1,550 research outputs found

    Preliminary study of antimicrobial action of essential oils on etiological agents of mastitis in shee

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    The control of mastitis is currently reliant on antibiotic utilization. Nevertheless antibiotics overuse and use without criteria leads to the development of resistant strains with negative consequences both in animal and public health. Essential oils (EOs) are classified as GRAS (generally recognized as safe), are provided with antimicrobial properties and no resistance has been reported after use. The aim of this study was to evaluate the antimicrobial activity of EOs of aromatic herbs, growing wild in Alentejo region and widely used in Mediterranean food, against microorganisms isolated from ovine mastitic milk

    Antimicrobial activity of essential oils of Lamiaceae aromatic spices towards sheep mastitis-causing Staphylococcus aureus and Staphylococcus epidermidis

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    Mastitis in ewes is responsible for massive economic losses. Antibiotics are routinely used for mastitis control but its excessive use leads to development of antibiotic resistance with deleterious outcomes both for animal and public health. Essential oils (EOs) show antibacterial proprieties and no resistance has been reported after prolonged exposure; however their efficacy depends on their chemical composition. In this study EOs chemical composition from four autochthonous aromatic herbs, from Alentejo region, southern Portugal, Calamintha nepeta subsp. nepeta, Lavandula stoechas subsp. luisieri, Rosmarinus oficinalis and Thymus mastichina was accessed. EOs of R. officinalis showed predominance in monoterpene hydrocarbons (63%) whereas EOs of T. mastichina, L. luisieri and C. nepeta were rich in oxygenated monoterpenes (71-95%). The antimicrobial activity of selected EOs was investigated towards Staphylococcus aureus (n= 24) and Staphylococcus epidermidis isolates (n= 24) from ovine mastitic milk origin. Results of disk diffusion assay revealed that C. nepeta, L. stoechas and T. mastichina EOs are highly active against both S. aureus and S. epidermidis strains, whereas R. officinalis EO is highly active against S. aureus strains but inactive against several S. epidermidis isolates. EOs concentration causing bacterial growth inhibition ranged from 500 to 4,000 µg mL-1 in liquid microassays

    Adenocarcinoma do pâncreas localmente avançado e metastizado com resposta completa a quimioterapia

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    Os autores apresentam o caso clínico de doente do sexo feminino, 54 anos, raça branca, que recorreu ao médico assistente por dor abdominal associada a manifestações constitucionais. A ecografia revelou massa pancreática e formações nodulares hepáticas compatíveis com lesões secundárias, resultado posteriormente corroborado por tomografia computorizada, que acrescentou critérios de irressecabilidade, nomeadamente invasão dos vasos mesen- téricos e do duodeno. A biopsia ecoguiada obteve material cujo estudo anatomopatológico revelou tratar-se de adeno- carcinoma do pâncreas. Iniciou quimioterapia, verifican- do-se melhoria clínica progressiva. A reavaliação imagio- lógica, após 7 ciclos de tratamento, não detectou a lesão primitiva nem as lesões secundárias, sugerindo resposta completa. Foi mantido esquema regular de quimioterapia, persistindo a remissão 8 meses após a documentação da resposta completa

    Migrations and habitat use of the smooth hammerhead shark (Sphyrna zygaena) in the Atlantic Ocean

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    The smooth hammerhead shark, Sphyrna zygaena, is a cosmopolitan semipelagic shark captured as bycatch in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. From 2012 to 2016, eight smooth hammerheads were tagged with Pop-up Satellite Archival Tags in the inter-tropical region of the Northeast Atlantic Ocean, with successful transmissions received from seven tags (total of 319 tracking days). Results confirmed the smooth hammerhead is a highly mobile species, as the longest migration ever documented for this species (> 6600 km) was recorded. An absence of a diel vertical movement behavior was noted, with the sharks spending most of their time at surface waters (0-50 m) above 23 degrees C. The operating depth of the pelagic long-line gear was measured with Minilog Temperature and Depth Recorders, and the overlap with the species vertical distribution was calculated. The overlap is taking place mainly during the night and is higher for juveniles (similar to 40% of overlap time). The novel information presented can now be used to contribute to the provision of sustainable management tools and serve as input for Ecological Risk Assessments for smooth hammerheads caught in Atlantic pelagic longline fisheries.Oceanario de Lisboa through Project "SHARK-TAG: Migrations and habitat use of the smooth hammerhead shark in the Atlantic Ocean"; Investigador-FCT from the Portuguese Foundation for Science and Technology (FCT, Fundacao para a Ciencia e Tecnologia) [Ref: IF/00253/2014]; EU European Social Fund; Programa Operacional Potencial Human

    Pathotypic diversity of Hyaloperonospora brassicae collected from Brassica oleracea

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    Downy mildew caused by Hyaloperonospora brassicae is an economically destructive disease of brassica crops in many growing regions throughout the world. Specialised pathogenicity of downy mildews from different Brassica species and closely related ornamental or wild relatives has been described from host range studies. Pathotypic variation amongst Hyaloperonospora brassicae isolates from Brassica oleracea has also been described; however, a standard set of B. oleracea lines that could enable reproducible classification of H. brassicae pathotypes was poorly developed. For this purpose, we examined the use of eight genetically refined host lines derived from our previous collaborative work on downy mildew resistance as a differential set to characterise pathotypes in the European population of H. brassicae. Interaction phenotypes for each combination of isolate and host line were assessed following drop inoculation of cotyledons and a spectrum of seven phenotypes was observed based on the level of sporulation on cotyledons and visible host responses. Two host lines were resistant or moderately resistant to the entire collection of isolates, and another was universally susceptible. Five lines showed differential responses to the H. brassicae isolates. A minimum of six pathotypes and five major effect resistance genes are proposed to explain all of the observed interaction phenotypes. The B. oleracea lines from this study can be useful for monitoring pathotype frequencies in H. brassicae populations in the same or other vegetable growing regions, and to assess the potential durability of disease control from different combinations of the predicted downy mildew resistance genes

    Avaliação toxicológica de lixiviados de aterro sanitário tratados usando o crustáceo de água doce Daphnia magna.

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    Os resíduos sólidos urbanos, gerados em grande escala pela sociedade moderna, precisam de ser corretamente descartados por forma a mitigar o seu impacto ambiental e na saúde pública. Estes resíduos são normalmente depositados em aterros sanitários, e, consequentemente, são gerados lixiviados altamente tóxicos que precisam de ser tratados. Este trabalho tem como objetivo avaliar a eficácia de diferentes tratamentos eletroquímicos na redução da toxicidade de um concentrado de lixiviado de aterro sanitário. O concentrado de lixiviado, resultante da aplicação de um processo de osmose inversa, foi tratado por processos eletroquímicos combinados, eletrocoagulação (EC) seguida de eletro-Fenton (EF) com diferentes intensidades de corrente e com diferentes concentrações iniciais de ferro. A eficácia do tratamento na diminuição da toxicidade foi avaliada através de ensaios de toxicidade aguda com o organismo modelo Daphnia magna. Os resultados obtidos mostraram que os ensaios de EF realizados à densidade de corrente mais alta (200 A m-2) e com uma concentração de Fe inferior (60 mg L-1) permitiram uma diminuição da toxicidade inicial de 61,305 unidades tóxicas (UTs) para 33,195 UTs, correspondente a uma redução da toxicidade de cerca de 46

    The effects of instrumental action on perceptual hand maps

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    Perceiving the external spatial location of body parts using position sense requires that immediate proprioceptive afferent signals be integrated with information about body size and shape. Longo and Haggard (Proc Natl Acad Sci USA 107:11727–11732, 2010) developed a method to measure perceptual hand maps reflecting this metric information about body size and shape. In this paradigm, participants indicate the perceived location of landmarks on their occluded hand by pointing with a long baton held in their other hand. By comparing the relative location of judgments of different hand landmarks, perceptual hand maps can be constructed and compared to actual hand structure. The maps show large and highly stereotyped distortions. Here, I investigated the potential effect of biases related to active motor control of the hand doing the pointing in these distortions. Participants localized the fingertip and knuckle of each finger on their occluded left hand either by actively pointing with a baton held in their right hand (pointing condition) or by giving verbal commands to an experimenter on how to move the baton (verbal condition). Similar distortions were clearly apparent in both conditions, suggesting that they are not an artifact of motor control biases related to the pointing hand

    Post-emergence selectivity of metribuzin to carrot.

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    The objective of this study was to evaluate the selectivity of the herbicide metribuzin to carrot plants as a function of genotype, dose, and plant growth stage at the time of application. Two experiments were carried out, one in a greenhouse and another in the field

    Molecular mechanisms of drug resistance in natural Leishmania populations vary with genetic background

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    The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L.) donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread applicability
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