Avalanches in a Bose-Einstein condensate

Collisional avalanches are identified to be responsible for an 8-fold increase of the initial loss rate of a large 87-Rb condensate. We show that the collisional opacity of an ultra-cold gas exhibits a critical value. When exceeded, losses due to inelastic collisions are substantially enhanced. Under these circumstances, reaching the hydrodynamic regime in conventional BEC experiments is highly questionable.Comment: 4 pages, 2 figures, 1 tabl

Moving to design-based education in hotel management school: proof of success and beyond — a research journey

NHL Stenden University of Applied Sciences adopted the innovative educational concept design-based education (DBE) in 2018. The Hotel Management School is one of the programmes that introduced a DBE curriculum.  It is important to explore to what extent DBE is successfully implemented and to monitor the long-term impact of DBE on students, lecturers and the industry. The purpose of the current article is to position a longitudinal research journey in which stakeholders’ personal and social experiences and perceptions are the starting point for the research focus. Using educational design research, the current research aims to contribute to the four intended impact areas: knowledge, personal development, system development and product development. Keywords: accompanying research, design thinking, educational design research, game changers, hospitality management education, innovative educatio

Optomechanical deformation and strain in elastic dielectrics

Light forces induced by scattering and absorption in elastic dielectrics lead to local density modulations and deformations. These perturbations in turn modify light propagation in the medium and generate an intricate nonlinear response. We generalise an analytic approach where light propagation in one-dimensional media of inhomogeneous density is modelled as a result of multiple scattering between polarizable slices. Using the Maxwell stress tensor formalism we compute the local optical forces and iteratively approach self-consistent density distributions where the elastic back-action balances gradient- and scattering forces. For an optically trapped dielectric we derive the nonlinear dependence of trap position, stiffness and total deformation on the object's size and field configuration. Generally trapping is enhanced by deformation, which exhibits a periodic change between stretching and compression. This strongly deviates from qualitative expectations based on the change of photon momentum of light crossing the surface of a dielectric. We conclude that optical forces have to be treated as volumetric forces and that a description using the change of photon momentum at the surface of a medium is inappropriate

Critical collisional opacity in a Bose-Einstein condensate

Summary form only given. In a Bose-Einstein condensate, due to the very low temperature, the s-wave scattering length can be used as a measure for the strength of the atom-atom interaction. Under typical experimental conditions, this interaction is weak and hence can be treated in terms of a mean field. However, when scattering length is large or the density is high, the mean field approximation breaks down. In this collisional (hydrodynamic) regime, effects of the interactions such as quantum depletion or shifts in the frequencies of the elementary excitations become large. It is therefore of great interest to study condensates close to or in the collisional regime. It has been demonstrated in recent experiments that the scattering length and thus the interactions among the atoms can be tuned by means of a Feshbach resonance (Inouye et al, 1998; Courteille et al., 1998; Vuleti et al., 1999; Cornish et al., 2000). In the vicinity of Feshbach resonances, however, the increase of the cross-section for elastic collisions is accompanied by a dramatic increase of particle losses. In this paper we report on the observation of anomalous losses from a 87Rb condensate with a high column density in the absence of an inelastic scattering resonance

Determination of Arsenic, Mercury and Barium in herbarium mount paper using dynamic ultrasound-assisted extraction prior to atomic fluorescence and absorption spectrometry

A dynamic ultrasound-assisted extraction method using Atomic Absorption and Atomic Flourescence spectrometers as detectors was developed to analyse mercury, arsenic and barium from herbarium mount paper originating from the herbarium collection of the National Museum of Wales. The variables influencing extraction were optimised by a multivariate approach. The optimal conditions were found to be 1% HNO3 extractant solution used at a flow rate of 1 mL min-1. The duty cycle and amplitude of the ultrasonic probe was found to be 50% in both cases with an ultrasound power of 400 W. The optimal distance between the probe and the top face of the extraction chamber was found to be 0 cm. Under these conditions the time required for complete extraction of the three analytes was 25 min. Cold vapour and hydride generation coupled to atomic fluorescence spectrometry was utilized to determine mercury and arsenic, respectively. The chemical and instrumental conditions were optimized to provide detection limits of 0.01ng g-1 and 1.25 ng g-1 for mercury and arsenic, respectively. Barium was determined by graphite-furnace atomic absorption spectrometry, with a detection limit of 25 ng g-1. By using 0.5 g of sample, the concentrations of the target analytes varied for the different types of paper and ranged between 0.4–2.55 µg g-1 for Ba, 0.035–10.47 µg g-1 for As and 0.0046–2.37 µg g-1 for Hg

Taxonomic revision of the Typhula ishikariensis complex

publishedVersio

Testing Reliability of Biophilic Design Matrix Within Urban Residential Playrooms

Playtime in urban cities has become an indoor activity for children due to limited access to natural outdoor environments. This product of urbanization makes the case for the introduction of biophilic design. However, playrooms are often neglected as a possibility in designing a natural space indoors. Interior designers and other specialists lack a reliable tool to identify and incorporate biophilic features into the design of these indoor environments in urban settings. The Biophilic Interior Design Matrix (BID-M) developed by McGee and Marshall-Baker quantifies 52 of Kellert’s biophilic design attributes to assess their presence and absence within interior spaces. We expanded its use by testing the matrix in a new type of space, urban playrooms, and coded images of 45 children’s playrooms within Manhattan residential buildings in New York City, including assessing a larger sample and reliability rate compared to McGee and Marshall-Baker’s research. Inter-rater reliability of the overall design matrix and individual matrix items was measured with percent agreement and free-marginal multirater kappa. Reliability testing showed overall good reliability of the overall design matrix. Several matrix items had low reliability between raters. Our findings show that the BID-M needs to be modified to better assess urban interior spaces for children

High-throughput screening in larval zebrafish identifies novel potent sedative-hypnotics

BACKGROUND: Many general anesthetics were discovered empirically, but primary screens to find new sedative-hypnotics in drug libraries have not used animals, limiting the types of drugs discovered. The authors hypothesized that a sedative-hypnotic screening approach using zebrafish larvae responses to sensory stimuli would perform comparably to standard assays, and efficiently identify new active compounds. METHODS: The authors developed a binary outcome photomotor response assay for zebrafish larvae using a computerized system that tracked individual motions of up to 96 animals simultaneously. The assay was validated against tadpole loss of righting reflexes, using sedative-hypnotics of widely varying potencies that affect various molecular targets. A total of 374 representative compounds from a larger library were screened in zebrafish larvae for hypnotic activity at 10 µM. Molecular mechanisms of hits were explored in anesthetic-sensitive ion channels using electrophysiology, or in zebrafish using a specific reversal agent. RESULTS: Zebrafish larvae assays required far less drug, time, and effort than tadpoles. In validation experiments, zebrafish and tadpole screening for hypnotic activity agreed 100% (n = 11; P = 0.002), and potencies were very similar (Pearson correlation, r > 0.999). Two reversible and potent sedative-hypnotics were discovered in the library subset. CMLD003237 (EC50, ~11 µM) weakly modulated γ-aminobutyric acid type A receptors and inhibited neuronal nicotinic receptors. CMLD006025 (EC50, ~13 µM) inhibited both N-methyl-D-aspartate and neuronal nicotinic receptors. CONCLUSIONS: Photomotor response assays in zebrafish larvae are a mechanism-independent platform for high-throughput screening to identify novel sedative-hypnotics. The variety of chemotypes producing hypnosis is likely much larger than currently known.This work was supported by grants from Shanghai Jiaotong University School of Medicine, Shanghai, China, and the Chinese Medical Association, Beijing, China (both to Dr. Yang). The Department of Anesthesia, Critical Care and Pain Medicine of Massachusetts General Hospital, Boston, Massachusetts, supported this work through a Research Scholars Award and an Innovation Grant (both to Dr. Forman). Contributions to this research from the Boston University Center for Molecular Discovery, Boston, Massachusetts (to Drs. Porco, Brown, Schaus, and Xu, and to Mr. Trilles), were supported by a grant from the National Institutes of Health, Bethesda, Maryland (grant No. R24 GM111625). (Shanghai Jiaotong University School of Medicine, Shanghai, China; Chinese Medical Association, Beijing, China; Department of Anesthesia, Critical Care and Pain Medicine of Massachusetts General Hospital, Boston, Massachusetts; R24 GM111625 - National Institutes of Health, Bethesda, Maryland)Accepted manuscript2019-09-0

Cross-cultural adaption and psychometric investigation of the German version of the Evidence Based Practice Attitude Scale (EBPAS-36D)

Background: The implementation of evidence-based practice (EBP) in mental health care confers many benefits to patients, and research into factors facilitating the implementation of EBP is needed. As an important factor affecting the implementation of EBP, service providers’ attitudes toward EBP emerged. The Evidence-Based Practice Attitude Scale (EBPAS-36) is an instrument with good psychometric characteristics that measures positive and ambivalent attitudes toward EBP. However, a German version is missing. The present study therefore aims to provide a validated German translation of the EBPAS-36. Methods: The scale was translated and back-translated as recommended by standard procedures. German psychotherapists were recruited to participate in an online survey. They provided demographic and professional information, completed the EBPAS-36, the Implementation Climate Scale (ICS) and the Intention Scale for Providers (ISP). Standard item and reliability analyses were conducted. Construct validity was evaluated with exploratory (EFA) and confirmatory factor analyses (CFA) in two subsamples (random split). Convergent validity was tested by predicting a high positive correlation of the EBPAS-36D with two scores of attitudes of the ISP and an interest in EBP score. It was tested whether the EBPAS-36D predicts the intention to use EBP. Results: N = 599 psychotherapists participated in the study. The item analyses showed a mean item difficulty of pi = 0.64, a mean inter-item correlation of r = 0.18, and a mean item-total correlation of ritc = 0.40. The internal consistency was very good for the total scale (α = 0.89) and ranged from adequate to very good for the subscales (0.65–0.89), indicating high reliability. The original factor structure showed an acceptable model fit (RMSEA = 0.064 (90% CI = 0.059–0.068); SRMR = 0.0922; AIC = 1400.77), confirming the 12-factor structure of the EBPAS-36. However, a second-order factor structure derived by the EFA had an even better model fit (RMSEA = 0.057 (90% CI = 0.052–0.062); SRMR = 0.0822; AIC = 1274.56). When the EBPAS-36D was entered in a hierarchical regression model with the criterion Intention to use EBP, the EBPAS-36D contributed significantly to the prediction (Change in R2 = 0.28, p < 0.001) over and above gender, age and participants’ report of ever having worked in a university context. Conclusions: The present study confirms good psychometric properties and validity of a German version of the EBPAS-36 in a sample of psychotherapists