A Phase Space Beam Position Monitor for Synchrotron Radiation

The stability of the photon beam position on synchrotron beamlines is critical for most if not all synchrotron radiation experiments. On wiggler and bend magnet beamlines, the vertical position is most critical due to the large horizontal width of the beam. The position of the beam at the experiment or optical element location is set by the position and trajectory of the electron beam source as it traverses the magnetic field of the bend magnet or the insertion device. Thus an ideal photon beam monitor would be able to simultaneously measure the photon beam’s vertical position and angle, or its position in phase space. X-ray diffraction is commonly used to prepare a monochromatic beam on x-ray beamlines usually in the form of a double crystal monochromator using perfect crystals. Diffraction from crystals couples the photon wavelength or energy to the incident angle on the crystal or lattice planes within the crystal. A monochromatic beam from such a monochromator will contain a spread of energies due to the vertical divergence of the photon beam from the source. This range of energies can easily cover the absorption edge of an element such as iodine at 33.17keV. It has been found that a system composed of a double crystal monochromator and an iodine filter that horizontally covers part of the monochromatic beam and an imaging detector can be used to independently and simultaneously measure the position and angle of the photon beam. This information can then be translated back to determine the vertical position and angle, or vertical phase space, of the electron beam source. This approach to measurement of the phase space of the source has not been done before and thus this study is the first of its kind. The goal of this thesis is to investigate the use of this combined monochromator, filter and detector as a phase space beam position monitor. The system was tested for sensitivity to position and angle under a number of synchrotron operating conditions (normal operations and special operating modes where the beam is intentionally altered in position and angle). These results were compared to other methods of beam position measurement from the literature to assess the utility of such a system as a beam diagnostic, a feedback element for electron beam control and a source of information that could be used to correct the experimental data to account for beam position and angle motion

A REAL TIME PHASE SPACE BEAM SIZE AND DIVERGENCE MONITOR FOR SYNCHROTRON RADIATION

My prior work has shown that an electron beam position and angle monitoring system was able to measure the electron source position and angle at a single location in a beamline at a synchrotron source. This system, a phase space ̶ Beam Position Monitor (ps-BPM), relies on a monochromator to prepare a photon beam whose energy is at that of K-edge of an absorber filter. The natural divergence of the photon beam from the source gives an energy range that will encompass the K-edge of the filter. A measurement of the center of the monochromatic beam and the K-edge location through the absorber filter gives the position and angle of the electron source with sensitivity comparable to any beam position measurement system. Further, this thesis shows that this system is capable of measuring the source size and divergence at the same time by measuring the photon beam spatial distribution and the K-edge filtered beam distribution also with a sensitivity comparable to other existing methods for the source size; no other single measurement method is capable of divergence measurements. This was validated by measurements and simulations as the beam size in the storage ring was changed. The position measurements can be done in near real time and the size measurements can be done near 1 Hz. The system was extensively modeled for its application at the CLS as well as possible implementations at other higher brightness sources such as the Advanced Photon Source Upgrade (APS-U). The modeled performance of the ps-BPM system was compared against other methods for measuring the electron source properties for high brightness sources. These methods included pinhole imaging and double-slit interferometry. This system is being considered as a candidate system for the APS-U

Evolution of compound eye morphology underlies differences in vision between closely related Drosophila species

Background: Insects have evolved complex visual systems and display an astonishing range of adaptations for diverse ecological niches. Species of Drosophila melanogaster subgroup exhibit extensive intra- and interspecific differences in compound eye size. These differences provide an excellent opportunity to better understand variation in insect eye structure and the impact on vision. Here we further explored the difference in eye size between D. mauritiana and its sibling species D. simulans. Results: We confirmed that D. mauritiana have rapidly evolved larger eyes as a result of more and wider ommatidia than D. simulans since they recently diverged approximately 240,000 years ago. The functional impact of eye size, and specifically ommatidia size, is often only estimated based on the rigid surface morphology of the compound eye. Therefore, we used 3D synchrotron radiation tomography to measure optical parameters in 3D, predict optical capacity, and compare the modelled vision to in vivo optomotor responses. Our optical models predicted higher contrast sensitivity for D. mauritiana, which we verified by presenting sinusoidal gratings to tethered flies in a flight arena. Similarly, we confirmed the higher spatial acuity predicted for Drosophila simulans with smaller ommatidia and found evidence for higher temporal resolution. Conclusions: Our study demonstrates that even subtle differences in ommatidia size between closely related Drosophila species can impact the vision of these insects. Therefore, further comparative studies of intra- and interspecific variation in eye morphology and the consequences for vision among other Drosophila species, other dipterans and other insects are needed to better understand compound eye structure–function and how the diversification of eye size, shape, and function has helped insects to adapt to the vast range of ecological niches

Doxorubicin-induced renal inflammation in rats: Protective role of Plantago major

Objective: The aim of the present study was to evaluate the possible protective effect of Plantago major (P. major) extract against doxorubicin (DXR)-induced renal inflammation in rats. Materials and Methods: 80 male albino rats were randomly divided into 8 groups as follows: control, DXR, Ext (extract) 600, Ext1200, dexamethasone+DXR, vitamin E+DXR, Ext600+DXR, and Ext1200+DXR. Duration of the study was 35 days and DXR was intravenously injected on the 7th day of the experiment. Tumor necrosis factor-alpha (TNF-α) production and monocyte chemoattractant protein-1 (MCP-1) expression levels were assessed in the left kidney. Serum creatinine concentration and osmolarity were determined on the 1st, 14th, 21st, 28th and 35th days of the experiment. Results: DXR caused a significant increase in renal expression of MCP-1 and TNF-α production compared to control animals. Administration of dexamethasone, vitamin E and P. major extract significantly improved the expression of these inflammatory mediators compared to DXR group. Compared to day 1 in DXR group, serum osmolarity showed a significant increase on days 21, 28 and 35. Also, on these days, serum osmolarity in DXR group was significantly higher than that on the same days in control group. In Vit E+DXR and Ext 1200+DXR groups, there was no significant changes in serum osmolarity among different days of the study. However, in these groups, serum osmolarity on days 21, 28 and 35 showed a significant decrease compared to the same days in DXR group. Conclusion: Present results suggest that hydroethanolic extract of P. major protected renal tissue against DXR–induced renal inflammation

Evolution of compound eye morphology underlies differences in vision between closely related Drosophila species

Background. Insects have evolved complex visual systems and display an astonishing range of adaptations for diverse ecological niches. Species of Drosophila melanogaster subgroup exhibit extensive intra- and interspecific differences in compound eye size. These differences provide an excellent opportunity to better understand variation in insect eye structure and the impact on vision. Here we further explored the difference in eye size between D. mauritiana and its sibling species D. simulans. Results. We confirmed that D. mauritiana have rapidly evolved larger eyes as a result of more and wider ommatidia than D. simulans since they recently diverged approximately 240,000 years ago. The functional impact of eye size, and specifically ommatidia size, is often only estimated based on the rigid surface morphology of the compound eye. Therefore, we used 3D synchrotron radiation tomography to measure optical parameters in 3D, predict optical capacity, and compare the modelled vision to in vivo optomotor responses. Our optical models predicted higher contrast sensitivity for D. mauritiana, which we verified by presenting sinusoidal gratings to tethered flies in a flight arena. Similarly, we confirmed the higher spatial acuity predicted for Drosophila simulans with smaller ommatidia and found evidence for higher temporal resolution. Conclusions. Our study demonstrates that even subtle differences in ommatidia size between closely related Drosophila species can impact the vision of these insects. Therefore, further comparative studies of intra- and interspecific variation in eye morphology and the consequences for vision among other Drosophila species, other dipterans and other insects are needed to better understand compound eye structure–function and how the diversification of eye size, shape, and function has helped insects to adapt to the vast range of ecological niches

Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin

Annals of Allergy, Asthma & Immunology / The role of gastrointestinal permeability in food allergy

Selective intestinal epithelial permeability is essential for uptake of water and nutrients and contributes to oral tolerance development. Altered intestinal epithelial barrier function and composition is observed in food allergy. Subepithelial mediators and small intestinal luminal content influence barrier integrity. The gastric milieu and physiological function contribute to antigen separation from the immune induction sites. A dysfunctional barrier of the entire gastrointestinal tract has an essential contribution to food allergic reactions.(VLID)468939

Mouse Chow Composition Influences Immune Responses and Food Allergy Development in a Mouse Model

Our diet is known to substantially influence the immune response not only by support of mucosal barriers but also via direct impact on immune cells. Thus, it was of great interest to compare the immunological effect of two mouse chows with substantial differences regarding micro-, macronutrient, lipid and vitamin content on the food allergic response in our previously established mouse model. As the two mouse chows of interest, we used a soy containing feed with lower fatty acid (FA) amount (soy-containing feed) and compared it to a soy free mouse chow (soy-free feed) in an established protocol of oral immunizations with Ovalbumin (OVA) under gastric acid suppression. In the animals receiving soy-containing feed, OVA-specific IgE, IgG1, IgG2a antibody levels were significantly elevated and food allergy was evidenced by a drop of body temperature after oral immunizations. In contrast, mice on soy-free diet had significantly higher levels of IL-10 and were protected from food allergy development. In conclusion, soy-containing feed was auxiliary during sensitizations, while soy-free feed supported oral tolerance development and food allergy prevention

A spatial beam property analyzer based on dispersive crystal diffraction for low-emittance X-ray light sources

The advent of low-emittance synchrotron X-ray sources and free-electron lasers urges the development of novel diagnostic techniques for measuring and monitoring the spatial source properties, especially the source sizes. This work introduces an X-ray beam property analyzer based on a multi-crystal diffraction geometry, including a crystal-based monochromator and a Laue crystal in a dispersive setting to the monochromator. By measuring the flat beam and the transmitted beam profiles, the system can provide a simultaneous high-sensitivity characterization of the source size, divergence, position, and angle in the diffraction plane of the multi-crystal system. Detailed theoretical modeling predicts the system’s feasibility as a versatile characterization tool for monitoring the X-ray source and beam properties. The experimental validation was conducted at a bending magnet beamline at the Swiss Light Source by varying the machine parameters. A measurement sensitivity of less than 10% of a source size of around 12 µm is demonstrated. The proposed system offers a compact setup with simple X-ray optics and can also be utilized for monitoring the electron source.ISSN:2045-232