3 research outputs found
Conceptual design studies of an advanced Mariner spacecraft. Volume III - Lander design
Conceptual design study of advanced Mariner space probe - Mars lander configuratio
Ground-motion prediction for subduction-zone earthquakes: insights from South and Central American data
Models to predict the ground motion for earthquakes that occur in subduction
zones are of great importance for earthquake risk reduction and mitigation in many
parts of the world where there is a significant hazard from large earthquakes along
the subduction interface and from earthquakes within the subducting slab. Most
existing ground-motion predictive equations for subduction-zone events are
primarily based on strong-motion recordings from Japan, Cascadia, Mexico, Alaska
and New Zealand. In contrast, few records from South and Central America have
been included in global predictive equations to date, although a major proportion of
the seismicity of these regions is related to subduction-zone processes. The
development of a strong-motion database from subduction-type events in South and
Central America is therefore an important and essential step for ground-motion
prediction in these regions as well as other subduction zones in the world.
In this project two databases of strong-motion records from subduction-zone
events along the Peruvian-Chilean and the Central American subduction zones have
been developed. The Central American database compiled during this study consists
of 554 triaxial ground-motion recordings from both interface and intraslab-type
events of magnitudes between 5.0≤MW≤7.7. The database compiled for South
America consists of 98 triaxial ground-motion recordings from 15 subduction-type
events of magnitudes 6.3≤MW≤8.4, recorded at 55 different sites in Peru and Chile,
between 1966 and 2007. These datasets have then been used to investigate the extent
to which global and regional models for subduction regimes could be applied for the
prediction of ground motions from the subduction events in these regions, following
a maximum-likelihood approach. Regional differences in the ground-motion
amplitudes amongst the South and Central America subduction zones are examined
and preliminary adjustments to existing equations are made in order to resolve the
differences between observed ground motions and predictions from these equations.
This has led to suggestions for the prediction of ground motions from subductionzone
earthquakes in the South and Central American regions
Human mitochondrial DNA variability: multidisciplinary applications in the fields of forensic, medical and population genetics
The results of the present project indicate that the analysis of the mtDNA variation can be useful in medical, forensic, and population genetic studies. The particular features of the mtDNA, including high copy number, lack of recombination, and high average mutation rate; also determine its usefulness and limitations in genetic studies. For instance, the reconstruction of the phylogeny is straightforward because the lineages are passed through the matriline with the only changes generated by mutation. However, this is a single marker and only tells the history of female population, which not necessarily match the demography of the whole population. We have applied these principles to the analysis of several human populations, to the forensic field, and to some medical study. All of them have many aspects in common, indicating also the important interplay that should be always needed in all mtDNA studies. For instance, one cannot carry out a forensic or medical genetic study ignoring population variation patterns or the important heterogeneity that exists regarding site specific mutation rates.
We have contributed to improve our knowledge of the variation in several African, European, and American populations. In this project we have also focussed our attention in several aspects of forensic interest, concerning the analysis of degraded and low DNA amount samples. And finally, we have tried to establish a necessary bridge between the different fields of research, indicating that proper quality standards can help to avoid false positives of instabilities in cancer studies, erroneous conclusions in forensic casework, or errors in datasets that could have consequences in population studies or indirectly in forensic or medical genetic ones