Chinese Experience with Global G3 Standard-Setting

China’s growth strategy as set out in the 11th 5-year plan in 2005 called for upgrading of product quality, the development of an innovation society, and reduced reliance on foreign intellectual property with high license fees. Consistent with this policy, China has been involved in recent years with the development of a Chinese standard in third generation (3G) mobile phone technology, both in negotiating the standard and seeing it through to commercialization. This is the first case of a developing country both originating and successfully negotiating a telecommunications standard and this experience raises issues for China’s future development strategy based on product and process upgrading in manufacturing. We argue that while precedent setting from an international negotiating point of view, the experience has thus far is unproven commercially. But the lessons learned will benefit future related efforts in follow-on technologies if similar Chinese efforts are made.This paper documents Chinese standard-setting efforts from proposal submission to ITU to the current large-scale trial network deployment in China and overseas trial networks deployment. We discuss the underlying objectives for this initiative, evaluate its effectiveness, and assess its broader implications for Chinese development policy.

Pleckstrin Homology (PH) Domain Leucine-Rich Repeat Protein Phosphatase Controls Cell Polarity by Negatively Regulating the Activity of Atypical Protein Kinase C

The proper establishment of epithelial polarity allows cells to sense and respond to signals that arise from the microenvironment in a spatiotemporally controlled manner. Atypical PKCs (aPKCs) are implicated as key regulators of epithelial polarity. However, the molecular mechanism underlying the negative regulation of aPKCs remains largely unknown. In this study, we demonstrated that PH domain leucine-rich repeat protein phosphatase (PHLPP), a novel family of Ser/Thr protein phosphatases, plays an important role in regulating epithelial polarity by controlling the phosphorylation of both aPKC isoforms. Altered expression of PHLPP1 or PHLPP2 disrupted polarization of Caco2 cells grown in 3D cell cultures as indicated by the formation of aberrant multi-lumen structures. Overexpression of PHLPP resulted in a decrease in aPKC phosphorylation at both the activation loop and the turn motif sites; conversely, knockdown of PHLPP increased aPKC phosphorylation. Moreover, in vitro dephosphorylation experiments revealed that both aPKC isoforms were substrates of PHLPP. Interestingly, knockdown of PKCζ, but not PKCι, led to similar disruption of the polarized lumen structure, suggesting that PKCζ likely controls the polarization process of Caco2 cells. Furthermore, knockdown of PHLPP altered the apical membrane localization of aPKCs and reduced the formation of aPKC-Par3 complex. Taken together, our results identify a novel role of PHLPP in regulating aPKC and cell polarity

Tailoring the Direct Current Modulation Response of Electrically Pumped Semiconductor Nano-Laser Arrays

Semiconductor nano-lasers have been a topic of interest from the perspective of advancing the capabilities of photonic integration. Nano-lasers are perceived as the means to achieve improved functionality in photonic integrated circuits. The properties and performance of nano-lasers have been examined by means of simulations and laboratory measurements. Nano-lasers lend themselves to integration to form dense arrays in both one and two dimensions. In a recent work, a theoretical treatment was presented for the dynamic behaviour of stand-alone electrically pumped nano-laser arrays. In this work, the response of nano-laser arrays to direct current modulation is examined. As in previous works, attention is given to two prototype array geometries: a linear three-element linear array and an equilateral triangular array. Large one-dimensional arrays can be built by repeating this elementary linear array. Two-dimensional photonic integrated circuits can incorporate the triangular arrays studied here. Such prototypical configurations offer opportunities to tailor the modulation response of the nano-laser arrays. The principal factors which provide that capability are the coupling strengths between lasers in the arrays and the direct modulation parameters. The former are fixed at the design and manufacture stage of the array whilst the latter can be chosen. In addition, the enhancement of the spontaneous emission rate via the so-called Purcell effect in nano-lasers offers a device-specific means for accessing a range of modulation responses. Two-dimensional portraits of the regimes of differing modulation responses offer a convenient means for determining the dynamics that may be accessed by varying the laser drive current. It is shown by these means that a rich variety of modulation responses can be accessed in both linear and triangular arrays

Imaging and variability studies of CTA~102 during the 2016 January γ\gamma-ray flare

The $\gamma$-ray bright blazar CTA 102 is studied using imaging (new 15 GHz and archival 43 GHz Very Long Baseline Array, VLBA data) and time variable optical flux density, polarization degree and electric vector position angle (EVPA) spanning between 2015 June 1 and 2016 October 1, covering a prominent $\gamma$-ray flare during 2016 January. The pc-scale jet indicates expansion with oscillatory features upto 17 mas. Component proper motions are in the range 0.04 - 0.33 mas/yr with acceleration upto 1.2 mas followed by a slowing down beyond 1.5 mas. A jet bulk Lorentz factor $\geq$ 17.5, position angle of 128.3 degrees, inclination angle $\leq$ 6.6 degrees and intrinsic half opening angle $\leq$ 1.8 degrees are derived from the VLBA data. These inferences are employed in a helical jet model to infer long term variability in flux density, polarization degree, EVPA and a rotation of the Stokes Q and U parameters. A core distance of $r_{\rm core,43 \ GHz}$ = 22.9 pc, and a magnetic field strength at 1 pc and the core location of 1.57 G and 0.07 G respectively are inferred using the core shift method. The study is useful in the context of estimating jet parameters and in offering clues to distinguish mechanisms responsible for variability over different timescales.Comment: 20 pages, 7 figures, 3 tables; accepted for publication in Ap

Reconstruction of 7T-Like Images From 3T MRI

In the recent MRI scanning, ultra-high-field (7T) MR imaging provides higher resolution and better tissue contrast compared to routine 3T MRI, which may help in more accurate and early brain diseases diagnosis. However, currently, 7T MRI scanners are more expensive and less available at clinical and research centers. These motivate us to propose a method for the reconstruction of images close to the quality of 7T MRI, called 7T-like images, from 3T MRI, to improve the quality in terms of resolution and contrast. By doing so, the post-processing tasks, such as tissue segmentation, can be done more accurately and brain tissues details can be seen with higher resolution and contrast. To do this, we have acquired a unique dataset which includes paired 3T and 7T images scanned from same subjects, and then propose a hierarchical reconstruction based on group sparsity in a novel multi-level Canonical Correlation Analysis (CCA) space, to improve the quality of 3T MR image to be 7T-like MRI. First, overlapping patches are extracted from the input 3T MR image. Then, by extracting the most similar patches from all the aligned 3T and 7T images in the training set, the paired 3T and 7T dictionaries are constructed for each patch. It is worth noting that, for the training, we use pairs of 3T and 7T MR images from each training subject. Then, we propose multi-level CCA to map the paired 3T and 7T patch sets to a common space to increase their correlations. In such space, each input 3T MRI patch is sparsely represented by the 3T dictionary and then the obtained sparse coefficients are used together with the corresponding 7T dictionary to reconstruct the 7T-like patch. Also, to have the structural consistency between adjacent patches, the group sparsity is employed. This reconstruction is performed with changing patch sizes in a hierarchical framework. Experiments have been done using 13 subjects with both 3T and 7T MR images. The results show that our method outperforms previous methods and is able to recover better structural details. Also, to place our proposed method in a medical application context, we evaluated the influence of post-processing methods such as brain tissue segmentation on the reconstructed 7T-like MR images. Results show that our 7T-like images lead to higher accuracy in segmentation of white matter (WM), gray matter (GM), cerebrospinal fluid (CSF), and skull, compared to segmentation of 3T MR images

PHLPP Regulates Hexokinase 2-Dependent Glucose Metabolism in Colon Cancer Cells

Increased glucose metabolism is considered as one of the most important metabolic alterations adapted by cancer cells in order to generate energy as well as high levels of glycolytic intermediates to support rapid proliferation. PH domain leucine-rich repeat protein phosphatase (PHLPP) belongs to a novel family of Ser/Thr protein phosphatases that function as tumor suppressors in various types of human cancer. Here we determined the role of PHLPP in regulating glucose metabolism in colon cancer cells. Knockdown of PHLPP increased the rate of glucose consumption and lactate production, whereas overexpression of PHLPP had the opposite effect. Bioenergetic analysis using Seahorse Extracelluar Flux Analyzer revealed that silencing PHLPP expression induced a glycolytic shift in colon cancer cells. Mechanistically, we found that PHLPP formed a complex with Akt and hexokinase 2 (HK2) in the mitochondrial fraction of colon cancer cells and knockdown of PHLPP enhanced Akt-mediated phosphorylation and mitochondrial localization of HK2. Depletion of HK2 expression or treating cells with Akt and HK2 inhibitors reversed PHLPP loss-induced increase in glycolysis. Furthermore, PHLPP knockdown cells became addicted to glucose as a major energy source in that glucose starvation significantly decreased cancer cell survival. As HK2 is the key enzyme that determines the direction and magnitude of glucose flux, our study identified PHLPP as a novel regulator of glucose metabolism by controlling HK2 activity in colon cancer cells

VLBI observations of a sample of Palomar-Green quasars - I. Parsec-scale morphology

We observed 20 Palomar-Green quasars at low redshi ft (z < 0.5) with total flux density >1 mJy, including four radio-loud quasars (RLQs) and 16 radio-quiet quasars (RQQs), using the Very Long Baseline Array (VLBA) at 5 GHz. 10 RQQs are clearly detected in the VLBA images, and a compact radio core is identified in eight of them, indicating the prevalence of active galactic nucleus (AGN)-related radio emission in this flux-density-limited RQQ sample. The RQQs and RLQs in our sample have a division at similar to 30 mJy. The radio emission from RQQs appears to be the result of a combination of star formation and AGN-associated activities. All RQQs in our sample have a 5 GHz flux density ratio of Very Large Array (VLA) A-array to D-array f(c) = S-A(VLA)/S-D(VLA) above 0.2. The RQQs with f(a)(VLBA and VLA flux density ratio S-VLBA/S-A(VLA)) > 0.2 versus f(a) < 0.2 show significant differences in morphology, compactness, and total flux density. f(a) of RQQs is systematically lower than that of RLQs, probably due to the extended jets or relic jets of RQQs on tens to hundreds parsecs that are resolved out in VLBA images. Future larger samples, especially with the addition of milliarcsec resolution radio images of RQQs with total flux densities below 1 mJy, can test the conclusions of this paper and contribute to the understanding of the radio emission mechanism of RQQs, and the dichotomy and physical connection between RQQs and RLQs