37 research outputs found

    Cost implications of new treatments for advanced colorectal cancer: Cost-effectiveness of CRC Treatment

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    Since 1996, six new drugs have been introduced for the treatment of metastatic colorectal cancer. While promising, these drugs are frequently given in the palliative, and are much more expensive than older treatments. The objective of this study is to measure the cost implications of treatment with sequential regimens that include chemotherapy and/or monoclonal antibodies

    Penaid Nonproliferation: Hindering the Spread of Countermeasures Against Ballistic Missile Defenses

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    For more information on this publication, visit www.rand.org/t/RR378This research describes an approach to hindering the spread of countermeasures against ballistic missile defenses. (Such countermeasures, when incorporated in an attacker’s missile, are also called penetration aids, or penaids.) The approach involved compiling an unclassified list of penaid-relevant items that might be subject to internationally agreed-upon export controls. The list is formatted to fit into the export-control structure of current international policy against the proliferation of missiles capable of delivering weapons of mass destruction. This policy, the Missile Technology Control Regime, creates two levels of control. One is a set of tight restrictions against a small number of items, such as complete missiles or their major subsystems. The other is a set of case-by-case export reviews for lower-level components and dual-use items.Prepared for the Naval Postgraduate School, Project on Advanced Systems and Concepts for Combating WM

    Cruise Missile Penaid Nonproliferation: Hindering the Spread of Countermeasures Against Cruise Missile Defenses

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    For more information on this publication, visit www.rand.org/t/RR743This research describes an approach to hindering the spread of countermeasures against cruise missile defenses. (Such countermeasures, when incorporated in an attacker’s missile or employed in conjunction with such a missile, are called penetration aids, or penaids.) This approach involved compiling an unclassified list of penaid-relevant items that might be subject to internationally agreed-upon export controls. The list is designed to fit into the export-control structure of the current international policy against the proliferation of missiles capable of delivering weapons of mass destruction. This policy, the Missile Technology Control Regime (MTCR), sets rules agreed to by 34 governments for restricting the export of items, listed in a technical annex. This report recommends controls on 18 penaid-relevant items and subitems. Because cruise missile penaids can have applications either not restricted by the MTCR (e.g., for manned aircraft) or subject only to the regime’s less rigorous controls (e.g., for relatively small cruise missiles), the report recommends that the 18 items be subject to case-by-case export reviews under MTCR procedures. To be effective, these less rigorous controls will require energetic implementation, and cooperation by Russia and China will be critical.Prepared for the Naval Postgraduate School, Project on Advanced Systems and Concepts for Combating WMDDefense Threat Reduction AgencyPrepared for the Naval Postgraduate School, Project on Advanced Systems and Concepts for Combating WM

    Refining epileptogenic high-frequency oscillations using deep learning: a reverse engineering approach.

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    Intracranially recorded interictal high-frequency oscillations have been proposed as a promising spatial biomarker of the epileptogenic zone. However, its visual verification is time-consuming and exhibits poor inter-rater reliability. Furthermore, no method is currently available to distinguish high-frequency oscillations generated from the epileptogenic zone (epileptogenic high-frequency oscillations) from those generated from other areas (non-epileptogenic high-frequency oscillations). To address these issues, we constructed a deep learning-based algorithm using chronic intracranial EEG data via subdural grids from 19 children with medication-resistant neocortical epilepsy to: (i) replicate human expert annotation of artefacts and high-frequency oscillations with or without spikes, and (ii) discover epileptogenic high-frequency oscillations by designing a novel weakly supervised model. The 'purification power' of deep learning is then used to automatically relabel the high-frequency oscillations to distill epileptogenic high-frequency oscillations. Using 12 958 annotated high-frequency oscillation events from 19 patients, the model achieved 96.3% accuracy on artefact detection (F1 score = 96.8%) and 86.5% accuracy on classifying high-frequency oscillations with or without spikes (F1 score = 80.8%) using patient-wise cross-validation. Based on the algorithm trained from 84 602 high-frequency oscillation events from nine patients who achieved seizure-freedom after resection, the majority of such discovered epileptogenic high-frequency oscillations were found to be ones with spikes (78.6%, P < 0.001). While the resection ratio of detected high-frequency oscillations (number of resected events/number of detected events) did not correlate significantly with post-operative seizure freedom (the area under the curve = 0.76, P = 0.06), the resection ratio of epileptogenic high-frequency oscillations positively correlated with post-operative seizure freedom (the area under the curve = 0.87, P = 0.01). We discovered that epileptogenic high-frequency oscillations had a higher signal intensity associated with ripple (80-250 Hz) and fast ripple (250-500 Hz) bands at the high-frequency oscillation onset and with a lower frequency band throughout the event time window (the inverted T-shaped), compared to non-epileptogenic high-frequency oscillations. We then designed perturbations on the input of the trained model for non-epileptogenic high-frequency oscillations to determine the model's decision-making logic. The model confidence significantly increased towards epileptogenic high-frequency oscillations by the artificial introduction of the inverted T-shaped signal template (mean probability increase: 0.285, P < 0.001), and by the artificial insertion of spike-like signals into the time domain (mean probability increase: 0.452, P < 0.001). With this deep learning-based framework, we reliably replicated high-frequency oscillation classification tasks by human experts. Using a reverse engineering technique, we distinguished epileptogenic high-frequency oscillations from others and identified its salient features that aligned with current knowledge

    Glutamate Is a Positive Autocrine Signal for Glucagon Release

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    An important feature of glucose homeostasis is the effective release of glucagon from the pancreatic α cell. The molecular mechanisms regulating glucagon secretion are still poorly understood. We now demonstrate that human α cells express ionotropic glutamate receptors (iGluRs) that are essential for glucagon release. A lowering in glucose concentration results in the release of glutamate from the α cell. Glutamate then acts on iGluRs of the AMPA/kainate type, resulting in membrane depolarization, opening of voltage-gated Ca 2+ channels, increase in cytoplasmic free Ca 2+ concentration, and enhanced glucagon release. In vivo blockade of iGluRs reduces glucagon secretion and exacerbates insulin-induced hypoglycemia in mice. Hence, the glutamate autocrine feedback loop endows the α cell with the ability to effectively potentiate its own secretory activity. This is a prerequisite to guarantee adequate glucagon release despite relatively modest changes in blood glucose concentration under physiological conditions
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