Species associations of congeneric species in a tropical seasonal rain forest of China

2016 ◽  
Vol 32 (3) ◽  
pp. 201-212 ◽  
Author(s):  
Guoyu Lan ◽  
Yunbing Zhang ◽  
Fangliang He ◽  
Yuehua Hu ◽  
Hua Zhu ◽  
...  
Keyword(s):  
Species Interactions ◽  
Rain Forest ◽  
Biotic Interactions ◽  
Second Order ◽  
Small Scale ◽  
Order Effects ◽  
Congeneric Species ◽  
First Order ◽  
Large Trees ◽  
Tropical Seasonal Rain Forest

Abstract:In tropical plant communities with diverse species, many congeners are found to coexist. Do environment or biotic interactions structure the coexistence of congeners in tropical forest communities? In this paper, we aimed to disentangle the effect of environment (first-order effects) and species interactions (second-order effects) on the spatial distributions of tree species. We used a classification scheme and torus-translation to test the first-order interaction of 48 species from 17 genera in a fully mapped 20-ha dipterocarp tropical seasonal rain-forest plot in Xishuangbanna, south-west China. Then we used heterogeneous Poisson null models to reveal significant uni- and bivariate second-order interactions. The results demonstrated that (1) 34 of the 48 studied species showed a significant relation with at least one topographic variable. This confirmed that topographical heterogeneity is important for distribution of these congeners. Spatial segregation (36.6%) and partial overlap (34.8%) were the most common bivariate association types in Xishuangbanna plot, which indicated first-order effects (environment) were strong. (2) For small-scale associations, 51% saplings (1 to ≤ 5 cm) (68.8% for large trees with dbh > 5 cm) of the species showed non-significant associations. For large-scale associations, 61.6% saplings (81.2% for large trees) of the species showed non-significant associations. Lack of significant species interactions provides evidence for the unified neutral theory. In conclusion, both environment and biotic interactions structure congeneric species' coexistence in tropical seasonal rain forest in this region.

scholarly journals Statistical analysis of second order effects variation with the stories height of reinforced concrete buildings

2017 ◽  
Vol 10 (2) ◽  
pp. 333-357
Author(s):  
D.M. OLIVEIRA ◽  
N.A. SILVA ◽  
C.C. RIBEIRO ◽  
S.E.C. RIBEIRO
Keyword(s):  
Reinforced Concrete ◽  
Statistical Analysis ◽  
Second Order ◽  
Order Effects ◽  
Reinforced Concrete Buildings ◽  
First Order ◽  
Concrete Buildings ◽  
Ideal Situation ◽  
Second Order Effects ◽  
The Ideal

Abstract In this paper the simplified method to evaluate final efforts using γ z coefficient is studied considering the variation of the second order effects with the height of the buildings. With this purpose, several reinforced concrete buildings of medium height are analyzed in first and second order using ANSYS software. Initially, it was checked that the (z coefficient should be used as magnifier of first order moments to evaluate final second order moments. Therefore, the study is developed considering the relation (final second order moments/ first order moments), calculated for each story of the structures. This moments relation is called magnifier of first order moments, "γ", and, in the ideal situation, it must coincide with the γ z value. However, it is observed that the reason γ /γ z varies with the height of the buildings. Furthermore, using an statistical analysis, it was checked that γ /γ z relation is generally lower than 1.05 and varies significantly in accordance with the considered building and with the presence or not of symmetry in the structure.

The Politics of the Knowledge Economy and the Rise of Populism

2019 ◽  
pp. 216-255
Author(s):  
Torben Iversen ◽  
David Soskice
Keyword(s):  
Knowledge Economy ◽  
Second Order ◽  
Government Support ◽  
The Political ◽  
Order Effects ◽  
First Order ◽  
Policy Responses ◽  
The Poor ◽  
Political Conditions ◽  
Political Economic

This chapter considers the “second-order” effects of the transition to the knowledge economy. This means the set of preferences, beliefs, and party allegiances that are crystallizing as a consequence of the political-economic realities brought about by the knowledge economy. Chapter 3 considered “first-order” effects—immediate policy responses reflecting existing political coalitions—and showed that these responses were relatively limited and in most countries, failed to offer much compensation for those who lost out in the collapse of the Fordist economy. This chapter argues that this failure has created the political conditions for the rise of populism. Populism refers to a set of preferences and beliefs that rejects established parties and elites, that sees established politicians as gaming the system to their own advantage, and that at the same time sees the poor as undeserving of government support.

An Energy Method for Certain Second-Order Effects With Application to Torsion of Elastic Bars Under Tension

1980 ◽  
Vol 47 (1) ◽  
pp. 75-81 ◽  
Author(s):  
R. T. Shield
Keyword(s):  
Axial Force ◽  
Strain Energy Function ◽  
Incompressible Material ◽  
Elastic Cylinder ◽  
Second Order ◽  
The Other ◽  
Circular Cylinders ◽  
Order Effects ◽  
First Order ◽  
Wide Range

When a mechanical system has a potential energy, it is a simple matter to show that if the generalized force corresponding to a coordinate p is known to first order in p for a range of the other coordinates of the system, then the other generalized forces can be found immediately to second order in p, without requiring a second-order analysis of the system. By this method the second-order change in the axial force when a finitely extended elastic cylinder is twisted is found from the first-order value of the twisting moment. Numerical results for a realistic form of the strain-energy function for an incompressible material suggest that the second-order expression for the axial force is very accurate for a wide range of twist for circular cylinders of rubber-like materials extended 100 percent or more.

scholarly journals Application of multiplet structure deconvolution to extract scalar coupling constants from 1D NMR spectra

2021 ◽  
Author(s):  
Damien Jeannerat ◽  
Carlos Cobas
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Second Order ◽  
Coupling Constants ◽  
Scalar Coupling ◽  
Order Effects ◽  
Robust Method ◽  
Multiplet Structure ◽  
First Order ◽  
Coupling Structure

Abstract. Multiplet structure deconvolution provides a robust method to determine the values of the coupling constants in first-order 1D NMR spectra. Functions simplifying the coupling structure for any spins and for doublet with unequal amplitudes were introduced. The chemical shifts of the coupling partners causing mild second-order effects can, in favourable cases, be calculated from the slopes measured in doublet structures. Illustrations demonstrate that deconvolution can straightforwardly analyse multiplet posing difficulties to humans and, in some cases, extract coupling constants from unresolved multiplets.

An Experimental Study of Deviations from the Linear Transfer Function

1974 ◽  
Vol 32 ◽  
pp. 400-401
Author(s):  
William A. Voter ◽  
Harold P. Erickson
Keyword(s):  
Experimental Study ◽  
Image Formation ◽  
Order Theory ◽  
Second Order ◽  
Diffraction Spot ◽  
Order Effects ◽  
First Order ◽  
First Order Theory ◽  
Second Order Effects ◽  
The Fourier Transform

In a previous experimental study of image formation using a thin (20 nm) negatively stained catalase crystal, it was found that a linear or first order theory of image formation would explain almost entirely the changes in the Fourier transform of the image as a function of defocus. In this case it was concluded that the image is a valid picture of the object density. For thicker, higher contrast objects the first order theory may not be valid. Second order effects could generate false diffraction spots which would lead to spurious and artifactual image details. These second order effects would appear as deviations of the diffraction spot amplitudes from the first order theory. Small deviations were in fact noted in the study of the thin crystals, but there was insufficient data for a quantitative analysis.

Second Order Wave Loads on TLP-TAD Multi-Body System

2017 ◽  
Author(s):  
Miguel A. M. Ramirez ◽  
Antonio Carlos Fernandes
Keyword(s):  
Wave Amplitude ◽  
Natural Frequencies ◽  
Numerical Study ◽  
Direct Method ◽  
Second Order ◽  
Order Effects ◽  
Wave Loads ◽  
Body System ◽  
First Order ◽  
Multi Body

The motions of floating moored structures are affected by first order wave loads which are proportional to the wave amplitude and associated with the wave frequency. On the other hand, second order wave loads are proportional to the square of the wave amplitude and related to the sum or difference of a pair of frequencies of the irregular sea. Although the second order loads are usually smaller compared to the first order loads, these loads can excite resonance motions in frequencies that the system has very low damping. Therefore, second order wave loads have particular importance in the design of mooring systems. The multi-body system composed by Tension Leg Platform (TLP) and Tender Assisted Drilling (TAD) is particularly susceptible to the second order effects, due to the very low natural frequencies of their horizontal modes and the very high natural frequencies of the vertical modes of the TLP. This work presents a numerical study of second order wave loads on the TLP-TAD multi-body system. An extensive hydrodynamic analysis focus on the hydrodynamic interactions between the floaters and how these effects modify the second order loads on the platforms was performed. The second order quadratic transform functions (QTFs) were evaluated using the indirect and the direct method. Moreover, the importance of the free surface integral was checked. Finally, the accuracy of Newman approximation for the low-frequency QTF was evaluated.

Acoustofluidic Simulations: Ultrasound Handling of Liquids and Particles in Microfluidic Systems

2008 ◽  
Author(s):  
Peder Skafte-Pedersen ◽  
Henrik Bruus
Keyword(s):  
Acoustic Radiation ◽  
Acoustic Streaming ◽  
Radiation Force ◽  
Second Order ◽  
Order Effects ◽  
Perturbation Approach ◽  
First Order ◽  
At Resonance ◽  
Liquid Flows ◽  
Second Order Equations

Within the field of lab-on-a-chip systems large efforts are devoted to the development of onchip tools for particle handling and mixing in viscosity-dominated liquid flows on the sub-mm scale. One technology involves ultrasound with frequencies in the MHz range, which leads to wavelengths of the order of 0.1–1 mm suitable for mm-sized microchambers. Due to the nonlinearity of the governing acoustofluidic equations, second-order effects will induce steady forces on fluids and suspended particles through the effects known as acoustic streaming and acoustic radiation force. We extend the basic perturbation approach for treating these effects in systems at resonance in various geometries. The first-order eigenmodes are used as source terms for the time-averaged viscous second-order equations. The theory is applied to explain experimental results on aqueous microbead solutions in silicon-glass microchips.

scholarly journals Sources of Bias and Solutions to Bias in the Consumer Price Index

2003 ◽  
Vol 17 (1) ◽  
pp. 23-44 ◽  
Author(s):  
Jerry Hausman
Keyword(s):  
Price Index ◽  
Consumer Price Index ◽  
Second Order ◽  
Order Effects ◽  
Scanner Data ◽  
Cost Of Living ◽  
First Order ◽  
Consumer Prices ◽  
Substitution Bias ◽  
Cost Of Living Index

Four sources of bias in the Consumer Prices Index (CPI) have been identified. The most discussed is substitution bias, which creates a second order bias in the CPI. Three other changes besides prices changes create first order effects on a correctly measured cost of living index (COLI). I explain in this paper that a “pure price” based approach of surveying prices to estimate a COLI cannot succeed in solving the 3 problems of first order bias. I discuss economic and econometric approaches to measuring the first order bias effects as well as the availability of scanner data that would permit implementation of the techniques.

scholarly journals SECOND ORDER THEORY OF MANOMETER WAVE MEASUREMENT

1982 ◽  
Vol 1 (18) ◽  
pp. 8
Author(s):  
F. Biesel
Keyword(s):  
Gravity Wave ◽  
Wave Theory ◽  
Order Theory ◽  
Second Order ◽  
Order Effects ◽  
Mean Values ◽  
Surface Level ◽  
First Order ◽  
Wave Measurements ◽  
Wave Measurement

The paper refers to pressure gage wave measurements . First order transformation of the pressure spectrum into a surface level spectrum leads to hitherto unexplained discrepancies with prototype simultaneous pressure and level measurements . Use of second order gravity wave theory allows to draw the following conclusions » Second order effects appear to give a reasonable explanation of the observed discrepancies . A complete check would require specially made wave measurements and analyses . Second order corrections do not significantly affect mean values, such as significant height, if the manometer depth is not unduly large.

Sign in / Sign up

Export Citation Format

Share Document