Identificación de características forenses avanzadas a partir del ADN: etnogeografía, patología delictiva y morfoanatomía

Resumen: El uso de la molécula de ADN ha revolucionado el mundo de la Genética forense, convirtiéndose en una herramienta poderosa para resolver un gran número de casos judiciales. El ADN permite identificar a una persona determinada con una probabilidad de error ínfima. Utilizando el análisis del ADN los ámbitos clásicos de actuación han sido: la resolución de grandes delitos, las pruebas de paternidad o de parentesco en general y por último la identificación de restos humanos que estuviesen muy dañados. Sin embargo, los investigadores policiales buscan obtener más información a partir de las moléculas de ADN extraídas de muestras biológicas (sangre, saliva, semen, células epiteliales, etc.). En este trabajo abordaremos los conocimientos que en la actualidad se tienen de algunas de las características del aspecto externo de los individuos a partir del análisis del ADN de las muestras, su interés desde el punto de vista jurídico y sus limitaciones. En concreto nos centraremos en cuatro grandes áreas de estudio: el análisis del origen geográfico de los ancestros, la genética del comportamiento, la genética médica y las predicciones de características externas tales como el color de los ojos, del cabello, de la piel, la estatura y la edad. Palabras clave: Genética forense, ADN. Origen étnico-geográfico. Patología delictiva. Características externas visibles.

Analysis of the process of inspection in recreational craft in Spain. Suggestions for safety improvement

Inspections of pleasure boats in Spain can be carried out by collaborating entities of inspection, entities that must be authorized by the Maritime Administration. This authorization allows to perform effective inspections and technical controls of recreational crafts. Recreational crafts are subjected to surveys that are based on the registration list and on the material used in the hull. In addition, required safety equipment of the recreational boat depends on the distance that the recreational boat is authorized to navigate. Following data obtained from inspections of recreational craft, this paper aims to analyze information about hulls within dry and afloat conditions, about the equipment for rescue and safety, and about other nautical equipment; as well as to perform and improve different verifications during the inspections. All this information points to several aspects relevant for the optimization of the inspection process, the ultimate target being increasing efficiency and effectiveness, and ensuring more safety in recreational craft.

Reflexiones sobre el miedo en el siglo XXI: Filosofía, política, genética y evolución

La actualidad y los acontecimientos de las últimas décadas han puesto de manifiesto la importancia del miedo en la vida pública. El miedo como tal y sus factores desencadenantes están presentes en la prensa, el discurso político, la neurociencia, la ciencia y la filosofía política. Entendemos que la gestión del miedo intuitivo, cognitivo y heurístico debe contemplarse como un elemento básico en la vida del ciudadano de este siglo. Tanto en la visión moderna de la nación y el contrato social, como en las visiones más futuristas de cosmopolitismo y estados supranacionales, la heurística del miedo difícilmente podrá desaparecer de los sistemas jurídicos y sociales, no solo por su utilidad intrínseca, sino también por su inmanencia y consubstancialidad genético-biológica y psico-social. El hecho de que exista miedo consideramos que es positivo puesto que nos alerta de riesgos que pueden afectar negativamente el futuro del individuo.

Chromosomal polymorphism of D. subobscura: no differences between wild males and sons of wild females

When analyzing the chromosomal polymorphism of D. subobscura natural populations it is assumed that the information provided by wild males and sons of wild females is equivalent. Thus, using both in the analysis it is possible to increase the sample size. However, it is important to verify whether there are significant differences between both groups or not. The aim of this research has been to statistically compare the results of chromosomal polymorphism of both groups. We have used data from Avala Mountain (Serbia) where D. subobscura flies were collected from the 30th May to the 5th June 2011. Avala is located 18 km south of Belgrade and the trapping place is a forest with polydominant communities of Fagetum submontanum Table 1. Number and percentage of adult flies collected in Font Groga (Barcelona, Spain) on 9th October 2013. Males and sons of wild females were crossed with virgin females of the Küsnacht strain. Third instar larvae from F1 were dissected to obtain the salivary glands and the polytene chromosomes were stained and squashed in aceto-orcein solution. No significant differences were observed for any chromosome of the karyotype: A (p-value = 0.485), J (p-value = 0.230), U (p-value =0.572), E (p-value = 0.536), and O (p-value = 0.338). Thus, it seems that the two groups can be grouped together to obtain the chromosomal polymorphism of the population.

Study of linkage between miniature and singed genes in Drosophila melanogaster

We have developed a practical exercise for undergraduate students whose main aim is to identify, using genetic crosses, a pair of D. melanogaster mutations (miniature and singed). Each student receives a vial with the problem strain containing two unknown mutations. The first step is to observe and describe both mutations. Then, the students carry out genetic crosses between mutant and normal strains: (P) ♀ mutant strain × ♂ normal strain (P) ♀ normal strain × ♂ mutant strain A different offspring is expected in these crosses: in the first one we will obtain normal females and m sn males, whereas in the second all individuals will present normal phenotype. It is possible to deduce that both are sex linked mutations. With this information and to simplify the amount of work, only F1 individuals from the first cross will be used (m+sn+ / m sn × m sn / Y chrom.) to obtain the F2 generation. By counting the number of miniature (recombinant type), singed (recombinant type), miniature-singed (parental type) and normal (parental type) flies it is possible to estimate the recombination frequency between both genes. Knowing the phenotype, their chromosomal location (X chromosome) and the genetic distance between both mutations, it is possible to identify them by finding all this information in a Drosophila melanogaster genetic map. Additionally, a statistical analysis can be carried out to compare the number of expected F2 individuals with those observed in the experiment. As the distance between both genes is 15.1 m.u., then the expected percentages for each phenotype would be: normal (42.45%), miniature-signed (42.45%), miniature (7.55%) and singed (7.55%). Multiplying the frequency of each class by the total number of individuals obtained in the F2 it is possible to estimate the expected number of flies for each class. Finally, a χ2 test can be computed to ascertain whether there are significant differences between expected and observed number of individuals.

New sample of drosophilids from the Font Groga site, Barcelona (Spain)

A new sample of drosophilids was obtained from Font Groga (Barcelona) on 9th October 2013. Flies were netted over 12 baits containing fermenting bananas placed along a trail from 4 to 7 pm. The number of flies classified according to species and sex is presented in Table 1. The most abundant species is D. subobscura (62.60%). This is expected because the sample was obtained during its autumn peak of expansion. Also interesting is to find again D. suzukii, and in a percentage similar (9.20%) to that obtained in 2012 sample. This species invaded recently many European regions and seems it is well established. We have finally estimated the species diversity using H" (Shannon diversity index) and J (Shannon uniformity index). The values obtained were 0.990 and 0.615, respectively. They are similar to those estimates obtained in the same site by Calabria in autumn 2007 and higher than those of Canals et al. in late autumn 2012.

Inbreeding and thermal adaptation in Drosophila subobscura

Using a well-adapted Drosophila subobscura population (Avala, Serbia), a drastic experiment of inbreeding was carried out to assess whether the expected level of homozygosity could be reached or if other evolutionary forces affected the process. In general, no significant changes of inversion (or arrangement) frequencies were detected after 12 brother sister mating generations. Furthermore, no significant differences were obtained between observed and expected (under the inbreeding model) karyotypic frequencies. Thus, these results seemed to indicate that the main evolutionary factor in the experiment was inbreeding. However, in the G12 generation, complete chromosomal fixation was reached only in two out of the eight final inbred lines. In these lines, the chromosomal compositions were difficult to interpret, but they could be likely a consequence of adaptation to particular laboratory conditions (constant 18 °C, food, light period, etc.). Finally, in a second experiment, the inbred lines presented higher fertility at 18 °C than at 13 °C. Also, there was a significant line effect on fertility: inbred line number 6 (A1, J1, U1+2; U1+2+6, E8, and O3+4+7) presented the highest values, which maybe the result of an adaptation to laboratory conditions. Thus, the results obtained in our experiments reflect the adaptive potential of D. subobscura inversions.

Justicia y ciencia. Uniendo lo mejor de ambos mundos

La justicia y la ciencia son ámbitos muy diferentes de la actividad humana. Sin embargo, los conocimientos científicos dan lugar a la aparición de una serie de disciplinas aplicadas que son de gran utilidad en forensia y que pueden ser trascendentales en la Administración de la Justicia. El problema es reconocer primero si una especialidad es realmente científica y si puede utilizarse de manera fiable en el ámbito de la justicia. En este sentido, la utilización de las pruebas de ADN es un buen ejemplo de cómo, poco a poco, se ha ido ajustando su uso en los tribunales. Además los laboratorios donde se practican esas técnicas forenses están correctamente homologados y al mismo tiempo los especialistas que trabajan en ellos son profesionales con una sólida formación y que se mantienen constantemente al día. Otro elemento crucial es que los expertos que aportan su testimonio deben hacerlo de manera precisa y comprensible. En los casos en que se presente una prueba pericial basada en una aproximación científica novedosa, ésta debe cumplir toda una serie de requisitos para poder ser aceptada por los tribunales.

La genética forense en el fraude alimentario: implicaciones jurídicas y sociales

La introducción de las técnicas basadas en el ADN ha dado una nueva dimensión a la forensia dedicada a combatir el fraude alimentario. En este artículo se presentan de manera conceptual estas técnicas y se muestra una serie de ejemplos aplicados. Las ciencias forenses están en continua expansión y sus nuevos procedimientos de análisis pueden aplicarse en los dictámenes periciales y forenses de la Administración de Justicia en el ámbito alimentario.

Vist pel medievalisme. Les drassanes al segle XIII

Des de l'antiguitat, la construcció de vaixells ha estat fonamental per al desenvolupament dels pobles de la Mediterrània, tant per al transport de mercaderies com per a la creació de naus de guerra. A Sant Feliu de Guíxols, la importància de la indústria naval es pot documentar des del segle XIII, com també la participació de la vila en l’expansió marítima de la Corona d’Aragó