Showing papers by "Emory University published in 1978"

The Theory of the Firm and the Structure of the Franchise Contract

Abstract: Uses the tools of Coase's (1937) theory of the firm, and an analysis of property rights, incentives and monitoring, to assess the nature of the franchise contract. Franchising is of interest to economists because it represents a situation in which there is not a sharp distinction between interfirm and intrafirm transactions. The institutional structure of the franchise is discussed, and a franchise agreement is defined as a contract between two legal firms--the franchisor, or parent company, and the franchisee, a firm set up in a specific location to market the product or service offered by the parent company. The franchisee pays a specific amount of money for the right to market this product or service. The standard explanation of franchising, in terms of capital markets, is then considered and rejected. The theory debated is that franchisors use franchising as a means to raise capital. However, by considering this argument in light of modern capital theory, it is concluded that the franchisor interested in raising capital would do better to create a portfolio of shares in many franchise outlets in order to diversify risks and maximize profit potential. An alternative explanation of franchisee motivations is given which suggests that both parts of the contract give property rights to the parties, i.e., the franchisor and the franchisee, for areas they can most efficiently control. Finally, the application of antitrust law to franchising is found to be false, since it confuses legal categories with economically meaningful ones. (SFL)

Adrenarche: A Survey of Rodents, Domestic Animals, and Primates

Abstract: The concentrations of the adrenal steroids dehydroepiandrosterone (DHA), dehydroepiandrosterone sulfate (DHAS), and Δ4-androstenedione (Δ4-A) have been measured by RIA before and after sexual maturation in plasma of rodents, domestic animals, and primates to determine whether these species exhibit an adrenarchal process comparable to man. The average concentrations of DHA and DHAS were less than 60 ng/dl and 5 μg/dl, respectively, in plasma of sexually mature rodents and domestic animals, and a significant increase in the plasma DHA level after sexual maturation was seen only in the rabbit and dog. The concentrations of DHA, DHAS, and Δ4-A in 21 rhesus monkeys from 0–3 yr of age were 2021 ± 235 ng/dl (mean ± SE), 357 ± 60 μg/dl, and 107 ± 9 ng/dl, respectively, and did not increase during sexual maturation. By contrast, DHA, DHAS, and Δ4-A levels in plasma of chimpanzees were 5.9-fold, 3.3-fold, and 4.8-fold greater, respectively, in 7- to 22- compared to 0- to 3-yr-old animals. Temporally, the increase i...

Development and maintenance of morphine tolerance and dependence in the rat by scheduled access to morphine drinking solutions.

Abstract: Rats were housed on a cabinet designed to control their access to water or morphine solutions. They were trained to drink all of their fluid as morphine solutions or tap water during 5-minute access periods scheduled at 2 A.M., 8 A.M., 2 P.M. and 8 P.M. On this schedule, the morphine drinking rats consumed an average of 29, 27, 21 and 23% of their total daily fluid during the four respective access periods. The rats that had access to the 0.05% morphine solution drank an average of 53 mg/kg/day of morphine. Separate groups of rats were tested for morphine tolerance and dependence at 4-day intervals. Tolerance to the analgesic effect of challenge doses of morphine (3, 6 and 9 mg/kg) was first detected after 10 days of morphine drinking and reached a plateau after 18 days. Withdrawal scores for rats injected with 0.3 or 3 mg/kg of naloxone reached a plateau between 14 and 18 days of morphine drinking, whereas the scores of rats given 0.03 mg/kg were still increasing after 26 days of drinking. Plasma levels of morphine ranged between 167 and 300 ng/ml in blood samples collected 1 hour after each access period on the 18th day of morphine drinking. Six hours after the 8 A.M. access period, the levels of morphine in the plasma had decreased to 50% of the levels detected at 1 hour after the access period. Ninety percent of the rats accepted the morphine solutions and drank regularly for the 26 days the solutions were offered. They remained healthy throughout this period and, except for the fact that they gained 11% less body weight over the 26 days, they were visibly indistinguishable from the water drinking control rats.

Techniques to improve the seating of castings

Abstract: The effects of several variables—degree of convergence of preparations, cements, occlusal venting, relief by aqua-regia acid etching, and the use of die spacing before fabrication of the wax pattern—on the seating of castings were examined in this study. The frustrations of the incomplete seating of castings are commonly experienced. This study of over 200 castings describes methods for eliminating the effect of internal discrepancies which cause a rebound effect, requiring occlusal reduction and adjustment of faulty margins. Technique variables included preparation convergence, venting, and types of cements used. Die spacing and other relief methods were additionally found to provide space for cement thickness, ensuring improved marginal adaptation. In addition to reducing chair time and improving marginal integrity, die spacing provided 25% better retention than when stress areas were not relieved.

Dopamine Levels in Hypophysial Stalk Blood in the Rat are Sufficient to Inhibit Prolactin Secretion In Vivo

Abstract: Much evidence indicates that dopamine can inhibit PRL secretion However, it is still unclear whether dopamine acts on hypothalamic neurons to stimulate PRL-inhibiting factor (PIF) release or whether dopamine is itself PIF, acting directly on the pituitary This study was designed to determine if PRL secretion is inhibited by dopamine infusions producing plasma dopamine levels which mimic those found in hypophysial stalk plasma Stalk plasma dopamine concentration in urethane-anesthetized diestrus-1 rats was 60 ± 11 ng/ml (mean ± SE; n = 10) During a dopamine infusion, stalk plasma dopamine levels were 70% of arterial levels Therefore, dopamine was infused at a rate which achieved arterial levels of 9–10 ng/ml and the effect on PRL secretion in urethane-anesthetized female rats was measured In diestrus rats, dopamine did not inhibit PRL secretion In rats pretreated with α-methyl-p-tyrosine to elevate serum PRL levels, dopamine suppressed PRL secretion 70% In rats with PRL levels elevated by median

Symbolic communication between two chimpanzees (Pan troglodytes)

Abstract: Through use of learned symbols, two chimpanzees accurately specified 11 foods by name to one another when the food item's identity was known by only one. They could not do this when denied use of the symbols. The chimpanzees then spontaneously requested specific foods of one another by name. Requests resulted in cooperative and reciprocal symbolically mediated food exchange.

Extra-Legal Factors in Chicago's Criminal Courts: Testing The Conflict Model of Criminal Justice

Abstract: Recently several researchers using empirical evidence have tested the conflict model of criminal sanctioning In this paper we develop a theoretical model which embodies propositions derived from the conflict perspective The model defines three types of discrimination in the criminal sentencing process They are: (1) labelling processes which define as more serious crimes committed by lower SES persons and blacks; (2) economic discrimination through which lower SES persons and blacks have mediocre attorneys and are less able to make bail, and (3) prejudice, due to which judges and juries assign sentences along racial and occupational lines Data from the Chicago trial courts show gross inequality in sentencing practice between occupations and races due to prejudice and economic discrimination We estimate the “cost” of being of a particular occupation or race in terms of pre-trial incarceration and final disposition With other factors equivalent to those of white proprietors, laborers and non-whites are found to be twice as likely as proprietors to stay incarcerated between arrest and final disposition Further, other factors being equal, laborers and non-whites are given longer prison sentences than the higher SES groups

Linguistically Mediated Tool Use and Exchange by Chimpanzees (Pan Troglodytes)

Abstract: It is surprising that, given the enduring interest in the ability of apes to communicate symbolically with one another, all language work with apes has hitherto concentrated upon their ability to demonstrate language functions and syntax in interaction with human beings (Fouts 1974a; Gardner & Gardner 1969, 1971; Patterson 1977; Premack 1976a; Rumbaugh 1977; Terrace & Bever this volume). As Steklis and Harnad (1976) point out, the true adaptive function of language lies in the ability it confers upon man to transmit specific information in an abstract, context-free form. Previous work with apes has, for the most part, placed a highly sophisticated and competent, language-using human being in the role of either the receiver or the transmitter in every linguistic interchange. This essentially allows the chimpanzee to “fill in the blanks” while the nature of the interchange is basically structured by the human being. Anecdotal reports on chimpanzees learning American Sign Language (ASL) have suggested that the animals are communicating with one another through signs (Fouts 1973, 1974a; Gardner & Gardner 1978); however, what is not clear in any of these cases is (1) whether the chimpanzees were indeed gesturing to one another and not to the humans who were nearby, (2) whether the ASL gestures used were essentially different from the nonverbal gestures reported for wild chimpanzees, (3) whether the recipient of the gesture altered his behavior in specific response to the gesture, or (4) whether the animals were capable of reversing transmitter’s and receiver’s roles.

"Inflammatory pseudotumor" of liver with occlusive phlebitis: report of a case in a child and review of the literature.

Abstract: An unusual "tumor" involving the right lobe of the liver of a young child is reported. Morphologically, the lesion had the features of "inflammatory pseudotumor." We were able to find only one previous report of a similar case in the literature. Unusual changes, which may be designated "occlusive phlebitis," were present in the medium-sized and large veins. Histologically, the lesion, including the vascular changes, had similaritites to the entities included in the group of "multifocal fibrosclerosis." It is believed that these unusual vascular changes, which have also been observed in a case of "inflammatory pseudotumor" of the parotid gland, probably contributed to the disease process.

Carotid sinus hypersensitivity and syncope.

Abstract: Hyperactivity of the carotid sinus reflex is common in older men. However, an unequivocal diagnosis of carotid sinus syncope is difficult to establish because the symptoms are nonspecific, and both hyperactivity of the carotid sinus reflex and syncope are common. Twenty-one men were evaluated for episodes of lightheadedness or syncope, or both, associated with a hypersensitive carotid sinus reflex. Seventeen patients had the cardioinhibitory type, two the vasodepressor type and two both the cardioinhibitory and vasodepressor types. Patients with the cardioinhibitory type benefited from the insertion of a permanent pacemaker if they had multiple episodes of syncope. A history of syncope associated with some event capable of stimulating the carotid sinus was also helpful in selecting patients for pacemaker treatment. The combination of the cardioinhibitory and vasodepressor types may be missed unless carotid sinus stimulation is repeated after the administration of atropine. The results of electrophysiologic studies in 17 patients with the cardioinhibitory type suggest that intrinsic sinus nodal dysfunction is not the major cause for asystole after carotid sinus stimulation.

Symptomatic myocardial bridging of coronary artery

Abstract: Two cases of symptomatic myocardial bridging of the left anterior descending coronary artery requiring surgery for relief are reported. One patient experienced the sudden onset of ventricular fibrillation, had evolving electrocardiographic evidence of an anterior myocardial infarction and subsequently continued to have chest pain. The second patient presented with a long-standing history of repeated episodes of paroxysmal supraventricular tachycardia accompanied by chest pain. During one such episode he had prolonged chest pain and a syncopal episode, but evidence for myocardial necrosis did not develop. On coronary arteriography the only abnormality noted was severe systolic narrowing of the left anterior descending coronary artery in the first patient and similar narrowing of both this artery and a large diagonal vessel in the second. Each patient successfully underwent coronary arterial debridging and, in addition, had a bypass graft to the distal left anterior descending artery. Both patients are In stable condition and show considerable improvement 46 and 9 months, respectively, after operation. Although in most cases of bridging detected on coronary arteriography there is no evidence of ischemic heart disease, the occurrence of symptoms with tachycardia and, in particular, the unusual length of the bridged segments and the severity of systolic narrowing may have played a significant role in the development of disease in these two patients.

An electromyographic analysis of forelimb muscles during overground stepping in the cat

Abstract: The patterns of activity of 33 forelimb muscles during unrestrained overground stepping in eight adult cats were analysed using intramuscular electromyography. Three general patterns were found. Some muscles began activity during the first extension epoch (E1) and ceased near the end of the third extension epoch (E3) and were considered extensors. Others, considered flexors, began activity just prior to the flexion (F) epoch and ceased at or just after the onset of E1. Other muscles showed a biphasic pattern of activation; one period of activity occurring during F, the other during the extension epochs. In all regions of the limb, individual muscles displayed variation in the onset and time course of activity. The results are interpreted in terms of a model of locomotor generation which proposes specific neural output to individual muscles. Muscles of the shoulder region are proposed to act mainly to produce translatory and rotatory movements of the scapula associated with lengthening the step. Muscles of the elbow region and antebrachium are interpreted as playing roles both in producing flexion-extension movements and in the absorption of energy. The latter group are considered especially suitable to energy absorption because of their pennate arrangement of muscle fasciculi and their long tendons.

Value of coronary bypass surgery. Controversies in cardiology: Part I.

Abstract: The value of coronary bypass surgery has been studied carefully during the last decade. Four methods, none perfect, have been used to compare the results of such surgery with the results of medical therapy. New data are likely to be merely supportive rather than the outcome of a definitive study with a new and a acceptable experimental design. It is therefore time to analyze the available data in light of the treacherousness of the disease and to determine if a clear trend is evident. There appears to be sufficient evidence to state that properly performed coronary bypass surgery will increase coronary blood flow and relieve angina pectoris in 90 percent of patients; total relief of angina can be expected in 60 percent and partial relief in 30 percent. Compared with modern medical therapy, properly performed coronary bypass surgery appears to prolong the life of patients who have obstruction of the left main coronary artery or triple or double vessel disease. There is not adequate evidence to state that the procedure will prolong the life of patients with single vessel obstruction. However, patients with single vessel obstruction and unacceptable angina pectoris should be considered for bypass surgery (especially patients with obstruction of the left anterior descending coronary artery). In practice, at Emory University Hospital, Atlanta, bypass surgery is recommended for young people with few symptoms if compelling obstructing lesions are present and in older patients only if their symptoms require it. Medical therapy is given before and after bypass surgery. When bypass surgery is performed in an excellent fashion (operative risk 1 percent) a great deal of "controversy" about this problem vanishes.

Liquid Chromatographic-Electrochemical Measurement of Dopamine in Hypophysial Stalk Blood of Rats*

Abstract: Evidence is accumulating that dopamine is the hypothalamic PRL-inhibiting factor, but the quantitative relationship between its secretion and that of PRL has not been established. To this end, we have developed a liquid chromatographic-electrochemical assay for measurement of dopamine and other catecholamines in hypophysial stalk plasma. Dopamine in plasma was adsorbed onto alumina, eluted with 0.5 M HClO4 and injected into a cation exchange column (1000 × 2 mm id). Elution of dopamine occurred in 17 min using a citrate-acetate buffer (pH 5.2) at a flow rate of 20-30 ml/h (500 psi). Detection resulted from oxidation of dopamine at the surface of a carbon paste electrode, with the resulting electrochemical current being linearly related to dopamine from 20 pg to 10 ng. With a 50% extraction loss of dopamine, the limit of detection using 100 μl plasma was 0.4–0.6 ng/ml. Specificity is provided by the limited number of compounds having oxidation potentials similar to dopamine, by alumina adsorbing only catec...

Mixed mesenchymal and neuroectodermal tumor of the cerebellum.

Abstract: An unusual cerebellar tumor composed of mixed mesenchymal and neuroectodermal elements in a 44 year old man is reported. The mesenchymal element is well-differentiated adipose tissue, whereas the neuroectodermal components exhibit a variety of medulloblastomatous, astrocytomatous, oligodendrogliomatous and ependymomatous areas. A possible origin of such unusual mixed neoplasms is briefly discussed.

Functional analysis of the shoulder girdle of cats during locomotion.

Abstract: The movements of the shoulder girdle of eight adult cats during overground stepping were studied, using standard slow motion cinematographic techniques. The patterns of activity of shoulder muscles were examined, using simultaneous intramuscular electromyography. Walking, trotting and galloping steps were analyzed from digitized single motion picture frame images. Angular movements of the shoulder girdle consist of biphasic flexion and extension of the shoulder joint and a monophasic flexion-extension alternation of the scapula on the thorax during each step cycle. In addition, the center of the scapula moves craniad during the swing phase and caudad during the stance phase with respect to a fixed reference point on the animal. Similar vertical movements of the center of the scapula also occur in each step cycle. Results of EMG studies of the 17 muscles capable of acting on the shoulder girdle indicate that three overall patterns of activity are found: (1) a pattern typical of extensor muscles, active during all the extension epochs; (2) a pattern typical of flexor muscles, active during the flexion epoch; and (3) a biphasic pattern of activity, active twice in each step. There data are used, along with a re-examination of previous models of the mechanics of the shoulder girdle of carnivores to examine the function and mechanics of shoulder motion. It is concluded that the rotary and translatory movements of the shoulder girdle during stepping combine to enhance step length.

The Use of Specific Radioimmunoassays to Determine the Renal Clearance Rates of Estrone and 17β-Estradiol during the Menstrual Cycle

Abstract: Specific RIAs requiring ether extraction only were established for estrone and 17β-estradiol both in plasma and in urine from the nonpregnant female. These assays were used to measure the renal clearance rates of estrone and of 17β-estradiol in eight ambulatory women in the follicular and in the luteal phases of the menstrual cycle. The mean (±SE) for the renal clearance rate of estrone was 0.71 ± 0.058 ml/min in the follicular phase and 1.26 ± 0.35 ml/min in the luteal phase. The mean (±SE) renal clearance rate of 17β-estradiol was 0.44 ± 0.055 ml/min in the follicular phase and 0.29 ± 0.043 ml/min in the luteal phase. There was no significant difference in the renal clearance rates of either estrone or of 17β-estradiol between the follicular and luteal phases of the cycle. The renal clearances of estrone and 17β-estradiol were highly correlated (r = 0.84; P < 0.01). The renal clearance rate of estrone was significantly greater than that of 17β-estradiol in both phases of the cycle (P < 0.01).