441 research outputs found

    Interview with Franklin Miller Jr.

    Get PDF
    Franklin Miller Jr. talks about growing up in Knox County and being a Professor at Kenyon.https://digital.kenyon.edu/ps_interviews/1040/thumbnail.jp

    A Conceptual and Computational Model of Moral Decision Making in Human and Artificial Agents

    Get PDF
    Recently there has been a resurgence of interest in general, comprehensive models of human cognition. Such models aim to explain higher order cognitive faculties, such as deliberation and planning. Given a computational representation, the validity of these models can be tested in computer simulations such as software agents or embodied robots. The push to implement computational models of this kind has created the field of Artificial General Intelligence, or AGI. Moral decision making is arguably one of the most challenging tasks for computational approaches to higher order cognition. The need for increasingly autonomous artificial agents to factor moral considerations into their choices and actions has given rise to another new field of inquiry variously known as Machine Morality, Machine Ethics, Roboethics or Friendly AI. In this paper we discuss how LIDA, an AGI model of human cognition, can be adapted to model both affective and rational features of moral decision making. Using the LIDA model we will demonstrate how moral decisions can be made in many domains using the same mechanisms that enable general decision making. Comprehensive models of human cognition typically aim for compatibility with recent research in the cognitive and neural sciences. Global Workspace Theory (GWT), proposed by the neuropsychologist Bernard Baars (1988), is a highly regarded model of human cognition that is currently being computationally instantiated in several software implementations. LIDA (Franklin et al. 2005) is one such computational implementation. LIDA is both a set of computational tools and an underlying model of human cognition, which provides mechanisms that are capable of explaining how an agent’s selection of its next action arises from bottom-up collection of sensory data and top-down processes for making sense of its current situation. We will describe how the LIDA model helps integrate emotions into the human decision making process, and elucidate a process whereby an agent can work through an ethical problem to reach a solution that takes account of ethically relevant factors

    Consciousness And Ethics: Artificially Conscious Moral Agents

    Get PDF
    What roles or functions does consciousness fulfill in the making of moral decisions? Will artificial agents capable of making appropriate decisions in morally charged situations require machine consciousness? Should the capacity to make moral decisions be considered an attribute essential for being designated a fully conscious agent? Research on the prospects for developing machines capable of making moral decisions and research on machine consciousness have developed as independent fields of inquiry. Yet there is significant overlap. Both fields are likely to progress through the instantiation of systems with artificial general intelligence (AGI). Certainly special classes of moral decision making will require attributes of consciousness such as being able to empathize with the pain and suffering of others. But in this article we will propose that consciousness also plays a functional role in making most if not all moral decisions. Work by the authors of this article with LIDA, a computational and conceptual model of human cognition, will help illustrate how consciousness can be understood to serve a very broad role in the making of all decisions including moral decisions

    Dwarf AGNs from Variability for the Origins of Seeds (DAVOS): Optical Variability of Broad-line Dwarf AGNs from the Zwicky Transient Facility

    Full text link
    We study the optical variability of a sample of candidate low-mass (dwarf ang Seyfert) active galactic nuclei (AGNs) using Zwicky Transient Facility g-band light curves. Our sample is compiled from broad-line AGNs in dwarf galaxies reported in the literature with single-epoch virial black hole (BH) masses in the range MBH∼104M_{\rm{BH}} \sim 10^{4}--108 M⊙10^{8}\ M_{\odot}. We measure the characteristic ``damping'' timescale of the optical variability τDRW\tau_{\rm{DRW}}, beyond which the power spectral density flattens, of a final sample of 79 candidate low-mass AGNs with high-quality light curves. Our results provide further confirmation of the MBH−τDRWM_{\rm{BH}} - \tau_{\rm{DRW}} relation from Burke et al. 2022 within 1σ1\sigma agreement, adding 78 new low-mass AGNs to the relation. The agreement suggests that the virial BH mass estimates for these AGNs are generally reasonable. We expect that the optical light curve of an accreting intermediate-mass black hole (IMBH) to vary with a rest-frame damping timescale of ∼\sim tens of hours, which could enable detection and direct mass estimation of accreting IMBHs in wide-field time-domain imaging surveys with sufficient cadence like with the Vera C. Rubin Observatory.Comment: 9 pages plus 6 appendix, 7 figure

    Dwarf AGNs from Variability for the Origins of Seeds (DAVOS): Intermediate-mass black hole demographics from optical synoptic surveys

    Full text link
    We present a phenomenological forward Monte Carlo model for forecasting the population of active galactic nuclei (AGNs) in dwarf galaxies observable via their optical variability. Our model accounts for expected changes in the spectral energy distribution of AGNs in the intermediate-mass black hole (IMBH) mass range and uses observational constraints on optical variability as a function of black hole (BH) mass to generate mock light curves. Adopting several different models for the BH occupation function, including one for off-nuclear IMBHs, we quantify differences in the predicted local AGN mass and luminosity functions in dwarf galaxies. As a result, we are able to model the variable fraction of AGNs as a function of physical host properties, such as host galaxy stellar mass, in the presence of complex selection effects. We find that our adopted occupation fractions for the "heavy" and "light" initial BH seeding scenarios can be distinguished with variability data at the 2−3σ2-3 \sigma level for galaxy host stellar masses below ∼108M⊙\sim 10^8 M_\odot with the Vera C. Rubin Observatory. We demonstrate the prevalence of a selection bias whereby recovered IMBH masses fall, on average, above the predicted value from the local host galaxy - BH mass scaling relation with the strength of the bias dependent on the survey sensitivity. The methodology developed in this work can be used more broadly to forecast and correct for selection effects for AGN demographic studies in synoptic surveys. Finally, we show that a targeted ∼\sim hourly cadence program over a few nights with the Rubin Observatory can provide strong constraints on IMBH masses given their expected rapid variability timescales.Comment: 26 pages, 16 figures incl. 5 appendices; re-submitted to MNRAS following referee repor

    Extra-Mitochondrial CU/Zn Superoxide Dismutase (SOD1) Is Dispensable for Protection Against Oxidative Stress but Mediates Peroxide Signaling in Saccharomyces Cerevisiae

    Get PDF
    Cu/Zn Superoxide Dismutase (Sod1) is a highly conserved and abundant metalloenzyme that catalyzes thedisproportionation of superoxide radicals into hydrogen peroxide and molecular oxygen. As a consequence, Sod1serves dual roles in oxidative stress protection and redox signaling by both scavenging cytotoxic superoxideradicals and producing hydrogen peroxide that can be used to oxidize and regulate the activity of downstreamtargets. However, the relative contributions of Sod1 to protection against oxidative stress and redox signaling arepoorly understood. Using the model unicellular eukaryote, Baker\u27s yeast, we found that only a small fraction ofthe total Sod1 pool is required for protection against superoxide toxicity and that this pool is localized to themitochondrial intermembrane space. On the contrary, wefind that much larger amounts of extra-mitochondrialSod1 are critical for peroxide-mediated redox signaling. Altogether, our results force the re-evaluation of thephysiological role of bulk Sod1 in redox biology; namely, we propose that the vast majority of Sod1 in yeast isutilized for peroxide-mediated signaling rather than superoxide scavenging

    Changes in the Oligodendrocyte Progenitor Cell Proteome with Ageing.

    Get PDF
    Following central nervous system (CNS) demyelination, adult oligodendrocyte progenitor cells (OPCs) can differentiate into new myelin-forming oligodendrocytes in a regenerative process called remyelination. Although remyelination is very efficient in young adults, its efficiency declines progressively with ageing. Here we performed proteomic analysis of OPCs freshly isolated from the brains of neonate, young and aged female rats. Approximately 50% of the proteins are expressed at different levels in OPCs from neonates compared with their adult counterparts. The amount of myelin-associated proteins, and proteins associated with oxidative phosphorylation, inflammatory responses and actin cytoskeletal organization increased with age, whereas cholesterol-biosynthesis, transcription factors and cell cycle proteins decreased. Our experiments provide the first ageing OPC proteome, revealing the distinct features of OPCs at different ages. These studies provide new insights into why remyelination efficiency declines with ageing and potential roles for aged OPCs in other neurodegenerative diseases

    The Lobby in transition: what the 2009 MPs’ expenses scandal revealed about the changing relationship between politicians and the Westminster Lobby?

    Get PDF
    The 2009 MPs' expenses scandal was one of the most significant political stories of modern times. It raised questions, not just about the ethics and behaviour of MPs but also about the relationship between politicians at Westminster and the political correspondents who follow them on a daily basis, known as ‘the lobby’. For the significance of this scandal, in media terms, was that the story was not broken by members of the lobby but came from outside the traditional Westminster news gathering process. This paper examines why this was the case and it compares the lobby today with that which was described and analysed by Jeremy Tunstall and Colin Seymour-Ure in their respective studies more than 40 years ago. The article concludes that the lobby missed the story partly because of the nature of the lobby itself and partly as a result of a number of specific changes which have taken place in the media and the political systems over the past 40 years

    Detection of Crab Giant Pulses Using the Mileura Widefield Array Low Frequency Demonstrator Field Prototype System

    Get PDF
    We report on the detection of giant pulses from the Crab Nebula pulsar at a frequency of 200 MHz using the field deployment system designed for the Mileura Widefield Array's Low Frequency Demonstrator (MWA-LFD). Our observations are among the first high-quality detections at such low frequencies. The measured pulse shapes are deconvolved for interstellar pulse broadening, yielding a pulse-broadening time of 670 ± 100 μs, and the implied strength of scattering (scattering measure) is the lowest that is estimated toward the Crab Nebula from observations made so far. The sensitivity of the system is largely dictated by the sky background, and our simple equipment is capable of detecting pulses that are brighter than ∼9 kJy in amplitude. The brightest giant pulse detected in our data has a peak amplitude of ∼50 kJy, and the implied brightness temperature is 10 31.6 K. We discuss the giant pulse detection prospects with the full MWA-LFD system. With a sensitivity over 2 orders of magnitude larger than the prototype equipment, the full system will be capable of detecting such bright giant pulses out to a wide range of Galactic distances; from ∼ 15 to ∼30 kpc depending on the frequency. The MWA-LFD will thus be a highly promising instrument for the studies of giant pulses and other fast radio transients at low frequencies
    • …
    corecore