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51.
Food Competition Between Wild Orangutans in Large Fig Trees 总被引:1,自引:0,他引:1
Utami Sri Suci Wich Serge A. Sterck Elisabeth H. M. van Hooff Jan A. R. A. M. 《International journal of primatology》1997,18(6):909-927
Orangutans are usually solitary. However, occasionally aggregations are formed, especially in large fruiting fig trees. Individuals in these aggregations may experience scramble or contest competition for food. We investigated the type and strength of food competition in large figs among wild Sumatran orangutans. Adult males foraged more efficiently than adult females and subadult males did. The availability of ripe fruit is positively related to the number of orangutans visiting a fig tree and their foraging efficiency. The number of orangutans in a fig tree did not affect patch residence time and foraging behavior, though orangutans spent more time feeding when aggregation size increased in a fig tree. Dominance relationships could be measured in a number of dyads. Differences in dominance did not affect foraging behavior. The patch residence time of subordinate individuals was reduced on days that a dominant individual also visited the fig. In conclusion, orangutans seem to adjust aggregation size to the number of available ripe fruits in a fig tree in such a way that scramble competition was absent. Contest competition determined access to large fig trees. 相似文献
52.
Thirteen species in four genera of mites of the family Macrochelidae phoretic on dung beetles were collected in the eastern part of the Lesser Sunda Islands, Indonesia, providing the first record of the family for that area. Of these, two species, Macrocheles entetiensis Hartini and Takaku, sp. nov. and Macrocheles sumbaensis Hartini and Takaku, sp. nov., are new to science. The remaining 11 species are Glyptholaspis fimicola, Holostaspella bifoliata, Macrocheles baliensis, Macrocheles sp. aff. glaber, M. hallidayi, M. kraepelini, M. krantzi, M. limue, M. merdarius, M. oigru and Neopodocinum sinicum. 相似文献
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Information about meat-eating behavior by wild orangutans (Pongo pygmæus) is scant. The first article about such a case dates from 1981. Since 1989, seven incidents of adult female Sumatran orangutans eating slow lorises (Nycticebus coucang) have been witnessed. Three females from two study sites were involved. In three cases the females were seen catching the prey. There are too few cases to conclude whether this behavior is typically female. Am. J. Primatol. 43:159–165, 1997. © 1997 Wiley-Liss, Inc. 相似文献
56.
Butler NS Theodossis A Webb AI Nastovska R Ramarathinam SH Dunstone MA Rossjohn J Purcell AW Perlman S 《PLoS pathogens》2008,4(10):e1000186
High affinity antigen-specific T cells play a critical role during protective immune responses. Epitope enhancement can elicit more potent T cell responses and can subsequently lead to a stronger memory pool; however, the molecular basis of such enhancement is unclear. We used the consensus peptide-binding motif for the Major Histocompatibility Complex molecule H-2K(b) to design a heteroclitic version of the mouse hepatitis virus-specific subdominant S598 determinant. We demonstrate that a single amino acid substitution at a secondary anchor residue (Q to Y at position 3) increased the stability of the engineered determinant in complex with H-2K(b). The structural basis for this enhanced stability was associated with local alterations in the pMHC conformation as a result of the Q to Y substitution. Recombinant viruses encoding this engineered determinant primed CTL responses that also reacted to the wildtype epitope with significantly higher functional avidity, and protected against selection of virus mutated at a second CTL determinant and consequent disease progression in persistently infected mice. Collectively, our findings provide a basis for the enhanced immunogenicity of an engineered determinant that will serve as a template for guiding the development of heteroclitic T cell determinants with applications in prevention of CTL escape in chronic viral infections as well as in tumor immunity. 相似文献
57.
Fourteen mite species in three genera of the family Macrochelidae were collected from the body surface of dung beetles (Scarabaeidae) in Mt Merapi National Park, Jogyakarta, Indonesia. Of these, three species, Macrocheles turgoensis n. sp., M. pumilus n. sp. and Glyptholaspis merapiensis n. sp., were described as new to science. The remaining 11 species were Glyptholaspis fimicola (Sellnick, 1931), Neopodocinum spinirostris (Berlese, 1910), M. dispar (Berlese, 1910), M. entetiensis Hartini and Takaku, 2005, M. hallidayi Walter and Krantz, 1986, M. jabarensis Hartini and Takaku, 2003, M. merdarius (Berlese, 1889), M. muscaedomesticae (Scopoli, 1772), M. oigru Walter and Krantz, 1986, M. sukaramiensis Takaku, 2001 and M. sp. aff. glaber (Müller, 1860). 相似文献
58.
Batai (Falcataria moluccana) is a valuable tree species for forest plantations in Malaysia and Indonesia. Since 1993, a gall rust disease has caused
severe damage to all growth stages, from seedlings in the nursery to mature trees in the field. To identify the fungus causing
gall rust disease on F. moluccana in Malaysia and Indonesia, study of the mode of infection and changes in the anatomy of infected cells were carried out in
the anatomy laboratory. The disease in Malaysia and Indonesia is caused by Uromycladium tepperianum. The fungus produces three longitudinally ridged teliospores on each head, with spores measuring 13–20 μm wide and 17–28 μm
long. The fungus is microcyclic, completing its entire life cycle on F. moluccana. This study confirmed that the teliospores themselves cannot infect the host. Under favorable conditions, about 10 h after
inoculation, teliospores germinate to produce basidiospores that form penetration pegs about 6 h later, and it is this peg
which penetrates the host cells directly through the epidermis. Pycnia, recognized as small brown pustules, break through
the epidermis about 7 days after inoculation. 相似文献
59.
Sri Balasubashini M Karthigayan S Somasundaram ST Balasubramanian T Viswanathan V Raveendran P Menon VP 《Bioorganic & medicinal chemistry letters》2006,16(24):6219-6225
The present study was carried out to assess the effect of Pterios volitans venom (mixture of peptides) on Ehrlich’s ascites carcinoma (EAC) and its influence on antioxidant status in the liver. Among six groups of albino mice, three were treated with sublethal doses of venom, along with the standard drug, 5-fluorouracil. In EAC-bearing mice, mean life span and antioxidants were significantly decreased, whereas, body weight, tumor volume, viable tumor cell count, lipid peroxidation and expression of proliferating cell nuclear antigen were significantly increased. These changes were brought back to near normal in treatment groups. The findings are further confirmed by histopathological observations. 相似文献
60.
Disulfide-rich domains are small protein domains whose global folds are stabilized primarily by the formation of disulfide bonds and, to a much lesser extent, by secondary structure and hydrophobic interactions. Disulfide-rich domains perform a wide variety of roles functioning as growth factors, toxins, enzyme inhibitors, hormones, pheromones, allergens, etc. These domains are commonly found both as independent (single-domain) proteins and as domains within larger polypeptides. Here, we present a comprehensive structural classification of approximately 3000 small, disulfide-rich protein domains. We find that these domains can be arranged into 41 fold groups on the basis of structural similarity. Our fold groups, which describe broader structural relationships than existing groupings of these domains, bring together representatives with previously unacknowledged similarities; 18 of the 41 fold groups include domains from several SCOP folds. Within the fold groups, the domains are assembled into families of homologs. We define 98 families of disulfide-rich domains, some of which include newly detected homologs, particularly among knottin-like domains. On the basis of this classification, we have examined cases of convergent and divergent evolution of functions performed by disulfide-rich proteins. Disulfide bonding patterns in these domains are also evaluated. Reducible disulfide bonding patterns are much less frequent, while symmetric disulfide bonding patterns are more common than expected from random considerations. Examples of variations in disulfide bonding patterns found within families and fold groups are discussed. 相似文献