Multi-contrast computed laminography at ANKA light source

X-ray computed laminography has been developed as a non-destructive imaging technique for inspecting laterally extended objects. Benefiting from a parallel-beam geometry, high photon flux of synchrotron sources and modern high-resolution detector systems, synchrotron radiation computed laminography (SRCL) results in a powerful three-dimensional microscopy technique. SRCL can be combined with different contrast modes, such as absorption, phase and dark-field contrasts, in order to provide complementary information for the same specimen. Here we show the development of SRCL at the TopoTomo beamline of the ANKA light source. A novel instrumentation design is reported and compared to the existing one. For this design, experimental results from different contrast modalities are shown

Measurement of jet-substructure observables in top quark, W boson and light jet production in proton-proton collisions at √s=13 TeV with the ATLAS detector

A measurement of jet substructure observables is presented using data collected in 2016 by the ATLAS experiment at the LHC with proton-proton collisions at s√ = 13 TeV. Large-radius jets groomed with the trimming and soft-drop algorithms are studied. Dedicated event selections are used to study jets produced by light quarks or gluons, and hadronically decaying top quarks and W bosons. The observables measured are sensitive to substructure, and therefore are typically used for tagging large-radius jets from boosted massive particles. These include the energy correlation functions and the N-subjettiness variables. The number of subjets and the Les Houches angularity are also considered. The distributions of the substructure variables, corrected for detector effects, are compared to the predictions of various Monte Carlo event generators. They are also compared between the large-radius jets originating from light quarks or gluons, and hadronically decaying top quarks and W bosons

Three-dimensional reconstructions come to life - Interactive 3D PDF animations in functional morphology

Digital surface mesh models based on segmented datasets have become an integral part of studies on animal anatomy and functional morphology; usually, they are published as static images, movies or as interactive PDF files. We demonstrate the use of animated 3D models embedded in PDF documents, which combine the advantages of both movie and interactivity, based on the example of preserved Trigonopterus weevils. The method is particularly suitable to simulate joints with largely deterministic movements due to precise form closure. We illustrate the function of an individual screw-and-nut type hip joint and proceed to the complex movements of the entire insect attaining a defence position. This posture is achieved by a specific cascade of movements: Head and legs interlock mutually and with specific features of thorax and the first abdominal ventrite, presumably to increase the mechanical stability of the beetle and to maintain the defence position with minimal muscle activity. The deterministic interaction of accurately fitting body parts follows a defined sequence, which resembles a piece of engineering

Research data supporting “Development of structural colour in leaf beetles”

Original or unprocessed data is provided in support of the article “Development of structural colour in leaf beetles”. The article was accepted for publication in 2017 in the journal "Scientific Reports". Electronic supporting Information is available from the publisher. The data is structured into eight folders, each correlating to a specific data type presented in the published article. Folder 1: Photographs of the beetles at different stages of life. Folder 2: the data sets used to reconstruct the 3D volumes shown in Figure 2 (Synchrotron microtomography) in the manuscript. Folder 3: the complete set of TEM (Transmission Electron Microscopy) images available. The folder is further subdivided by beetle’s stage of life. Folder 4: optical microscope images before processing. The scale bar is included for reference. Folder 5 is relative to the Figure 5 in the manuscript: it is divided into two folders. The first one contains the Python code used to generate the simulated spectra. This file also includes the input files (i.e. the layer thickness as measured from the TEM sections). The second main folder includes the MATLAB files used to generate Fig.5 (that is, the experimental spectra collected by optical microspectroscopy and the simulated signal). In folder “Supporting”, one can find the two supporting video and the MATLAB code used to generate the supplementary images and the relative input files.This work was supported by the BBSRC David Phillips fellowship [BB/K014617/1], The Isaac Newton Trust Cambridge 76933 and the ERC-2014-STG H2020 639088. Research at KIT was partially funded by the German Federal Ministry of Education and Research by grants 05K10CKB and 05K12CK2

Movements and morphology under sexual selection: tsetse fly genitalia

artículo (arbitrado)--Universidad de Costa Rica. Escuela de Biología, 2010. Este documento es privado debido a limitaciones de derechos de autorSHÖN (2009, Ethology Ecology & Evolution 21: 161–172) pointed out that in order to understand the functional morphology of sexually selected structures that are used as signaling devices in birds, it is crucial to understand how these structures move during sexual interactions. This insight applies not only to bird feathers, but also to many other types of possible signaling devices, including male genitalia. This note highlights the need for studies of the behavior of genitalia, and describes two promising techniques, using a tsetse fly as an example. Observations of this species revealed otherwise cryptic, highly rhythmic and forceful thrusting, pinching, pressing, and scraping movements by the male’s genitalia within the female’s body that have no obvious relation to sperm transfer. Thus even though on the outside the male`s body is nearly motionless during long lapses during copulation, the female is subject to a barrage of possible stimulation from his genitalia during copulation. Similar studies are needed in other groups to understand the functional significance of genital morphology.Universidad de Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí