Macro- and Microplastics in the Antarctic Environment: Ongoing Assessment and Perspectives

The number of scientists and tourists visiting Antarctica is on the rise and, despite the management framework for environmental protection, some coastal areas, particularly in the Antarctic Peninsula region, are affected by plastic contamination. The few data available on the occurrence of microplastics (<5 mm) are difficult to compare, due to the different methodologies used in monitoring studies. However, indications are emerging to guide future research and to implement environmental protocols. In the surface and subsurface waters of the Southern Ocean, plastic debris >300 p.m appears to be scarce and far less abundant than paint chips released from research vessels. Yet, near some coastal scientific stations, the fragmentation and degradation of larger plastic items, as well as microbeads and microfibers released into wastewater from personal care products and laundry, could potentially affect marine organisms. Some studies indicate that, through long-range atmospheric transport, plastic fibers produced on other continents can be deposited in Antarctica. Drifting plastic debris can also cross the Polar Front, with the potential to carry alien fouling organisms into the Southern Ocean. Sea ice dynamics appear to favor the uptake of microplastics by ice algae and Antarctic krill, the key species in the Antarctic marine food web. Euphausia superba apparently has the ability to fragment and expel ingested plastic particles at the nanoscale. However, most Antarctic organisms are endemic species, with unique ecophysiological adaptations to extreme environmental conditions and are likely highly sensitive to cumulative stresses caused by climate change, microplastics and other anthropogenic disturbances. Although there is limited evidence to date that micro- and nanoplastics have direct biological effects, our review aims at raising awareness of the problem and, in order to assess the real potential impact of microplastics in Antarctica, underlines the urgency to fill the methodological gaps for their detection in all environmental matrices, and to equip scientific stations and ships with adequate wastewater treatment plants to reduce the release of microfibers

Phenotypic and Gene Expression Profiles of Embryo Development of the Ascidian Ciona robusta Exposed to Dispersants

Within EU approval policies, most dispersant ecotoxicity testing considers lethal concentrations for marine adult species, overlooking the embryotoxicological effects. Here we studied the ecotoxicity of two commercial dispersant formulations (dispersant A and B) on the embryogenesis of the ascidian Ciona robusta. Embryotoxicity and phenotypic alterations stated that dispersant B resulted more toxic than A (EC50 value of 44.30 and 160 µg mL−1, respectively) and induced severe larvae malformations at lower concentrations. Furthermore, the analysis of genes involved in different cellular response pathways indicated that those belonging to biotransformation were upregulated by dispersant A treatment, likely related to the presence of hydrocarbons. Instead, dispersant B induced cas8 gene downregulation, probably as a result of the prolonged exposure to mixture components. Our preliminary findings support the use of the C. robusta embryotoxicity test as a valuable tool for dispersant approval procedures, by providing sub-lethal responses on marine invertebrates closely related to vertebrates

In silico approach for the definition of radiomirnomic signatures for breast cancer differential diagnosis

Personalized medicine relies on the integration and consideration of specific characteristics of the patient, such as tumor phenotypic and genotypic profiling. BACKGROUND: Radiogenomics aim to integrate phenotypes from tumor imaging data with genomic data to discover genetic mechanisms underlying tumor development and phenotype. METHODS: We describe a computational approach that correlates phenotype from magnetic resonance imaging (MRI) of breast cancer (BC) lesions with microRNAs (miRNAs), mRNAs, and regulatory networks, developing a radiomiRNomic map. We validated our approach to the relationships between MRI and miRNA expression data derived from BC patients. We obtained 16 radiomic features quantifying the tumor phenotype. We integrated the features with miRNAs regulating a network of pathways specific for a distinct BC subtype. RESULTS: We found six miRNAs correlated with imaging features in Luminal A (miR-1537, -205, -335, -337, -452, and -99a), seven miRNAs (miR-142, -155, -190, -190b, -1910, -3617, and -429) in HER2+, and two miRNAs (miR-135b and -365-2) in Basal subtype. We demonstrate that the combination of correlated miRNAs and imaging features have better classification power of Luminal A versus the different BC subtypes than using miRNAs or imaging alone. CONCLUSION: Our computational approach could be used to identify new radiomiRNomic profiles of multi-omics biomarkers for BC differential diagnosis and prognosis

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

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

Method for High-Resolution Frequency Measurements in the Extreme Ultraviolet Regime: Random-Sampling Ramsey Spectroscopy

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Laparotomic intrauterine insemination with frozen-thawed semen in Sopravissana breed ewes in Central Italy

Intrauterine laparoscopic insemination is diffuse in sheep breeding, yet requires veterinary expertise and expensive equipment. Our aim was to evaluate the time required, reproductive outcome and post-operative complications of mini invasive laparotomic intrauterine insemination, as an alternative approach to laparoscopy. A total of 115 Sopravvissana breed ewes were enrolled, including 75 adults and 40 lamb ewes, after oestrus synchronisation. Ewes were sedated and restrained in dorsal recumbence. Uterine horns were exposed through an abdominal incision of 4\u20137 cm, cranially to the udder. Thawed semen, containing 100 7 106 progressive motile (70%) and morphologically normal (80%) sperm cells, was inoculated into uterine lumen through an intravenous catheter. The abdominal incision was then routinely closed. The time interval for: (a) laparotomy and uterine exteriorisation, (b) intrauterine insemination, (c) abdominal wall closure and (d) total procedure was recorded. Pregnancy, lambing, twinning rates and sex ratio were submitted to chi-square test, comparing lamb and adult ewes. Time intervals and the duration of laparotomic procedure were compared in lamb and adults through Mann\u2013Whitney U test for independent samples. Median \ub1 standard error (SE) of total time for laparotomic intrauterine insemination was 5.53 \ub1 0.07 and 4.99 \ub1 0.11 min, for adult and lamb ewes (p<.05), which was similar to what was reported for laparoscopic methods. At pregnancy check, 60% and 70% of adult and lamb ewes resulted pregnant. Laparotomy is poorly applied due to risk of adherence and decreased fertility. In our study, ewes were naturally bred in the following season with 90% pregnancy rate. Our results showed that time for laparotomy is quite similar to laparoscopic insemination, as for the conception and lambing rates.HIGHLIGHTS Time required for the overall procedure (5.53 \ub1 0.07 and 4.99 \ub1 0.11 min, for adult and lamb ewes, respectively, with significant difference (p<.05)) was similar to laparoscopic artificial insemination. About 60% and 70% of adult and lamb ewes resulted pregnant, respectively. No decreased fertility was observed in the following breeding season (90% pregnancy rate at natural insemination). Laparotomic approach is quite similar to laparoscopic insemination, in terms of time required for its complete achievement, for the conception and lambing rates; furthermore it has the advantage of reducing equipment costs

Pioneer settlement of the cold-water coral Desmophyllum dianthus (Esper, 1794) on plastic

Larval settlement is a critical step for sessile benthic species such as corals, whose ability to thrive on diverse natural and anthropogenic substrates may lead to a competitive advantage in the colonization of new environments with respect to a narrow tolerance for a specific kind of substratum. Plastic debris, widespread in marine waters, provides a large, motile, and solid substratum supporting a highly diverse biological community. Here we present the first observation of a floating plastic bottle colonized by the deep-sea coral Desmophyllum dianthus. The density pattern and co-occurring species composition suggest a pioneer behavior of this coral species, whose peculiar morphologic plasticity response when interacting with the plastic substrate (i.e., low density polyethylene) has not been observed before. The tolerance of D. dianthus for such plastic substrate may affect ecological processes in deep water environments, disrupting interspecific substrate competition in the benthic community

Melnikov theory to all orders and Puiseux series for subharmonic solutions

We study the problem of subharmonic bifurcations for analytic systems in the plane with perturbations depending periodically on time, in the case in which we only assume that the subharmonic Melnikov function has at least one zero. If the order of zero is odd, then there is always at least one subharmonic solution, whereas if the order is even in general other conditions have to be assumed to guarantee the existence of subharmonic solutions. Even when such solutions exist, in general they are not analytic in the perturbation parameter. We show that they are analytic in a fractional power of the perturbation parameter. To obtain a fully constructive algorithm which allows us not only to prove existence but also to obtain bounds on the radius of analyticity and to approximate the solutions within any fixed accuracy, we need further assumptions. The method we use to construct the solution -- when this is possible -- is based on a combination of the Newton-Puiseux algorithm and the tree formalism. This leads to a graphical representation of the solution in terms of diagrams. Finally, if the subharmonic Melnikov function is identically zero, we show that it is possible to introduce higher order generalisations, for which the same kind of analysis can be carried out.Comment: 30 pages, 6 figure

The ejection of triatomic molecular hydrogen ions H-3(+) produced by the interaction of benzene molecules with ultrafast laser pulses

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Novel CircRNA Discovery in Sheep Shows Evidence of High Backsplice Junction Conservation

Circular RNAs (circRNAs) are covalently closed circular non-coding RNAs. Due to their structure, circRNAs are more stable and have longer half-lives than linear RNAs making them good candidates for disease biomarkers. Despite the scientific relevance of these molecules, the study of circRNAs in non-model organisms is still in its infancy. Here, we analyse total RNA-seq data to identify circRNAs in sheep from peripheral blood mononuclear cells (PBMCs) and parietal lobe cortex. Out of 2510 and 3403 circRNAs detected in parietal lobe cortex and in PBMCs, a total of 1379 novel circRNAs were discovered. Remarkably, around 63% of all detected circRNAs were found to be completely homologous to a circRNA annotated in human. Functional enrichment analysis was conducted for both tissues based on GO terms and KEGG pathways. The enriched terms suggest an important role of circRNAs from encephalon in synaptic functions and the involvement of circRNAs from PBMCs in basic immune system functions. In addition to this, we investigated the role of circRNAs in repetitive vaccination experiments via differential expression analysis and did not detect any significant relationship. At last, our results support both the miRNA sponge and the miRNA shuttle functions of CDR1-AS in sheep brain. To our knowledge, this is the first study on circRNA annotation in sheep PBMCs or parietal lobe cortex samples.This work was supported by a Spanish Ministry of Economy grant AGL2013-49137-C3 to BMJ; EV-M is a predoctoral fellow from the University of the Basque Country (UPV/EHU) [PIF15/361] and received a grant for a short-term scientific mission (STSM) from the Functional Annotation of Animal Genomes—European network (FAANG-Europe) [COST Action CA15112