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Unsupervised domain adaptation (UDA) promotes target learning via a single-directional transfer from label-rich source domain to unlabeled target, while its reverse adaption from target to source has not been jointly considered yet. In real teaching practice, a teacher helps students learn and also gets promotion from students, and such a virtuous cycle inspires us to explore dual-directional transfer between domains. In fact, target pseudo-labels predicted by source commonly involve noise due to model bias; moreover, source domain usually contains innate noise, which inevitably aggravates target noise, leading to noise amplification. Transfer from target to source exploits target knowledge to rectify the adaptation, consequently enables better source transfer, and exploits a virtuous transfer circle. To this end, we propose a dual-correction-adaptation network (DualCAN), in which adaptation and correction cycle between domains, such that learning in both domains can be boosted gradually. To the best of our knowledge, this is the first naive attempt of dual-directional adaptation. Empirical results validate DualCAN with remarkable performance gains, particularly for extreme noisy tasks (e.g., approximately + 10 % on D → A of Office-31 with 40 % label corruption).

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High dielectric constant polymers have been widely studied and concerned in modern industry, and the induction of polar groups has been confirmed to be effective for high permittivity. However, the way of connection of polar groups with the polymer backbone and the mechanism of their effect on the dielectric properties are unclear and rarely reported. In this study, three polyimides (C0-SPI, C1-SPI, and C2-SPI) with the same rigid backbone and different linking groups to the dipoles were designed and synthesized. With their rigid structure, all of the polyimides show excellent thermal stability. With the increase in the flexibility of linking groups, the dielectric constant of C0-SPI, C1-SPI, and C2-SPI enhanced in turn, showing values of 5.6, 6.0, and 6.5 at 100 Hz, respectively. Further studies have shown that the flexibility of polar groups affected the dipole polarization, which was positively related to the dielectric constant. Based on their high permittivity and high temperature resistance, the polyimides exhibited outstanding energy storage capacity even at 200 °C. This discovery reveals the behavior of the dipoles in polymers, providing an effective strategy for the design of high dielectric constant materials.

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In this work, halloysite nanotubes (HNTs) were chosen as the fillers and high performance polyimide (PI) as the matrix to form a series of dielectric composite materials with high dielectric constant, low dielectric loss and excellent heat resistance. Firstly, KH550 was used to modify the surface of HNTs to make sure of a good dispersion of HNTs into the polymer. The results showed that the addition of KH550 modified HNTs (K-HNTs) can improve the dielectric constant of the composite films while maintaining their excellent dielectric loss properties. To further increase the dielectric constant of the HNTs/PI composites, conductive polyaniline (PANI) was used to coat the surface of HNTs to obtain PANI modified HNTs (PANI-HNTs). Compared with the K-HNTs filled systems, the dielectric constant of the PANI-HNTs/PI nanocomposite films is greatly enhanced. The highest dielectric constant of the PANI-HNTs/PI films can achieve 17.3 (100 Hz) with a low dielectric loss of 0.2 (100 Hz). More importantly, the as-prepared composite films have high breakdown strengths (>110.4 kV mm-1) and low coefficients of thermal expansion, as low as 7 ppm per °C, and a maximum discharge energy density of 0.93 J cm-3. Also, such properties are maintained stably up to 300 °C, which is critical for manufacturing heat-resisting film capacitors.

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Programmed cell death (PCD) is a genetically-based cell death mechanism with vital roles in eukaryotes. Although there is limited consensus on similar death mode programs in prokaryotes, emerging evidence suggest that PCD events are operative. Here we present cell death events in a cyanobacterium living endophytically in the fern Azolla microphylla, suggestive of PCD. This symbiosis is characterized by some unique traits such as a synchronized development, a vertical transfer of the cyanobacterium between plant generations, and a highly eroding cyanobacterial genome. A combination of methods was used to identify cell death modes in the cyanobacterium. Light- and electron microscopy analyses showed that the proportion of cells undergoing cell death peaked at 53.6% (average 20%) of the total cell population, depending on the cell type and host developmental stage. Biochemical markers used for early and late programmed cell death events related to apoptosis (Annexin V-EGFP and TUNEL staining assays), together with visualization of cytoskeleton alterations (FITC-phalloidin staining), showed that all cyanobacterial cell categories were affected by cell death. Transmission electron microscopy revealed four modes of cell death: apoptotic-like, autophagic-like, necrotic-like and autolytic-like. Abiotic stresses further enhanced cell death in a dose and time dependent manner. The data also suggest that dynamic changes in the peptidoglycan cell wall layer and in the cytoskeleton distribution patterns may act as markers for the various cell death modes. The presence of a metacaspase homolog (domain p20) further suggests that the death modes are genetically programmed. It is therefore concluded that multiple, likely genetically programmed, cell death modes exist in cyanobacteria, a finding that may be connected with the evolution of cell death in the plant kingdom.

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OBJECTIVE: To investigate the expression of microRNA-183 (miR-183) and Ezrin protein in stage II( gastric cancer (GC). METHODS: Specimens of stage II( GC and paracancer tissues (5 cm away from the tumor tissues) were collected from 72 patients. Real-time PCR was used to detect the miR-183 expression. Immunohistochemistry was used to examine the Ezrin protein expression in the tumor tissue. The associations of miR-183 expression with the clinicopathologic features of stage II( GC and Ezrin expression were analyzed. RESULTS: miR-183 expression was lower in stage II( gastric cancer tissues compared with the paracancer tissues samples(median relative expression, 0.676 vs. 1.000, P<0.05). Low expression of miR-183 was significantly associated with histological differentiation(0.429 vs. 0.907, P<0.05), lymph node metastasis(0.507 vs. 0.908, P<0.05). The survival was shorter in patient with low expression of miR-183(63.0±4.0) as compared to those with high expression of miR-183(75.2±3.8)(P<0.05). There was a negative correlation between the expression of miR-183 and Ezrin(r=-0.272, P<0.05). CONCLUSIONS: miR-183 is down-regulated in stage II( GC, and associated with the differentiation, metastasis, and prognosis. Ezrin is a potential regulatory protein of miR-183.

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Widespread fecal pollution of surface waters in developing countries is a threat to public health and may represent a significant pathway for the global dissemination of antibiotic resistance. The Minjiang River drainage basin in Fujian Province is one of China's most intensive livestock and poultry production areas and is home to several million people. In the study reported here, Escherichia coli isolates (n = 2,788) were sampled (2007 and 2008) from seven surface water locations in the basin and evaluated by PCR for carriage of selected genes encoding virulence factors, primarily for swine disease. A subset of isolates (n = 500) were evaluated by PCR for the distribution and characteristics of class 1 integrons, and a subset of these (n = 200) were evaluated phenotypically for resistance to a range of antibiotics. A total of 666 (24%) E. coli isolates carried at least one of the virulence genes elt, fedA, astA, fasA, estA, stx(2e), paa, and sepA. Forty-one percent of the isolates harbored class 1 integrons, and these isolates had a significantly higher probability of resistance to tobramycin, cefoperazone, cefazolin, ciprofloxacin, norfloxacin, azitromycin, and rifampin than isolates with no class 1 integron detected. Frequencies of resistance to selected antibiotics were as high as or higher than those in fecal, wastewater, and clinical isolates in published surveys undertaken in China, North America, and Europe. Overall, E. coli in the Minjiang River drainage basin carry attributes with public health significance at very high frequency, and these data provide a powerful rationale for investment in source water protection strategies in this important agricultural and urban setting in China.

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BACKGROUND: An ancient cyanobacterial incorporation into a eukaryotic organism led to the evolution of plastids (chloroplasts) and subsequently to the origin of the plant kingdom. The underlying mechanism and the identities of the partners in this monophyletic event remain elusive. METHODOLOGY/PRINCIPAL FINDINGS: To shed light on this evolutionary process, we sequenced the genome of a cyanobacterium residing extracellularly in an endosymbiosis with a plant, the water-fern Azolla filiculoides Lam. This symbiosis was selected as it has characters which make it unique among extant cyanobacterial plant symbioses: the cyanobacterium lacks autonomous growth and is vertically transmitted between plant generations. Our results reveal features of evolutionary significance. The genome is in an eroding state, evidenced by a large proportion of pseudogenes (31.2%) and a high frequency of transposable elements (approximately 600) scattered throughout the genome. Pseudogenization is found in genes such as the replication initiator dnaA and DNA repair genes, considered essential to free-living cyanobacteria. For some functional categories of genes pseudogenes are more prevalent than functional genes. Loss of function is apparent even within the 'core' gene categories of bacteria, such as genes involved in glycolysis and nutrient uptake. In contrast, serving as a critical source of nitrogen for the host, genes related to metabolic processes such as cell differentiation and nitrogen-fixation are well preserved. CONCLUSIONS/SIGNIFICANCE: This is the first finding of genome degradation in a plant symbiont and phenotypically complex cyanobacterium and one of only a few extracellular endosymbionts described showing signs of reductive genome evolution. Our findings suggest an ongoing selective streamlining of this cyanobacterial genome which has resulted in an organism devoted to nitrogen fixation and devoid of autonomous growth. The cyanobacterial symbiont of Azolla can thus be considered at the initial phase of a transition from free-living organism to a nitrogen-fixing plant entity, a transition process which may mimic what drove the evolution of chloroplasts from a cyanobacterial ancestor.

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The nitrogen-fixing symbiosis between cyanobacteria and the water fern Azolla microphylla is, in contrast to other cyanobacteria-plant symbioses, the only one of a perpetual nature. The cyanobacterium is vertically transmitted between the plant generations, via vegetative fragmentation of the host or sexually within megasporocarps. In the latter process, subsets of the cyanobacterial population living endophytically in the Azolla leaves function as inocula for the new plant generations. Using electron microscopy and immunogold-labeling, the fate of the cyanobacterium during colonization and development of the megasporocarp was revealed. On entering the indusium chamber of the megasporocarps as small-celled motile cyanobacterial filaments (hormogonia), these differentiated into large thick-walled akinetes (spores) in a synchronized manner. This process was accompanied by cytoplasmic reorganizations and the release of numerous membrane vesicles, most of which contained DNA, and the formation of a highly structured biofilm. Taken together the data revealed complex adaptations in the cyanobacterium during its transition between plant generations.

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OBJECTIVE: To provide DNA molecular marker for identification of Nelumbo nucifera by exploring the differences of nrDNA-ITS sequence of N. nucifera originated from different habitats. METHOD: To compare nrDNA-ITS base sequence using specific PCR-ITS. RESULT: The completed sequence of ITS and 5.8 S rDNA, and the partial sequences of 18S rDNA and 26S rDNA, totally 750 bp, from N. nucifera were obtained. The differences among N. nucifera from different habitats and from different cultivars were found. CONCLUSION: The method can be used to identify N. nucifera among different species and to distinguish their fakes. It provided the basis for identifying N. nucifera from different geographical regions by comparison of their ITS sequences.

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Cyanobacteria are one of the main components of the microbiota in rice paddy fields and significantly contribute to its fertilization. The diversity and changes of the cyanobacterial assemblage were investigated during a rice growth season and after harvest in a paddy field located in Fujian Province, China. The cyanobacterial populations were analyzed by a semi-nested PCR, followed by denaturing gradient gel electrophoresis analysis. Twenty-four phylotypes were identified from the denaturing gradient gel electrophoresis profiles. The number of cyanobacterial phylotypes showed a seasonal variation and reached a peak in September, both in the upper (0-5 cm) and the deeper (10-15 cm) soil fractions. Some cyanobacterial sequences were only present during the rice growth season, while others were only found after harvest.

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OBJECTIVE: To study the seed quality of Alisma orientalis (Sam.) Juzep. METHOD: Collecting seeds from different habitats and studying the thousand-grain weight, moisture content, purity and germination percentage. RESULT: The seeds reaped in summer friom Pengshan, Sichuan province are better than those from other habitats. Its thousand-grain weight is 0.4682 g, moisture content is 12.48%, purity of seeds is 89.18% and germination percentage is above 95%. CONCLUSION: The cause of qualitative differences in seeds of Alisma orientalis from different habitats were analysed in this paper.

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The genetic diversity of symbiotic cyanobacteria in coralloid roots of cycads was examined using PCR fingerprinting with primers derived from repetitive sequences. The highest genetic resolution was achieved using the primer corresponding to the short tandemly repeated repetitive sequences. The cyanobacteria were collected from the coralloid roots of a large number of indigenous cycad plants and used directly in the PCR. It could be demonstrated that numerous cyanobacteria were present in a single coralloid root. Even within a single cluster in the coralloid root, diversity could be observed between the apical, middle and basal regions.

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Symbiotic Anabeana azollae and its host plant Anabeana-free Azolla were isolated from 16 Azolla accessions representing different Azolla species or geographic origins.DNA polymorphic fragments were obtained by simultaneous RAPD amplification of both symbiont and host. The UPGMA clusters of Anabeana azollae and its host Azolla were established separately based on Dice coefficient caculation and a coordinated relationship was shown between Anabeana azollae and its Azolla host along both individual genetic divergence,but this genetic homology was reduced among different strains within Azolla species while the obvious mutants of Anabeana azollae were detected in some Azolla tested strains collected from different geographic area in the same host species.