226 research outputs found
Assessing Cu impacts on freshwater diatoms: biochemical and metabolomic responses of Tabellaria flocculosa (Roth) Kutzing
Metals are a recognised threat to aquatic organisms but the impact of metals such as copper (Cu) on benthic freshwater diatoms is poorly understood, even if diatoms are commonly used as water quality indicators. Our study aimed to elucidate the cellular targets of Cu toxicity and the mechanisms cells resort to counteract toxicity and to increase tolerance to Cu. A concerted approach analysing the biochemical, physiological and metabolome alterations in diatom cells was conducted by exposing the freshwater diatom Tabellaria flocattosa to 0, 0.3, 6 and 10 mu g Cu/L. Cu was already toxic to T. flocculosa at concentrations common in environments and which are not usually considered to be contaminated (0.3 mu g Cu/L). Under Cu impact, the metabolome of T. flocculosa changed significantly, especially at high concentrations (6 and 10 mu g Cu/L). Cu toxicity was counteracted by increasing extracellular immobilization (EPS, frustulins), antioxidant (SOD, CAT) and detoxifying (GSTs) enzymes activity and low molecular weight antioxidants (GSH). These mechanisms were fuelled by higher energy production (increased ETS activity). At the highest Cu concentration (10 mu g/L), these processes were specially enhanced in an attempt to restrain the oxidative stress generated by high intracellular Cu concentrations. However, these mechanisms were not able to fully protect cells, and damage in membranes and proteins increased. Moreover, the decrease of hydroxylamine and unsaturated fatty acids and the increase of saturated fatty acids, 2-palmiloylglycerol, glycerol and diterpenoid compounds should be tested as new specific markers of Cu toxicity in future studies. This information can support the prediction of diatom behaviour in different Cu contamination levels, including highly impacted environments, such as mining scenarios, and may assist in environmental risk assessment policies and restoration programs. (C) 2018 Elsevier B.V. All rights reserved
A viewpoint on the use of microalgae as an alternative feedstuff in the context of pig and poultry feeding - a special emphasis on tropical regions
With the current increase in meat and animal products consumption, there is a need to make production systems more sustainable. The use of microalgae in monogastric feeds, replacing widely used conventional feedstuffs such corn and soybean, can be a solution to overcome this problem. Several studies have shown promising results in the use of microalgae in feeding of both pigs and poultry. However, there are several important constraints associated to the production of microalgae. Such constraints are particularly limiting in the context of tropical regions. Research and scientific development on microalgae production systems are thus essential so that may be widely used in monogastric feeding. Herein, we conduct an overview of the major findings in the use of microalgae in the context of monogastric feeding and analyse the major constraints associated to its production and use, particularly in the specific context of tropical regions.info:eu-repo/semantics/submittedVersio
Evaluating Two Quantitative Ethnobotanical Techniques
A critical evaluation of two quantitative techniques used in ethnobotanical studies was undertaken using data concerning plant use in a rural community in the semi-arid region of Pernambuco State, northeastern Brazil. The relative importance of 36 native woody species reported as being useful by 98 informants was calculated employing the Use-Value (UV) and Relative Importance (RI) techniques. Both techniques place value on a given taxon based on the number of uses attributed to it. Results obtained for both techniques are positively correlated, suggesting that they can be used interchangeably to evaluate local knowledge of a given resource. The implications and interpretation limitations of these two techniques are discussed in detail
Fredholm methods for billiard eigenfunctions in the coherent state representation
We obtain a semiclassical expression for the projector onto eigenfunctions by
means of the Fredholm theory. We express the projector in the coherent state
basis, thus obtaining the semiclassical Husimi representation of the stadium
eigenfunctions, which is written in terms of classical invariants: periodic
points, their monodromy matrices and Maslov indices.Comment: 12 pages, 10 figures. Submitted to Phys. Rev. E. Comments or
questions to [email protected]
Cryptosporidium Spp. And Giardia Spp. In Feces And Water And The Associated Exposure Factors On Dairy Farms
The aims of this study were to verify the prevalence of Cryptosporidium spp. and Giardia spp. in animal feces and drinking water on dairy farms and to identify a possible relation between the exposure factors and the presence of these parasites. Fecal samples from cattle and humans and water samples were collected on dairy farms in Paraná, Brazil. Analysis of (oo)cysts in the feces was performed by the modified Ziehl-Neelsen staining and centrifugal flotation in zinc sulfate. Test-positive samples were subjected to nested PCR amplification of the 18SSU ribosomal RNA gene for identification of Cryptosporidium and Giardia and of the gp60 gene for subtyping of Cryptosporidium. Microbiological analysis of water was carried out by the multiple-tube method and by means of a chromogenic substrate, and parasitological analysis was performed on 31 samples by direct immunofluorescence and nested PCR of the genes mentioned above. Identification of the species of Cryptosporidium was performed by sequencing and PCR with analysis of restriction fragment length polymorphisms. The prevalence of Giardia and Cryptosporidium was higher in calves than in adults. Among the samples of cattle feces, Cryptosporidium parvum was identified in 41 (64%), C. ryanae in eight (12.5%), C. bovis in four (6.3%), C. andersoni in five (7.8%), and a mixed infection in 20 samples (31.3%). These parasites were not identified in the samples of human feces. Thermotolerant coliform bacteria were identified in 25 samples of water (45.5%). Giardia duodenalis and C. parvum were identified in three water samples. The gp60 gene analysis of C. parvum isolates revealed the presence of two strains (IIaA20G1R1 and IIaA17G2R2) in the fecal samples and one (IIaA17G2R1) in the water samples. The presence of coliforms was associated with the water source, structure and degradation of springs, rain, and turbidity. The prevalence of protozoa was higher in calves up to six months of age. C. parvum and G. duodenalis were identified in the water of dairy farms, as were thermotolerant coliforms; these findings point to the need for guidance on handling of animals, preservation of water sources, and water treatment. © 2017 Toledo et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.12
Performance And Economic Analysis Of Finished Lambs In Feedlot
This study aimed to evaluate animal performance and economic performance of feedlot crossbred lambs (Santa Inês+ - Suffolk) fed different diets based on hay from Cynodon dactylon genotypes, through the use of financial measures considering only the period of feedlot, without relating it to the complete management cycle. A total of 30 intact crossbred Suffolk lambs, identified with earrings, with an average age of 90 days and an average body weight of 21.5 kg were used in this study. Diets were formulated using as treatments a standard concentrate and hay of the Cynodon dactylon genotypes Jiggs, Vaquero, Tifton 68, Coast-Cross, Tifton 85 and Russell in a 60:40 forage-to-concentrate ratio. The treatments were distributed in a randomized complete block design with five replicates. There were significant differences between diets in terms of total expenditure on food, and the highest values were obtained for the Jiggs genotype (BRL 48.96/animal). The animals fed diets based on Tifton 68 hay had a higher rate of return (2.16%) and profitability (34.63%) compared to the other diets. The use of diets based on Tifton 68 hay for feedlot lambs in the finishing phase brings higher economic returns compared to the remaining diets.37129330
Cissus Sicyoides: Pharmacological Mechanisms Involved In The Anti-inflammatory And Antidiarrheal Activities
The objective of this study was to evaluate the pharmacological mechanisms involved in anti-inflammatory and antidiarrheal actions of hydroalcoholic extract obtained from the leaves of Cissus sicyoides (HECS). The anti-inflammatory effect was evaluated by oral administration of HECS against acute model of edema induced by xylene, and the mechanisms of action were analysed by involvement of arachidonic acid (AA) and prostaglandin E2 (PGE2). The antidiarrheal effect of HECS was observed and we analyzed the motility and accumulation of intestinal fluid. We also analyzed the antidiarrheal mechanisms of action of HECS by evaluating the role of the opioid receptor, α2 adrenergic receptor, muscarinic receptor, nitric oxide (NO) and PGE2. The oral administration of HECS inhibited the edema induced by xylene and AA and was also able to significantly decrease the levels of PGE2. The extract also exhibited significant anti-diarrheal activity by reducing motility and intestinal fluid accumulation. This extract significantly reduced intestinal transit stimulated by muscarinic agonist and intestinal secretion induced by PGE2. Our data demonstrate that the mechanism of action involved in the anti-inflammatory effect of HECS is related to PGE2. The antidiarrheal effect of this extract may be mediated by inhibition of contraction by acting on the intestinal smoothmuscle and/or intestinal transit. © 2016 by the authors; licensee MDPI, Basel, Switzerland.17
Tolerância de perda de solo por erosão para os principais solos do estado de Santa Catarina
Enhancing meat quality of weaned piglets with the dietary incorporation of Ulva lactuca and carbohydrases supplementation
Pubmed Free articleThe impact of the dietary incorporation of 7% Ulva lactuca, a green seaweed, on the quality and nutritional value of piglet’s meat was assessed. U. lactuca is rich in nutrients and bioactive compounds but its cell wall is composed of complex polysaccharides that reduce their bioavailability. Therefore, the effect of supplementing piglet diets with exogenous carbohydrases was also assessed here. A total of 40 male weaned piglets were divided into four dietary groups, each with 10 piglets: control (wheat, maize and soybean meal-based diet), UL (7% U. lactuca replacing the control diet), UL +R (UL and 0.005% Rovabio®), and UL +E (UL and 0.01% ulvan lyase). The piglets were fed the diets for 2 weeks. The results showed that incorporating U. lactuca in piglet diets did not influence most of the meat quality traits (P >0.05). However, the incorporation of U. lactuca with the commercial carbohydrase (UL +R) increased the amount of the docosahexaenoic acid (DHA; 22:6n-3) in their meat (P =0.011) compared with the control, by 54%. In addition, meat from piglets fed seaweed diets showed a nearly two-fold increase in iodine contents (P <0.001). Meat tenderness, juiciness and overall acceptability of piglets fed the control diet and the UL diet were lower than those fed the diets containing seaweed and carbohydrases (P <0.001). Overall, the findings indicate that 7% U. lactuca in the diets of weaned piglets had no major detrimental effects on meat quality and their carbohydrase supplementation has the potential to improve meat sensory traits.Funding: This research was funded by Fundação para a Ciência e a Tecnologia (FCT), Portugal, through PTDC/CAL-ZOO/30238/2017 grant, associated with a post-doc contract to M.C., and PhD fellowships to J.M. P. (SFRH/BPD/116816/2016) and D.M.R. (SFRH/BD/143992/2019). CIISA (UIDB/00276/2020), AL4AnimalS (LA/P/0059/2020) and LEAF (UIDB/04129/2020) grants, also from FCT, are also acknowledged. The authors acknowledge Teresa Costa from Indukern, Lda. (Sintra, Portugal), for the Rovabio® Excel AP kind donation. The graphical abstract was created using BioRender.com (https://biorender.com/).info:eu-repo/semantics/publishedVersio
Influence of Feeding Weaned Piglets with Laminaria digitata on the Quality and Nutritional Value of Meat
Laminaria digitata is a novel feedstuff that can be used in pig diets to replace conventional
feedstuffs. However, its resilient cell wall can prevent the monogastric digestive system from accessing
intracellular nutrients. Carbohydrate-active enzyme (CAZyme) supplementation is a putative
solution for this problem, degrading the cell wall during digestion. The objective of this work was to
evaluate the effect of 10% L. digitata feed inclusion and CAZyme supplementation on the meat quality
and nutritional value of weaned piglets. Forty weaned piglets were randomly allocated to four experimental
groups (n = 10): control, LA (10% L. digitata, replacing the control diet), LAR (LA + CAZyme
(0.005% Rovabio® Excel AP)) and LAL (LA + CAZyme (0.01% alginate lyase)) and the trial lasted for
two weeks. The diets had no effect on any zootechnical parameters measured (p > 0.05) and meat
quality traits, except for the pH measured 24 h post-mortem, which was higher in LAL compared
to LA (p = 0.016). Piglets fed with seaweed had a significantly lower n-6/n-3 PUFA ratio compared
to control, to which the higher accumulation of C20:5n-3 (p = 0.001) and C18:4n-3 (p < 0.0001) contributed.
In addition, meat of seaweed-fed piglets was enriched with bromine (Br, p < 0.001) and iodine
(I, p < 0.001) and depicted a higher oxidative stability. This study demonstrates that the nutritional value
of piglets’ meat could be improved by the dietary incorporation of L. digitata, regardless of CAZyme
supplementation, without negatively affecting growth performance in the post-weaning stageinfo:eu-repo/semantics/publishedVersio
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