Histopathology of Myxidium giardi Cepede, 1906 infection in European eels, Anguilla anguilla L., in Portugal     

M.T. Ventura  I. Paperna 《Aquaculture (Amsterdam, Netherlands)》1984,43(4):357-368

Infection of Myxidium giardi in skin, gills, cartilage, liver, spleen, kidney, urinary bladder and intestine of eels in different stages of development is described. Some 233 eels were examined by standard histological procedures. Histopathological and clinical findings demonstrated that pathological damage due to infection is severe only in the kidney of elvers. In older eels, histopathological findings indicate an established tolerance to infection. Findings of free spores and plasmodia with spores at different stages of differentiation in eels of all age groups suggest a continuous process of infestation among eels under culture conditions.  相似文献   

Optimization of agrotechniques in the cultivation of Luffa acutangula     

S. Huyskens  S. Mendlinger  A. Benzioni  M. Ventura 《The Journal of Horticultural Science and Biotechnology》2013,88(6):989-994

Germination requirements, flowering pattern, planting density and growing regimes were examined for Luffa acutangula (L.) Roxb. Maximum germination (50%) was obtained at 35°C, and at 8, 12, and 45°C germination was completely inhibited. Partial removal of the seed coat increased the percentage of germination while vernalization and exposure to salinity 5=50 mM NaCl reduced it. Planting season influenced flowering pattern, with significantly more female flowers being produced in spring-summer (long days and high temperatures) than in autumn-winter (short days and low temperatures). A high yield of 44.5-47.3 Mg ha 1 was obtained for plants trained on trellises at planting densities of 10,000 and 20,000 plants ha-1. Fruits kept at low temperatures showed the least deterioration during storage, a shelf life of about two weeks being demonstrated at 4°C.  相似文献   

Effects of suboptimal low temperature on yield,fruit appearance and quality in muskmelon (Cucumis melo L.) cultivars     

Yvonne Ventura  Samuel Mendlinger 《The Journal of Horticultural Science and Biotechnology》2013,88(5):602-607

Summary

The effects of suboptimal low temperature were investigated on an array of yield, fruit appearance and fruit quality characters in 23 cultivars of melon, Cucumis melo L. The cultivars were grown in two temperature regimes: (I) a heated greenhouse (T1) with temperatures similar to those used in commercial cultivation in the winter in Israel; and (ii) an unheated greenhouse (T2) that had significantly lower night temperatures than T1. Significant differences were found among the cultivars in all characters. Plants from T2 showed an extended fruiting period, more fruits and higher total yield but smaller and lighter fruits than in T1. Fruits from T2 also had significantly more netting and higher amounts of total soluble sugars (TSS), sucrose and fructose than fruits from T1. Hybrid cultivars showed significantly higher electrical conductivity (EC), pH, acidity, TSS, sucrose, fructose and total sugars than open pollinated cultivars. Three trends were found among the characters in respect to the performance of the cultivars between T1 and T2: (a) most cultivars had significantly higher amounts in T2 than T1 (fruit/plant, yield/plant and fructose); (b) only cultivars with amounts below the pooled mean in T1 had higher amounts in T2 (percent dry weight, sucrose, TSS and total sugars); (c) no trend was found between T1 and T2 (mean fruit weight, pH, EC, glucose). Suboptimal low temperatures, when used appropriately, can aid in improving fruit quality.  相似文献   

How learning to read changes the cortical networks for vision and language     

Dehaene S  Pegado F  Braga LW  Ventura P  Nunes Filho G  Jobert A  Dehaene-Lambertz G  Kolinsky R  Morais J  Cohen L 《Science (New York, N.Y.)》2010,330(6009):1359-1364

Does literacy improve brain function? Does it also entail losses? Using functional magnetic resonance imaging, we measured brain responses to spoken and written language, visual faces, houses, tools, and checkers in adults of variable literacy (10 were illiterate, 22 became literate as adults, and 31 were literate in childhood). As literacy enhanced the left fusiform activation evoked by writing, it induced a small competition with faces at this location, but also broadly enhanced visual responses in fusiform and occipital cortex, extending to area V1. Literacy also enhanced phonological activation to speech in the planum temporale and afforded a top-down activation of orthography from spoken inputs. Most changes occurred even when literacy was acquired in adulthood, emphasizing that both childhood and adult education can profoundly refine cortical organization.  相似文献   

Mutagenic and genotoxic effects of the Atrazine herbicide in Oreochromis niloticus (Perciformes, Cichlidae) detected by the micronuclei test and the comet assay     

Bruna de Campos Ventura 《Pesticide biochemistry and physiology》2008,90(1):42-51

Atrazine is the triazinic herbicide most found in the rural aquatic environments due to its extensive use and its stability in such places. The mutagenicity and the genotoxicity of different concentrations of the Atrazine herbicide were determinated by the micronucleus test and the comet assay, using Oreochromis niloticus as test-system. The tested concentrations of Atrazine herbicide were 6.25, 12.5 and 25 μg/L, both for the micronuclei test and for the comet assay. The results showed a significant rate of micronuclei and nuclear abnormalities for all the tested concentrations of Atrazine herbicide. For the comet assay, we also observed results significantly different from the control in 6.25, 12.5 and 25 μg/L concentrations. Due to these results, we could infer that such herbicide may be dangerous to the lives of those organisms exposed to it.  相似文献   

Mercury distribution in target organs and biochemical responses after subchronic and trophic exposure to Neotropical fish Hoplias malabaricus     

Maritana Mela  Francisco Filipak Neto  Flávia Yoshie Yamamoto  Ronaldo Almeida  Sonia Regina Grötzner  Dora Fix Ventura  Ciro Alberto de Oliveira Ribeiro 《Fish physiology and biochemistry》2014,40(1):245-256

In the present study, we investigated the mercury distribution, mercury bioaccumulation, and oxidative parameters in the Neotropical fish Hoplias malabaricus after trophic exposure. Forty-three individuals were distributed into three groups (two exposed and one control) and trophically exposed to fourteen doses of methylmercury each 5 days, totalizing the doses of 1.05 μg g^?1 (M1.05) and 10.5 μg g^?1 (M10.5 group). Autometallography technique revealed the presence of mercury in the intestinal epithelia, hepatocytes, and renal tubule cells. Mercury distribution was dose-dependent in the three organs: intestine, liver, and kidney. Reduced glutathione concentration, glutathione peroxidase, catalase, and glutathione S-transferase significantly decreased in the liver of M1.05, but glutathione reductase increased and lipid peroxidation levels were not altered. In the M10.5, most biomarkers were not altered; only catalase activity decreased. Hepatic and muscle mercury bioaccumulation was dose-dependent, but was not influenced by fish sex. The mercury localization and bioaccumulation corroborates some histopathological findings in this fish species (previously verified by Mela et al. in Ecotoxicol Environ Saf 68:426–435, 2007). However, the results of redox biomarkers did not explain histopathological findings previously reported in M10.5. Thus, fish accommodation to the stressor may reestablish antioxidant status at the highest dose, but not avoid cell injury.  相似文献   

Ecotoxicological Study of Insecticide Effects on Arthropods in Common Bean     

Emerson Cristi de Barros  Hudson Vaner Ventura  Pablo Costa Gontijo  Renata Ramos Pereira  Marcelo Coutinho Pican?o 《Journal of insect science (Online)》2015,15(1)

Arthropods are an important group of macroorganisms that work to maintain ecosystem health. Despite the agricultural benefits of chemical control against arthropod pests, insecticides can cause environmental damage. We examined the effects of one and two applications of the insecticides chlorfenapyr (0.18 liters a.i. ha-1) and methamidophos (0.45 liters a.i. ha-1), both independently and in combination, on arthropods in plots of common bean. The experiment was repeated for two growing seasons. Principal response curve, richness estimator, and Shannon–Wiener diversity index analyses were performed. The insecticides generally affected the frequency, richness, diversity, and relative abundance of the arthropods. In addition, the arthropods did not experience recovery after the insecticide applications. The results suggest that the insecticide impacts were sufficiently drastic to eliminate many taxa from the studied common bean plots.  相似文献   

Effects of the lack of forest management on spatiotemporal dynamics of a subalpine Pinus cembra forest     

Francesco Giammarchi  Giorgio Vacchiano  Andrea Bertagnolli  Maurizio Ventura  Pietro Panzacchi  Paolo Cherubini 《Scandinavian Journal of Forest Research》2017,32(2):142-153

Knowledge about the stand structure and dynamics of subalpine forests is crucial to preserve their multifunctionality. In the present study, we reconstructed the spatiotemporal dynamics of a subalpine Pinus cembra forest in the eastern Italian Alps in response to natural disturbances and forest management. We adopted a concurrent point pattern, dendroecological and growth dominance (GD) analysis. We mapped and measured all trees of Pinus cembra and Larix decidua in a 1?ha plot. We analyzed intra- and interspecific spatial patterns and spatial autocorrelation of tree size and age. We explored establishment dynamics and shifts in competition by analyzing growth suppression/release patterns and GD trends. Results showed a clumped, uneven-aged, multilayered structure where pine was dominant. The synergic action of ecological and human-induced factors is discussed to explain the prevalence of pine over time. Spatial pattern and autocorrelation analyses suggest a different colonization strategy of the two species, in which pine established after small-scale perturbations and experienced a stronger inter- and intra-specific competition. The interruption of tree establishment and shift in GD toward large trees resulting from the lack of forest management are the most important findings of this research. This highlights the importance of an active management to avoid the homogenization of the forest structure that is generally associated with a reduction in biodiversity and protective ability of forests.  相似文献   

Scale dependency of insect assemblages in response to landscape pattern   总被引：5，自引：0，他引：5  

Chust  Guillem  Pretus  Joan Ll.  Ducrot  Danielle  Ventura  Daniel 《Landscape Ecology》2004,19(1):41-57

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Physiological and pharmacokinetic responses in neotropical Piaractus mesopotamicus to the essential oil from Lippia sidoides (Verbenaceae) as an anesthetic     

Ventura  Arlene Sobrinho  de Castro Silva  Tarcila Sousa  Zanon  Ricardo Basso  Inoue  Luis Antonio Kioshi Aoki  Cardoso  Claudia Andrea Lima 《International Aquatic Research》2019,11(1):1-12

International Aquatic Research - The goal of the study was to evaluate Lippia sidoides essential oil as an anesthetic for the tropical fish pacu Piaractus mesopotamicus. The physiological and...  相似文献