Inter-observer agreement of paranasal sinus computed tomography scans.

CONCLUSION: The study demonstrated considerable inter-observer variation in certain surgically important structures. This would indicate the significance for consultation when evaluating sinus CT scans of CRS patients for planned advanced sinus surgery. OBJECTIVES: After the failure of medical treatment of chronic rhinosinusitis (CRS), the need for surgery and the pre-operative planning of safe surgery is based on computed tomography (CT) findings. The aim of this prospective study was to compare inter-observer agreement of anatomical and surgical structures of sinus CT scans. The hypothesis was that the agreement between observers is good. METHODS: Of these 57 CRS patients, Lund-Mackay (LM) scores and 43 other structural parameters were analyzed blinded. The reproducibility of the findings between three observers, a radiologist, an Ear, nose and throat (ENT) surgeon, and an ENT resident, were compared. RESULTS: In general, there was moderate inter-observer agreement of the structures by Cohen's kappa coefficient. Poor reproducibility was observed in the following structures: optic nerve, insertion of the uncinated process, anterior ethmoidal artery, and Keros class.

Short-term memory functions of the human fetus recorded with magnetoencephalography.

Studies in fetuses and in prematurely born infants show that auditory discriminative skills are present prior to birth. The magnetic fields generated by the fetal brain activity pass the maternal tissues and, despite their weakness, can be detected externally using MEG. Recent studies on the auditory evoked magnetic responses show that the fetal brain responds to sound onset. In contrast, higher-level auditory skills, such as those involving discriminative and memory functions, were not so far studied in fetuses with MEG. Here we show that fetal responses related to discriminating sounds can be recorded, implicating that the auditory change-detection system is functional. These results open new views to developmental neuroscience by enabling one to determine the sensory capabilities as well as the extent and accuracy of the short-term memory system of the fetus, and, further, to follow the development of these crucial processes.

STR analysis of artificially degraded DNA-results of a collaborative European exercise.

Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.

Acoustical analysis and model-based sound synthesis of the kantele.

The five-string Finnish kantele is a traditional folk music instrument that has unique structural features, resulting in a sound of bright and reverberant timbre. This article presents an analysis of the sound generation principles in the kantele, based on measurements and analytical formulation. The most characteristic features of the unique timbre are caused by the bridgeless string termination around a tuning pin at one end and the knotted termination around a supporting bar at the other end. These result in prominent second-order nonlinearity and strong beating of harmonics, respectively. A computational model of the instrument is also formulated and the algorithm is made efficient for real-time synthesis to simulate these features of the instrument timbre.