A framework for analysing the adoption of New Zealand pastoral farming systems in central Veracruz State, Mexico : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Farm Management at Massey University

Tropical areas of developing countries have significant potential for increased food production. In the case of Mexico, an important economic activity in the tropics is livestock production based on pasture. Tropical regions represent 25% of the total area of Mexico and support more than 50% of the country's cow production. Historically, however, animal production in Mexican, and other tropical areas, has been low. Low pasture utilisation, and associated poor herbage quality, is one factor that contributes to poor animal performance in the tropics. This situation contrasts with the success of New Zealand pastoral systems, which in comparative terms have been able to obtain high levels of animal production and efficient use of pasture. Differences in pasture productivity (both in quality and quantity) and social and economic conditions between the Mexican tropics and New Zealand are large. Nevertheless it was proposed that some of the pastoral farming methods used in New Zealand, could be adapted to the conditions of tropical farmers in Mexico, particularly in relation to effective planning and control of the farming system. To test this hypothesis, the consequences of implementing some of New Zealand's pastoral farming techniques under tropical conditions in Central Veracruz State were explored by developing a spreadsheet model to simulate local farming systems. The model included linked submodels for pasture growth and quality, livestock transactions, milk production and enterprise gross margins. The effect of improved farming systems of milk output and cash returns were evaluated relative to the average levels of performance currently achieved from a medium-sized farm in the Central region of Veracruz State in Mexico. Straight forward changes in the design of the farming system, such as synchronising calving with the pattern of pasture growth rather than year-round calving, would significantly affect milk production and cash returns to the farm family. The modelling process was seriously constrained by the lack of farm-level data on pasture production and animal performance. Nevertheless, the model framework clearly identifies which data should be collected, and priority should now be given to assembling these data so simulation decision support models such as that developed in this study, can be effectively used to plan improved farming systems. Keywords: tropical agricultural, Mexico, farming systems, spreadsheet model

Spatial storage of discrete dark solitons

The interaction between a mobile discrete dark soliton (DDS) and impurities in one-dimensional nonlinear (Kerr) photonic lattices is studied. We found that the scattering is an inelastic process where the DDS can be reflected or transmitted depending on its transversal speed and the strength of the impurities. In particular, in the reflection regime, the DDS increases its transversal speed after each scattering. A method for spatial storage of DDS solutions using two impurities is discussed, where the soliton can be trapped within a storage region until it reaches the critical speed needed to be transmitted. We show, numerically, that this method allows the storage of multiple DDS simultaneously.Comment: 6 pages and 6 figure

Classical Emergence of Intrinsic Spin-Orbit Interaction of Light at the Nanoscale

Traditionally, in macroscopic geometrical optics intrinsic polarization and spatial degrees of freedom of light can be treated independently. However, at the subwavelength scale these properties appear to be coupled together, giving rise to the spin-orbit interaction (SOI) of light. In this work we address theoretically the classical emergence of the optical SOI at the nanoscale. By means of a full-vector analysis involving spherical vector waves we show that the spin-orbit factorizability condition, accounting the mutual influence between the amplitude (spin) and phase (orbit), is fulfilled only in the far-field limit. On the other side, in the near-field region, an additional relative phase introduces an extra term that hinders the factorization and reveals an intricate dynamical behavior according to the SOI regime. As a result, we find a suitable theoretical framework able to capture analytically the main features of intrinsic SOI of light. Besides allowing for a better understanding into the mechanism leading to its classical emergence at the nanoscale, our approach may be useful in order to design experimental setups that enhance the response of SOI-based effects.Comment: 10 pages, 5 figure

La co-educación en el ámbito educativo : proyecto de intervención interdisciplinar en la materia de educación física

Treball Final de Màster Universitari en Igualtat i Gènere en l'Àmbit Públic i Privat (Pla de 2013). Codi: SRM042. Curs: 2015/2016La discriminación por motivos de género en el ámbito educativo es un reflejo de nuestra sociedad y no se puede negar que sucede actualmente en nuestros centros educativos. Nuestra herencia cultural procedente del androcentrismo considera el modelo masculino como universal, quedando todavía resquicios y actitudes sexistas derivadas del mismo. La materia de Educación Física no es una excepción ya que, a pesar de que ha ido perdiendo parte de la carga sexista que poseía en sus orígenes, todavía podemos percibir multitud de actitudes sexistas durante las clases de Educación Secundaria Obligatoria. Uno de los errores que se han cometido en torno a este tema es considerar que la escuela mixta garantizaba un trato igualitario al alumnado por el mero hecho de que tanto los alumnos como las alumnas convivieran en una misma clase. Es por ello que la coeducación en el ámbito educativo cobra especial importancia ya que ésta, además de educar conjuntamente tanto a alumnos como alumnas, pretende crear las condiciones necesarias para que se lleve a cabo una igualdad de oportunidades real a través del respeto y atendiendo a las características de ambos grupos. Los objetivos principales de este TFM se resumen en, por un lado, conocer y analizar la situación actual de todo lo comentado anteriormente y, por otro y en base a ello, diseñar un proyecto de intervención interdisciplinar para un centro de educación secundaria liderado desde la materia de Educación Física con el propósito de aplicar una serie de estrategias educativas y metodológicas apoyadas en los modelos globalizadores que permitan modificar actitudes, prejuicios y estereotipos sociales para eliminar las situaciones de desigualdad de género

Pricing Derivatives Securities with Prior Information on Long- Memory Volatility

This paper investigates the existence of long memory in the volatility of the Mexican stock market. We use a stochastic volatility (SV) model to derive statistical test for changes in volatility. In this case, estimation is carried out through the Kalman filter (KF) and the improved quasi-maximum likelihood (IQML). We also test for both persistence and long memory by using a long-memory stochastic volatility (LMSV) model, constructed by including an autoregressive fractionally integrated moving average (ARFIMA) process in a stochastic volatility scheme. Under this framework, we work up maximum likelihood spectral estimators and bootstraped confidence intervals. In the light of the empirical findings, we develop a Bayesian model for pricing derivative securities with prior information on long-memory volatility.contingent pricing, econometric modeling

The monkey’s smile: A satire by Herrera the Younger on knowledge in the Arts

Partiendo de una conocida anécdota literaria en la vida de Herrera el Mozo por Palomino se ofrece un análisis de la imagen satírica del mono cuyo significado remite a los excesos de la imitación servil y a la pintura como ciencia especulativa capaz de reivindicarse en la risaFocusing on a well-kown literary anecdote in Palomino’s life of Herrera the Younger, this article analyzes the satirical image of the ape whose meaning refers to the excesses of the servile imitation and claims for painting as an speculative science that uses laughter to vindicate itsel

Analysis of ultra low cycle fatigue problems with the barcelona plastic damage model

This paper presents a plastic formulation based on the Barcelona plastic damage model ([1], [2]) capable of predicting the material failure due to Ultra Low Cycle Fatigue. This is achieved taking into account the fracture energy dissipated during the cyclic process. This approach allows the simulation of ULCF in regular cyclic tests, but also in non-regular cases such as seismic loads

Universal Thinning of Liquid Filaments under Dominant Surface Forces

Theory and numerical simulations of the thinning of liquid threads at high superficial concentration of surfactants suggest the existence of an asymptotic regime where surface tension balances surface viscous stresses, leading to an exponential thinning with an $e$-fold time $F(\Theta)\,(3\mu_s + \kappa_s)/\sigma$, where $\mu_s$ and $\kappa_s$ are the surface shear and dilatational viscosity coefficients, $\sigma$ is the interfacial tension, $\Theta=\kappa_s/\mu_s$, and $F(\Theta)$ is a universal function. The potential use of this phenomenon to measure the surface viscosity coefficients is discussed.Comment: 6 pages, 3 figures. Published in Physical Review Letter