Sustainable Latent Fingermark Detection Protocols for Remote-Location and Resource-Limited Jurisdictions

This thesis proposes the concept of frugal forensics, establishing the first systematic framework for sustainable forensic science service provision, with an emphasis on latent fingermark detection in resource-limited jurisdictions. The application of frugal forensics was successfully demonstrated through the development of sustainable latent fingermark detection techniques for Seychelles. The adoption of such methods in support of the UN SDGs is key in bridging the gap in forensic science services that exist in the Global South

Wet SPF: A wet powder suspension for the detection of latent fingermarks on the sticky side of adhesive tape for use in Seychelles

WET UCIO is an inexpensive carbon-based powder suspension, reportedly as effective as commercially available formulations for latent fingermark detection on the sticky side of adhesive tapes. However, the surfactant solution used in WET UCIO is not readily accessible outside Europe, limiting its use in Seychelles or other non-European jurisdictions. In this study, the UCIO formulation was modified based on a ‘frugal forensic’ approach, by replacing the surfactant solution with an in-house sodium dodecyl sulfate solution prepared in 5% aqueous ethanol. A comparative assessment against Wetwop™ using eight different pressure-sensitive adhesive tapes found that the modified formulation was at least as effective as commercial powder suspension. Modifying this technique under the frugal forensic framework has enhanced its accessibility to other jurisdictions and is recommended for validation in Seychelles

Présentation de l’ouvrage de Charles Gadéa, Roland Lardinois (dir.), Les Mondes de l’ingénieur en Inde (XIXe-XXIe siècle)

Le riche ouvrage collectif dirigé par Charles Gadéa et Roland Lardinois s’intéresse de près à la construction et à l’essor du groupe professionnel des ingénieurs, en Inde, entre l’époque coloniale et la période contemporaine. L’examen de cette profession se distingue par la prise en considération des multiples dimensions sociales intriquées dans la vie quotidienne de ces individus. Sont ainsi convoquées tout au long de l’ouvrage des analyses empruntant aux études sur l’action publique, l’exp..

Forensic science in Seychelles: An example of a micro-jurisdiction forensic delivery system

Forensic science has become an indispensable tool for even the smallest of jurisdictions. However, micro-jurisdictions often face significant challenges with respect to resource availability, administration and local governance. This paper examines the forensic service provision in Seychelles as an example of a micro-jurisdiction forensic delivery system. The impact of limited resources and remote access to consumables or services have prompted the prospective shift to localise commonly utilised forensic services. The need to balance quality and cost for a sustainable forensic service is examined in relation to jurisdictions with more advanced forensic service delivery. Reforms of the legal framework, administration, and governance structures are some of the key underpinnings for an effective forensic delivery system built on a culture of transparent science that promotes justice and creates public confidence in the judicial system

Evidencing the chemical degradation of a hydrophilized pes ultrafiltration membrane despite protein fouling

International audienceHydrophilisation of polyethersulfone (PES) based membrane is often achieved by addition of polyvinylpyrrolidone (PVP) leading to a physical blend of the two polymers. This paper shows that the most commonly used membrane for UF in dairy industry is a PES/PVP based one. Nevertheless if hydrophilisation limits the organic fouling, PVP is also the Achilles heel of these membranes. It is particularly true when membranes are exposed to hypochlorite as it is the case for cleaning/disinfection steps. Evidencing the disappearance of PVP from a pristine PES/PVP membrane can be easily achieved by FTIR-ATR analyses. But when one wants to study the ageing of a membrane used in UF it gets more complicated: regardless of the cleaning efficiency the membrane always remains fouled by some proteins. As both PVP and proteins own chemical bounds leading to absorption at the same wavenumber in FTIR-ATR, it thereby prevents the easy highlighting of the PVP degradation. The aim of this paper is to propose a simple treatment of raw FTIR-ATR spectra to dissociate these two contributions, allowing consequently the study of the degradation of a fouled membrane. Then the procedure is applied to a real case study on a spiral membrane

Invasive Ductular Reaction Operates Hepatobiliary Junctions upon Hepatocellular Injury in Rodents and Humans.

Ductular reaction (DR) is observed in virtually all liver diseases in both humans and rodents. Depending on the injury, DR is confined within the periportal area or invades the parenchyma. On severe hepatocellular injury, invasive DR has been proposed to arise for supplying the liver with new hepatocytes. However, experimental data evidenced that DR contribution to hepatocyte repopulation is at the most modest, unless replicative capacity of hepatocytes is abrogated. Herein, we proposed that invasive DR could contribute to operating hepatobiliary junctions on hepatocellular injury. The choline-deficient ethionine-supplemented mouse model of hepatocellular injury and human liver samples were used to evaluate the hepatobiliary junctional role of the invasive form of DR. Choline-deficient ethionine-supplemented-induced DR expanded as biliary epithelium into the lobule and established new junctions with the canaliculi. By contrast, no new ductular-canalicular junctions were observed in mouse models of biliary obstructive injury exhibiting noninvasive DR. Similarly, in humans, an increased number of hepatobiliary junctions were observed in hepatocellular diseases (viral, drug induced, or metabolic) in which DR invaded the lobule but not in biliary diseases (obstruction or cholangitis) in which DR was contained within the portal mesenchyme. In conclusion, our data in rodents and humans support that invasive DR plays a hepatobiliary junctional role to maintain structural continuity between hepatocytes and ducts in disorders affecting hepatocytes

Nanocomposite sprayed films with photo-thermal properties for remote bacteria eradication

Currently there is a strong demand for novel protective materials with effcient antibacterial properties. Nanocomposite materials loaded with photo-thermally active nanoparticles can offer promising opportunities due to the local increase of temperature upon near-infrared (NIR) light exposure capable of eradicating bacteria. In this work, we fabricated antibacterial films obtained by spraying on glass slides aqueous solutions of polymers, containing highly photo-thermally active gold nanostars (GNS) or Prussian Blue (PB) nanoparticles. Under NIR light irradiation with low intensities (0.35W/cm2) these films demonstrated a pronounced photo-thermal effect: 06Tmax up to 26.4 ffC for the GNS-containing films and 06Tmax up to 45.8 ffC for the PB-containing films. In the latter case, such a local temperature increase demonstrated a remarkable effect on a Gram-negative strain (P. aeruginosa) killing (84% of dead bacteria), and a promising effect on a Gram-positive strain (S. aureus) eradication (69% of dead bacteria). The fabricated films are promising prototypes for further development of lightweight surfaces with effcient antibacterial action that can be remotely activated on demand

Microlenses fabricated by two-photon laser polymerization for cell imaging with non-linear excitation microscopy

Non-linear excitation microscopy offers several advantages for in-vivo imaging compared to conventional confocal techniques. However, tissue penetration can still be an issue due to scattering and spherical aberrations induced on focused beams by the tissue. The use of low numerical aperture objectives to pass through the outer layers of the skin, together with high dioptric power microlenses implanted in-vivo close to the observation volume, can be beneficial to the reduction of optical aberrations. Here, Fibroblast cell culture plano-convex microlenses to be used for non-linear imaging of biological tissue are developed and tested. The microlenses can be used as single lenses or multiplexed in an array. A thorough test of the lenses wavefront is reported together with the modulation transfer function and wavefront profile. Magnified fluorescence images can be retrieved through the microlenses coupled to commercial confocal and two-photon excitation scanning microscopes. The signal-to-noise ratio of the images is not substantially affected by the use of the microlenses and the magnification can be adjusted by changing the relative position of the microlens array to the microscope objective and the immersion medium. These results are opening the way to the application of implanted micro-optics for optical in-vivo inspection of biological processes