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Sci-fi dreaming
Published in Josie Malinowski, The Psychology of Dreaming, 2020
But TMR isn’t just limited to consolidating memories. It can also be used for the exact opposite purpose: erasing memories. In another sci-fi movie, Eternal Sunshine of the Spotless Mind, two lovers decide to erase the memories of their former relationship, and this memory erasure takes place during sleep. As the film progresses, the protagonist Joel Barish, played by Jim Carrey, realises that he is sleeping and that his memories are being erased, and changes his mind about having the procedure while it’s happening. Still asleep, he tries to stop it, but the memories are erased despite his efforts. This film is over 15 years old now, but the technology it so darkly portrays is being developed now – albeit in a different way.
Megavoltage Photon Beams: TMR and Dose Calculations
Published in Eric Ford, Primer on Radiation Oncology Physics, 2020
The previous chapter described the percent depth dose (PDD) and its dependence on energy, field size, and other factors. Unfortunately, the PDD is not directly useful for isocentric treatments. Instead a more useful, and closely related, quantity is the tissue-maximum ratio (TMR). The TMR is a key concept and is described in this section.
Acceptance Testing, Commissioning, and Quality Assurance of Linear Accelerators
Published in Ben Mijnheer, Clinical 3D Dosimetry in Modern Radiation Therapy, 2017
With that said, tanks which can accommodate scanning 40 cm × 40 cm fields at appropriate SDDs are prohibitively large and heavy to be widely produced and/or used. If large fields are required, one solution is to offset the water tank from being centered with the beam and scan one or more half-beam profiles; i.e., scanning from central axis (CAX) past the penumbra. Most commercially available scanning water tanks also come with a platform which allows them to be moved and leveled as the heft and size of the filled tanks may be difficult for patient support systems to stably hold and maneuver, and may exceed limits. Most modern water tanks come with computer software interface systems, which allow the tanks to be driven remotely and include integrated data collection modules. Other accessories/features are available with some scanning water tanks, such as mobile water storage and pumping systems, integrated pump/movement systems to facilitate tissue-phantom ratio (TPR)/tissue-maximum ratio (TMR) measurements, and automated leveling systems.
Effect of gap detection threshold and localisation acuity on spatial release from masking in older adults*
Published in International Journal of Audiology, 2022
Nirmal Kumar Srinivasan, Alexis Staudenmeier, Kelli Clark
A progressive tracking procedure (Gallun et al. 2013) was used to estimate co-located and spatially separated identification thresholds. The target speech was presented to the listeners at 20 dB sensation level (SL) relative to their hearing loss (calculated as the average of audiometric thresholds for the octave frequencies 500, 1000, 2000, and 4000 Hz) and was kept constant during the experiment. The masking sentences were presented at levels relative to the target and were appropriately scaled in SL to achieve the required target-to-masker ratios (TMRs). Responses were obtained using a computer monitor located in front of the listener. Feedback was given after each presentation in the form of “Correct” or “Incorrect”. Data collection was self-paced and listeners were instructed to take breaks whenever they felt the need. The progressive tracking procedure involves presenting 20 trials starting at 10 dB TMR and ending at −8 dB TMR (decreasing in steps of 2 dB). Two trials were presented at each of the 10 TMRs. TMR thresholds in dB were estimated by subtracting the number of correct responses from 10. This method has been successfully used to measure co-located and spatially separated identification thresholds (Srinivasan, Jakien, and Gallun 2016; Srinivasan, Stansell, and Gallun 2017) and it provides similar estimates of threshold in the co-located condition and only slightly underestimates thresholds in the spatially separated conditions compared to the thresholds measured using classic adaptive tracking procedures (Gallun et al. 2013).
Targeted Memory Reactivation During Sleep, But Not Wake, Enhances Sensorimotor Skill Performance: A Pilot Study
Published in Journal of Motor Behavior, 2018
Brian P. Johnson, Steven M. Scharf, Kelly P. Westlake
Methods have been developed to enhance sensorimotor learning during sleep through the reactivation of specific memories (Antony, Gobel, O'Hare, Reber, & Paller, 2012) via sensory cues previously conditioned to task performance (Rasch, Buchel, Gais, & Born, 2007). This approach is known as targeted memory reactivation (TMR). Providing TMR during sleep reactivates and increases the functional connectivity between brain regions that are also common to task performance while in the wake state. These strengthened neural network connections are thought to underlie memory consolidation and subsequent task performance (Cousins, El-Deredy, Parkes, Hennies, & Lewis, 2016; Diekelmann, Buchel, Born, & Rasch, 2011; Laventure et al., 2016; Rasch et al., 2007; Schönauer, Geisler, & Gais, 2014). The effectiveness of TMR, however, does not appear to be equal across all sleep stages. Non–rapid eye movement (NREM) sleep has been found to be more responsive to TMR than has rapid eye movement (REM) sleep (Laventure et al., 2016; Rasch et al., 2007).
Pharmacokinetics, metabolism and excretion of radiolabeled fostemsavir administered with or without ritonavir in healthy male subjects
Published in Xenobiotica, 2022
Peter Gorycki, Mindy Magee, Peter Ackerman, Xiusheng Miao, Katy Moore
Absorption of TMR and TR was immediate and comparable between treatment groups, with TMR Tmax values of 0.5 h in Group A + B (FTR alone) and 1.00 h in Group C + D (FTR + RTV). TR Tmax was comparable to TMR, being 0.5 h in Group A + B (FTR alone) and 0.78 h in C + D (FTR + RTV) (Tables 1 and 2). RTV pre-treatment (Group C + D) had no effect on TMR or TR half-lives; however, the half-life of TR was longer than that of TMR (approximately 7 h for TMR and between 77 and 143 h for TR). This result would suggest the presence of circulating metabolites with long half-lives (Tables 1 and 2).