ALBERT

Description: To investigate the air quality during 2010 World Expo, continuous measurements of particle number size distributions and optical parameters were performed at urban Shanghai from April to June 2010. Total particle number and volume concentrations in the size range 16–600 nm were 12 700±6200 cm −3 and 16±8 µm 3 /cm 3 , respectively. Meanwhile, the optical parameters, particle light-scattering coefficient b sp,532nm and absorption coefficient b ap,532nm were 210±140 Mm −1 and 26±20 Mm −1 , respectively. Strong correlation ( R =0.69) was observed between b sp,532nm and the number concentration of accumulation mode particles, especially in the specific size range 300–500 nm ( R =0.87). Cluster analysis on air mass history was performed to explore the relationship between air mass origins and the optical as well as microphysical parameters. Back trajectories were classified into four major clusters. Air masses came from the west direction, in which continental aerosols were predominant, associating with the polluted cases during the summertime in Shanghai. In addition, the northern air mass showed the lower values of aerosol single scattering albedo ω 0,532nm , indicating the presence of smaller light-absorbing particles originated from the North China Plain. Keywords: particle number size distribution, aerosol optical properties, air mass history, cluster analysis, 2010 World Expo (Published: 29 October 2014) Citation: Tellus B 2014, 66 , 22319, http://dx.doi.org/10.3402/tellusb.v66.22319

Description: Motivation: Given the importance of non-coding RNAs to cellular regulatory functions, it would be highly desirable to have accurate computational prediction of RNA 3D structure, a task which remains challenging. Even for a short RNA sequence, the space of tertiary conformations is immense; existing methods to identify native-like conformations mostly resort to random sampling of conformations to achieve computational feasibility. However, native conformations may not be examined and prediction accuracy may be compromised due to sampling. State-of-the-art methods have yet to deliver satisfactory predictions for RNAs of length beyond 50 nucleotides. Results: This paper presents a method to tackle a key step in the RNA 3D structure prediction problem, the prediction of the nucleotide interactions that constitute the desired 3D structure. The research is based on a novel graph model, called a backbone k-tree , to tightly constrain the nucleotide interaction relationships considered for RNA 3D structures. It is shown that the new model makes it possible to efficiently predict the optimal set of nucleotide interactions (including the non-canonical interactions in all recently revealed families) from the query sequence along with known or predicted canonical basepairs. The preliminary results indicate that in most cases the new method can predict with a high accuracy the nucleotide interactions that constitute the 3D structure of the query sequence. It thus provides a useful tool for the accurate prediction of RNA 3D structure. Availability and Implementation: The source package for BkTree is available at http://rna-informatics.uga.edu/index.php?f=software&p=BkTree . Contact: lding@uga.edu or cai@cs.uga.edu Supplementary information: Supplementary data are available at Bioinformatics online.

Description: Noninvasive prenatal testing (NIPT) using sequencing of fetal cell-free DNA from maternal plasma has enabled accurate prenatal diagnosis of aneuploidy and become increasingly accepted in clinical practice. We investigated whether NIPT using semiconductor sequencing platform (SSP) could reliably detect subchromosomal deletions/duplications in women carrying high-risk fetuses. We first showed that...

Description: Author(s): L. Xue, Y. G. Ma, J. H. Chen, and S. Zhang [Phys. Rev. C 92, 059901] Published Wed Nov 25, 2015

Description: Wallenda regulates JNK-mediated cell death in Drosophila Cell Death and Disease 6, e1737 (May 2015). doi:10.1038/cddis.2015.111 Authors: X Ma, W Xu, D Zhang, Y Yang, W Li & L Xue

Description: Menopause results from loss of ovarian function and marks the end of a woman's reproductive life. Alleles of the human SYCP2L locus are associated with age at natural menopause (ANM). SYCP2L is a paralogue of the synaptonemal complex protein SYCP2 and is expressed exclusively in oocytes. Here we report that SYCP2L localizes to centromeres of dictyate stage oocytes, which represent the limited pool of primordial oocytes that are formed perinatally and remain arrested till ovulation. Centromere localization of SYCP2L requires its C-terminal portion, which is missing in truncated variants resulting from low-frequency nonsense mutations identified in humans. Female mice lacking SYCP2L undergo a significantly higher progressive loss of oocytes with age compared with wild-type females and are less fertile. Specifically, the pool of primordial oocytes becomes more rapidly depleted in SYCP2L-deficient than in wild-type females, such that with aging, fewer oocytes undergo maturation in developing follicles. We find that a human SYCP2L intronic single nucleotide polymorphism (SNP) rs2153157, which is associated with ANM, changes the splicing efficiency of U12-type minor introns and may therefore regulate the steady-state amount of SYCP2L transcript. Furthermore, the more efficiently spliced allele of this intronic SNP in SYCP2L is associated with increased ANM. Our results suggest that SYCP2L promotes the survival of primordial oocytes and thus provide functional evidence for its association with ANM in humans.

Description: The canonical Wg signaling modulates Bsk-mediated cell death in Drosophila Cell Death and Disease 6, e1713 (April 2015). doi:10.1038/cddis.2015.85 Authors: S Zhang, C Chen, C Wu, Y Yang, W Li & L Xue

Description: Azimuthal anisotropy of attenuation is a physical phenomenon related to the directional change of attenuation. This study examines the frequency properties and directional attenuation of SKS waves. The directional frequency-dependent characteristics of SKS waves are investigated in the frequency band of 0.02–0.5 Hz using data from 53 permanent seismic stations located throughout the northern Yangtze Craton, the southern North China Craton and adjacent areas. In addition to normal splitting behavior, the analysis reveals that many SKS splitting measurements exhibit a lemniscate shape, reflecting frequency differences along fast and slow polarization directions. Frequency analysis shows that spectral ratios between fast/slow components of the lemniscate-type splitting results fluctuate strongly in a higher frequency band of 0.2–0.5 Hz, and fluctuate less within the main frequency band of 0.02–0.2 Hz. For each station, the ratio of the peak amplitude of the fast/slow components can be represented as a cotangential function of event backazimuth multiplying with a constant = 0.42 ± 0.10. This transformation shows that the regional average angles consistently fall within the relatively narrow range of –46.5 ± 3° with respect to the north, suggesting that a regional tectonic controlling factor dictates the relatively uniform directional attenuation of SKS waves within the frequency band of 0.02–0.2 Hz. Further analysis is performed by projecting the SKS waves onto the components along and perpendicular to the regional average angles. The calculation also shows that, in the 0.02–0.2 Hz band, the relationship between amplitude ratio and event backazimuth matches a cotangential functions with the same best matching angles and constant a 〈 1. Synthetic calculations demonstrate that although different filters influence the splitting parameters, attenuation anisotropy cannot be explained by elastic anisotropic media, including multilayer anisotropy and anisotropy with a tilting symmetrical axis. This observed behavior of the SKS wave may arise from the combined effects of frequency-dependent attenuation anisotropy and small-scale heterogeneities in the crust and the upper mantle.

Description: Author(s): L. Xue (薛亮), Y. G. Ma (马余刚), J. H. Chen (陈金辉), and S. Zhang (张松) A simple coalescence model is employed to investigate the production of light (anti)nuclei and (anti)hypertriton as well as di- Λ in the most central Au+Au collisions. The invariant yields of 3 He( 3 He̅ ), Λ  3 H ( Λ ̅  3 H̅ ), and 4 He( 4 He̅ ) obtained within current framework are ... [Phys. Rev. C 85, 064912] Published Mon Jun 18, 2012

Description: Unresolved problems associated with the production of graphene materials include the need for greater control over layer number, crystallinity, size, edge structure and spatial orientation, and a better understanding of the underlying mechanisms. Here we report a chemical vapor deposition approach that allows the direct synthesis of uniform single-layered, large-size (up to 10,000 μm2), spatially self-aligned, and single-crystalline hexagonal graphene flakes (HGFs) and their continuous films on liquid Cu surfaces. Employing a liquid Cu surface completely eliminates the grain boundaries in solid polycrystalline Cu, resulting in a uniform nucleation distribution and low graphene nucleation density, but also enables self-assembly of HGFs into compact and ordered structures. These HGFs show an average two-dimensional resistivity of 609 ± 200 Ω and saturation current density of 0.96 ± 0.15 mA/μm, demonstrating their good conductivity and capability for carrying high current density.