Mycobiota and mycotoxins present in finished fish feeds from farms in the Rio de Janeiro State, Brazil

The aim of the present study was to determine species of the fungal genera Aspergillus, Fusarium, and Penicillium and fumonisin B1 (FB1), aflatoxin B1 (AFB1), and ochratoxin A (OTA) contamination from feed intended for fish farms. A total of 60 samples were sampled from tilapia farms in the Rio de Janeiro State, Brazil. The quantitative enumeration of fungi as colony-forming units per gram of feed (CFU/g) was performed using the surface spread method in different culture media. The results were expressed as fungal isolation frequency and relative density. Fungal total counts ranged from <1 × 102 to 4.7 × 104 CFU/g. Fusarium counts were not observed. Among toxigenic genera, Aspergillus (68%) was the most prevalent, followed by Penicillium species (60%). Aspergillus niger aggregate (36%), Aspergillus flavus (35%), and Penicillium citrinum (71%) were the most prevalent species. A high percentage of samples (98%) were contaminated with FB1 levels, while 55% and 3.3% were contaminated with AFB1 and OTA, respectively. The simultaneous occurrence of these mycotoxins emphasizes the need for further research in the area to better assess the risk to the health of fish farms and their implications for the health of consumers of this meat.Fil: Barbosa, Tatiana S.. Universidade Federal Rural do Rio de Janeiro ; BrasilFil: Pereyra, Carina Maricel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Soleiro, Carla A.. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; BrasilFil: Dias, Erica O.. Universidade Federal Rural do Rio de Janeiro ; BrasilFil: Oliveira, Aguida A.. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; BrasilFil: Keller, Kelly M.. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; BrasilFil: Silva, Pedro P. O.. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Cavaglieri, Lilia Reneé. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rosa, Carlos Alberto da Rocha. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; Brasi

Bee Pollination Highly Improves Oil Quality in Sunflower

Sunflower is a pollinator-dependent crop and one of the most cultivated oilseeds in the world, supporting important sectors of the agricultural industry, such as the food supply, because it is an important source of vitamin E and unsaturated fatty acids for human health. Although it is well stablished that bee pollination improves sunflower seed set, it is still unknown if pollinators influence the nutritional composition. Considering the economic importance of sunflowers for several Brazilian agricultural sectors, the aim of this study was to evaluate the effect of the bee community for (1) achene quality (weight and nutritional composition) and (2) market value. Exclusion experiments were performed with hybrid sunflowers and showed that bee pollination enhanced the achene weight by 91 %, the levels of vitamin E by 45 % and unsaturated fatty acids by 0.3 %. Also, it was estimated that due to the pollination services provided by bees, the grower of the sunflower cultivar used in this study nearly duplicates the sale value of the achenes per hectare of cultivated area. Thus, the current study highlights the importance of bees as providers of cross- and self-pollination to nutritional quality of sunflower achenes and provides useful baseline figures to further evaluations of the effects of pollinators on human diets and health

Fipronil effect on the frequency of anomalous brood in honeybee reared in vitro

Larvae of honeybee workers were exposed to the insecticide fipronil during the feeding phase. To evaluate the effect of fipronil in the post-embryonic development of africanized Apis mellifera, bioassays of toxicity were done. The bioassays were performed by acute exposure applying 1μL of distilled water for control (I) and for experiments: 0.5 ng a.i./μL of fipronil; 5 ng a.i./μL of fipronil and 20 ng a.i./ μL of fipronil. Triplicates were performed for all treatments. The results showed that the rate of anomalous pupae in exposed honeybees was statistically significant in relationship to the control (p &lt;0:03). The most frequent abnormalities were: high pigmentation on the proximal and distal larval body and body malformation, such as absence of head and limbs. Pink eye pupa and white eyed pupae presented malformations in their larval bodies, but with the eye developed. It is assumed that the fat body is related to the high rate of anomalies, since this tissue has proteins linked to the process of metamorphosis. Furthermore, the fat body may be participating in the regulation of juvenile hormone during the process of metamorphosis, and consequently in the release of ecdysteroid hormones that are involved in the change from larva to adult. The high rate of abnormalities in the pupal stage of individuals exposed to fipronil raises concerns about the impacts caused in the colonies of bees and population decline of pollinators. Keywords: bees, larvae, pupae, metamorphosis, anomalies, fiproni

Nanopartículas de prata : análise dos efeitos anti-biofilme e anti-adesão sobre Candida albicans e Candida glabrata

Os objetivos deste trabalho foram: (1) avaliar o efeito sinergístico de nanopartículas de prata (NP) com Nistatina e Clorexidina contra biofilmes de Candida albicans e Candida glabrata; (2) verificar o efeito das NP na composição da matriz destes biofilmes e (3) investigar a capacidade de adesão a células epiteliais HeLa e a poliestireno de leveduras tratadas com NP. As drogas sozinhas ou em combinação com NP (5 nm) foram aplicadas sobre biofilmes maduros (48 h) e após 24 h de contato a atividade sinergística foi avaliada através da quantificação da biomassa total e por meio da contagem do número de colônias. Após o tratamento com NP, as matrizes dos biofilmes foram extraídas e analisadas em termos de proteínas, carboidratos e DNA. Ainda, leveduras viáveis foram recuperadas e adicionadas tanto às células HeLa quanto aos poços vazios de placas de poliestireno e, após 2 horas de contato, a adesão foi determinada usando violeta cristal. NP combinadas com Nistatina e Clorexidina exibiram atividade anti-biofilme sinergística dependente das espécies e concentrações de drogas usadas. Ainda, NP interferiram na composição da matriz extracelular dos biofilmes e a capacidade de adesão das leveduras viáveis foi significativamente reduzida após tratamento prévio com NP. Esses achados permitem concluir que NP podem contribuir na prevenção ou tratamento da estomatite protética associada à Candida. Entretanto, estudos adicionais são necessários para que estas NP sejam usadas com segurança

Quality versus quantity: foraging decisions in the honeybee (Apis mellifera scutellata) feeding on wildflower nectar and fruit juice

Foraging animals must often decide among resources which vary in quality and quantity. Nectar is a resource that exists along a continuum of quality in terms of sugar concentration and is the primary energy source for bees. Alternative sugar sources exist, including fruit juice, which generally has lower energetic value than nectar. We observed many honeybees (Apis mellifera scutellata) foraging on juice from fallen guava (Psidium guajava) fruit near others foraging on nectar. To investigate whether fruit and nectar offered contrasting benefits of quality and quantity, we compared honeybee foraging performance on P. guajava fruit versus two wildflowers growing within 50 m, Richardia brasiliensis and Tridax procumbens. Bees gained weight significantly faster on fruit, 2.72 mg/min, than on either flower (0.17 and 0.12 mg/min, respectively). However, the crop sugar concentration of fruit foragers was significantly lower than for either flower (12.4% vs. 37.0% and 22.7%, respectively). Fruit foragers also spent the most time handling and the least time flying, suggesting that fruit juice was energetically inexpensive to collect. We interpret honeybee foraging decisions in the context of existing foraging models and consider how nest-patch distance may be a key factor for central place foragers choosing between resources of contrasting quality and quantity. We also discuss how dilute solutions, such as fruit juice, can help maintain colony sugar–water balance. These results show the benefits of feeding on resources with contrasting quality and quantity and that even low-quality resources have value

Procedures for measuring the near point of convergence and the point of asthenopia in individuals with and without postural deficiency syndrome

Purpose: Postural Deficiency Syndrome is a multifactorial proprioceptive dysfunction with varied signs and symptoms, including convergence insufficiency and asthenopia which impact visual performance. The near point of convergence measurement is used to diagnose and clinically explore convergence insufficiency. Test speed and stimulus size influence values obtained. The definition of the most effective method to measure the near point of convergence and the point of asthenopia will allow early detection of alterations. This study aims to investigate the accuracy of measurements and variations in values obtained using different methods for the near convergence point and the point of asthenopia measurements in cases of Postural Deficiency Syndrome. Methods: The sample contained 39 patients, 27 with and 12 without Postural Deficiency Syndrome, measuring the near point of convergence and point of asthenopia with two stimuli (standard RAF rule and modified RAF rule) at two speeds (1cm/s and 3cm/s). Results: Neither method of measuring the near point of convergence had statistically significant values. The RAF near point rule at 1cm/s is more sensitive for alterations in the point of asthenopia (AUC 0.761 ± 0.084 standard error, p = 0.010). At 1cm/s, higher values for near point of convergence and point of asthenopia were measured, chiefly in the Postural Deficiency Syndrome group. Conclusion: Methods used to measure the parameters studied influenced the final values. No statistically significant values were obtained in the measurement of the near convergence point. To measure the point of asthenopia, the standard RAF rule at 1cm/s has the highest accuracy.info:eu-repo/semantics/publishedVersio

O desenvolvimento do projeto tutoria química essencial da Universidade Federal de Mato Grosso

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Population structure, adaptation and divergence of the meadow spittlebug, Philaenus spumarius (Hemiptera, Aphrophoridae), revealed by genomic and morphological data

Understanding patterns of population differentiation and gene flow in insect vectors of plant diseases is crucial for the implementation of management programs of disease. We investigated morphological and genome-wide variation across the distribution range of the spittlebug Philaenus spumarius (Linnaeus, 1758) (Hemiptera, Auchenorrhyncha, Aphrophoridae), presently the most important vector of the plant pathogenic bacterium Xylella fastidiosa Wells et al., 1987 in Europe. We found genome-wide divergence between P. spumarius and a very closely related species, P. tesselatus Melichar, 1899, at RAD sequencing markers. The two species may be identified by the morphology of male genitalia but are not differentiated at mitochondrial COI, making DNA barcoding with this gene ineffective. This highlights the importance of using integrative approaches in taxonomy. We detected admixture between P. tesselatus from Morocco and P. spumarius from the Iberian Peninsula, suggesting gene-flow between them. Within P. spumarius, we found a pattern of isolation-by-distance in European populations, likely acting alongside other factors restricting gene flow. Varying levels of co-occurrence of different lineages, showing heterogeneous levels of admixture, suggest other isolation mechanisms. The transatlantic populations of North America and Azores were genetically closer to the British population analyzed here, suggesting an origin from North-Western Europe, as already detected with mitochondrial DNA. Nevertheless, these may have been produced through different colonization events. We detected SNPs with signatures of positive selection associated with environmental variables, especially related to extremes and range variation in temperature and precipitation. The population genomics approach provided new insights into the patterns of divergence, gene flow and adaptation in these spittlebugs and led to several hypotheses that require further local investigation.Peer reviewe