3,140 research outputs found

    Terahertz dynamic aperture imaging at stand-off distances using a Compressed Sensing protocol

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    In this text, results of a 0.35 terahertz (THz) dynamic aperture imaging approach are presented. The experiments use an optical modulation approach and a single pixel detector at a stand-off imaging distance of approx 1 meter. The optical modulation creates dynamic apertures of 5cm diameter with approx 2000 individually controllable elements. An optical modulation approach is used here for the first time at a large far-field distance, for the investigation of various test targets in a field-of-view of 8 x 8 cm. The results highlight the versatility of this modulation technique and show that this imaging paradigm is applicable even at large far-field distances. It proves the feasibility of this imaging approach for potential applications like stand-off security imaging or far field THz microscopy.Comment: 9 pages, 13 figure

    Paying more than necessary? The wage cushion in Germany

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    Using a representative establishment data set for Germany, we show that more than 40 percent of plants covered by collective agreements pay wages above the level stipulated in the agreement, which gives rise to a wage cushion between the levels of actual and contractual wages. Cross-sectional and fixed-effects estimations for the period 2001-2006 indicate that the wage cushion mainly varies with the profit situation of the plant and with indicators of labour shortage and the business cycle. While plants bound by multi-employer sectoral agreements seem to pay wage premiums in order to overcome the restrictions imposed by the rather centralized system of collective bargaining in Germany, plants which make use of single-employer agreements are significantly less likely to have wage cushions. -- Anhand von reprĂ€sentativen Daten des IAB-Betriebs-panels zeigen wir, dass ĂŒber 40 Prozent der tarifgebundenen Betriebe in Deutschland höhere Löhne als im Tarifvertrag festgelegt zahlen, was zu einer Lohnspanne (bzw. einem Lohnpuffer) zwischen Effektiv- und Tariflöhnen fĂŒhrt. Querschnitts- und Fixe-Effekte-SchĂ€tzungen fĂŒr den Zeitraum 2001-2006 deuten darauf hin, dass die ĂŒbertarifliche Entlohnung hauptsĂ€chlich mit der Ertragslage des Betriebes und mit Indikatoren der ArbeitskrĂ€fteknappheit und des Konjunkturzyklus variiert. WĂ€hrend an FlĂ€chentarifvertrĂ€ge gebundene Betriebe ĂŒber Tarif entlohnen dĂŒrften, um BeschrĂ€nkungen zu ĂŒberwinden, die ihnen durch das relativ zentrali-sierte Tarifverhandlungssystem in Deutschland auferlegt werden, weisen Betriebe mit FirmentarifvertrĂ€gen wesentlich seltener eine ĂŒbertarifliche Entlohnung auf.wages,wage cushion,wage determination,bargaining,Germany

    Lights, Camera, Interaction: Studying Protein–Protein Interactions of the ER Protein Translocase in Living Cells

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    Various landmark studies have revealed structures and functions of the Sec61/SecY complex in all domains of live demonstrating the conserved nature of this ancestral protein translocase. While the bacterial homolog of the Sec61 complex resides in the plasma membrane, the eukaryotic counterpart manages the transfer of precursor proteins into or across the membrane of the endoplasmic reticulum (ER). Sec61 complexes are accompanied by a set of dynamically recruited auxiliary proteins assisting the transport of certain precursor polypeptides. TRAP and Sec62/Sec63 are two auxiliary protein complexes in mammalian cells that have been characterized by structural and biochemical methods. Using these ER membrane protein complexes for our proof-of-concept study, we aimed to detect interactions of membrane proteins in living mammalian cells under physiological conditions. Bimolecular luminescence complementation and competition was used to demonstrate multiple protein–protein interactions of different topological layouts. In addition to the interaction of the soluble catalytic and regulatory subunits of the cytosolic protein kinase A, we detected interactions of ER membrane proteins that either belong to the same multimeric protein complex (intra-complex interactions: Sec61α–Sec61ÎČ, TRAPα–TRAPÎČ) or protein complexes in juxtaposition (inter-complex interactions: Sec61α–TRAPα, Sec61α–Sec63, and Sec61ÎČ–Sec63). In the process, we established further control elements like synthetic peptide complementation for expression profiling of fusion constructs and protease-mediated reporter degradation demonstrating the cytosolic localization of a reporter complementation. Ease of use and flexibility of the approach presented here will spur further research regarding the dynamics of protein–protein interactions in response to changing cellular conditions in living cells

    The Golden Modes B^0 -> J/psi K_{S,L} in the Era of Precision Flavour Physics

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    The B^0 -> J/\psi K_{S,L} channels are outstanding probes of CP violation. We have a detailed look at the associated Standard-Model uncertainties, which are related to doubly Cabibbo-suppressed penguin contributions, and point out that these usually neglected effects can actually be taken into account unambiguously through the CP asymmetries and the branching ratio of the B^0 -> J/\psi pi^0 decay. Using the most recent B-factory measurements, we find a negative shift of the extracted value of beta, which softens the tension in the fits of the unitarity triangle. In addition, this strategy can be used to constrain a possible new-physics phase in B^0-\bar B^0 mixing. The proposed strategy is crucial to fully exploit the tremendous accuracies for the search for this kind of new physics that can be achieved at the LHC and future super-flavour factories.Comment: 4+1 pages, 4 figure

    Prosthetic outcomes and clinical performance of CAD-CAM monolithic zirconia versus porcelain-fused-to-metal implant crowns in the molar region: 1-year results of a RCT

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    OBJECTIVE To investigate the clinical performance of monolithic zirconia implant crowns as compared to porcelain-fused-to-metal (PFM) implant crowns. MATERIALS AND METHODS Seventy-six healthy patients received reduced diameter implants in the molar region. Following random allocation, either a monolithic zirconia crown (Mono-ZrO2_{2} ) or a (PFM) was inserted. Crown and implant survival rates, modified USPHS criteria, clinical measurements, and interproximal marginal bone level (MBL) were assessed at crown delivery (baseline, BL) and at the 1-year follow-up (1y-FU). Data were analyzed descriptively. Fisher's exact test and Wilcoxon rank sum test were applied for statistical analysis. The level of statistical significance was set at p < .05. RESULTS Thirty-nine Mono-ZrO2_{2} and 37 PFM crowns were delivered. At the 1y-FU, one crown in each group was lost due to loss of the implant. Technical complications occurred in the PFM group and were limited to four minor ceramic chippings resulting in a total technical complication rate of 11.1% (p = .024). Anatomical form and color match compared to the adjacent dentition were rated significantly inferior for the Mono-ZrO2_{2} crowns. Patient satisfaction was high in both groups at BL (34 Mono-ZrO2_{2} 34 PFM) and at 1y-FU (36 Mono-ZrO2_{2} 31 PFM). No significant differences between the groups were detected with respect to the change in MBL and to the soft tissue parameters. CONCLUSIONS Monolithic zirconia crowns are a similarly successful alternative option to PFM crowns for restoring single implants in the posterior area

    Pontic site development for fixed dental prostheses with and without soft tissue grafting: 1-year results of a cohort study

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    AIM To describe and compare the pontic site development for fixed-dental prostheses (FDPs) with and without soft tissue grafting up to one-year post insertion of FDPs. MATERIALS AND METHODS A convenience sample of 24 patients participating in an ongoing RCT was provided with three-unit tooth-borne FDPs. Six patients received a subepithelial connective tissue graft (SCTG) at the pontic site, whereas 18 patients were treated without any soft tissue graft (CONTROL). Digital impressions were taken prior to tooth preparation, after tooth preparation, after insertion of the final FDP, and at the 1 year of follow-up. The obtained stereolithography files (STL) were superimposed and profilometric as well as linear changes of the soft tissue profile were assessed at the pontic regions. Profilometric outcomes included changes of the ridge contour, the alveolar ridge width, and the crown height of the pontic. Further outcomes assessed included: the papilla index, the pink esthetic score (PES), probing depth (PD), bleeding on probing (BOP), and plaque control record (PCR). Descriptive and nonparametric statistics were applied for all outcome measures. RESULTS The median profilometric contour between tooth preparation and 1 year after the insertion of the final FDP decreased by - 0.25 mm [Q1, Q3: - 0.36, 0.14] in the CONTROL group and increased by 0.61 mm [Q1, Q3: - 0.18, 1.06] in the SCTG group (intergroup p = 0.038). The alveolar ridge width between prior to tooth preparation and the one-year follow-up amounted to - 0.12 mm [Q1, Q3: - 0.74, 0.70] (= loss) in the CONTROL group and to 2.23 mm [Q1, Q3: 0.62, 3.86] (= gain) in the SCTG group (intergroup p = 0.032). At one year, the median crown height of the pontic tended to decrease by - 1.24 mm [Q1, Q3: - 2.05, - 1.05] in the SCTG group (intragroup p = 0.094) and by - 0.22 mm [Q1, Q3: - 0.58, 0.66] in the CONTROL group (intragroup p = 0.831), with significant differences between the groups (intergroup p = 0.022). The papilla index between prior to tooth preparation and one year of follow-up improved significantly in both groups (p  0.05). CONCLUSION Within the limitations of the present study, soft tissue grafting tends to limit contour changes at pontic sites, thus maintaining the esthetic outcomes over time. The lack of soft tissue grafting results in stable clinical outcomes; however, it may lead to a decrease in aesthetic outcomes over time. CLINICAL RELEVANCE Autogenous soft tissue grafting seems to be a valid therapeutic option for the development of the pontic site to restore ridge defects prior to the delivery of fixed dental prostheses and to limit dimensional changes over time
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