In-cylinder pressure measurements with optical fiber and piezoelectric pressure transducers.

Highly accurate cylinder pressure data can be acquired using a wall-mounted and water-cooled quartz piezoelectric transducer. However, this type of transducer does not satisfy the cost and packaging constraints for use in a production engine application. A potential solution to these issues is the much smaller and less expensive optical fiber based pressure transducer. This research compares Kistler piezoelectric transducers to Optrand optical fiber transducers. The influence of the transducer type and mounting arrangement on the quality of cylinder pressure data was examined. The transducers were evaluated on a DaimlerChrysler 4.7L V-8 Compressed Natural Gas fuelled test engine. The analysis method is comprised of examining measured individual cycle and ensemble-averaged cylinder pressure records to assess the quality of the data and its potential usefulness for engine management. The variation in performance in terms of thermal shock error among the four Optrand transducers was much larger than those among the four Kistler transducers. The best performing Optrand transducer both over and underestimated cylinder pressure, leading to more accurate results of Indicated Mean Effective Pressure and overestimations in peak cylinder pressure compared to the Kistler transducer which always underestimated cylinder pressure. (Abstract shortened by UMI.)Dept. of Mechanical, Automotive, and Materials Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2002 .R68. Source: Masters Abstracts International, Volume: 44-01, page: 0427. Thesis (M.A.Sc.)--University of Windsor (Canada), 2002

Live Case Analysis: Pedagogical Problems And Prospects In Management Education

The selection of an appropriate and effective pedagogy has been a central theme in management education for decades. There currently exists a wide range of pedagogical options designed to match course content with the most appropriate technique(s) for effective learning outcomes. Most recently, a variety of experiential learning methods have been employed to provide students with real-life experiences and applications in the overall class design. Live case analysis is typically identified as one of a series of options within the domain of experiential learning methods. This paper examines the live case approach as a tool for achieving desired outcomes in management education. Perspectives are offered from multiple stakeholder groups that highlight both the challenges and prospects in the use of this method of teaching. Results demonstrate the usefulness of the live case approach for achieving assessment objectives and measuring important program outcomes

THE EFFECT OF JUVENILE IDIOPATHIC ARTHRITIS ON LOWER LIMB MUSCLE ACTIVITY IN THE PROPULSION PHASE OF THE COUNTER MOVEMENT JUMP

The purpose of this study was to investigate the effect of Juvenile Idiopathic Arthritis (JIA) on lower limb muscle activity during a countermovement jump (CMJ). Two groups of patient data were collected; 6 patients had unilateral arthritis, and 8 patients had bilateral arthritis. Activity of lower limb muscles was assessed using integrated EMG (iEMG) and peak EMG (pEMG) of the propulsion phase of the CMJ. Analysis of the unilateral patients compared the iEMG and pEMG differences of each muscle for the limb affected with arthritis versus the same muscles in the unaffected lower limb. Analysis for the bilateral group compared the left versus right side. No significance was found between sides when comparing lower limb iEMG and pEMG. It still needs to be determined if children who suffer from JIA have adverse muscle deficiencies as a result of the disease

Tail pinch induced stress-arousal facilitates brain stimulation reward

Adult male Sprague Dawley rats with chronic access to self stimulation were subjected to handling, tail pinch, or left undisturbed. Tail pinch increased responding for positive reinforcement while the other conditions did not. The stress related properties of tail pinch may therefore facilitate responding in the present and other situations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23691/1/0000661.pd

Stress, behavioral arousal, and open field activity--A reexamination of emotionality in the rat

The effects of stress upon emotionality, and of emotionality upon the open field activity of rats have now been studied for over four decades. Controversy remains however regarding the degree to which stress alters behavior, and the direction of that change. One reason for this is the absence of an adequate behavioral definition of stress. The present series of experiments demonstrates a standard relatively nontraumatic stress induction procedure which may be used in conjunction with open field testing. Pre-exposure to moderately intense light and white noise facilitated open field activity as measured by initial activity, lowered defecation scores, and supplementary measures (rearing, grooming, center field penetration). Further parametric, psychoendocrine, and pharmacological studies characterized the nature of the facilitation, its time course, and its modification by other manipulations. Our results suggest the initial behavioral response to stress in an open field is activation. Previous studies may have differed in their results relating stress and behavior because of subtle procedural distinctions, some of which may be identified using the present technique.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23706/1/0000678.pd

Further studies on a novel animal model of depression: Therapeutic effects of a tricyclic antidepressant

We have previously shown that rats given stress before open field testing have elevated activity in comparison with unstressed rats. This acute behavioral response may be eliminated by chronic stress and restored by pretreatment with the monoamine oxidase inhibitor pargyline. The present study replicated previous findings upon the effects of acute and chronic stress and extended results upon treatment to the class of tricyclic antidepressant drugs, using imipramine as a prototypic tricyclic antidepressant. Imipramine also restored both behavioral and psychoendocrine activity which was otherwise altered by chronic stress.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24331/1/0000598.pd

A ruptured ectopic pregnancy in a patient with an intrauterine device: A case report.

Intrauterine devices (IUDs) are used worldwide. The 2 types that are used are the levonorgestrel IUD and a copper containing IUD. This is a case study of a 30-year-old female with a levonorgestrel IUD who was diagnosed with a ruptured ectopic pregnancy in the emergency department (ED). Point-of-care urine pregnancy test and point-of-care ultrasound (POCUS) were vital in making this diagnosis and should be utilized in patients assigned female at birth who present with abdominal pain

Acute and chronic stress effects on open field activity in the rat: Implications for a model of depression

The initial activity of a rat placed in novel surroundings (i.e., open field activity) has been taken as an indicator of its emotional state. We have investigated the effects of immediately antecedent stress upon open field activity in comparison with basal (i.e., unstressed) activity, and additionally, the effects of a history of chronic stress upon the above behavioral patterns. Acute exposure to a non-traumatic, non-debilitating stress (noise and light) consistently increased activity in comparison with basal activity. A history of chronic stress on the other hand reduced basal activity from control levels, and eliminated the activation response to acute stress. This lack of acute activation may bear some resemblance to depression on several grounds. Behaviorally it represents a "refractory loss of interest". Also, chronically stressed rats showed endocrine changes similar to those seen in human depressives. Finally, antidepressant treatment with the monoamine oxidase inhibitor pargyline restored the ability of chronically stressed rats to respond actively to stress.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24330/1/0000597.pd

Appetitive determinants of self-stimulation

Previous reports have pointed to a biologically meaningful relationship between brain-stimulated reward and appetitive motivation such as feeding. The present experiments further examined this relationship in chronically self-stimulating Sprague-Dawley rats. In Expt 1 restriction of ad libitum food produced a subsequent increase in self-stimulation in the substantia nigra. In Expt 2 restriction of ad libitum self-stimulation, from the same sites, produced a subsequent gain in body weight. In Expt 3 restriction of ad libitum self-stimulation produced subsequent increases in responding for stimulation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22562/1/0000107.pd