262 research outputs found

    First records of Tarentola mauritanica (Linnaeus, 1758) (Reptilia; Gekkonidae) in the Azores

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    The Moorish gecko Tarentola mauritanica (Linnaeus, 1758) is a widespread species native to the Mediterranean region from southern France to Greece and northern Africa (Loveridge 1947; Martínez-Rica 1997; Hódar 2002; Perera et al. 2008, 2010; Plezeguelos et al. 2008). It has recently been reported as living and breeding in California (Marhdt 1998) and also as an introduced species in Madeira (Báez & Biscoito 1993). Tarentola mauritanica is paraphyletic with respect to T. angustimentalis Steindachner, 1891, a Canary Islands endemic (Harris et al. 2004a). Here we report new occurrences of the Moorish gecko on Terceira Island, Azores archipelago, and 3 other occurrences on the islands of São Miguel and Faial. The possibility of an already established breeding population is discussed

    Photocatalytic Bi2O3/TiO2:N thin films with enhanced surface area and visible light activity

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    Bi2O3 nanocone films functionalized with an overlayer of TiO2 were deposited by d.c. reactive magnetron sputtering. The aforementioned nanocone structures were formed via a vapour-liquid-solid (VLS) growth, starting from a catalytic bismuth seed layer. The resultant nanocones exhibit an improved surface area, measured by atomic force microscopy, when compared to non-VLS deposition of the same metal oxide. X-ray diffraction texture analysis enabled the determination of the crystallographic β-phase of Bi2O3. A very thin TiO2 overlayer (6 nm thick), undoped and doped with nitrogen, was deposited onto the nanocones template, in order to functionalize these structures with a photocatalytic, self-cleaning, cap material. N-doped TiO2 overlayers increased the selective absorption of visible light due to nitrogen doping in the anatase cell, thus, resulting in a concomitant increase in the overall photocatalytic efficiency.The authors acknowledge the financial support of the project “NANOPURIFY—Development of photocatalytic panels for air treatment units, Vieira & Lopes Lda.”, with the reference 024121, co-funded by the European Regional Development Fund (ERDF), through the Operational Programme for Competitiveness and Internationalisation (COMPETE 2020), under the PORTUGAL 2020 Partnership Agreement. Filipe C. Correia acknowledges the financial support from the Fundação para a Ciência e Tecnologia (FCT) for the Ph.D grant SFRH/BD/111720/2015

    Advances on the development of novel heterogeneous catalysts for transesterification of triglycerides in biodiesel

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    This paper describes experimental work done towards the search for more profitable and sustainable alternatives regarding biodiesel production, using heterogeneous catalysts instead of the conventional homogenous alkaline catalysts, such as NaOH, KOH or sodium methoxide, for the methanolysis reaction. This experimental work is a first stage on the development and optimization of new solid catalysts, able to produce biodiesel from vegetable oils. The heterogeneous catalytic process has many differences from the currently used in industry homogeneous process. The main advantage is that, it requires lower investment costs, since no need for separation steps of methanol/catalyst, biodiesel/catalyst and glycerine/catalyst. This work resulted in the selection of CaO and CaO modified with Li catalysts, which showed very good catalytic performances with high activity and stability. In fact FAME yields higher than 92% were observed in two consecutive reaction batches without expensive intermediate reactivation procedures. Therefore, those catalysts appear to be suitable for biodiesel production

    Current research, pressing issues, and lingering questions in marine invasion science: lessons from the Tenth International Conference on Marine Bioinvasions (ICMB-X)

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Fowler, A. E., Blakeslee, A. M. H., Bortolus, A., Dias, J., Tepolt, C. K., & Schwindt, E. Current research, pressing issues, and lingering questions in marine invasion science: lessons from the Tenth International Conference on Marine Bioinvasions (ICMB-X). Aquatic Invasions, 15(1), (2020): 1-10, doi:10.3391/ai.2020.15.1.01.Research on marine bioinvasions is an inherently international collaboration. Species range boundaries have become more fluid in recent decades as a result of enhanced human globalization, leading to species translocations across international boundaries through high profile vectors (e.g., shipping, hull fouling, aquaculture, etc.) (Ruiz et al. 2000; Seebens et al. 2013). Global trade and anthropogenic activities that promote invasive species spread continue to increase, rising by an average of 70% since 1970, with no sign of saturation (Pagad et al. 2015; Seebens et al. 2017). Even though these numbers are primarily based on terrestrial systems, recent work has demonstrated that marine ecosystems are as severely impacted by invasive species as by other human activities including overfishing, pollution (including plastics), climate change, and ocean acidification (Diaz et al. 2019). Species introductions to seas, coasts, and estuaries are therefore a global threat to human and non-human populations alike. As such, scientists and managers are increasingly focused on prevention and management, risk analysis and prioritization, and innovative technologies to detect novel species.The ICMB-X was supported by CONICET, MINCyT, SCTeIP Chubut, Consejo Federal de Inversiones, Biodiversity Heritage Library, Administración Portuaria de Puerto Madryn (APPM), Office of Naval Research Global, Aluar Aluminio Argentino, Madryn Bureau, Ente Mixto Puerto Madryn, Municipalidad de Puerto Madryn, and FAO-GEF-SAyDS

    The adhesion control of Listeria monocytogenes on food-processing surfaces by silver ion implantation

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    Bacterial adhesion to a solid surface is a crucial step in the biofilm process. Listeria monocytogenes can adhere to food-processing surfaces, survive and grow over a wide range of environmental conditions such as refrigeration temperatures and consequently cause severe disease. Several strategies have been developed with the aim to decrease the adherence of bacteria to surfaces, namely the silver ion implantation on surfaces. Thus, the aim of this work was to determine the Listeria monocytogenes CECT 4031 T adhesion ability onto four types of AISI 304 and AISI 430 surfaces usually used in food industry, restaurant, and kitchens, and simultaneously to evaluate the influence of the thermodynamics aspects on bacteria adhesion on these different surfaces.Coupons (1 cm-2) were cut from a 1 mm layer of AISI 304 and AISI 430 surfaces (N° 2B, 4 , 6 and 8). The silver ions (Ag+1) were implanted at 200 keV, 1.0 μA.cm-2 and a dose of 2.0×1016 ions.cm-2. All coupons were cleaned by immersion in 0.2% solution of a commercial detergent for 5 min, followed by immersion in ethanol for 15 min. The coupons were twice rising with ultrapure water and dried at 60 °C. Each strain was subcultured in trypticase soy broth (TSB) at 37 ºC in an orbital shaker (120 rpm), overnight. The cells were then harvested by centrifugation at 9000 rpm for 5 min and washed twice with phosphate buffered saline (PBS 0.1M pH 7). The pellets were resuspended in PBS to an inoculum level of 109 CFU.ml-1, determined by optical density. Adhesion assays were performed in sterile 24-well microtiter plates and each well was filled with 970 μl of TSB supplemented with 0.6% (w/v) of yeast extract, 30 μl of cell suspension and the respective coupon. The plates were incubated at 4 ºC for 2 h, with constant agitation at 120 rpm. After incubation, the coupons were washed once with 1.0 ml of minimal medium (MM) to remove non-adherent cells and replaced to a new well and the adhered cells were removed by scrapping on 1.0 ml of MM carefully. The number of viable cells was quantified by colony forming units (CFUs) on trypticase soy agar (TSA). The materials and Listeria cells hydrophobicity properties were evaluated through contact angle measurements and using the approach of van Oss and coworkers. The results showed that the strain used was able to adhere to all materials. It was not found significant differences (p > 0.05) between the means of the L. monocytogenes adhered cells on the twelve surfaces studied. However, the highest mean value of adherence cells occurred to AISI 304 N° 4 (4.78 ± 0.32 log CFU.cm-2) without silver ion implantation (wi) surface. Moreover, it was possible to observe that AISI 430 N° 8 with silver ion implantation (i) (4.29 ± 0.37 log CFU.cm-2) and AISI 430 N° 4 wi (3.60 ± 0.31 log CFU.cm-2) surfaces presentes the lowest means (p < 0.05). Concerning hydrophobicity, silver ion implantation increase the hydrophilicity of the surfaces, except in case of AISI 304 N° 6 (p.> 0.05). Furthermore, the results showed that L. monocytogenes cells are hydrophilic. Moreover, no correlation was observed between the number of adhered cells and substrate surface hydrophobicity, despite of the highest number of bacteria cells adhered mainly occured on surfaces with highest water contact angle value. The contact time between microorganism and silver implantated stainless steel surfaces seems not to be enough to confer antimicrobial activity. So, we consider that more studies are necessary to evaluate the effective effect of silver as antimicrobial agent to control the adhesion of L. monocytogenes cells and biofilms formation. As future work, we will study the effect of silver ion as antimicrobial different time periods

    Uncovering the Use of Fucoxanthin and Phycobiliproteins into Solid Matrices to Increase Their Emission Quantum Yield and Photostability

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    In the search for a better and brighter future, the use of natural luminescent renewable materials as substitutes for synthetic ones in the energy field is of prime importance. The incorporation of natural pigments (e.g., xanthophylls and phycobiliproteins) is a fundamental step in a broad spectrum of applications that are presently marred by their limited stability. The incorporation of bio-based luminescent molecules into solid matrices allows the fabrication of thin films, which may dramatically increase the range of applications, including sustainable photovoltaic systems, such as luminescent solar concentrators or downshifting layers. In this work, we incorporated R-phycoerythrin (R-PE), C-phycocyanin (C-PC), and fucoxanthin (FX) into poly(vinyl alcohol) (PVA) and studied their optical properties. It was found that the emission and excitation spectra of the phycobiliproteins and FX were not modified by incorporation into the PVA matrix. Moreover, in the case of FX, the emission quantum yield (η) values also remained unaltered after incorporation, showing the suitability of the PVA as a host matrix. A preliminary photostability study was performed by exposing the solid samples to continuous AM1.5G solar radiation, which evidenced the potential of these materials for future photovoltaics.publishe

    Toxocaríase humana: incidência de infecção em indivíduos residentes na periferia de Campinas, Estado de São Paulo, Brasil

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    With the aim of estimating the incidence of infection by Toxocara among residents in the outskirts of Campinas (State of São Paulo, Brazil) two serological surveys, using ELISA anti-Toxocara tests, were performed in January 1999 and January 2000, involving, respectively, 138 and 115 individuals, 75 of which examined in both occasions. Among this group 67 individuals did not show the presence of anti-Toxocara antibodies in 1999, and 12 presented seroconversion in the second survey, revealing an annual incidence rate of 17.9%.Dois inquéritos sorológicos empregando testes imunoenzimáticos (ELISA) anti-Toxocara foram realizados em moradores da periferia de Campinas (SP, Brasil) em janeiro de 1999 e janeiro de 2000, envolvendo, respectivamente, 138 e 115 indivíduos escolhidos aleatoriamente. Dos 75 indivíduos examinados em ambas as ocasiões, 67 apresentaram resultados negativos em 1999, observando-se soroconversão em 12 no segundo inquérito. Tais resultados indicam taxa anual de incidência de 17,9% para infecção por Toxocara na região
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