123 research outputs found

    O conceito de cientista em diferentes níveis de ensino

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    O ensino das ciências experimentais envolve um grande empenho, além de um consumo de tempo elevado, da parte dos professores para promover e induzir uma aprendizagem dinâmica de diversos conceitos científicos. Neste trabalho, é analisado o conceito de cientista no ensino básico e universitário. O presente estudo, relativo ao ano lectivo 2004 / 05, envolveu cerca de 600 alunos do ensino básico, desde o 5.º ao 9.º ano, com idades compreendidas entre os 10 e os 15 anos, das Escolas E.B. 2,3 D. Afonso III, Faro; E.B. 2,3 António Contreiras, Armação de Pêra e E.B. 2,3 Sto. António (n.º 4), Faro. Foram ainda abrangidos neste estudo cerca de 100 alunos do 1.º e 2.º anos das licenciaturas em Bioquímica, Engenharia do Ambiente e Oceanografia da Universidade do Algarve. Aos alunos foram colocadas duas questões, tendo sido definido um tempo máximo de 25 minutos para a primeira e de 15 minutos para a segunda: 1) Faça um desenho de um cientista; e, 2) O que é para ti um cientista

    Acoustic signalling during courtship in the painted goby, Pomatoschistus pictus

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    Gobies emit sounds during different stages of reproduction, including courtship, pre-spawning events (in the nest) and spawning. The breeding sounds of the painted goby Pomatoschistus pictus and associated courtship behaviour were recorded in captivity and described for the first time. Males emitted thump-like sounds mainly when displaying alone in the nest and produced drumming sounds outside the nest. Thumps have never been reported for other species of the genus Pomatoschistus. Thumps were short (~80 ms) very-low frequency (below 100 Hz) non-pulsed sounds, whereas drums were longer (hundreds of ms) and consisted of low frequency (~300 Hz) pulse trains. Thump characteristics varied significantly among males but also showed high within-male variability. The frequency of thump emissions and courtship behaviour (total number of courtship displays, lead and nest display) were positively correlated with male size but not with male somatic condition. Thump bursts emitted during nest displays were significantly longer than when emitted with other behaviours. These results suggest that larger males courted females more intensively, both with visual and acoustic displays, than smaller ones

    Male painted gobies (Pomatoschistus pictus) vocalise to defend territories

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    Many fish species emit sounds in agonistic contexts. During direct confrontations sounds are typically produced during the display phase in conjunction with visual exhibitions. Here we studied sound production during territorial defence in captive painted gobies, Pomatoschistus pictus, and related acoustic parameters with male traits and the date of recording (Julian day, i.e., with the approach of the peak of the breeding season). Territorial males emitted drumming sounds during displays that involved darkening the chin and fins, spreading fins and quivering the body. Drums were trains of low frequency pulses (≈23 pulses) repeated every 27 ms and usually lasting under a second. Drums were produced in short sequences of sounds (bursts). All acoustic parameters differed significantly among males. Drum and burst duration, and drum number of pulses increased significantly with male size. Calling duration (including drum, burst duration and drum number of pulses) also increased significantly with Julian date and presented a high intra-male variability, suggesting that these parameters may also depend on the individual’s motivation. We provide the first report for agonistic sound production in sand gobies and give evidence that sound parameters contain information that can be used during mutual assessment in contests over territories

    Serological and Molecular Survey of Leishmania infantum in a Population of Iberian Lynxes (Lynx pardinus)

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    This article belongs to the Special Issue Advances in Leishmania Research: From Basic Parasite Biology to Disease Control.Leishmania infantum, the sand fly-transmitted protozoan parasite responsible for leishmaniasis in humans, dogs, and cats, is endemic in the Iberian Peninsula. However, the impact of L. infantum infection on the conservation of the endangered Iberian lynx (Lynx pardinus) is unknown. Herein, we describe for the first time the occurrence of L. infantum infection among a population of reintroduced and wild-born L. pardinus living in the Portuguese Guadiana Valley Park. The presence of infection was addressed by molecular detection of Leishmania kinetoplast DNA (kDNA) in 35 lynxes, with further confirmation of L. infantum species performed by an internally transcribed spacer (ITS)-1 sequencing. Eight blood samples were positive for kDNA, and ITS-1 sequencing confirmed the presence of L. infantum in two of those samples. Exposure to Leishmania was screened in a group of 36 lynxes using an immunofluorescence antibody test (IFAT) and a multi-antigen enzyme-linked immunosorbent assay (ELISA), using SPLA, rK39, and CPX as Leishmania-specific antigens. Four animals presented a positive IFAT at a dilution of 1:40. Eight samples were considered seropositive to all ELISA Leishmania-specific antigens. Agreement between PCR, IFAT, and all ELISA antigens was found for 1 in 27 samples. These results highlight the susceptibility of autochthonous L. pardinus to L. infantum infection. Further investigation is required to assess the impact of L. infantum infection on this wild species conservation.This research was funded by the Parasite Disease Group at i3S, Porto, Portugal, and the Portuguese Foundation for Science and Technology (FCT) under the PhD scholarship number 2020.07306.BD and the project PTDC/CVT-CVT/6798/2020.info:eu-repo/semantics/publishedVersio

    Empleo de mostos Ugni blanc para reducir el contenido de alcohol y el pH de los vinos Tannat

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    Resumen El objetivo de esta investigación fue evaluar el efecto de la sustitución de mosto Tannat por mosto Ugni Blanc, sobre el contenido de alcohol, pH, color y composición fenólica de los vinos. Para ello, se realizaron vinificaciones por triplicado de mostos Tannat (VT) y mostos Tannat sustuidos con un 20% de mosto Ugni blanc (SM) en tres temporadas consecutivas. Se realizó un análisis climático de la región durante la maduración. Se evaluó la composición de la uva en cosecha y el color y la composición de los vinos a los cuatro meses del descube. Las características climáticas de las temporadas fueron contrastantes debido a la cantidad y distribución de las precipitaciones. Las uvas Tannat cosechada en el 2020 presentaron mayor concentración de azúcares, pH y riqueza fenólica. Las lluvias durante la temporada 2022 provocaron una mayor incidencia de Botrytis spp., afectando su potencial enológico. Los vinos SM presentaron menor contenido de etanol respecto a los VT. Los vinos SM y VT elaborados en la vendimia 2020, no presentaron diferencias en el pH, en tanto que para las demás temporadas los resultados fueron discordantes. La sustitución de mostos no afectó el color del vino, en tanto que las concentraciones de polifenoles totales, antocianos y taninos de los vinos SM fueron iguales o superiores a la de los vinos VT. La sustitución de mosto, parece ser una alternativa válida para la elaboración de vinos tintos con menos contenidos de alcohol, sin afectar negativamente su color ni su composición fenólica

    Diversity of Bacteria Associated with Bursaphelenchus xylophilus and Other Nematodes Isolated from Pinus pinaster Trees with Pine Wilt Disease

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    The pinewood nematode (PWN), Bursaphelenchus xylophilus, has been thought to be the only causal agent of pine wilt disease (PWD), however, since bacteria have been suggested to play a role in PWD, it is important to know the diversity of the microbial community associated to it. This study aimed to assess the microbial community associated with B. xylophilus and with other nematodes isolated from pine trees, Pinus pinaster, with PWD from three different affected forest areas in Portugal. One hundred and twenty three bacteria strains were isolated from PWN and other nematodes collected from 14 P. pinaster. The bacteria strains were identified by comparative analysis of the 16S rRNA gene partial sequence. All except one Gram-positive strain (Actinobacteria) belonged to the Gram-negative Beta and Gammaproteobacteria. Most isolates belonged to the genus Pseudomonas, Burkholderia and to the family Enterobacteriaceae. Species isolated in higher percentage were Pseudomonas lutea, Yersinia intermedia and Burkholderia tuberum. The major bacterial population associated to the nematodes differed according to the forest area and none of the isolated bacterial species was found in all different forest areas. For each of the sampled areas, 60 to 100% of the isolates produced siderophores and at least 40% produced lipases. The ability to produce siderophores and lipases by most isolates enables these bacteria to have a role in plant physiological response. This research showed a high diversity of the microbial community associated with B. xylophilus and other nematodes isolated from P. pinaster with PWD

    A complex scenario of tuberculosis transmission is revealed through genetic and epidemiological surveys in Porto

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    Tuberculosis (TB) incidence is decreasing worldwide and eradication is becoming plausible. In low-incidence countries, intervention on migrant populations is considered one of the most important strategies for elimination. However, such measures are inappropriate in European areas where TB is largely endemic, such as Porto in Portugal. We aim to understand transmission chains in Porto through a genetic characterization of Mycobacterium tuberculosis strains and through a detailed epidemiological evaluation of cases.This work was developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER), and supported by contributions from Iceland, Liechtenstein and Norway through the European Economic Area Grants under the Public Health Initiative programme, (PT06, Project 000138DT1). TR is supported by the Portuguese Foundation for Science and Technology (FCT) through a post-doctoral grant (SFRH/BPD/108126/2015)info:eu-repo/semantics/publishedVersio

    A“Dirty” Footprint: Macroinvertebrate diversity in Amazonian Anthropic Soils

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    International audienceAmazonian rainforests, once thought to be pristine wilderness, are increasingly known to have been widely inhabited, modified, and managed prior to European arrival, by human populations with diverse cultural backgrounds. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by pre-Columbian societies with sedentary habits. Much is known about the chemistry of these soils, yet their zoology has been neglected. Hence, we characterized soil fertility, macroinvertebrate communities, and their activity at nine archeological sites in three Amazonian regions in ADEs and adjacent reference soils under native forest (young and old) and agricultural systems. We found 673 morphospecies and, despite similar richness in ADEs (385 spp.) and reference soils (399 spp.), we identified a tenacious pre-Columbian footprint, with 49% of morphospecies found exclusively in ADEs. Termite and total macroinvertebrate abundance were higher in reference soils, while soil fertility and macroinvertebrate activity were higher in the ADEs, and associated with larger earthworm quantities and biomass. We show that ADE habitats have a unique pool of species, but that modern land use of ADEs decreases their populations, diversity, and contributions to soil functioning. These findings support the idea that humans created and sustained high-fertility ecosystems that persist today, altering biodiversity patterns in Amazonia

    Efeitos do estado de humor sobre os comportamentos alimentares inadequados de atletas de atletismo

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    O objetivo do presente estudo foi analisar os efeitos do estado de humor sobre os comportamentos alimentares inadequados (CAI) em atletas. Participaram 68 atletas de atletismo, do sexo feminino, com idades entre 12 e 17 anos. Utilizaram-se o Eating Attitudes Test (EAT-26) e a Escala de Humor de Brunel (BRUMS) para avaliar os CAI e o distúrbio total do humor (DTH), respectivamente. Dois modelos de regressão linear não indicaram influência estatisticamente significativa da BRUMS nas subescalas Dieta (p=0,42) e Bulimia e Preocupação com Alimentos (p=0,81) do EAT-26. Ao contrário, a BRUMS (p=0,04) demonstrou impacto significante (7%) sobre os escores da subescala Autocontrole Oral. Concluiu-se que as atletas com DTH elevado podem estar mais susceptíveis à influência ambiental para a ingestão alimentar
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