Extraction of Plumes in Turbulent Thermal Convection

We present a scheme to extract information about plumes, a prominent coherent structure in turbulent thermal convection, from simultaneous local velocity and temperature measurements. Using this scheme, we study the temperature dependence of the plume velocity and understand the results using the equations of motion. We further obtain the average local heat flux in the vertical direction at the cell center. Our result shows that heat is not mainly transported through the central region but instead through the regions near the sidewalls of the convection cell.Comment: 4 pages, 4 figures, submitted to Physical Review Letter

Bs(d)0−Bˉs(d)0B^0_{s(d)} - \bar{B}^0_{s(d)} mixing and new physics effects in a top quark two-Higgs doublet model

We calculate the new physics contributions to the neutral $B_d^0$ and $B_s^0$ meson mass splitting $\Delta M_d$ and $\Delta M_s$ induced by the box diagrams involving the charged-Higgs bosons in the top quark two-Higgs doublet model (T2HDM). Using the precision data, we obtain the bounds on the parameter space of the T2HDM: (a) for fixed $M_H=400$ GeV and $\delta=[0^\circ,60^\circ]$, the upper bound on $\tan{\beta}$ is $\tan \beta \leq 30$ after the inclusion of major theoretical uncertainties; (b) for the case of $\tan{\beta} \leq 20$, a light charged Higgs boson with a mass around 300 GeV is allowed; and (c) the bounds on $\tan{\beta}$ and $M_H$ are strongly correlated: a smaller (larger) $\tan{\beta}$ means a lighter (heavier) charged Higgs boson.Comment: 11 pages, 2 EPS figures, RevTex, new references adde

Atomic entanglement sudden death in a strongly driven cavity QED system

We study the entanglement dynamics of strongly driven atoms off-resonantly coupled with cavity fields. We consider conditions characterized not only by the atom-field coupling but also by the atom-field detuning. By studying two different models within the framework of cavity QED, we show that the so-called atomic entanglement sudden death (ESD) always occurs if the atom-field coupling lager than the atom-field detuning, and is independent of the type of initial atomic state

Surface chemistry and structure manipulation of graphene-related materials to address the challenges of electrochemical energy storage

Energy storage devices are important components in portable electronics, electric vehicles, and the electrical distribution grid. Batteries and supercapacitors have achieved great success as the spearhead of electrochemical energy storage devices, but need to be further developed in order to meet the ever-increasing energy demands, especially attaining higher power and energy density, and longer cycling life. Rational design of electrode materials plays a critical role in developing energy storage systems with higher performance. Graphene, the well-known 2D allotrope of carbon, with a unique structure and excellent properties has been considered a “magic” material with its high energy storage capability, which can not only aid in addressing the issues of the state-of-the-art lithium-ion batteries and supercapacitors, but also be crucial in the so-called post Li-ion battery era covering different technologies, e.g., sodium ion batteries, lithium-sulfur batteries, structural batteries, and hybrid supercapacitors. In this feature article, we provide a comprehensive overview of the strategies developed in our research to create graphene-based composite electrodes with better ionic conductivity, electron mobility, specific surface area, mechanical properties, and device performance than state-of-the-art electrodes. We summarize the strategies of structure manipulation and surface modification with specific focus on tackling the existing challenges in electrodes for batteries and supercapacitors by exploiting the unique properties of graphene-related materials

Raman Spectroscopy Study of alpha-, beta-, gamma-NaxCoO2 and gamma-(Ca,Sr)xCoO2

Raman spectroscopy measurements have been performed on alpha-, beta-, gamma-NaxCoO2 phases differing in their stacking of CoO6 octahedra along the c-axis direction. The results demonstrate that, in general, there are five active phonons for gamma-Na0.75CoO2, two Raman active phonons for alpha-NaCoO2, and four Raman active phonons for beta-NaCoO2. We have also performed Raman scattering measurements on several gamma-(Ca,Sr)xCoO2 (0.15 <= x <= 0.35) samples which show well-defined intercalated Ca/Sr-ordering. The experimental data show that the intercalated cation ordering could result in visible alterations on Raman spectral structures. The observations of the spectral changes along with the variation of the CoO6 stacking, as well as the intercalated Sr/Ca ordering suggest that the interlayer interaction plays an important role for understanding the lattice dynamics in this layered system.Comment: 23 pages, 5 figures, Physical Review B, in pres

GFI1 downregulation promotes inflammation-linked metastasis of colorectal cancer.

Inflammation is frequently associated with initiation, progression, and metastasis of colorectal cancer (CRC). Here, we unveil a CRC-specific metastatic programme that is triggered via the transcriptional repressor, GFI1. Using data from a large cohort of clinical samples including inflammatory bowel disease and CRC, and a cellular model of CRC progression mediated by cross-talk between the cancer cell and the inflammatory microenvironment, we identified GFI1 as a gating regulator responsible for a constitutively activated signalling circuit that renders CRC cells competent for metastatic spread. Further analysis of mouse models with metastatic CRC and human clinical specimens reinforced the influence of GFI1 downregulation in promoting CRC metastatic spread. The novel role of GFI1 is uncovered for the first time in a human solid tumour such as CRC. Our results imply that GFI1 is a potential therapeutic target for interfering with inflammation-induced CRC progression and spread

Variation of the Fine-Structure Constant from the de Sitter Invariant Special Relativity

There are obvious discrepancies among various experimental constraints on the variation of the fine-structure constant, $\alpha$. We attempt to discuss the issue in the framework of de Sitter invariant Special Relativity (${\cal SR}_{c,R}$) and to present a possible solution to the disagreement. In addition, on the basis of the observational data and the discussions presented in this Letter, we derive a rough theoretical estimate of the radius of the Universe.Comment: 8 pages, no figure

Development of microsatellite markers in Cocos nucifera and their application in evaluating the level of genetic diversity of Cocos nucifera

Cocos nucifera (coconut) is an economically important tropical crop, but opportunities for molecular breeding are limited by lack of DNA sequence information for this species. Previous assessments of coconut germplasm have been conducted based solely on phenotypic data for agronomic and quality traits, due to lack of available molecular markers. In this study, we developed 30 novel microsatellite markers from Illumina transcriptome sequence data, and used these markers to evaluate coconut genetic diversity in 30 individuals representing accessions from China (12 samples) and Southeast Asia (18 samples). The microsatellite markers displayed low to high genetic polymorphism across the population: observed heterozygosity varied from 0.06 to 0.79, with an average of 0.39 ± 0.15. Our results indicated that the Southeast Asian population had a significantly higher number of alleles (p = 0.02), but not significantly different (

Efficient isolation of high quality RNA from tropical palms for RNA-seq analysis

Currently, RNA-seq as a high throughput technology is being widely applied to various species to elucidate the complexity of the transcriptome and to discover large number of novel genes. However, the technology has had poor success in elucidating the transcriptome of tropical palms, as it is difficult to isolate high quality RNA from tropical palm tissues due to their high polysaccharide and polyphenol content. Here, we developed an RNA-isolation protocol for tropical palms, the MRIP method (Methods for RNA Isolation from Palms). The integrity of the RNA molecules extracted using this protocol was determined to be of high quality by means of gel electrophoresis and Agilent 2100 Bioanalyzer microfluidic electrophoresis chip examination with a RIN (RNA Integrity Number) value of more than 9, indicating that the mRNAs were of good integrity. Subsequently the isolated RNA was used for transcription analysis without further purification. With Illumina sequencing, we obtained 54.9 million short reads and then conducted de novo assembly to gain 57,304 unigenes with an average length of 752 base pairs. Moreover, the RNA isolated with this protocol was also successfully used for real-time RT-PCR. These results suggested that the RNA isolated was suitable for Illumina RNA sequencing and quantitative real-time RT-PCR. Furthermore, this method was also successful in isolating total RNA from the leaves of various Palmaceae species