Extremal unipotent representations for the finite Howe correspondence

We study the Howe correspondence for unipotent representations of irreducible dual pairs $(G',G)=(\text{U}_m(\mathbb{F}_q),\text{U}_n(\mathbb{F}_q))$ and $(G',G)=(\text{Sp}_{2m}(\mathbb{F}_q),\text{O}^\epsilon_{2n}(\mathbb{F}_q))$, where $\mathbb{F}_q$ denotes the finite field with $q$ elements ($q$ odd) and $\epsilon=\pm 1$. We show how to extract extremal (i.e. minimal and maximal) irreducible subrepresentations from the image of $\pi$ under the correpondence of a unipotent representation $\pi$ of $G$.Comment: 22 page

Analysis of Commodity Program Adjustments for U.S. Rice in Stochastic Framework

Potential adjustments in U.S. commodity program for rice are evaluated in this paper using stochastic analysis in a global modeling framework. Corresponding threshold and loss-compensatory increases in target price and loan rates are determined with assumed outright and gradual elimination of direct payments. Results show that if direct payments (DP) are eliminated in 2012, a 23% increase in both the target price (TP) and loan rate (LR) triggers counter-cyclical payments (CCP) 80% of the time; and it will take an increase of 48% in TP and LR to generate CCP enough to compensate for the loss in total DP. If DP is gradually removed over 5 years, the trigger and compensatory increases in TP and LR are 41% and 46%, respectively. Furthermore, if DP is eliminated outright and TP maintained, an increase of 71% in LR triggers loan deficiency payments (LDP) 75% of the time; and it will take an increase of 130% in LR to generate enough LDP to recoup the total loss in DP. Under gradual removal of DP, the trigger and compensatory increases in LR are 71% and 92%, respectively.U.S. commodity program, threshold and loss-compensatory increases, stochastic analysis, Agricultural and Food Policy, Crop Production/Industries, Q18,

ANALYSIS OF U.S. RICE POLICY IN A GLOBAL STOCHASTIC FRAMEWORK

Replaced with revised version of paper 04/13/11.Government payments, stochastic analysis, deterministic analysis, rice trade, empirical distribution, Arkansas Global Rice Model, Agricultural and Food Policy, Demand and Price Analysis, International Relations/Trade, Q11, Q17,

2011 Updated Arkansas Global Rice Model

The Arkansas Global Rice Model is based on a multi-country statistical simulation and econometric framework. The model is disaggregated by five world regions: Africa, the Americas, Asia, Europe, and Oceania. Each region includes country models which have a supply sector, a demand sector, a trade, stocks and price linkage equations. All equations used in this model are estimated using econometric procedures or identities. Estimates are based upon a set of explanatory variables including exogenous macroeconomic factors such as income, population, inflation rate, technology development, and especially, government determined policy variables which reflect the various mechanisms by which countries intervene in their rice sector economy. Individual country models are linked through net trade to recognize the interdependence of countries in the world rice economy.Rice, trade model, policy, Agricultural and Food Policy, Research and Development/Tech Change/Emerging Technologies, CO2, C61, F11, F14, Q17, Q18,

Optical BVRI Photometry of Common Proper Motion F/G/K+M Wide Separation Binaries

We present optical (BVRI) photometric measurements of a sample of 76 common proper motion wide separation main sequence binary pairs. The pairs are composed of a F-, G-, or K-type primary star and an M-type secondary. The sample is selected from the revised NLTT catalog and the LSPM catalog. The photometry is generally precise to 0.03 mag in all bands. We separate our sample into two groups, dwarf candidates and subdwarf candidates, using the reduced proper motion (RPM) diagram constructed with our improved photometry. The M subdwarf candidates in general have larger $V-R$ colors than the M dwarf candidates at a given $V-I$ color. This is consistent with an average metallicity difference between the two groups, as predicted by the PHOENIX/BT-Settl models. The improved photometry will be used as input into a technique to determine the metallicities of the M-type stars.Comment: 26 pages, 8 figures, accepted for publication in A

HYBRID RICE AND ITS IMPACT ON FOOD SECURITY AND THE PATTERN OF GLOBAL PRODUCTION AND TRADE

The hybrid rice technology is one of the many ways in which productivity of scarce resources devoted to rice production could be enhanced, with the consequent alleviation of food insecurity. The findings of this study show that the hybrid rice technology has so far made some sizable contributions to per-capita availability of rice in adopting countries with marginal spillover effects to other regions. However, at forecasted population growths, a massive intensification of adoption would be needed to maintain per-capita availability of rice at baseline levels. But even with adoption rates climbing significantly, much higher equilibrium prices are expected, which will represent a challenge for the hungry in many parts of the world. While hybrid rice has the potential to contribute significantly to improve production and food security, more efforts are needed to improve the productivity of the constraining production resources.hybrid rice, food security, technology change, Demand and Price Analysis, Food Security and Poverty, International Relations/Trade, Research and Development/Tech Change/Emerging Technologies, Q16, Q55,

Telling a Story, Changing the World: California Rural Legal Assistance

This capstone project attempts to provide an in-depth view of how stories influence change in our lives as well as in the field of law

Movement Patterns of a Federally Endangered Minnow in a Fragmented Desert River

Fishes are unified in their need to move within the systems they occupy, and their movement patterns can be fundamental to their ecology and survival. Many large rivers in North America are fragmented by dams that modify natural flow regimes, compromise connectivity, and imperil freshwater fishes dependent on unrestricted movement in order to complete their life history. Coincident with widespread river fragmentation, are the declines of numerous endemic desert fishes in the American southwest. The Rio Grande Silvery Minnow (Hybognathus amarus, RGSM), has experienced a 95% reduction in its historical range and is now restricted to a highly fragmented stretch of river. Despite the important role of movement in riverine fishes, there are few studies describing the movement patterns of RGSM. The overall goal of this study is to document and better understand the movement ecology and patterns of RGSM. We used Passive Integrated Transponder (PIT) tags in hatchery-reared RGSM with stationary and mobile PIT-tag antenna systems to detect and track movement patterns across time and space. We released a total of 37,215 PIT-tagged RGSM between 2018 and 2022. Of those released, we detected 13,706 RGSM making at least one movement (e.g., detected at two different locations). We found RGSM to be highly mobile and documented individuals moving farther distances than ever previously recorded. Individuals moved a mean total distance of 12.2 river kilometers (rkm) over the course of one year, with a maximum total distance of 103.0 rkm. Overall, total distances moved by individuals was larger than linear home range sizes within one year of release, suggesting RGSM were moving at finer scales within the extent of the river they occupied. Although individuals moved large distances, movement patterns were leptokurtic, with a larger portion of RGSM remaining near their initial release location. We documented a total 198 unique upstream passages through a diversion dam. The documentation of these passages is particularly meaningful as passage through this diversion by RGSM has not been previously documented and the diversion is not equipped with a formal fish passage. As indicated by the high number of repeated detections over the study period, as well as our high redetection rate (36.8%), the efficacy of our study design to detect an imperiled small-bodied fish species has crucial conservation applications. Our study elucidates the movement patterns of RGSM and can be an important model for other fish species in fragmented desert systems