bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal photosynthetic performance of Nereocystis luetkeana
Authors: Wheeler W. N. , Smith R. G. , Srivastava L. M.
Published: June 2008

Pigment levels, photosynthetic performance, and tissue nitrogen levels of three age-class blade disks of Nereocystis luetkeana were followed over one complete and two partial growth seasons. Chlorophyll (chl) a, fucoxanthin, and chlorophyll c all showed high levels in fall–winter and low levels in late summer. The molar ratios also varied with much higher fucoxanthin: chl a and chl c: chl a ratios in early spring than in late summer–fall. Plots of maximum photosynthetic rates (Pmax) at saturating light intensities and initial slopes (α) derived from photosynthetic rates at subsaturating light intensities also showed seasonal variations, with maxima in August and September and minima in April. The saturating light irradiance, IR, also showed a maximum in late summer and a minimum in winter. Tissue nitrate levels were high in winter, declined to near zero levels in May–August, and increased again in fall–winter. Amino acids and total N followed a similar pattern. The older tissues farthest from the bulb had higher Pmax and pigment levels as well as internal nitrate levels than young proximal tissues. Environmental data on sea-water nitrate, photon flux density, and temperature and data on mannitol and total C are presented. It appears that there is a significant negative correlation between photon flux density and initial slope of photosynthesis and between Pmax and temperature below 15 °C. At temperatures above 15 °C, internal N concentrations, which in turn are governed by the ambient nitrate concentration, appear to become limiting. Pigment levels, especially chlorophyll a, showed a direct correlation with ambient nitrate. These data are discussed in relation to the possible biennial nature and growth strategy of Nereocystis.
Microscopic observations on the trapping of nematodes by the predaceous fungus Dactylella cionopaga
Authors: Dowsett J. A. , Reid J. , Hopkin A. A.
Published: June 2008

The host–predator relationship between the predaceous hyphomycete Dactylella cionopaga Drechs. and the myceliophagous parthenogenetic nematode Aphelenchus avenae Bastian was investigated using interference-contrast and scanning electron microscopy of whole-mount preparations and transmission electron microscopy of ultrathin (Spurr) sections. The one-, two-, three-, or more-celled adhesive trapping structures of this fungus were found to be effective predatory mechanisms at all stages of their morphological development. The trapping structures, mode of capture, and penetration by D. cionopaga were compared with the adhesive knobs, constricting rings, and adhesive hyphal networks of Dactylaria species reported on previously.
Genera coelomycetum. XXII. Amphiciliella, Choanatiara anam. gen. nov., Ciferriella, Collonaemella, Cymbothyrium, Melanostroma, Phialophorophoma, and Thyrsidina
Authors: Raj T. R. Nag , DiCosmo F.
Published: June 2008

Amphiciliella, Cymbothyrium, and Melanostroma are reduced to synonymy with Bartalinia, Harknessia, and Ceuthospora, respectively. Ciferriella is shown to be a hyphomycete. The monotypic genera Collonaemella, Phialophorophoma, and Thyrsidina and their type species are redescribed. A new genus of coelomycetes is described to accommodate two new anamorph species.
The lateral thermal conductivity of leaves
Authors: Vogel Steven
Published: June 2008

The thermal conductivities in the plane of the blades of thin mesophytic leaves were determined by comparisons with nonliving materials of known conductivity. Results were as expected for structures made largely of water which was not capable of convective motion. Differences in the conductivity of models encompassing the range found in the present leaves had no effect on surface temperature distributions. Metallic models of much higher conductivity had much more nearly uniform surface temperatures than did models in the appropriate range of conductivity. Thus, metallic materials are unsuitable for thermal modelling of leaves.
Chromosome numbers of the Medicago sativa complex in Turkey
Authors: Small Ernest , Bauchan Gary R.
Published: June 2008

Turkish representatives of the Medicago sativa complex comprise three basic morphological classes distinguishable by the following: (1) purple flowers, coiled pods; (2) yellow flowers, uncoiled pods; (3) intermediates and recombinants between 1 and 2. Chromosome determinations were made for 329 plants representing 35 cultivated (alfalfa) and 87 wild populations. All cultivars collected fell into class 1 and were tetraploid (2n = 4x = 32). Wild plants representative of all three morphological classes were found at both the diploid (2n = 2x = 16) and tetraploid (2n = 4x = 32) level, and examples of hybrid zones between classes 1 and 2 were common at both levels. Most populations appeared to contain plants at the same ploidy level, but a few contained a mixture of both diploids and tetraploids, and at several locations diploid and tetraploid populations grew adjacent to each other. Tetraploids were widespread across Turkey whereas diploids were confined to the northeast region.
Resource allocation and floral sex ratios in Zizania aquatica
Authors: Willson Mary F. , Ruppel Kurt P.
Published: June 2008

Reproductive effort (RE) in Zizania aquatica (wild rice) averaged about 11% of total biomass except in extremely large plants, in which RE was about 17%. Plant biomass of wild rice was correlated positively with the numbers of male and female flowers produced. The average number of flowers per inflorescence varied markedly among stands and at different times in several lakes in northwestern Minnesota. Floral sex ratios of individuals (and of stands) consistently favored males, but the estimated allocation of biomass to female function (including seeds) consistently exceeded male allocation. Average flora sex ratios of individuals differed among stands and zones within stands, and very often declined steadily on successively produced inflorescences. The observed variation in biomass allocation to each gender and the consistent marked excess of biomass allocation to maternal function do not fit simple expectations of nearly equal expenditures in chiefly outcrossing cosexual plants nor of relatively high male allocation in wind-pollinated plants.
Leaf ultrastructure in species of Gomphrena and Pfaffia (Amaranthaceae)
Authors: Estelita-Teixeira Maria Emília , Handro Walter
Published: June 2008

Ultrastructural aspects, especially the organization of chloroplasts and their distribution, were studied in leaves of three species of Gomphrena (G. macrocephala, G. prostrata, and G. decipiens) presenting "Kranz anatomy," and in Pfaffia jubata, without that characteristic. In Gomphrena spp. the distribution of chloroplasts according to the complexity of their lamellar system seems to follow a gradient: most of the chloroplasts in the bundle sheath cells have poorly developed grana but some of them, in the cell side opposite to the vascular bundle, may present conspicuous grana. A similar situation occurs in "Kranz mesophyll cells," but in this case grana are more developed. Finally, chloroplasts in "non-Kranz mesophyll cells" have the more developed grana. In P. jubata no differences occur in chloroplast structure, all of them showing well-organized grana. Chloroplasts with well-developed grana were found in vascular parenchyma and in companion cells of Gomphrena spp. and P. jubata.
Étude préliminaire sur l'organogenèse adventive à partir d'embryons de tulipe cultivés in vitro (Tulipa gesneriana)
Authors: Aubert B. , Weber G. , Dorion N. , Nard M. Le , Bigot C.
Published: June 2008

In vitro tulip embryos have an active shoot-forming capacity (up to 320 neoformations per embryo, for a 20-month period) when cultured, at a temperature of 20–24 °C under a 16-h day length (4000 lx), with growth regulators: naphthalene-acetic acid (0.5 mg ∙ L−1) and benzylaminopurine (1 mg L−1) or kinetin (0.5 mg L−1) or isopentenyladenine (1 mg L−1). Repeated fragmentations improve or maintain shoot-forming ability. Nevertheless, an important genotypic effect is observed. When neoformations are subjected to a cold treatment of at least 40 days at 6 °C under short days (8 h, 2500 lx) and then transferred at 24 °C under long days (16 h, 800 lx), they produce numerous functional bulblets.
Photoperiod and temperature regulation of the life history of Porphyra columbina (Rhodophyta, Bangiales) from central Chile
Authors: Avila M. , Santelices B. , McLachlan J.
Published: June 2008

The effects of temperature (10, 15, 20 °C) and photoperiod (8:16, 12:12, 16:8 (hours of light: hours of dark)) on the growth and reproduction of different stages in the life history of Porphyra columbina Montagne were assessed. The conchocelis phase had higher growth rates at 12 h light:12 h dark, 45 μmol m−2 s−1, and 15 °C. Under all the temperatures and photoperiods tested, the conchocelis phase could propagate either by monospores or vegetative fragmentation. Conchosporangia were formed only at 10 °C and 8 h light:16 h dark or at 15 °C and either 8 h light:16 h dark or 12 h light:12 h dark. Long photoperiods inhibited conchosporangia formation at all temperatures tested with the exception of 20 °C and 16 h light:8 h dark, where sporangia was formed once. Conchospores were released when the temperature was decreased (15 to 10 °C) maintaining the photoperiod. Conchospore germination occurred under the three photoperiods and temperatures tested. Growth of juvenile fronds was maximum at 15 °C and either 12 h light:12 h dark or 16 h light:8 h dark. Fronds formed carpospores and spermatia at 15 °C and 16 h light:8 h dark only. With optimum conditions the life history was completed in 60 days. Spermatia had three chromosomes (n = 3).
Analysis by HPLC – mass spectrometry of the indole compounds released by the ectomycorrhizal fungus Hebeloma hiemale in pure culture
Authors: Rouillon R. , Gay G. , Bernillon J. , Favre-Bonvin J. , Bruchet G.
Published: June 2008

Indole compounds released by Hebeloma hiemale Bres. in pure culture were studied by cultivating the fungus on a nutrient solution supplemented or not with 1 mM tryptophan. Analytical thin-layer chromatography revealed numerous indole compounds in 7-week-old culture filtrates obtained in the presence of tryptophan. Such compounds were isolated by preparative thin-layer chromatography and purified by high performance liquid chromatography. The most abundant of them, i.e., indolyl-3-acetic acid, indolyl-3-carboxylic acid, and indole-3-aldehyde, were identified by mass spectrometry. Indole-3-aldehyde and indolyl-3-carboxylic acid, which were detected in filtrates throughout the culture period, might result from breakdown of indolyl-3-acetic acid by fungal exocellular enzymes.
The influence of diffused light and temperature on seed germination of three genetically nondormant lines of wild oats (Avena fatua) and its adaptive significance
Authors: Sawhney Ramma , Hsiao Andrew I. , Quick William A.
Published: June 2008

Freshly harvested seeds of three genetically nondormant populations of wild oat (Avena fatua L.) germinated readily in the dark at optimum temperatures. Direct or diffused light caused germination inhibition in seeds of all these populations. This light-induced germination inhibition was intensity dependent; the higher the light intensity, the greater the inhibition. Germination inhibition by light was accentuated by higher incubation temperatures, indicating an interaction between these two factors on the induction of secondary seed dormancy in genetically nondormant populations. This interaction may be of adaptive significance to the survival of nondormant populations, and reconciles some apparently conflicting reports in the literature.
In vitro control of caulogenesis by growth regulators and media components in embryonic explants of eastern white pine (Pinus strobus)
Authors: Flinn Barry S. , Webb David T. , Georgis Wanda
Published: June 2008

Horizontally oriented embryos of Pinus strobus (L.) produced shoots on Schenk and Hildebrandt medium containing cytokinin. Shoots developed primarily from cotyledons in contact with the medium. Seed pretreatments at 5 or 27 °C did not affect caulogenesis. N6-Benzyladenine (BA) and N6-(Δ2-isopentenyl)adenine (2iP) both induced caulogenesis, with BA being 10–20 times more potent than 2iP. High BA levels caused callus formation. BA exposures from 1 to 8 weeks were equally caulogenic with horizontal explants, but exposures longer than 2 weeks led to increased variability and callus formation. A 1-week, upside-down, vertical orientation during BA treatment increased the uniformity of cotyledon response and was as caulogenic as a 4-week horizontal BA exposure. Neither auxins nor triiodobenzoic acid induced or significantly enhanced shoot formation. Full-strength Schenk and Hildebrandt medium was superior to Murashige and Skoog medium for shoot induction. Dilution of Schenk and Hildebrandt medium had no significant effect on shoot production, but shoot elongation was suppressed on one quarter strength Schenk and Hildebrandt medium. Half-strength Murashige and Skoog medium was as caulogenic as Schenk and Hildebrandt medium. The NH4 level of the macronutrients was responsible for the difference between Schenk and Hildebrant medium and Murashige and Skoog medium. The higher NH4 concentration of Murashige and Skoog medium inhibited shoot formation.
O2 requirements for growth and survival of wood-decaying and sapwood-staining fungi
Authors: Scheffer Theodore C.
Published: June 2008

Various experiments were conducted to examine O2 requirements for growth and survival of a total of 48 wood-destroying basidiomycetes and 6 sapwood-staining fungi. An additional objective was to determine whether species that invade heartwood of living trees (heartrotters) are more tolerant of O2 deficiencies than those that attack better-aerated wood (product rotters). Growth of cultures exposed to flowing mixtures of O2 and N2 was moderately retarded by an O2 pressure of about 11 mm (1 mmHg = 133.322 Pa) and was severely retarded by a pressure near 2 mm. None of the fungi grew with 1.5 mm of O2. Comparable minimal O2 pressures for growth were found by growing the fungi in a closed chamber (with an attached manometer) containing NaOH to absorb CO2, then regularly measuring growth and internal O2 pressure. Fungi grown in a closed chamber consumed all of the available O2. Length of survival of species grown in sealed test tubes differed markedly, from less than 1 week to more than 2 years. The species surviving longest included more heartrotters than product rotters.
Primordia and leaf production in winter wheat, triticale, and rye under field conditions
Authors: Hunt L. A. , Chapleau Anne-Marie
Published: June 2008

Primordia production and leaf emergence were investigated in winter wheat (Triticum aestivum L. em Thell.) and two related species, winter rye (Secale cereale L.) and winter triticale (× Triticosecale Wittmack), under field conditions in Southern Ontario, a region with a humid continental climate. Primordia initiation could be adequately described by a linear regression of primordia number on accumulated degree-days in the 1st year of study, 1981 – 1982. In the 2nd year, however, a linear relationship was noticed only in the late winter and early spring, with the rate of primordia production being distinctly lower earlier in the season. The rate of primordia initiation was faster in the ryes than in the wheats, a superiority which was associated with greater spikelet production. Triticale had an intermediate rate of primordia initiation but was closer to wheat in the timing of double ridge and terminal spikelet formation. Leaves emerged at a constant rate (degree-days base) which was similar in most of the cultivars.
Gracilaria cornea, the correct name for the western Atlantic alga hitherto known as G. debilis (Rhodophyta, Gigartinales)
Authors: Bird C. J. , Oliveira E. C. de , McLachlan J.
Published: June 2008

The species reported as Gracilaria debilis (Forsskål) Børgesen in the tropical western Atlantic is incorrectly named. Type material of G. debilis, from the Red Sea, differs from the Atlantic alga in several essential aspects of vegetative anatomy and in size of tetrasporangia. The next oldest name that has been applied to the Atlantic species, G. poitei (Lamouroux) J. Agardh, is unavailable as its basionym has previously been shown to be based on a species of Laurencia Lamouroux. A later name, G. wrightii (Turner) J. Agardh, is also considered inappropriate on the grounds that its protologue, in the absence of a type specimen, is thought to encompass more than one taxon and, moreover, is inconsistent with the alga in question. It is argued that a more recent binomial, G. cornea J. Agardh, is the correct name for this familiar species in the western Atlantic flora.
Cytokinin concentration gradient in the developing grains and upper leaves of rice (Oryza sativa) during grain filling
Authors: Saha Shyamali , Nagar P. K. , Sircar P. K.
Published: June 2008

Changes in cytokinin activity in the flag, first, second, and third leaves and in the developing grain of rice (Oryza sativa L.) were studied using the soybean callus bioassay in relation to the movement of photosynthate during different developmental stages. Cytokininlike activity in leaves was highest at the 85th day after transplantation. The flag leaf maintained higher cytokinin activity than other upper leaves. In grains high cytokininlike activity during the 1st week after anthesis is correlated with the grain setting and cell division period. The concentration gradient of cytokininlike substances in the upper parts of the plant was highest in the panicle after anthesis. The data suggest that the developing rice grains attract most of their photoassimilate from their nearest neighbours, the metabolically active flag, first, and second leaves.
Analytical electrofocusing and two-dimensional electrophoresis of proteins extracted from the mycelia of aggressive and nonaggressive strains of Ophiostoma ulmi
Authors: Jeng Robert S.
Published: June 2008

Soluble mycelial proteins from Ophiostoma ulmi (Buism.) Nannf., the causal agent of Dutch elm disease, were separated by analytical electrofocusing and two-dimensional electrophoresis in polyacrylamide gels. Results showed the aggressive and nonaggressive strains of this pathogen each had about 60 Coomassie blue stained bands having isoelectric points from 3 to 7. Both strains of this fungus had their own characteristic electrofocusing patterns. Nonaggressive isolate S116, for example, lacked two protein bands, one near the anode and one near the cathode, but it had five additional protein bands distributed from pH 4 to 6. Two-dimensional electrophoresis of total soluble proteins depicted that there were 36 proteins found to be specific for the nonaggressive isolate S116 and 12 proteins for the aggressive isolate RR2.
On Trametes aethalodes and other species of Daedalea (Polyporaceae)
Authors: Rajchenberg Mario
Published: June 2008

Morphological and cultural studies of Trametes aethalodes Mont. were carried out to evaluate its taxonomic position. The new combination Daedalea aethalodes (Mont.) Rajchenberg is proposed. The genus Daedalea Pers.: Fr. is characterised by pileate fruit bodies, a trimitic hyphal system, presence of generative hyphae with irregularly thickened walls, skeletal hyphae, and tramal cystidia that protrude into the hymenium. These features are also present in D. stereoides Fr., D. dickinsii (Berk.) Bond., and D .moesta (Kalchb.) Rajchenberg, comb. nov. The relationships with Antrodia Karst. and the significance of coloured vegetative hyphae in Coriolopsis Murr. are discussed.
Sequence of events in the germination of the resting spore of Synchytrium endobioticum, European pathotype 2, the causal agent of potato wart disease
Authors: Hampson Michael C.
Published: June 2008

Populations of freshly harvested to 4-year-old resting spores of Synchytrium endobioticum (Schilb.) Perc. from sand compost and aqueous immersion cultures were observed, using normal and television microscopy. Germination vesicles were found in aging cultures: at 49 days in sand compost or peaking at the 11th day in aqueous immersion. Freshly harvested spores gave rise to the largest quantity of vesicles in aqueous immersion. The ability to produce vesicles fell off in rapid exponential fashion with time after spore harvest. Release of the sporangia from the enveloping vesicles and discharge of zoospores from sporangia were studied in detail through the use of videotape recordings. This is the first reported description of these phenomena in the life history of S. endobioticum.
Heterosis and the metabolism of [3H]gibberellin A1 in maize
Authors: Rood S. B.
Published: June 2008

Seedling growth and the metabolism of high specific activity (1.1 TBq mmol−1) [3H]gibberellin A1 were studied in two Canadian maize (Zea mays L.) inbreds, CM7 and CM49, and in their single cross F1 hybrid. As previously reported, the hybrid grew more rapidly than either parental inbred. Metabolism of the [3H]GA1 was qualitatively similar in all three genotypes and [3H]-labelled metabolites were tentatively identified through sequential, step-elution silicic acid partition chromatography followed by reversed-phase C18 high-performance liquid chromatography, relative to the retention times of authentic GAs. Although the expected 2β-hydroxylation product, [3H]GA8 was not detected, a metabolite was observed at the retention time of GA8-O(2)-glucoside. Additionally, another metabolite(s) eluted at the retention time of glucosyl conjugates of GA1, and enzymic cleavage with cellulase yielded a [3H]-labelled compound which subsequently eluted at the retention time of free GA1. While the ratio of the precursor [3H]GA1 to total [3H]GA conjugate-like metabolites was similar in the three genotypes, the hybrid contained higher levels of the [3H]GA8-glucosidelike metabolite, whereas the inbreds contained higher levels of the [3H]GA1 conjugatelike metabolite(s). Thus, there are differential rates of GA1 metabolism in a maize hybrid relative to its slower-growing inbred parents.
A 2-PARAMETER HIERARCHY OF INTEGRABLE LATTICE EQUATIONS
Authors: XU XI-XIANG , CAO WEI-LI
Published: June 2008

A new discrete matrix spectral problem with two arbitrary constants is introduced, and the corresponding 2-parameter hierarchy of integrable lattice equations is obtained by discrete zero curvature representation. The resulting integrable lattice equations reduce to the hierarchy of relativistic Toda lattice in rational form for a special choice of the parameters. Moreover, a sub-hierarchy of the resulting integrable lattice equations is discussed. It is shown that each lattice equation in the sub-hierarchy is a Liouville integrable discrete Hamiltonian equation.
STUDIES ON THE LOCAL STRUCTURE AND THE SPIN HAMILTONIAN PARAMETERS FOR THE TRIGONALMn2+CENTER INBi4Ge3O12
Authors: WANG XUE-FENG , WU SHAO-YI , ZHANG ZHI-HONG , WEI LI-HUA , HUA YUE-XIA
Published: June 2008

The local structure and the spin Hamiltonian parameters (the zero-field splitting D, the g factors g//, g⊥and the hyperfine structure constants A//and A⊥) for the trigonal Mn2+center in Bi4Ge3O12are theoretically studied from the perturbation formulas of these parameters for a 3d5ion in trigonal symmetry. The impurity Mn2+replacing host Bi3+is not found to occupy the exact Bi3+site but to suffer a large off-center displacement by about 0.36 Å towards the center of the oxygen octahedron along the C3-axis due to the size and charge mismatching substitution. The calculated spin Hamiltonian parameters based on the above displacement show good agreement with the observed values. The results and the mechanism of the impurity displacement are discussed.
NEAR STATIONARY DIELECTRIC PROPERTIES IN HALF-METALLIC FERROMAGNETIC Ag:CrO2 NANOCOMPOSITE PARTICLES AT HIGH FREQUENCIES
Authors: SINGH G. P. , RAM S. , THAKUR A. K.
Published: June 2008

Nanocomposite particles of silver modified CrO 2 were synthesized by a chemical CrO 3 → CrO 2 reduction in the presence of Ag + in an aqueous medium whereby the half-metallic ferromagnetic particles of CrO 2 are generated within a shell of silver. The dielectric constant εr, AC resistivity ρAC, and the dielectric power loss were studied after annealing recovered Ag:CrO 2 powder (compacted as the billets), at 300°C for 2 h in air, at 10–1000 kHz frequencies (f) at room temperature. At 10 kHz, the ρr has as large a value as 49, with ρ AC = 106 k Ω-cm and power loss 0.42. As f increases, all the three parameters are decreased monotonically to the values 28, 3.6 kΩ-cm, and 0.06 respectively. Almost a steady εr as well as ρAC value exists, with controlled power loss, useful for high frequency applications over f ≥ 400 kHz .
BIARC APPROXIMATION, SIMPLIFICATION AND SMOOTHING OF POLYGONAL CURVES BY MEANS OF VORONOI-BASED TOLERANCE BANDS
Authors: HEIMLICH MARTIN , HELD MARTIN
Published: June 2008

We present an algorithm for approximating multiple closed polygons in a tangent-continuous manner with circular biarcs. The approximation curves are guaranteed to lie within a user-specified tolerance of the original input. If requested, our algorithm can also ensure that the input is within a user-specified tolerance of the approximation curves. These tolerances can be either symmetric, asymmetric, one-sided, or even one-sided and completely disconnected from the inputs. Our algorithm makes use of Voronoi diagrams to build disjoint and continuous tolerance bands for every polygon of the input. In a second step the approximation curves are fitted into the tolerance bands. Our algorithm has a worst-case complexity of O(n log n) for an n-vertex input.

Extensive experiments with synthetic and real-world data sets show that our algorithm generates approximation curves with significantly fewer approximation primitives than previously proposed algorithms. This difference becomes more prominent the larger the tolerance threshold is or the more severe the noise in the input is. In particular, no heuristic is needed for smoothing noisy input prior to the actual approximation. Rather, our approximation algorithm can be used to smooth out noise in a reliable manner.
IMPROVING STABILITY IN THE TIME-STEPPING ANALYSIS OF STRUCTURAL NONLINEAR DYNAMICS
Authors: LOPEZ S. , RUSSO K.
Published: June 2008

A change in the representation of discrete motion equations for nonlinear structural dynamics of two-dimensional bodies is developed. The objective is to write the motion equation in a less nonlinear form. This leads to a significant increase in the range of stability of the time integration process and a reduction in the number of Newton iterations required in the time integration step.
DYNAMIC ASSESSMENT OF UNDERWATER PIPELINE SYSTEMS USING STATISTICAL MODEL UPDATING
Authors: ZHU X. Q. , HAO H. , PENG X. L.
Published: June 2008

This paper presents a statistical model updating technique for damage detection of underwater pipeline systems via vibration measurements. To verify the reliability of the method, laboratory tests of a scaled pipeline model were carried out in a towing tank. The model includes a plastic pipe and some removable springs which are designed and fabricated to link the pipe and the steel base to simulate the bedding conditions. Different damage scenarios, in terms of location and severity of scouring under the pipe, were simulated by removing one or several springs. The natural frequencies, damping ratios and mode shapes of the pipeline system were extracted from the measured vibrations using a stochastic subspace identification technique. Both the numerical and the experimental results show that the method is effective and reliable in identifying the underwater pipeline bedding conditions and the damage in the pipe structure.
PERFORMANCE OF THE HHT-α METHOD FOR THE SOLUTION OF NONLINEAR SYSTEMS
Authors: CHANG SHUENN-YIH
Published: June 2008

The HHT-α method previously developed shows favorable numerical dissipation, in addition to unconditional stability, in the solution of linear elastic systems. However, its performance in the solution of nonlinear systems has not been studied yet. In this paper, the numerical properties of a subfamily of this integration method with -⅓ ≤ α ≤ 0, β = ¼(1 - α)2and γ = ½-α for the solution of nonlinear systems are analytically explored using a linearized analysis, where the stiffness term in total form is used to determine the restoring force. A theoretical proof of unconditional stability for nonlinear systems is presented. The subfamily of the integration method is verified to possess favorable numerical dissipation for both linear and nonlinear systems. Period distortion affected by the step degree of either nonlinearity or convergence is studied. Although the analysis is conducted for a single-degree-of-freedom nonlinear system, the application to a multiple-degree-of-freedom nonlinear system is also illustrated. It is confirmed that the performance of the HHT-α method for nonlinear systems is generally the same as that for linear elastic systems, except for the high dependence on the step degree of nonlinearity.
SCHEME FOR IMPLEMENTING ASSISTED CLONING OF AN UNKNOWN BIPARTITE D-DIMENSION EQUATORIAL ENTANGLED STATE
Authors: MA PENG-CHENG , ZHAN YOU-BANG , ZHANG LING-LING
Published: June 2008

In this paper, we proposed a protocol which can produce a perfect copy of an unknown bipartite d-dimension equatorial entangled state with assistance from a state preparer. In this protocol, the maximally and non-maximally entangled bipartite d-dimension states are used as the quantum channels, respectively. The first stage of the protocol requires usual teleportation. In the second stage of the protocol, with the assistance (two-qudit projective measurement) of the preparer, the perfect copy of an original unknown state can be produced.
Cdc42 and RhoA have opposing roles in regulating membrane type 1-matrix metalloproteinase localization and matrix metalloproteinase-2 activation
Authors: Ispanovic Eric , Serio Damiano , Haas Tara L.
Published: June 2008

Proteolysis of the basement membrane and interstitial matrix occurs early in the angiogenic process and requires matrix metalloproteinase (MMP) activity. Skeletal muscle microvascular endothelial cells exhibit robust actin stress fibers, low levels of membrane type 1 (MT1)-MMP expression, and minimal MMP-2 activation. Depolymerization of the actin cytoskeleton increases MT1-MMP expression and MMP-2 activation. Rho family GTPases are regulators of actin cytoskeleton dynamics, and their activity can be modulated in response to angiogenic stimuli such as vascular endothelial growth factor (VEGF). Therefore, we investigated their roles in MMP-2 and MT1-MMP production. Endothelial cells treated with H1152 [an inhibitor of Rho kinase (ROCK)] induced stress fiber depolymerization and an increase in cortical actin. Both MMP-2 and MT1-MMP mRNA increased, which translated into greater MMP-2 protein production and activation. ROCK inhibition rapidly increased cell surface localization of MT1-MMP and increased PI3K activity, which was required for MMP-2 activation. Constitutively active Cdc42 increased cortical actin polymerization, phosphatidylinositol 3-kinase activity, MT1-MMP cell surface localization, and MMP-2 activation similarly to inhibition of ROCK. Activation of Cdc42 was sufficient to decrease RhoA activity. Capillary sprout formation in a three-dimensional collagen matrix was increased in cultures treated with RhoAN19 or Cdc42QL and, conversely, decreased in cultures treated with dominant negative Cdc42N17. VEGF stimulation also induced activation of Cdc42 while inhibiting RhoA activity. Furthermore, VEGF-dependent activation of MMP-2 was reduced by inhibition of Cdc42. These results suggest that Cdc42 and RhoA have opposing roles in regulating cell surface localization of MT1-MMP and MMP-2 activation.
Transient membrane recruitment of IRAK-1 in response to LPS and IL-1β requires TNF R1
Authors: Lockett Angelia , Goebl Mark G. , Harrington Maureen A.
Published: June 2008

The transcription factor NF-κB is an essential regulator of the innate immune response that functions as the first line of defense against infections. Activation of the innate immune response by bacterial lipopolysaccharide (LPS) triggers production of tumor necrosis factor-α (TNF-α) followed by interleukin-1 (IL-1). The IL-1 receptor associated kinase-1 (IRAK-1) is an integral component of the LPS, TNF-α, and IL-1 signaling pathways that regulate NF-κB. Thus we hypothesized that IRAK-1 coordinates cellular NF-κB responses to LPS, TNF-α, and IL-1. In contrast to TNF-α where IRAK-1 subcellular localization does not change, treatment with LPS or IL-1 leads to a loss in cytoplasmic IRAK-1 with a coordinate increase in plasma membrane associated modified IRAK-1. In fibroblasts lacking the type 1 TNF-α receptor (TNF R1), IRAK-1 turnover is altered and modification of IRAK-1 in the plasma membrane is decreased in response to LPS and IL-1, respectively. When NF-κB controlled gene expression is measured, fibroblasts lacking TNF R1 are hyperresponsive to LPS, whereas a more variable response to IL-1 is seen. Further analysis of the LPS response revealed that plasma membrane-associated IRAK-1 is found in Toll 4, IL-1, and TNF R1-containing complexes. The data presented herein suggest a model whereby the TNF R1-IRAK-1 interaction integrates the cellular response to LPS, TNF-α, and IL-1, culminating in a cell poised to activate TNF-α-dependent NF-κB controlled gene expression. In the absence of TNF R1-dependent events, exposure to LPS or IL-1 leads to hyperactivation of the inflammatory response.
Mild endotoxemia, NF-κB translocation, and cytokine increase during exertional heat stress in trained and untrained individuals
Authors: Selkirk G. A. , McLellan T. M. , Wright H. E. , Rhind S. G.
Published: June 2008

This study examined endotoxin-mediated cytokinemia during exertional heat stress (EHS). Subjects were divided into trained [TR; n = 12, peak aerobic power (V̇o2peak) = 70 ± 2 ml·kg lean body mass−1·min−1] and untrained (UT; n = 11, V̇o2peak= 50 ± 1 ml·kg lean body mass−1·min−1) groups before walking at 4.5 km/h with 2% elevation in a climatic chamber (40°C, 30% relative humidity) wearing protective clothing until exhaustion (Exh). Venous blood samples at baseline and 0.5°C rectal temperature increments (38.0, 38.5, 39.0, 39.5, and 40.0°C/Exh) were analyzed for endotoxin, lipopolysaccharide binding protein, circulating cytokines, and intranuclear NF-κB translocation. Baseline and Exh samples were also stimulated with LPS (100 ng/ml) and cultured in vitro in a 37°C water bath for 30 min. Phenotypic determination of natural killer cell frequency was also determined. Enhanced blood (104 ± 6 vs. 84 ± 3 ml/kg) and plasma volumes (64 ± 4 vs. 51 ± 2 ml/kg) were observed in TR compared with UT subjects. EHS produced an increased concentration of circulating endotoxin in both TR (8 ± 2 pg/ml) and UT subjects (15 ± 3 pg/ml) (range: not detected to 32 pg/ml), corresponding with NF-κB translocation and cytokine increases in both groups. In addition, circulating levels of tumor necrosis factor-α and IL-6 were also elevated combined with concomitant increases in IL-1 receptor antagonist in both groups and IL-10 in TR subjects only. Findings suggest that the threshold for endotoxin leakage and inflammatory activation during EHS occurs at a lower temperature in UT compared with TR subjects and support the endotoxin translocation hypothesis of exertional heat stroke, linking endotoxin tolerance and heat tolerance.
Reciprocal Stimulation of Decay Between Serotonergic Facilitation and Depression of Synaptic Transmission
Authors: Lee Sun Hee Cho , Taylor Karen , Krasne Franklin B.
Published: June 2008

Serotonin can produce multiple, contradictory modulatory effects on strength of synaptic transmission in both vertebrate and invertebrate nerve circuits. In crayfish, serotonin (5-HT) can both facilitate and depress transmission to lateral giant escape command neurons; however, which effect is manifest during application, as well as the sign and duration of effects that may continue long after 5-HT washout, may depend on history of application as well as on concentration. We report that protein kinase A (PKA) signaling is essential to the production of facilitation but depression is mediated by non-cAMP/PKA signaling pathways. However, we unexpectedly found that PKA activity is essential for the decay of depression when serotonin is washed out. This, and evidence from the effects of a variety of serotonin application regimens, suggest that facilitatory and depressive states coexist and compete and that the decay of each is dependent on stimulation by the other. A computational model that incorporates these assumptions can account for and rationalize the varied effects of a wide range of serotonin application regimens.
Single‐Walled Carbon Nanotubes as Fluorescence Biosensors for Pathogen Recognition in Water Systems
Authors: Upadhyayula Venkata K. K. , Ghoshroy Soumitra , Nair Vinod S. , Smith Geoffrey B. , Mitchell Martha C. , Deng Shuguang
Published: June 2008

The possibility of using single‐walled carbon nanotubes (SWCNTs) aggregates as fluorescence sensors for pathogen recognition in drinking water treatment applications has been studied. Batch adsorption study is conducted to adsorb large concentrations of Staphylococcus aureus aureus SH 1000 and Escherichia coli pKV‐11 on single‐walled carbon nanotubes. Subsequently the immobilized bacteria are detected with confocal microscopy by coating the nanotubes with fluorescence emitting antibodies. The Freundlich adsorption equilibrium constant
(k) for S.aureus and E.coli determined from batch adsorption study was found to be 9 × 108 and 2 × 108 ml/g, respectively. The visualization of bacterial cells adsorbed on fluorescently modified carbon nanotubes is also clearly seen. The results indicate that hydrophobic single‐walled carbon nanotubes have excellent bacterial adsorption capacity and fluorescent detection capability. This is an important advancement in designing fluorescence biosensors for pathogen recognition in water systems.
The Role of Fermi Resonance in Formation of Valence Band of Water Raman Scattering
Authors: Burikov Sergey A. , Dolenko Tatiana A. , Fadeev Victor V.
Published: June 2008

The role of Fermi resonance in formation of valence band of water Raman scattering was investigated. Simultaneous measurement of characteristics of bending and valence bands of water in solutions, KBr, and KCl and using genetic algorithms in conjunction with variation methods allowed increasing accuracy of estimation of Fermi resonance coupling constant and of Fermi resonance contribution into formation of water Raman valence band.
Development in Rice Genome Research Based on Accurate Genome Sequence
Authors: Matsumoto Takashi , Wu Jianzhong , Antonio Baltazar A. , Sasaki Takuji
Published: June 2008

Rice is one of the most important crops in the world. Although genetic improvement is a key technology for the acceleration of rice breeding, a lack of genome information had restricted efforts in molecular-based breeding until the completion of the high-quality rice genome sequence, which opened new opportunities for research in various areas of genomics. The syntenic relationship of the rice genome to other cereal genomes makes the rice genome invaluable for understanding how cereal genomes function. Producing an accurate genome sequence is not an easy task, and it is becoming more important as sequence deviations among, and even within, species highlight functional or evolutionary implications for comparative genomics.
Imperfect Reworking Process Consideration in Integrated Inventory Model under Permissible Delay in Payments
Authors: Lo Ming-Cheng , Yang Ming-Feng
Published: June 2008

This study develops an improved inventory model to help the enterprises to advance their profit increasing and cost reduction in a single
vendor single‐buyer environment with general demand curve, adjustable production rate, and imperfect reworking process under permissible delay in payments. For advancing practical use in a real world,
we are concerned with the following strategy determining, which includes the buyer_s optimal selling price, order quantity, and the number of shipments per production run from the vendor to the buyer. An algorithm and numerical analysis are used to illustrate the solution procedure.
Microglia and Astrocyte Activation by Toll‐Like Receptor Ligands: Modulation by PPAR‐γ Agonists
Authors: Gurley Catherine , Nichols Jessica , Liu Shuliang , Phulwani Nirmal K. , Esen Nilufer , Kielian Tammy
Published: June 2008

Microglia and astrocytes express numerous members of the Toll‐like receptor (TLR) family that are pivotal for recognizing conserved microbial motifs expressed by a wide array of pathogens. Despite the critical role for TLRs in pathogen recognition, when dysregulated these pathways can also exacerbate CNS tissue destruction. Therefore, a critical balance must be achieved to elicit sufficient immunity to combat CNS infectious insults and down‐regulate these responses to avoid pathological tissue damage. We performed a comprehensive survey on the efficacy of various PPAR‐γ agonists to modulate proinflammatory mediator release from primary microglia and astrocytes in response to numerous TLR ligands relevant to CNS infectious diseases. The results demonstrated differential abilities of select PPAR‐γ agonists to modulate glial activation. For example, 15d‐PGJ2 and pioglitazone were both effective at reducing IL‐12 p40 release by TLR ligand‐activated glia, whereas CXCL2 expression was either augmented or inhibited by 15d‐PGJ2, effects that were dependent on the TLR ligand examined. Pioglitazone and troglitazone demonstrated opposing actions on microglial CCL2 production that were TLR ligand‐dependent. Collectively, this information may be exploited to modulate the host immune response during CNS infections to maximize host immunity while minimizing inappropriate bystander tissue damage that is often characteristic of such diseases.
Effect of Process Parameters on Catalytic Incineration of Solvent Emissions
Authors: Ojala Satu , Lassi Ulla , Perämäki Paavo , Keiski Riitta L.
Published: June 2008

Catalytic oxidation is a feasible and affordable technology for solvent emission abatement. However, finding optimal operation conditions is important, since they are strongly dependent on the application area of VOC incineration. This paper presents the results of the laboratory experiments concerning four most central parameters, that is, effects of concentration, gas hourly space velocity (GHSV), temperature, and moisture on the oxidation of n-butyl acetate. Both fresh and industrially aged commercial Pt/Al2O3catalysts were tested to determine optimal process conditions and the significance order and level of selected parameters. The effects of these parameters were evaluated by computer-aided statistical experimental design. According to the results, GHSV was the most dominant parameter in the oxidation of n-butyl acetate. Decreasing GHSV and increasing temperature increased the conversion of n-butyl acetate. The interaction effect of GHSV and temperature was more significant than the effect of concentration. Both of these affected the reaction by increasing the conversion of n-butyl acetate. Moisture had only a minor decreasing effect on the conversion, but it also decreased slightly the formation of by products. Ageing did not change the significance order of the above-mentioned parameters, however, the effects of individual parameters increased slightly as a function of ageing.
Potent synergy of dual antitumor peptides for growth suppression of human glioblastoma cell lines
Authors: Kondo Eisaku , Tanaka Takehiro , Miyake Takayoshi , Ichikawa Tomotsugu , Hirai Masahiko , Adachi Masaki , Yoshikawa Kazuhiro , Ichimura Koichi , Ohara Nobuya , Moriwaki Akiyoshi , Date Isao , Ueda Ryuzo , Yoshino Tadashi
Published: June 2008

Molecular targeting agents have become formidable anticancer weapons, which show much promise against the refractory tumors. Functional peptides are among the more desirable of these nanobio-tools. Intracellular delivery of multiple functional peptides forms a basis for potent, non-invasive mode of delivery, providing distinctive therapeutic advantages. Here, we examine growth suppression efficiency of human glioblastomas by dual-peptide targeting. We did simultaneous introduction of two tumor suppressor peptides (p14ARF and p16INK4a or p16INK4a and p21CIP1 functional peptides) compared with single-peptide introduction using Wr-T-mediated peptide delivery. Wr-T-mediated transport of both p14ARF and p16INK4a functional peptides (p14-1C and p16-MIS, respectively) into human glioblastoma cell line, U87ΔEGFR, reversed specific loss of p14 and p16 function, thereby drastically inhibiting tumor growth by >95% within the first 72 h, whereas the growth inhibition was ∼40% by p14 or p16 single-peptide introduction. Additionally, the combination of p16 and p21CIP1 (p21-S154A) peptides dramatically suppressed the growth of glioblastoma line Gli36ΔEGFR, which carries a missense mutation in p53, by >97% after 120 h. Significantly, our murine brain tumor model for dual-peptide delivery showed a substantial average survival enhancement (P < 0.0001) for peptide-treated mice. Wr-T-mediated dual molecular targeting using antitumor peptides is highly effective against growth of aggressive glioblastoma cells in comparison with single molecule targeting. Thus, jointly restoring multiple tumor suppressor functions by Wr-T-peptide delivery represents a powerful approach, with mechanistic implications for development of efficacious molecular targeting therapeutics against intractable human malignancies. [Mol Cancer Ther 2008;7(6):1461–71]
DNA vaccination with CD44 variant isoform reduces mammary tumor local growth and lung metastasis
Authors: Wallach-Dayan Shulamit Batya , Rubinstein Ariel M. , Hand Carla , Breuer Raphael , Naor David
Published: June 2008

We have shown recently that cDNA vaccination, using a virtual lymph node, ameliorates experimental allergic encephalomyelitis. Successful cure from mammary tumor requires resolution of local tumor growth and metastases. We have examined whether targeting of CD44 cell surface adhesion molecule by cDNA vaccination plays a role in resolving mammary tumor development. We show here that CD44 cDNA vaccination decreases the tumor mass and metastatic potential in experimental mammary tumor of BALB/c mice. Vaccination of mice, inoculated with the mammary tumors, by cDNA of CD44 variant (CD44v) but not by cDNA of standard CD44, markedly reduced local tumor development and lung metastasis. Concomitantly, transfection of CD44 antisense into a highly metastatic mammary tumor cell line disrupted the CD44 expression of the cells and reduced their ability to establish local tumors as well as metastatic colonies in the lung. Moreover, when CD44v, but not standard CD44 sense cDNA, was transfected into the poorly metastatic cell line, tumor development was markedly enhanced. It is possible therefore that DNA vaccination with a specific CD44v construct could induce an immune resistance to mammary tumor progression. [Mol Cancer Ther 2008;7(6):1615–23]