198 research outputs found
Electrooptical Determination of Polarizability for On-Line Viability and Vitality Quantification of Lactobacillus plantarum Cultures
The rapid assessment of cell viability is crucial for process optimization, e.g., during media selection, determination of optimal environmental growth conditions and for quality control. In the present study, the cells' electric anisotropy of polarizability (AP) as well as the mean cell length in Lactobacillus plantarum batch and fed-batch fermentations were monitored with electrooptical measurements coupled to fully automated sample preparation. It was examined, whether this measurement can be related to the cells' metabolic activity, and thus represents a suitable process analytical technology. It is demonstrated that the AP is an early indicator to distinguish between suitable and unsuitable growth conditions in case of a poor energy regeneration or cell membrane defects in L. plantarum batch and fed-batch cultivations. It was shown that the applied method allowed the monitoring of physiological and morphological changes of cells in various growth phases in response to a low pH-value, substrate concentration changes, temperature alterations, exposure to air and nutrient limitation. An optimal range for growth in batch mode was achieved, if the AP remained above 25·10−28 F·m2 and the mean cell length at ~2.5 μm. It was further investigated, in which way the AP develops after freeze-drying of samples, which were taken in different cultivation phases. It was found that the AP increased most rapidly in resuspended samples from the retardation and late stationary phases, while samples from the early stationary phase recovered slowly. Electrooptical measurements provide valuable information about the physiologic and morphologic state of L. plantarum cells, e.g., when applied as starter cultures or as probiotic compounds.DFG, 325093850, Open Access Publizieren 2017 - 2018 / Technische Universität BerlinEC/H2020/643056/EU/Rapid Bioprocess Development/Biorapi
p-adaptive discontinuous Galerkin method for the shallow water equations on heterogeneous computing architectures
Heterogeneous computing and exploiting integrated CPU-GPU architectures has
become a clear current trend since the flattening of Moore's Law. In this work,
we propose a numerical and algorithmic re-design of a p-adaptive
quadrature-free discontinuous Galerkin method (DG) for the shallow water
equations (SWE). Our new approach separates the computations of the
non-adaptive (lower-order) and adaptive (higher-order) parts of the
discretization form each other. Thereby, we can overlap computations of the
lower-order and the higher-order DG solution components. Furthermore, we
investigate execution times of main computational kernels and use automatic
code generation to optimize their distribution between the CPU and GPU. Several
setups, including a prototype of a tsunami simulation in a tide-driven flow
scenario, are investigated, and the results show that significant performance
improvements can be achieved in suitable setups
Buchbesprechungen aus Botanik und Naturschutz in Hessen Bd. 24
Es werden folgende Publikationen rezensiert: Chytrý: Vegetation of the Czech Republic 1, Chytrý: Vegetation of the Czech Republic 2, Chytrý: Vegetation of the Czech Republic 3, Eger & Kesper: Flechten zwischen Eder und Diemel, Gerster: Kräuterwissen, Meyer: Pflanzen Nordhessens, Mollenhauer: Gregor Kraus, Seibold: Schmeil-Fitschen, Suck & Bushart: Karte der Potentiellen Natürlichen Vegetation Deutschlands, Süß & al.: Ried und Sand
LUBAC assembles a ubiquitin signaling platform at mitochondria for signal amplification and transport of NF-κB to the nucleus
Mitochondria are increasingly recognized as cellular hubs to orchestrate signaling pathways that regulate metabolism, redox homeostasis, and cell fate decisions. Recent research revealed a role of mitochondria also in innate immune signaling; however, the mechanisms of how mitochondria affect signal transduction are poorly understood. Here, we show that the NF-κB pathway activated by TNF employs mitochondria as a platform for signal amplification and shuttling of activated NF-κB to the nucleus. TNF treatment induces the recruitment of HOIP, the catalytic component of the linear ubiquitin chain assembly complex (LUBAC), and its substrate NEMO to the outer mitochondrial membrane, where M1- and K63-linked ubiquitin chains are generated. NF-κB is locally activated and transported to the nucleus by mitochondria, leading to an increase in mitochondria-nucleus contact sites in a HOIP-dependent manner. Notably, TNF-induced stabilization of the mitochondrial kinase PINK1 furthermore contributes to signal amplification by antagonizing the M1-ubiquitin-specific deubiquitinase OTULIN. Overall, our study reveals a role for mitochondria in amplifying TNF-mediated NF-κB activation, both serving as a signaling platform, as well as a transport mode for activated NF-κB to the nuclear
NEMO reshapes the α-Synuclein aggregate interface and acts as an autophagy adapter by co-condensation with p62
NEMO is a ubiquitin-binding protein which regulates canonical NF-kappa B pathway activation in innate immune signaling, cell death regulation and host-pathogen interactions. Here we identify an NF-kappa B-independent function of NEMO in proteostasis regulation by promoting autophagosomal clearance of protein aggregates. NEMO-deficient cells accumulate misfolded proteins upon proteotoxic stress and are vulnerable to proteostasis challenges. Moreover, a patient with a mutation in the NEMO-encoding IKBKG gene resulting in defective binding of NEMO to linear ubiquitin chains, developed a widespread mixed brain proteinopathy, including alpha-synuclein, tau and TDP-43 pathology. NEMO amplifies linear ubiquitylation at alpha-synuclein aggregates and promotes the local concentration of p62 into foci. In vitro, NEMO lowers the threshold concentrations required for ubiquitin-dependent phase transition of p62. In summary, NEMO reshapes the aggregate surface for efficient autophagosomal clearance by providing a mobile phase at the aggregate interphase favoring co-condensation with p62. Selective autophagy helps to degrade aggregated proteins accumulating in neurodegenerative diseases. Here, the authors show that NEMO, a ubiquitin binding protein previously linked to innate immune signaling, is recruited to misfolded proteins and promotes their autophagic clearance by forming condensates with the autophagy receptor p62
Effects of pulsed electric field on the viscoelastic properties of potato tissue
We have investigated whether transient permeabilization caused by the application of pulsed electric field would give rise to transient changes in the potato tissue viscoelastic properties. Potato tissue was subjected to nominal field strengths (E) ranging from 30 to 500 V/cm, with a single rectangular pulse of 10−5, 10−4, or 10−3 s. The changes on the viscoelastic properties of potato tissue during pulsed electric fields (PEF) were monitored through small amplitude oscillatory dynamic rheological measurements. The elastic (G′) and viscous moduli (G″) were measured every 30 s after the delivery of the pulse and the loss tangent change (tan-δ) was calculated. The results were correlated with measurements of changes on electrical resistance during the delivery of the pulse. Results show a drastic increase of tan-δ in the first 30 s after the application of the pulse, followed by a decrease 1 min after pulsation. This response is strongly influenced by pulsing conditions and is independent of the total permeabilization achieved by the pulse. Our results, supported by similar measurements on osmotically dehydrated control samples, clearly show that PEF causes a rapid change of the viscoelastic properties of the tissue that could be attributed to a partial loss in turgor pressure. This would be an expected consequence of electroporation. The recovery of tan-δ to values similar to those before pulsation strongly suggests recovery of cell membrane properties and turgor, pointing at reversible permeabilization of the cells. A slight increase of stiffness traduced by a negative change of tan-δ after application of certain PEF conditions may also give an indication of events occurring on cell wall structure due to stress responses. This study set the basis for further investigations on the complex cell stress physiology involving both cell membrane functional properties and cell wall structure that would influence tissue physical properties upon PEF application.Fundação para a Ciência e a Tecnologia (FCT
Fine Mapping of Genetic Variants in BIN1, CLU, CR1 and PICALM for Association with Cerebrospinal Fluid Biomarkers for Alzheimer's Disease
Recent genome-wide association studies of Alzheimer's disease (AD) have identified variants in BIN1, CLU, CR1 and PICALM that show replicable association with risk for disease. We have thoroughly sampled common variation in these genes, genotyping 355 variants in over 600 individuals for whom measurements of two AD biomarkers, cerebrospinal fluid (CSF) 42 amino acid amyloid beta fragments (Aβ42) and tau phosphorylated at threonine 181 (ptau181), have been obtained. Association analyses were performed to determine whether variants in BIN1, CLU, CR1 or PICALM are associated with changes in the CSF levels of these biomarkers. Despite adequate power to detect effects as small as a 1.05 fold difference, we have failed to detect evidence for association between SNPs in these genes and CSF Aβ42 or ptau181 levels in our sample. Our results suggest that these variants do not affect risk via a mechanism that results in a strong additive effect on CSF levels of Aβ42 or ptau181
Relationship of work schedules to gastrointestinal diagnoses, symptoms, and medication use in auto factory workers
Background Gastrointestinal (GI) complaints are common in shift workers. This study examines the relationship between work schedules and GI symptoms, medications, and diagnoses. Methods In a cross-sectional survey of 343 US auto factory workers, four work schedule variables were examined: assigned shift, number of hours worked, number of night hours, and schedule variability. Multiple regression tested the relationship between GI outcomes and work schedule variables while controlling for covariates. Results The evening shift was associated with more GI symptoms and GI diagnoses. Unexpectedly, more consistent work times were associated with having a GI diagnosis. As schedule variability increased the probability of GI medication use increased in low noise exposure. Conclusion Findings suggest that evening shift and widely varying work start and end times may increase risks for GI disturbances. Am. J. Ind. Med. 46:586–598, 2004. © 2004 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34826/1/20099_ftp.pd
- …