Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Vitreous humour in the eye helps to establish time of death

08.12.2008
A team of researchers from the University of Santiago de Compostela has proposed a new method to estimate the approximate time of death.

This is based on the analysis of several substances from the vitreous humour of the eye of cadavers, according to an article published in the journal entitled Statistics in Medicine. Using this system, scientists have developed a piece of software that makes it possible to establish precisely the post mortem interval (PMI), information that will make the work of the police and the courts of justice easier.

To apply this technique the researchers analyse initially potassium, urea and hypoxantine (a DNA metabolite) concentrations present in the vitreous humour of the eye of the human cadaver, and introduce these figures into a computer programme. The software that has been invented by these Galician scientists uses this information and is capable of establishing the time at which death occurred.

“The equations we have developed now make it possible for us to estimate the PMI more precisely than before, and provide a useful and accessible tool to forensic pathologists that is easy to use” José Ignacio Munoz Barús, one of the authors of the study, explains to SINC, and who is also a specialist doctor from the Institute of Legal Medicine at the University of Santiago de Compostela.

The traditional techniques for estimating the PMI are based on the study of parameters such as the rectal temperature of the cadaver or one of the organs, such as the liver, in rigor mortis, or post mortem lividity examination. These methods are complemented by biochemical analyses of the body fluids. One of these is the vitreous humour, the gelatinous liquid that is found behind the crystalline lens of the eye.

Muñoz Barús points out that the study, published recently in Statistics in
Medicine, suggests mathematical models that are “more flexible, useful and efficient” than those that have been applied until now. The doctor describes some of the previous techniques as “not very reproducible, not very precise and untested in the field”, such as the deterioration of DNA, immunoreaction or the traditional techniques based on the biochemistry of the vitreous humour.

In this last case the researcher specifies that previous studies used a “linear regression mathematical model” which assumes that the concentrations of potassium, hypoxantine and urea increase in a linear way that is more or less constant throughout the post mortem interval. However, the new analyses suggest that those premises are not valid and that the statistical models known as generalized additive models (GAM) or the support vector machine (SVM) models are more flexible and much more useful, since they avoid the assumption of linearity”.

The precision and usefulness of these two models have been confirmed by chemical analysis in more than 200 vitreous humour samples. The doctor and the two mathematicians who have performed the study have verified that the SVM method offers more precise data, although the GAM method is more easy to assimilate to the linear model and understand graphically and numerically, “ for which reason both complement each other”.

The three scientists have incorporated all this information into the development of a free computer package (based on code “R”) which makes it possible to establish the PMI using four predictive variables: concentrations of potassium, hypoxantine and urea, and cause of death. In addition, the software makes it possible to show the results graphically. “In this way the estimation of the time of death and expert examination are made easier when attending the courts of justice”, Munoz Barús points out to SINC

“The precise determination of the exact time of death has been the subject of various studies going back to the 19th century, since this information is of paramount importance in the field of legal medicine, owing to its repercussions on crime and civil society. This new method offers an important contribution to this field”, the researcher concludes.

SINC Team | alfa
Further information:
http://www.plataformasinc.es

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>