Multifactor Productivity and its Determinants: Al Empirical Analysis for Mexican Manufacturing.

We use data from the Annual Industrial Survey for 1996-2003. First, we estimate production functions by means of growth accounting exercises and panel data econometrics for the whole sector and for 14 comprehensive groups. Various measures of Multifactor Productivity (MFP) are constructed, as we consider diverse combinations of inputs with capital, labour, electricity and transport. This allows us to compare MFP growth rates between groups. Second, we analyse econometrically some of the determinants of MFP and Labour Productivity (LP) growth. We find that, on the one hand, there is some evidence of a positive relationship between market concentration and technology adoption; on the other hand, both technology adoption and human capital seem to be promoting productivity, whilst market concentration is exerting a negative influence on it. In sum, our results suggest that, once controlling for the effect on technology adoption, more concentration (conversely, less competition) has a negative impact on productivity.Panel data, Productivity, Manufacturing, Competition

Translog Cost Functions: An Application for Mexican Manufacturing.

We use translog cost functions to estimate own-price and substitution elasticities of input demands, economies of scale and average costs in Mexican manufacturing. Data from the Mexican Annual Industrial Survey is used for 1996, 2000 and 2003. We show that a model that allows for nonhomotheticity and nonunitary elasticities of substitution is appropriate to represent the production structure. Allen-Uzawa elasticities indicate the existence of substitution possibilities amongst inputs. The demand for electricity is essentially unitary elastic. All cross-price elasticities are less than one. Both scale economies and average costs diminish as the size of activity class increases. Economies of scale increased for any level of output. The differences in average costs between small and large activity classes were reduced and some disparities prevail in a number of manufacturing groups.Simultaneous equation models, Translog cost function, Manufacturing

Even-dimensional General Relativity from Born-Infeld gravity

It is an accepted fact that requiring the Lovelock theory to have the maximun possible number of degree of freedom, fixes the parameters in terms of the gravitational and the cosmological constants. In odd dimensions, the Lagrangian is a Chern-Simons form for the (A)dS group. In even dimensions, the action has a Born-Infeld-like form. Recently was shown that standard odd-dimensional General Relativity can be obtained from Chern-Simons Gravity theory for a certain Lie algebra B. Here we report on a simple model that suggests a mechanism by which standard even-dimensional General Relativity may emerge as a weak coupling constant limit of a Born-Infeld theory for a certain Lie subalgebra of the algebra B. Possible extension to the case of even-dimensional supergravity is briefly discussed

Chern-Simons and Born-Infeld gravity theories and Maxwell algebras type

Recently was shown that standard odd and even-dimensional General Relativity can be obtained from a $(2n+1)$-dimensional Chern-Simons Lagrangian invariant under the $B_{2n+1}$ algebra and from a $(2n)$-dimensional Born-Infeld Lagrangian invariant under a subalgebra $\cal{L}^{B_{2n+1}}$ respectively. Very Recently, it was shown that the generalized In\"on\"u-Wigner contraction of the generalized AdS-Maxwell algebras provides Maxwell algebras types $\cal{M}_{m}$ which correspond to the so called $B_{m}$ Lie algebras. In this article we report on a simple model that suggests a mechanism by which standard odd-dimensional General Relativity may emerge as a weak coupling constant limit of a $(2p+1)$-dimensional Chern-Simons Lagrangian invariant under the Maxwell algebra type $\cal{M}_{2m+1}$, if and only if $m\geq p$. Similarly, we show that standard even-dimensional General Relativity emerges as a weak coupling constant limit of a $(2p)$-dimensional Born-Infeld type Lagrangian invariant under a subalgebra $\cal{L}^{\cal{M}_{2m}}$ of the Maxwell algebra type, if and only if $m\geq p$. It is shown that when $m<p$ this is not possible for a $(2p+1)$-dimensional Chern-Simons Lagrangian invariant under the $\cal{M}_{2m+1}$ and for a $(2p)$-dimensional Born-Infeld type Lagrangian invariant under $\cal{L}^{\cal{M}_{2m}}$ algebra.Comment: 30 pages, accepted for publication in Eur.Phys.J.C. arXiv admin note: text overlap with arXiv:1309.006

Effectiveness of delayed-release dimethyl fumarate on patient-reported outcomes and clinical measures in patients with relapsing-remitting multiple sclerosis in a real-world clinical setting: PROTEC.

Ensaio clínico PROTEC, Protocolo nº 109MS408Abstract BACKGROUND: Patient-reported outcomes (PRO) and clinical outcomes give a broad assessment of relapsing-remitting multiple sclerosis (RRMS) disease. OBJECTIVE: The aim is to evaluate the effectiveness of delayed-release dimethyl fumarate (DMF) on disease activity and PROs in patients with RRMS in the clinic. METHODS: PROTEC, a phase 4, open-label, 12-month observational study, assessed annualized relapse rate (ARR), proportion of patients relapsed, and changes in PROs. Newly diagnosed and early MS (≤3.5 EDSS and ≤1 relapse in the prior year) patient subgroups were evaluated. RESULTS: Unadjusted ARR at 12 months post-DMF versus 12 months before DMF initiation was 75% lower (0.161 vs. 0.643, p < 0.0001) overall (n = 1105) and 84%, 77%, and 71% lower in newly diagnosed, ≤3.5 EDSS, and ≤1 relapse subgroups, respectively. Overall, 88% of patients were relapse-free 12 months after DMF initiation (84%, newly diagnosed; 88%, ≤3.5 EDSS; 88%, ≤1 relapse). PRO measures for fatigue, treatment satisfaction, daily living, and work improved significantly over 12 months of DMF versus baseline. CONCLUSION: At 12 months after versus 12 months before DMF initiation, ARR was significantly lower, the majority of patients were relapse-free, and multiple PRO measures showed improvement (overall and for subgroups), suggesting that DMF is effective based on clinical outcomes and from a patient perspective.Clinical trial: A Study Evaluating the Effectiveness of Tecfidera (Dimethyl Fumarate) on Multiple Sclerosis (MS) Disease Activity and Patient-Reported Outcomes (PROTEC), NCT01930708,info:eu-repo/semantics/publishedVersio

Aspects of the Unitarized Soft Multipomeron Approach in DIS and Diffraction

We study in detail the main features of the unitarized Regge model (CFKS), recently proposed to describe the small-$Q^2$ domain. It takes into account a two-component description with two types of unitarized contributions: one is the multiple pomeron exchange contribution, interacting with the large dipole configurations, and the other one consists of a unitarized dipole cross section, describing the interaction with the small size dipoles. We analyze the ratio between soft and hard pieces as a function of the virtuality, and also compare the resulting dipole cross section to that from the saturation model. Diffraction dissociation is also considered, showing the scaling violations in diffractive DIS and estimating the corresponding logarithmic slope.Comment: 14 pages, 5 postscript figures. Version to be published in Eur. Phys. J.

Inductive Entanglement Classification of Four Qubits under SLOCC

Using an inductive approach to classify multipartite entangled states under stochastic local operations and classical communication introduced recently by the authors [Phys. Rev. A 74, 052336 (2006)], we give the complete classification of four-qubit entangled pure states. Apart from the expected degenerate classes, we show that there exist eight inequivalent ways to entangle four qubits. In this respect, permutation symmetry is taken into account and states with a structure differing only by parameters inside a continuous set are considered to belong to the same class.Comment: 11 pages and no figures. Accepted in PR

Sequential Quantum Cloning

Not all unitary operations upon a set of qubits can be implemented by sequential interactions between each qubit and an ancillary system. We analyze the specific case of sequential quantum cloning 1->M and prove that the minimal dimension D of the ancilla grows linearly with the number of clones M. In particular, we obtain D = 2M for symmetric universal quantum cloning and D = M+1 for symmetric phase-covariant cloning. Furthermore, we provide a recipe for the required ancilla-qubit interactions in each step of the sequential procedure for both cases.Comment: 4 pages, no figures. New version with changes. Accepted in Physical Review Letter