The number of endangered species has been increased due to shifts in the agricultural production, climate change, and poor urban planning. This has led to investigating new methods to address the problem of plant species identification/classification. In this paper, a plant identification approach using 2D digital leaves images was proposed. The approach used two features extraction methods based on one-dimensional (1D) and two-dimensional (2D) and the Bagging classifier. For the 1D-based methods, Principal Component Analysis (PCA), Direct Linear Discriminant Analysis (DLDA), and PCA + LDA techniques were applied, while 2DPCA and 2DLDA algorithms were used for the 2D-based method. To classify the extracted features in both methods, the Bagging classifier, with the decision tree as a weak learner was used. The five variants, i.e. PCA, PCA + LDA, DLDA, 2DPCA, and 2DLDA, of the approach were tested using the Flavia public dataset which consists of 1907 colored leaves images. The accuracy of these variants was evaluated and the results showed that the 2DPCA and 2DLDA methods were much better than using the PCA, PCA + LDA, and DLDA. Furthermore, it was found that the 2DLDA method was the best one and the increase of the weak learners of the Bagging classifier yielded a better classification accuracy. Also, a comparison with the most related work showed that our approach achieved better accuracy under the same dataset and same experimental setup.

.Seventeen isolates of Aeromonas hydrophila were isolated from 250 commercial broiler chicks with an incidence of 6.8 %. Most A. hydrophila isolates (88.24 %) were positive for exotoxin assay and congo red binding test, while 52.94 % were positive for crystal violet binding activity. Most strains of A. hydrophila were sensitive to chloramphenicol, ciprofloxacin and norfloxacin followed by gentamicin and neomycin while nalidixic acid, tetracycline, streptomycin and trimethoprim sulphamethoxazole had moderate effect. On the other hand, all A. hydrophila strains were resistant to amoxicillin, cephalothin, erythromycin and penicillin G. All chicks infected with 1.5 X 109 organisms via subcutaneous and yolk sac were dead within 24 h. A. hydrophila was isolated from most organs. The lesions observed included congestion in the internal organs and few cases showed hepatic and muscular petechiae. Histopathological examination of experimentally infected chicks revealed severe necrosis in hepatic, splenic and muscular tissue in the two days old chicks. The ultrastructural study of this group showed presence of the bacilli inside the hepatocytes and macrophages with marked cellular changes. An attempt was made to determine a correlation between level of exposure and mortality. It was found that the mortality rate was relatively high (52.5 %) than in lower dose (35 %). A. hydrophila was isolated from most organs examined. Marked degenerative and necrobiotic changes in both hepatic and splenic tissue and characteristic muscular lesions manifested by muscular hemorrhage, degeneration, oedema and myositis in low dose treatment group. In the group injected with high dose, the lesions were more severe and characterized by diffuse areas of necrosis in hepatic tissue, thrombus formation in the blood vessels together with large number of bacterial colonies and bacilli in the hepatic tissue. Marked muscular necrosis and myophagia were also noticed. The ultrastructural study using transmission electron microscope for this group showed heterocells and hepatocytes contain bacilli. In other cases, the bacilli were present in the phagosomes of phagocytic cells in the splenic tissue. Cytopathological lysis was common evidence in the examined cells.