Search

Liquefaction-induced lateral spreading that has resulted in devastating damages to lifelines and buildings has been widely reported in recent earthquakes. Although it is impossible to preclude the occurrence of earthquakes, it is possible to predict its adverse effects through computer science such as machine learning (ML) algorithms. In this study, the ability of recently developed and powerful ML algorithms such as eXtreme Gradient Boosting (XGBoost), Categorical Boosting (CatBoost), and Light Gradient Boosting Machine (LightGBM) was investigated to predict the occurrence of liquefaction-induced lateral spreading. A relatively large dataset was used to develop ML models, including 6704 lateral spread observations from the 2011 Christchurch earthquake in New Zealand. The particle swarm optimization (PSO) algorithm is utilized for hyperparameter optimization of the gradient boosting models, called the PSO-XGBoost, PSO-LightGBM, and PSO-CatBoost. For comparison, the prediction results of the PSO optimized gradient boosting models were compared with that of the models using default parameters (i.e., XGBoost, CatBoost, and LightGBM). In addition, the SHapley Additive exPlanations approach is employed to explore the feature importance of the variables included in the dataset. The findings demonstrated that all the three gradient boosting algorithms performed well in predicting lateral spreading occurrence. Moreover, PSO-CatBoost outperformed other state-of-the-art models in terms of performance metrics. However, the PSO-LightGBM model may be considered the best choice for computers with older-gen hardware and important tasks that need to be completed in a short time. This study confirms the effectiveness of the proposed models, and the use of these boosting algorithms especially optimized with PSO is recommended for predicting the occurrence of liquefaction-induced lateral spreading. [ABSTRACT FROM AUTHOR]

Surgical treatment of chest wall deformities is done with costal cartilage resection in selected patients in adolescence. In this study, we evaluated the effect of costal cartilage resections on the lung volume stereologically by using computed tomography. In this study, sixteen four weeks old New Zealand rabbits were used. Young subjects were preferred to evaluate the effect of the operation on the growth process. In order to avoid postoperative complications, only two costal cartilage resections were performed. In the surgical group the right 4th and 5th costal cartilages were resected (n=8). The group that was not operated was accepted as the control group (n=8). The growth of the subjects was followed. Computed thorax tomography (CTT) scans of all animals were performed preoperatively and at the 4th postoperative week. Estimation of pre- and postoperative lung volumes was performed with the Cavalieri's principle. In the control group followed up during growth, bilateral lung volumes were increased (15.75% and 20.62% respectively right and left lungs). In the surgical group, both the surgical side and the opposite lung volume decreased after costal cartilage resection (20.09% and 1.07% respectively right and left lungs). Even though the number of resected cartilages was limited, total lung volume decreased after costal cartilage resection. In the treatment of chest wall deformities, costal cartilage resection should be considered as the last option in children. [ABSTRACT FROM AUTHOR]

The aim of this research was to determine brain, cerebral hemispheres and cerebellum volume and volume ratios by using stereological methods and investigate morphological differences between female and male New Zealand rabbits. The study was applied on 14‐month old (10 male and 10 female) New Zealand rabbits. The materials removed from the cavum cranii using dorsal approach. After following routine histological procedure, paraffin blocks were prepared and cut every seventieth section at 10 μm thickness. Slides were stained with Crossmon's triple stain and photographed. The sectional images obtained were transferred to ImageJ program to estimate grey and white matter volume on cerebral hemispheres and cerebellum with principle of Cavalieri. According to results, there was no asymmetry on the left and right cerebral hemispheres of New Zealand rabbits. In the total hemisphere volume calculated by Cavalieri principle, grey and white matter ratio was 81.57% and 18.43% in female, 82.80% and 17.20% in male. It was found that the white matter was significantly higher in females than males in cerebral hemispheres (p <.05). Also, it was found that grey and white matter ratio in total cerebellum volume was 67.82% and 32.18% in female, 67.94% and 32.06% in male respectively. It was determined that the females' white matter was larger than male rabbits in cerebellum (p <.05). It is thought that morphometric data obtained from this study will contribute to the existing anatomical knowledge and also considered as reference values in the clinical sciences. [ABSTRACT FROM AUTHOR]

Objective: Laboratory animals, which are an organ complex, are used as model for human in biomedical studies. For this reason, information about the normal physiological values of laboratory animals provide important information on their health status. In this study, it is aimed to determine the serum normal biochemical values of New Zealand rabbits. Methods: Blood was taken from the ears of 93 rabbits. Biochemical tests were performed on serum samples. For analyses, commercial diagnostic kits were used for determination of biochemical parameters. Statistically, the difference between the mean values of the variables according to male and female rabbit was analyzed by independent sample t-test. Results: Albumin, protein, CK (creatin kinase) and LDH (lactade dehydrogenase) (p <0.05) values were found statistically significant between male and female rabbits. On the other hand, creatinine, cholesterol and Mg values (p <0.05) increased significantly in female rabbits. Conclusion: Biochemical tests should be conducted at regular intervals to assess the health status of animals. Since many variables are linked, the animals used in the research should be based on the values of the control group on the same conditions. [ABSTRACT FROM AUTHOR]

Abstract Aim The current study was based on the hypothesis that the use of PRF with bone graft materials might increase bone regeneration and focus on the histopathological and immunohistochemical aspects following application of PRF with autogenous graft, xenograft and B-TCP in a rabbit model. Material and methods This study was performed on the twenty-eight male New Zealand divided into four group. Two defects with a diameter 10 mm were opened in calvarium. After PRF preparation, right defects were evaluated as empty defect or graft group, and left defects were evaluated as PRF test group. All animals were sacrificed at the end of 8 weeks and specimens were examined histopathologically and immunohistochemically. Results The most superior histopathological results were obtained in the autograft group. The combination of β-TCP-PRF could not provide superiority over the β-TCP group. The immunohistochemical results showed that, in the PRF/BTCP group, the expression of osteopontin and osteonectin was relatively higher compared to the only-BTCP group. Conclusion In terms of new bone formation, autograft combined with PRF yielded superior results but the combination of β-TCP-PRF had no effect compared to the only-BTCP group. However, further experimental and clinical studies might be beneficial to clarify the exact mechanism and results of combining PRF with bone grafts on bone healing process. [ABSTRACT FROM AUTHOR]