Lower Bounds for the Weak Pigeonhole Principle and Random Formulas beyond Resolution

We work with an extension of Resolution, called Res(2), that allows clauses with conjunctions of two literals. In this system there are rules to introduce and eliminate such conjunctions. We prove that the weak pigeonhole principle PHP^cn_n and random unsatisfiable CNF formulas require exponential-size proofs in this system. This is the strongest system beyond Resolution for which such lower bounds are known. As a consequence to the result about the weak pigeonhole principle, Res(log) is exponentially more powerful than Res(2). Also we prove that Resolution cannot polynomially simulate Res(2) and that Res(2) does not have feasible monotone interpolation solving an open problem posed by Krají ek.     

Measurement of the degree of salinity of water with a fiber-optic sensor

A fiber-optic sensor based on surface-plasmon resonance for the determination of the refractive index is used for measuring the degree of salinity of water. The transducing element consists of a multilayer structure deposited on a side-polished monomode optical fiber. Measuring the attenuation of the power transmitted by the fiber shows that a linear relation with the refractive index of the outer medium of the structure is obtained. The system is characterized by use of a varying refractive index obtained with a mixture of water and ethylene glycol. Experimental results show that the sensor can be used as a salinity-degree measurement device with environmental applications.     

Involvement of growth factors in thymic involution

The thymus undergoes an age-dependent degenerative process which is mainly characterized by a progressive loss of lymphoid tissue. Thymic involution is particularly important in relation to immunosenescence and its various associated diseases; this fact has prompted many studies aimed at understanding the causes and mechanisms of thymic degeneration which may, ultimately, lead to the possibility of manipulating it. In this sense, one of the aspects which has deserved most attention is the thymic microenvironment, and more precisely, the many growth factors to which the cells present in the organ are exposed. Thus, the levels of several of such factors have been reported to undergo age-dependent changes in the thymus, which may point at an influence on the regression of the organ. In this article we consider which growth factors and growth factor receptors occur in the vertebrate thymus. Then, focusing on those whose influences are better documented, i.e., neurotrophins, cytokines and IGFs, we discuss their potential role in the organ and the possibility of their being involved in thymic involution.     

Effective parameter study for the facile and controlled growth of silver molybdate nano/micro rods

Controlled growth of nano/micro structures by controlling the effective parameters is the basic requirement for the application point of view in various areas. Here we report the facile growth of silver molybdate nano/micro rods by mixing the solution of silver nitrate and ammonium molybdate at ambient condition followed by hydrothermal treatment at various temperatures for 12 h. To achieve the goal for the synthesis of long, high yield and homogeneous nanorods various effective parameters have been studied to set the most effective conditions for the growth. Among possible effective parameters first the temperature of the furnace was set by warring the temperature and then at the set temperature the concentration of reactants (NH₄)₆Mo₇O₂₄ and silver nitrate are varied respect to each other. The pH and temperature values were monitored during the mixing of the reactants. Structural/microstructural characterization revealed the optimum condition of 150°C of the furnace and the concentration of (NH₄)₆Mo₇O₂₄ and silver nitrate as described in various tables.     

A liquid-liquid extractor model based on UNIFAC

A steady state liquid-liquid extractor model using the UNIFAC group contribution method for phase equilibria has been developed. A heuristic method, which limits the number of stage calculations per iteration to a low number is used, according to the residuals calculated in the previous iteration, the method either selects or rejects a stage for the calculations. With this approach, the same accuracy in results have been obtained at about half the computing time with respect to without use of heuristic method. The model has been applied to simulate staged extractors as well as continuous extractors (plate columns). The model is based on a very robust flash calculation routine and on a versatile package (UNIFAC) for the prediction of thermodynamic properties.     

Usefulness of the neuroandrologic profile study in patients with erectile dysfunction: review of a series of 180 cases

OBJECTIVES: To determine the usefulness of a complete neuroandrologic evaluation and SPACE (Single Potential Analysis Cavernous Electromyography) in the study of impotence. METHODS: We performed a clinical study, erection test with papaverine-phentolamine and neuroandrologic evaluation (bulbocavernous EMG, S2-S4 evoked potentials, evoked somatosensorial potentials, SPACE, D10-L2 skin sympathetic potentials, cystometrogram, and filling videocystography) in 180 patients consulting for impotence. RESULTS: We observed a relationship between the clinical diagnosis of impotence and the data from the neuroandrogenic study. The results of the study were classified as normal [in the clinical diagnosis of psychogenic impotence (100%), hormonal (80%) and vascular (60%)], abnormal [prevalent in the clinical diagnosis of structural impotence (87%)]. The erection test was mainly negative in all clinical diagnoses of impotence, except in psychogenic and vascular impotence (60% positive tests). CONCLUSIONS: The clinical data are useful in the diagnosis of impotence. The pharmacological erection test was not found to be very reliable. Complete neuroandrologic evaluation is indicated in non typified and mixed impotence, and can be performed in neurogenic impotence to identify the level of the lesion. Alone, SPACE does not appear to be useful as a screening test for neurologic lesions, but can be useful as a screening test for neuromuscular cavernous lesions. SPACE is indicated in structural, vascular and hormonal impotence. If SPACE is abnormal, the differential diagnosis between neurogenic and myogenic lesion can be made through a complete neuroandrologic evaluation.     

Finite‐time sliding mode observer for uncertain nonlinear systems based on a tunable algebraic solver

In this paper, a finite‐time sliding mode observer for nonlinear systems with unknown inputs is proposed. The observer is based on a method for the solution of time‐varying algebraic equations. This algebraic solver is shown to converge in finite time by means of Lyapunov analysis; furthermore, a way to tune it so that it converges after a user‐defined amount of time is presented. Through the use of this technique and sliding mode differentiators, the state variables and unknown inputs of a class of nonlinear systems, which do not need to be affine in the inputs, can be estimated without the explicit use of state transformations. Both the algebraic solver and the proposed observer are illustrated through simulation examples. Copyright © 2017 John Wiley & Sons, Ltd.     

Regeneration of the spinal ventral roots. An experimental study in cats

From a clinical standpoint recovery of spinal nerve roots is less likely than that of peripheral nerves, despite their identical structures. This may be due to several factors including the length of gap to be bridged, changes in the proximal stump or neuroma, and chromatolysis. In this paper we discuss the roles of some of these factors in relation to the neuronal depopulation in the spinal cord anterior horn area following section of the anterior root. The lack of growth or the successful growth of the axon through the gap in the root influences the degree of depopulation in the anterior horn area.