Antibiotics and malachite green residues in farmed rainbow trout (Oncorhynchus mykiss) from the Iranian markets: A risk assessment

ABSTRACTAntibiotic and malachite green residues in farmed rainbow trout muscles were determined by high-performance liquid chromatography for a food risk assessment. The surveillance was carried out on total of 120 rainbow trout fillets, all fishes were randomly sampled from 20 fish markets of Iran. All antibiotics were detected in the range of 0.42–1.20 μg/g for Oxytetracycline, 0.02–0.34 μg/g for Enrofloxacin, 0.21–2.61 μg/g for Florfenicol, and finally 0.02–0.89 μg/g for Malachite green. Our results showed that 99 (82.5%), 36 (30%), 56 (46.6%), and 70 (58.4%) samples contained detectable residues of Oxytetracycline, Enrofloxacin, and Florfenicol antibiotics, and Malachite green, respectively. Our results showed that fish farmers use these drugs in large scale. Further investigations are needed to prevent: the foodborne risk to consumers, the possible environmental contamination, and the antimicrobial resistances

Assessment of Base Flow Separation Methods at Karaj Dam Watershed

Assessing existing water resources along with different routes of the river in a watershed is essential for its optimum use, conservation, and predicting flood and minimum flow. In addition, identification of runoff production processes is also important for assessing the effects of climate change and landuse on the hydrologic response of the watershed. There are several methods for separating base flow. In this study, the minimum local methods, sliding intervals, fixed intervals, one -parameter recursive digital filter and two -parameters recursive digital filter method were used for separating base flow at four hydrometric stations of Karaj River basin with a statistical period of 22 years (1991-2012). Then, the results were compared to determine the most appropriate method. The results showed that at Sierra-Kalvan and Nashtarod stations, the one-parameter recurrsive filter method with alpha of 0.925 and 0.950 could be a suitable method for estimating the base flow, due to the lack of significant differences between their results, as well as the minimum standard deviation. For Mored and Sierra stations, the one -parameter recursive digital filter with alpha values ​​of 0.950 and 0.975 was considered as a suitable method in separating base flow because of the lack of significant differences between their results as well as the standard deviation. The one -parameter recursive digital filter, therefore, has high spped in separating the flow hydrograph and can determine the continuous values of base flow

Effects of dietary rainbow trout visceral protein hydrolysate on hematological, immunological and biochemical serum parameters and antioxidant enzymes of juvenile Siberian sturgeon, Acipenser baerii

This study evaluated the effect of different levels of dietary rainbow trout by-product protein hydrolysate on hematological, immunological and biochemical serum parameters and antioxidant enzymes of juvenile Siberian sturgeon (Acipenser baerii). For this purpose, 300 fish with an average weight of 67 ± 3 g were distributed in 12 tanks and were fed for 56 days with different levels of by-product protein hydrolysate (PH) in 4 treatments including 0 (control), 5g (5PH), 10g (10PH) and 20g (20PH per kg of feed. The highest white blood cell count and hematocrit percentage were observed in the treatments of 10PH and 20PH which was significantly different from those fed with 5PH and control (p<0.05). The highest amount of the serum glucose and the lowest amount of triglyceride were obtained in 10PH and 20PH. Fish fed 10PH and 20PH exhibited lower levels of AST and ALP enzymes than the control group (p<0.05). Evaluation of serum immune indices showed that there was a significant difference in IgM, C3, ACH50 and serum respiratory burst activity of fish fed 10PH compared to other treatments (p<0.05). Also, lysozyme activity, total protein content, complement component C4 in fish fed with 10PH and 20PH displayed a significant difference with 5PH and control group (p<0.05). In this study, serum superoxide dismutase and catalase indices in 10PH and 20PH revealed a significant difference with other treatments (p<0.05), in addition to the activity of the glutathione peroxidase (p<0.05). Overall, effects of PH, especially 10PH on the examined indices in Siberian Sturgeon were positive and significant

Experimental study to evaluate the pathogenicity of Streptococcus iniae in Guppy (Poecilia reticulata)

Streptococcus iniae has emerged as an important fish pathogen over the last decade in farmed rainbow trout in Iran. The main objective of this study was to evaluate the pathogenicity of S. iniae in Poecilia reticulata. Atotal of 60 apparently healthy P. reticulata were obtained from ornamental fish pet store and injected intraperitoneally with 1.5×106 cfu of bacteria. For 14 days after challenge, the rate of mortality and clinical signs were recorded. The first clinical signs was observed in challenged fish 48 hrs after injection of S. iniae and first mortality was observed 72 hrs after injection. No significant differences in mortality and clinical signs between both sexes were observed. Streptococcus iniae was collected from internal organs of fishes challenged, and was confirmed using the conventional biochemical tests and PCR. It is concluded that, P. reticulata is susceptible to streptococcosis and can play an important role in transmission of the disease to other ornamental fish species and also cultured fish

Temperature effects on the design parameters of a geothermal pile

In geotechnical engineering, geostructures with thermo-active functions establish direct thermal exchange between the ground and buildings. They can transfer energy from or into the ground to heat or cool a building. However, adapting foundation piles, completely or in part, to produce energy piles results in heat exchange with the soil, which changes the temperature of the soil and could thereby and affects the geotechnical properties and load bearing capacity of the geostructure. Most calculations of the bearing capacities of deep foundations conducted in France are currently based on in-situ testing results using a pressuremeter. Using finite element method to model the pressuremetric behaviour of a compacted soil subjected to thermo-mechanical variations is the main motivation for this work. In this study, several pressuremeter tests were conducted on a compacted illitic soil in a laboratory tank at temperatures between 1° and 40°C. The impact of temperature variation on the limit pressure (Pl), the creep pressure (Pf) and the Ménard pressuremeter modulus (EM) were determined. The results showed a significant decrease for both limit pressure (Pl) and creep pressure (Pf) with the increase of temperature. Numerical simulations of these tests were used to calibrate a bilinear constitutive model, taking into account temperature effects on soil compressibility within a coupled thermo-mechanical framework. Thereafter, a case study of a heat exchanger pile was simulated using the proposed approach

Metformin inhibits polyphosphate-induced hyper-permeability and inflammation

Circulating inflammatory factor inorganic polyphosphate (polyP) released from activated platelets could enhance factor XII and bradykinin resulted in increased capillary leakage and vascular permeability. PolyP induce inflammatory responses through mTOR pathway in endothelial cells, which is being reported in several diseases including atherosclerosis, thrombosis, sepsis, and cancer. Systems and molecular biology approaches were used to explore the regulatory role of the AMPK activator, metformin, on polyP-induced hyper-permeability in different organs in three different models of polyP-induced hyper-permeability including local, systemic shortand systemic long-term approaches in murine models. Our results showed that polyP disrupts endothelial barrier integrity in skin, liver, kidney, brain, heart, and lung in all three study models and metformin abrogates the disruptive effect of polyP. We also showed that activation of AMPK signaling pathway, regulation of oxidant/ anti-oxidant balance, as well as decrease in inflammatory cell infiltration constitute a set of molecular mechanisms through which metformin elicits it's protective responses against polyP-induced hyper-permeability. These results support the clinical values of AMPK activators including the FDA-approved metformin in attenuating vascular damage in polyP-associated inflammatory diseases.Peer reviewe

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10&nbsp;years; 78.2% included were male with a median age of 37&nbsp;years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020