Browsing by Issue Date, starting with "2021-01"
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- Quina retouch does not maintain edge angle over reductionPublication . Lin, Sam C.; Marreiros, JoaoThe Quina scraper features an important role in the discussion of European Middle Palaeolithic variability. Explanations for its characteristic retouch and blank morphology have ranged from economic to functional and cultural considerations. One hypothesis is that Quina retouch maintains the edge angle of the retouched margin, allowing the upkeep of high cutting potential despite repeated resharpening. In this study, we examine this hypothesis by using a sample of scrapers from the Middle Palaeolithic site of Roc de Marsal in southwest France. The results show that, when the influence of reduction intensity and flake thickness are controlled, Quina retouch has no detectable impact on the retouched edge angle. Instead, the overall higher edge angles among Quina scrapers are a product of continuous reduction and the use of thicker blanks. We discuss possible factors underlying the occurrence of Quina retouch with respect to lithic economy and function.
- Recent Macaronesian kinematics from GNSS ground displacement analysisPublication . Barbero, Ignacio; Torrecillas, Cristina; Paez, Raul; Prates, Gonçalo; Berrocoso, ManuelMacaronesia is a complex oceanic region spanning three tectonic plates in the northeast Atlantic ocean. It is composed of four archipelagos, widely distributed and limited to the east by the Iberian Peninsula and north-western coast of Africa. This study aims to clarify recent Macaronesian kinematics from 19 GNSS stations located on the four archipelagos and the Iberian and African coastlines. The analysis is based on nearly 15 years of common data acquisition and aimed to detect new effects of intraplate tectonics or similar local/regional events consistent with calculated ground displacements. Evaluating the GNSS stations residual velocities relative to those expected from the NNR-MORVEL56 model, higher residuals were found at continental coastal stations (Africa) than at oceanic ones (Canaries and Madeira). From the computed strain rate map, the possible existence of a shear zone connecting the Gloria and Transmoroccan fault systems, already mentioned by other authors, was depicted. Cluster statistical analysis of the horizontal residual velocities helped to identify tectonic boundaries in Macaronesia and four groups of analogous intraplate residual velocities within this region. Three of four groups were identified in the Azores, highlighting the African-Nubian-Eurasian diffuse plate boundary in this region. Furthermore, in the Canary Islands, two distinct kinematic behaviours were detected, possibly due to the activity along a previously detected tectonic fault between Tenerife and Gran Canaria, where some stations have similar intraplate residuals to those at Madeira and Cape Verde stations, while others have similar intraplate residuals to those of continental stations. Finally, all stations on oceanic crust, except Cape Verde, present recent ground subsidence which may be attributed to isostatic adjustment.
- The genus Cystoseira s.l. (Ochrophyta, Fucales, Sargassaceae) in the Black Sea: morphological variability and molecular taxonomy of Gongolaria barbata and endemic Ericaria crinita f. bosphorica comb. nov.Publication . Sadogurska, Sofia S.; Neiva, João; Falace, Annalisa; Serrao, Ester; Israel, AlvaroBrown algae of the genus Cystoseira sensu lato form the most diverse and productive marine ecosystems throughout the Mediterranean Sea and have equal roles also in the Black Sea where they have been decreasing in the recent years. The taxonomy of Cystoseira s.l. taxa from the Black Sea is still not well understood, and questions arise when related taxa have to be delimited. In addition to morphological descriptions, this study provides for the first time molecular data of the Black Sea Cystoseira s.l. distinct morphologies as an additional tool to clarify their identities and phylogenetic affinities. The analysis of two mitochondrial markers (cytochrome oxidase subunit 1-COI, and 23S-tRNAVal intergenic spacer-mt-spacer) showed that Cystoseira s.l. specimens from the Black Sea belong to two recently resurrected genera, namely Gongolaria and Ericaria. Molecular data confirm the morphological identification of G. barbata, which is characterized by high morphological plasticity in the Black Sea. The morphological data presented in this study support the transition of G. barbata to the genus Gongolaria, which was previously proposed based solely on genetic data. For the Black Sea endemic taxon C. bosphorica, sequence divergence suggests conspecificity with Mediterranean Sea species E. crinita and E. barbatula. However, considering original morphological characteristics of the taxon, its geographical isolation, and endemism, the new combination Ericaria crinita f. bosphorica comb. nov. is proposed.
- Environmental protection requires accurate application of scientific evidencePublication . Smith, Craig R.; Tunnicliffe, Verena; Colaco, Ana; Drazen, Jeffrey C.; Gollner, Sabine; Levin, Lisa A.; Mestre, Nélia; Metaxas, Anna; Molodtsova, Tina N.; Morato, Telmo; Sweetman, Andrew K.; Washburn, Travis; Amon, Diva J.
- A realistic scenario on microalgae based biodiesel production: third generation biofuelPublication . Ananthi, V.; Raja, Rathinam; Carvalho, Isabel Saraiva de; Brindhadevi, Kathirvel; Pugazhendhi, Arivalagan; Arun, A.Microalgae are the widely employed sources of third generation biofuels, which attracted huge attention by the researchers of the present decade because of their great productivity with lipid content. But to date, the utilization of microalgae for renewable biofuel production is not considered economically viable. The various growth modes employed for microalgal cultivation, such as phototrophic, heterotrophic, mixotrophic, photo-heterotrophic has been compared and conferred in the current investigation. A wide variety of microalgal harvesting techniques that balance energy and economic sustainability is being carried out nowadays. Based on the culture employed, mode and conditions of microalgal cultivation, the choice of bioreactor differs like an open system or closed system bioreactor. This review discusses the basis, key challenges and the future perspective of present-day microalgal cultivation conditions regarding biomass and lipid production. Concurrently the impacts of cultivation mode, bioreactor used for lipid productivity to improve profitable microalgal biodiesel have also been summarized.
- Two new deep-sea species of Laonice (Annelida: Spionidae) from the Mediterranean SeaPublication . Sikorski, Andrey V.; Pavlova, Lyudmila V.; Sarda, Rafael; Langeneck, Joachim; Gil, João; Ravara, AscensaoTwo new deep-sea species of the genus Laonice belonging to the subgenera Sarsiana and Appelloefia respectively, are described from the Mediterranean Sea. Complete specimens of the subgenus Appelloefia were studied for the first time, and the new information collected raised questions on the boundaries between the subgenera Appelloefia and Norgensia. The presence of characters in L. barcinensis sp. nov. previously considered to be exclusive to each these two subgenera suggests that they should be regarded as synonymous. The name Appelloefia being given precedence here, according to the Principle of the First Reviser. A correction is made regarding the depth range of Laonice rasmusseni Sikorski & Pavlova, 2018.
- Removal of seston by Crassostrea rhizophorae (Guilding, 1828) in the Vitoria bay estuarine system, BrazilPublication . Leite, Thayana de Alencar; Barroso, Gilberto Fonseca; Pereira Tognella, Monica Maria; Pascoalini, Savia Soares; Chicharo, LuisThe clearance of organic suspended particles by bivalve mollusks in estuarine ecosystems has been considered a critical regulating service. In Neotropical estuaries and associated mangrove ecosystems, the mangrove oyster, Crassostrea rhizophorae, is a key species in such process. To evaluate C. rhizophorae clearance rates (CRbd), biodeposit experiments were carried out at dry (2015) and wet (2016) seasons, in three sites of the Vitoria Bay Estuarine System (VBES), southeastern Brazil. The average CRbd was 0.67 L.g(-1).h(-1), which can be regarded as low CR. Although organic fraction predominates in the particulate matter (>60%), high estuarine salinity caused by low river discharge during prolonged regional drought, impaired oyster feeder rates. When the CRbd take into account the estimate entire mangrove oyster biomass at the VBES (3.77 x 10(5) kg.km(-2)) it yields a rate of 6.51 x 10(6) m(3).kg(-1).day(-1), corresponding to a mean daily capacity of organic seston removal of 26% of the total estuarine volume. Even conservative, this result highlights the importance of mangrove oyster for the estuarine regulation, emphasizing its ecological importance and the need to sustain the critical ecosystem services of regulating estuarine environmental quality. (C) 2021 European Regional Centre for Ecohydrology of the Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.
- Fusing convolutional generative adversarial encoders for 3D printer fault detection with only normal condition signalsPublication . Li, Chuan; Cabrera, Diego; Sancho, Fernando; Sanchez, Rene-Vinicio; Cerrada, Mariela; Long, Jianyu; Oliveira, José Valente deCollecting data from mechanical systems in abnormal conditions is expensive and time consuming. Consequently, fault detection approaches based on classical supervised learning working with both normal and abnormal data are not applicable in some condition-based maintenance tasks. To address this problem, this paper proposes Fusing Convolutional Generative Adversarial Encoders (fCGAE) method to create fault detection models from only normal data. Firstly, to obtain an adequate deep feature space, encoder models based on 1D convolutional neural networks are created. Then, these encoders are optimized in an unsupervised way through Bidirectional Generative Adversarial Networks. Finally, the multi-channel features collected from the system are merged with One-Class Support Vector Machine. fCGAE is applied to fault detection in 3D printers, where experimental results in two fault detection cases show excellent generalization capabilities and better performance compared to peer methods. (C) 2020 Elsevier Ltd. All rights reserved.
- Untangling the origin of the newcomer Phorcus sauciatus (Mollusca: Gastropoda) in a remote Atlantic archipelagoPublication . Baptista, Lara; Santos, Antonio M.; Melo, Carlos S.; Rebelo, Ana C.; Madeira, Patricia; Cordeiro, Ricardo; Botelho, Andrea Z.; Hipolito, Ana; Pombo, Joana; Voelker, Antje; Avila, Sergio P.The marine topshell Phorcus sauciatus is currently found along the temperate-subtropical shores of the Northeast Atlantic Ocean. Although present in the Iberian Peninsula, Madeira, and Canaries for centuries, P. sauciatus has only recently reached another oceanic volcanic archipelago in the region. In 2013, a small population was recorded for the first time in Santa Maria Island (Azores), widening its distribution around the entire island and to the neighbouring island of SAo Miguel in a short period of time. The success of such colonization of the remote archipelago by P. sauciatus still awaits an explanation. To better understand the populational dynamics of the species in the NE Atlantic Ocean, we used a molecular approach to evaluate the genetic structure of P. sauciatus aiming at the determination of a potential origin for the first individuals that reached the Azores. On the foundations of detailed oceanographic, palaeontological, and ecological data, we discuss the impact of climate change as a trigger for colonization of remote oceanic islands and suggest a mechanism that might explain the long-distance dispersal of the non-planktotrophic gastropod P. sauciatus across important biogeographical barriers in the NE Atlantic.
- Leaf mineral element content and soil characteristics on in vitro antioxidant and enzymatic inhibitory activities of aqueous fennel extractsPublication . MAJDOUB, Nesrine; EL-GEUNDOUZ, Soukaina; Carlier, Jorge; Clara Costa, Maria; Guerrero, Carlos; Duarte, João; Miguel, Mariahis study was conducted to evaluate the biochemical characterization of three harvested Foeniculum vulgare plants collected from two bioclimatic zones in order to investigate the soil growing conditions effect. The results showed a great variability of the phenolic amounts and biological properties of samples rely on localities. FvSEN contained the highest amounts of phenolic compounds. These amounts were accompanied by the greatest antioxidant ability through almost studied assays. FvSEN and FvZO were significantly different. In addition, the samples exhibited a significant and variable enzymatic inhibition activity with values ranging from 30 to 50 mu g/mL for lipoxygenase assay. But these extracts did not revealed significant differences on their tyrosinase abilities. On the other hand, the levels of mineral elements were also estimated. These contents varied depending on sample and locality. The growing soil conditions of samples in terms of different parameters is likely related to their antioxidant and enzyme inhibition potentialities added to their mineral composition which settled by Spearman's correlation. These data may confirm the interesting potential of F. vulgare as a valuable source for natural antioxidant molecules but the growing soil conditions can affect all the potentialities of these plants set for human consumption and other uses.