Application of a picosecond soft x-ray source to time-resolved plasma dynamics

We demonstrate the application of an ultrashort x-ray source as an external probe to measure plasma dynamics. The plasma is generated by a 100-fs Ti:sapphire laser focused onto thin metallic films. Time-resolved spectroscopy of the gold x-ray probe transmission through a perturbed 1000 Å aluminum film reveals redshifts of the LL-shell photoabsorption edge. We show that the dynamic behavior of this shift is consistent with the relaxation of the aluminum following the compression generated by a shock wave traveling through the film. An analytic plasma model, with comparison to a numerical hydrodynamics model, indicates compression up to 1.4 times solid density. © 1997 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69766/2/APPLAB-70-3-312-1.pd

New experimental test of Bell inequalities by the use of a non-maximally entangled photon state

We report on the first realisation of a test of Bell inequalities using non-maximally entangled states. It is based on the superposition of type I parametric down conversion produced in two different non-linear crystals pumped by the same laser, but with different polarisations. We discuss the advantages and the possible developments of this configuration.Comment: accepted for publicatio

Semi-Phenomenological Analysis of Dynamics of Nonlinear Excitations in One-Dimensional Electron-Phonon System

The structure of moving nonlinear excitations in one-dimensional electron-phonon systems is studied semi-phenomenologically by using an effective action in which the width of the nonlinear excitation is treated as a dynamical variable. The effective action can be derived from Su, Schrieffer and Heeger's model or its continuum version proposed by Takayama, Lin-Liu and Maki with an assumption that the nonlinear excitation moves uniformly without any deformation except the change of its width. The form of the action is essentially the same as that discussed by Bishop and coworkers in studying the dynamics of the soliton in polyacetylene, though some details are different. For the moving excitation with a velocity $v$, the width is determined by minimizing the effective action. A requirement that there must be a minimum in the action as a function of its width provides a maximum velocity. The velocity dependence of the width and energy can be determined. The motions of a soliton in p olyacetylene and an acoustic polaron in polydiacetylene are studied within this formulation. The obtained results are in good agreement with those of numerical simulations.Comment: 19 pages, LaTeX, 7 Postscript figures, to be published in J. Phys. Soc. Jpn. vol.65 (1996) No.

Maternal stress, child behavior and the promotive role of older siblings

Abstract Background: In the first years of their lives, children develop the cognitive, social and emotional skills that will provide the foundations for their lifelong health and achievements. To increase their life prospects and reduce the long-term effects of early aversive conditions, it is therefore crucial to understand the risk factors that negatively affect child development and the factors that are instead beneficial. In this study, we tested (i) the effects of different social and environmental stressors on maternal stress levels, (ii) the dynamic relationship between maternal stress and child behavior problems during development, and (iii) the potential promotive (i.e. main) or protective (i.e. buffering) effect of siblings on child behavior problems during development.Methods: We used longitudinal data from 373 mother–child pairs (188 daughters, 185 sons) from pregnancy until 10 years of age. We assessed maternal stress and child behavior problems (internalizing and externalizing) with vali-dated questionnaires, and then used linear mixed models, generalized linear mixed models and longitudinal cross-lagged models to analyze the data.Results: Our results showed that higher maternal stress levels were predicted by socio-environmental stressors (i.e. the lack of sufficient social areas in the neighborhood). Moreover, prenatal maternal stress reliably predicted the occurrence of behavior problems during childhood. Finally, the presence of older siblings had a promotive function, by reducing the likelihood that children developed externalizing problems.Conclusions: Overall, our results confirm the negative effects that maternal stress during pregnancy may have on the offspring, and suggest an important main effect of older siblings in promoting a positive child development

Impact of short stature on quality of life: A systematic literature review

Objective: We sought to obtain a better understanding of the burden of short stature using a systematic literature review. Methods: Studies of the burden of short stature, of any cause in adults and children, were searched using Embase, MEDLINE and Cochrane databases in April 2020, capturing publications from 2008 onwards. Case series and populations with adult-onset growth hormone deficiency (GHD) were excluded. Results: Of 1684 publications identified, 41 studies (33 in children, 8 in adults) were included. All studies assessed human burden. Most study populations in children included short stature due to GHD, idiopathic short stature (ISS) and short stature after being born small for gestational age (SGA). In these populations, four studies showed that quality of life (QoL) in children with short stature was significantly worse than in children with normal stature. A significant association between QoL and short stature was observed in children with chronic kidney disease (CKD) (3 studies), achondroplasia (1 study) and transfusion-dependent β-thalassaemia (1 study), and in samples with mixed causes of short stature (3 studies). Three studies (one in GHD/ISS/SGA and two in CKD) found no significant association between short stature and QoL, and several studies did not report statistical significance. Approximately half of adult studies showed that QoL was reduced with short stature, and the other half showed no association. Two studies, one in adults with Prader–Willi syndrome and one in children with GHD, suggested a potential association between short stature and poorer cognitive outcomes. Three studies demonstrated an increased caregiver burden in parents of children with short stature. Conclusions: Evidence suggests that, compared with those with normal stature, children and adults with short stature of any cause may experience poorer QoL. Further research could extend our understanding of the human burden in this field

Spirituality in general practice

In a pluraIist and secular society, as well as in a medical world which is becoming increasingly evidence-based, making a case for consideration of spirituaIity in general practice may seem futile and irrelevant. Notwithstanding such an apparent paradoxical proposal, developments occurring in other specialties 1 as well as in general practice abroad reveal that it is high time that this theme is addressed academically and impIications appIied in local practice.peer-reviewe

Magnetic fields of opposite polarity in sunspot penumbrae

Context. A significant part of the penumbral magnetic field returns below the surface in the very deep photosphere. For lines in the visible, a large portion of this return field can only be detected indirectly by studying its imprints on strongly asymmetric and three-lobed Stokes V profiles. Infrared lines probe a narrow layer in the very deep photosphere, providing the possibility of directly measuring the orientation of magnetic fields close to the solar surface. Aims. We study the topology of the penumbral magnetic field in the lower photosphere, focusing on regions where it returns below the surface. Methods. We analyzed 71 spectropolarimetric datasets from Hinode and from the GREGOR infrared spectrograph. We inferred the quality and polarimetric accuracy of the infrared data after applying several reduction steps. Techniques of spectral inversion and forward synthesis were used to test the detection algorithm. We compared the morphology and the fractional penumbral area covered by reversed-polarity and three-lobed Stokes V profiles for sunspots at disk center. We determined the amount of reversed-polarity and three-lobed Stokes V profiles in visible and infrared data of sunspots at various heliocentric angles. From the results, we computed center-to-limb variation curves, which were interpreted in the context of existing penumbral models. Results. Observations in visible and near-infrared spectral lines yield a significant difference in the penumbral area covered by magnetic fields of opposite polarity. In the infrared, the number of reversed-polarity Stokes V profiles is smaller by a factor of two than in the visible. For three-lobed Stokes V profiles the numbers differ by up to an order of magnitude.Comment: 11 pages 10 figures plus appendix (2 pages 3 figures). Accepted as part of the A&A special issue on the GREGOR solar telescop

Nuclear Materials Stewardship Within the DOE Environmental Management Program

The Department of Energy (DOE) Environmental Management (EM) Program has made significant progress in planning disposition of its excess nuclear materials and has recently completed several noteworthy studies. Since establishment in 1997, the EM Nuclear Material Stewardship Program has developed disposition plans for excess nuclear materials to support facility deactivation. All nuclear materials have been removed from the Miamisburg Environmental Management Project (Mound), and disposition planning is nearing completion for the Fernald Environmental Management Project and the Rocky Flats Environmental Technology Site. Only a few issues remain for materials at the Hanford and Idaho sites. Recent trade studies include the Savannah River Site Canyons Nuclear Materials Identification Study, a Cesium/Strontium Management Alternatives Trade Study, a Liquid Technical Standards Trade Study, an Irradiated Beryllium Reflectors with Tritium study, a Special Performance Assessment Required Trade Study, a Neutron Source Trade Study, and development of discard criteria for uranium. A Small Sites Workshop was also held. Potential and planned future activities include updating the Plutonium-239 storage study, developing additional packaging standards, developing a Nuclear Material Disposition Handbook, determining how to recover or dispose of Pu-244 and U-233, and working with additional sites to define disposition plans for their nuclear materials

A new human adipocyte model with PTEN haploinsufficiency

Few human cell strains are suitable and readily available as in vitro adipocyte models. We used resected lipoma tissue from a patient with germline phosphatase and tensin homolog (PTEN) haploinsufficiency to establish a preadipocyte cell strain termed LipPD1 and aimed to characterize cellular functions and signalling pathway alterations in comparison to the established adipocyte model Simpson-Golabi-Behmel-Syndrome (SGBS) and to primary stromal-vascular fraction cells. We found that both cellular life span and the capacity for adipocyte differentiation as well as adipocyte-specific functions were preserved in LipPD1 and comparable to SGBS adipocytes. Basal and growth factor-stimulated activation of the PI3 K/AKT signalling pathway was increased in LipPD1 preadipocytes, corresponding to reduced PTEN levels in comparison to SGBS cells. Altogether, LipPD1 cells are a novel primary cell model with a defined genetic lesion suitable for the study of adipocyte biology. © 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

On Preparing Entangled Pairs of Polarization Qubits in the Frequency Non-Degenerate Regime

The problems associated with practical implementation of the scheme proposed for preparation of arbitrary states of polarization ququarts based on biphotons are discussed. The influence of frequency dispersion effects are considered, and the necessity of group velocities dispersion compensation in the frequency non-degenerate case even for continuous pumping is demonstrated. A method for this compensation is proposed and implemented experimentally. Physical restrictions on the quality of prepared two-photon states are revealed.Comment: 9 pages, 6 figure