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Cyanoacrylate fuming is a popular technique commonly used by evidence examiners for the development of latent fingermarks on nonporous surfaces. The process involves the preferential formation of hard, white polycyanoacrylate along the ridgelines of the fingerprint as opposed to the substrate background. This preferential deposition results in contrast between the fingerprint and substrate. This contrast may be further enhanced through the use of staining techniques such as rhodamine 6G. Because the cyanoacrylate mechanism is believed to be initiated by fingerprint constituents and catalyzed by moisture, it follows that fingerprints subjected to harsh conditions (e.g., heat, low humidity, or UV light) often produce poorly developed results. This study aimed to further investigate and validate the use of 10% w/v methylamine as a pretreatment strategy to overcome the limitations associated with the cyanoacrylate development of dry fingerprints and to compare the results with those obtained using previously proposed pretreatment solutions. The effectiveness of this treatment was demonstrated on samples similar to those encountered in casework, and scanning electron microscopy (SEM) of the treated fingerprints confirmed the rejuvenation of the dry latent deposits through a qualitative assessment of the polymer morphology. [ABSTRACT FROM AUTHOR]

A significant amount of research has been conducted into the use of stable isotopes to assist in determining the origin of various materials. The research conducted in the forensic field shows the potential of isotope ratio mass spectrometry (IRMS) to provide a level of discrimination not achievable utilizing traditional forensic techniques. Despite the research there have been few, if any, publications addressing the validation and measurement uncertainty of the technique for forensic applications. This study, the first in a planned series, presents validation data for the measurement of bulk nitrogen isotope ratios in ammonium nitrate (AN) using the DELTAplusXP (Thermo Finnigan) IRMS instrument equipped with a ConFlo III interface and FlashEA™ 1112 elemental analyzer (EA). Appropriate laboratory standards, analytical methods and correction calculations were developed and evaluated. A validation protocol was developed in line with the guidelines provided by the National Association of Testing Authorities, Australia (NATA). Performance characteristics including: accuracy, precision/repeatability, reproducibility/ruggedness, robustness, linear range, and measurement uncertainty were evaluated for the measurement of nitrogen isotope ratios in AN. AN (99.5%) and ammonium thiocyanate (99.99+%) were determined to be the most suitable laboratory standards and were calibrated against international standards (certified reference materials). All performance characteristics were within an acceptable range when potential uncertainties, including the manufacturer’s uncertainty of the technique and standards, were taken into account. The experiments described in this article could be used as a model for validation of other instruments for similar purposes. Later studies in this series will address the more general issue of demonstrating that the IRMS technique is scientifically sound and fit-for-purpose in the forensic explosives analysis field. [ABSTRACT FROM AUTHOR]

Zinc oxide is evaluated as a fluorescent powder for the detection of fingermarks on non-porous surfaces. Pure and lithium-doped nanostructured zinc oxide powders were characterized using scanning electron microscopy, X-ray diffraction, and fluorescence spectroscopy. The zinc oxide powders were applied to fresh and aged fingermarks deposited on non-porous surfaces such as glass, polyethylene and aluminium foil. Zinc oxide was found to produce clear fluorescent impressions of the latent fingermarks when illuminated with long-wave UV light. [ABSTRACT FROM AUTHOR]

A total of 1,215 pigs (L337×1050, PIC, Hendersonville, TN) were used in a 156-d wean-to-finish experiment. Pigs were weaned at 21 d of age and placed in pens based on initial body weight (BW) with 27 pigs/pen. There were three dietary treatments including a: 1) control; 2) pigs fed diets containing AviPlus (microencapsulated sorbic and citric acids and synthetic thymol and vanillin botanicals; Vetagro Inc., Chicago, IL) during the nursery and finisher phases; or 3) pigs fed AviPlus during the nursery but not the finishing phase. AviPlus was included at 2.72 kg/ton from d 0 to 21, 0.90 kg/ton from d 21 to 42, and 0.45 kg/ton from d 42 to 156. Thus, there were 15 control pens and 30 Aviplus pens in the nursery and 15 pens for the 3 treatments in the finisher phase. On d 42, pigs were transported as intact pens to the finishing facility. Data were analyzed as a RCBD with pen as experimental unit. For the overall nursery period (d 0 to 42), pigs fed AviPlus had improved (P < 0.05) G:F, with no evidence of difference (P > 0.05) for d 42 BW, ADG, or ADFI. For the overall finishing period (d 42 to 156) and overall experimental period (d 0 to 156), there was no evidence of difference (P > 0.05) for BW, ADG, ADFI, or G:F. There was no evidence of difference (P > 0.05) observed for mortality and removals during the nursery, finisher, or overall. In summary, providing AviPlus during the nursery improved nursery G:F, but there was no effect on overall wean-to-finish performance. [ABSTRACT FROM AUTHOR]