259 research outputs found
Coarse Nonlinear Dynamics and Metastability of Filling-Emptying Transitions: Water in Carbon Nanotubes
Using a Coarse-grained Molecular Dynamics (CMD) approach we study the
apparent nonlinear dynamics of water molecules filling/emptying carbon
nanotubes as a function of system parameters. Different levels of the pore
hydrophobicity give rise to tubes that are empty, water-filled, or fluctuate
between these two long-lived metastable states. The corresponding
coarse-grained free energy surfaces and their hysteretic parameter dependence
are explored by linking MD to continuum fixed point and bifurcation algorithms.
The results are validated through equilibrium MD simulations.Comment: 4 pages, 3 figures; accepted versio
Evaluation of relative roles of LH and FSH in regulation of differentiation of Leydig cells using an ethane 1,2-dimethylsulfonate-treated adult rat model
The relative role of LH and FSH in regulation of differentiation of Leydig cells was assessed using an ethane 1,2-dimethylsulfonate (EDS)-treated rat model in which endogenous LH or FSH was neutralized from day 3 to day 22 following EDS treatment. Serum testosterone and the in vitro response of the purified Leydig cells to human chorionic gonadotropin (hCG) was monitored. In addition RNA was isolated from the Leydig cells to monitor the steady-state mRNA levels by RT-PCR for 17α-hydroxylase, side chain cleavage enzyme, steroidogenic acute regulatory protein (StAR), LH receptor, estrogen receptor (ER-α) and cyclophilin (internal control). Serum testosterone was undetected and the isolated Leydig cells secreted negligible amount of testosterone on stimulation with hCG in the group of rats that were treated with LH antiserum following EDS treatment. RT-PCR analysis revealed the absence of message for cholesterol side chain cleavage enzyme and 17α-hydroxylase although ER-alpha and LH receptor mRNA could be detected, indicating the presence of undifferentiated precursor Leydig cells. In contrast, the effects following deprival of endogenous FSH were not as drastic as seen following LH neutralization. Deprival of endogenous FSH in EDS-treated rats led to a significant decrease in serum testosterone and in vitro response to hCG by the Leydig cells. Also, there was a significant decrease in the steady-state mRNA levels of 17α-hydroxylase, cholesterol side chain cleavage enzyme, LH receptor and StAR as assessed by a semiquantitative RT-PCR. These results establish that while LH is obligatory for the functional differentiation of Leydig cells, repopulation of precursor Leydig cells is independent of LH, and also unequivocally establish an important role for FSH in regulation of Leydig cell function
A machine learning approach to predict DevOps readiness and adaptation in a heterogeneous IT environment
Software and information systems have become a core competency for every business in this connected world. Any enhancement in software delivery and operations will tremendously impact businesses and society. Sustainable software development is one of the key focus areas for software organizations. The application of intelligent automation leveraging artificial intelligence and cloud computing to deliver continuous value from software is in its nascent stage across the industry and is evolving rapidly. The advent of agile methodologies with DevOps has increased software quality and accelerated its delivery. Numerous software organizations have adopted DevOps to develop and operate their software systems and improve efficiency. Software organizations try to implement DevOps activities by taking advantage of various expert services. The adoption of DevOps by software organizations is beset with multiple challenges. These issues can be overcome by understanding and structurally addressing the pain points. This paper presents the preliminary analysis of the interviews with the relevant stakeholders. Ground truths were established and applied to evaluate various machine learning algorithms to compare their accuracy and test our hypothesis. This study aims to help researchers and practitioners understand the adoption of DevOps and the contexts in which the DevOps practices are viable. The experimental results will show that machine learning can predict an organization's readiness to adopt DevOps
Suitability of Killai backwaters for prawn farming-a preliminary micro level survey
Brackishwater areas have been given much importance for prawn farming. No information was
available on the Killai backwaters about factors like water quality, topography, contour, extent
of the area, tidal amplitude, seed potential and possibilities of flooding etc. Hence during 1982-'84
Klllai area was thoroughly surveyed on the above aspects and the results have been discussed in this
paper. From this it is inferred that a total area of about 155 ha is readily available for undertaking
both pond and pen culture in this backwater
Multiscale Computations on Neural Networks: From the Individual Neuron Interactions to the Macroscopic-Level Analysis
We show how the Equation-Free approach for multi-scale computations can be
exploited to systematically study the dynamics of neural interactions on a
random regular connected graph under a pairwise representation perspective.
Using an individual-based microscopic simulator as a black box coarse-grained
timestepper and with the aid of simulated annealing we compute the
coarse-grained equilibrium bifurcation diagram and analyze the stability of the
stationary states sidestepping the necessity of obtaining explicit closures at
the macroscopic level. We also exploit the scheme to perform a rare-events
analysis by estimating an effective Fokker-Planck describing the evolving
probability density function of the corresponding coarse-grained observables
Control of oocyte release by progesterone receptor-regulated gene expression
The progesterone receptor (PGR) is a nuclear receptor transcription factor that is essential for female fertility, in part due to its control of oocyte release from the ovary, or ovulation. In all mammals studied to date, ovarian expression of PGR is restricted primarily to granulosa cells of follicles destined to ovulate. Granulosa cell expression of PGR is induced by the pituitary Luteinizing Hormone (LH) surge via mechanisms that are not entirely understood, but which involve activation of Protein Kinase A and modification of Sp1/Sp3 transcription factors on the PGR promoter. Null mutations for PGR or treatment with PGR antagonists block ovulation in all species analyzed, including humans. The cellular mechanisms by which PGR regulates ovulation are currently under investigation, with several downstream pathways having been identified as PGR-regulated and potentially involved in follicular rupture. Interestingly, none of these PGR-regulated genes has been demonstrated to be a direct transcriptional target of PGR. Rather, in ovarian granulosa cells, PGR may act as an inducible coregulator for constitutively bound Sp1/Sp3 transcription factors, which are key regulators for a discrete cohort of ovulatory genes
TAp73 is a central transcriptional regulator of airway multiciliogenesis.
Motile multiciliated cells (MCCs) have critical roles in respiratory health and disease and are essential for cleaning inhaled pollutants and pathogens from airways. Despite their significance for human disease, the transcriptional control that governs multiciliogenesis remains poorly understood. Here we identify TP73, a p53 homolog, as governing the program for airway multiciliogenesis. Mice with TP73 deficiency suffer from chronic respiratory tract infections due to profound defects in ciliogenesis and complete loss of mucociliary clearance. Organotypic airway cultures pinpoint TAp73 as necessary and sufficient for basal body docking, axonemal extension, and motility during the differentiation of MCC progenitors. Mechanistically, cross-species genomic analyses and complete ciliary rescue of knockout MCCs identify TAp73 as the conserved central transcriptional integrator of multiciliogenesis. TAp73 directly activates the key regulators FoxJ1, Rfx2, Rfx3, and miR34bc plus nearly 50 structural and functional ciliary genes, some of which are associated with human ciliopathies. Our results position TAp73 as a novel central regulator of MCC differentiation
Incorporating life cycle assessment and ecodesign tools for green chemical engineering: a case study of competences and learning outcomes assessment
Chemical engineers assume a broad range of roles in industry, spanning the development of new process designs, the maintenance and optimization of complex systems, and the production of intermediate materials, final products and new technologies. The technical aptitude that enables chemical engineers to fulfill these various roles along the value chain makes them compelling participants in the environmental assessment of the product in question. Therefore, the introduction of life cycle assessment (LCA) and ecodesign concepts into the chemical engineering curriculum is essential to help these future professionals to face design problems with a holistic view of the technical, economic, social and environmental impacts of their solutions. The teaching of these and other disciplines by means of student-centered methods, based on a holistic structure, have demonstrated better teamwork and communication skills. For that reason, this paper proposes a Micro (Assess-Analyze-Act) (M-3A) model of assessment mainly focused on closing the loop of the learning activities. This model has been applied to an ecodesign case study of the "University master's Degree in chemical engineering" of the University of Cantabria/University of the Basque Country, with positive feedback of the students. They felt that the approach has allowed them to utilize their analytical skills in quantifying a situation before applying other subjective measures, and that the public discussion of the results was a satisfactory element for improving their communication skills. Moreover, the students found that the workload was nicely adjusted, highlighting the acquisition of 4 competences preferentially: teamwork, creativity; relevance of environmental issues and initiative and entrepreneurship. Finally, the students suggest that the application of this methodology into their degree could motivate future students improving their performance
The Complete Nucleotide Sequences of the 5 Genetically Distinct Plastid Genomes of Oenothera, Subsection Oenothera: II. A Microevolutionary View Using Bioinformatics and Formal Genetic Data
A unique combination of genetic features and a rich stock of information make the flowering plant genus Oenothera an appealing model to explore the molecular basis of speciation processes including nucleus–organelle coevolution. From representative species, we have recently reported complete nucleotide sequences of the 5 basic and genetically distinguishable plastid chromosomes of subsection Oenothera (I–V). In nature, Oenothera plastid genomes are associated with 6 distinct, either homozygous or heterozygous, diploid nuclear genotypes of the 3 basic genomes A, B, or C. Artificially produced plastome–genome combinations that do not occur naturally often display interspecific plastome–genome incompatibility (PGI). In this study, we compare formal genetic data available from all 30 plastome–genome combinations with sequence differences between the plastomes to uncover potential determinants for interspecific PGI. Consistent with an active role in speciation, a remarkable number of genes have high Ka/Ks ratios. Different from the Solanacean cybrid model Atropa/tobacco, RNA editing seems not to be relevant for PGIs in Oenothera. However, predominantly sequence polymorphisms in intergenic segments are proposed as possible sources for PGI. A single locus, the bidirectional promoter region between psbB and clpP, is suggested to contribute to compartmental PGI in the interspecific AB hybrid containing plastome I (AB-I), consistent with its perturbed photosystem II activity
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