541 research outputs found
Effective Discriminative Feature Selection with Non-trivial Solutions
Feature selection and feature transformation, the two main ways to reduce
dimensionality, are often presented separately. In this paper, a feature
selection method is proposed by combining the popular transformation based
dimensionality reduction method Linear Discriminant Analysis (LDA) and sparsity
regularization. We impose row sparsity on the transformation matrix of LDA
through -norm regularization to achieve feature selection, and
the resultant formulation optimizes for selecting the most discriminative
features and removing the redundant ones simultaneously. The formulation is
extended to the -norm regularized case: which is more likely to
offer better sparsity when . Thus the formulation is a better
approximation to the feature selection problem. An efficient algorithm is
developed to solve the -norm based optimization problem and it is
proved that the algorithm converges when . Systematical experiments
are conducted to understand the work of the proposed method. Promising
experimental results on various types of real-world data sets demonstrate the
effectiveness of our algorithm
Comparative analysis of dental implant treatment outcomes following mandibular reconstruction with double‐barrel fibula bone grafting or vertical distraction osteogenesis fibula: a retrospective study
PurposeThe purpose of this study was twofold: (i) to compare vertical bone height (VBH) after tumor resection through grafting with either a double‐barrel fibula (DBF) technique or vertical distraction osteogenesis of the fibula (VDOF); (ii) to compare the performance of loaded dental implants following either DBF or VDOF with special focus on implant survival, implant success, and bone resorption.Materials and methodsThis retrospective clinical study involved 19 patients who underwent implant placement following DBF (group A, n = 9) or VDOF (group B, n = 10) for mandibular reconstruction from March 2006 to May 2008. Clinical and radiographic assessments, including VBH, modified Plaque Index (mPI), modified Sulcus Bleeding Index (mSBI), and marginal bone level (MBL), were taken for both groups after delivery of the final prostheses and annually thereafter.ResultsNine patients underwent DBF with 24 implants placed and 10 patients underwent VDOF with 27 implants placed for mandibular reconstruction after tumor resection. Overall, all DBF and VDOF procedures were successful for group A and group B. VBH for group A and group B were 20 and 17 mm. There was no statistically significant difference of mSBI scores between group A and group B in the 3‐year follow‐up (P = 0.40). In four cases with eight implants of group A and two cases with three implants of group B, granulomatous soft tissue grew. There was no statistically significant differences of MBL between group A and group B in the 3‐year follow‐up (p = 0.736). The cumulative survival and success rates of implants for group A were 100% and 87.5%, and for group B were 100% and 85.2% in 3‐year follow‐up, respectively.ConclusionsOn the basis of the study of 19 patients who received a total of 51 implants, reconstruction of the mandible with DBF flap or VDOF flap, combined with dental implant therapy, was considered a predictable option. Compared with implants placed in VDOF bone, implants placed in DBF bone had a relative higher incidence of associated gingival inflammation. The DBF bone seems more resistant to peri‐implant resorption processes than VDOF bone during functional loading.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110599/1/clr12300.pd
Venous thromboembolism after oral and maxillofacial oncologic surgery : report and analysis of 14 cases in Chinese population
Venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) is a leading cause of death in cancer patients. The aim of this study was to explore the potential risk factor of VTE in oral and maxillofacial oncological surgery. The data of patients who received operation in our institution were gathered in this retrospective study. A diagnosis of VTE was screened and confirmed by computer tomography angiography (CTA) of pulmonary artery or ultrasonography examination of lower extremity. Medical history and all perioperative details were analyzed. 14 patients were diagnosed as VTE, including 6 cases of PE, 7 cases of DVT, 1case of DVT and PE. The mean age of these patients was 62.07 years. Reconstruction was performed in 12 patients of these cases, most of which were diagnosed as malignance. Mean length of surgery was 8.74 hours, and lower extremity deep venous cannula (DVC) was performed in all these patients. We analyzed several characters of oral and maxillofacial surgery and suggested pay attention to lower extremity DVC which had a high correlation with DVT according to our data
Ultrasound hyperthermia induces apoptosis in head and neck squamous cell carcinoma : an in vitro study
Hyperthermia is considered an efficient complement in the treatment of head and neck squamous cell carcinoma (HNSCC). Hyperthermia induces cell apoptosis in a temperature- and time-dependent manner. However, the molecular mechanism of hyperthermia remains unclear. The aim of this study was to investigate the mechanism of apoptosis induced by ultrasound hyperthermia in HNSCC cell lines HN-30 and HN-13. We examined the dynamic changes of early apoptosis and secondary necrosis in HN-30 and HN-13 cells treated by hyperthermia at 42°C for 10 min. We further examined mitochondrial membrane potential in vitro by ultrasound hyperthermia for different heating temperatures (38-44°C, 10 min) and heating times (42°C, 10-50 min). After heating by ultrasound at 42°C for 10 min, the apoptosis index achieved its highest level at 8 h after treatment, decreased rapidly and remained constant at a reduced level at 12 h. The level of secondary necrosis increased with the level of early apoptosis but remained at a higher level until 14 h. The level of secondary necrosis correlated with the level of early apoptosis (HN-13: r=0.7523, P=0.0030; HN-30: r=0.6510, P=0.016). The fractions of cells with low mitochondrial membrane potential (??) in the heating-temperature grads group and heating-time grads group decreased significantly over time. Therefore, HN-30 and HN-13 cells developed apoptosis after ultrasound hyperthermia treatment with decreases in the mitochondrial transmembrane potential level. Ultrasound hyperthermia induces apoptosis in HN-30 and HN-13 cells, possibly via the mitochondrial caspase pathway
Balancing Efficiency and Depth in the Integration of Generative Artificial Intelligence into EAP Learning for Chinese Undergraduates
This study explores the integration of generative artificial intelligence tools into English for Academic Purposes (EAP) learning among Chinese undergraduates. The study adopts a questionnaire to investigate behavioral patterns, attitudinal structures, and perceived advantages of AI-assisted academic English learning. Findings indicate high level of AI exposure and positive perceived functionality of AI tools, especially in facilitating literature reading and writing. However, students demonstrated limited awareness of academic conventions and AI-related integrity issues, revealing an efficiency-depth paradox. Exploratory factor analysis identified three attitudinal dimensions, including perceived usefulness, self-assessed evaluation skills, and ethical apprehension. While students recognized dependence and plagiarism risks, such concerns coexisted with high reliance on AI. The findings highlight the need for targeted instructional strategies, such as offering dual literacy development, ethical training, and AI-integrated tasks in EAP courses, to balance productivity with critical skill development in AIGC-enhanced EAP contexts
Cognitive Strategies for the Management of Culture-Specific Items in English-Chinese Simultaneous Interpreting
Simultaneous interpreting presents significant cognitive challenges, particularly when interpreters encounter Culture-Specific Items (CSIs). This study explores the cognitive processes involved in interpreting CSIs between English and Chinese, focusing on the difficulties posed by the lack of extra-linguistic knowledge, comprehension ambiguity, and the absence of equivalents in the target language. Through comprehensive analysis and professional interviews, the research identifies and discusses effective coping strategies employed by interpreters to mitigate cognitive load. These strategies include paraphrasing, finding equivalents, literal interpreting, and strategic omission. Findings from this study offer valuable insights and practical guidance for learners and practitioners of simultaneous interpreting, enhancing their ability to manage CSIs more effectively and improve overall interpreting performance
Gabor Systems about any Symmetric Points in Two Dimensions
Gabor system plays an important role in signal processing, image processing and other applications because of their redundancy properties. In this paper, symmetric or antisymmetric Gabor frames in two dimensions about any symmetric points are constructed from Gabor frames given. In special, symmetric or antisymmetric Parseval Gabor frames with better properties are obtained. DOI : http://dx.doi.org/10.11591/telkomnika.v12i1.337
The effects of solar ultraviolet-b on the proteome and antioxidant defense systems in soybean leaves
Stratospheric ozone depletion has caused an increase in the amount of ultraviolet-B (UV-B) radiation reaching the earth's surface. Some investigations have demonstrated that UV-B has effects on protein accumulation and active oxygen species (AOS) metabolism in plants. Because of the unrealistically high UV-B level and low levels of ultraviolet-A (UV-A) and photosythetically active radiation (PAR) in indoor studies it has been questioned whether results from these studies can be extrapolated to field responses. In the present study two isolines of the soybean cultivar Clark with different flavonoid contents were grown in the field with or without natural levels of UV-B. The leaf proteome and AOS metabolism were examined.
Ambient solar UV-B radiation changed AOS metabolism by decreasing superoxide dismutase activity and increasing the activities of ascorbate peroxidase, catalase and glutathione reductase relative to UV-B exclusion treatments. This resulted in decreased ascorbic acid and increased dehydroascorbate content. Proteomic analysis showed that the accumulations of 67 protein spots were significantly affected by solar UV-B. Proteins related to photosystems in photosynthesis were increased in abundance while enzymes involved in the primary carbon and nitrogen metabolism were decreased. This could lead to overreduction of the photosynthetic electron transport chain and enhance the formation of superoxide radicals and singlet oxygen. The magenta line, which has reduced flavonoid levels, had greater proteomic and oxidative responses than the standard line, suggesting that flavonoids act as screening compounds and antioxidants in protecting plants from UV-B radiation. These line-specific differences occurred even under UV-B exclusion, which may be due to high UV-A, PAR or temperature. More detailed studies are needed to elucidate the effects of other environmental factors on the soybean leaf proteome and AOS metabolism under field conditions
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