Identification and quantification of cannabinol as a biomarker for local hemp retting in an ancient sedimentary record by HPTLC-ESI-MS

Cannabis products have been used in various fields of everyday life for many centuries, and applications in folk medicine and textile production have been well-known for many centuries. For traditional textile production, hemp fibers were extracted from the stems by water retting in stagnant or slow-moving waters. During this procedure, parts of the plant material‚ among them phytocannabinoids‚ are released into the water. Cannabinol (CBN) is an important degradation product of the predominant phytocannabinoids found in Cannabis species. Thus, it is an excellent indicator for present as well as ancient hemp water retting. In this study, we developed and validated a simple and fast method for the determination of CBN in sediment samples using high-performance thin-layer chromatography (HPTLC) combined with electrospray ionization mass spectrometry (ESI-MS), thereby testing different extraction and cleanup procedures‚ as well as various sorbents and solvents for planar chromatography. This method shows a satisfactory overall analytical performance with an average recovery rate of 73%. Our protocol enabled qualitative and quantitative analyses of CBN in samples of a bottom sediment core‚ having been obtained from a small lake in Northern India, where intense local retting of hemp was suggested in the past. The analyses showed a maximum CBN content in pollen zone 4 covering a depth range of 262–209 cm, dating from approximately 480 BCE to 1050 CE. These findings correlate with existing records of Cannabis-type pollen. Thus, the method we propose is a helpful tool to track ancient hemp retting activities

High fidelity simulations of ion trajectories in miniature ion traps using the boundary-element method

In this paper we present numerical modeling results for endcap and linear ion traps, used for experiments at the National Physical Laboratory in the UK and Innsbruck University respectively. The secular frequencies for Strontium-88 and Calcium-40 ions were calculated from ion trajectories, simulated using boundary-element and finite-difference numerical methods. The results were compared against experimental measurements. Both numerical methods showed high accuracy with boundary-element method being more accurate. Such simulations can be useful tools for designing new traps and trap arrays. They can also be used for obtaining precise trapping parameters for desired ion control when no analytical approach is possible as well as for investigating the ion heating rates due to thermal electronic noise.Comment: 6 pages, 5 figures, changes made to the text according to the editor's and referee's comment

Too Imperfect to Fall Asleep: Perfectionism, Pre-sleep Counterfactual Processing, and Insomnia

Previous research suggests that certain dimensions of perfectionism are associated with insomnia. However, the exact processes whereby perfectionism may influence sleep have as yet remained unexplored. The present study tested the hypothesis that perfectionistic individuals are particularly prone to engage in counterfactual thinking and to experience counterfactual emotions (regret, shame, and guilt) at bedtime, which have been shown to impair sleep. One hundred eighty university students completed questionnaires on perfectionism, counterfactual processing, and insomnia severity. Analyses revealed that three dimensions of perfectionism were significantly related to insomnia severity: Concern over mistakes and doubts about action showed positive correlations, whereas organization showed a negative correlation. Moreover, the frequency of counterfactual thoughts and emotions at bedtime largely mediated the effects of these dimensions of perfectionism on insomnia severity. These findings highlight how personality-related patterns of behavior may translate into affective arousal at bedtime, thereby increasing the risk of insomnia

Mesoscopic interplay of superconductivity and ferromagnetism in ultra-small metallic grains

We review the effects of electron-electron interactions on the ground-state spin and the transport properties of ultra-small chaotic metallic grains. Our studies are based on an effective Hamiltonian that combines a superconducting BCS-like term and a ferromagnetic Stoner-like term. Such terms originate in pairing and spin exchange correlations, respectively. This description is valid in the limit of a large dimensionless Thouless conductance. We present the ground-state phase diagram in the fluctuation-dominated regime where the single-particle mean level spacing is comparable to the bulk BCS pairing gap. This phase diagram contains a regime in which pairing and spin exchange correlations coexist in the ground-state wave function. We discuss the calculation of the tunneling conductance for an almost-isolated grain in the Coulomb-blockade regime, and present measurable signatures of the competition between superconductivity and ferromagnetism in the mesoscopic fluctuations of the conductance.Comment: 6 pages, 3 figures, To be published in the proceedings of the NATO Advance Research Workshop "Recent Advances in Nonlinear Dynamics and Complex System Physics.

Reliability and Validity of S3 Pressure Sensation as an Alternative to Deep Anal Pressure in Neurologic Classification of Persons With Spinal Cord Injury.

OBJECTIVE: To determine whether pressure sensation at the S3 dermatome (a new test) could be used in place of deep anal pressure (DAP) to determine completeness of injury as part of the International Standards for Neurological Classification of Spinal Cord Injury. DESIGN: Prospective, multicenter observational study. SETTING: U.S. Spinal Cord Injury Model Systems. PARTICIPANTS: Persons (N=125) with acute traumatic spinal cord injury (SCI), neurologic levels T12 and above, were serially examined at 1 month (baseline), 3, 6, and 12 months postinjury. There were 80 subjects with tetraplegia and 45 with paraplegia. INTERVENTIONS: S3 pressure sensation at all time points, with a retest at the 1-month time point. MAIN OUTCOME MEASURES: Test-retest reliability and agreement (κ), sensitivity, specificity, positive and negative predictive values. RESULTS: Test-retest reliability of S3 pressure at 1 month was almost perfect (κ=.98). Agreement of S3 pressure with DAP was substantial both at 1 month (κ=.73) and for all time points combined (κ=.76). The positive predictive value of S3 pressure for DAP was 89.3% at baseline and 90.3% for all time points. No pattern in outcomes was seen in those cases where S3 pressure and DAP differed at 1 month. CONCLUSIONS: S3 pressure sensation is reliable and has substantial agreement with DAP in persons with SCI at least 1 month postinjury. We suggest S3 pressure as an alternative test of sensory sacral sparing for supraconus SCI, at least in cases where DAP cannot be tested. Further research is needed to determine whether S3 pressure could replace DAP for classification of SCI

LHC Machine Protection

For nominal beam parameters at 7 TeV/c each of the two LHC proton beams has a stored energy of 362 MJ threatening to damage accelerator equipment in case of uncontrolled beam loss. The energy stored in the magnet system at 7 TeV/c will exceed 10 GJ. In order to avoid damage of accelerator equipment, complex machine protection systems are required. Magnet protection and powering interlock systems must be operational already before commissioning the magnet powering system. Beam operation, throughout the operational cycle from injection to colliding beams, requires fully operational protection systems, including beam interlock systems, beam dumping system, beam instrumentation (mainly beam loss monitors) as well as collimators and beam absorbers. Details of LHC machine protection have been presented on several occasions and the systems involved in protection are well documented [1]. This paper gives an overview of LHC machine protection, discusses the progress with the implementation and presents first results from the commissioning of some systems

Spin transitions in a small Si quantum dot

We have studied the magnetic field dependence of the ground state energies in a small Si quantum dot. At low fields the first five electrons are added in a spin-up -- spin-down sequence minimizing the total spin. This sequence does not hold for larger number of electrons in the dot. At high fields the dot undergoes transitions between states with different spins driven entirely by Zeeman energy. We identify some features that can be attributed to transitions between different spin configurations preserving the total spin of the dot. For a few peaks we observed large linear shifts that correspond to the change of the spin of the dot by 3/2. Such a change requires that an electron in the dot flips its spin during every tunneling event.Comment: Revtex, 5 pages, 3 figure

Nanometer Scale Dielectric Fluctuations at the Glass Transition

Using non-contact scanning probe microscopy (SPM) techniques, dielectric properties were studied on 50 nanometer length scales in poly-vinyl-acetate (PVAc) films in the vicinity of the glass transition. Low frequency (1/f) noise observed in the measurements, was shown to arise from thermal fluctuations of the electric polarization. Anomalous variations observed in the noise spectrum provide direct evidence for cooperative nano-regions with heterogeneous kinetics. The cooperative length scale was determined. Heterogeneity was long-lived only well below the glass transition for faster than average processes.Comment: 4 pages, 4 embedded PS figures, RevTeX - To appear in Phys. Rev. Let