24 research outputs found
Variation in amino acid and lipid composition of latent fingerprints
The enhancement of latent fingerprints, both at the crime scene and in the laboratory using an array of chemical, physical and optical techniques, permits their use for identification. Despite the plethora of techniques available, there are occasions when latent fingerprints are not successfully enhanced. An understanding of latent fingerprint chemistry and behaviour will aid the improvement of current techniques and the development of novel ones. In this study the amino acid and fatty acid content of ‘real’ latent fingerprints collected on a non-porous surface was analysed by gas chromatography–mass
spectrometry. Squalene was also quantified in addition. Hexadecanoic acid, octadecanoic acid and cis-9-
octadecenoic acid were the most abundant fatty acids in all samples. There was, however, wide variation in the relative amounts of each fatty acid in each sample. It was clearly demonstrated that touching sebum-rich areas of the face immediately prior to fingerprint deposition resulted in a significant increase in the amount of fatty acids and squalene deposited in the resulting ‘groomed’ fingerprints. Serine was the most abundant amino acid identified followed by glycine, alanine and aspartic acid. The significant
quantitative differences between the ‘natural’ and ‘groomed’ fingerprint samples seen for fatty acids
were not observed in the case of the amino acids. This study demonstrates the variation in latent fingerprint composition between individuals and the impact of the sampling protocol on the quantitative analysis of fingerprints
Système simple d’aide à la pose d’aiguilles de biopsie
Dans le cadre de la chirurgie assistée par ordinateur, le groupe VRAI, en collaboration avec l’entreprise Atracsys, est en train de développer le vTrack, un système de mesure optique 3D. Ce système repère, par triangulation, la position de marqueurs positionnés sur les outils chirurgicaux et le patient. Les marqueurs sont composés de LEDs infrarouges et communiquent par un canal sans fils avec la caméra. Le but de ce projet est, dans un premier temps, de réaliser un logiciel pour la planification de biopsie sur la base d’images scanner et ultrason. Dans un second temps, les marqueurs existants seront adaptés aux outils du radiologue. Finalement, un prototype utilisable dans un milieu hospitalier sera réalisé
Identification of promising antigenic components in latent fingermark residues
An analysis of latent fingermark residues by Sodium-Dodecyl-Sulfate PolyAcrylamide Gel Electrophoresis (SDS-PAGE) followed by silver staining allowed the detection of different proteins, from which two major bands, corresponding to proteins of 56 and 64 kDa molecular weight, could be identified. Two other bands, corresponding to proteins of 52 and 48 kDa were also visualizable along with some other weaker bands of lower molecular weights. In order to identify these proteins, three antibodies directed against human proteins were tested on western blots of fingermarks residues: anti-keratin 1 and 10 (K1/10), anti-cathepsin-D (Cat.D) and anti-dermcidin (Derm.). The corresponding antigens are known to be present in the stratum corneum of desquamating stratified epithelium (K1/10, Cat.D) and/or in eccrine sweat (Cat.D, Derm.).
The two major bands were identified as consistent with keratin 1 and 10. The pro-form and the active form of the cathepsin-D have also been identified from two other bands. Dermcidin could not be detected in the western blot.
In addition, these antibodies have been tested on latent fingermarks left on polyvinylidene fluoride (PVDF) membrane, as well as on whitened and non-whitened paper. The detection of fingermarks was successful with all three antibodies
Exploring adaptive locomotion with YaMoR, a novel autonomous modular robot with Bluetooth interface
Purpose – this paper aims to present a novel modular robot that provides a flexible framework for exploring adaptive locomotion.design/methodology/approach – a new modular robot is presented called yamor (for “yet another modular robot”). Each yamor module contains an fpga and a microcontroller supporting a wide range of control strategies and high computational power. The bluetooth interface included in each yamor module allows wireless communication between the modules and controlling the robot from a pc. A control software called bluemove was developed and implemented that allows easy testing of the capabilities for locomotion of a large variety of robot configurations.findings – with the help of the control software called bluemove, different configurations of the yamor modules were tested like a wheel, caterpillar or configurations with limbs and their capabilities for locomotion.originality/value – this paper demonstrates that modular robots can act as a powerful framework for exploring locomotion of a large variety of different types of robots. Although present research is limited to exploring locomotion, yamor modules are designed to be general purpose and support a variety of applications
Study of latent fingermarks by matrix-assisted laser desorption/ionisation mass spectrometry imaging of endogenous lipids
Identification of suspects via fingermark analysis is one of the mainstays of forensic science. The
success in matching fingermarks, using conventional fingermark scanning and database searching,
strongly relies on the enhancement method adopted for fingermark recovery; this in turn depends on
the components present in the fingermarks, which will change over time. This work aims to develop a
robust methodology for improved analytical detection of the fingermark components. For the first
time, matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) has been
used to image endogenous lipids from fresh and aged, groomed and ungroomed fingermarks. The
methodology was initially developed using oleic acid which was detected along with its degradation
products over a 7-day period, at three different temperatures in a time-course experiment. The
optimised methodology was then transferred to the imaging analysis of real fingermark samples.
Fingermark patterns were reconstructed by retrieving the m/z values of oleic acid and its degradation
products. This allowed the three aged fingermarks to be distinguished. In order to prove that MALDIMSI
can be used in a non-destructive way, a simple washing protocol was adopted which returned a
fingermark that could be further investigated with classical forensic approaches. The work reported
here proves the potential and the feasibility of MALDI-MSI for the forensic analysis of fingermarks,
thus making it competitive with other MSI techniques such as desorption electrospray ionisation
(DESI)-MS. The feasibility of using MALDI-MSI in fingermark ageing studies is also demonstrated
along with the potential to be integrated into routine fingermark forensic analysis