RESUMEN
This paper proposes an unsupervised classification method for multilook polarimetric synthetic aperture radar (Pol-SAR) data. The proposed method simultaneously deals with the heterogeneity and incorporates the local correlation in PolSAR images. Specifically, within the probabilistic framework of the Dirichlet process mixture model (DPMM), an observed PolSAR data point is described by the multiplication of a Wishartdistributed component and a class-dependent random variable (i.e., the textual variable). This modeling scheme leads to the proposed textured DPMM (tDPMM), which possesses more flexibility in characterizing PolSAR data in heterogeneous areas and from high-resolution images due to the introduction of the classdependent texture variable. The proposed tDPMM is learned by solving an optimization problem to achieve its Bayesian inference. With the knowledge of this optimization-based learning, the local correlation is incorporated through the pairwise constraint, which integrates an appropriate penalty term into the objective function so as to encourage the neighboring pixels to fall into the same category and to alleviate the "salt-and-pepper" classification appearance.We develop the learning algorithm with all the closed-form updates. The performance of the proposed method is evaluated with both low-resolution and high-resolution PolSAR images, which involve homogeneous, heterogeneous, and extremely heterogeneous areas. The experimental results reveal that the class-dependent texture variable is beneficial to PolSAR image classification and the pairwise constraint can effectively incorporate the local correlation in PolSAR images.
RESUMEN
BACKGROUND: Avian influenza A/H5N1 has threatened human health for nearly 2 decades. Avian influenza A vaccine without adjuvant is poorly immunogenic. A flexible rapid tactic for mass vaccination will be needed if a pandemic occurs. METHODS: A multicenter, randomized, blinded phase 1 clinical trial evaluated safety and antibody responses after point-of-use mixing of influenza A/Indonesia/05/2005 (H5N1) vaccine with MF59 adjuvant. Field-site pharmacies mixed 3.75, 7.5, or 15 mcg of antigen with or without MF59 adjuvant just prior to intramuscular administration on days 0 and 21 of healthy adults aged 18-49 years. RESULTS: Two hundred and seventy subjects were enrolled. After vaccination, titers of hemagglutination inhibition antibody ≥1:40 were achieved in 80% of subjects receiving 3.75 mcg + MF59 vs only 14% receiving 15 mcg without adjuvant (P < .0001). Peak hemagglutination inhibition antibody geometric mean titers for vaccine + MF59 were â¼65 regardless of antigen dose, and neutralizing titers were 2- to 3-fold higher. Vaccine + MF59 produced cross-reactive antibody responses against 4 heterologous H5N1 viruses. Excellent safety and tolerability were demonstrated. CONCLUSIONS: Point-of-use mixing of H5N1 antigen and MF59 adjuvant achieved target antibody titers in a high percentage of subjects and was safe. The feasibility of the point-of-use mixing should be studied further.
RESUMEN
AIMS: Recently, the European Society of Cardiology (ESC) released a consensus statement for the diagnosis of heart failure with preserved ejection fraction (HFPEF). It state that E/e' > 15 or <8 clearly define those with or without HFPEF and that for those in the range 8-15, other parameters should be examined. METHODS AND RESULTS: We retrospectively analysed 1229 consecutive echocardiograms (57% males) for the utility of echocardiographic measures including left atrial volume index (LAVI), left ventricular mass index (LVMI), and pulmonary venous and mitral inflow Doppler. LAVI of 40 ml/m(2) provided the greatest sensitivity and specificity of 76 and 77%, respectively, with reference to E/e' for the detection of diastolic dysfunction. The ESC definition of raised LVMI yielded a sensitivity and specificity of 32 and 99%, respectively. We found that the mitral and pulmonary inflow provided little incremental information. These results remained consistent between those with normal and abnormal ejection fraction. CONCLUSIONS: There appears to be little incremental value of pulmonary and mitral Doppler measures beyond the measure of mitral E wave. An LAVI cut-off of 40 ml/m(2) maximizes both sensitivity and specificity. However, ESC guidelines of raised LVMI in patients with HFPEF would appear to heavily trade sensitivity for specificity.