INCORPORATING UNCERTAINTY IN THE ANALYSIS OF OPTIMAL BEEF-FORAGE PRODUCTION SYSTEMS

A risk programming model was developed to evaluate the tradeoffs between risk and expected returns in beef-forage production systems. The specification represents nutrient and intake considerations when allocating forage among cattle enterprises; it also incorporates the various sources of risk facing livestock producers. Efficient ranch organizations were derived for a representative eastern Oklahoma ranch using MOTAD and Target-MOTAD formulations. Diversification of forage enterprises, introduction of cow-calf enterprises, and retained ownership of weaned calves were identified as important responses to reductions in acceptable levels of risk. Results also indicated efficient ranch plans to be sensitive to the risk criteria and producer's willingness to accept risk.Livestock Production/Industries, Risk and Uncertainty,

Black alumnae of predominantly white colleges : their effect upon the development of entitlement in Black students.

Black alumnae are a major resource for informed opinion about the experiences of Black students on predominantly white college campuses. Their wisdom, energy, knowledge and support have remained largely untapped. The literature regarding this resource is scanty and seldom deals with the perspective of Black alumnae, especially those who have been successful in negotiating the system. Knowledge of the past informs the direction of the future. Knowledge of and understanding about the past is available in the minds and from the experiences of Black graduates. They need to be recruited to share, in retrospect, their wisdom and insight about their college experiences and the effect it had on them as Black students. In addition, they needed to inspire, encourage and be a source of support to Black students of the present and in the future. Following a decade or more in which predominantly white colleges and universities actively recruited Black students as well as Black faculty and staff, the situation has been reversed dramatically. Black students who attend these colleges and universities in the eighties and nineties find themselves facing diminished numbers of both student and faculty; more stringent entrance requirements in the form of increased reliance on standardized test scores; financial aid more often in the form of loans than grants; and a distinct change in attitude about the support they can expect to find throughout the campus. Undergirding this change in attitude on the part of institutions of higher education is the increasingly conservative, sometimes even hostile, political and social situation in the country at large. The steady erosion of the idea that education is an entitlement and the insurance for all citizens against an uneducated citizenry who will, at the turn of the century, become our leaders, is the message of the eighties. The dissertation will seek to demonstrate the benefits to the college to be derived from the participation of Black alumnae of a predominantly white college or university. Historically these colleges have faced a major dilemma in their attempts to involve Black alumnae in the ongoing affairs of the college through the alumnae association. The methods used to encourage participation of the general body of the alumnae have failed to get significant participation or positive results from Black alumnae. An Entitlement Symposium held on the weekend of April 7, 8 and 9 at Simmons College can serve as a model of a way to involve these alumnae. The dissertation will present a journalistic report of the planning and the events. It will include the results of the discourse in the form of plans for future direction, activities and recommendations

Effects of Uncertainty in Climate Inputs on Simulated Evapotranspiration and Runoff in the Western Arctic

Hydrological models require accurate precipitation and air temperature inputs in order to adequately depict water fluxes and storages across Arctic regions. Biases such as gauge undercatch, as well as uncertainties in numerical weather prediction reanalysis data that propagate through water budget models, limit the ability to accurately model the terrestrial arctic water cycle. A hydrological model forced with three climate datasets and three methods of estimating potential evapotranspiration (PET) was used to better understand the impact of these processes on simulated water fluxes across the Western Arctic Linkage Experiment (WALE) domain. Climate data were drawn from the NCEP–NCAR reanalysis (NNR) (NCEP1), a modified version of the NNR (NCEP2), and the Willmott–Matsuura (WM) dataset. PET methods applied in the model were Hamon, Penman–Monteith, and Penman–Monteith using adjusted vapor pressure data. High vapor pressures in the NNR lead to low simulated evapotranspiration (ET) in model runs using the Penman–Monteith PET method, resulting in increased runoff. Annual ET derived from simulations using Penman–Monteith PET was half the magnitude of ET simulated when the Hamon method was used. Adjustments made to the reanalysis vapor pressure data increased the simulated ET flux, reducing simulated runoff. Using the NCEP2 or WM climate data, along with the Penman–Monteith PET function, results in agreement to within 7% between the simulated and observed runoff across the Yukon River basin. The results reveal the high degree of uncertainty present in climate data and the range of water fluxes generated from common model drivers. This suggests the need for thorough evaluations of model requirements and potential biases in forcing data, as well as corroborations with observed data, in all efforts to simulate arctic water balances

Spectral identification/elimination of molecular species in spacecraft glow

Computer models of molecular electronic and vibrational emission intensities were developed. Known radiative emission rates (Einstein coefficients) permit the determination of relative excited state densities from spectral intensities. These codes were applied to the published spectra of glow above shuttle surface and to the Spacelab 1 results of Torr and Torr. The theoretical high-resolution spectra were convolved with the appropriate instrumental slit functions to allow accurate comparison with data. The published spacelab spectrum is complex but N2+ Meinel emission can be clearly identified in the ram spectrum. M2 First Positive emission does not correlate well with observed features, nor does the CN Red System. Spectral overlay comparisons are presented. The spectrum of glow above shuttle surfaces, in contrast to the ISO data, is not highly structured. Diatomic molecular emission was matched to the observed spectral shape. Source excitation mechanisms such as (oxygen atom)-(surface species) reaction product chemiluminescence, surface recombination, or resonance fluorescent re-emission will be discussed for each tentative assignment. These assignments are the necessary first analytical step toward mechanism identification. Different glow mechanisms will occur above surfaces under different orbital conditions

Temporal and spatial variations in maximum river discharge from a new Russian data set

Floods cause more damage in Russia than any other natural disaster, and future climate model projections suggest that the frequency and magnitude of extreme hydrological events will increase in Russia with climate change. Here we analyze daily discharge records from a new data set of 139 Russian gauges in the Eurasian Arctic drainage basin with watershed areas from 16.1 to 50,000 km2 for signs of change in maximum river discharge. Several hypotheses about changes in maximum daily discharge and their linking with trends in precipitation over the cold season were tested. For the magnitude of maximum daily discharge we found relatively equal numbers of significant positive and negative trends across the Russian Arctic drainage basin, which draws into question the hypothesis of an increasing risk of extreme floods. We observed a significant shift to earlier spring discharge, which is consistent with documented changes in snowmelt and freeze‐thaw dates. Spatial analysis of changes in maximum discharge and cold season precipitation revealed consistency across most of the domain, the exception being the Lena basin. Trends in maximum discharge of the small‐ to medium‐sized rivers were generally consistent with aggregated signals found for the downstream gauges of the six largest Russian rivers. Although we observe regional changes in maximum discharge across the Russian Arctic drainage basin, no evidence of widespread trends in extreme discharge can be assumed from our analysis

Evaluation of trends in derived snowfall and rainfall across Eurasia and linkages with discharge to the Arctic Ocean

To more fully understand the role of precipitation in observed increases in freshwater discharge to the Arctic Ocean, data from a new archive of bias-adjusted precipitation records for the former USSR (TD9813), along with the CRU and Willmott-Matsuura data sets, were examined for the period 1936–1999. Across the six largest Eurasian river basins, snowfall derived from TD9813 exhibits a strongly significant increase until the late 1950s and a moderately significant decrease thereafter. A strongly significant decline in derived rainfall is also noted. Spatially, snowfall increases are found primarily across north-central Eurasia, an area where the rainfall decreases are most prominent. Although no significant change is determined in Eurasian-basin snowfall over the entire 64 year period, we note that interpolation from early, uneven station networks causes an overestimation of spatial precipitation, and that the local snowfall trends determined from gridded TD9813 data are likely underestimated. Yet, numerous uncertainties in historical Arctic climate data and the sparse, irregular nature of Arctic station networks preclude a confident assessment of precipitation-discharge linkages during the period of reported discharge trends

Are data collected to support farm management suitable for monitoring soil indicators at the national scale?

Monitoring of topsoil properties (referred to as indicators) at the national scale has been limited in general to government-funded representative surveys. We consider a cost-effective complementary source of soil information for monitoring agricultural soil across England and Wales (E&W): soil measurements paid for by farmers that we refer to as farmers' data (FD). A potential problem in using FD for soil monitoring is any unattributable sources of bias, such as the sample design. Farmers may choose to focus their measurements (purposively) where they perceive a particular problem. Such a source of bias is avoided in the random sampling adopted by statistically designed surveys, such as the Countryside Survey (CS2007) and LUCAS (Land Use/Cover Area frame statistical Survey). We used measurements from 143 000 FD soil samples from a single laboratory to estimate national mean values and confidence intervals of five topsoil indicators (pH, available P (Olsen), K, Mg and organic matter (OM)) across three combinations of nation (England or Wales) and land use (arable and horticulture (A&H) or improved grassland (IG)). We computed mean estimates for FD over two time periods (2004–9 and 2010–2105) and assessed the significance of any change. We compared these estimates with those from representative national surveys to establish whether there was evidence for bias and whether it could be explained. Mean estimates of topsoil pH for the FD and the LUCAS survey (same analytical method) were consistent for both A&H and IG. Although FD estimates of mean Olsen P (OP) concentrations were similar to previous surveys, we show it is likely that the larger mean OP concentrations observed in the LUCAS survey compared with FD for arable topsoil in England are partly due to an attributable source of analytical bias. For such quantifiable sources of bias, it might be possible to adjust estimated mean values from FD. However, FD might also include sources of unattributable bias, such as the effect of purposive sampling. It is important that contemporaneous data from surveys with statistically unbiased designs are available so that we can assess whether unattributable sources exert a significant effect over estimates of mean values computed from FD. Highlights Assessment of farmers' data (FD) to provide a potentially cost-effective way to monitor topsoil indicators. Few studies have compared national-scale estimates of topsoil indicators with survey data from statistically unbiased designs and FD. Bias between mean estimates from national surveys and FD could be accounted for. The denser sampling of FD enables mapping of national survey data with greater accuracy

Ultraviolet absorption: Experiment MA-059

A technique devised to permit the measurement of atmospheric species concentrations is described. This technique involves the application of atomic absorption spectroscopy and the quantitative observation of resonance fluorescence in which atomic or molecular species scatter resonance radiation from a light source into a detector. A beam of atomic oxygen and atomic nitrogen resonance radiation, strong unabsorbable oxygen and nitrogen radiation, and visual radiation was sent from Apollo to Soyuz. The density of atomic oxygen and atomic nitrogen between the two spacecraft was measured by observing the amount of resonance radiation absorbed when the line joining Apollo and Soyuz was perpendicular to their velocity with respect to the ambient atmosphere. Results of postflight analysis of the resonance fluorescence data are discussed

Got Milk? The Impact of Heifer International\u27s Livestock Donation Programs in Rwanda on Nutritional Outcomes

International animal donation programs have become an increasingly popular way for people living in developed countries to transfer resources to families living in developing countries. We evaluate the impact of Heifer International’s dairy cow and meat goat donation programs in Rwanda. We find that the program substantially increases dairy and meat consumption among Rwandan households who were given a dairy cow or a meat goat, respectively. We also find marginally statistically significant reductions in weight-for-height z-scores and weight-for-age z-scores of about 0.4 standard deviations among children aged 0-5 years in households that were recipients of meat goats, and reductions in heightfor- age z-scores of about 0.5 standard deviations among children in households that received dairy cows. Our results suggest that increasing livestock ownership in developing countries may significantly increase consumption of nutrient dense animal-source foods and improve nutrition outcomes