394 research outputs found
Non-Smooth Stochastic Lyapunov Functions With Weak Extension of Viscosity Solutions
This paper proposes a notion of viscosity weak supersolutions to build a
bridge between stochastic Lyapunov stability theory and viscosity solution
theory. Different from ordinary differential equations, stochastic differential
equations can have the origins being stable despite having no smooth stochastic
Lyapunov functions (SLFs). The feature naturally requires that the related
Lyapunov equations are illustrated via viscosity solution theory, which deals
with non-smooth solutions to partial differential equations. This paper claims
that stochastic Lyapunov stability theory needs a weak extension of viscosity
supersolutions, and the proposed viscosity weak supersolutions describe
non-smooth SLFs ensuring a large class of the origins being noisily
(asymptotically) stable and (asymptotically) stable in probability. The
contribution of the non-smooth SLFs are confirmed by a few examples;
especially, they ensure that all the linear-quadratic-Gaussian (LQG) controlled
systems have the origins being noisily asymptotically stable for any additive
noises
α-Smooth muscle actin expression in cancerassociated fibroblasts in canine epithelial tumors
Tumor tissues contain not only cancer cells but also other cell types including, fibroblasts, immune cells, and endothelial cells, which interact with cancer cells. In human medicine, cancer-associated fibroblasts (CAFs) have been reported to promote tumor growth. CAFs are known to express α-smooth muscle actin (α-SMA), and this expression is correlated with poor prognosis in humans with cancer. However, the role of CAFs in canines and α-SMA expression in canine CAFs remains unknown. This study evaluated whether CAFs are present within the stroma of various types of canine epithelial tumors, for example, mammary gland tumors, squamous cell carcinoma, and anal sac adenocarcinoma, and assessed α-SMA expression in CAFs isolated from canine epithelial tumors. α-SMA analysis of tumor tissues revealed a cytoplasmic localization with variable levels of expression. α-SMA was detected in 60.9% (14/23) of epithelial tumor tissues and in 80% (8/10) of anal sac adenocarcinoma tissues. CAFs and normal fibroblasts (NFs) were isolated from tumor and skin tissues. The size of CAFs was variable, and most CAFs had large cell volume, in contrast to NFs. Most CAFs expressed α-SMA stress fibers and had higher α-SMA protein levels than NFs. Taken together, our findings provide evidence that canine CAFs express α-SMA in various canine epithelial tumors. Further studies are required to investigate the correlation between canine CAFs and clinical parameters and to elucidate the mechanisms underlying the effects of CAFs on cancer progression
Weakly invertible cells in a weak -category
We study weakly invertible cells in weak -categories in the sense of
Leinster, adopting Cheng's coinductive definition of weak invertibility. We
show that weakly invertible cells in a weak -category are closed under
globular pasting. Using this, we generalise elementary properties of weakly
invertible cells known to hold in strict -categories to weak
-categories, and show that every weak -category has a largest
weak -subgroupoid.Comment: 21 pages. Comments welcome
Verifying the validity and reliability of the Japanese version of the Face, Legs, Activity, Cry, Consolability (FLACC) Behavioral Scale
BackgroundPediatric patients, especially in the preverbal stage, cannot self-report intensity of pain therefore several validated observational tools, including the Face, Legs, Activity, Cry, Consolability (FLACC) Behavioral Scale, have been used as a benchmark to evaluate pediatric pain. Unfortunately, this scale is currently unavailable in Japanese, precluding its widespread use in Japanese hospitals.ObjectivesTo translate and verify the validity and reliability of the Japanese version of the FLACC Behavioral Scale.MethodBack-translation was first conducted by eight medical researchers, then an available sample of patients at the University of Tsukuba Pediatric Intensive Care Unit (from May 2017 to August 2017) was enrolled in a clinical study. Two researchers evaluated the validity of the translated FLACC Behavioral Scale by weighted kappa coefficient and intraclass correlation coefficients (ICC). Observational pain was simultaneously measured by the visual analog scale (VAS obs) and reliability was evaluated by correlation analysis.ResultThe original author approved the translation. For the clinical study, a total of 121 observations were obtained from 24 pediatric patients. Agreement between observers was highly correlated for each of the FLACC categories (Face: κ = 0.85, Leg: κ = 0.74, Activity: κ = 0.89, Cry: κ = 0.93, Consolability: κ = 0.93) as well as the total score (Total: κ = 0.95,). Correlation analysis demonstrated a good criterion validation between the FLACC scale and the VAS obs. (r = 0.96)ConclusionOur Japanese version of the FLACC Behavioral Scale shows high validity and reliability
Methyl-compound use and slow growth characterize microbial life in 2-km-deep subseafloor coal and shale beds
The past decade of scientific ocean drilling has revealed seemingly ubiquitous, slow-growing microbial life within a range of deep biosphere habitats. Integrated Ocean Drilling Program Expedition 337 expanded these studies by successfully coring Miocene-aged coal beds 2 km below the seafloor hypothesized to be “hot spots” for microbial life. To characterize the activity of coal-associated microorganisms from this site, a series of stable isotope probing (SIP) experiments were conducted using intact pieces of coal and overlying shale incubated at in situ temperatures (45 °C). The 30-month SIP incubations were amended with deuterated water as a passive tracer for growth and different combinations of ^(13)C- or ^(15)N-labeled methanol, methylamine, and ammonium added at low (micromolar) concentrations to investigate methylotrophy in the deep subseafloor biosphere. Although the cell densities were low (50–2,000 cells per cubic centimeter), bulk geochemical measurements and single-cell–targeted nanometer-scale secondary ion mass spectrometry demonstrated active metabolism of methylated substrates by the thermally adapted microbial assemblage, with differing substrate utilization profiles between coal and shale incubations. The conversion of labeled methylamine and methanol was predominantly through heterotrophic processes, with only minor stimulation of methanogenesis. These findings were consistent with in situ and incubation 16S rRNA gene surveys. Microbial growth estimates in the incubations ranged from several months to over 100 y, representing some of the slowest direct measurements of environmental microbial biosynthesis rates. Collectively, these data highlight a small, but viable, deep coal bed biosphere characterized by extremely slow-growing heterotrophs that can utilize a diverse range of carbon and nitrogen substrates
Atribacteria from the Subseafloor Sedimentary Biosphere Disperse to the Hydrosphere through Submarine Mud Volcanoes
Submarine mud volcanoes (SMVs) are formed by muddy sediments and breccias extruded to the seafloor from a source in the deep subseafloor and are characterized by the discharge of methane and other hydrocarbon gasses and deep-sourced fluids into the overlying seawater. Although SMVs act as a natural pipeline connecting the Earth’s surface and subsurface biospheres, the dispersal of deep-biosphere microorganisms and their ecological roles remain largely unknown. In this study, we investigated the microbial communities in sediment and overlying seawater at two SMVs located on the Ryukyu Trench off Tanegashima Island, southern Japan. The microbial communities in mud volcano sediments were generally distinct from those in the overlying seawaters and in the well-stratified Pacific margin sediments collected at the Peru Margin, the Juan de Fuca Ridge flank off Oregon, and offshore of Shimokita Peninsula, northeastern Japan. Nevertheless, in-depth analysis of different taxonomic groups at the sub-species level revealed that the taxon affiliated with Atribacteria, heterotrophic anaerobic bacteria that typically occur in organic-rich anoxic subseafloor sediments, were commonly found not only in SMV sediments but also in the overlying seawater. We designed a new oligonucleotide probe for detecting Atribacteria using the catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). CARD-FISH, digital PCR and sequencing analysis of 16S rRNA genes consistently showed that Atribacteria are abundant in the methane plumes of the two SMVs (0.58 and 1.5 × 104 cells/mL, respectively) but not in surrounding waters, suggesting that microbial cells in subseafloor sediments are dispersed as “deep-biosphere seeds” into the ocean. These findings may have important implications for the microbial transmigration between the deep subseafloor biosphere and the hydrosphere
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