Topological quantum states are characterized by nonlocal invariants. We present a new dynamical approach for ultracold-atom systems to uncover their band topology, and we provide solid evidence to ...demonstrate its experimental advantages. After quenching a two-dimensional (2D) Chern band, realized in an ultracold ^{87}Rb gas from a trivial to a topological parameter regime, we observe an emerging ring structure in the spin dynamics during the unitary evolution, which uniquely corresponds to the Chern number for the postquench band. By extracting 2D bulk topology from the 1D ring pattern, our scheme displays simplicity and is insensitive to perturbations. This insensitivity enables a high-precision determination of the full phase diagram for the system's band topology.
Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide because of metastasis. Epithelial‐mesenchymal transition (EMT) is widely considered to be crucial to the invasion‐metastasis ...cascade during cancer progression. Actin‐like 6A (ACTL6A) is initially verified important for cell proliferation, differentiation, and migration. In this study, we find that ACTL6A plays an essential role in metastasis and EMT of HCC. ACTL6A expression is up‐regulated in HCC cells and tissues. A high level of ACTL6A in HCCs is correlated with aggressive clinicopathological features and is an independent poor prognostic factor for overall and disease‐free survival of HCC patients. Ectopic expression of ACTL6A markedly promotes HCC cells migration, invasion, as well as EMT in vitro and promotes tumor growth and metastasis in the mouse xenograft model. Opposite results are observed when ACTL6A is knocked down. Mechanistically, ACTL6A promotes metastasis and EMT through activating Notch signaling. ACTL6A knockdown has the equal blockage effect as the Notch signaling inhibitor, N‐N‐(3,5‐difluorophenacetyl)‐L‐alanyl‐S‐phenylglycine t‐butylester, in HCC cells. Further studies indicate that ACTL6A might manipulate SRY (sex determining region Y)‐box 2 (SOX2) expression and then activate Notch1 signaling. Conclusions: ACTL6A promotes metastasis and EMT by SOX2/Notch1 signaling, indicating a prognostic biomarker candidate and a potential therapeutic target for HCC. (Hepatology 2016;63:1256–1271)
PurposePrefabricated construction (PC) will play a vital role in the transformation and upgrading of the construction industry in the future. However, high capital cost is currently one of the ...biggest obstacles to the application and promotion of PC in China. Clarifying the factors that affect the PC cost from the perspectives of stakeholders and exploring key cost control paths help to achieve effective cost management, but few studies have paid enough attention to this. Therefore, this research aims to explore the critical cost influencing factors (CIFs) and critical stakeholders of PC based on stakeholder theories and propose corresponding strategies for different stakeholders to reduce the cost of PC.Design/methodology/approachBased on the stakeholder theory and social network theory, literature review and two rounds of expert interviews were used to obtain the stakeholder-associated CIFs and their mutual effects, then the consistency of the data was tested. After that, social network analysis was applied to identify the critical CIFs, critical interaction and key stakeholders in PC cost control and mine the influence conduction paths between CIFs.FindingsThe results reveal that the cognition and attitude of developer and relevant standards and codes are the most critical CIFs while the government, developer and contractor are crucial to the cost control of PC. The findings further suggest that measures should be taken to reduce the transaction costs of the developer, and the contractor ought to efficiently apply information technology. Moreover, the collaborative work between designer and manufacturer can avoid unnecessary cost consumption.Originality/valueThis research combines stakeholder management and cost management in PC for the first time and explores the effective cost control paths. The research results can contribute to clarifying the key points of cost management for different stakeholders and improving the cost performance of PC projects.
Weyl semimetals are three-dimensional (3D) gapless topological phases with Weyl cones in the bulk band. According to lattice theory, Weyl cones must come in pairs, with the minimum number of cones ...being two. A semimetal with only two Weyl cones is an ideal Weyl semimetal (IWSM). Here we report the experimental realization of an IWSM band by engineering 3D spin-orbit coupling for ultracold atoms. The topological Weyl points are clearly measured via the virtual slicing imaging technique in equilibrium and are further resolved in the quench dynamics. The realization of an IWSM band opens an avenue to investigate various exotic phenomena that are difficult to access in solids.
Transboundary conservation is playing an increasingly important role in maintaining ecosystem integrity and halting biodiversity loss caused by anthropogenic activities. However, lack of information ...on species distributions in transboundary regions and understanding of the threats in these areas impairs conservation. We developed a spatial conservation plan for the transboundary areas between Yunnan province, southwestern China, and neighboring Myanmar, Laos, and Vietnam in the Indo‐Burma biodiversity hotspot. To identify priority areas for conservation and restoration, we determined species distribution patterns and recent land‐use changes and examined the spatiotemporal dynamics of the connected natural forest, which supports most species. We assessed connectivity with equivalent connected area (ECA), which is the amount of reachable habitat for a species. An ECA incorporates the presence of habitat in a patch and the amount of habitat in other patches within dispersal distance. We analyzed 197,845 locality records from specimen collections and monographs for 21,004 plant and vertebrate species. The region of Yunnan immediately adjacent to the international borders had the highest species richness, with 61% of recorded species and 56% of threatened vertebrates, which suggests high conservation value. Satellite imagery showed the area of natural forest in the border zone declined by 5.2% (13,255 km2) from 1995 to 2018 and monoculture plantations increased 92.4%, shrubland 10.1%, and other cropland 6.2%. The resulting decline in connected natural forest reduced the amount of habitat, especially for forest specialists with limited dispersal abilities. The most severe decline in connectivity was along the Sino‐Vietnamese border. Many priority areas straddle international boundaries, indicating demand and potential for establishing transboundary protected areas. Our results illustrate the importance of bi‐ and multilateral cooperation to protect biodiversity in this region and provide guidance for future conservation planning and practice.
Planeación de la Conservación en las Fronteras de China con Myanmar, Laos y Vietnam
Resumen
La conservación transfronteriza cada vez juega un papel más importante en la preservación de la integridad del ecosistema y en el freno a la pérdida local de la biodiversidad causada por las actividades antropogénicas. Sin embargo, la falta de información sobre la distribución de las especies en las regiones transfronterizas y de la comprensión de las amenazas en estas áreas obstaculiza la conservación. Desarrollamos un plan de conservación espacial para las áreas transfronterizas entre la provincia de Yunnan, al suroeste de China, y los países vecinos Myanmar, Laos y Vietnam localizadas en el punto caliente de biodiversidad Indo‐Burma. Para identificar las áreas prioritarias para la conservación y la restauración, determinamos los patrones de distribución de las especies y los recientes cambios en el uso de suelo y examinamos las dinámicas espaciotemporales del bosque natural conectado, el cual mantiene a la mayoría de las especies. Evaluamos la conectividad con el área equivalente conectada (AEC), que es la cantidad de hábitat accesible para una especie. Un AEC incorpora la presencia del hábitat en un fragmento y la cantidad de hábitat en otros fragmentos dentro de la distancia de dispersión. Analizamos 197,845 registros de localidades desde colecciones de especímenes y monografías para 21,004 especies de plantas y de vertebrados. La región de Yunnan inmediatamente adyacente a las fronteras internacionales tuvo la riqueza de especies más alta con el 61% de las especies registradas y el 56% de los vertebrados amenazados, lo que sugiere un elevado valor de conservación. Las imágenes satelitales mostraron que el área del bosque natural en la zona fronteriza declinó en un 5.2% (13,255 km2) entre 1995 y 2018 y que los sembradíos de monocultivos incrementaron en un 92.4%, los matorrales en un 10.1% y otras tierras de cultivo en un 6.2%. La declinación resultante en el bosque natural conectado redujo la cantidad del hábitat, especialmente para los especialistas del bosque con habilidades limitadas de dispersión. La declinación más grave en la conectividad ocurrió a lo largo de la frontera entre China y Vietnam. Muchas áreas prioritarias atraviesan las fronteras internacionales, lo que indica una demanda y un potencial para el establecimiento de áreas protegidas transfronterizas. Nuestros resultados ejemplifican la importancia de la cooperación bi‐ y multilateral para proteger la biodiversidad en esta región y proporciona información para la planeación y práctica de la conservación en el futuro.
中国及其毗邻缅甸、老挝和越南边境上的保护规划
跨境保护在维持生态系统完整和阻止人类活动引起的生物多样性丧失方面起着重要的作用。然而, 跨境区域的物种分布信息和所受威胁的认识都很匮乏, 这不利于进一步的保护。在印‐缅生物多样性热点地区, 我们为中国云南省及其毗邻的缅甸, 老挝和越南的跨境区域提供了一个空间保护计划。通过分析物种分布格局, 近期土地利用变化以及为大多数物种提供了生境的天然林的连通性时空动态, 我们识别了该跨境区域的保护和恢复优先区。我们利用等同连接面积(ECA)指数来评估连通性。该指数可以测量一个物种在其扩散距离范围内可以到达的总的生境数量。我们从标本和专著中收集了21,004个植物和脊椎动物物种并分析了197,845条分布记录, 结果显示云南省边境地区具有最高的物种丰富度, 61%的已记录的物种和56%的受威胁脊椎动物分布在云南边境地区, 这表明边境地区具有高的保护价值。卫星影像分析显示, 从1995至2018年, 跨境区域天然林面积减少了5.2% (13,255 km2), 而单一种植的人工林面积增加了92.4%, 灌丛面积增加了10.1%, 农田面积增加了6.2%。由此引起的连通的天然林面积的下降减少了生境数量, 这对扩散能力较弱的森林特化物种的影响尤为明显。中‐越边境上的连通性下降最为严重。许多优先区跨越了国界线, 这表明了建立跨境保护地的需求和潜力。我们的结果阐明了双边或多边合作保护生物多样性的重要性, 同时也为该跨境区域未来的保护规划和实践提供了指导。
Article impact statement: Species distribution pattern and connectivity change call for transboundary conservation on China's borders with Myanmar, Laos, and Vietnam.
We report the realization of a robust and highly controllable two-dimensional (2D) spin-orbit (SO) coupling with a topological nontrivial band structure. By applying a retro-reflected 2D optical ...lattice, phase tunable Raman couplings are formed into the antisymmetric Raman lattice structure, and generate the 2D SO coupling with precise inversion and C_{4} symmetries, leading to considerably enlarged topological regions. The lifetime of the 2D SO coupled Bose-Einstein condensate reaches several seconds, which enables exploring fine-tuning interaction effects. These essential advantages of the present new realization open the door to explore exotic quantum many-body effects and nonequilibrium dynamics with novel topology.
Quantum dynamics induced in quenching a d-dimensional topological phase across a phase transition may exhibit a nontrivial dynamical topological pattern on the (d−1)D momentum subspace, called band ...inversion surfaces (BISs), which have a one-to-one correspondence to the bulk topology of the postquench phase. Here we report the experimental observation of such dynamical bulk-surface correspondence through measuring the topological charges in a 2D quantum anomalous Hall model realized in an optical Raman lattice. The system can be quenched with respect to every spin axis by suddenly varying the two-photon detuning or phases of the Raman couplings, in which the topological charges and BISs are measured dynamically by the time-averaged spin textures. We observe that the total charges in the region enclosed by BISs define a dynamical topological invariant, which equals the Chern number of the postquench band and also characterizes the topological pattern of a dynamical field emerging on the BISs, rendering the dynamical bulk-surface correspondence. This study opens a new avenue to explore topological phases dynamically.
Existing studies suggest that dietary vitamins and carotenoids might be associated with a reduced risk of age-related cataract (ARC), although a quantitative summary of these associations is lacking.
...The aim of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) and cohort studies of dietary vitamin and carotenoid intake and ARC risk.
The MEDLINE, EMBASE, ISI Web of Science, and Cochrane Library databases were searched from inception to June 2018. The adjusted RRs and corresponding 95% CIs for the associations of interest in each study were extracted to calculate pooled estimates. Dose-response relations were assessed with the use of generalized least-squares trend estimation.
We included 8 RCTs and 12 cohort studies in the meta-analysis. Most vitamins and carotenoids were significantly associated with reduced risk of ARC in the cohort studies, including vitamin A (RR: 0.81; 95% CI: 0.71, 0.92; P = 0.001), vitamin C (RR: 0.80; 95% CI: 0.72, 0.88; P < 0.001), vitamin E (RR: 0.90; 95% CI: 0.80, 1.00; P = 0.049), β-carotene (RR: 0.90; 95% CI: 0.83, 0.99; P = 0.023), and lutein or zeaxanthin (RR: 0.81; 95% CI: 0.75, 0.89; P < 0.001). In RCTs, vitamin E (RR: 0.97; 95% CI: 0.91, 1.03; P = 0.262) or β-carotene (RR: 0.99; 95% CI: 0.92, 1.07; P = 0.820) intervention did not reduce the risk of ARC significantly compared with the placebo group. Further dose-response analysis indicated that in cohort studies the risk of ARC significantly decreased by 26% for every 10-mg/d increase in lutein or zeaxanthin intake (RR: 0.74; 95% CI: 0.67, 0.80; P < 0.001), by 18% for each 500-mg/d increase in vitamin C intake (RR: 0.82; 95% CI: 0.74, 0.91; P < 0.001), by 8% for each 5-mg/d increase in β-carotene intake (RR: 0.92; 95% CI: 0.88, 0.96; P < 0.001), and by 6% for every 5 mg/d increase in vitamin A intake (RR: 0.94; 95% CI: 0.90, 0.98; P < 0.001).
Higher consumption of certain vitamins and carotenoids was associated with a significant decreased risk of ARC in cohort studies, but evidence from RCTs is less clear.
Niche differentiation has long been identified as an essential stabilizing mechanism for the coexistence of sympatric species. Using camera trapping data obtained during 2012–2016, we identified ...Macaca leonina and M. mulatta as the dominant macaque species in the Naban River Watershed National Nature Reserve (NRW‐NNR), a tropical forest in southwestern China. In general, M. leonina exhibited a wider distribution and greater niche breadth than co‐occurring M. mulatta. According to a fitted maximum entropy model (MaxEnt), M. leonina was predicted to predominantly occur in forest at higher elevation, whereas M. mulatta was predicted at lower elevation; the broadleaved evergreen forest was predicted as the most suitable vegetation for both species to inhabit, while the unsuitable area was bordered by rubber plantation, in which both food scarcity and human disturbance restricted the movement of macaques. Although the niches of these two species highly overlapped across space and time, we also found evidence for their spatiotemporal niche differentiation. When the two species inhabited independent areas with different elevations and vegetation, they maintained a similar activity pattern; however, in the zones of overlap, their activity patterns differed significantly. Further comparative field studies of these two macaques, considering other niche dimensions, are required to ensure their coexistence and long‐term conservation.
Research Highlights
Macaca leonina generally has a larger distribution and niche breadth than M. mulatta.
While niche differentiation occurs along at least one dimension, there is substantial overlap.
Space limitation drives niche differentiation over time.
In response to various stimuli, vascular smooth muscle cells (SMCs) can de-differentiate, proliferate and migrate in a process known as phenotypic modulation. However, the phenotype of modulated SMCs ...in vivo during atherosclerosis and the influence of this process on coronary artery disease (CAD) risk have not been clearly established. Using single-cell RNA sequencing, we comprehensively characterized the transcriptomic phenotype of modulated SMCs in vivo in atherosclerotic lesions of both mouse and human arteries and found that these cells transform into unique fibroblast-like cells, termed 'fibromyocytes', rather than into a classical macrophage phenotype. SMC-specific knockout of TCF21-a causal CAD gene-markedly inhibited SMC phenotypic modulation in mice, leading to the presence of fewer fibromyocytes within lesions as well as within the protective fibrous cap of the lesions. Moreover, TCF21 expression was strongly associated with SMC phenotypic modulation in diseased human coronary arteries, and higher levels of TCF21 expression were associated with decreased CAD risk in human CAD-relevant tissues. These results establish a protective role for both TCF21 and SMC phenotypic modulation in this disease.
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