Bayes Linear Calibrated Prediction for Complex Systems

A calibration-based approach is developed for predicting the behavior of a physical system that is modeled by a computer simulator. The approach is based on Bayes linear adjustment using both system observations and evaluations of the simulator at parameterizations that appear to give good matches to those observations. This approach can be applied to complex high-dimensional systems with expensive simulators, where a fully Bayesian approach would be impractical. It is illustrated with an example concerning the collapse of the thermohaline circulation (THC) in the Atlantic Ocean

In healthy subjects, the sitting position can be used to validate the postural effects induced by wearing a lumbar lordosis brace

AbstractAim of the studyTo assess the validity of the sitting position when testing lumbar braces for the maintenance of lordosis.Patients and methodsTwelve young adult subjects participated in the experiment, in which they were seated on force platform. The four experimental conditions (with or without a brace and with or without enforced lordosis) were chosen in order to distinguish between the roles played by lordosis and the brace, respectively. The trajectories of the centre of pressure (CP) were analyzed and compared, in order to assess postural orientation and stabilisation processes.ResultsAlthough no effect was seen in terms of orientation, our data showed that use of a lumbar brace led to a notable reduction in CP displacement along the mediolateral and anteroposterior axes. Lordosis barely affected postural performance and only an increase in the mean CP velocity was observed. Lastly, an analysis of variance failed to reveal an interaction between the “lordosis” and “brace” factors.ConclusionA lumbar brace (in the absence or presence of lordosis) helps subjects to improve their sitting performance. In contrast to previous studies based on the standing posture, the fact that significant differences were found as a function of brace wear emphasises the discriminant power of the sitting position. This task should therefore be applied more widely in the development of more appropriate, validated equipment for lower back pain sufferers

Study of one class boundary method classifiers for application in a video-based fall detection system

In this paper, we introduce a video-based robust fall detection system for monitoring an elderly person in a smart room environment. Video features, namely the centroid and orientation of a voxel person, are extracted. The boundary method, which is an example one class classification technique, is then used to determine whether the incoming features lie in the ‘fall region’ of the feature space, and thereby effectively distinguishing a fall from other activities, such as walking, sitting, standing, crouching or lying. Four different types of boundary methods, k-center, k-th nearest neighbor, one class support vector machine and single class minimax probability machine are assessed on representative test datasets. The comparison is made on the following three aspects: 1). True positive rate, false positive rate and geometric means in detection 2). Robustness to noise in the training dataset 3). The computational time for the test phase. From the comparison results, we show that the single class minimax probability machine achieves the best overall performance. By applying one class classification techniques with 3-d features, we can obtain a more efficient fall detection system with acceptable performance, as shown in the experimental part; besides, it can avoid the drawbacks of other traditional fall detection methods

Precalibrating an intermediate complexity climate model

Credible climate predictions require a rational quantification of uncertainty, but full Bayesian calibration requires detailed estimates of prior probability distributions and covariances, which are difficult to obtain in practice. We describe a simplified procedure, termed precalibration, which provides an approximate quantification of uncertainty in climate prediction, and requires only that uncontroversially implausible values of certain inputs and outputs are identified. The method is applied to intermediate-complexity model simulations of the Atlantic meridional overturning circulation (AMOC) and confirms the existence of a cliff-edge catastrophe in freshwaterforcing input space. When uncertainty in 14 further parameters is taken into account, an implausible, AMOC-off, region remains as a robust feature of the model dynamics, but its location is found to depend strongly on values of the other parameters

The Miocene mammal Necrolestes demonstrates the survival of a Mesozoic nontherian lineage into the late Cenozoic of South America

The early Miocene mammal Necrolestes patagonensis from Patagonia, Argentina, was described in 1891 as the only known extinct placental "insectivore" from South America (SA). Since then, and despite the discovery of additional well-preserved material, the systematic status of Necrolestes has remained in flux, with earlier studies leaning toward placental affinities and more recent ones endorsing either therian or specifically metatherian relationships. We have further prepared the best-preserved specimens of Necrolestes and compared them with newly discovered nontribosphenic Mesozoic mammals from Argentina; based on this, we conclude that Necrolestes is related neither to marsupials nor placentals but is a late-surviving member of the recently recognized nontherian clade Meridiolestida, which is currently known only from SA. This conclusion is supported by a morphological phylogenetic analysis that includes a broad sampling of therian and nontherian taxa and that places Necrolestes within Meridiolestida. Thus, Necrolestes is a remnant of the highly endemic Mesozoic fauna of nontribosphenic mammals in SA and extends the known record of meridiolestidans by almost 45 million years. Together with other likely relictual mammals from earlier in the Cenozoic of SA and Antarctica, Necrolestes demonstrates the ecological diversity of mammals and the mosaic pattern of fauna replacement in SA during the Cenozoic. In contrast to northern continents, the Cenozoic faunal history of SA was characterized by a long period of interaction between endemic mammalian lineages of Mesozoic origin and metatherian and eutherian lineages that probably dispersed to SA during the latest Cretaceous or earliest Paleocene.Fil: Rougier, Guillermo W.. University of Louisville; Estados Unidos. Carnegie Museum Of Natural History; Estados UnidosFil: Wible, John R.. Carnegie Museum Of Natural History; Estados UnidosFil: Beck, Robin M. D.. University of New South Wales; AustraliaFil: Apesteguía, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentin

Origin and age of an ongoing radioactive contamination of soils near La hague reprocessing plant based on ^239+240Pu/²³⁸Pu and ²⁴¹Am/²⁴¹Pu current ratios and ⁹⁰Sr and Ln(III) soil contents.

Nuclear reprocessing plants are sources of environmental contamination by gaseous or liquid discharges. Numerous radionuclides are of concern, with actinides and <sup>90</sup> Sr being the most radiotoxic. Environmental radioactivity survey programs mostly use γ-spectrometry to track contaminations because γ-spectrometry is very cost effective and can be carried out on raw samples. On the other hand, the determination of β- or α-emitting radionuclides in environmental samples requires rather sophisticated analytical methods, and are thus dedicated to specific goals. However, measuring radionuclides such as Pu, Am, and Sr often provides more information about the presence of a current or prior contamination and on its origin, based on the isotopic composition of the samples. We found that the analysis of <sup>241</sup> Pu, <sup>239+240</sup> Pu, <sup>241</sup> Am, and <sup>90</sup> Sr of a few selected soil samples taken near the nuclear reprocessing plant of La Hague, France, revealed the presence of a previous environmental contamination originating from several incidents in La Hague site involving atmospheric transfer and leaks in flooded waste pits. The <sup>241</sup> Am- <sup>241</sup> Pu dating method indicated a contamination period prior to 1983. The presence of elevated levels of light non-radioactive lanthanides and yttrium in the soil samples confirmed the involvement of cold fuel. Our results demonstrate how long-lived actinides are likely to reveal a long-term contamination of the environment by spent fuel. Our study indicates that there is a requirement to use more sophisticated tools than γ-spectrometry when surveying the environments surrounding industrial plants for nuclear power and nuclear reprocessing with a potential for the accidental release of radioactivity into the environment

Examining Associations of Coping Strategies with Stress, Alcohol, and Substance use among College Athletes: Implications for Improving Athlete Coping

Mental health challenges and substance use are common among college athletes, yet few studies have been conducted to understand substance use as a coping strategy. The pressures of collegiate athletics - including commitments to training, travel, and competition - can contribute to maladaptive coping among college athletes, including alcohol and other substance use. An online survey was completed by 188 college athletes competing across NCAA/NJCAA divisions at six institutions in the United States to examine factors associated with substance use coping and whether specific strategies of coping were associated with risk of substance use. Alcohol and drug use were assessed using the CRAFFT Screening Test, NIDA-Modified ASSIST, and Alcohol Use Disorders Identification Test. Coping was assessed with the Coping Orientation to Problems Experienced Inventory, stress was assessed using an adapted Graduate Stress Inventory, athletics-related anxiety was assessed with the Sport Anxiety Scale, and perceived control of stress was assessed using the Perceived Control Questionnaire. Older athletes, men, and those with higher stress were more likely to use substances to cope. Higher behavioral disengagement, higher substance use coping, and lower religious coping were associated with increased likelihood of binge drinking and substance-related risk behaviors. These findings point to the importance of developing targeted interventions aimed at addressing stress and facilitating healthy coping to reduce problematic drinking and substance use among college athletes