The impact of visualization on flexible Bayesian reasoning

There is wide consensus that visualizations of statistical information can support Bayesian reasoning. This article focusses on the conceptual understanding of Bayesian reasoning situations and investigates whether the tree diagram or the unit square is more appropriate to support the understanding of the influence of the base rate, which is introduced as being a part of flexible Bayesian reasoning. As a statistical graph, the unit square reflects the influence of the base rate not only in a numerical but also in a geometrical way. Accordingly, in two experiments with undergraduate students (N = 148 and N = 143) the unit square outperformed the tree diagram referring to the understanding of the influence of the base rate. Our results could inform the discussion about how to visualize Bayesian situations and has practical consequences for the teaching and learning of statistics

A training in visualizing statistical data with a unit square

International audienceRecent research yielded empirical evidence for a unit square being a useful visualization of Bayesian situations. However, most of the studies in the research field of visualizing Bayesian problem situations were conducted in well-controlled experimental settings with university students as parti¬cipants. Therefore, we focus in this paper on a training study with 38 eleventh graders in school about visualizing statistical data with a unit square for coping with Bayesian problem situations. Firstly, we outline some theoretical and empirical basics concerning research about Bayesian situations and a unit square as a facilitating visualization tool. Afterwards, we present a short training sequence in using the unit square effectively. We report on methods, implementation and results of a pilot study in school. The promising results were discussed at the end

Point-of-care mobile digital microscopy and deep learning for the detection of soil-transmitted helminths and Schistosoma haematobium

Background: Microscopy remains the gold standard in the diagnosis of neglected tropical diseases. As resource limited, rural areas often lack laboratory equipment and trained personnel, new diagnostic techniques are needed. Low-cost, point-of-care imaging devices show potential in the diagnosis of these diseases. Novel, digital image analysis algorithms can be utilized to automate sample analysis. Objective: Evaluation of the imaging performance of a miniature digital microscopy scanner for the diagnosis of soil-transmitted helminths and Schistosoma haematobium, and training of a deep learning-based image analysis algorithm for automated detection of soil-transmitted helminths in the captured images. Methods: A total of 13 iodine-stained stool samples containing Ascaris lumbricoides, Trichuris trichiura and hookworm eggs and 4 urine samples containing Schistosoma haematobium were digitized using a reference whole slide-scanner and the mobile microscopy scanner. Parasites in the images were identified by visual examination and by analysis with a deep learning-based image analysis algorithm in the stool samples. Results were compared between the digital and visual analysis of the images showing helminth eggs. Results: Parasite identification by visual analysis of digital slides captured with the mobile microscope was feasible for all analyzed parasites. Although the spatial resolution of the reference slide-scanner is higher, the resolution of the mobile microscope is sufficient for reliable identification and classification of all parasites studied. Digital image analysis of stool sample images captured with the mobile microscope showed high sensitivity for detection of all helminths studied (range of sensitivity = 83.3-100%) in the test set (n = 217) of manually labeled helminth eggs. Conclusions: In this proof-of-concept study, the imaging performance of a mobile, digital microscope was sufficient for visual detection of soil-transmitted helminths and Schistosoma haematobium. Furthermore, we show that deep learning-based image analysis can be utilized for the automated detection and classification of helminths in the captured images.Peer reviewe

Inverse correlation between endothelin-1-induced peripheral microvascular vasoconstriction and blood pressure in glaucoma patients

• Background: The potent vasoconstrictor peptide endothelin-I has been shown to participate in the control of peripheral vascular tone and in the regulation of ocular perfusion. In glaucoma patients vasospasms and arterial hypotension have been identified as risk factors for the progression of glaucomatous damage, and the regulation of endothelin-1 release is disturbed in some of these patients. The aim of this study was to assess the relationship between resting blood pressure and cutaneous vascular responsiveness to endothelin-1 and phenylephrine in patients with glaucoma and in matched controls. • Methods: In 9 patients with primary open-angle glaucoma (POAG), 7 patient with normal tension glaucoma (NTG), and 16 age- and sex-matched controls, endothelin-1 and phenylephrine responses were assessed in the human forearm microcirculation using laser Doppler flowmetry during intra-arterial drug administration. Blood pressure was measured intra-arterially. • Results: In contrast to α1-adrenergic effects, endothelin-1 responses were inversely correlated to both systolic (r 2 = 0.27,P = 0.05) and diastolic (r 2 = 0.54,P = 0.001) blood pressure in glaucoma patients, whereas there was no such correlation in controls. Patients with lower blood pressure values were more sensitive to the vasoconstrictor effects of endothelin-1. Cutaneous responsiveness to endothelin-1 and phenylephrine was similar in glaucoma patients and in controls. • Conclusion: These results reveal that glaucoma patients appear to have peripheral microvascular abnormalities which are exhibited as altered responsiveness to endothelin-1. Thus, this study supports the hypothesis that endothelin-l-related microvascular dysfunction may be involved in the pathogenesis of glaucomatous damag

A novel inhibitor of proteasome deubiquitinating activity renders tumor cells sensitive to TRAIL-mediated apoptosis by natural killer cells and T cells

The proteasome inhibitor bortezomib simultaneously renders tumor cells sensitive to killing by natural killer (NK) cells and resistant to killing by tumor-specific T cells. Here, we show that b-AP15, a novel inhibitor of proteasome deubiquitinating activity, sensitizes tumors to both NK and T cell-mediated killing. Exposure to b-AP15 significantly increased the susceptibility of tumor cell lines of various origins to NK (p<0.0002) and T cell (p=0.02) –mediated cytotoxicity. Treatment with b-AP15 resulted in increased TRAIL [tumor necrosis factor-related apoptosis-inducing ligand] receptor-2 expression (p=0.03) and decreased cFLIP expression in tumor cells in vitro. In tumor-bearing SCID/Beige mice, treatment with b-AP15 followed by infusion of either human NK cells or tumor-specific T cells resulted in a significantly delayed tumor progression compared with mice treated with NK cells (p=0.006), T cells (p<0.0001), or b-AP15 alone (p=0.003). Combined infusion of NK and T cells in tumor-bearing BALB/c mice following treatment with b-AP15 resulted in a significantly prolonged long-term survival compared with mice treated with b-AP15 and NK or T cells (p≤0.01). Our findings show that b-AP15-induced sensitization to TRAIL-mediated apoptosis could be used as a novel strategy to augment the anti-cancer effects of adoptively infused NK and T cells in patients with cancer.VetenskapsrådetEuropean Research CouncilAccepte