ABSTRACT
Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong "numerical" effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative "identity" effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.
Subject(s)
Crops, Agricultural , Introduced Species , Animals , Bees , Brazil , SeasonsABSTRACT
O presente trabalho apresenta uma metodologia para segmentação automática de candidatos a nódulos pulmonares solitários usando Autômato Celular. A detecção precoce de nódulos pulmonares solitários que podem vir a se tornar câncer é essencial para sobrevida dos pacientes. Para auxiliar os especialistas na identificação desses nódulos estão sendo desenvolvidos sistemas auxiliados por computadores que visam automatizar os trabalhos de detecção e classificação. A etapa de segmentação desempenha um papel fundamental na detecção automática de nódulos pulmonares, pois permite separar os elementos de imagem em regiões que apresentam a mesma propriedade ou característica. A metodologia utilizada nessa pesquisa inclui aquisição das imagens, eliminação de ruídos, segmentação do parênquima pulmonar e segmentação dos candidatos a nódulos pulmonares solitários. Os testes foram realizados utilizando conjunto de imagens da base LIDC-IDRI, contendo 739 nódulos. Os resultados mostram uma sensibilidade de 95,66% dos nódulos considerados.
The present work presents a methodology for automatic segmentation of pulmonary solitary nodules candidates using cellular automaton. Early detection of pulmonary solitary nodules that may become cancer is essential for survival of patients. To assist the experts in the identification of these nodules are being developed computer aided systems that aim to automate the work of detection and classification. The segmentation stage plays a key role in automatic detection of lung nodules, as it allows separating the image elements in regions, which have the same property or characteristic. The methodology used in the article includes acquisition of images, noise elimination, pulmonary parenchyma segmentation and segmentation of pulmonary solitary nodules candidates. The tests were conducted using set of images of the LIDC-IDRI base, containing 739 nodules. The test results show a sensitivity of 95.66% of the nodules.
Subject(s)
Humans , Image Processing, Computer-Assisted , Tomography, X-Ray Computed , Solitary Pulmonary Nodule , Congresses as TopicABSTRACT
Frugivory is not frequent among bees. Although stingless bees visit aged fruits for pulp, the use of fresh fruits is recorded only for Trigona hypogea Silvestri, a species that does not visit flowers. Here we report the occurrence of frugivory in Trigona amazonensis (Ducke), a flower-visiting stingless bee.
Subject(s)
Animals , Bees , Food Preferences , FruitABSTRACT
Frugivory is not frequent among bees. Although stingless bees visit aged fruits for pulp, the use of fresh fruits is recorded only for Trigona hypogea Silvestri, a species that does not visit flowers. Here we report the occurrence of frugivory in Trigona amazonensis (Ducke), a flower-visiting stingless bee.
