A Hawk-Dove game in kleptoparasitic populations

Kleptoparasitism, the parasitism by theft, is a widespread biological phenomenon. In this paper we extend earlier models to investigate a population of conspecifics involved in foraging and, potentially, kleptoparasitism. We assume that the population is composed of two types of individuals, Hawks and Doves. The types differ according to their strategic choices when faced with an opportunity to steal and to resist a challenge. Hawks use every opportunity to steal and they resist all challenges. Doves never resist and never steal. The fitness of each type of individual depends upon various natural parameters, for example food density, the handling time of a food item, density of the population, as well as the duration of potential fights over the food. We find the Evolutionarily Stable States (ESSs) for all arameter combinations and show that there are three possible ESSs, pure Hawks, pure Doves, and a mixed population of Hawks and Doves. We show that for any set of parameter values there is exactly one ESS. We further investigate the relationship between our findings and the classical Hawk-Dove game as defined in Maynard Smith 1982. We also show how our model extends the classical on

Long-term Global Agricultural Output Supply-Demand Balance and Real Farm and Food Prices

Global food demand is estimated from population projections of the United Nations and food supply is projected from Food and Agriculture Organization yield data to quantify the global food supply-demand balance for 2025 and 2050. The eight food categories examined account for 95 percent of global food consumption. Results indicate that the historic era of secularly falling real food prices is over. The real price of corn, for example, is not expected to fall over the next four decades at the annual rate of 1.3 percent that it fell annually from 1960 to 2006. The analysis foresees future real food prices fluctuating around a flat or rising trend. Slowed national economic growth from flat or rising real food prices may be little more than an irritant for consumers in affluent countries, but will entail severe hardship for consumers in the many countries currently troubled by poverty and hunger. Opportunities exist to expand food output by adding cropland in Brazil and irrigation in Africa, for example, but in the long term such developments will be offset by cropland removed from production by urban and industrial development, soil degradation, and the like. Although cropland can be expanded through higher real farm and food prices, higher yields rather than added cropland offer the most attractive opportunities for farm output expansion at low cost to consumers and the environment. The slowing rate of increase in crop and livestock yields corresponds with a slowing rate of increase in public and in private agricultural research and development spending. The world will not have the luxury of curtailing spending on agricultural technology and rejecting promising technologies such as genetically modified organisms (GMOs) if is to keep real food costs from rising. Productive new cropland, irrigation, genetically modified varieties, and other technologies will be hard pressed indeed to match the massive historic gains from hybrid varieties, irrigation, synthetic fertilizers, and mechanization. On the demand side, subsidies to expand demand for farming resources such as biofuels will need revisiting if rising food costs are to be contained.World Food Supply-Demand, Food Prices, Agricultural Markets, Crop and Livestock Yields, Agricultural and Food Policy, Demand and Price Analysis, International Development, Q11, Q18,

A method of hardware qualification for flight by analyses, similarity and integrated testing

The results are described of a study on four pieces of flight hardware from the Saturn 1U and S-4B stages to determine whether the objectives of the formal qualification tests on that hardware could have been obtained within that program by methods other than performing the qualification tests. These methods include qualification by analyses, similarity and integrated testing, i.e., distribution of the objectives among the other tests in the program. It was found that it is feasible to delete the requirements for formal qualification testing provided that it is accomplished early in the program to allow adequate planning for accomplishing the qualification objectives by other means. Additionally, a scorekeeping system was defined that is simple, straightforward, easy to implement. This scorekeeping system provides complete visibility of equivalent qualification status at any point during the program. A set of groundrules for implementing this study was established as a result of findings on the specific items of hardware studied

A Third-order and a Fourth-order Iteration Process for Nonlinear Equations

Convergence proof and procedure for third-order and fourth-order iteration process for nonlinear equations - Newton-Raphson second-order iteratio

A game-theoretic model of kleptoparasitic behavior in polymorphic populations

Kleptoparasitism, the stealing of food by one animal from another, is a widespread biological phenomenon. In this paper we build upon earlier models to investigate a population of conspecifics involved in foraging and, potentially, kleptoparasitism. We assume that the population is composed of four types of individuals, according to their strategic choices when faced with an opportunity to steal and to resist an attack. The fitness of each type of individual depends upon various natural parameters, for example food density, the handling time of a food item and the probability of mounting a successful attack against resistance, as well as the choices that they make. We find the evolutionarily stable strategies (ESSs) for all parameter combinations and show that there are six possible ESSs, four pure and two mixtures of two strategies, that can occur. We show that there is always at least one ESS, and sometimes two or three. We further investigate the influence of the different parameters on when each type of solution occurs

D-Zero Central Calorimeter Pressure Vessel and Vacuum Vessel Safety Notes

The relief valve and relief piping capacity was calculated to be 908 sefm air. This exceeds all relieving conditions. The vessel also has a rupture disc with a 2640 scfm air stamped capacity. In order to significantly decrease the amount of time required to fill the cryostats, it is desired to raise the setpoint of the 'operating' relief valve on the argon storage dewar to 20 psig from its existing 16 psig setting. This additional pressure increases the flow to the cryostats and will overwhelm the relief capacity if the temperature of the modules within these vessels is warm enough. Using some conservative assumptions and simple calculations within this note, the maximum average temperature that the modules within each cryostat can be at prior to filling from the storage dewar with liquid argon is at least 290 K. The average temperature of the module mass for any of the three cryostats can be as high as 290 K prior to filling that particular cryostat. This should not be confused with the average temperature of a single type or location which is useful in protecting the modules-not necessarily the vessel itself. A few modules of each type and at different elevations should be used in an average which would account for the different weights of each module. Note that at 290 K, the actual flow of argon through the relief valve and the rupture disk was under the maximum theoretical flows for each relief device. This means that the bulk temperature could actually have been raised to flow argon through the reliefs at their maximum capacity. Therefore, the temperature of 290 K is a conservative value for the calculated flow rate of 12.3 gpm. Safeguards in addition to and used in conjunction with operating procedures shall be implemented in such a way so that the above temperature limitation is not exceeded and such that it is exclusive of the programmable logic controller (PLC). One suggestion is using a toggle switch for each cryostat mounted in the PLC I/O box which would maintain control of the signals to open the cold fill valves of each cryostat. With the safeguards in place while carefully monitoring the temperatures during a cooldown cycle in each cryostat, the set pressure in the argon storage dewar can safely be increased to 20 psig

Stability of Vitamin A in Mixed Feeds

The study reported here was conducted to determine how different types of feed mixtures and storage conditions affect the biological activity of vitamin A acetate. The study was initiated June 19, 1978, continued through the summer months and completed January 9, 1979

CULTURALLY DIVERSE STUDENT ENGAGEMENT AND PROFESSIONAL DEVELOPMENT NEEDS OF UNDERGRADUATE FACULTY: A QUALITATIVE CASE STUDY

This qualitative single-site case study explored how undergraduate faculty members engaged culturally diverse students and determined the professional development needs of those faculty members to engage culturally diverse student populations. Exploring culturally sensitive practices will enable faculty members of institutions of higher education (IHEs) to engage diverse student populations. Determining the professional development needs of IHEs faculty members will assist IHEs’professional developers to implement training that will enhance the engagement of culturally diverse student populations. Qualitative data were collected through interviews from five undergraduate education faculty members at an institution of higher education (IHE) in the southeastern region of the United States. A cross-case analysis of the five interviews was conducted, and the interviews were coded and categorized. The findings from the study revealed that utilizing various materials and methods engaged culturally diverse students. Furthermore, the findings described the undergraduate faculty need for formal and informal professional development focused on cultural sensitivity, understanding diverse perspectives, and creating global and lifelong learner mindsets to engage culturally diverse students

Deposition and diagenesis of a portion of the Frobisher-Alida Interval (Mississippian Madison Group), Wiley Field, North Dakota

This study focused on the Frobisher-Alida interval, in particular, the Glenburn bed or the Mississippian Mission canyon Formation. Wireline logs and cores from closely spaced wells in, and adjacent to, the Wiley Field, Williston Basin, North Dakota were examined. Information derived from the wireline logs was used to construct several maps which show that there was little or no topographic relief or slope in the study area during deposition or the Glenburn bed. In addition, the maps show that structural derormation occurred subsequent to deposition or the Frobisher-Alida interval. Six distinct lithoracies were recognized in cores or the Glenburn bed from the Wiley Field area: 1) fossilirerous grainy mudstone packstone (LF-1); 2) coated-grain wackestone-grainstone (LF-2); 3) peloidal/intraclastic wackestone-packstone (LF-3); 4) dolowacke stone-mudstone and nodular anhydrite (LF-4); 5) massive anhydrite (LF-5); and, 6) siliciclastic sandstone-siltstone (LF-6). or the six lithoracies, all but LF-6 were deposited in a low-energy, shallow sublittoral, marine setting. The siliciclastic sandstone-siltstone lithoracies {LF-6) was deposited by eolian processes as a silici clastic-dominated sabkha. Facies within the Glenburn bed are stacked vertically rather than prograding either basinward or shoreward. Vertical stacking indicates that depositional processes were stable and did not shirt laterally by any significant amount, and that equilibrium conditions existed between sedimentation rates and rates or subsidence/sea level-change. Near the end or Glenburn time, the most shoreward lithoracies prograded across the study area in a basinward direction, indicating a drop in sea level or an increase in sedimentation rate. Within the study area, the distribution of fossils, dominant lithologies, and cement types indicate that lithofacies were formed in response to a horizontal salinity gradient in the water mass with salinities increasing to the northeast. The relative position of salinity values laterally across the area appears to have remained static during most of Glenburn bed deposition. Most of the sediments deposited in the study area are abiotic in origin, but may have formed due to, or in conjunction with, biochemical processes such as photosynthesis. Marine water flowing into the study area to replace water lost by evaporation became increasingly saline as it evaporated along its flow path. A digitate pattern (in plane view) of carbonate and anhydrite deposition formed due to the shoreward flow of relatively fresh, marine-water plumes, and the laterally adjacent, basinward flow of dense, hypersaline brines respectively. Diagenetic processes occurring due to the movement of surface or near surface hypersaline brines include dolomitization and calcite dissolution. Basinward-flowing, magnesium-rich brines derived from gypsum precipitating areas formed dolomite in a near surface, sublittoral setting. The same brines carried sulfide ions basinward where they were oxidized, creating an acid corrosive to carbonates that then caused vugular/enlarged fenestral porosity to develop in limestone lithofacies. The occurrence of plant megaspores (five new species) and fluorite in Mississippian rocks of the Williston Basin are reported for the first time in this report. Local hydrocarbon sourcing may have occurred

Dehorning Yearling Beef Cattle

The cattle feeder is interested in information on dehorning yearling cattle since many cattle reach the yearling age without being dehorned. Information on losses from dehorning, shrinkage following dehorning, rate of recovery of this shrink, and comparative rate of gain during the feeding period will help the feeder to determine how profitable it will be to dehorn yearling cattle. To answer some of these questions, five experiments were conducted using yearling steers and heifers