Role of heparan sulfate proteoglycans in optic disc and stalk morphogenesis

Background Heparan sulfate proteoglycans (HSPG) are important for embryonic development via the regulation of gradient formation and signaling of multiple growth factors and morphogens. Previous studies have shown that Bmp/Shh/Fgf signaling are required for the regionalization of the optic vesicle (OV) and for the closure of the optic fissure (OF), the disturbance of which underlie ocular anomalies such as microphthalmia, coloboma and optic nerve hypoplasia. Results To study HSPG-dependent coordination of these signaling pathways during mammalian visual system development, we have generated a series of OV-specific mutations in the heparan sulfate (HS) N-sulfotransferase genes (Ndst1 and Ndst2) and HS O-sulfotransferase genes (Hs2st, Hs6st1 and Hs6st2) in mice. Interestingly, the resulting HS undersulfation still allowed for normal retinal neurogenesis and optic fissure closure, but led to defective optic disc and stalk development. The adult mutant animals further developed optic nerve aplasia/hypoplasia and displayed retinal degeneration. We observed that MAPK/ERK signaling was down-regulated in Ndst mutants, and consistent with this, HS-related optic nerve morphogenesis defects in mutant mice could partially be rescued by constitutive Kras activation. Conclusions These results suggest that HSPGs, depending on their HS sulfation pattern, regulate multiple signaling pathways in optic disc and stalk morphogenesis

Phase transitions in a holographic s+p model with backreaction

In a previous paper (arXiv:1309.2204, JHEP 1311 (2013) 087), we present a holographic s+p superconductor model with a scalar triplet charged under an SU(2) gauge field in the bulk. We also study the competition and coexistence of the s-wave and p-wave orders in the probe limit. In this work we continue to study the model by considering the full back-reaction The model shows a rich phase structure and various condensate behaviors such as the "n-type" and "u-type" ones, which are also known as reentrant phase transitions in condensed matter physics. The phase transitions to the p-wave phase or s+p coexisting phase become first order in strong back-reaction cases. In these first order phase transitions, the free energy curve always forms a swallow tail shape, in which the unstable s+p solution can also play an important role. The phase diagrams of this model are given in terms of the dimension of the scalar order and the temperature in the cases of eight different values of the back reaction parameter, which show that the region for the s+p coexisting phase is enlarged with a small or medium back reaction parameter, but is reduced in the strong back-reaction cases.Comment: 15 pages(two-column), 9 figure

2-tert-Butyl 4-methyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxyl­ate

In the title mol­ecule, C13H19NO4, except for two C atoms of the tert-butyl group, the non-H atoms are almost coplanar (r.m.s. deviation = 0.2542 Å). In the crystal, mol­ecules are linked into centrosymmetric dimers by two inter­molecular N—H⋯O hydrogen bonds, forming an R 2 2(10) ring motif

Fast and Accurate Neural Word Segmentation for Chinese

Neural models with minimal feature engineering have achieved competitive performance against traditional methods for the task of Chinese word segmentation. However, both training and working procedures of the current neural models are computationally inefficient. This paper presents a greedy neural word segmenter with balanced word and character embedding inputs to alleviate the existing drawbacks. Our segmenter is truly end-to-end, capable of performing segmentation much faster and even more accurate than state-of-the-art neural models on Chinese benchmark datasets.Comment: To appear in ACL201

Study on Traffic Status Threshold Based on Floating Taxi

AbstractThe applications of floating car in road traffic condition identification are taken seriously and gradually developed. The paper studies the variables threshold in traffic condition information based on the floating taxi: section traffic information update cycle, data sampling interval, section covering ratio, floating taxi sample size. The optimization idea of floating taxi sample size is given. The traffic condition identification algorithm based on the floating taxi is put forward. The practice in two road sections shows that the algorithm is feasible which can offer useful reference for urban traffic management and resident trips decision

Service Quality Evaluation Model of Public Living Facilities in a Community

Accurate evaluating the service quality of public living facilities in a community by quantitative method is significant to urban planning. However, the performances of existing methods are usually limited for service quality evaluation due to single data source or single index. To solve the above problems, we propose a service quality evaluation model of public living facilities in a community. Firstly, POI data and subjective residents\u27 satisfaction evaluation data was pre-processed for data preparation. Then, the four evaluation indicators included in the model were established, namely, accessibility, diversity, selectivity, and satisfaction. Finally, after the completion of the calculation of the four indexes, standardized processing of the calculation results was performed, and the entropy method was used to assign different weights to the indexes, thereby achieving the quantitative evaluation of the service quality of community public living facilities. We chose the central urban area of Chengdu, China, as a case study for modeling analysis, and the case study successfully estimated the service quality and spatial difference of community living facilities. The results of this model can provide a reliable basis for future urban planning and the location of commercial facilities