746 research outputs found

    Impacts of climate change on the biogeography of three amnesic shellfish toxin producing diatom species

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    Harmful algal blooms (HABs) are considered one of the main risks for marine ecosystems and human health worldwide. Climate change is projected to induce significant changes in species geographic distribution, and, in this sense, it is paramount to accurately predict how it will affect toxin-producing microalgae. In this context, the present study was intended to project the potential biogeographical changes in habitat suitability and occurrence distribution of three key amnesic shellfish toxin (AST)-producing diatom species (i.e., Pseudo-nitzschia australis, P. seriata, and P. fraudulenta) under four different climate change scenarios (i.e., RCP-2.6, 4.5, 6.0, and 8.5) up to 2050 and 2100. For this purpose, we applied species distribution models (SDMs) using four abiotic predictors (i.e., sea surface temperature, salinity, current velocity, and bathymetry) in a MaxEnt framework. Overall, considerable contraction and potential extirpation were projected for all species at lower latitudes together with projected poleward expansions into higher latitudes, mainly in the northern hemisphere. The present study aims to contribute to the knowledge on the impacts of climate change on the biogeography of toxin-producing miinfo:eu-repo/semantics/publishedVersio

    Projecting future climate change-mediated impacts in Three Paralytic Shellfish Toxins-Producing dinoflagellate species

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    Simple Summary Harmful algal blooms present a particular risk for marine ecosystems and human health alike. In this sense, it is important to accurately predict how toxin-producing microalgae could be affected by future climate change. The present study applied species distribution models (SDMs) to project the potential changes in the habitat suitability and distribution of three key paralytic shellfish toxin (PST)-producing dinoflagellate species (i.e., Alexandrium catenella, A. minutum, and Gymnodinium catenatum), up to 2040/50 and 2090/2100, across four different greenhouse gas emission scenarios, and using four abiotic predictors (i.e., sea surface temperature, salinity, current velocity, and bathymetry). In general, considerable contractions were observed for all three species in the lower latitudes of their distribution, together with projected expansions into higher latitudes, particularly in the Northern Hemisphere. This study aims to entice further research on the future biogeographical impacts of climate change in toxin-producing microalgae species while, at the same time, helping to advise the correct environmental management of coastal habitats and ecosystems. Toxin-producing microalgae present a significant environmental risk for ecosystems and human societies when they reach concentrations that affect other aquatic organisms or human health. Harmful algal blooms (HAB) have been linked to mass wildlife die-offs and human food poisoning episodes, and climate change has the potential to alter the frequency, magnitude, and geographical extent of such events. Thus, a framework of species distribution models (SDMs), employing MaxEnt modeling, was used to project changes in habitat suitability and distribution of three key paralytic shellfish toxin (PST)-producing dinoflagellate species (i.e., Alexandrium catenella, A. minutum, and Gymnodinium catenatum), up to 2050 and 2100, across four representative concentration pathway scenarios (RCP-2.6, 4.5, 6.0, and 8.5; CMIP5). Despite slightly different responses at the regional level, the global habitat suitability has decreased for all the species, leading to an overall contraction in their tropical and sub-tropical ranges, while considerable expansions are projected in higher latitudes, particularly in the Northern Hemisphere, suggesting poleward distributional shifts. Such trends were exacerbated with increasing RCP severity. Yet, further research is required, with a greater assemblage of environmental predictors and improved occurrence datasets, to gain a more holistic understanding of the potential impacts of climate change on PST-producing species.info:eu-repo/semantics/publishedVersio

    Produção de azeitona e estado nutritivo das árvores após quatro anos sem fertilização com azoto e boro

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    Azoto e boro podem ser lixiviados dos solos por acção da água das chuvas de inverno. Por conseguinte, a aplicação destes elementos é feita anualmente numa dose única ou, eventualmente, de forma fraccionada, no caso do azoto. Contudo, literatura controversa sugere que no olival não haverá necessidade de se aplicar azoto anualmente se os teores foliares estiverem na zona de concentrações adequadas. Neste trabalho, o efeito da aplicação de N e B na produção, na concentração dos elementos nas folhas e na disponibilidade de N e B no solo foram investigados num ensaio de campo localizado em Trás-os-Montes, no qual estes dois elementos não foram aplicados durante quatro estações de crescimento consecutivas. Os tratamentos consistiram em: testemunha, no qual foi aplicado um plano de fertilizante completo (N+B); -N, em que o N foi excluído do plano de fertilização e -B em que foi excluído o B

    DODAB:MO versus novel liposomes for protein delivery: comparing toxicity and encapsulation efficiency

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    UID/BIA/04050/2019, funded by national funds through the FCT IP, and project FUN2CYT: Harnessing the potential for biomedical applications of pleiotropic cytokines LIF and oncostatin M (PTDC/BTM-MAT/30568/2017, POCI-01-0145-FEDER-030568) supported by POCI through FEDER and FCT IPinfo:eu-repo/semantics/publishedVersio

    Detection of biogenic amines in mead of social bee

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    Mead is an alcoholic beverage, resulting from the fermentation of honey and water, although it is an old drink, some fermentation products are still unknown. Biogenic amines have driven research on food and beverages due to their toxicity and capacity to cause damage to the human health. This study aimed to evaluate the presence of biogenic amines in mead from honey of two species of social bees, using different fining agents (bentonite, banana peel flour, and passion fruit peel flour) and storage in oak barrel for 120 days. We observed the presence of three biogenic amines for each type of mead. Putrescine was reported only in samples of mead of Apis mellifera. Tryptamine and histamine were not detected, while tyramine was observed in the mead samples of honey from Melipona quadrifasciata anthidioides. Samples clarified with fruit peels increased the number of amines. In the analysis of the histamine, used as standard, obtained limits of detection and quantification of 2.47 mg/L and of 7.48 mg/L, respectively. In this study, the amines observed remained below the limit of detection, and did not pose a risk to consumers. The finings used demonstrated a profile similar to the control mead, and its use was satisfactory.We thank the National Council of Technological and Scientific Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq) under Grant (305885/2017 to C.A.L.C.). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES) - Finance Code 001. We also thank the Fundação de Amparo a Pesquisa do Estado da Bahia - FAPESB, under Grant 8797/2015.info:eu-repo/semantics/publishedVersio

    Click chemistry oligomerisation of azido-alkyne-functionalised galactose accesses triazole-linked linear oligomers and macrocycles that inhibit Trypanosoma cruzi macrophage invasion

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    AbstractReaction of 2-(2-(2-azidoethoxy)ethoxy)ethyl 6-O-(prop-2-ynyl)-β-d-galactopyranoside (7) under CuAAC conditions gives rise to mixed cyclic and linear triazole-linked oligomers, with individual compounds up to d.p. 5 isolable, along with mixed larger oligomers. The linear compounds resolve en bloc from the cyclic materials by RP HPLC, but are separable by gel permeation chromatography. The triazole-linked oligomers—pseudo-galactooligomers—were demonstrated to be acceptor substrates for the multi-copy cell surface trans-sialidase of the human parasite Trypanosoma cruzi. In addition, these multivalent TcTS ligands were able to block macrophage invasion by T. cruzi

    Evolution of Globus Pallidus Targeting for Parkinson\u27s and Dystonia Deep Brain Stimulation: A 15-Year Experience

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    Objective: The aim of this study is to evaluate the evolution of GPi DBS targeting. Methods: This retrospective, single-center study included patients implanted with GPi DBS leads for dystonia or PD during the years 2004 to 2018 at the University of Florida Fixel Institute for Neurological Diseases. Each patient underwent a high-resolution targeting study on the day prior to the surgery, which was fused with a high resolution CT scan that was acquired on the day of the procedure. Intraoperative target location was selected using a digitized 3D Schaltenbrand-Bailey atlas. All patients underwent a high-resolution head CT scan without contrast approximately one month after lead implantation and accurate measurement of neuroanatomical lead position was acquired after fusion of pre-operative and post-operative image studies. Results: We analyzed 253 PD patients with 352 leads and 80 dystonia patients with 141 leads. During 15 years of follow-up, lead locations in the PD group migrated more laterally (beta = 0.09, p \u3c 0.0001), posteriorly [slope (beta) = 0.04, p \u3c 0.05], and dorsally (beta = 0.07, p \u3c 0.001), whereas leads in the dystonia group did not significantly change position aside from a trend in the dorsal direction (beta = 0.06, p = 0.053). Conclusion: The evolving target likely results from multiple factors including improvements in targeting techniques and clinical feedback intraoperatively and post-operatively. Our demonstrates the potential importance of a systematic post-operative DBS lead measurement protocol to ensure quality control and to inform and optimize DBS programming
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