1,720,967 research outputs found
The toxic effect of an oxylipins-containing macroalgae extract on sea urchin reproduction and development
No full textBackground - Algae possess complex and highly evolved chemical defenses against their grazers, including the production of bioactive molecules such as oxylipins. Ericaria brachycarpa, a canopy-forming brown algae, contribute to form the habitat in the Mediterranean Sea for the sea urchin species Arbacia lixula. The aim of this work was to evaluate the effects of an oxylipins-containing extract from E. brachycarpa on the reproduction and development of A. lixula, evaluating the fertilization success and the embryotoxic activity from fertilization (0 h) to the pluteus stage (72 h).
Methods - The extract was tested in gametes to test the fertilization success and at three developmental endpoints (zygote, gastrula and pluteus). The range of concentrations tested was chosen to cover a full 0-100 % abnormality curve, with doses ranging from 0 to 40 μg/mL.
Results – We found a strong dose-dependent effect on the fertilization success and on development. Gastrulae were the most sensitive to the extract with the lowest EC50. At low doses we found an impairment in development and biomineralization, while the highest concentration tested caused 100% mortality of the embryos at all stages. Western Blot experiments showed the modulation of different molecular markers (HSP60, LC3, p62, CHOP and cleaved caspase-7), indicating enhanced autophagy at low concentrations and apoptosis at high concentrations. The TUNEL assay confirmed high levels of fragmented DNA.
Conclusion - These data support the hypothesis that macroalgae may exert a sort of population control against their grazers, releasing in the marine environment toxic compounds, such as oxylipins, following their tissue disruption by sea urchins and other grazers.
Project funded by the European Union – NextGenerationEU under the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2, Project NBFC CUP B73C2200079000
ENVIRONMENTAL DNA: A POSSIBLE TOOL TO EVALUATE THE VERTEBRATE BIODIVERSITY USING WATER SAMPLES OF THREE SICILIAN LAKE
No full textFreshwater ecosystems play a key role for the biogeochemical cycles and are subject to several anthropic impact that cause a biodiversity loss. Conventional census methods seem to be insufficient and not very convenient for the detection of species. The organisms inhabiting these sites continuously release DNA, called "environmental DNA" (eDNA), through cells, excrement, gametes and/or decomposing material and its evaluation could revolutionize the monitoring of biodiversity (HARPER et al., 2019; SCHENEKAR, 2023). On the other hand, today there are considerable doubts about it: seems to be the non-existence of well-defined protocols which depend on the sampling site, environmental factors and extraction methods; degradation processes are very rapid and the costs of evaluations are very high (many samples are needed in different points). The aim of this study (part of RTDA-PON project) was to fine-tune the sampling and eDNA extraction protocol, reducing the costs and evaluating the potential of this method compared to the conventional methods. Another aim was evaluating the biodiversity of vertebrate in some Sicilian Lake for which until to date no more is known. In this study, the eDNA technique was used for the first time in three Sicilian lakes: Poma Lake, Piana degli Albanesi Lake and Scanzano Lake.The water sampled in each site was filtered and eDNA was extracted using extraction kit. Metabarcoding analysis was performed by IGA Technology Services s.r.l. The results showed the possibility to understand which types of phyla, class, order, family, gender, or species lives in these sites. The species not captured or not sighted using conventional methods were detected thanks to the use of eDNA and vice versa highlighting that the evaluation of eDNA can be useful to evaluate not only aquatic species but also other species that use these sites as a source of supply. Another important result was the possibility to detect DNA of species not typical of freshwater sites highlighting the contamination process. eDNA is a very important tool to evaluate the biodiversity and the health status of the environment, but on the other hand, for a more complete census, it is very important use also other conventional methods at the same times. Our preliminary results showed that eDNA method have the potential to replace the traditional methods of census but it is not yet the time to do it, using both methods is surely the best approach
Anthropic impact, bioactive molecules, sustainable development, my keyword? Biodiversity!
No full textBiodiversity is my main research focus and that of my research group. We study a range of different aspects concerning biodiversity, such as the impact anthropic activities have on biodiversity and how to improve its preservation, its use as a valuable resource for the extraction of bioactive molecules, and the study of its distribution. The research group has over twenty years of experience in the study
of zoology, and, more in particular, the immune and behavioural responses of aquatic invertebrates and fish. For many years, the group has observed the effects of various anthropogenic activities, such as the acoustic and chemical impacts on the physiological and behavioral responses of invertebrate organisms, such as Arbacia lixula and Mytilus galloprovincialis, and of fishes, such as Sparus aurata, evaluating not only adult stage but also embryonic stage [1,2]. From a sustainable
development perspective, we have recently turned our attention to an evaluation of the nutritional potential of aquaculture species which are recent additions to farming in Sicily: Cherax quadricarinatus and Cherax destructor [3]. However, biodiversity, as well as needing our protection, is also a resource which we can seek to harness in an eco-sustainable way. In recent years, research in our group has focused on the extraction of bioactive molecules from invertebrates and vertebrate living organisms (including from waste from the processing industry), with evident antimicrobial, anticancer and food preservation potential [4]. Last but not least, the regenerative capacities of invertebrate organisms such as Holothuria tubulosa [5] were evaluated with the possibility of transferring this knowledge to the biomedical sector. In addition to carrying out the aforementioned research, we are currently working on a nationally funded PON research project to conduct a
freshwater biodiversity census in Palermo, including environmental DNA evaluation
EFFECTS OF ERICARIA BRACHYCARPA EXTRACT ON THE DEVELOPMENT OF ARBACIA LIXULA SEA URCHIN EMBRYOS
No full textBeing macroalgae sessile organisms, they need to constantly adapt to either the abiotic and biotic components of the marine ecosystem and have developed complex adaptations to survive, including the production of bioactive molecules. The aim of this work was to evaluate the effects of an extract of the brown macroalga Ericaria brachycarpa on the development of Arbacia lixula sea urchin embryos, to evaluate the embryotoxic activity from fertilization (0 h) to the pluteus stage (72 h). The range of concentrations tested was chosen to cover a full 0-100 % abnormality curve, with doses ranging from 0 to 40 μg/mL. The extract was added at three developmental endpoints: zygote (0 hpf), gastrula (24 hpf) and pluteus (48 hpf), founding that gastrulae were the most sensitive to the extract with the lowest EC50 (5.366 μg/mL). In all treatments there was a dose-dependent effect. At low concentrations we found a significant variation in two morphometric parameters at the pluteus stage, compared to controls. The highest concentration tested (40 μg/ml) caused 100% mortality of the embryos at all embryo stages. Western Blot experiments showed the modulation of different molecular markers (HSP60, LC3, p62, CHOP and cleaved caspase-7), showing enhanced autophagy at low concentrations and apoptosis at high concentrations. The TUNEL assay confirmed high levels of fragmented DNA in 48 h exposed embryos. Further studies by means of HPLC/MS/QToF are in progress to identify which compound(s) of the E. brachycarpa extract are responsible for the embryotoxic activity
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
MACROALGA EXTRACT EFFECT’S ON BIOCHEMICAL RESPONSES OF SEA URCHINS ARBACIA LIXULA (Linnaeus, 1758)
No full textMarine algae produce important secondary metabolites that vary between the different species, spatial distribution and the seasonal period. The production of these secondary metabolites by macroalgae allows to protect themselves from environmental stress conditions (competitors, pathogens, grazers, epiphytes). Several studies report different biological properties of the extracts or molecules obtained from these macroalgae such us: immunomodulatory (RAPOSO et al., 2016), antioxidant (FISCH et al., 2003), anticancer (ABU-KHUDIR et al., 2021) and antimicrobial (PINTEUS et al., 2015).
In light of that, the aim of this study was to evaluate the effect of extract the macroalga Ericaria crinita (J. Agardh, Molinari and Guiry, 2020), on the innate immune system of sea urchin A. lixula. The animals were in vivo treated with macroalgae extract and the effects were analysed after three hours sampling coelomic fluid in which total cells counts were evaluated. Then, the cells were separated from cell free. On cellular lysate and on cell free protein concentration, enzyme activity and antioxidant responses (inhibition of oxidative stress through the evaluation of reactive oxygen/nitrogen species (RONS) and glutathione (GSH) levels) were evaluated. Our results showed important changes in enzymatic activities and decrease in the inflammatory marker nitric oxide (NO). Further studies are needed to better understand the action of these bioactive molecules however, these results are certainly encouraging and prompt us to investigate the potential use that can be made of these compounds produced by macroalgae in the bio-medical and industrial fields
NOT ALL LIKE IT HOT: THE CONTRASTING EFFECTS OF TWO GLOBAL WARMING CONDITIONS ON KEY MEDITERRANEAN SEA URCHIN SPECIES EXPOSED TO POLLUTION
No full textGradual ocean warming and marine heatwaves represent major threats for marine organisms already facing other anthropogenic-derived hazards, such as chemical contamination in coastal areas. Sea urchin larvae are a common model system in marine ecotoxicological studies to assess the impacts of climate change and pollution. Here I report the combined effects of thermal stress and exposure to three different pollutants of the marine environment (gadolinium, vanadium and phthalates) on embryos of two common Mediterranean sea urchin species with predicted opposite responses to warming, the temperate Paracentrotus lividus and the sub-tropical Arbacia lixula. These species are among the most abundant echinoids living in shallow rocky reefs of the southwestern Mediterranean and are ecologically important because their herbivorous grazing impacts macroalgae and leads to the formation of barrens habitats. Embryos were exposed to several treatments of three temperatures (18°C, 21°C, 24°C) and different concentrations of the three pollutants (from environmentally relevant to cytotoxic). We tested the single and combined effects to thermal stress and pollutants at three functional levels: i) exposure–response relationships, ii) morphological, analyzing impacts of treatments on larval phenotypes and morphometric traits of larval growth and biomineralization; iii) biochemical/cellular, investigating the effects on activity of enzyme biomarkers, protein expression and the activation of the cellular stress response. With respect to developmental progression, elevated temperatures at near-future projections (+3°C, 21°C) accelerated development and achievement of the larval stage, while extreme warming at present-day marine heatwave conditions (+6°C, 24°C) breached the thermotolerance threshold of both species with a high proportion of abnormal larvae (30 %).
We found a fascinating double side effect of increased temperature combined to pollution: a mild temperature increase (+3°C) reduced the negative effects of pollutants on development with a lower percentage of abnormality and improved skeleton growth, while combined heatwave conditions (+6°C) and pollution resulted in a lower proportion of embryos reaching the advanced larval stages.
Our results indicate that the negative effects of pollutants-exposure on P. lividus and A. lixula larval development and biomineralization will be mitigated by a near-future ocean warming, up to a thermotolerance threshold when negative synergistic effects were evident. Our data highlight the use of biomarkers as sensitive tools to detect environmental impacts as well as the need for a better understanding of the interactions between the multiple stressors faced by marine species in coastal environments
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