Electromagnetic levitation coil fabrication technique for MSFC containerless processing facilities

A technique is described for more reproducible fabrication of electromagnetic levitation coils. A split mandrel was developed upon which the coil is wound. After fabrication the mandrel can be disassembled to remove it from the coil. Previously, a full day was required to fabricate a levitation coil and the success rate for a functional coil was only 50 percent. About eight coils may be completed in one day using the technique developed and 95 percent of them are good levitation coils

Out of Africa: High aerosol concentrations in the upper troposphere over Africa

International audienceIn the year 2000, six flights (three southbound and three northbound) of the CARIBIC project were conducted between Germany and two destinations in the southern hemisphere (Windhoek, Namibia and Cape Town, South Africa). In the present report, results on particle number concentrations are discussed in three size ranges (>4 nm, >12 nm, and >18 nm particle diameter) during the unique transequatorial Africa flights. The flights covered a total of about 80 h in May, July, and December. Thus, no claim can be made for long-term representativeness of the aerosol data. Nevertheless, they are the first upper systematic tropospheric transequatorial aerosol profiles over Africa. The average aerosol results show a broad maximum, roughly symmetrical to the equator, which compares well in latitudinal extent to a maximum of CO concentrations measured on the same flights. This export of continental surface aerosol to the upper troposphere will be dispersed on a global scale both with the easterly flow near the equator and with the westerlies in the adjacent subtropical regions. There was strong evidence of recent new particle formation before aerosol arrival at flight level, in particular during the time periods between 9:00 and 13:00 local time over Africa. Direct and indirect climate effects of the respective particulate matter remain to be investigated by future flights with the ongoing extension of the CARIBIC payload towards size-resolved measurements above 100 nm particle diameter. At the same time global chemical transport models and aerosol dynamics models need to be extended to be able to reproduce the CARIBIC findings over Africa

Out of Africa: High aerosol concentrations in the upper troposphere over Africa

In the year 2000, six flights (three southbound and three northbound) of the CARIBIC project were conducted between Germany and two destinations in the southern hemisphere (Windhoek, Namibia and Cape Town, South Africa). In the present report, results on particle number concentrations are discussed in three size ranges (>4 nm, >12 nm, and >18 nm particle diameter) during the unique transequatorial Africa flights. The flights covered a total of about 80 h in May, July, and December. Thus, no claim can be made for long-term representativeness of the aerosol data. Nevertheless, they are the first upper systematic tropospheric transequatorial aerosol profiles over Africa. The average aerosol results show a broad maximum, roughly symmetrical to the equator, which compares well in latitudinal extent to a maximum of CO concentrations measured on the same flights. This export of continental surface aerosol to the upper troposphere will be dispersed on a global scale both with the easterly flow near the equator and with the westerlies in the adjacent subtropical regions. There was strong evidence of recent new particle formation before aerosol arrival at flight level, in particular during the time periods between 9:00 and 13:00 local time over Africa. Direct and indirect climate effects of the respective particulate matter remain to be investigated by future flights with the ongoing extension of the CARIBIC payload towards size-resolved measurements above 100 nm particle diameter. At the same time global chemical transport models and aerosol dynamics models need to be extended to be able to reproduce the CARIBIC findings over Africa

Anisotropic dielectric function in polar nano-regions of relaxor ferroelectrics

The paper suggests to treat the infrared reflectivity spectra of single crystal perovskite relaxors as fine-grained ferroelectric ceramics: locally frozen polarization makes the dielectric function strongly anisotropic in the phonon frequency range and the random orientation of the polarization at nano-scopic scale requires to take into account the inhomogeneous depolarization field. Employing a simple effective medium approximation (Bruggeman symmetrical formula) to dielectric function describing the polar optic modes as damped harmonic oscillators turns out to be sufficient for reproducing all principal features of room temperature reflectivity of PMN. One of the reflectivity bands is identified as a geometrical resonance entirely related to the nanoscale polarization inhomogeneity. The approach provides a general guide for systematic determination of the polar mode frequencies split by the inhomogeneous polarization at nanometer scale.Comment: 5 pages, 2 figure

Patterns of labour solidarity towards precarious workers and the unemployed in critical times in Greece, Poland and the UK

The purpose of this article is to examine whether and by what means traditional unions and other labour-oriented organisations engage in solidarity activities in favour of precarious workers and the unemployed. Our findings derive from qualitative data analysed from 10 in-depth interviews per country conducted as part of a large collaborative project with participants sampled from trade unions and other labour-oriented solidarity organisations based in three European national contexts: Greece, Poland, and the UK. Our aim here is to discern common features and differences in the strategies and answers given, within the three national contexts. To this end, we examine the actors engaged in labour solidarity; the value frames upon which these actions draw; the beneficiaries of their solidarity actions; the type of activities adopted mainly in favour of precarious workers and the unemployed; and their engagement in transnational labour solidarity activities

Current Strategies in Prevention of Postoperative Infections in Spine Surgery.

Study Design: Narrative review. Objectives: Postoperative surgical site infections (SSIs) are among the most common acute complications in spine surgery and have a devastating impact on outcomes. They can lead to increased morbidity and mortality as well as greater economic burden. Hence, preventive strategies to reduce the rate of SSIs after spine surgery have become vitally important. The purpose of this article was to summarize and critically analyze the available evidence related to current strategies in the prevention of SSIs after spine surgery. Methods: A literature search utilizing Medline database was performed. Relevant studies from all the evidence levels have been included. Recommendations to decrease the risk of SSIs have been provided based on the results from studies with the highest level of evidence. Results: SSI prevention occurs at each phase of care including the preoperative, intraoperative, and postoperative periods. Meticulous patient selection, tight glycemic control in diabetics, smoking cessation, and screening/eradication of Conclusions: Although preventive strategies are already in use alone or in combination, further high-level research is required to prove their efficacy in reducing the rate of SSIs in spine surgery before evidence-based standard infection prophylaxis guidelines can be built

Silicon nanoparticles and interstellar extinction

To examine a recently proposed hypothesis that silicon nanoparticles are the source of extended red emission (ERE) in the interstellar medium, we performed a detailed modeling of the mean Galactic extinction in the presence of silicon nanoparticles. For this goal we used the appropriate optical constants of nanosized Si, essentially different from those of bulk Si due to quantum confinement. It was found that a dust mixture of silicon nanoparticles, bare graphite grains, silicate core-organic refractory mantle grains and three-layer silicate-water ice-organic refractory grains works well in explaining the extinction and, in addition, results in the acceptable fractions of UV/visible photons absorbed by silicon nanoparticles: 0.071-0.081. Since these fractions barely agree with the fraction of UV/visible photons needed to excite the observed ERE, we conclude that the intrinsic photon conversion efficiency of the photoluminescence by silicon nanoparticles must be near 100%, if they are the source of the ERE.Comment: Latex2e, uses emulateapj.sty (included), multicol.sty, epsf.sty, 6 pages, 3 figures (8 Postscript files), accepted for publication in ApJ Letters, complete Postscript file is also available at http://physics.technion.ac.il/~zubko/eb.html#SNP

Computed tomographic findings in incisors and canine teeth with equine odontoclastic tooth resorption and hypercementosis: a retrospective study in 115 Warmblood horses

Computed tomography (CT) has become a routine method to examine the equine skull. Its clinical use for the diagnosis of diseases of the incisors and canine teeth has not been reported so far. The goal of this study was to study the prevalence and relationship of single CT features and equine odontoclastic tooth resorption and hypercementosis (EOTRH) in equine incisors and canine teeth. In this descriptive retrospective study, helical CT studies of 115 warmblood horses of the age of 5 years or older examined between 2007 and 2020 for reasons unrelated to the incisors and canine teeth were included. Resorption in the crown or root, hypercementosis, widening of the periodontal space, clubbing of the root, lysis of the lamina dura, an abnormal pulp cavity and fracture of the root were recorded in all incisors and canine teeth. The length of the pulp cavity and the labial and lingual/palatal length of the enamel and root was measured in each incisor and canine tooth. Additionally, the angulation was assessed in each incisor. The variable EOTRH was defined based on the presence of resorptive lesions, hypercementosis and clubbing. In result median age of the included horses was 12 years (range, 5-29 years). With regard to the investigated population of horses, 44.3% of all horses had normal incisors whereas 55.7% of the horses had mild EOTRH changes in one incisor at least. Regarding the canine teeth, 54.7% of the horses had normal canine teeth whereas 43.3% horses had mild EOTRH in one canine tooth at least. With regard to all investigated teeth, 868 teeth (53.0%) were classified as normal, whereas 769 incisors and canine teeth (47.0%) showed at least one abnormal CT criterion. Clubbing of the root and hypercementosis were most common (37.1% and 22.7%, respectively) and EOTRH was present in 27.1% of all teeth. Mild changes were more common than moderate or severe abnormalities. In the lower jaw, hypercementosis and widening of the periodontal space at the anatomical root and apex of the root was significantly more frequent (p = 0.004 and 0.02), whereas clubbing of the root was more common in the upper jaw (p = 0.009). In canine teeth, resorption in the anatomical crown and anatomical root, widening of the periodontal space, clubbing and lysis of the lamina dura were significantly more common whereas hypercementosis was more common in incisors (p < 0.001). Frequency of certain CT changes significantly increased from central to middle and corner incisors. Severity of all single CT criteria as well as prevalence and severity of EOTRH significantly increased with age (r = 0.08-0.56). Linear forward and backward multivariate regression analysis confirmed a significant association between prevalence and severity of EOTRH and age, changes of the pulp cavity, widening of the periodontal space at the anatomical root and incisor group (central, middle, corner) (p = 0.01 - < 0.001). In conclusion computed tomographic changes of the incisors and canine teeth are common and age-related in warmblood horses. Therefore, treatment of EOTRH should not be based on diagnostic imaging alone, but always in combination with a thorough clinical examination

A novel interaction between ATOH8 and PPP3CB

ATOH8 is a bHLH transcription factor playing roles in a variety of developmental processes such as neurogenesis, differentiation of pancreatic precursor cells, development of kidney and muscle, and differentiation of endothelial cells. PPP3CB belongs to the catalytic subunit of the serine/threonine phosphatase, calcineurin, which can dephosphorylate its substrate proteins to regulate their physiological activities. In our study, we demonstrated that ATOH8 interacts with PPP3CB in vitro with different approaches. We show that the conserved catalytic domain of PPP3CB interacts with both the N-terminus and the bHLH domain of ATOH8. Although the interaction domain of PPP3CB is conserved among all isoforms of calcineurin A, ATOH8 selectively interacts with PPP3CB instead of PPP3CA, probably due to the unique proline-rich region present in the N-terminus of PPP3CB, which controls the specificity of its interaction partners. Furthermore, we show that inhibition of the interaction with calcineurin inhibitor, cyclosporin A (CsA), leads to the retention of ATOH8 to the cytoplasm, suggesting that the interaction renders nuclear localization of ATOH8 which may be critical to control its activity as transcription factor