Design of a short-term training program in group facilitation skills.

Describes the program's 3 goals: having trainees develop as a group and examine their own group process, acquiring knowledge about issues in group dynamics, and learning group leadership skills. Feedback exercises to help trainees develop as a group and exercises that focus on conceptual issues in group dynamics are described briefly. The leadership skill, which is emphasized in training, is making interventions in an ongoing group. In a 4-stage process, trainees practice intervening in situations that successively approximate an actual group. A 3-dimensional model for viewing and evaluating interventions is also presented. The training program is intended for use with paraprofessionals or with prepracticum students in professional training programs. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identifying efficient dairy producers using data envelopment analysis

The objective of this research was to calculate the efficiency of a group of Pennsylvania dairy farms to determine factors that contributed to efficiency in production and business management. Data envelopment analysis (DEA) was used to estimate the efficiency. Two models were developed to measure the efficient use of physical (land, cows, and labor) inputs to produce physical (milk and butterfat) outputs, and the use of physical and economic (debt capital) inputs to produce physical and economic (income) outputs. The results showed that about 29% of the producers in our sample were DEA-efficient and demonstrated that there was no combination of inputs used by efficient producers that was best. In addition, the method of analysis illustrated the benefits of DEA in that it is possible to identify the set of efficient producers that inefficient producers can benchmark to in an effort to achieve similar levels of efficiency. Finally, the analysis demonstrated that producers should not benchmark to the highest level of production, but rather should combine resources in land, labor, cows, and debt capital to achieve an efficient level of production, which indeed may be less than the maximum production level of the group.     

Effects of sodium bicarbonate with three ratios of hay crop silage to concentrate for dairy cows

Three ruminally cannulated Holstein cows were fed total mixed diets of hay crop silage and concentrate (30:70, 50:50, 70:30, 100:0) to evaluate effects of sodium bicarbonate supplements equivalent to 0, .4, and .7% of total ration dry matter (0, 68, and 114 g/d). Yields of milk, fat-corrected milk, fat, protein, and solids-not-fat, percentages of milk protein and solids-not-fat, and efficiency of production of fat-corrected milk declined with decreasing concentrate proportion. Buffer supplementation reduced milk fat percentage and milk yield was greater with 68 g/d sodium bicarbonate than with 114 g/d. Digestibilities of dry matter, organic matter, gross energy, cell solubles, and crude protein declined with decreasing proportion of concentrate while cellulose digestibility increased linearly. The proportion of dietary nitrogen transferred to milk decreased linearly with decreasing proportion of concentrate and sodium bicarbonate increased this transfer with the 70% concentrate diet. Sodium bicarbonate increased ruminal pH and acetate proportion while decreasing ammonia concentration. Acetate:propionate ratio was decreased by sodium bicarbonate addition to the 70% concentrate diet. High concentrate diets with hay crop silage may require higher amounts of buffers to influence production.     

Slow slumping of a very viscous liquid bridge

A layer of very viscous liquid (e.g. tar, molten glass) spans a chasm between two vertical walls. The slow fall or slump of this initially-rectangular liquid bridge is analysed. A semi-analytical solution is obtained for the initial motion, for arbitrary thickness/width ratios. The formal limits of large and small thickness/width ratios are also investigated. For example, the centre section of a thin bridge of liquid of density and viscosity µ, with width 2w and thickness 2h2w falls under gravity g at an initial velocity gw⁴/(32h²). A finite element technique is then employed to determine the slumping motion at later times, confirming in passing the semi-analytical prediction of the initial slumping velocity.     

Effect of troglitazone (Rezulin) on fructose 2,6-bisphosphate concentration and glucose metabolism in isolated rat hepatocytes

The effect of troglitazone, an orally effective thiazolidinedione, on lactate- and glucagon-stimulated gluconeogenesis (in the absence of insulin) was examined in hepatocytes isolated from rats under different nutritional states. Hepatocytes obtained from fed or 20-24 hr fasted male Sprague-Dawley rats were incubated in Krebs-Henseleit Bicarbonate buffer (KHBC) (in presence or absence of 10.0 mM glucose) containing 2.0 mM [U-14C]lactate (0.1-0.25 microCi) with or without 10.0 nM glucagon and troglitazone (30.0 microM) or the appropriate vehicle. Aliquots were removed at specified endpoints and assayed for glucose and fructose 2,6-bisphosphate (F-2,6-P2) concentrations. In 20-24 hour starved hepatocytes, troglitazone produced a 26.1% inhibition of lactate-stimulated gluconeogenesis. This inhibitory effect of troglitazone on hepatic gluconeogenesis was further potentiated by incubation of the cells with glucose in vitro. In hepatocytes obtained from fasted rats (and incubated with 10 mM glucose in vitro) troglitazone reduced lactate-and glucagon-stimulated gluconeogenesis by 53% and 56%, respectively. This reduction in hepatic glucose production was associated with 1.06 and 1.04 fold increase in the hepatocyte F-2,6-P2 content. In isolated hepatocytes from fed animals and incubated with 10 mM glucose in vitro, troglitazone (15 and 30 microM) did not have any effect on either lactate- or glucagon-stimulated gluconeogenesis. However, 30 microM troglitazone significantly enhanced (36%) F-2,6-P2 concentrations during lactate-stimulated gluconeogenesis. These findings demonstrate that troglitazone decreases hepatic glucose production through alterations in the activity of one or more gluconeogenic/glycolytic enzymes, depending upon the nutritional state of the animal and the presence or absence of hormonal modulation. All of the effects of troglitazone in the present study were observed in the absence of insulin, suggesting an "insulinomimetic" effect. However, this does not exclude the possibility that troglitazone may also function as an "insulin sensitizer" in hepatic and certain other tissues.     

Vibration welding of thermoplastics. Part III: Strength of polycarbonate butt welds

In vibration welding of thermoplastics, frictional work done by vibrating two parts under pressure, along their common interface, is used to generate heat to effect a weld. The main process parameters are the weld frequency, the amplitude of the vibratory motion, the weld pressure, and the weld time or weld penetration; The effects of these parameters on weld quality were systematically studied by first butt-welding polycarbonate specimens under controlled conditions over a wide range of process parameters, and by then determining the strengths and ductilities of these welds by tensile tests, A significant result is the apparent existence of a weld-penetration threshold above which high weld strengths are attained, but below which the strength drops off. Under the right conditions, the strengths of polycarbonate butt welds are shown to equal the strength of the virgin polymer.     

Morphology and strength of polycarbonate to poly(butylene terephthalate) vibration-welded butt joints

Under the right conditions, the strength of vibration-welded butt joints of amorphous polycarbonate (PC) to semicrystalline poly(butylene terephthalate) (PBT) are shown to be as high as the strength of PBT, the weaker of the two materials. Optical, scanning and transmission electron microscopy are used to examine the morphology of the weld zone. Acoustic microscopy is used to visualize poorly bonded regions. The effects of the weld parameters on weld strength and weld morphology are considered in detail.