Climatic Control on Plant and Soil d13C along an Altitudinal Transect of Lushan Mountain in Subtropical China: Characteristics and Interpretation of Soil Carbon Dynamics

<div><p>Decreasing temperature and increasing precipitation along altitude gradients are typical mountain climate in subtropical China. In such a climate regime, identifying the patterns of the C stable isotope composition (δ¹³C) in plants and soils and their relations to the context of climate change is essential. In this study, the patterns of δ¹³C variation were investigated for tree leaves, litters, and soils in the natural secondary forests at four altitudes (219, 405, 780, and 1268 m a.s.l.) in Lushan Mountain, central subtropical China. For the dominant trees, both leaf and leaf-litter δ¹³C decreased as altitude increased from low to high altitude, whereas surface soil δ¹³C increased. The lower leaf δ¹³C at high altitudes was associated with the high moisture-related discrimination, while the high soil δ¹³C is attributed to the low temperature-induced decay. At each altitude, soil δ¹³C became enriched with soil depth. Soil δ¹³C increased with soil C concentrations and altitude, but decreased with soil depth. A negative relationship was also found between O-alkyl C and δ¹³C in litter and soil, whereas a positive relationship was observed between aromatic C and δ¹³C. Lower temperature and higher moisture at high altitudes are the predominant control factors of δ¹³C variation in plants and soils. These results help understand C dynamics in the context of global warming.</p></div

Interleukin-33 predicts poor prognosis and promotes ovarian cancer cell growth and metastasis through regulating ERK and JNK signaling pathways

Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer, it remains a huge challenge to understand the cellular and molecular mechanisms of the aggressive behavior of EOC cells. Here we investigated the role of an immunomodulatory cytokine IL-33 and its receptor ST2 in mediating the growth and metastasis of EOC. Our data show that both IL-33 and ST2 were highly up-regulated in EOC tumors compared with normal ovary and ovarian benign tumors, and the expression levels were further increased in tumor tissues at the metastatic site. The expression levels of IL-33 and ST2 were positively correlated with the Ki-67 expression, and negatively correlated with the patient survival time. Using EOC cell lines, we observed that cells knocked down of IL-33 gene by siRNA had reduced migratory and invasive potential, while full length human IL-33 (fl-hIL-33) promoted the invasive, migratory and proliferative capacity of EOC cells and this process could be inhibited by IL-33 decoy receptor sST2. Signaling pathway analysis suggested that IL-33 increased the phosphorylation of ERK and JNK which was blocked by sST2. Fl-hIL-33-induced increases in EOC cell migration, invasive potential and proliferation were specifically abrogated by treatment with the ERK inhibitor U0126 while JNK inhibitor SP600125 only disrupted IL-33-induced enhancement of cell viability. Taken together, our data suggest that IL-33/ST2 axis closely associates with poor prognosis of EOC patients, and it promotes ovarian cancer growth and metastasis through regulating ERK and JNK signaling pathways. Thus IL-33/ST2 might be potential prognosis markers and therapeutic targets for EOC patients

Aridity-driven shift in biodiversity–soil multifunctionality relationships

From Springer Nature via Jisc Publications RouterHistory: received 2021-01-07, accepted 2021-08-12, registration 2021-08-25, pub-electronic 2021-09-09, online 2021-09-09, collection 2021-12Publication status: PublishedFunder: National Natural Science Foundation of China (National Science Foundation of China); doi: https://doi.org/10.13039/501100001809; Grant(s): 31770430Abstract: Relationships between biodiversity and multiple ecosystem functions (that is, ecosystem multifunctionality) are context-dependent. Both plant and soil microbial diversity have been reported to regulate ecosystem multifunctionality, but how their relative importance varies along environmental gradients remains poorly understood. Here, we relate plant and microbial diversity to soil multifunctionality across 130 dryland sites along a 4,000 km aridity gradient in northern China. Our results show a strong positive association between plant species richness and soil multifunctionality in less arid regions, whereas microbial diversity, in particular of fungi, is positively associated with multifunctionality in more arid regions. This shift in the relationships between plant or microbial diversity and soil multifunctionality occur at an aridity level of ∼0.8, the boundary between semiarid and arid climates, which is predicted to advance geographically ∼28% by the end of the current century. Our study highlights that biodiversity loss of plants and soil microorganisms may have especially strong consequences under low and high aridity conditions, respectively, which calls for climate-specific biodiversity conservation strategies to mitigate the effects of aridification

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Traveling waves for two SIV models

The existence of traveling waves is established for a diffusive SIV system with constant total population. The approach used is the geometric singular perturbation method. The same result is suitable to another SIV system with exponential input

Investigation into Micro-Polishing Photonic Crystal Fibers for Surface Plasmon Resonance Sensing

In this work, we propose and demonstrate a micro-polishing-fiber (MPF)-based surface plasmon resonance (SPR) sensor. The structure of the sensor is simple and consists of three layers of regular air holes and two small air holes. The sensitivity seldom depends on the sizes of the air holes, which leads to a sensor with high structure tolerance. A tiny polishing depth ensures the mechanical strength of the polished fiber. There are three decisive factors for mass production and application of the sensor. A thin layer of indium tin oxide (ITO) film is applied to the polished surface to excite plasmonic interactions and facilitate refractive index (RI) detection. The SPR sensor is designed and analyzed by the finite element method (FEM), and optimized in terms of the air holes&rsquo; diameter, the ITO film thickness, and the core-to-surface interval. In the wide detection range between 1.32 and 1.39, the wavelength sensitivity can reach up to 11,600 nm/RIU. The MPF&ndash;SPR sensor exhibits great potential in the fields of optics, biomedicine, and chemistry

Investigation into Micro-Polishing Photonic Crystal Fibers for Surface Plasmon Resonance Sensing

In this work, we propose and demonstrate a micro-polishing-fiber (MPF)-based surface plasmon resonance (SPR) sensor. The structure of the sensor is simple and consists of three layers of regular air holes and two small air holes. The sensitivity seldom depends on the sizes of the air holes, which leads to a sensor with high structure tolerance. A tiny polishing depth ensures the mechanical strength of the polished fiber. There are three decisive factors for mass production and application of the sensor. A thin layer of indium tin oxide (ITO) film is applied to the polished surface to excite plasmonic interactions and facilitate refractive index (RI) detection. The SPR sensor is designed and analyzed by the finite element method (FEM), and optimized in terms of the air holes’ diameter, the ITO film thickness, and the core-to-surface interval. In the wide detection range between 1.32 and 1.39, the wavelength sensitivity can reach up to 11,600 nm/RIU. The MPF–SPR sensor exhibits great potential in the fields of optics, biomedicine, and chemistry

Beam Tailoring Devices Using Transmission-Type Subwavelength Grating

Subwavelength gratings (SWGs) possess an excellent ability to manipulate the wavefronts of light waves. We investigated the beam tailoring mechanism of aperiodic SWGs in our current work, and a bifocal lens, a beam splitter, and a beam combiner based on transmission-type one-dimensional SWGs are presented and simulated here. By designing grating nanobar parameters to meet the predetermined phase shift profile of the diffraction light, desired beam steering is accurately achieved for the three devices while maintaining high transmissivity. All the simulated results show good agreement with the theoretical predictions

Temperature Sensing Utilizing Stimulate Brillouin Scattering Fast Light in Liquid-Filled Photonic Crystal Fibers

A novel temperature sensor designed on stimulate Brillouin scattering fast light in liquid-filled photonic crystal fibers is proposed. The time advancement and the Brillouin frequency shift of fast light are simulated according to the three-wave coupling equations of stimulate Brillouin scattering, and the temperature sensing characteristics of the fast light in liquid-filled hexagonal photonic crystal fibers with three different air filling factors are simulated from 20 &deg;C to 70 &deg;C by using the full-vector finite element method. The alcohol-filled photonic crystal fibers exhibit rather sensitive responses to temperature. With temperature varying from 20 &deg;C to 70 &deg;C, the variation of the effective mode area is 2.75 &micro;m at the air filling factor of 0.6, the Brillouin frequency shift is about 11 GHz and its average modification is 1.15 MHz. The time advancement increases with the rise of temperature, its increment can reach up to 4.53 ns at the air filling factor of 0.6 and the pump power of 60 mW, the temperature sensitivity of the time advancement is 0.272 ns/&deg;C

Quantitative proteomics analysis of proteins involved in alkane uptake comparing the profiling of <i>Pseudomonas aeruginosa</i> SJTD-1 in response to n-octadecane and n-hexadecane

<div><p>While many data are available on genes encoding proteins for degradation of hydrocarbons in bacteria, the impact of alkane on transporter protein expression is unclear. <i>Pseudomonas aeruginosa</i> SJTD-1 is a strain that can consume medium- and long-chain n-alkanes. In order to study the proteins involved in n-octadecane uptake, we use iTRAQ and label free comparative proteomics analysis to identify the proteins of alkane uptake in response to n-octadecane (C18) comparing with n-hexadecane (C16) in <i>P</i>. <i>aeruginosa</i> SJTD-1. A total of 1102 and 1249 proteins were identified by iTRAQ-based and label free quantitative methodologies, respectively. By application of 1.5 (iTRAQ) or 2-fold (label free) for upregulated and 0.65 (iTRAQ) or 0.5-fold (label free) for downregulated cutoff values, 91 and 99 proteins were found to be differentially expressed comparing SJTD-1 cultivated on C18 with C16 respectively. There are six proteins with the common differential expression by iTRAQ and label free-based methods. Results of bioinformational analysis suggested the involvement of bacterial chemotaxis in responds to C18. Additionally, quantitative reverse transcriptase PCR (qRT-PCR) results confirmed C18-induced change in levels of FleQ, FliC, NirS, FadL and FadD proteins and the role of the proteins in n-octadecane uptake was further discussed in <i>P</i>. <i>aeruginosa</i>. In conclusion, results of the present study provided information about possible target-related proteins of bacterial chemotaxis, swimming performance, alkane transport to stimulus of n-ctadecane rather than n-hexadecane in <i>P</i>. <i>aeruginosa</i> SJTD-1.</p></div