The Maize Seed Industries of Brazil and Mexico: Past Performance, Current Issues, and Future Prospects

This paper describes results of a study of the main factors affecting the development of the maize seed industries in Brazil and Mexico (and, by extension, other developing countries). The authors develop a framework that researchers and policy makers can use to evaluate seed industry performance in developing countries. This framework is used to analyze the seed industries of Brazil and Mexico, where very different sets of circumstances influence seed industry development, efficiency, and structure. The analysis gives special attention to the different maize breeding strategies pursued by the public and private sectors, measures of industry competitiveness and efficiency, and the trade-offs involved in developing and producing different kinds of maize seed, particularly improved open-pollinated maize varieties versus different types of hybrids. The authors identify key seed industry issues for researchers, administrators of national maize programs, and agricultural policy makers in developing countries, especially issues related to the appropriate roles for public and private organizations in maize seed industries in the developing world.Crop Production/Industries,

Probing the "μ\mu from ν\nu" supersymmetric standard model with displaced multileptons from the decay of a Higgs boson at the LHC

The "$\mu$ from $\nu$" supersymmetric standard model ($\mu\nu$SSM) cures the $\mu$-problem and concurrently reproduces measured neutrino data by using a set of usual right-handed neutrino superfields. Recently, the LHC has revealed the first scalar boson which naturally makes it tempting to test $\mu\nu$SSM in the light of this new discovery. We show that this new scalar while decaying to a pair of unstable long-lived neutralinos, can lead to a distinct signal with non-prompt multileptons. With concomitant collider analysis we show that this signal provides an unmistakable signature of the model, pronounced with light neutralinos. Evidence of this signal is well envisaged with sophisticated displaced vertex analysis, which deserves experimental attention.Comment: 5 pages, 3 figures, title, text, abstract and references modifie

Hunting physics beyond the standard model with unusual W±W^\pm and ZZ decays

Nonstandard on-shell decays of $W^\pm$ and $Z$ bosons are possible within the framework of extended supersymmetric models, i.e., with singlet states and/or new couplings compared to the minimal supersymmetric standard model. These modes are typically encountered in regions of the parameter space with light singlet-like scalars, pseudoscalars, and neutralinos. In this letter we emphasize how these states can lead to novel signals at colliders from $Z$- or $W^\pm$-boson decays with prompt or displaced multileptons/tau jets/jets/photons in the final states. These new modes would give distinct evidence of new physics even when direct searches remain unsuccessful. We discuss the possibilities of probing these new signals using the existing LHC run-I data set. We also address the same in the context of the LHC run-II, as well as for the future colliders. We exemplify our observations with the "$\mu$ from $\nu$" supersymmetric standard model, where three generations of right-handed neutrino superfields are used to solve shortcomings of the minimal supersymmetric standard model. We also extend our discussion for other variants of supersymmetric models that can accommodate similar signatures.Comment: New discussions and references added, 8 pages, 1 figure, matches with the published version in Phys. Rev.

Appellation of Origin Status and Economic Development: A Case Study of the Mezcal Industry

Mezcal is an alcoholic beverage produced only in selected regions of Mexico under appellation of origin status from the Word Intellectual Property Organization. While it has been produced in Mexico for many centuries, mezcal’s appellation of origin was only granted in 1995. Therefore efforts to produce and market it as a premium product have a relatively short history. This case study examines developments in the production and marketing of this unique product, and the activities of the marketing cooperative El Tecuán in Guerrero State in this process.mezcal, Mexico, appellation, marketing, cooperative, Community/Rural/Urban Development, Marketing,

The top-quark mass in SU(5)xU(1) supergravity

We show that the currently experimentally preferred values of the top-quark mass (\ie, 130\lsim m_t\lsim180\GeV) are naturally understood in the context of string models, where the top-quark Yukawa coupling at the string scale is generically given by $\lambda_t={\cal O}(g)$, with $g$ the unified gauge coupling. A detailed study of the Yukawa sector of $SU(5)\times U(1)$ supergravity shows that the ratio of the bottom-quark to tau-lepton Yukawa couplings at the string scale is required to be in the range 0.7\lsim\lambda_b/\lambda_\tau\lsim1, depending on the values of $m_t$ and $m_b$. This result is consistent with $SU(5)\times U(1)$ symmetry, which does {\em not} require the equality of these Yukawa couplings in the unbroken symmetry phase of the theory. As a means of possibly predicting the value of $m_t$, we propose a procedure whereby the size of the allowed parameter space is determined as a function of $m_t$, since all sparticle and Higgs-boson masses and couplings depend non-trivially on $m_t$. At present, no significant preference for particular values of $m_t$ in $SU(5)\times U(1)$ supergravity is observed, except that high-precision LEP data requires m_t\lsim180\GeV.Comment: latex, 10 pages, 4 figures (included), CERN-TH.7138/94, CTP-TAMU-05/9

Characterization of HIV-1 RNA forms in the plasma of patients undergoing successful HAART

An assay to characterize plasma human immunodeficiency virus 1 (HIV-1) sequences for patients with low viral loads was developed by combining the selective binding of anti-CD44 MicroBeads with a nested RT-PCR targeting the env C2V4 region. Sequences were obtained from 10 of 20 HIV+ patients who had viral loads below 48 copies/ml. Sequences derived from plasma were compared to those from CD14+ CD16 +monocytes and CD4+ T cells. The plasma sequences were most closely related to those amplified from monocytes, suggesting that during successful antiretroviral therapy, the predominant plasma virus originates from myeloid cells. By characterizing HIV-1 RNA sequences from 8 ml of plasma while avoiding multiple steps, which can lead to contamination and deterioration, this method can help elucidate the viral forms in patients with therapeutically suppressed HIV-1. Understanding the source of residual viremia is crucial in developing approaches for viral eradication

Quantum Flows for Secret Key Distribution

Despite the unconditionally secure theory of quantum key distribution (QKD), several attacks have been successfully implemented against commercial QKD systems. Those systems have exhibited some flaws, as the secret key rate of corresponding protocols remains unaltered, while the eavesdropper obtains the entire secret key. We propose a new theoretical approach called quantum flows to be able to detect the eavesdropping activity in the channel without requiring additional optical components different from the BB84 protocol because the system can be implemented as a high software module. In this approach, the transmitter interleaves pairs of quantum states, referred to here as parallel and orthogonal (non-orthogonal) states, while the receiver uses active basis selection

gl(3)gl(3) polynomial integrable system: different faces of the 3-body/A2A_2 elliptic Calogero model

It is shown that the $gl(3)$ polynomial integrable system, introduced by Sokolov-Turbiner, is equivalent to the $gl(3)$ quantum Euler-Arnold top in a constant magnetic field. Their Hamiltonian and Integral can be rewritten in terms of $gl(3)$ algebra generators. All these $gl(3)$ generators can be represented by the non-linear elements of the universal enveloping algebra of the Heisenberg algebra $h_5({p}_{1,2},{q}_{1,2}, I)$, thus, the Hamiltonian and Integral are two elements of the universal enveloping algebra $U_{h_5}$. In this paper four different representations of the $h_5$ Heisenberg algebra are used: by differential operators in two real (complex) variables and by finite-difference operators on uniform or exponential lattices. If $({p},{q})$ are represented by finite-difference operators on uniform or exponential lattice, the Hamiltonian and the Integral of the 3-body elliptic Calogero model become the isospectral, finite-difference operators on uniform-uniform or exponential-exponential lattices (or mixed) with polynomial coefficients. If $({p},{q})$ are written in complex $(z, \bar{z})$ variables the Hamiltonian corresponds to a complexification of the 3-body elliptic Calogero model on ${\bf C^2}$.Comment: 28 pages, considerable editing performe

Composición briofítica de los hayedos de Navarra (España)

Se presenta un catálogo de 175 especies de briófitos recolectados en 19 hayedos de Navarra (España). Se establecen comparaciones entre las taxocenosis muscinales propias de cada tipo de hayedo reconocido (Saxifrago hirsutae-Fagetum Br.-BI. 1967, Helleboro-Fagetum O. de Bolos (1948) 1957, Scillo-Fagetum Br.-BI. 1952 em. O. de Bolos 1957 e Isopyro-Fagetum Montserrat 1968). Los porcentajes de elementos corológicos y afinidades ecológicas de la flora muscinal en cada sintaxon difieren entre sí y respecto al conjunto de la brioflora de los hayedos; estas diferencias están en relación con la sinecología de los "Fagetum". Summary: Bryophytic composition of the Fagus sylvatica L. woods in Navarra (Spain). A check-list of 175 species of bryophytes collected over 19 woods of Fagus sylvatica L. in Navarra (Spain) is presented. Comparations between the moss flora of every kind of wood (Saxifrago hirsutae-Fagetum Br.-BI. 1967, Helleboro-Fagetum O. de Bolos (1948) 1957, Scillo-Fagetum Br.-BI. 1952 em. O. de Bolos 1957 and Isopyro-Fagetum Montserrat 1968) are made. The chorologie and ecology composition of the moss flora of every sintaxa is different; differences are related with the sinecology of "Fagetum"

The singlet scalar as FIMP dark matter

The singlet scalar model is a minimal extension of the Standard Model that can explain the dark matter. We point out that in this model the dark matter constraint can be satisfied not only in the already considered WIMP regime but also, for much smaller couplings, in the Feebly Interacting Massive Particle (FIMP) regime. In it, dark matter particles are slowly produced in the early Universe but are never abundant enough to reach thermal equilibrium or annihilate among themselves. This alternative framework is as simple and predictive as the WIMP scenario but it gives rise to a completely different dark matter phenomenology. After reviewing the calculation of the dark matter relic density in the FIMP regime, we study in detail the evolution of the dark matter abundance in the early Universe and the predicted relic density as a function of the parameters of the model. A new dark matter compatible region of the singlet model is identified, featuring couplings of order 10^-11 to 10^-12 for singlet masses in the GeV to TeV range. As a consequence, no signals at direct or indirect detection experiments are expected. The relevance of this new viable region for the correct interpretation of recent experimental bounds is emphasized.Comment: 12 pages, 6 figure