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排序方式: 共有347条查询结果,搜索用时 15 毫秒
271.
José Zenóbio De Souza Renato De Mello Prado Sylvia Letícia de Oliveira Silva Thiago Palhares Farias Júlio Garcia Neto 《Communications in Soil Science and Plant Analysis》2019,50(2):164-172
This study aimed to evaluate the effects of silicon (Si) leaf fertilization in different concentrations and sources on the production and quality of chard and kale. We carried out two experiments with chard and kale under a completely randomized design with four replicates in a 2 × 4 factorial scheme and two sources of silicon: potassium silicate and stabilized sodium potassium silicate with four concentrations of Si: 0.00; 0.84; 1.68 and 2.52 g L?1. We performed three leaf sprays every 10 days. The chard and kale were harvested at 48 and 54 days after transplanting the seedlings, respectively. Silicon leaf fertilization is important for leafy vegetables like chard and kale because it increases the content and the accumulation of Si and the growth and production of the vegetables. It also improved growth, productivity, and quality. The Silicon leaf fertilization of 2.52 g L?1 in the form of potassium silicate was the most notable. 相似文献
272.
Paixão TA Ferreira C Borges AM Oliveira DA Lage AP Santos RL 《Veterinary immunology and immunopathology》2006,109(1-2):37-42
Natural resistance against brucellosis in cattle is linked to the Nramp1 gene, which encodes a divalent cation transporter that localizes in the phagolysosome membrane in macrophages. Nramp1 gene in mouse plays a critical role in innate immunity favoring bacterial killing by macrophages in addition to its influence on adaptative immunity. Polymorphisms at the bovine Nramp1 3' untranslated region (3'UTR), detectable by Single Strand Conformational Analysis (SSCA), are associated with natural resistance against brucellosis. Such polymorphisms are associated with variation in the number of GT repeats. This study compared the frequency of Nramp1 3'UTR polymorphisms between Zebu and European bovine breeds. Eighty-one Holsteins (Bos taurus taurus) and 167 Zebu (Bos taurus indicus), including the following breeds: Nelore (n=95), Guzerá (n=37), and Gir (n=35), totaling 248 pure breed cattle studied. DNA extraction was performed using the guanidium protocol and genotyping was performed by SSCA. DNA from cattle considered genotypically resistant to brucellosis resulted in a single band (homozygous) with 175bp, corresponding to the 3'UTR with 13 GT pairs (GT13), whereas DNA from genotypically susceptible cattle generated one single band with 177bp (homozygous GT14) or double bands with both 175 and 177bp, or 175 and 179bp (heterozygous GT13/GT14 or GT13/GT15, respectively). A marked difference in the frequency of alleles was detected between the Zebu and Holstein cattle. Holsteins had an extremely homogeneous genotype, with 100% of the individuals with a GT13 genotype. In sharp contrast the Nelore breed had the most heterogeneous genotype with four allelic combinations, namely, homozygous GT13, homozygous GT14, heterozygous GT13/GT14, and heterozygous GT13/GT15. When the Zebu breeds were compared to each other, the only significant difference observed was the frequencies of the genotypes GT13 and GT14 between the Nelore and Guzerá breeds. The knowledge of allelic frequencies in different breeds of cattle may prove to be very useful in the future for planning breeding strategies for selection of resistant cattle. 相似文献
273.
Randi G Pelucchi C Gallus S Parpinel M Dal Maso L Talamini R Augustin LS Giacosa A Montella M Franceschi S La Vecchia C 《Public health nutrition》2007,10(3):306-310
OBJECTIVE: To analyse the association between macronutrient intake and body mass index (BMI). DESIGN: A series of hospital-based case-control studies. SETTINGS: Selected teaching and general hospitals in several Italian regions. SUBJECTS: A total of 6619 subjects from the comparison groups of the case-control studies were included in the analysis. METHODS: We obtained data from a validated 78-item food-frequency questionnaire submitted between 1991 and 2002. For various macronutrients, the partial regression coefficient (variation of BMI (kg m(-2)) per 100 kcal increment of energy intake) was derived from multiple linear regression models, after allowance for age, study centre, education, smoking habits, number of eating episodes and mutual adjustment for macronutrients. RESULTS: BMI was directly associated with protein intake among women only (beta = 0.68) and with unsaturated fats in both genders (for monounsaturated fats beta = 0.27 for men and 0.26 for women; for polyunsaturated fats beta = 0.27 for men and 0.54 for women), and inversely related to carbohydrates (beta = -0.05 for men and -0.21 for women) and number of eating episodes in both genders (beta = -0.42 for men and -0.61 for women) and to saturated fats among women only (beta = -0.57). CONCLUSIONS: These results confirm and provide convincing evidence that, after allowance for selected covariates including total energy intake, a protein-rich diet is not inversely related to BMI, and a carbohydrate-rich diet is not directly related to BMI. 相似文献
274.
Sporadic autonomic dysregulation and death associated with excessive serotonin autoinhibition 总被引:1,自引:0,他引:1
Audero E Coppi E Mlinar B Rossetti T Caprioli A Banchaabouchi MA Corradetti R Gross C 《Science (New York, N.Y.)》2008,321(5885):130-133
Sudden infant death syndrome is the leading cause of death in the postneonatal period in developed countries. Postmortem studies show alterations in serotonin neurons in the brainstem of such infants. However, the mechanism by which altered serotonin homeostasis might cause sudden death is unknown. We investigated the consequences of altering the autoinhibitory capacity of serotonin neurons with the reversible overexpression of serotonin 1A autoreceptors in transgenic mice. Overexpressing mice exhibited sporadic bradycardia and hypothermia that occurred during a limited developmental period and frequently progressed to death. Moreover, overexpressing mice failed to activate autonomic target organs in response to environmental challenges. These findings show that excessive serotonin autoinhibition is a risk factor for catastrophic autonomic dysregulation and provide a mechanism for a role of altered serotonin homeostasis in sudden infant death syndrome. 相似文献
275.
dos Santos DR de Paula VS de Oliveira JM Marchevsky RS Pinto MA 《Veterinary microbiology》2011,149(1-2):236-241
Hepatitis E is an infectious disease which virus (HEV) is highly disseminated in swine herd populations. Sporadic acute human hepatitis E cases have been associated to genotype 3 and 4 strains of HEV also reported in swine populations of endemic and non-endemic areas. With the aim to evaluate the incidence of animals with current infection of HEV, 115 bile samples were collected from three slaughterhouses under inspection by Animal Sanitary Protection Agency of Rio de Janeiro, Brazil. In parallel, effluent samples were collected from six sewage pipe exit sites of two slaughterhouses. HEV RNA was detected in 11 out of 115 (9.6%) bile samples collected and three waste samples from one slaughterhouse. Viral loads observed for bile samples varied from 10(1)-10(5) genome copies/mL and for effluent samples mean load was 10(2) genome copies/mL. Sequencing and phylogenetic analysis classified samples within genotype 3 subtype 3b closely related to the sample obtained from the first reported autochthonous human case and samples from swine of commercial herds in Brazil. Our data demonstrates that although most animals achieve slaughter age (around 20 weeks old) already immune to HEV, a significant number of animals are with current infection at commercial age. Further studies should be addressed to consider risk analysis and possible evaluation of inspection regulations considering food safety measures regarding hepatitis E zoonotic aspect in Brazil. 相似文献
276.
277.
Penaeid shrimp fisheries are an important source of income for the fishing communities that live in estuarine zones around the world. Off Buenaventura, the habitat of the western white shrimp (Litopenaeus occidentalis) is subject to high precipitation associated with the intertropical convergence zone, contributions from numerous short rivers descending from the Andes Mountains, and seasonal alternations in Trade Winds directions responsible for the upwelling in the Panama Bight. This work analyzes the relationship of precipitation, the San Juan River runoff, and sea level height with Litopenaeus occidentalis abundance in fishing areas between 1968 and 1989. The results indicate that precipitation is significantly correlated (p < 0.01) with the catch per unit effort on a monthly scale with a lag of approximately 1 calendar year but the inclusion of the data in a transfer function model does not improve considerably the forecasting power of a simpler autoregressive moving average model of the catch per unit effort. On an annual scale, the catch per unit effort for white shrimp depends significantly [r2 = 0.36, p (corrected for autocorrelation) 0.01] on the precipitation that fell the previous December, whereas the residuals of this regression are significantly associated with variations of mean sea level between January and March (the upwelling season in the Panama Bight) of the current year at Buenaventura (r2 = 0.61, p (corrected for autocorrelation) 0.01). The inclusion of these two variables in a multiple linear regression model accounted for a substantial proportion of the total annual variance of the mean CPUE (r2 = 0.54), suggesting that freshwater contributions (lower salinities) and offshore transport during the main settlement period of postlarvae in the estuaries play a significant role in determining the strength of the cohorts recruited in the fishing areas. The industrial fishing yield decreased sharply after the 1982–1983 El Niño event. However, a high percentage of this change can be explained not by invoking El Niño effects but by a decreasing tendency of precipitation and offshore advection of early life stages between December and March, which took place on a multi-annual scale since the mid 1980s 相似文献
278.
Donati M Di Francesco A Gennaro R Benincasa M Magnino S Pignanelli S Shurdhi A Moroni A Mazzoni C Merialdi G Baldelli R Cevenini R 《Veterinary microbiology》2007,123(1-3):269-273
Nine Chlamydia suis isolates, obtained from pigs with conjunctivitis, were molecularly characterized by ompA sequencing and their in vitro susceptibility to six cathelicidin peptides (SMAP-29, BAC-7, BMAP-27, BMAP-27, BMAP-28, PG-1, LL-37) determined in cell culture. SMAP-29 was the most active peptide, reducing the intracellular inclusion number by > or =50% at a concentration of 10 microg/ml (3 microM) in six of the nine isolates tested. Three molecularly identical isolates were insensitive at a concentration as high as 80 microg/ml (25 microM). Of the remaining cathelicidin peptides tested, BAC-7 and BMAP-27 were active against six C. suis isolates at a concentration of 80 microg/ml (25 and 26 microM, respectively). Cathelicidins LL-37 and PG-1 did not show any anti-chlamydial activity at 80 microg/ml. 相似文献
279.
280.
Vanessa Paes da Cruz Aisni Mayumi Corrêa de Lima Adachi Giovana da Silva Ribeiro Pablo Henrique de Oliveira Cláudio de Oliveira Rinaldo Oriano Junior Renato Hajenius Aché de Freitas Fausto Foresti 《水产资源保护:海洋与淡水生态系统》2021,31(7):1650-1659
- The illegal sale of endangered elasmobranchs has been recorded in a number of different Brazilian states, where sharks and rays are being marketed primarily as ‘cação’ or ‘viola’. Brazil is ranked among the top 10 nations worldwide that harvest most sharks, causing an immeasurable impact on the local elasmobranch populations.
- The present study applied the DNA barcoding technique, based on the cytochrome C oxidase subunit I gene, for the molecular identification of the elasmobranch species sold as processed products under the generic names of ‘cação’, ‘mangona’, ‘azul’, ‘cambeva’, ‘fiuso’ and ‘lombo preto’, in the fish market of the city of Florianópolis, capital of the state of Santa Catarina, Brazil.
- Nine elasmobranch species were identified in the 56 samples analysed, including six sharks and three rays, representing six families, the Carcharhinidae, Sphyrnidae, Squatinidae, Arhynchobatidae, Myliobatidae and Gymnuridae. Prionace glauca, identified in more than half (56%) of the samples analysed, is listed as Near Threatened by the International Union for the Conservation of Nature.
- Six species identified in the present study, Sphyrna zygaena, Sphyrna lewini, Squatina guggenheim, Carcharhinus signatus, Gymnura altavela and Rioraja agassizii, are under some level of risk of extinction, while two others (Rhizoprionodon lalandii and Myliobatis goodei) are listed as Data Deficient.
- Our results indicate that the commercial exploitation of endemic sharks and rays at risk of extinction is commonplace in southern Brazil. This reinforces the need for more systematic monitoring of the trade in fishery products and more effective application of the environmental legislation and conservation programmes.