RESUMO
Soil and water bioengineering is a technology that encourages scientists and practitioners to combine their knowledge and skills in the management of ecosystems with a common goal to maximize benefits to both man and the natural environment. It involves techniques that use plants as living building materials, for: (i) natural hazard control (e.g., soil erosion, torrential floods and landslides) and (ii) ecological restoration or nature-based re-introduction of species on degraded lands, river embankments, and disturbed environments. For a bioengineering project to be successful, engineers are required to highlight all the potential benefits and ecosystem services by documenting the technical, ecological, economic and social values. The novel approaches used by bioengineers raise questions for researchers and necessitate innovation from practitioners to design bioengineering concepts and techniques. Our objective in this paper, therefore, is to highlight the practice and research needs in soil and water bioengineering for reconciling natural hazard control and ecological restoration. Firstly, we review the definition and development of bioengineering technology, while stressing issues concerning the design, implementation, and monitoring of bioengineering actions. Secondly, we highlight the need to reconcile natural hazard control and ecological restoration by posing novel practice and research questions.
Assuntos
Conservação dos Recursos Naturais/métodos , Recuperação e Remediação Ambiental/métodos , Água Doce , Águas Salinas , Solo , Biodegradação Ambiental , Recuperação e Remediação Ambiental/instrumentaçãoRESUMO
There is a great deal of confusion in the literature as to whether or not true angiosarcomas of the thyroid exist or whether these are all anaplastic carcinomas of the thyroid which have an angiosarcomatoid appearance. Due to the fact that undifferentiated carcinomas of this organ can strikingly resemble various sarcomas it is recommended that great care should be taken prior to qualify as an angiosarcoma a malignant thyroid tumor. A lot of viewpoints have been expressed so far in literature concerning this theme, and they can be summarized as follows. On one side and not admitting the existence of angiosarcoma in this location there are opinions which think of it as a "variant" of undifferentiated carcinoma (a pure carcinoma with a pseudovascular pattern or a carcinoma with an intermingled non-neoplastic reactive vascular component), or as a neoplasm in transition from epithelial to endothelial differentiation ("mesenchymal neometaplasia"), or as a carcinoma with aberrant expression of endothelial markers, or as a carcinoma with a non-specific uptake of endothelial antigens(e.g. from serum in case of F-VIII R-Ag positivity). On the other side there are opinions in favor of the existence of such an entity, based upon light microscopy features coupled with immunocytochemical results (endothelial antigens expression without or with cytokeratins expression) and with the possible support of electron microscopy. Anyway ultrastructural findings of specific markers (Weibel-Palade bodies, pericellular basal lamina, tight junctions, subplasmalemmal pinocytotic vesicles) according to some authors are not a prerequisite: so poorly differentiated neoplasma can fail to show those histogenetic markers.(ABSTRACT TRUNCATED AT 250 WORDS)
