bluuebunny/crossref_metadata_2025 huggingface dataset:
Leaf anatomy of species in some dicotyledon families as related to the C3 and C4 pathways of carbon fixation
Authors: Welkie G. W. , Caldwell M.
Published: September 2008

Species in the families Amaranthaceae, Aizoaceae, Chenopodiaceae, Convolvulaceae, Euphorbiaceae, Nyctaginaceae, Portulacaceae, and Zygophyllaceae were examined for leaf anatomy typical of plants having the C4 type photosynthetic carbon fixation pathway. They are assembled by families into three groups: genera in which all species possess the specialization; genera in which some but not all species possess the specialization; and genera in which no species possess the specialization. The specialization in leaf anatomy was noted in species of 24 genera. Its presence is highly correlated with a habitat of limited water availability and (or) with a tropical origin. The carbon dioxide compensation points of nine species in the Chenopodiaceae family were measured. Low values were obtained only for those species that possess a form of specialized leaf anatomy (Atriplex confertifolia (Torr. & Frem.) Wats., A. falcata (M. E. Jones) Standl., Halogeton glomeratus (Bieb.) Meyer, Salsola kali L. var. tenuiflora Tausch.). The latter two species, having centric leaves, do not possess the more typical differential bundle sheath chlorenchyma but do possess two, individually distinct, single-cell layers of chlorenchyma, adjacent and external to the peripheral veins.
Ontogeny of spore forms in Uredinales
Authors: Hughes S. J.
Published: September 2008

Spore ontogeny in the Uredinales is considered in the light of methods of conidium production known to occur in ascomycetous Fungi Imperfecti. It is concluded that pycniospores are phialospores, aeciospores are meristem arthrospores, and urediniospores are sympodioconidia. Teliospores are produced either as terminal, chlamydospore-like cells of hyphae of determinate growth, as sympodioconidia, or as meristem arthrospores.
Surface structure of the urediniospores of Puccinia coronata f. sp. avenae
Authors: Corlett Michael
Published: September 2008

The surface structure of the echinulate urediniospores of Puccinia coronata f. sp. avenae race 320 was examined with the light microscope and the electron microscope. The scanning electron microscope revealed a network of ridges encircling the spines. On many urediniospores, small ring-like ridges, about 1 μ across, closely encircled the bases of the spines and sometimes were connected by fine linear ridges. On other spores, the ridges took the shape of four- to seven-sided polygons, 2–3 μ across, with triangles at their corners.
Selective filtering of light by coniferous forests and minimum light energy requirements for regeneration
Authors: Atzet Thomas , Waring R. H.
Published: September 2008

Spectroradiometric analyses were made to examine the light-filtering capacity of coniferous forests and to establish the lower limits of light energy for growth of Pseudotsuga menziesii (Mirb.) Franco, Abies concolor (Gord. and Glend.) Lindl., and Pinns ponderosa Dougl. Light energy (400–750 nm) was recorded periodically on clear days in June and July at 48 points under four mixed conifer stands and segregated into four spectral bands (blue, 400–450; green, 500–550; red, 650–700; far-red, 700–750 nm). Minor changes in the proportion of light in one band to that in another occur throughout the day, but in general the 400- to 700-nm range appears rather uniformly absorbed by a coniferous forest canopy. Averaged for an entire day, only the far-red band showed a significant proportional increase under a coniferous canopy compared to unfiltered sunlight.The relation between the energy received in each of the spectral bands and the total recorded in the 400- to 700-nm range was linear. The sampled canopies transmitted up to 25% of full sunlight. Beneath the canopies, the ratio of blue to total energy (400–700 nm) was 0.1540. Green, red, and far-red had ratios of 0.1853, 0.1220, and 0.1207.Terminal growth of 34 seedlings was measured at the light-sampling points to provide a means of establishing lower limits of light energy for survival. The lower limit for Abies and Pseudotsuga was 1.85 langleys (ly) per day (400–700 nm). Pinus grew only where the light energy exceeded 36.8 ly/day.An interaction with moisture appears to influence the minimum requirements for light energy of a species. Where moisture was adequate throughout the growing season, the lower limit of light for Pseudotsuga seedling establishment was 1.85 ly/day; where moisture became limiting, the minimum light requirement increased to 6.64 ly/day.
Studies on sunflower rust. VI. Penetration and infection of sunflowers susceptible and resistant to Puccinia helianthi race I
Authors: Sood Praim N. , Sackston W. E.
Published: September 2008

Spore germination, appressorium formation, and penetration by rust race 1 appeared identical on a susceptible and a resistant sunflower variety. Haustoria were formed in 24 h. They were round to elongated and numerous in the susceptible variety, and round and few in the resistant variety.Mycelial growth was faster and more extensive in susceptible than in resistant tissue. In susceptible tissues no injury was apparent 96 h after inoculation. Urediospore production started 144 h after inoculation. Host cells under incipient pustules collapsed. Chloroplasts appeared fewer in infected than uninfected mesophyll cells.Collapse of mycelium in resistant tissue was observed 96 h and death of invaded cells 120 h after inoculation. Chloroplasts degenerated in infected and neighboring cells.
Meiosis in Coprinus. III. Timing of meiotic events in C. lagopus (sensu Buller)
Authors: Raju N. B. , Lu B. C.
Published: September 2008

The close synchrony of meiotic events within the basidiocarp of Coprinus lagopus permits the time sequence study of division stages. It takes about 16 h from the beginning of karyogamy to the completion of meiosis (zygotene to tetrad formation). Nuclear fusion and chromosome pairing occupy about 4 h, pachytene 5 h, diplotene 4 h, and all the other stages including the second meiotic division appear to be very transitory and together occupy less than 3 h. The centrosome divides at late diplotene. The entire second meiotic division takes about 1 hour and different stages overlap a great deal. The four sterigmata are formed after the completion of second division. The basidiospores mature in 8–10 h after the tetrad formation.
The dependence of electrical impedance of woody stems on various frequencies and tissues
Authors: Glerum C. , Krenciglowa E. M.
Published: September 2008

The electrical impedance of 1-year-old twigs of three hardwoods and conifers was measured at several frequencies before and after boiling. In all species the impedance before killing decreased as frequency increased from 100 to 40 000 c.p.s. The rate of decrease in conifers was greater than in hardwoods, particularly at low frequencies. After the twigs were killed, the drastically reduced impedance exhibited only a slight dependence on frequency. The variability relative to the mean was about the same at all frequencies.The contribution of xylem and bark (i.e., periderm, phloem, and cambium combined) to the impedance was determined by measuring the impedance of the two tissues together and separately. The importance of uniform electrode penetration was demonstrated.
Growth of excised tomato roots in glucose; an effect on ageing
Authors: Weston G. D.
Published: September 2008

IAA, 1-NAA, 2,4-D, kinetin, and benzyl adenine were inhibitory to the growth of excised tomato roots in glucose medium. GA3, myo-inositol, and two antiauxins, 2-NAA and NMSP, were stimulatory but growth did not approach that in sucrose medium. Glucose was not inhibitory in the presence of optimal sucrose, and was stimulatory in the presence of suboptimal sucrose. Glucose pretreatment markedly enhanced the ageing of roots in a subsequent growth period in sucrose, and the significance of this is discussed in relation to the growth stimulation caused by the antiauxins.
Seimatosporium leaf spot of Ledum and Rhododendron
Authors: Pirozynski K. A. , Shoemaker R. A.
Published: September 2008

Seimatosporium ledi sp. nov. causing leaf spot of Ledum groenlandicum Oeder. in Canada is described and its relationship with allied fungi including S. lichenicola (Corda) Shoemaker & Müller (= Coryneum vaccinii Fuckel; = C. rhododendri Schw. var. fusoideum Dearness nom. nud.) and S. rhododendri (Schw.) comb. nov. (≡ C. rhododendri Schw.; = C. triseptatum Peck) is discussed.
Growth and differentiation in gametophytes of Pinus resinosa cultured in vitro
Authors: Bonga J. M. , Fowler D. P.
Published: September 2008

Young megagametophytes, microsporangiate strobili, microsporophylls, and pollen grains of Pinus resinosa Ait. were cultured on a variety of media. Megagametophytes from strobili collected between mid-July and mid-August showed various degrees of internal growth and differentiation or developed small calluses on White's medium with various supplements. Undifferentiated haploid callus developed from young microspores in cultures of microsporangiate strobili and microsporophylls on Brown and Lawrence's medium. Pollen grains germinated and branched on all media but failed to divide and form callus.
Induction of tumor formation in Nicotiana amphiploids with triiodobenzoic acid
Authors: Ames Ira H.
Published: September 2008

Young seedlings of two tumorous Nicotiana amphiploids and the parental species, grown aseptically on nutrient medium, were treated with 2,3,5-triiodobenzoic acid. The incidence of tumor formation was scored for 18 days subsequent to exposure. Triiodobenzoic acid markedly accelerated the rate of tumorigenesis in both amphiploids, but it did not induce tumors in the parental species. The compound also induced tumor formation in a small percentage of seedlings of a non-tumorous mutant of the N. glauca × N. langsdorffii amphiploid. These results are discussed in relation to the problem of the trigger mechanism for tumor induction in Nicotiana species hybrids.<
Some metabolic responses of bush bean plants to a subherbicidal concentration of certain s-triazine compounds
Authors: Singh B. , Salunkhe D. K.
Published: September 2008

A solution containing 0.5 p.p.m. of atrazine, simazine, igran, or GS-14254 with 0.2% triton-B 1956 was applied to the foliage of 11-day-old seedlings of bush beans, Phaseolus vulgaris L. cultivar Tender-green, growing on vermiculite in a controlled environment. The activities of nitrate reductase, glutamic-pyruvic transaminase, α-amylase, starch phosphorylase, and adenosine triphosphatase were determined 5,10, and 20 days after treatment. In general, the activity of each of the five enzymes was stimulated by the treatment. The results suggest that protein increase following the application of.s-triazines to bean plants may stem in part from an enhanced rate of amino acid formation resulting from the induced increment in nitrate reductase and transaminase activity. The application of these chemicals also creates a metabolic condition favorable for greater use of carbohydrates needed for nitrate reduction and protein synthesis, and as a source of organic acid synthesis.
Mycotribulus, a new genus of Sphaeropsidales
Authors: Raj T. R. Nag , Kendrick W. B.
Published: September 2008

Mycotribulus gen. nov. and M. mirabilis are described. The type species produces uniloculate pycnidia without definite ostioles; hyaline, unicellular, solitary, blastic conidia with a single apical appendage and two to four basal appendages; and paraphyses.
The regulation of proline biosynthesis in maize roots
Authors: Oaks Ann , Mitchell D. J. , Barnard R. A. , Johnson F. J.
Published: September 2008

Proline or the proline analogues hydroxy-L-proline and azetidine-2-COOH inhibit the formation of proline from acetate-2-14C or glutamate-UL-14C in the 5-mm maize root tip. The inhibition of the incorporation of acetate-derived proline into protein is more severe than the inhibition of the total biosynthesis (soluble plus insoluble proline-14C). The results suggest that a portion of the proline biosynthesis, which becomes more prominent as the cells mature, is refractory to end product inhibition. The results also show that simultaneous additions of glucose promote the incorporation of proline-UL-14C into protein, exaggerate its accumulation as soluble proline, and reduce its oxidation.
Changes in the cotyledons of Cucurbita maxima during germination. III. Plastids and chlorophylls
Authors: Lott John N. A.
Published: September 2008

The chronological age of a seedling does not ensure that the tissue is similar in cell structure. At 4 days of age the positioning of the 8-h night cycle with relation to the planting time had profound influence over plastid structure. Mesophyll tissue, which had a long light period before fixation at 4 days, contained chloroplasts with well-developed grana and fret systems. Tissue which had an 8-h dark period before fixation at 4 days contained plastids with large prolamellar bodies and no grana. Apparently during a short time period the night period can result in the formation of crystalline prolamellar bodies in chlorophyll containing tissue (about 0.5 mg chlorophyll per gram fresh weight). Thus in greening squash cotyledons the prolamellar body is a part of normal plastid development.Mesophyll tissue, which received a long light period before fixation at 5 days, contained normal chloroplasts with abundant starch whereas tissue receiving 8 h darkness before fixation at 5 days contained normal chloroplasts which were devoid of starch.The chlorophyll a to chlorophyll b ratio changed during the greening of the cotyledons. Prolonged dark germination greatly reduced the ability of the cotyledons to synthesize chlorophyll when the plants were subsequently placed in 16 h light/day.
Nicotinamide adenine dinucleotide metabolism in plants. I. Intermediates of biosynthesis in wheat leaves and the effect of benzimidazole
Authors: Godavari H. R. , Waygood E. R.
Published: September 2008

Leaves of wheat (Triticum aestivum L. var. Selkirk) were incubated with nicotinic acid-7-14C and nicotinamide-7-14C for varying time periods from 5 min to 12 h. Aliquots of alcoholic extracts of leaves were subjected to paper chromatography and radioautography to isolate the intermediates of the synthesis and breakdown of nicotinamide adenine dinucleotide. Nine compounds were isolated quantitatively and identified as intermediates in the pathway of NAD metabolism. All the intermediates were labeled rapidly and the rapidity of labeling became a problem in rigorously proving the sequential operation of the pathway. The results indicate that the Preiss-Handler pathway: nicotinic acid→nicotinic acid mononucleotide→nicotinic acid adenine dinucleotide→NAD operates in wheat leaves. The degradation of NAD proceeded from NAD→nicotinamide mononucleotide→nicotinamide riboside→nicotinamide. Deamidation of the nicotinamide to nicotinic acid initiated a fresh cycle of biosynthesis. The total radioactivity recovered in the intermediates indicates that no measurable amount was lost to other metabolic pathways. Nicotinamide is recovered without significant loss and recycled. The rapid appearance of labeled nicotinamide indicates a possible interconversion of nicotinic acid and nicotinamide. About 80% of the radioactivity accumulated was present in trigonelline which is considered, on the basis of other evidence, to be a non-toxic form of nicotinic acid. Benzimidazole treatment of the leaves increased the incorporation of 14C into NADP.
Ultrastructure and cleavage of chlamydospore chains of Thielaviopsis basicola
Authors: Christias Christos , Baker Kenneth F.
Published: September 2008

Electron microscopy revealed that numerous spherical or ellipsoidal globules of reserve nutrient material fill the chlamydospore cells, with cytoplasm as a thin film between these globules. The basal cell of the chain is not a chlamydospore; it is filled with cytoplasm and does not contain these globules. Its plasma membrane, nucleus, mitochondria, lomasomes, and endoplasmic reticulum are evident in ultra-thin section. The walls of chlamydospore cells are thick and without distinct layers, except for an electron-dense outer region and a more electron-transparent inner region. Chlamydospore cells in the chain are separated by a very thin electron-transparent binding layer. A thin two-layered envelope surrounds the entire chain. When chlamydospore chains are treated with chitinase, this envelope remains attached around single separated cells, rather than dissolving away. Cytoplasm of cells in the chain is continuous through septal pores. The end walls of the cells become the opercula after the cells are freed from the chain. The germ tube always emerges at the side where the operculum opens, never through the septal pore.
The development of photosynthesis in dark-grown barley leaves upon illumination
Authors: Tamàs Imre A. , Yemm E. W. , Bidwell R. G. S.
Published: September 2008

Dark-grown barley leaves (Hordeum vulgare L.) were exposed to varying periods of illumination, followed by the supply of 14CO2 for 14 min in light or in darkness. Alcoholic extracts of the leaves were analyzed by chromatography. It was found that leaves without previous illumination were able to synthesize only malate, aspartate, glutamate, citrate, and succinate, equally in light or darkness. The products of dark fixation of 14CO2 were not affected by the length of prior illumination. In light, after 2 to 4 h of illumination, the synthesis of malate, aspartate, and glutamate was greatly accelerated. At this time intermediates of the Calvin cycle began to appear, followed by a rapid increase in sucrose synthesis. After more than 6 h of illumination, sucrose became the main photosynthetic product. A kinetic examination of the carbon flow into intermediates of carboxylation in light and in darkness was also conducted.The results indicate that during chloroplast development upon illumination there is a successive activation of distinct components of photosynthesis. The first photosynthetic reaction is a light-dependent β-carboxylation. This is followed by the development of the Calvin cycle, and the glycolate pathway. Dark CO2 fixation appears to be a different process from light-requiring β-carboxylation, located in a separate part of the cell.
Growth and metabolism of Ricinus communis endosperm in tissue culture
Authors: Brown D. J. , Canvin D. T. , Zilkey B. F.
Published: September 2008

Endosperm tissue from both developing and germinating castor oil seeds (Ricinus communis L.) was grown as a callus in tissue culture. Callus growths were established from endosperm explants (without embryo) at all stages of seed development except from the quiescent unimbibed seed. Best tissue culture growth was observed with endosperm tissue obtained from seeds that had been germinated for 2 days.The lipid reserves diminished in all endosperm tissue which had been established on culture from germinating seeds but the rate of breakdown was much slower in cultures from 0-day germinated seeds. Glyoxylate cycle activity, as tested by acetate-1- and -2-14C incorporation, was not evident in long-term cultures.The process of lipid accumulation found in normal developing endosperm (24 to 36 days after fertilization) was not retained in culture but was replaced by a process resulting in the rapid loss of the already accumulated oil reserves.As far as could be determined the in vivo biochemical capabilities of the castor bean endosperm were not retained for a lengthy period in the tissue culture conditions used.
Studies in the Arundinelleae (Gramineae). X. Preliminary taximetrics
Authors: Phippa J. B.
Published: September 2008

The work presented in this paper is part of a larger study devoted to the question of the establishment of generic limits and the question of the numbers of characters to be used in taxonomic studies. The taximetric studies reported below indicate broadly the existence of the following groups: a large and isolated genus Arundinella, a very large Loudetioid–Tristachyoid group, a Danthoniopsoid group, and Trichopteryx. This is in accord with the most recent conclusions of α-taxonomies based on morphology and leaf and awn anatomy. The genus Loudetiopsis, sens. lat., however, is shown to be very widely dispersed through the Loudetioid–Tristachyoid region, a finding not in close accord with earlier taxonomies. The dimensions of the taxa studied are given, together with those characteristics maximally contributing to group structure. The methods used, cluster analysis and ordination, are now more or less standard in numerical taxonomy. However, special attention is paid to the density effect and criteria for establishing named taxa.
Stimulation of in vitro growth of plant tissues by dl-mevalonic acid
Authors: McChesney James D.
Published: September 2008

The effects of mevalonic acid on nine different tissue cultures of plant cells were studied. Mevalonic acid did not substitute for auxin or cytokinin requirement by the tissues but does markedly increase the rate of growth of some of the tissues when incorporated into the normal media of those tissues. A tobacco tissue growing on mevalonic acid in the presence of auxin but the absence of cytokinin may be selected. Standard media may be improved by addition of mevalonic acid, especially media of slow-growing tissues.
Hydathodal pores in lodicules of Avena (Gramineae)
Authors: Baum B. R. , Findlay J. N.
Published: September 2008

The occurrence of hydathodal pores in lodicules of various species of Avena is reported for the first time. Those of cultivated oats (A. sativa L.) are described from examinations made under interference contrast and scanning electron microscopes.
EMERGENCE OF PREFERRED FIRING SEQUENCES IN LARGE SPIKING NEURAL NETWORKS DURING SIMULATED NEURONAL DEVELOPMENT
Authors: IGLESIAS JAVIER , VILLA ALESSANDRO E. P.
Published: September 2008

Two main processes concurrently refine the nervous system over the course of development: cell death and selective synaptic pruning. We simulated large spiking neural networks (100 × 100 neurons "at birth") characterized by an early developmental phase with cell death due to excessive firing rate, followed by the onset of spike timing dependent synaptic plasticity (STDP), driven by spatiotemporal patterns of stimulation. The cell death affected the inhibitory units more than the excitatory units during the early developmental phase. The network activity showed the appearance of recurrent spatiotemporal firing patterns along the STDP phase, thus suggesting the emergence of cell assemblies from the initially randomly connected networks. Some of these patterns were detected throughout the simulation despite the activity-driven network modifications while others disappeared.
ADAPTIVE FUZZY CONTROL WITH OUTPUT FEEDBACK FOR H∞ TRACKING OF SISO NONLINEAR SYSTEMS
Authors: RIGATOS GERASIMOS G.
Published: September 2008

Observer-based adaptive fuzzy H∞ control is proposed to achieve H∞ tracking performance for a class of nonlinear systems, which are subject to model uncertainty and external disturbances and in which only a measurement of the output is available. The key ideas in the design of the proposed controller are (i) to transform the nonlinear control problem into a regulation problem through suitable output feedback, (ii) to design a state observer for the estimation of the non-measurable elements of the system's state vector, (iii) to design neuro-fuzzy approximators that receive as inputs the parameters of the reconstructed state vector and give as output an estimation of the system's unknown dynamics, (iv) to use an H∞ control term for the compensation of external disturbances and modelling errors, (v) to use Lyapunov stability analysis in order to find the learning law for the neuro-fuzzy approximators, and a supervisory control term for disturbance and modelling error rejection. The control scheme is tested in the cart-pole balancing problem and in a DC-motor model.
THE LABELED SYSTEMS OF MULTIPLE NEURAL NETWORKS
Authors: NEMISSI M. , SERIDI H. , AKDAG H.
Published: September 2008

This paper proposes an implementation scheme of K-class classification problem using systems of multiple neural networks. Usually, a multi-class problem is decomposed into simple sub-problems solved independently using similar single neural networks. For the reason that these sub-problems are not equivalent in their complexity, we propose a system that includes reinforced networks destined to solve complicated parts of the entire problem. Our approach is inspired from principles of the multi-classifiers systems and the labeled classification, which aims to improve performances of the networks trained by the Back-Propagation algorithm. We propose two implementation schemes based on both OAO (one-against-all) and OAA (one-against-one). The proposed models are evaluated using iris and human thigh databases.
STABILITY OF A 2-STATION-5-CLASS RE-ENTRANT LINE WITH INFINITE SUPPLY OF WORK
Authors: GUO YONGJIANG , YANG JIANKUI , WANG XUEWU
Published: September 2008

This paper considers a 2-station-5-class re-entrant line with infinite supply of work. We obtain the necessary and sufficient condition for its corresponding fluid model to be stable. As an application of the result, the positive Harris recurrence of the 2-station-5-class re-entrant line is established via the fluid model.
OPTIMAL STRATEGIES IN ONE-DAY CRICKET
Authors: NORTON PAM , PHATARFOD RAVI
Published: September 2008

Using a dynamic programming formulation, an analysis is presented of both the first and second innings of a one-day cricket match assuming variation in type of ball bowled and subsequent selection of a strategy by the batsman. We assume that the team batting first uses the strategy to maximize the expected score, and the team batting second uses the strategy to maximize the probability of outscoring the first team and thus of maximizing the probability of a win. The dynamic programming formulation allows a calculation, at any stage of the innings, of the optimal scoring strategy depending on the type of ball bowled, along with an estimate of the maximum of the expected number of runs scored in the remainder of the first innings, and the maximum probability of a win in the second innings. Modifications are then introduced to examine the effect of tailender batsmen and a "fifth bowler". Finally a simulation is done to estimate the variance in total score by following the optimal strategy used in the first innings.
THE LEARNING EFFECT ON SETUP COST REDUCTION FOR MIXTURE INVENTORY MODELS WITH VARIABLE LEAD TIME
Authors: PAN JASON CHAO-HSIEN , LO MING-CHENG
Published: September 2008

This paper investigates the impact of learning curve effect on setup cost for the continuous review inventory model involving controllable lead time with the mixture of backorder and partial lost sales. A learning curve is a well known tool which describes the relation between the performance of a task and the number of repetitions of that task. The objective of this study is to minimize the expected total annual cost by simultaneously optimizing order quantity, safety factor and lead time under different setup learning rates. There are two models considered in the paper, one with normal demand distribution and another with general demand distribution having both mean and variance known and finite. Numerical examples are presented to illustrate the procedures of the proposed solution algorithms, along with the savings on the total costs of the models with the inclusion of the learning effect on setup.
M/G/c/K PERFORMANCE MODELS IN MANUFACTURING AND SERVICE SYSTEMS
Authors: SMITH J. MACGREGOR
Published: September 2008

Multi-server, finite buffer, performance models of queueing systems are very useful tools for manufacturing, telecommunication, transportation and facility modelling applications. Exact computation of performance measures for general service multi-server queueing systems remains an intractable problem. Approximations of these performance measures are important to quickly and accurately reveal the performance of a system. This is desirable for both performance evaluation as well as optimization of these systems. Two-moment approximation formulas are presented for performance modelling of multi-server systems involving servers of 2,3,…,10 servers. Extensive computational results are provided to evaluate the approximation results against simulation, known tabular results, and other approximation formulas. Applications of the model to optimizing manufacturing and service systems using a marginal allocation algorithm are briefly illustrated. Extensions of the two-moment methodology to larger multi-server systems c = {25, 50, 100} round out the paper.
FINDING THE REFERENCE SET OF A DECISION MAKING UNIT
Authors: JAHANSHAHLOO G. R. , SHIRZADI A. , MIRDEHGHAN S. M.
Published: September 2008

In this paper we propose a method for finding the reference set of a decision making unit (DMU), without chasing down all alternative optimal solutions of the envelopment form, which is a strong degenerate problem. The reference set is useful as a benchmark for an inefficient DMU, for identifying the status of returns to scale, ranking of DMUs and so on. Lastly, numerical examples are shown to illustrate our proposed approach.
NEW DEA PERFORMANCE EVALUATION INDICES AND THEIR APPLICATIONS IN THE AMERICAN FUND MARKET
Authors: LIN RUIYUE , CHEN ZHIPING
Published: September 2008

The data envelopment analysis (DEA) method is a mathematical programming approach to evaluate the relative performance of portfolios. Considering that the risk input indicators of existing DEA performance evaluation indices cannot reflect the pervasive fat tails and asymmetry in return distributions of mutual funds, we originally introduce new risk measures CVaR and VaR into inputs of relevant DEA indices to measure relative performance of portfolios more objectively. To fairly evaluate the performance variation of the same fund during different time periods, we creatively treat them as different decision making units (DMUs). Different from available DEA applications which mainly investigate the American mutual fund performance from the whole market or industry aspect, we analyze in detail the effect of different input/output indicator combinations on the performance of individual funds. Our empirical results show that VaR and CVaR, especially their combinations with traditional risk measures, are very helpful for comprehensively describing return distribution properties such as skewness and leptokurtosis, and can thus better evaluate the overall performance of mutual funds.
STUDIES OF THE FORMATION OF MICROPOROUS POLYMER FILMS IN "BREATH FIGURE" CONDENSATION PROCESSES
Authors: BARROW M. S. , JONES R. L. , PARK J. O. , WRIGHT C. J. , WILLIAMS P. R. , SRINIVASARAO MOHAN
Published: September 2008

We report studies of the formation of ordered microporous polymer films by the evaporation of polymer solutions following exposure to a humid atmosphere. High-speed microphotographic (HSMP) studies of the formation process reveal that near the surface of the polymer solution, vapor condensation produces near monodisperse water droplets which crystallize to form a close-packed array. Following the evaporation of the solvent, characterization of the solid by Atomic Force Microscopy, confocal microscopy and white light interferometry reveals that the surface of the polymer film features extensive regions of hexagonally close-packed microscopic pores, whose spatial arrangement replicates that of the initial droplet monolayer. Defects recorded by HSMP in the packing of the colloidal monolayer of liquid droplets formed above the surface of the polymer solution are found to correspond to those transferred into the eventual solid film, providing the first direct evidence of the structure templating role of the droplet monolayer.
FURTHER STUDIES OF SOME TL CHARACTERISTICS OF MgB4O7:Dy, Na PHOSPHOR
Authors: CANO A. , GONZÁLEZ P. R. , FURETTA C.
Published: September 2008

Nowadays, the pacific use of ionizing radiation has attracted a great deal of attention in medicine, as well as in radiodiagnostic, and radiotherapy. However to avoid unnecessary irradiations to the healthy tissue, a strict quality control is required. This has led to the development of a new dosimeter equivalent to the tissue that could be highly suitable for the radiation dosimetry. The borate of magnesium with its low effective atomic number (Z eff ), is considered equivalent to the human-tissue. For this reason, in this work, we present the results obtained of the thermoluminescent characterization of this material. The test that was carried out includes the lower detection limit, sensitivity, reproducibility of the TL measurement, stability of information (fading), and TL response as a function of the delivered dose and energy response, which are recommended by the International Commission on Radiological Units and Measurements (ICRU) and International Commission on Radiological Protection (ICRP). Two different concentrations of Dy activator were used i.e. 1.25 (batch A) and 1.5 (batch B) mol%. Meanwhile, the Na activator was 0.5 mol% in both cases. The results show that this new thermoluminescent material is adequate for radiation dosimetry in different medical applications.
EFFECT OF SAMARIUM DOPING ON THE STRUCTURAL AND MAGNETIC PROPERTIES OF THE LITHIUM–NICKEL FERRITE
Authors: AI LUNHONG , JIANG JING , GAO HEJUN
Published: September 2008

Sm -doped Li – Ni ferrites were synthesized by a soft chemistry method. The effects of Sm -doping on the structural and magnetic properties of the Li – Ni ferrites were investigated. The structural, morphological and magnetic properties of the ferrite samples were characterized by X-ray diffractometer (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The results revealed that the Sm -doped samples had the single spinel phase at low Sm content. The increase in Sm content increased the lattice parameter and decreased the particle sizes. The magnetic properties of the Sm -doped Li – Ni ferrites were strongly affected by Sm content. The saturation magnetization decreased, while coercivity increased with increasing Sm content.
FINDING AND DISENTANGLING COMPLICATED UNITARY OPERATORS BY VIRTUE OF THE INTEGRATION OVER DIRAC'S KET–BRA OPERATORS
Authors: FAN HONG-YI
Published: September 2008

Usually complicated unitary operators in exponential form are hard to handle and the transformation stated by them are not physically clear until these operators are disentangled. By virtue of the technique of integration within an ordered product (IWOP) of operators, we can disentangle some complicated unitary operators and then reveal their physical role. Many new unitary operators can be found after new quantum mechanical representations are constructed by virtue of the IWOP technique. The unitary operators for permutation, Hilbert transform, Householder transform, and Hardmad transform can also be introduced. The IWOP technique thus bridges this mathematical gap between classical mechanics and quantum mechanics and provides a new route connecting classical transformations to quantum mechanical unitary operators. In this way, the symbolic method exhibits further beauty and elegance and can be increasingly used for developing various fields of quantum physics.
CASE-BASED-REASONING FOR IMAGE SEGMENTATION
Authors: FRUCCI MARIA , PERNER PETRA , SANNITI DI BAJA GABRIELLA
Published: September 2008

This paper proposes to use case-based-reasoning for grey-level image segmentation. Different approaches to image segmentation have been proposed in the literature. The selection of the segmentation approach and the assignment of the values to the parameters involved in the selected algorithm depend on image domain and on the specific application. Case-based-reasoning seems a promising way to make the above selection automatic. In this paper, we describe the results of a preliminary study done in this respect. In particular, we refer to the automatic selection of the values of the parameters for a new watershed image segmentation algorithm.
COGNITIVE ROLE OF SPEECH PAUSES AND ALGORITHMIC CONSIDERATIONS FOR THEIR PROCESSING
Authors: ESPOSITO ANNA , STEJSKAL VOJTĚCH , SMÉKAL ZDENĚK
Published: September 2008

This study investigates pausing strategies, focusing the attention on empty speech pauses. A cross-modal analysis (video and audio) of spontaneous narratives produced by male and female children and adults showed that a remarkable amount of empty speech pauses was used to signal new concepts in the speech flow and to segment discourse units such as clauses and paragraphs. Based on these results, an adaptive mathematical model for pause distribution was suggested, that exploits, as pause features, the absence of signal and/or the changes of energy over different acoustic dimensions strongly related to the auditory perception. These considerations inspired the formulation and the implementation of two pause detection procedures that proved to be more effective than the Likelihood Ratio Test (LRT) and Long-Term Spectral Divergence (LTSD) algorithms recently proposed in literature and applied for Voice Activity Detection (VAD).
EMBEDDING DIFFUSION IN VARIATIONAL BAYES: A TECHNIQUE FOR SEGMENTING IMAGES
Authors: BOCCIGNONE GIUSEPPE , NAPOLETANO PAOLO , FERRARO MARIO
Published: September 2008

In this paper, we discuss how image segmentation can be handled by using Bayesian learning and inference. In particular variational techniques relying on free energy minimization will be introduced. It will be shown how to embed a spatial diffusion process on segmentation labels within the Variational Bayes learning procedure so as to enforce spatial constraints among labels.
INDEPENDENT COMPONENTS OF OPTICAL FLOW IN A MULTIRESOLUTION IMAGE SEQUENCE
Authors: OHNISHI NAOYA , IMIYA ATSUSHI
Published: September 2008

In this paper, we present an algorithm for the hierarchical recognition of an environment using independent components of optical flow fields for the visual navigation of a mobile robot. For the computation of optical flow, the pyramid transform of an image sequence is used for the analysis of global and local motion. Our algorithm detects the planar region and obstacles in the image from optical flow fields at each layer in the pyramid. Therefore, our algorithm allows us to achieve both global perception and local perception for robot vision. We show experimental results for both test image sequences and real image sequences captured by a mobile robot. Furthermore, we show some aspects of this work from the viewpoint of information theory.
NON-INVASIVE BRAIN-MACHINE INTERACTION
Authors: DEL R. MILLÁN JOSÉ , FERREZ PIERRE W. , GALÁN FERRAN , LEW EILEEN , CHAVARRIAGA RICARDO
Published: September 2008

The promise of Brain-Computer Interfaces (BCI) technology is to augment human capabilities by enabling interaction with computers through a conscious and spontaneous modulation of the brainwaves after a short training period. Indeed, by analyzing brain electrical activity online, several groups have designed brain-actuated devices that provide alternative channels for communication, entertainment and control. Thus, a person can write messages using a virtual keyboard on a computer screen and also browse the internet. Alternatively, subjects can operate simple computer games, or brain games, and interact with educational software. Work with humans has shown that it is possible for them to move a cursor and even to drive a wheelchair. This paper briefly reviews the field of BCI, with a focus on noninvasive systems based on electroencephalogram (EEG) signals. It also describes three brain-actuated devices we have developed: a virtual keyboard, a brain game, and a wheelchair. Finally, it shortly discusses current research directions we are pursuing in order to improve the performance and robustness of our BCI system, especially for real-time control of brain-actuated robots.
OBJECT MOTION DETECTION AND TRACKING BY AN ARTIFICIAL INTELLIGENCE APPROACH
Authors: MADDALENA LUCIA , PETROSINO ALFREDO , FERONE ALESSIO
Published: September 2008

The aim of this paper is to propose an artificial intelligence based approach to moving object detection and tracking. Specifically, we adopt an approach to moving object detection based on self organization through artificial neural networks. Such approach allows to handle scenes containing moving backgrounds and gradual illumination variations, and achieves robust detection for different types of videos taken with stationary cameras. Moreover, for object tracking we propose a suitable conjunction between Kalman filtering, properly instanced for the problem at hand, and a matching model belonging to the class of Multiple Hypothesis Testing. To assess the validity of our approach, we experimented both proposed moving object detection and object tracking over different color video sequences that represent typical situations critical for video surveillance systems.
THREE CONCEPTUAL LEVELS FOR THE ARTIFACTS DESIGN
Authors: CALABRESE ANTONIO , MELE FRANCESCO , SORGENTE ANTONIO , TALAMO OLIVIERO , COPPOLA CARLO
Published: September 2008

In this paper we present a theoretical framework for the formalization of design methodologies of artifacts, in which we distinguish three levels: the design strategies level, the artifacts representation level, and the level of graphics systems for 3D rendering. This work proposes both a formal apparatus for the definition of design strategies, considered as processes operating on representations of artefacts, and provides a methodological contribution to the building of knowledge-based aid design systems. The key idea of the paper is that, independently of the design type, it is essential to separate the level of design strategy from that of artifact representation and to connect them through appropriate translation rules. The strategy level is a "meta"-level with respect to the representation level. Therefore when we formalize a strategy, we must represent it through a language of greater order than the one used in formalizing the artifact representation. In this paper we present a formalization of some typical design strategies classes for every-day artifact in which an artifact is represented as a class of a formal ontology. Though the methodological and formal apparatus presented has been defined for the generative design operating method, we think that the concepts here exposed apply also to other architectural design approaches.
PERIODIC ADAPTIVE ACTIVATION OF BEHAVIORS IN ROBOTIC SYSTEMS
Authors: BURATTINI ERNESTO , ROSSI SILVIA
Published: September 2008

The main goal of our current research is the design of a robotic architecture that has the capability of adapting the robot's behavior to the rate of change of a dynamic environment. We present a model which takes free inspiration from some features of biological clocks. In particular, we associate the concept of Innate Releasing Mechanisms (IRM) to the concept of periodic behavior activation in order to link the variability of the behavior to the circumstances in which it is activated. We propose an architecture in which the frequency of access to the sensory system is modified in accordance to the environmental changes. To this purpose we use the Schema Theory paradigm. Some first experimental results are reported and discussed.
LOGICAL REASONING VIA SATISFIABILITY MAPPED INTO ENERGY FUNCTIONS
Authors: LIMA PRISCILA M. V. , MORVELI-ESPINOZA M. MARIELA M. , PEREIRA GLAUCIA C. , FERREIRA TALITA O. , FRANÇA FELIPE M. G.
Published: September 2008

This paper presents the implementation of ARQ-PROP II, a limited-depth propositional neural reasoner based on the Resolution Principle. The SATyrus platform was used in the synthesis of Energy functions from a set of pseudo-Boolean constraints specifying ARQ-PROP II architectures for different inferencing depths. Global minima of the Energy functions produced by SATyrus are associated to SATisfiability of a formula and, in the case of ARQ-PROP II, are associated to Resolution-based refutations. This allows for simplified abduction, prediction and planning to be unified with deduction in a goal-driven style, i.e. there is no need for presetting a reasoning style upon a target set of clauses. Experimental results on deduction with ARQ-PROP II using different propositional depth settings are presented together with a correction of Gadi Pinkas' mapping of SATisfiability into Energy minima.
DESIGN AND RESULTS OF THE 3RD ANNUAL SATISFIABILITY MODULO THEORIES COMPETITION (SMT-COMP 2007)
Authors: BARRETT CLARK , DETERS MORGAN , OLIVERAS ALBERT , STUMP AARON
Published: September 2008

The Satisfiability Modulo Theories Competition (SMT-COMP) is an annual competition aimed at stimulating the advance of the state-of-the-art techniques and tools developed by the Satisfiability Modulo Theories (SMT) community. As with the first two editions, SMT-COMP 2007 was held as a satellite event of CAV 2007, held July 3-7, 2007. This paper gives an overview of the rules, competition format, benchmarks, participants and results of SMT-COMP 2007.
TOWARDS PATTERN-BASED REASONING FOR FRIENDLY ONTOLOGY DEBUGGING
Authors: JARRAR MUSTAFA , HEYMANS STIJN
Published: September 2008

Reasoning with ontologies is a challenging task specially for non-logic experts. When checking whether an ontology contains rules that contradict each other, current description logic reasoners can only provide a list of the unsatisfiable concepts. Figuring out why these concepts are unsatisfiable, which rules cause conflicts, and how to resolve these conflicts, is all left to the ontology modeler himself. The problem becomes even more challenging in case of large or medium size ontologies, because an unsatisfiable concept may cause many of its neighboring concepts to be unsatisfiable.

The goal of this article is to empower ontology engineering with a user-friendly reasoning mechanism. We propose a pattern-based reasoning approach, which offers 9 patterns of constraint contradictions that lead to unsatisfiability in Object-role (ORM) models. The novelty of this approach is not merely that constraint contradictions are detected, but mainly that it provides the causes and suggestions to resolve contradictions. The approach is implemented in the DogmaModeler ontology engineering tool, and tested in building the CCFORM ontology. We discuss that, although this pattern-based reasoning covers most of contradictions in practice, compared with description logic based reasoning, it is not complete. We argue and illustrate both approaches, pattern-based and description logic-based, their implementation in the DogmaModeler, and conclude that both complement each other from a methodological perspective.
A STUDY OF TEXTUAL ENTAILMENT
Authors: RUS VASILE , McCARTHY PHILIP M. , McNAMARA DANIELLE S. , GRAESSER ARTHUR C.
Published: September 2008

In this paper we study a graph-based approach to the task of Recognizing Textual Entailment between a Text and a Hypothesis. The approach takes into account the full lexico-syntactic context of both the Text and Hypothesis and is based on the concept of subsumption. It starts with mapping the Text and Hypothesis on to graph structures that have nodes representing concepts and edges representing lexico-syntactic relations among concepts. An entailment decision is then made on the basis of a subsumption score between the Text-graph and Hypothesis-graph. The results obtained from a standard entailment test data set were promising. The impact of synonymy on entailment is quantified and discussed. An important advantage to a solution like ours is its ability to be customized to obtain high-confidence results.