bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure and reconstruction of the flagellar apparatus in Chrysochromulina apheles sp. nov. (Prymnesiophyceae = Haptophyceae)
Authors: Moestrup Øjvind , Thomsen Helge A.
Published: December 2009

A new marine species of Chrysochromulina, C. apheles, is described from light and electron microscopy of a culture established from Danish coastal waters. The cells are among the smallest known in any species of Chrysochromulina, measuring ca. 4 μm in diameter. The general fine structure is illustrated and the structure of the haptonema and the flagellar apparatus is described in detail, based on serial sections. The flagellar root system, not previously examined in detail in any member of Chrysochromulina, is shown to consist of four microtubular roots, while cross-banded roots are lacking. Four cross-banded fibres were seen to interconnect the flagellar bases and the haptonema base. The haptonema belongs to the rather unusual six-stranded type. Two very similar looking types of small organic scales are present on the cell body. Unpublished data on the flagellar roots of the type species of Chrysochromulina, C. parva, are included. Chrysochromulina apheles is apparently cosmopolitan. It has presently been found in material from Denmark, Finland, England, Thailand, Australia, and New Zealand.
Spatial variation in seed production among and within sites and within individuals of Thalictrum thalictroides (Ranunculaceae)
Authors: Lubbers Anne E.
Published: December 2009

Spatial variation in seed and ovule numbers and percent seed set is described for three populations of the perennial herb Thalictrum thalictroides. Total ovule number of an individual was positively correlated with its seed number, but correlations between ovule number and percent seed set were negative or nonsignificant. Ovule and seed numbers, and to some extent percent seed set, varied among flower positions and inflorescences within plants. Within sites, log-normal distributions of total seed number indicate that a few individuals contributed a large number of seeds relative to the rest of the population. At two sites high values of percent seed set suggest that factors that determine ovule number can be at least as critical to variation in seed number as other factors acting later on. Quadrat reproductive means were not correlated from one year to the next, implying that the relative favorability of certain quadrats is not consistent among years. Sites varied in their reproductive means as well as in their frequency distribution of percent seed set, indicating that the importance of initial ovule number to final seed number per plant not only varies among species as is commonly observed but within as well.
Mitosis in the protostelid Ceratiomyxella tahitiensis (Eumycetozoa)
Authors: Spiegel F. W. , Feldman J.
Published: December 2009

Mitosis is dimorphic in the protostelid Ceratiomyxella tahitiensis. The spindle in the amoebo-flagellate state of the life cycle is open and centric; the microtubular rootlet system which surrounds the centrioles during interphase breaks down during mitosis. The spindle in the plasmodial state is open and acentric. The spindle develops outside the nuclear envelope during prophase and drops into the nucleus during prometaphase when the nuclear envelope breaks down. A polar microtubular organizing center appears at metaphase and lasts through telophase. Amoebo-flagellate mitosis is similar to that found in the amoebo-flagellates of other Eumycetozoa. Plasmodial mitosis is unique among the eumycetozoans. This provides support for the hypothesis that the flagellate Eumycetozoa are derived from a common flagellate ancestor and that certain groups of eumycetozoans have independently evolved unique, obligately amoeboid states.
Phytoalexines et réactions de défense de la tomate aux infections par Phytophthora parasitica et Verticillium albo-atrum
Authors: Vernenghi Annie , Einhorn J. , Kunesch G. , Malosse C. , Ramiandrasoa Florence , Ravisé A.
Published: December 2009

Two cultivars of tomato of Saint-Pierre phénotype, isogenic for the resistance against verticilliosis and different for the resistance against mildew (and against Phytophthora parasitica Dast.), were inoculated with P. parasitica and with Verticillium albo-atrum Reinke et Berth. Associated with the defence reactions, an accumulation of sesquiterpenes phenolic compounds, tomatin, and oxygenated compounds of methyl linoleate took place in the tissues. Synthesis of these compounds in the host varies with the cultivars and the parasites in presence. In vitro studies on the inhibition of P. parasitica have shown an important synergism between the dienols on one side and the phenolic compounds and tomatin on the other side. [Translated by the Journal]
Dark reversion of blue-light inhibition of conidiation in Alternaria cichorii
Authors: Vakalounakis Demetrios J. , Christias Christos
Published: December 2009

Prolonged exposure to blue light was necessary for almost complete inhibition of sporulation in Alternaria cichorii Nattrass. When a 24-h blue light exposure was followed by darkness, the inhibition of sporulation decreased gradually.
La répartition et la dynamique des principales espèces arborescentes du Bois-de-Saraguay, Montréal (Québec)
Authors: Domon Gérald , Bouchard André , Bergeron Yves , Gauvin Claire
Published: December 2009

Reciprocal factor analysis of data obtained from 70 stands in the Bois-de-Saraguay, points to drainage and succession – disturbance as the principal factors governing floristic composition. Successional vectors of the 11 most abundant tree species were also plotted on the ordination. The position of the vectors characterizes the species with regards to the two gradients which were identified. The shape of successional vectors allows the recognition of three classes. The first one includes those species showing an association pattern with other species, which hardly varies during the different growth phases. The second one groups together those with distinctly better reproduction in communities where they are scarce in the tree stratum. The third one regroups those which cannot maintain high densities in the intermediate strata of communities where they are common among trees and seedlings. However, further studies showed that the exact shape of the vectors is also related to abiotic variables, especially drainage modifications. A detailed analysis of these successional vectors allows a better understanding of what determines the occupancy of the study site by the species present. [Translated by the Journal]
Vegetative compatibility groups among nonpathogenic root-colonizing strains of Fusarium oxysporum
Authors: Correll J. C. , Puhalla J. E. , Schneider R. W.
Published: December 2009

A total of 110 isolates of Fusarium oxysporum were collected from apparently healthy celery roots from the major celery production areas of California. All isolates used in this study were nonpathogenic on celery. Nitrate-nonutilizing mutants (nit mutants) were used to test for vegetative compatibility among the isolates. Twenty-eight isolates were randomly selected from the collection and used as tester isolates. Complementary nit mutants, arbitrarily designated nitA and nitB, were recovered from each of the 28 tester isolates and paired in all combinations to test for vegetative compatibility among the isolates. Fourteen distinct vegetative compatibility groups, designated VCG2001 through VCG2014, were recovered. The remaining 82 isolates were then tested for vegetative compatibility with these 14 vegetative compatibility groups. Fifty of the 110 isolates belong to one of the 14 vegetative compatibility groups. Two vegetative compatibility groups, VCG2001 and VCG2002, were found in the highest frequency and from the most fields. The data suggest that some vegetative compatibility groups found colonizing celery roots may be much more common than others. Vegetative compatibility may be a way to identify and characterize strains of nonpathogenic F. oxysporum.
Increased growth responses induced by a nonpathogenic Rhizoctonia solani
Authors: Sneh B. , Zeidan M. , Ichielevich-Auster M. , Barash I. , Koltin Y.
Published: December 2009

A nonpathogenic isolate of Rhizoctonia solani (No. 521, AG-4) induced increased growth in a variety of crops. In field experiments, it was expressed in increases of plant weight, cotton fiber weight, or grain yield. The increases for treated compared with untreated plants were as follows: radish, 13.4–19.8% fresh weight and 28.4–36.0% dry weight; carrot, 30.0–97.6% fresh weight and 55.0–150.5% dry weight; lettuce, 58.4% fresh weight and 61.8% dry weight; cotton, 28.7% fiber weight; wheat, 10.6–25.3% weight per grain and 15.4–36.5% grain yield. For the potato crop, although an increase in leaf, shoot, and tuber weight was induced by R. solani 63–70 days after planting, it was not expressed in yield at harvest time.
The effects of external pH, temperature, and substrate concentration on acid phosphatase activity of ectomycorrhizal fungi
Authors: Antibus Robert K. , Kroehler Carolyn J. , Linkins Arthur E.
Published: December 2009

Isolates of the ectomycorrhizal fungi Cenococcum geophilum, Hebeloma pusillum, and Entoloma sericeum were grown in axenic culture to study the effects of assay pH, temperature, and substrate concentration on the activity of surface acid phosphatases. In addition, isolates were grown at 12 and 20 °C to determine whether the Arrhenius activation energies of surface phosphatases were affected by temperature acclimation. Four of the six isolates examined demonstrated distinct pH optima at pH 5.0; one isolate showed optimal activity at pH 4.5. None of the fungi examined produced significant surface alkaline phosphatase activity. Arrhenius activation energy values were not affected by lowering the growth temperature, suggesting that a phenotypic change in surface acid phosphatases did not occur with acclimation. Vmax and Km values for the hydrolysis of p-nitrophenyl phosphate were found to differ significantly among the isolates examined. Our findings support previous research by confirming the existence of interspecific and intraspecific differences in acid phosphatase activity, but they demonstrate the importance of considering assay pH and substrate concentration when making such comparisons.
Wound repair and disease resistance in stems of Pachysandra terminalis
Authors: Hudler George W. , Banik Mark T.
Published: December 2009

Changes in cortical cells around wounds in pachysandra (Pachysandra terminalis Sieb. & Zucc.) stems were monitored by microscopic examination of some wounds and by inoculation of others with conidia of Volutella pachysandricola B. O. Dodge. Stems with young wounds ( < 3 days old) were readily colonized by the pathogen. In progressively older wounds, reduced frequency of infection was correlated with deposition of lignin in cell walls and intercellular spaces, and of suberin on inner lignified cell wall surfaces in one or two layers of parenchyma around the wound. Histological events associated with wound repair in pachysandra appear to be similar to those described for other species of angiosperms and gymnosperms.
The effect of temperature on development and reproduction in Chorda filum and C. tomentosa (Phaeophyta, Laminariales) from Nova Scotia
Authors: Novaczek I. , Bird C. J. , McLachlan J.
Published: December 2009

The occurrence of sporophytes of Chorda tomentosa and C. filum in the southern Gulf of St. Lawrence was correlated with the field temperature regime. Temperature tolerances of gametophytes and young sporophytes of both species were tested in culture, using isolates from both the gulf and the outer Atlantic coast of Nova Scotia. Chorda tomentosa sporophytes appeared in late winter when the water surface was frozen, were fertile from April to June, and died when water temperature approached 20 °C. In culture, sporophytes tolerated −1 to 15 but became moribund at 20 °C. Gametophytes in constant temperature reproduced readily at 5 °C, occasionally at 0 and 10 °C, but not at higher temperatures; they survived to 24 °C. After 6 months in dim light at 10 °C some gametophytes also released gametes at 15 °C. Sporophytes of C. filum appeared in the field in spring after the water temperature had risen above 1 °C and persisted through the warm months. New sporophytes appeared in the autumn after the water temperature dropped below 15 °C but did not survive the winter. In culture, sporophytes died at −1 and 28 °C and survived between 0 and 24 °C. Gametophytes reproduced readily from 5 to 12, rarely at 0 and 15 °C, and not at higher temperatures. Gametophytes of both species survived 5 months in 0 ± 2 °C, [Formula: see text].
Distribution of uranium series radionuclides in upland vegetation of northern Saskatchewan. II. Patterns of accumulation among species and localities
Authors: Sheard J. W.
Published: December 2009

Multivariate methods are used to explore patterns of accumulation of radionuclides and stable elements among 10 plant species at four localities in northern Saskatchewan. Principal components analysis and canonical correlation analysis of the radionuclides and stable elements showed that lead-210 and polonium-210 are correlated with crustal elements distributed in the atmosphere and therefore are accumulated more abundantly by lichen and moss species than by vascular plants. Uranium showed a similar trend. Neither these radionuclides nor radium-226 showed strong correlations with other stable elements. The highest accumulation of uranium was in the Wollaston Lake region, especially for the nonvascular plants, where the soil levels are lowest. This tends to substantiate previous suggestions that uranium available for uptake by vascular plants is associated with groundwater rather than soil particles. Canonical variates analysis on radionuclide levels in vegetation by species group shows that trees, shrubs, lichens, and moss all have significantly different patterns of accumulation. The vascular and nonvascular groups are separated primarily by lead-210 and polonium-210 accumulation. The trees and shrubs are separated by radium-226 levels. A similar analysis by locality showed significant differences in radionuclide accumulation by vegetation in all possible pairs of localities, except between the two Wollaston Lake localities. The largest distances were between regions and were based primarily on uranium accumulation in the nonvascular plants. Differences in radium-226 levels among the shrub species are responsible for the significant difference between the two localities in the Churchill River region.
A quantitative and structural comparison of Citrus pollen tube development in cross-compatible and self-incompatible gynoecia
Authors: Kahn Tracy L. , DeMason Darleen A.
Published: December 2009

Pollen tube development in Orlando tangelo (Citrus paradisi Macf. × C. reticulata Blanco.) was compared within and between cross-compatible pollinations of Orlando pollen on Dancy tangerine (C. reticulata Blanco.) stigmas and self-incompatible pollinations on Orlando tangelo stigmas. Orlando and Dancy gynoecia were morphologically similar but differed slightly in stigma, style, and ovary lengths. Orlando pollen tube development was studied 1, 3, 6, 9, and 12 days after both cross- and self-pollination to record the number of pollen tubes at each of five levels: stigma surface, upper style, lower style, ovary, and entrance into ovules. In the incompatible cross (self-pollinated Orlando), the stigma was the primary region of pollen tube arrest. In the compatible cross (Orlando pollen on Dancy), some pollen tubes penetrated ovules between 9 and 12 days after cross pollination; however, other pollen tubes were arrested in the stigma. Pollen tubes that successfully penetrated ovules in the compatible cross differed morphologically from pollen tubes arrested in both the compatible and incompatible situations. Successful compatible pollen tubes were straight with thin-walled tips and regularly spaced callose plugs behind the growing tips. Many pollen tube abnormalities associated with the self-incompatible pollination of Orlando were also present among arrested pollen tubes from the compatible cross.
An ecological interpretation of the chemistry of mire waters from selected sites in eastern Canada
Authors: Comeau Paul L. , Bellamy David J.
Published: December 2009

Water samples (132) were collected from selected mires in eastern Canada. Sites chosen included ombrotrophic, transition, and minerotrophic mire in both maritime and continental areas in Nova Scotia, New Brunswick, and Quebec. Chemical analysis of the major ions found in mire waters revealed that concentrations increased from ombrotrophic to minerotrophic conditions. Chloride, sodium, and magnesium were more abundant in maritime mires, while calcium, potassium, and sulfate had higher levels in transition and ombrotrophic mire in agricultural areas. Comparison with studies in Europe indicates similar ionic conditions for the three mire categories with respect to proximity to the sea and human disturbance.
Nature of the "black line" produced between different biological species of the Armillaria mellea complex
Authors: Mallett K. I. , Hiratsuka Y.
Published: December 2009

The zone of antagonism or black line, formed between the confronting margins of different biological species of the Armillaria mellea complex when paired on malt agar medium, was investigated. Light microscopy showed that the black line was composed of melanized hyphal cells from both species and was bordered on either side by the bladderlike cells of the pseudosclerotial plate of each species.
Studies on the Stellaria longipes complex: phenotypic plasticity. II. Gibberellins, abscisic acid, and stem elongation
Authors: Macdonald S. Ellen , Reid David M. , Chinnappa C. C.
Published: December 2009

Clonal material of one genotype of Stellaria longipes Goldie s.l. was used to investigate whether environmental regulation of the phenotype was mediated through phytohormones. Photoperiod and temperature modified the response of this species to exogenous application of gibberellins (GAs) and abscisic acid (ABA). Application of GAs to ramets in short or long days and low temperature increased stem elongation but did not induce elongation equivalent to that seen in control ramets in long warm days. Application of GAs to ramets in short days (warm or cold) induced elongation equivalent to that of ramets in long days at a similar temperature. Application of (2-chloroethyl)-trimethylammonium chloride resulted in dwarfing at some concentrations, while exposure to other concentrations initially stimulated elongation. Application of ABA reduced elongation in short, cold days but showed no effect under other conditions. Metabolism of radiolabeled ABA and GA3 was similar in both short cold days and long warm days. It was concluded that photoperiodically induced stem elongation could be partially mediated through endogenous levels of GAs. However, a hypothesis based on the idea that temperature-induced changes in elongation are controlled by suboptimal levels of GAs or supraoptimal levels of ABA is inadequate.
Heteroblastic seedlings of green ash. III. Cell division activity and marginal meristems
Authors: Merrill E. K.
Published: December 2009

The early developmental stages of simple and compound leaves of green ash (50–400 μm long) were used to relate cell division activity (mitotic index) to developing leaf form and histological differentiation. Densely cytoplasmic cells within cross-sectioned leaf primordia have higher mitotic indices than protodermal cells and other internal cells that are more vacuolate. Among densely cytoplasmic cells mitotic indices decrease from the primordial leaf margin toward the procambium. Ground meristem cells within three to five cell widths of the primordial margin had the highest mitotic indices. Actual cell counts indicate that densely cytoplasmic cells increase in number in areas of leaf blade or leaflet initiation more than do vacuolate cells or protodermal cells. It is proposed that marginal meristems defined by spatial and histological criteria are important in producing new cells that are the basis for the generation of simple and compound leaf forms.
Effects of induced translocation stress and bark beetle attack (Dendroctonus ponderosae) on heat pulse velocity and the dynamic wound response of lodgepole pine (Pinus contorta var. latifolia)
Authors: Miller R. H. , Whitney H. S. , Berryman A. A.
Published: December 2009

The effects of induced translocation stress upon heat pulse velocity, reactions to pathogenic fungi, and bark beetle attack dynamics were compared before, during, and after severe cooling of the bole and after girdling of xylem and phloem in Pinus contorta Douglas var. latifolia Engelmann. Cooled trees evidenced a reduction of heat pulse velocity and the elimination of observable wound responses, which returned to normal upon cessation of the stress the following year. A tree naturally attacked and colonized by Dendroctonus ponderosae Hopkins also evidenced reduced heat pulse velocity within 2 weeks of bark beetle attack. Heat pulse velocity in girdled trees did not change. Stress due to drought and (or) bark beetle attack in nature may be analogous to that induced by cooling. Such stress may reduce a tree's ability to resist bark beetle attack and fungus invasion.
Nomenclatural changes in the Asteraceae of British Columbia. II. Astereae, Eupatoreae, Inuleae, Lactuceae, and Heliantheae
Authors: Douglas George W.
Published: December 2009

New combinations or changes in status are given for eight taxa in Astereae, Eupatoreae, Inuleae, Lactuceae, and Heliantheae (Asteraceae) of British Columbia, Canada.
Preservation and separation of endomembrane marker enzyme activity in potato leaf homogenates
Authors: Nagahashi Gerald , Seibles Thomas S.
Published: December 2009

To minimize rapid browning and membrane degradation of crude microsomes, leaves of Solanum tuberosum (cv. Kennebec and cv. Katahdin) were initially homogenized in the presence of various inhibitors of polyphenol oxidase, phospholipase, and protease activity. To obtain and maintain marker enzyme activities used to identify plasma membranes, Golgi membranes, and endoplasmic reticulum, it was necessary to homogenize young leaves in the presence of sulfhydryls at pH 7.8. Further separation of these membranes, as determined by distribution of total activities of marker enzymes in linear sucrose density gradients, indicated a relatively pure plasma membrane fraction (1.15 g/cm3) free from contamination by thylakoids (1.19 g/cm3) and other endomembrane components. However, the distribution of specific activities across the gradient revealed that plasma membranes isolated from green tissue may be contaminated by Golgi membranes and not necessarily by plastid membranes.
Seasonal and successional changes in light quality and quantity in the understory of boreal forest ecosystems
Authors: Ross Michael S. , Flanagan Lawrence B. , Roi George H. La
Published: December 2009

Surveys of the spectral photon distribution of light in the understory of eight boreal forest stands in northern Alberta were made during 1984. Two seasonal patterns of change in the red:far-red (R:FR) ratio and in the amount of photosynthetically active radiation (expressed as a percentage of full sun, %PAR) were observed. In stands dominated by broadleaf deciduous trees, the R:FR ratio and %PAR values declined rapidly in May and June during the time of leaf expansion and then increased in association with leaf senescence in September. In stands dominated by mature evergreen conifers, both the R:FR ratio and %PAR values declined continuously from an early season high to a late season low. Several young evergreen stands exhibited no seasonal change in light characteristics. During mid-July, the R:FR ratios and %PAR values were lower in older stands than in younger stands of the same successional sequence. The variability in light characteristics within mature forests was higher in mid-July than in September; the difference was attributed to the lower solar angle in September. The differences in light regime in early and late successional forests may have important implications for phytochrome-controlled development and succession in understory plant species.
Influence of cellular metabolites on RNA and protein syntheses by Xanthium nuclei of different developmental phases
Authors: Jana A. , Sen S. P.
Published: December 2009

Leaf nuclei of vegetative and reproductive plants of Xanthium strumarium L. were incubated with the postribosomal supernatant of either phase and changes at the transcriptional level were studied in homologous and heterologous combinations. In the presence of the supernatant of reproductive plants, RNA synthesis by vegetative nuclei was decreased by 25%. Reproductive nuclei were less active in RNA synthesis. Gel electrophoretic studies revealed four RNA bands in vegetative nuclei incubated with reproductive supernatant, including a fast-moving low molecular weight band that could not be detected when the "vegetative" supernatant was used. The adenine/uracil ratios of the newly synthesized RNA of vegetative nuclei treated with vegetative and reproductive supernatants were 1.46 and 1.54, respectively, compared with 1.15 and 1.04 in the reproductive nuclei. Competitive DNA–RNA hybridization experiments indicated that about 2% of the [3H]RNA synthesized by nuclei of vegetative plants in the presence of the supernatant of reproductive plants could not be beaten out by the RNA of vegetative plants. Small quantitative differences, thus, may be expected in the RNA molecules synthesized by nuclei in the presence of the supernatant fraction of vegetative and reproductive plants. The supernatant fraction of the reproductive tissues decreased the incorporation of [3H]alanine and [3H]leucine in both the buffer-soluble and acid-soluble proteins and the nuclei of vegetative plants were more active in protein synthesis. Protein patterns as studied by acrylamide gel electrophoresis revealed alterations when vegetative leaf nuclei were incubated with the supernatant of reproductive tissues.
Gracilaria chilensis sp.nov. (Rhodophyta, Gigartinales), from Pacific South America
Authors: Bird C. J. , McLachlan J. , Oliveira E. C. de
Published: December 2009

Gracilaria chilensis sp.nov. is described and recorded from 30° S to 42° S on the coast of Chile. It closely resembles G. lemaneiformis (Bory) Weber-van Bosse, which also occurs in this region, and has been known by both this name and G. verrucosa (Hudson) Papenfuss. Gracilaria chilensis differs fundamentally from these species in having spermatangia in deep cortical (textorii-type) conceptacles and in having basal absorbing filaments in the cystocarp. Isolates of the species from sites 1300 km apart were cultured through the complete life history and used to verify conspecificity of reproductive plants in field collections. Moreover, the isolates were interfertile, thus demonstrating genetic compatibility of widely disjunct populations and verifying the distribution range. Because of its wide thermal and halotolerance, it is suggested that G. chilensis is distributed farther north and south in the eastern Pacific than present records indicate.
Variation and taxonomy of Biscutella valentina in Spain
Authors: Olowokudejo J. Dele
Published: December 2009

Morphological studies have been made on herbarium specimens and 25 population samples of Biscutella valentina (Cruciferae) in Spain. The discontinuities in morphological characters warrant the recognition of three varieties, var. leptophylla, var. pinnata, and var. valentina, from the mass collections, and a fourth taxon, var. tenuicaulis, based on herbarium material. Experimental cultivation revealed that the combination of distinguishing characters for each taxon is genetically fixed while the observed phenotypic plastic range of the vegetative features is not wide enough to affect their taxonomic importance. Artificial crosses performed reciprocally in various combinations on seven of the populations representing three of the varieties resulted in the production of fertile hybrids. A key for identifying the varieties is presented.
Pollen morphology of Ginkgo biloba and Cycas revoluta
Authors: Sahashi N. , Ueno J.
Published: December 2009

Morphological studies on pollen grains of Ginkgo biloba L. and Cycas revoluta Thunb. were carried out by scanning electron microscopy. The pollen grains of both species are generally oblong with 1-sulcate apertures which are shrunken as a result of dryness. However, the swollen grains show an almost spherical form with a large and rounded germinal aperture. This aperture may not correspond to any aperture type so far known, although the term "anaporate" can be fitted to the swollen pollen grains. Auricular projections, which may be derived from protrusions of the ectosexine, can be seen sometimes on the surface of the pollen grains. These projections remind us of degraded versions of the bladders that may have been present on the pollen grains of the fossil ancestor. The inner side of the exine, which can be seen in thin sections obtained with the freezing microtome, is ornamented with reticulumlike sculptures. These endosculptures may be the first reported among gymnosperm pollen grains.
NONLINEAR MATHEMATICAL PROGRAMMING FOR OPTIMAL MANAGEMENT OF CONTAINER TERMINALS
Authors: SEYEDALIZADEH GANJI S. R. , JAVANSHIR H. , VASEGHI F.
Published: December 2009

Berth scheduling is the process of determining the time and position at which each arriving ship will berth. This paper attempts to minimize the serving time to ships, after introducing a proposed mathematical model, considers the berth allocation problem in form of mixed integer nonlinear programming. Then, to credit the proposed model, the results of Imai et al.'s model have been used. The results indicate that because the number of nonlinear variables in the proposed model is less than prior model, so by using the proposed model, we can obtain the results of model in less time rather than prior model.
CLASSIFICATION OF LIFE BY THE MECHANISM OF GENOME SIZE EVOLUTION
Authors: LI DIRSON JIAN , ZHANG SHENGLI
Published: December 2009

We find that the global relationships among species should be of circular phylogeny, which is quite different from common sense based on phylogenetic trees. A domain can be defined by a distinct phylogenetic circle, which is a global and stable characteristic of the living system. The mechanism in genome size evolution has been clarified; hence the main component questions on C-value enigma can be explained. We find the intrinsic relationship between genome size evolution and protein length evolution; that is the genome size and non-coding DNA ratio can be calculated based on protein length distributions.
REGULARIZED LEAST SQUARE REGRESSION WITH SPHERICAL POLYNOMIAL KERNELS
Authors: LI LUOQING
Published: December 2009

This article considers regularized least square regression on the sphere. It develops a theoretical analysis of the generalization performances of regularized least square regression algorithm with spherical polynomial kernels. The explicit bounds are derived for the excess risk error. The learning rates depend on the eigenvalues of spherical polynomial integral operators and on the dimension of spherical polynomial spaces.
Aggregate dynamics for dense crowd simulation
Authors: Narain Rahul , Golas Abhinav , Curtis Sean , Lin Ming C.
Published: December 2009

Large dense crowds show aggregate behavior with reduced individual freedom of movement. We present a novel, scalable approach for simulating such crowds, using a dual representation both as discrete agents and as a single continuous system. In the continuous setting, we introduce a novel variational constraint calledunilateral incompressibility, to model the large-scale behavior of the crowd, and accelerate inter-agent collision avoidance in dense scenarios. This approach makes it possible to simulate very large, dense crowds composed of up to a hundred thousand agents at near-interactive rates on desktop computers.
Approximating subdivision surfaces with Gregory patches for hardware tessellation
Authors: Loop Charles , Schaefer Scott , Ni Tianyun , Castaño Ignacio
Published: December 2009

We present a new method for approximating subdivision surfaces with hardware accelerated parametric patches. Our method improves the memory bandwidth requirements for patch control points, translating into superior performance compared to existing methods. Our input is general, allowing for meshes that contain both quadrilateral and triangular faces in the input control mesh, as well as control meshes with boundary. We present two implementations of our scheme designed to run on Direct3D 11 class hardware equipped with a tessellator unit.
Structure-aware error diffusion
Authors: Chang Jianghao , Alain Benoît , Ostromoukhov Victor
Published: December 2009

We present an original error-diffusion method which produces visually pleasant halftone images while preserving fine details and visually identifiable structures present in the original images. Our method is conceptually simple and computationally efficient. The source image is analyzed, and its local frequency content is detected. The main component of the frequency content (main frequency, orientation and contrast) serve as lookup table indices to a pre-calculated database of modifications to a standard error diffusion. The modifications comprise threshold modulation and variation of error-diffusion coefficients. The whole system is calibrated in such a way that the produced halftone images are visually close to the original images (patches of constant intensity, patches containing sinusoidal waves of different frequencies/orientations/contrasts, as well as natural images of different origins). Our system produces images of visual quality comparable to that presented in [Pang et al. 2008], but much faster. When processing typical images of linear size of several hundreds of pixels, our error-diffusion system is two to three orders of magnitude faster than [Pang et al. 2008]. Thanks to its speed combined with high visual quality, our error-diffusion algorithm can be used in many practical applications which may require digital halftoning: printing, visualization, geometry processing, various sampling techniques, etc.
CA-NFS
Authors: Batsakis Alexandros , Burns Randal , Kanevsky Arkady , Lentini James , Talpey Thomas
Published: December 2009

We develop a holistic framework for adaptively scheduling asynchronous requests in distributed file systems. The system is holistic in that it manages all resources, including network bandwidth, server I/O, server CPU, and client and server memory utilization. It accelerates, defers, or cancels asynchronous requests in order to improve application-perceived performance directly. We employ congestion pricing via online auctions to coordinate the use of system resources by the file system clients so that they can detect shortages and adapt their resource usage. We implement our modifications in the Congestion-Aware Network File System (CA-NFS), an extension to the ubiquitous network file system (NFS). Our experimental result shows that CA-NFS results in a 20% improvement in execution times when compared with NFS for a variety of workloads.
An event-based framework for characterizing the evolutionary behavior of interaction graphs
Authors: Asur Sitaram , Parthasarathy Srinivasan , Ucar Duygu
Published: December 2009

Interaction graphs are ubiquitous in many fields such as bioinformatics, sociology and physical sciences. There have been many studies in the literature targeted at studying and mining these graphs. However, almost all of them have studied these graphs from a static point of view. The study of the evolution of these graphs over time can provide tremendous insight on the behavior of entities, communities and the flow of information among them. In this work, we present an event-based characterization of critical behavioral patterns for temporally varying interaction graphs. We use nonoverlapping snapshots of interaction graphs and develop a framework for capturing and identifying interesting events from them. We use these events to characterize complex behavioral patterns of individuals and communities over time. We show how semantic information can be incorporated to reason about community-behavior events. We also demonstrate the application of behavioral patterns for the purposes of modeling evolution, link prediction and influence maximization. Finally, we present a diffusion model for evolving networks, based on our framework.
Reflect and correct
Authors: Bilgic Mustafa , Getoor Lise
Published: December 2009

Information diffusion, viral marketing, graph-based semi-supervised learning, and collective classification all attempt to model and exploit the relationships among nodes in a network to improve the performance of node labeling algorithms. However, sometimes the advantage of exploiting the relationships can become a disadvantage. Simple models like label propagation and iterative classification can aggravate a misclassification by propagating mistakes in the network, while more complex models that define and optimize a global objective function, such as Markov random fields and graph mincuts, can misclassify a set of nodes jointly. This problem can be mitigated if the classification system is allowed to ask for the correct labels for a few of the nodes during inference. However, determining the optimal set of labels to acquire is intractable under relatively general assumptions, which forces us to resort to approximate and heuristic techniques. We describe three such techniques in this article. The first one is based on directly approximating the value of the objective function of label acquisition and greedily acquiring the label that provides the most improvement. The second technique is a simple technique based on the analogy we draw between viral marketing and label acquisition. Finally, we propose a method, which we refer to as
reflect and correct
, that can learn and predict when the classification system is likely to make mistakes and suggests acquisitions to correct those mistakes. We empirically show on a variety of synthetic and real-world datasets that the reflect and correct method significantly outperforms the other two techniques, as well as other approaches based on network structural measures such as node degree and network clustering.
Barriers to the adoption of software product line engineering
Authors: Catal Cagatay
Published: December 2009

Software development costs and time to deploy a software-intensive system significantly decrease when Software Product Line Engineering (SPLE) approach is applied. Numerous case stu-dies in industrial and military domains have shown that reliability, quality, productivity and user interface consistency improve drasti-cally in addition to the decrease of cost and time-to-market. Also, this system engineering approach is very effective in three market strategies known as cost leadership, differentiation, and focusing. Despite these measurable benefits, product line engineering adop-tion is slower than the other technological trends such as Service Oriented Architecture (SOA), Model Driven Development (MDD), and Aspect Oriented Software Development (AOSD). In this pa-per, we investigate the barriers to the adoption of SPLE and ex-plore the root causes of them from three points of views: Project sponsor, organization, and SPLE community. We provide sugges-tions for how the industry and SPLE community can solve these multi-dimensional issues in a short term.
Group communication techniques in overlay networks
Authors: Vik Knut-Helge , Halvorsen Paal , Griwodz Carsten , Zimmermann Roger , Roedig Utz
Published: December 2009

One type of Internet services that have recently gained much attention are services that enable people around the world to communicate in real-time. Such services of real-time interaction are offered by applications most commonly referred to as distributed interactive applications. Concrete examples of distributed interactive applications are multiplayer online games, audio/video conferencing, and many virtual-reality applications linked to education, entertainment, military, etc. A time-dependent requirement generally applies to all distributed interactive applications that aim to support real-time interaction, and is usually in terms of a few hundred milliseconds. The latency requirements are manifested in terms of event-distribution, group membership management, group dynamics, etc., far exceeding the requirements of many other applications.
Modularization and multi-granularity reuse of learning resources
Authors: Meyer Marek , Steinmetz Ralf , El Saddik Abdulmotaleb
Published: December 2009

This thesis investigates modular reuse of learning resources. In particular, it considers a scenario of reuse in which existing learning resources serve as preliminary products for the creation of new learning resources for Web based training. Authors are interested in reusing the learning resources created by other authors. It is assumed that these authors belong to different organizations. Furthermore, these authors do not use a common authoring tool because they are obliged to use the tools specified by their respective organizations.
Grafitter
Authors: Li Ian , Dey Anind , Forlizzi Jodi
Published: December 2009

"Know thyself". Carved in stone in front of the Temple of Apollo at Delphi, that was the first thing people saw when they visited the Oracle to find answers. The benefits of knowing oneself are many. It fosters insight, increases self-control, and promotes positive behaviors such as exercise and energy conservation.
Are your friends who they say they are?
Authors: Feizy Roya , Wakeman Ian , Chalmers Dan
Published: December 2009

How sure are you that your friends are who they say they are? In real life, unless you are the target of some form of espionage, you can usually be fairly certain that you know whom your friends are because you have a history of shared interests and experiences. Likewise, most people can tell, just by using common sense, if someone is trying to sell them on a product, idea, or candidate. When we interact with people face-to-face, we reevaluate continuously whether something just seems off based on body language and other social and cultural cues.
SIRT1 inhibits inflammatory pathways in macrophages and modulates insulin sensitivity
Authors: Yoshizaki Takeshi , Schenk Simon , Imamura Takeshi , Babendure Jennie L. , Sonoda Noriyuki , Bae Eun Ju , Oh Da Young , Lu Min , Milne Jill C. , Westphal Christoph , Bandyopadhyay Gautam , Olefsky Jerrold M.
Published: December 2009

Chronic inflammation is an important etiology underlying obesity-related disorders such as insulin resistance and type 2 diabetes, and recent findings indicate that the macrophage can be the initiating cell type responsible for this chronic inflammatory state. The mammalian silent information regulator 2 homolog SIRT1 modulates several physiological processes important for life span, and a potential role of SIRT1 in the regulation of insulin sensitivity has been shown. However, with respect to inflammation, the role of SIRT1 in regulating the proinflammatory pathway within macrophages is poorly understood. Here, we show that knockdown of SIRT1 in the mouse macrophage RAW264.7 cell line and in intraperitoneal macrophages broadly activates the JNK and IKK inflammatory pathways and increases LPS-stimulated TNFα secretion. Moreover, gene expression profiles reveal that SIRT1 knockdown leads to an increase in inflammatory gene expression. We also demonstrate that SIRT1 activators inhibit LPS-stimulated inflammatory pathways, as well as secretion of TNFα, in a SIRT1-dependent manner in RAW264.7 cells and in primary intraperitoneal macrophages. Treatment of Zucker fatty rats with a SIRT1 activator leads to greatly improved glucose tolerance, reduced hyperinsulinemia, and enhanced systemic insulin sensitivity during glucose clamp studies. These in vivo insulin-sensitizing effects were accompanied by a reduction in tissue inflammation markers and a decrease in the adipose tissue macrophage proinflammatory state, fully consistent with the in vitro effects of SIRT1 in macrophages. In conclusion, these results define a novel role for SIRT1 as an important regulator of macrophage inflammatory responses in the context of insulin resistance and raise the possibility that targeting of SIRT1 might be a useful strategy for treating the inflammatory component of metabolic diseases.
RELAP5/MOD3.3 Best Estimate Analyses for Human Reliability Analysis
Authors: Prošek Andrej , Mavko Borut
Published: December 2009

To estimate the success criteria time windows of operator actions the conservative approach was used in the conventional probabilistic safety assessment (PSA). The current PSA standard recommends the use of best-estimate codes. The purpose of the study was to estimate the operator action success criteria time windows in scenarios in which the human actions are supplement to safety systems actuations, needed for updated human reliability analysis (HRA). For calculations the RELAP5/MOD3.3 best estimate thermal-hydraulic computer code and the qualified RELAP5 input model representing a two-loop pressurized water reactor, Westinghouse type, were used. The results of deterministic safety analysis were examined what is the latest time to perform the operator action and still satisfy the safety criteria. The results showed that uncertainty analysis of realistic calculation in general is not needed for human reliability analysis when additional time is available and/or the event is not significant contributor to the risk.
Endothelial Estrogen Receptor-α Plays a Crucial Role in the Atheroprotective Action of 17β-Estradiol in Low-Density Lipoprotein Receptor–Deficient Mice
Authors: Billon-Galés Audrey , Fontaine Coralie , Douin-Echinard Victorine , Delpy Laurent , Berges Hortense , Calippe Bertrand , Lenfant Françoise , Laurell Henrik , Guéry Jean-Charles , Gourdy Pierre , Arnal Jean-François
Published: December 2009

Background—

The prevention of early atheroma by estrogens has been clearly demonstrated in all animal models and appears to be mediated through a direct action on the arterial wall rather than through an effect on the lipoprotein profile. The goal of the present study was to evaluate which cellular target is crucial in this beneficial action of estradiol.

Methods and Results—

We first confirmed the key role of estrogen receptor-α (ERα) in the atheroprotective effect of estradiol, because this action was completely abolished in mice deficient in both the low-density lipoprotein receptor (LDLr) and ERα. Second, using chimeric mice with an ERα deficiency in the hematopoietic lineage, we showed the persistence of the protective action of estradiol, which suggests the involvement of extrahematopoietic ERα. Third, we showed that loxP-flanked ERα mice (ERα
flox/flox
) bred with Tie2-Cre
+
mice on an LDLr
−/−
background had complete inactivation of ERα in most hematopoietic and all endothelial cells. Remarkably, in this mouse model, the atheroprotective effect of estradiol was completely abolished. Fourth, the atheroprotective effect of estradiol remained abolished in Tie2-Cre
+
ERα
flox/flox
LDLr
−/−
mice transplanted with either Tie2-Cre
+
ERα
flox/flox
or ERα
−/−
bone marrow, whereas it was present in analogous chimeric Tie2-Cre
−
ERα
flox/flox
LDLr
−/−
receivers expressing endothelial ERα.

Conclusions—

We demonstrate directly and for the first time that endothelial ERα represents a key target of the atheroprotective effect of estradiol, whereas hematopoietic ERα is dispensable. Selective estrogen receptor modulators that mimic the endothelial action of estradiol should now be considered in atheroprotection.