CONVERGENCE, HARMONIZATION, AND COMPATIBILITY UNDER NAFTA: A 2003 STATUS REPORT

In the 2001 Workshop the authors developed and applied a taxonomy and framework for assessing the status of agricultural and food policies in each of the NAFTA countries (Knutson, Loyns and Ochoa, 2002). It divided the policies into the following areas: -Facilitate growth and progress. Regulation. Market intervention. For each area the paper identified the major points of conflict that existed in 2001 at the time the paper was written and the requirements for harmonization. The major areas of conflict included; -Facilitate growth and progress: particularly grades and standards in grains (US-CA) and beef (US-CA); trade policy in dairy (US-CA), sugar (US-MX), poultry (US-MX), and wheat (US-CA); infrastructure policies (border conflicts US-MX). Regulation: particularly plant and animal protection (US-MX), food safety (US-MX), pesticides (US-CA-MX). Market interventions: particularly disaster assistance (US-CA-MX), price supports and safety nets (US-CA-MX), and supply management and state trading. The purpose of this paper is to update that paper and to draw conclusions as to whether progress has been made since 2001 has been positive, negative, or neutral in each of these areas of conflict for policy/program convergence, harmonization, and compatibility. The 2001 policies, therefore, can be looked upon as a policy baseline point of reference for comparison in 2003. Many of the policy changes were embodied in the precipitated by the US 2002 farm bill. However, care was taken to review each of the policy/program areas covered in the 2001 taxonomy to identify changes in the level of conflict.International Relations/Trade,

Z' boson detection in the Minimal Quiver Standard Model

We undertake a phenomenological study of the extra neutral Z' boson in the Minimal Quiver Standard Model and discuss limits on the model's parameters from previous precision electroweak experiments, as well as detection prospects at the Large Hadron Collider at CERN. We find that masses lower than around 700 GeV are excluded by the $Z$-pole data from the CERN-LEP collider, and below 620 GeV by experimental data from di-electron events at the Fermilab-Tevatron collider. We also find that at a mass of 1 TeV the LHC cross section would show a small peak in the di-lepton and top pair channel.Comment: 15 pages, 5 figures. v2: substantial revisions and improvements, final version accepted for publicatio

Combined photo- and electroreflectance of multijunction solar cells enabled by subcell electric coupling

Electric coupling between subcells of a monolithically grown multijunction solar cell in short circuit allows their simultaneous and independent characterization by means of photo- and electroreflectance. The photovoltage generated by selective absorption of the pump beam in a given subcell during photoreflectance measurements results in reverse biasing the complementary subunits at the modulation frequency set on the pump illumination. Such voltage bias modulation acts then as external perturbation on the complementary subcells. The spectral separation of the different subcell absorption ranges permits the probe beam to record in a single spectrum the response of the complete device as a combination of photo- and electroreflectance, thereby providing access for diagnosis of subcells on an individual basis. This form of modulation spectroscopy is demonstrated on a GaInP/GaAs tandem solar cell.Comment: 5 pages, 4 figures. This article has been accepted by Appl. Phys. Lett. After it is published, it will be found at https://doi.org/10.1063/1.506260

MasterChem: Cooking 2D-polymers

2D-polymers are still dominated by graphene and closely related materials such as boron nitride, transition metal sulphides and oxides. However, the rational combination of molecules with suitable design is already showing the high potential of chemistry in this new research field. The aim of this feature article is to illustrate, and provide some perspectives, the current state-of-the-art in the field of synthetic 2D-polymers showing different alternatives to prepare this novel type of polymers based on the rational use of chemistry. This review comprises a brief revision of the essential concepts, the strategies of preparation following the two general approaches, bottom-up and top-down, and a revision of the promising seminal properties showed by some of these nanomaterials.Financial support from Spanish MINECO (MAT2013-46753-C2-1-P and MAT2013-46502-C2-2-P). D. R. thanks the Spanish MECD for a FPU gran

The light CP-even MSSM Higgs mass resummed to fourth logarithmic order

We present the calculation of the light neutral CP-even Higgs mass in the MSSM for a heavy SUSY spectrum by resumming enhanced terms through fourth logarithmic order (N$^3$LL), keeping terms of leading order in the top Yukawa coupling $\alpha_t$, and NNLO in the strong coupling $\alpha_s$. To this goal, the three-loop matching coefficient for the quartic Higgs coupling of the SM to the MSSM is derived to order $\alpha_t^2\alpha_s^2$ by comparing the perturbative EFT to the fixed-order expression for the Higgs mass. The new matching coefficient is made available through an updated version of the program Himalaya. Numerical effects of the higher-order resummation are studied using specific examples, and sources of theoretical uncertainty on this result are discussed.Comment: 26 pages, 3 figures, matches version published in EPJ

Examining the Effects of Power Posing on Stress Reactivity and Performance

Power posing is a concept that has garnered widespread attention due to claims thatan expansive powerful posture can improve self-perceptions of power, trigger changes in hormone levels, and improve behavioral outcomes including enhanced performance in social evaluative situations. Recently, these claims have been challenged by studies that failed to replicate the power boosting effects of expansive poses. This study aimed to address inconsistencies in the power posing literature and replicate original findings while controlling for potential effects of experimenter bias and touch. It was predicted that a high-power pose would reduce cortisol, increase perceptions of power, and improve performance. To test this, 60 undergraduate participants were recruited and assigned to a high-power or low-power group. The TSST was utilized to induce psychosocial stress. Cortisol was examined as a physiological marker of stress via salivary samples. Perceived power was measured prior to and following power posing and stress induction. Performance was scored via the SPES, a scale designed to systematically evaluate TSST performance. Findings did not reveal any significant differences between the high-power and low-power group for any dependent measures, and the results are discussed in the context of previous findings. This experiment joins the growing number of studies that have examined the effects of power posing and have been unable to replicate previous findings

Evaluación cuantitativa de la influencia de los espacios de color para la detección automática de células

En este artículo proponemos el estudio de los espacios de color en el marco de la segmentación automática de estructuras celulares. En contraste con estudios neuro-físicos orientados a describir la percepción humana del color nosotros desarrollamos un análisis cuantitativo tomando como referencia el resultado de algoritmos de segmentación y plantillas generadas manualmente. Los resultados obtenidos demuestran que el color tiene una influencia considerable sobre la capacidad de análisis de una imagen y que los espacios de color que además de separar la cromaticidad y luminancia procuran la normalización de las distancias entre colores proveen una mejor representación de la información presente en la imagen a diferencia de los espacios de color tales como el RGB y HSI que han dominado la literatura de procesamiento de imágenes biomédicas en el pasadoIn this paper we study color spaces in the framework of automatic segmentation of cellular structures. In contrast to neuro-physical studies focused on human perception of color we resort to a quantitative evaluation of such impact using as reference segmentation outputs and ground truth images. The results show that color representation has a considerable influence in the capabilities of such algorithms and color spaces that separate chromaticity and luminance components, and normalize color differences, provide a representation of image data better than color spaces such as RGB and HSI used extensively in the field of biomedical image processing in the past

Generation of Circular Polarization of the Cosmic Microwave Background

The standard cosmological model, which includes only Compton scattering photon interactions at energy scales near recombination, results in zero primordial circular polarization of the cosmic microwave background. In this paper we consider a particular renormalizable and gauge-invariant standard model extension coupling photons to an external vector field via a Chern-Simons term, which arises as a radiative correction if gravitational torsion couples to fermions. We compute the transport equations for polarized photons from a Boltzmann-like equation, showing that such a coupling will source circular polarization of the microwave background. For the particular coupling considered here, the circular polarization effect is always negligible compared to the rotation of the linear polarization orientation, also derived using the same formalism. We note the possibility that limits on microwave background circular polarization may probe other photon interactions and related fundamental effects such as violations of Lorentz invariance.Comment: 20 pages. Revised version includes an explicit calculation of gauge invariance. Text reorganized to improve clarity, and references adde