fundamental formula
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2021 ◽  
Vol 12 ◽  
Author(s):  
Guilin Shan ◽  
Victoria Rosner ◽  
Andreas Milimonka ◽  
Wolfgang Buescher ◽  
André Lipski ◽  
...  

The microbiome in silage may vary substantially from the onset to the completion of fermentation. Improved additives and inoculants are being developed to accelerate the ensiling process, to enhance fermentation quality, and to delay spoilage during feed-out. However, current methods for preselecting and characterizing these amendments are time-consuming and costly. Here, we have developed a multi-sensor mini-bioreactor (MSMB) to track microbial fermentation in situ and additionally presented a mathematical model for the optimal assessment among candidate inoculants based on the Bolza equation, a fundamental formula in optimal control theory. Three sensors [pH, CO2, and ethanol (EtOH)] provided data for assessment, with four additional sensors (O2, gas pressure, temperature, and atmospheric pressure) to monitor/control the fermentation environment. This advanced MSMB is demonstrated with an experimental method for evaluating three typical species of lactic acid bacteria (LAB), Lentilactobacillus buchneri (LB) alone, and LB mixed with Lactiplantibacillus plantarum (LBLP) or with Enterococcus faecium (LBEF), all cultured in De Man, Rogosa, and Sharpe (MRS) broth. The fermentation process was monitored in situ over 48 h with these candidate microbial strains using the MSMB. The experimental results combine acidification characteristics with production of CO2 and EtOH, optimal assessment of the microbes, analysis of the metabolic sensitivity to pH, and partitioning of the contribution of each species to fermentation. These new data demonstrate that the MSMB associated with the novel rapid data-processing method may expedite development of microbial amendments for silage additives.


Author(s):  
Eugenio Megías ◽  
Mariano Quirós

In this work, we study a warped five-dimensional (5D) model with ultraviolet (UV) and infrared (IR) branes, that solves the hierarchy problem with a fundamental 5D Planck scale [Formula: see text], and curvature parameter [Formula: see text], of the order of the 4D Planck mass [Formula: see text] TeV. The model exhibits a continuum of Kaluza–Klein (KK) modes with different mass gaps, at the TeV scale, for all fields. We have computed Green’s functions and spectral densities, and shown how the presence of a continuum KK spectrum can produce an enhancement in the cross-section of some Standard Model processes. The metric is linear near the IR, in conformal coordinates, as in the linear dilaton (LD) and 5D clockwork models, for which [Formula: see text] TeV. We also analyze a pure (continuum) LD scenario, solving the hierarchy problem with more conventional fundamental [Formula: see text] and [Formula: see text] scales of the order of [Formula: see text], and a continuum spectrum.


2018 ◽  
Vol 115 (39) ◽  
pp. 9738-9743 ◽  
Author(s):  
Felix Wong ◽  
Annwesha Dutta ◽  
Debashish Chowdhury ◽  
Jeremy Gunawardena

The Michaelis–Menten (MM) fundamental formula describes how the rate of enzyme catalysis depends on substrate concentration. The familiar hyperbolic relationship was derived by timescale separation for a network of three reactions. The same formula has subsequently been found to describe steady-state input–output responses in many biological contexts, including single-molecule enzyme kinetics, gene regulation, transcription, translation, and force generation. Previous attempts to explain its ubiquity have been limited to networks with regular structure or simplifying parametric assumptions. Here, we exploit the graph-based linear framework for timescale separation to derive general structural conditions under which the MM formula arises. The conditions require a partition of the graph into two parts, akin to a “coarse graining” into the original MM graph, and constraints on where and how the input variable occurs. Other features of the graph, including the numerical values of parameters, can remain arbitrary, thereby explaining the formula’s ubiquity. For systems at thermodynamic equilibrium, we derive a necessary and sufficient condition. For systems away from thermodynamic equilibrium, especially those with irreversible reactions, distinct structural conditions arise and a general characterization remains open. Nevertheless, our results accommodate, in much greater generality, all examples known to us in the literature.


Author(s):  
Frederic Ayant

Recently, Raina and Srivastava and Srivastava and Hussain have provided closed-form expressions for a number of an Eulerian integral involving multivariable H-functions. Motivated by these recent works, we aim at evaluating a general class of multiple Eulerian integrals concerning the product of two multivariable A-functions defined by Gautam et Asgar [4], a class of multivariable polynomials and the extension of the Hurwitz-Lerch Zeta function. These integrals will serve as a fundamental formula from which one can deduce numerous useful integrals.


2002 ◽  
Vol 17 (25) ◽  
pp. 1673-1684 ◽  
Author(s):  
EEF VAN BEVEREN ◽  
FRIEDER KLEEFELD ◽  
GEORGE RUPP ◽  
MICHAEL D. SCADRON

The quark-level linear σ model (LσM) is revisited, in particular concerning the identification of the f0(400–1200) (or σ(600)) scalar meson as the chiral partner of the pion. We demonstrate the predictive power of the LσM through the ππ and πNs-wave scattering lengths, as well as several electromagnetic, weak, and strong decays of pseudoscalar and vector mesons. The ease with which the data for these observables are reproduced in the LσM lends credit to the necessity to include the σ as a fundamental [Formula: see text] degree of freedom, to be contrasted with approaches like chiral perturbation theory or the confining NJL model of Shakin and Wang.


1997 ◽  
Vol 49 (3) ◽  
pp. 417-467 ◽  
Author(s):  
Brian D. Boe ◽  
Joseph H. G. Fu

AbstractWe give explicit combinatorial expresssions for the characteristic cycles associated to certain canonical sheaves on Schubert varieties X in the classical Hermitian symmetric spaces: namely the intersection homology sheaves IHX and the constant sheaves ℂX. The three main cases of interest are the Hermitian symmetric spaces for groups of type An (the standard Grassmannian), Cn (the Lagrangian Grassmannian) and Dn. In particular we find that CC(IHX) is irreducible for all Schubert varieties X if and only if the associated Dynkin diagramis simply laced. The result for Schubert varieties in the standard Grassmannian had been established earlier by Bressler, Finkelberg and Lunts, while the computations in the Cn and Dn cases are new.Our approach is to compute CC(ℂX) by a direct geometric method, then to use the combinatorics of the Kazhdan-Lusztig polynomials (simplified for Hermitian symmetric spaces) to compute CC(IHX). The geometric method is based on the fundamental formula where the Xr ↓ X constitute a family of tubes around the variety X. This formula leads at once to an expression for the coefficients of CC(ℂX) as the degrees of certain singular maps between spheres.


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