A study of citizens' apathy toward civic responsibility in two communities with contrasting socio-economic status

Thesis (M.S.)--Boston Universit

Bioassay of milk for estrogen content from stilbestrol-treated and non-treated cows

Call number: LD2668 .T4 1956 B37Master of Scienc

Carrier type, fat content, capsaicin concentration and sample temperature: effects on perceived pungency

In a study of pungency in food systems, three carriers (water, cheese sauce, starch paste) with varying fat levels (none, low, medium, and high), synthetic capsaicin concentration (0.0, 0.4, 0.8, and 1.3), and serving temperatures (25 and 38°C) were formulated. The study was an incomplete block design. Proximate composition and viscosity were measured for each batch of sample. Panelists were selected and trained according to ASTM (1991) method E 1083-88. They evaluated sensory heat intensity every 15 sec for 3 min, two samples per sittings, two sittings per day (block) for 12 days. Sixty-four samples were included (3 carriers x 1,3, or 4 fat levels within carrier x 2 serving temperatures x 4 capsaicin levels). The data were analyzed to determine differences attributable to main effects (capsaicin level, carrier, fat within carrier, temperature, block, and time) and interactions. Time-intensity parameters (maximum intensity-MAX, time to maximum intensity-TMAX, and rate of release-RATE) were evaluated. Viscosity differences were observed among fat levels and serving temperatures within each carrier. However viscosity was not correlated (p\u3e0.05) to MAX values. Water MAX scores were generally higher than those for other carriers within the same capsaicin level. MAX scores tended to decrease as fat level increased. TMAX did not appear to be a useful parameter in this study. RATE values for room temperature samples were significantly lower than those for warm samples. Heat intensity scores increased as capsaicin concentration increased across the 3-min time interval. Intensity of starch samples across time decreased as fat level increased. A similar trend was not observed with cheese sauce samples. Overall, intensity scores increased as capsaicin concentration increased. The increase was related to carrier and fat level. Water samples (0.4, 0.8, and 1.3) were perceived as more intense than cheese or starch samples at the same capsaicin level. Generally, increasing the fat level resulted in lower intensity scores. Temperature, in most cases, did not affect the pungency. The training method was effective when water was the carrier. However physical or chemical interaction that occur in simple food systems may influence perceived pungency

Experimental implementation of a real-time token-based network protocol on a microcontroller

The real-time token-based RTnet network protocol has been implemented on a standard Ethernet network to investigate the possibility to use cheap components with strict resource limitations while preserving Quality of Service guarantees. It will be shown that the proposed implementation is feasible on a small network. For larger networks a different approach is necessary, using delegation by means of proxies. A delegation proposal will be discussed. For small networks it is possible to use a PIC microcontroller in combination with a standard Ethernet controller to run the RTnet network protocol. As more systems are added to the network the performance of this combination becomes insufficient. When this happens it is necessary for the microcontroller to delegate some tasks to a more powerful master and to organize a low-level communication protocol between master and slave

Spatial weed distribution determined by ground cover measurements

A portable dual-camera video system was used to evaluate the potential for using total projected green cover as an indirect measure of weed infestations in a wheat crop during early growth stages. The video system would have applications in mapping weed infestations to assist precision farming operations. The two cameras provided a real-time composite image of reflected light measured in red (640 nm), and near-infrared (860 nm) wavelengths. A simple ratio of reflected light intensity in each wavelength was used to isolate the growing plants from the background. Software was developed to automatically adjust for varying ambient light conditions and calculate the percentage of the image occupied by growing plants. Total green cover was measured at randomly selected sites prior to direct seeding wheat and at four growth stages following wheat emergence. The portion of green cover observed was compared to crop and weed dry matter at each location. Weed infestations at each location were estimated by measuring the total green cover and subtracting the projected green cover due to the crop alone. A minimum weed dry matter of 20 g/m2 and 30 g/m2 could be detected by the video system at the 3-leaf and 5-leaf growth stages, respectively. Weed dry matter less than 20 g/m2 could not be detected reliably due to the variability of the wheat crop. Detection of weeds within the crop beyond the 5-leaf stage using this method was difficult due to crop canopy closure

Uncertainty and the Theory of Tax Incidence in a Stock Market Economy

[Introduction] Commencing with Harberger's (1962) classic paper, a number of studies have analyzed the incidence of taxation in the context of a deterministic, two-sector, two-factor general equilibrium model. Recently, R. N. Batra (1975) and R. A. Ratti and P. Shame (1977a, 1977b) have reexamined the robustness of these deterministic results for the case in which production uncertainty is incorporated into the model. By using "entrepreneurial" models in which the firm is assumed to maximize the expected utility of profits, they find that the incidence of taxes depends on the preferences and probability assessments of the entrepreneur, and in general, the deterministic results no longer obtain

Models of the firm and international trade under uncertainty

One of the significant advances in economic theory has been the incorporation of uncertainty into the models used to investigate economic behavior. The explicit treatment of uncertainty has permitted economists to predict the behavior of economic agents operating in an uncertain environment and to explain, for example, the existence of insurance, stock markets, and forward exchange markets that have no necessary role in a deterministic world. One natural application of the economics of uncertainty has been to the study of international trade and exchange in which uncertainty regarding exchange rates and relative prices is a prominent feature of the environment of economic agents. The purpose of this paper is to frame the international trade results developed in the recent works of Wolfgang Mayer and Raveendra Batra in light of the current state of the theory of the firm under uncertainty. Before analyzing the effect of uncertainty on international trade, a perspective on the application of the economics of uncertainty to neoclassical theory will be presented with an emphasis on the theory of the firm