Radio Sources in the NCP Region Observed with the 21 Centimeter Array

We present a catalog of 624 radio sources detected around the North Celestial Pole (NCP) with the 21 Centimeter Array (21CMA), a radio interferometer dedicated to the statistical measurement of the epoch of reionization (EoR). The data are taken from a 12 h observation made on 2013 April 13, with a frequency coverage from 75 to 175 MHz and an angular resolution of ~ 4 arcmin. The catalog includes flux densities at eight sub-bands across the 21CMA bandwidth and provides the in-band spectral indices for the detected sources. To reduce the complexity of interferometric imaging from the so-called "w" term and ionospheric effects, the present analysis are restricted to the east-west baselines within 1500 m only. The 624 radio sources are found within 5 degrees around the NCP down to ~ 0.1 Jy. Our source counts are compared, and also exhibit a good agreement, with deep low-frequency observations made recently with the GMRT and MWA. In particular, for fainter radio sources below ~ 1 Jy, we find a flattening trend of source counts towards lower frequencies. While the thermal noise (~0.4 mJy) is well controlled to below the confusion limit, the dynamical range (~10^4) and sensitivity of current 21CMA imaging is largely limited by calibration and deconvolution errors, especially the grating lobes of very bright sources, such as 3C061.1, in the NCP field which result from the regular spacings of the 21CMA. We note that particular attention should be paid to the extended sources, and their modeling and removals may constitute a large technical challenge for current EoR experiments. Our analysis may serve as a useful guide to design of next generation low-frequency interferometers like the Square Kilometre Array.Comment: 16 pages, 21 figures, 7 tables, 1 machine readable table, accepted for publication in Ap

Psychometric properties of the Chinese version of the pediatric quality of life inventory 4.0 Generic core scales among children with short stature

BACKGROUND: The quality of life in children with short stature was rarely studied in China, so we explore these children’s quality of life and psychometric properties of the Chinese version of the Pediatric Quality of Life Inventory 4.0(PedsQL4.0) Generic Core Scales among children with short stature. METHODS: A total of 201 children aged 8 ~ 18 years from the short stature clinic and other clinics of capital institute of pediatrics attended this study. The questionnaires include demographic information and PedsQL4.0 generic core scales. According to children’s height, we divided them into three groups: short stature, normal short and normal group, then compared the score of scales by the height category. Moreover, we analyzed the reliability and validity of PedsQL4.0 generic core scales in these 201 children. RESULTS: The child self-report total PedsQL mean score, for the short stature, normal short and normal groups were 77.77 ± 9.69, 83.50 ± 8.56 and 87.36 ± 7.23; the parent-proxy total PedsQL mean score were 77.62 ± 10.50, 82.69 ± 8.35 and 84.91 ± 9.96 respectively. Both for children self- and parent proxy-reports, the Cronbach’s α coefficients of total scale, psychosocial health and social functioning ranged between 0.74 and 0.80, it ranged between 0.51 and 0.66 in other dimensions. For child self-reports, the correlation coefficients of 17 items’ scores (total 23 items) with the scores of dimensions they belong to were above 0.5, with the highest 0.759; the other 6 items’ correlation coefficients were below 0.5, with the lowest 0.280. For parent proxy-reports, the correlation coefficients of 19 items’ scores with the scores of dimension they belong to were above 0.5, with the highest 0.793, the other 4 items’ below 0.5 with the lowest 0.243. CONCLUSIONS: The quality of life in children with short stature is worse than their normal peers by Peds QL4.0 generic core scales, the statues of their quality of life was positively related to their stature

Using optimized random amplified polymorphic DNA (RAPD) markers to identify the category status of Citrus nobilis Lour. Gonggan

Citrus nobilis Lour. Gonggan is an excellent fruit variety which is widely planted in South China. The origin of Gonggan is not clear. It is conjectured that its origin is from a cross between tangerine and orange; however, there is no direct evidence to confirm this. Here, we applied the optimized random amplified polymorphic DNA (RAPD)-PCR to amplify genus Citrus species: 1) to better understand the genetic relationship between C. nobilis Lour. Gonggan and other Citrus species; and (2) to address the phylogenetic relationship among Citrus species. A total of 21 RAPD primers were used to screen 4 Citrus species and 10 of them efficiently amplified the genomic DNA of 23 Citrus accessions. A total of 87 locus/alleles were generated by those 10 primers with an average of 97.7% polymorphic. Our data supported that C. nobilis Lour. Gonggan belongs to a big group with most tested tangerine and orange and a subgroup with Citrus haniana and Citrus flamea, implying that either C. haniana or C. flamea is likely to be one of the parents of C. nobilis Lour. Gonggan.Key words: Citrus nobilis Lour. Gonggan, random amplified polymorphism DNA (RAPD), phylogeneticrelationshi

Geochemical modeling of groundwater in southern plain area of Pengyang County, Ningxia, China

AbstractThe purpose of this paper is to examine the evolution mechanisms of a hydrochemical field and to promote its benefits to the living standards of local people and to the local economy in the southern plain area of Pengyang County, in Ningxia, China. Based on understanding of the hydrogeological conditions in Pengyang County, the chemical evolution characteristics of groundwater in the plain area were analyzed. PHREEQC geochemical modeling software was used to perform hydrochemical modeling of water-rock interaction and to quantitatively analyze the evolution processes and the formation mechanisms of the local groundwater. Geochemical modeling was performed for two groundwater paths. The results showed that, along path 1, Na+ adsorption played the leading role in the precipitation process and its amount was the largest, up to 6.08 mmol/L; cation exchange was significant along path 1, while along simulated path 2, albite accounted for the largest amount of dissolution, reaching 9.06 mmol/L, and the cation exchange was not significant. According to the modeling results, along the groundwater flow path, calcite and dolomite showed oversaturated status with a precipitation trend, while the fluorite and gypsum throughout the simulated path were not saturated and showed a dissolution trend. The total dissolved solids (TDS) increased and water quality worsened along the flow path. The dissolution reactions of albite, CO2, and halite, the exchange adsorption reaction of Na+, and the precipitation of sodium montmorillonite and calcite were the primary hydrogeochemical reactions, resulting in changes of hydrochemical ingredients

Design and simulation analysis of an improved lower limb exoskeleton

The lower extremity exoskeleton robot is a type of power assisted robot which can enhance the human walking function. A fundamental problem in the development of the exoskeleton is the choice of lightweight actuators. Thus in the mechanical structure design in this paper, the linear motor is selected as it greatly reduces the complexity of the mechanical structure. Furthermore, the limit switch inside the motor improves the safety performance. Based on the last version of the exoskeleton, the band positions, length adjusting holes and mechanical limit structures are increased. In addition, a control system based on DSP is designed. Furthermore, a kinematics analysis is carried out using the D-H parameter method and a dynamic analysis is developed using the Newton-Euler method. The driving force of every joint is obtained during the simulation using ADAMS software

Dynamics and kinematics analysis and simulation of lower extremity power-assisted exoskeleton

According to the walking character of lower extremity power-assisted exoskeleton that was designed by our Robotics Laboratory, D-H convention was applied to the kinematics analysis of this exoskeleton model. Lagrangian dynamics was used to analyzing dynamics for the single-foot support model, double-feet support model and double-feet support with one redundancy model respectively. The kinematical equation was obtained and MATLAB was used to verify its validity. Meanwhile, the kinetic equations and torque of each joint were obtained by virtue of ADAMS. Our study provided a theoretical foundation for the control strategies, and optimization design of the mechanical structure and promoted the practical application of this lower extremity power-assisted exoskeleton in further research

Endoglin Is Essential for the Maintenance of Self-Renewal and Chemoresistance in Renal Cancer Stem Cells.

Renal cell carcinoma (RCC) is a deadly malignancy due to its tendency to metastasize and resistance to chemotherapy. Stem-like tumor cells often confer these aggressive behaviors. We discovered an endoglin (CD105)-expressing subpopulation in human RCC xenografts and patient samples with a greater capability to form spheres in vitro and tumors in mice at low dilutions than parental cells. Knockdown of CD105 by short hairpin RNA and CRISPR/cas9 reduced stemness markers and sphere-formation ability while accelerating senescence in vitro. Importantly, downregulation of CD105 significantly decreased the tumorigenicity and gemcitabine resistance. This loss of stem-like properties can be rescued by CDA, MYC, or NANOG, and CDA might act as a demethylase maintaining MYC and NANOG. In this study, we showed that Endoglin (CD105) expression not only demarcates a cancer stem cell subpopulation but also confers self-renewal ability and contributes to chemoresistance in RCC