Strengthening Soil Databases for Climate Change and Food Security Modeling Applications

Climate change is a hazard to the food security of a growing world population since it affects agriculture and likewise, agriculture and natural resource management affect the climate system. The relationships between all these factors including polices, political conditions, economical management and pest and diseases, and how they interact are not currently well-understood, nor are the advantages and disadvantages of different responses to climate change. In the face of climate change it is important to integrate knowledge about it to generate realistic solutions for agriculture, and food security in a meaningful and innovative way. Research in this topic has focused on addressing the needs for methods, models, databases and system metrics aimed at enhanced assessment and improved methodologies for the impact of climate change on agricultural systems and the development of different policy and program interventions to foster adaptation and mitigation in terms of poverty alleviation, food security and environmental health. This work should be in a framework and set of modeling tools and databases to analyze the implications of human responses to the climate challenge in terms of regional food security and the preservation of important ecosystem services, upon which the long-term sustainability of global agriculture must be based

Linear and field-independent relation between vortex core state energy and gap in Bi2Sr2CaCu2O8+d

We present a scanning tunneling spectroscopy study on quasiparticle states in vortex cores in Bi2Sr2CaCu2O8+δ. The energy of the observed vortex core states shows an approximately linear scaling with the superconducting gap in the region just outside the core. This clearly distinguishes them from conventional localized core states and is a signature of the mechanism responsible for their discrete appearance in high-temperature superconductors. The energy scaling of the vortex core states also suggests a common nature of vortex cores in Bi2Sr2CaCu2O8+δ and YBa2Cu3O7-δ. Finally, these states do not show any dependence on the applied magnetic field between 1 and 6 T

Cooperon propagator description of high temperature superconductivity

A phenomenological description of the high-Tc superconductors based on the Cooperon propagator is presented. This model allows one to study the effects of local pairing correlations and long-range phase fluctuations on the same footing, both above and below Tc. Based on numerical calculations, it is shown that the two types of correlations contribute to the gap/pseudogap in the single-particle excitation spectra. The concourse of these two effects can induce low energy states, which should be observable in underdoped materials at very low temperature.Comment: LaTeX, 6 pages, 2 EPS figures; paper presented at New^3SC-3, Hawaii, 01/2001. To appear in Physica

Distribuição espacial das necessidades hídricas das culturas do feijão, milho e soja na bacia do rio Tibaji, PR.

bitstream/item/89786/1/BOP-16.pd

英語教育における流暢さと即興力の育成 ── 中学生の話すことにおける意識の一考察 ──

The major goals of this study are to examine junior high school students’ awareness of fluency and impromptu skill in terms of speaking in English as a Foreign Language (hereafter, EFL) and to consider what to do, by way of future research and creation of daily lessons, in order to raise awareness and to develop their practical speaking abilities.　Recent Japanese EFL education (see MEXT 2017a-e) emphasizes that developing learners’ fluency and impromptu skill is particularly important.　This is because traditional Japanese EFL education has focused on acquisition of grammar, drawing learners’ attention to individual forms rather than to meaning.　Problematic outcomes of such an approach are tendencies for learners to comprehend texts/utterances in a heavy bottom-up manner and to refrain from speaking/writing without confirming that what they are about to say/write is grammatically correct.　In this study, 419 junior high school students in 1st to 3rd grades responded to a short paper-and-pencil questionnaire that examined their awareness of fluency and impromptu skill in EFL speaking.　Results of analyses showed a significant difference in awareness of impromptu skill between 1st and 2nd grades and between 1st and 3rd grades, whereas no significant differences were found in awareness of fluency between these three grades.　Moreover, results of analyses showed no correlation between 1st graders’ mid-term/ final exam scores and their awareness of fluency/impromptu skill, but showed a correlation between 2nd graders’ final exam scores and their awareness of fluency and between 2nd graders’ final exam scores and their awareness of impromptu skill.　Based on this and other information obtained in the study, we consider issues for future research and creation of classroom activities that develop fluency and impromptu skill in Japanese EFL education

Magnetic field induced charge and spin instabilities in cuprate superconductors

A d-wave superconductor, subject to strong phase fluctuations, is known to suffer an antiferromagnetic instability closely related to the chiral symmetry breaking in (2+1)-dimensional quantum electrodynamics (QED3). On the basis of this idea we formulate a "QED3 in a box" theory of local instabilities of a d-wave superconductor in the vicinity of a single pinned vortex undergoing quantum fluctuations around its equilibrium position. As a generic outcome we find an incommensurate 2D spin density wave forming in the neighborhood of a vortex with a concomitant "checkerboard" pattern in the local electronic density of states, in agreement with recent neutron scattering and tunneling spectroscopy measurements.Comment: 4 pages REVTeX + 2 PostScript figures included in text. Version to appear in PRL (minor stylistic changes, references updated). For related work and info visit http://www.physics.ubc.ca/~fran

Imaging the essential role of spin-fluctuations in high-Tc superconductivity

We have used scanning tunneling spectroscopy to investigate short-length electronic correlations in three-layer Bi2Sr2Ca2Cu3O(10+d) (Bi-2223). We show that the superconducting gap and the energy Omega_dip, defined as the difference between the dip minimum and the gap, are both modulated in space following the lattice superstructure, and are locally anti-correlated. Based on fits of our data to a microscopic strong-coupling model we show that Omega_dip is an accurate measure of the collective mode energy in Bi-2223. We conclude that the collective mode responsible for the dip is a local excitation with a doping dependent energy, and is most likely the (pi,pi) spin resonance.Comment: 4 pages, 4 figure