Chemical Oscillations out of Chemical Noise

The dynamics of one species chemical kinetics is studied. Chemical reactions are modelled by means of continuous time Markov processes whose probability distribution obeys a suitable master equation. A large deviation theory is formally introduced, which allows developing a Hamiltonian dynamical system able to describe the system dynamics. Using this technique we are able to show that the intrinsic fluctuations, originated in the discrete character of the reagents, may sustain oscillations and chaotic trajectories which are impossible when these fluctuations are disregarded. An important point is that oscillations and chaos appear in systems whose mean-field dynamics has too low a dimensionality for showing such a behavior. In this sense these phenomena are purely induced by noise, which does not limit itself to shifting a bifurcation threshold. On the other hand, they are large deviations of a short transient nature which typically only appear after long waiting times. We also discuss the implications of our results in understanding extinction events in population dynamics models expressed by means of stoichiometric relations

Correction of Errors During The Manufacture by Computer Numerical Control (CNC) of Blades for an Axial Hydrokinetic Turbine

The design and manufacture of new systems for providing electric power to non-interconnected areas is one of the challenges for engineering. There are several alternatives, including water or wind-power generation systems, where hydrokinetic turbines are highlighted. This work establishes the methodology, identification and correction of errors generated during the manufacture by machining, using CAD/CAPP/CAM techniques, for an axial hydrokinetic turbine. During the manufacturing process, the generation of an error on the edges of the blades was identified, which was attributed to problems in the design of the model since the degrees of freedom of the manufacturing system used were not considered. For the manufacture of complex surfaces in the design of models, the most extreme points of the surfaces in contact must match the tangent edges to ensure that the tools of machining can reach them with the trajectories generated from the CAM

On the relationship between head circumference, brain size, prenatal long-chain PUFA/5-methyltetrahydrofolate supplementation and cognitive abilities during childhood

Head circumference in infants has been reported to predict brain size, total grey matter volume (GMV) and neurocognitive development. However, it is unknown whether it has predictive value on regional and subcortical brain volumes. We aimed to explore the relationship between several head circumference measurements since birth and distributions of GMV and subcortical volumes at later childhood. We examined seventy-four, Caucasian, singleton, term-born infants born to mothers randomised to receive fish oil and/or 5-methyltetrahydrofolate or placebo prenatal supplementation. We assessed head circumference at birth and at 4 and 10 years of age and cognitive abilities at 7 years of age. We obtained brain MRI at 10 years of age, on which we performed voxel-based morphometry, cortical surface extraction and subcortical segmentation. Analyses were controlled for sex, age, height, weight, family status, laterality and total intracranial volume. Prenatal supplementation did not affect head circumference at any age, cognitive abilities or total brain volumes. Head circumference at 4 years presented the highest correlation with total GMV, white matter volume and brain surface area, and was also strongly associated with GMV of frontal, temporal and occipital areas, as well as with caudate nucleus, globus pallidus, putamen and thalamus volumes. As relationships between brain volumes in childhood and several outcomes extend into adulthood, we have found that ages between 0 and 4 years as the optimal time for brain growth; postnatal factors might have the most relevant impact on structural maturation of certain cortical areas and subcortical nuclei, independent of prenatal supplementation

Open loop amplitudes and causality to all orders and powers from the loop-tree duality

Multiloop scattering amplitudes describing the quantum fluctuations at high-energy scattering processes are the main bottleneck in perturbative quantum field theory. The loop-tree duality is a novel method aimed at overcoming this bottleneck by opening the loop amplitudes into trees and combining them at integrand level with the real-emission matrix elements. In this Letter, we generalize the loop-tree duality to all orders in the perturbative expansion by using the complex Lorentz-covariant prescription of the original one-loop formulation. We introduce a series of mutiloop topologies with arbitrary internal configurations and derive very compact and factorizable expressions of their open-to-trees representation in the loop-tree duality formalism. Furthermore, these expressions are entirely independent at integrand level of the initial assignments of momentum flows in the Feynman representation and remarkably free of noncausal singularities. These properties, that we conjecture to hold to other topologies at all orders, provide integrand representations of scattering amplitudes that exhibit manifest causal singular structures and better numerical stability than in other representations.Comment: Final version to appear in Physical Review Letter

A phase 1 trial of SGNâ CD70A in patients with CD70â positive, metastatic renal cell carcinoma

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148406/1/cncr31912.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148406/2/cncr31912_am.pd

Direct transformation of crystalline MoO3_3 into few-layers MoS2_2

We fabricate large-area atomically thin MoS$_2$ layers through the direct transformation of crystalline molybdenum MoS$_2$ (MoO$_3$) by sulfurization at relatively low temperatures. The obtained MoS2 sheets are polycrystalline (~10-20 nm single-crystal domain size) with areas of up to 300x300 um$^2$ with 2-4 layers in thickness and show a marked p-type behaviour. The synthesized films are characterized by a combination of complementary techniques: Raman spectroscopy, X-ray diffraction, transmission electron microscopy and electronic transport measurements.Comment: 6 figures in main text, 2 figures in supp. inf

Systematic study of optical potential strengths in reactions on Sn 120 involving strongly bound, weakly bound, and exotic nuclei

We present new experimental angular distributions for the elastic scattering of Li6+Sn120 at three bombarding energies. We include these data in a wide systematic involving the elastic scattering of He4,6,Li7, Be9,B10, and O16,18 projectiles on the same target at energies around the respective Coulomb barriers. Considering this data set, we report on optical model analyses based on the double-folding São Paulo potential. Within this approach, we study the sensitivity of the data fit to different models for the nuclear matter densities and to variations in the optical potential strengths.Fil: Alvarez, M. A. G.. Universidad de Sevilla; EspañaFil: Fernández García, J. P.. Universidad de Sevilla; EspañaFil: León García, J. L.. Universidad de Sevilla; EspañaFil: Rodríguez Gallardo, M.. Universidad de Sevilla; EspañaFil: Gasques, L. R.. Universidade de Sao Paulo; BrasilFil: Chamon, L. C.. Universidade de Sao Paulo; BrasilFil: Zagatto, V. A. B.. Universidade de Sao Paulo; BrasilFil: Lépine Szily, A.. Universidade de Sao Paulo; BrasilFil: Oliveira, J. R. B.. Universidade de Sao Paulo; BrasilFil: Scarduelli, V.. Universidade Federal Fluminense; BrasilFil: Carlson, B. V.. Instituto Tecnologico de Aeronautica.; BrasilFil: Casal, J.. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Arazi, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Torres, D. A.. Universidad Nacional de Colombia; ColombiaFil: Ramirez, F.. Universidad Nacional de Colombia; Colombi

MYC activation impairs cell-intrinsic IFNγ signaling and confers resistance to anti-PD1/PD-L1 therapy in lung cancer

Elucidating the adaptive mechanisms that prevent host immune response in cancer will help predict efficacy of anti-programmed death-1 (PD1)/L1 therapies. Here, we study the cell-intrinsic response of lung cancer (LC) to interferon-y (IFNy), a cytokine that promotes immunoresponse and modulates programmed death-ligand 1 (PD-L1) levels. We report complete refractoriness to IFNy in a subset of LCs as a result of JAK2 or IFNGR1 inactivation. A submaximal response affects another subset that shows constitutive low levels of IFNy-stimulated genes (IySGs) coupled with decreased H3K27ac (histone 3 acetylation at lysine 27) depo-sition and promoter hypermethylation and reduced IFN regulatory factor 1 (IRF1) recruitment to the DNA on IFNy stimulation. Most of these are neuroendocrine small cell LCs (SCLCs) with oncogenic MYC/MYCL1/ MYCN. The oncogenic activation of MYC in SCLC cells downregulates JAK2 and impairs IySGs stimulation by IFNy. MYC amplification tends to associate with a worse response to anti-PD1/L1 therapies. Hence alterations affecting the JAK/STAT pathway and MYC activation prevent stimulation by IFNy and may predict anti-PD1/L1 efficacy in LC