Bioreactor for microalgal cultivation systems: strategy and development

Microalgae are important natural resources that can provide food, medicine, energy and various bioproducts for nutraceutical, cosmeceutical and aquaculture industries. Their production rates are superior compared to those of terrestrial crops. However, microalgae biomass production on a large scale is still a challenging problem in terms of economic and ecological viability. Microalgal cultivation system should be designed to maximize production with the least cost. Energy efficient approaches of using light, dynamic mixing to maximize use of carbon dioxide (CO2) and nutrients and selection of highly productive species are the main considerations in designing an efficient photobioreactor. In general, optimized culture conditions and biological responses are the two overarching attributes to be considered for photobioreactor design strategies. Thus, fundamental aspects of microalgae growth, such as availability of suitable light, CO2 and nutrients to each growing cell, suitable environmental parameters (including temperature and pH) and efficient removal of oxygen which otherwise would negatively impact the algal growth, should be integrated into the photobioreactor design and function. Innovations should be strategized to fully exploit the wastewaters, flue-gas, waves or solar energy to drive large outdoor microalgae cultivation systems. Cultured species should be carefully selected to match the most suitable growth parameters in different reactor systems. Factors that would decrease production such as photoinhibition, self-shading and phosphate flocculation should be nullified using appropriate technical approaches such as flashing light innovation, selective light spectrum, light-CO2 synergy and mixing dynamics. Use of predictive mathematical modelling and adoption of new technologies in novel photobioreactor design will not only increase the photosynthetic and growth rates but will also enhance the quality of microalgae composition. Optimizing the use of natural resources and industrial wastes that would otherwise harm the environment should be given emphasis in strategizing the photobioreactor mass production. To date, more research and innovation are needed since scalability and economics of microalgae cultivation using photobioreactors remain the challenges to be overcome for large-scale microalgae production

A skull of the extinct tayassuid Brasiliochoerus stenocephalus (Lund in Reinhardt, 1880) (Mammalia, Cetartiodactyla) from the Late Pleistocene of southern Brazil: morphology and taxonomy

Among the several fossils of South American tayassuids, it is remarkable the presence of a well-preserved skull from southern Brazil (Chuí Creek, Santa Vitória do Palmar, Santa Vitória Formation). Here, we provide an update in the taxonomic arrangement and anatomical description of this specimen assigned to Brasiliochoerus stenocephalus based on the combination of the following traits: 1) long rostrum with a markedly convex profile; 2) anterior margin of the orbits located behind the vertical plane of the distal part of M3; 3) facial crests of the zygomatic arch forming an angle of about 80° relative to the molar series; 4) postorbital process more developed and ventrally projected in comparison to other tayassuids; 5) absence of a sagittal crest and presence of short parasagittal crests; 6) presence of curved temporal crests; 7) accentuated basicranial flexion; 8) bunodont and brachydont cheek teeth; 9) conspicuous pneumatization; 10) short postcanine diastema; and 11) cranium with no postorbital depression. This specimen was collected from sedimentary levels that contain a diverse assemblage of Pleistocene terrestrial mammals. Based on living analogous species, the presence of this taxon indicates dry and relatively open environments at some part of the Late Pleistocene in the study area.Fil: Copetti, Paula Lopes. Universidade Federal de Santa Maria; BrasilFil: Gasparini, Germán Mariano. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico de Paleontología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Pereira, Jamil Corrêa. Museu Coronel Tancredo Fernandes de Mello; BrasilFil: Fontoura, Emmanuelle. Universidade Federal de Santa Maria; BrasilFil: Lopes, Renato Pereira. Universidade Federal do Rio Grande do Sul; BrasilFil: Kerber, Leonardo. Universidade Federal de Santa Maria; Brasi

Differentiation of Urinary Stone and Vascular Calcifications on Non-contrast CT Images: An Initial Experience using Computer Aided Diagnosis

The purpose of this study was to develop methods for the differentiation of urinary stones and vascular calcifications using computer-aided diagnosis (CAD) of non-contrast computed tomography (CT) images. From May 2003 to February 2004, 56 patients that underwent a pre-contrast CT examination and subsequently diagnosed as ureter stones were included in the study. Fifty-nine ureter stones and 53 vascular calcifications on pre-contrast CT images of the patients were evaluated. The shapes of the lesions including disperseness, convex hull depth, and lobulation count were analyzed for patients with ureter stones and vascular calcifications. In addition, the internal textures including edge density, skewness, difference histogram variation (DHV), and the gray-level co-occurrence matrix moment were also evaluated for the patients. For evaluation of the diagnostic accuracy of the shape and texture features, an artificial neural network (ANN) and receiver operating characteristics curve (ROC) analyses were performed. Of the several shape factors, disperseness showed a statistical difference between ureter stones and vascular calcifications (p < 0.05). For the internal texture features, skewness and DHV showed statistical differences between ureter stones and vascular calcifications (p < 0.05). The performance of the ANN was evaluated by examining the area under the ROC curves (AUC, Az). The Az value was 0.85 for the shape parameters and 0.88 for the texture parameters. In this study, several parameters regarding shape and internal texture were statistically different between ureter stones and vascular calcifications. The use of CAD would make it possible to differentiate ureter stones from vascular calcifications by a comparison of these parameters