scholarly journals Biodiversity Hotspots for Conservation of Hancornia speciosa GOMES

2021 ◽  
Author(s):  
Sheila Valéria Álvares-Carvalho ◽  
Thiago Roberto Soares Vieira ◽  
Bruno Antonio Lemos de Freitas ◽  
Erica Moraes Santos de Souza ◽  
Laura Jane Gomes ◽  
...  
Keyword(s):  
Potential Distribution ◽  
Maximum Entropy Method ◽  
Natural Populations ◽  
Distribution Patterns ◽  
Entropy Method ◽  
Biodiversity Hotspots ◽  
Variable Environments ◽  
Hancornia Speciosa ◽  
Priority Populations ◽  
Issr Molecular Markers

Abstract Hancornia speciosa is the target of research on genetic diversity, ethnobotanical and medicinal studies. However, information on the genetic variability of populations associated with modeling the potential distribution in the state of Sergipe has not yet been performed. The objective of this study was to predict the potential occurrence of H. speciosa in areas of high use of their fruits. The maximum entropy method was used to detect the distribution patterns of H. speciosa in variable environments. The diversity of four natural populations, situated in areas of extractivist, was determined by ISSR molecular markers. The species occurs more densely in the coastal regions of Sergipe. The prediction of occurrence indicates that the species reduces areas of occurrence, mainly due to anthropic actions. It is suggested that the species needs public policies aimed at its conservation and the priority populations for conservation.

Enhanced Information Recovery in 2D On-and Off-Resonance Nutation NQR using the Maximum Entropy Method

1996 ◽  
Vol 51 (5-6) ◽  
pp. 337-347 ◽  
Author(s):  
Mariusz Maćkowiak ◽  
Piotr Kątowski
Keyword(s):  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Theoretical Description ◽  
Entropy Method ◽  
Zero Field ◽  
Resonance Effects ◽  
Information Recovery ◽  
Truncation Errors ◽  
Enhanced Resolution ◽  
2D Data

Abstract Two-dimensional zero-field nutation NQR spectroscopy has been used to determine the full quadrupolar tensor of spin - 3/2 nuclei in serveral molecular crystals containing the 3 5 Cl and 7 5 As nuclei. The problems of reconstructing 2D-nutation NQR spectra using conventional methods and the advantages of using implementation of the maximum entropy method (MEM) are analyzed. It is shown that the replacement of conventional Fourier transform by an alternative data processing by MEM in 2D NQR spectroscopy leads to sensitivity improvement, reduction of instrumental artefacts and truncation errors, shortened data acquisition times and suppression of noise, while at the same time increasing the resolution. The effects of off-resonance irradiation in nutation experiments are demonstrated both experimentally and theoretically. It is shown that off-resonance nutation spectroscopy is a useful extension of the conventional on-resonance experiments, thus facilitating the determination of asymmetry parameters in multiple spectrum. The theoretical description of the off-resonance effects in 2D nutation NQR spectroscopy is given, and general exact formulas for the asymmetry parameter are obtained. In off-resonance conditions, the resolution of the nutation NQR spectrum decreases with the spectrometer offset. However, an enhanced resolution can be achieved by using the maximum entropy method in 2D-data reconstruction.

Estimating the distribution of primary reflection coefficients

Geophysics ◽  
2003 ◽  
Vol 68 (4) ◽  
pp. 1417-1422 ◽  
Author(s):  
Danilo R. Velis
Keyword(s):  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Entropy Method ◽  
Reflection Coefficients ◽  
Log Data ◽  
Neuquen Basin ◽  
Neuquén Basin ◽  
Skewness And Kurtosis

The distribution of primary reflection coefficients can be estimated by means of the maximum entropy method, giving rise to smooth nonparametric functions which are consistent with the data. Instead of using classical moments (e.g. skewness and kurtosis) to constraint the maximization, nonconventional sample statistics help to improve the quality of the estimates. Results using real log data from various wells located in the Neuquen Basin (Argentina) show the effectiveness of the method to estimate both robust and consistent distributions that may be used to simulate realistic sequences.

ISLAND-SIZE DISTRIBUTIONS OF Ag ON Pd(111)

1996 ◽  
Vol 03 (03) ◽  
pp. 1393-1402 ◽  
Author(s):  
R. FISCHER ◽  
TH. FAUSTER ◽  
W. VON DER LINDEN ◽  
V. DOSE
Keyword(s):  
Maximum Entropy Method ◽  
Entropy Method ◽  
Bayesian Probability ◽  
Magic Numbers ◽  
Size Distributions ◽  
Island Size ◽  
Two Phase ◽  
Two Photon ◽  
Small Clusters ◽  
Image State

Island-size distributions of submonolayer Ag films on Pd(111) adsorbed at 90 K and after annealing of the film are recovered from two-photon photoemission spectra of the first image state. The inversion of the ill-conditioned problem with the maximum-entropy method reveals magic numbers in the island-size distributions. Hypothesis testing within the framework of Bayesian probability theory indicates a critical nucleus size i=1. After annealing of the film large islands coexist with small clusters in a two-phase state.

Maximum entropy method in phase-encoding NMR imaging

1987 ◽  
Vol 4 (1) ◽  
pp. 78-82 ◽  
Author(s):  
B. C. De Simone ◽  
F. De Luca ◽  
B. Maraviglia
Keyword(s):  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Entropy Method ◽  
Nmr Imaging ◽  
Phase Encoding
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