In this study, a leaf extract from Schinus terebinthifolius was evaluated for effects on survival, development, and midgut of A. aegypti fourth instar larvae (L4), as well as for toxic effect on Artemia salina. Leaf extract was obtained using 0.15 M NaCl and evaluated for phytochemical composition and lectin activity. Early L4 larvae were incubated with the extract (0.3–1.35%, w/v) for 8 days, in presence or absence of food. Polymeric proanthocyanidins, hydrolysable tannins, heterosid and aglycone flavonoids, cinnamic acid derivatives, traces of steroids, and lectin activity were detected in the extract, which killed the larvae at an LC50 of 0.62% (unfed larvae) and 1.03% (fed larvae). Further, the larvae incubated with the extract reacted by eliminating the gut content. No larvae reached the pupal stage in treatments at concentrations between 0.5% and 1.35%, while in the control (fed larvae), 61.7% of individuals emerged as adults. The extract (1.0%) promoted intense disorganization of larval midgut epithelium, including deformation and hypertrophy of cells, disruption of microvilli, and vacuolization of cytoplasms, affecting digestive, enteroendocrine, regenerative, and proliferating cells. In addition, cells with fragmented DNA were observed. Separation of extract components by solid phase extraction revealed that cinnamic acid derivatives and flavonoids are involved in larvicidal effect of the extract, being the first most efficient in a short time after larvae treatment. The lectin present in the extract was isolated, but did not show deleterious effects on larvae. The extract and cinnamic acid derivatives were toxic to A. salina nauplii, while the flavonoids showed low toxicity. S. terebinthifolius leaf extract caused damage to the midgut of A. aegypti larvae, interfering with survival and development. The larvicidal effect of the extract can be attributed to cinnamic acid derivatives and flavonoids. The data obtained using A. salina indicates that caution should be used when employing this extract as a larvicidal agent.
In this study, the effects of Opuntia ficus-indica lectin (OfiL) on the survival and nutritional parameters of Sitophilus zeamais (maize weevil) adults were evaluated. OfiL was incorporated into the artificial diets at concentrations of 15, 60, and 95 mg/g (mg of lectin per g of wheat flour). Mortality was evaluated after 7 and 15 days, and the amount of food ingested and the weight of the insects were determined on the 7th day. In addition, the in vitro effects of OfiL on the gut enzymes of the insect were investigated. The ingestion of OfiL did not show any significant difference in the mortality rates compared to control. The relative consumption rate was also similar to that of the control, and no deterrent effect was detected. However, the values of the relative biomass variation and the efficiency of ingested food conversion were negative in the treatments at 60 and 95 mg/g, showing that lectin ingestion resulted in weight loss. OfiL exhibited a stimulatory effect on the protease activity from S. zeamais gut extract, which may cause uncontrolled hydrolysis of proteins in the digestive tract. This lectin did not promote significant alteration in the amylase activity. In conclusion, OfiL was able to exert anti-nutritional effects without causing a deterrent effect.
∙ Transport by road is the main mechanism for integrating Brazil, but roads are drivers of land cover conversion, fragmentation, and direct mortality by wildlife-vehicle collisions. In Aquidauana, BR419 and MS170 are important unpaved roads into the rural Pantanal region, and improvement and paving has been planned for BR419, which may increase risks to local avifauna. The aim of this study was to assess the species composition and richness of conspicuous avifauna (defined as being easily quantifiable using roadside surveys), and their spatial and seasonal variation among two important roadways. One of the surveyed roadways accessing rural areas of the Aquidauana region of the Pantanal was scheduled for improvement and paving. Transects of 73 km long were sampled along both highways, six samples along each transect between February and May 2012, for a full sample effort of 103:06 hours. A total of 6888 individuals from 33 families and 93 species were observed in the transects combined, and 83 species were identified in each transect. Jaccard Similarity Index was 0.79, and we found a statistically significant difference (P < 0.05) among the bird communities between the highways. Species associated with freshwater environments were more abundant along and indicator species of MS170. That avifauna along MS170 varied temporally and species richness was strongly correlated with river discharge, while the same was not true with BR419. Species particularly vulnerable to wildlife-vehicle collisions, e.g., vultures (Coragyps atratus, C. aura) and Southern Caracara (Caracara plancus), were abundant along BR419. While mitigation measures for mammals, reptiles, and amphibians are common and effective, the vertical movement of most birds into the roadway presents a different challenge for which a technical solution may not currently exist. To protect species observed along the currently unpaved roadways of Pantanal’s Aquidauana region, following road improvement, speed limits should be calibrated to facilitate safe transportation for drivers and the continued existence of wild species. Resumo · Espécies de pássaros conspicuentes variação sazonal em ambientes de ecotone e pântano na região Aquidauana do Pantanal O transporte rodoviário é o principal mecanismo de integração do Brasil, mas as estradas são propulsoras da conversão, fragmentação e mortalidade direta da cobertura vegetal por colisões de veículos silvestres. Em Aquidauana, a BR419 e a MS170 são importantes estradas não pavimentadas para a região rural do Pantanal, melhorias e pavimentação foram planejadas para a BR419, o que pode aumentar os riscos para a avifauna local. O objetivo deste estudo foi avaliar a composição de espécies e a riqueza da avifauna conspícua (definido como sendo facilmente quantificável usando levantamentos de beira de estrada) e sua variação espacial e sazonal entre duas estradas importantes. Uma das estradas pesquisadas acessando áreas rurais da região de Aquidauana do Pantanal foi programada para melhorias e pavimentação. Transectos de 73 km de extensão foram amostrados ao longo das duas rodovias, seis amostras ao longo de cada transecto entre fevereiro e maio de 2012, para um esforço amostral completo de 103:06 horas. Um total de 6888 indivíduos de 33 famílias e 93 espécies foram observados nos transectos combinados, e 83 espécies foram identificadas em cada transecto. Índice de Similaridade de Jaccard foi de 0,79, e encontramos uma diferença estatisticamente significativa (P < 0,05) entre as comunidades de aves entre as rodovias. Espécies associadas a ambientes de água doce foram mais abundantes e espécies indicadoras da MS170. Essa avifauna ao longo da MS170 variou temporalmente e a riqueza de espécies foi fortemente correlacionada com a descarga do rio, enquanto o mesmo não ocorreu com a BR419. Espécies particularmente vulneráveis a colisões de veículos silvestres , por exemplo, abutres (Coragyps atratus, C. aura) e Caracará (Caracara plancus), foram abundantes ao longo da BR419. Embora as medidas de mitigação para mamíferos, répteis e anfíbios sejam comuns e eficazes, o movimento vertical da maioria das aves na pista apresenta um desafio diferente para o qual uma solução técnica pode não existir atualmente. Para proteger as espécies observadas ao longo das estradas atualmente não pavimentadas da região de Aquidauana, no Pantanal, seguindo a melhoria das estradas, os limites de velocidade devem ser calibrados para facilitar o transporte seguro dos motoristas e a existência contínua de espécies silvestres.
Este estudo avaliou o efeito dos cimentos resinosos (RelyX Ultimate e RelyX U200) e a espessura da cerâmica reforçada por disilicato de lítio (IPS e.max Press) na resistência de união ao microcisalhamento (RUµC), após submetidos a ciclagem térmica. Discos com 12 mm de diâmetro nas espessuras de 0,5 mm, 1,2 mm e 2,0 mm foram confeccionados com a cerâmica (IPS e.max Press), sobre os quais foram confeccionados cilindros dos cimentos resinosos a partir de tubos de Tygon (0,7 mm de diâmetro e 1,0 mm de altura). A fotoativação foi efetuada com a fonte de luz LED-(Radii Plus) interposta pelos discos cerâmicos nas diferentes espessuras. Em seguida, os tubos foram removidos, e as amostras armazenadas em água deionizada a 37º C, por 24 horas e submetidos à ciclagem térmica (3.000 ciclos-5°/55 °C). Após, as amostras foram submetidas ao ensaio de RUµC na máquina de ensaio Instron a velocidade de 1,0 mm/min, até ocorrer fratura. Os dados foram submetidos à Análise de Variância 3 fatores e ao teste de Tukey (α = 0,05). Os valores de RUµC (MPa) mostraram que a espessura de 0,5 mm (32,6±1,4) apresentou valores significativamente superior as espessuras de 1,5 mm (25,6±1,8) e 2 mm (23,6±2,3), e a espessura de 1,5 mm foi significantemente superior à de 2 mm (p<0,001). Os grupos sem ciclagem térmica (28,5±1,2) foi significativamente superior ao grupo submetido à ciclagem térmica (25,9±2,8) (p<0,001). Nenhuma diferença estatística foi observada entre os cimentos RelyX Ultimate (27,2±2,4) e o RelyX U200 (27,4±1,1) (p=0,60). A espessura da cerâmica e a ciclagem térmica influenciaram significativamente nos valores de resistência de união. Já os cimentos resinosos não influenciaram a resistência de união.
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