Analysis of a dose-response assay in Scaptotrigona bipunctatabees, Lepeletier, 1836 (Hymenoptera: Apidae) using the logistic regression model under the Bayesian approach

This paper shows the results of a dose-response study in Scaptotrigona bipunctatabees, Lepeletier, 1836 (Hymenoptera: Apidae) exposed to the insecticide Fastac Duo. The aim was to evaluate the lethal concentration that causes the death of 50% of bees (LC50) and investigate the odd of mortality after exposure to different concentrations, using the logistic regression model under the Bayesian approach. In this approach, it is possible to incorporate a prior information and gives more accurate inferential results. Three independent dose-response experiments were analyzed, dissimilar in their lead time according to guidelines from the Organisation for Economic Co-operation and Development (OECD), in which each assay contained four replicates at the concentration levels investigated, including control. Observing exposure to the agrochemical, it was identified that the higher the concentration, the greater the odd of mortality. Regarding the estimated lethal concentrations for each experiment, the following values were found, 0.03 g a.i. L-1, for 24hours, 0.04 g a.i. L-1, for 48hoursand 0.06 g a.i. L-1for 72hours, showing that in experiments with longer exposure times there was an increase in LC50. Concluding, the study showed an alternative approach to classical methods for dose-response studies in Scaptotrigona bipunctatabees exposed to the insecticide Fastac Duo.

Determinação do trajeto do canal mandibular por meio de tomografia computadorizada em dez mandíbulas de cadáveres de cães mesaticefálicos / Mandibular canal course determination by means of computerized tomography in ten mandibles of mesaticephalic dogs cadavers

Sabe-se que durante qualquer procedimento cirúrgico na região da mandíbula no homem, um dano iatrogênico ao feixe vasculonervoso que percorre o canal mandibular (CM) poderia causar desde parestesia até dor constante. Na odontologia veterinária, diferentes procedimentos cirúrgicos são realizados no tecido ósseo adjacente ao CM, o que implica no conhecimento acurado da localização do mesmo. O objetivo desta pesquisa foi determinar por meio da Tomografia Computadorizada (TC) o trajeto do CM em relação às faces da mandíbula: lingual, vestibular, ventral e crista alveolar em dez mandíbulas de cadáveres de cães mesaticefálicos. Os tomogramas foram realizados no plano transversal, tomando como referência para cada corte o forame mandibular, as raízes dentárias dos dentes molares, pré-molares e forame mentoniano médio. No tomógrafo foram realizadas medidas desde o CM até as diferentes faces. Conclui-se que a partir do dente 3º molar, no sentido rostral, o CM aumenta gradualmente a distância em relação à crista alveolar, alcançando a sua máxima profundidade na região dente 1º molar. Em relação às faces vestibular e lingual, o CM apresentou-se lingualizado na região dos dentes molares. O CM continua rostralmente ocupando a região ventral do corpo da mandíbula, mantendo uma distância similar entre a superfície vestibular e lingual. Já na região do dente 3º pré-molar o canal mandibular aumenta ligeiramente a sua distância com relação à face ventral e lingual da mandíbula, antes do seu fim no forame mentoniano medial na face vestibular da mandíbula.

As it is known, during any surgical procedure in the human mandible, an iatrogenic damage to the neurovascular bundle that runs along the mandibular canal (MC) could cause from paresthesia to constant pain. In veterinary dentistry, different surgical procedures are performed on the bone tissue adjacent to the MC, which implies accurate knowledge of its localization. The purpose of this study was to determine by means of computerized tomography (CT) the path of the MC in relation with: lingual surface, vestibular surface, alveolar crest, and ventral mandible surface in ten mesaticephalic dogs. The slices were performed in transverse plane using as reference the mandibular foramen, the medial mental foramen and the tooth roots of molars and premolars; several measures among the MC and the mandibular faces were performed. The conclusion of this study was that from the 3rd molar tooth (following in rostral direction), the MC gradually increases its distance from the alveolar crest, reaching its maximum depth in the 1st molar tooth area. In the molar area, the MC was located nearly of the mandibular lingual surface. The CM continues rostrally occupying the ventral region of the mandible body keeping a similar distance between the buccal and lingual surface. Then in the 3rd premolar area the MC increases slightly its distance from the ventral aspect of the mandible, before its end in the medial mental foramen on the face of the mandible.