Sub-quadratic dependence of visible upconversion on infra-red direct luminescence decay owing to static energy-transfer upconversion

Because of their broadband luminescence, TM-ion-doped materials are of high interest for applications as tunable and short-pulse lasers. Systems with a d1 electron configuration possess only one excited 3d level and excited-state absorption into higher-lying 3d levels is impossible. One of these d1 systems, Ti:sapphire has become the most successful tunable and short-pulse laser system to date. Mn6+ is a promising d1 ion for a tunable laser system. In BaSO4, near-infrared emission from Mn6+ was observed. The room-temperature stimulated-emission cross section is larger than the excited-state-absorption cross section in the spectral range 920-1600 nm [1], i.e., as a laser material BaSO4:Mn6+ can offer a broad tuning range.\ud Here we report on the first epitaxial growth of Mn6+-doped BaSO4 layers. Growth techniques such as the melt growth fail, because barium sulphate has a phase transition at 1090°C and exhibits thermal decomposition at 1590°C. Therefore, we grew BaSO4 substrate crystals by the flux method. The Mn6+ ions tend to reduce to Mn5+ at T  620°C. We used a CsCl-KCl-NaCl solvent [2] for the LPE of BaSO4:Mn6+. This solvent has a low solidification temperature of 480°C and the growth process could be performed at temperatures well below 620°C. The nominal Mn6+ concentration was up to 0.8 mol%. High quality, lack of large-size inclusions, and low defect concentration were achieved. These Mn6+-doped BaSO4 layers were investigated spectroscopically by absorption, emission, and luminescence-excitation measurements at room temperature. Excitation at 800 nm leads to broadband Mn6+ emission between 850 and 1600 nm. Currently, we investigate the lasing potential of our BaSO4:Mn6+ layers.\ud [1] T.C. Brunold, H.U. Güdel, S. Kück, G. Huber, JOSA B 14, 2373 (1997).\ud [2] D. Ehrentraut, M. Pollnau, J. Cryst. Growth 234, 533 (2002)

Superquadratic behavior of upconversion luminescence transients in rare-earth-ion doped laser crystals

Inhomogeneous active-ion distributions in laser materials lead to strong deviations of upconversion versus direct luminescence transients from the quadratic law of energy-transfer upconversion. Measured luminescence decay curves in LaSc3(BO3)4:Nd3+ and GdVO4:Nd3+ confirm experimentally the predicted deviations. Differences in energy migration within the metastable level of Nd3+ are identified

Tomographic reconstruction of treponemal cytoplasmic filaments reveals novel bridging and anchoring components

An understanding of the involvement of bacterial cytoplasmic filaments in cell division requires the elucidation of the structural organization of those filamentous structures. Treponemal cytoplasmic filaments are composed of one protein, CfpA, and have been demonstrated to be involved in cell division. In this study, we used electron tomography to show that the filaments are part of a complex with a novel molecular organization that includes at least two distinct features decorating the filaments. One set of components appears to anchor the filaments to the cytoplasmic membrane. The other set of components appears to bridge the cytoplasmic filaments on the cytoplasmic side, and to be involved in the interfilament spacing within the cell. The filaments occupy between 3 and 18% of the inner surface of the cytoplasmic membrane. These results reveal a novel filamentous molecular organization of independent filaments linked by bridges and continuously anchored to the membrane

Survival after Laparoscopic versus Abdominal Radical Hysterectomy in Early Cervical Cancer: A Randomized Controlled Trial

Previous studies have reported the safety of laparoscopic radical hysterectomy for treatment of early cervical cancer, as option to laparotomy. This study aims to compare overall survival between laparoscopic versus abdominal radical hysterectomy for early cervical cancer. Methods: A single-center randomized controlled trial enrolled 30 patients with clinically staged IA2 cervical cancer and lymphovascular invasion, IB and IIA, who underwent laparoscopic radical hysterectomy (16) or abdominal radical hysterectomy (14). Result: The mean overall survival time was 74.74 months (CI 95%: 54.15-95.33) for LRH 91.67 months (CI 95%: 74.97-108.37) for ARH (logrank test = 0.30). The mean disease-free survival time was 81.07 months (CI 95%: 60.95-101.19) for LRH and 95.82 months (CI 95%: 80.18-111.47) for ARH (log-rank test = 0.371). The overall survival hazard ratio was 2.05 (CI 95%: 0.51-8.24), and the disease-free hazard ratio was 2.13 (CI 95%: 0.39-11.7). Conclusion: Our study suggests a nonsignificant trend of worse outcomes for LRH. In light of recent controversy and need for prospective studies, further studies in different populations are required for definite conclusions and until then, patients should be aware of risks and benefits, survival data and quality of life outcomes related to both surgical techniques.info:eu-repo/semantics/publishedVersio

The impact of seismic noise produced by wind turbines on seismic borehole measurements

Seismic signals produced by wind turbines can have an adverse effect on seismological measurements up to distances of several kilometres. Based on numerical simulations of the emitted seismic wave field, we study the effectivity of seismic borehole installations as a way to reduce the incoming noise. We analyse the signal amplitude as a function of sensor depth and investigate effects of seismic velocities, damping parameters and geological layering in the subsurface. Our numerical approach is validated by real data from borehole installations affected by wind turbines. We demonstrate that a seismic borehole installation with an adequate depth can effectively reduce the impact of seismic noise from wind turbines in comparison to surface installations. Therefore, placing the seismometer at greater depth represents a potentially effective measure to improve or retain the quality of the recordings at a seismic station. However, the advantages of the borehole decrease significantly with increasing signal wavelength.</p

Periplasm Organization in \u3ci\u3eTreponema denticola\u3c/i\u3e as Studied by Cryo-electron Tomography

As a spirochete, the genus Treponema is one of the few major bacterial groups whose natural phylogenic relationships are evident at the level of gross phenotypic characteristics such as their morphology. Treponema spp. are highly invasive due to their unique motility in dense media, and their ability to penetrate cell layers [1]. This feature is associated with the helical cell body and the presence of flagellar filaments in the periplasm [2]. Treponema denticola is an oral pathogen involved in endodontic infections and periodontal diseases. The presence and quantity of T. denticola in the subgingival biofilm is correlated with the severity of periodontal disease and tissue destruction [3,4]. The organism has also been detected in 75% of severe endodontic abscesses [5]. A better understanding of Treponema ultrastructure and motility will aid development of new strategies to control infection. Because of the similarity in ultrastructural organization among spirochetes, knowledge gained from T. denticola can be applied to other spirochetes causing diseases in human and animals (syphilis, digital dermatitis, Lyme disease, relapsing fever, leptospirosis, etc.)

Predicting Delay in Goal-Directed Action: An Experience Sampling Approach Uncovering Within-Person Determinants Involved in the Onset of Academic Procrastination Behavior

Academic procrastination involves the delayed implementation of actions required to fulfill study-related tasks. These behavioral delays are thought to result from momentary failures in self-regulation (i.e., within-person processes). Most previous studies focused on the role of trait-based individual differences in students’ procrastination tendencies. Little is known about the within-person processes involved in the occurrence of procrastination behavior in real-life academic situations. The present study applied an event-based experience sampling approach to investigate whether the onset of task-specific delay behavior can be attributed to unfavorable changes in students’ momentary appraisals of tasks (value, aversiveness, effort, expectations of success), which may indicate failures in self-regulation arise between critical phases of goal-directed action. University students (N = 75) used an electronic diary over eight days to indicate their next days’ intentions to work on academic tasks and their task-specific appraisals (n = 582 academic tasks planned). For each task, a second query requested the next day determined whether students’ task-related appraisals changed and whether they implemented their intention on time or delayed working on the respective task (n = 501 completed task-specific measurements). Students’ general procrastination tendency was assessed at baseline using two established self-report questionnaires. Stepwise two-level logistic regression analyses revealed that within-person changes in task-related appraisals that reflected a devaluation of the study-related tasks increased the risk for an actual delay. The risk to delay decreased when students maintained a positive attitude toward the task. Students’ general procrastination tendency did not predict individual differences in their task-specific delay behavior. We discuss these findings in light of the growing effort to understand the within-person processes that contribute to induce procrastination behavior under real-life academic conditions and illustrate how this knowledge can benefit the design of tasks and instructions that support students’ self-regulation to their best

Evaluation of whole-wheat flour blends with fat replacer.

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Tomographic reconstruction of treponemal cytoplasmic filaments reveals novel bridging and anchoring components

An understanding of the involvement of bacterial cytoplasmic filaments in cell division requires the elucidation of the structural organization of those filamentous structures. Treponemal cytoplasmic filaments are composed of one protein, CfpA, and have been demonstrated to be involved in cell division. In this study, we used electron tomography to show that the filaments are part of a complex with a novel molecular organization that includes at least two distinct features decorating the filaments. One set of components appears to anchor the filaments to the cytoplasmic membrane. The other set of components appears to bridge the cytoplasmic filaments on the cytoplasmic side, and to be involved in the interfilament spacing within the cell. The filaments occupy between 3 and 18% of the inner surface of the cytoplasmic membrane. These results reveal a novel filamentous molecular organization of independent filaments linked by bridges and continuously anchored to the membrane

Privateers, merchant ships and their crews between the Mediterranean and the North Sea during the War of the Spanish Succession (1702-1714): new insights from Southern-Netherlandish Prize Papers

Privateers, merchant ships and their crews between the Mediterranean and the North Sea during the War of the Spanish Succession (1702-1714): new insights from Southern-Netherlandish Prize Papers Our paper sheds new light on the early 18th century history of maritime trade connecting the North Sea area with the Mediterranean, via privateering and merchant ships sailing between the ports of Dunkirk and Ostend, and the Spanish ports of Cadiz and Alicante. While the history of early modern mercantile communities and trade networks connecting Spain and the Southern Netherlands has been well studied, our contribution aims at investigating the ships, their crews and the sea itself as elements enabling these connections. This paper is based on ‘Prize Papers’ captured by British privateers from Spanish and Flemish ships during the War of the Spanish Succession, a hitherto unexplored source which gives a good account of these elements. As the history of maritime trade and privateering are inextricably linked during this period, these sources form a new window into the lives, identities, and conditions of merchants, crewmembers, ships and their cargo. It will focus particularly on privateering ships and crew members, and the role played by Mediterranean captains and merchants. The cases presented in this paper form a prime example of the potential of these unexplored sources for collaborative research aimed towards global maritime connections in the early modern period. Bio VLIZ (Flanders Marine Institute, Belgium) recently initiated marine historical research with a project on the 18th century Southern Netherlandish Prize Papers. Wim De Winter has previously written on European maritime trade with Asia in the 17th and 18th century, and is now engaged in the 18th Century Prize Papers research at VLIZ. Michiel Vandegehuchte is VLIZ Research Director. Prof. dr. Michael Limberger is Associate Professor at Ghent University (Belgium), specialized in the fields of early modern maritime and commercial history, and has written on sixteenth-century Antwerp, and port cities. Dr. Jan Parmentier is curator of the maritime collections before 1830 at the MAS (Museum aan de Stroom, Antwerp)