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

Colitis is associated with loss of LHPP and up-regulation of histidine phosphorylation in intestinal epithelial cells

Protein histidine phosphorylation (pHis) is a posttranslational modification involved in cell cycle regulation, ion channel activity and phagocytosis (1). Using novel monoclonal antibodies to detect pHis (2), we recently reported that loss of the histidine phosphatase LHPP results in elevated pHis levels in hepatocellular carcinoma (3). Here, we show that intestinal inflammation correlates with loss of LHPP, in DSS-treated mice and in inflammatory bowel disease (IBD) patients. Increased histidine phosphorylation was observed in intestinal epithelial cells (IECs), as determined by pHis immunofluorescence staining of colon samples from a colitis mouse model. However, ablation of Lhpp did not cause increased pHis or promote intestinal inflammation in physiological conditions or after DSS treatment. Our observations suggest that increased histidine phosphorylation plays a role in colitis, but loss of LHPP is not sufficient to increase pHis or to cause inflammation in the intestine

Recombinant Spider Silk Protein and Delignified Wood Form a Strong Adhesive System

For developing novel fully biological materials, a central question is how we can utilize natural components in combination with biomimetic strategies in ways that both allow feasible processing and high performance. Within this development, adhesives play a central role. Here, we have combined two of nature's excellent materials, silk and cellulose, to function as an adhesive system. As an initial step in processing, wood was delignified. Without lignin, the essential microstructure and alignment of the wood remain, giving a strong scaffold that is versatile to process further. A recombinant spider silk protein was used as a fully biological and water-based adhesive. The adhesive strength was excellent with an average value of 6.7 MPa, with a maximum value of up to 10 MPa. Samples of different strengths showed characteristic features, with high tear-outs for weaker samples and only little tear-out for strong samples. As references, bovine serum albumin and starch were used. Based on the combined data, we propose an overall model for the system and highlight how multiple variables affect performance. Adhesives, in particular, biobased ones, must be developed to be compatible with the overall adherend system for suitable infiltration and so that their mechanical properties match the adherend. The engineering of proteins gives an unmatched potential for designing adhesive systems that additionally have desired properties such as being fully water-based, biologically produced, and renewable.Peer reviewe

Desde la investigación sobre razonamiento Bayesiano a la intervención en el aula

III Congreso Internacional Virtual de Educación Estadística (CIVEEST), 21-24 febrero de 2019. [www.ugr.es/local/fqm126/civeest.html]Dealing with Bayes’ rule is the mathematical part of judgement in situations of uncertainty. These situations are of importance for crucial judgements in medicine, law and further professions. Since laymen and experts have severe difficulties of applying Bayes’ rule, the question how to facilitate dealing with Bayesian situations, i.e. situations in which Bayes’ rule could be applied is posed. Our research built upon the well-established facilitating strategy of using natural frequencies as information format in Bayesian situations. On this basis, we have investigated different visualizations and developed a training of dealing and understanding Bayesian situations. Our results suggest that the unit square and the double tree diagram are appropriate visualizations for a training concerning Bayesian situations and that also a brief training has strong effects.La parte matemática del razonamiento en situaciones de incertidumbre implica el uso del teorema de Bayes. Estas situaciones son importantes para la emisión de juicios en medicina, derecho y otras profesiones. Puesto que tanto las personas ordinarias como los expertos tiene dificultades severas para aplicar el teorema de Bayes, se plantea la cuestión de cómo facilitar el tratamiento de las situaciones de Bayes, esto es, situaciones en las que la regla de Bayes puede ser aplicada. Nuestra investigación se basa en la estrategia facilitadora bien establecida de usar frecuencias naturales como formato de información en situaciones Bayesianas. Sobre esta base, hemos investigado diferentes visualizaciones y desarrollado una intervención formativa para tratar y comprender situaciones Bayesianas. Nuestros resultados sugieren que el cuadrado unitario y el doble diagrama en árbol son visualizaciones apropiadas para el entrenamiento relativo a las situaciones Bayesianas y que incluso un breve entrenamiento tiene fuertes efectos

Matematizando situaciones Bayesianas en la escuela usando múltiples representaciones

III Congreso Internacional Virtual de Educación Estadística (CIVEEST), 21-24 febrero de 2019. [www.ugr.es/local/fqm126/civeest.html]Bayesian problem situations are well known as being difficult for people to judge adequately. Teachers in school are confronted with the question what can be done on the long run to support their students in coping with Bayesian situations. In this regard the paper refers to the learning about mathematizing Bayesian situations in school, especially focused on using the unit square in settings of learning with multiple representations. Firstly, the topic of Bayesian reasoning will be analysed from the different perspectives of mathematical, modelling, and mathematizing structure. Afterwards, potentials of theories of learning with multiple representations will be reflected within the topic of Bayesian reasoning. Bringing both together yields in in a 2x2 matrix which allows for categorizing task types about Bayesian situations.Se conocen bien las dificultades de las personas para juzgar adecuadamente las situaciones- problemas Bayesianas. Los profesores se enfrentan en la escuela a la cuestión de qué se puede hacer a largo plazo para apoyar a sus estudiantes en la resolución de situaciones Bayesianas. A este respecto este artículo refiere al aprendizaje de la matematización de situaciones Bayesianas en la escuela, especialmente centrado en el uso del cuadrado unidad en entornos de aprendizaje con múltiples representaciones. En primer lugar, se analizará el tema del razonamiento Bayesiano desde las diferentes perspectivas de matematización y modelización de la estructura matemática. Seguidamente, el potencial de teorías del aprendizaje que tienen en cuenta el uso de múltiples representaciones será reflejado dentro del tópico del razonamiento Bayesiano. Conjuntando ambos campos se elabora una matriz de 2x2 que permite la categorización de tipos de tareas sobre situaciones Bayesianas

Lenalidomide in cancer cachexia: a randomized trial of an anticancer drug applied for anti-cachexia

Background Cancer cachexia (CC) impacts quality of life, physical function, anticancer treatment response, and survival. Inflammation is a prominent pathomechanism of CC. This small-scale study sets out to investigate the immunomodulatory drug lenalidomide in inflammatory CC in a randomized, double-blind, placebo-controlled trial. Methods Patients with advanced solid malignancies, documented weight loss, no or unchanged anticancer treatment, and C-reactive protein > 30 mg/L were included. In a 2:2:1 randomization, patients received either lenalidomide 25 mg once daily or C-reactive protein-guided dose, starting with 5 mg lenalidomide once daily or placebo once a day for 8 weeks. Dose adaption and safety were assessed twice a week. Treatment response was defined as an increase of lean body mass of more than 2% in a lower lumbar computed tomography and an increase in dynamometer-assessed handgrip strength of 4 kg. Secondary endpoints included adverse events, C-reactive protein response, nutritional intake, and symptoms. Results Of 24 eligible patients, 16 were included (25% female). At baseline, the mean age was 67 (range 51–88) years, and mean body weight was 64.7 kg (range 39.8–87.2 kg). Five were diagnosed with mesothelioma, two with non-small-cell lung cancer, two with renal cell carcinoma, two with neuroendocrine tumours, and five with other malignancies. Mean survival was 43 days. Eleven adverse events (four of which were severe) were recorded with a probable link to study participation. Nine patients completed the study. No participant showed a treatment response. C-reactive protein-guided dosing did not result in lower doses of lenalidomide. Lean body mass decreased less in the treatment groups. For the lenalidomide and placebo groups respectively, handgrip strength decreased by 2.3 vs. 5.5 kg, nutritional intake decreased by 249 vs. 32 kcal/day, and C-reactive protein increased by 35 mg/dL vs. decreased by 17 mg/dL. The study was closed prematurely due to slow accrual and the need for concurrent anticancer treatments. Conclusions No treatment response on muscle mass and muscle strength was observed with lenalidomide. Because of several limiting factors, including low recruitment caused in part by an ambitious study design and concomitant anticancer treatment, this study did not generate adequate data to draw reliable conclusions

Molecular crowding facilitates assembly of spidroin-like proteins through phase separation

Gaining insights into the processes that transform dispersed biopolymers into well-ordered structures, such as soluble spidroin-proteins to spider silk threads, is essential for attempts to understand their biological function and to mimic their unique properties. One of these processes is liquid-liquid phase separation, which can act as an intermediate step for molecular assembly. We have shown that a self-coacervation step that occurs at a very high protein concentration (> 200 gl(-1)) is crucial for the fiber assembly of an engineered triblock silk-like molecule. In this study, we demonstrate that the addition of a crowding agent lowers the concentration at which coacervation occurs by almost two orders of magnitude. Coacervates induced by addition of a crowding agent are functional in terms of fiber formation, and the crowding agent appears to affect the process solely by increasing the effective concentration of the protein. Furthermore, induction at lower concentrations allows us to study the thermodynamics of the system, which provides insights into the coacervation mechanism. We suggest that this approach will be valuable for studies of biological coacervating systems in general.Peer reviewe