Variation of Oriental Oak (Quercus variabilis) Leaf δ13C across Temperate and Subtropical China: Spatial Patterns and Sensitivity to Precipitation

The concentration of the carbon-13 isotope (leaf δ13C) in leaves is negatively correlated with the mean annual precipitation (MAP) atlarge geographical scales. In this paper, we explain the spatial pattern of leaf δ13C variation for deciduous oriental oak (Quercus variabilis Bl.) across temperate and subtropical biomes and its sensitivity to climate factors such as MAP. There was a 6‰ variation in the leaf δ13C values of oak with a significant positive correlation with latitude and negative correlations with the mean annual temperature (MAT) and MAP. There was no correlation between leaf δ13C and altitude or longitude. Stepwise multiple regression analyses showed that leaf δ13C decreased 0.3‰ per 100 mm increase in MAP. MAP alone could account for 68% of the observed variation in leaf δ13C. These results can be used to improve predictions for plant responses to climate change and particularly lower rainfall

Predator diversity and abundance provide little support for the enemies hypothesis in forests of high tree diversity

Peer reviewedPublisher PD

Roll reduction and course keeping for the ship moving in waves with factorized NGMV control

A factorized Nonlinear Generalized Minimum Variance (NGMV) control law is developed for a combined roll and yaw motion compensation using rudders and fins. The nonlinear model used for control design includes the non-minimum phase interaction from rudder to roll motion, and the dynamics from fins to yaw motion. This controller is developed using the polynomial approach to ensure that the non-minimum phase system remains stable in closed-loop. The effectiveness of the approach is demonstrated on a simulated nonlinear ship model

Alkaline protease production by solid state fermentation on polyurethane foam

This paper investigated the process of solid state fermentation (SSF) using PUF (polyurethane foam) as inert solid support to produce alkaline protease. Maximal enzyme activity was 2185U/ml at pH 9.0, incubation temperature 32 0C inoculum amount of 1.0 % (v/v) , nutrient solution3.75 ml/g PUF, incubation time for 2 h and 15.0 mM of added CaCl2. Under the same conditions, the yield of alkaline protease produced by SSF using PUF as support is higher than that by submerged fermentation (SMF)

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

Designing forest biodiversity experiments : general considerations illustrated by a new large experiment in subtropical China

Funded by German Research Foundation. Grant Number: DFG FOR 891/1 and 2 National Natural Science Foundation of China. Grant Numbers: NSFC 30710103907, 30930005, 31170457 , 31210103910 Swiss National Science Foundation (SNSF) Sino-German Centre for Research Promotion in BeijingPeer reviewedPublisher PD

Multiple Forms of Knowing in Mathematics: A Scoping Literature Study

We present a scoping review of published literature on ethnomathematics and Indigenous mathematics as a step towards a goal to decolonize the prevailing Eurocentric view of the provenance of mathematics. Mathematical practices were identified globally from 169 included studies. We map three development stages of ethnomathematical research from 1984 to 2023 and identify 20 categories of Indigenous and traditional cultural activities that evidence mathematical design and expression. We address two challenges of investigating non-Western based mathematics: where to look for mathematical knowledge, and how to decode it from cultural practices. These two hurdles are overcome by cluster analysis of the keywords of included studies. Existing research falls into two categories: I. identification of mathematical concepts used in Indigenous societies, and II. systematizing identified mathematical concepts. Both approaches are essential for research on Indigenous mathematics to flourish, in order to empower Indigenous knowledge holders and deconstruct restrictive colonial boundaries of mathematical knowledge and education

Clavulanic Acid Production by Streptomyces clavuligerus using Solid State Fermentation on Polyurethane Foam

Clavulanic acid (CA), a metabolite of Streptomyces clavuligerus, is a potent β-lactamase inhibitor. In this study, polyurethane foam (PUF) was used as inert solid support to produce clavulanic acid by solid state fermentation (SSF). Maximal CA yield of 263 µg/ml was obtained at pH 6.5, incubation temperature 29°C, 10 ml medium per 3 g PUF, 0.015% added glycerol, 2% added lithium chloride (LiCl), and 2 g/L added ornithine. Under the same conditions, the yield of CA produced by SSF on PUF is apparently higher than that by submerged fermentation (SMF). In addition, CA produced by using this method is of higher purity and easier to be extracted. Citation: Wang, H. and Chen, H. (2016). Clavulanic Acid Production by Streptomyces clavuligerus using Solid State Fermentation on Polyurethane Foam. Trends in Renewable Energy, 2(1), 2-12. DOI: 10.17737/tre.2016.2.1.001