Ingestion rate and feeding behavior of guppy (Poecilia reticulata Peters) larvae fed on nauplii of Artemia urmiana and Artemia franciscana

Artemia nauplii, despite their marine origin, have a good potential for application in the freshwater ornamental fish culture. In this study, two types of Artemia urmiana and Artemia franciscana were used for feeding of Guppy (Poecilia reticulata Peters) Larvae. Newly hatched fresh nauplii at three different densities of 3, 6, and 12 ind./ml as live feeds were compared for measuring larval ingestion rate. Results showed that type and density of Artemia nauplii had significant effects on ingestion rate (P<0.05). The average ingestion rate in larvae which maintain 12 hours starvation (first set of experiment) were 36, 244, and 664 ind./larvae/day for A. urmiana, correspondingly, for A. franciscana were 160, 480, and 880 ind./larvae/day at densities of 3, 6, and 12 ind./ml, respectively. The average ingestion rate of guppy larvae with 24, 48 and 72 hours feeding preconditions (2^nd, 3^rd and 4^th set of experiment) were significantly (P<0.05) decreased. After starvation, the ingestion rate of guppy larvae fed A. urmiana had range 22-54, 86-102, and 148-188 ind./larvae/day, correspondingly, for A. franciscana 66-100, 100-260, and 200-224 ind./larvae/day at 3, 6, and 12 ind./ml, respectively. The use of suitable densities of 6 and 12 ind./ml from Artemia nauplii could increase efficiency of utilization and also improve Guppy larvae production

Finite Element Modelling and Damage Detection of Seam Weld

© Springer Nature Singapore Pte Ltd 2020. Seam welds are widely used in assembled structures for connecting components. However, the dynamic effects of a seam weld are often difficult to characterise in numerical models for several reasons: (1) it is often not wise to build a fine mesh on the seam line which will add considerable computational cost for a structure with many welds, (2) the mechanical properties of weld materials are not well known; (3) sometimes some geometric information about welds is not known beforehand. In this work, the finite element model of a welding connection part is developed by employing CSEAM element in NASTRAN and its feasibility for representing a seam weld is investigated. Based on this result, a damage detection method by updating the properties of the built CSEAM elements is also proposed for welding quality assurance. The damage takes the form of a gap in the weld which causes a sharp change of model strain energy at the edges of the gap for certain vibration modes. Specifically, the model strain energy shape is used as the objective function. A Kriging model is introduced for efficiency and simulation of a T-shaped welded plate structure to demonstrate the effectiveness of this method

The Effects of Dietary Supplements of Calcium, Vitamin D and Estrogen Hormone on Serum Levels of OPG and RANKL Cytokines and their Relationship with Increased Bone Density in Rats

Introduction: Osteoprotegerin (OPG)-Receptor activator of nuclear factor kappa-B ligand(RANKL) pathway is one of the contributing factors in the regulation of osteogenesis and bone resorption routes. Aim: The purpose of this study was to evaluate the effects of various dietary supplements on this pathway. Materials and Methods: The samples for this study (24 newborn rats) were divided in three groups according to the experiment applied for each group. Rats were given special diet according to their group plan for six weeks. Blood samples were collected to measure their serum levels of OPG and RANKL and all organs of rats were used to measure their bone density too. The results were analysed using appropriate statistical analysing tests. Results: Levels of whole-body bone mineral density in calcium plus vitamin D plus Estrogen (Ca + D + E) group and calcium plus vitamin D (Ca + D) group were significantly increased compared to control group. Mineral density was highest in calcium plus vitamin D plus Estrogen group and was about 0.1357 g/cm(2). RANKL had a significant decrease in calcium plus vitamin D plus Estrogen group compared to control and calcium plus vitamin D groups. There was a significant increase in the mean calcium and OPG in both experimental groups rather than control. Also, significant increase in estrogen was observed in Ca + D group than the control group. Conclusion: The results showed that intake of calcium and vitamin D and estrogen at determined dose led to an increase in OPG and RANKL cytokines reduction which ultimately led to an increase in bone mineral density. But Ca, D and E synergies were more effective in increasing bone mineral density compared to only the use of Ca and D

Fecal Helicobacter pylori GlmM and 16S rRNA genes correlate with serum TNF-α and IL-1β cytokine fluctuations

The proinflammatory cytokines of TNF-α and IL-1β have been reported to be increased in gastric mucosal surfaces in people with Helicobacter pylori infection. Accordingly, this study was conducted to investigate the relationship between the presence of H. pylori genes and the serum oscillations of these cytokines. In this study, DNA was first extracted from the stool samples of infected individuals and used as DNA template to investigate the presence of glmM and 16S rRNA genes in PCR. The ELISA assay was employed to examine serum levels of TNF-α and IL-1β cytokines. According to statistical analysis, there was a significant correlation between the presence of glmM and 16S rRNA genes in the stool samples of infected persons and the serum oscillations of TNF-α and IL-1β cytokines. At the end of study and analysis of the data in case group with HPSAg+, 47.6 of the glmM gene and 23.6 of the 16S rRNA gene were positive. In addition, a significant correlation was observed between the presence of glmM and 16S rRNA genes in the stool specimens of infected individuals and the serum levels of TNF-α and IL-1β cytokines (p < 0.05). Considering the results, it can be concluded that fluctuations in the amount of HPSA, TNF-α, and IL-1β in H. pylori infection depend on the presence of glmM and 16S rRNA genes. The presence of glmM and 16S rRNA in the stool sample increases by boosting the response level to stool antigen (HPSA), IL-1β, and TNF-α, suggesting the prognosis of the disease with a bacterial virulence form using stool tests. © 2018 Akademiai Kiado Rt..All rights reserved

Effects of transplanted olfactory ensheathing cells on functional improvement and axonal regeneration in acute and delayed spinal cord injury in rats: A comparative study

Introduction: Cell therapy is known as one of the most common methods used for treating a spinal cord injury (SCI); particularly, olfactory ensheathing cells (OECs), which have attracted much more attention among scholars due to their properties such as promotion of axonal regeneration, remyelination, and angiogenesis. Thus, the present study compared the effects of transplanted OECs on functional improvement and axonal regeneration of contused rats during acute and delayed phases. Material and Methods: For this purpose, a total of 56 male Wistar rats were randomly divided into eight groups including sham, control, three vehicle groups (immediately, 3 and 7 days after injury), and three cell transplantation groups (immediately, 3 and 7 days following injury). The sham group had experienced only laminectomy and other groups had undergone the SCI. The olfactory mucosa of the 7-day-old rat pups was also used for cell culture. The cell type was then confirmed by immunocytochemistry. In the vehicle and cell transplantation groups, the cell culture medium was injected by itself or accompanied by cells, respectively. Subsequently, the motor function was evaluated. Finally, luxol fast blue (LFB) staining was used for histological assessment. Results: Motor test results showed an increase in the Basso, Beattie, and Bresnahan locomotor scale scores immediately after injury in the transplantation group compared to those in other two cell-treated groups; but it was not significant. Discussion and Conclusion: Based on the LFB staining results, the regeneration rate in the transplantation group immediately after injury was considerably higher than that in two other treated groups. Therefore, considering these findings, it seemed that cell transplantation immediately after injury was better than that 3 and 7 days following injury