A new Stark decelerator based surface scattering instrument for studying energy transfer at the gas-surface interface

We report on the design and characterization of a new apparatus for performing quantum-state resolved surface scattering experiments. The apparatus combines optical state-specific molecule preparation with a compact hexapole and a Stark decelerator to prepare carrier gas-free pulses of quantum-state pure CO molecules with velocities controllable between 33 and 1000 m/s with extremely narrow velocity distributions. The ultrahigh vacuum surface scattering chamber includes homebuilt ion and electron detectors, a closed-cycle helium cooled single crystal sample mount capable of tuning surface temperature between 19 and 1337 K, a Kelvin probe for non-destructive work function measurements, a precision leak valve manifold for targeted adsorbate deposition, an inexpensive quadrupole mass spectrometer modified to perform high resolution temperature programmed desorption experiments and facilities to clean and characterize the surface

Phrenology in Selected Stories of Edgar Allan Poe

Edgar Allan Poe used terms and concepts of phrenology in his tales. This paper has a two-fold purpose: (1) to analyze these phrenological elements in several of Poe\u27s tales and draw conclusions about the influence of phrenology on Poe\u27s writing, (2) to impart some background in phrenology to the reader of Poe who knows nothing about phrenology. Included in the background discussion of phrenological terms and concepts is a replica of George Combe\u27s phrenological chart which gives the locations of the phrenological faculties discussed in relationship to Poe\u27s characters. The popularity of phrenology in the United States during the 1830\u27s and later is reflected by the large number of books and magazine articles written on phrenology during this time. The fifth edition of George Combe\u27s The Constitution of Man was printed in 1835, and Poole\u27s Index to Periodical Literature (Volume I, 1802-1881) lists over one hundred and twenty articles on crainiology and phrenology. Poe\u27s acquaintance with phrenology can be traced after 1836, but definite indications in Berenice, Morella, and King Pest -- all written in 1835—suggest that Poe may have known about phrenology before 1836. The physical descriptions of Poe\u27s characters in these tales hint of phrenological motivation. Edward Hungerford, in Poe and Phrenology, American Literature, March 1931, has indicated that Poe first became familiar with phrenology in 1836 when he reviewed forThe Southern Literary Messenger a phrenology text written by Mrs. L. Miles. After this review, more varied uses of phrenological concepts appeared in Poe\u27s writings, including his phrenologizing of several contemporaries in The Literati of New York City; his humorous uses of phrenology in The Business Man, The Imp of the Perverse, and The Man That Was Used Up; and his use of the depression on Dirk Peters\u27 head in The Narrative of A. Gordon Pym. Many critics have noted that Poe\u27s buildings and characters often bear a striking resemblance to each other. The possibility to be explored here is that the buildings in certain Poe short stories may be symbolic descriptions in phrenological terms and concepts of the character\u27s mental condition. Tales which reflect this building-mind relationship are Ligeia, The Fall of the House of Usher, and The Masque of the Red Death. It is hoped that this study may be a corrective influence on interpretations of Poe made by the twentieth century reader who is unacquainted with phrenology

Space Weathering Experiments on Spacecraft Materials

A project to investigate space environment effects on specific materials with interest to remote sensing was initiated in 2016. The goal of the project is to better characterize changes in the optical properties of polymers found in multi-layered spacecraft insulation (MLI) induced by electron bombardment. Previous analysis shows that chemical bonds break and potentially reform when exposed to high energy electrons like those seen in orbit. These chemical changes have been shown to alter a material's optical reflectance, among other material properties. This paper presents the initial experimental results of MLI materials exposed to various fluences of high energy electrons, designed to simulate a portion of the geosynchronous Earth orbit (GEO) space environment. It is shown that the spectral reflectance of some of the tested materials changes as a function of electron dose. These results provide an experimental benchmark for analysis of aging effects on satellite systems which can be used to improve remote sensing and space situational awareness. They also provide preliminary analysis on those materials that are most likely to comprise the high area-to-mass ratio (HAMR) population of space debris in the geosynchronous orbit environment. Finally, the results presented in this paper serve as a proof of concept for simulated environmental aging of spacecraft polymers that should lead to more experiments using a larger subset of spacecraft materials

Fluorescence characterization of clinically-important bacteria

Healthcare-associated infections (HCAI/HAI) represent a substantial threat to patient health during hospitalization and incur billions of dollars additional cost for subsequent treatment. One promising method for the detection of bacterial contamination in a clinical setting before an HAI outbreak occurs is to exploit native fluorescence of cellular molecules for a hand-held, rapid-sweep surveillance instrument. Previous studies have shown fluorescence-based detection to be sensitive and effective for food-borne and environmental microorganisms, and even to be able to distinguish between cell types, but this powerful technique has not yet been deployed on the macroscale for the primary surveillance of contamination in healthcare facilities to prevent HAI. Here we report experimental data for the specification and design of such a fluorescence-based detection instrument. We have characterized the complete fluorescence response of eleven clinically-relevant bacteria by generating excitation-emission matrices (EEMs) over broad wavelength ranges. Furthermore, a number of surfaces and items of equipment commonly present on a ward, and potentially responsible for pathogen transfer, have been analyzed for potential issues of background fluorescence masking the signal from contaminant bacteria. These include bedside handrails, nurse call button, blood pressure cuff and ward computer keyboard, as well as disinfectant cleaning products and microfiber cloth. All examined bacterial strains exhibited a distinctive double-peak fluorescence feature associated with tryptophan with no other cellular fluorophore detected. Thus, this fluorescence survey found that an emission peak of 340nm, from an excitation source at 280nm, was the cellular fluorescence signal to target for detection of bacterial contamination. The majority of materials analysed offer a spectral window through which bacterial contamination could indeed be detected. A few instances were found of potential problems of background fluorescence masking that of bacteria, but in the case of the microfiber cleaning cloth, imaging techniques could morphologically distinguish between stray strands and bacterial contamination

Sensory reweighting of proprioceptive input during balance control in healthy elderly

Sensory (re)weighting is the automated and unconscious process of combining sensory inputs, e.g. proprioception, graviception and vision, during human balance control. Typically reliable sensory inputs are weighted more than unreliable and noisy sensory inputs, to prevent deterioration of human balance control. Malfunctioning of sensory reweighting may be an important determinant of balance deficits in elderly with the consequence of falls. In this study we compared sensory (re)weighting of prioprioceptive input of the ankle joints, as one of the available sensory inputs, in healthy young versus healthy elderly during upright stance. Ten healthy young (aged 20-30 years) and ten healthy elderly (aged 75-80 years) were asked to maintain balance while proprioceptive input of each ankle was perturbed by rotations of the support surfaces around the ankle axes. Support surface rotations were applied with specific frequency content and increasing perturbation amplitude over trials. Body sway and reactive ankle torques were recorded. The sensitivity of the ankle torques to perturbation amplitude was determined using system identification techniques. The gain of a sensitivity function describes the ratio of perturbation amplitude and response amplitude as a function of frequency. Overall, elderly had a significant higher gain of the sensitivity function than young subjects. Increasing amplitude of the sensory perturbation resulted in a significant decrease of the gain of the sensitivity function from the perturbation amplitude to the ankle torque. Significant frequency-dependent interactions between group and perturbation amplitude could be established. A significant higher ankle torque sensitivity to perturbations indicates that elderly rely more strongly on proprioceptive input to maintain balance compared to younger subjects. Different reactions of elderly versus young subjects to perturbation amplitudes are indicative of differences in sensory reweighting. Results are important to understand interplay between available sensory inputs in balance and falling

A Durable, Realistic, Low-Cost Training Model for Percutaneous Renal Access Using Ballistic Gelatin

The purpose of this study was to design and implement a durable, realistic, and low-cost phantom kidney model for percutaneous renal access that could improve a novice surgeon’s technical skills without compromising patient safety

Incidences and Risk Factors of Organ Manifestations in the Early Course of Systemic Sclerosis: A Longitudinal EUSTAR Study

Objective Systemic sclerosis (SSc) is a rare and clinically heterogeneous autoimmune disorder characterised by fibrosis and microvascular obliteration of the skin and internal organs. Organ involvement mostly manifests after a variable period of the onset of Raynaud's phenomenon (RP). We aimed to map the incidence and predictors of pulmonary, cardiac, gastrointestinal (GI) and renal involvement in the early course of SSc. Methods In the EUSTAR cohort, patients with early SSc were identified as those who had a visit within the first year after RP onset. Incident SSc organ manifestations and their risk factors were assessed using Kaplan-Meier methods and Cox regression analysis. Results Of the 695 SSc patients who had a baseline visit within 1 year after RP onset, the incident non-RP manifestations (in order of frequency) were: skin sclerosis (75%) GI symptoms (71%), impaired diffusing capacity for monoxide40mmHg (14%), and renal crisis (3%). In the heart, incidence rates were highest for diastolic dysfunction, followed by conduction blocks and pericardial effusion. While the main baseline risk factor for a short timespan to develop FVC impairment was diffuse skin involvement, for PAPsys>40mmHg it was higher patient age. The main risk factors for incident cardiac manifestations were anti-topoisomerase autoantibody positivity and older age. Male sex, anti-RNA-polymerase-III positivity, and older age were risk factors associated with incident renal crisis. Conclusion In SSc patients presenting early after RP onset, approximately half of all incident organ manifestations occur within 2 years and have a simultaneous rather than a sequential onset. These findings have implications for the design of new diagnostic and therapeutic strategies aimed to ‘widen' the still very narrow ‘window of opportunity'. They may also enable physicians to counsel and manage patients presenting early in the course of SSc more accurately

Modern foraminifera, δ\u3csup\u3e13\u3c/sup\u3eC, and bulk geochemistry of central Oregon tidal marshes and their application in paleoseismology

We assessed the utility of δ13C and bulk geochemistry (total organic content and C:N) to reconstruct relative sea-level changes on the Cascadia subduction zone through comparison with an established sea-level indicator (benthic foraminifera). Four modern transects collected from three tidal environments at Siletz Bay, Oregon, USA, produced three elevation-dependent groups in both the foraminiferal and δ13C/bulk geochemistry datasets. Foraminiferal samples from the tidal flat and low marsh are identified by Miliammina fusca abundances of \u3e 45%, middle and high marsh by M. fusca abundances of \u3c 45% and the highest marsh by Trochamminita irregularis abundances \u3e 25%. The δ13C values from the groups defined with δ13C/bulk geochemistry analyses decrease with an increasing elevation; − 24.1 ± 1.7‰ in the tidal flat and low marsh; − 27.3 ± 1.4‰ in the middle and high marsh; and − 29.6 ± 0.8‰ in the highest marsh samples. We applied the modern foraminiferal and δ13C distributions to a core that contained a stratigraphic contact marking the great Cascadia earthquake of AD 1700. Both techniques gave similar values for coseismic subsidence across the contact (0.88 ± 0.39 m and 0.71 ± 0.56 m) suggesting that δ13C has potential for identifying amounts of relative sea-level change due to tectonics

A maximum rupture model for the central and southern Cascadia subduction zone—reassessing ages for coastal evidence of megathrust earthquakes and tsunamis

A new history of great earthquakes (and their tsunamis) for the central and southern Cascadia subduction zone shows more frequent (17 in the past 6700 yr) megathrust ruptures than previous coastal chronologies. The history is based on along-strike correlations of Bayesian age models derived from evaluation of 554 radiocarbon ages that date earthquake evidence at 14 coastal sites. We reconstruct a history that accounts for all dated stratigraphic evidence with the fewest possible ruptures by evaluating the sequence of age models for earthquake or tsunami contacts at each site, comparing the degree of temporal overlap of correlated site age models, considering evidence for closely spaced earthquakes at four sites, and hypothesizing only maximum-length megathrust ruptures. For the past 6700 yr, recurrence for all earthquakes is 370–420 yr. But correlations suggest that ruptures at ∼1.5 ka and ∼1.1 ka were of limited extent (<400 km). If so, post-3-ka recurrence for ruptures extending throughout central and southern Cascadia is 510–540 yr. But the range in the times between earthquakes is large: two instances may be ∼50 yr, whereas the longest are ∼550 and ∼850 yr. The closely spaced ruptures about 1.6 ka may illustrate a pattern common at subduction zones of a long gap ending with a great earthquake rupturing much of the subduction zone, shortly followed by a rupture of more limited extent. The ruptures of limited extent support the continued inclusion of magnitude-8 earthquakes, with longer ruptures near magnitude 9, in assessments of seismic hazard in the region