50 research outputs found
Design and construction of the asymptotic pavilion
Digital tools have made it easy to design freeform surfaces and structures. The challenges arise later in respect to planning and construction. Their realization often results in the fabrication of many unique and geometrically-complex building parts. Current research at the Chair of Structural Design investigates curve networks with repetitive geometric parameters in order to find new, fabrication-aware design methods. In this paper, we present a method to design doubly-curved grid structures with exclusively orthogonal joints from flat and straight strips. The strips are oriented upright on the underlying surface, hence normal loads can be transferred via bending around their strong axis. This is made possible by using asymptotic curve networks on minimal surfaces 1, 2. This new construction method was tested in several prototypes from timber and steel. Our goal is to build a largescale (9x12m) research pavilion as an exhibition and gathering space for the Structural Membranes Conference in Munich. In this paper, we present the geometric fundamentals, the design and modelling process, fabrication and assembly, as well as the structural analysis based on the Finite Element Method of this research pavilion
Haystack: a panoptic scene graph dataset to evaluate rare predicate classes
Current scene graph datasets suffer from strong long-tail distributions of their predicate classes. Due to a very low number of some predicate classes in the test sets, no reliable metrics can be retrieved for the rarest classes. We construct a new panoptic scene graph dataset and a set of metrics that are designed as a benchmark for the predictive performance especially on rare predicate classes. To construct the new dataset, we propose a model-assisted annotation pipeline that efficiently finds rare predicate classes that are hidden in a large set of images like needles in a haystack. Contrary to prior scene graph datasets, Haystack contains explicit negative annotations, i.e. annotations that a given relation does not have a certain predicate class. Negative annotations are helpful especially in the field of scene graph generation and open up a whole new set of possibilities to improve current scene graph generation models. Haystack is 100% compatible with existing panoptic scene graph datasets and can easily be integrated with existing evaluation pipelines. Our dataset and code can be found here: https://lorjul.github.io/haystack/. It includes annotation files and simple to use scripts and utilities, to help with integrating our dataset in existing work
Haystack: A Panoptic Scene Graph Dataset to Evaluate Rare Predicate Classes
Current scene graph datasets suffer from strong long-tail distributions of
their predicate classes. Due to a very low number of some predicate classes in
the test sets, no reliable metrics can be retrieved for the rarest classes. We
construct a new panoptic scene graph dataset and a set of metrics that are
designed as a benchmark for the predictive performance especially on rare
predicate classes. To construct the new dataset, we propose a model-assisted
annotation pipeline that efficiently finds rare predicate classes that are
hidden in a large set of images like needles in a haystack.
Contrary to prior scene graph datasets, Haystack contains explicit negative
annotations, i.e. annotations that a given relation does not have a certain
predicate class. Negative annotations are helpful especially in the field of
scene graph generation and open up a whole new set of possibilities to improve
current scene graph generation models.
Haystack is 100% compatible with existing panoptic scene graph datasets and
can easily be integrated with existing evaluation pipelines. Our dataset and
code can be found here: https://lorjul.github.io/haystack/. It includes
annotation files and simple to use scripts and utilities, to help with
integrating our dataset in existing work
Locally Anisotropic Wormholes and Flux Tubes in 5D Gravity
In this article we examine a class of wormhole and flux tube like solutions
to 5D vacuum Einstein equations. These solutions possess generic local
anisotropy, and their local isotropic limit is shown to be conformally
equivalent to the spherically symmetric 5D solutions of gr-qc/9807086. The
anisotropic solutions investigated here have two physically distinct
signatures: First, they can give rise to angular-dependent, anisotropic
``electromagnetic'' interactions. Second, they can result in a gravitational
running of the ``electric'' and ``magnetic'' charges of the solutions. This
gravitational running of the electromagnetic charges is linear rather than
logarithmic, and could thus serve as an indirect signal for the presence of
higher dimensions. The local anisotropy of these solutions is modeled using the
technique of anholonomic frames with respect to which the metrics are
diagonalized. If holonomic coordinates frames were used then such metrics would
have off-diagonal components.Comment: 14 pages, revtex, references added, extra section added giving
physical motivation for the solutions. To be published in PL
Understanding and controlling filamentous growth of fungal cell factories: Novel tools and opportunities for targeted morphology engineering
Filamentous fungal cell factories are efficient producers of platform chemicals, proteins, enzymes and natural products. Stirred-tank bioreactors up to a scale of several hundred m³ are commonly used for their cultivation. Fungal hyphae self-assemble into various cellular macromorphologies ranging from dispersed mycelia, loose clumps, to compact pellets. Development of these macromorphologies is so far unpredictable but strongly impacts productivities of fungal bioprocesses. Depending on the strain and the desired product, the morphological forms vary, but no strain- or product-related correlations currently exist to improve process understanding of fungal production systems. However, novel genomic, genetic, metabolic, imaging and modelling tools have recently been established that will provide fundamental new insights into filamentous fungal growth and how it is balanced with product formation. In this primer, these tools will be highlighted and their revolutionary impact on rational morphology engineering and bioprocess control will be discussed.DFG, 315305620, Untersuchung des Einflusses von Scherkräften auf das morphogenetische Gennetzwerk, die Zellintegrität, mikroskopische und makroskopische Morphologie von Aspergillus niger sowie Bildungsraten intra- und extrazellulärer ProdukteDFG, 315384307, Verallgemeinerte morphologische Modellierung aggregierender, filamentöser MikroorganismenDFG, 315457657, Untersuchung und Modellierung der mechanischen und Oberflächen-induzierten Beanspruchung von Pellets filamentöser Mikroorganismen am Beispiel von Lechevalieria aerocolonigenesTU Berlin, Open-Access-Mittel – 202
Individual regional associations between Aβ-, tau- and neurodegeneration (ATN) with microglial activation in patients with primary and secondary tauopathies
& beta;-amyloid (A & beta;) and tau aggregation as well as neuronal injury and atrophy (ATN) are the major hallmarks of Alzheimer's disease (AD), and biomarkers for these hallmarks have been linked to neuroinflammation. However, the detailed regional associations of these biomarkers with microglial activation in individual patients remain to be elucidated. We investigated a cohort of 55 patients with AD and primary tauopathies and 10 healthy controls that underwent TSPO-, A & beta;-, tau-, and perfusion-surrogate-PET, as well as structural MRI. Z-score deviations for 246 brain regions were calculated and biomarker contributions of A & beta;(A), tau (T), perfusion (N1), and gray matter atrophy (N2) to microglial activation (TSPO, I) were calculated for each individual subject. Individual ATN-related microglial activation was correlated with clinical performance and CSF soluble TREM2 (sTREM2) concentrations. In typical and atypical AD, regional tau was stronger and more frequently associated with microglial activation when compared to regional A & beta;(AD: & beta;(T) = 0.412 & PLUSMN;0.196 vs. & beta;(A) = 0.142 & PLUSMN;0.123, p < 0.001;AD-CBS: & beta;(T) = 0.385 & PLUSMN;0.176 vs. & beta;(A) = 0.131 & PLUSMN;0.186, p = 0.031). The strong association between regional tau and microglia reproduced well in primary tauopathies (& beta;(T) = 0.418 & PLUSMN;0.154). Stronger individual associations between tau and microglial activation were associated with poorer clinical performance. In patients with 4RT, sTREM2 levels showed a positive association with tau-related microglial activation. Tau pathology has strong regional associations with microglial activation in primary and secondary tauopathies. Tau and A & beta;related microglial response indices may serve as a two-dimensional in vivo assessment of neuroinflammation in neurodegenerative diseases
Individual regional associations between Aβ-, tau- and neurodegeneration (ATN) with microglial activation in patients with primary and secondary tauopathies.
β-amyloid (Aβ) and tau aggregation as well as neuronal injury and atrophy (ATN) are the major hallmarks of Alzheimer's disease (AD), and biomarkers for these hallmarks have been linked to neuroinflammation. However, the detailed regional associations of these biomarkers with microglial activation in individual patients remain to be elucidated. We investigated a cohort of 55 patients with AD and primary tauopathies and 10 healthy controls that underwent TSPO-, Aβ-, tau-, and perfusion-surrogate-PET, as well as structural MRI. Z-score deviations for 246 brain regions were calculated and biomarker contributions of Aβ (A), tau (T), perfusion (N1), and gray matter atrophy (N2) to microglial activation (TSPO, I) were calculated for each individual subject. Individual ATN-related microglial activation was correlated with clinical performance and CSF soluble TREM2 (sTREM2) concentrations. In typical and atypical AD, regional tau was stronger and more frequently associated with microglial activation when compared to regional Aβ (AD: βT = 0.412 ± 0.196 vs. βA = 0.142 ± 0.123, p < 0.001; AD-CBS: βT = 0.385 ± 0.176 vs. βA = 0.131 ± 0.186, p = 0.031). The strong association between regional tau and microglia reproduced well in primary tauopathies (βT = 0.418 ± 0.154). Stronger individual associations between tau and microglial activation were associated with poorer clinical performance. In patients with 4RT, sTREM2 levels showed a positive association with tau-related microglial activation. Tau pathology has strong regional associations with microglial activation in primary and secondary tauopathies. Tau and Aβ related microglial response indices may serve as a two-dimensional in vivo assessment of neuroinflammation in neurodegenerative diseases