Preparing Tomorrow’s World Language Teacher Today: The Case for Seamless Induction

This essay is a call to action. It offers a comprehensive overview of the challenges facing world language (WL) teacher educators and their employers, the K-12 schools, during the teacher induction period. We propose a new paradigm for WL teacher education based on national accreditation standards, best-practice pedagogy, insights from the professional literature on methods education, and the enhanced role of the methods instructor/supervisor. In order to become successful in the classroom, the pre-service educator undergoes a seamless period of induction that is student-centered and college/university-supported beyond the classroom arena

Global and Unified Analysis of Solar Neutrino Data

We discuss the status of the solutions of the solar neutrino problem in terms of oscillations of $\nu_e$ into active or sterile neutrinos. We present the results of a global fit to the full data set corresponding to the latest data presented at the $\nu$-2000 conference. We show the possible solutions in the full parameter space including both MSW and vacuum, as well as quasi-vacuum oscillations (QVO) and matter effects for mixing angles in the second octant (the so called dark side). Our conclusion is that from the statistical point of view, all solutions for oscillations into active neutrinos: LMA, LOW, SMA and the QVO solutions are acceptable since they all provide a reasonable GOF to the full data set. The same holds for the SMA solution for oscillations into sterile neutrinos. LMA and LOW-QVO solutions for oscillations into active neutrinos seem slightly favoured over SMA solutions for oscillations into active or sterile neutrinos. We also analyze the dependence of these conclusions on the uncertainty of the SSM $^8$B flux and on the removal of the data from one of the experimental rates. We also present the results in the framework of four neutrino oscillations which allows for oscillations into a state which is a combination of active and sterile neutrino.Comment: 18 pages with 18 postscript figures included (some of them bitmapped for compression, better resolution at http://ific.uv.es/~penya

Genetic consequences of artificial selection on amino acid synthesis: Cysteine synthase and chorismate mutase

Abstract only availableFaculty Mentor: Michael D. McMullen, AgronomyGenetic diversity is crucial for progress in plant breeding as well as for adaptation to future environmental challenges. Maize is the most genetically diverse crop species. Maize was domesticated from teosinte about 7,500 years ago. Both domestication and crop improvement involved selection of specific alleles at genes controlling key morphological and agronomic traits, resulting in reduced genetic diversity relative to unselected genes. The McMullen Laboratory is interested in the genetic consequences of selection on genes of agronomic importance. Prior research by the Laboratory has identified a series of selected genes, including two key genes for the synthesis of amino acids, cysteine synthase and chorismate mutase. One approach to define the importance of a gene is to isolate a mutation and examine the resulting phenotype. A Mutator insertion was isolated in the cysteine synthase gene. An F2 population segregating for an albino phenotype and the Mutator insertion was genotyped by PCR to determine if the insertion was casual for the phenotype. The albino phenotype was found to be closely linked, but distinct from the insertion site leading to the conclusion that the albino phenotype is caused by a second linked mutation. The chorismate mutase gene in maize shows strong evidence of selection, with high diversity in teosinte accessions and essentially no diversity among inbred lines. Did the selection that reduced the diversity in this gene occur at domestication or during subsequent plant breeding? To answer this question, three segments of the chorismate mutase gene were sequenced in a panel of 14 landraces, the historical intermediate between teosinte and inbreds. Four landraces contained numerous polymorphism not found in inbreds, indicating that much of the selection occurred during recent crop improvement. This result is significant as it indicates genetic diversity can be reintroduced into selected amino acid genes by crosses with landraces

Kadath: a spectral solver for theoretical physics

Kadath is a library that implements spectral methods in a very modular manner. It is designed to solve a wide class of problems that arise in the context of theoretical physics. Several types of coordinates are implemented and additional geometries can be easily encoded. Partial differential equations of various types are discretized by means of spectral methods. The resulting system is solved using a Newton-Raphson iteration. Doing so, Kadath is able to deal with strongly non-linear situations. The algorithms are validated by applying the library to four different problems of contemporary physics, in the fields of gauge field theory and general relativityComment: Accepted to Journal of Computational Physic

Association Between Weight Loss and Physical Activity On Change In Blood Pressure In Overweight Adults

Please view abstract in the attached PDF file

Non-equilibrium Goldstone phenomenon in tachyonic preheating

The dominance of the direct production of elementary Goldstone waves is demonstrated in tachyonic preheating by numerically determining the evolution of the dispersion relation, the equation of state and the kinetic power spectra for the angular degree of freedom of the complex matter field. The importance of the domain structure in the order parameter distribution for the quantitative understanding of the excitation mechanism is emphasized. Evidence is presented for the very early decoupling of the low-momentum Goldstone modes.Comment: 14 LaTeX pages, 5 figures, version published in Phys. Rev.

Standard and Non-Standard Physics in Neutrino Oscillations

We analyze the impact of recent solar and atmospheric data in the determination of the neutrino oscillation parameters, taking into account that both the solar nu_e and the atmospheric nu_mu may convert to a mixture of active and sterile neutrinos. Furthermore, in the context of the atmospheric neutrino problem we discuss an extended mechanism of neutrino propagation which combines both oscillations and non-standard neutrino-matter interactions. We use the most recent neutrino data, including the 1496-day Super-K solar and atmospheric data samples, the latest SNO spectral and day/night solar data, and the final MACRO atmospheric results. We confirm the clear preference of all the data for pure-active oscillation solutions, bounding the fraction of sterile neutrino involved in oscillations to be less than 52% in the solar sector and less than 40% in the atmospheric sector, at 3 sigma. For the atmospheric case we also derive a bound on the total amount of non-standard neutrino-matter interactions, bounding the flavor-changing component to -0.03 <= epsilon <= 0.02 and the non-universal component to |epsilon'| <= 0.05.Comment: 6 pages, LaTeX file using espcrc2.sty, 1 table and 3 figures included. Talk given at the XXX International Meeting on Fundamental Physics (Jaca, Spain, 28/01-1/02/2002

Constraints on neutrino oscillation parameters from the SNO salt phase data

The physics implications of the just published salt phase data from the SNO experiment are examined. The effect of these data on the allowed ranges of the solar neutrino oscillation parameters, \Delta_m^2_{21} and $\sin^2\theta_{12}$, are studied in the cases of two- and three- neutrino mixing. In the latter case we derive an upper limit on the angle $\theta_{13}$. Constraints on the solar $\nu_e$ transitions into a mixture of active and sterile neutrinos are also presented. Finally, we give predictions for the day-night asymmetry in the SNO experiment, for the event rate in the BOREXINO and LowNu experiments, and discuss briefly the constraints on the solar neutrino oscillation parameters which can be obtained with prospective KamLAND data.Comment: Version to appear in PL