166 research outputs found
Multiphysics discovery with moving boundaries using Ensemble SINDy and Peridynamic Differential Operator
This study proposes a novel framework for learning the underlying physics of
phenomena with moving boundaries. The proposed approach combines Ensemble SINDy
and Peridynamic Differential Operator (PDDO) and imposes an inductive bias
assuming the moving boundary physics evolve in its own corotational coordinate
system. The robustness of the approach is demonstrated by considering various
levels of noise in the measured data using the 2D Fisher-Stefan model. The
confidence intervals of recovered coefficients are listed, and the
uncertainties of the moving boundary positions are depicted by obtaining the
solutions with the recovered coefficients. Although the main focus of this
study is the Fisher-Stefan model, the proposed approach is applicable to any
type of moving boundary problem with a smooth moving boundary front without a
mushy region. The code and data for this framework is available at:
https://github.com/alicanbekar/MB_PDDO-SINDy.Comment: 26 pages, 22 figures, submitted to Proceedings of the Royal Society
Ectopic splenic tissue in the testis: a case report
Splenogonadal fusion is a rare congenital anomaly that has been encountered in all age groups. It is defined as an abnormal connection between spleen and gonad or mesonephros derivatives. We report a case of splenogonadal fusion which was diagnosed incidentally in a 38-year-old man with a history of infertility. This rare entity should be considered in the differential diagnosis of testicular masses.Key Words: Splenogonadal fusion, testicular mass
Usability and Usefulness of Circularity Indicators for Manufacturing Performance Management
Advances in industrial digitalization present many opportunities for process and product data exploitation in manufacturing, unlocking new systemic measures of performance beyond a single machine, process, facility area and even beyond the factory gates. However, existing data models and manufacturing systems\u27 performance measures are still focused on productivity, quality and delivery time, which could potentially lead to an accelerated linear economy. To shift to more circular industrial systems, we need to identify and assess circularity opportunities in ways that align the goals of sustainable and industrial development. In this study, micro-level circular indicators were reviewed, selected, analysed and tested in a manufacturing company to evaluate their usability and usefulness to guide process improvements. The aim is to enable circular and eco-efficient solutions towards sustainable production systems. Usability and usefulness of the indicators are essential to their integration into established environmental and operations management systems. The main contribution of this study is in the identification of key features making circularity indicators usable and useful from a manufacturer\u27s perspective. The conclusion also suggests directions for further research on tools and methods to support circular manufacturing
Forebrain Engraftment by Human Glial Progenitor Cells Enhances Synaptic Plasticity and Learning in Adult Mice
SummaryHuman astrocytes are larger and more complex than those of infraprimate mammals, suggesting that their role in neural processing has expanded with evolution. To assess the cell-autonomous and species-selective properties of human glia, we engrafted human glial progenitor cells (GPCs) into neonatal immunodeficient mice. Upon maturation, the recipient brains exhibited large numbers and high proportions of both human glial progenitors and astrocytes. The engrafted human glia were gap-junction-coupled to host astroglia, yet retained the size and pleomorphism of hominid astroglia, and propagated Ca2+ signals 3-fold faster than their hosts. Long-term potentiation (LTP) was sharply enhanced in the human glial chimeric mice, as was their learning, as assessed by Barnes maze navigation, object-location memory, and both contextual and tone fear conditioning. Mice allografted with murine GPCs showed no enhancement of either LTP or learning. These findings indicate that human glia differentially enhance both activity-dependent plasticity and learning in mice.Video Abstrac
Drilled by the jet? XMM-Newton discovers a Compton-thick AGN in the GPS galaxy Mkn668
We report the XMM-Newton discovery of the first Compton-thick obscured AGN in
a Broad Line Radio Galaxy, the Gigahertz Peaked-Spectrum source Mkn668
(OQ+208). The remarkably flat 2-10 keV X-ray spectrum (observed photon index,
\Gamma ~ 0.7), alongside with a prominent iron K-alpha fluorescent emission
line, is a clear signature of a Compton-reflection dominated spectrum. Mkn688
represents a remarkable example of discrepancy between X-ray spectral
properties and optical classification, as its optical spectrum is characterized
by broad and asymmetric Balmer lines. The obscuring matter is constrained to be
located within the radio hotspots, in turn separated by about 10 pc. If the
jets are piercing their way through a Compton-thick medium pervading the
nuclear environment, one could be largely underestimating the radio activity
dynamical age determined from the observed hotspot recession velocity. The soft
X-ray spectrum is dominated by a much steeper component, which may be due to
nuclear continuum electron scattering, or inverse Compton of the - remarkably
large - far infrared emission. Soft X-rays are suppressed by a further
Compton-thin (N_H ~ 10^21/cm/cm) absorbing system, that we identify with matter
responsible for free-free absorption of the radio lobes.Comment: 11 pages, 7 figures, To appear in Astronomy & Astrophysic
Optogenetics and deep brain stimulation neurotechnologies
Brain neural network is composed of densely packed, intricately wired neurons whose activity patterns ultimately give rise to every behavior, thought, or emotion that we experience. Over the past decade, a novel neurotechnique, optogenetics that combines light and genetic methods to control or monitor neural activity patterns, has proven to be revolutionary in understanding the functional role of specific neural circuits. We here briefly describe recent advance in optogenetics and compare optogenetics with deep brain stimulation technology that holds the promise for treating many neurological and psychiatric disorders
Brain herniation in a patient with apparently normal intracranial pressure: a case report
Introduction
Intracranial pressure monitoring is commonly implemented in patients with neurologic injury and at high risk of developing intracranial hypertension, to detect changes in intracranial pressure in a timely manner. This enables early and potentially life-saving treatment of intracranial hypertension.
Case presentation
An intraparenchymal pressure probe was placed in the hemisphere contralateral to a large basal ganglia hemorrhage in a 75-year-old Caucasian man who was mechanically ventilated and sedated because of depressed consciousness. Intracranial pressures were continuously recorded and never exceeded 17 mmHg. After sedation had been stopped, our patient showed clinical signs of transtentorial brain herniation, despite apparently normal intracranial pressures (less than 10 mmHg). Computed tomography revealed that the size of the intracerebral hematoma had increased together with significant unilateral brain edema and transtentorial herniation. The contralateral hemisphere where the intraparenchymal pressure probe was placed appeared normal. Our patient underwent emergency decompressive craniotomy and was tracheotomized early, but did not completely recover.
Conclusions
Intraparenchymal pressure probes placed in the hemisphere contralateral to an intracerebral hematoma may dramatically underestimate intracranial pressure despite apparently normal values, even in the case of transtentorial brain herniation
Comparison of prognostic scores and surgical approaches to treat spinal metastatic tumors: A review of 57 cases
Surgical treatment of metastatic spinal cord compression with or without neural deficit is controversial. Karnofsky and Tokuhashi scores have been proposed for prognosis of spinal metastasis. Here, we conducted a retrospective analysis of Karnofsky and modified Tokuhashi scores in 57 consecutive patients undergoing surgery for secondary spinal metastases to evaluate the value of these scores in aiding decision making for surgery. Comparison of preoperative Karnofsky and modified Tokuhashi scores with the type of the surgical approach for each patient revealed that both scores not only reliably estimate life expectancy, but also objectively improved surgical decisions. When the general status of the patient is poor (i.e., Karnofsky score less than 40% or modified Tokuhashi score of 5 or greater), palliative treatments and radiotherapy, rather than surgery, should be considered
G protein-coupled receptor-mediated calcium signaling in astrocytes
Astrocytes express a large variety of G~protein-coupled receptors (GPCRs)
which mediate the transduction of extracellular signals into intracellular
calcium responses. This transduction is provided by a complex network of
biochemical reactions which mobilizes a wealth of possible calcium-mobilizing
second messenger molecules. Inositol 1,4,5-trisphosphate is probably the best
known of these molecules whose enzymes for its production and degradation are
nonetheless calcium-dependent. We present a biophysical modeling approach based
on the assumption of Michaelis-Menten enzyme kinetics, to effectively describe
GPCR-mediated astrocytic calcium signals. Our model is then used to study
different mechanisms at play in stimulus encoding by shape and frequency of
calcium oscillations in astrocytes.Comment: 35 pages, 6 figures, 1 table, 3 appendices (book chapter
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