1,203 research outputs found

    Habitat Suitability of Threespine Stickleback (Gasterosteus aculeatus L.) in the Southern Limit of Its Global Distribution: Implications for Species Management and Conservation

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    The conservation of fish biodiversity requires reliable information on their distribution and habitat use, especially of endemic species that generally occur in restricted geographic areas and specific habitats. This is the case of threespine stickleback (G. aculeatus L.), that is a small freshwater fish listed as Endangered (EN) in Portugal, which represents the southern limit of the species global distribution. The monitoring and conservation of populations placed near to the species distribution limits is very important because in these places, small environmental changes can lead to the significant decline of local populations. However, due to the lack of knowledge about its regional distribution, ecology, and macrohabitat preferences, few measures have been proposed aiming the conservation of this species. This project aimed to identify which macro-scale environmental factors determine regional distribution of G. aculeatus, to predict their potential distribution and, therefore, define the most important areas for their protection and conservation. The occurrence data, from existing databases and specific sampling campaigns, together with 15 environmental macrohabitat predictors, were used to model the potential distribution of sticklebacks in Portugal, through an ensemble of species distributions models (SDM). Through the results of our ensemble model, we found that threespine stickleback may occur predominantly at lower stretches of river systems, where sandy substrate is dominant, and flow is higher. Sticklebacks are also more likely to occur in sites with high levels of rainfall in the driest month, thus avoiding locations with high potential for drying during summer, which tend to be common in the Iberian Peninsula. The species also tends to avoid steep slope areas, with high levels of annual precipitation. Based on our results, a probability map of occurrence was generated; from this, some river stretches were categorized into levels according to their importance for the conservation of the species. With the results obtained, it was also possible to identify some atypical populations, occurring in areas with low or null habitat suitability, which need to be further studied, because they must have developed physiological characteristics that allow them to subsist in places that are not conducive to their survival

    Into the Wild: A New Approach to the Aquaculture Production of Brown Trout (Salmo trutta L.) to Enhance Restocking Success

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    The brown trout (Salmo trutta L.) is one of the most iconic native species from European river ecosystems and is also one of the main species of interest for recreational fishing activities (e.g., fly fishing). This species has a significant potential to attract anglers and related investment to the main fishing grounds, which are usually located in poorly developed areas and away from main city centers. Due to its environmental and socioeconomic value, this species is often targeted by management programs directed to the protection and sustainable exploitation of this valuable natural resource. One of the most common actions to enhance the abundance and condition of trout populations is the restocking of wild populations with fish from aquaculture facilities. However, most fish come from fishfarms using production methods such as high densities in the tanks, use of commercial food and standardized feeding methods, lack of environmental stimulus, and domestication of breeding stocks, which usually results in poor fitness and very low survival rates after release. This consequently leads to reduced success of these management actions. To contribute to solving these problems and enhancing the success of restocking actions for the recovery and sustainable enhancement of wild trout populations, we propose a novel approach to the production of this species, by testing and implementing a new protocol that aims to produce wild-reared trout. These fish come from wild breeders and will be produced with the least human contact in conditions that mimic their natural habitat. Taking advantage of a recently remodeled and re-equipped aquaculture facility, located in Central Portugal (Posto Aquícola de Campelo, Figueiró dos Vinhos), we are rearing trout in low densities (10–20 trout/m3 ), like the ones observed in natural habitats, using live food (larvae and insects), and subjected to environmental stimuli such as refuges, and water and flow variability, equivalent to those observed in local streams. Accompanied by a pre- and post-restocking monitoring program (e.g., evaluation of trout abundances and habitat in the target stream, dispersion and movement patterns and survival), this study will contribute to enhancing the success of future restocking actions, promoting the sustainable enhancement of wild trout populations, and, thus, increasing the interest of restocked fishing grounds for angling activities and associated incomes

    Genetic Structure and Diversity of Brown Trout (Salmo trutta L.) in Portugal

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    Population genetic studies have been extensively used as tools for the management and conservation of salmonid species and related habitats. The brown trout, Salmo trutta (Linnaeus 1758), is one of the most studied species within its family, and is frequently used as a population model. It can have a highly complex and variable life history, often presenting a migratory ecotype (i.e., sea trout), and it is considered an indicator of the quality of aquatic ecosystems. Moreover, it has a high socioeconomic value for commercial and recreational fishing. The destruction or alteration of aquatic habitats, over-exploitation, exotic species and climate change are some of the factors that threaten the sustainability of the species in Portugal. To analyse the genetic structure, gene flow and connectivity patterns among Portuguese brown trout populations, we sampled approximately 392 individuals from 15 sites across the distribution of the species in its national territory. DNA fingerprinting methodologies were carried out to determine the structural differences between populations, using a set of microsatellite loci developed for salmonids. The overall results suggest significant genetic differences between the populations sampled. This study has enabled a breakthrough in understanding the genetic structure of Salmo trutta populations in the southern limit of the species’ global distribution, assessing the impact of natural and human factors on the genetic structure of its populations, and consequently developing mitigation measures for the effective management and conservation of the species

    The Health-Promoting Potential of Salix spp. Bark Polar Extracts: Key Insights on Phenolic Composition and In Vitro Bioactivity and Biocompatibility

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    Salix spp. have been exploited for energy generation, along with folk medicine use of bark extracts for antipyretic and analgesic benefits. Bark phenolic components, rather than salicin, have demonstrated interesting bioactivities, which may ensure the sustainable bioprospection of Salix bark. Therefore, this study highlights the detailed phenolic characterization, as well as the in vitro antioxidant, anti-hypertensive, Staphylococcus aureus growth inhibitory effects, and biocompatibility of Salix atrocinerea Brot., Salix fragilis L., and Salix viminalis L. bark polar extracts. Fifteen phenolic compounds were characterized by ultra-high-performance liquid chromatography-ultraviolet detection-mass spectrometry analysis, from which two flavan-3-ols, an acetophenone, five flavanones, and a flavonol were detected, for the first time, as their bark components. Salix bark extracts demonstrated strong free radical scavenging activity (5.58–23.62 µg mL−1 IC50 range), effective inhibition on angiotensin-I converting enzyme (58–84%), and S. aureus bactericidal action at 1250–2500 µg mL−1 (6–8 log CFU mL−1 reduction range). All tested Salix bark extracts did not show cytotoxic potential against Caco-2 cells, as well as S. atrocinerea Brot. and S. fragilis L. extracts at 625 and 1250 µg mL−1 against HaCaT and L929 cells. These valuable findings can pave innovative and safer food, nutraceutical, and/or cosmetic applications of Salix bark phenolic-containing fractions.info:eu-repo/semantics/publishedVersio

    Red and near-infrared absorbing dicyanomethylene squaraine cyanine dyes: photophysicochemical properties and anti-tumor photosensitizing effects

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    Photodynamic therapy is a medical modality developed for the treatment of several diseases of oncological and non-oncological etiology that requires the presence of a photosensitizer, light and molecular oxygen, which combined will trigger physicochemical reactions responsible for reactive oxygen species production. Given the scarcity of photosensitizers that exhibit desirable characteristics for its potential application in this therapeutic strategy, the main aims of this work were the study of the photophysical and photochemical properties and the photobiological activity of several dicyanomethylene squaraine cyanine dyes. Thus, herein, the study of their aggregation character, photobleaching and singlet oxygen production ability, and the further application of the previously synthesized dyes in Caco-2 and HepG2 cancer cell lines, to evaluate their phototherapeutic effects, are described. Dicyanomethylene squaraine dyes exhibited moderate light-stability and, despite the low singlet oxygen quantum yields, were a core of dyes that exhibited relevant in vitro photodynamic activity, as there was an evident increase in the toxicity of some of the tested dyes exclusive to radiation treatments.This research was funded by the European Investment Funds by FEDER/COMPETE/POCI under projects POCI-01-0145-FEDER-006958 (CITAB) and POCI-01-0145-FEDER-007491 (CICS-UBI) and Funds by FCT – Portuguese Foundation for Science and technology, under the projects UIDB/04033/2019 (CITAB) and UIDB/00616/2020 (CQ-VR). This work was also supported by funds from the Health Sciences Research Center (CICS-UBI) through National Funds by FCT—Foundation for Science and Technology (UID/Multi/00709/2019). The research at CQFM was supported by Project UID/NAN/50024/2019 and M-ERA-NET/0002/2015 from FCT. E. L. was supported by the FCT PhD grant SFRH/BD/147645/2019

    A vida no limite: gestão e conservação das populações de salmão do Atlântico em Portugal

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    O salmão do Atlântico (Salmo salar L.) é uma espécie migradora diádroma emblemática dos ecossistemas aquáticos do hemisfério norte. Em Portugal, que representa o limite sul da distribuição global desta espécie, o salmão encontra-se classificado como Criticamente em Perigo, ocorrendo apenas nas bacias hidrográficas dos rios Minho, a população mais abundante, e Lima, registando-se algumas ocorrências ocasionais nos rios Cávado e Douro. Em Portugal a espécie está sujeita a diversas pressões (e.g., barreiras à continuidade fluvial, legislação pesqueira desadequada, alterações climáticas), e existe um reduzido conhecimento sobre estas populações que impede a definição e concretização de medidas de gestão e conservação adequadas. A presente comunicação tem como objetivo dar a conhecer os objetivos e trabalhos práticos previstos no âmbito de dois projetos científicos atualmente a decorrer e focados nas populações nacionais de salmão, com particular enfoque nas bacias dos rios Minho e Lima. Através de uma parceria entre cientistas e pescadores comerciais e recreativos, o projeto “SalmonLink - Contribuição dos cientistas e pescadores para a conservação e gestão participada das populações de salmão do Atlântico em Portugal”, financiado pelo MAR2020 e coordenado pela Universidade de Évora/MARE, pretende contribuir para aumentar o conhecimento sobre as populações nacionais de salmão e propor medidas que possam promover a gestão sustentável desta espécie. De forma complementar, o projeto internacional “SMOLTrack III - Quantifying smolt survival from source to sea: informing management strategies to optimise returns”, financiado pela Comissão Europeia no âmbito da NASCO (North Atlantic Salmon Conservation Organization), integra vários especialistas europeus num esforço conjunto para estudar a migração para o mar dos juvenis de salmão e os fatores que podem contribuir para a mortalidade destes indivíduos. Em Portugal, este projeto decorrerá ao longo de três anos, nos rios Minho e Lima, igualmente sob a coordenação nacional da Universidade de Évora/MARE. Para além de contribuir para melhorar os programas de gestão e conservação dirigidos ao salmão nas bacias hidrográficas nacionais, o aumento do conhecimento sobre as populações desta espécie que ocorrem no limite sul da sua distribuição global, irá permitir a identificação de eventuais estratégias de vida alternativas, associadas à sobrevivência em locais com condições ambientais sub-ótimas para espécie como são os nossos rios, de extrema importância num contexto de alterações climáticas e aquecimento global

    Photodynamic inactivation of a RNA-virus model using water-soluble β-octa-Substituted pyridinium-pyrazolyl phthalocyanines

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    Among the various groups of microorganisms, viruses have generally a greater capacity for mutation, especially RNA viruses, as was demonstrated by SARS-CoV2 virus mutations. This high mutation rate promotes the development of their resistance to traditional antivirals and establishes the resistance behaviour in virus populations, decreasing their susceptibility to these drugs. In this context, the photodynamic treatment appears as a potentially effective method against microorganisms and, considering its mode of action is not likely to lead to the development of resistance. In this work, two newly zinc(II) phthalocyanines (ZnPcs) bearing pyridinium-pyrazolyl groups (2a and 3a) were synthesized, characterized, and applied in photodynamic inactivation (PDI) of bacteriophage Φ6 (or Phage Phi6) as a RNA-virus model. These quaternized dyes were applied at different concentrations (from 5.0 to 20 μM, and under white light irradiation in the irradiance range between 50 and 150 mW/cm2) to test their efficiency for possible clinical or environmental applications. The results showed that the new cationic ZnPcs 2a and 3a efficiently inactivate the RNA-virus model (bacteriophage Φ6), even at the lowest tested irradiance. These compounds are thus promising photosensitizers to be used in various contexts.info:eu-repo/semantics/publishedVersio

    Regular insulin added to total parenteral nutrition vs subcutaneous glargine in non-critically ill diabetic inpatients, a multicenter randomized clinical trial: INSUPAR trial

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    Background: There is no established insulin regimen in T2DM patients receiving parenteral nutrition. Aims: To compare the effectiveness (metabolic control) and safety of two insulin regimens in patients with diabetes receiving TPN. Design: Prospective, open-label, multicenter, clinical trial on adult inpatients with type 2 diabetes on a non-critical setting with indication for TPN. Patients were randomized on one of these two regimens: 100% of RI on TPN or 50% of Regular insulin added to TPN bag and 50% subcutaneous Gl. Data were analyzed according to intention-to-treat principle. Results: 81 patients were on RI and 80 on GI. No differences were observed in neither average total daily dose of insulin, programmed or correction, nor in capillary mean blood glucose during TPN infusion (165.3 +/- 35.4 in RI vs 172.5 +/- 43.6 mg/dL in GI; p = 0.25). Mean capillary glucose was significantly lower in the GI group within two days after TPN interruption (160.3 +/- 45.1 in RI vs 141.7 +/- 43.8 mg/dL in GI; p = 0.024). The percentage of capillary glucose above 180 mg/dL was similar in both groups. The rate of capillary glucose <= 70 mg/dL, the number of hypoglycemic episodes per 100 days of TPN, and the percentage of patients with non-severe hypoglycemia were significantly higher on GI group. No severe hypoglycemia was detected. No differences were observed in length of stay, infectious complications, or hospital mortality. Conclusion: Effectiveness of both regimens was similar. GI group achieved better metabolic control after TPN interruption but non-severe hypoglycemia rate was higher in the GI group. (C) 2019 The Author(s). Published by Elsevier Ltd

    Birds and bioenergy within the americas: A cross‐national, social–ecological study of ecosystem service tradeoffs

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    Although renewable energy holds great promise in mitigating climate change, there are socioeconomic and ecological tradeoffs related to each form of renewable energy. Forest‐related bioenergy is especially controversial, because tree plantations often replace land that could be used to grow food crops and can have negative impacts on biodiversity. In this study, we examined public perceptions and ecosystem service tradeoffs between the provisioning services associated with cover types associated with bioenergy crop (feedstock) production and forest habitat‐related supporting services for birds, which themselves provide cultural and regulating services. We combined a social survey‐based assessment of local values and perceptions with measures of bioenergy feedstock production impacts on bird habitat in four countries: Argentina, Brazil, Mexico, and the USA. Respondents in all countries rated birds as important or very important (83–99% of respondents) and showed lower enthusiasm for, but still supported, the expansion of bioenergy feedstocks (48–60% of respondents). Bioenergy feedstock cover types in Brazil and Argentina had the greatest negative impact on birds but had a positive impact on birds in the USA. In Brazil and Mexico, public perceptions aligned fairly well with the realities of the impacts of potential bioenergy feedstocks on bird communities. However, in Argentina and the USA, perceptions of bioenergy impacts on birds did not match well with the data. Understanding people’s values and perceptions can help inform better policy and management decisions regarding land use changes

    The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

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    The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr
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