10 research outputs found

    Nanoplastics affect moulting and faecal pellet sinking in Antarctic krill (Euphausia superba) juveniles

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    Plastic debris has been identified as a potential threat to Antarctic marine ecosystems, however, the impact of nanoplastics (<1 μm) is currently unexplored. Antarctic krill (Euphausia superba) is a keystone species of Southern Ocean pelagic ecosystems, which plays a central role in the Antarctic food webs and carbon (C) cycle. Krill has been shown to rapidly fragment microplastic beads through the digestive system, releasing nanoplastics with unknown toxicological effects. Here we exposed krill juveniles to carboxylic (COOH, anionic) and amino- (NH2, cationic) polystyrene nanoparticles (PS NPs) and we investigated lethal and sub-lethal endpoints after 48 h. The analysis of PS NP suspensions in Antarctic sea water (SW) media showed that PS-COOH formed large agglomerates (1043 ± 121 nm), while PS-NH2 kept their nominal size (56.8 ± 3 nm) during the exposure time. After 48 h, no mortality was found but increase in exuviae production (12.6 ± 1.3%) and reduced swimming activity were observed in juveniles exposed to PS-NH2. The microbial community composition in SW supports the release of krill moults upon PS NP exposure and stimulates further research on the pivotal role of krill in shaping Southern Ocean bacterial assemblages. The presence of fluorescent signal in krill faecal pellets (FPs) confirmed the waterborne ingestion and egestion of PS-COOH at 48 h of exposure. Changes in FP structure and properties were also associated to the incorporation of PS NPs regardless of their surface charge. The effects of PS NPs on krill FP properties were compared to Control 0 h as a reference for full FPs (plastic vs food) and Control 48 h as a reference for more empty-like FPs (plastic vs lack of food). Exposure to PS NPs led to a FP sinking rate comparable to Control 48 h, but significantly lower than Control 0 h (58.40 ± 23.60 m/d and 51.23 ± 28.60 m/d for PS-COOH and PS-NH2; 168.80 ± 74.58 m/d for Control 0 h). Considering the important role played by krill in the food web and C export in the Southern Ocean, the present study provides cues about the potential impact of nanoplastics on Antarctic pelagic ecosystems and their biogeochemical cycles

    The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

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    The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF)

    Induction of CYP1A and ABC transporters in European sea bass (Dicentrarchus labrax) upon 2,3,7,8-TCDD waterborne exposure

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    The aim of this study was to characterize the responsiveness of CYP1A and ABC transport proteins in European Sea bass (Dicentrarchus labrax) waterborne exposed to 2,3,7,8-tetrachlorodibenzo- p-dioxin (2,3,7,8-TCDD) (46 pg/L) for 24 h and 7 days. Genes modulation (abcb1, abcc1. -2, cyp1a), EROD activity were investigated in liver and 2,3,7,8-TCDD bioconcentration in liver and muscle. TCDD induced significantly cyp1a gene expression and EROD activity at 24 h and 7 d. A significant up-regulation of abcb1 was also observed but only after 7 days. No modulation of abcc1 and abcc2 genes was observed. Waterborne TCDD exposure was able to induce CYP1A and abcb1 encoding for P-glycoprotein in juvenile of European sea bass

    Characterization of CYP1A and gene expression profiling in three mysticete species

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    7sireservedThe Cytochrome P450 1A (CYP1A) gene of the three balenopterids Balaenoptera edeni (Bryde's whale), B. musculus (blue whale) and B. physalus (fin whale) has been characterized in this work to compare significant differences in the gene sequence related to its function and to compare the gene expression profile in the three species. CYP1A is of the most important enzyme involved in the bioactivation of exogenous compounds and its activity is well known to be induced after contaminants' exposure, in particular to persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) which can be bioaccumulated in the whales' blubber. We used non-lethal sampling methods to obtain skin biopsies from the specimens in the Gulf of California (Mexico). Since the cetacean's CYP is poorly investigated, we fully amplified, cloned and sequenced the gene in these very closely related specieswhich, however, differs in feeding habits (zooplanktonic vs fish-eating species) and migratory behavior (resident vs. migratoryspecies). Once obtained the full sequences of the CYPs in all the three species, mRNA levels were quantified by quantitative Real-Time PCR. Interestingly, the highest up-regulation of the gene was found in the fish-eating species Bryde'swhale, that also presents regionswith higher homology to the odontocetes species thanmysticetes. The lowestmRNA values were found in the resident species fin whale and the blue whale showed intermediate values. On this regard, the blue whale (zooplanktonic species) accumulates high concentration of POPs during the migration southwards to the Gulf of California while the fin whale (zooplanktonic species) is resident in the Gulf. Moreover the fish-eating species Bryde's whale, resident in the Gulf, showed the lowest levels of POPs in blubber. In conclusion, the diet and the migratory behavior and the evolution of CYP1A gene of the three species investigated could explain the different responses of CYP1A in metabolism of POPs.mixedPanti, C.; Urban, J.; Vannuccini, M.L.; Maltese, S.; Marsili, L.; Frati, F.; Fossi, M.C.Panti, C.; Urban, J.; Vannuccini, M. L.; Maltese, S.; Marsili, L.; Frati, F.; Fossi, M. C

    Influence of titanium dioxide nanoparticles on 2,3,7,8-tetrachlorodibenzo-p-dioxin bioconcentration and toxicity in the marine fish European sea bass (Dicentrarchus labrax)

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    The present study investigated the influence of nano-TiO2 (1 mg L-1) on 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) (46 pg L-1) bioconcentration and toxicity in the European sea bass (Dicentrarchus labrax) during 7 days in vivo exposure. A multimarkers approach was applied in different organs: detoxification in liver; innate immunity and pro-inflammatory response and adaptive immunity in gills and spleen; genotoxicity in peripheral erythrocytes and muscle. Bioconcentration of 2,3,7,8-TCDD in presence of nano-TiO2 was investigated in liver, skin and muscle as well as interaction between nano-TiO2 and organic pollutants in artificial sea water (ASW). Nano-TiO2 negatively influenced immune response induced by 2,3,7,8-TCDD in spleen but not in gills and reduced the DNA damage induced by 2,3,7,8-TCDD in erythrocytes. nano-TiO2 did not interfere with 2,3,7,8-TCDD detoxification and bioconcentration according to the observed no interaction of the nano-TiO2 with organic pollutants in ASW

    Performance of PSI, CURB-65, and SCAP scores in predicting the outcome of patients with community-acquired and healthcare-associated pneumonia

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    The objective was to compare three score systems, pneumonia severity index (PSI), the Confusion-Urea-Respiratory Rate-Blood pressure-65 (CURB-65), and severe community-acquired pneumonia (SCAP), for prediction of the outcomes in a cohort of patients with community-acquired (CAP) and healthcare-associated pneumonia (HCAP). Large multi-center, prospective, observational study was conducted in 55 hospitals. HCAP patients were included in the high classes of CURB-65, PSI and SCAP scores have a mortality rate higher than that of CAP patients. HCAP patients included in the low class of the three severity rules have a significantly higher incidence of adverse events, including development of septic shock, transfer into an ICU, and death (p < 0.01). At multivariate Cox regression analysis, inclusion in the severe classes of PSI, CURB-65, or SCAP scores and receipt of an empirical therapy not adherent to international guidelines prove to be risk factors independently associated with poor outcome. PSI, CURB-65, and SCAP score have a good performance in patients with CAP but are less useful in patients with HCAP, especially in patients classified in the low-risk classes

    The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

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    The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF)
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