bluuebunny/crossref_metadata_2025 huggingface dataset:
Flexible organic light-emitting diodes with improved performance by insertion of an UV-sensitive layer
Authors: Hui Lin , Junsheng Yu , Nana Wang , Chunhua Huang , Yadong Jiang
Published: August 2008

A flexible organic light-emitting diode (FOLED) was fabricated on an indium tin oxide (ITO) plastic substrate by inserting an UV-curable epoxy resin as a buffer layer between the plastic substrate and ITO film. The structure of the FOLED devices was ITO/NPB (50nm)∕Alq(50nm)∕Mg:Ag(100nm). The surface morphology of three kinds of substrates was characterized by atomic force microscopy. The results show that with a spin-coated buffer layer, the surface roughness of ITO films on PET substrate decreased from 1.08to0.34nm. With the assistance of UV-sensitive resin, the adhesive force between the plastic substrate and ITO anode was significantly increased. The maximum luminance of FOLEDs was enhanced from 2720to4860cd∕m2 at 12V.
Direct UV-imprint lithography using conductive nanofiller-dispersed UV-curable resin
Authors: Choi Jun-Hyuk , Lee Soon-Won , Choi Dae-Geun , Kim Ki-Don , Jeong Jun-Ho , Lee Eung-Suk
Published: August 2008

In many early investigations of the ultraviolet (UV) imprinting process, imprint resists served as sacrificial etch barrier masks for pattern transfer onto the underlying layer. In this study, conductive photocurable resin incorporating silver nanoparticles was used in UV imprinting for the direct manufacture of electronic device structures. The materials were formulated simply by mixing acrylate-based UV-curable resin with nanosilver colloids. Successful photopolymerization was possible with these formulations without affecting the antistiction-treated surface chemistry of the stamp. Even with the increased viscosity due to silver (Ag) particulate inclusions, resin infiltration into the master patterns several micrometers deep occurred successfully during the imprinting process. Heat treatment and wet chemical etching followed the UV imprinting to shrink the polymer phase even further and to remove imprint residue to complete electrically conductive continuous media based on Ag nanoparticles.
Ion beam synthesis of Ni nanoparticles embedded in quartz
Authors: Kumar P. , Kumar Ravi , Kanjilal D. , Knobel M. , Thakur P. , Chae K. H.
Published: August 2008

Fabrication and fluence dependent growth of Ni nanoparticles in quartz matrix using a low energy ion implantation followed by thermal annealing are reported. 100keV Ni ions are implanted (at room temperature) in quartz at different ion fluences using a low energy ion beam facility. The samples are postannealed at 600°C and then characterized using atomic force microscopy, magnetic force microscopy, field cooled and zero field cooled magnetization measurements, x-ray absorption spectroscopy, and UV-visible spectroscopy. Nanoclusters of Ni of nearly uniform size are synthesized at an ion fluence of 5×1016ions∕cm2. The size of these nanoclusters could be varied by varying ion fluence. Formation of NiO nanoclusters is observed for ion fluence of 2×1017ions∕cm2.
Comparison between GaN thin film grown by femtosecond and nanosecond pulsed laser depositions
Authors: Tong X. L. , Jiang D. S. , Liu L. , Dai H.
Published: August 2008

GaN thin films have been grown by femtosecond and nanosecond pulsed laser depositions (PLDs), respectively. X-ray diffraction, atomic force microscopy, micro-Raman spectroscopy, fluorescence spectra, scanning electronic microscope (SEM), and field emission measurements were carried out to analyze the crystalline structure, morphology, optical properties, and field emission characteristics of the deposited GaN thin films. Although GaN thin films deposited by both femtosecond and nanosecond PLD were polycrystalline and hexagonal, the crystalline quality and properties were found to be different. The SEM image of the polymer microtips array coated with GaN thin film grown by femtosecond PLD is considerably different from that of nanosecond PLD. A distortion in the shape of the polymer field emission array can be seen in the nanosecond PLD, which has been related to the differences in the laser-target interaction as well as the plume characteristics during femtosecond PLD and nanosecond PLD. The optical properties and field emission characteristics of the GaN thin film grown by femtosecond PLD are superior to the excimer laser-deposited film, suggesting that femtosecond PLD is a potential application for GaN thin films growth at low temperature.
Atomic-scale cellular model and profile simulation of poly-Si gate etching in high-density chlorine-based plasmas: Effects of passivation layer formation on evolution of feature profiles
Authors: Osano Yugo , Ono Kouichi
Published: August 2008

Atomic-scale cellular model has been developed to simulate the feature profile evolution during poly-Si gate etching in high-density Cl2 and Cl2∕O2 plasmas, with emphasis being placed on the formation of passivation layers on feature surfaces. The model took into account the behavior of Cl+ ions, Cl and O neutrals, and etch products and byproducts of SiClx and SiClxOy in microstructural features. The transport of ions and neutrals in microstructures and in substrates was analyzed by the two-dimensional Monte Carlo calculation with three velocity components. The surface chemistry included ion-enhanced etching, chemical etching, and passivation layer formation through surface oxidation and deposition of etch products and byproducts. The computational domain was taken to consist of two-dimensional square cells or lattices of atomic size, and the evolving interfaces were represented by removing Si atoms from and/or allocating them at the cells concerned. Calculations were performed for different line-and-space pattern features of down to 30nm space width, with an incoming ion energy, ion flux, and neutral reactant-to-ion flux ratio of Ei=50eV, Γi0=1.0×1016cm−2s−1, and Γn0∕Γi0=10. Numerical results reproduced the evolution of feature profiles, critical dimensions, and their microscopic uniformity (or aspect-ratio dependence) on nanometer scale, depending on substrate temperature, incoming flux of oxygen and etch byproducts, and sticking probability of etch products and byproducts on feature surfaces: the lateral etching on sidewalls is suppressed by surface oxidation thereon. The oxidation also reduces the etch rate on bottom surfaces, leading to a transition from regular to inverse reactive ion etching (RIE) lag with increasing flux of oxygen; in practice, the RIE lag remains almost unchanged for narrow space features owing to reduced oxygen fluxes thereinto, thus leading to regular and inverse RIE lags coexistent in a series of different pattern features. The deposition or redeposition of etch products (desorbed from feature surfaces) onto sidewalls results in the sidewall tapering, which is more significant for narrower space features; in contrast, the deposition of byproducts (coming from the plasma) onto sidewalls results in the tapering, which is more significant for wider features. Synergistic effects between the deposition of etch products/byproducts and surface oxidation enhance the passivation layer formation on feature surfaces, which in turn increases the sidewall tapering and the degree of regular and inverse RIE lags depending on feature width. The present model also enabled the authors to simulate the surface reaction multilayers and passivation layers on atomic scale, along with their chemical constituents and surface roughness.
Effect of contact metals on the piezoelectric properties of aluminum nitride thin films
Authors: Harman J. , Kabulski A. , Pagán V. R. , Famouri P. , Kasarla K. R. , Rodak L. E. , Peter Hensel J. , Korakakis D.
Published: August 2008

The converse piezoelectric response of aluminum nitride evaluated using standard metal insulator semiconductor structures has been found to exhibit a linear dependence on the work function of the metal used as the top electrode. The apparent d33 of the 150–1100nm films also depends on the dc bias applied to the samples.
Control of the Reversibility of Cellular Quiescence by the Transcriptional Repressor HES1
Authors: Sang Liyun , Coller Hilary A. , Roberts James M.
Published: August 2008

The mechanisms by which quiescent cells, including adult stem cells, preserve their ability to resume proliferation after weeks or even years of cell cycle arrest are not known. We report that reversibility is not a passive property of nondividing cells, because enforced cell cycle arrest for a period as brief as 4 days initiates spontaneous, premature, and irreversible senescence. Increased expression of the gene encoding the basic helix-loop-helix protein HES1 was required for quiescence to be reversible, because HES1 prevented both premature senescence and inappropriate differentiation in quiescent fibroblasts. In some human tumors, the HES1 pathway was activated, which allowed these cells to evade differentiation and irreversible cell cycle arrest. We conclude that HES1 safeguards against irreversible cell cycle exit both during normal cellular quiescence and pathologically in the setting of tumorigenesis.
Response to Comment on "Protein Sequences from Mastodon and
Tyrannosaurus rex
Revealed by Mass Spectrometry"
Authors: Asara John M. , Schweitzer Mary H. , Cantley Lewis C. , Cottrell John S.
Published: August 2008

Endogenous peptide sequences extracted from a 68-million-year-old
Tyrannosaurus rex
fossil bone and obtained by mass spectrometry have been shown to be statistically significant based on protein database searches using two different search engines and similarity comparisons to authentic tandem mass spectrometry spectra. Specifically, we have validated the sequence GVVGLP
(OH)
GQR.
Targeting QseC Signaling and Virulence for Antibiotic Development
Authors: Rasko David A. , Moreira Cristiano G. , Li De Run , Reading Nicola C. , Ritchie Jennifer M. , Waldor Matthew K. , Williams Noelle , Taussig Ron , Wei Shuguang , Roth Michael , Hughes David T. , Huntley Jason F. , Fina Maggy W. , Falck John R. , Sperandio Vanessa
Published: August 2008

Many bacterial pathogens rely on a conserved membrane histidine sensor kinase, QseC, to respond to host adrenergic signaling molecules and bacterial signals in order to promote the expression of virulence factors. Using a high-throughput screen, we identified a small molecule, LED209, that inhibits the binding of signals to QseC, preventing its autophosphorylation and consequently inhibiting QseC-mediated activation of virulence gene expression. LED209 is not toxic and does not inhibit pathogen growth; however, this compound markedly inhibits the virulence of several pathogens in vitro and in vivo in animals. Inhibition of signaling offers a strategy for the development of broad-spectrum antimicrobial drugs.
Grueneberg Ganglion Cells Mediate Alarm Pheromone Detection in Mice
Authors: Brechbühl Julien , Klaey Magali , Broillet Marie-Christine
Published: August 2008

Alarm pheromones (APs) are widely used throughout the plant and animal kingdoms. Species such as fish, insects, and mammals signal danger to conspecifics by releasing volatile alarm molecules. Thus far, neither the chemicals, their bodily source, nor the sensory system involved in their detection have been isolated or identified in mammals. We found that APs are recognized by the Grueneberg ganglion (GG), a recently discovered olfactory subsystem. We showed with electron microscopy that GG neurons bear primary cilia, with cell bodies ensheathed by glial cells. APs evoked calcium responses in GG neurons in vitro and induced freezing behavior in vivo, which completely disappeared when the GG degenerated after axotomy. We conclude that mice detect APs through the activation of olfactory GG neurons.
Biological and Phylogenetic Characterization of Pigeon Paramyxovirus Serotype 1 Circulating in Wild North American Pigeons and Doves
Authors: Kim L. Mia , King Daniel J. , Guzman Hilda , Tesh Robert B. , da Rosa Amelia P. A. Travassos , Bueno Rudy , Dennett James A. , Afonso Claudio L.
Published: August 2008

As part of West Nile virus surveillance programs in Rhode Island and eastern Texas between 2000 and 2007, brain tissue was collected from 5,608 dead birds representing 21 avian orders found in public places or reported by homeowners. Fifteen Newcastle disease virus isolates were recovered only from birds of the order Columbiformes and were positively identified by the USDA-validated real-time reverse transcription-PCR assay targeting the matrix gene and more specifically as pigeon paramyxovirus serotype 1 (PPMV-1) by hemagglutinin inhibition with monoclonal antibodies. Based upon partial genomic sequencing and phylogenetic analysis, the newly isolated viruses represent a distinct sublineage within class II genotype VIb. All of the viruses (15/15) were classified as virulent based upon their fusion cleavage site motif (
112
RRKKRF
117
) and intracerebral pathogenicity indices of >0.7 (ranging from 0.98 to1.35); however, these viruses escaped detection by the fusion gene-based real-time PCR test for virulence. Modifications introduced to the probe site of the fusion gene-based assay allowed rapid virulence detection within this distinct sublineage.
Discordance between Mycobacterial Interspersed Repetitive-Unit-Variable-Number Tandem-Repeat Typing and IS6110Restriction Fragment Length Polymorphism Genotyping for Analysis ofMycobacterium tuberculosisBeijing Strains in a Setting of High Incidence of Tuberculosis
Authors: Hanekom M. , van der Spuy G. D. , van Pittius N. C. Gey , McEvoy C. R. E. , Hoek K. G. P. , Ndabambi S. L. , Jordaan A. M. , Victor T. C. , van Helden P. D. , Warren R. M.
Published: August 2008

IS6110restriction fragment length polymorphism (RFLP) genotyping is the most widely used genotyping method to study the epidemiology ofMycobacterium tuberculosis. However, due to the complexity of the IS6110RFLP genotyping technique, and the interpretation of RFLP data, mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) genotyping has been proposed as the new genotyping standard. This study aimed to determine the discriminatory power of different MIRU-VNTR locus combinations relative to IS6110RFLP genotyping, using a collection of Beijing genotypeM. tuberculosisstrains with a well-established phylogenetic history. Clustering, diversity index, clustering concordance, concordance among unique genotypes, and divergent and convergent evolution were calculated for seven combinations of 27 different MIRU-VNTR loci and compared to IS6110RFLP results. Our results confirmed previous findings that MIRU-VNTR genotyping can be used to estimate the extent of recent or ongoing transmission. However, molecular epidemiological linking of cases varied significantly depending on the genotyping method used. We conclude that IS6110RFLP and MIRU-VNTR loci evolve independently and at different rates, which leads to discordance between transmission chains predicted by the respective genotyping methods. Concordance between the two genotyping methods could be improved by the inclusion of genetic distance (GD) into the clustering formulae for some of the MIRU-VNTR loci combinations. In summary, our findings differ from previous reports, which may be explained by the fact that in settings of low tuberculosis incidence, the genetic distance between epidemiologically unrelated isolates was sufficient to define a strain using either marker, whereas in settings of high incidence, continuous evolution and persistence of strains revealed the weaknesses inherent to these markers.
Natural Killer Cells as Novel Helpers in Anti-Herpes Simplex Virus Immune Response
Authors: Nandakumar Subhadra , Woolard Stacie N. , Yuan Dorothy , Rouse Barry T. , Kumaraguru Uday
Published: August 2008

Innate defenses help to eliminate infection, but some of them also play a major role in shaping the magnitude and efficacy of the adaptive immune response. With regard to influencing subsequent adaptive immunity, NK cells aided by dendritic cells may be the most relevant components of the innate reaction to herpes simplex virus (HSV) infection. We confirm that mice lacking or depleted of NK cells are susceptible to HSV-induced lesions. The quantity and quality of CD8+cytotoxic T lymphocytes generated in the absence of NK cells were diminished, thereby contributing to susceptibility to HSV-induced encephalitis. We demonstrate a novel helper role for NK cells, in that NK cells compensate for the loss of CD4 helper T cells and NK cell supplementation enhances the function of wild type anti-HSV CD8 T cells. In addition, NK cells were able to partially rescue the dysfunctional CD8+T cells generated in the absence of CD4 T helper cells, thereby performing a novel rescue function. Hence, NK cells may well be exploited for enhancing and rescuing the T-cell response in situations where the CD4 helper response is affected.
A Dynamic View of Hepatitis C Virus Replication Complexes
Authors: Wölk Benno , Büchele Benjamin , Moradpour Darius , Rice Charles M.
Published: August 2008

Hepatitis C virus (HCV) replicates its genome in a membrane-associated replication complex (RC). Specific membrane alterations, designated membranous webs, represent predominant sites of HCV RNA replication. The principles governing HCV RC and membranous web formation are poorly understood. Here, we used replicons harboring a green fluorescent protein (GFP) insertion in nonstructural protein 5A (NS5A) to study HCV RCs in live cells. Two distinct patterns of NS5A-GFP were observed. (i) Large structures, representing membranous webs, showed restricted motility, were stable over many hours, were partitioned among daughter cells during cell division, and displayed a static internal architecture without detectable exchange of NS5A-GFP. (ii) In contrast, small structures, presumably representing small RCs, showed fast, saltatory movements over long distances. Both populations were associated with endoplasmic reticulum (ER) tubules, but only small RCs showed ER-independent, microtubule (MT)-dependent transport. We suggest that this MT-dependent transport sustains two distinct RC populations, which are both required during the HCV life cycle.
Structural Characterization of the 1918 Influenza Virus H1N1 Neuraminidase
Authors: Xu Xiaojin , Zhu Xueyong , Dwek Raymond A. , Stevens James , Wilson Ian A.
Published: August 2008

Influenza virus neuraminidase (NA) plays a crucial role in facilitating the spread of newly synthesized virus in the host and is an important target for controlling disease progression. The NA crystal structure from the 1918 “Spanish flu” (A/Brevig Mission/1/18 H1N1) and that of its complex with zanamivir (Relenza) at 1.65-Å and 1.45-Å resolutions, respectively, corroborated the successful expression of correctly folded NA tetramers in a baculovirus expression system. An additional cavity adjacent to the substrate-binding site is observed in N1, compared to N2 and N9 NAs, including H5N1. This cavity arises from an open conformation of the 150 loop (Gly147 to Asp151) and appears to be conserved among group 1 NAs (N1, N4, N5, and N8). It closes upon zanamivir binding. Three calcium sites were identified, including a novel site that may be conserved in N1 and N4. Thus, these high-resolution structures, combined with our recombinant expression system, provide new opportunities to augment the limited arsenal of therapeutics against influenza.
Herpes Simplex Virus Type 1 ICP0 Phosphorylation Mutants Impair the E3 Ubiquitin Ligase Activity of ICP0 in a Cell Type-Dependent Manner
Authors: Boutell Chris , Everett Roger , Hilliard Joshua , Schaffer Priscilla , Orr Anne , Davido David
Published: August 2008

Herpes simplex virus type 1 (HSV-1) infected cell protein 0 (ICP0) is a 110-kDa nuclear phosphoprotein that is required for both the efficient initiation of lytic infection and the reactivation of quiescent viral genomes from latency. The ability of ICP0 to act as a potent viral transactivator is mediated by its N-terminal zinc-binding RING finger domain. This domain confers E3 ubiquitin ligase activity to ICP0 and is required for the proteasome-dependent degradation of a number of cellular proteins during infection, including the major nuclear domain 10 (ND10) constituent protein promyelocytic leukemia. In previous work we mapped three phosphorylation regions within ICP0, two of which directly affected its transactivation capabilities in transient transfection assays (Davido et al., J. Virol. 79:1232-1243, 2005). Because ICP0 is a phosphoprotein, we initially sought to test the hypothesis that phosphorylation regulates the E3 ubiquitin ligase activity of ICP0. Although none of the mutations affected ICP0 E3 ligase activity in vitro, transient transfection analysis indicated that mutations within one or more of the phosphorylated regions impaired the ability of ICP0 to form foci with colocalizing conjugated ubiquitin and to disrupt ND10. Mutations within one of the regions also affected ICP0 stability, and all of these phenomena occurred in a cell type-dependent manner. In the context of viral infection, only one ICP0 phosphorylation mutant (P1) showed a significant defect in viral replication and enhanced protein stability compared to all the other viruses tested. This study suggests that specific cellular environments and context of expression (transfection versus infection) differentially regulate several activities of ICP0 related to its E3 ubiquitin ligase activity via phosphorylation.
FUNGI ISOLATED FROM ARCTIC AIR IN 1947
Authors: Pady S. M.
Published: August 2008

In nutrient plates exposed in 1947 in the arctic and subarctic from aircraft for two minutes by hand, 1062 colonies developed in 51 plates. Cultures were made from typical colonies on corn meal agar. Of the 208 cultures, 55 were non-sporulating. Cladosporium was the most frequently isolated organism with 33 (15.8%) cultures, most being C. herbarum. Other genera isolated were Streptomyces 23 (11%), Sporormia 17 (8.1%), Penicillium 13 (6.2%), Pullularia 11 (5.4%), Verticillium 7 (3.2%), Stemphylium 6 (2.7%), Phoma 4 (1.8%). Botrytis, Alternaria, Phialophora, yeast two each, with a single culture of Cephalosporium, Chaetamium, Fusarium, Gliocladium, Papularia, Pestallozia, Sphaeronema. With the possible exception of Sporormia the fungi are considered to be largely saprophytic soil borne organisms carried into the arctic by southerly winds.
THE SPLASH-CUP DISPERSAL MECHANISM IN PLANTS
Authors: Brodie Harold J.
Published: August 2008

The late Prof. A. H. R. Buller regarded certain cup-shaped reproductive bodies found among cryptogams as "splash-cups" which make use of the energy of raindrops for the dispersal of spores, sperms, and gemmae. Buller's concepts are presented and supplemented by investigations carried out since his death. Raindrops cause the peridioles of the Nidulariaceae or bird's-nest fungi to be thrown about four feet by splash action. In the genus Cyathus, as a peridiole is jerked out of its cup, the funiculus is torn and this makes possible the expansion of a mass of adhesive hyphae (the hapteron) which clings to any object in the line of flight. The momentum of the peridiole causes a long cord to be pulled out of a sheath attached to the peridiole. The peridiole is checked in flight and the jerk causes the funicular cord to become wound around stems or entangled among plant hairs. Thus the peridiole becomes attached to vegetation and may be eaten subsequently by herbivorous animals. Several morphological features of fruit bodies of the Nidulariaceae are regarded as related to the utilization of the energy of raindrops in rain dispersal and the significance of the splash-cup principle is emphasized. Other splash-cups, the operation of which is described, are: the gemma cups of Marchantia and Lunularia; the antheridial disk of Marchantia; the leaf rosette of the male Polytrichum plant; the sclerotium cups of Aleurodiscus Minnsiae; the cupulate fruits of Sagina decumbens and Oenothera rosea.
STUDIES OF CANADIAN THELEPHORACEAE: VIII. CORTICIUM GALACTINUM (FR.) BURT
Authors: White L. T.
Published: August 2008

During the course of an investigation into the decays of white pine in certain regions of Ontario it was found that the fungus, Corticium galactinum (Fr.) Burt, was important as an organism destroying considerable woody material in the roots and butts of living trees. Because of the increasing interest in this species, the early history and the literature concerning the pathogenicity on roots of apple-trees as well as other hardwood and coniferous species has been reviewed. A revised description, based on the study of a portion of the type specimen from the Fries herbarium and a comparison with specimens from apple and coniferous species, is presented. The taxonomy and relationships of C. galactinum are discussed. Detailed comparison is made with C. odoratum (Fr.) B. & G. and a description of that species is included. Cultural studies show that C. galactinum is heterothallic and of the tetrapolar type of interfertility and may possess multiple allelomorphs at the loci responsible for heterothallism002E
MUTATIONS IN POLYPLOID CEREALS: IV. A SEGMENTAL CHROMOSOME DEFICIENCY DETERMINING AN α SERIES RATIO IN A SPELTOID WHEAT
Authors: Smith Stanley G.
Published: August 2008

The C chromosome of beardless Triticum vulgare carries epistatic inhibitors, about 30 crossover units apart on the longer arm of the chromosome, which prevent the expression of the bearded-speltoid complex of genes. It has earlier been shown that het speltoid mutants may lack one of the two sets of inhibitors through the loss of the entire C chromosome, or its longer arm, or an interstitial segment of this arm. The first determines Series β segregation (1 normal: ca. 5 het speltoids: ca. 0.03 speltoids), the last two Series γ (1: 1: ca. 0.05). A third type of progeny ratio, α, is a distortion of a 1: 2: 1 caused by a greater or lesser deficiency of speltoids and, less markedly, of het speltoids. Some workers regard α ratios as resulting from mutation of the epistatic inhibitors to their recessive state; others as due to chromosome aberration similar to, but less extensive than, that observed in typical γ strains. The latter interpretation is proved correct herein. That deviations from the ratios characteristic of the three Series are determined by the degree of pollen certation superimposed on the proportion in which normal and mutant ovules are formed has been shown by analyses involving natural hybrids and crosses made with other types. The extent of certation in α and γ Series may be measured from their progeny ratios—normal pollen = N + H − Sp: mutant pollen = 2 × Sp. A rough correlation has been established between the length of the mutant C chromosome, percentage conjugation with C, proportion of N: Sp progeny, percentage β het Sp progeny, and the coefficient of certation. The percentage het Sp of Series β expected as secondary mutants in the het Sp progeny of α and γ het Sp approximates to [Formula: see text].
SYNTHESIS AND HYDROLYSIS OF SUCROSE BY WHEAT LEAVES, AS DETERMINED BY THE VACUUM INFILTRATION METHOD
Authors: Krotkov G. , Bennett W. Constance G.
Published: August 2008

Using the technique of vacuum infiltration, either a mixture of glucose plus fructose or a solution of sucrose alone was introduced into detached wheat leaves, and the rates of sucrose synthesis or hydrolysis from these infiltrated sugars were observed. It was found that these rates were not constant during 24 hr., but depended on the time of the day or night when the leaves were cut. Synthesis was high in leaves detached in the forenoon, before sunset, and in the first part of the night. Changes in the rate of hydrolysis were usually mirror images of those of synthesis. It has been concluded that in wheat leaves there exists a diurnal rhythm in their synthetic and hydrolytic potential and that the observed diurnal changes in the rates of sucrose synthesis and hydrolysis represent one of the manifestations of such a rhythm. Sodium fluoride, sodium cyanide, iodoacetate, and dinitrophenol always increased hydrolysis, and usually decreased synthesis. When glucose-1-phosphate, fructose-6-phosphate, and fructose-1, 6-diphosphate were substituted for the corresponding free sugar in a mixture of glucose plus fructose, a decrease in sucrose synthesis was observed. After 24 hr. of starvation the rate of sucrose synthesis declined, and eventually dropped practically to zero at the end of five days. In the same time there was a progressive increase in the rate of hydrolysis.
THE EFFECT OF SALTS ON THE GROWTH OF MICROCOCCUS HALODENITRIFICANS N. SP.
Authors: Robinson J , Gibbons N. E.
Published: August 2008

A halophilic coccus, Micrococcus halodenitrificans n. sp., isolated from meat curing brines is described. This organism grows optimally in media containing between 4.4 and 8.8% sodium chloride as determined by viable counts and manometric methods. The viable count decreases in media containing 2.2% or less sodium chloride. As salt concentrations increase above 8.8%, the length of the lag phase increases and the rate of growth decreases. The organism exhibits a specific sodium chloride requirement for growth. However, it continues to respire in the presence of sodium bromide.
OBSERVATIONS ON AMYLOLYTIC BACTERIA: III. CULTURAL CONDITIONS INFLUENCING THE BREAKDOWN OF STARCH BY STENOTHERMOPHILIC BACTERIA BELONGING TO BACILLUS STEAROTHERMOPHILUS
Authors: Stark Egon , Tetrault P. A.
Published: August 2008

Thirty-five cultures of Bacillus stearothermophilus hydrolyzed five starches under various cultural conditions. Hydrolysis occurred regardless of the type, brand, or batch of starch; regardless of the initial pH or of the subsequent pH changes of the medium. Starch in broth was better attacked than in agar media. Some cultures hydrolyzed 0.5%, but not 1% starch; others hydrolyzed easily 10% soluble starch. Length of incubation was important. Certain cultures never formed acid or sugar from starch. Dextrinization was a more reliable indication of starch hydrolysis than was the formation of acid or sugar. Soluble starch gave more consistent results in repeated experiments than did nonsoluble starches. The type of protein medium determines strongly the formation of amylase. Trypticase was the best commercial medium, yeast extract came second. The other 10 media yielded fewer amylolytic cultures. Yeast extract added to media enhanced amylase formation, except with trypticase. Tryptose, proteose-peptone, and neopeptone inhibited the growth of most cultures.
A STUDY OF THE SPECIES OF CINTRACTIA ON CAREX, KOBRESIA, AND SCIRPUS IN NORTH AMERICA
Authors: Savile D. B. O.
Published: August 2008

This is a taxonomic study of Cintractia spp. on nearly one hundred host species, mainly in Canada, northern United States, and southern Alaska. Coverage is very incomplete for northern Alaska, Greenland, and parts of the Canadian arctic archipelago. Eighteen species and varieties are recognized including one new species, Cint. atratae, and four new varieties, Cint. carpophila vars. kenaica and verrucosa and Cint. caricis vars. intermedia and acutarum. Two recombinations are made. The biology and phylogeny of the group are also discussed.
AN INHIBITOR IN A NEW HOST OF TOBACCO RING SPOT VIRUS
Authors: Weintraub M. , Gilpatrick J. D.
Published: August 2008

Of four seedling-clones of Dianthus barbatus L. tested for susceptibility to tobacco ring spot virus, two were consistently infected, one occasionally missed infection, and the fourth was insusceptible. Symptoms of infection were primary local lesions, followed by systemic chlorosis and death of the growing point. Further adventitious growth was symptomless, but still contained the virus and was protected from reinfection. Intracellular inclusions of the amorphous type occurred in diseased leaves. Difficulty in transmitting tobacco ring spot virus from D. barbatus to tobacco was caused by an inhibitor in healthy D. barbatus leaves. Some of the physical characteristics of this inhibitor were studied. It had no effect on transmission of tobacco ring spot virus to D. barbatus, but in cucumber, Datura stramonium, and snapdragon, it caused either a delay of symptom expression or an insusceptibility of a proportion of inoculated plants. The inhibitor reduced infectivity of tobacco mosaic, cucumber mosaic, and tobacco etch viruses.
THE GENUS TYMPANIS
Authors: Groves J. Walton
Published: August 2008

This paper is a taxonomic study of the genus Tympanis with a discussion of its history, morphology, conidial relations, parasitism, and distribution. Thirty-six species and one variety are recognized, of which 23 species have been studied in cultures. Sixteen new species are described and one new name is proposed. The conidial states of Tympanis species belong in the form genus Pleurophomella v. Höhn. In a section on doubtful and excluded species an attempt is made to account for all the Tympanis names in the literature.
GLUTAMIC CARBOXYLASE OF THE MATURE WHEAT LEAF
Authors: Weinberger P. , Clendenning K. A.
Published: August 2008

A study of the distribution of glutamic carboxylase within the developing wheat plant revealed that it was absent in young plants, and was present only in traces in mature roots, and that it accumulated in mature leaves. Glutamic carboxylase was particularly abundant in the mature and senescent third leaf. Extracts of leaves of other cereals showed only weak activity, while extracts of roots, other than barley, were inactive. The high enzyme activity of the barley root extracts was exceeded only by that of mature wheat leaf extracts. A convenient method is described for enzyme storage at −40 °C. and a purification procedure was developed which effected a 500-fold concentration (nitrogen basis). The glutamic carboxylase activity of crude extracts was enhanced by preparatory exposure to phosphate buffer; after selective salt precipitation and lengthy dialysis, activity was reduced, but could be restored by the addition of pyridoxal phosphate. A heat-stable inhibitor of glutamic carboxylase at its pH optimum was found in the ether-soluble organic acid fraction of the cell sap of Kalanchoe leaves. Similar inhibiting effects were shown by malate, tartrate, and citrate, but not by succinate, fumarate, aspartate, and alanine. Kinetic studies indicated that the inhibition of plant glutamic carboxylase by cyanide is noncompetitive.
Tuna Purse-Seine Fishing with Fish-Aggregating Devices (FAD): Models of Tuna FAD Interactions
Authors: Hilborn Ray , Medley Paul
Published: August 2008

A model is proposed for the analysis of fishing tuna from fish-aggregating devices (FAD), and parameters for the model are estimated. Methods are described for determining the optimum number of FAD's to be deployed and the optimum number of vessels in a fishery. Field measurement of recruitment and loss of fish associated with FAD's is needed for adequate biological or economic analysis of FAD fishing. Results show that if recruitment to FAD's is proportional to the biomass not associated with FAD's, then increasing the number of FAD's beyond some limit will actually decrease total catch. Similar models could be used in any trap fishery, particularly for crabs or lobsters.
Genetic Variation in Steelhead (Salmo gairdneri) from the North Coast of Washington
Authors: Reisenbichler R. R. , Phelps S. R.
Published: August 2008

Steelhead (Salmo gairdneri) collected from various sites in nine drainages in northwestern Washington were genetically characterized at 65 protein-coding loci by starch-gel electrophoresis. Genetic differentiation within and among drainages was not significant, and genetic variation among drainages was much less than that reported in British Columbia; these results may be the consequence of gene flow from hatchery stocks that have been released in Washington since the 1940's. Allele frequencies varied significantly among year-classes (hence, genetic characterization studies must include data from several year-classes), and also between hatchery fish (including a stock developed with local wild fish) and wild fish, indicating that few wild fish have been successfully and routinely included in hatchery brood stocks. Conservation of genetic diversity along the north coast of Washington should be facilitated by reducing the numbers of hatchery fish that spawn in streams and by including wild fish in hatchery brood stocks.
Slower Growth Results in Larger Otoliths: An Experimental Test with Guppies (Poecilia reticulata)
Authors: Reznick David , Lindbeck Eric , Bryga Heather
Published: August 2008

We demonstrate that slowly growing guppies (Poecilia reticulata) have larger otoliths than equal-sized, rapidly growing guppies. This relationship has been suggested by previous authors, but they compared wild or pond-reared fish from different poopulations, thereby confounding their observations with the different environments. Our experiment controlled for the genetic background, food quality, and the aquatic environment and assessed the influences of food availability and growth rate on relative otolith size. This difference in relative otolith dimensions could aid in comparing growth rates among populations or could improve the use of otolith dimensions for estimating population age structures. In both cases, these methods could also complement data based on counting daily increments or annuli on otoliths and other structures to characterize growth rates and age structures.
Thyroid Activity Concomitant with Olfactory Learning and Heart Rate Changes in Atlantic Salmon Salmo salar, during Smoltification
Authors: Morin Pierre-Philippe , Dodson Julian J. , Doré François Y.
Published: August 2008

Thyroid-histological (epithelial cell height, follicular eccentricity) and thyroid-radiochemical (thyroxine, triiodothyronine) activities were examined in Atlantic salmon, Salmo salar, undergoing smoltification in relation to cardiac conditioning to L-cysteine (olfactory learning). Changes in plasma levels of thyroxine were also examined along with those of resting heart rate, during and after smoltification. In a related study, we reported greater learning ability in age-groups 3 (612–619 d since birth) and 6 (642–649 d) as well as a greater long-term olfactory memory in age-group 3. In the present study, thyroid-histological activity was correlated with olfactory learning during smoltification. Higher histological values occurred concomitantly with greater learning in age-groups 3 and 6. During smoltification, changes in thyroid-histological activity were different from those of radiochemical activity. Apparently different plasma–tissue fluxes of thyroid hormones occurred between age-groups 3 and 6. Plasma thyroxine was correlated with resting heart rate. Our results suggested that thyroid hormones play a role in olfactory learning and imprinting in anadromous salmonids.
Influence of Sediment Disturbance and Water Flow on the Growth of the Soft-Shell Clam,Mya arenariaL.
Authors: Emerson Craig W.
Published: August 2008

The importance of sediment disturbance and water flow to the production of the soft-shell clam, Mya arenaria, was assessed in laboratory flumes by measuring growth rates of clams exposed to a gradation of bed shear stress, free-stream velocity, and frequency and depth of sediment disturbance over a 10-m period. In the absence of sediment disturbance, growth of soft-tissue was directly proportional to both free-stream (U) and shear (U*) velocity (r2 = 0.64 and 0.72, respectively). It was suggested that increased organic seston flux linked higher water flow to higher growth. In all treatments, maximum growth rates were observed with daily disturbance of the top centimeter of sediment. No level of disturbance resulted in growth rates lower than those of undisturbed clams in low flow (U = 0.4 cm∙s−1, U* = 0.1 cm∙s−1). The stimulation of growth under maximum sediment disturbance was removed when U exceeded ~3 cm∙s−1(U* = 0.7 cm∙s−1). An energy budget for M. arenaria indicated that the amount of organic material suspended during sediment disturbance was insufficient to account for the increased growth in clams subjected to high levels of disturbance. It was suggested that the sediment disturbance associated with intense clam harvesting, and changes in local hydrography resulting from coastal development, may be responsible for some of the unexplained growth variation in commercial clam stocks.
Testing a Bioenergetics-Based Habitat Choice Model: Bluegill (Lepomis macrochirus) Responses to Food Availability and Temperature
Authors: Wildhaber Mark L. , Crowder Larry B.
Published: August 2008

Using an automated shuttlebox system, we conducted patch choice experiments with 32, 8–12 g bluegill sunfish (Lepomis macrochirus) to test a behavioral energetics hypothesis of habitat choice. When patch temperature and food levels were held constant within patches but different between patches, we expected bluegill to choose patches that maximized growth based on the bioenergetic integration of food and temperature as predicted by a bioenergetics model. Alternative hypotheses were that bluegill may choose patches based only on food (optimal foraging) or temperature (behavioral thermoregulation). The behavioral energetics hypothesis was not a good predictor of short-term (from minutes to weeks) patch choice by bluegill; the behavioral thermoregulation hypothesis was the best predictor. In the short-term, food and temperature appeared to affect patch choice hierarchically; temperature was more important, although food can alter temperature preference during feeding periods. Over a 19-d experiment, mean temperatures occupied by fish offered low rations did decline as predicted by the behavioral energetics hypothesis, but the decline was less than 1.0 °C as opposed to a possible 5 °C decline. A short-term, bioenergetic response to food and temperature may be precluded by physiological costs of acclimation not considered explicitly in the behavioral energetics hypothesis.
Genetic Variation at the Malic Enzyme-2 Locus and Age at Maturity in Sea-run Atlantic Salmon (Salmo salar)
Authors: Jordan W. C. , Youngson A. F. , Webb J. H.
Published: August 2008

Variation in the diallelic polymorphism at the malic enzyme-2 locus (Me-2) in Atlantic salmon is used extensively in descriptions of the population structure of this species. Genotypes at the Me-2 locus were examined in adult Atlantic salmon captured at the Girnock Burn, a tributary of the Aberdeenshire Dee, over 3 yr (1986–88), and in salmon caught in the commercial fishery in the estuary of the River Tay in 2 yr (1987–88). Initial observations on the Girnock Burn data suggested that Me-2 genotype frequency distributions differed between one-sea-winter fish (grilse) and multi-sea-winter fish (salmon) groups from the same hatch-year class. Data from the River Tay supported hypotheses constructed on the basis of the Girnock Burn data. Genotype frequencies in some grilse groups at both sites differed significantly from those expected under Hardy–Weinberg equilibrium, while those in salmon groups did not. The frequency of heterozygotes was generally significantly higher in grilse than in salmon from the same hatch-year class. The data suggest a variable association between Me-2 genotype and age at maturity, and a selective influence on the Me-2 locus. The implications of selective influences on this locus for estimates of gene flow among Atlantic salmon populations are discussed.
Characteristics of Coarse Woody Debris for Several Coastal Streams of Southeast Alaska, USA
Authors: Robison E. George , Beschta Robert L.
Published: August 2008

Coarse woody debris (> 0.2 m in diameter and 1.5 m long) was measured along five undisturbed low-gradient stream reaches; volume, decay class, and horizontal orientation in relation to channel flow of first-, second-, third-, and fourth-order coastal streams were determined. Debris was also classified into four influence zones based on stream hydraulics and fish habitat. Average debris length, diameter, and volume per piece increased with stream size. Eighty percent of debris volume of the first-order and the smaller second-order streams was suspended above or lying outside the bankfull channel, while less than 40% was similarly positioned in the fourth-order stream. Approximately one-third of all debris was oriented perpendicular to stream flow, regardless of stream size. First-, second-, and third-order streams had a higher proportion of recent debris in the channel than the fourth-order stream ([Formula: see text]19 vs. 8%), most new debris being attributable to a major 1984 windstorm. Tree blowdown had a major influence on debris distribution along the smaller stream reaches. Debris jams and accumulations in the largest stream were formed from floated debris. These characterizations are useful for evaluating the distribution and amount of woody debris associated with land-management activities.
Distribution of Shrimp and Fish By-Catch Assemblages in the Canadian Eastern Arctic in Relation to Water Circulation
Authors: Hudon Christiane
Published: August 2008

In the Canadian eastern Arctic, the catches of common species of decapods and fish in bottom trawls reveal a continuum of increasing species richness and abundance in an easterly direction through Hudson Strait. Species richness is greatest in Ungava Bay, where Arctic and Labrador Sea components of the fauna coexist. Over the study area, species could be divided in three associations corresponding to the origin of the predominant water masses: Arctic cod, cottids, zoarcids, and liparids predominate in the Arctic waters of western and central Hudson Strait; Greenland halibut, roughhead grenadier, and three-beard rockling are characteristic of the northern Labrador Sea; pandalid shrimp are abundant in areas of deep (> 300 m), intensely mixed waters near the mouth of Hudson Strait. Pink shrimp (Pandalus borealis) predominates in Davis Strait–Labrador Sea, whereas it is replaced by the striped pink shrimp (P. montagui) in eastern Hudson Strait, reflecting environmental optima in subarctic and Arctic dominated waters, respectively. The yearly catches of striped pink shrimp are highly variable, possibly related to mixing intensity in eastern Hudson Strait. In Canadian Arctic waters, species richness, distribution, and abundance are related to temperature, salinity, mixing, and general circulation of water masses.
Large-Lake Responses to Declines in the Abundance of a Major Fish Planktivore—the Lake Michigan Example
Authors: Evans Marlene S.
Published: August 2008

Alewife abundances declined dramatically in southeastern Lake Michigan over 1973–77, several years before the lakewide decline occurred. The regional effects of this decline on adult copepod abundances, zooplankton biomass, and water clarity are examined. In the offshore region, the two largest copepods, Limnocalanus macrurus and Diaptomus sicilis, increased in abundance during the mid-1970's, reflecting the decrease in alewife predation. Limnocalanus macrurus abundances declined in later years, reflecting increased prédation pressures from the increasing bloater population. The small-bodied D. minutus and the medium-bodied D. ashlandi exhibited no apparent response to the decline in alewife abundance. Large-bodied D. oregonensis and small-bodied C. bicuspidatus thomasi declined in abundance. Size-selective fish prédation pressures continued to remain high in the inshore region: increased abundances of yellow perch and rainbow smelt apparently compensated for the alewife decline. Zooplankton biomass, zooplankton mean dry weight, and water clarity apparently were not affected by the decline in alewife abundance in either the inshore or offshore region. The results of this study are evaluated in terms of the lakewide decline in alewife abundance, the summer 1983 dominance of Daphnia pulicaria in offshore waters, the 1983 marked improvement in offshore water clarity, and later changes in summer offshore D. pulicaria populations.