Tuplix Calculus

We introduce a calculus for tuplices, which are expressions that generalize matrices and vectors. Tuplices have an underlying data type for quantities that are taken from a zero-totalized field. We start with the core tuplix calculus CTC for entries and tests, which are combined using conjunctive composition. We define a standard model and prove that CTC is relatively complete with respect to it. The core calculus is extended with operators for choice, information hiding, scalar multiplication, clearing and encapsulation. We provide two examples of applications; one on incremental financial budgeting, and one on modular financial budget design.Comment: 22 page

Optical mammography combined with fluorescence imaging: lesion detection using scatterplots

Using scatterplots of 2 or 3 parameters, diffuse optical tomography and fluorescence imaging are combined to improve detectability of breast lesions. Small or low contrast phantom-lesions that were missed in the optical and fluorescence images were detected in the scatterplots. In patient measurements, all tumors were visible and easily differentiated from artifacts and areolas in the scatterplots. The different rate of intake and wash out of the fluorescent contrast agent in the healthy versus malignant tissues was also observed in the scatterplot: this information can be used to discriminate malignant lesion from normal structures

Prediction and treatment of asthma in preschool children at risk: study design and baseline data of a prospective cohort study in general practice (ARCADE)

Background: Asthma is a difficult diagnosis to establish in preschool children. A few years ago, our group presented a prediction rule for young children at risk for asthma in general practice. Before this prediction rule can safely be used in practice, cross-validation is required. In addition, general practitioners face many therapeutic management decisions in children at risk for asthma. The objectives of the study are: (1) identification of predictors for asthma in preschool children at risk for asthma with the aim of cross-validating an earlier derived prediction rule; (2) compare the effects of different treatment strategies in preschool children. Design: In this prospective cohort study one to five year old children at risk of developing asthma were selected from general practices. At risk was defined as 'visited the general practitioner with recurrent coughing (≥ 2 visits), wheezing (≥ 1) or shortness of breath (≥ 1) in the previous 12 months'. All children in this prospective cohort study will be followed until the age of six. For our prediction rule, demographic data, data with respect to clinical history and additional tests (specific immunoglobulin E (IgE), fractional exhaled nitric oxide (FENO), peak expiratory flow (PEF)) are collected. History of airway specific medication use, symptom severity and health-related quality of life (QoL) are collected to estimate the effect of different treatment intensities (as expressed in GINA levels) using recently developed statistical techniques. In total, 1,938 children at risk of asthma were selected from general practice and 771 children (40%) were enrolled. At the time of writing, follow-up for all 5-year olds and the majority of the 4-year olds is complete. The total and specific IgE measurements at baseline were carried out by 87% of the children. Response rates to the repeated questionnaires varied from 93% at baseline to 73% after 18 months follow-up; 89% and 87% performed PEF and FENO measurements, respectively. Discussion: In this study a prediction rule for asthma inyoung children, to be used in (general) practice, will be cross-validated. Our study will also provide more insight in the effect of treatment of asthma in preschool children

Large Torque Variations in Two Soft Gamma Repeaters

We have monitored the pulse frequencies of the two soft gamma repeaters SGR 1806-20 and SGR 1900+14 through the beginning of year 2001 using primarily Rossi X-ray Timing Explorer Proportional Counter Array observations. In both sources, we observe large changes in the spin-down torque up to a factor of ~4, which persist for several months. Using long baseline phase-connected timing solutions as well as the overall frequency histories, we construct torque noise power spectra for each SGR. The power spectrum of each source is very red (power-law slope ~-3.5). The torque noise power levels are consistent with some accreting systems on time scales of ~1 year, yet the full power spectrum is much steeper in frequency than any known accreting source. To the best of our knowledge, torque noise power spectra with a comparably steep frequency dependence have only been seen in young, glitching radio pulsars (e.g. Vela). The observed changes in spin-down rate do not correlate with burst activity, therefore, the physical mechanisms behind each phenomenon are also likely unrelated. Within the context of the magnetar model, seismic activity cannot account for both the bursts and the long-term torque changes unless the seismically active regions are decoupled from one another.Comment: 26 pages, 11 figures included, accepted for publication in ApJ, analysis of torque noise power density spectra is revised from previous version and minor text changes were mad

Determination of the diffusion constant using phase-sensitive measurements

We apply a pulsed-light interferometer to measure both the intensity and the phase of light that is transmitted through a strongly scattering disordered material. From a single set of measurements we obtain the time-resolved intensity, frequency correlations and statistical phase information simultaneously. We compare several independent techniques of measuring the diffusion constant for diffuse propagation of light. By comparing these independent measurements, we obtain experimental proof of the consistency of the diffusion model and corroborate phase statistics theory.Comment: 9 pages, 8 figures, submitted to Phys. Rev.

Dating and provenancing the <i>Woman with lantern</i> sculpture – A contribution towards attribution of Netherlandish art

Studying the wood of art objects such as sculptures, panel paintings and furniture can be crucial to elucidate their chronology and production centre. Here we present an approach that considers the provenance of the wood and its potential availability in different areas as a means to identify the provenance of wooden art objects. We illustrate this approach with an interdisciplinary study aimed to determine the date and provenance of the Woman with lantern, a carved altar fragment from the Rijksmuseum's collections (Amsterdam, The Netherlands). The origin of this object is undocumented, but based on stylistic and iconographic features its provenance was proposed to be the altarpiece of Rennes cathedral (France), carved in Antwerp (Belgium) around 1520 C.E. However, doubts arose when curators tested the potential fit of the sculpture in that altarpiece and could not find a neat match. Dating and provenancing the wood of the sculpture by standard dendrochronological means failed to produce a date, and comparison of the tree-ring pattern from the sculpture with those of the sculptures from Rennes altarpiece delivered no results either, supporting the suspicion that the Woman with lantern belonged elsewhere. In 2019, X-ray computed tomography (CT) provided digital cross-sections throughout the sculpture and a longer tree-ring series was obtained. This time, the outermost ring was dated to the year 1487 C.E. The tree was estimated to have been cut after 1495 C.E., indicating a likely production in the first quarter of the 16th century. The origin of the timber in the eastern Netherlands/northwest Germany, combined with empirical evidence about timber availability in various regions of the Low Countries at that time, suggests that the sculpture was made in a workshop located north of the Rhine in the (current) Netherlands, rather than Antwerp. This research has led to the hypothesis that workshops north and south of the Rhine river branches in the Low Countries were supplied by forests located in different areas. If proven correct, establishing the wood provenance will assist in determining the origin of Netherlandish works of art from the late-Gothic and Northern Renaissance periods