A mathematical model applied for assisting the estimation of PMI in a case of forensic importance. First record of Conicera similis (Diptera: Phoridae) in a corpse.

We present a forensic case associated with skeletonized human remains found inside a cistern in a coastal town located in the eastern Iberian Peninsula (Valencian Regional Government, Spain). In order to analyse the particular environmental conditions that occurred during oviposition and development of the collected insects, estimated temperatures at the crime scene were calculated by a predictive mathematical model. This model analyses the correlation between the variability of the internal temperature depending on the variability of the external ones. The amplitude of the temperature oscillations inside the tank and the containment of the enclosure is reduced by the presence of water. Such variation occurred within about 2h due to the time required for heat exchange. The differential equations employed to model differences between outdoor and indoor temperatures were an essential tool which let us estimate the post-mortem interval (PMI) that was carried out by the study of the insect succession and the development time of the collected Diptera specimens under the adjusted temperatures. The presence of live larvae and pupae of Sarcophagidae and empty pupae of Calliphoridae, Sarcophagidae, Fanniidae, Muscidae, Phoridae and Piophilidae and the decomposition stage suggested the possibility that the remains were in the tank at least a year. We highlight the absence of Calliphora and Lucilia spp., and the first occurrence of the phorid Conicera similis in a human cadaver among the entomological evidence.

Determinación del intervalo postmortem mediante el estudio de la sucesión de insectos en dos cadáveres hallados en el interior de una finca rústica en Madrid / Assessment of post-mortem interval through the study of the insect succession in two corpses found indoors in a country house in Madrid

En este artículo se presenta un caso estudiado en el Laboratorio de Entomología Forense de la Sección de Antropología de la Comisaría General de Policía Científica (Cuerpo Nacional de Policía). En él, se analizaron muestras entomológicas recogidas en dos cadáveres durante la práctica de la Inspección Ocular Técnico Policial, llevada a cabo en la localidad de Fuenlabrada, sita en la zona Sur de Madrid (España, Región Paleártica). Los dos cadáveres, en avanzado estado de descomposición, fueron encontrados en el interior de una finca rústica en invierno del año 2001. Las evidencias de interés forense recogidas consistieron en dípteros de las Familias Calliphoridae, Muscidae y Phoridae y Coleoptera de las Familias Cleridae, Dermestidae e Histeridae. Además, arácnidos que permitieron afirmar la compatibilidad de los especímenes con el entorno. La sucesión de los insectos recogidos permitió estimar el intervalo post-mortem en un año (AU)

In this paper, it is reported a case which was studied in the Forensic Entomology Laboratory belonging to the Anthropology Section from the General Department of the Scientific Police (Spanish National Police). We analysed entomological evidences collected during death scene investigation performed in Fuenlabrada, south of Madrid administrative region (Spain, Paleartic Region). Both corpses, in advanced decomposition stage, were found indoors in a country house in winter 2001. Samples collected consisted of Diptera identified as Calliphoridae, Muscidae and Phoridae Families; Coleoptera corresponding to Cleridae, Dermestidae and Histeridae ones. Furthermore, spiders which allowed us to confirm the compatibility with the place where carcasses were found. The study of the insect succession allowed the estimation of post-mortem interval in one year (AU)

Nuclear Regulatory Authority low energy germanium detection system: performance for the uranium individual monitoring.

The lung counter facility of the Nuclear Regulatory Authority (ARN) is presented. A calibration was carried out using the Lawrence Livermore National Laboratory (LLNL) phantom. This phantom is provided with a pair of lungs and lymph nodes containing uranium homogeneously distributed and a set of four overlay plates covering a chest wall thickness (CWT) ranging from 1.638 to 3.871 cm. Individual organ calibration factors were acquired for 235U photopeaks energies and for each effective chest thickness. Using these factors, a collection of theoretical fitting curves were found. A counting efficiency formulae and a curve for simultaneously active lymph nodes and lung was obtained and checked through measures. Background measurements of the chamber with and without volunteer persons were performed in order to obtain the detection limits (DL) of the system. As this task involves the knowledge of the volunteers CWTs, these magnitudes were determined through formulae selected from the literature taking into account the detection system characteristics. The deviation in the CWT assigned to an individual, generated by applying different equations, produces variations up to 33% in the estimations of the incorporated activity and DL. An analysis of the changes in efficiencies as consequences of the detectors locations and CWT was also performed. This reveals that the DL of the camera (detectors, shield and blank phantom) is between 2.7 and 6.4 Bq of 235U, which implies 4.9 and 11.5 mg lung burden of natural uranium. An estimation of the minimum detectable intake performed with the DL considering blank persons shows that a system with the characteristics described is only adequate for non-routine individual monitoring.

A protocol for the calibration of gamma cameras to estimate internal contamination in emergency situations.

The concern about accidents involving radioactive materials has led to the search of alternative methods to quickly identify and quantify radionuclides in workers and in the population. One of the options to face up an eventual demand for mass monitoring of internal contamination is the use of a nuclear medicine diagnostic equipment known as gamma camera, a device used to scan patients who have been administered specific amounts of radioactive materials for medical purposes. Although the gamma camera is used for image diagnosis, it can be calibrated with anthropomorphic phantoms or point sources for the quantification of radionuclide activities in the human body. This work presents a protocol for the calibration of gamma cameras for such application. In order to evaluate the suitability of this type of equipment, a gamma camera available in a public hospital located in Rio de Janeiro was calibrated for the in vivo measurement of 131I. The calibration includes the determination of detection efficiencies and minimum detectable activities for each radionuclide. The results show that the gamma camera presents enough sensitivity to detect activity levels corresponding to effective doses below 1 mSv. The protocol is the basis to establish a network of Nuclear Medicine Centres, located in public hospitals in eight countries of Latin America (Argentina, Brazil, Colombia, Cuba, Chile, Mexico, Peru and Uruguay) and in Spain that could be requested to collaborate in remediation actions in the event of an accident involving incorporation of radioactive materials. This protocol is one of the most significant outputs of the IAEA-ARCAL Project (RLA/9/049-LXXVIII) aimed to the Harmonization of Internal Dosimetry Procedures.