3D Reconstruction of Tomographic Images Applied to Largely Spaced Slices

This paper presents a full reconstruction process of magnetic resonance images. The first step is to bring the acquired data from the frequency domain, using a Fast Fourier Transform algorithm. A Tomographic Image Interpolation is then used to transform a sequence of tomographic slices in an isotropic volume data set, a process also called 3D Reconstruction. This work describes an automatic method whose interpolation stage is based on a previous matching stage using Delaunay Triangulation. The reconstruction approach uses an extrapolation procedure that permits appropriate treatment of the boundaries of the object under analysis.     

ISFG: Recommendations on biostatistics in paternity testing

The Paternity Testing Commission (PTC) of the International Society for Forensic Genetics has taken up the task of establishing the biostatistical recommendations in accordance with the ISO 17025 standards and a previous set of ISFG recommendations specific to the genetic investigations in paternity cases. In the initial set, the PTC recommended that biostatistical evaluations of paternity are based on a likelihood ratio principle – yielding the paternity index, PI. Here, we have made five supplementary biostatistical recommendations. The first recommendation clarifies and defines basic concepts of genetic hypotheses and calculation concerns needed to produce valid PIs. The second and third recommendations address issues associated with population genetics (allele probabilities, Y-chromosome markers, mtDNA, and population substructuring) and special circumstances (deficiency/reconstruction and immigration cases), respectively. The fourth recommendation considers strategies regarding genetic evidence against paternity. The fifth recommendation covers necessary documentation, reporting details and assumptions underlying calculations. The PTC strongly suggests that these recommendations should be adopted by all laboratories involved in paternity testing as the basis for their biostatistical analysis.     

Cumulative impact of adding frozen-thawed cycles to single versus double fresh embryo transfers

Randomized control trials have shown that single embryo transfer (SET) results in lower live birth rates than double embryo transfer (DET), while observational, retrospective studies find no decrease in overall live birth rate when using a SET policy. The cumulative (fresh transfer followed by frozen - thawed transfers of embryos from the same stimulated cycle) live birth rate after the first and the second stimulated cycle of SET and DET respectively has been analysed. All couples who received their first fresh embryo transfer at Sahlgrenska University Hospital during 2003 and 2004 were included (n = 689). The live birth rates after DET versus SET in the first and second fresh cycles were 29.7 (47/158) versus 23.9% (127/531) and 30.8 (41/133) versus 22.0% (45/205). The cumulative live birth rate per patient after the addition of frozen-thawed embryo transfers were similar: 33.5 (53/158) and 34.8% (185/531) for DET and SET respectively after the first cycle and 32.3 (43/133) versus 32.2% (66/205) after the second cycle. A logistic regression analysis showed no significant correlation for SET or DET with cumulative live birth. Thus, cumulative live birth rates are similar after SET and DET in a routine IVF programme with a majority of SET transfers, although a higher number of frozen-thawed cycles were needed in the SET group.     

Optimal pressure waveforms for pressure-limited ventilation

In this paper, we find the pressure waveform that minimizes the work of distending the alveoli in the lungs while achieving the desired mean airway pressure and alveolar tidal volume. The model used takes into account the compliance of the airway. The main result is a formula for the pressure waveform at the mouth as a function of time and lung parameters.     

Evaluation of Provider Continuity in Primary Care: Actual Versus Random and Potential Continuity

Continuity of care is an important factor in the quality ofprimary care. Unfortunately there is no common view about itsdefinition, measurement, determinants or relationship to outcome.Using a visit-based approach to the measurement of continuity,the present study examines the effects of organizational changes,including the introduction of a new appointment system, on physiciancontinuity at a Swedish primary health care centre. This allowsthe concepts of random and potential continuity to be introduced,providing norms against which the achieved levels of actualcontinuity can be rated. The results show that the actual physiciancontinuity, although not particularly high, was considerablyhigher than what could be expected according to chance alone(random continuity). Moreover, actual continuity did appearto increase after the organizational changes were implemented–absolutelyas well as in relation to potential continuity. The importanceof reducing the mobility of physicians is emphasized in orderto further improve the situation.