186 research outputs found
Semantically Informed Multiview Surface Refinement
We present a method to jointly refine the geometry and semantic segmentation
of 3D surface meshes. Our method alternates between updating the shape and the
semantic labels. In the geometry refinement step, the mesh is deformed with
variational energy minimization, such that it simultaneously maximizes
photo-consistency and the compatibility of the semantic segmentations across a
set of calibrated images. Label-specific shape priors account for interactions
between the geometry and the semantic labels in 3D. In the semantic
segmentation step, the labels on the mesh are updated with MRF inference, such
that they are compatible with the semantic segmentations in the input images.
Also, this step includes prior assumptions about the surface shape of different
semantic classes. The priors induce a tight coupling, where semantic
information influences the shape update and vice versa. Specifically, we
introduce priors that favor (i) adaptive smoothing, depending on the class
label; (ii) straightness of class boundaries; and (iii) semantic labels that
are consistent with the surface orientation. The novel mesh-based
reconstruction is evaluated in a series of experiments with real and synthetic
data. We compare both to state-of-the-art, voxel-based semantic 3D
reconstruction, and to purely geometric mesh refinement, and demonstrate that
the proposed scheme yields improved 3D geometry as well as an improved semantic
segmentation
Medium Cut-Off (MCO) Membranes Reduce Inflammation in Chronic Dialysis Patients—A Randomized Controlled Clinical Trial
Background To increase the removal of middle-sized uremic toxins a new
membrane with enhanced permeability and selectivity, called Medium Cut-Off
membrane (MCO-Ci) has been developed that at the same time ensures the
retention of albumin. Because many middle-sized substances may contribute to
micro-inflammation we hypothesized that the use of MCO-Ci influences the
inflammatory state in hemodialysis patients. Methods The randomized crossover
trial in 48 patients compared MCO-Ci dialysis to High-flux dialysis of 4 weeks
duration each plus 8 weeks extension phase. Primary endpoint was the gene
expression of TNF-α and IL-6 in peripheral blood mononuclear cells (PBMCs),
secondary endpoints were plasma levels of specified inflammatory mediators and
cytokines. Results After four weeks of MCO-Ci the expression of TNF-α mRNA
(Relative quantification (RQ) from 0.92 ± 0.34 to 0.75 ± 0.31, -18.5%,
p<0.001)-α and IL-6 mRNA (RQ from 0.78 ± 0.80 to 0.60 ± 0.43, -23.1%, p<0.01)
was reduced to a significantly greater extent than with High-flux dialyzers
(TNF mRNA-RQ: -14.3%; IL-6 mRNA-RQ: -3.5%). After retransformation of
logarithmically transformed data, measurements after MCO were reduced to 82%
of those after HF (95% CI 74%–91%). 4 weeks use of MCO-Ci resulted in long-
lasting change in plasma levels of several cytokines and other substances with
a significant decrease for sTNFR1, kappa and lambda free light chains, urea
and an increase for Lp-PLA2 (PLA2G7) compared to High-flux. Albumin levels
dropped significantly after 4 weeks of MCO dialysis but increased after
additional 8 weeks of MCO dialysis. Twelve weeks treatment with MCO-Ci was
well tolerated regarding the number of (S)AEs. In the extension period levels
of CRP, TNF-α-mRNA and IL-6 mRNA remained stable in High-flux as well as in
MCO-Ci. Conclusions MCO-Ci dialyzers modulate inflammation in chronic HD
patients to a greater extent compared to High-flux dialyzers. Transcription of
pro-inflammatory cytokines in peripheral leukocytes is markedly reduced and
removal of soluble mediators is enhanced with MCO dialysis. Serum albumin
concentrations stabilize after an initial drop. These results encourage
further trials with longer treatment periods and clinical endpoints
Drug Discovery under Covariate Shift with Domain-Informed Prior Distributions over Functions
Accelerating the discovery of novel and more effective therapeutics is an
important pharmaceutical problem in which deep learning is playing an
increasingly significant role. However, real-world drug discovery tasks are
often characterized by a scarcity of labeled data and significant covariate
shift\unicode{x2013}\unicode{x2013}a setting that poses a challenge to
standard deep learning methods. In this paper, we present Q-SAVI, a
probabilistic model able to address these challenges by encoding explicit prior
knowledge of the data-generating process into a prior distribution over
functions, presenting researchers with a transparent and probabilistically
principled way to encode data-driven modeling preferences. Building on a novel,
gold-standard bioactivity dataset that facilitates a meaningful comparison of
models in an extrapolative regime, we explore different approaches to induce
data shift and construct a challenging evaluation setup. We then demonstrate
that using Q-SAVI to integrate contextualized prior knowledge of drug-like
chemical space into the modeling process affords substantial gains in
predictive accuracy and calibration, outperforming a broad range of
state-of-the-art self-supervised pre-training and domain adaptation techniques.Comment: Published in the Proceedings of the 40th International Conference on
Machine Learning (ICML 2023
Maternal Diabetes Leads to Unphysiological High Lipid Accumulation in Rabbit Preimplantation Embryos
According to the "developmental origin of health and disease" hypothesis, the metabolic set points of glucose and lipid metabolism are determined prenatally. In the case of a diabetic pregnancy, the embryo is exposed to higher glucose and lipid concentrations as early as during preimplantation development. We used the rabbit to study the effect of maternal diabetes type 1 on lipid accumulation and expression of lipogenic markers in preimplantation blastocysts. Accompanied by elevated triglyceride and glucose levels in the maternal blood, embryos from diabetic rabbits showed a massive intracellular lipid accumulation and increased expression of fatty acid transporter 4, fatty acid-binding protein 4, perilipin/adipophilin, and maturation of sterol-regulated element binding protein. However, expression of fatty acid synthase, a key enzyme for de novo synthesis of fatty acids, was not altered in vivo. During a short time in vitro culture of rabbit blastocysts, the accumulation of lipid droplets and expression of lipogenic markers were directly correlated with increasing glucose concentration, indicating that hyperglycemia leads to increased lipogenesis in the preimplantation embryo. Our study shows the decisive effect of glucose as the determining factor for fatty acid metabolism and intracellular lipid accumulation in preimplantation embryos
Functionality of Two Origins of Replication in Vibrio cholerae Strains With a Single Chromosome
Chromosomal inheritance in bacteria usually entails bidirectional replication of a single chromosome from a single origin into two copies and subsequent partitioning of one copy each into daughter cells upon cell division. However, the human pathogen Vibrio cholerae and other Vibrionaceae harbor two chromosomes, a large Chr1 and a small Chr2. Chr1 and Chr2 have different origins, an oriC-type origin and a P1 plasmid-type origin, respectively, driving the replication of respective chromosomes. Recently, we described naturally occurring exceptions to the two-chromosome rule of Vibrionaceae: i.e., Chr1 and Chr2 fused single chromosome V. cholerae strains, NSCV1 and NSCV2, in which both origins of replication are present. Using NSCV1 and NSCV2, here we tested whether two types of origins of replication can function simultaneously on the same chromosome or one or the other origin is silenced. We found that in NSCV1, both origins are active whereas in NSCV2 ori2 is silenced despite the fact that it is functional in an isolated context. The ori2 activity appears to be primarily determined by the copy number of the triggering site, crtS, which in turn is determined by its location with respect to ori1 and ori2 on the fused chromosome
Resource-aware Research on Universe and Matter: Call-to-Action in Digital Transformation
Given the urgency to reduce fossil fuel energy production to make climate
tipping points less likely, we call for resource-aware knowledge gain in the
research areas on Universe and Matter with emphasis on the digital
transformation. A portfolio of measures is described in detail and then
summarized according to the timescales required for their implementation. The
measures will both contribute to sustainable research and accelerate scientific
progress through increased awareness of resource usage. This work is based on a
three-days workshop on sustainability in digital transformation held in May
2023.Comment: 20 pages, 2 figures, publication following workshop 'Sustainability
in the Digital Transformation of Basic Research on Universe & Matter', 30 May
to 2 June 2023, Meinerzhagen, Germany, https://indico.desy.de/event/3748
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