248 research outputs found
Visual analytics methods for shape analysis of biomedical images exemplified on rodent skull morphology
In morphometrics and its application fields like medicine and biology experts are interested in causal relations of variation in organismic shape to phylogenetic, ecological, geographical, epidemiological or disease factors - or put more succinctly by Fred L. Bookstein, morphometrics is "the study of covariances of biological form". In order to reveal causes for shape variability, targeted statistical analysis correlating shape features against external and internal factors is necessary but due to the complexity of the problem often not feasible in an automated way. Therefore, a visual analytics approach is proposed in this thesis that couples interactive visualizations with automated statistical analyses in order to stimulate generation and qualitative assessment of hypotheses on relevant shape features and their potentially affecting factors. To this end long established morphometric techniques are combined with recent shape modeling approaches from geometry processing and medical imaging, leading to novel visual analytics methods for shape analysis. When used in concert these methods facilitate targeted analysis of characteristic shape differences between groups, co-variation between different structures on the same anatomy and correlation of shape to extrinsic attributes. Here a special focus is put on accurate modeling and interactive rendering of image deformations at high spatial resolution, because that allows for faithful representation and communication of diminutive shape features, large shape differences and volumetric structures. The utility of the presented methods is demonstrated in case studies conducted together with a collaborating morphometrics expert. As exemplary model structure serves the rodent skull and its mandible that are assessed via computed tomography scans
Baseline exposure, antibody subclass, and hepatitis B response differentially affect malaria protective immunity following RTS,S/AS01E vaccination in African children
Background: The RTS,S/AS01E vaccine provides partial protection against malaria in African children, but immune
responses have only been partially characterized and do not reliably predict protective efficacy. We aimed to
evaluate comprehensively the immunogenicity of the vaccine at peak response, the factors affecting it, and the
antibodies associated with protection against clinical malaria in young African children participating in the multicenter
phase 3 trial for licensure.
Methods: We measured total IgM, IgG, and IgG1–4 subclass antibodies to three constructs of the Plasmodium falciparum
circumsporozoite protein (CSP) and hepatitis B surface antigen (HBsAg) that are part of the RTS,S vaccine, by quantitative
suspension array technology. Plasma and serum samples were analyzed in 195 infants and children from two sites in
Ghana (Kintampo) and Mozambique (Manhiça) with different transmission intensities using a case-control study design.
We applied regression models and machine learning techniques to analyze immunogenicity, correlates of protection, and
factors affecting them.
Results: RTS,S/AS01E induced IgM and IgG, predominantly IgG1 and IgG3, but also IgG2 and IgG4, subclass responses.
Age, site, previous malaria episodes, and baseline characteristics including antibodies to CSP and other antigens reflecting
malaria exposure and maternal IgGs, nutritional status, and hemoglobin concentration, significantly affected vaccine
immunogenicity. We identified distinct signatures of malaria protection and risk in RTS,S/AS01E but not in comparator
vaccinees. IgG2 and IgG4 responses to RTS,S antigens post-vaccination, and anti-CSP and anti-P. falciparum antibody levels
pre-vaccination, were associated with malaria risk over 1-year follow-up. In contrast, antibody responses to HBsAg (all
isotypes, subclasses, and timepoints) and post-vaccination IgG1 and IgG3 to CSP C-terminus and NANP were associated
with protection. Age and site affected the relative contribution of responses in the correlates identified. Conclusions: Cytophilic IgG responses to the C-terminal and NANP repeat regions of CSP and anti-HBsAg antibodies
induced by RTS,S/AS01E vaccination were associated with malaria protection. In contrast, higher malaria exposure at
baseline and non-cytophilic IgG responses to CSP were associated with disease risk. Data provide new correlates of
vaccine success and failure in African children and reveal key insights into the mode of action that can guide
development of more efficacious next-generation vaccines
Introduction to Surface Avatar: the First Heterogeneous Robotic Team to be Commanded with Scalable Autonomy from the ISS
Robotics is vital to the continued development toward Lunar and Martian exploration, in-situ resource utilization, and surface infrastructure construction. Large-scale extra-terrestrial missions will require teams of robots with different, complementary capabilities, together with a powerful, intuitive user interface for effective commanding. We introduce Surface Avatar, the newest ISS-to-Earth telerobotic experiment series, to be conducted in 2022-2024. Spearheaded by DLR, together with ESA, Surface Avatar builds on expertise on commanding robots with different levels of autonomy from our past telerobotic experiments: Kontur-2, Haptics, Interact, SUPVIS Justin, and Analog-1. A team of four heterogeneous robots in a multi-site analog environment at DLR are at the command of a crew member on the ISS. The team has a humanoid robot for dexterous object handling, construction and maintenance; a rover for long traverses and sample acquisition; a quadrupedal robot for scouting and exploring difficult terrains; and a lander with robotic arm for component delivery and sample stowage. The crew's command terminal is multimodal, with an intuitive graphical user interface, 3-DOF joystick, and 7-DOF input device with force-feedback. The autonomy of any robot can be scaled up and down depending on the task and the astronaut's preference: acting as an avatar of the crew in haptically-coupled telepresence, or receiving task-level commands like an intelligent co-worker. Through crew performing collaborative tasks in exploration and construction scenarios, we hope to gain insight into how to optimally command robots in a future space mission. This paper presents findings from the first preliminary session in June 2022, and discusses the way forward in the planned experiment sessions
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