Intestinal Parasites in Gorillas,Chimpanzees, and Humans at Mondika Research Site,Dzanga-Ndoki National Park,Central African Republic

We report prevalences and eggs/protozoa per g (EPG; PPG) of helminths and protozoa in gorillas, chimpanzees, agile mangabeys, indigenous Ba'Aka and Bantu, and western researchers at a remote field site in the Central African Republic. We examined fecal samples for eggs, larvae, proglottids, cysts, amoeba, trophozoites, and flagellates. For helminths, strongylates were most prevalent, infecting 82–94% of nonhuman primates (NH) and 30–93% of human (H) groups, followed by ascaroids (14–88% NH; 0–15% H), and threadworms (0–22% NH; 0–29% H). For protozoa, Entamoeba histolytica (2–100% NH; 33–52% H) and trichomonads (11–88% NH; 0–54% H) were most prevalent. Among gorilla samples (n = 156) there were significant age/sex differences in EPG/PPG for strongylates, threadworms, Entamoeba histolytica, and trichomonads, with infants exhibiting the highest mean EPG/PPG for all parasites except trichomonads. Between group analyses revealed that the Ba'Aka had significantly higher mean EPG of strongylates, ascaroids and threadworms than all other primate groups, except the mangabeys. For Entamoeba histolytica, E. coli, Balantidium coli, and Iodamoeba butschlii, the agile mangabeys had significantly higher mean PPG than other groups; for trichomonads, the chimpanzees, and mangabeys had the highest mean PPG. Relative to other African ape sites, the gorillas and chimpanzees at Mondika appear to have high prevalences of intestinal parasites. This may be the result of the high proportion of swamp and seasonally flooded areas, which provide optimal viability for parasite eggs and ova. At Mondika, the significantly higher parasite levels of Ba'Aka probably result from more traditional methods of hygiene and lack of available medical treatment. All workers at research sites should be monitored and treated to minimize cross-transmission between humans and local fauna.     

Bertiella sp. (Meyner, 1895) infection of Alouatta caraya (Humboldt, 1812) in urban and natural environments in Ñeembucú, southwest Paraguay

Bertiella sp., a cestode known to infect a variety of hosts, including nonhuman primates and humans, was identified in Paraguay as early as 1895, but no systematic analysis of wild primates’ gastrointestinal parasites has ever been carried out in Paraguay. Increased urbanization in southwest Paraguay has pushed the Paraguayan howler monkey (Alouatta caraya) into anthropogenic habitats, particularly in the city of Pilar (Ñeembucú department), giving rise to greater potential for zoonotic transmission between wild primates and humans. From July to December 2018, fecal samples were noninvasively collected from 48 howlers inside Pilar (urban environment), the Pilar Military Base (intermediate environment), and a ranch 27 km outside Pilar in the humid Chaco (natural environment) and analyzed for Bertiella eggs and proglottids using macro-analysis and formol-ether sedimentation. Howlers living in the urban environment had the highest rates of Bertiella infection (50% prevalence), with considerably lower infection rates in the intermediate environment (6.25% prevalence) and natural habitats (0% prevalence). A χ² goodness-of-fit test indicated a significant difference between the three habitat types (p = .007, χ² = 10.005, df = 2). While the habitat seems to impact the frequency of infection, Bertiella was not observed to select for other factors such as age or sex of the primate host. Here we identified a significant increase in the frequency of Bertiella infection in an urban environment, which can then be further transmitted to new hosts with more direct primate contact. Bertiella infection has already been documented in humans in Paraguay, all of which were associated with close primate contact. As howlers move into more urban habitats due to urbanization and habitat fragmentation, Bertiella could be introduced into this new ecosystem and has the potential to cause further infections in humans.     

大学毕业生压力应对的性别差异研究

采用＂压力应对方式问卷＂对陕西师范大学148名大四毕业生进行调查,结果发现：（1）大学毕业生面临压力时以积极应对方式为主;（2）大学毕业生在消极应对因素上存在显著的性别差异,女生高于男生;在积极应对因素上不存在性别差异;（3）大学毕业生在解决问题、求助取向、自责、幻想、合理化这5个应对因子上不存在性别差异,而在退避这一应对因子上存在显著的性别差异,女生高于男生。     

大学毕业生压力应对的性别差异研究

采用\"压力应对方式问卷\"对陕西师范大学148名大四毕业生进行调查,结果发现:(1)大学毕业生面临压力时以积极应对方式为主;(2)大学毕业生在消极应对因素上存在显著的性别差异,女生高于男生;在积极应对因素上不存在性别差异;(3)大学毕业生在解决问题、求助取向、自责、幻想、合理化这5个应对因子上不存在性别差异,而在退避这一应对因子上存在显著的性别差异,女生高于男生。     

Microsatellite DNA variation in Bornean orangutans (Pongo pygmaeus)

Orangutans (Pongo pygmaeus) on the islands of Borneo and Sumatra are considered two separate subspecies. However, the genetic relationships between isolated populations on Borneo are not clear. This study determined the extent of variation within the Bornean subspecies of orangutan, using microsatellite DNA analysis. Blood samples were collected from 96 individuals of known origin from East, West and Central Kalimantan. Human microsatellite primer pairs located at human map position D2S141, D4S431, D 11S925, D16S420 and D17S791 were suitable for use in primates. D4S431 appeared monomorphic for all orangutans. In three cases (D2S141 East and West and D16S420 West), a highly significant excess of homozygous allele frequencies was detected, but with other primer pairs no significant difference in allele frequencies occurred. We conclude that the divergence between the different populations on Borneo is less than the variation within the populations. There was also evidence that inbreeding occurred within the populations.     

Effects of Ecology on the Gastrointestinal Parasites of Alouatta pigra

We examined the effects of demographic and ecological variables on the prevalence of intestinal parasites in free-ranging black howlers, Alouatta pigra, from Belize and Mexico. We collected 253 fecal samples from 50 individually identified monkeys during 2003. We processed all samples via standard centrifugation concentration techniques with sugar and zinc sulfate as flotation media. We used antigen capture enzyme-linked immunosorbent assays to detect protozoa. We analyzed data for each season separately. The most important factor in predicting whether an Alouatta pigra would be infected with a parasite was its membership in a particular social troop. It was not possible to isolate the effects of human presence, forest fragmentation, primate density, and the absence of Ateles geoffroyi on the prevalence of parasites in Alouatta pigra because the factors covaried. We detected few species of gastrointestinal parasites, possibly due to Alouatta pigra’s arboreal and herbivorous lifestyle and small geographic range. The prevalence of each parasite had a different pattern, with Controrchis sp. (presumed to be C. biliophilus), a fluke, tending to be more prevalent in Alouatta pigra that inhabited disturbed habitats, and Trypanoxyuris minutus, a pinworm, tending to be more prevalent in primates from undisturbed habitats. Giardia sp. tended to be more prevalent in primates at high densities. These results indicated that it is important to examine each parasite’s infection pattern separately to obtain a more accurate representation of the dynamics among the host, parasites, and ecology.     

Primates and parasites: A case for a multidisciplinary approach

Examinations of primate parasitic infections can inform both primatologists and parasitologists about evolutionary and ecological relationships. Interspecific, intraspecific, and interindividual variation in parasitic infections may correlate with environmental, demographic, behavioral, and human variables. Understanding these relationships is particularly important for conservation management issues for endangered species. We describe techniques for the noninvasive collection and preservation of fecal samples from wild primates and the salvaging of parasitological information from primate hosts in the field.     

Primate Community Dynamics in Old Growth Forest over 23.5 Years at Ngogo,Kibale National Park,Uganda: Implications for Conservation and Census Methods

Few data exist regarding long-term changes in primate populations in old-growth, tropical forests. In the absence of this information, it is unclear how to assess population trends efficiently and economically. We addressed these problems by conducting line-transect censuses 23.5 years apart at the Ngogo study area in Kibale National Park, Uganda. We conducted additional censuses over short time intervals to determine the degree to which the temporal distribution of censuses affected estimates of primate numbers. Results indicate that two species, blue monkeys and red colobus, may have experienced significant reductions over the past 23.5 years at Ngogo. In contrast, five other species, baboons, black-and-white colobus, chimpanzees, mangabeys, and red-tailed guenons, have not changed in relative abundance. Additional findings indicate that different observers may vary significantly in their estimates of sighting distances of animals during censuses, thus rendering the use of measures of absolute densities problematic. Moreover, censuses conducted over short periods produce biased estimates of primate numbers. These results provide guidelines for the use of line-transect censuses and underscore the importance of protecting large blocks of forests for primate conservation.