Optimal experimental design for cytogenetic dose-response calibration curves

Purpose: To introduce optimal experimental design techniques in the cytogenetic biological dosimetry practice. This includes the development of a new optimality criterion for the calibration of radiation doses. Materials and Methods: The most typical optimal design criterion and the one developed in this research are introduced and applied in an example from the litera- ture. In another example from the literature, a simulation study has been performed to compare the standard error of the dose estimation using different experimental designs. An RStudio project and a GitHub project have been developed to repro- duce these results. Results: In the paper it is observed that the application of optimal experimental design techniques can reduce the standard error of biodosimetric dose estimations. Conclusions: Optimal experimental design techniques jointly with practitioners re- quirements may be applied. This practice would not involve an additional laboratory work

A simple Bayesian linear excess relative risk model

A new Bayesian Poisson relative risk model is proposed for displaying the excess relative risk associated to a unique exposure as a probability distribution in a closed form. The background risk can be modelled by a unique two levels factor, e.g. gender or smoking status.Cancer Research U

A note on Poisson goodness-of-fit tests for ionizing radiation induced chromosomal aberration samples

Purpose: To present Poisson exact goodness-of-fit tests as alternatives and complements to the asymptotic u-test, which is the most widely used in cytogenetic biodosimetry, to decide whether a sample of chromosomal aberrations in blood cells comes from an homogeneous or inhomogeneous exposure. Materials and methods: Three Poisson exact goodness-of-fit test from the literature are introduced and implemented in the R environment. A Shiny R Studio application, named GOF Poisson, has been updated for the purpose of giving support to this work. The three exact tests and the u-test are applied in chromosomal aberration data from clinical and accidental radiation exposure patients. Results: It is observed how the u-test is not an appropriate approximation in small samples with small yield of chromosomal aberrations. Tools are provided to compute the three exact tests, which is not as trivial as the implementation of the u-test. Conclusions: Poisson exact goodness-of-fit tests should be considered jointly to the u-test for detecting inhomogeneous exposures in the cytogenetic biodosimetry practice

Phoenician pottery from underwater sites in La Caleta (Cadiz, Spain): Contextualization and historical interpretation

El carácter esencialmente marítimo y comercial de la fundación fenicia de Gadir en la bahía gaditana es un tópico histórico recurrente en la investigación de la protohistoria del Occidente mediterráneo desde hace décadas, debatido casi tanto como la propia ubicación del primer núcleo del hábitat fenicio. Recientes hallazgos en el área insular septentrional de la isla de Cádiz han proporcionado nuevos datos acerca de estas zonas residenciales, artesanales y cultuales de época fenicia y púnica vinculadas con Gadir, iniciando una nueva fase de la investigación y del diálogo histórico con los yacimientos amurallados situados en los rebordes continentales de la bahía. En este trabajo se pretende aportar un modesto pero interesante conjunto de testimonios materiales vinculados a otra parte fundamental del asentamiento gaderita como debió ser el litoral insular usado como fondeadero o puerto. En particular, se discute un conjunto de cerámicas recuperadas en actuaciones arqueológicas recientes en el entorno de La Caleta las cuales documentan el tránsito marítimo en la zona durante la fase fenicia arcaica y su relación con los yacimientos de carácter cultual y residencial de las inmediacionesThe maritime and commercial nature of the foundation of Phoenician Gadir in the Bay of Cadiz has been a recurring topic for the research of the pre-Classical history of the Mediterranean West for decades, discussed almost as much as the very location of the first Phoenician habitat. Recent findings in the northern insular area of Cadiz Island have provided new data on these residential, industrial and cultic areas of Phoenician and Punic Gadir, initiating a new phase of historical research and a new-fangled dialogue with the walled settlements located in the continental shores of the bay. This paper aims to provide a modest but interesting set of material evidence linked to the insular coastal section probably used as an anchorage or port, another fundamental part of Gaderitan settlement. Concretely, a collection of ceramics recovered in recent archaeological activities in the vicinity of La Caleta is discussed. The pottery supplies explicit evidence on the maritime traffic in the area during the Phoenician stage and also on the connection of La Caleta with the nearby residential and cultic area

An exact goodness-of-fit test based on the occupancy problems to study zero-inflation and zero-deflation in biological dosimetry data

The goal in biological dosimetry is to estimate the dose of radiation that a suspected irradiated individual has received. For that, the analysis of aberrations (most commonly dicentric chromosome aberrations) in scored cells is performed and dose response calibration curves are built. In whole body irradiation (WBI) with X- and gamma-rays, the number of aberrations in samples is properly described by the Poisson distribution, although in partial body irradiation (PBI) the excess of zeros provided by the non-irradiated cells leads, for instance, to the Zero-Inflated Poisson distribution. Different methods are used to analyse the dosimetry data taking into account the distribution of the sample. In order to test the Poisson distribution against the Zero-Inflated Poisson distribution, several asymptotic and exact methods have been proposed which are focused on the dispersion of the data. In this work, we suggest an exact test for the Poisson distribution focused on the zero-inflation of the data developed by Rao and Chakravarti (Some small sample tests of significance for a Poisson distribution. Biometrics 1956;12 : 264–82.), derived from the problems of occupancy. An approximation based on the standard Normal distribution is proposed in those cases where the computation of the exact test can be tedious. A Monte Carlo Simulation study was performed in order to estimate empirical confidence levels and powers of the exact test and other tests proposed in the literature. Different examples of applications based on in vitro data and also data recorded in several radiation accidents are presented and discussed. A Shiny application which computes the exact test and other interesting goodness-of-fit tests for the Poisson distribution is presented in order to provide them to all interested researchers

Importaciones efesias en Cádiz: nuevos hallazgos de La Punta del Nao (La Caleta)

Prospecciones subacuáticas recientes (2008-2010) en la zona de La Caleta han sacado a la luz interesantes materiales relacionados con las distintas fases de la historia de la Bahía de Cádiz. Dentro del estudio general de dichos conjuntos, en este artículo se presentan unas pequeñas ánforas producidas en el Hinterland de Éfeso, primeras muestras de este tipo de importaciones en la ciudad de Cádiz. Dichas ánforas pueden tomase como una primera muestra representativa del comercio de larga distancia y del consumo de productos de alta gama por parte de las élites gaditanas durante el periodo imperial romano y la tardía Antigüedad. Para ello se hace referencia a la producción de productos agrícolas en Éfeso, principalmente vino, y a las estructuras productivas y comerciales de la metrópolis egea.Recent underwater archaeological surveys (2008-2010) carried out in La Caleta area brought to light interesting material from differenthistorical phases in the Bay of Cadiz. Some small amphorae produced in the hinterland of Ephesus are studied in this paper, all of them found in La Caleta, as first evidence of imports from the Aegean metropolis in Cadiz. Those Ephesian pieces could be a representative example of the long distance commerce and the high quality products consumed by the Gaditan elites during the Roman period and the Late Antiquity.To examen in detail this trade we will also refer to the Ephesian agricultural production, particularly wine, and the production and commercial structures of the Aegean metropolis

Optimal experimental design for cytogenetic dose-response calibration curves

Purpose: To introduce optimal experimental design techniques in the cytogenetic biological dosimetry practice. This includes the development of a new optimatility criterion for the calibration of radiation doses. Materials and Methods: The most typical optimal design criterion and the one developed in this research are introduced and applied in an example from the litera- ture. In another example from the literature, a simulation study has been performed to compare the standard error of the dose estimation using di erent experimental designs. An RStudio project and a GitHub project have been developed to repro- duce these results. Results: It is appreciated how the application of optimal experimental design tech- niques can reduce the standard error of biodosimetric dose estimations. Conclusions: Optimal experimental design techniques jointly with practitioners re- quirements may be applied. This practice would not involve an additional laboratory work

Efectos de la exposición y calidad de la prevención escolar en el consumo de drogas y factores de riesgo de estudiantes de secundaria

La presente tesis doctoral pretende estudiar las diferencias en: (a) el consumo de tabaco, alcohol y cannabis, y (b) el perfil de factores de riesgo/protección de los estudiantes de educación secundaria, en relación a dos atributos clave en la prevención escolar sobre drogas: la cantidad de exposición recibida y su calidad

A statistical framework for radiation dose estimation with uncertainty quantification from the γ-H2AX assay

Over the last decade, the γ–H2AX focus assay, which exploits the phosphorylation of the H2AX histone following DNA double–strand–breaks, has made considerable progress towards acceptance as a reliable biomarker for exposure to ionizing radiation. While the existing literature has convincingly demonstrated a dose–response effect, and also presented approaches to dose estimation based on appropriately defined calibration curves, a more widespread practical use is still hampered by a certain lack of discussion and agreement on the specific dose–response modelling and uncertainty quantification strategies, as well as by the unavailability of implementations. This manuscript intends to fill these gaps, by stating explicitly the statistical models and techniques required for calibration curve estimation and subsequent dose estimation. Accompanying this article, a web applet has been produced which implements the discussed methods