Metabolic pathways: does the actual Gibbs free-energy change affect the flux rate?

Abstract Energy dissipation fulfils an important function in metabolism driving the flux of matter through metabolic pathways. The flux rate is a multivariable function. One of such variables affecting the flux is the actual free energy change. A particular case of metabolic pathway is analysed to illustrate this fact, using only general enzymic and thermodynamic concepts.

Compact maximal hypersurfaces in globally hyperbolic spacetimes

Several uniqueness results on compact maximal hypersurfaces in a wide class of globally hyperbolic spacetimes are provided. They are obtained from the study of a distinguished function on the maximal hypersurface and under suitable natural _rst order conditions of the spacetime. As a consequence, several applications to Geometric Analysis are given

Spacelike hypersurfaces with functionally bounded mean curvature in Lorentzian warped products and generalized Calabi-Bernstein type problems

We study spacelike hypersurfaces with functionally bounded mean curvature in Lorentzian warped products M = I × f F , where F is a (non-compact) complete Riemannian mani- fold whose universal covering is parabolic. In particular, we provide several rigidity results under appropriate mathematical and physical assumptions. As an application, several Calabi- Bernstein type results are obtained which widely extend the previous ones in this setting

What Process Is Glycolytic Stoichiometry Optimal For

Abstract. It has been proposed that the glycolytic stoichiometry of 2 ATP per glucose is the result of an optimization that maximizes the rate of ATP production. However, using a nonequilibrium thermodynamic approach, we show here that glycolysis operates under optimal output power and not at optimal flow of ATP production. Furthermore, it can be proved that the same maximal output power can be achieved with different stoichiometries. However, changes in the glycolytic stoichiometry would dramatically affect the efficiency of all those cellular processes powered by ATP. Our results suggest that the stoichiometric coefficient, as found in most contemporary cells, may be the outcome of an evolutionary process leading to yield an operative quantum energy for the hydrolysis of ATP

What is the evidence for giving chemoprophylaxis to children or students attending the same preschool, school or college as a case of meningococcal disease?

We performed a systematic literature review to assess the effectiveness of chemoprophylaxis for contacts of sporadic cases of invasive meningococcal disease (IMD) in educational settings. No studies directly compared IMD risk in contacts with/without chemoprophylaxis. However, compared to the background incidence, an elevated IMD risk was identified in settings without a general recommendation for chemoprophylaxis in pre-schools [pooled risk difference (RD) 58·2/10⁵, 95% confidence interval (CI) 27·3-89·0] and primary schools (pooled RD 4·9/10⁵, 95% CI 2·9-6·9) in the ~30 days after contact with a sporadic IMD case, but not in other educational settings. Thus, limited but consistent evidence suggests the risk of IMD in pre-school contacts of sporadic IMD cases is significantly increased above the background risk, but lower than in household contacts (pooled RD for household contacts with no chemoprophylaxis vs. background incidence: 480·1/10⁵, 95% CI 321·5-639·9). We recommend chemoprophylaxis for pre-school contacts depending on an assessment of duration and closeness of contact

Height estimates for Killing graphs

The paper aims at proving global height estimates for Killing graphs defined over a complete manifold with nonempty boundary. To this end, we first point out how the geometric analysis on a Killing graph is naturally related to a weighted manifold structure, where the weight is defined in terms of the length of the Killing vector field. According to this viewpoint, we introduce some potential theory on weighted manifolds with boundary and we prove a weighted volume estimate for intrinsic balls on the Killing graph. Finally, using these tools, we provide the desired estimate for the weighted height in the assumption that the Killing graph has constant weighted mean curvature and the weighted geometry of the ambient space is suitably controlled.Comment: 26 pages. Final version. To appear on Journal of Geometric Analysi