Search

In the process of coal mining, the coal quality is greatly reduced due to the mixing of gangue, and the stacking and burning of coal and gangue can cause serious environmental pollution. The fast identification of coal and gangue is an important technology for gangue sorting. Considering tiny YOLO v3 has the advantages of fast running speed, simple network and good effectiveness, an improved tiny-YOLO-v3-based fast identification model is proposed in this paper, which including the spatial pyramid pooling (SPP) net, the squeeze-and-excitation (SE) module and the dilated convolution. Firstly, the SPP net preprocesses the input images into acceptable size via a single convolution layer. Then, the SE module, which can strengthen the attention among channels in RGB image, is adopted to capture the key information and enhance the sensitivity of network accurately. Finally, the dilated convolution, which can enlarge the receptive filed without increasing parameters, is used to further optimize and realize the fast identification of coal and gangue. The experiments show that, compared with the tiny YOLO v3 the average intersection over union (Avg IOU) of proposed model is as high as 0.39%, the required time for each image and the loss reduced by 7.41 and 53.01%, respectively. The mean Average Precision (mAP@0.5) of the proposed network is 3.12% higher than Faster RCNN, reaching 0.964. It is an efficient fast identification model for gangue-sorting. [ABSTRACT FROM AUTHOR]

Miamiensis avidus Thompson & Moewus, 1964, is a cosmopolitan and well-known marine pathogenic ciliated protist. However, the taxonomy of this species up to now has remained controversial, especially with respect to the validity of the morphologically similar species, Philasterides dicentrarchi, which was considered as a junior synonym of M. avidus. In this study, a population of M. avidus was collected from the skin of pharaoh cuttlefish (Sepia pharaonis) cultured near the East China Sea, Ningbo, China and its morphology and phylogeny were investigated in detail based on living characters, infraciliature, small subunit (SSU) rDNA and ITS1-5.8S-ITS2 region sequences. In addition, the morphometrics of a previously reported free-living population, collected from the Bohai Sea, were rechecked and analyzed. We compared the present two isolates with all historic populations of M. avidus and P. dicentrarchi, and found that their morphological characters were either highly similar or exactly identical, indicating that they are the same morphospecies. However, the phylogenetic analyses based on SSU rDNA or ITS1-5.8S-ITS2 region sequences revealed that most M. avidus and P. dicentrarchi populations formed one clade, and the two isolates of M. avidus from Weifang and American Type Culture Collection clustered in another clade, which indicated that there might be cryptic species in Miamiensis avidus. [ABSTRACT FROM AUTHOR]

The morphology and phylogeny of two hypotrichous ciliates, Metaurostylopsis parastruederkypkeae n. sp. and Neourostylopsis flavicana (Wang et al., 2011) Chen et al., 2013 were investigated based on morphology, infraciliature and the small subunit (SSU) ribosomal RNA gene (rRNA) sequence. The new species, M. parastruederkypkeae n. sp. was identified according to its characteristics: body shape ellipsoidal, size about (165-200) × (45-60) μm in vivo, cell color reddish; two types of cortical granules including wheat grain-like and yellow-greenish larger ones along the marginal cirri rows and dorsal kineties and dot-like and reddish smaller ones, grouped around marginal cirri on ventral side and arranged in short lines on dorsal side; 26-41 adoral membranelles; three frontal and one parabuccal, five to seven frontoterminal, one buccal, and three to six transverse cirri; seven to thirteen midventral pairs; five to nine unpaired ventral cirri, five to seven left and three to five right marginal rows; and three complete dorsal kineties. Phylogenetic analysis based on SSU rDNA sequences showed that both Metaurostylopsis and Neourostylopsis are monophyletic. As the internal relationship between and within both genera are not clear, further studies on the species in these two genera are necessary. The key characteristics of all known twelve Metaurostylopsis-Apourostylopsis-Neourostylopsis species complex were updated. [ABSTRACT FROM AUTHOR]

Key message: Two new alleles of arc3 in Arabidopsis thaliana, arc3-4 and arc3-5, were isolated in the Columbia-0 ecotype. The mutants were characterized in detail using microscopy and molecular techniques. Abstract: Chloroplasts are essential organelles for photosynthesis in plant cells. Division of chloroplasts is coordinated by the internal division machinery (mainly the tubulin-like FtsZ ring) and the external division machinery (mainly the dynamin-like ARC5 ring). Accumulation and replication of chloroplasts3 (ARC3) is important for the correct positioning of chloroplast division machinery. During evolution, ARC3 has probably replaced minicellC (MinC), an important factor involved in positioning of the division site in bacteria. However, the working mechanism of ARC3 is still unclear. Using forward genetic approaches, we isolated two new alleles of arc3 in Arabidopsis thaliana, arc3-4 and arc3-5, in which mutant loci differed from those of previously reported arc3 mutants. Microscopy analyses showed more detailed, and some new, phenotypes of arc3 mutants. Reverse-transcription polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR (qRT-PCR) results indicated that the mRNA of the ARC3 gene was unstable in arc3-4 and arc3-5 mutant plants. Also, RNA secondary structures of the ARC3 gene were predicted to differ between these two arc3 mutants and wild type. Our studies increase our understanding of the function of ARC3 in chloroplast division. [ABSTRACT FROM AUTHOR]