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11.
Wilson Wasielesky Jr Paulo César Abreu Luis Henrique Poersch Fabiano Thompson Eduardo Luis Cupertino Ballester 《Aquaculture Research》2012,43(5):706-712
A reduction in light intensity may increase shrimp activity, although it may also negatively affect the development of photoautotrophic organisms present in biofilm, an important natural food source for shrimp. This experiment evaluated the influence of light intensity on biofilm development and on the growth of cultured Farfantepenaeus paulensis juveniles. Six cages were deployed in a shrimp culture pond and stocked with 60 juveniles (0.72 ± 0.03 g). Three cages were randomly chosen and covered with five layers of polyamide net to reduce light incidence (shaded treatment), while the other three cages were not covered (control treatment). Biofilm chlorophyll a and microorganism abundance, as well as shrimp growth, were monitored during the experiment. Chlorophyll a concentration and the abundance of bacteria and flagellates were significantly lower in the shaded treatment (P<0.05). After 75 rearing days, shrimp stocked in control treatment achieved significantly higher (5.98 g) (P<0.05) mean weight than shrimp reared in shaded treatment cages (5.13 g). Similarly, the biomass produced was also significantly higher (P<0.05) in the control treatment (322.92 g) than in the shaded treatment (287.31 g). The results of this study demonstrate that light intensity has a huge influence on shrimp performance mainly due to the increase in natural food availability. 相似文献
12.
Izquierdo MS Robaina L Juárez-Carrillo E Oliva V Hernández-Cruz CM Afonso JM 《Fish physiology and biochemistry》2008,34(2):117-127
The Δ6 and Δ5 desaturases and elongases show only very limited activity in marine fish, and little is known of the possibility
of enhancing Δ6 desaturase gene expression in these fish. The use of plant oils in marine fish diets is limited by their lack
of n−3 highly unsaturated fatty acids (HUFA) despite an abundant content of the 18C fatty acid precursor linoleic and α-linolenic
acids. The objective of the present study was to determine the ability of larval gilthead seabream to utilize vegetable oils
and assess the nutritional regulation of Δ6 desaturase gene expression. Seventeen-day-old gilthead seabream larvae were fed
during a 17-day period with one of four different microdiets formulated with either sardine fish oil (FO), soybean, rapeseed
or linseed oils, respectively, or a fifth diet containing defatted squid meal and linseed oil. Good larval survival and growth,
both in terms of total length and body weight, were obtained by feeding the larvae either rapeseed, soybean or linseed oils.
The presence of vegetable oils in the diet increased the levels of 20:2n−9 and 20:2n−6, 18:2n−9, 18:3n−6, 20:3n−6 and 20:4n−6, in larvae fed rapeseed and soybean oils in comparison to those fed FO. In addition, a sixfold increase in the relative
expression of Δ6 desaturase-like gene was found in larvae fed rapeseed and soybean oils, denoting the nutritional regulation
of desaturase activity through its gene expression in this fish species. However, feeding linseed oil did not increase the
expression of the Δ6 desaturase gene to such a high extent. 相似文献
13.
Javier M. Obando-Ulloa Iban Eduardo Antonio J. Monforte J. Pablo Fernández-Trujillo 《Scientia Horticulturae》2009
The soluble sugar and organic acid composition of melon (Cucumis melo L.) fruit flesh has become a major focus of plant breeding worldwide in an attempt to improve taste. Thus, sugar and organic acid profiles were characterized using near-isogenic lines (NILs) derived from the Spanish cultivar Piel de Sapo (PS) and the exotic Korean accession Shongwan Charmi (PI 161375). Fruits were cultivated in only one environment. These data were used to map 60 quantitative trait loci (QTLs): 18 for individual sugars, eight for sucrose equivalents, five for the glucose-to-fructose ratio, seven for the total sugar content and 21 for organic acids. Within the QTLs that were associated with the sugar profile, 27 defined the sugar content: eight for fructose, six for glucose, four for sucrose, and nine for sucrose equivalents. Although increased sweetness of selected NILs compared with the parental PS was achieved by an increased glucose or fructose content, only glucose heritability was above 0.5. A total of 21 QTLs (two with positive effects and nineteen with detrimental effects compared with the PS levels) controlled the organic acid profile: l-glutamic, ascorbic and succinic acids (the principal ones) and fumaric, citric, oxalacetic, and isocitric acids. The levels of sugars imparted by the PI 161375 introgression frequently decreased the score grades given to NILs by consumers. Within the 32 QTLs mapped for sensory traits, 27 were associated with lower scores in taste (nine QTLs), sweetness (eight QTLs) or global quality appreciation (nine QTLs); two with increased fruit sourness or sweetness and three with increased fruit bitterness. The QTLs defined herein may assist breeders to understand the overall organoleptic balance (sweetness, sourness, and umami taste) in melon fruit, particularly those located within linkage groups III, V, VI, and VIII to XI. 相似文献
14.
Janaina Braga do Carmo Marisa de Cssia Piccolo Cristiano Alberto de Andrade Carlos Eduardo Pellegrino Cerri Brigitte Josefine Feigl Erclito Sousa Neto Carlos Clemente Cerri 《Soil & Tillage Research》2007,96(1-2):250-259
Anthropogenic conversion of primary forest to pasture for cattle production is still frequent in the Amazon Basin. Practices adopted by ranchers to restore productivity to degraded pasture have the potential to alter soil N availability and N gas losses from soils. We examined short-term (35 days) effects of tillage prior to pasture re-establishment on soil N availability, CO2, NO and N2O fluxes and microbial biomass C and N under degraded pasture at Nova Vida ranch, Rondônia, Brazilian Amazon. We collected soil samples and measured gas fluxes in tilled and control (non tilled pasture) 12 times at equally spaced intervals during October 2001 to quantify the effect of tillage. Maximum soil NH4+ and NO3− pools were 13.2 and 6.3 kg N ha−1 respectively after tillage compared to 0.24 and 6.3 kg N ha−1 in the control. Carbon dioxide flux ranged from 118 to 181 mg C–CO2 m2 h−1 in the control (non-tilled) and from 110 to 235 mg C–CO2 m2 h−1 when tilled. Microbial biomass C varied from 365 to 461 μg g−1 in the control and from 248 to 535 μg g−1 when tilled. The values for N2O fluxes ranged from 1.22 to 96.9 μg N m−2 h−1 in the tilled plots with a maximum 3 days after the second tilling. Variability in NO flux in the control and when tilled was consistent with previous measures of NO emissions from pasture at Nova Vida. When tilled, the NO/N2O ratio remained <1 after the first tilling suggesting that denitrification dominated N cycling. The effects of tilling on microbial parameters were less clear, except for a decrease in qCO2 and an increase in microbial biomass C/N immediately after tilling. Our results suggest that restoration of degraded pastures with tillage will lead to less C matter, at least initially. Further long-term research is needed. 相似文献
15.
Do Carmo Barbosa Mendes De Vasconcelos M Bennett RN Rosa EA Ferreira Cardoso JV 《Journal of agricultural and food chemistry》2007,55(9):3508-3516
Chestnut (Castanea sativa) is an important basic food in rural diets and a major starch crop used in a similar way to potatoes. Chestnuts are a fundamental economic resource in the "chestnut regions" not only for the fruit but also for the chestnut wood. Chestnuts have become increasingly important with respect to human health, for example, as an alternative gluten-free flour source. Chestnuts are also a rich source of other beneficial compounds, but there have been few studies on the composition during processing. In this study, we analyzed the chemical composition of three Portuguese cultivars at different stages of industrial processing. The chestnut cultivars were Longal, Judia, and Martaínha. All three cultivars had high moisture contents but were low in ash, crude fat, and crude protein contents, with high starch and low fiber contents. The free amino acid contents, including various essential amino acids, varied depending on the cultivar. All three cultivars also had a significant content of polyphenolics with gallic acid; ellagic acid was predominant among hydrolyzable and condensed tannins. Many of these compounds are known to exert significant positive effects on human health. The one-way analysis of variance for fresh chestnut shows significant differences among the three cultivars for most of the studied parameters. The same statistical analysis applied to each one of the two cultivars (Judia and Longal) sampled for the four processing steps analyzed indicates a significant effect of this factor in practically all of the constituents. On the other hand, the two-way analysis of variance shows that, besides the residual, the processing step and the interaction cultivar x processing step were the factors that more contributed for the total variation observed in the constituents analyzed, while the contribution of cultivar was much less significant. 相似文献
16.
Romero-Bastida CA Flores-Huicochea E Martin-Polo MO Velazquez G Torres JA 《Journal of agricultural and food chemistry》2004,52(8):2230-2235
The effect of moisture content and film composition on biodegradability is the focus of this study. Flexible films were first characterized for the effect on water sorption isotherms of relative humidity, temperature, zein content, and the addition of the plasticizers stearic acid, poly(ethylene glycol), or etoxylated ricine oil. Zein/ethylcellulose (EC) mixture films had a behavior between that for pure zein and EC films, which had the lowest water sorption. For films with plasticizer, the lowest water sorption at 25 degrees C was observed for those with stearic acid. Biodegradability of zein/EC films, evaluated using bacterial cultures selected for their zein proteolytic activity and isolated from a local solid waste landfill and a lagoon, showed no plasticizer effect even though its effect on moisture content was significant. Large differences were observed at different film zein concentration with the highest biodegradability for 100% zein. However, biodegradability did not mimic the water sorption behavior of zein/EC mixture films. 相似文献
17.
Uemeson José dos Santos Gustavo Pereira Duda Marise Conceição Marques José Romualdo de Sousa Lima Eduardo Soares de Souza 《Arid Land Research and Management》2019,33(3):255-273
Caatinga is a Brazilian dry ecosystem that occupies around 1 million km2 and is one of the largest tropical dry forests of the world. About 46% of the area that was originally covered has been deforested. Land use can cause pronounced reduction in soil carbon stocks that play a major role in the global carbon cycle. The objective of this study was to improve our understanding of the effect of land use on oxidizable carbon fractions, total carbon stocks and humic substances in different layers of soil in a Brazilian semi-arid region. We analyzed soils from tropical dry forest (TDF), forest succession with Anadenanthera falcata (ANA), with Tabebuia alba (TAB), secondary scrubby regeneration (SCR), and non-irrigated maize (MS). Forests showed larger fractions of more labile carbon, except for TDF. The most recalcitrant fraction of carbon stock, humin fraction stock, with the different land use decreased by 38–53% compared to TDF. Oxidizable carbon fractions, carbon stocks, and humic fraction stocks were able to differentiate the successional land uses and agricultural cover from TDF, mainly in the 0–5?cm layer. Our results show that changes in land use, especially with ANA forest succession, showed a larger labile carbon fraction, indicating easy decomposition and loss. Our results provide an alternative tool for the management of deforested areas in tropical dry caatinga ecosystems. This would contribute to the conservation of dry forest systems and could serve as guideline for sustainable management of agriculturally impacted caatinga areas. 相似文献
18.
Santana Pedro Henrique Lopes Burak Diego Lang Thiengo Cássio Carlette Peçanha Anderson Lopes Neves Mirna Aparecida Mendonça Eduardo de Sá 《Journal of Soils and Sediments》2020,20(11):4103-4110
Journal of Soils and Sediments - After the greatest environmental disaster in the history of Brazil and the deposition of the iron ore tailings in alluvial regions, the process of revegetation for... 相似文献
19.
Karina Janice Guadalupe Díaz-Resendiz Carlos Eduardo Covantes-Rosales Alma Betsaida Benítez-Trinidad Migdalia Sarahy Navidad-Murrieta Francisco Fabian Razura-Carmona Christian Daniel Carrillo-Cruz Edwin Jaime Frias-Delgadillo Daniela Alejandra Prez-Díaz Matxil Violeta Díaz-Benavides Mercedes Zambrano-Soria Guadalupe Herminia Ventura-Ramn Aurelio Romero-Castro David Alam-Escamilla Manuel Ivn Girn-Prez 《Marine drugs》2022,20(2)
Fucoidan is a polysaccharide obtained from marine brown algae, with anti-inflammatory, anti-viral, and immune-enhancing properties, thus, fucoidan may be used as an alternative treatment (complementary to prescribed medical therapy) for COVID-19 recovery. This work aimed to determine the ex-vivo effects of treatment with fucoidan (20 µg/mL) on mitochondrial membrane potential (ΔΨm, using a cationic cyanine dye, 3,3′-dihexyloxacarbocyanine iodide (DiOC6(3)) on human peripheral blood mononuclear cells (HPBMC) isolated from healthy control (HC) subjects, COVID-19 patients (C-19), and subjects that recently recovered from COVID-19 (R1, 40 ± 13 days after infection). In addition, ex-vivo treatment with fucoidan (20 and 50 µg/mL) was evaluated on ΔΨm loss induced by carbonyl cyanide 3-chlorophenylhydrazone (CCCP, 150 µM) in HPBMC isolated from healthy subjects (H) and recovered subjects at 11 months post-COVID-19 (R2, 335 ± 20 days after infection). Data indicate that SARS-CoV-2 infection induces HPBMC loss of ΔΨm, even 11 months after infection, however, fucoidan promotes recovery of ΔΨm in PBMCs from COVID-19 recovered subjects. Therefore, fucoidan may be a potential treatment to diminish long-term sequelae from COVID-19, using mitochondria as a therapeutic target for the recovery of cellular homeostasis. 相似文献
20.
Lidiane Cristina Gonçalves de Sandre Hellen Buzollo Thiago Matias Torres do Nascimento Lígia Maria Neira Eduardo Gianini Abimorad Rosangela Kiyoko Jomori Carlos Ducatti Maria Célia Portella Dalton José Carneiro 《Journal of the World Aquaculture Society》2016,47(1):113-122
This study evaluated the application of stable isotopes of carbon as an alternative and more accurate method to determine gastrointestinal transit time (GTT) in fish by comparing it to the inert marker method. The stable isotope method detects alterations of the normal carbon flow in a biological system by analyzing naturally occurring isotopes of carbon, contrary to studies based on conventional techniques that apply external markers to the diet to determine GTT through visual observation of the color change in feces. Therefore, 320 pacu, Piaractus mesopotamicus juveniles were reared in 32 tanks under two different temperatures (25 and 29 C). The pacu juveniles received two different diets, one based on ingredients derived from C3 photosynthetic cycle plants and the other based on C4 plant ingredients, both containing titanium oxide (TiO2) as a marker. After 40 d, the isotopic signature of the diets was changed, and the marker was replaced by chromic oxide (Cr2O3). In the isotopic technique, the feces were analyzed to determine the exchange in the isotopic ratio of carbon δ13C. Both methods found that GTT was faster (nearly 6 h) in fish at 29 C when using the C4/C3 feeding strategy and slower in fish at 25 C using the C3/C4 strategy (15 h by inert marker and 18 h by the isotopic method). In conclusion, GTT determination in pacu juveniles using the stable isotope technique exhibits the same accuracy obtained with the inert marker method at temperatures suitable (nearly 29 C) for the metabolism of these animals. 相似文献