In this paper we report a quantitative laser Biospeckle method using VDRL plates to monitor the activity of Trypanosoma cruzi and the calibration conditions including three image processing algorithms and three programs (ImageJ and two programs designed in this work). Benznidazole was used as a test drug. Variable volume (constant density) and variable density (constant volume) were used for the quantitative evaluation of parasite activity in calibrated wells of the VDRL plate. The desiccation process within the well was monitored as a function of volume and of the activity of the Biospeckle pattern of the parasites as well as the quantitative effect of the surface parasite quantity (proportion of the object’s plane). A statistical analysis was performed with ANOVA, Tukey post hoc and Descriptive Statistics using R and R Commander. Conditions of volume (100μl) and parasite density (2-4x104 parasites/well, in exponential growth phase), assay time (up to 204min), frame number (11 frames), algorithm and program (RCommander/SAGA) for image processing were selected to test the effect of variable concentrations of benznidazole (0.0195 to 20μg/mL / 0.075 to 76.8μM) at various times (1, 61, 128 and 204min) on the activity of the Biospeckle pattern. The flat wells of the VDRL plate were found to be suitable for the quantitative calibration of the activity of Trypanosoma cruzi using the appropriate algorithm and program. Under these conditions, benznidazole produces at 1min an instantaneous effect on the activity of the Biospeckle pattern of T. cruzi, which remains with a similar profile up to 1 hour. A second effect which is dependent on concentrations above 1.25μg/mL and is statistically different from the effect at lower concentrations causes a decrease in the activity of the Biospeckle pattern. This effect is better detected after 1 hour of drug action. This behavior may be explained by an instantaneous effect on a membrane protein of Trypanosoma cruzi that could mediate the translocation of benznidazole. At longer times the effect may possibly be explained by the required transformation of the pro-drug into the active drug.

Disease mapping seeks to represent the risk of a disease. This paper focuses on the spatial analysis of risk for pandemic COVID-19 in Europe and the Mediterranean. Morbidity and mortality data for 54 countries in ratio format were used. Two hypotheses were considered, the first one is that the data are homogeneous and the second one is that the ratios are defined in a heterogeneous manner requiring the stratification on the basis of covariables and the methodology of Jenks’ intervals. Spatial risk models were applied as well as methods for the representation of clusters. The results show that the best representation is obtained with the Poisson-Gamma Model under stratification. The variations in the ratios are due to the individual policies of each country for the management of the pandemic. The cluster analysis shows that there is a high mortality process in Eastern Europe. The behavior of the pandemic should be evaluated in the space-time process as well as in other heterogeneous and highly unequal regions.

Antibiotic susceptibility testing is a necessary step prior to the treatment of clinical infections. A major concern is the time required to obtain a fast and reliable result. The aim of this work is to use Biospeckle laser in a 15min assay for an antimicrobial susceptibility test of Ciprofloxacin in serial two-fold dilutions on Escherichia coli K-12 using Venereal Disease Research Laboratory (VDRL) plates. Analysis of images by video edition is performed on a quantitatively selected region of interest, and processed with ImageJ-ImageDP; and by the construction of time series and analysis with either statistical diagnostics tests or Autoregressive Integrated Moving Average (ARIMA) models.Antimicrobial susceptibility tests are also performed for the purpose of quantitative comparison, showing a profile that is comparable to the result obtained with ImageJ-ImageDP processing after 15min of antibiotic action. Only the time series of the least affected bacteria (low Ciprofloxacin concentration) behaves in an expected manner, being non-independent and mainly non-linear, non-normal, and heteroscedastic. The most affected bacteria (higher Ciprofloxacin concentration) are non-independent and tend to be linear, normal and heteroscedastic. Adjustment to a linear regression identifies both, the culture medium without bacteria and the most affected bacteria, normality identifies the most affected bacteria and heteroscedasticity-homoscedasticity distinguishes the presenceabsence of bacteria, respectively. ARIMA models (1,1,1)(1,0,1) 11 and (4,1,1)(1,1,1) 11 fit the time series of the most affected bacteria while the latter also fits the culture medium without bacteria. The time series of the least affected bacteria are identified by a (7,1,2)(1,0,1) 11 model. The non-linear, non-normal and heteroscedastic behavior of this group is probably responsible for its adjustment to a model with a relatively high parameter. The four methods: diagnostic statistical tests, fitting of ARIMA models, ImageJ-ImageDP and antimicrobial susceptibility tests, show similar results, being able to distinguish among the groups of assays with bacteria and Ciprofloxacin below and above the Minimal Inhibitory Concentration.

47Antibiotic susceptibility testing is a necessary step prior to the treatment of clinical 48 infections. A major concern is the time required to obtain a fast and reliable result. The aim 49 of this work is to use Biospeckle laser in a 15min assay for an antimicrobial susceptibility 50 test of Ciprofloxacin in serial two-fold dilutions on Escherichia coli K-12 using Venereal 51 Disease Research Laboratory (VDRL) plates. Analysis of images by video edition is 52 performed on a quantitatively selected region of interest, and processed with ImageJ-53 ImageDP; and by the construction of time series and analysis with either statistical 54 diagnostics tests or Autoregressive Integrated Moving Average (ARIMA) models. 55 Antimicrobial susceptibility tests are also performed for the purpose of quantitative 56 comparison, showing a profile that is comparable to the result obtained with ImageJ-57 ImageDP processing after 15min of antibiotic action. Only the time series of the least 58 affected bacteria (low Ciprofloxacin concentration) behaves in an expected manner, being 59 non-independent and mainly non-linear, non-normal, and heteroscedastic. The most 60 affected bacteria (higher Ciprofloxacin concentration) are non-independent and tend to be 61 linear, normal and heteroscedastic. Adjustment to a linear regression identifies both, the 62 culture medium without bacteria and the most affected bacteria, normality identifies the 63 most affected bacteria and heteroscedasticity-homoscedasticity distinguishes the presence-64absence of bacteria, respectively. ARIMA models () 11 fit the 65 time series of the most affected bacteria while the latter also fits the culture medium 66 without bacteria. The time series of the least affected bacteria are identified by a 67 (7,1,2)(1,0,1) 11 model. The non-linear, non-normal and heteroscedastic behavior of this 68 group is probably responsible for its adjustment to a model with a relatively high 69 parameter. The four methods: diagnostic statistical tests, fitting of ARIMA models, ImageJ-70 ImageDP and antimicrobial susceptibility tests, show similar results, being able to 71 distinguish among the groups of assays with bacteria and Ciprofloxacin below and above 72 the Minimal Inhibitory Concentration. 74 Author Summary 75Biospeckle laser patterns occur when a dynamic surface is illuminated. This research 76 describes its application to the activity of Escherichia coli bacteria and the effect of 18 77 different concentrations of an antibiotic (Ciprofloxacin) in a 15min assay, using VDRL 78 plates where the sample has a relatively small volume and is flat shaped. The assay is 79 performed on an anti-vibration table in a dark room with a laser that sequentially 80 illuminates each of the wells of the plate. A camera takes short 30sec videos with 81 approximately 750 frames and sends them to a computer where image processing takes 82 place. In order to select a segment of 80 successive frames to analyze, the region with the 83 higher variation was identified, punched out and edited as a "fl...

The estimation of the minimum inhibitory concentration is usually performed by a method of serial dilutions by a factor of 2, introducing the overestimation of antimicrobial efficacy, quantified by a simulation model that shows that the variability of the bias is higher for the standard deviation, being dependent on the metric distance to the values of the concentrations used. We use a methodological approach through modeling and simulation for the measurement error of physical variables with censored information, proposing a new inference method based on the calculation of the exact probability for the set of possible samples from nmeasurements that allows quantifying the p-value in one or two independent sample tests for the comparison of censored data means. Tests based on exact probability methods offer a reasonable solution for small sample sizes, with statistical power varying according to the hypothesis evaluated, providing insight into the limitations of censored data analysis and providing a tool for decision making in the diagnosis of antimicrobial efficacy.

Se generó un Modelo Digital de Elevación (MDE) del Compartimiento 9, en la Reserva Forestal El Dorado-Tumeremo, utilizando modelado y simulación Geoestadística, se dispuso de las curvas de nivel a escala 1:20.000. Se obtuvo que los datos no son estacionarios por media, ya que se ajustó un modelo polinomial de segundo orden que sigue dirección Este-Oeste. Se ajustó sobre los residuales un modelo de semivariograma Esférico Isotrópico y se ejecutó un Kriging simple residual cuyo error fue de -0.10 m. Finalmente, ante la falta de información se aplicó un modelo de simulación condicional multi-Gaussiana, de la que se obtuvo nuevas realizaciones que reflejen las mismas propiedades estadísticas de la función aleatoria. Los resultados muestran que, el proceso fue altamente efectivo, reconstruyendo la forma del terreno, pero la simulación corresponde con un proceso altamente volumétrico y de elevado costo computacional que requiere de un adecuado criterio estadístico.

The central western area of Venezuela has an unequal distribution of precipitation. Due to its agricultural importance, is necessary to plan water accounting and this requires a evaluation of spatial and temporal variability of precipitation and an estimate of local geophysical effect from the relief. In this research we use an iterative computationally lattice approach to perform a confirmatory analysis of the variability and the spatial correlation structure in monthly precipitation stations. Spatial correlograms and pooled empirical semivariogram were applied to evaluate the most appropriate spatial weighting matrix to estimate the Moran’s I. The altitude effect over monthly rainfall was estimated through spatial regression algorithm which determine the predominant spatial process in each slice. A homogeneous spatial stochastic process with positive spatial autocorrelation is evidenced. There is a trend towards a higher frequency of spatial error and spatial auto-regressive processes between the months of June and August whilst there are not dominant process between October and December. This response is caused by the dynamics of the intertropical convergence zone, which generates a seasonal effect on precipitation. These estimations allows decision-making in modeling and will lead to an improvement for analysis and forecasting in areas strongly affected by climate change and water stress.

Los patrones de puntos espaciales son una aproximación para el análisis de la estructura funcional del bosque. En este sentido, se evaluó y comparó la distribución espacial de árboles en bosques periurbanos de Mérida, Venezuela. Se planteó la hipótesis nula de la Aleatoriedad Espacial Completa (CSR), aplicando métodos exploratorios y confirmatorios espaciales sin marcas (e involucrando las marcas para las variables dasométricas) y pruebas de patrones puntuales multivariantes (α = 0.05) a parcelas de bosque primario y secundario (cinco en c/u). Ambos bosques exhibieron una densidad media similar (310 y 339 ind.ha-1). Además, se identificó un proceso CSR para los árboles sin considerar marcas en las variables de altura total y DAP, y en las marcas remanentes de volumen y especie este fue catalogado como no aleatorio, pues no se presentaron diferencias entre los procesos espaciales multivariantes. Se recomienda, por lo tanto, ampliar el área de trabajo y aplicarlo en bosques mejor diferenciados.