An investigation into the detection of latent marks on the feathers and eggs of birds of prey.
There are numerous enhancement techniques (physical and chemical) which have been developed for the successful visualisation of latent fingermarks. Nonetheless, problems arise when latent fingermarks require enhancement on difficult surfaces such as human skin, food stuffs, fabric and animals. The ability to develop latent fingermarks on the surface of bird of prey feathers and that of their eggs was investigated. Red and green magnetic fluorescent powders proved to be most suitable on the surface of bird of prey feathers whereas black magnetic powder was the most suitable technique on the eggs. These powders produced the highest quality of visible ridge-detailed developments over a controlled period of time.
Still making a mark? Fingerprints in the 21st century.
By the time that this editorial is published, the new Home Office Fingermark Visualisation Manual will have been launched. Having had the privilege of being part of the tremendous team effort that has brought this to fruition, I am grateful to the Editor-in-Chief for the invitation to contribute this editorial article and the opportunity to place the Manual, and fingermark visualisation, in the broader context of the forensic science landscape. Fingerprints have been an essential element of forensic science since the late 19th century, and one objective of the newManual is to provide a strong foundation for their continued use in the 21st century and beyond. Although there has beenmuch debate aboutwhether the identification element of fingerprints can be regarded as science, fingermark visualisation and imaging has a strong scientific basis and chemical, physical and to a lesser extent biological processes are all used in fingermark recovery. The Manual is primarily concerned with the processes associated with visualisation and imaging of fingermarks and although often overlooked, it can be argued that without these important stages in fingermark recovery the role of the identification specialist would become redundant. Since the first edition of the Manual of Fingerprint Development Techniques was published in 1986, it has been the core reference document for UK police fingermark enhancement laboratories and become adopted by many other agencies in countries around the world. Changes to such a publication therefore required careful consideration, but by the end of the 2000s it was clear that significant revision had become necessary. Ongoing research into fingermark enhancement had resulted in the introduction of new processes and improved, more effective formulations of others. The appointment of the Forensic Science Regulator also brought all classes of forensic evidence under scrutiny and highlighted a need to bring transparency to how the fingermark enhancement processes and processing sequences presented in the Manual had been validated. With regard to validation of fingermark enhancement processes, the new Manual represents the last in the series of documents that have been produced to underpin the results of over 40 years of Home Office research. The Home Office Fingerprint Source Book (available for download from www.GOV.UK) provides the history, theory and experimental results behind all of the processes in theManual, and themethodology document [1] details the experimental approaches used in evaluating them. The Manual essentially presents the outcomes of the research, and outlines the processes, formulations, processing parameters and processing sequences recommended for optimum recovery of fingermarks on a wide range of different surfaces. The new publication is significantly expanded in terms of the information presented within it, and promotes two key messages: the need for both competence and communication.
VLA stereoscopy of solar active regions. 2: Altitude, relative motion, and center-to-limb darkening of 20 centimeter emission
A newly developed method of stereoscopic correlation is applied to solar radio maps at a wavelength of 20 cm. On the basis of stereoscopic correlations between radio maps obtained on 6 different days we establish the presence of 66 radio source components associated with 22 active regions. We find the following statistical results for active region source structures at 20 cm: 1. The observed lifetime is consistent with an exponential distribution having an e-folding time scale of greater than 18 days. 2. The average altitude of 20 cm sources is 25 +/- 15 Mm; 90% of the sources are found in heights less than 40 Mm. 3. The average diameter of discrete source structures is 48 +/- 15 Mm, implying a vertical/horizontal aspect ratio of q(sub A) approx. = 0.5. 4. No significant source motion has been found with respect to the standard differential rotation rate of Omega = 13.45 deg - ((3 deg (sin(exp 2)B)). 5. We find a statistical limb darkening, which can be described by the relation (T(sub B)(alpha))/T(sub B)(0)) = 0.4 + ((0.6(cos(exp 2) alpha)) for sources with T(sub B) greater than 0.5 MK. 6. The degree of source polarization is 15% +/- 10% and is independent of source location. 7. Bright sources (greater than or approximately equal to 0.5 MK), or equivalently, long-lived sources (greater than or approximately equal to 5 days) show a systematic variation of their altitude as function of the center-limb distance.