298 research outputs found
Sounding Bodies: Modeling 3D Spatial Sound of Humans Using Body Pose and Audio
While 3D human body modeling has received much attention in computer vision,
modeling the acoustic equivalent, i.e. modeling 3D spatial audio produced by
body motion and speech, has fallen short in the community. To close this gap,
we present a model that can generate accurate 3D spatial audio for full human
bodies. The system consumes, as input, audio signals from headset microphones
and body pose, and produces, as output, a 3D sound field surrounding the
transmitter's body, from which spatial audio can be rendered at any arbitrary
position in the 3D space. We collect a first-of-its-kind multimodal dataset of
human bodies, recorded with multiple cameras and a spherical array of 345
microphones. In an empirical evaluation, we demonstrate that our model can
produce accurate body-induced sound fields when trained with a suitable loss.
Dataset and code are available online.Comment: 37th Conference on Neural Information Processing Systems (NeurIPS
2023
Can greater muscularity in larger individuals resolve the 3/4 power-law controversy when modelling maximum oxygen uptake?
BACKGROUND: The power function relationship, MR = a.m(b), between metabolic rate (MR) and body mass m has been the source of much controversy amongst biologists for many years. Various studies have reported mass exponents (b) greater than the anticipated 'surface-area' exponent 0.67, often closer to 0.75 originally identified by Kleiber. AIM: The study aimed to provide a biological explanation for these 'inflated' exponents when modelling maximum oxygen uptake (max), based on the observations from this and previous studies that larger individuals develop disproportionately more muscle mass in the arms and legs. RESEARCH DESIGN AND SUBJECTS: A cross-sectional study of 119 professional soccer players from Croatia aged 18-34 was carried out. RESULTS: Here we confirm that the power function relationship between max and body mass of the professional soccer players results in an 'inflated' mass exponent of 0.75 (95% confidence interval from 0.56 to 0.93), but also the larger soccer players have disproportionately greater leg muscle girths. When the analysis was repeated incorporating the calf and thigh muscle girths rather than body mass as predictor variables, the analysis not only explained significantly more of the variance in max, but the sum of the exponents confirmed a surface-area law. CONCLUSIONS: These findings confirm the pitfalls of fitting body-mass power laws and suggest using muscle-girth methodology as a more appropriate way to scale or normalize metabolic variables such as max for individuals of different body sizes
Context-Dependent Risk Aversion: A Model-Based Approach
Most research on risk aversion in behavioral science with human subjects has focused on a component of risk aversion that does not adapt itself to context. More recently, studies have explored risk aversion adaptation to changing circumstances in sequential decision-making tasks. It is an open question whether one can identify evidence, at the single subject level, for such risk aversion adaptation. We conducted a behavioral experiment on human subjects, using a sequential decision making task. We developed a model-based approach for estimating the adaptation of risk-taking behavior with single-trial resolution by modeling a subject's goals and internal representation of task contingencies. Using this model-based approach, we estimated the subject-specific adaptation of risk aversion depending on the current task context. We found striking inter-subject variations in the adaptation of risk-taking behavior. We show that these differences can be explained by differences in subjects' internal representations of task contingencies and goals. We discuss that the proposed approach can be adapted to a wide range of experimental paradigms and be used to analyze behavioral measures other than risk aversion
Supervised structure learning
This paper concerns structure learning or discovery of discrete generative
models. It focuses on Bayesian model selection and the assimilation of training
data or content, with a special emphasis on the order in which data are
ingested. A key move - in the ensuing schemes - is to place priors on the
selection of models, based upon expected free energy. In this setting, expected
free energy reduces to a constrained mutual information, where the constraints
inherit from priors over outcomes (i.e., preferred outcomes). The resulting
scheme is first used to perform image classification on the MNIST dataset to
illustrate the basic idea, and then tested on a more challenging problem of
discovering models with dynamics, using a simple sprite-based visual
disentanglement paradigm and the Tower of Hanoi (cf., blocks world) problem. In
these examples, generative models are constructed autodidactically to recover
(i.e., disentangle) the factorial structure of latent states - and their
characteristic paths or dynamics
The Sting of Rejection: Deferring Blood Donors due to Low Hemoglobin Values Reduces Future Returns
Background: Roughly one quarter of short-term temporary deferrals (STTD) of blood donors are low-hemoglobin deferrals (LHD), i.e. STTD due to a hemoglobin (Hb) value falling below a cutoff of 125 g/L for female and 135 g/L for male donors. Since voluntarily donating blood is a prosocial activity, donors may perceive deferral as social exclusion, which can cause social pain, decrease self-esteem, and lead to antisocial behavior. However, little is known about the causal impacts of LHD on donor return. Study Design and Methods: We conducted a quasi-experiment with 80,060 donors invited to blood drives in the canton of Zurich, Switzerland, between 2009 and 2014. Within a narrow window of Hb values around the predetermined cutoff, the rate of LHD jumps discontinuously. This discontinuous jump allows us to quantify the causal effects of LHD on donor return, as it is uncorrelated with other unobserved factors that may also affect donor return. Results: We found different behavioral reactions to LHD for female and male donors. Female donors do not react to the first LHD. However, after any repeated LHD, they are 13.53 percentage points (p <0.001) less likely to make at least 1 donation attempt within the next 18 months and make 0.389 fewer donation attempts (p <0.001). Male donors react to the first LHD. They are 5.32 percentage points (p = 0.139) less likely to make at least 1 donation attempt over the next 18 months and make 0.227 (p = 0.018) fewer donation attempts. After any repeated LHD, male donors are 13.30 percentage points (p = 0.004) less likely to make at least 1 donation attempt and make 0.152 (p = 0.308) fewer donation attempts. Conclusion: LHD have detrimental impacts on donor return, especially if they occur repeatedly – suggesting that avoiding false LHD and helping donors to better cope with them helps to maintain the pool of prospective donors
Surgery of primary melanomas
Surgery remains the mainstay of melanoma therapy, regardless of the tumor site. Only the early diagnosis combined with proper surgical therapy currently gives patients affected by this malignancy the chance for a full cure. The main goal of surgical therapy is to provide the local control of the disease and to secure long-term survival of the patient without reasonable functional and esthetic impairment. The recommended method of biopsy-excisional biopsy, as an initial diagnostic and, to some extent, therapeutic procedure-is performed under local anesthesia as an elliptical incision with visual clear margins of 1-3 mm and with some mm of subcutaneous tissue. The extent of radical excision of the primary tumor (or scar after excisional biopsy) is based on the histopathologic characteristics of the primary tumor and usually consists of 1-2 cm margins with primary closure. The philosophy behind conducted randomized clinical trials has been to find the most conservative surgical approach that is able to guarantee the same results as more demolitive treatment. This has been the background of the trials designed to define the correct margins of excision around a primary cutaneous melanoma. Much less definition can be dedicated to the surgical management of patients with non-cutaneous melanomas
Payers' views of the changes arising through the possible adoption of adaptive pathways
Payers are a major stakeholder in any considerations and initiatives concerning adaptive licensing of new medicinal products, also referred to as Medicines Adaptive Pathways to patients (MAPPs). Firstly, the scope and necessity of MAPPs need further scrutiny, especially with regard to the definition of unmet need. Conditional approval pathways already exist for new medicines for seriously debilitating or life-threatening diseases and only a limited number of new medicines are innovative. Secondly, MAPPs will result in new medicines on the market with limited evidence about their effectiveness and safety. Additional data are to be collected after approval. Consequently, adaptive pathways may increase the risk of exposing patients to ineffective or unsafe medicines. We have already seen medicines approved conventionally that subsequently proved ineffective or unsafe amongst a wider, more co-morbid population as well as medicines that could have been considered for approval under MAPPs but subsequently proved ineffective or unsafe in Phase III trials and were never licensed. Thirdly, MAPPs also put high demands on payers. Routine collection of patient level data is difficult with high transaction costs. It is not clear who will fund these. Other challenges for payers include shifts in the risk governance framework, implications for evaluation and HTA, increased complexity of setting prices, difficulty with ensuring equity in the allocation of resources, definition of responsibility and liability and implementation of stratified use. Exit strategies also need to be agreed in advance, including price reductions, rebates, or reimbursement withdrawals when price premiums are not justified. These issues and concerns will be discussed in detail including potential ways forward
Peripheral blood biomarkers in multiple sclerosis.
Multiple sclerosis is the most common autoimmune disorder affecting the central nervous system. The heteroge-neity of pathophysiological processes in MS contributes to the highly variable course of the disease and unpre-dictable response to therapies. The major focus of the research on MS is the identification of biomarkers inbiologicalfluids, such as cerebrospinalfluid or blood, to guide patient management reliably. Because of the diffi-culties in obtaining spinalfluid samples and the necessity for lumbar puncture to make a diagnosis has reduced,the research of blood-based biomarkers may provide increasingly important tools for clinical practice. However,currently there are no clearly established MS blood-based biomarkers. The availability of reliable biomarkerscould radically alter the management of MS at critical phases of the disease spectrum, allowing for interventionstrategies that may prevent evolution to long-term neurological disability. This article provides an overview ofthis researchfield and focuses on recent advances in blood-based biomarker researc
- …