351 research outputs found
Age and growth of the Atlantic chub mackerel Scomber colias Gmelin, 1789 off Madeira Island
The Atlantic chub mackerel, Scomber colias Gmelin, 1789, is one of the main fisheries resources of Madeira Island. It is caught by a small and coastal purse-seine fleet that traditionally operates around the island. From January 2002 to December 2003, monthly samples of chub mackerel were collected from landings by this commercial fishing fleet. A total of 2212 sagitta otoliths were extracted for age readings from 1068 males (17.4-41.7 cm total length, TL), 1066 females (18.0-41.2 cm TL) and 78 undetermined (13.0-26.8 cm TL). A single reader aged the fishes using surface-read whole otoliths aiming to build annual age-length keys. Age readings precision and reader consistency were assessed by using the average percentage error index (APE ≤ 1.52). Ages were validated up to 4 years using marginal
analyses. Estimated mean lengths at age and length von Bertalanffy growth curve parameters, estimated by non-linear methods, showed no significant differences (p>0.05) between sexes (L∞=50.08 cm TL, k=0.252 yr-1 and t0=-1.339 yr; males and females combined). Length-weight relationships were estimated aiming to convert growth in length to growth in weight. No differences between sexes were found in length-weight parameters (P>0.05). For sexes combined, total weight (TW, g) = 0.00218.LT 3.40 and the estimated asymptotic weight, W∞=1523.7 g
Trends in the control of hexapod robots: a survey
The static stability of hexapods motivates their design for tasks in which stable locomotion is required, such as navigation across complex environments. This task is of high interest due to the possibility of replacing human beings in exploration, surveillance and rescue missions. For this application, the control system must adapt the actuation of the limbs according to their surroundings to ensure that the hexapod does not tumble during locomotion. The most traditional approach considers their limbs as robotic manipulators and relies on mechanical models to actuate them. However, the increasing interest in model-free models for the control of these systems has led to the design of novel solutions. Through a systematic literature review, this paper intends to overview the trends in this field of research and determine in which stage the design of autonomous and adaptable controllers for hexapods is.The first author received funding through a doctoral scholarship from the Portuguese Foundation for Science and Technology (FCT) (Grant No. SFRH/BD/145818/2019), with funds from the Portuguese Ministry of Science, Technology and Higher Education and the European Social Fund through the Programa Operacional Regional Norte. This work has been supported by the FCT national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020
Hexapod posture control for navigation across complex environments
Hexapod locomotion in unstructured environments relies on an efficient posture adjustment with the terrain topology. This paper presents a strategy to adapt the hexapod torso orientation through ground plane estimation. With an Inertial Measurement Unit (IMU) and the robot kinematic model, the current supporting feet coordinates are calculated, and the relative inclination between the ground and the torso angular position can be obtained. This information is used to adjust the novel foothold positions, in order to ensure the hexapod posture remains stable. The torso height is also controlled to avoid collisions with the ground asperities and decrease its deviation during motion. The proposed method is evaluated in a complex terrain made of 0.1×0.1 m blocks with variable height, causing different slopes across the field. Through result analysis, a significant behavior improvement is observed, due to the reduction of the torso posture oscillation and the increase of its locomotion
efficiency.The first author received funding through a doctoral scholarship from the Portuguese Foundation for Science and Technology (FCT) (Grant No. SFRH/BD/145818/2019), with funds from the Portuguese Ministry of Science, Technology and Higher Education and the European Social Fund through the Programa Operacional Regional
Norte. This work has been supported by FCT within the R&D Units Project Scope:
UIDB/00319/2020, UIDB/04436/2020 and UIDP/04436/2020
EEG Mode: emotional episode generation for social sharing of emotions
Social sharing of emotions (SSE) occurs when one communicates their feelings and reactions to a certain event in the course of a social interaction. The phenomenon is part of our social fabric and plays an important role in creating empathetic responses and establishing rapport. Intelligent social agents capable of SSE will have a mechanism to create and build long-term interaction with humans. In this paper, we present the Emotional Episode Generation (EEG) model, a fine-tuned GPT-2 model capable of generating emotional social talk regarding multiple event tuples in a human-like manner. Human evaluation results show that the model successfully translates one or more event-tuples into emotional episodes, reaching quality levels close to human performance. Furthermore, the model clearly expresses one emotion in each episode as well as humans. To train this model we used a public dataset and built upon it using event extraction techniques(1).info:eu-repo/semantics/publishedVersio
Chemical characterization, antioxidant and antimicrobial activities of winemaking industry by-products
The exploitation of bioactive compounds trom agri-food by-products has been
attracting an increasing interest from different industries within a circular economy
context since several of compounds may have health properties or be used as
natural colorants or preservatives. So far, several studies have been developed on
the characterization of red wine grape pomace and its components (seeds, skins,
and stems). However, less attention has been paid to other by-products, such as
grape pomace from white wine, the residues after distillation, wine lees, and
diatomaceous earth, the latter used in the filtration of wine and corresponding to
about 250 tons/year of waste in Portugal. In this work, samples of these by-products
were evaluated for their chemical composition by HPLC-DAD-ESI-Msn and
bioactivities (antioxidant activity by TBARS, DPPH, and reducing power assays, and
antimicrobial activity against eight bacteria and two fungi). Fifteen non-anthocyanin
phenolic compounds were found, including 5 phenolic acids, 4 flavan-3-0Is, 2 0-
glycosylated flavanols, 3 flavanol aglycones, and one unknown. In the red wine byproducts
12 anthocyanins were detected, most being malvidin derivatives. Wine
lees and white grape pomace before distillation presented the highest contents of
phenolic compounds. Ali samples showed antibacterial and antifunga! activity
against most of the tested microorganisms, with red and white grape pomace and
diatomaceous earth having the best bacteriostatic activity, while the lees stood out
against fungi. Ali samples showed promising antioxidant capacity, with very good
results obtained on TBARS for the white pomace after distillation and diatomaceous
earth. Overall, the results show that besides grape pomace other wine industry byproducts
are also good sources of bioactive compounds with high potential for
exploitation.To Campelo for the winemaking residues. To projecl "BacchusTech - Inlegrated Approach for
lhe Valorization of Winemaking Residues" (POCI-01-0247-FEDER-069583) and national
funds FCT/MCTES to CIMO (UIDB/00690/2020). L. Barros, M. Dias, S. Heleno Ihank FCT,
P.L, for Iheir scienlific employmenl program-contractinfo:eu-repo/semantics/publishedVersio
Chemical composition and biological activity of different residues obtained from the wine industry
In recent years, the bioactive compounds present in agri-food sub-products have attracted increased attention due
to their health benefits and advantages within a circular economy context. Annually, wine production is responsible
for the production of large amounts of phytotoxic waste, which elimination is considered challenging since these
residues can be hazardous to the environment when used as fertilizers or just discarded. Phenolic compounds are
secondary metabolites processed by plants that have shown several health benefits, acting as antioxidants,
antimicrobials, anticarcinogenic, or antidiabetics, among others. Bioactive phenolic molecules have attracted
considerable attention from the pharmaceutical, cosmetic, and food industries. So far, several studies have been
developed on the characterization of grape pomace and its components (seeds, skins, and stems), especially directed
to the residues of red varieties.1 However, less attention has been paid to other by-products generated during
winemaking, such as waste from the production of white wine, wine lees and diatomaceous earth. The latter is used
in the filtration of wine and constitutes about 250 tons/year of waste from the wine sector in Portugal alone, making
it a very pertinent residue with still scarce information being found in the literature. In this context, within the
framework of the BacchusTech project that seeks to develop new innovative processes, comprising the extraction,
purification, and concentration of bioactive compounds present in winemaking residues, different residues including
pomace, lees and diatomaceous earth were evaluated for their chemical composition and bioactivities. Residues were
extracted using an hydroalcoholic solvent (80%, v/v), total phenolic compounds were estimated using the Folin-
Ciocalteu reagent and individual phenolic compounds were identified and quantified by liquid chromatography
coupled to mass spectrophotometry (HPLC-DAD-ESI-MSn). Additionally, the biological activity was assessed through
TBARS, DPPH, and reducing power assays to determine the antioxidant activity, and the antimicrobial activity was
evaluated by broth microdilution against eight bacteria and two fungi.
The phenolic composition was in accordance with the previously reported in red wines.2,3 Fifteen non-anthocyanin
phenolic compounds were found, five phenolic acids (gallic acid and derivatives, p-hydroxybenzoic and p-coumaric
acid), four flavan-3-ols (procyanidin dimers), two O-glycosylated flavanols (isorhamnetin and quercetin derivatives),
three flavanol aglycones (quercetin, kaempferol, and myricetin), and one unknown compound. Regarding
anthocyanins, five compounds were found, namely malvidin derivatives linked to acyl groups. Wine lees and white
grape pomace before distillation presented the highest contents of phenolic compounds; however, only
diatomaceous earth sample reveal the presence of O-glycosylated flavonoids. All samples showed antibacterial and
antifungal activity against most of the tested microorganisms. The best bacteriostatic activity was evidenced by the
red and white grape pomace before distillation and diatomaceous earth, while the wine lees stood out for their
fungistatic activity. In general, all samples showed promising antioxidant capacity, with very good results being
obtained on TBARS assay, particularly for the white pomace after distillation (EC50 = 0.016±0.002 mg/mL),
diatomaceous earth (EC50 = 0.063±0.001 mg/mL) and red pomace before distillation (EC50 = 0.08±0.04 mg/mL).
Overall, the results obtained showed that the residues analyzed are good sources of bioactive compounds, namely
anthocyanins and other phenolic compounds, which can be used as raw materials for the steps of concentration,
purification and/or isolation of compounds of added value.To Campelo for supplying the winemaking residues. To project “BacchusTech - Integrated Approach for the
Valorization of Winemaking Residues” (POCI-01-0247-FEDER-069583). L. Barros, M.I. Dias, and S. Heleno (CEECIND/00831/2018)
thank the national funding by FCT, P.I., through the institutional and individual scientific employment program-contract for their
contract.
Funding: This work was financially supported by the Competitiveness and Internationalization Operational Program (COMPETE
2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and
Foundation for Science and Technology (FCT, Portugal) through national funds FCT/MCTES to the CIMO (UIDB/00690/2020). The
GIP-USAL is financially supported by the Spanish “Ministerio de Ciencia and Innovación” (PID2019-106167RB-I00) and “Junta de
Castilla y León” (SA093P20 and CLU-2018-04).info:eu-repo/semantics/publishedVersio
First records of Tarentola mauritanica (Linnaeus, 1758) (Reptilia; Gekkonidae) in the Azores
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
Valorization of seaweed carbohydrates: autohydrolysis as a selective and sustainable pretreatment
Seaweeds are promising feedstocks; nevertheless, the lack of systematic approaches to recover different high-value fractions in a clean and sustainable mode hampers their exploitation. Due to this necessity, an innovative environmentally friendly strategy was proposed in this article for the development of a sugar platform from Gelidium sesquipedale: for the first time, autohydrolysis followed by enzymatic saccharification (with cellulolytic and agarolytic cocktails) was applied to agarophyte seaweeds. The wide range of severities (between 2.47 and 4.94) studied in this work proved that the autohydrolysis-based process can be tuned to selectively extract different target carbohydrate fractions. Gelling agents (reaching 30 g/100 g DW) can be obtained by the application of low severity treatments, fermentable sugars or oligosaccharides with the nutraceutical potential (reaching 14 g/100 g DW) are produced when severity is increased, and at the highest severity, platform chemicals (reaching 4 g/100 g DW) are the final product. The reduction of processing times compared to traditional extraction methodologies and the elimination of chemicals used in dilute acid treatments make this strategy a clean and sustainable alternative for the valorization of both glucan and galactan fractions of G. sesquipedale.This work was supported by the Portuguese Foundation forScience and Technology (FCT), under the scope of thestrategic funding of UID/BIO/04469/2020 unit and under thescope of the project “AlgaePlas-Biorefinery of macroalgae forvalorization of the carbohydrate fraction to sustainablebioplastics,”PTDC/BII-BIO/29242/2017.info:eu-repo/semantics/publishedVersio
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