753 research outputs found
Collective cell migration: Implications for wound healing and cancer invasion.
During embryonic morphogenesis, wound repair and cancer invasion, cells often migrate collectively via tight cell-cell junctions, a process named collective migration. During such migration, cells move as coherent groups, large cell sheets, strands or tubes rather than individually. One unexpected finding regarding collective cell migration is that being a "multicellular structure" enables cells to better respond to chemical and physical cues, when compared with isolated cells. This is important because epithelial cells heal wounds via the migration of large sheets of cells with tight intercellular connections. Recent studies have gained some mechanistic insights that will benefit the clinical understanding of wound healing in general. In this review, we will briefly introduce the role of collective cell migration in wound healing, regeneration and cancer invasion and discuss its underlying mechanisms as well as implications for wound healing
Genetic Polymorphisms and Posttraumatic Complications
Major trauma is the leading cause of death in young adults. Despite advances in prehospital system and treatment in hospital, mortality rates have not improved significantly over the past decades. Victims of severe injuries who survive the initial hours have great risk for additional life-threatening complicaitons, including uncontrollable infection (sepsis) and multiple organ dysfunction syndrome (MODS). Single nucleotide polymorphisms (SNPs) have been shown to affect susceptibility to the course of numerous diseases. Accumulating evidence suggests that genetic backgrounds also play important roles in posttraumatic complications. Genetic polymorphisms may become powerful biomarkers for diagnosis and prognosis of trauma-induced complications. Recent advances in studies on associations between genetic polymorphisms and sepsis or MODS have led to better understanding of posttraumatic complications. Here we summarise recent findings on genetic variations in molecules of the innate immune system and other systems as well as their connection with susceptibility to posttraumatic complications
Tars: Timeliness-aware Adaptive Replica Selection for Key-Value Stores
In current large-scale distributed key-value stores, a single end-user
request may lead to key-value access across tens or hundreds of servers. The
tail latency of these key-value accesses is crucial to the user experience and
greatly impacts the revenue. To cut the tail latency, it is crucial for clients
to choose the fastest replica server as much as possible for the service of
each key-value access. Aware of the challenges on the time varying performance
across servers and the herd behaviors, an adaptive replica selection scheme C3
is proposed recently. In C3, feedback from individual servers is brought into
replica ranking to reflect the time-varying performance of servers, and the
distributed rate control and backpressure mechanism is invented. Despite of
C3's good performance, we reveal the timeliness issue of C3, which has large
impacts on both the replica ranking and the rate control, and propose the Tars
(timeliness-aware adaptive replica selection) scheme. Following the same
framework as C3, Tars improves the replica ranking by taking the timeliness of
the feedback information into consideration, as well as revises the rate
control of C3. Simulation results confirm that Tars outperforms C3.Comment: 10pages,submitted to ICDCS 201
Physics-constrained Active Learning for Soil Moisture Estimation and Optimal Sensor Placement
Soil moisture is a crucial hydrological state variable that has significant
importance to the global environment and agriculture. Precise monitoring of
soil moisture in crop fields is critical to reducing agricultural drought and
improving crop yield. In-situ soil moisture sensors, which are buried at
pre-determined depths and distributed across the field, are promising solutions
for monitoring soil moisture. However, high-density sensor deployment is
neither economically feasible nor practical. Thus, to achieve a higher spatial
resolution of soil moisture dynamics using a limited number of sensors, we
integrate a physics-based agro-hydrological model based on Richards' equation
in a physics-constrained deep learning framework to accurately predict soil
moisture dynamics in the soil's root zone. This approach ensures that soil
moisture estimates align well with sensor observations while obeying physical
laws at the same time. Furthermore, to strategically identify the locations for
sensor placement, we introduce a novel active learning framework that combines
space-filling design and physics residual-based sampling to maximize data
acquisition potential with limited sensors. Our numerical results demonstrate
that integrating Physics-constrained Deep Learning (P-DL) with an active
learning strategy within a unified framework--named the Physics-constrained
Active Learning (P-DAL) framework--significantly improves the predictive
accuracy and effectiveness of field-scale soil moisture monitoring using
in-situ sensors
The Effect of Different Optimization Strategies to Physics-Constrained Deep Learning for Soil Moisture Estimation
Soil moisture is a key hydrological parameter that has significant importance
to human society and the environment. Accurate modeling and monitoring of soil
moisture in crop fields, especially in the root zone (top 100 cm of soil), is
essential for improving agricultural production and crop yield with the help of
precision irrigation and farming tools. Realizing the full sensor data
potential depends greatly on advanced analytical and predictive domain-aware
models. In this work, we propose a physics-constrained deep learning (P-DL)
framework to integrate physics-based principles on water transport and water
sensing signals for effective reconstruction of the soil moisture dynamics. We
adopt three different optimizers, namely Adam, RMSprop, and GD, to minimize the
loss function of P-DL during the training process. In the illustrative case
study, we demonstrate the empirical convergence of Adam optimizers outperforms
the other optimization methods in both mini-batch and full-batch training
miR-181a increases FoxO1 acetylation and promotes granulosa cell apoptosis via SIRT1 downregulation.
Oxidative stress impairs follicular development by inducing granulosa cell (GC) apoptosis, which involves enhancement of the transcriptional activity of the pro-apoptotic factor Forkhead box O1 (FoxO1). However, the mechanism by which oxidative stress promotes FoxO1 activity is still unclear. Here, we found that miR-181a was upregulated in hydrogen peroxide (
Simultaneous saccharification and cofermentation of lignocellulosic residues from commercial furfural production and corn kernels using different nutrient media
<p>Abstract</p> <p>Background</p> <p>As the supply of starch grain and sugar cane, currently the main feedstocks for bioethanol production, become limited, lignocelluloses will be sought as alternative materials for bioethanol production. Production of cellulosic ethanol is still cost-inefficient because of the low final ethanol concentration and the addition of nutrients. We report the use of simultaneous saccharification and cofermentation (SSCF) of lignocellulosic residues from commercial furfural production (furfural residue, FR) and corn kernels to compare different nutritional media. The final ethanol concentration, yield, number of live yeast cells, and yeast-cell death ratio were investigated to evaluate the effectiveness of integrating cellulosic and starch ethanol.</p> <p>Results</p> <p>Both the ethanol yield and number of live yeast cells increased with increasing corn-kernel concentration, whereas the yeast-cell death ratio decreased in SSCF of FR and corn kernels. An ethanol concentration of 73.1 g/L at 120 h, which corresponded to a 101.1% ethanol yield based on FR cellulose and corn starch, was obtained in SSCF of 7.5% FR and 14.5% corn kernels with mineral-salt medium. SSCF could simultaneously convert cellulose into ethanol from both corn kernels and FR, and SSCF ethanol yield was similar between the organic and mineral-salt media.</p> <p>Conclusions</p> <p>Starch ethanol promotes cellulosic ethanol by providing important nutrients for fermentative organisms, and in turn cellulosic ethanol promotes starch ethanol by providing cellulosic enzymes that convert the cellulosic polysaccharides in starch materials into additional ethanol. It is feasible to produce ethanol in SSCF of FR and corn kernels with mineral-salt medium. It would be cost-efficient to produce ethanol in SSCF of high concentrations of water-insoluble solids of lignocellulosic materials and corn kernels. Compared with prehydrolysis and fed-batch strategy using lignocellulosic materials, addition of starch hydrolysates to cellulosic ethanol production is a more suitable method to improve the final ethanol concentration.</p
Novel, rosin‐based, hydrophobically modified cationic polyacrylamide for kaolin suspension flocculation
A novel, hydrophobically modified cationic polyacrylamide (HMPAM) was synthesized via the copolymerization of acrylamide, diallyl dimethyl ammonium chloride (DMDAAC), and diallylmethyl dehydroabietic acid propyl ester ammonium bromide. Optimum conditions for preparing HMPAM were such that the amount of initiator was 0.075 wt % of the total monomer mass, the monomer concentration was 20 wt %, and the amount of DMDAAC was 18 mol % of the total monomer molar mass. HMPAM was characterized with an UV–visible spectrometer, 1H‐NMR, Ubbelohde viscometer, rotational viscometer, and rotational rheometer. HMPAM solutions exhibited strong hydrophobic associations, and the critical association concentration of the HMPAM aqueous solution was about 0.7 wt %; the HMPAM solutions also showed salt thickening and shear resistance. The surface morphologies of the freeze‐dried HMPAM samples (1 wt %) were also observed via scanning electron microscopy. Compared with unmodified cationic polyacrylamide, Synthesis of HMPAM‐0.5 exhibited a stronger flocculation capacity, and the optimal transmittance of the supernatants was above 95%. HMPAM‐0.5 showed significant flocculation performances for 3–4 and 3–5 wt % kaolin suspensions at 40 and 50 mg/L, respectively. Moreover, the flocculation performance was enhanced with the addition of NaCl and CaCl2. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46637.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144283/1/app46637.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144283/2/app46637_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144283/3/app46637-sup-0001-suppinfo1.pd
Is exponential gravity a viable description for the whole cosmological history?
Here we analysed a particular type of gravity, the so-called
exponential gravity which includes an exponential function of the Ricci scalar
in the action. Such term represents a correction to the usual Hilbert-Einstein
action. By using Supernovae Ia, Barionic Acoustic Oscillations, Cosmic
Microwave Background and data, the free parameters of the model are well
constrained. The results show that such corrections to General Relativity
become important at cosmological scales and at late-times, providing an
alternative to the dark energy problem. In addition, the fits do not determine
any significant difference statistically with respect to the CDM
model. Finally, such model is extended to include the inflationary epoch in the
same gravitational Lagrangian. As shown in the paper, the additional terms can
reproduce the inflationary epoch and satisfy the constraints from Planck data.Comment: 20 pages, 6 figures, analysis extended, version published in EPJ
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