Larval ontogeny and morphology of giant trahira Hoplias lacerdae

In the present study, the morphology and behaviour of giant trahira Hoplias lacerdae larvae were investigated, from hatching to complete absorption of the yolk sac, under laboratory conditions. In the first day post-hatching (dph), the larvae presented a big ovoid-shaped yolk sac that underwent regression during larval ontogeny. The mouth opened 3 dph, when the pectoral fins were evident. From this day, the larvae were able to perform sudden bursts of activity and appear to be able to swim a few centimetres before sinking again. The branchial apparatus was defined at 5 dph, and by 6 dph the operculum was formed. The internal organs such as intestine, liver, kidney and external sensorial structures were present at 7 dph. The yolk sac remained until 7 dph.76485286

Factorial design applied to concentrate bioactive component of Cymbopogon citratus essential oil using short path distillation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Cymbopogon citratus (DC.) Stapf (Gramineae) is the scientific name of a plant known as lemongrass. it is characterized by the high concentrations of citral. This work aimed to analyze the influence of short path distillation process variables (evaporator temperature (EVT), volumetric feed flow rate (Q) and interactions between them), on the concentration of citral in the distillate stream of the process. Factorial design experiments were carried out, starting with a 2(2) design trials at experimental range from 60 to 80 degrees C for EVT and from 1.5 to 6.0 mL/min for Q followed by 2(2) with central point design trials at experimental range from 60 to 120 degrees C for EVT and between 1.5 and 4.5 mL/min for Q. The concentration of citral in the distillate (CCD) was analyzed by gas chromatography-mass spectrometry (GC-MS). The effect of each variable studied on the dependent variable (CCD), is indicated by influence of EVT and Q on CCD. The increase of EVT increases CCD to 2.048 x 10(3) mg citral/g sample, when compared with the initial sample of essential oil, which presented a CCD of 9.908 x 10(2) mg citral/g sample. The linear model, statistically significant, describes the dependence of the variable CCD with the variables of the process inside the experimental range. (C) 2009 The Institution of Chemical Engineers. Published by Elsevier B.V All rights reserved.882A239244Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq