3,397 research outputs found
Characterizing the variation of propagation constants in multicore fibre
We demonstrate a numerical technique that can evaluate the core-to-core
variations in propagation constant in multicore fibre. Using a Markov Chain
Monte Carlo process, we replicate the interference patterns of light that has
coupled between the cores during propagation. We describe the algorithm and
verify its operation by successfully reconstructing target propagation
constants in a fictional fibre. Then we carry out a reconstruction of the
propagation constants in a real fibre containing 37 single-mode cores. We find
that the range of fractional propagation constant variation across the cores is
approximately .Comment: 17 pages; preprint format; 5 figures. Submitted to Optics Expres
Threading Granules in Freiburg : 2nd International Symposium on "One Mitochondrion, Many Diseases – Biological and Molecular Perspectives", a FRIAS Junior Researcher Conference, Freiburg im Breisgau, Germany, March 9th/10th, 2016
Altered mitochondrial activities play an important role in many different human disorders, including cancer and neurodegeneration. At the Freiburg Institute of Advanced Studies (FRIAS) Junior Researcher Conference “One Mitochondrion, Many Diseases – Biological and Molecular Perspectives” (University of Freiburg, Freiburg, Germany), junior and experienced researches discussed common and distinct mechanisms of mitochondrial contributions to various human disorders
Semiquantitative interpretation of anticardiolipin and antiβ2glycoprotein I antibodies measured with various analytical platforms: communication from the ISTH SSC subcommittee on Lupus Anticoagulant/Antiphospholipid antibodies
Background
Antiβ2glycoprotein I (aβ2GPI) and anticardiolipin (aCL) IgG/IgM show differences in positive/negative agreement and titers between solid phase platforms. Method specific semiquantitative categorization of titers could improve and harmonize the interpretation across platforms.
Aim
To evaluate the traditionally 40/80 units thresholds used for aCL and aβ2GPI for categorization into moderate/high positivity with different analytical systems, and to compare with alternative thresholds.
Material and methods
aCL and aβ2GPI thresholds were calculated for two automated systems (chemiluminescent immunoassay (CLIA) and multiplex flow immunoassay (MFI)) by ROC-curve analysis on 1108 patient samples, including patients with and without APS, and confirmed on a second population (n=279). Alternatively, regression analysis on diluted standard material was applied to identify thresholds. Thresholds were compared to 40/80 threshold measured by an enzyme linked immunosorbent assay (ELISA). Additionally, likelihood ratios (LR) were calculated.
Results
Threshold levels of 40/80 units show poor agreement between ELISA and automated platforms for classification into low/moderate/high positivity, especially for aCL/aβ2GPI IgG. Agreement for semiquantitative interpretation of aPL IgG between ELISA and CLIA/MFI improves with alternative thresholds. LR for aPL IgG increase for thrombotic and obstetric APS based on 40/80 thresholds for ELISA and adapted thresholds for the other systems, but not for IgM.
Conclusion
Use of 40/80 units as medium/high thresholds is acceptable for aCL/aβ2GPI IgG ELISA, but not for CLIA and MFI. Alternative semiquantitative thresholds for non-ELISA platforms can be determined by a clinical approach or by using monoclonal antibodies. Semiquantitative reporting of aPL IgM has less impact on increasing probability for APS
Three-Dimensional Integrable Models and Associated Tangle Invariants
In this paper we show that the Boltzmann weights of the three-dimensional
Baxter-Bazhanov model give representations of the braid group, if some suitable
spectral limits are taken. In the trigonometric case we classify all possible
spectral limits which produce braid group representations. Furthermore we prove
that for some of them we get cyclotomic invariants of links and for others we
obtain tangle invariants generalizing the cyclotomic ones.Comment: Number of pages: 21, Latex fil
Modal noise mitigation in a photonic lantern fed near-IR spectrograph
Recently we have demonstrated the potential of a hybrid astrophotonic device, consisting of a multi-core fiber photonic lantern and a 3D waveguide reformatting component, to efficiently reformat the multimode point spread function of a telescope to a diffracted limited pseudo-slit. Here, we report on an investigation into the potential of this device to mitigate modal noise-one of the main hurdles of multi-mode fiber-fed spectrographs. The modal noise performance of the photonic reformatter and other fiber feeds was assessed using a bench-Top spectrograph based on an echelle grating. In a first method of modal noise quantification, we used broadband light as the input, and assessed the modal noise performance based on the variations in the normalized spectrum as the input coupling to the fiber feed is varied. In a second method, we passed the broadband light through an etalon to generate a source with spectrally narrow peaks. We then used the spectral stability of these peaks as the input coupling to the fiber feed was varied as a proxy for the modal noise. Using both of these approaches we found that the photonic reformatter could significantly reduce modal noise compared to the multi-mode fiber feed, demonstrating the potential of photonic reformatters to mitigate modal noise for applications such as near-IR radial velocity measurements of M-dwarf stars. </p
Aplicação de água residuária de processamento de mandioca em sistema de irrigação por gotejamento
The wastewater discarded from the cassava processing causes a serious environmental problem when dumped into water bodies. On the other hand, this residue can be used as a source of nutrients for crops. However, it is necessary to control the quality of this effluent because of the negative effects that it may cause to the irrigation system. This study aimed to evaluate a drip irrigation system with the application of cassava wastewater by determining the coefficients of variation of emitter discharge (CVq), distribution uniformity (DUC) and Christiansen’s uniformity (CUC). The experiment was conducted at C. Vale cassava processing factory in the city of Terra Roxa (Paraná, Brazil). Four systems of 66 m² were installed, with 7 lateral lines of 11 m, spaced in 1 m, with one dripper at each 0.30 m. The systems were fed by two tanks of 1000 L, situated at 1.5 m and 2.0 m above the ground and containing water for irrigation and the cassava wastewater for fertigation. A plastic mesh filter was installed in the tank and two digital manometers controlled the pressure. Thirty trials were performed for each treatment, using the methodologies of Keller and Karmeli (1975) and Denículi (1980). Excellent averages, above 90%, were obtained for both DUC and CUC. The results showed no expressive differences between the use of water and the use of effluent, demonstrating that cassava wastewater can be applied efficiently on a drip irrigation system.A água residuária do processamento de mandioca ocasiona um sério problema ambiental quando lançada em corpos hídricos. Por outro lado, este resíduo pode ser utilizado como fonte de nutrientes para as culturas. Contudo, é necessário controlar a qualidade desse efluente devido aos efeitos negativos que pode acarretar ao sistema. O presente estudo teve como objetivo avaliar um sistema de irrigação por gotejamento com aplicação de resíduo de mandioca, por meio da determinação dos coeficientes de variação de vazão total (CVt), de uniformidade de distribuição (CUD) e de uniformidade de Christiansen (CUC). O estudo foi conduzido na Amidonaria da C. Vale, em Terra Roxa (PR). Foram instalados quatro sistemas de 66 m², com sete linhas laterais de 11 m, espaçadas em 1 m, com um gotejador a cada 0,30 m. Os sistemas foram alimentados por dois reservatórios de 1000 L, elevados a 1,5 m e 2,0 m do chão, onde foram armazenadas a água para irrigação e a água residuária do processamento de mandioca para fertirrigação. Foram instalados um filtro de tela plástica de 1” junto ao reservatório e dois manômetros digitais. Foram realizados 30 ensaios para cada tratamento, por meio das metodologias de Keller e Karmeli (1975) e de Denículi (1980). Obteve-se uma média geral excelente, acima dos 90%, para CUD e CUC. Os resultados evidenciam que não houve diferença expressiva entre a utilização de água ou de efluente no sistema, demonstrando que a água residuária de processamento de mandioca pode ser aplicada com eficiência em um sistema de irrigação por gotejamento
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