1,721,051 research outputs found
Estimating oxygen consumption of rainbow trout (Oncorhynchus mykiss) in a raceway: a precision fish farming approach
Full text linkThe Precision Fish Farming (PFF) approach was applied to the estimation of fish oxygen consumption of rainbow trout in a raceway farm. A dynamic model, simulating the evolution of Dissolved Oxygen concentration, was identified: the daily oscillation of fish oxygen consumption rate was simulated by means of a sinusoidal function. The model was applied to the data set collected during a four-week field study, which was carried out in July 2019. Water temperature and Dissolved Oxygen concentration were measured with an hourly frequency in farm influent and effluent. Fish biomass was monitored on a daily basis by combining the data provided by a state-of-the art system for non-invasive estimation of fish weight distribution with mortality counting. The monitoring period was partitioned into two time-windows, as fish was not fed during the first two weeks. These windows were further partitioned into a calibration and validation set. Three model parameters, i.e. the average daily respiration rate, the amplitude of its daily oscillation, and its phase were estimated by fitting the model output to the time series of DO concentration in the effluent. The results of the calibration show that: 1) the daily average oxygen consumption rate is consistent with the literature; 2) the amplitude of the daily oscillation when fish is regularly fed is more than twice that estimated for fasting fish. The results of the validation suggest that the model could be used to implement a cost-effective automatic control of oxygen supply, based on the short-term prediction of oxygen deman
Changes in middle cerebral artery blood velocity in uremic patients after hemodialysis.
No full textBACKGROUND AND PURPOSE: Strokes are a frequent complication in uremic patients on dialysis. We wanted to evaluate the effect of this treatment on cerebral hemodynamic parameters, particularly those of patients with carotid stenosis, who are at higher risk for atherothrombotic ischemic events. METHODS: We used transcranial Doppler ultrasonography to evaluate blood velocity of the middle cerebral artery in 18 uremic patients before and after hemodialysis. Carotid stenosis was evaluated by echo-Doppler investigation. Six patients were also studied before and after recombinant human erythropoietin treatment. RESULTS: Dialysis treatment decreased mean blood velocity in all patients (p less than 0.001). Eight of 18 patients (44%) with mild (16-50%), moderate (51-80%), or severe (greater than 80%) carotid stenosis had lower velocity than patients with normal carotid arteries (p less than 0.01), and they experienced a further decrease to even lower levels after hemodialysis (p less than 0.05). In patients treated with recombinant human erythropoietin, hematocrit increased from 28 +/- 8% to 37 +/- 5% (p less than 0.001), and blood velocity had a further decrease by 11%. All changes were associated with modifications toward normality of pH, PaCO2, and hematocrit. CONCLUSIONS: Transcranial Doppler ultrasonography represents a useful method for monitoring cerebral circulation of uremic patients, especially of those at possible risk for ischemia
From feed to fork: life cycle assessment on an Italian rainbow trout (Oncorhynchus mykiss) supply chain
No full textThe body of knowledge in trout farming sustainability is still not exhaustive, mainly due to the variability in the production system and in the methodological approach and partly to data quality issues. As such, Life Cycle Assessment (LCA) was applied to a trout supply chain located in Northern Italy, basing the inventory dataset almost entirely on primary data gathered from producers and extending the system boundaries beyond the conventional farm-gate, in order to include: phase 1. feed production; phase 2. trout grow-out in freshwater flow-through systems; phase 3. trout processing into foodstuff; phase 4. fish by-products processing into pet-food ingredients.
The results highlight that, while resource sharing in phase 3 is a winning practice and leads to decrease in environmental impacts, the other three phases present crucial aspects which require either technological or methodological improvements. Firstly, the relative contribution of feed ingredients is very high, with respect to all the impact categories considered. Secondly, despite on-farm effluents account alone for 92% of downstream river eutrophication (phase 2), data from rivers environmental monitoring prove this result to be an overestimation, due to the fact that LCA does not adequately cover proximate ecological concerns as yet. Finally, the energy demand for the recovery and recycling of the fish by-products (phase 4) is high, causing a high impact on global warming, terrestrial ecotoxicity, freshwater ecotoxicity and cumulative energy demand.
In order to improve the overall sustainability of the supply chain, changes are required mainly in the feed production and by-product processing phases. As far as the former is concerned, a winning strategy would be the formulation of feeds with more sustainable feed ingredients and further improvements in the feed quality (palatability, digestibility, nutritional content). In regard to the latter, more attention should be paid towards the source and amount of energy consumed. For instance, the use of renewable energy sources might be coupled with an improved insulation of the facilities and the use of less energivorous machineries/processes
Effect of including a seaweed meal in the diet on slaughter yield and major quality traits of rainbow trout (Oncorhynchus mykiss Walbaum, 1792)
No full textSeaweeds are promising ingredients for aquafeed for improving fish growth and as source of n3
fatty acids. The present study aimed at assessing the effects on marketable and qualitative traits of rainbow
trout (Oncorhynchus mykiss Walbaum, 1792) fillets of a low-level inclusion (5%) of a commercial mix of
seaweed formulation in a soybean-rich diet. The fish were fed for 12 weeks and sampled immediately after
the acclimation period (T0), after 6 weeks (T1) and 12 weeks (end of the trial, T2). Six fish per treatment
were sacrificed at each sampling, individually weighed and submitted to the sectioning to obtain the body
components that, after measurements, were needed to calculate the marketable indexes (condition factor,
dressed and fillet yields, hepatosomatic index and viscerosomatic index). On fillets, physical properties
such as pH, texture and color were measured and the cholesterol content, the proximate and the fatty acid
composition were analyzed. Results revealed that the inclusion of seaweed mixture in a soybean rich diet
significantly affected fillet yield and hepatosomatic index after 12 weeks of administration. The physical
parameters of muscle, such as color, pH, water holding capacity and texture were not modified in
comparison to the vegetable rich diet. Slight modifications in the proximate composition emerged at the end
of the trial, especially concerning the protein content, which increased in parallel to a decrease of lipid
content. However, the fatty acid profile of the muscle was deeply modified by the administered diets in
comparison to the first 6 weeks. The inclusion level of seaweeds utilized in the present study was not
sufficient for improving PUFAn-3 level of a diet rich in vegetable protein and oi
Idiopathic facial aseptic granuloma in a child: a possible expression of childhood rosacea
No full textSmall dense low-density lipoprotein in familial combined hyperlipidemia: Independent of metabolic syndrome and related to history of cardiovascular events.
No full text1. Atherosclerosis. 2009 Mar;203(1):320-4. Epub 2008 Jul 12. Small dense low-density lipoprotein in familial combined hyperlipidemia: Independent of metabolic syndrome and related to history of cardiovascular events. Pauciullo P, Gentile M, Marotta G, Baiano A, Ubaldi S, Jossa F, Iannuzzo G, Faccenda F, Panico S, Rubba P. Department of Clinical and Experimental Medicine, University Federico II Medical School, Nuovo Policlinico, Edificio 1, Via Pansini 5 - 80131 - Naples, Italy. [email protected] INTRODUCTION: It is unclear whether small dense low-density lipoprotein (sdLDL) are associated with familial combined hyperlipidemia (FCHL), independently of the metabolic syndrome (MS). It is also unclear whether sdLDL are related to history of cardiovascular (CVD) events in FCHL patients, independently of MS. PATIENTS AND METHODS: Serum levels of sdLDL, expressed as percentage of total LDL cholesterol (LDL score), were determined in 137 probands with FCHL and in 133 normolipidemic, normotensive, normoglycemic healthy subjects. RESULTS: In binary logistic regression age- and gender-adjusted LDL score values above the 90th and 95th percentiles of the values in the control group (10.23 and 13.11%, respectively) were found to be significant predictors of FCHL status, independently of MS diagnosis (p=0.007 and p<0.0001, respectively). Values of the LDL score above the 90th and the 95th percentile of the control group resulted to be significantly related to FCHL status, even after adjustment for the components of MS (p=0.006 and p=0.001, respectively). Among FCHL patients, values of the LDL score above 95th percentile of the values in the control group were found to be significantly related to personal and/or family history of CVD events, independently of age, gender, total cholesterol, apolipoprotein (apo) B, and MS status (p=0.016). The same significant relationship was found adjusting for all components of MS (p=0.034). CONCLUSIONS: High concentrations of sdLDL are highly specific markers of FCHL, independently of concomitant MS. In FCHL patients high levels of sdLDL are related to history of CVD events, independently of MS, total cholesterol and apo B. PMID: 18760784 [PubMed - indexed for MEDLINE
Growth performance of different rainbow trout(Oncorhynchus mykiss)strains reared in Trentino (Northern Italy)
No full textWe will present some results of an ongoing project aimed at
analysing the major biotic and abiotic factors that influence the
rainbow trout (O. mykiss) productive yield in the Trentino region
(Northern Italy). Five trout strains were compared for their overall
farming performance and suitability to be reared in the local
farms. Eyed-egg samples of different strains were obtained from
local and foreign suppliers. In the first part of the trial, the
strains were compared in terms of egg size, hatching and growth
rates up to the parr stage in a single farm and the intraspecific
genetic variability was assessed using a microsatellites technique
by analysing DNA extracted from random samples of caudal
fin tissue. Significant among-strains differences in growth
performance were found after 8 rearing months. In the second
phase of the trial, parrs of each strain were divided into 4 lots.
Then the lots of the 5 strains were transferred to 4 selected
Trentino trout farms to carry out a performance test up to a market
size of around 0.7 kg. Regardless of the location, all fish lots
were kept at the same density and were fed the same commercial
trout feed, six days a week. Individual weight and length were
measured on random samples of 100 fish per lot every 2 months.
At the same time, major water parameters were registered in the
different farms. Specific growth rate (SGR), thermal growth rate
(TGR), condition factor and feed conversion ratio (FCR) were
calculated. Statistical analyses were performed with SAS and
STATISTICA 9.0. The growth graphs fit quadratic equations and
average daily gain ranged from 1.46 to 1.77 g. Among-strains differences
in growth performance, condition factor, feed conversion
and age at sexual maturity were found at market size
- …
