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91.
This study assessed the potential of two types of primate exhibit both for enhancing zoo visitors' interest, knowledge, and enjoyment and for promoting conservation education. Visitors' reactions to a free-ranging group of cotton-top tamarins were compared with their responses to caged tamarins in three ways: 1) timing how long visitors spent at each exhibit, 2) recording the comments made by visitors about the exhibits, and 3) asking visitors to respond to questionnaires about the two exhibits. The results showed that the free-ranging group of tamarins provoked wider comment from members of the public than caged groups and that visitors were willing to spend much more time looking for and watching monkeys in trees than monkeys in cages. Visitors felt that improvements in the animals' welfare were obtained from allowing them to live free in the trees, thought that they could learn more from such groups than from caged animals, and enjoyed seeing the free-ranging tamarins more than the monkeys in cages. These results suggest that developing more naturalistic zoo exhibits can have considerable benefits not only for the animals involved, but also for public education in conservation issues. © 1994 Wiley-Liss, Inc. 相似文献
92.
Mengbing Li Daniel E. Park Maliha Aziz Cindy M. Liu Lance B. Price Zhenke Wu 《Biometrics》2023,79(1):264-279
This paper is concerned with using multivariate binary observations to estimate the probabilities of unobserved classes with scientific meanings. We focus on the setting where additional information about sample similarities is available and represented by a rooted weighted tree. Every leaf in the given tree contains multiple samples. Shorter distances over the tree between the leaves indicate a priori higher similarity in class probability vectors. We propose a novel data integrative extension to classical latent class models with tree-structured shrinkage. The proposed approach enables (1) borrowing of information across leaves, (2) estimating data-driven leaf groups with distinct vectors of class probabilities, and (3) individual-level probabilistic class assignment given the observed multivariate binary measurements. We derive and implement a scalable posterior inference algorithm in a variational Bayes framework. Extensive simulations show more accurate estimation of class probabilities than alternatives that suboptimally use the additional sample similarity information. A zoonotic infectious disease application is used to illustrate the proposed approach. The paper concludes by a brief discussion on model limitations and extensions. 相似文献
93.
Melinda A. Novak Amy Musante Heather Munroe Peggy L. O'Neill Cristofer Price Stephen J. Suomi 《Zoo biology》1993,12(3):285-298
Recent research has indicated that old, individually housed monkeys show little interest in novel objects. Yet unanswered is whether this effect is caused primarily by age or housing condition. The purpose of this study was to assess the role of social living in promoting responsiveness to objects. We measured the rates of object manipulation in older animals, assessed responsiveness over time to particular objects as a measure of habituation, and examined social influences on object use. Several social groups of rhesus monkeys that contained older adults were studied. These groups were housed in indoor pens or in an outdoor enclosure, and all monkeys had continuous access to a variety of objects in their home environment. In contrast to previous studies of individually housed monkeys, our group-housed monkeys showed sustained interest in objects. Old monkeys manipulated objects extensively, and this response was all the more significant, given that the objects were not novel. Monkeys housed in an outdoor enclosure showed object manipulation patterns that were not different from monkeys housed in indoor pens. However, females exhibited much higher object-related responses than males. Social facilitation played a role in the reactions of some monkeys to objects. Patterns of social facilitation as well as avoidance were present in two of the three indoor groups that were observed. Failure to manipulate objects in rhesus macaques appears to be more a function of individual housing than of old age. Factors such as environmental complexity, social needs, and early experience should be considered in order to understand why individually housed rhesus monkeys are unresponsive to objects. © 1993 Wiley-Liss, Inc. 相似文献
94.
Sam Price 《Economic botany》1963,17(2):97-106
Modern sugar cane varieties are derived from interspecific crosses involving as many as four species. Because a chromosome increase accompanies certain crosses and backcrosses, modern varieties have very high aneuploid chromosome numbers and complicated genetics. Despite this complexity, the chromosome behavior of some modern varieties approaches that of allopolyploids. In achieving homozygosity, therefore, such varieties should respond to inbreeding almost like diploids. The meiotic chromosome behavior of F1 hybrids and modern varieties indicates little or no genetic exchange between chromosomes ofSaccharum officinarum andS. spontaneum. Irradiation may break linkages between desirable and undesirableS. spontaneum genes not ordinarily broken by crossing-over between the chromosomes of the two species. The quick success of nobilizingS. spontaneum (recurrently back-crossing to “noble canes”) depends on a peculiar increase of the chromosomes ofS. officinarum. Experience with nobilizingS. spontaneum should not make breeders impatient when they turn to interspecific crosses unaccompanied by chromosome increases. 相似文献
95.
96.
Diane R. Campbell Nickolas M. Waser Mary V. Price Elizabeth A. Lynch Randall J. Mitchell 《Evolution; international journal of organic evolution》1991,45(6):1458-1467
In the hummingbird-pollinated herb Ipomopsis aggregata, selection through male function during pollination favors wide corolla tubes. We explored the mechanisms behind this selection, using phenotypic selection analysis to compare effects of corolla width on two components of male pollination success, pollinator visit rate and pollen exported per visit. During single visits by captive hummingbirds, flowers with wider corollas exported more pollen, and more dye used as a pollen analogue, to stigmas of recipient flowers. Corolla width was less strongly related to visit rate in the field, and had no direct effect on visit rate after nectar production and corolla length were controlled for. Moreover, the phenotypic selection differential was 80% higher for the effect on pollen exported per visit, suggesting that this is the more important mechanism of selection. 相似文献
97.
Trevor Price Dolph Schluter 《Evolution; international journal of organic evolution》1991,45(4):853-861
Life-history traits such as longevity and fecundity often show low heritability. This is usually interpreted in terms of Fisher's fundamental theorem to mean that populations are near evolutionary equilibrium and genetic variance in total fitness is low. We develop the causal relationship between metric traits and life-history traits to show that a life-history trait is expected to have a low heritability whether or not the population is at equilibrium. This is because it is subject to all the environmental variation in the metric traits that affect it plus additional environmental variation. There is no simple prediction regarding levels of additive genetic variance in life-history traits, which may be high at equilibrium. Several other patterns in the inheritance of life-history traits are readily predicted from the causal model. These include the strength of genetic correlations between life-history traits, levels of nonadditive genetic variance, and the inevitability of genotype-environment interaction. 相似文献
98.
Martin J. Michaelson H. James Price John R. Ellison J. Spencer Johnston 《American journal of botany》1991,78(2):183-188
An improved procedure is reported for determining DNA amounts of plant nuclei. Nuclei stained with propidium iodide, isolated from chopped plant leaves, were passed through an Ortho Cytofluorograph with a Lexel model 95 argon laser (514 nm) and the fluorescence measured, integrated, and recorded using an Ortho 2140 Data Acquisition computer. All nuclear samples were mixed with nuclei of Sultan barley (2C DNA content = 11.12 pg [picogram]) as an internal standard. DNA contents of ten plant species, ranging from 2C = 1.7 pg to 36.1 pg measured by flow cytometry, correlated strongly (r = 0.99, slope = + 1.00) with DNA contents determined from Feulgen-stained nuclei of the same species using microspectrophotometry. The flow cytometric procedures were sufficiently sensitive to detect differences in DNA content between inbred lines of corn and their F1 hybrids. Our results obtained with improved procedures, specifically using propidium iodide as a fluorochrome and plant nuclei instead of chicken erythrocytes as an internal standard, demonstrate that laser flow cytometry can be a precise, rapid, and reliable method for determining nuclear DNA content of plants. 相似文献
99.
The biology of the arrhenotokous autoparasitoid,Encarsia pergandiella Howard, was studied in the laboratory on the silverleaf whitefly,Bemisia argentifolii Bellows & Perring. Egg to adult development of parasitoid females averaged ca. 14 days at about 25.3+0.2?C regardless of whether the whitefly host was reared on tomato, eggplant or squash. While all instars ofB. argentifolii were accepted for primary parasitization, a greater percentage of third and fourth instars were parasitized. Mortality of whitefly nymphs in the absence of parasitization did not differ among instars and averaged about 35%. Second instar to pupal parasitoid females were accepted for secondary parasitization although a greater percent of pupal females were parasitized. About 40% of immatureE. pergandiella females more than 4 days old died in the absence of secondary parasitization when exposed to adultE. pergandiella females. 相似文献
100.
Net O2 evolution, gross CO2 uptake and net HCO
inf3
su–
uptake during steady-state photosynthesis were investigated by a recently developed mass-spectrometric technique for disequilibrium flux analysis with cells of the marine cyanobacterium Synechococcus PCC7002 grown at different CO2 concentrations. Regardless of the CO2 concentration during growth, all cells had the capacity to transport both CO2 and HCO
inf3
su–
; however, the activity of HCO
inf3
su–
transport was more than twofold higher than CO2 transport even in cyanobacteria grown at high concentration of inorganic carbon (Ci = CO2 + HCO
inf3
su–
). In low-Ci cells, the affinities of CO2 and HCO
inf3
su–
transport for their substrates were about 5 (CO2 uptake) and 10 (HCO
inf3
su–
uptake) times higher than in high-Ci cells, while air-grown cells formed an intermediate state. For the same cells, the intracellular accumulated Ci pool reached 18, 32 and 55 mM in high-Ci, air-grown and low-Ci cells, respectively, when measured at 1 mM external Ci. Photosynthetic O2 evolution, maximal CO2 and HCO
inf3
su–
transport activities, and consequently their relative contribution to photosynthesis, were largely unaffected by the CO2 provided during growth. When the cells were adapted to freshwater medium, results similar to those for artificial seawater were obtained for all CO2 concentrations. Transport studies with high-Ci cells revealed that CO2 and HCO
inf3
su–
uptake were equally inhibited when CO2 fixation was reduced by the addition of glycolaldehyde. In contrast, in low-Ci cells steady-state CO2 transport was preferably reduced by the same inhibitor. The inhibitor of carbonic anhydrase ethoxyzolamide inhibited both CO2 and HCO
inf3
su–
uptake as well as O2 evolution in both cell types. In high-Ci cells, the degree of inhibition was similar for HCO
inf3
su–
transport and O2 evolution with 50% inhibition occurring at around 1 mM ethoxyzolamide. However, the uptake of CO2 was much more sensitive to the inhibitor than HCO
inf3
su–
transport, with an apparent I50 value of around 250 M ethoxyzolamide for CO2 uptake. The implications of our results are discussed with respect to Ci utilisation in the marine Synechococcus strain.Abbreviations Chl
chlorophyll
- Ci
inorganic carbon (CO2 + HCO
inf3
su–
)
- CA
carbonic anhydrase
- CCM
CO2-concentrating mechanism
- EZA
ethoxyzolamide
- GA
glycolaldehyde
- K1/2
concentration required for half-maximal response
- Rubisco
ribulose-1,5,-bisphosphate carboxylase-oxygenase
D.S. is a recipient of a research fellowship from the Deutsche Forschungsgemeinschaft (D.F.G.). In addition, we are grateful to Donald A. Bryant, Department of Molecular and Cell Biology and Center of Biomolecular Structure Function, Pennsylvania State University, USA, for sending us the wild-type strain of Synechococcus PCC7002. 相似文献