1,718 research outputs found

    Ptychographic X-ray computed tomography of extended colloidal networks in food emulsions

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    As a main structural level in colloidal food materials, extended colloidal networks are important for texture and rheology. By obtaining the 3D microstructure of the network, macroscopic mechanical properties of the material can be inferred. However, this approach is hampered by the lack of suitable non-destructive 3D imaging techniques with submicron resolution. We present results of quantitative ptychographic X-ray computed tomography applied to a palm kernel oil based oil-in-water emulsion. The measurements were carried out at ambient pressure and temperature. The 3D structure of the extended colloidal network of fat globules was obtained with a resolution of around 300 nm. Through image analysis of the network structure, the fat globule size distribution was computed and compared to previous findings. In further support, the reconstructed electron density values were within 4% of reference values.Comment: 19 pages, 4 figures, to be published in Food Structur

    Studies in t)le Sphingolipids Series. XII. Structure of the Cerebrin Anhydro Base of Yeast (C20 - Phytosphingosine Anhydro Base)

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    It was confirmed that the cerebrin anhydro base from yeast (Ila) isolated according to the procedure established by Reindel et ai.2 ,a h as a C20 -structure rather than C1 s-structure as one might conclude erroneously by simple comparison of physical constants \u27C/f both bases. The tetrahydrofuran structure was a lso d emonstrated by means of the IR spectroscopy. For this purpose following new compounds derived from C20 -anhydro b ase were prepared: N,0-diacetyl (lib), N,0-ditosyl (Ile), 0-acetyl-N-benzoyl (!Id) and Nphthaloyl derivative (III);· in addition, 2-hexadecyl-3 ,4-dihydroxytetrahydrofuran(IV) - a deamination product of the base was described

    Optical bistability involving planar metamaterial with broken structural symmetry

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    We report on a bistable light transmission through a planar metamaterial composed of a metal pattern of weakly asymmetric elements placed on a nonlinear substrate. Such structure bears the Fano-like sharp resonance response of a trapped-mode excitation. The feedback required for bistability is provided by the coupling between the strong antiphased trapped-mode-resonance currents excited on the metal elements and the intensity of inner field in the nonlinear substrate.Comment: 4 pages, 4 figure

    Design, theory, and measurement of a polarization insensitive absorber for terahertz imaging

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    We present the theory, design, and realization of a polarization-insensitive metamaterial absorber for terahertz frequencies. We derive geometrical-independent conditions for effective medium absorbers in general, and for resonant metamaterials specically. Our fabricated design reaches and absorptivity of 78% at 1.145 ThzComment: 6 Pages, 5 figures; figures update

    Avian oncogenesis induced by lymphoproliferative disease virus: a neglected or emerging retroviral pathogen?

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    Lymphoproliferative disease virus (LPDV) is an exogenous oncogenic retrovirus that induces lymphoid tumors in some galliform species of birds. Historically, outbreaks of LPDV have been reported from Europe and Israel. Although the virus has previously never been detected in North America, herein we describe the widespread distribution, genetic diversity, pathogenesis, and evolution of LPDV in the United States. Characterization of the provirus genome of the index LPDV case from North America demonstrated an 88% nucleotide identity to the Israeli prototype strain. Although phylogenetic analysis indicated that the majority of viruses fell into a single North American lineage, a small subset of viruses from South Carolina were most closely related to the Israeli prototype. These results suggest that LPDV was transferred between continents to initiate outbreaks of disease. However, the direction (New World to Old World or vice versa), mechanism, and time frame of the transcontinental spread currently remain unknown

    Perinatal psychiatric episodes: a population-based study on treatment incidence and prevalence

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    Perinatal psychiatric episodes comprise various disorders and symptom severity, which are diagnosed and treated in multiple treatment settings. To date, no studies have quantified the incidence and prevalence of perinatal psychiatric episodes treated in primary and secondary care, which we aimed to do in the present study. We designed a descriptive prospective study and included information from Danish population registers to study first-time ever and recurrent psychiatric episodes during the perinatal period, including treatment at psychiatric facilities and general practitioners (GPs). This was done for all women who had records of one or more singleton births from 1998 until 2012. In total, we had information on 822 439 children born to 491 242 unique mothers. Results showed first-time psychiatric episodes treated at inpatient facilities were rare during pregnancy, but increased significantly shortly following childbirth (0.02 vs 0.25 per 1000 births). In comparison, first-time psychiatric episodes treated at outpatient facilities were more common, and showed little variation across pregnancy and postpartum. For every single birth resulting in postpartum episodes treated at inpatient psychiatric facilities, 2.5 births were followed by an episode treated at outpatient psychiatric facility and 12 births by GP-provided pharmacological treatment. We interpret our results the following way: treated severe and moderate psychiatric disorders have different risk patterns in relation to pregnancy and childbirth, which suggests differences in the underlying etiology. We further speculate varying treatment incidence and prevalence in pregnancy vs postpartum may indicate that the current Diagnostic and Statistical Manual of Mental Disorders-5 peripartum specifier not adequately describes at-risk periods across moderate and severe perinatal psychiatric episodes

    Probing Solar Convection

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    In the solar convection zone acoustic waves are scattered by turbulent sound speed fluctuations. In this paper the scattering of waves by convective cells is treated using Rytov's technique. Particular care is taken to include diffraction effects which are important especially for high-degree modes that are confined to the surface layers of the Sun. The scattering leads to damping of the waves and causes a phase shift. Damping manifests itself in the width of the spectral peak of p-mode eigenfrequencies. The contribution of scattering to the line widths is estimated and the sensitivity of the results on the assumed spectrum of the turbulence is studied. Finally the theoretical predictions are compared with recently measured line widths of high-degree modes.Comment: 26 pages, 7 figures, accepted by MNRA

    Tides on Other Earths: Implications for Exoplanet and Palaeo-Tidal Simulations

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    A key controller of a planet's rotational evolution, and hence habitability, is tidal dissipation, which on Earth is dominated by the ocean tides. Because exoplanet or deep‐time Earth topographies are unknown, a statistical ensemble is used to constrain possible tidal dissipation rates on an Earth‐like planet. A dedicated tidal model is used together with 120 random continental configurations to simulate Earth's semidiurnal lunar tide. The results show a possible ocean tidal dissipation range spanning 3 orders of magnitude, between 2.3 GWto 1.9 TW (1 TW=1012 W). When model resolution is considered, this compares well with theoretical limits derived for the energetics of Earth's present‐day deep ocean. Consequently, continents exert a fundamental control on tidal dissipation rates and we suggest that plate tectonics on a planet will induce a time‐varying dissipation analogous to Earth's. This will alter rotational periods over millions of years and further complicate the role of tides for planetary evolution. Plain Language Summary The daylength of a planet is key for habitability because it regulates the rate with which solar radiation is received and redistributed at the surface. A main controller of a planet's daylength is the ocean tide, because the dissipation of tidal energy works as a brake on the planet's spin, increasing the daylength. Tides are sensitive to the continental arrangement on a planet, but there are no details of the surface of any exoplanet and only limited information of what Earth looked like in the distant past. The change in Earth's daylength forces the Moon to recede into a higher orbit, but the present‐day recession rate is very high and does not fit our age models of the moon, implying that the tides must have been much weaker in the distant past. Here, we use a series of tidal predictions for random continental configurations of Earth to provide a range of tidal dissipation rates and thus an estimate of how the tides in the deep past may have evolved as Earth's continents grew more and more complex. This research also provides a range of dissipation rates that can be used for simulations of the rotational and orbital evolution of exoplanets

    Clinical decision making and outcome in the routine care of people with severe mental illness across Europe (CEDAR)

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    Aims. There is a lack of knowledge on clinical decision making and its relation to outcome in the routine treatment of people with severe mental illness. This study examined preferred and experienced clinical decision making from the perspectives of patients and staff, and how these affect treatment outcome. Methods. CEDAR (ISRCTN75841675) is a naturalistic prospective observational study with bimonthly assessments during a 12-month observation period. 588 adults with severe mental illness were consecutively recruited from caseloads of community mental health services at the six study sites (Germany, UK, Italy, Hungary, Denmark, and Switzerland). Clinical decision making was measured using two instruments (Clinical Decision Making Style Scale. CDMS;Clinical Decision Making Involvement and Satisfaction Scale, CDIS) from patient and staff perspectives. Outcomes assessed were unmet needs (Camberwell Assessment of Need Short Appraisal Schedule, CANSAS). Mixed-effects multinomial regression was used to examine differences in involvement in and satisfaction with actual decision making. The effect of clinical decision making on outcome was examined using hierarchical linear modelling controlling for covariates. Results. Shared decision making was preferred by patients (2=135.08; p<0.001) and staff (2=368.17; p<0.001). Decision making style of staff significantly affected unmet needs over time, with unmet needs decreasing more in patients whose clinicians preferred active to passive (-0.406 unmet needs per two months, p=0.007) or shared (-0.303 unmet needs per two months, p=0.015) decision making. Conclusions. A shift from shared to active involvement of patients is indicated, including the development and rigorous test of targeted interventions
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