Macro- and microstructural descriptions of the zebrafish (Danio rerio) liver

The liver is an essential metabolically active organ, responsible for many vital life functions such as metabolism, synthesis, and storage. This study describes the macroscopic and microscopic zebrafish liver and its temporal changes during a period of 13 weeks. Forty-six adult zebrafish were used (46), of which 27 were females and were 19 males. Seven fish were euthanized initially for macroscopic evaluation and 3 fish were euthanized weekly for 13 weeks for microscopic evaluation. Routine histological technique was performed; the slides were stained with haematoxylin/eosin and periodic acid-Schiff. The volumetric (Vv(h)) and numerical (Nv(h)) densities of hepatocytes and vacuolation intensity were determined weekly. The liver was located in the coelomic cavity ventrally to the swim bladder, slightly brownish and divided into 3 hepatic lobes. Microscopically, it consisted of hepatocytes forming a muralium duplex around the sinusoids. The staining of the cytoplasm of hepatocytes was more eosinophilic and more basophilic in males and females, respectively. There was no formation of portal triads and phagocytic cells. The gallbladder had transitional epithelium, and the bile ducts had simple cuboidal epithelium. The volume and numerical density of hepatocytes during the 13 weeks was not statistically different, but these parameters displayed a positive correlation. The vacuolation was due to the presence of glycogen. The zebrafish liver has macro and micro structural particular features while, quantitatively, the volume and number of hepatocytes showed great capacity to respond to the physiological needs of the animal at the time

A reversible system based on hybrid toggle radius-4 cellular automata and its application as a block cipher

The dynamical system described herein uses a hybrid cellular automata (CA) mechanism to attain reversibility, and this approach is adapted to create a novel block cipher algorithm called HCA. CA are widely used for modeling complex systems and employ an inherently parallel model. Therefore, applications derived from CA have a tendency to fit very well in the current computational paradigm where scalability and multi-threading potential are quite desirable characteristics. HCA model has recently received a patent by the Brazilian agency INPI. Several evaluations and analyses performed on the model are presented here, such as theoretical discussions related to its reversibility and an analysis based on graph theory, which reduces HCA security to the well-known Hamiltonian cycle problem that belongs to the NP-complete class. Finally, the cryptographic robustness of HCA is empirically evaluated through several tests, including avalanche property compliance and the NIST randomness suite.Comment: 34 pages, 12 figure

Reference Structure Model for Degree Alert Classification During Seasonal Hydrological Events for Humanitarian Assistence in the Brazilian Amazon

AbstractRecent events in the rivers of the Amazon region show the distinct need for concern in this region and the vulnerability of the Amazonian people in regards to these events. Organizations for humanitarian aid developed procedures in the Amazon region. But to what extent are these actions effective if little is done prior to disasters? This work seeks to develop a frame of reference for classifying alertness in cities likely to suffer from flooding and ebbing of the hydrographic network in the Amazon Basin. The objective is to serve warning to the riverside communities in the state of Amazonas, establish future provisions of supplies and to form a solid database of information concerning the needs and impacts of these events, hence creating a historical record

Electrosynthesis of Composites Consisting of FeOOH and Reduced Graphene Oxide in Graphite Electrodes

Carbon-based composite nanomaterials, such as graphene oxide, have demonstrated a great potential for applications in several areas. The present work sought to obtain, via electrosynthesis, a composite material based on graphene oxide and iron oxyhydroxide deposited onto graphite pencil surface. The electrodes modifications by electrosynthesis was performed using the cyclic voltammetry technique. The graphene oxide and the electrosynthesized FeOOH cuboids were characterized by SEM-FEG, EDX. The cyclic voltammetry was used to characterize the electrochemical behavior of the graphite pencil electrode (PEG). The composites electrodes of PEG modified with GO/FeOOH (PEG/GO/FeOOH) were formed in two stages. In the first stage, there was the formation of FeHCF in PEG/GO, and subsequently, there was the formation of PEG/GO/FeOOH in alkaline medium. DOI: http://dx.doi.org/10.17807/orbital.v12i3.147