bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of [4-t-Butyl-2,6-bis(N,N-dimethylaminomethyl)phenyl]thioxophosphine Sulfide with Intramolecular Participation of Nitrogen Lone Pair in Stabilization
Authors: Yoshifuji Masaaki , Otoguro Akihiko , Toyota Kozo
Published: July 2006

The 4-t-butyl-2,6-bis(N,N-dimethylaminomethyl)phenyl group was utilized to prepare [4-t-butyl-2,6-bis(N,N-dimethylaminomethyl)phenyl]thioxophosphine sulfide. A 31P NMR chemical shift of the thioxophosphine sulfide shows a high field shift by 153 ppm compared with that of (2,4,6-tri-t-butylphenyl)thioxophosphine sulfide, suggesting a strong intramolecular participation with the lone-pair electrons of the nitrogen atom in stabilization of the –P(=S)2 group.
Silylation of 2- or 3-Alkenenitriles with Iodosilanes/Triethylamine Affording 2- or 4-Silyl-2-alkenenitriles
Authors: Yamashita Hiroshi , Reddy N Prabhakar , Tanaka Masato
Published: July 2006

2- or 3-Alkenenitriles, (R1R2HC)R3C=CHCN or R1R2C=CR3CH2CN (R1, R2, R3 = H, Me, etc.), react with iodosilanes, R4Me2SiI (R4 = Me, Me3Si), in the presence of Et3N to give 2-silyl-2-alkenenitriles, (R1R2HC)R3C=C(SiMe2R4)(CN), in good to moderate yields with high E selectivity (R3 = H). A 2-methylalkenenitrile, H2C=CHCHMe(CN) or MeCH=CMe(CN), is silylated with Me3SiI to provide a 4-silyl-2-alkenenitrile, Me3SiCH2CH=CMe(CN).
Estimation of the Ratio of Hidden Multivalent Ions in Nematic Lyomesophases by Using Heteronuclear NMR
Authors: Iida Masayasu , Mizuno Yuri , Miyagawa Yasuko
Published: July 2006

An estimation of the peak areas of the 59Co NMR spectra for cobalt(III) complex ions and of the 25Mg spectra for magnesium aqua ions gave population ratios of their hidden ions, which are defined as too strongly interacting with nematic lyomesophases (composed of cationic or anionic surfactants) to contribute to the NMR spectra. The cobalt(III) complex ions used were [Co(NH3)6]3+, [Co(en)3]3+ (en = ethylenediamine), [Co(phen)3]3+ (phen = 1,10-phenanthroline), and [Co(CN)6]3−. It was revealed that appreciable amounts of multivalent ions are present as hidden ions on the lyomesophase, whose sign of charge is opposite to that of the ion in question. For such hydrophilic ions as [Co(NH3)6]3+, [Co(en)3]3+, [Co(CN)6]3−, and magnesium ions, the ions binding to the mesophases are classified into two states based on the NMR spectra: One is an outer-sphere complex (ion pair); the other is a hidden ion. In these systems the hidden ion/total ion population ratios depending on the composition of the surfactant are roughly proportional to the ion pair/total ion population ratios, which are monitored by the magnitude of the quadrupole splitting. For the phen complex, the presence of a hidden ion was observed in the range where the fraction of the anionic surfactant is high; the quadrupole splittings were also observed only in limited composition ranges.
Studies on the Surface Property of Pt/KL Zeolite Catalysts
Authors: Dai Lian-Xin , Sakashita Haru , Tatsumi Takashi
Published: July 2006

Pt/KL catalysts prepared by ion exchange (IE), ion exchange followed by the addition of KCl (IE-KCl), incipient wetness impregnation (IWI), and coimpregnation with KCl (IWI-KCl) were compared regarding the aromatization of hexane, and were characterized by transmission electron microscopy, the chemisorption of H2 and NH3, the competitive hydrogenation of toluene and benzene, and the infrared spectroscopy of adsorbed CO. The majority of Pt particles on the various Pt/KL catalysts seem to be highly dispersed inside the zeolite channels. The presence of KCl in the Pt/KL catalysts resulted in a decrease in the acidity of zeolite, giving rise to a reduction in the C1–C5 selectivity, regardless of the method of catalyst preparation. The competitive reaction of toluene/benzene and FT-IR results consistently show that the Pt particles on the IE-KCl catalyst have the most electron-rich sites among the Pt/KL samples examined. The high specific activity for benzene production of the IE-KCl catalyst should be attributed to these Pt particle sites with high electron-donating ability. It is proposed that the terminal adsorption of hexane, resulting in the formation of primary alkyl species, is favorable on electron-rich Pt particles, leading to a 1,6-ring closure, and eventually benzene.
Dansyl-β-cyclodextrins as Fluorescent Sensors Responsive to Organic Compounds
Authors: Wang Yong , Ikeda Tsukasa , Ikeda Hiroshi , Ueno Akihiko , Toda Fujio
Published: July 2006

6-O-, 2-O-, and 3-O-Dansyl-β-cyclodextrins (1, 2, and 3) were synthesized and characterized. Compounds 1 and 2 decrease their fluorescence intensities upon intermolecular complex formation. This property enables 1 and 2 to act as fluorescent sensors, converting binding of organic compounds into fluorescence variations.
Photochemical Cis to Trans One-Way Isomerization of Styrylazulenes on Their Triplet Excited State. Examination of Ethylenes with Non-Benzenoid Substituents of Low Triplet Energies
Authors: Karatsu Takashi , Kitamura Akihide , Arai Tatsuo , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

1-Styrylazulene and 7-isopropyl-1,4-dimethyl-3-styrylazulene (3-styrylguaiazulene) underwent one-way isomerization from the cis to the trans isomer on triplet sensitization. Their triplet states as intermediates of the isomerization were observed by laser flash photolysis. However, their excitation to either the lowest excited singlet state (S1) or the second excited singlet state (S2) by direct irradiation afforded photostationary mixtures comprising 98% of the trans and 2% the cis isomers, which implies the participation of a singlet isomerization path.
Mechanisms for (Porphinato)manganese(III)-Catalyzed Oxygenation and Reduction of Styrenes in Benzene–Ethanol Containing Sodium Borohydride
Authors: Takeuchi Masayuki , Kano Koji
Published: July 2006

1-Phenylethanol, acetophenone, 2,3-diphenylbutane, and ethylbenzene are produced in the (porphinato)manganese(III)-catalyzed reaction of styrene with NaBH4 in aerobic benzene–ethanol. Chloro(5,10,15,20-tetraphenylporphinato)manganese(III) ([MnIIICl(tpp)]) and chloro[5,10,15,20-tetrakis(2,4,6-trimethylphenyl)porphinato]manganese(III) ([MnIIICl(tmp)]) have been used as the catalysts. It is suggested that the [MnIII(tpp)]-mediated reaction of styrene with NaBH4 yields 1-phenylethyl radical and [MnII(tpp)]. The 1-phenylethyl radical reacts with dioxygen to generate a peroxyl radical, (C6H5)(CH3)CHOO·, which is stabilized by coordinating to [MnII(tpp)]. [MnIII[OOCH(CH3)(C6H5)](tpp)] thus formed may yield [MnIIIOH(tpp)] and acetophenone which is readily reduced to 1-phenylethanol with NaBH4. The coupling and disproportionation reactions of the 1-phenylethyl radicals afford 2,3-diphenylbutane and ethylbenzene, respectively. Slower reaction of styrene observed in the catalysis by [MnIII(tmp)]+ can be interpreted in terms of a steric hindrace in the formation of the radical and [MnII(tmp)]. Similarly, all results obtained for α-methylstyrene can be explained by the formation of the 1-methyl-1-phenylethyl radical which is less reactive than the 1-phenylethyl radical and is free from the interaction with the manganese complex. The reaction mechanism involving the free radicals has been supported by the results on the effects of TEMPO.
NONEXISTENCE OF THE TWO MODIFICATIONS IN LIQUID NITROBENZENE AND CARBON BISULPHIDE
Authors: Murakami Eiji
Published: July 2006

The heating rate and the volume dilatation of nitrobenzene have been measured between 8° and 11°C. and the refractive index between 7° and 20°C. The density of nitrobenzene is d204=1.2030, and the refractive index for Hα line is given by the equation. n_c=1.555030–0.000455 t. The heating curve of carbon bisulphide has been measured between −100° and −85°C.

No arrest in the heating curves, no distinct change of the slope in the dilatation curve and no distinct change in the value of the refractive index have been observed within the range of the observed temperatures. Two layers in liquid carbon bisulphide at −90°C. could not be observed.

None of these results proves the existence of the two modifications of the liquid nitrobenzene and carbon bisulphide such as suggested by Wolfke and Mazur.
OBSERVATIONS ON THE ABSORPTION SPECTRA OF THE RARE EARTHS. II
Authors: Uzumasa Yasumitsu
Published: July 2006

1. The absorption spectra of chloride and nitrate of neodymium in various organic solvents were compared.

2. The changes of the bands of neodymium nitrate produced by adding a normal liquid to the alcoholic solution were examined.

3. It is suggested that the absorption bands of neodymium salts are shifted by solvent molecules as well as by the anion.
THE VISCOSITY OF VAPOURS OF ORGANIC COMPOUNDS. PART III
Authors: Titani Toshizo
Published: July 2006

(1) An apparatus, based on the principle of Trautz and Weizel, was constructed for measuring the viscosity of vapours.

(2) With this apparatus the viscosity of vapours of the following substances were measured at temperatures between about 120° and 300°C.: air, n-pentane, n-hexane, hexamethylene, benzene, methyl acetate, ethyl acetate, ethyl ether, methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, acetone, chloroform, carbon tetrachloride and carbon disulphide.

(3) From these measurements the constants of both Sutherland and Reinganum as well as collision diameters of molecules were calculated.

(4) The collision diameters calculated from viscosity data were found to be nearly equal to those computed from the constants b in the van der Waals equation and they came out to be proportional to the cube roots of molecular volumes at boiling points, as was already pointed out in the preceding paper except few cases.

(5) Values obtained for collision diameters of non-polar compounds such as carbon tetrachloride and hexamethylene seem to be too large and those for strong polar compounds such as methyl alcohol too small as compared with the values of molecular diameters computed from b or from the molecular volumes at boiling points.
STUDIES ON THE CONSTITUENTS OF THE VOLATILE OIL FROM THE WOOD OF CHAMAECYPARIS FORMOSENSIS, MATSUM
Authors: Kafuku Kinzo , Ichikawa Nobutoshi
Published: July 2006

(i) The volatile oil from the wood of Chamaecyparis formosensis, Matsum., or Formosa cypress (benihi), contains much less terpenes and much more terpenes alcohols as compared with the volatile oil from the leaf of the same plant.

(ii) The predominant terpenes in the oil are d-a-pinene and d-camphene, and they are optically strongly active.

(iii) Among the terpenic alcoholic components there have been proved two new substances ‘benihiol’ C10H18O, and ‘benihinol’ C10H18O.

(iv) In the sesquiterpene fraction, a new sesquiterpene whose hydrochloride has the melting point 103°–104°C. was isolated, and it was named sesquibenihene.

(v) Among the sesquiterpene alcohol fraction, there are, along with a tertiary alcohol of cadinol type, at least one more primary alcohol the exact nature of which is not yet definitely known.
HETEROGENEOUS CHEMICAL REACTIONS IN THE SILENT ELECTRIC DISCHARGE. XI
Authors: Miyamoto Susumu
Published: July 2006

The chemical reactions under the silent electric discharge were studied when hydrogen reacted with the following inorganic solid substances. (1) Potassium thiocyanate. Reaction products: hydrogen cyanide, hydrogen sulphide, and potassium sulphide.

(2) Potassium silver cyanide. Reaction products: silver and hydrogen cyanide.

(3) Calcium thiocyanate. Reaction products: hydrogen cyanide,hydrogen sulphide, and calcium hydroxide.

(4) Ammonium thiocyanate. Reaction products: hydrogen cyanide, ammonia, and hydrogen sulphide.

(5) Sodium thiosulphate. Reaction products: sodium sulphite, hydrogen sulphide, and sulphur.

(6) Magnesium thiosulphate. Reaction products: Magnesium sulphite, hydrogen sulphide, and sulphur.

(7) Barium thiosulphate. Reaction products: Barium sulphite, barium sulphide, hydrogen sulphide, and sulphur.

(8) Barium chlorate. Reaction products: barium chloride and water.

The writer wishes to express his appreciation of a grant from the Imperial Academy towards the expenses of this research.
Pathology of Naturally Occurring Paratuberculosis in Water Buffaloes (Bubalus bubalis)
Authors: Sivakumar P. , Tripathi B. N. , Singh N. , Sharma A. K.
Published: July 2006

Gross and histologic lesions of paratuberculosis were studied in water buffaloes. Small intestines and associated mesenteric lymph nodes of 405 water buffaloes were examined. Of these, 20 animals having visible changes of intestinal thickening, mucosal corrugations, and enlargement of mesenteric lymph nodes exhibited histologic alteration characteristics of mild to moderate granulomatous inflammation. The histologic lesions observed in these animals were classified into 3 grades on the basis of type of cellular infiltration, granuloma formation, and presence of acid-fast bacilli. Grade-1 lesions observed in 8 animals were marked by the presence of scattered epithelioid macrophages amid large number of lymphocytes in the intestinal villi and in the paracortical regions of the associated mesenteric lymph nodes. Another 8 animals classified under grade-2 revealed microgranulomas, infiltration with a larger number of epithelioid macrophages besides lymphocytes in the intestinal villi, and granulomas in the mesenteric lymph nodes. Grade-3 lesions observed in 4 animals were characterized by the presence of epithelioid granulomas and giant cells in the intestines and the mesenteric lymph nodes. The Ziehl-Neelsen's stained tissue sections revealed acid-fast bacilli in grade-3 and −2 animals and acid-fast granular debris in grade-1 animals. Among these 20 buffaloes, 14 (70%) were positive in the IS900 specific polymerase chain reaction and 6 (30%) were positive in the bacterial culture.
Fetus in Fetu in a Harbor Seal (Phoca vitulina richardi): Histopathologic, Genetic, and Toxicologic Analysis
Authors: Buckles E. L. , Gulland F. M. D. , Aldridge B. M. , Gelatt T. S. , Ross P. S. , Haulena M. , Lowenstine L. J.
Published: July 2006

A young harbor seal (Phoca vitulina richardi), stranded on the coast of California, was found to have a 20-cm-diameter cranial cervical mass. Surgical excision revealed the subcutaneous mass to be covered in haired skin with multiple glabrous areas and structures resembling a jaw with tooth buds, eyelids, and a tail. The mass deformed the host pup's skull. Histologic examination revealed a complete vertebra in the tail, teeth in the jaw, and areas resembling tongue and larynx. Class 1 MHC sequences amplified by polymerase chain reaction from the mass and the host twin were identical. The mass was diagnosed as a fetus in fetu, a rare congenital anomaly in which 1 conjoined twin is completely enclosed in the body of the other twin. The host pup died, and no additional defects were found; however, blubber levels of persistent organic pollutants were high. The cause of the congenital anomaly in this pup is uncertain.
Fibrosarcoma with Typical Features of Postinjection Sarcoma at Site of Microchip Implant in a Dog: Histologic and Immunohistochemical Study
Authors: Vascellari M. , Melchiotti E. , Mutinelli F.
Published: July 2006

A 9-year-old, male French Bulldog was examined for a subcutaneous mass located at the site of a microchip implant. Cytologic examination of the mass was suggestive of a malignant mesenchymal neoplasm. Histologically, the mass was confirmed as a high-grade infiltrative fibrosarcoma, with multifocal necrosis and peripheral lymphoid aggregates. By immunohistochemistry, the sample was investigated for vimentin, smooth-muscle actin (SMA), CD3, CD79α, and CD18. All the neoplastic cells were positive for vimentin. Scattered cells at the periphery of the lesion were also positive for SMA, highlighting a myofibroblastic phenotype. The lymphoid cells were positive for CD18 and CD3. No aluminum deposits were detected by the aurintricarboxylic acid method. A diagnosis of fibrosarcoma morphologically similar to feline postinjection sarcomas was made. Fibrosarcomas at the site of injections have been reported in dogs and ferrets. Furthermore, neoplastic growth at the site of microchip implant in dog and laboratory rodents has been described.
Disorder in alkali lead fluorides Na2–xKxPb11F18X6 with X = Cl, Br
Authors: Kubel Frank , Rief Andreas
Published: July 2006

The crystal structures of five new alkali-lead halide compounds of the family M′2–x
M″xPb11F18X6 with M′, M″ = Na, K, Na/K mixed and X = Cl, Br were studied. The compounds crystallize in space group P63/m [176]. A disordered lead/alkali halide network around alkali-filled trigonal prismatic channels builds the structure. Both lead sites are partially replaced by alkaline ions. The trigonal prismatic channels formed by fluorides are filled with Na+ in Wyckoff site 2b (CN 6) with pop = 0.5 or K+ in Wyckoff site 2a (CN of 3 + 6) with pop = 0.5. For the potassium sample, a split position of the fluorides forming the channel was found.

The structures with one alkaline ion show lattice parameters of a = b = 14.0679(9) Å, c = 3.9954(4) Å (Na/Cl), a = b = 14.2617(14) Å, c = 3.9991(4) Å (K/Cl), a = b = 14.5267(7) Å, c = 4.0580(3) Å (K/Br).

In NaKPb11F18Br6 and the Na0.714(16)K1.286(16)Pb11F18Cl6 (lattice parameters a = b = 14.4377(12) Å, c = 4.0576(3) Å and a = b = 14.1780(7) Å, c = 4.0093(3) Å), the lead ions in the matrix are partially substituted only with potassium. The occupation of the channels however is different: both alkaline ions are found in the chloride, (but in different Wyckoff positions) whereas in the bromide only sodium was observed. NaKPb11F18Br6, can therefore be described as a new type in this structure family.

Lattice parameters of the alkaline mixed samples show unexpected increase of the c-axis for both heavy halides. This property may be related with the occupation of Wyckoff position 2b. A similar behaviour was found for Ba7F12Cl2 (Ba2+ with CN 3 + 6) doped with Ca2+ (CN 6).

The vibrational parameters of all alkaline ions in the channel are strongly anisotropic.
Syntheses, spectroscopic and X-ray structure analyses of two dioxouranium (VI) complexes: supramolecular framework built from O—H…O, C—H…O and stacking interactions
Authors: Chakraborty Santu , Dinda Subhajit , Bhattacharyya Ramgopal , Mukherjee Alok Kumar
Published: July 2006

Two dioxouranium(VI) complexes, [UO2(PBHA)2(DMSO)] (I) and [UO2(SALOP)(H2O)] (II), PBHA = N-phenyl benzohydroxamate, DMSO = dimethyl sulfoxide, SALOP = N,N′-bis (salicylidene)-o-phenylene diaminate have been synthesized, and characterized by spectroscopic and X-ray studies. Both compounds (I) and (II) crystallize in orthorhombic system with space group Pbca. The molecules in (I) are linked by intermolecular C–H…O hydrogen bonds into 32-membered tetrameric clusters (U4C12O8N4H4), which are further connected via uranyl oxygen atoms forming a three-dimensional supramolecular framework. In (II), intermolecular O—H…O hydrogen bonds between molecules related by inversion and translation generate infinite zigzag chains of R
2
2(8) rings running along the [010] direction. The parallel chains are interlinked through C—H…O hydrogen bonds producing a complex supramolecular architecture in (II).
Effects on Production Traits of Haplotypes Among Casein Genes in Norwegian Goats and Evidence for a Site of Preferential Recombination
Authors: Hayes Ben , Hagesæther Nina , Ådnøy Tormod , Pellerud Grunde , Berg Paul R , Lien Sigbjørn
Published: July 2006

In goat milk the most abundant proteins are the casein genes, CSN1S1, CSN2, CSN1S2, and CSN3. Mutations have been identified within these genes affecting the level of gene expression, and effects on milk production traits have been reported. The aim of this study was to detect polymorphisms (SNPs) in the casein genes of Norwegian goats, resolve haplotype structures within the loci, and assess the effect of these haplotypes on milk production traits. Four hundred thirty-six Norwegian bucks were genotyped for 39 polymorphic sites across the four loci. The numbers of unique haplotypes present in each locus were 10, 6, 4, and 8 for CSN1S1, CSN2, CSN1S2, and CSN3, respectively. The effects of the CSN1S1 haplotypes on protein percentage and fat kilograms were significant, as were the effects of CSN3 haplotypes on fat percentage and protein percentage. A deletion in exon 12 of CSN1S1, unique to the Norwegian goat population, explained the effects of CSN1S1 haplotypes on fat kilograms, but not protein percentage. Investigation of linkage disequilibrium between all possible pairs of SNPs revealed higher levels of linkage disequilbrium for SNP pairs within casein loci than for SNP pairs between casein loci, likely reflecting low levels of intragenic recombination. Further, there was evidence for a site of preferential recombination between CSN2 and CSN1S2. The value of the haplotypes for haplotype-assisted selection (HAS) is discussed.
Effects of Sex and Insulin/Insulin-Like Growth Factor-1 Signaling on Performance in an Associative Learning Paradigm inCaenorhabditis elegans
Authors: Vellai Tibor , McCulloch Diana , Gems David , Kovács Attila L
Published: July 2006

Learning is an adaptive change in behavior in response to environmental stimuli. In mammals, there is a distinct female bias to learn skills that is still unprecedented in other animal taxa. Here we have investigated the biological determinants of performance in an associative learning paradigm in the nematode Caenorhabditis elegans. Using an assay of chemotactic reactions associated with food deprivation, wild-type male worms show inferior learning ability relative to hermaphrodites. Sex-based learning difference is therefore an ancient evolutionary feature appearing even in relatively simple animals. C. elegans mutants with reduced insulin/IGF-1 signaling also exhibit a greatly reduced learning ability in this assay. In addition, hyperactivation of insulin/IGF-1 signaling through loss-of-function mutations in the PTEN phosphatase daf-18, a negative regulator of insulin/IGF-1 signaling, enhances learning ability beyond that of wild type. According to our epistasis analysis, the effect of DAF-2 on learning acts via phosphatidylinositol 3,4,5-trisphosphate (PIP3) production, but not the DAF-16 FOXO transcription factor. This implies that the signaling pathway from DAF-2 affecting this learning paradigm branches between PIP3 production and DAF-16. However, learning capacity of nematodes is lowered by loss-of-function mutations in daf-16, suggesting involvement of noninsulin/IGF-1 signaling-dependent DAF-16 activation in learning. Potentially, sex and insulin/IGF-1 signaling affect performance in this learning assay via effects on the neurobiology of learning.
An Efficient Genetic Screen in Drosophila to Identify Nuclear-Encoded Genes With Mitochondrial Function
Authors: Liao T S Vivian , Call Gerald B , Guptan Preeta , Cespedes Albert , Marshall Jamie , Yackle Kevin , Owusu-Ansah Edward , Mandal Sudip , Fang Q Angela , Goodstein Gelsey L , Kim William , Banerjee Utpal
Published: July 2006

We conducted a screen for glossy-eye flies that fail to incorporate BrdU in the third larval instar eye disc but exhibit normal neuronal differentiation and isolated 23 complementation groups of mutants. These same phenotypes were previously seen in mutants for cytochrome c oxidase subunit Va. We have molecularly characterized six complementation groups and, surprisingly, each encodes a mitochondrial protein. Therefore, we believe our screen to be an efficient method for identifying genes with mitochondrial function.
An Unconventional Nuclear Localization Motif Is Crucial for Function of the Drosophila Wnt/Wingless Antagonist Naked Cuticle
Authors: Waldrop Sharon , Chan Chih-Chiang , Cagatay Tolga , Zhang Shu , Rousset Raphaël , Mack Judy , Zeng Wenlin , Fish Matt , Zhang Mei , Amanai Manami , Wharton Keith A
Published: July 2006

Wnt/β-catenin signals orchestrate cell fate and behavior throughout the animal kingdom. Aberrant Wnt signaling impacts nearly the entire spectrum of human disease, including birth defects, cancer, and osteoporosis. If Wnt signaling is to be effectively manipulated for therapeutic advantage, we first must understand how Wnt signals are normally controlled. Naked cuticle (Nkd) is a novel and evolutionarily conserved inducible antagonist of Wnt/β-catenin signaling that is crucial for segmentation in the model genetic organism, the fruit fly Drosophila melanogaster. Nkd can bind and inhibit the Wnt signal transducer Dishevelled (Dsh), but the mechanism by which Nkd limits Wnt signaling in the fly embryo is not understood. Here we show that nkd mutants exhibit elevated levels of the β-catenin homolog Armadillo but no alteration in Dsh abundance or distribution. In the fly embryo, Nkd and Dsh are predominantly cytoplasmic, although a recent report suggests that vertebrate Dsh requires nuclear localization for activity in gain-of-function assays. While Dsh-binding regions of Nkd contribute to its activity, we identify a conserved 30-amino-acid motif, separable from Dsh-binding regions, that is essential for Nkd function and nuclear localization. Replacement of the 30-aa motif with a conventional nuclear localization sequence rescued a small fraction of nkd mutant animals to adulthood. Our studies suggest that Nkd targets Dsh-dependent signal transduction steps in both cytoplasmic and nuclear compartments of cells receiving the Wnt signal.
Evidence That Sea Lamprey Control Led to Recovery of the Burbot Population in Lake Erie
Authors: Stapanian Martin A. , Madenjian Charles P. , Witzel Larry D.
Published: July 2006

Between 1987 and 2003, the abundance of burbot Lota lota in eastern Lake Erie increased significantly, especially in Ontario waters. We considered four hypotheses to explain this increase: (1) reduced competition with lake trout Salvelinus namaycush, the other major coldwater piscivore in Lake Erie; (2) increased abundance of the two main prey species, rainbow smelt Osmerus mordax and round goby Neogobius melanostomus; (3) reduced interference with burbot reproduction by alewives Alosa pseudoharengus; and (4) reduced predation by sea lampreys Petromyzon marinus on burbot. Species abundance data did not support the first three hypotheses. Our results suggested that the apparent recovery of the burbot population of Lake Erie was driven by effective sea lamprey control. Sea lamprey predation appeared to be the common factor affecting burbot abundance in Lakes Michigan, Huron, Erie, and Ontario. In addition, relatively high alewife density probably depressed burbot abundance in Lakes Ontario and Michigan. We propose that a healthy adult lake trout population may augment burbot recovery in some lakes by serving as a buffer against sea lamprey predation and will not negatively impact burbot through competition.
Molecular clock divergence estimates and the fossil record of
Cetartiodactyla
Authors: Theodor Jessica M.
Published: July 2006

Molecular clock estimates of divergence times for artiodactyls and
whales vary widely in their agreement with the fossil record. Recent
estimates indicate that the divergence of whales from artiodactyls occurred
60 Ma, a date which compares well with the first appearances of fossil
whales around 53.5 Ma, and artiodactyls at 55 Ma. Other estimates imply
significant gaps in the fossil record. A date of 65 Ma for the divergence of
Suidae and Ruminantia predates the appearance of Ruminantia by over 10
million years, and an estimate of 58 Ma for the divergence of Suidae from
Cetacea implies a gap of over 20 million years. Further, although a
molecular clock estimate has not been reported, the hypothesis that hippos
are the closest living relatives of the whales implies a potential ghost
lineage for hippos of over 40 million years. There are only two living
species of hippos, and their fossil record is sparse, while cetaceans and
other artiodactyls are speciose and have rich fossil records. A
40-million-year gap in the fossil record of hippos could be explained by
several possibilities: inadequate biogeographic sampling, taphonomic biases,
or undifferentiated primitive morphology. Similarly, a number of possible
problems may exist in the molecular data: rate variation in the genes
sampled, the low numbers of genes examined, and insufficient age
calibrations. In addition, there are potential problems in molecular
phylogeny estimation, such as long branch attraction and inappropriate
taxonomic sampling. Additional estimates of divergence times among living
taxa should provide a broader framework for comparison with the fossil
record and provide information to help identify which of these factors are
causing conflict.
Late Permian foraminifers from the limestone block in the Southern
Chichibu Terrane of west Shikoku, SW Japan
Authors: Kobayashi Fumio
Published: July 2006

A limestone block in the Shirokawa-Nomura area of western Shikoku
(Japan) is interpreted to have been originated as a Panthalassan seamount,
and is assigned to the northern part of the Southern Chichibu Terrane. The
Late Permian foraminiferal fauna from this block is composed of 33 species,
and is characterized by Nanlingella? sp., three
unidentified species of Staffellidae, Paraglobivalvulina mira,
Dagmarita chanakchiensis, Paradagmarita sp., and
Partisania sp. Among them, four unidentified
species are systematically described and discussed. Although this fauna is
indeterminately either Wuchiapingian or Changhsingian, it is clearly Late
Permian in age by comparison with Late Permian faunas in the Tethyan
regions, and by the complete absence of neoschwagerinids, verbeekinids, and
schwagerinids, which became extinct by the end of Middle Permian time. The
limestone block in the Shirokawa-Nomura area is clearly distinguished from
Upper Permian shelf limestones from the Kurosegawa, Southern Kitakami, and
Maizuru terranes by its lithology and by the complete absence of the
foraminifer Colaniella, one of the most important
index genera in Upper Permian strata throughout the Tethyan and
peri-Gondwana regions.
Intraspecific variation in a new solitary rugose coral, Commutia
exoleta, from the Lower Carboniferous of the Baoshan Block,
Southwest China
Authors: Wang Xiang-Dong , Tetsuo Sugiyama , Zhang Feng
Published: July 2006

Based on 137 specimens examined, the new species Commutia
exoleta is characterized by a small, slightly scolecoid
shape with 21 septa at a mean maximum corallite diameter of 6 mm (range 3 to
10.5 mm); a persistent inner wall, which encloses an aulos with a mean
maximum diameter of 1.2 mm, formed during an early ontogenetic stage when
the axial ends of the cardinal, alar and counter-lateral septa fused; short
counter septa are lacking in the earliest stage of development.

Corallites are highly variable. Characters exhibiting a wide range of
variation are: size and shape of corallites, number of septa, diameter of
aulos and the timing of its appearance, number of septa connected to the
inner wall, and the septal arrangement in each growth quadrant. Combinations
of these variable characters result in corallites that are each uniquely
different. Variations of those characters are partly due to stressed
environments, such as unstable, muddy substrates resulting in corallite
rejuvenescence and redirection.
A new family of Triassic lobsters (Decapoda: Astacidea) from British
Columbia and its phylogenetic context
Authors: Amati Lisa , Feldmann Rodney M. , Zonneveld John-Paul
Published: July 2006

Chimaerastacus pacifluvialis, new genus and
species, is established on the basis of fossils from the Middle Triassic
Liard Formation of northeastern British Columbia. It has well-defined
cervical, postcervical, and branchiocardiac grooves; three longitudinal
ridges on the cephalic region; and true chelae on the first through third
pereiopods. The morphological features of the carapace are a combination of
traits used to define both the erymids and the glypheids. A cladistic
analysis of 31 decapod genera defines the Astacidea as a monophyletic group,
supports the inclusion of the Glypheoidea within the infraorder Astacidea,
illustrates the relationships of the Glypheoidea with other astacid groups,
and suggests erection of a new family, the Chimaerastacidae, for our new
genus and species of decapod. Specimens of C.
pacifluvialis are preserved in a sandy bioclastic
floatstone that was deposited near the Peace River Embayment in the Middle
Triassic. The host lithology suggests that the decapods inhabited a
transitional environment between low relief biostromes and the shoreface.
This environment provided a unique set of conditions that allowed
exceptional preservation of the decapod material.
Morphology and taxonomy of Paleozoic millipedes (Diplopoda: Chilognatha: Archipolypoda) from Scotland
Authors: Wilson Heather M. , Anderson Lyall I.
Published: July 2006

New millipede specimens from the Paleozoic of Scotland are described, includingArchidesmus macnicoliPeach, 1882, from the Lower Devonian (Lochkovian) Tillywhandland Quarry SSSI and three new taxa—Albadesmus almondi, Pneumodesmus newmani, andCowiedesmus eroticopodus—from the mid Silurian (late Wenlock—early Ludlow) Cowie Formation at Cowie Harbour.Cowiedesmus eroticopodusnew species is placed within the new Cowiedesmidae within the new order Cowiedesmida.Kampecaris tuberculataBrade-Birks from the Lower Devonian (Siegenian) of the Lanark Basin near Dunure is shown not to be a kampecarid myriapod, redescribed asPalaeodesmus tuberculataand placed order incertae sedis within Archipolypoda.Anthracodesmus macconochieiPeach is also redescribed and tentatively placed order incertae sedis within Archipolypoda.Archidesmus macnicoli, Albadesmus almondi, andPalaeodesmus tuberculataare each demonstrated to have broad sternites with laterally placed coxal sockets and paramedian pores containing paired valves. These pores are interpreted as having housed eversible vesicles. Some specimens ofArchidesmus macnicoliandCowiedesmus eroticopodusare male and have a pair of modified legs on trunk segment 8, identified as leg pairs 10 and 11, respectively. The presence of modified anterior legs restricted to segment 8 increases the range of variability known in modified appendage location in male millipedes and compounds existing uncertainty about using the presence of gonopods on trunk segment 7 as a synapomorphy of Helminthomorpha. An affinity between Archidesmida and Cowiedesmida is suggested based on possession of modified legs on segment 8 and Archidesmida + Cowiedesmida is placed along with Euphoberiida in Archipolypoda based on possession of free, broad sternites with bivalved paramedian pores and fused pleurotergites. The oldest known evidence of spiracles is demonstrated inPneumodesmus newmani, proving that the oldest known millipedes were fully terrestrial.
A Pennsylvanian (Morrowan) ostracode fauna from Texas
Authors: Hoare Richard D. , Merrill Glen K.
Published: July 2006

A Lower Pennsylvanian (Morrowan) silicified ostracode fauna occurs just
above the conformable Mississippian-Pennsylvanian boundary within the
Barnett Formation in Texas. The fauna contains several taxa that were
previously restricted to the Upper Mississippian and numerous taxa only
known from the Lower Pennsylvanian. New taxa proposed include
Amphissites (Amphissites) morrowanensis n.
sp., Polytylites subrectus n. sp.,
Kirkbyella (Berdanella) delicata n. sp.,
Kindlella proscillata n. sp.,
Libumella walkerorum n. sp.,
Moorites tumidus n. sp.,
Leptoderos arytaina n. gen. and sp., and
Cribroconcha prolixa n. sp.
Late Triassic gastrochaenid and lithophaginid borings (Mollusca: Bivalvia) from Nevada (USA) and Austria
Authors: Carter Joseph G. , Stanley George D.
Published: July 2006

The endolithic life habit has evolved several times in the Bivalvia, e.g., in the superfamilies Modiolopsoidea (family Modiolopsidae), Mytiloidea (family Mytilidae, subfamily Lithophaginae), Arcoidea (family Arcidae), Cardioidea (family Tridacnidae), Veneroidea (family Petricolidae), Gastrochaenoidea, Myoidea (family Myidae), Hiatelloidea, and Pholadoidea (families Pholadidae and Teredinidae) (Otter, 1937; Yonge, 1963; Cox, 1969; Carter, 1978; Kleemann, 1980). The oldest known definite bivalve borings are Ordovician slotlike depressions in stromatoporoids, made by the facultative nestler/borer modiolopsidCorallidomusWhitfield, 1893 [1895] (Pojeta and Palmer, 1976; Wilson and Palmer, 1988). Pojeta and Palmer (1976) and Morton (1990) citedCorallidomusas the ancestor of the Lithophaginae. However, lithophaginids more likely evolved from modiolinid mytilids, which in turn evolved from modiolopsids (Fang and Morris, 1997; Fang, 1998; Carter et al., 2000).Lithophaga-like shells are known from the Carboniferous and Permian, but these Upper Paleozoic examples are not known to have been endolithic (Kleemann, 1983, 1990, table 2). Wilson and Palmer (1998) attributed certain borings without associated shells in Upper Carboniferous limestone cobbles to lithophaginids because the borings are widest near their anterior end and they lack a constricted neck. However, if, as Wilson and Palmer suggested, these borings are not posteriorly truncated, then their openings are relatively much wider than typical lithophaginid borings. One boring illustrated by Wilson and Palmer (1998, fig. 4) has an irregular anterior cross-sectional shape that is unlike lithophaginid and gastrochaenid borings. This irregularity recalls the Early Ordovician ichnospeciesGastrochaenolites oelandicusEkdale and Bromley, 2001, which is similarly vase-shaped. Ekdale and Bromley (2001) noted that the latter boring predates known endolithic bivalves, so they attributed it to an unknown invertebrate.
Evolutionary implications of a duplivincular ligament in the
Carboniferous pinnid Pteronites (Mollusca, Bivalvia,
Pteriomorphia)
Authors: Carter Joseph G.
Published: July 2006

Modern pinnoideans, or “pen shells,” are shallowly to deeply
endobyssate, equivalved, edentulous, ham-shaped bivalves with a single,
slightly submerged, opisthodetic ligament. Malacologists have generally
regarded pinnids as closely related to the pterioid superfamily Pterioidea,
especially its Paleozoic family Pterineidae (e.g., Zittel, 1927, p. 446;
Thiele, 1935, p. 803; Pojeta, 1978; Waller, 1978). As early as 1890, Jackson
suggested that pinnids evolved from the Silurian-Permian pterineid
Leptodesma Hall, 1883. More recently, Pojeta
(1978, p. 239) speculated that they evolved from the pterineid
Pteronitella Billings, 1874 (a Silurian genus
similar to Leptodesma) through the
morphologically intermediate Devonian Palaeopinna
Hall, 1883. The hinge and ligament of Palaeopinna
remain unknown, so its family-level placement is uncertain (Newell and
LaRocque, 1969, p. N301). However, Leptodesma and
Pteronitella have hinge teeth, inequivalved
shells, and a duplivincular ligament similar to other pterineids (Newell and
LaRocque, 1969, p. N299–N301; Pojeta, 1978, p. 239; Pojeta and Runnegar,
1985, fig. 16D; Carter, 1990a, p. 205; 1990b, p. 334).
Bivalve taphonomy in tropical mixed siliciclastic-carbonate settings. I. Environmental variation in shell condition
Authors: Best Mairi M. R. , Kidwell Susan M.
Published: July 2006

Contrary to the geological stereotype of pure-carbonate reef platforms, approximately 50% of shallow shelf area in the Tropics is accumulating siliciclastic and mixed siliciclastic-carbonate sediments. Taphonomic characterization of these settings is thus essential for assessing variation among major facies types within the Tropics, as well as for eventual comparison with higher-latitude settings. Our grab samples and dredge samples of bivalve death assemblages from nine stations in five subtidal habitats in a large marine embayment of Caribbean Panama (Bocas del Toro) provide the first actualistic information on the taphonomic condition of shells in Recent tropical siliciclastic sediments. Focusing on unambiguous damage to bivalve shell interiors, we found that the quality of shell preservation in fine-grained siliciclastics is superb: commonly «10% of specimens are affected by encrustation, boring, edge-rounding fine-scale surface alteration via dissolution, microbioerosion maceration. Pure-carbonate and mixed siliciclastic-carbonate environments containing hard substrata (patch reefs, Halimeda gravelly sand, mud among patch reefs) contain higher numbers of more severely damaged shells (generally >25%) and also higher diversities of fossilizable encrusters and borers. Disarticulation and fragmentation are pervasive across all environments and are probably related to predation rather than to postmortem processes. As in other shallow subtidal study areas, the taxonomic compositions of death assemblages have not been homogenized by postmortem transport but show high spatial fidelity to the distribution of living species. Assemblages from the five sedimentary environments have distinct taphonomic signatures, but the strongest differences are between the two fine-grained, exclusively soft-sediment siliciclastic environments on the one hand and the three environments containing hard substrata on the other. Experimental tests for rates and agents of damage, still in progress, indicate that the most critical environmental variables are exhumation cycles and burial rate. Bivalve death assemblages from Bocas del Toro demonstrate that damage levels in tropical fine-grained siliciclastic environments are much lower than in closely associated reefs and algal sands suggest a less filtered record of biological information.
Can C3 plants faithfully record the carbon isotopic composition of atmospheric carbon dioxide?
Authors: Arens Nan Crystal , Jahren A. Hope , Amundson Ronald
Published: July 2006

Atmospheric carbon dioxide is the raw material for the biosphere. Therefore, changes in the carbon isotopic composition of the atmosphere will influence the terrestrial δ13C signals we interpret. However, reconstructing the atmospheric δ13C value in the geologic past has proven challenging. Land plants sample the isotopic composition of CO2during photosynthesis. We use a model of carbon isotopic fractionation during C3 photosynthesis, in combination with a meta–data set (519 measurements from 176 species), to show that the δ13C value of atmospheric CO2can be reconstructed from the isotopic composition of plant tissue. Over a range of pCO2(198–1300 ppmv), the δ13C value of plant tissue does not vary systematically with atmospheric carbon dioxide concentration. However, environmental factors, such as water stress, can influence the δ13C value of leaf tissue. These factors explained a relatively small portion of variation in the δ13C value of plant tissue in our data set and emerged strongly only when the carbon isotopic composition of the atmosphere was held constant. Members of the Poaceae differed in average δ13C value, but we observed no other differences correlated with plant life form (herbs, trees, shrubs). In contrast, over 90% of the variation the carbon isotopic composition of plant tissue was explained by variation in the δ13C value of the atmosphere under which it was fixed. We use a subset of our data spanning a geologically reasonable range of atmospheric δ13C values (−6.4‰ to −9.6‰) and excluding C3 Poaceae to develop an equation to reconstruct the δ13C value of atmospheric CO2based on plant values. Reconstructing the δ13C value of atmospheric CO2in geologic time will facilitate chemostratigraphic correlation in terrestrial sediments, calibrate pCO2reconstructions based on soil carbonates offer a window into the physiology of ancient plants.
Homeotic evolution in Cambrian trilobites
Authors: Sundberg Frederick A.
Published: July 2006

Hox genes are known from a wide variety of organisms. In arthropods, these genes control segment characteristics. Trilobites, being arthropods, probably contained eight major Hox genes that controlled their segment types. The trilobite Bauplan contains eight regions that are most likely under the influence of one or more of these Hox genes. The cephalon contains the frontal lobe, glabellar, and occipital ring regions; the thorax contains the anterior thoracic and posterior thoracic regions; and the pygidium contains the articulating ring, axial, and terminal piece regions. Changes in character distribution within or between these regions represent homeotic evolution, which may have resulted from the modification of Hox transcription or of downstream regulatory genes. A phylogenetic analysis is used to recognize homeotic evolution in trilobites, leading to the conclusion that homeotic evolution is common among Cambrian trilobites.
Herbivore paleodiet and paleoenvironmental changes in Chad during the Pliocene using stable isotope ratios of tooth enamel carbonate
Authors: Zazzo Antoine , Bocherens Hervé , Billiou Daniel , Mariotti André , Brunet Michel , Vignaud Patrick , Beauvilain Alain , Mackaye Hassane Taisso
Published: July 2006

Chad is a key region for understanding early hominid geographic expansion in relation to late Miocene and Pliocene environmental changes, owing to its location 2500 km west from the Rift Valley and to the occurrence of sites ranging in age from about 6 to 3 Ma, some of which yield fossil hominids. To reconstruct changes in herbivore paleodiet and therefore changes in the paleoenvironment, we measured the carbon and oxygen isotope composition of 80 tooth-enamel samples from three time horizons for nine families of Perissodactyla, Proboscidea, and Artiodactyla. The absence of significant alteration of in vivo isotopic signatures can be determined for carbon, thus allowing paleodietary and paleoenvironmental interpretations to be made.

While the results generally confirm previous dietary hypotheses, mostly based on relative crown height, there are some notable surprises. The main discrepancies are found among low-crowned proboscideans (e.g., Anancus) and high-crowned rhinocerotids (Ceratotherium). Both species were more opportunistic feeders than it is usually believed. This result confirms that ancient feeding ecology cannot always be inferred from dental morphology or extant relatives.

There is an increase in the average carbon isotope composition of tooth enamel from the oldest unit to the youngest, suggesting that the environment became richer in C4 plants with time. In turn, more C4 plants indicate an opening of the plant cover during this period. This increase in carbon isotope composition is also recorded within genera such as Nyanzachoerus, Ceratotherium, and Hexaprotodon, indicating a change from a C3-dominated to a C4-dominated diet over time. It appears that, unlike other middle Pliocene hominid sites in eastern and southern Africa, this part of Chad was characterized by very open conditions and that savanna-like grasslands were already dominant when hominids were present in the area.