Dual selections based knowledge transfer learning for cross-subject motor imagery EEG classification

IntroductionMotor imagery electroencephalograph (MI-EEG) has attracted great attention in constructing non-invasive brain-computer interfaces (BCIs) due to its low-cost and convenience. However, only a few MI-EEG classification methods have been recently been applied to BCIs, mainly because they suffered from sample variability across subjects. To address this issue, the cross-subject scenario based on domain adaptation has been widely investigated. However, existing methods often encounter problems such as redundant features and incorrect pseudo-label predictions in the target domain.MethodsTo achieve high performance cross-subject MI-EEG classification, this paper proposes a novel method called Dual Selections based Knowledge Transfer Learning (DS-KTL). DS-KTL selects both discriminative features from the source domain and corrects pseudo-labels from the target domain. The DS-KTL method applies centroid alignment to the samples initially, and then adopts Riemannian tangent space features for feature adaptation. During feature adaptation, dual selections are performed with regularizations, which enhance the classification performance during iterations.Results and discussionEmpirical studies conducted on two benchmark MI-EEG datasets demonstrate the feasibility and effectiveness of the proposed method under multi-source to single-target and single-source to single-target cross-subject strategies. The DS-KTL method achieves significant classification performance improvement with similar efficiency compared to state-of-the-art methods. Ablation studies are also conducted to evaluate the characteristics and parameters of the proposed DS-KTL method

Universal Quantum Optimization with Cold Atoms in an Optical Cavity

Cold atoms in an optical cavity have been widely used for quantum simulations of many-body physics, where the quantum control capability has been advancing rapidly in recent years. Here, we show the atom cavity system is universal for quantum optimization with arbitrary connectivity. We consider a single-mode cavity and develop a Raman coupling scheme by which the engineered quantum Hamiltonian for atoms directly encodes number partition problems (NPPs). The programmability is introduced by placing the atoms at different positions in the cavity with optical tweezers. The NPP solution is encoded in the ground state of atomic qubits coupled through a photonic cavity mode, that can be reached by adiabatic quantum computing (AQC). We construct an explicit mapping for the 3-SAT and vertex cover problems to be efficiently encoded by the cavity system, which costs linear overhead in the number of atomic qubits. The atom cavity encoding is further extended to quadratic unconstrained binary optimization (QUBO) problems. The encoding protocol is optimal in the cost of atom number scaling with the number of binary degrees of freedom of the computation problem. Our theory implies the atom cavity system is a promising quantum optimization platform searching for practical quantum advantage.Comment: 13 pages, 2 figure

Plant Regeneration from Cassava Protoplasts

Cassava is an important crop for food, feed, and industrial raw materials. Given that traditional conventional breeding is restricted by various factors, biotechnology breeding has become an important breeding method. Tissue culture regeneration is the basis of biotechnology breeding. This chapter reviews the establishment and development of cassava tissue culture and regeneration systems and the technical processes of tissue culture and regeneration starting from the induction of explants of tissue-cultured cassava plantlets to embryogenic calli, isolation to protoplasts, culture to embryogenic calli followed by differentiation into embryos, and then sprouting, stemming, and rooting into complete plants. This chapter focuses on the technical processes from protoplast to complete plant and summarizes the important influencing factors of protoplast regeneration, which is the key and difficult point in the entire regeneration process of cassava protoplasts. This chapter aims to provide technical guidance for cassava protoplast regeneration, offer useful inspiration and reference for cassava tissue culture, and lay a foundation for the genetic improvement of cassava

Micropathogen community analysis in Hyalomma rufipes via high-throughput sequencing of small RNAs

Ticks are important vectors in the transmission of a broad range of micropathogens to vertebrates, including humans. Because of the role of ticks in disease transmission, identifying and characterizing the micropathogen profiles of tick populations have become increasingly important. The objective of this study was to survey the micropathogens of Hyalomma rufipes ticks. Illumina HiSeq2000 technology was utilized to perform deep sequencing of small RNAs (sRNAs) extracted from field-collected H. rufipes ticks in Gansu Province, China. The resultant sRNA library data revealed that the surveyed tick populations produced reads that were homologous to St. Croix River Virus (SCRV) sequences. We also observed many reads that were homologous to microbial and/or pathogenic isolates, including bacteria, protozoa, and fungi. As part of this analysis, a phylogenetic tree was constructed to display the relationships among the homologous sequences that were identified. The study offered a unique opportunity to gain insight into the micropathogens of H. rufipes ticks. The effective control of arthropod vectors in the future will require knowledge of the micropathogen composition of vectors harboring infectious agents. Understanding the ecological factors that regulate vector propagation in association with the prevalence and persistence of micropathogen lineages is also imperative. These interactions may affect the evolution of micropathogen lineages, especially if the micropathogens rely on the vector or host for dispersal. The sRNA deep-sequencing approach used in this analysis provides an intuitive method to survey micropathogen prevalence in ticks and other vector species

New early oligocene zircon U-Pb dates for the ‘Miocene’ Wenshan Basin, Yunnan, China: Biodiversity and paleoenvironment

The sedimentary basins of Yunnan, Southwest China, record detailed histories of Cenozoic paleoenvironmental change. They track regional tectonic and palaeobiological evolution, both of which are critically important for the development of modern floral diversity in southwestern China and throughout Asia more generally. However, to be useful, the sedimentary archives within the basins have to be placed within a well-constrained timeframe independent of biostratigraphy. Using high resolution U-Pb dating, we redefine the age of fossil-bearing strata in the Wenshan Basin. Regarded as Miocene for the last half century, these basin sediments encompass 30±2 and 32±1 Ma early Oligocene tuffaceous horizons, thus indicating a significantly greater antiquity than previously recognized. Together with other regional age revisions our result points to widespread Yunnan basin and orographic development as largely having taken place by the end Paleogene. This age revision provides an important new perspective on the preserved biotas and their evolution in Yunnan, and especially our understanding of the origin of Asian biodiversity which, regionally, had a near-modern composition by the early Oligocene. Crucially, this revised age evidences late Eocene-early Oligocene regional tectonism, pointing to the rise of eastern Tibet and the Hengduan Mountains before the growth of the Himalaya, and that Asia's high plant diversity has a Paleogene origin

Nano-particles fabrication on Ag film by femtosecond laser direct ablation

We present the formation of the nano-particles on 30nm Ag thin film on substrate of SiO 2 by using fs pulses laser ablation. Nano-particles size distribution is influenced by different laser pulse energy and the number of laser pulses. The mechanism of the formation of nano-particles is discussed through Three Temperature Model (TTM)

The LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap I. The Spectroscopic Redshift Catalog

We present a spectroscopic redshift catalog from the LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap (SGC), which is designed to observe all sources (Galactic and extra-galactic) by using repeating observations with a limiting magnitude of $r=18.1~mag$ in two $20~deg^2$ fields. The project is mainly focusing on the completeness of LAMOST ExtraGAlactic Surveys (LEGAS) in the SGC, the deficiencies of source selection methods and the basic performance parameters of LAMOST telescope. In both fields, more than 95% of galaxies have been observed. A post-processing has been applied to LAMOST 1D spectrum to remove the majority of remaining sky background residuals. More than 10,000 spectra have been visually inspected to measure the redshift by using combinations of different emission/absorption features with uncertainty of $\sigma_{z}/(1+z)<0.001$. In total, there are 1528 redshifts (623 absorption and 905 emission line galaxies) in Field A and 1570 redshifts (569 absorption and 1001 emission line galaxies) in Field B have been measured. The results show that it is possible to derive redshift from low SNR galaxies with our post-processing and visual inspection. Our analysis also indicates that up to 1/4 of the input targets for a typical extra-galactic spectroscopic survey might be unreliable. The multi-wavelength data analysis shows that the majority of mid-infrared-detected absorption (91.3%) and emission line galaxies (93.3%) can be well separated by an empirical criterion of $W2-W3=2.4$. Meanwhile, a fainter sequence paralleled to the main population of galaxies has been witnessed both in $M_r$/$W2-W3$ and $M_*$/$W2-W3$ diagrams, which could be the population of luminous dwarf galaxies but contaminated by the edge-on/highly inclined galaxies ($\sim30\%$).Comment: 19 pages, 14 figures, 2 MRT, accepted by ApJ