| objectively measuring effects of electro-acupuncture in parkinsonian rhesus monkeys. | acupuncture has increasingly been used as an alternative therapy for treatment of parkinson's disease (pd). however, the efficacy of acupunture for pd still remains unclear. the present study was designed to objectively and safely monitor anti-parkinsonian effects of electroacupuncture (ea) and brain activity in nonhuman primates modeling human pd. six middle-aged rhesus monkeys were extensively studied by a computerized behavioral testing battery and by pharmacological mri (phmri) scans with sp ... | 2018 | 29017909 |
| glucocorticoid treatment facilitates development of a metabolic syndrome in ovariectomized macaca mulatta fed a high fat diet. | metabolic syndrome (mets) is characterized by a cluster of key features, which include abdominal obesity, insulin resistance, hypertension, and dyslipidemia. the aim of this study was to assess the impact of elevated glucocorticoid levels on the development of mets in middle-aged female rhesus monkeys (macaca mulatta) after ovariectomy. six female ovariectomized rhesus monkeys (9-13years) were randomly assigned to either a control group (normal diet, n=3) or a group in which mets was facilitated ... | 2017 | 28988119 |
| hebbian learning in a random network captures selectivity properties of the prefrontal cortex. | complex cognitive behaviors, such as context-switching and rule-following, are thought to be supported by the prefrontal cortex (pfc). neural activity in the pfc must thus be specialized to specific tasks while retaining flexibility. nonlinear "mixed" selectivity is an important neurophysiological trait for enabling complex and context-dependent behaviors. here we investigate (1) the extent to which the pfc exhibits computationally relevant properties, such as mixed selectivity, and (2) how such ... | 2017 | 28986463 |
| organ doses associated with partial-body irradiation with 2.5% bone marrow sparing of the non-human primate: a retrospective study. | a partial-body irradiation model with approximately 2.5% bone marrow sparing (pbi/bm2.5) was established to determine the radiation dose-response relationships for the prolonged and delayed multi-organ effects of acute radiation exposure. historically, doses reported to the entire body were assumed to be equal to the prescribed dose at some defined calculation point, and the dose-response relationship for multi-organ injury has been defined relative to the prescribed dose being delivered at this ... | 2017 | 28985133 |
| isoflurane exposure for three hours triggers apoptotic cell death in neonatal macaque brain. | retrospective clinical studies suggest there is a risk for neurodevelopmental impairment following early childhood exposure to anaesthesia. in the developing animal brain, including those of non-human primates (nhps), anaesthetics induce apoptotic cell death. we previously reported that a 5 h isoflurane (iso) exposure in infant nhps increases apoptosis 13-fold compared with control animals. however, the majority of paediatric surgeries requiring anaesthesia are of shorter durations. we examined ... | 2017 | 28969320 |
| a complex stereochemical relay approach to the antimalarial alkaloid ocimicide a1. evidence for a structural revision. | ocimicide a1 (1) and the semisynthetic derivative ocimicide a2 (2) are highly potent antimalarial agents efficacious against chloroquine-sensitive and -resistant plasmodium falciparum strains with ic50 values in the nanomolar and picomolar range, respectively. members of this family have demonstrated radical cure in rhesus monkeys, without detectable toxicity, but their structure-function relationships and mechanism of action are unknown. herein we describe a twelve-step synthesis of an advanced ... | 2017 | 28959410 |
| efficient targeting and activation of antigen-presenting cells in vivo after modified mrna vaccine administration in rhesus macaques. | mrna vaccines are rapidly emerging as a powerful platform for infectious diseases because they are well tolerated, immunogenic, and scalable and are built on precise but adaptable antigen design. we show that two immunizations of modified non-replicating mrna encoding influenza h10 hemagglutinin (ha) and encapsulated in lipid nanoparticles (lnp) induce protective ha inhibition titers and h10-specific cd4+ t cell responses after intramuscular or intradermal delivery in rhesus macaques. administra ... | 2017 | 28958578 |
| isoform evolution in primates through independent combination of alternative rna processing events. | recent rna-seq technology revealed thousands of splicing events that are under rapid evolution in primates, whereas the reliability of these events, as well as their combination on the isoform level, have not been adequately addressed due to its limited sequencing length. here, we performed comparative transcriptome analyses in human and rhesus macaque cerebellum using single molecule long-read sequencing (iso-seq) and matched rna-seq. besides 359 million rna-seq reads, 4,165,527 iso-seq reads w ... | 2017 | 28957512 |
| fetal skin as a pro-inflammatory organ: evidence from a primate model of chorioamnionitis. | intrauterine infection is a primary cause of preterm birth and fetal injury. the pro-inflammatory role of the fetal skin in the setting of intrauterine infection remains poorly characterized. whether or not inflammation of the fetal skin occurs in primates remains unstudied. accordingly, we hypothesized that: i) the fetal primate skin would mount a pro-inflammatory response to preterm birth associated pro-inflammatory agents (lipopolysaccharides from escherichia coli, live ureaplasma parvum, int ... | 2017 | 28957335 |
| neural decoding: a predictive viewpoint. | decoding in the context of brain-machine interface is a prediction problem, with the aim of retrieving the most accurate kinematic predictions attainable from the available neural signals. while selecting models that reduce the prediction error is done to various degrees, decoding has not received the attention that the fields of statistics and machine learning have lavished on the prediction problem in the past two decades. here, we take a more systematic approach to the decoding prediction pro ... | 2017 | 28957019 |
| neonatal perirhinal cortex lesions impair monkeys' ability to modulate their emotional responses. | the medial temporal lobe (mtl) is a collection of brain regions best known for their role in perception, memory, and emotional behavior. within the mtl, the perirhinal cortex (prh) plays a critical role in perceptual representation and recognition memory, although its contribution to emotional regulation is still debated. here, rhesus monkeys with neonatal perirhinal lesions (neo-prh) and controls (neo-c) were tested on the human intruder (hi) task at 2 months, 4.5 months, and 5 years of age to ... | 2017 | 28956946 |
| an appropriate loading control for western blot analysis in animal models of myocardial ischemic infarction. | an appropriate loading control is critical for western blot analysis. housekeeping proteins (hkps), such as β-actin, glyceraldehyde-3-phosphate dehydrogenase (gapdh), and β-tubulin, are commonly used to normalize protein expression. but hkp expression can be impacted by certain experimental conditions, such as ischemic myocardial infarction. this study was undertaken to look for an appropriate loading control for western blot analysis of ischemic myocardium. myocardial ischemic infarction was in ... | 2017 | 28955798 |
| alpha male status and availability of conceptive females are associated with high glucocorticoid concentrations in high-ranking male rhesus macaques (macaca mulatta) during the mating season. | the relationship between male mating opportunities, stress, and glucocorticoid concentrations is complicated by the fact that physiological stress and glucocorticoid concentrations can be influenced by dominance rank, group size, and the stability of the male dominance hierarchy, along with ecological factors. we studied the three highest-ranking males in nine different social groups within the same free-ranging population of rhesus macaques on cayo santiago, puerto rico, during the mating seaso ... | 2018 | 28954215 |
| effects of morphine/cp55940 mixtures on an impulsive choice task in rhesus monkeys. | µ-opioid receptor agonists are commonly used to treat pain despite their adverse effects. in preclinical studies, cannabinoid receptor agonists increase the potency of opioids for producing antinociceptive but not reinforcing effects. it is unknown whether other adverse effects of these drugs, such as impairment of complex behavior, are enhanced by their co-administration. this study characterized the effects of morphine (µ-opioid receptor agonist; 0.32-5.6 mg/kg, subcutaneously) and cp55940 (cb ... | 2018 | 28952976 |
| [expression of vegf and pedf in early-stage retinopathy in diabetic macaca mulatta]. | to explore the expression of vascular endothelial growth factor (vegf) and pigment epithelium-derived factor (pedf) in early stage of diabetic retinopathy (dr) in macaca mulatta. | 2017 | 28951365 |
| vcftotree: a user-friendly tool to construct locus-specific alignments and phylogenies from thousands of anthropologically relevant genome sequences. | constructing alignments and phylogenies for a given locus from large genome sequencing studies with relevant outgroups allow novel evolutionary and anthropological insights. however, no user-friendly tool has been developed to integrate thousands of recently available and anthropologically relevant genome sequences to construct complete sequence alignments and phylogenies. | 2017 | 28950836 |
| comparison of emergence times and quality between isoflurane and sevoflurane in rhesus macaque ( macaca mulatta) undergoing neurosurgical procedure. | volatile agents for anaesthesia are widely used for anaesthetizing laboratory primates, and isoflurane is one of the most frequently used agents. sevoflurane has been shown to offer a more rapid recovery than isoflurane in a number of species, but no comparisons have been made in non-human primates. this study compared the recovery characteristics of isoflurane and sevoflurane in rhesus macaques undergoing experimental neurosurgery. twelve primates (7 males and 5 females) were randomly allocated ... | 2017 | 28948899 |
| subcutaneous ovarian tissue transplantation in nonhuman primates: duration of endocrine function and normalcy of subsequent offspring as demonstrated by reproductive competence, oocyte production, and telomere length. | the main purposes of the study were to investigate the endocrine function of ovarian tissue transplanted to heterotopic subcutaneous sites and the reproductive competence and telomere length of a nonhuman primate originating from transplanted tissue. | 2017 | 28942525 |
| preliminary studies on the use of pertussis toxin for the modulation of intravaginal siv transmission in rhesus macaques. | pertussis toxin (ptx) blocks gpcr signaling resulting in the inhibition of chemotaxis/cell adhesion. it was reasoned that inhibition of cell trafficking may be an approach to prevent hiv/siv transmission. | 2017 | 28940591 |
| a combination of alfaxalone, medetomidine and midazolam for the chemical immobilization of rhesus macaque (macaca mulatta): preliminary results. | chemical immobilization of non-human primates can be required to perform scientific or veterinary procedure with different invasiveness degrees. this preliminary study was undertaken to assess the clinical effects of a combination of alfaxalone, medetomidine and midazolam (amm). | 2017 | 28940590 |
| integrative analysis associates monocytes with insufficient erythropoiesis during acute plasmodium cynomolgi malaria in rhesus macaques. | mild to severe anaemia is a common complication of malaria that is caused in part by insufficient erythropoiesis in the bone marrow. this study used systems biology to evaluate the transcriptional and alterations in cell populations in the bone marrow during plasmodium cynomolgi infection of rhesus macaques (a model of plasmodium vivax malaria) that may affect erythropoiesis. | 2017 | 28938907 |
| coccidioidomycosis in an indoor-housed rhesus macaque (macaca mulatta). | coccidioides spp. are saprophytic, dimorphic fungi that are endemic to arid climates, are capable of infecting many species, and result in diverse clinical presentations. an indoor-housed laboratory rhesus macaque presented with weight loss and decreased activity and appetite. during the diagnostic evaluation, a bronchiolar-alveolar pattern in the cranial lung lobes, consistent with bronchopneumonia, was noted on radiographs. given the poor prognosis, the macaque was euthanized. confirming the r ... | 2017 | 28935008 |
| the search for a subtype-selective pet imaging agent for the gabaa receptor complex: evaluation of the radiotracer [11c]ado in nonhuman primates. | the myriad physiological functions of γ-amino butyric acid (gaba) are mediated by the gaba-benzodiazepine receptor complex comprising of the gabaa, gabab, and gabac groups. the various gabaa subunits with region-specific distributions in the brain subserve different functional and physiological roles. for example, the sedative and anticonvulsive effects of classical benzodiazepines are attributed to the α1 subunit, and the α2 and α3 subunits mediate the anxiolytic effect. to optimize pharmacothe ... | 2018 | 28929924 |
| guidelines for the management of a brain death donor in the rhesus macaque: a translational transplant model. | the development of a translatable brain death animal model has significant potential to advance not only transplant research, but also the understanding of the pathophysiologic changes that occur in brain death and severe traumatic brain injury. the aim of this paper is to describe a rhesus macaque model of brain death designed to simulate the average time and medical management described in the human literature. | 2017 | 28926566 |
| dynamic representation of partially occluded objects in primate prefrontal and visual cortex. | successful recognition of partially occluded objects is presumed to involve dynamic interactions between brain areas responsible for vision and cognition, but neurophysiological evidence for the involvement of feedback signals is lacking. here, we demonstrate that neurons in the ventrolateral prefrontal cortex (vlpfc) of monkeys performing a shape discrimination task respond more strongly to occluded than unoccluded stimuli. in contrast, neurons in visual area v4 respond more strongly to unocclu ... | 2017 | 28925354 |
| a model of plasmodium vivax concealment based on plasmodium cynomolgi infections in macaca mulatta. | plasmodium vivax can cause severe malaria. the total parasite biomass during infections is correlated with the severity of disease but not necessarily quantified accurately by microscopy. this finding has raised the question whether there could be sub-populations of parasites that are not observed in peripheral blood smears but continue to contribute to the increase in parasite numbers that drive pathogenesis. non-human primate infection models utilizing the closely related simian malaria parasi ... | 2017 | 28923058 |
| mirror trends of plasticity and stability indicators in primate prefrontal cortex. | research on plasticity markers in the cerebral cortex has largely focused on their timing of expression and role in shaping circuits during critical and normal periods. by contrast, little attention has been focused on the spatial dimension of plasticity-stability across cortical areas. the rationale for this analysis is based on the systematic variation in cortical structure that parallels functional specialization and raises the possibility of varying levels of plasticity. here, we investigate ... | 2017 | 28921934 |
| [comparative metabolism of three amide alkaloids from piper longum in five different species of liver microsomes]. | piperine, piperlonguminine and pellitorine are three major amide alkaloids from piper longum, showing a variety of pharmacological activities. in order to investigate the different metabolism pathways of these compounds in five species of liver microsomes in vitro, the data of full mass spectrum, and ms2, ms3 spectra of these three alkaloids were collected and analyzed by using ultra-high-performance liquid chromatography coupled with a ltq-orbitrap mass spectrometer (uhplc-ltq-orbitrap ms); gra ... | 2016 | 28920353 |
| recombinant humanized anti-vascular endothelial growth factor monoclonal antibody efficiently suppresses laser-induced choroidal neovascularization in rhesus monkeys. | neovascular age-related macular degeneration, characterized by abnormal choroidal neovascularization (cnv), is a major cause of blindness worldwide. anti-vascular endothelial growth factor (vegf) antibodies have demonstrated significant efficacy in improving visual acuity. tmab001 is a new recombinant humanized rabbit anti-vegf monoclonal antibody. it presents high activities in vitro studies. in the binding affinity assay, tmab001 exhibited a high binding capability to vegf with an affinity con ... | 2017 | 28916483 |
| visual responses in fef, unlike v1, primarily reflect when the visual context renders a receptive field salient. | when light falls within a neuronal visual receptive field (rf) the resulting activity is referred to as the visual response. recent work suggests this activity is in response to both the visual stimulation and the abrupt appearance, or salience, of the presentation. here we present a novel method for distinguishing the two, based on the timing of random and nonrandom presentations. we examined these contributions in frontal eye field (fef; n = 51) and as a comparison, an early stage in the prima ... | 2017 | 28912158 |
| methodological considerations for a chronic neural interface with the cuneate nucleus of macaques. | while the response properties of neurons in the somatosensory nerves and anterior parietal cortex have been extensively studied, little is known about the encoding of tactile and proprioceptive information in the cuneate nucleus (cn) or external cuneate nucleus (ecn), the first recipients of upper limb somatosensory afferent signals. the major challenge in characterizing neural coding in cn/ecn has been to record from these tiny, difficult-to-access brain stem structures. most previous investiga ... | 2017 | 28904101 |
| evaluation of a zinc gluconate neutralized with arginine product as a nonsurgical method for sterilization of rhesus macaques (macaca mulatta). | because rhesus macaques (macaca mulatta) are prolific breeders, overpopulation can be problematic in both research and feral populations. currently, the most effective contraceptive methods are hormonal control in female macaques and vasectomies in males. these methods each come with innate challenges, the foremost being the alteration of necessary hormonal patterns. in this study, we assessed the use of zinc gluconate neutralized with arginine as a novel, nonsurgical alternative to male contrac ... | 2017 | 28903822 |
| multiple spatial representations interact to increase reach accuracy when coordinating a saccade with a reach. | reaching is an essential behavior that allows primates to interact with the environment. precise reaching to visual targets depends on our ability to localize and foveate the target. despite this, how the saccade system contributes to improvements in reach accuracy remains poorly understood. to assess spatial contributions of eye movements to reach accuracy, we performed a series of behavioral psychophysics experiments in nonhuman primates (macaca mulatta). we found that a coordinated saccade wi ... | 2017 | 28768742 |
| hiv env conserved element dna vaccine alters immunodominance in macaques. | sequence diversity and immunodominance are major obstacles in the design of an effective vaccine against hiv. hiv env is a highly-glycosylated protein composed of 'conserved' and 'variable' regions. the latter contains immunodominant epitopes that are frequently targeted by the immune system resulting in the generation of immune escape variants. this work describes 12 regions in hiv env that are highly conserved throughout the known hiv m group sequences (env ce), and are poorly immunogenic in m ... | 2017 | 28678607 |
| spontaneous endometriosis in rhesus macaques: evidence for a genetic association with specific mamu-a1 alleles. | endometriosis is a poorly understood common debilitating women's reproductive disorder resulting from proliferative and ectopic endometrial tissue associated with variable clinical symptoms including dysmenorrhea (painful menstrual periods), dyspareunia (pain on intercourse), female infertility, and an increased risk of malignant transformation. the rhesus macaque (macaca mulatta) develops a spontaneous endometriosis that is very similar to that seen in women. we hypothesized that specific major ... | 2017 | 32110699 |
| revisiting a quarter of a century of simian immunodeficiency virus (siv)-associated cardiovascular diseases at the german primate center. | human immunodeficiency virus (hiv) comorbidities have become clinically more important due to antiretroviral therapy. although therapy increases life expectancy, it does not completely suppress immune activation and its associated complications. the simian immunodeficiency virus (siv)-infected rhesus macaque (macaca mulatta) represents a valuable model for the investigation of siv-associated diseases. although cardiovascular (cv) changes are common in hiv-infected patients, there are only a few ... | 2017 | 32110698 |
| morphological and immunohistochemical characterization of spontaneous endometriosis in rhesus macaques (macaca mulatta). | several cases of spontaneous endometriosis in middle-aged to old rhesus macaques (macaca mulatta) from the breeding colony of the german primate center were thoroughly characterized with regards to anatomical distribution and macroscopic appearance, histological differentiation and immunohistochemical profile including somatic markers, hormonal receptors, and proliferation indices. more than half of the examined animals (five of nine) were directly related to one breeding male, supporting a stro ... | 2017 | 32110695 |
| unique case of granulomatous arteritis in a grey mouse lemur (microcebus murinus) - first case description. | overall, diseases of the vascular system are rarely observed entities among nonhuman primates that are commonly associated with systemic infections, septicemia or bacteremia. rhesus monkeys infected with simian immunodeficiency virus (siv) may develop a chronic occlusive arteriopathy of unknown etiology in late stages of the disease. this siv associated arteriopathy is the only well-known specific vascular entity described in nonhuman primates. we herein report a unique case of granulomatous art ... | 2017 | 32110694 |
| suspect guillain-barré syndrome in a male rhesus macaque (macaca mulatta). | guillain-barré syndrome (gbs) is a rare, mainly acute inflammatory polyneuropathy in humans. it is frequently post-infectious with auto antibodies being formed against myelin sheaths, resulting in a progressive and more-or-less severe paralysis of the motor neuron and cranial nerves. mortality is low and 60 % of the patients recover completely from the disease after intensive treatment. in animals, there are a few diseases that closely resemble gbs, but cases of gbs in monkeys seem to be scarce. ... | 2017 | 32110689 |
| mapping in-vivo optic nerve head strains caused by intraocular and intracranial pressures. | although it is well documented that abnormal levels of either intraocular (iop) or intracranial pressure (icp) can lead to potentially blinding conditions, such as glaucoma and papilledema, little is known about how the pressures actually affect the eye. even less is known about potential interplay between their effects, namely how the level of one pressure might alter the effects of the other. our goal was to measure in-vivo the pressure-induced stretch and compression of the lamina cribrosa du ... | 2017 | 29618852 |
| [biochemical characteristics of blood sera in dominant and subordinate rhesus monkey males]. | study of relationship between the biochemical characteristics of blood serum from rhesus monkeys and their social rank was carried out. some biochemical characteristics, first of all the content of urea and creatinine, the activity of aspartateaminotransferase and alkaline phosphatase were positively correlated with a relative rank of males, and negatively - with their weight. the body weight of dominant males was significantly lower than that of subordinate males. the data obtained show a signi ... | 2016 | 30198250 |
| [studying the interaction of rhesus monkeys with the tactile monitor during their observation of low-frequency visual test images]. | in behavioral experiments rhesus macaque monkeys were trained to interact with the computer using a tactile display. we used grayscale gabor patches of low spatial frequency as stimuli. monkeys' task was to touch the screen with his hand in the area of the target stimulus, followed by automatic food or juice reinforcement. after two successive correct answers, stimulus contrast gradually decreased. using a two-alternative forced choice method the contrast threshold was measured within which monk ... | 2016 | 30193412 |
| [comparison of healing results between tibial nerve and common peroneal nerve after sciatic nerve injury repair in rhesus monkey]. | to investigate the regularity of myelin degeneration and regeneration and the difference of axonal density between tibial nerve and common peroneal nerve after sciatic nerve injury repair in rhesue monkey. | 2016 | 29786305 |
| [metagenomic analysis of wild rhesus monkey virome in longhu mountain in guangxi area, china]. | several viruses have been found in non-human primates, among which some are pathogenic to humans. to further characterize the spectrum of viruses present in wild rhesus monkeys, miseq high-throughput sequencing were used to analyze 280 fecal samples collected from guangxi, china. a total of 23,372,679 reads were obtained, of which 4,641 were annotated to 27 viral families or subfamilies, including five vertebrate viruses families(78.2%),six insect virus families(5.5%),eleven plant virus families ... | 2016 | 29962198 |
| [comparison of the behavior of rhesus monkey males in individual and group keeping conditions: aggressiveness and anxiety]. | | 2016 | 30188662 |
| who cares? experimental attention biases provide new insights into a mammalian sexual signal. | the effects of intrasexual and intersexual selection on male trait evolution can be difficult to disentangle, especially based on observational data. male-male competition can limit an observer's ability to identify the effect of female mate choice independently from sexual coercion. here, we use an experimental approach to explore whether an ornament, the red facial skin exhibited by male rhesus macaques (macaca mulatta), might be involved in both female mate choice and male-male competition. w ... | 2020 | 29622915 |
| advancing research in regeneration and repair of the motor circuitry: non-human primate models and imaging scales as the missing links for successfully translating injectable therapeutics to the clinic. | regeneration and repair is the ultimate goal of therapeutics in trauma of the central nervous system (cns). stroke and spinal cord injury (sci) are two highly prevalent cns disorders that remain incurable, despite numerous research studies and the clinical need for effective treatments. neural engineering is a diverse biomedical field, that addresses these diseases using new approaches. research in the field involves principally rodent models and biologically active, biodegradable hydrogels. pro ... | 2016 | 29600289 |
| establishment of a microsatellite set for noninvasive paternity testing in free-ranging macaca mulatta tcheliensis in mount taihangshan area, jiyuan, china. | within multi-male and multi-female mammalian societies, paternity assignment is crucial for evaluating male reproductive success, dominance hierarchy, and inbreeding avoidance. it is, however, difficult to determine paternity because of female promiscuity during reproduction. noninvasive molecular techniques (e.g., fecal dna) make it possible to match the genetic father to his offspring. in the current study, a troop of free-ranging taihangshan macaques (macaca mulatta tcheliensis) in mt. taihan ... | 2015 | 31966095 |
| drawing the line on metacognition. | only two of the many experiments described by smith et al., as indicating metacognitive ability in nonhuman animals, involved metacognition as understood in the human literature. of these, one gave negative results. in the other, one of two rhesus monkeys provided data suggesting that he might have metacognitive ability. the conjecture that any nonhuman animals have metacognitive ability is, therefore, tenuous. | 2003 | 18241457 |
| immune responses of a designed hiv-1 dna vaccine on rhesus monkeys. | an effective hiv-1 vaccine will be the ultimate solution for the prevention of hiv/aids, though haart plays important roles in treating the disease. in this study, a large-scale recombinant dna plasmid containing a designed hiv-1 multi-epitope-p24 chimeric gene was prepared and purified. rhesus monkeys were then inoculated muscularly with the plasmid for four times in week 0, 4, 8 and 18. whole blood was collected two weeks after the third and fourth inoculation, followed by serum and peripheral ... | 2006 | 32214722 |
| early maternal recognition of offspring vocalizations in rhesus macaques (macaca mulatta). | this study investigated the development of maternal recognition of infant calls in rhesus macaques (macaca mulatta). fifteen mothers and their offspring, of age ranging from several hours to 28 days, served as subjects of an experiment in which the offspring's distress vocalizations were recorded and then played back to their mothers simultaneously with those of an age-matched control infant. the proportion of time looking at, but not the proportion of orientations to the speaker playing the off ... | 2000 | 30545206 |
| allelic variation of the serotonin transporter gene polymorphic region in apes. | to assess the change of serotonin transporter (5-htt) gene-linked polymorphic region that has occurred during the process of hominization, we examined the allelic variation of 5-htt gene-linked polymorphic region (5-httlpr) in anthropoid apes such as chimpanzees, gorillas, orang-utans, and gibbons, and determined the dna sequences of the alleles in each species. all chimpanzees examined shared only the 17.5 repeat allele, while polymorphism was observed in the other apes and the 16 and 20 repeat ... | 2000 | 30545178 |
| impaired reconciliation in rhesus macaques with a history of early weaning and disturbed socialization. | an attempt had been made to create five social groups from rhesus macaques with a history of early separation from their mothers, early weaning and hand feeding and, in most cases, previous housing in single cages. we investigated the exchange of affiliative behaviours after an aggressive encounter and selective attraction to the former opponent, a phenomenon previously well described in rhesus monkeys and called reconciliation. evidence for reconciliation was only found in one of the five group ... | 2000 | 30545193 |
| the development of behavioural sex differences in infant rhesus macaques (macaca mulatta). | studies of infant rhesus macaques have generally reported sex differences in the frequency of expression of some behaviour patterns, such as rough-and-tumble play and socio-sexual mounting. in contrast, sex differences in other behaviour patterns, such as proximity to the mother, have been less consistantly reported. using data on the behavioural development of infant rhesus macaques living in captive social groups, we have attempted to provide further evidence for, or against, sex differences i ... | 2000 | 30545192 |
| acute effects of dexfenfluramine (d-fen) and methylenedioxymethamphetamine (mdma) before and after short-course, high-dose treatment. | the acute behavioral effects of methylenedioxymethamphetamine (mdma) and dexfenfluramine (d-fen) were assessed in six rhesus monkeys using performance in the national center for toxicological research (nctr) operant test battery (otb); three additional animals served as controls for neurochemical endpoints. the otb consists of five food-reinforced tasks designed to model aspects of learning, short-term memory and attention, time estimation, motivation, and color and position discrimination. shor ... | 1998 | 29090816 |
| the effects of cocaine on nonhuman primate brain function are age dependenta. | the effects of acute intravenous (i.v.) cocaine (coc) on several complex brain functions were studied in rhesus monkeys at 1.5, 3 and 10-11 years of age. subjects performed several operant tasks (for food) that were used to model learning, short-term memory, color and position discrimination, and motivation, and disruption of performance of these tasks was used to quantitate drug effect. drug effects were age dependent: the youngest subjects were 3 to 10 times less sensitive than the oldest. pre ... | 1998 | 29090798 |
| moderate alcohol consumption and psychological stress during pregnancy induce attention and neuromotor impairments in primate infants. | this study examined the effect of moderate alcohol and/or psychological stress during prenancy on off-spring growth and behavior in 33 rhesus monkey infants (macaca mulatta). infants were derived from 1 of 3 groups of female: (1) alcohol-consuming,0.6g/kg, daily throughou gestation (equivalet, to 1-2 drinks), beginning 5 day prior to breeding;(2) alcohol-consuming (as above) and exposed to mild psychological stress(removal from home cage and exposed to 3 random noise bursts); (3) sucrose-consumi ... | 1997 | 29106730 |
| effects of social and inanimate enrichment on the behavior of yearling rhesus monkeys. | certain types of inanimate environmental enrichment have been shown to positively affect the behavior of laboratory primates, as has housing them in appropriate social conditions. while social housing is generally advocated as an important environmental enhancement, few studies have attempted to measure the influence of social conditions on the effects of inanimate enrichment or to compare the relative merits of social and inanimate enhancements. in the present study, inanimate enrichment (predo ... | 1996 | 31918516 |
| frequency of prenatal loss in a macaque breeding colony. | an accurate knowledge of the historical incidence of prenatal loss is essential for management of breeding colonies and for performing developmental toxicity studies in nonhuman primates. data from the california regional primate research center indoor (timed-mated) and outdoor (random-mated) colonies of rhesus, cynomolgus, and bonnet macaques (macaca mulatta, m. fascicularis, and m. radiata) were evaluated for a 10 year breeding period from 1984 to 1993. pregnancy outcome data for the three spe ... | 1996 | 31918514 |
| effector and target cells in the assessment of natural cytotoxic activity of rhesus monkeys. | in humans, decreased natural killer cell (nk) activity has been associated with stressful life events, whereas acute arousal and disturbance frequently has been reported to result in increased nk activity. this bidirectional immune modulation prompted us to investigate the effects of a social stressor on the lymphocyte cytolytic activity of 31 infant rhesus monkeys. the first of three studies evaluated the effects of an 8 hr maternal separation on the infants' cytolytic response against the k562 ... | 1996 | 31918508 |
| behavioral, immunological, and hormonal responses associated with social change in rhesus monkeys (macaca mulatta). | twelve animals to be socially reorganized in a group of 49 animals were compared with ten animals in a socially stable group (n = 51) for reproductive hormones, cortisol concentrations, immune function, and behavioral patterns for a 6 week baseline and 16 week postreorganization period. cortisol values, mitogen-induced lymphocyte blastogenesis, and rates of behavior reflected social events. increased cortisols, increased noncontact aggression, and decreased mitogen response were associated with ... | 1996 | 31918507 |
| group formation of female pigtail macaques (macaca nemestrina). | human epidemiological studies have suggested that social variables can modulate the effects of stress on the immune system, and this concept has been gaining increasing attention with positive results emerging from empirical studies using nonhuman primates over the last two decades. results from a previous study in rhesus monkeys suggested that receiving grooming positively affected recovery of t-helper and t-suppressor cells following the initial stress associated with group formation, and this ... | 1996 | 31918503 |
| birth sex ratios and maternal social rank in a captive colony of rhesus monkeys (macaca mulatta). | data from a 35-year study of rhesus macaques (macaca mulatta) at madingley, cambridge, were used to investigate sex ratio biases associated with maternal rank. data were available from two colonies, the old colony (1960-81) and new colony (1982-93). overall, top-ranking mothers gave birth to 30.9% sons, while non-top mothers gave birth to 58.4% sons. among non-top mothers, middle- and bottom-ranking ones had 59.0 and 55.0% sons, respectively. top mothers' daughter biases were strongest in matril ... | 1996 | 31918493 |
| cbc and serum chemistry differences between indian-derived and chinese-indian hybrid rhesus monkey infants. | hematological and clinical biochemistry measures are commonly utilized as indicators of the health status of nonhuman primates. among individuals in a population of a given species, there may be considerable variation in these parameters. still wider variation may be found among different strains or subspecies of some orders. to date, few studies have addressed this phenomenon among strains of nonhuman primates of a given species. blood samples for hematological and serum biochemical analyses we ... | 1996 | 31918489 |
| influence of kinship and spatial density on reconciliation and grooming in rhesus monkeys. | some cercopithecine primates direct disproportionate amounts of grooming, huddling, and agonistic support toward maternal kin. disproportionate amounts of aggression are also directed toward maternal kin, however, suggesting that mechanisms that restore relationships damaged by aggression, such as reconciliation, might be biased toward these preferred social partners. studies investigating kinship effects and reconciliation are inconsistent, however, perhaps because of differences in the environ ... | 1996 | 31918487 |
| do female rhesus macaques choose novel males? | prior research has shown that estrous female rhesus macaques (macaca mulatto) maintain spatial proximity preferentially to lower-ranking males. in this paper, 657 h of focal individual follows of 48 free-ranging estrous female rhesus macaques of two social groups during two mating seasons are used to evaluate the hypothesis that this phenomenon is attributable to female mate choice for novel males. this hypothesis is plausible because of the positive correlation between dominance rank and the le ... | 1995 | 31936956 |
| ultrasound measurement of fetal growth in macaca nemestrina. | longitudinal ultrasound data were collected for 18 structures in 37 pigtailed macaque (macaca nemestrina) fetuses to 1) generate standards of normal fetal growth, 2) measure operator reliability, 3) assess the accuracy of linear and nonlinear regression models to estimate gestational age and dates of delivery, and 4) evaluate the portability of equations and absolute values derived from data at one facility (seattle) to describe independently collected data on the same species at another facilit ... | 1995 | 31924085 |
| delayed dispersal and elevated monoaminergic activity in free-ranging rhesus monkeys. | male rhesus monkeys typically disperse from their groups of birth when they are between 3 and 5 years of age. some males, however, delay dispersal from their natal groups until after they are 5 years old. the current study evaluated central monoaminergic neurotransmitter activity as a potential correlate of such "delayed" dispersal among 54 randomly selected adolescent and adult male rhesus monkeys (macaca mulatta) captured on cayo santiago during an annual trapping season. specifically, cerebro ... | 1995 | 31924074 |
| measures of body size and growth in rhesus and squirrel monkeys subjected to long-term dietary restriction. | although many studies have reported the robust effects of dietary restriction (dr) in retarding numerous aging processes in rodents, little is known about the outcomes of reducing caloric intake of a nutritious diet on aging in primates. most primate studies have concerned the effects of malnutrition. we hypothesized that dr influences aging processes in primate species as it does in rodents. in the present study, 24 male rhesus (macaca mulatta) monkeys (ages 0.6-5 years) and 25 male squirrel (s ... | 1995 | 31924069 |
| behavioral effects of enrichment on singly-housed, yearling rhesus monkeys: an analysis including three enrichment conditions and a control group. | three cohorts of yearling rhesus monkeys (macaca mulatta) were maintained in single cages for one year as part of a derivation program to produce a breeding colony of specific pathogen-free (spf) monkeys. during this year of social restriction, subjects were provided with three different types of environmental enrichment (physical, feeding, and sensory) to counteract the known effects of social restriction and to quantify the effects of these different conditions of enhancement on their behavior ... | 1995 | 31924063 |
| interleukin-1 induces sleep-like behavior and alters call structure in juvenile rhesus macaques. | to date, there have been no investigations of the behavioral effects of interleukin-1 (il-1) in nonhuman primates. in this study the locomotor behavior and vocalizations of juvenile rhesus monkeys were monitored for 45 minutes following intravenous injections of recombinant human il-1 alpha. in addition, their reaction to a broadcasted recording of infant monkey distress calls was determined 20 minutes after the beginning of each test session. il-1 induced sleep-like inactivity and significantly ... | 1995 | 31924062 |
| menopause in female rhesus monkeys. | fifteen female rhesus monkeys (macaca mulatto), ranging in age from 8 to 34 years, were studied for one year to characterize the endocrine and menstrual changes associated with menopause in this species. five monkeys were premenopausal; these younger monkeys, ages 8-11 years, menstruated and showed cyclic ovarian activity during the 12-month study period, as evidenced by menses and periodic elevations of serum estradiol (e2) and luteinizing hormone (lh) concentrations. four females, ages 24-26 y ... | 1995 | 31924061 |
| avoidance of close consanguineous inbreeding in captive groups of rhesus macaques. | in three captive groups of rhesus macaques (macaca mulatto) the intensity of inbreeding avoidance was directly correlated with the closeness of kinship. the incidence of inbreeding between matrilineal relatives was lower than expected were mating to occur randomly with regard to matrilineal affiliation. the avoidance of mating between sons and their mothers and between matrilineal sibs contributed about squally to this outcome. the incidence of mating between more remote matrilineal relatives wa ... | 1995 | 31924057 |
| incidence of atresia or of luteinization without rupture of the dominant ovarian follicle in rhesus monkeys treated with estradiol-17β on day 8 of the menstrual cycle. | previous results have established that 17β-estradiol (e2) administered in capsules for 24 h on day 6 of the menstrual cycle results in atresia of the dominant follicle (df). the present experiment was designed to determine if atresia could be induced similarly as late as day 8, when the df is presumably larger, to facilitate biochemical analyses. on the morning of day 8, laparoscopy was used to confirm the presence of the df, and 4, 6, or 8 silastic capsules containing e2 were placed s.c. for 12 ... | 1994 | 31936965 |
| psychological well-being in paired adult female rhesus (macaca mulatta). | we assessed the effects of social living (pairing) on improving the psychological well-being of adult female rhesus macaques (mucuca mulutta) housed under laboratory conditions. we measured well-being in 12 pairs and 12 singly housed females through multiple indices of health (hematology, clinical morbidity, and body weight), stress (immune responses), behavior (preferences for social proximity, exhibition of species typical affliative behavior, and rates of abnormal behavior), and reproduction ... | 1994 | 31936932 |
| behavioral effects of enrichment on pair-housed juvenile rhesus monkeys. | among captive primates, inanimate environmental enrichment can lead to measurable changes in behavior indicative of an improvement in psychological well-being. although this has been demonstrated repeatedly for singly caged primates, the relationship is not as well studied for pairhoused animals. study of the pair-housed setting has become increasingly relevant because of the social housing mandate of the animal welfare act regulations. we therefore observed 68 juvenile rhesus monkeys born in 19 ... | 1994 | 31936917 |
| progressive improvement in the transfer of maternal antibody across the order primates. | antibody levels were determined in adults and newborn offspring of five primate species. this cross-species comparison of intant igg levels indicated that prosimians and new world monkeys transfer lower levels of maternal antibody via placental transmission than do old world monkeys, apes, and humans. the evolutionary trend toward an increased reliance on prenatal antibody transfer in the higher primates appears to be most pronounced in the human infant, because our placenta has evolved an activ ... | 1994 | 31936907 |
| kinship, association, and social relationships in rhesus monkeys (macaca mulatta). | data on social interactions with matrilineal kin were collected from two groups of rhesus monkeys for 6 years. all behavioral states, including time within one meter of another, involved kin more often than would be expected by chance. significant associations were also found between kinship and the frequencies of various forms of agonistic as well as affiliative acts. frequency of social interaction, however, was not a simple function of time in proximity. although animals spent more time with ... | 1993 | 32070084 |
| observations of increased activity and tool use in captive rhesus monkeys exposed to troughs of water. | this study investigated the effects of water troughs on nonhuman primates housed in a captive environment. two groups of rhesus monkeys (macaca mulatta) were exposed to water-filled troughs under three conditions: (1) standing water, (2) running water, and (3) a replication of standing and running water with novel objects. the effects of water exposure were assessed using a pretest phase (baseline), test phase (trough present), and posttest phase (baseline) design for each of the three condition ... | 1993 | 31941197 |
| non-surgical uterine flushing for the recovery of preimplantation embryos in rhesus monkeys: lack of seasonal infertility. | a non-surgical uterine flushing technique was employed to recover rhesus monkey preimplantation embryos during april--september, a period thought to be associated with reduced fertility. a total of 22 females of proven fertility, maintained indoors under strict light and temperature control, were employed for the study in which 72 menstrual cycles were monitored. the average length of their menstrual cycle was 27.9 ± 3.8 days. the percentages of cycles that showed normal cyclic patterns of estro ... | 1993 | 31941195 |
| testis size, epididymis weight, and sperm competition in rhesus macaques. | the intensity of sperm competition is often measured using the gonadosomatic index (testes/body weight). but sperm competition could be mediated more by size of the epididymis than by size of the testicles, and little information is available on the relationship between testicular and epididymal size. we found that both organs were positively correlated in size among male rhesus macaques. body weight accounted for over 70% of the variance in testicle size and volumetric estimates of testicle siz ... | 1993 | 31937016 |
| preliminary analysis of drinking from seawater sources by free-ranging rhesus macaques (macaca mulatta). | rhesus macaques on key lois island were observed drinking seawater that flowed into four holes they had excavated in the sand. data were gathered to determine the salinity (tds) and ph levels of the water and which animals were using the holes. average tds level (4,506.8 ± 1,750.8), but not ph (8.1 ± .30) level, of water from the holes differed from the surrounding seawater (tds = 29,000, ph = 8.0). there were significant variations in tds and ph levels of water between holes. a total of 249 dri ... | 1993 | 31936999 |
| sex differences in adolescent rhesus monkey (macaca mulatta) behavior. | sex differences in the behavior of 2.5- to 4.5-year-old rhesus monkeys, living in two social groups approximating natural compositions, were studied over a period of 3 years. both sexes interacted significantly more often with members of their own sex in agonistic and affiliative interactions even when total rates and durations for male and female subjects did not differ. strong sexual segregation was also seen in proximity, nonspecific contact, and huddling partners. males were more involved in ... | 1993 | 31936997 |
| localization of estrogen receptors in rhesus monkey ovary. | we have previously demonstrated that the exogenous administration of estradiol-17β (e2) to rhesus monkeys induces atresia of the dominant preovulatory follicle (df); and that this effect is mediated centrally, via the inhibition of follicle-stimulating hormone, and is also exerted directly at the level of the ovarian granulosa cell. we wished to investigate whether the local effect of e2 is transduced through interaction with the nuclear receptor for estrogen, particularly in light of certain ev ... | 1993 | 31936993 |
| control of postpartum mating behavior in free-ranging rhesus monkeys. | this paper explores the effect that a dependent rhesus macaque infant (macaca mulatta) has on the timing of its mother's resumption of mating. toward this end, behavioral data from the rhesus populations at tughlaqabad, india, and cayo santiago, puerto rico, are compared. specifically, the intervals between parturition and subsequent resumption of mating for individual parous females are examined in order to shed light on the relative importance of environmental and internal factors (such as lac ... | 1992 | 31948160 |
| interplay between various aspects in social relationships of young rhesus monkeys: dominance, agonistic help, and affiliation. | relationships between group-living primates depend strongly on their position in the group dominance hierarchy and on their relationships with other group members. the influence of various behaviours on social relationships of immature rhesus monkeys (macaca mulatta) was investigated here. dominance ranks were established and related to the degree of affiliation in a dyad. older monkeys were mostly dominant to the younger ones, regardless of kinship. subordinate monkeys left proximity of their d ... | 1992 | 31948151 |
| the secretion of bioactive and immunoreactive follicle-stimulating hormone (fsh) and luteinizing hormone (lh) throughout the menstrual cycle of the rhesus monkey (macaca mulatta). | the present study provides the first evaluation of related changes in serum levels of bioactive fsh (bio fsh) and immunoreactive fsh (ifsh), and concurrent dynamics of lh and fsh bioactivity throughout the menstrual cycle of the rhesus monkey. mean concentrations of bio fsh were elevated on days 0 and 1 (n = 7; p < 0.05; day 0 = preovulatory lh surge). data from individual animals revealed that an average (± sem) of 1.43 ± 0.29 and 2.71 ± 0.61 discrete surges of bio fsh occurred in each monkey's ... | 1992 | 31948148 |
| variability in nuclear dna among nonhuman primates: application of molecular genetic techniques to intra- and inter-species genetic analyses. | nuclear dna clones and sequence information derived from human genetic analyses were used to detect and characterize intra- and inter-species dna variation at several nuclear loci in hominoids and cercopithecoids. restriction fragment length polymorphisms were found at five loci among captive rhesus monkeys. cross-species polymerase chain reaction (pcr) amplification detected an insertion within the beta-globin gene cluster in hylobatids. the combined use of cross-species pcr and denaturing grad ... | 1992 | 31948144 |
| genetic structure of three populations of rhesus macaques (macaca mulatta): implications for genetic management. | one of the prime concerns at zoos and at primate breeding facilities is to maintain genetic variability. this can be accomplished by avoiding inbreeding. it is relatively easy to assess genetic variability and the level of inbreeding by using pedigree information and genetic markers. in this study we used genetic markers controlled by 6 independent polymorphic loci (gpi, pgd, ca2, mpi, dia1, tf) to ascertain genetic variation in two captive and one wild population of rhesus monkeys. two other lo ... | 1992 | 31948138 |
| biochemical and biological properties of urinary follicle-stimulating hormone (fsh) from the rhesus monkey (macaca mulatta). | follicle-stimulating hormone (fsh) is routinely used for the induction of superovulation in women. homologous gonadotropin preparations that could be used for reproductive studies in macaques would have valuable research applications. accordingly, we set out to characterize the physical and biological characteristics of urinary fsh (ufsh) in the ovariectomized rhesus monkey. in urine from 7 monkeys, concentrations of bioactive fsh ranged from 16 to 57 μg/1, relative to cynfsh-rpi (niddk). ufsh w ... | 1992 | 31948134 |
| survey of parasites of rhesus monkeys housed in small social groups. | a survey of specific parasites in fecal samples randomly collected from socially housed rhesus monkeys was done over a 1‐year period. differences in frequency of samples with parasites, and number of different species per sample, were assessed by social group composition, social group size, female reproductive status, and season of the year. common parasites were entamoeba coli, iodamoeba bütschlii, balantidium coli, strongyloides fülleborni, and trichuris trichiura. samples from juvenile/subadu ... | 1992 | 31941229 |
| adjustments and adaptations to indoor and outdoor environments: continuity and change in young adult rhesus monkeys. | optimal environments for captive primates are assumed to be those which simulate certain ecological features and elicit a wide range of species-typical behavior patterns. outdoor environments are often thought to be more suitable than indoor environments in that they provide more space and potentially higher levels of stimulation. the purpose of this study was to compare the long-term behavioral responses of several groups of animals that had been reared identically during the first two years of ... | 1992 | 31941216 |
| collection and fertilization potential of sperm from the sulawesi crested black macaque (macaca nigra). | in this study, semen was obtained by rectal probe electrostimulation (rpe) from the sulawesi crested black macaque (macaca nigra). three experimental series were conducted. first, semen was collected from four animals anesthetized with either tiletamine-zolazepam (telazol®) or ket-amine-hcl (vetalar®) (five collections from each animal with each drug). because of greater muscle relaxation and analgesia, we found tiletaminezolazepam to be an attractive alternative to ketamine-hcl as an anesthetic ... | 1992 | 31941206 |
| the reduction of abnormal behaviors in individually housed rhesus monkeys (macaca mulatta) with a foraging/grooming board. | a new environmental enrichment device, termed a "foraging/grooming board," was presented to 8 individually housed rhesus monkeys for the explicit purpose of reducing the level of aberrant behaviors manifested by these animals. the device, consisting of a piece of plexiglass covered with artificial fleece, had particles of food treats rubbed into it and was attached to the outside of each animal's home cage. all animals foraged from the board to the point that a significant reduction in the level ... | 1991 | 31952413 |
| effects of woodchips and buried food on behavior patterns and psychological well-being of captive rhesus monkeys. | the effects of adding woodchip litter to bare-floored pens, burying monkey chow in the woodchips, and scattering sunflower seeds in woodchips was studied in 2 stable social groups of rhesus macaques (macaca mulatta) to ascertain the effects of these manipulations on levels of foraging, exploration, abnormal behavior, social interactions, and urinary cortisol levels. the addition of woodchips increased exploration and feeding levels and decreased social interactions. burial of regular monkey chow ... | 1991 | 31952404 |
| estradiol-induced follicular atresia in rhesus monkeys is not prevented by exogenous gonadotropins. | estradiol-17β (e2) induces atresia of the dominant preovulatory follicle (df) when administered on day 6 of the menstrual cycle. the present study was designed to determine whether the atretogenic effect of e2 could be averted by the administration of exogenous gonadotropins, in an attempt to determine whether e2-induced atresia in primates is due to a direct action at the ovarian level or is mediated via pituitary secretion. after identification of the df during laparoscopy, cyclic monkeys rece ... | 1991 | 31952397 |
| testosterone changes during the period of adolescence in male rhesus monkeys (macaca mulatta). | testosterone levels of 59 male rhesus monkeys were monitored over a period of 5 years. longitudinal comparisons revealed consistent rises in mid-morning levels of circulating hormone in successive years from age 2.5 to 6.5 years of age, whereas cross-sectional comparisons failed to detect significant differences among the older subjects. the first mid-morning hormonal elevation could be detected in some males as young as 2.5 years of age, whereas other males showed no detectable rises until age ... | 1991 | 31952393 |
| suppression of luteinizing hormone release by the α1-adrenergic receptor antagonist prazosin in the ovariectomized female rhesus monkey. | the effects of adrenergic antagonists on lh release were examined in ovariectomized female rhesus monkeys implanted with indwelling jugular catheters. while the α2-adrenergic antagonist rauwolscine and the vehicle were without effect, the α1-antagonist prazosin suppressed lh release. in 5 of the 8 monkeys tested, lh pulses were completely arrested; in the remaining 3 monkeys, small lh pulses were detectable after the administration of 0.2 mg/kg prazosin. in a second series of experiments, the ef ... | 1991 | 31952378 |
| laboratory assessment of temperament and environmental enrichment in rhesus monkey infants (macaca mulatta). | this study investigated the combined effects of early temperamental characteristics and environmental enrichment on a variety of developmental measures in nursery-reared rhesus monkey infants. twenty-three infants, reared in either standard laboratory cages or enriched environments, were tested during the 1st month of life for interactive, motor, and temperamental capabilities and characteristics. at 8 months of age, all subjects were assessed on a second series of tests designed to measure thei ... | 1991 | 31948180 |
| population ecology of rhesus monkeys (macaca mulatta) at nanwan nature reserve, hainan, china. | rhesus monkeys (macaca mulatta) at the nanwan peninsula of hainan island, china, have been observed in the field for 25 years, and have been studied intensively for eight years, beginning in 1981. there were about 115 monkeys in 5 natural groups when the nanwan reserve was founded in 1965. from 1965 to 1984, the number of groups increased from 5 to 19, and the total population increased from 115 to 930 individuals, an annual population increase of 12.7%. from 1984 to 1987, the population continu ... | 1991 | 31948175 |