73 research outputs found
Identification and quantification of polystyrene microplastics in marine sediments facing a river mouth through NMR spectroscopy
Accurate identification and quantification of microplastic pollution in marine sediments are crucial for assessing their ecological impact. In this study, we explored the potential of Nuclear Magnetic Resonance (NMR) spectroscopy as an analytical tool for the analysis of microplastics in complex environmental matrices such as marine sediments. Two common plastic polymers, polystyrene (PS) and acrylonitrile butadiene styrene (ABS), were investigated. The marine sediments facing the Tiber River mouth (Italy) were collected according to a bathy-metric gradient. Results demonstrated the successful detection and quantification of PS in all sediment samples (within a range of 12.3-64.6 mu g/L), while no ABS significant signals were found. An increment trend with depth was observed in the PS signal, relatable to its physicochemical properties and the Tiber River plume hydrodynamic characteristics. The NMR's non-destructive nature and minimal sample preparation represent a promising avenue for standardizing protocols to assess the microplastic distribution and impact in marine sediments
Observations on development and anomalies in the appendicular skeleton of sea bass, Dicentrarchus labrax L. 1758, larvae and juveniles
The development of the fin skeleton has been studied in both the wild and hatchery sea bass, Dicentrarchus labrax L., larvae, in order to identify and define morphofunctional criteria for larval quality assessments. The cartilaginous and bony skeletal elements of the larvae were studied and standard length and notochord flexure recorded. Fin anomalies were present in reared larvae, whereas they were rare or absent in specimens from the wild. These anomalies were recognizable from the very beginning of skeletal development, indicating that environmental, genetic and broodstock management factors influence even the very early stages of larval development
Skeletal anomalies in gilthead seabream (Sparus aurata) larvae reared in different densities and water volumes
This study describes the effects on the skeletal phenotype of two pivotal factors, density and water volume, don the hatchery (larval) phase of gilthead seabream (Sparus aurata) larvae previoulsy described for two model species (Danio rerio and Oryzias latipes) and sub-adult (pre-ongrowing) gilthead seabream (Sparus aurata). The experimental trial was conducted using single conditions in a pilot study, starting with a total of 615,385 eggs from the same batch. Three densities (LD low density: 25 larvae/L; MD medium density: 125 larvae/L; and HD high density: 250 larvae/L) and two water volumes (500 and 1000 L) were tested from spawning up to 60 days post-hatching (dph) (average standard length: 1.79 cm; average dry weight: 27.11 mg). On the final samples, morphometric, anatomical, and histological data were collected for data pertinent to meristic counts and skeletal anomalies. The results (analyzed by means of multivariate analyses) indicated that the LD-reared larvae were significantly longer and heavier than HD-reared fish. Furthermore, LD-reared gilthead seabream exhibited a significant reduction in the frequency of individuals with anomalies of jaws, vertebral body shape, and vertebral arches than the MD and HD conditions, which is in agreement with previous experiments carried out on model species and gilthead seabream sub-adults
Effects of the dietary supplementation of copper on growth, oxidative stress, fatty acid profile and skeletal development in gilthead seabream (Sparus aurata) larvae
The effect of dietary copper (Cu) levels on growth, oxidative stress, fatty acid profile and bone health of gilthead seabream larvae (Sparus aurata) was studied in 47 days-post-hatching fish fed 4 experimental diets containing 17, 18, 19 and 25 mg Cu/kg diet. After 21 days of feeding, larval growth and survival were not affected by the dietary Cu levels. However, larvae fed the non-supplemented diet (17 mg Cu/kg) showed clear symptoms of Cu deficiency, including increased lipid peroxidation and reduced bone mineralization. Increased peroxidation risk caused a reduction in essential fatty acids and n-3 PUFA (polyunsaturated fatty acids) contents in whole body lipids, whereas the poor vertebral body mineralization in seabream larvae was related to a marked increase in abdominal vertebrae anomalies. On the contrary, dietary Cu supplementation raised whole-body contents in DHA, EPA and n-3 PUFA and reduced MUFA, TBARS and the incidence of severe, cranial, branchiostegal rays and abdominal vertebral anomalies. Polynomial regression models applied to all these parameters suggested optimum dietary Cu levels to be 21.5–22.6 mg/kg in gilthead seabream larvae microdiets supplemented with CuSO4.5H2O. These levels (21.5–22.6 mg/kg) are in the range of the Cu contents in copepods (12–38 mg/kg) and on the verge of the dietary levels authorized by EU Commission in feeds for cultured fish species (25 mg Cu/kg diet).publishedVersio
Skeletal Anomalies in Senegalese Sole (Solea senegalensis, Kaup) Fed with Different Commercial Enriched Artemia: A Study in Postlarvae and Juveniles
The high incidence of skeletal anomalies in Senegalese sole (Solea senegalensis) still constitutes a bottleneck constraining its production. There are diverse commercially available products for the enrichment of live preys, but few reports of their influence on skeletogenesis in Senegalese sole. This study evaluated the presence of vertebral anomalies in postlarvae and juvenile Senegalese sole fed with Artemia spp. metanauplii enriched with four commercial products (EA, EB, EC, and ED) in a fish farm. The most frequent alterations consisted of deformations of the neural/haemal arches and spines and fusions and deformations of hypurals, epural, or parhypural. The correspondence analysis ordered fish from each age in separated semiaxis, indicating the presence of different anomaly patterns for the two sampled stages. The results showed only very light changes in the frequency of vertebral abnormalities among tested enrichment products, i.e., individuals from EC and EA lots displayed less vertebral body anomalies and/or vertebral column deviations at 31 and 105 days after hatching, respectively. The existence of a large shared malformation pattern in all the experimental groups leads to impute to the rearing conditions as the main driving factor of the onset of such group of anomalies, probably masking some dietary effectThis research was funded by “Consellería de Economía e Industria” of Xunta de Galicia (10MMA020E) and Stolt Sea Farm and by “Programa de Consolidación e Estructuración de Unidades de Investigación Competitivas GPC2015/034”, SpainS
Distinguishing the effects of Water volumes versus stocking densities on the skeletal quality during the Pre-Ongrowing Phase of Gilthead Seabream (Sparus aurata)
Gilthead seabream (Sparus aurata) production is a highly valued aquaculture industry
in Europe. The presence of skeletal deformities in farmed gilthead seabream represents a major
bottleneck for the industry leading to economic losses, negative impacts on the consumers’ perception
of aquaculture, and animal welfare issues for the fish. Although past work has primarily focused on
the hatchery phase to reduce the incidence of skeletal anomalies, this work targets the successive preongrowing phase in which more severe anomalies affecting the external shape often arise. This work
aimed to test the effects of: (i) larger and smaller tank volumes, stocked at the same density; and (ii)
higher and lower stocking densities maintained in the same water volume, on the skeleton of gilthead
seabream fingerlings reared for ~63 days at a pilot scale. Experimental rearing was conducted with
gilthead seabream juveniles (~6.7 ± 2.5 g), which were selected as ‘non-deformed’ based on external
inspection, stocked at three different densities (Low Density (LD): 5 kg/m3
; Medium Density (MD):
10 kg/m3
; High Density (HD): 20 kg/m3
) in both 500 L and 1000 L tanks. Gilthead seabream were
sampled for growth performance and radiographed to assess the skeletal elements at the beginning
and end of the experimental trial. Results revealed that (i) LD fish were significantly longer than
HD fish, although there were no differences in final weights, regardless of the water volume; (ii) an
increase in the prevalence of seabream exhibiting cranial and vertebral axis anomalies was found to
be associated with increased density. These results suggest that farmers can significantly reduce the
presence of some cranial and axis anomalies affecting pre-ongrown gilthead seabream by reducing
the stocking density.info:eu-repo/semantics/publishedVersio
Versatile Application of rfid technology to commercial and laboratory research contexts: fresh fish supply-chain and behavioural tests
Peer Reviewe
Empirical Evaluation of Deep Learning Approaches for Landmark Detection in Fish Bioimages
In this paper we perform an empirical evaluation of variants of deep learning methods to automatically localize anatomical landmarks in bioimages of fishes acquired using different imaging modalities (microscopy and radiography). We compare two methodologies namely heatmap based regression and multivariate direct regression, and evaluate them in combination with several Convolutional Neural Network (CNN) architectures. Heatmap based regression approaches employ Gaussian or Exponential heatmap generation functions combined with CNNs to output the heatmaps corresponding to landmark locations whereas direct regression approaches output directly the (x, y) coordinates corresponding to landmark locations. In our experiments, we use two microscopy datasets of Zebrafish and Medaka fish and one radiography
dataset of gilthead Seabream. On our three datasets, the heatmap approach with Exponential function and U-Net architecture performs better. Datasets and open-source code for training and prediction are made available to ease future landmark detection research and bioimaging applications.2. Zero hunger3. Good health and well-being9. Industry, innovation and infrastructur
Fatality rate and predictors of mortality in an Italian cohort of hospitalized COVID-19 patients
Clinical features and natural history of coronavirus disease 2019 (COVID-19) differ widely among different countries and during different phases of the pandemia. Here, we aimed to evaluate the case fatality rate (CFR) and to identify predictors of mortality in a cohort of COVID-19 patients admitted to three hospitals of Northern Italy between March 1 and April 28, 2020. All these patients had a confirmed diagnosis of SARS-CoV-2 infection by molecular methods. During the study period 504/1697 patients died; thus, overall CFR was 29.7%. We looked for predictors of mortality in a subgroup of 486 patients (239 males, 59%; median age 71 years) for whom sufficient clinical data were available at data cut-off. Among the demographic and clinical variables considered, age, a diagnosis of cancer, obesity and current smoking independently predicted mortality. When laboratory data were added to the model in a further subgroup of patients, age, the diagnosis of cancer, and the baseline PaO2/FiO2 ratio were identified as independent predictors of mortality. In conclusion, the CFR of hospitalized patients in Northern Italy during the ascending phase of the COVID-19 pandemic approached 30%. The identification of mortality predictors might contribute to better stratification of individual patient risk
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