Inverse altitude effect disputes the theoretical foundation of stable isotope paleoaltimetry

Stable isotope paleoaltimetry that reconstructs paleoelevation requires stable isotope (δD or δ18O) values to follow the altitude effect. Some studies found that the δD or δ18O values of surface isotopic carriers in some regions increase with increasing altitude, which is defined as an “inverse altitude effect” (IAE). The IAE directly contradicts the basic theory of stable isotope paleoaltimetry. However, the causes of the IAE remain unclear. Here, we explore the mechanisms of the IAE from an atmospheric circulation perspective using δD in water vapor on a global scale. We find that two processes cause the IAE: (1) the supply of moisture with higher isotopic values from distant source regions, and (2) intense lateral mixing between the lower and mid-troposphere along the moisture transport pathway. Therefore, we caution that the influences of those two processes need careful consideration for different mountain uplift stages before using stable isotope palaeoaltimetry

Effect of Pomegranate Juice on Dextran Sulfate Sodium Salt-Induced Ulcerative Colitis in Mice

Ulcerative colitis is a chronic inflammatory bowel disease with unclear pathogenesis and is difficult to cure. The incidence rate is increasing year by year, and there is high drug dependence for the treatment of ulcerative colitis, which leads to obvious the treatment resistance to s side effects. Therefore, seeking natural health products for nutritional therapy has become an attention focus of attention. In this articlestudy, dextran sulfate sodium salt (DSS) was used to establish a mouse model of ulcerative colitis. The mice were intervened with 5-aminosalicylic acid (5-ASA) (130 mg/(kg mb∙d)) or pomegranate juice (30% and 100%, 10 mL/d). Body mass, disease activity index (DAI) and colon length were measured, liver and kidney function and oxidative stress were measured by biochemical kits, the levels of inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA), colon tissue sections were observed, and the contents of fecal short-chain fatty acids (SCFAs) were determined by gas chromatography-mass spectrometry (GC-MS). Finally, a comprehensive evaluation of the effect and mechanism of pomegranate juice against ulcerative colitis in mice was exploredperformed. Compared with the DSS group, body mass and colon length in the pomegranate juice intervention group was increased, DAI was decreased, liver and kidney functions were improved, and could the expression of proinflammatory factors was significantly decreased (P < 0.01). In addition, anti-inflammatory factor expression was significantly enhanced (P < 0.01), reduce the level of oxidative stress and the activity of inflammatory marker myeloperoxidase (MPO) were significantly reduced (P < 0.01), the level of up-regulate fecal SCFAs was up-regulated, andimprove the colonic epithelial structure was improved. Pomegranate juice can attenuate intestinal mucosal damage and liver and kidney dysfunction, and has a good therapeutic effect on DSS-induced ulcerative colitis in mice

Do 2H and 18O in leaf water reflect environmental drivers differently?

We compiled hydrogen and oxygen stable isotope compositions (δ H and δ O) of leaf water from multiple biomes to examine variations with environmental drivers. Leaf water δ H was more closely correlated with δ H of xylem water or atmospheric vapour, whereas leaf water δ O was more closely correlated with air relative humidity. This resulted from the larger proportional range for δ H of meteoric waters relative to the extent of leaf water evaporative enrichment compared with δ O. We next expressed leaf water as isotopic enrichment above xylem water (Δ H and Δ O) to remove the impact of xylem water isotopic variation. For Δ H, leaf water still correlated with atmospheric vapour, whereas Δ O showed no such correlation. This was explained by covariance between air relative humidity and the Δ O of atmospheric vapour. This is consistent with a previously observed diurnal correlation between air relative humidity and the deuterium excess of atmospheric vapour across a range of ecosystems. We conclude that H and O in leaf water do indeed reflect the balance of environmental drivers differently; our results have implications for understanding isotopic effects associated with water cycling in terrestrial ecosystems and for inferring environmental change from isotopic biomarkers that act as proxies for leaf water

Direct and indirect effects of climate on richness drive the latitudinal diversity gradient in forest trees

Data accessibility statement: Full census data are available upon reasonable request from the ForestGEO data portal, http://ctfs.si.edu/datarequest/ We thank Margie Mayfield, three anonymous reviewers and Jacob Weiner for constructive comments on the manuscript. This study was financially supported by the National Key R&D Program of China (2017YFC0506100), the National Natural Science Foundation of China (31622014 and 31570426), and the Fundamental Research Funds for the Central Universities (17lgzd24) to CC. XW was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB3103). DS was supported by the Czech Science Foundation (grant no. 16-26369S). Yves Rosseel provided us valuable suggestions on using the lavaan package conducting SEM analyses. Funding and citation information for each forest plot is available in the Supplementary Information Text 1.Peer reviewedPostprin

Switchgrass (Panicum virgatum L.) polyubiquitin gene (PvUbi1 and PvUbi2) promoters for use in plant transformation

<p>Abstract</p> <p>Background</p> <p>The ubiquitin protein is present in all eukaryotic cells and promoters from ubiquitin genes are good candidates to regulate the constitutive expression of transgenes in plants. Therefore, two switchgrass (<it>Panicum virgatum </it>L.) ubiquitin genes (<it>PvUbi1 </it>and <it>PvUbi2</it>) were cloned and characterized. Reporter constructs were produced containing the isolated 5' upstream regulatory regions of the coding sequences (i.e. <it>PvUbi1 </it>and <it>PvUbi2 </it>promoters) fused to the <it>uidA </it>coding region (<it>GUS</it>) and tested for transient and stable expression in a variety of plant species and tissues.</p> <p>Results</p> <p><it>PvUbi1 </it>consists of 607 bp containing <it>cis</it>-acting regulatory elements, a 5' untranslated region (UTR) containing a 93 bp non-coding exon and a 1291 bp intron, and a 918 bp open reading frame (ORF) that encodes four tandem, head -to-tail ubiquitin monomer repeats followed by a 191 bp 3' UTR. <it>PvUbi2 </it>consists of 692 bp containing <it>cis</it>-acting regulatory elements, a 5' UTR containing a 97 bp non-coding exon and a 1072 bp intron, a 1146 bp ORF that encodes five tandem ubiquitin monomer repeats and a 183 bp 3' UTR. <it>PvUbi1 </it>and <it>PvUbi2 </it>were expressed in all examined switchgrass tissues as measured by qRT-PCR. Using biolistic bombardment, <it>PvUbi1 </it>and <it>PvUbi2 </it>promoters showed strong expression in switchgrass and rice callus, equaling or surpassing the expression levels of the CaMV <it>35S, 2x35S, ZmUbi1</it>, and <it>OsAct1 </it>promoters. GUS staining following stable transformation in rice demonstrated that the <it>PvUbi1 </it>and <it>PvUbi2 </it>promoters drove expression in all examined tissues. When stably transformed into tobacco (<it>Nicotiana tabacum</it>), the <it>PvUbi2+3 </it>and <it>PvUbi2+9 </it>promoter fusion variants showed expression in vascular and reproductive tissues.</p> <p>Conclusions</p> <p>The <it>PvUbi1 </it>and <it>PvUbi2 </it>promoters drive expression in switchgrass, rice and tobacco and are strong constitutive promoter candidates that will be useful in genetic transformation of monocots and dicots.</p

Estimation on solutions of a class of generalized nonlinear Volterra-Fredholm type integral inequalities with applications

We establish a class of new nonlinear retarded Volterra-Fredholm type integral inequalities, where a known function σ1(s) in integral functions in [Ma, QH, Peˇcari´c, J: Estimates on solutions of some new nonlinear retarded Volterra-Fredholm type integral inequalities. Nonlinear Anal. 69(2008) 393-407] is changed into the function w(u(s))f(s), where w(u(s)) is the composite function of the unknown function u(s) and a nonlinear function w(u). By adopting novel analysis techniques, such as: change of variable, amplification method, differential and integration, inverse function, and the dialectical relationship between constants and variables, the upper bounds of the embedded unknown functions are estimated explicitly. The derived results can be applied in the study of solutions of a class of integral equations

Dynamic Ontologies and Semantic Web Rules as Bigraphical Reactive Systems

We show how a subpart of OWL ontologies and Semantic Web Rule Language (SWRL) rules can be represented as bigraphs and bigraphical reaction rules. While OWL allows for defining a static ontology and SWRL allows for inferring and adding more information to an ontology, we show that the bigraphical representation of ontologies and rules naturally allows for more general dynamic changes and modification of ontologies. We describe how the representation is implemented in BigRED, a recently developed Eclipse-based bigraphical editing tool allowing to simulate and perform state exploration in the defined systems using the BigMC bigraph model checker which is integrated in the BigRED editor. We discuss the potential uses of the approach for model-driven design and analysis of context-aware systems, and propose a first naive method to deal with the frame and ramification problems in the bigraphical ontology.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000345645600008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Information SystemsComputer Science, Software EngineeringComputer Science, Theory &amp; MethodsEICPCI-S(ISTP)

Understanding the Determinants of Structural Change in World Food Markets

This study assesses the interaction between climate change and agricultural trade policies. We distinguish between two dimensions of agricultural trade policy: market insulation and subsidy levels. Building on the previous work of Tsigas, Frisvold and Kuhn (1997) we find that, in the presence of current levels of agricultural subsidies, increased price transmission --as called for under the Uruguay Round Agreement on Agriculture-- reduces global welfare in the wake of climate change. This is due to the positive correlation between productivity changes and current levels of agricultural support. Increases in subsidized output under climate change tend to exacerbate inefficiencies in the global agricultural economy in the absence of market insulation. However, once agricultural subsidies have also been eliminated, price transmission via the global trading system contributes positively to economic adaptation under climate change. products. This may partially explain the relatively slow growth of world grain import demand in recent years. In addition, bilateral agreements with East Asia, NAFTA, and the evolution of the CAP, have all had important impacts on the structure of world food and agricultural trade. The objective of this paper is to assess the relative role of each of the major forces-- consumer demand, factor accumulation, transport costs, and policy change--in driving changes in the composition of world food trade in 1980-1995. To do so, we employ a modified version of the Global Trade Analysis Project (GTAP) model of world trade which permits us to isolate the contribution of each of these related factors to the changing composition of world food trade in a general equilibrium context. We evaluate the relative role of each of these factors by simulating the model backwards in time, from 1995 to 1980 under different assumptions. This general approach, termed “backcasting” (i.e. backwards forecasting), takes as exogenous the basic drivers of change and attempts to explain the resulting change in food trade composition. The model-produced changes in the composition of agricultural and food trade are compared with historical trade data, to determine the relative importance of each factor on the changing composition of food trade. Given limited space, our focus will be on explaining the changes in the global composition of food and agriculture trade. A natural follow-on effort would target specific markets in more detail. This type of backcasting approach was first employed by Gehlhar (1997) who sought to explain the shift in exports of primary commodities to manufactures in East Asia in the 1980\u27s. He calibrated the GTAP model to 1992 data, then implemented shocks to factor endowments and economywide total factor productivity (TFP) in order to force each economy back to its 1982 levels of population, land, labor, human capital, physical capital and technology. By comparing actual and predicted changes in export shares in this period, he found human capital accumulation played a key role in explaining the change in the aggregate composition of East Asian exports. Gehlhar, Hertel and Martin (1994) built on this work in an effort to predict future changes in the pattern of agricultural trade from 1992-2002. They also emphasized the importance of supply-side determinants of agricultural trade. In this paper, we go beyond this earlier work in a number of ways. First, we focus on the composition of agricultural exports, rather than simply looking at the share of agriculture in total trade. Secondly, we incorporate the Cranfield et al. estimates of Rimmer and Powell’s recently developed, implicitly directly additive demand system (nicknamed AIDADS) into the GTAP model. This permits us to better capture the impact of demand-side changes on the pattern of global trade. Thirdly, we incorporate new and imroved estimates of the factor shares driving the supply side of the story. Finally, we bring in estimates of historical changes in the costs of trading, due either to changes in protection or innovation in global shipping

2000: Collision efficiencies of ice crystals at low-intermediate Reynolds numbers colliding with supercooled cloud droplets: A numerical study

ABSTRACT The efficiencies with which ice crystals at low-intermediate Reynolds numbers collide with supercooled cloud droplets are determined numerically. Three ice crystal habits are considered here: hexagonal ice plates, broadbranch crystals, and columnar ice crystals. Their Reynolds numbers range from 0.1 to slightly beyond 100. The size of cloud droplets range from a few to about 100 m in radius. The collision efficiencies are determined by solving the equation of motion for a cloud droplet under the influence of the flow field of the falling ice crystal. The flow fields of the falling ice crystals were determined previously by numerically solving the unsteady Navier-Stokes equations. Features of these efficiencies are discussed. The computed efficiencies are compared with those obtained by previous investigators and improvements are indicated. New results fit better with the observed riming droplet sizes and cutoff riming ice crystal sizes

A Temperature and Emissivity Separation Algorithm for Landsat-8 Thermal Infrared Sensor Data

On-board the Landsat-8 satellite, the Thermal Infrared Sensor (TIRS), which has two adjacent thermal channels centered roughly at 10.9 and 12.0 μm, has a great benefit for the land surface temperature (LST) retrieval. The single-channel algorithm (SC) and split-window algorithm (SW) have been applied to retrieve the LST from TIRS data, which need the land surface emissivity (LSE) as prior knowledge. Due to the big challenge of determining the LSE, this study develops a temperature and emissivity separation algorithm which can simultaneously retrieve the LST and LSE. Based on the laboratory emissivity spectrum data, the minimum-maximum emissivity difference module (MMD module) for TIRS data is developed. Then, an emissivity log difference method (ELD method) is developed to maintain the emissivity spectrum shape in the iterative process, which is based on the modified Wien’s approximation. Simulation results show that the root-mean-square-errors (RMSEs) are below 0.7 K for the LST and below 0.015 for the LSE. Based on the SURFRAD ground measurements, further evaluation demonstrates that the average absolute error of the LST is about 1.7 K, which indicated that the algorithm is capable of retrieving the LST and LSE simultaneously from TIRS data with fairly good results