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Showing papers by "Cornell University published in 1981"


Journal ArticleDOI
TL;DR: Gender schema theory as mentioned in this paper proposes that the phenomenon of sex typing derives, in part, from gender-based schematic processing, from a generalized readiness to process information on the basis of the sex-linked associations that constitute the gender schema.
Abstract: Gender schema theory proposes that the phenomenon of sex typing derives, in part, from gender-based schematic processing, from a generalized readiness to process information on the basis of the sex-linked associations that constitute the gender schema. In particular, the theory proposes that sex typing results from the fact that the self-concept itself gets assimilated to the gender schema. Several studies are described which demonstrate that sex-typed individuals do, in fact, have a greater readiness to process information—including information about the self—in terms of the gender schema. It is speculated that such gender-based schematic processing derives, in part, from the society's ubiquitous insistence on the functional importance of the gender dichotomy. The political implications of gender schema theory are discussed, as is the relationship of the theory to the concept of androgyny. The distinction between male and female serves as a basic organizing principle for every human culture. Although societies differ in the specific tasks they assign to the two sexes, all societies allocate adult roles on the basis of sex and anticipate this allocation in the socialization of their children. Not only are boys and girls expected to acquire sex-specific skills, they are also expected to have or to acquire sex-specific self

3,374 citations


Journal ArticleDOI
TL;DR: In this paper, individual discount rates for losses and gains were estimated from survey evidence and they were found to vary inversely with the size of the reward and the length of time to be waited.

2,141 citations


Journal ArticleDOI
TL;DR: It is concluded that one determinant of lung injury in sarcoidosis in the presence of large numbers of lung helper T cells, which are important in granuloma formation, is concluded.
Abstract: Using the monoclonal antibodies OKT4 and OKT8, we determined the proportions of helper and suppressor T cells in patients with sarcoidosis and high-intensity alveolitis, patients with sarcoidosis and low-intensity alveolitis, patients with idiopathic pulmonary fibrosis (IPF), and normal controls. In controls and patients with IPF, the ratio of helper to suppressor T cells was 1.8:1 in lungs and blood. In contrast, this ratio was 10.5:1 in lungs (P less than 0.001) and 0.8:1 in blood (P less than 0.05) in patients with sarcoidosis and high-intensity alveolitis. The ratio of helper to suppressor T cells was not higher in the lungs or blood of patients with sarcoidosis and low-intensity alveolitis; on the contrary, because of the higher proportions of suppressor cells, the ratio of helper to suppressor cells was lower in both lungs and blood. In studies of function, lung T cells from patients with sarcoidosis and high-intensity alveolitis released monocyte chemotactic factor (a lymphokine critical to granuloma formation) and polyclonally activated B cells to produce immunoglobulins. We conclude that one determinant of lung injury in sarcoidosis in the presence of large numbers of lung helper T cells, which are important in granuloma formation.

777 citations


Journal ArticleDOI
TL;DR: It is condude that EF can be determined accurately with 2‐D echo in a large group of patients with and without dyssynergy by a simple method that eliminates the need for planimetry or computer assistance.
Abstract: A new method to determine left ventricular (LV) ejection fraction (EF) with wide-angle, two-dimensional echocardiography (2-D echo) has been developed using the parasternal long-axis, apical four-chamber and apical long-axis views. End-diastolic and end-systolic measurements of LV short axes at the base and mid-LV cavity in the parasternal long-axis view and at the upper, middle and lower thirds of the cavity in the apical views are made, from which an averaged minor axis at end-diastolic and at end-systole is calculated. Fractional shortening of the LV long axis (delta L) is estimated from apical contraction. Satisfactory 2-D echoes were obtained in 55 of 58 nonselected patients (all three views in 32 patients, two views in 22 and one view in one); 42 of 55 patients had coronary artery disease. EF by 2-D echo was compared with EF by gated cardiac blood pool imaging in all patients (r = 0.927, SEE = 6.7%) and to EF by single-plane cineangiography (angio) in 35 of 55 patients (r = 0.913, SEE = 7.4%). LV dy...

724 citations


Journal ArticleDOI
TL;DR: The Cornell Program Synthesizer demands a structural perspective at all stages of program development and its separate features are unified by a common foundation: a grammar for the programming language.
Abstract: Programs are not text; they are hierarchical compositions of computational structures and should be edited, executed, and debugged in an environment that consistently acknowledges and reinforces this viewpoint. The Cornell Program Synthesizer demands a structural perspective at all stages of program development. Its separate features are unified by a common foundation: a grammar for the programming language. Its full-screen derivation-tree editor and syntax-directed diagnostic interpreter combine to make the Synthesizer a powerful and responsive interactive programming tool.

715 citations


Journal ArticleDOI
M. Alexander1
09 Jan 1981-Science
TL;DR: Type reactions are proposed for major categories of enzymatic transformation of synthetic chemicals in soils, natural waters, and sewage and some organic molecules are resistant to microbial attack, and explanations for the persistence of such compounds are suggested.
Abstract: Microorganisms in soils and waters convert many synthetic organic chemicals to inorganic products. Other compounds are transformed only by cometabolism. These microbial processes may lead to environmental detoxication, the formation of new toxicants, or the biosynthesis of persistent products. Type reactions are proposed for major categories of enzymatic transformation of synthetic chemicals in soils, natural waters, and sewage. Some organic molecules are resistant to microbial attack, and explanations for the persistence of such compounds are suggested.

689 citations


Journal ArticleDOI
TL;DR: Relative availabilities determined for a series of meals containing ascorbic acid, eggs, orange juice, tea, coffee, cola, or whole wheat bread show that the method accurately reflects actual food iron availability.

685 citations


Journal ArticleDOI
01 Aug 1981-Ecology
TL;DR: In this article, tree replacement in gaps was studied in old-growth mesic forest stands in western Pennsylvania, Ohio, and the southern Appalachian Mountains in western and central Appalachia.
Abstract: Tree replacement in gaps was studied in old-growth mesic forest stands in western Pennsylvania, Ohio, and the southern Appalachian Mountains. Predictions of future overstory com- position, based on sapling composition in small gaps (average 200 M2), were compared to current canopy composition. Both Markov analyses and simple average sapling composition of gaps support the hypothesis that regeneration in small gaps was sufficient to perpetuate the current canopy species composition of the stands studied. In some cases the saplings most likely to replace a dead canopy tree were of the same species. In other cases, especially low-diversity beech-sugar maple stands, each species seemed to enhance significantly the success of the other species.

681 citations


Journal ArticleDOI
TL;DR: It is concluded that metoclopramide in high intravenous doses has greater antiemetic activity than placebo or prochlorperazine in patients receiving cisplatin chemotherapy in patients with advanced cancer.
Abstract: In a study of the effectiveness of high intravenous doses of metoclopramide as an antiemetic, 41 patients with advanced cancer who were being treated with cisplatin were entered into two double-blind trials. In the first trial patients were randomly assigned to receive either metoclopramide or placebo, and in the second trial they received either metoclopramide or prochlorperazine. Patients given metoclopramide had significantly fewer episodes of emesis than patients given placebo (medians, 1.0 vs. 10.5; P = 0.001) or prochlorperazine (medians, 1.5 vs. 12.0; P = 0.005). Metoclopramide was superior to placebo and to prochlorperazine in reducing the volume of emesis (P = 0.001 and P = 0.022, respectively) and was more effective than placebo in shortening the duration of nausea (P = 0.042) and vomiting (P = 0.028). Side effects from metoclopramide were minor, with mild sedation frequently observed; one patient had a brief extrapyramidal reaction. We conclude that metoclopramide in high intravenous d...

664 citations


Journal ArticleDOI
TL;DR: The result suggest that self-induced vomiting is not a necessary symptom for diagnosis of bulimia, and a significant relationship between laxative use and self- induced vomiting was detected.
Abstract: A survey of 355 college students was carried out to determine the prevalence of the psychiatric disorder bulimia (the binge-eating syndrome). Results of the survey indicate that, within the normal college population, 13% experienced all of the major symptoms of bulimia as outlined in the DSM-III. Within the bulimia population, 87% were females (19% of the female population) and 13% were males (5% of the male population). Although self-induced vomiting may accompany other symptoms of bulimia, the result suggest that self-induced vomiting is not a necessary symptom for diagnosis. A significant relationship between laxative use and self-induced vomiting was detected. These forms of behaviour, termed purging behaviour, occurred in an average of 10% of the students. Individuals who experienced the symptoms of bulimia had a history of being overweight or tended to be in the upper portion of their normal weight range (age, sex, and weight corrected) when compared with those individuals who had not experienced the symptoms of bulimia. No significant weight history differences were detected between vomiters and non-vomiters.

620 citations


Journal ArticleDOI
TL;DR: In this article, a multidomain boundary element formulation for the analysis of general two-dimensional plane strain/stress crack problems is presented, and the analyses were performed using traction singular quater-point boundary elements on each side of the crack tip(s) with and without transition elements.
Abstract: A multidomain boundary element formulation for the analysis of general two-dimensional plane strain/stress crack problems is presented. The numerical results were accurate and efficient. The analyses were performed using traction singular quater-point boundary elements on each side of the crack tip(s) with and without transition elements. Traction singular quarter-point boundary elements contain the correct √r displacement and 1/√r traction variations at the crack tip. Transition elements are appended to the traction singular elements to model the √r displacement variation. The 1/√r traction singularity is not represented with these elements. Current research studies for the crack propagation analysis of quasi-static and fatigue fracture problems are discussed.

Journal ArticleDOI
TL;DR: The changes occuring from the early to the late prenatal stages of development appear to be the result of an increase in number of cells and continued aggregation and migration of the labeled neurons.
Abstract: The immunocytochemical localization of tyrosine hydroxylase is examined at embryonic (E) days 18 and 21 in rat brain in order to determine changes in the distribution and cytology of neurons showing immunoreactivity for the enzyme during late prenatal development. As compared with earlier stages of development, the distribution and morphology of the tyrosine hydroxylase-containing neurons at E18 and E21 more closely resemble catecholaminergic neurons in the adult brain. The changes occurring from the early to the late prenatal stages of development appear to be the result of an increase in number of cells and continued aggregation and migration of the labeled neurons. The major differences in the distribution of labeled perikarya between E18 and E21 are in the olfactory bulb and cerebral cortex. In the olfactory bulb, tyrosine hydroxylase-containing neurons are not detected until E21. In contrast in the cerebral cortex, a few neurons are transiently labeled for the enzyme at E18, but are not detected at E21 and have not been reported in the adult brain. The most striking change in the tyrosine-hydroxylase labeled structures in the late prenatal period is the increase in detectable immunoreactivity in bundles of axons and in terminal aborizations. The orderly appearance of tyrosine hydroxylase-labeled axons in the neostriatum and cortex are discussed in relation to the formation of these two contrasting regions innervated by catecholaminergic neurons.

Journal ArticleDOI
Ulric Neisser1
TL;DR: Comparison of John Dean's testimony with the actual transcripts shows systematic distortion at one level of analysis combined with basic accuracy at another; many of the distortions reflected Dean's own self-image; he tended to recall his role as more central than it really was.

Journal ArticleDOI
TL;DR: The formation of austenite during intercritical annealing at temperatures between 740 and 900 °C was studied in a series of 1.5 pct manganese steels containing 0.06 to 0.20 pct carbon and with a ferrite-pearlite starting microstructure.
Abstract: The formation of austenite during intercritical annealing at temperatures between 740 and 900 °C was studied in a series of 1.5 pct manganese steels containing 0.06 to 0.20 pct carbon and with a ferrite-pearlite starting microstructure, typical of most dual-phase steels.

Journal ArticleDOI
TL;DR: This review deals with the tissue distribution and localization of the enzymes in mammals, the catalytic properties of the enzyme (including its inhibition by reversible and irreversible inhibitors), structural studies on the enzyme, and new findings about its physiological function.
Abstract: γ-Glutamyl transpeptidase catalyzes transfer of the γ-glutamyl moiety of glutathione to amino acids, dipeptides, and to glutathione itself; the enzyme also catalyzes the hydrolysis of glutathione to glutamate and cysteinyl-glycine. This review deals with the tissue distribution and localization of the enzyme in mammals, the catalytic properties of the enzyme (including its inhibition by reversible and irreversible inhibitors), structural studies on the enzyme, and new findings about its physiological function.

Journal ArticleDOI
TL;DR: In the Hubhard Brook watershed, the water path length in the soil zone is the crucial factor in the state of acid rain neutralization, aluminum chemistry and chemical weathering as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this article, the potential model of the quark-antiquark potential was analyzed in the framework of a recently proposed potential model which incorporates linear confinement and asymptotic freedom.
Abstract: The $\ensuremath{\psi}$ and $\ensuremath{\Upsilon}$ spectroscopies are analyzed in the framework of a recently proposed potential model which incorporates linear confinement and asymptotic freedom. Given the Regge slope ${\ensuremath{\alpha}}^{\ensuremath{'}}$ (${\ensuremath{\alpha}}^{\ensuremath{'}}$ taken to be 1 ${\mathrm{GeV}}^{\ensuremath{-}2}$) and the quantum-chromodynamics (QCD) scale parameter $\ensuremath{\Lambda}$ (${\ensuremath{\Lambda}}_{\stackrel{-}{\mathrm{MS}}}$ taken to be 0.5 GeV, where $\stackrel{-}{\mathrm{MS}}$ refers to the modified minimal-subtraction scheme) the potential is completely determined. Excellent agreement with experiment is found, including in particular leptonic widths and hyperfine splittings. This supports a short-distance behavior of the quark-antiquark potential as predicted by QCD. We also demonstrate in a model-independent way that the $\ensuremath{\Psi}$ and $\ensuremath{\Upsilon}$ spectra provide a lower bound on the QCD scale parameter $\ensuremath{\Lambda}$; we find ${\ensuremath{\Lambda}}_{\stackrel{-}{\mathrm{MS}}}g0.1$ GeV. The properties of ($b\overline{c}$) and possible ($t\overline{t}$), ($t\overline{c}$), and ($t\overline{b}$) spectroscopies are studied, including weak-interaction effects. The implications of the $\ensuremath{\Psi}$, $\ensuremath{\Upsilon}$, and possible heavier quarkonium families for quantitative tests of QCD are discussed. It is shown that a ($t\overline{t}$) system with $m(t\overline{t})\ensuremath{\ge}40$ GeV would provide an accurate determination of ${\ensuremath{\Lambda}}_{\stackrel{-}{\mathrm{MS}}}$.

Journal ArticleDOI
TL;DR: A combination of new agents with high dose cisplatin and vindesine supports the approach of new drug investigation in patients with lung cancer and the importance of the incorporation of active new agents into initial chemotherapy regimens.
Abstract: Eighty-five patients with advanced squamous carcinoma or adenocarcinoma of the lung were randomly assigned to receive vindesine with either high dose (120 mg/m2 of body surface area) or low dose (60 mg/m2) cisplatin. All patients had measurable disease and had not previously received chemotherapy. The response rate was similar with both treatments (43% complete and partial remission rate), but the high dose cisplatin regimen was superior to the low dose in median duration of response (12 versus 5.5 months; p = 0.05) and in median survival for responding patients (21.7 versus 10 months; p = 0.02). Myelosuppression was generally not a treatment problem; peripheral neuropathy and moderate azotemia were the major dose-limiting toxicities. With improved survival and response rates over those reported for conventional regimens, this combination of new agents supports the approach of new drug investigation in patients with lung cancer and the importance of the incorporation of active new agents into initial chemotherapy regimens.

Journal ArticleDOI
TL;DR: A new type of higher plant alkaloid, 1,6,7,8-tetrahydroxyoctahydroindolizine, designated castanospermine, has been isolated from the toxic seeds of the Australian legume Castanospermum australe.

Journal ArticleDOI
01 Oct 1981-Ecology
TL;DR: In this paper, an experimental approach was used in which all organic debris dams were re- moved from a 175m section of second-order stream, just above a gauging weir, to examine the relative importance of these structures in retention of sediment and organic matter in a small stream ecosystem.
Abstract: An organic debris dam is an accumulation of organic matter in a stream which obstructs water flow. Debris dams trap sediments in the pool formed upstream from them and the dam structure itself collects particulate organic matter. This study was done at the Hubbard Brook Experimental Forest, in New Hampshire, to examine the relative importance of these structures in retention of sediment and organic matter in a small stream ecosystem. An experimental approach was used in which all organic debris dams were re- moved from a 175-m section of second-order stream, just above a gauging weir. The material being exported from the watershed was separated into three size categories: dissolved matter ( 1 mm). Export of each size fraction was monitored for at least 1 yr prior to dam removal, and for 1 yr following removal. Following dam removal, export of dissolved matter increased slightly due to an increase in the concentration of dissolved organic carbon in the stream water during periods of high discharge. Fine particulate matter export increased dramatically at high discharges following dam removal; concen- trations in some instances achieved values five times higher than any observed before dam removal. Coarse particulate matter export also was greatly increased. Calculating dissolved matter and particulate matter export from the watershed, with and without organic debris dams, showed that dam removal brought about a 6% increase in the export of dissolved matter and a 500% increase in the export of both fine particulate and coarse particulate matter.

Journal ArticleDOI
TL;DR: The matrix M m,n is defined in this paper as the matrix having as rows, every nth row starting with the first row, then every Nth row beginning with the second row, and so on.
Abstract: The vec-permutation matrix I m,n is defined by the equation vec A m × n = I m,n vecA′, Where vec is the vec operator such that vecA is the vector of columns of A stacked one under the other. The variety of definitions, names and notations for I m,n are discussed, and its properties are developed by simple proofs in contrast to certain lengthy proofs in the literature that are based on descriptive definitions. For example, the role of I m,n in reversing the order of Kronecker products is succinctly derived using the vec operator. The matrix M m,n is introduced as M m,n = I m,n M; it is the matrix having as rows,every nth row starting with the first, then every nth row starting with the second, and so on. Special cases of M m,n are discussed.

Journal ArticleDOI
TL;DR: This article attempts to make regression diagnostics more readily available to those who compute regressions with packaged statistics programs, highlighting ambiguities of terminology and relationships among similar methods.
Abstract: Multiple regression diagnostic methods have recently been developed to help data analysts identify failures of data to adhere to the assumptions that customarily accompany regression models. However, the mathematical development of regression diagnostics has not generally led to efficient computing formulas. Conflicting terminology and the use of closely related but subtly different statistics has caused confusion. This article attempts to make regression diagnostics more readily available to those who compute regressions with packaged statistics programs. We review regression diagnostic methodology, highlighting ambiguities of terminology and relationships among similar methods. We present new formulas for efficient computing of regression diagnostics. Finally, we offer specific advice on obtaining regression diagnostics from existing statistics programs, with examples drawn from Minitab and SAS.

Journal ArticleDOI
TL;DR: It is suggested that energy balance during the first 20 days of lactation is important in determining the onset of ovarian activity following parturition.
Abstract: Energy balance and serum progesterone concentrations were monitored during early lactation in a group of high producing Holstein cows. The postpartum interval to normal ovulation averaged 36 +/- 6 days (range 6 to 83 days). Average energy balance during the first 20 days of lactation (cumulative daily calculated energy balance divided by days in milk) was inversely related to days to normal ovulation (r = -.60) and to milk production (r = -.80). Milk yield during this period was not closely related to days to ovulation (r = .30). Milk yield was also not significantly related to serum prolactin concentrations over the first 12 weeks of lactation (r = .27). During early lactation, energy balance was maximally negative until peak milk yield and then began returning toward zero, with the magnitude and duration of negative energy balance being quite variable. On the average, ovulation and the initiation of the first normal luteal phase occurred approximately 10 days after energy balance began returning toward zero. During this 10-day interval, a transient elevation in serum progesterone concentrations occurred in eight of 13 cows. These results suggest that energy balance during the first 20 days of lactation is important in determining the onset of ovarian activity following parturition.

Journal ArticleDOI
TL;DR: In this article, detailed leading-order quantum-chromodynamics (QCD) predictions are given for the scaling, angular, and helicity dependence of the reactions of a large momentum transfer.
Abstract: Detailed leading-order quantum-chromodynamics (QCD) predictions are given for the scaling, angular, and helicity dependence of the reactions $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}M\overline{M}$ ($M=\ensuremath{\pi},K,\ensuremath{\rho}$, etc) at large momentum transfer In addition to providing a basic test of QCD at short distances, measurements can be used to determine the process-independent meson distribution amplitudes ${\ensuremath{\varphi}}_{M}(x,Q)$ Other related two-photon channels such as $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\rho}$, ${\ensuremath{\gamma}}^{*}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0},{\ensuremath{\eta}}^{0},{\ensuremath{\eta}}^{\ensuremath{'}}$, and ${\ensuremath{\eta}}_{c}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$ are also discussed We also prove the existence of a fixed Regge singularity at $J=0$ which couples to $\ensuremath{\gamma}\ensuremath{\rho}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\rho}$ in the $t$ channel but not to $\ensuremath{\gamma}\ensuremath{\pi}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\pi}$

Journal ArticleDOI
TL;DR: In this paper, the nature of food foams, the possible relationships between the molecular structure and the foaming capacity of different proteins, and factors affecting these are discussed, as well as the possible relationship between different proteins and their foaming capacities.

Journal ArticleDOI
TL;DR: It is argued that the openness of desert vegetation and the patterns of climatic variation favor atelechory while antitelechory is generally a side-effect of mechanisms whose adaptive value is not directly related to dispersal.
Abstract: The rarity of long-range seed dispersal (telechory) and commonness of antitelechory in desert plants are examined in light of contemporary mathematical theories of the evolution of dispersal and germination behaviors. Analysis of dispersal 3-habitat relationships in the flora of Israel supports the general trend towards atelechory in deserts; in particular epizoochory and tumbleweeds are practically absent from the desert and heterocarpy is centered in the Mediterranean region. In contradiction to the accepted "mother-site" theory, we find that (a) there is a high turnover in microscale spatial pattern among antitelechoric species; (b) antitelechoric (especially basicarpic) species are widespread and dominant in the desert vegetation of Israel; (c) amphicary and geocary are rare in the desert flora of Israel.We argue that the openness of desert vegetation and the patterns of climatic variation favor atelechory while antitelechory is generally a side-effect of mechanisms whose adaptive value is not directly related to dispersal. Thus for example the desert plants of Israel have evolved a variety of dispersal-restricting seed-containers that protect the seed from predation and flooding, regulate the within-season timing of germination, and spread dispersal and germination over several years.

Book ChapterDOI
01 Jan 1981
TL;DR: In this article, a technique for calculating organized structures in turbulent shear flows is proposed, based on a homogeneous function decomposition and involves representation of a random function as a series of coherent structures occurring at stochastic locations with sparsity.
Abstract: A technique is proposed for calculating organized structures in turbulent shear flows. The proposed approach is based on a homogeneous function decomposition and involves representation of a random function as a series of coherent structures occurring at stochastic locations with stochastic strengths. Attention is given to the retrieval of phase information and information on overlap and spacing, nearly parallel shear flows, dynamical equations, and applications to measurements.

Journal ArticleDOI
TL;DR: Findings indicate that while the dopaminergic terminals may form axoaxonic connections, the primary synaptic contacts are with dendrites of intrinsic neurons in all regions of n.

Proceedings ArticleDOI
01 Aug 1981
TL;DR: A new reflectance model for rendering computer synthesized images that describes the directional distribution of the reflected light and a color shift that occurs as the reflectance changes with incidence angle is presented.
Abstract: This paper presents a new reflectance model for rendering computer synthesized images. The model accounts for the relative brightness of different materials and light sources in the same scene. It describes the directional distribution of the reflected light and a color shift that occurs as the reflectance changes with incidence angle. The paper presents a method for obtaining the spectral energy distribution of the light reflected from an object made of a specific real material and discusses a procedure for accurately reproducing the color associated with the spectral energy distribution. The model is applied to the simulation of a metal and a plastic.

Journal ArticleDOI
23 Jul 1981-Nature
TL;DR: The results suggest that mitotic gene conversion may occur by a different pathway from that occurring in meiosis, and may be important in yeast mating type interconversion and the maintenance of sequence homogeneity in families of repeated eukaryotic genes.
Abstract: The mitotic recombination behaviour of a duplication of the his4 region on chromosome III in the yeast Saccharomyces cerevisiae was studied. The major recombination event between the duplicated segments is gene conversion unassociated with reciprocal recombination. The rad52-1 mutation preferentially decreases mitotic gene conversion. These results suggest that mitotic gene conversion may occur by a different pathway from that occurring in meiosis. This mitotic gene conversion may be important in yeast mating type interconversion and the maintenance of sequence homogeneity in families of repeated eukaryotic genes.