1,288 research outputs found

    Non-spherical micro- and nanoparticles

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    Floral scent emission and pollinator attraction in two species of Gymnadenia (Orchidaceae)

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    We investigated scent composition and pollinator attraction in two closely related orchids, Gymnadenia conopsea (L.) R.Br. s.l. and Gymnadenia odoratissima (L.) Rich. in four populations during the day and night. We collected pollinators of both species using hand nets and sampled floral odour by headspace sorption. We analysed the samples by gas chromatography with mass spectrometry to identify compounds and with electroantennographic detection to identify compounds with physiological activity in pollinators. In order to evaluate the attractiveness of the physiologically active compounds, we carried out trapping experiments in the field with single active odour substances and mixtures thereof. By collecting insects from flowers, we caught eight pollinators of G. conopsea, which were members of four Lepidoptera families, and 37 pollinators of G. odoratissima, from five Lepidopteran families. There was no overlap in pollinator species caught from the two orchids using nets. In the scent analyses, we identified 45 volatiles in G. conopsea of which three (benzyl acetate, eugenol, benzyl benzoate) were physiologically active. In G. odoratissima, 44 volatiles were identified, of which seven were physiologically active (benzaldehyde, phenylacetaldehyde, benzyl acetate, 1-phenyl-2,3-butandione, phenylethyl acetate, eugenol, and one unknown compound). In field bioassays using a mixture of the active G. odoratissima compounds and phenylacetaldehyde alone we caught a total of 25moths, some of which carried Gymnadenia pollinia. A blend of the active G. conopsea volatiles placed in the G. odoratissima population did not attract any pollinators. The two orchids emitted different odour bouquets during the day and night, but G. odoratissima showed greater temporal differences in odour composition, with phenylacetaldehyde showing a significant increase during the night. The species differed considerably in floral odour emission and this differentiation was stronger in the active than non-active compounds. This differentiation of the two species, especially in the emission of active compounds, appears to have evolved under selection for attraction of different suites of Lepidopteran pollinator

    Non-spherical micro- and nanoparticles

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    Area-dependent enlargement ratios of panoramic tomography depending on incorrect patient positioning and its significance for implant dentistry

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    Dokument 1: Teil 1: Orthograde Patientenpositionierung Dokument 2: Teil 2: Asymmetric patient positioning - Englische Version Dokument 3: Teil 2: Unsymetrische Fehlpositionierung - Deutsche Version Dokument 4: Teil 3: Symmetric patient positioning - Englische Version Dokument 5: Teil 3: Symetrische Fehlpositionierung - Deutsche Version Dokument 6: Anhang: Horizontale Vergrößerung an der apikalen Implantatstufe - Deutsche Version Dokument 7: Appendix: Horizontal magnification factors at the apical implant step - Englische Version *************************************************** In der vorliegenden Arbeit wurde das Verhalten der vertikalen und horizon-talen Vergrößerungsfaktoren auf der Panoramaschichtaufnahme in den ver-schiedenen Implantatregionen des Ober- und Unterkiefers untersucht. Ein Verfahren wird vorgestellt, das die Bestimmung der regionalen Vergrößerungsfaktoren in Abhängigkeit von der Implantatregion und der Fehlpositionierung des Patienten zuläßt. Dabei werden gut definierte Merkmale am Implantatkörper (Frialit 2- Implantat) als Referenzpunkte herangezogen. Da in der horizontalen Dimension die Patientenpositionierung einen großen Einfluß auf die Vergrößerungs-faktoren vor allem in der Interforaminalregion nimmt, kann die Aufnahme metalldichter Strukturen bekannter Abmessungen, wie z.B. von 5 mm Kugeln, auch weiterhin empfohlen werden. Wenn diese Ergebnisse berücksichtigt werden, stellt die Panoramaschichttechnik ein geeignetes Verfahren sowohl für die präimplantologische Diagnostik als auch für die Verlaufs- und Erfolgskontrollen dar.Dokument 1: Teil 1: Orthograde Patientenpositionierung Dokument 2: Teil 2: Asymmetric patient positioning - English version Dokument 3: Teil 2: Unsymetrische Fehlpositionierung - German version Dokument 4: Teil 3: Symmetric patient positioning - English version Dokument 5: Teil 3: Symetrische Fehlpositionierung - German version Dokument 6: Anhang: Horizontale Vergrößerung an der apikalen Implantatstufe - German version Dokument 7: Appendix: Horizontal magnification factors at the apical implant step - English version *************************************************** The aim of this work was to study the behavior of vertical and horizontal enlargement ratios in panoramic tomography in the various implant regions of maxilla and the mandible. A method is presented that admits determination of regional enlargement ratios as a function of implant region. Clearly defined characteristics on the implant body (Frialit 2-implants) are used as reference positions. Because the patient positioning in the horizontal dimension has a great influence on the magnification factors, particularly in the interforaminal region, imaging of dense metallic structures of known dimensions, such as 5-mm balls, can also continue to be recommended. When these results are considered, the panoramic radiography technique is demonstrated to be a suitable procedure for both pre-implant diagnostics and also for monitoring the procedure and the success of the procedure

    Introduction to statistical simulations in health research

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    In health research, statistical methods are frequently used to address a wide variety of research questions. For almost every analytical challenge, different methods are available. But how do we choose between different methods and how do we judge whether the chosen method is appropriate for our specific study? Like in any science, in statistics, experiments can be run to find out which methods should be used under which circumstances. The main objective of this paper is to demonstrate that simulation studies, that is, experiments investigating synthetic data with known properties, are an invaluable tool for addressing these questions. We aim to provide a first introduction to simulation studies for data analysts or, more generally, for researchers involved at different levels in the analyses of health data, who (1) may rely on simulation studies published in statistical literature to choose their statistical methods and who, thus, need to understand the criteria of assessing the validity and relevance of simulation results and their interpretation; and/or (2) need to understand the basic principles of designing statistical simulations in order to efficiently collaborate with more experienced colleagues or start learning to conduct their own simulations. We illustrate the implementation of a simulation study and the interpretation of its results through a simple example inspired by recent literature, which is completely reproducible using the R-script available from online supplemental file 1

    Serum Neurofilament Light Trajectories and Their Relation to Subclinical Radiological Disease Activity in Relapsing Multiple Sclerosis Patients in the APLIOS Trial

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    Introduction: Several studies have described prognostic value of serum neurofilament light chain (sNfL) at the group level in relapsing multiple sclerosis (RMS) patients. Here, we aimed to explore the temporal association between sNfL and development of subclinical disease activity as assessed by magnetic resonance imaging (MRI) at the group level and evaluate the potential of sNfL as a biomarker for capturing subclinical disease activity in individual RMS patients. Methods: In the 12-week APLIOS study, patients (N = 284) received subcutaneous ofatumumab 20 mg. Frequent sNfL sampling (14 time points over 12 weeks) and monthly MRI scans enabled key analyses including assessment of the group-level temporal relationship of sNfL levels with on-study subclinical development of gadolinium-enhancing (Gd +)T1 lesions. Prognostic value of baseline sNfL ("high" vs. "low") level for subsequent on-study clinical relapse or Gd + T1 activity was assessed. Individual patient-level development of on-study Gd + T1 lesions wascompared across three predictors: baseline Gd + T1 lesion number, baseline sNfL ("high" vs. "low"), and time-matched sNfL. Results: In patients developing Gd + T1 lesions at week 4 (absent at baseline), sNfL levels increased during the month preceding the week-4 MRI scan and then gradually decreased back to baseline. High versus low baseline sNfL conferred increased risk of subsequent on-study clinical relapse or Gd + T1 activity (HR, 2.81; p < 0.0001) in the overall population and, notably, also in the patients without baseline Gd + T1 lesions (HR, 2.48; p = 0.0213). Individual patient trajectories revealed a marked difference in Gd + T1 lesions between patients with the ten highest vs. lowest baseline sNfL levels (119 vs. 19 lesions). Prognostic value of baseline or time-matched sNfL for on-study Gd + T1 lesions was comparable to that of the number of baseline MRI Gd + T1 lesions. Conclusions: sNfL measurement may have utility in capturing and monitoring subclinical disease activity in RMS patients. sNfL assessments could complement regular MRI scans and may provide an alternative when MRI assessment is not feasible. ClinicalTrials.gov: NCT03560739. Classification of Evidence: This study provides class I evidence that serum neurofilament light may be used as a biomarker for monitoring subclinical disease activity in relapsing multiple sclerosis patients, as shown by its elevation in the weeks preceding the development of new gadolinium-enhancing T1 lesion activity

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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