176 research outputs found

    Computational experimentation to understand C2 for Teams of Autonomous Systems and People

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    The technological capabilities of autonomous systems (AS) continue to accelerate. Although AS are replacing people in many skilled mission domains and demanding environmental circumstances, people and machines have complementary capabilities, and integrated performance by AS and people working together can be superior to that of either AS or people working alone. We refer to this increasingly important phenomenon as Teams of Autonomous Systems and People (TASP), and we identify a plethora of open, command and control (C2) research, policy and decision making questions. Computational experimentation offers unmatched yet largely unexplored potential to address C2 questions along these lines. The central problem is, this kind of C2 organization experimentation capability has yet to be developed and demonstrated in the TASP domain. This is where our ongoing research project begins to make an important contribution. In this article, we motivate and introduce such TASP research, and we provide an overview of the computational environment used to experiment on TASP C2 organizations and phenomena. We summarize in turn the research method. Key results follow, and we conclude then by summarizing our agenda for continued research along these lines.Consortium for Robotics and Unmanned Systems Education and Research (CRUSER)Consortium for Robotics and Unmanned Systems Education and Research (CRUSER)Approved for public release; distribution is unlimited

    Toward Computational Modeling of C2 for Teams of Autonomous Systems and People (19th ICCRTS)

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    19th ICCRTS, Toward Computational Modeling of C2 for Teams of Autonomous Systems and People, Autonomy Track – Paper 116The technological capabilities of autonomous systems (AS) continue to accelerate. Although AS are replacing people in many skilled mission domains and demanding environmental circumstances, people and machines have complementary capabilities, and integrated performance by AS and people working together can be superior to that of either AS or people working alone. We refer to this increasingly important phenomenon as Teams of Autonomous Systems and People (TASP), and we identify a plethora of open, command and control (C2) research, policy and decision making questions. Computational modeling and simulation offer unmatched yet largely unexplored potential to address C2 questions along these lines. The central problem is, this kind of C2 organization modeling and simulation capability has yet to be developed and demonstrated in the TASP domain. This is where our ongoing research project begins to make an important contribution. In this article, we motivate and introduce such TASP research, and we provide an overview of the computational environment used to model and simulate TASP C2 organizations and phenomena. We follow in turn with an approach to characterizing a matrix of diverse TASP C2 contexts, as well as a strategy for specifying, tailoring and using this computational environment to conduct experiments to examine such contexts. We conclude then by summarizing our agenda for continued research along these lines

    Rupture by damage accumulation in rocks

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    The deformation of rocks is associated with microcracks nucleation and propagation, i.e. damage. The accumulation of damage and its spatial localization lead to the creation of a macroscale discontinuity, so-called "fault" in geological terms, and to the failure of the material, i.e. a dramatic decrease of the mechanical properties as strength and modulus. The damage process can be studied both statically by direct observation of thin sections and dynamically by recording acoustic waves emitted by crack propagation (acoustic emission). Here we first review such observations concerning geological objects over scales ranging from the laboratory sample scale (dm) to seismically active faults (km), including cliffs and rock masses (Dm, hm). These observations reveal complex patterns in both space (fractal properties of damage structures as roughness and gouge), time (clustering, particular trends when the failure approaches) and energy domains (power-law distributions of energy release bursts). We use a numerical model based on progressive damage within an elastic interaction framework which allows us to simulate these observations. This study shows that the failure in rocks can be the result of damage accumulation

    The assessment of neuromuscular fatigue during 120 min of simulated soccer exercise

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    Purpose This investigation examined the development of neuromuscular fatigue during a simulated soccer match incorporating a period of extra time (ET) and the reliability of these responses on repeated test occasions. Methods Ten male amateur football players completed a 120 min soccer match simulation (SMS). Before, at half time (HT), full time (FT), and following a period of ET, twitch responses to supramaximal femoral nerve and transcranial magnetic stimulation (TMS) were obtained from the knee-extensors to measure neuromuscular fatigue. Within 7 days of the first SMS, a second 120 min SMS was performed by eight of the original ten participants to assess the reliability of the fatigue response. Results At HT, FT, and ET, reductions in maximal voluntary force (MVC; −11, −20 and −27%, respectively, P ≤ 0.01), potentiated twitch force (−15, −23 and −23%, respectively, P < 0.05), voluntary activation (FT, −15 and ET, −18%, P ≤ 0.01), and voluntary activation measured with TMS (−11, −15 and −17%, respectively, P ≤ 0.01) were evident. The fatigue response was robust across both trials; the change in MVC at each time point demonstrated a good level of reliability (CV range 6–11%; ICC2,1 0.83–0.94), whilst the responses identified with motor nerve stimulation showed a moderate level of reliability (CV range 5–18%; ICC2,1 0.63–0.89) and the data obtained with motor cortex stimulation showed an excellent level of reliability (CV range 3–6%; ICC2,1 0.90–0.98). Conclusion Simulated soccer exercise induces a significant level of fatigue, which is consistent on repeat tests, and involves both central and peripheral mechanisms

    ZBP1/DAI is an innate sensor of influenza virus triggering the NLRP3 inflammasome and programmed cell death pathways

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    The interferon (IFN)–inducible protein Z-DNA binding protein 1 [ZBP1; also known as DNA-dependent activator of IFN regulatory factors (DAI) and DLM-1] was identified as a double-stranded DNA sensor, which instigates innate immune responses. However, this classification has been disputed, and whether ZBP1 functions as a pathogen sensor during an infection has remained unknown. We demonstrated ZBP1-mediated sensing of the influenza A virus (IAV) proteins NP and PB1, triggering cell death and inflammatory responses via the receptorinteracting protein kinase 1 (RIPK1)–RIPK3–caspase-8 axis. ZBP1 regulates NLRP3 (nucleotide and oligomerization domain, leucine-rich repeat–containing protein family, pyrin domain containing 3) inflammasome activation as well as induction of apoptosis, necroptosis, and pyroptosis in IAV-infected cells. ZBP1 deficiency protected mice from mortality during IAV infection owing to reduced inflammatory responses and epithelial damage. Overall, these findings indicate that ZBP1 is an innate immune sensor of IAV and highlight its importance in the pathogenesis of IAV infection.T.-D.K. is supported by the U.S. NIH (AI101935, AI124346, AR056296, and CA163507) and the American Lebanese Syrian Associated Charities; S.M.M. is supported by the National Health and Medical Research Council of Australia R.G. Menzies Early Career Fellowship

    Venetoclax Alone or in Combination With Chemotherapy in Paediatric and Adolescent/Young Adult Patients With Relapsed/Refractory Acute Myeloid Leukaemia

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    Background: Venetoclax is a potent, oral BCL-2 inhibitor approved as combination therapy for the treatment of adults with newly diagnosed acute myeloid leukaemia (AML) who are ineligible for intensive chemotherapy. This study evaluated the safety and preliminary efficacy of venetoclax alone or combined with chemotherapy in paediatric and adolescent/young adult patients with relapsed/refractory AML. Procedure: In this phase 1, open-label, two-part, multicentre study, paediatric and adolescent/young adult patients (&lt;25 years of age) with relapsed/refractory AML were treated with venetoclax alone or in combination with hypomethylating agents or cytarabine. The study is registered with ClinicalTrials.gov, NCT03236857. Results: A total of 37 patients received treatment with either venetoclax as a monotherapy (n = 3) or in combination with decitabine (n = 5), azacitidine (n = 19), low-dose cytarabine (n = 1) or high-dose cytarabine (HDAC; n = 9). Febrile neutropenia (57%), hypokalaemia (38%), and thrombocytopenia (35% [thrombocytopenia, 19%; platelet count decreased, 16%]) were the most common grade 3/4 treatment-emergent adverse events. Across all venetoclax combinations, the overall response rate (ORR) was 24% (9/37), and the median duration of response was 2.6 months (95% CI, 0.5–7.9). Among the combinations, ORR was 44% with venetoclax plus HDAC and 21% with venetoclax plus azacitidine. In biomarker-evaluable patients, responses to venetoclax plus chemotherapy were observed in patients harbouring mutations across a range of functional classifications and heterogeneous BH3 family member dependencies. Conclusions: Venetoclax alone or combined with chemotherapy was well tolerated in paediatric and adolescent/young adult patients with relapsed/refractory AML, with promising, although transient, responses with venetoclax plus HDAC or azacitidine.</p

    The Public Repository of Xenografts enables discovery and randomized phase II-like trials in mice

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    More than 90% of drugs with preclinical activity fail in human trials, largely due to insufficient efficacy. We hypothesized that adequately powered trials of patient-derived xenografts (PDX) in mice could efficiently define therapeutic activity across heterogeneous tumors. To address this hypothesis, we established a large, publicly available repository of well-characterized leukemia and lymphoma PDXs that undergo orthotopic engraftment, called the Public Repository of Xenografts (PRoXe). PRoXe includes all de-identified information relevant to the primary specimens and the PDXs derived from them. Using this repository, we demonstrate that large studies of acute leukemia PDXs that mimic human randomized clinical trials can characterize drug efficacy and generate transcriptional, functional, and proteomic biomarkers in both treatment-naive and relapsed/refractory disease
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