165 research outputs found

    Comparison Tests of the Column Coefficient and the Gravity Coefficient Models

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    This study presents a comparison of the 1947, 1958, 1963, 1970, and 1980 regional outputs estimated using the column coefficient and gravity coefficient models. An evaluation is made of the accuracy of the two models in estimating 1947, 1958, and 1963 outputs. A detailed review of the industrial and regional estimation errors is provided by the authors, supplemented by appendix tables showing the errors for each of 10 industries in each of 9 regions

    Electron-Beam Driven Relaxation Oscillations in Ferroelectric Nanodisks

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    Using a combination of computational simulations, atomic-scale resolution imaging and phenomenological modelling, we examine the underlying mechanism for nanodomain restructuring in lead zirconate titanate (PZT) nanodisks driven by electron beams. The observed subhertz nanodomain dynamics are identified with relaxation oscillations where the charging/discharging cycle time is determined by saturation of charge traps and nanodomain wall creep. These results are unusual in that they indicate very slow athermal dynamics in nanoscale systems.Comment: 5 pages, 2 figure

    A Case of a Nonpetrous Cholesterol Granuloma Presenting as a Temporal Mass

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    Objective. A case of a skull base cholesterol granuloma (CG) of the squamosal temporal bone. This is the first ever reported case of CG in a well-pneumatized squamous temporal bone. Design. Case report and review of the literature. Discussion. CG is a cystic mass typically found in the petrous apex and occasionally in the paranasal sinuses and orbit. Experience with the treatment of these expansile and inflammatory processes has largely been garnered from those occurring in the petrous apex, where they are surgically drained, via a transtympanic, transmastoid, or middle fossa approach. We report a case of cholesterol granuloma situated in the temporal fossa presenting as a temporal mass. The accessible location of this particular lesion made it amenable to total excision, avoiding the need for surgical drainage and possibility for recurrence. Conclusion. This case supports the theory of pathogenesis of such lesions typically occurring where pneumatized air spaces interface with bone marrow, in this case, where the reaches of pneumatized cells in the squamous portion of the temporal bone meet diploic bone

    Lateral Size and Thickness Dependence in Ferroelectric Nanostructures Formed by Localized Domain Switching

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    Ferroelectric nanostructures can be formed by local switching of domains using techniques such as piezo-force microscopy (PFM). Understanding lateral size effects is important to determine the minimum feature size for writing ferroelectric nanostructures. To understand these lateral size effects, we use the time-dependent-Ginzburg-Landau equations to simulate localized switching of domains for a PFM type and parallel-plate capacitor configurations. Our investigations indicate that fringing electric fields lead to switching via 90 deg domain wedge nucleation for thicker films while at smaller thicknesses, the polarization switches directly by 180 deg rotations. The voltage required to switch the domain increases by decreasing the lateral size and at very small lateral sizes the coercive voltage becomes so large that it becomes virtually impossible to switch the domain. In all cases, the width of the switched region extends beyond the electrodes, due to fringing.Comment: 21 pages, 11 figure

    Zerumbone-loaded nanostructured lipid carrier induces apoptosis in human colorectal adenocarcinoma (Caco2) cell line

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    The incorporation of zerumbone (Zer) into nanostructured lipid carrier (NLC) is hypothesized to increase the efficacy of the drug. Nanostructured lipid carrier has sustained-drug release characteristics and is able to improve the solubility and bioavailability of the lipophilic drug. In this study, the anti-cancer effect of Zer was tested on human colorectal adenocarcinoma (Caco-2) cell line. The effect of Zer, zerumbone-loaded nanostructured lipid carrier (Zer-NLC) and NLC on the Caco-2 cell viability were determined using the MTT assay. The treatment concentration ranges from 0 to 120 μM at four different time intervals (i.e., 0 h, 24 hrs, 48 hrs and 72 hrs) were evaluated. At 24 hrs, the half-growth inhibitory concentration (GI50) of Zer-NLC (i.e., 4.25 μM) is lower than that of Zer (i.e., 23.75 μM). However, Zer outperformed the Zer-NLC at the subsequent time points. Similar trend was observed in other parameters including the cytostatic concentration (CC) and half-lethal concentration 50 (LC50). Phase contrast imaging and AO/PI fluorescence staining were performed at the CC and LC50 values. The morphological changes and the apoptosis features could be seen in cells treated with Zer and Zer-NLC while cells treated with NLC showed minor morphological changes. The cells treated with Zer-NLC demonstrated a slightly slower progression of apoptosis, which could be due to the controlled release of Zer from the NLC matrix. It was concluded that the incorporation of Zer into NLC did not compromise the potency and efficacy of the drug

    Do the Rewards Justify the Means? Measuring Trade-Offs Between Rewards and Ethical Behavior in the MACHIAVELLI Benchmark

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    Artificial agents have traditionally been trained to maximize reward, which may incentivize power-seeking and deception, analogous to how next-token prediction in language models (LMs) may incentivize toxicity. So do agents naturally learn to be Machiavellian? And how do we measure these behaviors in general-purpose models such as GPT-4? Towards answering these questions, we introduce MACHIAVELLI, a benchmark of 134 Choose-Your-Own-Adventure games containing over half a million rich, diverse scenarios that center on social decision-making. Scenario labeling is automated with LMs, which are more performant than human annotators. We mathematize dozens of harmful behaviors and use our annotations to evaluate agents' tendencies to be power-seeking, cause disutility, and commit ethical violations. We observe some tension between maximizing reward and behaving ethically. To improve this trade-off, we investigate LM-based methods to steer agents' towards less harmful behaviors. Our results show that agents can both act competently and morally, so concrete progress can currently be made in machine ethics--designing agents that are Pareto improvements in both safety and capabilities.Comment: ICML 2023 Oral; 31 pages, 5 figure
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