Nitrogen acquisition strategy and its effects on invasiveness of a subtropical invasive plant

IntroductionPreference and plasticity in nitrogen (N) form uptake are the main strategies with which plants absorb soil N. However, little effort has been made to explore effects of N form acquisition strategies, especially the plasticity, on invasiveness of exotic plants, although many studies have determined the effects of N levels (e.g. N deposition).MethodsTo address this problem, we studied the differences in N form acquisition strategies between the invasive plant Solidago canadensis and its co-occurring native plant Artemisia lavandulaefolia, effects of soil N environments, and the relationship between N form acquisition strategy of S. canadensis and its invasiveness using a 15N-labeling technique in three habitats at four field sites.ResultsTotal biomass, root biomass, and the uptakes of soil dissolved inorganic N (DIN) per quadrat were higher for the invasive relative to the native species in all three habitats. The invader always preferred dominant soil N forms: NH4+ in habitats with NH4+ as the dominant DIN and NO3- in habitats with NO3- as the dominant DIN, while A. lavandulaefolia consistently preferred NO3- in all habitats. Plasticity in N form uptake was higher in the invasive relative to the native species, especially in the farmland. Plant N form acquisition strategy was influenced by both DIN levels and the proportions of different N forms (NO3-/NH4+) as judged by their negative effects on the proportional contributions of NH4+ to plant N (fNH4+) and the preference for NH4+ (βNH4+). In addition, total biomass was positively associated with fNH4+ or βNH4+ for S. canadensis, while negatively for A. lavandulaefolia. Interestingly, the species may prefer to absorb NH4+ when soil DIN and/or NO3-/NH4+ ratio were low, and root to shoot ratio may be affected by plant nutrient status per se, rather than by soil nutrient availability.DiscussionOur results indicate that the superior N form acquisition strategy of the invader contributes to its higher N uptake, and therefore to its invasiveness in different habitats, improving our understanding of invasiveness of exotic plants in diverse habitats in terms of utilization of different N forms

Targeting USP1-dependent KDM4A protein stability as a potential prostate cancer therapy

The histone demethylase lysine-specific demethylase 4A (KDM4A) is reported to be overexpressed and plays a vital in multiple cancers through controlling gene expression by epigenetic regulation of H3K9 or H3K36 methylation marks. However, the biological role and mechanism of KDM4A in prostate cancer (PC) remain unclear. Herein, we reported KDM4A expression was upregulation in phosphatase and tensin homolog knockout mouse prostate tissue. Depletion of KDM4A in PC cells inhibited their proliferation and survival in vivo and vitro. Further studies reveal that USP1 is a deubiquitinase that regulates KDM4A K48-linked deubiquitin and stability. Interestingly, we found c-Myc was a key downstream effector of the USP1-KDM4A/androgen receptor axis in driving PC cell proliferation. Notably, upregulation of KDM4A expression with high USP1 expression was observed in most prostate tumors and inhibition of USP1 promotes PC cells response to therapeutic agent enzalutamide. Our studies propose USP1 could be an anticancer therapeutic target in PC

Bulk ultrafine grained/nanocrystalline metals via slow cooling.

Cooling, nucleation, and phase growth are ubiquitous processes in nature. Effective control of nucleation and phase growth is of significance to yield refined microstructures with enhanced performance for materials. Recent studies reveal that ultrafine grained (UFG)/nanocrystalline metals exhibit extraordinary properties. However, conventional microstructure refinement methods, such as fast cooling and inoculation, have reached certain fundamental limits. It has been considered impossible to fabricate bulk UFG/nanocrystalline metals via slow cooling. Here, we report a new discovery that nanoparticles can refine metal grains to ultrafine/nanoscale by instilling a continuous nucleation and growth control mechanism during slow cooling. The bulk UFG/nanocrystalline metal with nanoparticles also reveals an unprecedented thermal stability. This method overcomes the grain refinement limits and may be extended to any other processes that involve cooling, nucleation, and phase growth for widespread applications

Topographic beta spiral and onshore intrusion of the Kuroshio Current

Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 45 (2018): 287–296, doi:10.1002/2017GL076614.The Kuroshio intrusion plays a vitally important role in carrying nutrients to marginal seas. However, the key mechanism leading to the Kuroshio intrusion remains unclear. In this study we postulate a mechanism: when the Kuroshio runs onto steep topography northeast of Taiwan, the strong inertia gives rise to upwelling over topography, leading to a left-hand spiral in the stratified ocean. This is called the topographic beta spiral, which is a major player regulating the Kuroshio intrusion; this spiral can be inferred from hydrographic surveys. In the world oceans, the topographic beta spirals can be induced by upwelling generated by strong currents running onto steep topography. This is a vital mechanism regulating onshore intruding flow and the cross-shelf transport of energy and nutrients from the Kuroshio Current to the East China Sea. This topographic beta spiral reveals a long-term missing link between the oceanic general circulation theory and shelf dynamic theory.Strategic Priority Research Program of the Chinese Academy of Sciences Grant Numbers: XDA11020104, XDA110203052; National Natural Science Foundation of China (NSFC) Grant Numbers: 41576023, 41376030, 41476019; Foundation for Innovative Research Groups of NSFC Grant Number: 41421005; NSFC-Shandong Joint Fund for Marine Science Research Centers Grant Number: U1406401; Aoshan Sci-Tec Innovative Project of Qingdao National Laboratory for Marine Science and Technology Grant Number: 2016ASKJ02; National Key Research and Development Program of China Grant Numbers: 2017YFC1404000, 2016YFC1401601; National Key research and development Plan Sino-Australian Center for Healthy Coasts Grant Number: 2016YFE01015002018-07-1

Notch 1 signaling pathway is the potential target of novel anticancer drugs for the treatment of human nasopharyngeal cancer

Activation of Notch signaling pathway in cancer stem cells plays a crucial role in the regulation of selfrenewal and maintenance of side population cells.  In the present study, we have identified cancer stem like 2.7% side population cells from nasopharyngeal carcinoma samples whose prevalence was significantly reduced to 0.3% upon verapamil treatment. The protein level of Notch1 and Hes-1 are highly up-regulated in fluorescence-activated cell sorting purified side population cells and thus leads to the elevated expression of stem cell surface proteins (Oct-4, Sox2 and Nanog), which are essential for side population cells self-renewal. In addition, these nasopharyngeal carcinoma side population cells are CD133 and CD44 positive and they possess enhanced cell proliferation rate, highly tumorgenic and invasive. Our findings suggest that Notch1 signaling is a potential target of novel anticancer drugs, which could efficiently target and eradicate the cancer stem cells

Downregulation of Fat Mass and Obesity Associated (FTO) Promotes the Progression of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) ranks as the second most malignant type of primary liver cancer with a high degree of incidence and a very poor prognosis. Fat mass and obesity-associated protein (FTO) functions as an eraser of the RNA m6A modification, but its roles in ICC tumorigenesis and development remain unknown. We showed here that the protein level of FTO was downregulated in clinical ICC samples and cell lines and that FTO expression was inversely correlated with the expression of CA19-9 and micro-vessel density (MVD). A Kaplan-Meier survival analysis showed that a low expression of FTO predicted poor prognosis in ICC. in vitro, decreased endogenous expression of FTO obviously reduced apoptosis of ICC cells. Moreover, FTO suppressed the anchorage-independent growth and mobility of ICC cells. Through mining the database, FTO was found to regulate the integrin signaling pathway, inflammation signaling pathway, epidermal growth factor receptor (EGFR) signaling pathway, angiogenesis, and the pyrimidine metabolism pathway. RNA decay assay showed that oncogene TEAD2 mRNA stability was impaired by FTO. In addition, the overexpression of FTO suppressed tumor growth in vivo. In conclusion, our study demonstrated the critical roles of FTO in ICC

Career adaptability and perceived overqualification: Testing a dual-path model among Chinese human resource management professionals

Based on career construction theory, the current research examined the relationship between career adaptability and perceived overqualification among a sample of Chinese human resource management professionals (N = 220). The results of a survey study showed that career adaptability predicted perceived overqualification through a dual-path model: On the one hand, career adaptability positively predicted employees' perceived delegation, which had a subsequent negative effect on perceived overqualification. At the same time, career adaptability also positively predicted career anchor in challenge, which in turn positively predicted overqualification. This dual-path mediation model provides a novel perspective to understand the mechanisms through which career adaptability affects perceived overqualification, and demonstrates the coexistence of opposite effects in this process. In addition, the results also showed that the effects of perceived delegation and career anchor in challenge on perceived overqualification were stronger among employees with a higher (vs. lower) level of organizational tenure. These findings carry implications for both career development theories and organizational management practices

A Mutation in Intracellular Loop 4 Affects the Drug-Efflux Activity of the Yeast Multidrug Resistance ABC Transporter Pdr5p

Multidrug resistance protein Pdr5p is a yeast ATP-binding cassette (ABC) transporter in the plasma membrane. It confers multidrug resistance by active efflux of intracellular drugs. However, the highly polymorphic Pdr5p from clinical strain YJM789 loses its ability to expel azole and cyclohexmide. To investigate the role of amino acid changes in this functional change, PDR5 chimeras were constructed by segmental replacement of homologous BY4741 PDR5 fragments. Functions of PDR5 chimeras were evaluated by fluconazole and cycloheximide resistance assays. Their expression, ATPase activity, and efflux efficiency for other substrates were also analyzed. Using multiple lines of evidence, we show that an alanine-to-methionine mutation at position 1352 located in the predicted short intracellular loop 4 significantly contributes to the observed transport deficiency. The degree of impairment is likely correlated to the size of the mutant residue

Postoperative Fever: The Potential Relationship with Prognosis in Node Negative Breast Cancer Patients

Background: Postoperative fever may serve as an indirect sign to reflect the alterations of the host milieu caused by surgery. It still remains open to investigation whether postoperative fever has a bearing on prognosis in patients with lymph node negative breast cancers. Methods: We performed a retrospective study of 883 female unilateral patients with lymph node negative breast cancer. Fever was defined as an oral temperature $38 in one week postoperation. Survival curves were performed with Kaplan-Meier method, and annual relapse hazard was estimated by hazard function. Findings: The fever patients were older than those without fever (P,0.0001). Hypertensive patients had a propensity for fever after surgery (P = 0.011). A statistically significant difference was yielded in the incidence of fever among HR+/ERBB2-, ERBB2+, HR-/ERBB2- subgroups (P = 0.012). In the univariate survival analysis, we observed postoperative fever patients were more likely to recur than those without fever (P = 0.0027). The Cox proportional hazards regression analysis showed that postoperative fever (P = 0.044, RR = 1.89, 95%CI 1.02–3.52) as well as the HR/ERBB2 subgroups (P = 0.013, HR = 1.60, 95%CI 1.09–2.31) was an independent prognostic factor for relapse-free survival. Conclusion: Postoperative fever may contribute to relapse in node negative breast cancer patients, which suggests that changes in host milieu related to fever might accelerate the growth of micro-metastatic foci. It may be more precise t