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1.
Females of several species of macaques form cohesive matrilineal units in which all members share a collective status. The relationship between rank and kinship inMacaca radiata has not previously been studied. Analysis of observations of social interactions in a large and stable captive group ofM. radiata and longitudinal study of kinship and reproductive success indicate that with few exceptions a matrilineal dominance hierarchy exists in that group. Four young, upwardly mobile females are responsible for the exceptions. Contrary to the pattern noted in other species of macaques, several adult females outrank their daughters. Old age and deteriorating physical condition of mothers appear to be associated with mother-daughter rank reversals. The age and lineage size of females when they entered the group have had a lasting impact. Females who entered the group as adults have achieved higher rank and greater reproductive success than females who entered the group as juveniles without relatives. This research was conducted at the California Primate Research Center in Davis, supported by USPHS grant RR00169.  相似文献   

2.
Beinghurst, R. S., and Daud Ahmad Khan. (U. California, Davis.) Natural pentaploid Fragaria chiloensis–F. vesca hybrids in coastal California and their significance in polyploid Fragaria evolution. Amer. Jour. Bot. 50(7): 658–661. Illus. 1963.—Two natural pentaploid (35 chromosome) hybrids of Fragaria chiloensis (2n = 56)–F. vesca (2n = 14) were found in coastal California, an extensive colony of a sterile female clone ascertained to be over 40 years old at Point Sur, and a younger male clonal colony near Montara. The putative parents were present at each site. Apparently the hybrids successfully compete with F. chiloensis because of superior stolon productivity. Hybrids of this type are probably fairly common and may have already led to the development of fertile decaploid colonies through somatic doubling or the functioning of unreduced gametes.  相似文献   

3.
Summary Disposal of rice straw through soil incorporation may contribute to anaerobic fermentation processes producing concentrations of organic acids which are toxic to rice plants. The present studies were conducted to determine the kind, amount, and time of production of organic acids as a function of rice straw additions (0, 0.25, and 0.5 per cent of soil weight), and temperature (10, 20, and 30°C). Nine samples were taken at 5, and 10 day intervals for 60 days to measure concentrations of organic acids.Only acetic acid was detected in the incubated soil with rice straw added. The amount and peak production of acetic acid increased with the rate of straw added and temperature. Acetic acid concentrations varied between 10.6 and 22.7 eq/20 g soil, and the peak production occurred between 15 and 20 days after incubation. Organic acids were not found in sufficient amounts to affect the growth of rice plants grown in soils that were not previously puddled or in a reduced state.Contribution from the Department of Agronomy and Range Science, University of California, Davis, California 95616.Contribution from the Department of Agronomy and Range Science, University of California, Davis, California 95616.  相似文献   

4.
The lac insect genus Tachardiella Cockerell is reviewed and 17 species are recognized, including one new species. The adult female of Tachardiella palobrea Kondo & Gullan sp. n. is described and illustrated based on material collected in Argentina on 'brea', Parkinsonia praecox (Fabaceae). The adult female of Tachardiella argentina (Dominguez) is redescribed and a lectotype is designated based on newly discovered syntype material in the Bohart Museum of Entomology, University of California, Davis (BME). Diagnoses and notes are provided for the other species of Tachardiella studied and a lectotype is designated for Tachardiella ferrisi Chamberlin. A taxonomic key to separate all known species of lac insects in the New World is provided.  相似文献   

5.
The inbred FVB/N mouse strain is widely used for creating transgenic mice. Over the past decade, persistent mammary hyperplasia has been detected in many multiparous FVB/N female mice sent to the University of California, Davis (UCD) Mutant Mouse Pathology Laboratory (MMPL) by a number of different laboratories. However, the experimental details concerning most specimens were not always available. To confirm these empiric findings, experiments were carried out to evaluate the mammary glands of FVB/N mice under controlled conditions. Persistent mammary hyperplasia that related to parity was found. Weeks after their first to fourth pregnancy, 10 FVB/N female mice from the Lawrence Berkeley National Laboratory (LBNL) colony were studied and the mammary glands were evaluated. The percentage of fat pad filled was estimated, using image analysis. Serum samples and the pituitary gland from other FVB/N mice from the LBNL were assayed for prolactin concentration. Multiparous FVB/N females consistently had persistent mammary hyperplasia. Four of seven females in the LBNL colony had hyperplasia after three pregnancies. A few foci of squamous nodules and sporadic carcinomas also were observed. Thus, some FVB/N females may have persistent mammary hyperplasia after three pregnancies without detectable pituitary abnormalities. Mammary carcinomas also may develop sporadically. These background phenotypes must be considered when interpreting the effect of genetic manipulation in FVB/N mice.  相似文献   

6.
The gross composition of the outer epidermal cell wall from third internodes of Pisum sativum L. cv. Alaska grown in dim red light, and the effect of auxin on that composition, was investigated using interference microscopy. Pea outer epidermal walls contain as much cellulose as typical secondary walls, but the proportion of pectin to hemicellulose resembles that found in primary walls. The pectin and hemicellulose fractions from epidermal peels, which are enriched for outer epidermal wall but contain internal tissue as well, are composed of a much higher percentage of glucose and glucose-related sugars than has been found previously for pea primary walls, similar to non-cellulosic carbohydrate fractions of secondary walls. The epidermal outer wall thus has a composition rather like that of secondary walls, while still being capable of elongation. Auxin induces a massive breakdown of hemicellulose in the outer epidermal wall; nearly half the hemicellulose present is lost during 4 h of growth in the absence of exogenous sugar. The percentage breakdown is much greater than has been seen previously for whole pea stems. It has been proposed that a breakdown of xyloglucan could be the basis for the mechanical loosening of the outer wall. This study provides the first evidence that such a breakdown could be occurring in the outer wall.M.S. Bret-Harte would like to thank Dr. Peter M. Ray, of Stanford University, for helpful discussions and for technical and editorial assistance, Dr. Winslow R. Briggs, of the Camegie Institude of Washington, for the use of experimental facilities and for helpful discussions, Dr. Wendy K. Silk, of the University of California, Davis, for helpful discussions and financial support, Dr. Paul B. Green for financial support, and Drs. John M. Labavitch and L.C. Greve, of the University of California, Davis, for performing the -cellulose analysis on short notice, in response to a request by an anonymous reviewer. This work was supported by a National Science Foundation Graduate Fellowship to M.S. B.-H., National Science Foundation Grant DCB8801493 to Paul B. Green, and the generosity of Wendy K. Silk (Department of Land, Air, and Water Resources, University of California, Davis) during the final writing.  相似文献   

7.
We are now beginning to be able to evaluate the results of the rapid growth of family practice residency training programs during the past decade. Because this growth has been supported by federal and state funds, it is particularly important to review these programs to measure their progress toward the public policy goals established by legislation. The University of California, Davis, School of Medicine has been an innovator and leader in training family physicians. Graduates of the UC Davis Network of Family Practice Residency Programs are locating in medically underserved areas and are helping to respond to the perceived problems of specialty and geographic maldistribution of physicians.  相似文献   

8.
A method is described for recording many separate primate social behaviors in one session. The equipment utilized to facilitate these recordings offers the following advantages over conventional paper and pencil shorthand scoring systems: 1) an entire session may be recorded without losing sight of the subjects, 2) higher interobserver reliabilities are obtained, 3) sessions are accurately timed and exactly repeatable, 4) absolute rather than modified frequencies and durations are recorded, and 5) no upper limits are imposed on the data obtained.Supported by NIH Grant FR-00169 to the National Center for Primate Biology, University of California, Davis, California, and by NIH Grants MH-17425 and HDOH-335.  相似文献   

9.
A review of the literature on macaque play, emphasizing the social correlates of such behavior, is presented and summarized. In general, males are more playful than females, adults are relatively nonplayful, and nurturant behavior is negatively correlated with play. However, the currently inadequate definitions, conceptualizations, and experimental treatments of play make generalizations tentative. Supported in part by faculty research grant D-552, University of California, Davis, and by RR00169 to the California Primate Research Center.  相似文献   

10.
Spectacular Nature: Corporate Culture and the Sea World Experience. Susan G. Davis. Berkeley: University of California Press, 1997.314 pp.  相似文献   

11.
A list of the deposited type specimens, historical highlights, and maintenance procedures are given for the type section of the University of California Davis Nematode Collection (UCDNC). The type specimen section contains more than 630 species and 10,740 individual specimens mounted on more than 3,600 microscope slides. This list of deposited types is only a type specimen location reference and should not be used for type status or as a check list.  相似文献   

12.
柳二十斑叶甲包括两个亚种,分别为指名亚种和高山亚种.两者可以通过头部、前胸背板、足和鞘翅的斑纹区分开来.本文对这两个亚种的外部和内部的形态结构进行了研究,主要包括触角、口器、中胸、后胸、后翅、足、雌雄外生殖器、成虫和幼虫的相关结构.并对确定亚种的形态特征进行了探讨.  相似文献   

13.
The University of California, Davis hosted a symposium on innate immunity in January 2012. Professors Bruce Beutler, Jules Hoffmann, Luke O'Neill and Pamela Ronald discussed their research on mechanisms that multicellular organisms use to recognize microbes.  相似文献   

14.
Distinguished Economic Botanist’s address delivered 15 August 1988 at the 29th Annual Meeting of the Society for Economic Botany, University of California, Davis, CA.  相似文献   

15.
“Profiles of Pioneer Women Scientists: Katherine Esau” tells the story of a noted botanist, plant anatomist, and electron microscopist who was born in the Russian Ukraine (in 1898), forced to flee the Bolshevik Revolution with her family—her father a mayor of Ekaterinoslav under the Czar—to Germany, where she received a bachelor’s degree in agriculture, education she put to good use in America. Beginning in a sugarbeet field in Salinas, California, she progressed through the doctoral degree at the University of California at Davis (UC Davis) and there began her exceptional research on plant anatomy and plant viral diseases. Her textbookPlant Anatomy became known among college students as “Aunt Kitty’s Bible,” and all of her textbooks have gone into second, and some to third, editions. Transferring to the University of California at Santa Barbara (with its new Chancellor, V. I. Cheadle) only two years before retirement, she blossomed anew, producing some of her best work there and obtaining National Science Foundation support for a new electron microscope and other research funds through her 89th year. Katherine Esau started accruing awards and honors at a relatively early age (Faculty Research Lecturer at age 50, election to the National Academy of Sciences at 59) and has never stopped (the President’s Medal of Science at age 91, a UC Santa Barbara building named for her at age 93). It has been her good fortune to live to enjoy these honors. The short autobiography of her father, a truly enterprising engineer, is included here, as are the recollections of Celeste Turner Wright. Celeste, who arrived at UC Davis the same year as Katherine Esau, became an acclaimed poet, and chaired the English Department for many years. She has added a lively reminiscence of the days she and Katherine spent at UC Davis. The introduction to the book by one of Esau’s former graduate students, Ray Franklin Evert, himself a renowned plant pathologist, provides a heartfelt tribute to his greatly admired professor.  相似文献   

16.
Causes for the death of the eggs in the prawn Macrobrachium nobilii are: i) shedding of eggs by ovigerous female, and ii) infection by epibionts: a Saprolegnial fungus, bacteria (gram negative) and protozoans (Vorticellids and Paramecium). A cause for the death of freshly hatched larvae of some decapods is the reduction in reserve yolk energy in the larvae hatched in the last few batches. To circumvent these disadvantages, an artificial incubator was designed, in which 70% of the 3-day old eggs can successfully be incubated and hatched simultaneously. The isolted eggs are irrigated with filtered and aerated water over a diaphragm in the incubator; the water flushed from below through the diaphragm in the artificial incubator, sways and keeps the eggs continuously in a suspended motion, simulating the irrigation technique of the mother.Presented in the Second International Symposium on Invertebrate Reproduction held in Davis, California during August, 1979  相似文献   

17.
Ultrastructure of Lampropedia hyalina   总被引:6,自引:4,他引:2  
Pangborn, Jack (University of California, Davis), and Mortimer P. Starr. Ultrastructure of Lampropedia hyalina. J. Bacteriol. 91:2025-2030. 1966.-In an effort to learn more about the structural bases for the sheeting format of Lampropedia hyalina, ultrathin sections were cut which were precisely oriented either parallel to or perpendicular to the plane of growth; these were examined by electron microscopy. Lampropedia cells show cytological features typical of gram-negative bacteria. In addition, three uniquely structured layers are found exterior to the cell walls. Details are presented regarding the fine structures and geometric relationships of these layers; their probable origins and involvements in the characteristic cellular juxtaposition are discussed.  相似文献   

18.
I tested the utility of Seyfarth's (1977) model of rank-related attractiveness to explain the distribution of allogrooming behavior among captive bonobos (Pan paniscus). Adult female bonobos generally have high social status and may be dominant over males. As predicted by the model, I found that high-ranking adult females received most allogrooming within each of the four investigated groups. Among adult female-adult female dyads, however, allogrooming was not clearly associated with dominance rank. Contradictory to predictions of the model, the highest-ranking females were responsible for most displacements over allogrooming, and grooming competition is positively correlated with dominance rank. In the second part of this study, I investigated the social significance of allogrooming body site preferences. Bonobos direct significantly most allogrooming to the face of conspecifics, and high- and low-ranking individuals, as well as males and females, differ significantly in their preferences for certain allogrooming sites. Subordinates and males tended to avoid facial grooming and preferred the back and anogenital region, while high-ranking individuals and females directed most allogrooming to the face and head of grooming partners. Data from this study support the hypothesis that high-ranking females are the most attractive grooming partners within a female-centered bonobo society. Many other aspects of allogrooming behavior, however, are not consistent with the model of rank-related attractiveness.  相似文献   

19.
Summary Flooded soils, which accumulate gaseous products of anaerobic fermentation, are often associated with poor rice plant growth. In the present experiment the effects of CO2, CH4, N2, and air on rice seedling growth and nutrition were evaluated. Nutrient culture techniques were used to avoid secondary soil effects normally experienced.Carbon dioxide gas in the root zone of rice reduced seedling growth significantly, whereas CH4 and N2 had no significant effect. Methane gave no stimulatory benefits, unlike results reported by some earlier workers. Of three major nutrient elements studied, P uptake was affected more than N or K. Phosphorus uptake was significantly reduced in leaves and sheaths by all three gases, but was significantly increased in roots. This suggests an immobilization mechanism affecting P in roots, and since CO2, CH4, and N2 behaved similarly in contrast to air, a lack of oxygen in the root system is suspected as the causal mechanism rather than toxic effects of gases. Effects on N and K uptake were minimal and insignificant.Contribution from the Department of Agronomy and Range Science, University of California, Davis, California 95616.Contribution from the Department of Agronomy and Range Science, University of California, Davis, California 95616.  相似文献   

20.
Research over the past 15 years indicates, contrary to earlier results, that women do not synchronize their menstrual cycles. If women do not synchronize their cycles, this implies there is no mechanism for synchronizing cycles. Since a pheromone mechanism of synchronization is the only plausible mechanism that has been proposed, it follows that that there are no pheromones that modulate the length of menstrual cycles. To test this hypothesis, eight studies were reviewed that reported pheromone effects on menstrual cycles, other behavior, or physiological correlates in women. The prediction was that serious problems would be found in each of these studies. As predicted, serious problems were found in all eight studies. Taken together, these results cast doubt on the existence of pheromones that modulate the length of menstrual cycles. Jeff Schank is associate professor of psychology at the University of California, Davis. His main research interests are in computational and biorobotic modeling of group behavior and the development of sensorimotor behavior in animals.  相似文献   

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