Showing papers by "Washington State University published in 1988"

Introduction to the Theory and Practice of Econometrics

Abstract: This book interweaves inferential approaches and theory and practice in econometrics. Basic statistical and linear algebra concepts are introduced as they are needed to give life to the statistical model under study. Most econometric applications start with a tentative theory or hypothesis a sample of data and the goal of learning something about the phenomena under study from the limited set of observations. Therefore a sample of data that may be used to investigate a particular economic hypothesis is presented to motivate the analysis of each of the statistical models presented. This linkage between the economic process that is thought to have generated the data and a particular statistical model is a unifying theme throughout the book. It progresses from the special case of investigating the possibilities for determining the location and scale parameters for a population from a sample of observations to investigating a complex simultaneous system of structural equations under general stochastic assumptions. To ensure that the reader understands the basic concepts and conclusions as they relate to linear statistical models simple special case models are evaluated and then the analysis is repeated for the general case. The 1st half of book gives the student a solid introduction to the formulation and use of linear statistical models. The 2nd half introduces the student to the econometric problems that arise when it is taken into account that economic data are stochastic dynamic and simultaneous and that the optimal statistical procedure sometimes changes as we change the statistical model the amount and type of information used and the measure of performance.

Evolutionary ecology of the relationship between oviposition preference and performance of offspring in phytophagous insects

Abstract: The relationship between oviposition preference and growth, survival, and reproduction of offspring is the crux of the problem in the evolution of host associations between phytophagous insects and plants. Observed relationships between oviposition preference and performance of offspring range from good to poor. At least four hypotheses have been suggested to explain observed use of particular host plants that may not result in the fastest growth rates or greatest pupal masses: time, patch dynamics, parasite versus grazer lifestyles, and enemy-free space. Our current understanding of these relationships, however, is hampered by an almost complete lack of data on how preference and performance are related genetically. These data are needed to understand the origins of covariance between preference and performance and constraints on the evolution of host associations.

Interactive influence of infectious disease and genetic diversity in natural populations.

Abstract: The importance of infectious disease in the survival and adaptation of animal populations is rapidly becoming apparent. Throughout evolution, animal species have been continually afflicted with devastating disease outbreaks which have influenced the demographic and genetic status of the populations. Some general population consequences of such epidemics include selection for disease resistance, the occasional alteration of host gene frequencies by a genetic ‘founder effect' after an outbreak, and genetic adaptation of parasites to abrogate host defense mechanisms. A wide variety of host cellular genes which are polymorphic within species and which confer a regulatory effect on the outcome of infectious diseases has recently been discovered. The critical importance of maintaining genetic diversity with respect to disease defense genes in natural populations is indicated by certain populations which have reduced genetic variability and apparent increased vulnerability to infectious disease.

Amphetamine injection into the ventral mesencephalon sensitizes rats to peripheral amphetamine and cocaine.

Abstract: The daily administration of indirect dopamine agonists, including amphetamine and cocaine, results in a progressive increase in the behavioral stimulant effect of these drugs. Behavioral augmentation also has been shown with opioids such as morphine, and it is known that a stimulant action on dopaminergic perikarya in the ventromedial mesencephalon is critical to the development of behavioral sensitization to morphine. To determine if amphetamine-induced behavioral sensitization might also involve the mesencephalic dopamine neurons, amphetamine was microinjected daily for 2 days into regions of the rat brain containing dopamine cell bodies (A10 and A9 dopamine regions), or dopamine terminals (nucleus accumbens and striatum), and 6 days later amphetamine was given peripherally. It was found that daily amphetamine injection into the A10 or A9 dopamine region, but not into the dopamine terminal fields, significantly potentiated the motor stimulant effect of peripherally administered amphetamine. The behavioral sensitization produced by intracranial injection of amphetamine was found to be dose-dependent. Intra-A10 injection of amphetamine also was found to potentiate the motor stimulant effect of peripheral cocaine. These data indicate that an action by amphetamine in the A10 and A9 dopamine regions may play a critical role in the development of behavioral sensitization.

Biochemistry and Immunology of Infectious Bursal Disease Virus

Abstract: Introduction. The aetiological agent of infectious bursal disease (IBD), IBD virus (IBDV), belongs to a new group of viruses referred to as ‘birnaviruses’ (Dobos et al., 1979), which has been characterized only recently (Brown, 1986). There are excellent reviews dealing with the clinical, pathological, serological and epidemiological aspects of IBDV infection (Faragher, 1972; Becht, 1980; Okoye, 1984; Cummings et al., 1986). The molecular biology of birnaviruses has also been reviewed (Dobos & Roberts, 1983) but with an emphasis on infectious pancreatic necrosis virus (IPNV), the birnavirus genus prototype. The purpose of the present review is to compile information on structural and immunological aspects of IBDV. These are subjects of much recent interest, and have great relevance to the control of IBD in chickens. IBD is a highly contagious viral disease of young chickens which is characterized by destruction of the lymphoid cells in the bursa of Fabricius; other lymphoid organs are also affected but to a lesser degree (Cheville, 1967).

Behavioral and neurochemical effects of acute and daily cocaine administration in rats.

Abstract: Daily cocaine injection into rodents produces a progressive increase in the motor stimulant effect of acute cocaine administration. In this study it was found that daily cocaine injection (15 mg/kg i.p. x 3 days) produced an enhanced motor stimulant response to acute cocaine injection. The behavioral augmentation was linear with regards to dose in horizontal activity and behavioral intensity rating, but was biphasic in vertical activity. Augmented vertical, but not horizontal, activity in response to acute cocaine was found to persist for 2 weeks after the last daily injection of cocaine. Acute injection of cocaine was found to significantly decrease the level of dopamine (DA) metabolites in the nucleus accumbens, striatum and A10 DA region. In rats pretreated with daily injections of cocaine (15 mg/kg i.p. x 3 days), an acute challenge of cocaine 14 days after the last daily injection produced a more consistent decrease in DA metabolites in the nucleus accumbens, striatum and prefrontal cortex compared to daily saline-pretreated rats. In contrast, daily cocaine treatment abolished the decrease in DA metabolites produced in the A10 region by an acute cocaine challenge. Acute injection with cocaine was found to significantly depress dopa accumulation in the A10 region, nucleus accumbens and striatum. This effect was abolished in the A10 region in rats pretreated 14 days previously with daily injections of cocaine (7.5, 15.0 or 30 mg/kg i.p. x 3 days), but remained intact in the nucleus accumbens and striatum, except after daily pretreatment with the highest dose of cocaine.(ABSTRACT TRUNCATED AT 250 WORDS)

Nonconstructive tools for proving polynomial-time decidability

Abstract: Recent advances in graph theory and graph algorithms dramatically alter the traditional view of concrete complexity theory, in which a decision problem is generally shown to be in P by producing an efficient algorithm to solve an optimization version of the problem. Nonconstructive tools are now available for classifying problems as decidable in polynomial time by guaranteeing only the existence of polynomial-time decision algorithms. In this paper these new methods are employed to prove membership in P for a number of problems whose complexities are not otherwise known. Powerful consequences of these techniques are pointed out and their utility is illustrated. A type of partially ordered set that supports this general approach is defined and explored.

Modulation of folding pathways of exported proteins by the leader sequence

Abstract: Leader peptides that function to direct export of proteins through membranes have some common features but exhibit a remarkable sequence diversity. Thus there is some question whether leader peptides exert their function through conventional stereospecific protein-protein interaction. Here it is shown that the leader peptides retarded the folding of precursor maltose-binding protein and ribose-binding protein from Escherichia coli. This kinetic effect may be crucial in allowing precursors to enter the export pathway.

Gender Identity, Self-Esteem, and Physical and Sexual Abuse in Dating Relationships

Abstract: This paper examines the roles of gender identity and self-esteem in both physical and sexual abuse in dating relationships. A sample of heterosexual college dating relationships is examined. Data are collected on both inflicting and sustaining physical and sexual abuse for men and for women. No support is found for the long-held theory that abuse is a result of compulsive masculinity. Instead, in accordance with identity theory, we find that physical and sexual abuse are associated with the playing out of a less masculine (more feminine) identity for both males and females. In addition, low self-esteem appears to be associated with inflicting physical abuse for men and sexual abuse for women only in a spurious fashion: both low self-esteem and inflicting abuse result from a more feminine gender identity. (Abstract Adapted from Source: Social Psychology Quarterly, 1988. Copyright © 1988 by the American Sociological Association) Gender Roles Adult Female Adult Male Adult Offender Adult Self-Esteem Adult Victim Adult Violence Female Self-Esteem Female Victim Female Violence Female Offender Male Self-Esteem Male Offender Male Victim Male Violence College Student Research Partner Violence Violence Against Women Dating Violence Causes Dating Violence Offender Dating Violence Victim Date Rape Sexual Assault Causes Sexual Assault Victim Sexual Assault Offender Offender Self-Esteem Victim Self-Esteem Gender Differences 01-03

Protein secretions of Sertoli cells

Abstract: As was stated in the introduction, many of the functions of the Sertoli cells are apparently carried out by the protein secretions of these cells. The use of Sertoli cell cultures and appropriate biochemical and immunological techniques has allowed the characterization of some of these secretion products. It is likely that many of the functions of the Sertoli cells are necessary because of the presence of the blood-testis barrier. Many growth and nutritive factors which are necessary for cell viability are available to most cells via the serum. The germinal cells within the adluminal compartment do not have access to serum factors and one of the functions of the Sertoli cells is to synthesize serum-like components and secrete them into the adluminal compartment. The historical description of Sertoli cells as "nurse cells" thus appears to have been accurate. The nurse-cell function is most clearly demonstrated by the proposed mechanism by which germinal cells obtain ferric ions. The Sertoli cells have developed a system to move serum-derived iron through their own cytoplasm and to secrete it bound to newly synthesized testicular transferrin molecules which can deliver it to specific receptors on the germinal cell surface (Huggenvik et al., 1984). Functionally, all of the secreted proteins from Sertoli cells which have been characterized or proposed fall into one of five basic classes. First, Sertoli cells secrete a number of transport proteins including transferrin, ceruloplasmin, and ABP. The proposed function of these proteins is the transport of Fe3+, Cu2+, and androgens to the germinal cells or to the epididymis (ABP). Second, Sertoli cells synthesize and secrete a number of proteins which have a hormone-like or growth factor-like activity. AMH is a clear and well-documented example of this type of product while the evidence for inhibin, somatomedin C, EGF-like growth factor, and seminiferous growth factor will require further corroboration. Third, Sertoli cells secrete proteins which have enzymatic activities. Plasminogen activator is the best characterized example of this class of products and the alpha-lactalbumin-like activity is of potential interest. The fourth class of Sertoli cell secretion products includes those proteins which contribute to the basement membrane, namely, type IV collagen and laminin. Finally, there is a very important group of Sertoli cell secretion products for which there is, as yet, no evidence for a defined function. This group includes SGP-1 and SGP-2 which are the major sertoli cell products in rats and which have been well-characterized biochemically.(ABSTRACT TRUNCATED AT 400 WORDS)

Biosynthesis and molecular cloning of sulfated glycoprotein 1 secreted by rat Sertoli cells: sequence similarity with the 70-kilodalton precursor to sulfatide/GM1 activator

Abstract: Sulfated glycoprotein 1 (SGP-1) is one of the abundant proteins secreted by rat Sertoli cells. Pulse-chase labeling shows that SGP-1 is synthesized as a cotranslationally glycosylated 67-kilodalton (kDa) precursor which is posttranslationally modified to a 70-kDa form before secretion to the extracellular space. A plasmid cDNA library was constructed from immunopurified mRNA, and two overlapping clones coding for the entire protein coding sequence were isolated. The cDNAs represent 27 nucleotides of 5' noncoding sequence, 1554 nucleotides of coding sequence, and 594 nucleotides of 3' noncoding sequence. The derived SGP-1 sequence contains 554 amino acids and has a molecular weight of 61,123. Four potential N-glycosylation sites occur within the sequence. An internal region of SGP-1 shows 78% sequence identity with the 67 N-terminal amino acids described for human sulfatide/GM1 activator (SAP-1). Sequence comparisons suggest that SGP-1 is the precursor to sulfatide/GM1 activator; however, the secretion of the protein from Sertoli cells is distinct from the proteolytic processing and lysosomal compartmentalization which have been described for human fibroblasts. The presence of internal sequence similarity suggests that three additional binding sites may occur in SGP-1. Northern blots show similar levels of expression for the 2.6-kilobase SGP-1 mRNA in all tissues examined. The site of SGP-1 synthesis in testis was localized to Sertoli cells by immunofluorescence and in situ hybridization.

Contingencies for Dispositional Disparities in Juvenile Justice

Abstract: Studies of juvenile court processing are reviewed and found generally to contradict a discrimination argument. Nevertheless, enough evidence of disparity exists to justify a search for contingencies under which discrimination is more or less likely to occur. The literature yields five contingent hypotheses which we test using data from 31 counties in Florida. The results suggest that differential sanctioning is not a pervasive phenomenon but rather that it is contingent on whether the individual is a member of an aggregate which poses a threat to elites. But it appears that the relevant threats are not strictly political but are mostly of a symbolic, social-psychological nature wherein white adults react to resented youthful traits often stereotypically associated with nonwhites. The results suggest that theoretical development about differential sanctioning will require deemphasis on the ability of individuals to resist power and a strengthened focus on the contingencies under which power is wielded. A strong interest in disparities in criminal justice processing among those with differential power or resources has been present in sociology for the past two decades (Hawkins 1987; Myers 1987). One manifestation of this interest is the extensive empirical literature concerning juvenile justice processing (Liska and Tausig 1979; Smith, Black & Weir 1980) which includes at least 35 studies since 1967 about juvenile court dispositions alone. Much of the research on criminal justice processing has been undertaken within the framework of either labeling or conflict theory (Myers 1987). Both approaches are concerned with the exercise of power and with *We acknowledge helpful comments by Elton E Jackson and Raymond Paternoster as well as the cooperation of the office of the Florida Attorney General headed by Mr. Jim Smith. Direct correspondence to Charles R. Tittle, Department of Sociology, Washington State University, Pullman, WA 99164-4020. ? 1988 The University of North Carolina Press

Capsaicin attenuates suppression of sham feeding induced by intestinal nutrients

Abstract: The ability of intraintestinal nutrient infusions to suppress sham feeding was examined in intact rats and in rats with total subdiaphragmatic vagal transections. Vagotomy abolished the suppression of sham feeding by intraintestinal infusion of maltose or oleate. Suppression of sham feeding by intraintestinal L-phenylalanine was reduced but not abolished by vagotomy. The results of this examination indicate that the vagus nerve mediates suppression of the sham feeding by intraintestinal maltose and oleate but is only partially responsible for suppression of food intake produced by L-phenylalanine. Taken together with previously published data these results suggest that effects on feeding by specific nutrients may be mediated by anatomically distinct populations of visceral afferent neurons.

Affective Issues in Mathematical Problem Solving: Some Theoretical Considerations.

Abstract: Mathematics students often report feelings of frustration or satisfaction when they work on nonroutine problems. These affective responses are an important factor in problem solving and deserve increased attention in research. Mandler's theory of emotion is suggested as a framework for investigating affective issues in problem solving. Several dimensions of the emotional states of problem solvers are specified, including the magnitude and direction of the emotions, their duration, and the students' level of awareness and level of control of the emotions. The implications of this framework for research on affective issues in problem solving are also discussed.

Capsaicin-induced neuronal degeneration: silver impregnation of cell bodies, axons, and terminals in the central nervous system of the adult rat.

Abstract: Capsaicin is a neurotoxic substance valued in neurobiological research because of its ability to selectively damage small unmyelinated primary sensory neurons. Previous work has indicated that systemic capsaicin administration causes permanent neuronal degeneration in neonatal rats, but evidence that capsaicin has a similar effect in adults is equivocal and incomplete. Therefore, we used silver impregnation, a method that labels degenerating neurons, to examine the central nervous system of adult rats after systemic capsaicin treatment. Adult rats were injected with a single intraperitoneal dose of capsaicin (50 or 90 mg/kg) or vehicle solution and killed 6, 12, 18, 24, 48, 96, or 240 hours later. Sections of brain and spinal cord were stained with the Carlsen-de Olmos cupric silver method. As reported previously, stained sections revealed degeneration in areas known to be innervated by small-diameter primary sensory fibers: the substantia gelatinosa of the spinal cord dorsal horn and spinal trigeminal nucleus, the solitary nucleus and tract, and the lateral borders of the area postrema. In addition, axon and terminal degeneration was observed in several discrete forebrain and hindbrain areas not previously associated with capsaicin-induced degeneration in either adult or neonatal rats: the inferior olive, the olivary pretectal nucleus, the interpeduncular nucleus, the suprachiasmatic nucleus, and the lateral septum/medial accumbens region. Furthermore, degenerating cell bodies were observed in the intrafascicular nucleus of the ventromedial midbrain tegmentum, in the supramammillary nucleus, and in the posterior hypothalamic area. Unilateral nodose ganglionectomy produced terminal staining on the denervated side very similar to that induced bilaterally by capsaicin. In addition, unilateral nodose ganglionectomy 1 month prior to capsaicin injection greatly attenuated staining in the ipsilateral nucleus of the solitary tract, confirming the hypothesis that capsaicin damages vagal sensory neurons innervating this nucleus. Capsaicin-induced damage in adult rats was long-lasting, since the second of two capsaicin treatments spaced 4.5 months apart produced no additional degeneration.

Prehension in Cebus and Saimiri: I. Grip type and hand preference.

Abstract: Prehension was examined in tufted capuchins (Cebus apella) and squirrel monkeys (Saimiri sciureus). Individual subjects were videotaped from frontal and sagittal planes while they grasped small objects presented in several ways (in view, out of view, embedded, moving). Capuchins used a precision grip in 30% of trials and in more than half of trials with stationary objects. Most (54%) of the precision grips used were opposition of the thumb to the index finger; however, eight other forms were also observed. Squirrel monkeys never used a precision grip. Data on hand preference, preliminary data on movement velocity, and preliminary observations of movement trajectories (up to the time of hand shaping prior to contact with the object) do not indicate significant differences across genera in these aspects of prehension. The presence of varied precision grips in capuchins and no form of precision grip in squirrel monkeys leads to two conclusions. First, a thumb classification of "opposable" (vs. "pseudo-opposable") is not essential for precision gripping. Capuchins, with pseudo-opposable thumbs, use precision grips routinely. Second, the fundamental difference between these genera, which accommodates precision gripping in capuchins, is the capacity in capuchins (but not in squirrel monkeys) to produce lateral pressure between opposing digits. The anatomy of the spinal pyramidal tract and neuromuscular interfacing in the hands may be more sensitive gauges of manual dexterity than the anatomy of the thumb.

A Molecular Reexamination Of Introgression Between Helianthus Annuus And H. Bolanderi (Compositae)

Abstract: Heiser (1949) hypothesized that a weedy race of Helianthus bolanderi had originated by the introgression of genes from H. annum into a serpentine race of H. bolanderi. Although Heiser's investigation of these species is frequently cited as one of the best examples of introgression in plants, definitive evidence of gene exchange is lacking (Heiser, 1973). To determine whether the weedy race of H. bolanderi actually originated via introgression, we analyzed allozyme, chloroplast-DNA (cpDNA), and nuclear-ribosomal-DNA (rDNA) variation. Evidence from enzyme electrophoresis did not support the proposed introgressive origin of weedy H. bolanderi. We detected a total of 37 low-frequency alleles distinguishing the serpentine race of H. bolanderi from H. annuus. Weedy H. bolanderi possessed only four of the 37 marker alleles. Further analysis demonstrated that serpentine H. bolanderi combined seven of the 35 alleles distinguishing H. annuus from weedy H. bolanderi, indicating that serpentine H. bolanderi shares three more marker alleles with H. annuus than does weedy H. bolanderi. These results are similar to expectations for race divergence from a single common ancestor and suggest that, if introgression occurred, the majority of marker alleles were rapidly lost following the initial hybridization event. Even more compelling evidence opposing Heiser's (1949) hypothesis, however, was from restriction-fragment analysis of cpDNA and nuclear rDNA. We detected a total of 17 cpDNA and five rDNA restriction-site mutations among the 19 populations examined. No parallel or back mutations were observed in phylogenetic trees constructed using either cpDNA or rDNA mutations, and both phylogenies were completely congruent regarding the alignment of all three taxa. In addition, the weedy race of H. bolanderi possessed a unique cpDNA, which was outside the range of variation observed among populations of either of the presumed parental species. Mean sequence divergences between the cpDNAs of weedy H. bolanderi and those of serpentine H. bolanderi and H. annuus were 0.30% and 0.35%, respectively. These estimates are comparable to sequence-divergence values observed between closely related species in other plant groups. Given the lack of parallel or convergent mutations in the cpDNA and rDNA phylogenetic trees, the complete congruence of these trees with flavonoid- and allozyme-variation patterns, and the presence of a unique and divergent chloroplast genome in the weedy race of H. bolanderi, we suggest that the weedy race of H. bolanderi was not derived recently through introgression, as hypothesized, but is relatively ancient in origin.

Comparison of soil properties as influenced by organic and conventional farming systems

Abstract: This paper summarizes data from previous and current studies on two adjacent farms, one organically managed and the other conventionally managed, in the Palouse region of eastern Washington. The 320-hectare organic farm has been managed without the use of commercial fertilizers and only limited use of pesticides since the farm was first plowed in 1909. The 525-hectare conventional farm, first cultivated in 1908, began receiving recommended rates of commercial fertilizers and pesticides in 1948 and the early 1950's, respectively. The organically-farmed Naff silt loam soil had significantly higher organic matter, cation exchange capacity, total nitrogen, extractable potassium, water content, pH, polysaccharide content, enzyme levels, and microbial biomass than did the conventionally-farmed Naff soil. Also, the organically-farmed soil had significantly lower modulus of rupture, more granular structure, less hard and more friable consistence, and 16 centimeters more topsoil. This topsail difference between farms was attributed to significantly greater erosion on the conventionally-farmed soil between 1948 and 1985. The difference in erosion rates between farms was most probably due to their different crop rotation systems; Le., only the organic farm included a green manure crop in its rotation, and it had different tillage practices. These studies indicate that, in the long-term, the organic farming system was more effective than the conventional farming system in maintaining the tilth and productivity of the Naff soil and in reducing its loss to erosion.

The Predynastic of Egypt

Abstract: The Predynastic of Egypt, spanning an interval from ca. 4000 to 3050 B.C., was an eventful period. After the inception of food production in the Nile Valley at least a millennium before, it was the time when the identity of Egyptian society was forged. Egypt was settled by refugees from the deserts of the eastern Sahara and the southern Levant, fleeing from mid-Holocene droughts, and became a melting pot of indigenous Nilotes and desert herders, part-time cultivators, and hunters. Within a millennium, an increasing dependence on agriculture led to sedentary life and, in some cases, to the development of sizable communities. By 4000 B.C., the settled communities had also developed a distinct division of labor between men and women and ritual and religious beliefs in which women, grain, fertility, and death were salient and interrelated elements. The Predynastic communities were also faced by the most destabilizing factor of agricultural economy, namely, fluctuations of yield. Attempts to dampen the fluctuations through interregional integration led to the emergence of community representatives and eventually chiefs. Legitimation of the status of chiefs through affiliation with the traditional and supernatural power associated with women, fertility, and death and the acquisition of exotic goods stimulated trade and an industry in funerary goods. Enlargement of economic units through alliances, with occasional incidences of fighting, especially after 3600 B.C., led to the rise of a state society governed by supreme rulers. The wedding of the funerary cult of Late Predynastic Egypt with political power and military might was the basis for the most fascinating aspects of Ancient Egypt—religion and kingship.

A services marketing management model: integrating internal and external marketing functions

Abstract: In services marketing, the employee plays a central role in attracting, building and maintaining relationships with customers. The recognition of the central role of employees in service marketing has given rise to “internal marketing” programs strongly oriented to employee development. This paper explores the linkage between internal marketing activities (directed at employee recruitment, training, motivation, communication, and retention) and the more traditional external marketing activities (e.g., pricing, advertising, and personal selling). An examination of the relationship between the key elements of the services marketing management model (internal and external marketing, employee attitudes and behavior, and customer attitudes and behavior) demonstrates how service managers can enhance customer loyalty, satisfaction and perception of quality.

On achieving consensus using a shared memory

Abstract: Chor, Israeli and Li recently published three randomized algorithms for a version of the consensus problem for a shared memory model of distributed computing. Their model requires, as atomic instructions on the shared memory, reads and random writes (in which a random choice and a write are done together in a single atomic instruction). This paper develops randomized algorithms for a model in which the only atomic operations on the shared memory are reads and writes.

Effects of daily cocaine and morphine treatment on somatodendritic and terminal field dopamine release.

Abstract: Daily injections of cocaine or morphine into rodents produces behavioral sensitization such that the last daily injection results in a greater motor stimulant effect than the first injection. To evaluate a role for brain dopamine in behavioral sensitization to cocaine and morphine, tissue slices from the ventromedial mesencephalon (containing dopamine cell bodies), the nucleus accumbens, and striatum (dopamine terminal fields) were obtained from rats pretreated with daily cocaine, morphine, or saline 2–3 weeks earlier. When the tissue slices were depolarized by increasing potassium concentration in the superfusate, the release of endogenous dopamine from the ventromedial mesencephalon of cocaine- and morphine-pretreated rats was significantly decreased. In contrast, the release of dopamine from the nucleus accumbens and striatum was either unaltered or slightly enhanced in rats pretreated with cocaine and morphine. When dopamine was released by amphetamine, a significant decrease in dopamine release from the ventromedial mesencephalon of cocaine-pretreated rats was measured. No other significant changes were measured after amphetamine-induced release. It is postulated that the decrease in dopamine release from the ventromedial mesencephalon of cocaine- and morphinesensitized rats results in less somatodendritic autoreceptor stimulation, and thereby produces an increase in dopamine neuronal activity.

Cloning and sequencing of cDNA for a highly anionic peroxidase from potato and the induction of its mRNA in suberizing potato tubers and tomato fruits

Abstract: A highly anionic peroxidase was strongly suggested to be involved in the deposition of the aromatic domain of suberin. cDNA containing the coding region of the suberization-associated anionic peroxidase from potato has been cloned and sequenced. The deduced amino acid sequence of the peroxidase shows that it is an anionic protein with considerable homology to other peroxidases. The amino acid sequence of two tryptic peptides obtained from the anionic peroxidase purified from suberizing potato tuber slices matched exactly with two segments of the amino acid sequence deduced from the nucleotide sequence of the cloned cDNA. The identity of the cloned cDNA is further supported by hybrid-selected translation and immunological recovery of the product with antibodies prepared against the purified anionic peroxidase. This anionic peroxidase was barely detectable at 2 days after wounding, and reached a maximal level at 8 days after wounding. Using the cDNA for the anionic peroxidase as a probe, we showed that the mRNA for the enzyme was induced in suberizing potato. The mRNA levels increased from an undetectable level in control tuber tissue to a maximal level in suberizing tuber tissue aged for four days. In suberizing tomato fruit the peroxidase mRNA showed induction and the level reached a maximum in three days. Ine data suggest that the induction of the peroxidase by wounding is preceded by transcriptional activation of the peroxidase gene or by increased stabilization of the mRNA. The time course of increase in mRNA for the anionic peroxidase was consistent with its postulated role in suberization.