154 research outputs found

    Sub-mW Neuromorphic SNN audio processing applications with Rockpool and Xylo

    Full text link
    Spiking Neural Networks (SNNs) provide an efficient computational mechanism for temporal signal processing, especially when coupled with low-power SNN inference ASICs. SNNs have been historically difficult to configure, lacking a general method for finding solutions for arbitrary tasks. In recent years, gradient-descent optimization methods have been applied to SNNs with increasing ease. SNNs and SNN inference processors therefore offer a good platform for commercial low-power signal processing in energy constrained environments without cloud dependencies. However, to date these methods have not been accessible to ML engineers in industry, requiring graduate-level training to successfully configure a single SNN application. Here we demonstrate a convenient high-level pipeline to design, train and deploy arbitrary temporal signal processing applications to sub-mW SNN inference hardware. We apply a new straightforward SNN architecture designed for temporal signal processing, using a pyramid of synaptic time constants to extract signal features at a range of temporal scales. We demonstrate this architecture on an ambient audio classification task, deployed to the Xylo SNN inference processor in streaming mode. Our application achieves high accuracy (98%) and low latency (100ms) at low power (<100Ό\muW inference power). Our approach makes training and deploying SNN applications available to ML engineers with general NN backgrounds, without requiring specific prior experience with spiking NNs. We intend for our approach to make Neuromorphic hardware and SNNs an attractive choice for commercial low-power and edge signal processing applications.Comment: This submission has been removed by arXiv administrators because the submitter did not have the authority to grant a license to the work at the time of submissio

    Low energy effects of a left-right symmetric model extended by a heavy quark

    Get PDF
    This thesis sets out to explore the methods of and the space available when adding new quarks to the particle content of the Standard Model and the Left-Right Symmetric Model (LRSM). Most observations of interactions mediated by the electromagnetic, weak and strong forces can be adequately explained by the Standard Model. It is known, however, that the Standard Model must be the effective theory of an extended model which is possibly broken down at a higher energy scale. The rare deviations of measurements from the Standard Model predictions make it difficult to grasp and constrain new physics. There are also a number of models which suffer under a large number of parameters and therefore reveal a difficulty which occurs during model-building, namely that there exists a fine line between a model which can predict the outcome of an experiment after inserting a reasonable number of parameters and a model which loses its predictive capability since the large number of parameters can be arranged in such a way that almost every possible outcome can be produced. There is thus a wide range of models based on similar principles to the Standard Model which have been proposed as possible extensions, including Spontaneous Symmetry Breaking, an extended Higgs sector and an extended gauge symmetry at a higher energy scale. This thesis lists and describes some representatives of those models, specifically the Left-Right Symmetric Model, the Little Higgs Model and the Standard Model with an extended quark sector. Methods of introducing new quarks to a Lagrangian and the quarks’ mass-gaining process are discussed in detail. Subsequently the Left-Right Symmetric Model is extended by a vector-like quark isosinglet and it is shown that in effect, a model extended by an additional Top-quark receives two additional parameters, the Top-quark mass and the mixing angle theta, as well as a quark mass sign for every quark. Parameters of the LRSM with and without an additional heavy quark involved in the calculations of the B_d-meson mass-mixing, the CP-violating parameter epsilon_K and the B_s-meson decay to two muons are constrained when calculating those quantities including one-loop corrections. It emerges that the B-meson mass-mixing and the CP-violating parameter only leave space for an LRS extension or an additional Top-quark if one allows the Standard Model parameters to alter. Thus lower bounds, depending on the uncertainty of the Standard Model input parameters, of the right-handed W-mass are derived and compared with bounds derived in the literature. It is found that considering both the LRSM and an additional heavy quark leaves space for the new particles even without altering the Standard Model parameters, due to cancellations between the two new contributions. Therefore fixing the right-handed W-mass gives a an upper bound to the Top-mass. The mixing angle theta is constrained by using the decoupling theorem. When analysing the CP-violating parameter in the LRSM extended by a Top-quark two regions of quark mass sign choices are found as well as a constraint on the phase of the vacuum expectation value arising in the Higgs sector of the LRSM. In discussing the Bs-meson decay to two muons, the problem of imprecise hadron matrix elements and the model-dependent interpretation of measured CKM matrix element values is solved by introducing the new physics-measuring quantity A_s. It is shown that the branching ratio of the Bs-decay in the LRSM is enhanced for all choices of new parameters and all mass signs set to plus one. Thus measuring the branching ratio could distinguish between the LRSM and the Standard Model. The enhancement becomes larger the smaller the W_R-mass and thus once the branching ratio is observed, a lower bound on the right-handed W-mass can be derived. A qualitative discussion on the ways in which to extend the calculation of the B_s-meson decay branching ratio in order to describe an additional Top-quark is made. It is concluded that an enhancement of A_s is possible

    Systematic review and individual patient data meta-analysis of sex differences in depression and prognosis in persons with myocardial infarction: a MINDMAPS study

    Get PDF
    Objective - Using combined individual patient data (IPD) from prospective studies, we explored sex differences in depression and prognosis post-myocardial infarction (MI), and determined whether disease indices could account for found differences. Methods - Meta-analysis of IPD from 10,175 MI patients who completed diagnostic interviews or depression questionnaires from 16 prospective studies of MI patients, identified by systematic review for the MINDMAPS study. Multilevel logistic and Cox regression models were used to determine sex differences in prevalence of depression and sex-specific effects of depression on subsequent cardiovascular morbidity and all-cause mortality. Results - Combined interview and questionnaire data from observational studies showed that 36% (635/1760) of women and 29% (1575/5526) of men reported elevated levels of depression (age-adjusted OR=0.68, 95% CI 0.60 to 0.77, p (sex*depression interaction p Conclusions - The prevalence of depression post-MI was higher in women than men, but the association between depression and cardiac prognosis was worse for men. LVEF was associated with depression in men only, and accounted for the increased risk of all-cause mortality in depressed men versus women, suggesting that depression in men post-MI may in part reflect cardiovascular disease severity

    Role of Self-Stigma in Pathways from HIV-Related Stigma to Quality of Life among People Living with HIV

    Get PDF
    Funding Information: This study was supported by Viiv Healthcare, Gilead, and Aidsfonds (research Grant Number AF-P.42601). The funders had no role in decisions regarding the study design, data analysis, or publication. Acknowledgments We extend our gratitude to all PLHIV who completed the survey. We further thank the HIV specialist nurses and doctors at OLVG hospital for their effort in recruiting patients to complete the surveys.Peer reviewedPublisher PD

    Ten essentials for action-oriented and second order energy transitions, transformations and climate change research

    Get PDF
    The most critical question for climate research is no longer about the problem, but about how to facilitate the transformative changes necessary to avoid catastrophic climate-induced change. Addressing this question, however, will require massive upscaling of research that can rapidly enhance learning about transformations. Ten essentials for guiding action-oriented transformation and energy research are therefore presented, framed in relation to second-order science. They include: (1) Focus on transformations to low-carbon, resilient living; (2) Focus on solution processes; (3) Focus on ‘how to’ practical knowledge; (4) Approach research as occurring from within the system being intervened; (5) Work with normative aspects; (6) Seek to transcend current thinking; (7) Take a multi-faceted approach to understand and shape change; (8) Acknowledge the value of alternative roles of researchers; (9) Encourage second-order experimentation; and (10) Be reflexive. Joint application of the essentials would create highly adaptive, reflexive, collaborative and impact-oriented research able to enhance capacity to respond to the climate challenge. At present, however, the practice of such approaches is limited and constrained by dominance of other approaches. For wider transformations to low carbon living and energy systems to occur, transformations will therefore also be needed in the way in which knowledge is produced and used

    Panta Rhei benchmark dataset: socio-hydrological data of paired events of floods and droughts

    Get PDF
    As the adverse impacts of hydrological extremes increase in many regions of the world, a better understanding of the drivers of changes in risk and impacts is essential for effective flood and drought risk management and climate adaptation. However, there is currently a lack of comprehensive, empirical data about the processes, interactions and feedbacks in complex human-water systems leading to flood and drought impacts. Here we present a benchmark dataset containing socio-hydrological data of paired events, i.e., two floods or two droughts that occurred in the same area. The 45 paired events occurred in 42 different study areas and cover a wide range of socio-economic and hydro-climatic conditions. The dataset is unique in covering both floods and droughts, in the number of cases assessed, and in the quantity of socio-hydrological data. The benchmark dataset comprises: 1) detailed review style reports about the events and key processes between the two events of a pair; 2) the key data table containing variables that assess the indicators which characterise management shortcomings, hazard, exposure, vulnerability and impacts of all events; 3) a table of the indicators-of-change that indicate the differences between the first and second event of a pair. The advantages of the dataset are that it enables comparative analyses across all the paired events based on the indicators-of-change and allows for detailed context- and location-specific assessments based on the extensive data and reports of the individual study areas. The dataset can be used by the scientific community for exploratory data analyses e.g. focused on causal links between risk management, changes in hazard, exposure and vulnerability and flood or drought impacts. The data can also be used for the development, calibration and validation of socio-hydrological models. The dataset is available to the public through the GFZ Data Services (Kreibich et al. 2023, link for review: https://dataservices.gfz-potsdam.de/panmetaworks/review/923c14519deb04f83815ce108b48dd2581d57b90ce069bec9c948361028b8c85/).</p

    Physiological Correlates of Volunteering

    Get PDF
    We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation

    Fine-Scale Mapping of the 4q24 Locus Identifies Two Independent Loci Associated with Breast Cancer Risk

    Get PDF
    Background: A recent association study identified a common variant (rs9790517) at 4q24 to be associated with breast cancer risk. Independent association signals and potential functional variants in this locus have not been explored. Methods: We conducted a fine-mapping analysis in 55,540 breast cancer cases and 51,168 controls from the Breast Cancer Association Consortium. Results: Conditional analyses identified two independent association signals among women of European ancestry, represented by rs9790517 [conditional P = 2.51 × 10−4; OR, 1.04; 95% confidence interval (CI), 1.02–1.07] and rs77928427 (P = 1.86 × 10−4; OR, 1.04; 95% CI, 1.02–1.07). Functional annotation using data from the Encyclopedia of DNA Elements (ENCODE) project revealed two putative functional variants, rs62331150 and rs73838678 in linkage disequilibrium (LD) with rs9790517 (r2 ≄ 0.90) residing in the active promoter or enhancer, respectively, of the nearest gene, TET2. Both variants are located in DNase I hypersensitivity and transcription factor–binding sites. Using data from both The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), we showed that rs62331150 was associated with level of expression of TET2 in breast normal and tumor tissue. Conclusion: Our study identified two independent association signals at 4q24 in relation to breast cancer risk and suggested that observed association in this locus may be mediated through the regulation of TET2. Impact: Fine-mapping study with large sample size warranted for identification of independent loci for breast cancer risk

    Evidence for widespread hydrated minerals on asteroid (101955) Bennu

    Get PDF
    Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 ”m and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 ”m) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth
    • 

    corecore