Measurement of gauge blocks by interferometry

The key comparison EURAMET.L-K1.2011 on gauge blocks was carried out in the framework of a EURAMET project starting in 2012 and ending in 2015. It involved the participation of 24 National Metrology Institutes from Europe and Egypt, respectively. 38 gauge blocks of steel and ceramic with nominal central lengths between 0.5 mm and 500 mm were circulated. The comparison was conducted in two loops with two sets of artifacts. A statistical technique for linking the reference values was applied. As a consequence the reference value of one loop is influenced by the measurements of the other loop although they did not even see the artifacts of the others. This influence comes solely from three "linking laboratories" which measure both sets of artifacts. In total there were 44 results were not fully consistent with the reference values. This represents 10% of the full set of 420 results which is a considerable high number. At least 12 of them are clearly outliers where the participants have been informed by the pilot as soon as possible. The comparison results help to support the calibration and measurement capabilities (CMCs) of the laboratories involved in the CIPM MRA

Similarity of Traveling-Wave Delays in the Hearing Organs of Humans and Other Tetrapods

Transduction of sound in mammalian ears is mediated by basilar-membrane waves exhibiting delays that increase systematically with distance from the cochlear base. Most contemporary accounts of such “traveling-wave” delays in humans have ignored postmortem basilar-membrane measurements in favor of indirect in vivo estimates derived from brainstem-evoked responses, compound action potentials, and otoacoustic emissions. Here, we show that those indirect delay estimates are either flawed or inadequately calibrated. In particular, we argue against assertions based on indirect estimates that basilar-membrane delays are much longer in humans than in experimental animals. We also estimate in vivo basilar-membrane delays in humans by correcting postmortem measurements in humans according to the effects of death on basilar-membrane vibrations in other mammalian species. The estimated in vivo basilar-membrane delays in humans are similar to delays in the hearing organs of other tetrapods, including those in which basilar membranes do not sustain traveling waves or that lack basilar membranes altogether

Effect of hearing loss and age on human cochlear traveling wave delay

Bibliography: p. 81-86.The cochlear traveling wave delay can be derived from distortion product emission (DPE) phase measurements [Kimberley et al., 1993]. By testing ears with mild cochlear hearing damage as well as ears with normal hearing thresholds (~25 dB SPL, ANSI 1969), it was shown that cochlear latencies measured in this way are not significantly affected by hearing loss. Traveling wave delay however does increase slightly with age. Optimal f2/ fi ratio and associated DPE amplitude were also tested for age or threshold effects. The f2/fi ratio remained unaffected by age or hearing loss, but decreased with increasing frequency. The maximum DPE amplitude decreased with both advancing age and with increasing pure-tone threshold, so it was impossible to isolate the contribution of each individual factor. The linearity between maximum DPE amplitude and threshold, at the frequencies tested, shows potential for clinical use

Fingermarks as a new proteomic specimen: state of the art and perspective of in situ proteomics

For at least the first three decades since its advent, proteomics has exclusively largely belonged to a clinical, diagnostic, or fundamental biology context. However, the range and the significance of information that proteomes can disclose have led this discipline to be also applied to forensics, ranging from human identification from hair samples, identification of bodily fluids, and microbial forensics to doping investigations. Fingermarks are a relatively new specimen for proteomic studies with any form of proteomic investigation only appearing in 2012 with the analysis of intact peptides and small proteins in situ published by the research group at Sheffield Hallam University. It was not until 2015 that further developments allowed bottom-up proteomics to be also applied directly in situ. While in situ proteomics of fingermarks has many advantages, encompassing simplified sample preparation protocols, speed and the opportunity to perform molecular imaging analyses, this area remains under-investigated. This is probably due to the unique challenges of working with fingermark specimens. The relatively low protein content and the predominantly eccrine origin of fingermarks have been shown to severely impact protein detection at least when the “intact” protein approach is used both in full scan and using a top down approach. In this chapter, advantages, application, challenges and perspective of in situ fingermark proteomics are discussed and compared with classic approaches