Understanding Indirect Causal Relationships in Node‐Link Graphs

To find correlations and cause and effect relationships in multivariate data sets is central in many data analysis problems. A common way of representing causal relations among variables is to use node‐link diagrams, where nodes depict variables and edges show relationships between them. When performing a causal analysis, analysts may be biased by the position of collected evidences, especially when they are at the top of a list. This is of crucial importance since finding a root cause or a derived effect, and searching for causal chains of inferences are essential analytic tasks when investigating causal relationships. In this paper, we examine whether sequential ordering influences understanding of indirect causal relationships and whether it improves readability of multi‐attribute causal diagrams. Moreover, we see how people reason to identify a root cause or a derived effect. The results of our design study show that sequential ordering does not play a crucial role when analyzing causal relationships, but many connections from/to a variable and higher strength/certainty values may influence the process of finding a root cause and a derived effect.     

Full body virtual autopsies using a state-of-the-art volume rendering pipeline

This paper presents a procedure for virtual autopsies based on interactive 3D visualizations of large scale, high resolution data from CT-scans of human cadavers. The procedure is described using examples from forensic medicine and the added value and future potential of virtual autopsies is shown from a medical and forensic perspective. Based on the technical demands of the procedure state-of-the-art volume rendering techniques are applied and refined to enable real-time, full body virtual autopsies involving gigabyte sized data on standard GPUs. The techniques applied include transfer function based data reduction using level-of-detail selection and multi-resolution rendering techniques. The paper also describes a data management component for large, out-of-core data sets and an extension to the GPU-based raycaster for efficient dual TF rendering. Detailed benchmarks of the pipeline are presented using data sets from forensic cases.     

Age-induced hypertrophy of astrocytes in rat supraoptic nucleus: a cytological, morphometric, and immunocytochemical study

BACKGROUND: In the adult rat, neuron-astroglia interactions in the supraoptic nucleus (SON) are characterized by the structural and functional plasticity of astrocytes in response to several physiological and experimental conditions. This study has analyzed the plasticity of the supraoptic nucleus astrocytes in response to the age-induced changes in neuronal activity. METHODS: The study was performed in 5-, 12-, 18- and 24-month-old rats. The cytology and organization of astrocytes in the SON were examined using glial fibrillary acidic and vimentin immunocytochemistry and ultrastructural and morphometric analysis. RESULTS: No significant age-related variations in the total number of neurons and astrocytes in the SON were detected, although a few degenerating neurons were found in old rats. An age-dependent increase in GFAP immunoreactivity was observed at the ventral glial lamina, perivascularly and between neuronal perikarya. Vimentin overexpression was also detected in ventral lamina astrocytes with advancing age. At the cell nucleus level, we observed an age-associated increase in nuclear size and in the number of coiled bodies, nuclear bodies, and "cleared" nucleoplasmic areas, as well as changes in the nucleolar organization. At the cytoplasmic level, characteristic ultrastructural features in astrocytes of old rats were the hypertrophy of intermediate filament bundles and the formation of an extensive network of Golgi stacks interlinked by tubulovesicular elements. Glial filaments were often associated with the nuclear envelope and polyribosomes. CONCLUSIONS: The increased GFAP and vimentin immunoreactivity and the morphometric and cytological changes in rat SON astrocytes may reflect a sustained upregulation of cellular activity with age, resulting in hypertrophy of glial perikarya and cell processes. Several factors that are known to influence the expression of the astrocytic phenotype, such as signals produced by degenerating neurons and activated microglia, as well as variations in neuronal activity are considered possible causes of the age-associated changes in SON astrocytes.     

Personal contact from friends to increase mammography usage

To increase the use of mammography among women 40 years of age and older, the American Cancer Society (ACS) designed a telephone intervention strategy (the "Tell A Friend" program) that relied on ACS volunteers. During a half-day training session, each volunteer provided a list of 10 women she was willing to contact over a 6-month period and encourage to have a mammogram. Each list was randomized, and five names were returned to each volunteer for inclusion in the intervention. The other women served as controls and were not contacted by the volunteers. All women were subsequently interviewed at the end of the intervention period. Forty-nine percent of the women in the intervention group (n = 289) had received their most recent mammogram since the start of the intervention period, whereas 34% of control women (n = 305) received mammograms during the same time period (p < or = .001, rate ratio = 1.4, 95% confidence interval = 1.2, 1.7). The effectiveness of the intervention remained after controlling for demographic characteristics. The strategy was effective for both black and white women of all ages, but principally among women with annual household incomes of less than $40,000. We conclude that a telephone intervention strategy of personal contacts between acquainted women can significantly increase mammography use, particularly among women with low-to-moderate income.     

Fe-doped SnO2 obtained by mechanical alloying

In this work, iron-doped SnO₂ powders were prepared by two methods: mechanical alloying and mechanochemical alloying with successive thermal treatment. The influence of different milling conditions such as ball to powder weight ratio, milling time, rotation velocity of supporting disc and the type of iron starting reactive and their Fe concentration on the structural and magnetic properties of the products were investigated. A greater incorporation of Fe in the SnO₂ structure was observed when the samples were prepared by using mechanochemical alloying and successive thermal treatment.     

Influence of 16-week monotherapy with acarbose on cardiovascular risk factors in obese subjects with non-insulin-dependent diabetes mellitus: a controlled, double-blind comparison study with placebo

A 49-year-old patient suffered from a binocular perforating trauma with metal foreign bodies in 1974. During an MRI examination in 1992 for a lumbar spine herniation a metal foreign body was mobilised from the deeper vitreal and retinal area, now causing optical disturbances freely floating in the anterior vitreous. Refusing an operation, the patient, an electrical engineer, tried himself to remove the foreign body out of the optical axis by exposing his head to the electro-magnetic field of an induction coil (pulsed magnetic induction B at t0 of 0.26 Tesla). The foreign body was split into multiple small parts no longer disturbing the patient. To early detect a siderosis regular ophthalmological controls including ERG are necessary. This example stresses that even small intraocular metal foreign bodies are a contraindication for the usually applied field strength of MRI examinations.     

Robustness Comparison of 15 Real Telecommunication Networks: Structural and Centrality Measurements

Multiple failures can have catastrophic consequences on the normal operation of telecommunication networks. In this sense, guaranteeing network robustness to avoid users and services being disconnected is essential. A wide range of metrics have been proposed for measuring network robustness. In this paper the taxonomy of robustness metrics in telecommunication networks has been extended and a classification of multiple failures scenarios has been made. Moreover, a structural and centrality robustness comparison of 15 real telecommunication networks experiencing multiple failures was carried out. Through this analysis the topological properties which are common for grouping networks with similar robustness are able to be identified.     

Impact of the customer demand on order fulfilment strategies based on floating decoupling point: a simulation analysis

Order Fulfilment Strategies have become more and more popular, thanks to their capability of improving the delivery times and reducing the inventory levels. Among the postponement strategies of Mass Customisation are the Virtual Build-To-Order (VBTO) and i-Virtual Build-To-Order (i-VBTO) systems which are two systems with the ability to serve customers from anywhere in the inventory (Work-in-Process and Finished Goods Inventory) showing an interesting potential of adaptation to the variability of the demand. This study is aimed at testing the suitability of the basis of the i-VBTO system against the VBTO system through the study of the influence of characteristics of demand that are common in real environments. Regarding the contribution of this work, some weaknesses of the VBTO system can be highlighted (e.g. under certain demand conditions it loses the efficiency), and some benefits of the i-VBTO system (e.g. it turns out to be more robust and stable regarding changes in demand than the VBTO system).     

Association of Helicobacter pylori infection with cardiovascular and cerebrovascular disease in diabetic patients

We present the case of 44-yr-old man who presented syncope with ventricular tachycardia in the setting of Brugada syndrome. In addition to the electrocardiographic evidence of the syndrome and the absence of apparent structural heart disease, clear defects of myocardial neuronal metaiodobenzylguanidine (MIBG) uptake on MIBG SPECT imaging also were found in inferior, apical and septal walls. Thallium-201 SPECT distribution was homogeneous along the left ventricle. Thus, cardiac MIBG scintigraphy provides information about left ventricular dysinnervation in a patient with Brugada syndrome, enhancing the clinical utility of myocardial MIBG SPECT imaging in life-threatening ventricular arrhythmias.     

Self-Cleaning Transparent Dust Shields for Protecting Solar Panels and Other Devices

The development of transparent flexible dust shields using both single- and three-phase electrodynamic shields is reported here for possible application on Mars and Earth to minimize obscuration of solar panels from the deposition of dust. The electrodynamic screens (EDS) are made of transparent plastic sheets, such as polyethylene terephthalate (PET) for its UV radiation resistance, and a set of parallel conducting electrodes made of transparent indium tin oxide (ITO) embedded under a thin transparent film. The basic principle of EDS operation, a simplified mathematical model of particle trajectories, the experimental setup used for testing the screens, and their dust removal efficiencies (DRE) are described. Results of our measurements on dust removal efficiency of EDS as a function of the particle size and electrostatic charge distributions of Mars simulant dust are reported. The results show that the EDS technology has a strong potential for protecting solar panels against dust hazards with DRE higher than 80% for dust. The power requirements will be approximately 10 watts per square meter of the panels when cleaning is needed.