Characterization of the Ichthyological Population of Hydrosystèmes in the Lagoon Area of the Azagny National Park (Ivory Coast)

The conservation of protected areas is nowadays one of the concerns of international and national institutions. This study aims to contribute to better conservation of the ichthyological fauna of the lagoon area of the Azagny National Park (PNA). This national park has been dealing with the harmful effects of human activities for years. Thus, from March 2019 to February 2020, sampling campaigns were carried out to characterize this space, for better conservation. The results obtained are based on the analysis of abiotic and biotic (fish) data collected at 6 stations. The physicochemical parameters were measured using a multiparameter and the fish population collected using 10 gillnet batteries of 10, 25, 30, 35, 40 and 50 mm mesh void. The analysis of the ichthyological population of the lagoon area reveals a diversity of 53 species belonging to 30 families and 12 orders. 11 species were newly collected while 31 species previously recorded in these hydrosystems were not captured in the present study. The Shannon (H’> 2) and Equitability (E> 0.5) indices calculated reflect a good organization and stability of the ichthyological population of the hydrosystems of the PNA lagoon zone. The Monte-Carlo test indicates that the variables rate of nitrate, width, rate of dissolved oxygen, water temperature, alkalinity, salinity, rate of dissolved solid and phosphorus are those which discriminate specific richness, abundance and the distribution of the stand.

Monte Carlo Test for Stochastic Trend in Space State Models for the Location-Scale Family

In space state models for time series, a key point is the decision between modeling the trend of non-stationary processes through a deterministic or a stochastic term. The present paper introduces a Monte Carlo hypothesis test procedure to guide in such a decision. The method works for any time series distribution belonging to the location-scale family. The proposed method provides an alpha-level test for any time series of length greater than 3 and it does not demand assumptions on the distribution of the trend term when it is actually stochastic.

Geochemical Variability of Surface Sediment in Post-Mining Lakes Located in the Muskau Arch (Poland) and Its Relation to Water Chemistry

Water and sediment chemical compositions were investigated in 75 post-mining lakes in the eastern part of the Muskau Arch region (Western Poland, Central Europe). The lakes, originating from lignite and clay surfaces and underground mining activity, exhibited a wide gradient of physical and chemical water parameters. The most pronounced variability in water parameters was observed in pH values, conductivity, and oxygen concentration in the mixolimnion and monimolimnion. In addition, the lakes varied in terms of their trophic status, indicated by their dissolved organic carbon (DOC) and phosphorous concentrations. In general, lakes with higher pH values had higher trophic states, and some even exhibited hypertrophic conditions. The Monte Carlo test indicated that the water pH, phosphorus, DOC, and silicon concentrations could significantly explain the chemical characteristics of sediments.

Equilibrio competitivo en Liga española de futbol de Primera División: Un test de Montecarlo basado en datos funcionales

The supremacy of a few teams over the other participants is a common factor in the major European football leagues. The Spanish First Division league is not an exception. In order to demonstrate this fact, functional data analysis is used to analyze football league classifications for last ten seasons, 2002-03 to 2011-12. Not only the use of these techniques distinguish this work from similar, another distinctive feature is the use of a non-uniform probability distribution on the three possible outcomes of a match, obtained from the results of the 3800 matches of the 10 seasons taking into account the difference between the categories of the teams in the match. A Monte Carlo test allows to test the hypotheses of uniformity and non-uniformity in the results.

Phytosociology in areas of the Brazilian Cerrado: Cerrado stricto sensu, municipality of Porto Nacional, State of Tocantins

Phytosociological studies are essential for the elaboration of conservation strategies for the Cerrado. The goal of this study was to survey two areas of cerrado stricto sensu: Fazenda Canaã and Fazenda Providência, located in the Municipality of Porto Nacional, State of Tocantins. There were 10 plots of 100 m2 allocated in each area. All individuals with circumference equal to or greater than 10 cm, at ground height ≥10 cm were sampled, soil samples were taken for physical-chemical analysis. Sampling in Canaã resulted in 379 individuals belonging to 28 families and 50 species. In Providência, there were 300 individuals from 27 families and 49 species. The Shannon-Wiener Index for the Canaã was 3.48 and for Providência, 3.45. The studied areas presented a large number of small sized individuals, presenting a reverse J-shaped diameter structure. The Canonical Correspondence Analysis showed significant scores for the first axes (p < 0.05) according to the Monte Carlo test, which explained 70% total variability of the data. The variables with the highest structure coefficient in axis 1 were clay (0.94), pH (0.62) and magnesium (-0.32). On axis 2, the most important variables were aluminum (0.29), silt (0.25) and potassium (-0.078). These soil variables show a differentiation of the study areas.

Aridity Trends in Central America: A Spatial Correlation Analysis

Trend analyses are common in several types of climate change studies. In many cases, finding evidence that the trends are different from zero in hydroclimate variables is of particular interest. However, when estimating the confidence interval of a set of hydroclimate stations or gridded data the spatial correlation between can affect the significance assessment using for example traditional non-parametric and parametric methods. For this reason, Monte Carlo simulations are needed in order to generate maps of corrected trend significance. In this article, we determined the significance of trends in aridity, modeled runoff using the Variable Infiltration Capacity Macroscale Hydrological model, Hagreaves potential evapotranspiration (PET) and near-surface temperature in Central America. Linear-regression models were fitted considering that the predictor variable is the time variable (years from 1970 to 1999) and predictand variable corresponds to each of the previously mentioned hydroclimate variables. In order to establish if the temporal trends were significantly different from zero, a Mann Kendall and a Monte Carlo test were used. The spatial correlation was calculated first to correct the variance of each trend. It was assumed in this case that the trends form a spatial stochastic process that can be modeled as such. Results show that the analysis considering the spatial correlation proposed here can be used for identifying those extreme trends. However, a set of variables with strong spatial correlation such as temperature can have robust and widespread significant trends assuming independence, but the vast majority of the stations can still fail the Monte Carlo test. We must be vigilant of the statistically robust changes in key primary parameters such as temperature and precipitation, which are the driving sources of hydrological alterations that may affect social and environmental systems in the future.

ENSO Frequency Asymmetry and the Pacific Decadal Oscillation in Observations and 19 CMIP5 Models

&lt;p&gt;Using observational data and the pre-industrial simulations of 19 models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), the El Ni&amp;#241;o (EN) and La Ni&amp;#241;a (LN) events in positive and negative Pacific Decadal Oscillation (PDO) phases are examined. In the observational data, with EN (LN) events the positive (negative) SST anomaly in the equatorial eastern Pacific is much stronger in positive (negative) PDO phases than in negative (positive) phases. Meanwhile, the models cannot reasonably reproduce this difference. Besides, the modulation of ENSO frequency asymmetry by the PDO is explored. Results show that, in the observational data, EN is 300% more (58% less) frequent than LN in positive (negative) PDO phases, which is significant at the 99% confidence level using the Monte Carlo test. Most of the CMIP5 models exhibit results that are consistent with the observational data.&lt;/p&gt;

Monte Carlo test-particle model of Mercury's ionized exosphere: Global structure and dynamics

&lt;div&gt;The Mercury plasma environment is enriched in heavy ions (mass-per-charge ratio m/q &gt; 4) from photo-ionization of the tenuous exosphere. The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) time-of-flight spectrometer Fast Imaging Plasma Spectrometer (FIPS) has detected many planetary ion species of which He&lt;sup&gt;+&lt;/sup&gt;, the Na&lt;sup&gt;+&lt;/sup&gt;-group (including Na&lt;sup&gt;+&lt;/sup&gt;, Mg&lt;sup&gt;+&lt;/sup&gt; and Si&lt;sup&gt;+&lt;/sup&gt;) and the O&lt;sup&gt;+&lt;/sup&gt;-group (including O&lt;sup&gt;+&lt;/sup&gt; and several water group ions) are the most abundant. The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) UltraViolet and Visible Spectrometer (UVVS) has also detected Ca&lt;sup&gt;+&lt;/sup&gt; ions in the nightside plasma sheet. Models of the planetary ion distribution inside Mercury's magnetosphere have mostly concentrated on the abundant Na&lt;sup&gt;+&lt;/sup&gt; and H&lt;sup&gt;+&lt;/sup&gt; ion populations. Comparison with FIPS data has been limited to the first two MESSENGER flybys and no comparison has been made with MASCS/UVVS observations.&lt;/div&gt;&lt;div&gt;&amp;#160;&lt;/div&gt;&lt;div&gt;We have developed a Monte Carlo test-particle model which describes the ion density distribution produced from photo-ionization of several neutral species in Mercury's exosphere. The global ion density and energy distribution of Ca&lt;sup&gt;+&lt;/sup&gt;, Mg&lt;sup&gt;+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, O&lt;sup&gt;+&lt;/sup&gt; and He&lt;sup&gt;+&lt;/sup&gt; will be presented here. We will review the influence of the interplanetary magnetic field (IMF) B&lt;sub&gt;x&lt;/sub&gt; and B&lt;sub&gt;y&lt;/sub&gt;&amp;#160;components on the global structure of the ion density distribution, the composition of the nightside plasma sheet and the evolution of the Na&lt;sup&gt;+&lt;/sup&gt; ion density along the Mercury year.&lt;/div&gt;