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排序方式: 共有19条查询结果,搜索用时 31 毫秒
1.
The objective of this experiment was to test the probiotic Efinol®L during transportation of cardinal tetra, Paracheirodon axelrodi (Schultz). For the transportation, fish were distributed in 18 plastic tanks, of which nine contained the Efinol®L (10 mg L−1; probiotic treatment) and the remaining had no probiotic (control treatment). Transport lasted 24 h and three different boxes of each treatment were sampled at 3, 12 and 24 h. Up to the 12-h sampling period, no significant difference in the survival was observed; on the other hand, survival was higher at the end of the transport (24 h) in the probiotic treatment. No significant difference was found in dissolved oxygen and temperature between treatments. Conductivity, pH and alkalinity increased along the transport, but without a difference between treatments. Ammonia increased in all treatments, although it was significantly lower in the probiotic group at 24 h. Cortisol levels were significantly higher in all transported fish when compared with the basal values. At 24 h, cortisol levels in control fish were significantly higher than those in the probiotic treatment. With the observed results, we are able to conclude that the probiotic Efinol®L is efficient during cardinal transport, lowering the mortality and helping maintain water quality possibly by lowering metabolic wastes.  相似文献   
2.
  • ? The elucidation of relationships between biodiversity and ecosystem processes has been limited by the definition of metrics of biodiversity and their integration into experimental design. Functional trait screening can strengthen the performance of these designs.
  • ? We suggest the use of Rao’s quadratic entropy to measure both functional diversity and phylogenetic diversity of species mixtures proposed for an experimental design, and demonstrate how they can provide complementary information.
  • ? We also present an index assessing the statistical performance of these independent variables in different experimental designs. Measurement of independent variables as continuous vs. discrete variables reduces statistical performance, but improves the model by quantifying species differences masked by group assignments.
  • ? To illustrate these advances, we present an example from a tropical forest tree community in which we screened 38 species for nine functional traits. The proposed TropiDEP design is based on the relative orthogonality of two multivariate trait axes defined using principal component analysis.
  • ? We propose that independent variables describing functional diversity might be grouped to calculate independent variables describing suites of different traits with potentially different effects on particular ecosystem processes. In other systems these axes may differ from those reported here, yet the methods of analysis integrating functional and phylogenetic diversity into experimental design could be universal.
  •   相似文献   
    3.
    The objective of this experiment was to test the efficacy of a probiotic (Efinol®L) during transportation of marbled hatchetfish, Carnegiella strigata . Wild specimens were captured from a small stream and transported for 24 h in plastic fish boxes with a probiotic (10 mg L−1) and probiotic-free water. The boxes were sampled at 3, 12 and 24 h of transport. At the end of the experiment, the survival rate was close to 100% in both treatments. Dissolved oxygen diminished with time in both treatments, but the probiotic group had significantly higher levels. Conductivity, pH and ammonia increased significantly during the transport, demonstrating higher levels in the probiotic-free group. Fish from both treatments presented very high net Na+ and K+ effluxes after 3 h of transport. At 24 h, net K+ effluxes in fish of the probiotic treatment reached values close to zero and a significantly lower Na+ efflux was observed. Cortisol levels in both treatments at 3 and 12 h were significantly higher than that in control samples. Higher body cortisol levels were observed in the probiotic-free group than that in the probiotic group at 3 and 12 h. The results demonstrate that addition of a probiotic during fish transport improves water quality and leads to fish presenting a lower stress response intensity.  相似文献   
    4.
    Curcumin-containing nanocapsule powder formulations have not been used in ruminant feed to date, despite the fact that curcumin is known to be a functional food additive. The objective of this study was to determine whether ethyl polymethacrylate (Eudragit L-100) nanocapsules loaded with curcumin (N-CU) would improve health and growth of lambs. Thirty-two male Lacaune lambs (body weight [BW] = 16 ± 0.99 kg; 45 d of age) were randomly assigned to 1 of 4 treatments: T0, T1, T2 and T4, representing supplementation of curcumin at 0, 1, 2, and 4 mg/kg concentrate, respectively. The animals in each treatment were allocated in 4 pens of 2 lambs each (8 lambs per treatment). The experiment lasted 17 d, with samples and measurements collected on d 0, 7, 12, and 17. The T2 lambs had greater average daily gain than T0 lambs. Regression analysis showed that the ideal dose of N-CU to enhance weight gain was 1.89 mg/kg concentrate. There were significant interactions (P < 0.05) between treatments × time for hematological variables, particularly for increases in erythrocytes (T2) and reductions in counts of leukocytes, neutrophils, and lymphocytes in T1 and T2. There were significant interactions between treatment × time for total protein, globulin, urea, and triglyceride levels. Stimulation of the antioxidant system was also observed. There were increased levels of non-protein thiols (NPSH), as well as increased activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) in the supplemented animals. Levels of reactive oxygen species (ROS) were lower in the serum of supplemented lambs. In general, the 4 mg/kg dose had no positive effects on growth or health. This was an unexpected result, given the known properties of curcumin. Taken together, these findings suggest that addition of low concentrations of nanoencapsulated curcumin (T1 and T2) in lamb feed improves health, minimizing oxidative stress and generates anti-inflammatory effects that may have contributed indirectly to greater weight gain. Nanocapsules potentiate the effects of curcumin and may emerge as a new tool in animal nutrition.  相似文献   
    5.
    Loquat is a subtropical fruit tree that presents an annual cycle reverse to that of the well-known temperate fruit crops. Loquat rests during summer, blooms in autumn, develops its fruit through winter and ripens them in early spring. Its unusual phenology allows growers to obtain high prices for its fruits, especially for early harvests. Although loquat is harvested based on skin colour, a minimum soluble solid content (TSS) of 10° Brix is often required for commercialization. However, we have noticed that the relationship between skin colour and eating quality seems to change along the season leading costumers to complain for the high acidity of the earliest fruits. In order to establish a reliable maturity index, we have evaluated the changes in different fruit maturation parameters along the harvest period in four consecutive seasons for ‘Algerie’ loquat. The results show that in samples collected with similar skin colour, TSS and, especially, fruit titratable acidity (TA) tend to decline as harvest season progresses. This makes fruit skin colour on its own not suitable as a harvest index to assure an adequate fruit quality under all circumstances. We propose instead to monitor continuously TSS and TSS/TA ratio along the season in order to fulfill consumer's expectations.  相似文献   
    6.
    –  • Chlorophyll meters such as the SPAD-502 offer a simple, inexpensive and rapid method to estimate foliar chlorophyll content. However, values provided by SPAD-502 are unitless and require empirical calibrations between SPAD units and extracted chlorophyll values.  相似文献   
    7.
    Blood parameters are useful to measure physiological disturbances in chelonians. Thus they can provide important information for the diagnosis and prognosis of diseases. The aim of this paper was to determine the reference range of plasma glucose, total protein, triglycerides, cholesterol and urea levels, as well as hematocrit, hemoglobin, red blood cell, thrombocyte and white blood cell counts for healthy Podocnemis expansa (Schweigger, 1812), bred in a turtle farm in the Amazonas State, Brazil. Plasma glucose, hemoglobin, mean corpuscular volume (MCV), lymphocytes and heterophils were the parameters with the smallest variations. Significant (p < 0.001) correlations between red blood cells count and hematocrit and hemoglobin concentration were found. Turtle P. expansa had lymphocytes, azurophils, heterophils, eosinophils and basophils with morphologic features similar to the ones of others turtles species. No investigated blood parameter was influenced by sex. In further studies, the established reference ranges might be useful for the health assessment of this turtle species.  相似文献   
    8.
    We characterised the among species variability in leaf gas exchange and morphological traits under controlled conditions of seedlings of 22 tropical rainforest canopy species to understand the origin of the variability in leaf carbon isotope discrimination (Δ) among species with different growth and dynamic characteristics (successional gradient). Our results first suggest that these species pursue a consistent strategy in terms of Δ throughout their ontogeny (juveniles grown here versus canopy adult trees from the natural forest). Second, leaf Δ was negatively correlated with WUE and N, and positively correlated with gs, but among species differences in Δ were mainly explained by differences in WUE. Finally, species belonging to different successional groups display distinct leaf functional and morphological traits. We confirmed that fast growing early successional species maximise carbon assimilation with high stomatal conductance. In contrast, fast and slow growing late successional species are both characterised by low carbon assimilation values, but by distinct stomatal conductance and leaf morphological features. Along the successional gradient, these differences result in much lower Δ for the intermediate species (i.e. fast growing late successional) as compared to the two other groups.  相似文献   
    9.
    Periphyton and sediment samples were collected from 12 stations along Bayou d'Inde, a very polluted waterway, in Southwestern Louisiana. The samples were analyzed for Zn, Cu, Pb, Ni, Fe, Cr, Al, Cd, and Ag. When metal concentrations in periphyton or sediment are plotted vs sampling station, the metal distributions clearly indicate a major point source of metals at one station which is located at the mouth of an industrial ditch. Metal levels in periphyton generally parallel those found in surface sediments at the same location, but metal levels in periphyton are generally higher than in sediment from the same location, indicating an enrichment over sediment values. For sediments two types of extraction were investigated using leaching with concentrated HNO3 in a high-pressure decomposition vessel and shaking with 1 N HCl for 2 hr. Both methods correlate well for all metals except Ni, but HNO3 extracted more total metal. Correlations between periphyton and sediment were best for Pb, Fe, and Ag. Poorest correlations were seen for Mn, Ni, and Cd. When periphyton and sediment metal concentrations were normalized to Fe, Mn, and Al, correlation factors for some metals improved while others deteriorated.  相似文献   
    10.
    Preureteral vena cava (circumcaval ureter, retrocaval ureter) occurs in a third of the feline population and has been associated with ureteral strictures in humans. The aim of this retrospective cross‐sectional study was to describe the contrast‐enhanced multidetector row computed tomographic (MDCT) characteristics of presumed preureteral vena cava in a group of cats. Medical records from two institutions located in different continents were searched from 2010–2013 for cases with complete contrast‐enhanced MDCT examinations of the abdomen (i.e. included the entire course of the ureters and prerenal and renal segments of the caudal vena cava) and a diagnosis of preureteral caudal vena cava. For cases meeting inclusion criteria, CT scan data were retrieved and characteristics of the preureteral caudal vena cava were recorded. Presence of concomitant renal or ureteral diseases was also recorded. A total of 272 cats had contrast‐enhanced abdominal CT scans during the study period and of these, 68 cats (22.43 ± 4.96%) had a diagnosis of presumed preureteral vena cava. In all affected cats, a “reverse‐J ureter” was observed, i.e. a ureter running medially at the level of L4–5, passing dorsally to the caudal vena cava and then exiting ventrally between the caudal vena cava and aorta returning to its normal position. Having a preureteral vena cava resulted in an increased risk for concurrent urinary signs (OR = 3.00; CI: 95%; 1.28–6.99; P = 0.01). Findings supported the use of contrast‐enhanced MDCT for characterizing morphology of preureteral vena cava and its relation with ureters in cats.  相似文献   
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