138 research outputs found

    Foraging Behavior and Pollen Transport by Flower Visitors of the Madeira Island Endemic Echium candicans

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    The study of flower visitor behavior and pollen transport dynamics within and between plants can be of great importance, especially for threatened or rare plant species. In this work, we aim to assess the flower visitor assemblage of the Madeiran endemic Echium candicans and evaluate the performance of the most common visitors through the analysis of their foraging behavior and pollen loads. The flower visitor assemblage of E. candicans is diverse, including several insect groups and the endemic lizard Teira dugesii, but bees are the most common visitors. In general, large bees (Amegilla quadrifasciata, Apis mellifera, and Bombus spp.) had the highest average visitation rates (>18 flowers/min) and their pollen loads had higher percentages of homospecific pollen (>66%) when compared with butterflies and hoverflies. The honeybee (Apis mellifera) and two bumblebees (Bombus terrestris and B. ruderatus) were the most efficient flower visitors of E. candicans, but their foraging behavior seems to favor geitonogamy. Other visitors, such as butterflies and the small bee Lasioglossum wollastoni, may have a complementary role to the honeybee and bumblebee species, as their high mobility is associated with fewer flower visits on each plant and may promote xenogamy. Two non-native bees (A. mellifera and B. ruderatus) are important flower visitors of E. candicans and may contribute mostly to self-pollination rendering the endemic plant more vulnerable to inbreeding effects.The Fundação para a Ciência e a Tecnologia (FCT) provided financial support to field and laboratorial work through project PTDC/BIA-BIC/1013/2014. FE benefited from a grant by the Wallonia Brussels International (WBI) World Excellence Fellowships. Open access was funded by project FCT-UID/BIA/00329/2020-2024.info:eu-repo/semantics/publishedVersio

    Towards the semi-synthesis of phosphorylated mimics of glycosaminoglycans: Screening of methods for the regioselective phosphorylation of chondroitin

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    Glycosaminoglycan (GAG) mimics carrying phosphate rather than sulfate anionic groups have been poorly investigated, in spite of their interesting perspectives. While some GAG-mimicking phosphorylated polymers have been reported, to the best of our knowledge no phosphorylated polysaccharides having the same backbone of natural sulfated GAGs have been accessed yet. To fill this gap, in this work two standard phosphorylation protocols and two recently reported procedures have been screened on a set of polysaccharide species composed by microbial sourced chondroitin and three partially protected, semi-synthetic derivatives thereof. A detailed structural characterization by 1H, 13C and 31P NMR spectroscopy revealed the higher versatility of the innovative, biomimetic reaction employing monopotassium salt of phosphoenolpyruvate (PEP–K) with respect to standard phosphorylating agents (phosphoric acid or phosphorus oxychloride). Indeed, PEP-K and H3PO4 gave similar results in the regioselective phosphorylation of the primary hydroxyls of unprotected chondroitin, while only the former reacted on partially protected chondroitin derivatives in a controlled, regioselective fashion, affording chondroitin phosphate (CP) polysaccharides with different derivatization patterns. The reported results represent the first, key steps towards the systematic semi-synthesis of phosphorylated GAGs as a new class of GAG mimics and to the evaluation of their biological activities in comparison with native sulfated GAGs

    Pollen morphology of the endemic genera of the Madeira archipelago, Portugal

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    ABSTRACT: This study presents the first palynological characterisation of the five endemic plant genera of the Madeira archipelago: Chamaemeles Lindl, Melanoselinum Hoffm., Monizia Lowe, Musschia Dumort and Sinapidendron Lowe. Pollen grain morphology of ten endemic species was studied using light and scanning electron microscopy techniques. The size and shape of pollen grains, the polar axis, the equatorial diameter, and the exine ornamentation were measured and described. We found that the pollen grains of the five endemic genera are all medium-size monads. The close relative apiaceous Melanoselinum and Monizia differ in polar (P) and equatorial (E) diameter size and exine ornamentation while Sinapidendron species show differences in P, E, and P/E ratios. The pollen grains of the two Musschia species are very similar to each other, but differ in morphology and ornamentation from the Macaronesian endemic bellflowers Azorina vidalii and Canarina canariensis. This study unveiled differences between the endemic taxa and with their close related species, thus providing support to previous taxonomic findings.info:eu-repo/semantics/publishedVersio

    Silica Meets Tannic Acid: Designing Green Nanoplatforms for Environment Preservation

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    Hybrid tannic acid-silica-based porous nanoparticles, TA-SiO(2) NPs, have been synthesized under mild conditions in the presence of green and renewable tannic acid biopolymer, a glycoside polymer of gallic acid present in a large part of plants. Tannic acid (TA) was exploited as both a structuring directing agent and green chelating site for heavy metal ions recovery from aqueous solutions. Particles morphologies and porosity were easily tuned by varying the TA initial amount. The sample produced with the largest TA amount showed a specific surface area an order of magnitude larger than silica nanoparticles. The adsorption performance was investigated by using TA-SiO(2) NPs as adsorbents for copper (II) ions from an aqueous solution. The effects of the initial Cu(2+) ions concentration and the pH values on the adsorption capability were also investigated. The resulting TA-SiO(2) NPs exhibited a different adsorption behaviour towards Cu(2+), which was demonstrated through different tests. The largest adsorption (i.e., ~50 wt% of the initial Cu(2+) amount) was obtained with the more porous nanoplatforms bearing a higher final TA content. The TA-nanoplatforms, stable in pH value around neutral conditions, can be easily produced and their use would well comply with a green strategy to reduce wastewater pollution

    Angiotensin receptor I stimulates osteoprogenitor proliferation through TGFβ-mediated signaling:AT1R SIGNALING IN OSTEOBLAST DIFFERENTIATION

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    Clinical studies of large human populations and pharmacological interventions in rodent models have recently suggested that anti-hypertensive drugs that target angiotensin II (Ang II) activity may also reduce loss of bone mineral density. Here, we identified in a genetic screening the Ang II type I receptor (AT1R) as a potential determinant of osteogenic differentiation and, implicitly, bone formation. Silencing of AT1R expression by RNA interference severely impaired the maturation of a multipotent mesenchymal cell line (W20-17) along the osteoblastic lineage. The same effect was also observed after the addition of the AT1R antagonist losartan but not the AT2R inhibitor PD123,319. Additional cell culture assays traced the time of greatest losartan action to the early stages of W20-17 differentiation, namely during cell proliferation. Indeed, addition of Ang II increased proliferation of differentiating W20-17 and primary mesenchymal stem cells and this stimulation was reversed by losartan treatment. Cells treated with losartan also displayed an appreciable decrease of activated (phosphorylated)-Smad2/3 proteins. Moreover, Ang II treatment elevated endogenous transforming growth factor β (TGFβ) expression considerably and in an AT1R-dependent manner. Finally, exogenous TGFβ was able to restore high proliferative activity to W20-17 cells that were treated with both Ang II and losartan. Collectively, these results suggest a novel mechanism of Ang II action in bone metabolism that is mediated by TGFβ and targets proliferation of osteoblast progenitors

    Correction: Biodegradable nanoparticles bearing amine groups as a strategy to alter surface features, biological identity and accumulation in a lung metastasis model

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    Correction for 'Biodegradable nanoparticles bearing amine groups as a strategy to alter surface features, biological identity and accumulation in a lung metastasis model' by Diletta Esposito et al., J. Mater. Chem. B, 2018, 6, 5922–5930

    Endoscopic and Surgical Removal of Gastrointestinal Foreign Bodies in Dogs: An Analysis of 72 Cases

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    In emergency veterinary practice, gastrointestinal foreign body (GFB) removal is a common procedure that is performed with different techniques, such as endoscopy or surgery. The aims of this retrospective, multicentre, clinical study were to report the common locations and types of objects recovered and to investigate clinical factors and outcomes in dogs after surgical or endoscopic treatment for GFB removal. Records of dogs with a GFB diagnosis referred to the Teaching Veterinary Hospital or treated in three different veterinary hospitals from September 2017 to September 2019 were examined. The data obtained from each case included breed, age, clinical signs at presentation, duration of clinical signs, type and location of the GFB, treatment, length of hospitalisation and outcome. Seventy-two dogs were enrolled in the study. There were 42 males (58%) and 30 females (42%). The median age was 36 months (range: 3 months to 8 years). Endoscopic retrieval was performed in 56% of GFBs (located in the stomach or duodenum), whereas 44% of dogs underwent surgery. The type of FB detected varied greatly: kid toy (14%), metallic object/coin (13%), cloth (13%), sock (8%), ball (8%), plastic material (8%), peach stone (7%), fishhook (6%), sewing needle (4%), hair tie (4%), pacifier (3%), plant materials (3%) and others (9%). Moreover, the FBs were classified as sharp (13%, n = 9), pointed (33%, n = 24), blunt (26%, n = 19), or linear (28%, n = 20). In this study, 68% of FBs were localised in the stomach, 25% in the intestinal tract (50% duodenum, 28% jejunum, and 22% ileum), and 7% in both the stomach and small intestine. The type of GFB was not significantly associated with age, site or breed. There was a significant association between the type of GFB and sex: if the dog was male, there was a 38% probability of ingesting linear GFBs. The dog survival rate was 100% in cases treated by gastric endoscopic or surgical removal, 94% in cases treated with enterotomy and 33% in cases in which enterectomy was necessary. Enterectomy and multiple surgical sites were associated with a poor outcome. The presence of vomiting for more than 24 h was significantly associated with death

    An Italian survey of opioids misuse: Epidemiological and psychopathological aspects

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    © 2021 Published by Elsevier Ltd on behalf of International Society for the Study of Emerging Drugs. This is an open access article under the CC BY-NC-ND license, http://creativecommons.org/licenses/by-nc-nd/4.0/Objective Opioid abuse is a worrying reality especially in the US. The increase in the prescription of opioids in Europe poses the risk of a possible increase in the number of abusers also in Italy. The aim of the study is to evaluate the abuse of opioids in the youth population and to evaluate possible correlations with some psychopathological aspects. Methods A survey, conducted from July 2019 to March 2020, about the use of opioids was spread to a group of subjects aged between 18 and 40 years. A socio-demographical investigation and psychometric scales evaluating internet game addiction, gaming online, quality of life and general psychometric features were administrated. Results Nine-hundred and thirteen subjects completed the survey. Seventeen-five subjects (8.21%) have used one opioid at least once in their lifetime. Weak correlations were found between codeine and morphine intensity of use and sleep disturbance, cigarette smoked per day, while codeine correlates with the number of coffees taken per day and somatization. Conclusion Although the data of this survey do not show high percentages of use in Italy (8.21% of the sample have used one of the listed opioids at least once in their lifetime), the correlations founded confirm the literature data already present highlighting the need for constant monitoring of this phenomenon.Peer reviewedFinal Published versio
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