 in the wet season. The seed bank was very heterogeneous, both spatially and temporally, and it showed significant variation in size and composition in both sampling periods. The species similarity between the seed bank and the above‐ground vegetation in all plots was low (Sørensen's index = 0.00–0.44). The highest similarity was found in the recently grazed area. The seed bank was dominated by annuals and by early successional species. It is concluded that re‐vegetating the hill slopes with woody vegetation by using the seed bank will be difficult because seeds of woody species were not found in the soil.
Stimulation of seed germination in an abandoned hay meadow
Authors: Losvik M.H.
Published: May 2006

Abstract. In order to stimulate germination from the soil seed bank in a formerly species‐rich hay meadow for conservation purposes, eight gaps were made in each of four habitat types: (1) Dry/open, (2) Dry/shaded, (3) Moist/open and (4) Moist/ shaded; the meadow was abandoned 12 yr before the experiment started. The mean tree cover of the gaps was reduced from 50 % to 22 %. Light was estimated as distance to nearest tree towards south and shade as tree cover. Soil moisture content was estimated from topography and measured from soil samples.

There were no significant differences in total herb number between strata before the experiment started. The number of the target group herb indicators of old, traditional management, was however higher in dry, open areas than in shaded areas whether moist or dry. After the treatment, 15 herbs appeared anew in the gaps, nine of these were indicators of traditional management. 80 % of the indicators present after treatment were either new or had increased in frequency in the gaps. More indicators of traditional management appeared in gaps in the open, on dry soils in slopes than in shaded gaps, on moist soils and flat surface. In order to stimulate germination from the seed bank of as many herb indicators of traditional management as possible in abandoned hay meadows of the region, dry, sloping areas, situated as far as possible from large trees towards south and in the open, should be chosen for making gaps for germination.
Patterns of species richness in a limestone grassland under different treatments in relation to spatial scale
Authors: Huber Renate
Published: May 2006

Abstract. In an experiment in a limestone grassland on the Baltic island of Öland, SE Sweden, nutrient and water supply, light intensity and grazing regime were altered in 10 combinations during four years in 10 plots of 0.25 m2 with subplots of 0.01 m2 and 0.0004 m2.

Only the combined application of fertilizer and shade led to a strong decrease in average species richness (S1) at all scales. When comparing species numbers summed up over all 10 replicates of each treatment (Sn) at the three quadrat sizes, differences in effect of these treatments were much smaller, and were so already at the finest scale.

α‐diversity, measured as (Sn ‐ S1 was quite constant over different scales for most treatments, i.e. diversity did not increase with an increase in scale. The ‘richness ratio’Sn/S1 decreased with increasing scale, indicating an increasing degree of homogeneity at larger scales.

Treatments which only included fertilizer or shade, maintained high species richness; this high richness was also maintained in combination with grazing and could then be explained by the denser packing of vegetation. Patterns of species richness were correlated at the large scale, but not at the finer scales, indicating a high degree of spatial and temporal heterogeneity at the finer scales. With increasing quadrat size species persistence increased which explains the small effect of certain treatments.

Clearly, a range of scales has to be sampled in this type of vegetation to be able to measure different patterns, which may occur under different experimental treatments. The finest scale in this study can become too small, when certain treatments result in a coarse‐grained vegetation pattern. The quadrat size of 10 cm x 10 cm should be included in the range of scales. It combines accuracy in sampling with efficiency in time effort, a reasonably large number of species sampled, and a strong differentiation in the effects of the various treatments.
Quantitative Investigations of Leaf Pigments From Their Inception in Buds Through Autumn Coloration to Decomposition in Falling Leaves
Authors: Sanger Jon E.
Published: May 2006

Pigments in hazel (Corylus americana), aspen (Populus tremuloides), and pin oak (Quercus ellipsoidalis) leaves were measured from their inception in buds to development of a summer maximum, and through the autumn coloration period to decomposition in dry falling leaves. Leaves contained generally high but varyingconcentrations of chlorophyll and carotenoid pigments throughout the summer months. The summer pigment variations among the three species are discussed in the light of the usefulness of chlorophyll content as an index of net primary productivity. During the autumn coloration period, preceding leaf desiccation and fall, chlorophyll decays rapidly, producing low levels of pheophytin with only occasional faint traces of pheophorbide and chlorophyllide during the period of most rapid chlorophyll breakdown. The levels of carotenoids begin declining at the same time as chlorophyll, but at a much slower rate. Violaxanthin disappears most rapidly, followed closely by neoxanthin. Lutein and Beta—carotene are the most stable carotenoids. Falling oak leaves, whether dropped to the ground in autumn or held on the tree throughout the winter, in spring still contain measurable amounts of letuein and Beta—carotene and low concentrations of pheophytin a. Con—current with the autumn degradation of plastid pigments in an abrupt and substantial rise in anthocyanin of oak and hazel. At leaf—fall aspen and hazel leaves are devoid of all pigments.
Primary Productivity of Red Alder Ecosystems
Authors: Zavitkovski J. , Stevens R. D.
Published: May 2006

Fifty red alder communities from 1 to 65 years old were studied in western Oregon. Highly significant correlations were found between an index of volume and dry weights of whole trees, individual stems, crowns, tops, and roots. Correlations of dry weight with other independent variables (age, dbh, height) were variable and strongly curvilinear. Ratios of crown to stem in dominant trees were higher than those of suppressed or intermediate trees. Biomass of aboveground parts increased rapidly during the first 20 years and of maximum growth (between 10 and 15 years) averaged 26 mt/ha per year. Net assimilation rates ranged from 2.58 to 4.33 mt/mt per year. To produced best yields, red alder stands should be harvested for 20 years of age.
Predator‐Prey Interaction in a Tropical Lacustrine Ecosystem
Authors: Zaret Thomas M.
Published: May 2006

Two distinct morphs of the freshwater zooplankter Ceriodaphnia cornuta are distributed heterogeneously within the same tropical lake. One form, having a relative superior reproductive potential, is the numerically dominant morph in the open—water areas of the lake. The second form is found commonly only in the near—shore areas along with a nearly equal percentage of the first form. The second morph has a large advantage in terms of avoiding predation and its distribution coincides with that of the important lake predator, the planktivorous fish Melaniris chagresi. Complementary field and laboratory studies support the conclusion that the stable polymorphism of Ceriodaphnia cornuta, found only in the near—shore waters is maintained by predation pressure from melaniris chagresi. The relationship found in the study among predation, competition, and the primary productivity of the ecosystem is discussed in terms of how these factors interact to determine the final species diversity.
Spatial and Chronological Patterns of Purshia Tridentata as Influenced by Pinus Ponderosa
Authors: Sherman Robert J. , Chilcote William W.
Published: May 2006

Rodent caching is a significant factor in the establishment of Purshia tridentata in central Oregon pine forest. The pattern of cache placement is strongly influenced by pine litter patterns. As litter accumulates because of fire exclusion, desirable litter—free sites are becoming less abundant. As a result, a decline in Purshia populations may be expected.
Crayfish as Possible Agents of Dissemination of Fairy Shrimp into Temporary Ponds
Authors: Moore Walter G. , Faust Barry F.
Published: May 2006

Faxonella clypeata, coinhabitant with fairy shrimp in Louisiana temporary ponds, was fed ovigerous shrimp to test its role as a possible disseminator of anostracan eggs. Viable eggs of Artemia salina were recovered from crayfish feces. In tests utilizing Streptocephalus seali as food, intact eggs were recovered from the feces of 26% of the crayfish, of which 36% hatched.
The Use of a Fish‐Eye Lens to Study Nest Placement in Franklin's Gulls
Authors: Burger Joanna
Published: May 2006

A Franklin's Gull colony in northwestern Minnesota was sampled to determine if there is a correlation between closeness of adjacent nests and visibility. A method of vegetation analysis using a fish—eye lens in presented. Franklin's Gulls select nest sites which are least visible to neighboring gulls.
Effects of Low Soil Temperature on Transpiration, Photosynthesis, Leaf Relative Water Content, and Growth Among Elevationally Diverse Plant Populations
Authors: Anderson Jay E. , McNaughton S. J.
Published: May 2006

The effects of low soil temperature on photosynthesis and water relations were examined in 17 populations of 12 vascular plant species from native elevations ranging between 10 m and 3,170 m. Root permeability to water was sufficient in the majority of populations studied so that neither transpiration nor net photosynthesis was reduced at 3 degrees C soil temperature compared to the rates at 20 degrees C soil temperature. There was no evidence of differential natural selection along altitudinal gradients for ability to maintain photosynthesis rate when roots were chilled. Leaf relative water content was typically reduced in response to soil cooling. There is a critical relative water content above which both transpiration and photosynthesis are insensitive to water content reductions. Root chilling failed to reduce relative water content below this level in most populations studied. Low soil temperatures which had no adverse effects on transpiration or photosynthesis were found to significantly retard plant growth. The observed relative water content reductions might limit growth despite their failure to affect photosynthesis. Evidence for natural selection for ability to maintain turgor upon root chilling in high elevation populations was provided by an inverse relationship between the magnitude of depression in relative water content and native elevation. Thus, growth reduction at low soil temperatures must result from impaired turgor, decreased root growth and metabolism, or impaired cytokinin synthesis and translocation rather than direct limitation of carbon assimilation.
Effects of Thermal Additions From the Yellowstone Geyser Basins on the Benthic Algae of the Firehole River
Authors: Boylen Charles W. , Brock Thomas D.
Published: May 2006

During the spring and summer of 1971 and 1972 quantitative measurements of temperature, water chemistry, and standing crop of benthic algal mats were made at a series of stations along the Firehold River as it flows through the main geyser basins of Yellowstone National Park. The river is an ideal study area for assessing the long—term effects of thermal additions, since it has been subject to heating effects for hundreds of years. Hot springs and geysers in the geyser basins add to the river heated and nutrient—enriched water of about one—third the volume of river water. As the river flowed through the thermal areas, the temperature gradually increased to a maximum daily midsummer temperature 12 degrees higher than the unheated upper portion of the river (15 degrees to 27 degrees C), and the river began cooling when the thermal additions to the river ceased. The river was coldest in early June, when maximum input from melting snow occurred, and remained relatively warm in the heated areas throughout the winter. Alkalinity, pH, conductivity, phosphate, and chloride also increased markedly; nitrate and ammonium concentrations appeared not to be influenced by the additions of hot spring water. The quantity of chlorophyll per unit area extracted from epilithic algal mats also increased with the amount of thermal water input to 20 times that in the unheated control areas. The apparent growth rates of benthic algae calculated from periodic quantitative sampling of cleaned rocks were over fivefold greater in the warmer than in the cooler portion of the river. The effect of temperature on light—dependent incorporation of (14)CO_2 by epilithic, epipelic, and epiphytic algal communities at different stations was measured. The temperature optimum for CO_2 fixation paralleled the midsummer temperature of the habitat although it averaged about 3 degrees higher at each station. The algae retained their midsummer temperature optima even during the early June period of cold water, suggesting that these optima are controlled by the mid—summer maximum temperature. Photosynthesis with natural populations was measured in the presence of increased concentrations of the algal nutrients to determine whether the increased algal growth rate in the warmer parts of the river might be due to nutrient enrichment rather than to temperature. The results suggest that higher temperatures from the additions of thermal water increase the algal standing crop through increase in growth rate of the algae, and that the algae in the heated portion of the river are optimally adapted to the temperatures of their habitats.
Microfungal Populations in Surface Soils of Manipulated Prairie Stands
Authors: Wicklow Donald T.
Published: May 2006

Comparisons of populations of soil microfungi from surface soils of bare, mulched, harvested, and recently burned prairie stands, with those from a dry—mesic control stand (1 year post—burn), revealed some remarkable distribution patterns for various fungal isolates. With the exception of the harvested and the control stands, little similarity could be found among any of the populations. Furthermore, the overall species composition of the populations showed little resemblence to populations isolated from within the dry—mesic segment of the prairie continuum in southern Wisconsin. Numbers of fungi and bacteria also exhibited a great deal of variation depending on the stand treatment. The most significant variations in microbial density included reductions in the numbers of fungi in the bare stand and major increases in fungal densities in the recently fired stand. Bacterial counts were higher in the mulched and the burned stands, but significantly lower in the bare stand, and greatly reduced in the moss—covered harvested stand. Manipulation of the dry—mesic prairie stands so altered the microbial balance that the resulting populations differed more than those reported earlier for the entire prairie continuum. Certain physiochemical properties of the microenvironment are important in the selection of prevalent fungi isolated from these stands. Evidence shows that a post—fire fungal bloom occurs following grassland fires. Coniochaeta discospora and C. tetraspora, two pyrenomycetes, accounted for 60% of all isolates recovered from the burned stand. Both of these fungi produce ascospores whose dormancy is not readily broken.
Energetics of High and Low Populations of the Limpet, Acmaea Scabra (Gould)
Authors: Sutherland John P.
Published: May 2006

Individuals of Acmaea scabra on the "edge" of the species' range have been shown to grow faster and to attain a larger size than individuals in the "center" of the range. As a result, the subpopulation on the "edge" contained a higher biomass (Sutherland 1970). Energy flow was also measured during that study; the data are used here to test the hypothesis that energy flow should be greater in the "center" of the species' range, since that is the habitat where physiological adaptation is most precise. However, the flow of energy is shown to be approximately equal for both populations and the hypothesis is refuted. The possible reasons for this outcome are discussed.