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41.
Juliana DF Barbosa Viviane B Silva Péricles B Alves Giuseppe Gumina Roseli LC Santos Damião P Sousa Sócrates CH Cavalcanti 《Pest management science》2012,68(11):1478-1483
BACKGROUND: Dengue fever is a severe public health problem for several countries. In order to find effective larvicides to aid control programs, the structure‐activity relationships of eugenol derivatives against Aedes aegypti (Diptera: Culicidae) larvae were evaluated. Additionally, the composition and larvicidal activity of Syzygium aromaticum essential oil was assessed. RESULTS: Four compounds representing 99.05% of S. aromaticum essential oil have been identified. The essential oil was active against Ae. aegypti larvae (LC50 = 62.3 and 77.0 ppm, field‐collected and Rockefeller larvae respectively). The larvicidal activity of eugenol, the major compound of the essential oil, was further evaluated (LC50 = 93.3 and 71.9 ppm, field‐collected and Rockefeller larvae respectively). The larvicidal activity and structure‐activity relationships of synthetic derivatives of eugenol were also assessed. The larvicidal activity of the derivatives varied between 62.3 and 1614.9 ppm. Oxidation of eugenol allylic bond to a primary alcohol and removal of the phenolic proton resulted in decreased potency. However, oxidation of the same double bond in 1‐benzoate‐2‐methoxy‐4‐(2‐propen‐1‐yl)‐phenol resulted in increased potency. CONCLUSION: Structural characteristics were identified that may contribute to the understanding of the larvicidal activity of phenylpropanoids. The present approach may help future work in the search for larvicidal compounds. Copyright © 2012 Society of Chemical Industry 相似文献
42.
43.
Ana Alves Antonio Santos Philippe Rozenberg Luc E. Paques Jean-Paul Charpentier Manfred Schwanninger José Rodrigues 《Wood Science and Technology》2012,46(1-3):157-175
Wood density is defined as the ratio of mass to volume and therefore in principle it should be possible to calculate a unique partial least squares regression (PLS-R) model for several species. PLS-R models for wood density based on X-ray microdensity data were calculated for each species Pinus pinaster and Larix × eurolepis and for both species together. After cross-validation and test set validation the data sets were combined and final models were calculated. The common model gave a residual prediction deviation (RPD) of 3.1, a range error ratio (RER) of 11.7, and a SEP/SEC of 1.06. The single models for Pinus pinaster and Larix?×?eurolepis gave RPD’s of 3.5 and 3.2, RER’s of 13 and 11, and a SEP/SEC of 1.2. To the best knowledge of the authors all obtained PLS-R models are the first ones that fulfil the requirements according to AACC Method 39-00 (AACC in AACC Method, 39-00:15, 1999) to be used at least for screening (RPD?≥?2.5). Although this method and the defined limits were developed for the analysis of grains they can be used as a rough rule of thumb until limits for wood are available. The improvement of the PLS-R models, compared to published results, might be due to three facts (1) the higher number of scans collected for a single spectrum, (2) that the samples were better represented by the NIR spectra and X-ray microdensity values, and (3) that the sites for the measurement of NIR spectra and X-ray microdensity were coincided as strictly as possibly. 相似文献
44.
Almeida AP Saraiva MV Alves Filho JG Silva GM Gonçalves RF Brito IR Silva AW Lima AK Cunha RM Silva JR Figueiredo JR 《Reproduction in domestic animals》2012,47(1):20-25
This study quantified Fibroblast growth factor 2 (FGF-2) mRNA and localized FGF-2 protein in different categories of follicles isolated from goat ovaries. In addition, we verified the effects of this factor on the in vitro culture of preantral follicles isolated from goats. For mRNA quantification, we performed real-time PCR using primordial, primary and secondary follicles, as well as cumulus-oocyte complexes (COCs) and mural granulosa and theca cells of small and large antral follicles. For FGF-2 protein localization, the ovaries were subjected to conventional immunohistochemical procedures. Preantral follicles were isolated and cultured in vitro for 12 days in either control (basic) or supplemented with FGF-2 medium. The expression of FGF-2 mRNA was detected in all categories of follicles and there was no difference in preantral follicles and COCs or granulosa/theca cells from small and large antral follicles. However, in large antral follicles, COCs showed expression levels significantly lower than in granulosa/theca cells (p < 0.05). We observed moderate expression of FGF-2 protein in preantral follicles but not in granulosa cells of primordial follicles and theca cells of secondary follicles. In both small and large antral follicles, strong, moderate and weak staining was observed in oocytes, granulosa and theca cells, respectively. The addition of FGF-2 caused a significant increase in the daily follicular growth rate compared to the control group. We conclude that FGF-2 mRNA is expressed throughout follicular development and that its protein can be found in different patterns in preantral and antral follicles. Furthermore, FGF-2 increases the follicular growth rate in vitro. 相似文献
45.
R.M.P. Rocha L.F. Lima A.M.C.V. Alves J.J.H. Celestino M.H.T. Matos I.B. Lima-Verde M.P. Bernuci C.A.P. Lopes S.N. Báo C.C. Campello A.P.R. Rodrigues J.R. Figueiredo 《Domestic animal endocrinology》2013
The aim of this study was to investigate the effects of melatonin and follicle-stimulating hormone (FSH) on the in vitro culture of goat preantral follicles. Ovarian fragments were cultured for 7 d in α-minimum essential medium (α-MEM+) containing melatonin (100, 250, 500, or 1,000 pM), FSH (50 ng/mL), or a combination of the 2 hormones and further analyzed by histology and transmission electron and fluorescent microscopy. The results showed that after 7 d of culture, tissues cultured in α-MEM+ alone or supplemented with FSH alone, melatonin (500 and 1,000 pM), or the combination of FSH and melatonin (1,000 pM) maintained percentages of normal preantral follicles similar to the fresh control. In contrast to the noncultured tissues, the percentage of developing follicles was increased under all culture conditions after 7 d (P < 0.05). The addition of 1,000 pM melatonin associated with FSH to the culture medium increased follicular and oocyte diameters compared with α-MEM+ alone after 7 d of culture (P < 0.05). Ultrastructural and fluorescent analyses confirmed the integrity of follicles cultured with 1,000 pM of melatonin plus FSH for 7 d. In conclusion, this study demonstrated that the interaction between melatonin and FSH maintains ultrastructural integrity and stimulates further growth of cultured caprine preantral follicles. 相似文献
46.
Michel Anderson Almeida Colmanetti Allan Lopes Bacha Pedro Luis da Costa Aguiar Alves Rinaldo Cesar de Paula 《林业研究》2019,(2):537-543
In silvopasture system, the coexistence of eucalyptus seedlings with other species may result in growth reduction, especially during eucalyptus early development.Therefore, studies elucidating how forage species affect the eucalyptus growth can provide important information for their rational management aiming to obtain the maximum gain of the system. The aim of this work was to evaluate the effect of increasing densities of Urochloa brizantha cv.Marandu in the early development of Eucalyptus urograndis. An experiment was conducted in 20 L pots, in an open and semi-controlled area, during 90 days after planting of eucalyptus. A completely randomized design with four replications was used, in a 6 9 7 factorial system, meaning six evaluation periods and seven densities of U. brizantha: 0(control), 22, 33, 44, 67, 89 and111 plants m-2. Fortnightly, eucalyptus height, stem diameter and chlorophyll fluorescence(Fv/Fm) were evaluated. At the end of experimental period, the net assimilation rate, stomatal conductance and transpiration rate of eucalyptus plants were determined, in addition to the dry matter of eucalyptus(leaves and stem) and U. brizantha (leaves). In coexistence with 111 plants m-2, eucalyptus had reduction of 63.9% on total dry matter and 72.7% on leaf area, compared to the control. From the density of22 plants m-2, U. brizantha negatively interfere significantly the growth of E. urograndis. Up to 8 plants m-2 there are no reductions greater than 5% in eucalyptus height and stem diameter. 相似文献
47.
Species of Botryosphaeriaceae are associated with canker and dieback of Eucalyptus spp. worldwide, but little is known about their effect on the host physiology. The aim of this study was to evaluate the impact of Botryosphaeriaceae isolates from nine species in three genera (Botryosphaeria, Diplodia and Neofusicoccum), previously isolated from eucalypts, on three different Eucalyptus hosts (seedlings of E. nitens, cuttings of E. globulusand of E. globulus× E. cypellocarpa). An approach combining standard pathogenicity trials with evaluation of plant morpho‐physiological parameters was used. The size of the lesions produced revealed differences in fungal aggressiveness and host susceptibility. Isolates of Neofusicoccum kwambonambienseand Diplodia corticolawere the most aggressive, while Botryosphaeria dothidea and Diplodia seriataisolates were the least aggressive. In general, hybrid E. globulus× E. cypellocarpa plants developed smaller lesions, followed by E. nitens and E. globulus. Eucalyptus nitensplants showed minimal modifications on the morpho‐physiological profile when infected, although more severe symptoms and mortality were observed. This is probably due to a more variable genetic background of the plants. However, in general, no direct association between putative fungal aggressiveness and plant physiological disorders could be found. Results suggested that under optimal growth conditions plants manage to cope with pathogen attack and maintain their physiological performance. 相似文献
48.
Marta Salgueiro Alves Anabela Pereira Cludia Vicente Manuel Mota Isabel Henriques 《Forest Pathology》2019,49(6)
In this study, we characterized the diversity of Pseudomonas associated with Bursaphelenchus xylophilus, its insect vector (Monochamus galloprovincialis) and its host (Pinus pinaster), by a culture‐independent approach using rpoD clone libraries. Clone libraries of Pseudomonas rpoD were obtained from B. xylophilus, M. galloprovincialis and infected P. pinaster. Most M. galloprovincialis and B. xylophilus sequences grouped together in the P. fluorescens group. Genes related to xenobiotics degradation and phenylacetate synthesis were present in the genomes of the type strains closely related to sequences retrieved from the nematode libraries. Results demonstrated that the nematode, during its life stages inside the tree, maintains a diverse Pseudomonas community that is closely related to the one associated with the insect vector. These bacteria might contribute to degradation of xenobiotics and tree weakening during the nematode tree infection. 相似文献
49.
Edenise Segala Alves Bárbara Baêsso Moura Marisa Domingos 《Water, air, and soil pollution》2008,189(1-4):61-68
Bioindicators plants are important for the evaluation of air quality and Tillandsia usneoides L., an atmospheric epiphyte bromeliad, has been used for this purpose. The present study aims at evaluate the structural pattern of the leaf of this species when exposed to urban air pollutants, and determining whether the leaves present structural parameters that could be used as indicators of such pollutants. Samples of T. usneoides were exposed in São Paulo, the biggest city of Brazil, for 8, 16 and 24 weeks, and compared with others kept in a rural area. The urban pollution of São Paulo affected the structure of the leaves of T. usneoides causing alterations, especially in the scales, density of stomata and epidermis thickness. Qualitative alterations in the mesophyll were not observed in plants exposed at the polluted sites. These structural characteristics of T. usneoides seem to account for its high tolerance to heavy metal accumulation. The percentage of anomalous scales may potentially be used as an alternative bioindicator parameter. 相似文献
50.
Neto JO Azevedo SS Gennari SM Funada MR Pena HF Araújo AR Batista CS Silva ML Gomes AA Piatti RM Alves CJ 《Veterinary parasitology》2008,156(3-4):329-332
The prevalence and risk factors for anti-Toxoplasma gondii antibodies were investigated in goats of the Seridó Oriental microregion, Rio Grande do Norte state, Northeast region of Brazil. Three hundred and sixty-six blood samples from goats collected by jugular venopuncture were used. For the serologic diagnosis of Toxoplasma gondii infection, the indirect fluorescent-antibody test (IFAT) with cut-off value 1:64 was carried out. The prevalence of anti-T. gondii antibodies was 30.6% [95% CI=25.9-35.6%] with titers ranging from 1:64 to 1:16,384. The multivariate logistic regression analysis showed that the risk factors associated to anti-T. gondii antibodies were presence of cats in the herd, extensive/semi-intensive management systems and lack of mineral supplementation. 相似文献