Additions to the Epacridaceae in Tasmania

Three new taxa are described from the Epacridaceae, including a new species from each of Cyathodes and Epacris, and a subspecies from Monotoca. All are endemic to Tasmania

Aplicación de redes neuronales en la clasificación de imágenes

Tesis (Lic. en Ciencias de la Computación)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía y Física, 2014.La eficiencia de la combinación entre los ojos y cerebro humano en resolver problemas de reconocimiento de patrones permiten a los cientı́ficos considerar la posibilidad de aplicar, en los algoritmos de clasificación, sistemas computacionales basados en modelos simples del cerebro humano. La ingenierı́a del software provee un enfoque sistemático y disciplinado que permite crear esos sistemas de forma robusta y fiable. Se garantizan estas caracterı́sticas a través del seguimiento de estándares definidos. En este proyecto se pretende exponer un marco teórico sobre la categorización de imágenes digitales, y sobre la estructura y funcionamiento de la redes neuronales perceptrón multicapas y SOM (mapas de auto organización de Kohonen). A su vez, en base a estos conceptos, se desea desarrollar un sistema de software de clasificación de imágenes que permita explorar algoritmos de categorización que utilicen redes neuronales, para comparar su efectividad y eficiencia respecto a métodos estándares de clasificación estática.Fil: Mihaich, Florencia. Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía y Física; Argentina

Adult fathead minnow, Pimephales promelas, partial life‐cycle reproductive and gonadal histopathology study with bisphenol A

Bisphenol A (BPA) is an intermediate used to produce epoxy resins and polycarbonate plastics. Although BPA degrades rapidly in the environment with aquatic half‐lives from 0.5 to 6 d, it can be found in aquatic systems because of widespread use. To evaluate potential effects from chronic exposure, fathead minnows were exposed for 164 d to nominal concentrations of 1, 16, 64, 160, and 640 µg/L BPA. Population‐level endpoints of survival, growth, and reproduction were assessed with supplemental endpoints (e.g., vitellogenin, gonad histology), including gonad cell type assessment and quantification. No statistically significant changes in growth, gonad weight, gonadosomatic index, or reproduction variables (e.g., number of eggs and spawns, hatchability) were observed; however, there was a significant impact on male survival at 640 µg/L. Vitellogenin increased in both sexes at 64 µg/L or higher. Gonad cell type frequencies were significantly different from controls at 160 µg/L or higher in males with a slight decrease in spermatocytes compared with less mature cell types, and at 640 µg/L in females with a slight decrease in early vitellogenic cells compared with less mature cells. The decrease in spermatocytes did not correspond to a decrease in the most mature sex cell type (spermatozoa) and did not impair male fertility, as hatchability was not impacted. Overall, marginal shifts in gametogenic cell maturation were not associated with any statistically significant effects on population‐relevant reproductive endpoints (growth, fecundity, and hatchability) at any concentration tested.publishe