Stochastic models for atomic clocks

For the atomic clocks used in the National Bureau of Standards Time Scales, an adequate model is the superposition of white FM, random walk FM, and linear frequency drift for times longer than about one minute. The model was tested on several clocks using maximum likelihood techniques for parameter estimation and the residuals were acceptably random. Conventional diagnostics indicate that additional model elements contribute no significant improvement to the model even at the expense of the added model complexity

Netec Cold Crucible Induction Melter Demonstration for Srnl With Simulated Sludge Batch 4 Dwpf Waste

Cold Crucible Induction Melter (CCIM) Technology is being considered as a possible next generation melter for the Defense Waste Processing Facility (DWPF). Initial and baseline demonstrations that vitrified a Sludge Batch 4 (SB4) simulant at a waste loading of 50 weight percent (versus about 38 weight percent in the current DWPF Melter) were performed by the Nuclear Engineering and Technology Institute (NETEC) in South Korea via a subcontract from the Washington Savannah River Company (WSRC). This higher waste loading was achieved by using a CCIM which can run at higher glass processing temperatures (1250 C and higher) than the current DWPF Melter (1150 C). Higher waste loadings would result in less canisters being filled and faster waste throughput at the DWPF. The main demonstration objectives were to determine the maximum melt rate/waste throughput for the NETEC CCIM with a Sludge Batch 4 simulant as well as determine the viability of this technology for use in the DWPF

Delirium and delirium severity predict the trajectory of the Hierarchical Assessment of Balance and Mobility (HABAM) in hospitalised older people: findings from the DECIDE Study

BACKGROUND: Delirium is common, distressing and associated with poor outcomes. Despite this, delirium remains poorly recognised, resulting in worse outcomes. There is an urgent need for methods to objectively assess for delirium. Physical function has been proposed as a potential surrogate marker, but few studies have monitored physical function in the context of delirium. We examined if trajectories of physical function are affected by the presence and severity of delirium in a representative sample of hospitalised participants over 65 years. METHODS: During hospital admissions in 2016, we assessed participants from the DECIDE study daily for delirium and physical function, using the Hierarchical Assessment of Balance and Mobility (HABAM). We used linear mixed models to assess the effect of delirium and delirium severity during admission on HABAM trajectory. RESULTS: Of 178 participants, 58 experienced delirium during admission. Median HABAM scores in those with delirium were significantly higher (indicating worse mobility) than those without delirium. Modelling HABAM trajectories, HABAM scores at first assessment were worse in those with delirium than those without, by 0.76 (95% CI: 0.49-1.04) points. Participants with severe delirium experienced a much greater perturbance in their physical function, with an even lower value at first assessment and slower subsequent improvement. CONCLUSIONS: Physical function was worse in those with delirium compared to without. This supports the assertion that motor disturbances are a core feature of delirium and monitoring physical function, using a tool such as the HABAM, may have clinical utility as a surrogate marker for delirium and its resolution

Long-distance frequency transfer over an urban fiber link using optical phase stabilization

We transferred the frequency of an ultra-stable laser over 86 km of urban fiber. The link is composed of two cascaded 43-km fibers connecting two laboratories, LNE-SYRTE and LPL in Paris area. In an effort to realistically demonstrate a link of 172 km without using spooled fiber extensions, we implemented a recirculation loop to double the length of the urban fiber link. The link is fed with a 1542-nm cavity stabilized fiber laser having a sub-Hz linewidth. The fiber-induced phase noise is measured and cancelled with an all fiber-based interferometer using commercial off the shelf pigtailed telecommunication components. The compensated link shows an Allan deviation of a few 10-16 at one second and a few 10-19 at 10,000 seconds

Using a disciplinary discourse lens to explore how representations afford meaning making in a typical wave physics course

We carried out a case study in a wave physics course at a Swedish university in order to investigate the relations between the representations used in the lessons and the experience of meaning making in interview–discussions. The grounding of these interview–discussions also included obtaining a rich description of the lesson environment in terms of the communicative approaches used and the students’ preferences for modes of representations that best enable meaning making. The background for this grounding was the first two lessons of a 5-week course on wave physics (70 students). The data collection for both the grounding and the principal research questions consisted of video recordings from the first two lessons: a student questionnaire of student preferences for representations (given before and after the course) and video-recorded interview–discussions with students (seven pairs and one on their own). The results characterize the use of communicative approaches, what modes of representation were used in the lectures, and the trend in what representations students’ preferred for meaning making, all in order to illustrate how students engage with these representations with respect to their experienced meaning making. Interesting aspects that emerged from the study are discussed in terms of how representations do not, in themselves, necessarily enable a range of meaning making; that meaning making from representations is critically related to how the representations get situated in the learning environment; and how constellations of modes of disciplinary discourse may be necessary but not always sufficient. Finally, pedagogical comments and further research possibilities are presented.Web of Scienc

Evaluation the on-site Draeger DrugTest 5000 in occasional and chronic frequent smokers following controlled cannabis smoking Evaluation of the on-site Draeger DrugTest 5000 in occasional and chronic frequent smokers following controlled cannabis smoking

Abstract Background Cannabis is the most commonly reported illicit drug in drugged driving cases. Achieving accurate oral fluid (OF) cannabinoid on-site results is challenging and essential

Evaluation of Bedside Tests of Attention and Arousal Assessing Delirium in Parkinson's Disease, Dementia, and Older Adults

BACKGROUND: Delirium is a serious acute neuropsychiatric condition associated with altered attention and arousal. OBJECTIVE: To evaluate simple bedside tests for attention and arousal to detect delirium in those with and without Parkinson's disease (PD) and dementia. METHODS: Participants from two prospective delirium studies were pooled comprising 30 with PD without cognitive impairment, 24 with Lewy body cognitive impairment (PD dementia or dementia with Lewy bodies), 16 with another dementia and 179 PD and dementia-free older adults. Participants completed standardised delirium assessments including tests of attention: digit span, Memorial Delirium Assessment Scale (MDAS) attention and months of the year backwards; and arousal: Glasgow Coma Scale (GSC), Observational Scale of Level of Arousal (OSLA), Modified Richmond Agitation Scale and MDAS consciousness. Delirium was diagnosed using the DSM-5 criteria. RESULTS: On their first admission, 21.7%participants had prevalent delirium. Arousal measures accurately detected delirium in all participants (p <  0.01 for all), but only selected attention measures detected delirium in PD and dementia. In PD and dementia-free older adults, impaired digit span and OSLA were the optimal tests to detect delirium (area under the curve [AUC] = 0.838, p <  0.001) while in PD and dementia the optimal tests were MDAS attention and GCS LB. CONCLUSION: Simple bedside tests of attention and arousal at a single visit could accurately detect delirium in PD, dementia and PD and dementia-free older adults; however, the optimal tests differed between groups. Combined attention and arousal scores increased accuracy, which could have clinical utility to aid the identification of delirium neurodegenerative disorders

Recent Process and Equipment Improvements to Increase High Level Waste Throughput at the Defense Waste Processing Facility

The Savannah River Site's (SRS) Defense Waste Processing Facility (DWPF) began stabilizing high level waste (HLW) in a glass matrix in 1996. Over the past few years, there have been several process and equipment improvements at the DWPF to increase the rate at which the high level waste can be stabilized. These improvements have either directly increased waste processing rates or have desensitized the process to upsets, thereby minimizing downtime and increasing production. Improvements due to optimization of waste throughput with increased HLW loading of the glass resulted in a 6% waste throughput increase based upon operational efficiencies. Improvements in canister production include the pour spout heated bellows liner (5%), glass surge (siphon) protection software (2%), melter feed pump software logic change to prevent spurious interlocks of the feed pump with subsequent dilution of feed stock (2%) and optimization of the steam atomized scrubber (SAS) operation to minimize downtime (3%) for a total increase in canister production of 12%. A number of process recovery efforts have allowed continued operation. These include the off gas system pluggage and restoration, slurry mix evaporator (SME) tank repair and replacement, remote cleaning of melter top head center nozzle, remote melter internal inspection, SAS pump J-Tube recovery, inadvertent pour scenario resolutions, dome heater transformer bus bar cooling water leak repair and new Infra-red camera for determination of glass height in the canister are discussed

Early loss, fractionation, and redistribution of chlorine in the Moon as revealed by the low-Ti lunar mare basalt suite

The relative abundances of chlorine isotopes measured in low-Ti basalts from the Moon appear to reflect mixing between two reservoirs: One component representing the urKREEP—the final product of the crystallization of the lunar magma ocean, the other representing either a mare basalt reservoir or meteoritic materials.Jeremy W. Boyce, Sarah A. Kanee, Francis M. McCubbin, Jessica J. Barnes, Hayley Bricker. Allan H. Treima

Safety, pharmacokinetics, and preliminary assessment of efficacy of mecasermin (recombinant human IGF-1) for the treatment of Rett syndrome

Rett syndrome (RTT) is a severe X-linked neurodevelopmental disorder mainly affecting females and is associated with mutations in MECP2, the gene encoding methyl CpG-binding protein 2. Mouse models suggest that recombinant human insulin-like growth factor 1 (IGF-1) (rhIGF1) (mecasermin) may improve many clinical features. We evaluated the safety, tolerability, and pharmacokinetic profiles of IGF-1 in 12 girls with MECP2 mutations (9 with RTT). In addition, we performed a preliminary assessment of efficacy using automated cardiorespiratory measures, EEG, a set of RTT-oriented clinical assessments, and two standardized behavioral questionnaires. This phase 1 trial included a 4-wk multiple ascending dose (MAD) (40–120 μg/kg twice daily) period and a 20-wk open-label extension (OLE) at the maximum dose. Twelve subjects completed the MAD and 10 the entire study, without evidence of hypoglycemia or serious adverse events. Mecasermin reached the CNS compartment as evidenced by the increase in cerebrospinal fluid IGF-1 levels at the end of the MAD. The drug followed nonlinear kinetics, with greater distribution in the peripheral compartment. Cardiorespiratory measures showed that apnea improved during the OLE. Some neurobehavioral parameters, specifically measures of anxiety and mood also improved during the OLE. These improvements in mood and anxiety scores were supported by reversal of right frontal alpha band asymmetry on EEG, an index of anxiety and depression. Our data indicate that IGF-1 is safe and well tolerated in girls with RTT and, as demonstrated in preclinical studies, ameliorates certain breathing and behavioral abnormalities