6-Nitrodopamine is a novel catecholamine released by vascular tissues, heart, and vas deferens. The aim of this study was to investigate whether 6-nitrodopamine is released from the thoracic aorta and pulmonary artery rings of marmosets (Callithrix spp.) and to evaluate the relaxing and anti-contractile actions of this catecholamine. Release of 6-nitrodopamine, dopamine, noradrenaline, and adrenaline was assessed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The relaxations induced by 6-nitrodopamine and by the selective dopamine D2 receptor antagonist L-741,626 were evaluated on U-46619 (3 nM)-pre-contracted vessels. The effects of 6-nitrodopamine and L-741,626 on the contractions induced by electric-field stimulation (EFS), dopamine, noradrenaline, and adrenaline were also investigated. Both aorta and pulmonary artery rings exhibited endothelium-dependent release of 6-nitrodopamine, which was significantly reduced by the NO synthesis inhibitor L-NAME. Addition of 6-nitrodopamine or L-741,626 caused concentration-dependent relaxations of both vascular tissues, which were almost abolished by endothelium removal, whereas L-NAME and the soluble guanylate cyclase inhibitor ODQ had no effect on 6-nitrodopamine-induced relaxations. Additionally, pre-incubation with 6-nitrodopamine antagonized the dopamine-induced contractions, without affecting the noradrenaline- and adrenaline-induced contractions. Pre-incubation with L-741,626 antagonized the contractions induced by all catecholamines. The EFS-induced contractions were significantly increased by L-NAME, but unaffected by ODQ. Immunohistochemical assays showed no immunostaining of the neural tissue markers S-100 and calretinin in either vascular tissue. The results indicated that 6-nitrodopamine is the major catecholamine released by marmoset vascular tissues, and it acts as a potent and selective antagonist of dopamine D2-like receptors. 6-nitrodopamine release may be the major mechanism by which NO causes vasodilatation.

Resumo: Apresentamos a primeira lista de espécies de Odonata (Insecta) para o estado do Acre no Brasil, adicionando aspectos ecológicos e notas sobre o seu estado de conservação. O Acre é um dos estados com o menor esforço de coleta da região Norte do Brasil e uma área de importância geográfica, pois é uma transição entre os Andes e a Amazônia. Foram realizadas coletas em 35 riachos, distribuídos em nove municípios e também complementados com informações de dados secundários de revisão na literatura e bases de dados de coleções biológicas. Registramos 140 espécies, distribuídas em 55 gêneros, das quais 16 espécies são novos registros para o estado, tornando-o o segundo em número de espécies na região Norte do Brasil. Das espécies registradas, 113 estão classificadas dentro de alguma categoria de ameaça da lista vermelha da IUCN e 110 na lista nacional do ICMBio. Analisando as informações do conhecimento das espécies, o conhecimento das fêmeas e larvas ainda muito limitado e na maioria das vezes disponíveis apenas para os machos adultos. Pela primeira vez é registrada a ocorrência da Drepanoneura loutoni von Ellenrieder & Garrison (2008) no Brasil, também apresentamos fotos das principais estruturas, com comentários sobre sua biologia. Nosso trabalho mostra a importância da realização de estudos de biodiversidade em áreas ainda pouco estudadas como a do estado do Acre e serve como base para futuras expedições na região.

Abstract: Here we present the first Odonata (Insecta) species list for the state of Acre, Northern Brazil, adding ecological aspects and notes on its taxonomy and conservation status. Regarding Odonata samplings, Acre is one of the least explored states in the northern region of Brazil and an area of geographic importance, as it is a transition between the Andean and Amazon regions. Collections were carried out in 35 streams, distributed in nine municipalities. We also supplemented our database from the review of secondary literature and data from biological collections. We recorded 140 species, distributed in 55 genera, of which 16 species are new records for the state, making Acre state the second in the number of recorded species in northern Brazil. Of the recorded species, 113 are classified within some threat category of the IUCN red list and 110 in the ICMBio national list. Analyzing the taxonomic information on each recorded species, knowledge of females and larvae is still very limited and, most of the time, only available to adult males. For the first time, the occurrence of Drepanoneura loutonivon Ellenrieder & Garrison (2008) is reported for Brazil, and we also present photos of its main morphological characters, with comments on its biology. Our study shows the importance of conducting biodiversity research in poorly studied areas; such as the state of Acre, and serves as a basis for future expeditions in the region.

RESUMO O objetivo do presente estudo foi padronizar um protocolo de reação em cadeia da polimerase (PCR) para a autenticação de leite bovino e bubalino e a detecção da presença de Salmonella spp. e Listeria monocytogenes. Para isso, o DNA-alvo foi extraído, misturado e submetido ao ensaio de PCR. Amostras de leite foram fraudadas e contaminadas experimentalmente com os micro-organismos, para se avaliar a detecção do DNA-alvo em diferentes tempos de cultivo, os títulos bacterianos e a concentração de material genético. Além disso, o protocolo foi testado com DNA extraído diretamente do alimento, sem a etapa de pré-enriquecimento. A PCR quadriplex proposta mostrou boa precisão na identificação de sequências de DNA-alvo. Foi possível identificar simultaneamente todas as sequências de DNA no momento da inoculação (0h), quando as amostras estavam contaminadas com 2 UFC/250mL, e com seis horas de cultura, quando o inóculo inicial foi de 1 UFC/250mL. Também foi possível detectar diretamente as sequências de DNA do alimento quando este foi inoculado com 3 UFC/mL de bactérias. Dessa forma, a metodologia proposta apresentou desempenho satisfatório, otimização do tempo de análise e potencial para detecção de micro-organismos em baixos títulos, podendo ser utilizada para detecção de fraude e contaminação.

ABSTRACT The objective of the present study was to Standardize a Polymerase Chain Reaction (PCR) protocol for the authentication of bovine and buffalo milk, and to detect the presence of Salmonella spp. and Listeria monocytogenes. For this, the target DNA was extracted, mixed, and subjected to a PCR assay. Milk samples were defrauded and experimentally contaminated with microorganisms to assess the detection of target DNA at different times of cultivation, bacterial titers, and concentration of genetic material. In addition, the protocol was tested with DNA extracted directly from food, without a pre-enrichment step. The proposed quadruplex PCR showed good accuracy in identifying target DNA sequences. It was possible to simultaneously identify all DNA sequences at the time of inoculation (0h), when the samples were contaminated with 2 CFU/250mL and with 6h of culture when the initial inoculum was 1 CFU/250mL. It was also possible to directly detect DNA sequences from the food when it was inoculated with 3 CFU/mL bacteria. Thus, the proposed methodology showed satisfactory performance, optimization of the analysis time, and a potential for the detection of microorganisms at low titers, which can be used for the detection of fraud and contamination.

The present study compared the effects of a footwear designed to enhance energy return (thermoplastic polyurethane, TPU) vs minimalist shoes on running economy (RE) and endurance performance. In this counterbalanced and crossover design study, 11 recreational male runners performed two submaximal constant-speed running tests and two 3-km time-trials with the two shoe models. Oxygen uptake was measured during submaximal constant-speed running tests in order to determine the RE at 12 km/h and oxygen cost of running (CTO2) at individual average speed sustained during the 3-km running time-trials wearing either of the two shoes. Our results revealed that RE was improved (2.4%) with TPU shoes compared with minimalist shoes (P=0.01). However, there was no significant difference for CTO2 (P=0.61) and running performance (P=0.52) comparing the TPU (710±60 s) and the minimalist (718±63 s) shoe models. These novel findings demonstrate that shoes with enhanced mechanical energy return (i.e. TPU) produced a lower energy cost of running at low (i.e., 12 km/h) but not at high speeds (i.e., average speed sustained during the 3-km running time-trial, ∼15 km/h), ultimately resulting in similar running performance compared to the minimalist shoe.

Abstract The influence of environmental variables on planktonic biodiversity is widely known. However, the absence of information about the cyanobacterial community in tropical estuarine regions motivated this work, whose objective was to investigate the spatio-temporal variation of cyanobacterial density related to physicochemical factors in a Brazilian Amazonian estuary. For the qualitative and quantitative study of cyanobacteria and physicochemical variables, samples were collected in April/July/2009 and April/August/2010. We identified 31 species of the orders Chroococcales, Oscillatoriales and Nostocales. Species of the genera Aphanocapsa, Dolichospermum, Komvophoron, Microcystis, Pseudanabaena and Merismopedia were frequent and abundant throughout the study period. Some of the found genera have already been described as potential toxin producers. The dynamics of cyanobacteria were temporal, the highest densities occurred in 2010 (average= 1080.86 ± 702.86 cells.mL-1) mainly influenced by the high values of pH, temperature, electrical conductivity, total dissolved solids, ammonium nitrogen which led cyanobacteria to present different responses in terms of richness, density and diversity between the years.

This study evaluated histological changes in the digestive organs and kidneys of sheep fed sugarcane silage augmented with detoxified castor bean meal (CBM). Forty Santa Inês sheep (initial weight 20 ± 0.3 kg) were adapted to the experimental regime for 14 days, after which data were collected for 60 days. The treatments consisted of S0: sugarcane silage (SC); S5: SC augmented with 5% CBM; S10: SC augmented with 10% CBM; S15: SC augmented with 15% CBM; and S20: SC augmented with 20% CBM. After 74 days of confinement, the animals were slaughtered, and then fragments of the liver, rumen, intestine, and kidney were collected for histomorphometric analyses. The intake of dry matter and the average weight gain increased linearly with the level of CBM (P <0.05), as did the rumen absorption area, the height of the papillae and the width of the papillae. The thickness of the keratinized portion of the epithelium was not influenced, Thus, no effect was detected of the anti-nutritional factor of CBM on this organ. In the intestine, CBM increased the height of the villi and the number of goblet cells. However, S20 caused some kidney damage and decreased hepatic glycogen stock, but not sufficiently to reduce performance. Thus, augmentation of sugarcane with CBM, up to 20%, is viable in feeding sheep.

RESUMO O uso de anestésicos em pisciculturas é indispensável para reduzir o estresse durante o manejo. O presente trabalho propôs avaliar o efeito do eugenol como anestésico para manejo do curimatã (Prochilodus nigricans). Foram utilizados 50 espécimes (221,34±9,0 g; 25,8 ±1,1 cm), submetidos a cinco tratamentos com concentrações de 0, 25, 50, 100 e 200 mg L−1 de eugenol em exposição de 10 minutos. Foram registrados os tempos necessários para atingir cada estágio anestésico e a recuperação de cada peixe. Para verificação dos níveis de glicose sanguínea, foram realizadas coletas individuais de sangue dos peixes antes da imersão e após os 10 minutos de exposição ao anestésico. A avaliação do efeito do anestésico sobre as brânquias foi realizada por meio de análises histopatológicas. A concentração de 50 mg L−1 ficou dentro do limite ideal de três minutos preconizado para indução à anestesia cirúrgica e não elevou significativamente os níveis de glicose quando comparada ao grupo controle (35,7±19,4 mg dL−1), além de não provocar lesões branquiais. Nessa concentração, os peixes apresentaram níveis de glicose sanguínea controlada, dentro dos teores basais, além de não correrem o risco de apresentarem problemas posteriores em relação à mortalidade, pois essa concentração garante a boa saúde das brânquias e uma boa recuperação dos animais.

ABSTRACT The use of anesthetics in fish farming is essential to reduce stress during management. The present study proposes to evaluate the effect of eugenol as an anesthetic for the management of curimatã (Prochilodus nigricans). Fifty specimens were used (221.34±9.0 g; 25.8 ±1.1 cm), submitted to five treatments with concentrations of 0, 25, 50, 100 and 200 mgL−1 eugenol for 10 min. The times required to reach each anesthetic stage and the recovery of each fish were recorded. To check bloodglucose levels individual blood samples were taken from the fish before immersion and after ten minutes of anesthetic exposure. Evaluation of the anesthetic effect ongills was performed by histopathological analysis. The concentration of 50 mgL−1 was within the ideal limit of three minutes recommended for surgical anesthesia induction and did not significantly increase glucose levels when compared to the control group (35.7±19.4 mg dL−1), besides not causing gill injuries. At this concentration the fish presented controlled blood glucose levels within the basal levels, besides not taking the risk to have later problems concernig mortality, because this concentration ensures the good health of the gills and good recovery of the animals.

ABSTRACT In semi-arid zones, feedlots are considered a tool to minimize the impacts of seasonal forage on the production of sheep meat in the tropics. However, the use of alternative tropical ingredients as substitutes for corn (Zea mays L.) and soybean (Glycine max [L.] Merr.) meal in formulations of confined sheep diets is recurrent. The aim of this study was to evaluate the effect of diets containing corn and soybean meal (CS), corn (CU), cassava (Manihot esculenta Crantz) root (CRU) or spineless cactus (Opuntia ficus-indica [L.] Mill., SCU) associated with urea on the performance, carcass characteristics and meat quality of confined lambs. Forty non-castrated Santa Inês sheep with average age of 150 d and average initial weight of 22.6 ± 2.3 kg were confined in individual pens for 76 d and slaughtered. The diets effects were contrasted by Tukey test. Empty body weight was different among the treatments (P < 0.05) and was 27.3, 25.3, 23.0 and 21.1 kg for the animals fed CS, CU, CRU and SCU, respectively. CS diet presented higher cold carcass weights while SCU diet presented lower cold carcass weights (P < 0.05) (11.37 kg) and higher cooling losses. Luminosity, yellow color intensity and meat moisture content were higher (P < 0.05) in SCU than CS. Liver, skin and internal fat weights were similar (P > 0.05) in CU and CRU, but higher (P < 0.05) than SCU. The replacement of corn and soybean meal for different carbohydrate sources associated with urea reduces the body weight components in confined sheep.

Thirty-two mixed-breed ram lambs (average age, 5.6 ± 0.4 months, and average live weight, 17.61 ± 2.63 kg) were used to evaluate the effect of diets containing silages of forages adapted to a semi-arid environment on the metabolic profile in serum and the histopathological assessment of liver and kidney tissues of the lambs. Lambs were allocated, in a completely randomised design, to four treatments (silage of old man saltbush (Atriplex nummularia Lind), buffelgrass (Cenchrus ciliaris), gliricidia (Gliricidia sepium) and 'pornunça' (Manihot sp.). The feedlot period was 49 days, and animals were slaughtered at an average weight of 27 ± 4.6 kg. On the last day of the experiment, blood was collected from the jugular vein of all animals to measure the protein, metabolic and energy profiles of the lambs. At slaughter, kidney and liver samples were collected for histopathological examination. The consuming of the diet containing buffelgrass silage resulted in a significantly higher activity of alanine-aminotransferase (30.14 IU/L) and the concentrations of urea (44.25 mg/dL), creatinine (0.94 mg/dL) and albumin (4.48 g/dL) in serum. Diets containing gliricidia silage resulted in significantly higher gamma-glutamyl transferase activity (92.0 IU/L), while the diets with pornunça silage resulted in higher serum levels of triglycerides (37.85 mg/dL). The diets had no effect on aspartate-aminotransferase enzyme activity and total protein, cholesterol and globulin concentrations, or the albumin : globulin ratio in serum. Mild congestion, necrosis and foci of mineralisation were observed in the kidneys of animals fed diets containing old man saltbush (50%) and pornunça (25%) silages, and mild fatty degeneration and mild mononuclear inflammatory infiltrate in their livers. In conclusion, diets containing silages of forages that are adapted to semi-arid environments may be used for feeding lambs, given the absence of dysfunctioning plasmatic levels of liver enzymes and energy and protein profiles. Additionally, kidney failure was not observed in lambs fed these diets during the feedlot period.

RESUMO O objetivo deste trabalho foi analisar as leituras de composição do leite cru por meio de espectrofotometria FTIR, utilizando-se curva de regressão PLS, bem como as contagens de células somáticas e bacteriana total por citometria de fluxo, após adição de amido e sacarose. O leite cru foi adulterado com três concentrações de amido e sacarose (0,1%, 0,5% e 1%), colocado em frascos contendo bronopol ou azidiol, os quais foram armazenados em duas temperaturas (7±2°C e 25±2°C ). As análises foram realizadas após zero, três, 24, 48, 72 e 168 horas de armazenamento. O modelo de regressão linear múltipla foi utilizado para análise estatística. A adição de amido e sacarose resultou em mudança significativa (P<0,05) para todas as variáveis dependentes. O leite adulterado com amido resultou em aumento nas leituras de gordura, proteína, lactose, sólidos totais (ST), sólidos não gordurosos (SNG), CCS e CBT e em diminuição das leituras de caseína, do nitrogênio ureico do leite (NUL) e do ponto de congelamento. O leite adulterado com sacarose resultou no aumento das leituras da lactose, ST, SNG e NUL, enquanto as leituras de proteína, caseína, ponto de congelamento e CCS diminuíram. Este trabalho evidencia a importância do monitoramento de adulterantes reconstituintes no leite por afetarem os resultados analíticos da qualidade do leite, obtidos por métodos eletrônicos.

RESUMO O objetivo do presente trabalho foi avaliar a inclusão do concentrado proteico da destilação de etanol obtido de arroz (CPA) na alimentação do jundiá. Trezentos e setenta e cinco peixes foram distribuídos em sistema de recirculação de água com 15 caixas (125L). Foram testadas três dietas (37% PB e 3200kcal/kg de energia digestível), sendo uma controle e duas testando a substituição da proteína da farinha de peixe em 25% (CPA-25%) ou 50% (CPA-50%) pelo CPA. Aos 30 dias, foram avaliadas as variáveis de desempenho, composição corporal e índices somáticos. Os animais submetidos ao tratamento CPA-25% apresentaram resposta de crescimento equivalente aos que receberam o tratamento controle, mas superior aos peixes submetidos ao CPA-50%. Não foram observadas diferenças significativas entre os tratamentos para os índices somáticos avaliados. Os animais submetidos às dietas contendo CPA apresentaram maior teor de gordura corporal. Já a deposição de gordura corporal foi superior para os peixes alimentados com CPA-25%, e a deposição de proteína corporal menor para os alimentados com CPA-50%. Os resultados indicam que o CPA pode substituir em até 25% a proteína da farinha de peixe, sem comprometer o crescimento dos jundiás, tendo esse nível de substituição proporcionado, inclusive, uma redução de 8% no custo da dieta.

ABSTRACT The objective of this work was to evaluate the inclusion of protein concentrate from the distillation of ethanol from rice (CPA) in jundia feed. A total of 375 fish were distributed in water recirculation system with 15 boxes (125L). Three diets (37% PB and 3200kcal / kg digestible energy), one control and two were to test for the replacement of fishmeal protein by 25 (CPA-25%) and 50% (CPA-50%) by CPA. At 30 days, the variables of performance, body composition and somatic indexes were evaluated. The animals submitted to the CPA-25% treatment presented a growth response equivalent to those that received the Control treatment, but superior to the fish submitted to the CPA-50%. There were no significant differences between treatments for the somatic indices evaluated. Animals submitted to diets containing CPA had higher body fat content. Body fat deposition was higher for fish fed with CPA-25% and lower body protein deposition for those fed with CPA-50%. The results indicate that CPA can substitute up to 25% fish meal protein, without compromising the growth of jundias, and this level of substitution provided an 8% reduction in diet cost.

Epithelial cell migration is an essential response to enteric pathogens such as enteropathogenic Escherichia coli (EPEC). This study aimed to investigate the effects of EPEC infection on intestinal epithelial cell migration in vitro, as well as the involvement of type III secretion system (T3SS) and Rho GTPases. Crypt intestinal epithelial cells (IEC-6) were infected with EPEC strains (E2348/69, ΔescF, and the LDI001 strain isolated from a malnourished Brazilian child) and commensal E. coli HS. Wound migration and cell death assays were performed at different time-points. Transcription and expression of Rho GTPases were evaluated using real-time PCR and western blotting. Overall, EPEC E2348/69 reduced migration and increased apoptosis and necrosis levels compared to EPEC LDI001 and E. coli HS strains. Moreover, EPEC LDI001 impaired cell migration at a higher level than E. coli HS and increased necrosis after 24 hours compared to the control group. The different profiles of virulence genes between the two wild-type EPEC strains, characterized by the absence of espL and nleE genes in the LDI001, might explain the phenotypic results, playing significant roles on cell migration impairment and cell death-related events. Moreover, the type III secretion system is determinant for the inhibition of intestinal epithelial cell migration by EPEC 2348/69, as its deletion prevented the effect. Active Rac1 concentrations were increased in E2348/69 and LDI001-infected cells, while the T3SS-deficient strain did not demonstrate this activation. This study contributes with valuable insight to characterize the mechanisms involved in the impairment of intestinal cell migration induced by EPEC.

RESUMO Objetivou-se avaliar o efeito do cruzamento entre ovinos nativos no desempenho e características da carcaça. Foram utilizados vinte cordeiros, machos, inteiros, com idade inicial de quatro meses, e peso médio inicial 19,0±5,11, distribuídos em dois grupos genéticos: Rabo Largo (RL) e Santa Inês x Rabo Largo (F1SI x RL), em um delineamento inteiramente ao acaso. Os animais foram terminados em regime de confinamento durante 70 dias. Os cordeiros F1SI x RL apresentaram maiores pesos ao desmame, ao abate, do corpo vazio, das carcaças quente e fria, e maior rendimento biológico. Verificaram maiores valores para os parâmetros de morfometria da carcaça para animais F1SI x RL comparados aos animais Rabo Largo (P<0,05). Os pesos da hemi-carcaça e dos cortes comerciais foram superiores para cordeiros F1SI x RL. Nas medidas obtidas no músculo Longissimus dorsi, os cordeiros Rabo Largo apresentaram valores superiores para espessura de gordura subcutânea. A utilização da raça Santa Inês como base paterna acarreta em melhorias nas características de carcaça de cordeiros Rabo Largo podendo ser indicado em sistemas de produção de carne ovina.

ABSTRACT The aim of study was to evaluate the effect of crossbreeding among native sheep on performance and traits carcass. Twenty intact lambs, male, at four months of age, with an initial weight of 19.0±5.11kg, were distributed in two groups genetics: Rabo Largo (RL) e Santa Inês x Rabo Largo (F1SI x RL), in a completely randomized design. The animals were finished in feedlot by 70 days. The lambs F1SI x RL showed higher weight at weaning, to slaughter, of the empty body, and hot and cold carcass, and increased biological yield. Higher values for carcass morphometry in F1SI x RL animals were found in comparison to Rabo Largo animals (P<0.05). The weight of half-carcass and the commercial cuts were higher for lambs. On the measurements obtained in muscle Longissimus dorsi, Rabo Largo lambs showed higher values for subcutaneous fat thickness. The use of the breed Santa Inês like base paternal may bring in improvements in lambs’s carcass characteristics Rabo Largo and may be recommended in sheep meat production systems.

Abstract Background. The aim of this study was to validate five scales, based on a theoretical framework for the adoption of behaviours, designed to assess the determinants in binge drinking in adolescents, namely: attitude, social influence (model, norm and pressure) and self-efficacy. Methods. Observational, cross-sectional and multicentre study. Through convenience sampling, 397 adolescents between 15 to 18 years old enrolled in secondary schools in Seville and Huelva were included. After translation and review of the original instrument by a panel of experts, a questionnaire was obtained in Spanish that was administered to a pilot sample to assess comprehensibility and, subsequently, the participants completed the five scales to check the structural validity (factor analysis and reliability) and construct validity. Results. On the five scales, the first factor explained at least 28% of the variance and the total variance explained was always greater than 60%. After rotation, all items had weights >0.40 for the factor to which they belonged. Cronbach´s alpha ranged from 0.62 to 0.91. Spearman’s coefficient was lower than 0.7 when correlating the sub-dimensions of the scales, except on the self-efficacy scale, assuming multidimensionality with certain limitations. Conclusions. Five scales are presented with indications of reliability and validity, their items reflect the theoretical frame of reference and can evaluate the determinants of binge drinking. In the future, validation could be continued to determine its reproducibility, its criterion validity with a “gold standard” or objective measure.

Resumen Fundamento. Validar cinco escalas, basadas en un marco teórico para la adopción de comportamientos, que fueron diseñadas para evaluar los factores implicados en el consumo episódico excesivo de alcohol (CEEA) en adolescentes, concretamente: actitud, influencia social (Modelo, Norma y Presión) y autoeficacia. Material y métodos. Estudio observacional, transversal y multicéntrico. Mediante muestreo por conveniencia se incluyeron 397 adolescentes de 15 a 18 años escolarizados en institutos de Educación Secundaria de Sevilla y Huelva. Tras la traducción y revisión del instrumento por un panel de expertos se obtuvo un cuestionario en español que fue administrado a una muestra piloto para valorar la comprensibilidad y, posteriormente, los participantes completaron las cinco escalas para comprobar la validez estructural (análisis factorial y fiabilidad) y la validez de constructo. Resultados. En las cinco escalas, el primer factor explicó al menos el 28% de la varianza y la varianza total explicada fue siempre mayor que 60%. Tras la rotación, las cargas factoriales de los ítems fueron mayores a 0,40 para su factor de pertenencia. El alfa de Cronbach osciló desde 0,62 hasta 0,91. El coeficiente de Spearman fue menor a 0,7 al correlacionar las subdimensiones de las escalas, salvo en la escala de Autoeficacia, asumiendo multidimensionalidad con ciertas limitaciones. Conclusiones. Se presentan cinco escalas con indicios de fiabilidad y validez, cuyos ítems reflejan el marco teórico de referencia y que pueden evaluar los determinantes del CEEA. En el futuro se debería continuar con la validación para determinar su reproducibilidad, su validez de criterio con un “gold estándar” o medida objetiva.

Abstract Production of a bioherbicide for biological control of weeds requires a series of steps, from selection of a suitable microbial strain to final formulation. Thus, this study aimed to select fungi for production of secondary metabolites with herbicidal activity using biological resources of the Brazilian Pampa biome. Phytopathogenic fungi were isolated from infected tissues of weeds in the Pampa biome. A liquid synthetic culture medium was used for production of metabolites. The phytotoxicity of fungal metabolites was assessed via biological tests using the plant Cucumis sativus L., and the most promising strain was identified by molecular analysis. Thirty-nine fungi were isolated, and 28 presented some phytotoxic symptoms against the target plant. Fungus VP51 belonging to the genus Diaporthe showed the most pronounced herbicidal activity. The Brazilian Pampa biome is a potential resource for the development of new and sustainable chemical compounds for modern agriculture.