Model-Based Design (MBD) For Autonomous Underwater Vehicle

This project is to enhanced and upgraded a depth controller for Autonomous Underwater Vehicle (AUV) to submerge precisely at the certain depth. This poster demonstrated an AUV equipped with integrated sensor and depth controller based on the pressure sensing which able to continuously sending the depth data to controller. The depth Simulink Arduino algorithm is implemented on an Arduino Mega using ModelBased Design (MBD) with MATLAB and Simulink. MBD used to model, simulate and verify the Simulink control algorithm after obtained data through open-loop experiment test. Then, it deploys and tests the algorithm on the embedded AUV hardware. The focus was in controlling the AUV vertical trajectory as the AUV tried to remain stationary at the selected depth and consuming its rise time Tr, overshoot Os, and settling time Ts are minimized. The comparative study for the AUV depth-control by On-Off, Proportional Integral Derivative (PID) controller and Fuzzy Logic Controller (FLC) controllers. MBD has faster implementation with fewer coding error when deploy to AUV hardware

Reducing the Uncertainty in Estimating Soil Microbial-Derived Carbon Storage

Soil organic carbon (SOC) is the largest carbon pool in terrestrial ecosystems and plays a crucial role in mitigating climate change and enhancing soil productivity. Microbial-derived carbon (MDC) is the main component of the persistent SOC pool. However, current formulas used to estimate the proportional contribution of MDC are plagued by uncertainties due to limited sample sizes and the neglect of bacterial group composition effects. Here, we compiled the comprehensive global dataset and employed machine learning approaches to refine our quantitative understanding of MDC contributions to total carbon storage. Our efforts resulted in a reduction in the relative standard errors in prevailing estimations by an average of 71% and minimized the effect of global variations in bacterial group compositions on estimating MDC. Our estimation indicates that MDC contributes approximately 758 Pg, representing approximately 40% of the global soil carbon stock. Our study updated the formulas of MDC estimation with improving the accuracy and preserving simplicity and practicality. Given the unique biochemistry and functioning of the MDC pool, our study has direct implications for modeling efforts and predicting the land-atmosphere carbon balance under current and future climate scenarios

Genome-wide variation study and inter-tissue communication analysis unveil regulatory mechanisms of egg-laying performance in chickens

Egg-laying performance is of great economic importance in poultry, but the underlying genetic mechanisms are still elusive. In this work, we conduct a multi-omics and multi-tissue integrative study in hens with distinct egg production, to detect the hub candidate genes and construct hub molecular networks contributing to egg-laying phenotypic differences. We identifiy three hub candidate genes as egg-laying facilitators: TFPI2, which promotes the GnRH secretion in hypothalamic neuron cells; CAMK2D, which promotes the FSHβ and LHβ secretion in pituitary cells; and OSTN, which promotes granulosa cell proliferation and the synthesis of sex steroid hormones. We reveal key endocrine factors involving egg production by inter-tissue crosstalk analysis, and demonstrate that both a hepatokine, APOA4, and an adipokine, ANGPTL2, could increase egg production by inter-tissue communication with hypothalamic-pituitary-ovarian axis. Together, These results reveal the molecular mechanisms of multi-tissue coordinative regulation of chicken egg-laying performance and provide key insights to avian reproductive regulation.</p

Crystal structure of rhodopsin bound to arrestin by femtosecond X-ray laser.

G-protein-coupled receptors (GPCRs) signal primarily through G proteins or arrestins. Arrestin binding to GPCRs blocks G protein interaction and redirects signalling to numerous G-protein-independent pathways. Here we report the crystal structure of a constitutively active form of human rhodopsin bound to a pre-activated form of the mouse visual arrestin, determined by serial femtosecond X-ray laser crystallography. Together with extensive biochemical and mutagenesis data, the structure reveals an overall architecture of the rhodopsin-arrestin assembly in which rhodopsin uses distinct structural elements, including transmembrane helix 7 and helix 8, to recruit arrestin. Correspondingly, arrestin adopts the pre-activated conformation, with a ∼20° rotation between the amino and carboxy domains, which opens up a cleft in arrestin to accommodate a short helix formed by the second intracellular loop of rhodopsin. This structure provides a basis for understanding GPCR-mediated arrestin-biased signalling and demonstrates the power of X-ray lasers for advancing the frontiers of structural biology

DDX3X loss is an adverse prognostic marker in diffuse large B-cell lymphoma and is associated with chemoresistance in aggressive non-Hodgkin lymphoma subtypes.

Funder: addenbrooke's charitable trust, cambridge university hospital

Superconductivity and Charge-density-wave-like Transition in Th2Cu4As5

We report the synthesis, crystal structure, and physical properties of a novel ternary compound, Th$_2$Cu$_4$As$_5$. The material crystallizes in a tetragonal structure with lattice parameters $a=4.0716(1)$ {\AA} and $c=24.8131(4)$ {\AA}. Its structure can be described as an alternating stacking of fluorite-type Th$_2$As$_2$ layers with antifluorite-type double-layered Cu$_4$As$_3$ slabs. The measurement of electrical resistivity, magnetic susceptibility and specific heat reveals that Th$_2$Cu$_4$As$_5$ undergoes bulk superconducting transition at 4.2 K. Moreover, all these physical quantities exhibit anomalies at 48 K, where the Hall coefficient change the sign. These findings suggest a charge-density-wave-like (CDW) transition, making Th$_2$Cu$_4$As$_5$ a rare example for studying the interplay between CDW and superconductivity.Comment: 11 pages, 6 figures, and 1 tabl

Rational synthesis of an atomically precise carboncone under mild conditions

在已知的碳的存在形态中，还有一种锥型的碳结构，早在50年前人们在热解碳时发现了这类结构，此前也常被人们称为碳纳米锥，虽然这类碳纳米锥有望作为扫描隧道显微镜的探针、场发射头等替代材料，但始终未能找到合适方法精准地合成它们。因此，这类锥型碳材料尚未得到人们足够重视和开发。功能团簇材料创新研究群体的谢素原、张前炎课题组与美国波士顿学院的Lawrence Scott教授合作，首次通过有机合成途径，在温和的条件下合成得到了首例结构明确的碳锥单元（碳锥子）C70H20及其可溶衍生物。他们通过实验、理论计算、结构分析，最终在他们合成的碳锥子结构中，仅有1个五元环在锥顶，而在锥顶和锥缘之间（围绕着中心五元环）有2圈由六元环组成的完整的稠圈层，谢素原等将这一碳锥子命名为carboncone[1,2]。通过这一典型的碳锥子（carboncone[1,2]），有望借助气相沉积等技术不断增加稠圈层数（m）来制备具有确定锥角的系列单壁纳米碳锥（carboncone[1,m>2]）。随着研究的深入，不久的将来人类有望合成出其它四种不同锥角的碳锥子（carboncone[n=2-5,m]），完整地研究探索和开发利用这类锥型结构的碳材料。 化学化工学院2015级硕士生朱正钟（主要负责合成）和2017级博士生陈佐长（主要负责理论计算）为该论文的共同第一作者。Carboncones, a special family of all-carbon allotropes, are predicted to have unique properties that distinguish them from fullerenes, carbon nanotubes, and graphenes. Owing to the absence of methods to synthesize atomically well-defined carboncones, however, experimental insight into the nature of pure carboncones has been inaccessible. Herein, we describe a facile synthesis of an atomically well-defined carboncone[1,2] (C70H20) and its soluble penta-mesityl derivative. Identified by x-ray crystallography, the carbon skeleton is a carboncone with the largest possible apex angle. Much of the structural strain is overcome in the final step of converting the bowl-shaped precursor into the rigid carboncone under mild reaction conditions. This work provides a research opportunity for investigations of atomically precise single-layered carboncones having even higher cone walls and/or smaller apex angles.This research was supported by the National Natural Science Foundation of China (21771152, 21721001, 21390390, 21827801, 51572231, 21571151, and 21701134), the 973 Program of China (2015CB932301), the Major Science and Technology Project between University-Industry Cooperation in Fujian Province (2016H6023), and the Fundamental Research Funds for the Central Universities (20720170028 and 20720160084). This research was also supported financially by the U.S. National Science Foundation (CHE-0809494 and CHE-1149096). 研究工作得到国家自然科学基金（21771152等）、科技部重大科学研究计划项目（2015CB932301）和福建省高校产学合作项目、中央高校基本科研业务费、美国国家科学基金等的资助