Evaluation of AIS Data for Agronomic and Rangeland Vegetation: Preliminary Results for August 1984 Flight over Nebraska Sandhills Agricultural Laboratory

Since 1978 scientists from the Center for Agricultural Meteorology and Climatology at the University of Nebraska have been conducting research at the Sandhills Agricultural Laboratory on the effects of water stress on crop growth, development and yield using remote sensing techniques. We have been working to develop techniques, both remote and ground-based, to monitor water stress, phenological development, leaf area, phytomass production and grain yields of corn, soybeans and sorghum. Because of the sandy soils and relatively low rainfall at the site it is an excellent location to study water stress without the necessity of installing expensive rainout shelters. The primary objectives of research with the airborne imaging spectrometer (AIS) data collected during an August 1984 flight over the Sandhills Agricultural Laboratory are to evaluate the potential of using AIS to: (1) discriminate crop type; (2) to detect subtle architectural differences that exist among different cultivars or hybrids of agronomic crops; (3) to detect and quantify, if possible, the level of water stress imposed on the crops; and (4) to evaluate leaf area and biomass differences for different crops

Institutional Investors and Executive Compensation

Due to institutional investors' increasing ownership and interest in corporate governance, we hypothesize that the presence of institutional investors is associated with certain executive compensation structures. We find a significantly negative relation between the level of compensation and the concentration of institutional ownership, suggesting that institutions serve a monitoring role in the shareholder-manager agency problem. We further find a significantly positive relation between the pay-for-performance sensitivity of executive compensation and both the level and concentration of institutional ownership. These results suggest that the institutions act as a complement rather than a substitute to incentive compensation in mitigating the agency problem

Kaluza-Klein 5D Ideas Made Fully Geometric

After the 1916 success of General relativity that explained gravity by adding time as a fourth dimension, physicists have been trying to explain other physical fields by adding extra dimensions. In 1921, Kaluza and Klein has shown that under certain conditions like cylindricity ($\partial g_{ij}/\partial x^5=0$), the addition of the 5th dimension can explain the electromagnetic field. The problem with this approach is that while the model itself is geometric, conditions like cylindricity are not geometric. This problem was partly solved by Einstein and Bergman who proposed, in their 1938 paper, that the 5th dimension is compactified into a small circle $S^1$ so that in the resulting cylindric 5D space-time $R^4\times S^1$ the dependence on $x^5$ is not macroscopically noticeable. We show that if, in all definitions of vectors, tensors, etc., we replace $R^4$ with $R^4\times S^1$, then conditions like cylindricity automatically follow -- i.e., these conditions become fully geometric.Comment: 14 page

Project Rafiki: Consumer and Provider Perspectives on Food Assistance and its Impact on Quality of Life for Individuals Living with HIV/AIDS

Project Rafiki was designed to provide nonperishable food assistance to individuals living with HIV/AIDS in Tanzania, East Africa. The research study was developed to examine the extent to which the Project Rafiki food assistance program had impacted its participants over the course of one year. The aim of this research can be divided into five smaller objectives: 1) to gage the effectiveness of the food assistance program; 2) to assist in the expansion of inter-professional knowledge of resource-development regarding health and nutrition for vulnerable communities or rural areas; 3) to involve and immerse students in learning on a global level; 4) to grow and develop cross-cultural collaborations; and 5) to improve the health and well-being of individuals living with HIV/AIDS. This study focuses on discussing whether the implementation of Project Rafiki made a difference, and to what extent, to the target population. Overall it is the research team’s aim to study the benefits and challenges of Project Rafiki in order to improve, sustain, and replicate the program in global communities. The goal is to be able to share findings, with the purpose of hopefully creating more and similar sustainable food assistance programs in order to assist people living with HIV/AIDS both in America and outside of the country. The project aims to utilize the pilot data that was collected in Tanzania to build a foundation for future studies in this area

Measuring and modeling near-surface reflected and emitted radiation fluxes at the FIFE site

Information is presented pertaining to the measurement and estimation of reflected and emitted components of the radiation balance. Information is included about reflectance and transmittance of solar radiation from and through the leaves of some grass and forb prairie species, bidirectional reflectance from a prairie canopy is discussed and measured and estimated fluxes are described of incoming and outgoing longwave and shortwave radiation. Results of the study showed only very small differences in reflectances and transmittances for the adaxial and abaxial surfaces of grass species in the visible and infrared wavebands, but some differences in the infrared wavebands were noted for the forbs. Reflectance from the prairie canopy changed as a function of solar and view zenith angles in the solar principal plane with definite asymmetry about nadir. The surface temperature of prairie canopies was found to vary by as much as 5 C depending on view zenith and azimuth position and on the solar azimuth. Aerodynamic temperature calculated from measured sensible heat fluxes ranged from 0 to 3 C higher than nadir-viewed temperatures. Models were developed to estimate incoming and reflected shortwave radiation from data collected with a Barnes Modular Multiband Radiometer. Several algorithms for estimating incoming longwave radiation were evaluated and compared to actual measures of that parameter. Net radiation was calculated using the estimated components of the shortwave radiation streams, determined from the algorithms developed, and from the longwave radiation streams provided by the Brunt, modified Deacon, and the Stefan-Boltzmann models. Estimates of net radiation were compared to measured values and found to be within the measurement error of the net radiometers used in the study

On the distribution of career longevity and the evolution of home run prowess in professional baseball

Statistical analysis is a major aspect of baseball, from player averages to historical benchmarks and records. Much of baseball fanfare is based around players exceeding the norm, some in a single game and others over a long career. Career statistics serve as a metric for classifying players and establishing their historical legacy. However, the concept of records and benchmarks assumes that the level of competition in baseball is stationary in time. Here we show that power-law probability density functions, a hallmark of many complex systems that are driven by competition, govern career longevity in baseball. We also find similar power laws in the density functions of all major performance metrics for pitchers and batters. The use of performance-enhancing drugs has a dark history, emerging as a problem for both amateur and professional sports. We find statistical evidence consistent with performance-enhancing drugs in the analysis of home runs hit by players in the last 25 years. This is corroborated by the findings of the Mitchell Report [1], a two-year investigation into the use of illegal steroids in major league baseball, which recently revealed that over 5 percent of major league baseball players tested positive for performance-enhancing drugs in an anonymous 2003 survey.Comment: 5 pages, 5 figures, 2-column revtex4 format. Revision has change of title, a figure added, and minor changes in response to referee comment

Religious Identity, Religious Attendance, and Parental Control

Using a national sample of adolescents aged 10–18 years and their parents (N = 5,117), this article examines whether parental religious identity and religious participation are associated with the ways in which parents control their children. We hypothesize that both religious orthodoxy and weekly religious attendance are related to heightened levels of three elements of parental control: monitoring activities, normative regulations, and network closure. Results indicate that an orthodox religious identity for Catholic and Protestant parents and higher levels of religious attendance for parents as a whole are associated with increases in monitoring activities and normative regulations of American adolescents

The Introduction of DTT in Latin America: Politics and Policies

The switch to digital terrestrial television is now a global trend. In Latin America, where the terrestrial platform has a dominant role, the introduction of DTT raises important questions for economic and industrial development, as well as pluralism. This article focuses on the earliest experiences (Brazil, México and Argentina) and those of the newcomers (Chile, Colombia and Uruguay). The aim is to outline the differences between the various political decision processes and the way with which they have been turned into communication policies, so as to draw some conclusions that contribute to visualizing the future of television in the region.Publicad