Anomaly Detection in Hyperspectral Images Using Adaptive Graph Frequency Location.

Graph theory-based techniques have recently been adopted for anomaly detection in hyperspectral images (HSIs). However, these methods rely excessively on the relational structure within the constructed graphs and tend to downplay the importance of spectral features in the original HSI. To address this issue, we introduce graph frequency analysis to hyperspectral anomaly detection (HAD), which can serve as a natural tool for integrating graph structure and spectral features. We treat anomaly detection as a problem of graph frequency location, achieved by constructing a beta distribution-based graph wavelet space, where the optimal wavelet can be identified adaptively for anomaly detection. Initially, a high-dimensional, undirected, unweighted graph is built using the pixels in the HSI as vertices. By leveraging the observation of energy shifting to higher frequencies caused by anomalies, we can dynamically pinpoint the specific Beta wavelet associated with the anomalies' high-frequency content to accurately extract anomalies in the context of HSIs. Furthermore, we introduce a novel entropy definition to address the frequency location problem in an adaptive manner. Experimental results from seven real HSIs validate the remarkable detection performance of our newly proposed approach when compared to various state-of-the-art anomaly detection methods.

[Survival and prognostic factors in resected satellite-nodule T4 non-small cell lung cancer].

OBJECTIVE: To study the survival and prognostic implication in surgically resected satellite-nodule T4 (T4 satellite) non-small cell lung cancer (NSCLC). METHODS: From January 1995 to March 2005, the complete resection was performed to 42 patients with NSCLC who were postoperatively identified as pathologic-stage T4 satellite. Survival and associations between clinicopathological parameters and prognosis were analyzed. Thirty-two patients with pathologic stage local-invasion T4 (T4 invasion) NSCLC who underwent resection at the same time were also analyzed. RESULTS: The 1-, 3- and 5-year survival was 76.2%, 57.1% and 46.0% for patients with T4 satellite, while 62.3%, 31.5% and 20.0% for patients with T4 invasion. There was a significant higher survival in T4 satellite group when compared to that in T4 invasion group (P < 0.05). Furthermore, patients with T4 satellite N0M0 got a better survival than those with T4 satellite N1-2M0, T4 invasion N0M0 and T4 invasion N1 -2M0 (P < 0.05). For patients with T4 satellite, univariate analysis showed that histology, main tumor size, lymph node status and adjuvant chemotherapy were linked with survival, while main tumor size, lymph node status and adjuvant chemotherapy served as the independent prognostic factors with multivariate analysis. CONCLUSIONS: Patients with completely resected T4 satellite NSCLC have a better prognosis than those with T4 invasion. Main tumor size over 3 cm, lymph node metastasis or no adjuvant chemotherapy means an unfavorable prognosis.

[Effects of high-yielding rice cultivar and cultivation pattern on methane emission from paddy field].

A field experiment was conducted to observe the effects of high-yielding rice cultivars (early rice Luliangyou No. 996 and Chuanfeng No. 1, and late rice T you No. 259) and cultivation patterns (direct sowing and transplanting) on the methane emission from paddy field. The methane emission from early rice field before drying was 52%-73% of the total, while drainage and drying decreased the methane emission significantly. For late rice field, the methane emission during vegetative growth stage was 70% of the total. Under direct sowing of early rice, the average methane flux was lower, but the total methane emission was higher, compared with those under transplanting. As for late rice, both the average methane flux and the total methane emission were higher under direct sowing than under transplanting. There existed significant differences in the methane emission per unit grain production of early rice and late rice between direct sowing and transplanting. The methane emission per unit grain production under direct sowing of early rice super hybrid was increased by 4.84 g CH4 x kg(-1), compared with that under transplanting, and the emission under direct sowing of conventional early rice was increased by 3.48 g CH4 x kg(-1), compared with that under transplanting. The emission under direct sowing of hybrid rice was 6.67 g CH4 x kg(-1) higher than that under transplanting. In the same cultivation area and the same time period of direct sowing and transplanting, the methane emission was in the order of direct sowing of conventional early rice > transplanting of conventional early rice > direct sowing of early rice super hybrid > transplanting of early rice super hybrid, and direct sowing of late rice > transplanting of late rice.

[Impact of different mediastinal lymphadenectomy on clinical-stage IA non-small cell lung cancer].

OBJECTIVE: To study the role of different lymphadenectomy in the treatment of selected clinical-stage IA non-small cell lung cancer. METHODS: All 115 postoperative patients admitted from January 1997 to May 2002 with pathologic-stage T1 who had been preoperatively diagnosed as clinical-stage I A non-small cell lung cancer were divided into a radical systematic mediastinal lymphadenectomy (LA) group and a mediastinal lymph node sampling (LS) group. Impacts on morbidity, N staging, overall survival (OS) and disease-free survival (DFS) were evaluated in each group respectively. Associations between clinical-pathological parameters (age, sex, tumor location, tumor size, pathological type and lymph node metastases) and OS, DFS were analyzed. The cumulative OS and DFS was calculated by the Kaplan-Meier method and compared by the Log-rank test. RESULTS: The mean number of dissected lymph nodes was (15.98 +/- 3.05) in LA group and (6.48 +/- 2.16) in LS group with a significant difference (P < 0.01). No statistically significant difference existed in modification of N staging, OS and DFS between LA group and LS group. However, for patients with lesions of a diameter more than 2 cm, 5-year OS in LA group was significantly higher than that in LS groups (LA vs. LS = 78.2% vs. 54.5% ,P < 0.05), also 5-year DFS was significantly higher (LA vs. LS = 75.1% vs. 51.3%, P < 0.05). For patients with lesions of 2 cm or less, 5-year OS and 5-year DFS were similar in both groups. The early surgery-related parameters (duration of surgery, drain secretion and morbidity) indicated a slighter invasion in LS group. In addition, patients with large cell carcinoma and adenosquamous carcinoma were associated with significantly poor 5-year OS (P < 0.05) , and patients with lymph node metastases were associated with poor 5-year OS as well as 5-year DFS (P < 0.01). CONCLUSIONS: After being intraoperatively identified as T1 stage, patients with lesions of more than 2 cm in clinical-stage IA non-small cell lung cancer should be performed with LA to get a better survival, and patients with lesions of 2 cm or less should be performed with LS to decrease invasion.

Radical systematic mediastinal lymphadenectomy versus mediastinal lymph node sampling in patients with clinical stage IA and pathological stage T1 non-small cell lung cancer.

PURPOSE: To explore the appropriate method of mediastinal lymph node dissection for selected clinical stage IA (cIA) non-small cell lung cancer (NSCLC). METHODS: From 1998 through 2002, the curative-intent surgery was performed to 105 patients with cIA NSCLC who had been postoperatively identified as pathologic-stage T1. According to the method of intraoperative medistinal lymph node dissection, they were divided into radical systematic mediastinal lymphadenectomy (LA) group (n = 42) and mediastinal lymph-node sampling (LS) group (n = 63). The effects of LS and LA on morbidity, N staging, overall survival (OS) and disease-free survival (DFS) were investigated. Also, associations between clinicopathological parameters and survival were analyzed. RESULTS: The mean numbers of dissected lymph nodes per patient in the LA group was significantly greater than that in the LS group (15.59 +/- 3.08 vs. 6.46 +/- 2.21, P < 0.001), and the postoperative overall morbidity rate was higher in the LA group than that in the LS group (26.2 vs. 11.1%, P = 0.045). There were no significant difference in migration of N staging, OS and DFS between two groups. However, for patients with lesions between 2 and 3 cm, the 5-year OS in LA group was significantly higher than that in LS group (81.6 vs. 55.8%, P = 0.041), and the 5-year DFS was also higher (77.9 vs. 52.5%, P = 0.038). For patients with lesions of 2 cm or less, 5-year OS and DFS were similar in both groups. Multivariate analysis showed that lymph node metastasis was the unique unfavorable prognostic factor (P < 0.001). CONCLUSIONS: After being intraoperatively identified as stage T1, patients with lesions between 2 and 3 cm in cIA NSCLC should be performed with LA to get a potentially better survival, and patients with lesions of 2 cm or less should be performed with LS to decrease invasion.