932 resultados para Aquatic invertebrates.
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In recent years, attacks by piranhas have become a common problem in dammed portions of rivers and streams in the State of Sao Paulo, Southeastern Brazil. In two outbreaks recorded in two neighboring counties in the Northwest region of the state, 74 bathers were bitten. Only one bite per person was recorded during a short period of the year. The bites were related to parental care and/or defense of spawning territory, which confirms previous studies and demystify the attacks by these legendary fish, as they are perceived by most people. Placement of fine mesh nets and removal of aquatic vegetation stopped the attacks.
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New emerging contaminants could represent a danger to the environment and Humanity with repercussions not yet known. One of the major worldwide pharmaceutical and personal care productions are antimicrobials products, triclosan, is an antimicrobial agent present in most products. Despite the high removal rate of triclosan present in wastewater treatments, triclosan levels are on the rise in the environment through disposal of wastewater effluent and use of sewage sludge in land application. Regulated in the EC/1272/2008 (annex VI, table 3.1), this compound is considered very toxic to aquatic life and it has been reported that photochemical transformation of triclosan produces dioxins. In the current work it was defined three objectives; determination of the most efficient process in triclosan degradation, recurring to photochemical degradation methods comparing different sources of light; identification of the main by-products formed during the degradation and the study of the influence of the Fenton and photo-Fenton reaction. Photochemical degradation methods such as: photocatalysis under florescent light (UV), photocatalysis under visible light (sunlight), photocatalysis under LEDs, photo-Fenton and Fenton reaction have been compared in this work. The degradation of triclosan was visualized through gas chromatography/mass spectrometry (GC/MS). In this study photo-Fenton reaction has successfully oxidized triclosan to H2O and CO2 without any by-products within 2 hours. Photocatalysis by titanium dioxide (TiO2) under LEDs was possible, having a degradation rate of 53% in an 8 hours essay. The degradation rate of the Fenton reaction, UV light and sunlight showed degradation between 90% and 95%. The results are reported to the data observed without statistic support, since this was not possible during the work period. Hydroquinone specie and 2,4-dichlorophenol by-products were identified in the first hour of photocatalysis by UV. A common compound, possibly identified has C7O4H , was present at the degradation by UV, sunlight and LEDs and was concluded to be a contaminant. In the future more studies in the use of LEDs should be undertaken given the advantages of long durability and low consumption of energy of these lamps and that due to their negative impact on the environment fluorescent lamps are being progressively made unavailable by governments, requiring new solutions to be found. Fenton and photo-Fenton reactions can also be costly processes given the expensive reagents used.
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INTRODUCTION: Findings of immature forms of Coquillettidia venezuelensis in temporary breeding sites, without the presence of aquatic plants or other submerged plant tissue are reported. METHODS: A systematic scooping technique to collect specimens was used at the breeding site. RESULTS: Immature forms of Coquillettidia venezuelensis, Anopheles rangeli, An. evansae and Culex sp. were collected from areas of the hydroelectric power station of São Salvador, State of Goiás. CONCLUSIONS This is a novel finding relating to the bioecology of Cq. venezuelensis, a species of medical interest that has been found naturally infected with arboviruses, including Oropouche and West Nile virus.
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Land plant evolution required the generation of a new body plan that could resist the harsher and fluctuating environmental conditions found outside of aquatic environments. Unraveling the genetic basis of plant developmental innovations is not only revealing in terms of an evolutionary point of view, but it is also important for understanding the emergence of agronomically important traits. Comparative genetic studies between basal and modern land plants, both at the genome and trancriptome levels, can help in the generation of hypotheses related to the genetic basis of plant evolutionary development.(...)
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INTRODUCTION: Injuries caused by sea urchins are the most common caused by marine animals in humans in Brazil, with the black sea urchin (Echinometra lucunter) causing the most injuries to bathers. METHODS: This study observed 314 human wounds with emphasis on the early observation of clinical signs and symptoms and their implications on the recommended treatment. RESULTS: All the injuries were caused by black sea urchins and were observed in bathers. The lesions and the pain were associated with penetration of the spines; there was no early inflammation or pain without pressure on the wounded places. Complications arising from this kind on injury, including infections and foreign body granulomas, are associated with the permanence of the spines in the wounds. CONCLUSIONS: The study confirmed that this kind of injury is the most common accident caused by aquatic animals in Brazil. The main therapeutical recommendation is early removal of the spines to prevent late complications, such as infections and the formation of foreign body granulomas.
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RESUMO: Introdução e Objetivos: O exercício é uma das modalidades mais utilizadas no tratamento da Dor Lombar Crónica (DLC) mas também a mais recomendada pela literatura atual. Apesar de efetivo, o exercício não parece responder às características cognitivas e comportamentais identificadas nesta população. Assim, existem recomendações para que seja coadjuvado por educação de forma a minimizar a influência nos resultados de variáveis como o medo do movimento. Porém não é conhecido o real impacto nos resultados de um programa educacional quando acrescentado a um programa de exercício. O objetivo deste estudo foi investigar os efeitos de um programa de exercício aquático coadjuvado por educação baseada na neurofisiologia da dor (grupo experimental) comparado a um programa de exercício aquático isolado (grupo controlo), ao nível da intensidade da dor, incapacidade funcional e medo do movimento, em indivíduos com DLC. Metodologia: Sessenta e dois indivíduos com DLC foram aleatoriamente distribuídos pelo grupo experimental (n= 30) e pelo grupo controlo (n= 32). Os participantes de ambos os grupos realizaram um programa de 6 semanas constituído por 12 sessões de exercício aquático. No caso do grupo experimental foram realizadas duas sessões de educação baseada na neurofisiologia da dor (EBN) antes do programa de exercício aquático. As medidas de avaliação primárias foram a intensidade da dor (Escala Visual Análoga) e a incapacidade funcional (Quebec Back Pain Disability Scale). Secundariamente avaliou-se o medo do movimento através da Tampa Scale of Kinesiophobia. Os participantes foram avaliados antes da intervenção, 3 semanas após o início do programa de exercício aquático, no final da intervenção e 3 meses após o final da intervenção. Resultados: Foram encontradas melhorias significativas no final da intervenção ao nível da intensidade da dor e incapacidade funcional em ambos os grupos. Após 3 meses, apenas o grupo experimental apresentou melhorias significativas nas variáveis primárias. Na comparação entre grupos, os resultados foram favoráveis ao grupo experimental para a intensidade da dor nas avaliações após a intervenção (p= 0,032) e após 3 meses (p= 0,007). Quanto à incapacidade funcional e medo do movimento não se verificaram diferenças significativas entre grupos em nenhum momento. Também as medidas de relevância clínica utilizadas (tamanho do efeito; risco relativo; number needed to treat) favoreceram o grupo experimental. Conclusões: Os resultados mostram que um programa de exercício aquático e EBN foi mais efetivo na melhoria da intensidade da dor a curto e médio prazo do que um programa de exercício aquático isolado. Apesar de serem necessárias mais investigações sobre este tema, este estudo demonstra que a EBN pode otimizar os resultados quando associada a outras intervenções ativas como o exercício aquático.----------------ABSTRACT: Introduction and Objectives: Exercise is one of the most used modalities in the treatment of Chronic Low Back Pain (CLBP) but also the most recommended in current literature. Although it’s effective, exercise does not seem to respond to the cognitive and behavioural characteristics identified in this population. Thus, it is recommended to be assisted by education in order to minimize the influence of variables on the results such as the fear of movement. However, the real impact on the results of an educational program when added to an exercise program is not known. The aim of this study was to investigate the effects of a program of aquatic exercise and neurophysiology pain education (experimental group) compared to aquatic exercise program alone (control group), on the outcomes of pain intensity, functional disability and fear of movement in individuals with CLBP. Methodology: Sixty two individuals with CLBP were randomly distributed in the experimental group (n = 30) and in the control group (n = 32). Participants in both groups performed a 6-week program consisting of 12 sessions of aquatic exercise. In the case of the experimental group two sessions of neurophysiology pain education (NPE) were performed before the aquatic exercise program. The primary outcomes were pain intensity (Visual Analogue Scale) and functional disability (Quebec Back Pain Disability Scale). Secondarily, the fear of movement through the Tampa Scale of Kinesiophobia was assessed. Participants were assessed before the intervention, three weeks after the start of the aquatic exercise program, at the end of the intervention and 3 months after the end of the intervention. Results: Significant improvements were found at the end of the intervention in both groups in what intensity of pain and functional disability were concerned. After 3 months, only the experimental group showed significant improvements in the primary outcomes. Comparing both groups, the results favoured to the experimental group for intensity of pain scores after the intervention (p = 0.032) and after 3 months (p = 0.007). The functional disability and fear of movement had no significant differences between groups at any time. In addition, the measures of clinical relevance used (size effect; relative risk; number needed to treat) favoured the experimental group. Conclusions: The results show that a program of aquatic exercise and NPE were more effective in improving pain intensity at a short and medium term than an aquatic exercise program alone. Although more research on this topic is needed, this study demonstrates that the NPE can optimize results when combined with other active interventions such as aquatic exercise.
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In Amazonian floodplains the trees are exposed to extreme flooding of up to 230 days a year. Waterlogging of the roots and stems affects growth and metabolic activity of the trees. An increased leaf fall in the aquatic period and annual increment rings in the wood indicate periodical growth reductions. The present study aims at documenting seasonal changes of metabolism and vitality of adult trees in the annual cycle as expressed by changes of leaf nitrogen content. Leaves of six tree species common in floodplains in Central Amazonia and typical representants of different growth strategies were collected every month between May 1994 and June 1995 in the vicinity of Manaus, Brazil. Mean leaf nitrogen content varied between 1.3% and 3.2% in the non-flooded trees. Three species showed significantly lower Ν content in the flooded period (p=0.05, 0.001, 0.001), the difference ranging 20-25% lower than in the non-flooded period. Two species showed no significant difference while Nectandra amazonum showed 32% more Ν in the flooded season (p=0.001). Leaf nitrogen content was generally high when new leaves were flushed (in the flooded period) and decreased continuously thereafter in all species. Three species showed an additional peak of nitrogen during the first month of the terrestrial phase, in leaves which had flushed earlier, indicating that flooding may disturb nitrogen uptake.
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The cardinal tetra (Paracheirodon axelrodi) is the most intensively commercialized ornamental fish from the Rio Negro Basin (Amazonas State, Brasil). Analysis of the stomach and gut contents of fish caught in their natural habitats show conclusively that the cardinal is essentially a predator, feeding on the mesofauna that adheres to submerged litter, roots and waterplants. Microcrustacea and chironomid larvae (Diptera) were the most frequently ingested prey, while algae intake was relatively infrequent. It is argued that the relatively small size of the cardinals captured in their natural habitat is due to the annual migrations imposed by the inundation cycles, rather than to resource limitation, because it is known from earlier investigations of similar habitats, that these plant substrates are densely colonized by the aquatic mesofauna. Cardinals raised in captivity are larger and have higher rates of growth.
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In an underwater environment it is difficult to implement solutions for wireless communications. The existing technologies using electromagnetic waves or lasers are not very efficient due to the large attenuation in the aquatic environment. Ultrasound reveals a lower attenuation, and thus has been used in underwater long-distance communications. The much slower speed of acoustic propagation in water (about 1500 m/s) compared with that of electromagnetic and optical waves, is another limiting factor for efficient communication and networking. For high data-rates and real-time applications it is necessary to use frequencies in the MHz range, allowing communication distances of hundreds of meters with a delay of milliseconds. To achieve this goal, it is necessary to develop ultrasound transducers able to work at high frequencies and wideband, with suitable responses to digital modulations. This work shows how the acoustic impedance influences the performance of an ultrasonic emitter transducer when digital modulations are used and operating at frequencies between 100 kHz and 1 MHz. The study includes a Finite Element Method (FEM) and a MATLAB/Simulink simulation with an experimental validation to evaluate two types of piezoelectric materials: one based on ceramics (high acoustic impedance) with a resonance design and the other based in polymer (low acoustic impedance) designed to optimize the performance when digital modulations are used. The transducers performance for Binary Amplitude Shift Keying (BASK), On-Off Keying (OOK), Binary Phase Shift Keying (BPSK) and Binary Frequency Shift Keying (BFSK) modulations with a 1 MHz carrier at 125 kbps baud rate are compared.
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Mesovelia mulsanti White, 1879 and M. zeteki Harris & Drake, 1941 are newly recorded in the Amazon River floodplain, Brazil. A key to the three known species ocurring in this region is also provided. Mesovelia mulsanti can be distinguished from M. amoena and M. zeteki by the body length larger than 2.50 mm, the head without longitudinal brown stripes near midline, and the forefemur and midfemur of the male, which have ventral rows of spines. Mesovelia amoena differs from M. zeteki in aspects of body color and in number of spinules near posterior margin of abdominal sternite VI of male.
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The biology and ecology of South American turtles is still poorly known, particularly, for the Brazilian species. Laboratory studies are essential to understand the life cycles of aquatic turtles species and to help in formulating management plans for their conservation. As a contribution to the knowledge of Podocnemis erythrocephala species, we give a description of its species-typical behaviors, categorized as: maintenance, locomotion, feeding, agonistic and reproduction, based on captives observations of four pairs of turtles in an aquarium in Manaus, Brazil. Similarities and differences with the repertoires of other turtle species are discussed, concluding that turtles have much more complex adaptative strategies and social life than was believed.
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Dissertação de mestrado integrado em Arquitectura
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Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Engenharia Clínica)
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We assessed aquatic hyphomycete diversity in autumn and spring on oak leaves decomposing in five streams along a gradient of eutrophication in the Northwest of Portugal. Diversity was assessed through microscopy-based (identification by spore morphology) and DNA-based techniques (Denaturing Gradient Gel Electrophoresis and 454 pyrosequencing). Pyrosequencing revealed five times greater diversity than DGGE. About 21% of all aquatic hyphomycete species were exclusively detected by pyrosequencing and 26% exclusively by spore identification. In some streams, more than half of the recorded species would have remained undetected if we had relied only on spore identification. Nevertheless, in spring aquatic hyphomycete diversity was higher based on spore identification, probably because many species occurring in this season are not yet connected to ITS barcodes in genetic databases. Pyrosequencing was a powerful tool for revealing aquatic hyphomycete diversity on decomposing plant litter in streams and we strongly encourage researchers to continue the effort in barcoding fungal species.
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Centipedes are opportunistic carnivore predators, and large species can feed on a wide variety of vertebrates, including bats. The aim of this study was to report the third record of bat predation by centipedes worldwide, the first record in the Amazon region, while covering aspects of foraging, capture and handling of prey. We observed the occurence in a fortuitous encounter at Cristalino State Park, located in the Amazon region of the state of Mato Grosso, Brazil. The attack took place in a small wooden structure, at about three meters from the floor, and was observed for 20 minutes. During the observation, the centipede stung the neck and abdominal region of the bat several times, grabbing the prey with its 15 pairs of front legs while hanging from the ceiling with its hind legs. This type of observation suggests that vertebrates can be important preys for invertebrates such as giant centipedes, both for its nutritional composition and for the amount of energy available in a single prey.