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Resistance to acetolactate synthase (ALS) inhibitors have increased recently in South Brazil where the major weeds of flooded rice (barnyardgrass and weedy rice) have evolved resistance to imazapyr+imazapic. The aim of this research was to evaluate a growth medium for tissue regeneration of tillers in barnyardgrass, as well as an agar-based bioassays test (also from tillers) to detect susceptible and resistant biotypes of weedy rice and barnyardgrass to imazapyr+imazapic in vitro. Greenhouse experiments were conducted to detect ALS-resistant (R) and susceptible (S) weedy rice and barnyardgrass biotypes, and bioassays were carried out to evaluate an adequate growth medium for barnyardgrass tiller regeneration and determine the concentration of herbicide to distinguish R and S plants. The culture medium that provided a suitable barnyardgrass growth was MS 50% with the addition of benzylamino-purine. The tissue regeneration in vitro with the growth medium containing imazapyr+imazapic allowed to discriminate between R and S barnyardgrass and weedy rice plants. The concentration required for satisfactory control of susceptible barnyardgrass and weedy rice explants grown in vitro was 0.9 µM and 1.3 µM of imazapyr+imazapic herbicide, respectively. The bioassay in vitro using tiller regeneration provides an opportunity to predict effectively imazapyr+imazapic resistance in barnyardgrass and weedy rice.

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One of the problems faced by entomotoxicological studies is the large variability of experimental set-ups and the absence of harmonized protocols to compare the data and results obtained by different research groups. Among the wide range of influencing factors on the development and growth of insects, food substrates are remarkably relevant. This article proposes a standardized growth medium to be employed in future entomotoxicological studies on the scuttle fly Megaselia scalaris (Loew, 1866), (Diptera: Phoridae). This species plays an important role in forensic cases related to the decomposition of human remains found indoors and/or in concealed environments, because of their small size and ability to enter these locations at an earlier time than many other insects. Because of these traits, it can be used for the estimation of the minimum postmortem interval (mPMI). We achieved the formulation of a medium that overcomes two traditional disadvantages of culture media used to raise necrophagous Diptera, the unknown media composition and different growth rates from those reared in tissue. The proposed medium is a known composition formulation, free of xenobiotics, in which M. scalaris shows growth rates and development times similar to those obtained when it is reared in tissue. This new diet might be used in future studies to test the effect of substances of forensic interest (prescription or illicit drugs, poisons, etc.) on the larval development time, helping to adjust the estimation of mPMI based on the presence of such substances. Additionally, the formulation revealed some interesting data about nutritional requirements of this species.

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The C. elegans NB327 mutant strain is characterized for the knockdown of the dic-1 gene. The dic-1 gene is homologous to the dice-1 gene in humans, encoding the protein DICE-1 as a tumor suppressor. Absence or under-regulation of the dice-1 gene can be reflected in lung and prostate cancer [17], [18]. This study evaluated the effect of EEAML on the C. elegans NB327 mutant strain. Phenotypic aspects such as morphology, body length, locomotion, and reproductive behaviour were analyzed. It is important to emphasize that the strain presents a phenotype characteristic with respect to egg laying and hatching. Reported studies showed that Annona muricata extract and its active components evidence anti-cancer and anti-tumor effects, through experimentation in vivo and in vitro models. However, neurotoxicity has been reported as a side effect. The results showed that the mutant strain NB327 was exposed to EEAML (5 mg/ml) concentration, it showed a significant decrease in average locomotion, resulting in 13 undulations in 30 s. This contrasts with the control strain's 17.5 undulations in 30 s. Similarly, the number of progenies was reduced from 188 progenies (control strain) to 114 and 92 progenies at the dose of (1 mg/ml and 5 mg/m) EEAML. The results of this study suggest that EEAML has a possible neurotoxic effect in concentrations equal to or greater than 5 mg/ml. Also, it does not have positive effects on the mutant strain of Caenorhabditis elegans NB327 phenotype.

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The mitochondrial redox state plays a central role in the link between mitochondrial overloading and insulin resistance. However, the mechanism by which the ROS induce insulin resistance in skeletal muscle cells is not completely understood. We examined the association between mitochondrial function and H2O2 production in insulin resistant cells. Our hypothesis is that the low mitochondrial oxygen consumption leads to elevated ROS production by a mechanism associated with reduced PGC1α transcription and low content of phosphorylated CREB. The cells were transfected with either the encoded sequence for catalase overexpression or the specific siRNA for catalase inhibition. After transfection, myotubes were incubated with palmitic acid (500µM) and the insulin response, as well as mitochondrial function and fatty acid metabolism, was determined. The low mitochondrial oxygen consumption led to elevated ROS production by a mechanism associated with ß-oxidation of fatty acids. Rotenone was observed to reduce the ratio of ROS production. The elevated H2O2 production markedly decreased the PGC1α transcription, an effect that was accompanied by a reduced phosphorylation of Akt and CREB. The catalase transfection prevented the reduction in the phosphorylated level of Akt and upregulated the levels of phosphorylated CREB. The mitochondrial function was elevated and H2O2 production reduced, thus increasing the insulin sensitivity. The catalase overexpression improved mitochondrial respiration protecting the cells from fatty acid-induced, insulin resistance. This effect indicates that control of hydrogen peroxide production regulates the mitochondrial respiration preventing the insulin resistance in skeletal muscle cells by a mechanism associated with CREB phosphorylation and ß-oxidation of fatty acids.

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Adaptation and selection of Arthrospira platensis strains, for cultivation in brackish water with excess boron (B) in the Lluta Valley can become an interesting alternative that would allow to extend these cultures to areas that possess the environmental conditions, but that lack the fresh water needed to do it. Strains TX98 and P88 were evaluated in laboratory conditions with three different media of brackish water and with the white medium, the Zarrouk modified medium (MZM). The growing media with brackish water with a B concentration present in the Lluta River of 20 mgL-1 (B20) and medium with 30 mgL-1 (B30), and 10 mg L-1 of B (B10). The effect of the different media on the growing parameters with a culture temperature of 25 +/- 1ºC in the three treatments, strains TX98 and P88 triplicate, Arthrospira platensis, showed tolerance. It was statistically determined that in the growth, the two strains, the three treatments and in the interrelation of both there were significant differences (p < 0.05). The TX98 strain reached a concentration of 1.139 g L-1 (dry weight) in brackish water with medium B20. Therefore, the highest rate of specific growth (μmax) was obtained with the TX98 strain grown in the brackish medium B30 and the lowest duplication time (0.597 days). Cells grown in brackish water with B had a slightly biochemically modified composition with the white, in relation to the protein content, in the cases in which there are differences in the B content, specifically B30 treatment. For the culture with brackish water from the Lluta River, the TX98 strain is recommended with 10 mg of B using a laboratory to pilot scale.

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A Ipomoea cairica (L.) Sweet é uma trepadeira herbácea nativa, amplamente utilizada na medicina popular brasileira e inexistem informações sobre a propagação vegetativa. Em vista disso, objetivou-se avaliar a presença de folhas nas estacas, o substrato e a dose de reguladores vegetais mais adequados para a propagação por estaquia. Foram conduzidos dois experimentos, no primeiro, foram avaliados dois tipos de estacas (com e sem folhas) e quatro substratos (areia, casca de arroz carbonizada, latossolo vermelho distrófico + matéria orgânica - 1:1, latossolo vermelho distrófico + matéria orgânica + areia - 1:1:2), enquanto no segundo foram testadas cinco concentrações diferentes de AIB (0, 250, 500, 750 e 1000 mg L-1). Após 20 dias, obteve-se 86,2% de estacas enraizadas no substrato areia e, no segundo experimento, observou-se que o AIB não influenciou a porcentagem de enraizamento (94% em média). Conclui-se que a presença de folhas melhora a qualidade do enraizamento, que os substratos indicados para a propagação são areia e casca de arroz carbonizada devido ao maior enraizamento, fácil disponibilidade e baixo custo, e que a utilização de AIB na concentração 250 mg L-1 é a mais adequada para propagação por estaquia de I. cairica.

Ipomoea cairica (L.) Sweet is an herbaceous climbing plant widely used in Brazilian folk medicine and there is no information regarding its vegetative propagation. In view of this, the aim of this study was to evaluate the presence of leaves on stem cuttings and the most adequate substrate and level of plant growth regulators for propagation by stem cuttings of this morning glory. Two experiments were conducted, in the first, two types of stem cuttings (with and without leaves) and four substrates (sand; carbonized rice hull; Haplortox + organic matter - 1:1; Haplortox + organic matter + sand - 1:1:2) were evaluated, and in the second experiment five different concentrations of IBA (0, 250, 500, 750 and 1000 mg L-1) were tested. After 20 days, we obtained 86.2% of cuttings rooted in sand substrate and in the second experiment IBA did not affect the rooting percentage (94% on average). We can conclude that the presence of leaves improved the quality of rooting, the substrates indicated for propagation are sand and carbonized rice hull due to greater rooting, easy availability and low cost, and the use of IBA at 250 mg L-1 is more appropriate to propagation by stem cuttings of I. cairica.

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From the mineral nutrient content of the banana plant a specific growth medium was developed for Musa cavendishii var. nanicão. The results showed an increase in the multiplication rate even with the reduction of the 6 - benzilaminopurin concentration.

Através dos dados de concentração de nutrientes minerais da bananeira, formulou-se um meio de cultura específico para Musa cavendishii var. nanicão. Os resultados indicaram aumento das taxas de multiplicação mesmo com redução das concentrações de 6 - benzilaminopurin.

RESUMO

From the mineral nutrient content of the banana plant a specific growth medium was developed for Musa cavendishii var. nanicão. The results showed an increase in the multiplication rate even with the reduction of the 6 - benzilaminopurin concentration.

Através dos dados de concentração de nutrientes minerais da bananeira, formulou-se um meio de cultura específico para Musa cavendishii var. nanicão. Os resultados indicaram aumento das taxas de multiplicação mesmo com redução das concentrações de 6 - benzilaminopurin.