Bias in genetic evaluations by records of cows treated with bovine somatotropin

Records from Dairy Records Management Systems in Raleigh were used to estimate effects of bovine somatotropin (bST) treatment and to predict breeding values for milk production traits. The data comprised 5245 test-day records of bST-treated cows and 126,223 test-day records of untreated cows in first lactation for milk, fat, and protein yields. Fixed effects of bST treatment were estimated from test-day animal models with herd-test-date as another fixed factor. Percentage increases due to bST treatment ranged from 7 to 8% for test-day milk, fat, and protein yields. Random regression coefficients for additive genetic and permanent environmental effects were included in the model. To assess the potential for bias in genetic evaluations when some and not all cows are treated with bST, breeding values predicted by the test-day model with and without effects of bST treatment were compared for cows and sires. Correlations between breeding values predicted from models with and without effects of bST treatment were 0.99. However, relatively large bias was found for individual animals. This result suggests that bias in genetic evaluation caused by ignoring bST treatment may be significant.     

Optical diffraction: applications to lamellar microstructures

Optical diffraction techniques have a wide range of applications which extend from the further interpretation of electron micrograph images to aerial photographs. Useful metallographic applications are based on optical or electron micrographs. A brief account is given of a typical system for obtaining optical transforms or diffraction patterns and reconstituted images. Structures which appear frequently in eutectics or eutecoids show laminations arising from the alternating formation of different constituents with planar interfaces. The diffraction patterns are relatively simple but may be affected by variations in spacing and orientation. Account should also be taken of geometrical and other factors due to the tilt of the lamellae with respect to the surface. Besides recording the spacings it is also useful to take account of the directions of traces in the surface in view of the possible presence of structural anisotropy. The eutectic which is the sole constituent in alloys containing aluminium with 33% copper provides a useful illustration of the principles. Some typical results are briefly presented. A second application refers to ‘pearlite’, the eutectoid which forms in iron-carbon alloys and many carbon and low alloy steels. The alternating lamellae are α-iron and the carbide Fe₃C. Two examples are given. The first refers to the use of spacing measurements in order to examine the dependence on temperature of transformation. The second shows how statistical spacing variations in a micrograph may reveal whether there is one or more basic spacing. The variation of the trace directions reveals structural anisotropy, and the relation of the spacing to this anisotropy is also examined.     

An integer goal programming model for determining capital expenditures for correctional facilities

The selection of capital expenditure projects for the construction of state correctional facilities is often complicated by the existence of multiple and conflicting objectives on the part of the various interest groups involved in the decision-making process. While some groups view the limited availability of state funds to construct such facilities as the paramount consideration, others might consider having adequate capacity to house prisoners in a satisfactory manner, and the effect of prison overcrowding on prisoner sentencing as the primary factors in the decision to construct new facilities. As such. it is imperative that the limited funds available for constructing correctional facilities be allocated in the most efficient and satisfactory manner possible. In this paper, integer goal programming is demonstrated via a case example as a means for allocating funds for capital expenditures for new and renovated correctional facilities. Sensitivity analysis is performed using the model in order to demonstrate its capability for testing various planning scenarios including alternative priority structures, goal constraints and goal levels.     

Fracture behavior of human molars

Despite the durability of human teeth, which are able to withstand repeated loading while maintaining form and function, they are still susceptible to fracture. We focus here on longitudinal fracture in molar teeth??channel-like cracks that run along the enamel sidewall of the tooth between the gum line (cemento-enamel junction??CEJ) and the occlusal surface. Such fractures can often be painful and necessitate costly restorative work. The following study describes fracture experiments made on molar teeth of humans in which the molars are placed under axial compressive load using a hard indenting plate in order to induce longitudinal cracks in the enamel. Observed damage modes include fractures originating in the occlusal region (??radial-median cracks??) and fractures emanating from the margin of the enamel in the region of the CEJ (??margin cracks??), as well as ??spalling?? of enamel (the linking of longitudinal cracks). The loading conditions that govern fracture behavior in enamel are reported and observations made of the evolution of fracture as the load is increased. Relatively low loads were required to induce observable crack initiation??approximately 100?N for radial-median cracks and 200?N for margin cracks??both of which are less than the reported maximum biting force on a single molar tooth of several hundred Newtons. Unstable crack growth was observed to take place soon after and occurred at loads lower than those calculated by the current fracture models. Multiple cracks were observed on a single cusp, their interactions influencing crack growth behavior. The majority of the teeth tested in this study were noted to exhibit margin cracks prior to compression testing, which were apparently formed during the functional lifetime of the tooth. Such teeth were still able to withstand additional loading prior to catastrophic fracture, highlighting the remarkable damage containment capabilities of the natural tooth structure.     

Analyzing court system congestion with Q-Gert network modeling and simulation

Judiciary court delay and congestion is one of the more serious problems confronting local, state and federal governments. Although a court system is basically a well-defined system of servers (i.e. administrators, clerks and judges) and queues of cases waiting to be tried, the application of operations research/management science techniques to court systems has been minimal. This paper will present a comprehensive Q-GERT network model and simulation analysis of a county court system. The model development is described in detail, and a general discussion of the simulation results and their use is presented.     

A mixed-integer goal programming model for capital budgeting within a police department

A difficult problem for most police departments is allocating limited dollars for capital expenditures in the most efficient manner possible. Because of the varied objectives of police services as perceived by police administrators, government officials and citizens, traditional allocation criteria, such as cost-benefit analysis, are not viable. As such, this paper proposes the use of mixed-integer goal programming as a methodology for selecting police expenditure items given a limited budget and multiple, conflicting objectives. In order to demonstrate this technique, a case example involving 18 potential expenditure items for a moderately-sized police department will be employed. This example model will be solved using a predetermined priority structure, and the results interpreted. Several alternative priority structures that reflect the objectives of different interest groups will then be tested in order to demonstrate the flexibility of this approach.     

A Goal Programming Application of Capital Project Selection in the Production Area

Managers of large production operations are often confronted with the necessity to invest in capital projects whose income generating capacity is not the prime consideration for selection. Examples of this type of investment include projects which satisfy safety, environmental, union and/or consumer requirements placed on the firm. This paper describes and demonstrates a goal programming model for project selection when both profit and nonprofit motivated projects are in competition for scarce resources.