1,371 research outputs found
Cold molecular welding study in ultra-high vacuum Final report, 8 Oct. 1964 - 17 Dec. 1965
Cold molecular welding in ultrahigh vacuum of metals for use in Apollo projec
Cooperative vs. Non-Cooperative Truels: Little Agreement, But Does That Matter?
It is well-known that non-cooperative and cooperative game theory may yield different solutions to games. These differences are particularly dramatic in the case of truels, or three-person duels, in which the players may fire sequentially or simultaneously, and the games may be one-round or n-round. Thus, it is never a Nash equilibrium for all players to hold their fire in any of these games, whereas in simultaneous one-round and n-round truels such cooperation, wherein everybody survives, is in both the alpha-core and beta-core. On the other hand, both cores may be empty, indicating a lack of stability, when the unique Nash equilibrium is one survivor. Conditions under which each approach seems most applicable are discussed. Although it might be desirable to subsume the two approaches within a unified framework, such unification seems unlikely since the two approaches are grounded in fundamentally different notions of stability.COOPERATIVE GAME; NON-COOPERATIVE GAME; TRUEL; NASH EQUILIBRIUM; CORE
Measurements of SCRF cavity dynamic heat load in horizontal test system
The Horizontal Test System (HTS) at Fermilab is currently testing fully
assembled, dressed superconducting radio frequency (SCRF) cavities. These
cavities are cooled in a bath of superfluid helium at 1.8K. Dissipated RF power
from the cavities is a dynamic heat load on the cryogenic system. The magnitude
of heat flux from these cavities into the helium is also an important variable
for understanding cavity performance. Methods and hardware used to measure this
dynamic heat load are presented. Results are presented from several cavity
tests and testing accuracy is discussed.Comment: 6 pp. Cryogenic Engineering Conference and International Cryogenic
Materials Conference 28 Jun - 2 Jul 2009. Tucson, Arizon
Pup Matching: Model Formulations and Solution Approaches
We model Pup Matching, the logistics problem of matching or pairing semitrailers known as pups to cabs that are able to tow one or two of the pups simultaneously, as an AfP-complete version of the Network Loading Problem (NLP). We examine a branch and bound solution approach tailored to the NLP formulation through the use of three families of cutting planes and four heuristic procedures. Theoretically, we specify facet defining conditions for a cut family that we refer to as odd flow inequalities and show that each heuristic yields a 2-approximation. Computationally, the cheapest of the four heuristic values achieved an average error of 1.3% among solved test problems randomly generated from realistic data. Branch and bound solved to optimality 67% of these problems. Application of the cutting plane families reduced the average relative difference between upper and lower bounds prior to branching from 18.8% to 6.4%
Role of dorsomedial striatum neuronal ensembles in incubation of methamphetamine craving after voluntary abstinence
Abstract
We recently developed a rat model of incubation of methamphetamine craving after choice-based voluntary abstinence. Here, we studied the role of dorsolateral striatum (DLS) and dorsomedial striatum (DMS) in this incubation. We trained rats to self-administer palatable food pellets (6 d, 6 h/d) and methamphetamine (12 d, 6 h/d). We then assessed relapse to methamphetamine seeking under extinction conditions after 1 and 21 abstinence days. Between tests, the rats underwent voluntary abstinence (using a discrete choice procedure between methamphetamine and food; 20 trials/d) for 19 d. We used in situ hybridization to measure the colabeling of the activity marker Fos with Drd1 and Drd2 in DMS and DLS after the tests. Based on the in situ hybridization colabeling results, we tested the causal role of DMS D1 and D2 family receptors, and DMS neuronal ensembles in "incubated" methamphetamine seeking, using selective dopamine receptor antagonists (SCH39166 or raclopride) and the Daun02 chemogenetic inactivation procedure, respectively. Methamphetamine seeking was higher after 21 d of voluntary abstinence than after 1 d (incubation of methamphetamine craving). The incubated response was associated with increased Fos expression in DMS but not in DLS; Fos was colabeled with both Drd1 and Drd2 DMS injections of SCH39166 or raclopride selectively decreased methamphetamine seeking after 21 abstinence days. In Fos-lacZ transgenic rats, selective inactivation of relapse test-activated Fos neurons in DMS on abstinence day 18 decreased incubated methamphetamine seeking on day 21. Results demonstrate a role of DMS dopamine D1 and D2 receptors in the incubation of methamphetamine craving after voluntary abstinence and that DMS neuronal ensembles mediate this incubation.
SIGNIFICANCE STATEMENT:
In human addicts, abstinence is often self-imposed and relapse can be triggered by exposure to drug-associated cues that induce drug craving. We recently developed a rat model of incubation of methamphetamine craving after choice-based voluntary abstinence. Here, we used classical pharmacology, in situ hybridization, immunohistochemistry, and the Daun02 inactivation procedure to demonstrate a critical role of dorsomedial striatum neuronal ensembles in this new form of incubation of drug craving
Urinary incontinence-85: an expanded prostate cancer composite (EPIC) score cutoff value for urinary incontinence determined using long-term functional data by repeated prospective EPIC-score self-assessment after radical prostatectomy
PURPOSE: To determine an objective cutoff value (COV) for urinary incontinence (UI) using the Expanded Prostate Cancer Composite (EPIC) score after radical prostatectomy (RP).
METHODS: From 2004-2013, all RP patients at our institution completed the EPIC urinary domain (EPIC-UD) questionnaire preoperatively and 6 weeks; 3, 6, 9, 12, and 18 months postoperatively; and yearly thereafter. The EPIC-UD is composed of several questions, 4 of which address UI qualitatively (EPIC-UI). Furthermore, patients were asked to complete a global quality of life (QoL) questionnaire regarding continence. The EPIC COV was calculated using receiver operating characteristic (ROC) analysis. Correlations between the EPIC-UI and quantitative QoL were evaluated using the Kendall-Tau test.
RESULTS: We analyzed 239 patients with a median age of 63 years (interquartile range [IQR], 59-66 years), a median follow-up of 48 months (IQR, 30-78 months) and a median preoperative EPIC-UI score of 100 (IQR, 91.75-100). The ROC analysis for the distinction between EPIC-UI and the use of ≤1 pad/day yielded an EPIC-UI COV of >85, which we termed the UI-85, with an area under the curve of 0.857 (P<0.0001). A stronger correlation was seen between QoL scores and the UI-85 (1 year postoperatively: correlation coefficient [CC], 0.592; P<0.0001) than between QoL and not using a pad (CC, 0.512; P<0.0001).
CONCLUSIONS: The calculated COV of the EPIC-UI for continence was 85. UI is a multidimensional condition that cannot be adequately characterized by a single piece of information, such as pad usage only. Hence, the UI-85 represents a nuanced and straightforward tool for monitoring and comparing continence between different time points and cohorts in a multidimensional and objective manner
Distinct fos-expressing neuronal ensembles in the ventromedial prefrontal cortex mediate food reward and extinction memories
In operant learning, initial reward-associated memories are thought to be distinct from subsequent extinction-associated memories.
Memories formed during operant learning are thought to be stored in “neuronal ensembles.” Thus, we hypothesize that different
neuronal ensembles encode reward- and extinction-associated memories. Here, we examined prefrontal cortex neuronal ensembles
involved in the recall of reward and extinction memories of food self-administration.Wefirst trained rats to lever press for palatable food
pellets for 7 d (1 h/d) and then exposed them to 0, 2, or 7 daily extinction sessions in which lever presses were not reinforced. Twenty-four
hours after the last training or extinction session, we exposed the rats to either a short 15 min extinction test session or left them in their
homecage (a control condition). We found maximal Fos (a neuronal activity marker) immunoreactivity in the ventral medial prefrontal
cortex of rats that previously received 2 extinction sessions, suggesting that neuronal ensembles in this area encode extinction memories.
We then used the Daun02 inactivation procedure to selectively disrupt ventral medial prefrontal cortex neuronal ensembles that were
activated during the 15 min extinction session following 0 (no extinction) or 2 prior extinction sessions to determine the effects of
inactivating the putative food reward and extinction ensembles, respectively, on subsequent nonreinforced food seeking 2 d later.
Inactivation of the food reward ensembles decreased food seeking, whereas inactivation of the extinction ensembles increased food
seeking. Our results indicate that distinct neuronal ensembles encoding operant reward and extinction memories intermingle within the
same cortical area
Application of Distributed Fiber Optic Strain Sensors to LMQXFA Cold Mass Welding
The future High Luminosity upgrade of the Large Hadron Collider (HL-LHC) at
CERN will include the low-beta inner triplets (Q1, Q2a/b, Q3) for two LHC
insertion regions. The Q1, Q3 components consist of eight 10 m-long LMQXFA
cryo-assemblies fabricated by the HL-LHC Accelerator Upgrade Project. Each
LMQXFA Cold mass contains two Nb3Sn magnets connected in series. A
stainless-steel shell is welded around the two magnets before the insertion
into the cryostat. There is a limit on how much coil preload increase induced
by the shell welding is allowed. Distributed Rayleigh backscattering fiber
optics sensors were used for the first time to obtain a strain map over a wide
area of a Nb3Sn magnet cold mass shell. Data were collected during welding of
the first LMQXFA cold mass and the results confirm that the increase of the
coil pole azimuthal pre-stress after welding do not exceed requirements
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