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#q

1 post1 participant0 posts today
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mʕ•ﻌ•ʔm bitPickup

@edit
Testpost um zu sehen ob und wie die Forumfunktion funkt.

@ jemensch will einen #friendica Server aufsetzten und der Text:
tupambae.org/display/0ac89072-
.. braucht "Verständnissfeedback" von Dritten.

Wenn @ jemensch dem Profil @ edit folgt und dann ein Thema Instalationsnotizen #Q&A anfängt, @ edit erwaehnt und auch in das verwiesene Thema direkt in die spezifischen Schritte reinkommentiert dann könnte das Reichen um das Thema zu veröffentlichen. Die v.05 ist jetzt auch schon ein Jahr alt ..

tupambae.orgVer. 05 | install and/or move friendica to ubuntu 22.04 LTS VPS serverEDIT - informationThis tutorial is supposed to be published by the tutorial profile of this server. It is designed to have several chapters, each being disti...
Public
The Propaganda Site

Soul, funk, and pop come together seamlessly in Q's sweet and tuneful songs that are coupled with his smooth voice and strong, nuanced delivery.

Find out more about his music at thepropagandasite.com/artist/q

Q
the PROPAGANDA siteQ | the PROPAGANDA siteQ Marsden (who goes by first name alone) is a singer, songwriter from Browder County, Florida, who currently plays retro soul with pop and funk connections. He roams the pop and soul world of the '80s, drawing inspiration from artists like Quincy Jones, Michael Jackson, and Prince all at their funkiest peaks. And he achieves this effect not only as a matter of arrangement and delivery, but also by somehow channelling the way the melodies feel. His previous work, on the other hand, was mostly in the alternative R&B universe with an obvious affection for lounge jazz, a low-key occasional Latin-flavored acoustic guitar, and dream pop tones lurking underneath the surface. He moved away from that on 2023's Soul, PRESENT, fully embracing a classic pop oriented soul sound complete with a lovely falsetto.
#music#musicdiscovery#tPsThrowback
Public
Rxiv mechanobio

📰 "Using Label-Free Raman Spectroscopy Integrated with Microfluidic Chips to Probe Ferroptosis Networks in Cells"
arxiv.org/abs/2503.04777 #Physics.Bio-Ph #Mechanical #Q-Bio.Cb #Cell

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arXiv.orgUsing Label-Free Raman Spectroscopy Integrated with Microfluidic Chips to Probe Ferroptosis Networks in CellsFerroptosis, a regulated form of cell death driven by oxidative stress and lipid peroxidation, has emerged as a pivotal research focus with implications across various cellular contexts. In this study, we employed a multifaceted approach, integrating label-free Raman spectroscopy and microfluidics to study the mechanisms underpinning ferroptosis. Our investigations included the ferroptosis initiation based on the changes in the lipid Raman band at 1436 cm-1 under different cellular states, the generation of reactive oxygen species (ROS), lipid peroxidation, DNA damage/repair, and mitochondrial dysfunction. Importantly, our work highlighted the dynamic role of vital cellular components, such as NADPH, ferredoxin clusters, and key genes like GPX-4, VDAC2, and NRF2, as they collectively influenced cellular responses to redox imbalance and oxidative stress. Quantum mechanical (QM) and molecular docking simulations (MD) provided further evidence of interactions between the ferredoxin (containing 4Fe-4S clusters), NADPH and ROS which led to the production of reactive Fe species in the cells. As such, our approach offered a real-time, multidimensional perspective on ferroptosis, surpassing traditional biological methods, and providing valuable insights for therapeutic interventions in diverse biomedical contexts.
Public
Rxiv mechanobio

📰 "Electron spin dynamics guide cell motility"
arxiv.org/abs/2503.02923 #Physics.Bio-Ph #Mechanical #Dynamics #Quant-Ph #Q-Bio.Cb #Cell

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arXiv.orgElectron spin dynamics guide cell motilityDiverse organisms exploit the geomagnetic field (GMF) for migration. Migrating birds employ an intrinsically quantum mechanical mechanism for detecting the geomagnetic field: absorption of a blue photon generates a radical pair whose two electrons precess at different rates in the magnetic field, thereby sensitizing cells to the direction of the GMF. In this work, using an in vitro injury model, we discovered a quantum-based mechanism of cellular migration. Specifically, we show that migrating cells detect the GMF via an optically activated, electron spin-based mechanism. Cell injury provokes acute emission of blue photons, and these photons sensitize muscle progenitor cells to the magnetic field. We show that the magnetosensitivity of muscle progenitor cells is (a) activated by blue light, but not by green or red light, and (b) disrupted by the application of an oscillatory field at the frequency corresponding to the energy of the electron-spin/magnetic field interaction. A comprehensive analysis of protein expression reveals that the ability of blue photons to promote cell motility is mediated by activation of calmodulin calcium sensors. Collectively, these data suggest that cells possess a light-dependent magnetic compass driven by electron spin dynamics.
Public
Rxiv mechanobio

📰 "Intercellular contact is sufficient to drive Fibroblast to Myofibroblast transitions"
arxiv.org/abs/2503.01834 #Extracellular #Mechanical #Q-Bio.Cb

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arXiv.orgIntercellular contact is sufficient to drive Fibroblast to Myofibroblast transitionsFibroblast cells play a key role in maintaining the extracellular matrix. During wound healing, fibroblasts differentiate into highly contractile myofibroblasts, which secrete extracellular matrix proteins like collagen to facilitate tissue repair. Under normal conditions, myofibroblasts undergo programmed cell death after healing to prevent excessive scar formation. However, in diseases like fibrosis, the myofibroblasts remain active even after the wound is closed, resulting in excessive collagen buildup and a stiff, fibrotic matrix. The reasons for the persistence of myofibroblasts in fibrosis are not well understood. Here we show the existence of a mechanism where direct physical contact between a fibroblast and a myofibroblast is sufficient for fibroblasts to transition into myofibroblasts. We show that fibroblast-myofibroblast transition can occur even in the absence of known biochemical cues such as growth factor activation or mechanical cues from a stiff, fibrotic matrix. Further, we show that contact-based fibroblast-myofibroblast activation can be blocked by Gαq/11/14 inhibitor FR9003591, which inhibits the formation of myofibroblasts. These findings offer new insights into the persistence of fibrosis despite therapeutic interventions and suggest a potential strategy to target fibroblast-to-myofibroblast transition in fibrosis.
Public
Rxiv mechanobio

📰 "How human-derived brain organoids are built differently from brain organoids derived from genetically-close relatives: A multi-scale hypothesis"
arxiv.org/abs/2304.08622 #Cond-Mat.Soft #Mechanical #Q-Bio.To #Cell

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arXiv.orgHow human-derived brain organoids are built differently from brain organoids derived from genetically-close relatives: A multi-scale hypothesisHow genes affect tissue scale organization remains a longstanding biological puzzle. As experimental efforts aim to quantify gene expression, chromatin organization, cellular structure, and tissue structure, computational modeling lags behind. To address this gap, we merge a cellular-based tissue model with a nuclear model that includes a deformable lamina shell and chromatin to test multiscale hypotheses linking chromatin and tissue scales. We propose a multiscale hypothesis focusing on brain organoids to explain structural differences between brain organoids built from induced-pluripotent human stem cells and induced-pluripotent gorilla and chimpanzee cells. Recent experiments discover that a cell fate transition from neuroepithelial to radial glial cells includes a new intermediate state delayed in human organoids, which narrows and lengthens cells on the apical side. Experiments show that the transcription factor ZEB2 plays a major role in the emergence of this intermediate state with ZEB2 mRNA levels peaking. We postulate that the enhancement of ZEB2 expression is potentially due to chromatin reorganization in response to mechanical deformations of the nucleus. A larger critical mechanical strain triggers reorganization in human-derived stem cells, causing delayed ZEB2 upregulation compared with genetically close relatives. We test this by exploring how slightly different initial configurations of chromatin reorganize under applied strain, with greater representing less genetically-close relatives. We find that larger configuration discrepancies produce increased differences in the magnitude of chromatin displacement that rise faster than linearly yet slower than exponentially. Changes in chromatin strain and contact maps can reveal species-specific differences, aiding our understanding of how one species differs in structure from another.
Public
Rxiv mechanobio

📰 "Engineering morphogenesis of cell clusters with differentiable programming"
arxiv.org/abs/2407.06295 #Morphogenesis #Mechanical #Q-Bio.Cb #Cs.Lg #Cell

arXiv logo
arXiv.orgEngineering morphogenesis of cell clusters with differentiable programmingUnderstanding the rules underlying organismal development is a major unsolved problem in biology. Each cell in a developing organism responds to signals in its local environment by dividing, excreting, consuming, or reorganizing, yet how these individual actions coordinate over a macroscopic number of cells to grow complex structures with exquisite functionality is unknown. Here we use recent advances in automatic differentiation to discover local interaction rules and genetic networks that yield emergent, systems-level characteristics in a model of development. We consider a growing tissue with cellular interactions mediated by morphogen diffusion, cell adhesion and mechanical stress. Each cell has an internal genetic network that is used to make decisions based on the cell's local environment. We show that one can learn the parameters governing cell interactions in the form of interpretable genetic networks for complex developmental scenarios, including directed axial elongation, cell type homeostasis via chemical signaling and homogenization of growth via mechanical stress. When combined with recent experimental advances measuring spatio-temporal dynamics and gene expression of cells in a growing tissue, the methodology outlined here offers a promising path to unraveling the cellular bases of development.
Public
Rxiv mechanobio

📰 "MIML: Multiplex Image Machine Learning for High Precision Cell Classification via Mechanical Traits within Microfluidic Systems"
arxiv.org/abs/2309.08421 #Mechanical #Q-Bio.Qm #Eess.Iv #Cs.Cv #Cs.Lg #Cell

arXiv.orgMIML: Multiplex Image Machine Learning for High Precision Cell Classification via Mechanical Traits within Microfluidic SystemsLabel-free cell classification is advantageous for supplying pristine cells for further use or examination, yet existing techniques frequently fall short in terms of specificity and speed. In this study, we address these limitations through the development of a novel machine learning framework, Multiplex Image Machine Learning (MIML). This architecture uniquely combines label-free cell images with biomechanical property data, harnessing the vast, often underutilized morphological information intrinsic to each cell. By integrating both types of data, our model offers a more holistic understanding of the cellular properties, utilizing morphological information typically discarded in traditional machine learning models. This approach has led to a remarkable 98.3\% accuracy in cell classification, a substantial improvement over models that only consider a single data type. MIML has been proven effective in classifying white blood cells and tumor cells, with potential for broader application due to its inherent flexibility and transfer learning capability. It's particularly effective for cells with similar morphology but distinct biomechanical properties. This innovative approach has significant implications across various fields, from advancing disease diagnostics to understanding cellular behavior.
Public
Rxiv mechanobio

📰 "Hierarchical poromechanical approach to investigate the impact of mechanical loading on human skin micro-circulation"
arxiv.org/abs/2502.17354 #Physics.App-Ph #Mechanical #Q-Bio.To #Cs.Ce #Cell

arXiv.orgHierarchical poromechanical approach to investigate the impact of mechanical loading on human skin micro-circulationResearch on human skin anatomy reveals its complex multi-scale, multi-phase nature, with up to 70% of its composition being bounded and free water. Fluid movement plays a key role in the skin's mechanical and biological responses, influencing its time-dependent behavior and nutrient transport. Poroelastic modeling is a promising approach for studying skin dynamics across scales by integrating multi-physics processes. This paper introduces a hierarchical two-compartment model capturing fluid distribution in the interstitium and micro-circulation. A theoretical framework is developed with a biphasic interstitium -- distinguishing interstitial fluid and non-structural cells -- and analyzed through a one-dimensional consolidation test of a column. This biphasic approach allows separate modeling of cell and fluid motion, considering their differing characteristic times. An appendix discusses extending the model to include biological exchanges like oxygen transport. Preliminary results indicate that cell viscosity introduces a second characteristic time, and at high viscosity and short time scales, cells behave similarly to solids. A simplified model was used to replicate an experimental campaign on short time scales. Local pressure (up to 31 kPa) was applied to dorsal finger skin using a laser Doppler probe PF801 (Perimed Sweden), following a setup described in Fromy Brain Res (1998). The model qualitatively captured ischemia and post-occlusive reactive hyperemia, aligning with experimental data. All numerical simulations used the open-source software FEniCSx v0.9.0. To ensure transparency and reproducibility, anonymized experimental data and finite element codes are publicly available on GitHub.
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