Femtosecond x-ray absorption spectroscopy of spin and orbital angular momentum in photoexcited Ni films during ultrafast demagnetization

We follow for the first time the evolution of the spin and orbital angular momentum of a thin Ni film during ultrafast demagnetization, by means of x-ray magnetic circular dichroism. Both components decrease with a 130 +/- 40 fs time constant upon excitation with a femtosecond laser pulse. Additional x-ray absorption measurements reveal an increase in the spin-orbit interaction by 6 +/- 2 % during this process. This is the experimental demonstration quantifying the importance of spin-orbit mediated processes during the demagnetization

Key Perfromance Indicators (KPI) for the implementation of lean methodologies in a manufacture-to-order small and medium enterprise

This paper presents a key performance indicator (KPI) concept for the implementation of Lean methodologies in a manufacture-to-order (MTO) small and medium enterprise (SME). Within a case study the concept is developed and improved. The purpose of the measurement system is to monitor the early Lean implementation process. The paper explores the current literature about Lean performance measurement and discusses the critical success factors of a Lean implementation. It is suggested to integrate the performance dimension “leadership” into a KPI concept. The KPI concept consists of five dimensions: leadership, quality, costs, time and people respectively organisation. Additionally the Lean metrics “Process Velocity” and “Value Velocity” are presented and adapted to the specific requirements of a MTO environment. The application of the KPI concept in the case study is discussed. The benefit of an early integration of an appropriate KPI system during a Lean implementation could be confirmed

Tissue engineering: a challenge of today's medicine

During the last years, tissue engineering-based therapies have been introduced in clinical practice in the head and face area. The regeneration of complex tissue structures for all sites of the body is envisioned for the future. In the present situation, specialists of the different fields publish excellent research papers in specialised journals. As a result, the scientific community, seperated towards distinct sub-specialities, has difficulties in communication. To overcome this problem, the demanding, complex and interdisciplinary aspects of tissue engineering has to be approached from new ways. We have conceptualised Head & Face Medicine therefore as a thematically broad ranged journal, including all disciplines involved in the head and neck area. We hope this journal will attract basic researchers and clinicians who are involved in investigating and applying complex themes (examplified by tissue engineering) in the head and face region and will contribute to a gain in scientific information, communication, and collaboration in order to improve the outcome of patient treatments

Levothyroxine effects on depressive symptoms and limbic glucose metabolism in bipolar disorder: a randomized, placebo-controlled positron emission tomography study.

Adding supraphysiologic doses of levothyroxine (L-T4) to standard treatment for bipolar depression shows promise, but the mechanisms underlying clinical improvement are unknown. In a previous pilot study, L-T4 treatment reduced depression scores and activity within the anterior limbic network. Here we extended this work in a randomized, double-blind, placebo-controlled study of patients with bipolar depression. Cerebral glucose metabolism was assessed with positron emission tomography and [F-18]fluorodeoxyglucose before and after 6 weeks of treatment with L-T4 (n=15) or placebo (n=10) in 12 volumes of interest (VOIs): the bilateral thalamus, amygdala, hippocampus, dorsal striatum and ventral striatum, and midline cerebellar vermis and subgenual cingulate cortex. Radioactivity in the VOIs, normalized to whole-brain radioactivity was taken as a surrogate index of glucose metabolism, and markers of thyroid function were assayed. Changes in brain activity and their association with clinical response were assessed using statistical parametric mapping. Adjunctive L-T4 treatment produced a significant decline in depression scores during the 6-week treatment. In patients treated with L-T4, we found a significant decrease in regional activity at P<0.05 after Bonferroni correction in the left thalamus, right amygdala, right hippocampus, left ventral striatum and the right dorsal striatum. Decreases in the left thalamus, left dorsal striatum and the subgenual cingulate were correlated with a reduction in depression scores (P<0.05 after Bonferroni correction). Placebo treatment was associated with a significant decrease in activity only in the right amygdala, and no region had a change in activity that was correlated with change in depression scores. The groups differed significantly in the relationship between the changes in depression scores and in activity in the thalamus bilaterally and the left ventral striatum. The findings provide evidence that administration of supraphysiologic thyroid hormone improves depressive symptoms in patients with bipolar disorder by modulating function in components of the anterior limbic network

Solar System Objects in the ISOPHOT 170 micron Serendipity Survey

The ISOPHOT Serendipity Survey (ISOSS) covered approximately 15 % of the sky at a wavelength of 170 micron while the ISO satellite was slewing from one target to the next. By chance ISOSS slews went over many solar system objects (SSOs). We identified the comets, asteroids and planets in the slews through a fast and effective search procedure based on N-body ephemeris and flux estimates. The detections were analysed from a calibration and scientific point of view. Through the measurements of the well-known asteroids Ceres, Pallas, Juno and Vesta and the planets Uranus and Neptune it was possible to improve the photometric calibration of ISOSS and to extend it to higher flux regimes. We were also able to establish calibration schemes for the important slew end data. For the other asteroids we derived radiometric diameters and albedos through a recent thermophysical model. The scientific results are discussed in the context of our current knowledge of size, shape and albedos, derived from IRAS observations, occultation measurements and lightcurve inversion techniques. In all cases where IRAS observations were available we confirm the derived diameters and albedos. For the five asteroids without IRAS detections only one was clearly detected and the radiometric results agreed with sizes given by occultation and HST observations. Four different comets have clearly been detected at 170 micron and two have marginal detections. The observational results are presented to be used by thermal comet models in the future. The nine ISOSS slews over Hale-Bopp revealed extended and asymmetric structures related to the dust tail. We attribute the enhanced emission in post-perihelion observations to large particles around the nucleus. The signal patterns are indicative of a concentration of the particles in trail direction.Comment: 15 pages, 6 figures, 6 tables; Accepted for publication in Astronomy and Astrophysic

Neighborhood Structure Configuration Models

We develop a new method to efficiently sample synthetic networks that preserve the d-hop neighborhood structure of a given network for any given d. The proposed algorithm trades off the diversity in network samples against the depth of the neighborhood structure that is preserved. Our key innovation is to employ a colored Configuration Model with colors derived from iterations of the so-called Color Refinement algorithm. We prove that with increasing iterations the preserved structural information increases: the generated synthetic networks and the original network become more and more similar, and are eventually indistinguishable in terms of centrality measures such as PageRank, HITS, Katz centrality and eigenvector centrality. Our work enables to efficiently generate samples with a precisely controlled similarity to the original network, especially for large networks

A retrospective analysis of submissions, acceptance rate, open peer review operations, and prepublication bias of the multidisciplinary open access journal Head & Face Medicine

<p>Abstract</p> <p>Background</p> <p><it>Head & Face Medicine </it>(HFM) was launched in August 2005 to provide multidisciplinary science in the field of head and face disorders with an open access and open peer review publication platform. The objective of this study is to evaluate the characteristics of submissions, the effectiveness of open peer reviewing, and factors biasing the acceptance or rejection of submitted manuscripts.</p> <p>Methods</p> <p>A 1-year period of submissions and all concomitant journal operations were retrospectively analyzed. The analysis included submission rate, reviewer rate, acceptance rate, article type, and differences in duration for peer reviewing, final decision, publishing, and PubMed inclusion. Statistical analysis included Mann-Whitney U test, Chi-square test, regression analysis, and binary logistic regression.</p> <p>Results</p> <p><it>HFM </it>received 126 articles (10.5 articles/month) for consideration in the first year. Submissions have been increasing, but not significantly over time. Peer reviewing was completed for 82 articles and resulted in an acceptance rate of 48.8%. In total, 431 peer reviewers were invited (5.3/manuscript), of which 40.4% agreed to review. The mean peer review time was 37.8 days. The mean time between submission and acceptance (including time for revision) was 95.9 days. Accepted papers were published on average 99.3 days after submission. The mean time between manuscript submission and PubMed inclusion was 101.3 days. The main article types submitted to HFM were original research, reviews, and case reports. The article type had no influence on rejection or acceptance. The variable 'number of invited reviewers' was the only significant (p < 0.05) predictor for rejection of manuscripts.</p> <p>Conclusion</p> <p>The positive trend in submissions confirms the need for publication platforms for multidisciplinary science. <it>HFM's </it>peer review time comes in shorter than the 6-weeks turnaround time the Editors set themselves as the maximum. Rejection of manuscripts was associated with the number of invited reviewers. None of the other parameters tested had any effect on the final decision. Thus, <it>HFM's </it>ethical policy, which is based on Open Access, Open Peer, and transparency of journal operations, is free of 'editorial bias' in accepting manuscripts.</p> <p>Original data</p> <p>Provided as a downloadable tab-delimited text file (URL and variable code available under section 'additional files').</p

The effect of e-learning on the quality of orthodontic appliances

Purpose: The effect of e-learning on practical skills in medicine has not yet been thoroughly investigated. Today’s multimedia learning environment and access to e-books provide students with more knowledge than ever before. The aim of this study is to evaluate the effect of online demonstrations concerning the quality of orthodontic appliances manufactured by undergraduate dental students. Materials and methods: The study design was a parallel-group randomized clinical trial. Fifty-four participants were randomly assigned to one of the three groups: 1) conventional lectures, 2) conventional lectures plus written online material, and 3) access to resources of groups one and two plus access to online video material. Three orthodontic appliances (Schwarz Plate, U-Bow Activator, and Fränkel Regulator) were manufactured during the course and scored by two independent raters blinded to the participants. A 15-point scale index was used to evaluate the outcome quality of the appliances. Results: In general, no significant differences were found between the groups. Concerning the appliances, the Schwarz Plate obtained the highest scores, whereas the Fränkel Regulator had the lowest scores; however, these results were independent of the groups. Females showed better outcome scores than males in groups two and three, but the difference was insignificant. Age of the participants also had no significant effect. Conclusion: The offer that students could use additional time and course-independent e-learning resources did not increase the outcome quality of the orthodontic appliances. The advantages of e-learning observed in the theoretical fields of medicine were not achieved in the educational procedures for manual skills. Factors other than e-learning may have a higher impact on manual skills, and this should be investigated in further studies