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  • Open Access

    ARTICLE

    A study of chlorophyll-like and phycobilin pigments in the C endosymbiont of the apple- snail Pomacea canaliculata

    ISRAEL A. VEGA*1,2, FEDERICO A. DELLAGNOLA1, JORGE A. HURST3, MARTÍN S. GODOY1 AND ALFREDO CASTRO-VAZQUEZ1,2

    BIOCELL, Vol.36, No.2, pp. 47-55, 2012, DOI:10.32604/biocell.2012.36.047

    Abstract Pigments present in the brown-greenish C morph of an intracellular endosymbiont of Pomacea canaliculata were investigated. Acetone extracts of the endosymbiotic corpuscles showed an absorption spectrum similar to that of chlorophylls. Three fractions obtained from silica gel column chromatography of the acetone extracts (CI , CII and CIII ), were studied by positive ion fast atom bombardment-mass spectrometry (FAB–MS) and hydrogen-nuclear magnetic resonance (H-NMR). Results indicated the presence of (1) a sterol in the yellow colored CI fraction; (2) a mixture of pheophorbides a and b in the major green fraction, CII; and (3) a modified pheophorbide a in the… More >

  • Open Access

    ARTICLE

    The importance of Arabidopsis seed mutants in the elucidation of the molecular basis of Endosperm Balance Number in tuberbearing Solanum species

    P. CORNEJO*, E.L. CAMADRO**, R.W. MASUELLI*

    BIOCELL, Vol.30, No.3, pp. 413-421, 2006, DOI:10.32604/biocell.2006.30.413

    Abstract The Endosperm Balance Number (EBN) is an important concept for potato breeding and has evolutionary importance in tuber-bearing Solanum species. The EBN is part of the post-zygotic hybridization barriers in the group and represents a reproductive isolating mechanism. Few genes have been proposed to be involved in its genetic control; until now, however, neither specific genes nor its molecular basis have been well established. Histological observations of embryo and endosperm development in inter-EBN crosses in tuber-bearing Solanum revealed phenotypes similar to those recently described in Arabidopsis seed mutants. The common feature between them is that the endosperm nuclei become greatly… More >

  • Open Access

    ARTICLE

    Intrahost distribution and trasmission of a new species of cyclopoid copepod endosymbiotic to a freshwater snail, Pomacea canaliculata (Caenogastropoda, Ampullariidae) from Argentina

    C. D. GAMARRA-LUQUES, I. A. VEGA, E. KOCH, A. CASTRO-VAZQUEZ

    BIOCELL, Vol.28, No.2, pp. 155-164, 2004, DOI:10.32604/biocell.2004.28.155

    Abstract A new species of cyclopoid copepod, Ozmana huarpium, is described as a symbiont to Pomacea canaliculata (Lamarck 1822) (Caenogastropoda, Ampullariidae). Rather large numbers (about one hundred copepods per snail) were found, although there was no evidence of harm to the host. To our knowledge, O. haemophila (symbiont to P. maculata), and the currently described species, O. huarpium, are the only copepod species ever recorded as endosymbionts to freshwater invertebrates. While O. haemophila is restricted to the haemocoel of its host, O. huarpium predominate in the penis sheath, the ctenidium and the mantle cavity, figuring in these pallial organs 63-65 %… More >

  • Open Access

    ARTICLE

    Effect of hydrocarbon concentration of pasture production (Brachiaria humidicola) in Texistepec, Veracruz

    Adams RH, AL Álvarez-Ovando, G Castañón N

    Phyton-International Journal of Experimental Botany, Vol.84, No.1, pp. 222-232, 2015, DOI:10.32604/phyton.2015.84.222

    Abstract In this study, the relationship between the concentration of extra-heavy crude petroleum in a clayey material and the toxicity, field capacity, temperature, and growth of a tropical forage grass (Brachiara humidicola) was determined empirically. For this type of petroleum the acute toxicity (Microtox®) was slight (CE50 = 63200 - 76400 mg/kg) even at high hydrocarbon concentrations (29279 mg/kg). Nonetheless, serious impacts were encountered in terms of an increase in soil temperature (+ 1.3 °C), reduction in field capacity (-10.7%) and reduction in aerial biomass (-97%). The relationship between hydrocarbon concentration and biomass resulted in a typical dose-response curve (r =… More >

  • Open Access

    ARTICLE

    Fertilization and association with pioneer herbaceous species on the performance of Pinus pseudostrobus

    Gómez-Romero M1, E de la Barrera2, J Villegas3, R Lindig-Cisneros4

    Phyton-International Journal of Experimental Botany, Vol.82, pp. 135-143, 2013, DOI:10.32604/phyton.2013.82.135

    Abstract When degradation is severe, as it is often the case on acrisols, it is necessary to test the effect of plant-plant interactions in their survival and growth. An experiment was conducted, with substrate from an eroded site (acrisols with gullies) in a shaded greenhouse (30% shade) to evaluate the effect of fertilization and the presence of pioneer herbaceous species in the performance of Pinus pseudostrobus. The pioneer species Lupinus mexicanus and Tithonia tubiformis were used in three experimental treatments and a control. To fertilize, KH2PO4 was applied in four concentration levels. There were a total of 16 treatment combinations when… More >

  • Open Access

    ARTICLE

    Nitrogen metabolism in roots and leaves of green bean plants exposed to different phosphorus doses

    Sánchez E1, G Ávila-Quezada1, AA Gardea1, E Muñoz1, JM Ruiz2, L Romero2

    Phyton-International Journal of Experimental Botany, Vol.78, pp. 11-16, 2009, DOI:10.32604/phyton.2009.78.011

    Abstract The objective of this work was to determine the effect of different P doses on nitrogen assimilation in roots and leaves of green beans plants (Phaseolus vulgaris L. cv. Strike). Phosphorus was applied in the nutrient solution as H3PO4, at the nutrient doses of: P1 = 0.40 mM; P2 = 0.80 mM; P3 = 1.60 mM; P4 = 3.20 mM; P5 = 4.80 mM, and P6 = 6.40 mM P. Our results indicate that both P toxicity and deficiency gave similar responses to N assimilation. Phosphorus and NO3 - interacted on the absorption and translocation processes affecting N assimilation. The… More >

  • Open Access

    ARTICLE

    Evidence for maternal transmission of a putative endosymbiont in the digestive gland of Pomacea canaliculata (Architaenioglossa, Ampullariidae)

    EDUARDO KOCH1,2, ISRAEL A. VEGA1,3,4, ALFREDO CASTRO-VAZQUEZ1,3,4

    BIOCELL, Vol.41, No.2-3, pp. 59-62, 2017, DOI:10.32604/biocell.2017.41.059

    Abstract The digestive gland of the apple snail Pomacea canaliculata lodges two types of pigmented corpuscles (identified as C and K corpuscles) which has been proposed as endosymbiont/s. Both corpuscular types are always present in the digestive gland of adult snails, they are released into the tubuloacinar lumen and are later expelled in the feces. On their part, hatchlings lack any C or K corpuscles in the digestive gland as well as in their feces, whereas C corpuscles appear in both the gland and feces within one week after hatching. Hence, it is possible that the detritivorous hatchlings acquire the putative… More >

  • Open Access

    ARTICLE

    The Mechanical Characteristics of Human Endothelial Cells in Response to Single Ionizing Radiation Doses By Using Micropipette Aspiration Technique

    Alireza Mohammadkarim1, Manijhe Mokhtari-Dizaji2,*, Ali Kazemian3, Hazhir Saberi4, Mohammad Mehdi Khani5, Mohsen Bakhshandeh6

    Molecular & Cellular Biomechanics, Vol.16, No.4, pp. 275-287, 2019, DOI:10.32604/mcb.2019.06280

    Abstract The mechanical properties of living cells are known to be promising biomarkers when investigating the health and functions of the human body. Ionizing irradiation results in vascular injury due to endothelial damage. Thus, the current study objective was to evaluate the influence of continuous radiation doses on the mechanical properties of human umbilical vein endothelial cells (HUVECs), and to identify Young’s modulus (E) and viscoelastic behavior. Single-dose (0, 2, 4, 6, and 8 Gy) radiation was applied to HUVECs using a Cobalt-60 treatment machine in the current vitro irradiation study. Thereafter, a micropipette-aspiration technique was used to measure the elastic… More >

  • Open Access

    ARTICLE

    Novel DDoS Feature Representation Model Combining Deep Belief Network and Canonical Correlation Analysis

    Chen Zhang1, Jieren Cheng1,2,3,*, Xiangyan Tang1, Victor S. Sheng4, Zhe Dong1, Junqi Li1

    CMC-Computers, Materials & Continua, Vol.61, No.2, pp. 657-675, 2019, DOI:10.32604/cmc.2019.06207

    Abstract Distributed denial of service (DDoS) attacks launch more and more frequently and are more destructive. Feature representation as an important part of DDoS defense technology directly affects the efficiency of defense. Most DDoS feature extraction methods cannot fully utilize the information of the original data, resulting in the extracted features losing useful features. In this paper, a DDoS feature representation method based on deep belief network (DBN) is proposed. We quantify the original data by the size of the network flows, the distribution of IP addresses and ports, and the diversity of packet sizes of different protocols and train the… More >

  • Open Access

    ARTICLE

    Low-Dose CT Image Denoising Based on Improved WGAN-gp

    Xiaoli Li1,*, Chao Ye1, Yujia Yan2, Zhenlong Du1

    Journal of New Media, Vol.1, No.2, pp. 75-85, 2019, DOI:10.32604/jnm.2019.06259

    Abstract In order to improve the quality of low-dose computational tomography (CT) images, the paper proposes an improved image denoising approach based on WGAN-gp with Wasserstein distance. For improving the training and the convergence efficiency, the given method introduces the gradient penalty term to WGAN network. The novel perceptual loss is introduced to make the texture information of the low-dose images sensitive to the diagnostician eye. The experimental results show that compared with the state-of-art methods, the time complexity is reduced, and the visual quality of low-dose CT images is significantly improved. More >

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