Revista Jurídica Digital UANDES
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Error Estimation for Appearance Model Segmentation of Musculoskeletal Structures using Multiple, Independent Sub-models
No full textSegmentation of structures in clinical images is a precursor to computer-aided detection (CAD) for many musculoskeletal pathologies. Accurate CAD systems could considerably improve the efficiency and objectivity of radiological practice by providing clinicians with image-based biomarkers calculated with minimal human input. However, such systems rarely achieve human-level performance, so extensive manual checking may be required. Their practical utility could therefore be increased by accurate error estimation, focusing manual input on the images or structures where it is needed. Standard techniques such as the minimum variance bound can estimate random errors, but provide no way to estimate any systematic errors due to model fitting failure. We describe the use of multiple, independent sub-models to estimate both systematic and random errors. The approach is evaluated on vertebral body segmentation in lateral spinal images, demonstrating large (up to 50%) and significant improvements in the accuracy of error classification with concurrent improvements in annotation accuracy. Whilst further work is required to elucidate the definition of “independence” in this context, we conclude that the approach provides a valuable component for appearance model based CAD systems.</p
The Tiered Radio Extragalactic Continuum Simulation (T-RECS)
No full textWe present the Tiered Radio Extragalactic Continuum Simulation (T-RECS): a new simulation of the radio sky in continuum, over the 150 MHz–20 GHz range. T-RECS models two main populations of radio galaxies: Active Galactic Nuclei (AGNs) and Star-Forming Galaxies (SFGs), and corresponding sub-populations. Our model also includes polarized emission over the full frequency range, which has been characterised statistically for each population using the available information. We model the clustering properties in terms of probability distributions of hosting halo masses, and use lightcones extracted from a high-resolution cosmological simulation to determine the positions of haloes. This limits the sky area for the simulations including clustering to a 25 deg2 field of view. We compare luminosity functions, number counts in total intensity and polarization, and clustering properties of our outputs to up-to-date compilations of data and find a very good agreement. We deliver a set of simulated catalogues, as well as the code to produce them, which can be used for simulating observations and predicting results from deep radio surveys with existing and forthcoming radio facilities, such as the Square Kilometre Array (SKA)
Suicidal ideation in people with psychosis not taking antipsychotic medication: Do negative appraisals and negative metacognitive beliefs mediate the effect of symptoms?
No full textBetween 5 and 10 percent of people with psychosis will die by suicide, a rate which is 20 to 75 times higher than the general population. This risk is even greater in those not taking antipsychotic medication. We examined whether negative appraisals of psychotic experiences and negative metacognitive beliefs about losing mental control mediated a relationship between psychotic symptoms and suicidal ideation in this group. Participants were diagnosed with schizophrenia-spectrum disorders, antipsychotic-free for 6 months at baseline, and were participating in an 18-month randomised controlled trial of cognitive therapy v. treatment as usual. We conducted a series of mediation analyses with bootstrapping on baseline (N=68), follow-up data (9-18 months; n=49), and longitudinal data (n=47). Concurrent general symptoms were directly associated with suicidal ideation at baseline, and concurrent negative symptoms were directly associated with suicidal ideation at 9-18 months. Concurrent positive, negative, general and overall symptoms were each indirectly associated with suicidal ideation via negative appraisals and/or negative metacognitive beliefs, at baseline and 9-18 months, except for negative symptoms at baseline. Controlling for baseline suicidal ideation and treatment allocation, baseline general symptoms were indirectly associated with later suicidal ideation, via baseline negative appraisals and negative metacognitive beliefs. Baseline negative metacognitive beliefs also had a direct association with later suicidal ideation. These findings suggest the clinical assessment of suicidal ideation in psychosis may be enhanced by considering metacognitive beliefs about the probability and consequences of losing mental control
Parallel Continuous Outlier Mining in Streaming Data
No full textIn this work, we focus on distance-based outliers in a metric space, where the status of an entity as to whether it is an outlier is based on the number of other entities in its neighborhood. In the recent years, several solutions have tackled the problem of distance-based outliers in data streams, where outliers must be mined continuously as new elements become available. An interesting research problem is to combine the streaming environment with massively parallel systems to provide scalable stream-based algorithms. However, none of the previously proposed techniques refer to a massively parallel setting. Our proposal fills this gap and studies transferring state-of-the-art techniques in Apache Flink, a modern platform for intensive streaming analytics. We thoroughly present the technical challenges encountered and the alternatives that may be applied. We show speed-ups up to 117 (resp. 2076) times over a naive parallel (resp. non-parallel) solution in Flink, by using just an ordinary 4-core machine and a real-world dataset. Our results demonstrate that oulier mining can be achieved in an efficient and scalable manner. The resulting techniques have been made publicly available in open-sourc
Biodiversity, physical health and climate change: a synthesis of recent evidence
No full textWe are at a point of history marked by unprecedented changes in the environmental foundations of human health and wellbeing. At the same time, the demands from human populations have never been greater with profound differences in how we engage with the natural environment. By the middle of this century, when climate change impacts are further increasing, the United Nations expects the global population to be approaching 10 billion. In this chapter, we provide a synthesis of published evidence of the complex and important relationships between elements of biodiversity, health and climate change. We draw primarily on reviews conducted in the past five years supplemented with evidence on additional themes. We also develop a detailed case study example focused on urban climate, climate change and biodiversity, taken from the perspective of a large and representative conurbation. The case study uses a body of existing published evidence together with new data and insights to demonstrate important pathways, impacts and outcomes. We end by identifying a set of research questions and stress the need for even more extensive multi-disciplinary and multi-sector approaches. Nevertheless, despite the need for more knowledge, it is already clear that more effective action could, and should, be taken
An experimental investigation of the impact of critical and warm comments on state paranoia in a non-clinical sample
No full textBackground and objectives: Interpersonal stress is key to the development and maintenance of paranoia. Much attention has been given to the impact of interpersonal stressors, such as criticism, on outcomes in psychosis. Less attention has been given to the potentially protective effects of positive interpersonal factors. This study tested experimentally whether criticism and warm comments elicited changes in state paranoia. Whether warm comments provided protective effects when participants faced subsequent social exclusion was also examined. Method: A nonclinical sample (N = 97) was randomised to criticism, warm comments, or neutral comments conditions. Participants then played a virtual ball game (Cyberball), during which they were systematically excluded from the game. State paranoia was measured before and after the affective stimuli and after social exclusion. Self-esteem and trait paranoia were also measured. Results: Paranoia levels increased following exposure to criticism (p =.011). Paranoia was not significantly lower following exposure to warm comments (p =.203). Warm comments did not provide protection against the effects of subsequent social exclusion. The warm comments condition was the only condition in which significant increases in paranoia were seen following social exclusion (p =.004). Limitations: Use of a non-clinical sample limits generalisation to clinical populations. Conclusions: Criticism is sufficient to elicit increases in paranoia in non-clinical participants. Warm comments are insufficient to significantly reduce paranoia or provide protective effects against subsequent negative interpersonal experiences, highlighting the need to balance therapeutic warmth with amelioration of social stressors in paranoia.</p
Representations and Regulations of Marriage Migration from Russian and Vietnam in the People's Republic of China
No full textMarriage migration has developed as a discursive field and a new direction of governing practices in the relations of post-Mao China with Russia and Vietnam. This article examines China's developing governing regime for international marriages from the perspective of its sovereign concerns related to border stability, population management, and national security. These concerns are considered through the analysis of material and affective processes informing and shaping the regulations and representations of marriage migration to China. This discussion not only shows how the Chinese state revises its administrative and legal terms of international marriage, but also highlights the historical, racialized, and gendered forces that shape the process. The regulatory framework of marriage migration is informed by the shifting structures of feeling shaping the contours of belonging in Chinese society. These intersecting spheres of state affective and regulatory practices signal new relations of power and inequality coalescing in China's relations with its neighbors
Arthur Lewis and the Classical Foundations of "Development": Economic History and Institutional Change
No full textIn/Visible Peoples, In/Visible Lands: Overlapping Histories in Wang Chia-hsiang’s Historical Fantasy
No full textThis essay considers two narrative texts by the nature essayist and fiction writer Wang Chia-hsiang (Wang Jiaxiang); namely, the short story collection titled On Lamatasinsin and Dahu Ali (1995), and the novella Mystery of the Little People (1996). Structured round ethnographic journeys into the Taiwanese mountainous hinterland, the texts concern the main protagonists, two earnest (Han) Taiwanese ethnographers, who narrate stories that traverse the island’s histories, lands, and written remnants. The paper argues that the two stories purposefully overlap multiple historical, colonial and environmental encounters and temporal moments as a means to fictionalise the past as inherently heterarchical. The tales thus fabulise new literary spaces in which the Taiwanese relationship to yesteryear -- the peoples, the lands -- can be cognised alternatively
Perthes Disease Classification Using Shape and Appearance Modelling
No full textWe propose to use statistical shape and appearance modelling to classify the proximal femur in hip radiographs of children into Legg-Calvé-Perthes disease and healthy. Legg-Calvé-Perthes disease affects the femoral head with avascular necrosis, which causes large shape deformities during the growth-stage of the child. Further, the dead or dying bone of the femoral head is prominent visually in radiographic images, leading to a distinction between healthy bone and bone where necrosis is present. Currently, there is little to no research into analysingthe shape and appearance of hips affected by Perthes disease from radiographic images. Our research demonstrates how the radiographic shape, texture and overall appearance of a proximal femur affected by Perthes disease differs and how this can be used for identifying cases with the disease. Moreover, we present a radiograph-based fully automatic Perthes classification system that achieves state-of-the-art results with an area under the receiver operator characteristic (ROC) curve of 98%