High-yielding preparation of a stable precursor of hydroxytyrosol by total synthesis and from the natural glycoside oleuropein     

Gambacorta A  Tofani D  Bernini R  Migliorini A 《Journal of agricultural and food chemistry》2007,55(9):3386-3391

The unprecedented acetonide of the antioxidant hydroxytyrosol has been synthesized by a two-step high-yielding procedure and found to be both purifiable by chromatography and stable over a wide pH range. The protection stabilizes hydroxytyrosol against oxidation, thereby allowing long-term storage. The protection can quantitatively be removed, under nonaqueous conditions, to afford pure hydroxytyrosol suitable for use as an additive in food and cosmetic preparations. Extension of the same methodology to the natural and easily accessible glycoside oleuropein, followed by saponification of the resulting complex mixture of acetonides, allowed hydroxytyrosol acetonide to be recovered in high yield. This constitutes a new interesting methodology to obtain the antioxidant hydroxytyrosol.  相似文献   

Evaluating the potential for farmer and plant breeder collaboration: A case study of farmer maize selection in Oaxaca, Mexico     

Daniela Soleri  Steven E. Smith  David A. Cleveland 《Euphytica》2000,116(1):41-57

Formal plant breeders could contribute much to collaboration with farmers for improving crop varieties for local use. To do so outside researchers must have some understanding of local selection practices and their impact on crop populations in terms of the genetic theory underlying plant breeding. In this research we integrated methods from social and biological sciences to better understand selection and its consequences from farmers' perspectives but based on the concepts used by plant breeders. Among the households we worked with, farmers' selection practices were not always effective yet they understood the reasons for this and had no expectations for response to selection in some traits given the methods available to them. Farmers' statements, practices and genetic perceptions regarding selection and the genetic response of their maize populations to their selection indicate selection objectives different than may be typically assumed, suggesting a role for plant breeder collaboration with farmers. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Estimation of soil salinity in semi‐arid land using a geostatistical model     

J. Navarro‐Pedreo  M. M. Jordan  I. Melndez‐Pastor  I. Gmez  P. Juan  J. Mateu 《Land Degradation \u0026amp; Development》2007,18(3):339-353

Soil salinity is one of the great problems in arid and semi‐arid environments. The estimation and prediction of spatial soil salinity may be considered as a stochastic process, observed at irregular locations in space. Environmental variables usually show spatial dependence among observations which is an important drawback to traditional statistical methods. Geostatistical techniques that analyse and describe the spatial dependence and quantify the scale and intensity of the spatial variation, provides spatial information for local estimation of soil salinity. In this paper we propose a Gaussian Spatial Linear Mixed Model (GSLMM), which involves a non‐parametric term, accounting for a deterministic trend given by exogenous variables, and a parametric component defining the purely spatial random variation, possibly due to latent spatial processes. We focus here on the analysis of the relationship between soil electrical conductivity as a parameter related directly to soil salinity as well as sodium content (sodicity) to identify spatial variations in these parameters. This kind of methodology is demonstrated as a useful tool for environmental land management. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

An integrated approach for cetacean knowledge and conservation in the central Mediterranean Sea using research and social media data sources     

Daniela Silvia Pace  Giancarlo Giacomini  Ilaria Campana  Miriam Paraboschi  Giuliana Pellegrino  Margherita Silvestri  Jessica Alessi  Dario Angeletti  Valentina Cafaro  Gianni Pavan  Giandomenico Ardizzone  Antonella Arcangeli 《水产资源保护:海洋与淡水生态系统》2019,29(8):1302-1323

Mesquite bean (Prosopis juliflora) meal in diets of Nile tilapia (Oreochromis niloticus): Nutritional value,growth, physiological responses and health     

Anderson Miranda de Souza  Adailton Thiago Silva  Altiery Felix e Silva  Daniela Ferraz Bacconi Campeche  Jos Fernando Bibiano Melo  Luiz Vítor Oliveira Vidal 《Aquaculture Research》2019,50(1):49-62

Two experiments were conducted to assess the nutritional value and potential use of mesquite bean (Prosopis juliflora) meal (MBM) to substitute corn in extruded diets for Nile tilapia (Oreochromis niloticus). Digestible energy and the content of protein, soluble carbohydrates and amino acids were measured for 160 Nile tilapia juveniles (average weight 25.58 ± 5.52 g), allocated to eight treatment groups (four fed the experimental diet, and four fed a reference diet). To determine the inclusion potential of MBM, 384 fish (average weight 21.85 ± 1.01 g) were used and allocated to 24 tanks (1,000 L capacity). The experimental design was completely randomized with six levels of substitution (0%, 20%, 40%, 60%, 80% and 100%), and four repetitions. After the feeding experiment, tissue samples (blood, liver, muscle and intestine) were used to analyse metabolic and haematological variables. MBM produced apparent digestibility coefficients (ADC) similar to those of traditional diet ingredients: 81.85% dry matter (DM), 83.02% crude energy, 88.57% crude protein, 82.88% lysine and 82.57% methionine. Differences were observed in the digestibility of soluble carbohydrates (p < 0.05), with MBM having higher levels of starch (72.19%) and sucrose (88.99%). A 20% substitution with MBM produced a decrease in zootechnical performance (p < 0.05). Enzymatic activity of amylase and sucrose seemed to be induced in response to the proportion of their respective substrate in the diets. We observed a reduction in the efficiency of dietary protein utilization, with reduced levels of plasma amino acids (p < 0.05), owing to the increase in the enzymatic activity of muscular alanine and aspartate transaminases (ALT and AST) and the deaminase glutamate dehydrogenase in the hepatic and muscular tissues. Haematological variables did not indicate any adverse effects of MBM on the health status or survival of the fish (100%). Therefore, we conclude that MBM may be a viable alternative to corn meal in the diet, enabling substitution of up to 20%.  相似文献   

The budget of nitrogen in the grow‐out of the Amazon river prawn (Macrobrachium amazonicum Heller) and tambaqui (Colossoma macropomum Cuvier) farmed in monoculture and in integrated multitrophic aquaculture systems     

Dallas L. Flickinger  Gelcirene A. Costa  Daniela P. Dantas  Patricia Moraes‐Valenti  Wagner C. Valenti 《Aquaculture Research》2019,50(11):3444-3461

This work determined the nitrogen inputs, outputs and accumulation in compartments of stagnant earthen ponds for the monoculture and integrated multi‐trophic aquaculture (IMTA) of the Amazon river prawn (Macrobrachium amazonicum) and tambaqui (Colossoma macropomum), using recycled hypereutrophic water. A completely randomized experiment was designed with four treatments and three replications: PM–monoculture with 30 prawns/m², FM ‐ monoculture with 3 fish/m², IMTA ‐ polyculture with 30 prawns/m² and 30 fish/m² free, POLY‐CAGE ‐ polyculture with 30 prawns/m² free and 40 fish/m³ in net‐cages. Animals, rain, water, feed, soil, gas, accumulated sludge, and suspended sediments were collected throughout the experiment to determine their nitrogen contents and to calculate the nitrogen budget. Results showed that much of the nitrogen available escapes to atmosphere as N₂ (~40%–56%) after denitrification or accumulated within bottom sludge (~14%–42%). The remaining nitrogen was converted in animal biomass (~5%–21%) or was discharged to receiving waterbodies in the outlet water (~11%–13%). Feed management appeared to influence the major biological processes in the aquatic nitrogen cycle, such as photosynthesis and denitrification. The fish‐prawn IMTA systems converted approximately 53%–75% of feed nitrogen into harvestable products, which is more efficient than the 19%–46% of feed nitrogen converted in the monocultures. However, a large amount of nitrogen is accumulated in the pond bottom in all systems. An increased prawn density or the addition of a mud‐feeder species to the culture may enhance the incorporation of this material in harvested biomass, improving the efficiency of the systems.  相似文献   

Spontaneous neoplasia in captive syngnathid species: A retrospective case series (2003–2014) and literature review     

Daniela Denk  Ranieri Verin  Lorenzo Ressel  Eleanor Lewis  Mark F Stidworthy 《Journal of fish diseases》2020,43(8):929-939

Syngnathidae (seahorses, pipefish and seadragons) are charismatic species commonly kept in commercial aquaria, but published literature on syngnathid diseases is limited and immunohistochemical techniques not routinely employed. A retrospective review of 2,541 syngnathid submissions received between March 2003 and October 2016 identified 18 neoplasms including germ cell tumours, exocrine pancreatic and intestinal carcinomas, chromatophoromas, and single cases of lymphoma, thyroid and renal carcinoma, swim bladder and pituitary adenoma. Big-bellied seahorses accounted for 19% of submissions, but 50% of neoplasms were diagnosed in this species. This study includes the first reported cases of germ cell tumours, chromatophoroma, thyroid carcinoma and pituitary adenoma in Syngnathidae and the first reports of neoplasia in pipefish species. Out of nine commercial antibodies trialled for immunohistochemical characterization of neoplastic tissue, only pan-cytokeratin proved cross-reactive. Electron microscopy was performed in four cases. Tumours should be considered as differential diagnosis in cases with buoyancy issues, debilitated or emaciated animals, and may predispose to secondary infections. This study highlights the value of histopathological disease surveillance for commercial aquarium settings.  相似文献   

Effect of diets on carotenoid content,body coloration,biochemical composition and spermatophore quality in the “red cherry” shrimp Neocaridina davidi (Caridea,Atyidae)     

Ana Laura Tomas  Daniela Eliana Sganga  Agustina Marciano  Laura Susana Lpez Greco 《Aquaculture Nutrition》2020,26(4):1198-1210

In aquarium industry trade markets, Neocaridina davidi, the “red cherry” shrimp, is one of the most attractive ornamental shrimps due to the striking reddish coloration of females. Five commercial diets formulated for ornamental species were evaluated over a 90‐day period in N. davidi males and females, based on survival, biochemical composition, body weight, carotenoid content and body coloration. Furthermore, histological and histochemical analyses of the male reproductive system were performed to evaluate the spermatophore quality. In all treatments, survival was >80%, and protein content was similar in both female and male shrimps. Lipid content was higher in females and males fed on a diet having the highest lipid level. Carotenoid content was higher and body coloration was brighter in females and males fed on a diet containing the highest carotenoid level. Histological and histochemical analyses of the spermatophore structure and composition showed no differences among diets, suggesting that the five commercial diets are adequate for satisfactory growth and spermatophore quality of N. davidi. The diverse sources and quantities of carotenoids in the highest carotenoid level diet render it more suitable for colour enhancement of this species.  相似文献   

Effect of experimental arginine supplementation on the growth,immunity and resistance of tilapia fingerlings to Streptococcus agalactiae     

Rafael Alves Vianna  Roberta Torres Chideroli  Arthur Roberto da Costa  Oswaldo Pinto Ribeiro Filho  Leandro Licursi de Oliveira  Juarez Lopes Donzele  Eduardo Arruda Teixeira Lanna  Daniela Dib Gonalves  Ulisses de Padua Pereira 《Aquaculture Research》2020,51(3):1276-1283

Streptococcosis causes serious economic losses to fish farms every year. A four‐week feeding trial was carried out to evaluate arginine (ARG) supplementation in the diet of Nile tilapia (Oreochromis niloticus) fingerlings challenged by Streptococcus agalactiae. Fish were fed with experimental diets containing five levels of supplementation with 1.39%, 1.76%, 1.97%, 2.18% or 2.39% analysed level of ARG. Each diet was randomly distributed in 30 tanks containing 20 fish/tank. After 30 days, no differences were observed in performance parameters, weight gain, daily weight gain, specific growth rate, feed intake or food conversion. After the performance assay, fingerlings were infected with 1.95 × 10⁸ CFU/fish of Streptococcus agalactiae. Mortality was verified daily, and the respiratory burst of leucocytes and nitric oxide production were measured at 0 hr, 24 hr, 7 days and 15 days after infection. The survival rate of the fish is compared using the Kaplan–Meier method, with values of 4.29%, 14.8%, 10.8%, 17.2% and 33.3% for the 1.39, 1.76, 1.97, 2.18 and 2.39 treatments respectively. A reduction in the mortality rate and a boost in the immune responses was observed in all the supplementations of ARG in the diet; however, the best survival rates were obtained in the treatments with 2.39% ARG as well as the most efficient immune responses.  相似文献   

Stress response and lipid composition in shrimp Litopenaeus vannamei fed diets enriched with squid or scallop viscera meal     

Celene Navarro  Roberto Civera  Olivia Arjona  Crisalejandra Rivera‐Perez  Hugo Sergio García  Miguel ngel Hurtado‐Oliva  Elena Palacios 《Aquaculture Research》2020,51(4):1602-1622

We substituted 10% of fishmeal with scallop (Argopecten ventricosus) or squid (Dosidiscus gigas) by‐product meal in a feed for shrimp (Litopenaeus vannamei) growth assay that lasted 60 days and then shrimps were submitted to handling stress. Shrimp fed the control diet had smaller weight gain and lower recovery after stress. Prostaglandins in gills were affected by diet and stress, with significant differences in shrimp fed the control diet before and after the stress. Hydroperoxides were increased after stress, while isoprostanoids were higher in shrimp fed the control diet. The gene expression of Glutathione peroxidase and Catalase was increased on the stressed shrimp fed the scallop diet, with no differences among diets for Superoxide dismutase or Cyclooxygenase. Arachidonic acid in the phospholipid fraction of muscle was the only fatty acid affected by stress and diet. Cholesterol oxidation products were significantly higher in shrimp fed the scallop diet compared to shrimp fed the control diet before applying the stress. A PCA analysis grouped in one‐factor growth variables, as well as Superoxide dismutase, esterified astaxanthin and isoprostane, while another factor was determined by stress, prostaglandin and hydroperoxide levels in gills. The partial substitution of fishmeal with scallop of squid by‐product meals affected growth and stress differently, indicating shrimp that grew up more were not necessarily more tolerant to handling stress, which can have a strong repercussion in aquaculture, particularly during density control, recording of growth and harvest.  相似文献