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1502. Apple aphid, Aphis spp. (Hemiptera: Aphididae), and predator populations in an apple orchard at the non-bearing stage: The impact of ground cover and cultivar
- Creator:
- Fréchette, Bruno, Cormier, Daniel, Chouinard, Gérald, Vanoosthuyse, Franz , and Éric , Lucas
- Type:
- article, model:article, and TEXT
- Subject:
- Predation, aphids, Aphis spp., aphidophagous predators, Harmonia axyridis, Aphidoletes aphidimyza, spiders, apple orchard, biological control, and conservation biological control
- Language:
- English
- Description:
- A two-year field experiment was conducted to determine whether a conservation biological control strategy could be applied to enhance the biological control of green apple aphids, Aphis spp., in a high-density and scab-resistant apple orchard at the non-bearing stage. The natural occurrence of aphid predators and their impact on aphid populations were evaluated in 2005. The impact of predation on aphid densities was evaluated by comparing a predator exclusion treatment with a control. In 2006, the possibility to enhance predator abundance/performance and aphid biological control with a flowering ground cover was tested: trees were grown either with a flowering ground cover of phacelia, Phacelia tanacetifolia Bentham, and buckwheat, Fagopyrum esculentum Moench, or with a conventional ground cover of mixed Poaceae species. In 2006, it was also determined whether aphid densities differ between Liberty and Topaz, 2 scab-resistant cultivars. Results indicate that the predatory arthropod community was dominated by Coccinellidae, Cecidomyiidae, and various spider species. The ladybird community was dominated by the exotic species Harmonia axyridis Pallas, and the abundance of this species was correlated with aphid density. Naturally occurring predators had little impact on aphid abundance, although the proportion of trees with aphid colonies was greater in the predator exclusion treatment on two consecutive dates in 2005. Ground cover types had no impact on aphid densities. The oviposition response of Cecidomyiidae to aphid density was greater in Liberty trees with flowering ground cover than with the conventional ground cover. Conversely, the response of ladybird adults to aphid density was more important in Topaz trees with the conventional ground cover than with the flowering ground cover. Finally, no difference occurred in aphid abundance between Liberty and Topaz trees. Those results are discussed from a biological control and ecological point of view.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1503. Application of (L) sets to some classes of operators
- Creator:
- El Fahri, Kamal, Machrafi, Nabil, H'michane, Jawad, and Elbour, Aziz
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- (L) set, order (L)-Dunford-Pettis operator, weakly sequentially continuous lattice operations, and Banach lattice
- Language:
- English
- Description:
- The paper contains some applications of the notion of (L) sets to several classes of operators on Banach lattices. In particular, we introduce and study the class of order (L)-Dunford-Pettis operators, that is, operators from a Banach space into a Banach lattice whose adjoint maps order bounded subsets to an (L) sets. As a sequence characterization of such operators, we see that an operator T : X → E from a Banach space into a Banach lattice is order (L)-Dunford-Pettis, if and only if |T (xn)| → 0 for σ(E, E′ ) for every weakly null sequence (xn) ⊂ X. We also investigate relationships between order (L)-DunfordPettis, AM-compact, weak* Dunford-Pettis, and Dunford-Pettis operators. In particular, it is established that each operator T : E → F between Banach lattices is Dunford-Pettis whenever it is both order (L)-Dunford-Pettis and weak* Dunford-Pettis, if and only if E has the Schur property or the norm of F is order continuous.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1504. Application of a center manifold theory to a reaction-diffusion system of collective motion of camphor disks and boats
- Creator:
- Ei, Shin-Ichiro, Ikeda, Kota, Nagayama, Masaharu, and Tomoeda, Akiyasu
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- center manifold theory, bifurcation, traveling wave solution, and collective motion
- Language:
- English
- Description:
- Unidirectional motion along an annular water channel can be observed in an experiment even with only one camphor disk or boat. Moreover, the collective motion of camphor disks or boats in the water channel exhibits a homogeneous and an inhomogeneous state, depending on the number of disks or boats, which looks like a kind of bifurcation phenomena. In a theoretical research, the unidirectional motion is represented by a traveling wave solution in a model. Hence it suffices to investigate a linearized eigenvalue problem in order to prove the destabilization of a traveling wave solution. However, the eigenvalue problem is too difficult to analyze even if the number of camphor disks or boats is 2. Hence we need to make a reduction on the model. In the present paper, we apply the center manifold theory and reduce the model to an ordinary differential system.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1505. Application of a multiphase flow code for investigation of influence of capillary pressure parameters on two-phase flow
- Creator:
- Mikyška, Jiří and Illangasekare, Tissa H.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- two-phase flow, non-aquous phase liquids (NAPL), control volume finite elements, capillary pressure parameters, Brooks-Corey model, and plume sensitivity
- Language:
- English
- Description:
- We have developed a multiphase flow code that has been applied to study the behavior of non-aqueous phase liquids (NAPL) in the subsurface. We describe model formulation, discretization, and use the model for numerical investigation of sensitivity of the NAPL plume with respect to capillary parameters of the soil. In this paper the soil is assumed to be spatially homogeneous. A 2-D reference problem has been chosen and has been recomputed repeatedly with modified parameters of the Brooks-Corey capillary pressure model. In this paper we present selected figures showing the resulting plumes as well as quantitative information regarding position of the center of mass of the plume and variances (spreads) of the plume in both axes. These data allow us to evaluate influence of the capillary pressure parameters on the plume morphology in a way that has already been used for characterization of the plume distribution in laboratory experiments. Results confirm the hypothesis that capillary pressure parameters are the key quantities that determine the fate of organic contaminants in the subsurface, and emphasize the significance of the residual NAPL saturation for correct modeling of the NAPL contamination.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1506. Application of a New Set of Pseudo-Distances in Documents Categorization
- Creator:
- Gadri, S. and Moussaoui, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- N -grams, language identification, text categorization, text mining, machine learning, Kullback-Leibler distance, X2 distance, and Cavnar-Trenkle distance
- Language:
- English
- Description:
- Automatic text classification is a very important task that consists in assigning labels (categories, groups, classes) to a given text based on a set of previously labeled texts called training set. The work presented in this paper treats the problem of automatic topical text categorization. It is a supervised classification because it works on a predefined set of classes and topical because it uses topics or subjects of texts as classes. In this context, we used a new approach based on $k$-NN algorithm, as well as a new set of pseudo-distances (distance metrics) known in the field of language identification. We also proposed a simple and effective method to improve the quality of performed categorization.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1507. Application of a probabilistic neural network for liquefaction assessment
- Creator:
- Xue, X., Yang, X., and Li, P.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- earthquake, soil liquefaction, probabilistic neural network, and particle swarm optimization
- Language:
- English
- Description:
- This paper presents a hybrid probabilistic neural network (PNN) and particle swarm optimization (PSO) techniques to predict the soil liquefaction. The PSO algorithm is employed in selecting the optimal smoothing parameter of the PNN to improve the forecasting accuracy. Seven parameters such as earthquake magnitude, normalized peak horizontal acceleration at ground surface, standard penetration number, penetration resistance, relative compaction, mean grain diameter and groundwater table are selected as the evaluating indices. The predictions from the PSO-PNN model were compared with those from two models: backpropagation neural network (BPNN) model and support vector machine (SVM) model. The study concluded that the proposed PSO-PNN model can be used as a reliable approach for predicting soil liquefaction.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1508. Application of adult mesenchymal stem cells in bone and vascular tissue engineering
- Creator:
- Trávníčková, M. and Bačáková, L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- adult mesenchymal stem cells, adipose-derived stem cells, patient factors, bone tissue engineering, and vascular tissue engineering
- Language:
- English
- Description:
- Tissue engineering is a very promising field of regenerative medicine. Life expectancy has been increasing, and tissue replacement is increasingly needed in patients suffering from various degenerative disorders of the organs. The use of adult mesenchymal stem cells (e.g. from adipose tissue or from bone marrow) in tissue engineering seems to be a promising approach for tissue replacements. Clinical applications can make direct use of the large secretome of these cells, which can have a positive influence on other cells around. Another advantage of adult mesenchymal stem cells is the possibility to differentiate them into various mature cells via appropriate culture conditions (i.e. medium composition, biomaterial properties, and dynamic conditions). This review is focused on current and future ways to carry out tissue replacement of damaged bones and blood vessels, especially with the use of suitable adult mesenchymal stem cells as a potential source of differentiated mature cells that can later be used for tissue replacement. The advantages and disadvantages of different stem cell sources are discussed, with a main focus on adipose-derived stem cells. Patient factors that can influence later clinical applications are taken into account.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1509. Application of compound mixture of caprylic acid, iron and mannan oligosaccharide against Sparicotyle chrysophrii (Monogenea: Polyopisthocotylea) in gilthead sea bream, Sparus aurata
- Creator:
- Rigos, George, Mladineo, Ivona, Nikoloudaki, Chrysa, Vrbatovic, Anamarija, and Kogiannou, Dimitra
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- parazitologie, parasitology, monogeneans, treatment, Sparidae, MOS, 2, and 59
- Language:
- English
- Description:
- We have evaluated the therapeutic effect of a compound mixture of caprylic acid (200 mg/kg fish), organic iron (0.2% of diet) and mannan oligosaccharide (0.4% of diet) in gilthead sea bream, Sparus aurata Linnaeus, infected with Sparicotyle chrysophrii Beneden et Hesse, 1863 in controlled conditions. One hundred and ten reared and S. chrysophrii-free fish (197 g) located in a cement tank were infected by the parasite two weeks following the addition of 150 S. chrysophrii-infected fish (70 g). Growth parameters and gill parasitic load were measured in treated against control fish after a ten-week-period. Differences in final weight, feed conversion ratio, specific growth rate and feed efficiency were not statistically significant between the experimental groups, suggesting no evident effect with respect to fish growth during the study period. Although the prevalence of S. chrysophrii was not affected by the mixture at the end of the experiment, the number of adults and larvae was significantly lower. The mean intensity encompassing the number of adults and larvae was 8.1 in treated vs 17.7 in control fish. Individual comparisons of gill arches showed that the preferred parasitism site for S. chrysophrii it the outermost or fourth gill arch, consistently apparent in fish fed the modified diet and in control fish. In conclusion, the combined application of caprylic acid, organic iron and mannan oligosaccharide can significantly affect the evolution of infection with S. chrysophrii in gilthead sea bream, being capable of reducing adult and larval stages of the monogenean. However, no difference in growth improvement was observed after the trial period, potentially leaving space for further optimisation of the added dietary compounds., George Rigos, Ivona Mladineo, Chrysa Nikoloudaki, Anamarija Vrbatovic, Dimitra Kogiannou., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1510. Application of direct and indirect methods for predicting geotechnical dam foundation issues on weathered metamorphic rocks under tropical conditions
- Creator:
- Leao, Marcio Fernandes and Marques, Eduardo Antonio Gomes
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Karst cavities, electrical resistivity, concrete-gravity dam, and weathering rocks
- Language:
- English
- Description:
- Weathering profiles in tropical regions usually present great heterogeneity and anisotropy of geological materials. High structural complexity and great bedrock irregularity are added when these profiles are composed of metamorphic rocks. Therefore, geological-geotechnical research initiatives in these regions imply indirect methods associated with direct methods. In this context, we studied the San Juan dam foundation in the Dominican Republic, geologically composed of young residual schist soil cover (up to 20 m), in which occurs schist layers of low resistance to SPT (2 SPT blows/30 cm) consistent with a massive and stratified marble rock, which tends to concentrate karst cavities. This geological condition, associated with the vast extent of the dam influence area, motivated the adoption of an indirect method by electrical resistivity intending to identify sites with the possibility of occurrence of cavities filled or not under the reservoir foundation and in the dam axis itself. Subsequently, a more rational initiative of mixed drillings was carried out in sites with such possibility, resulting in discarding these hypotheses and demonstrating that these cavities correspond to graphite schists and non-karst marbles, competent materials as dam foundation.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public