Infanticide by males is a common phenomenon in mammals, especially primates, as lactation lasts much longer than gestation in many species. Usually, infanticidal episodes occur soon after group takeovers, and are trad...Infanticide by males is a common phenomenon in mammals, especially primates, as lactation lasts much longer than gestation in many species. Usually, infanticidal episodes occur soon after group takeovers, and are traditionally considered a male reproductive strategy （i.e., support the sexual selection hypothesis, Hrdy, 1974）. To verify the validity of this conception, we observed one group of Franqois＇ langurs in the Nonggang Nature Reserve, China, between August 2003 and July 2004. During the study period, a Francois＇ langur female with the youngest infant in the group was attacked three times by immigrating males, and later disappeared by the third day after the final attack. We suggest that these attacks on the female-infant dyad represent infanticide attempts by males, and may be the cause of the adult female and her infant＇s disappearance. Presumably, that female dispersed with her infant to avoid infanticide and was not killed. Though these observations do not completely verify the sexual selection hypothesis, they are not inconsistent with it.展开更多
We studied the responsiveness of the Sichuan snub-nosed monkey Rhinopithecus roxellana, an arboreal Old World monkey, to the presence of novel stimuli associated with familiar food. We also determined differences in r...We studied the responsiveness of the Sichuan snub-nosed monkey Rhinopithecus roxellana, an arboreal Old World monkey, to the presence of novel stimuli associated with familiar food. We also determined differences in responses by age and sex. Results showed that monkeys exhibited neophilia and neophobia simultaneously when facing novel stimuli. Age affected the response to novel stimuli significantly, with immature individuals responding to novel stimuli most frequently and infants least frequently. No significant differences were observed for sex, although females were more responsive to the novel object than were males. Our results support the ＂readiness to eat＂ hypothesis that the presence of a novel object can increase latencies to consume familiar food .展开更多
Juvenile （2-3 years old） cynomolgus monkeys are frequently used as recipients in non-human primate islet transplantation studies. The aim of this study was to examine the effects of different doses of streptozotocin...Juvenile （2-3 years old） cynomolgus monkeys are frequently used as recipients in non-human primate islet transplantation studies. The aim of this study was to examine the effects of different doses of streptozotocin （STZ）, and find the optimal dose for inducing diabetes in these monkeys. Fifteen juvenile （2-3 years old） cynomolgus monkeys were separated into three groups and administered with different doses of STZ （100, 68 or 60 mg kg-l）. Basal and glucose-stimulated blood glucose, in- sulin, and C-peptide levels, as well as body weights were monitored. Hepatic and renal function tests and pancreatic immuno- histochemistry were performed before and after STZ treatment. Monkeys treated with both 100 and 68 mg kg-1 of STZ exhib- ited continuous hyperglycemia, which coincided with a nearly complete loss of islet 13-cells. Two monkeys received 60 mg kg-1 of STZ, but only one became completely diabetic. During the first week following STZ treatment, hepatic and renal func- tion slightly increased in these three groups. However. 24 hours post-STZ, serum total bile acid levels were significantly in- creased in monkeys treated with 100 mg kg-1 than those treated with 68 mg kg-I of STZ （P〈0.05）. These data suggest that 100 mg kg-1 and 68 mg kg-1 of STZ can safely induce diabetes in cynomolgus monkeys aged 2-3 years, but 68 mg kg-1 of STZ, rather than 100 mg kg-1 of STZ, may be more appropriate for inducing diabetes in these monkeys. Furthermore, body surface area, rather than body weight, was a more reliable determinant of dosage, where 700 mg m-2 of STZ should be the lower limit for inducing diabetes in juvenile monkeys.展开更多
基金supported by National Nature Science Foundation of China (31172122)Guangxi Nature Science Foundation (2012GXNSFAA053039)
文摘Infanticide by males is a common phenomenon in mammals, especially primates, as lactation lasts much longer than gestation in many species. Usually, infanticidal episodes occur soon after group takeovers, and are traditionally considered a male reproductive strategy （i.e., support the sexual selection hypothesis, Hrdy, 1974）. To verify the validity of this conception, we observed one group of Franqois＇ langurs in the Nonggang Nature Reserve, China, between August 2003 and July 2004. During the study period, a Francois＇ langur female with the youngest infant in the group was attacked three times by immigrating males, and later disappeared by the third day after the final attack. We suggest that these attacks on the female-infant dyad represent infanticide attempts by males, and may be the cause of the adult female and her infant＇s disappearance. Presumably, that female dispersed with her infant to avoid infanticide and was not killed. Though these observations do not completely verify the sexual selection hypothesis, they are not inconsistent with it.
基金We are grateful to the Director and staff of Zhouzhi National Nature Reserve for their permission to conduct this research. We appreciate Gou ST, Zhang P, Zhu WW, Ren Y, Zhang D, Huang K, Zhang HY, Wu LL, Wang XW, Zhao HT, and Wang CL for their help during the study. This study was supported by the National Natural Science Foundation of China （No.31130061, No30970444., No.31200293）, the Talent Introduction Fund of Tianjin Nor- mal University （No.5RLII5）, and the Cosmo Oil Eco Card Fund of Japan （2005-2012）.
文摘We studied the responsiveness of the Sichuan snub-nosed monkey Rhinopithecus roxellana, an arboreal Old World monkey, to the presence of novel stimuli associated with familiar food. We also determined differences in responses by age and sex. Results showed that monkeys exhibited neophilia and neophobia simultaneously when facing novel stimuli. Age affected the response to novel stimuli significantly, with immature individuals responding to novel stimuli most frequently and infants least frequently. No significant differences were observed for sex, although females were more responsive to the novel object than were males. Our results support the ＂readiness to eat＂ hypothesis that the presence of a novel object can increase latencies to consume familiar food .
基金supported by the National Basic Research Program of China(Grant No.2007CB947704)the National High Technology Research and Development Program of China(Grant Nos. 2006AA02A112 and 2006AA02A116)High Level Talent Fund of the Beijing Healthcare System(Grant No.2009-2-14)
文摘Juvenile （2-3 years old） cynomolgus monkeys are frequently used as recipients in non-human primate islet transplantation studies. The aim of this study was to examine the effects of different doses of streptozotocin （STZ）, and find the optimal dose for inducing diabetes in these monkeys. Fifteen juvenile （2-3 years old） cynomolgus monkeys were separated into three groups and administered with different doses of STZ （100, 68 or 60 mg kg-l）. Basal and glucose-stimulated blood glucose, in- sulin, and C-peptide levels, as well as body weights were monitored. Hepatic and renal function tests and pancreatic immuno- histochemistry were performed before and after STZ treatment. Monkeys treated with both 100 and 68 mg kg-1 of STZ exhib- ited continuous hyperglycemia, which coincided with a nearly complete loss of islet 13-cells. Two monkeys received 60 mg kg-1 of STZ, but only one became completely diabetic. During the first week following STZ treatment, hepatic and renal func- tion slightly increased in these three groups. However. 24 hours post-STZ, serum total bile acid levels were significantly in- creased in monkeys treated with 100 mg kg-1 than those treated with 68 mg kg-I of STZ （P〈0.05）. These data suggest that 100 mg kg-1 and 68 mg kg-1 of STZ can safely induce diabetes in cynomolgus monkeys aged 2-3 years, but 68 mg kg-1 of STZ, rather than 100 mg kg-1 of STZ, may be more appropriate for inducing diabetes in these monkeys. Furthermore, body surface area, rather than body weight, was a more reliable determinant of dosage, where 700 mg m-2 of STZ should be the lower limit for inducing diabetes in juvenile monkeys.
