49 research outputs found
Artificial Intelligence: Too Fragile to Fight?
The article of record may be found at https://www.usni.org/magazines/proceedings/2022/february/artificial-intelligence-too-fragile-fightInformation Warfare Essay Contest - First PrizeArtificial intelligence (Al) has become the technical focal point for advancing naval and Department of Defense (DoD) capabilities. Secretary of the Navy Carlos Del Toro listed AI first among his priorities for innovating U.S. naval forces. Chief of Naval Operations Admiral Michael Gilday listed it as his top priority during his Senate confirmation hearing. This focus is appropriate: ai/ offers many promising breakthroughs in battlefield capability and agility in decision making. Yet, the proposed advances come with substantial risk: automation-including AI- has persistent, critical vulnerabilities that must be thoroughly understood and adequately addressed if defense applications are to remain resilient and effective.Booz Allen Hamilito
System Safety Engineering for Social and Ethical ML Risks: A Case Study
Governments, industry, and academia have undertaken efforts to identify and
mitigate harms in ML-driven systems, with a particular focus on social and
ethical risks of ML components in complex sociotechnical systems. However,
existing approaches are largely disjointed, ad-hoc and of unknown
effectiveness. Systems safety engineering is a well established discipline with
a track record of identifying and managing risks in many complex sociotechnical
domains. We adopt the natural hypothesis that tools from this domain could
serve to enhance risk analyses of ML in its context of use. To test this
hypothesis, we apply a "best of breed" systems safety analysis, Systems
Theoretic Process Analysis (STPA), to a specific high-consequence system with
an important ML-driven component, namely the Prescription Drug Monitoring
Programs (PDMPs) operated by many US States, several of which rely on an
ML-derived risk score. We focus in particular on how this analysis can extend
to identifying social and ethical risks and developing concrete design-level
controls to mitigate them.Comment: 14 pages, 5 figures, 3 tables. Accepted to 36th Conference on Neural
Information Processing Systems, Workshop on ML Safety (NeurIPS 2022
PHD2 is a regulator for glycolytic reprogramming in macrophages.
The prolyl-4-hydroxylase domain (PHD) enzymes are regarded as the molecular oxygen sensors. There is an interplay between oxygen availability and cellular metabolism, which in turn has significant effects on the functionality of innate immune cells, such as macrophages. However, if and how PHD enzymes affect macrophage metabolism are enigmatic. We hypothesized that macrophage metabolism and function can be controlled via manipulation of PHD2. We characterized the metabolic phenotypes of PHD2-deficient RAW cells and primary PHD2 knockout bone marrow-derived macrophages (BMDM). Both showed typical features of anaerobic glycolysis, which were paralleled by increased pyruvate dehydrogenase kinase 1 (PDK1) protein levels and a decreased pyruvate dehydrogenase enzyme activity. Metabolic alterations were associated with an impaired cellular functionality. Inhibition of PDK1 or knockout of hypoxia-inducible factor 1 alpha (HIF-1 alpha) reversed the metabolic phenotype and impaired the functionality of the PHD2-deficient RAW cells and BMDM. Taking these results together, we identified a critical role of PHD2 for a reversible glycolytic reprogramming in macrophages with a direct impact on their function. We suggest that PHD2 serves as an adjustable switch to control macropha(g)e behavior
The Cercal Organ May Provide Singing Tettigoniids a Backup Sensory System for the Detection of Eavesdropping Bats
Conspicuous signals, such as the calling songs of tettigoniids, are intended to attract mates but may also unintentionally attract predators. Among them bats that listen to prey-generated sounds constitute a predation pressure for many acoustically communicating insects as well as frogs. As an adaptation to protect against bat predation many insect species evolved auditory sensitivity to bat-emitted echolocation signals. Recently, the European mouse-eared bat species Myotis myotis and M. blythii oxygnathus were found to eavesdrop on calling songs of the tettigoniid Tettigonia cantans. These gleaning bats emit rather faint echolocation signals when approaching prey and singing insects may have difficulty detecting acoustic predator-related signals. The aim of this study was to determine (1) if loud self-generated sound produced by European tettigoniids impairs the detection of pulsed ultrasound and (2) if wind-sensors on the cercal organ function as a sensory backup system for bat detection in tettigoniids. We addressed these questions by combining a behavioral approach to study the response of two European tettigoniid species to pulsed ultrasound, together with an electrophysiological approach to record the activity of wind-sensitive interneurons during real attacks of the European mouse-eared bat species Myotis myotis. Results showed that singing T. cantans males did not respond to sequences of ultrasound pulses, whereas singing T. viridissima did respond with predominantly brief song pauses when ultrasound pulses fell into silent intervals or were coincident with the production of soft hemi-syllables. This result, however, strongly depended on ambient temperature with a lower probability for song interruption observable at 21°C compared to 28°C. Using extracellular recordings, dorsal giant interneurons of tettigoniids were shown to fire regular bursts in response to attacking bats. Between the first response of wind-sensitive interneurons and contact, a mean time lag of 860 ms was found. This time interval corresponds to a bat-to-prey distance of ca. 72 cm. This result demonstrates the efficiency of the cercal system of tettigoniids in detecting attacking bats and suggests this sensory system to be particularly valuable for singing insects that are targeted by eavesdropping bats
Mechanistic insights into the translocation of full length HIV-1 Tat across lipid membranes
AbstractThe mechanism of how full length Tat (aa 1–86) crosses artificial lipid membranes was elucidated by means of fluorescence spectroscopy and fluorescence microscopy. It was shown that full length Tat (aa 1–86) neither forms pores in large unilamellar vesicles (LUVs) nor in giant unilamellar vesicles (GUVs) composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). In contrast, an N-terminally truncated Tat protein (aa 35–86) that lacks the structurally defined proline- and cysteine-rich region as well as the highly conserved tryptophan residue at position 11 generates pores in artificial POPC-membranes, through which a water-soluble dye up to a size of 10kDa can pass. By means of fluorescence microscopy, the transfer of fluorescently labeled full length Tat across POPC-bilayers was unambiguously visualized with a concomitant accumulation of the protein in the membrane interface. However, if the dye was attached to the protein, also pore formation was induced. The size of the pores was, however smaller than the protein size, i.e. the labeled protein with a mass of 11.6kDa passed the membrane, while a fluorescent dye with a mass of 10kDa was excluded from the vesicles' interior. The results demonstrate that pore formation is not the prime mechanism by which full length Tat crosses a membrane
The Effects of Age, Otological Factors and Occupational Noise Exposure on Hearing Threshold Levels of Various Populations
In this paper an analysis is presented of two investigations conducted in the Netherlands. One study concerns the effect of age on hearing threshold levels of populations not exposed to noise during working hours. The second investigation deals with the effect of occupational noise exposure on hearing threshold levels. There were about 500 test subjects in the first investigation and 2300 industrial workers in the second one. An analysis of the effects of otological factors on hearing threshold levels, based on both investigations, is given as well