Publications

substitution patterns are gc-biased in divergent sequences across the metazoans.	the fastest-evolving regions in the human and chimpanzee genomes show a remarkable excess of weak (a,t) to strong (g,c) nucleotide substitutions since divergence from their common ancestor. we investigated the phylogenetic extent and possible causes of this weak to strong (w ôåæ s) bias in divergent sequences (bds) using recently sequenced genomes and recombination maps from eight trios of eukaryotic species. to quantify evidence for bds, we inferred substitution histories using an efficient max ...	2011	21670083
molecular cloning, sequence characterization, polymorphism and association analysis of porcine ropn1 gene.	the full-length cdna sequence of one porcine gene, ropn1, was isolated using the rapid amplification of cdna ends (race) method based on one pig est sequence which was highly homologous to the coding sequence of human ropn1 gene. the porcine ropn1 gene encodes a protein of 212 amino acids which shares high homology with the rhophilin associated protein 1 (ropn1) of eight species: gray short-tailed opossum (96%), horse (95%), cattle (94%), mouse (93%), rat (92%), chimpanzee (85%), human (85%) and ...	2011	21667248
chimpanzees' use of conspecific cues in matching-to-sample tasks: public information use in a fully automated testing environment.	social animals have much to gain from observing and responding appropriately to the actions of their conspecific group members. this can in turn lead to the learning of novel behavior patterns (social learning) or to foraging, ranging, or social behavioral choices copied from fellow group members, which do not necessarily result in long-term learning, but at the time represent adaptive responses to environmental cues (public information use). in the current study, we developed a novel system for ...	2011	21667080
psychological health of orphan bonobos and chimpanzees in african sanctuaries.	facilities across africa care for apes orphaned by the trade for "bushmeat." these facilities, called sanctuaries, provide housing for apes such as bonobos (pan paniscus) and chimpanzees (pan troglodytes) who have been illegally taken from the wild and sold as pets. although these circumstances are undoubtedly stressful for the apes, most individuals arrive at the sanctuaries as infants and are subsequently provided with rich physical and social environments that can facilitate the expression of ...	2011	21666743
[anatomy of the skull].	the anatomy of the human body based on a special teleological system is one of the greatest miracles of the world. the skull's primary function is the defence of the brain, so every alteration or disease of the brain results in some alteration of the skull. this analogy is to be identified even in the human embryo. proportions of the 22 bones constituting the skull and of sizes of sutures are not only the result of the phylogeny, but those of the ontogeny as well. e.g. the age of the skeletons i ...	2010	21661257
strategies for the use of fallback foods in apes.	researchers have suggested that fallback foods (fbfs) shape primate food processing adaptations, whereas preferred foods drive harvesting adaptations, and that the dietary importance of fbfs is central in determining the expression of a variety of traits. we examine these hypotheses in extant apes. first, we compare the nature and dietary importance of fbfs used by each taxon. fbf importance appears greatest in gorillas, followed by chimpanzees and siamangs, and least in orangutans and gibbons ( ...	2011	21654902
chimpanzee problem-solving: contrasting the use of causal and arbitrary cues.	humans are able to benefit from a causally structured problem-solving context rather than arbitrarily structured situations. in order to better understand nonhuman causal cognition, it is therefore important to isolate crucial factors that might differentiate between events that follow a purely spatial and temporal contingency and those that hold a "true" causal relationship. in the first of two experiments, chimpanzee subjects were required to detect a bottle containing juice from five opaque b ...	2011	21647648
species difference in the timing of gaze movement between chimpanzees and humans.	how do humans and their closest relatives, chimpanzees, differ in their fundamental abilities for seeing the visual world? in this study, we directly compared the gaze movements of humans and the closest species, chimpanzees, using an eye-tracking system. during free viewing of a naturalistic scene, chimpanzees made more fixations per second (up to four) than did humans (up to three). this species difference was independent of the semantic variability of the presented scenes. the gap-overlap par ...	2011	21647647
effects of aging and blood contamination on the urinary protein-creatinine ratio in captive chimpanzees (pan troglodytes).	the initial goal of this study was to evaluate proteinuria by using the protein to creatinine (upc) ratio of urine obtained by cystocentesis of healthy adult captive chimpanzees. urine samples were collected by using ultrasound-guided cystocentesis from 125 (80 male, 45 female) captive chimpanzees. all samples were collected over a 17-mo time period (august 2008 to january 2010) during the animal's annual physical examination. samples were assayed at a veterinary diagnostic laboratory. results i ...	2011	21640034
a porcine gene, pbk, differentially expressed in the longissimus muscle from meishan and large white pig.	an investigation of differences in gene expression in the longissimus muscle of meishan and large white pigs was undertaken, using the mrna display technique. a fragment of one differentially expressed gene was isolated and sequenced, whereupon the complete cdna sequence was then obtained by using the rapid amplification of cdna ends (race). the nucleotide sequence of the gene is not related to any known porcine gene. sequence analysis revealed that the open reading frame of this gene encodes a ...	2009	21637452
strontium isotope evidence for landscape use by early hominins.	ranging and residence patterns among early hominins have been indirectly inferred from morphology, stone-tool sourcing, referential models and phylogenetic models. however, the highly uncertain nature of such reconstructions limits our understanding of early hominin ecology, biology, social structure and evolution. we investigated landscape use in australopithecus africanus and paranthropus robustus from the sterkfontein and swartkrans cave sites in south africa using strontium isotope analysis, ...	2011	21637256
tool-use to obtain honey by chimpanzees at bulindi: new record from uganda.	honey-gathering from bee nests has been recorded at chimpanzee (pan troglodytes) study sites across tropical africa. different populations employ different strategies, ranging from simple 'smash-and grab' raids to use of sophisticated tool-sets, i.e., two or more types of tool used sequentially in a single task. in this paper i present evidence of tool-use, and the probable use of a tool-set, for honey-gathering by unhabituated chimpanzees at bulindi, a forest-farm mosaic south of the budongo fo ...	2011	21633915
memory processing in great apes: the effect of time and sleep.	following encoding, memory remains temporarily vulnerable to disruption. consolidation refers to offline time-dependent processes that continue after encoding and stabilize, transform or enhance the memory trace. memory consolidation resulting from sleep has been reported for declarative and non-declarative memories in humans. we first investigated the temporal course of memory retrieval in chimpanzees, bonobos and orangutans. we found that the amount of retrieved information was time dependent: ...	2011	21632621
antiviral efficacy upon administration of a hepdirect prodrug of 2'-c-methylcytidine to hepatitis c virus-infected chimpanzees.	hepatitis c virus (hcv) infects an estimated 170 million individuals worldwide and the current standard of care, a combination of pegylated interferon alpha and ribavirin, is efficacious in achieving sustained viral response in ∼50% of treated patients. novel therapies under investigation include the use of nucleoside analog inhibitors of the viral rna dependent rna polymerase. nm283, a 3' -valyl ester prodrug of 2' -c-methylcytidine, has demonstrated antiviral efficacy in hcv infected patients ...	2011	21628542
refinement of primate cnv hotspots identifies candidate genomic regions evolving under positive selection.	abstract: background: copy number variants (cnvs), defined as losses and gains of segments of genomic dna, are a major source of genomic variation. results: in this study, we identified over two thousand human cnvs that overlap with orthologous chimpanzee or orthologous macaque cnvs. of these, 170 cnvs overlap with both chimpanzee and macaque cnvs, and these were collapsed into 34 hotspot regions of cnv formation. many of these hotspot regions of cnv formation are functionally relevant, with a b ...	2011	21627829
immunolocalization of spetex-1 at the connecting piece in spermatozoa of the musk shrew (suncus murinus).	spetex-1, which has been isolated by differential display and rat cdna library screening as a haploid spermatid-specific gene, encodes a protein with two coiled-coil motifs that locates at both the segmented column in the connecting piece and outer dense fibers-affiliated satellite fibrils in rat sperm flagella. orthologs of spetex-1 are identified in many animal species, including human, chimpanzee, macaque, cow, dog, african clawed frog, green spotted puffer, and zebrafish. in this study, we u ...	2011	21627455
systematic review of chimpanzee use in monoclonal antibody research and drug development: 1981-2010.	this survey examines the extent to which live chimpanzees have been used in monoclonal antibody (mab) research and the drug approval process. the survey covers 193 scientific articles published during the years 1981-2010, as well as preclinical studies leading to the approval of mab drugs by the food and drug administration of the united states. the frequency of the articles has decreased by more than two- thirds from their highs in the late 1980's, and the aggregate number of chimpanzees used i ...	2011	21625827
orangutans (pongo pygmaeus) do not form expectations based on their partner's outcomes.	several primate species form expectations based on others' outcomes, responding negatively when their outcomes differ from their partners'. the function and evolutionary pathway of this behavior are unknown, in part because all of the species which have been tested thus far share traits related to a gregarious lifestyle, intelligence, and cooperativeness. our goal was to test whether inequity is a homology among primates or a convergence by comparing one species known to show social comparisons, ...	2011	21625145
the parental antagonism theory of language evolution: preliminary evidence for the proposal.	abstract language as with most communication systems likely evolved by means of natural selection. accounts for the genetieal selection of language can usually be divided into two scenarios, either of which used in isolation of the other appear insufficient to explain the phenomena: (1) there are group benefits from communicating, and (2) there are individual benefits from being a better communicator. in contrast, it is hypothesized that language phenotypes emerged during a coevolutionary strugg ...	2011	21615287
communication and the primate brain: insights from neuroimaging studies in humans, chimpanzees and macaques.	abstract considerable knowledge is available on the neural substrates for speech and language from brain-imaging studies in humans, but until recently there was a lack of data for comparison from other animal species on the evolutionarily conserved brain regions that process species-specific communication signals. to obtain new insights into the relationship of the substrates for communication in primates, we compared the results from several neuroimaging studies in humans with those that have r ...	2011	21615285
rhesus macaque kir bind human mhc class i with broad specificity and recognize hla-c more effectively than hla-a and hla-b.	human killer cell immunoglobulin-like receptors (kir) recognize a3/11, bw4, c1, and c2 epitopes carried by mutually exclusive subsets of human leukocyte antigen (hla)-a, -b, and -c allotypes. chimpanzee and orangutan have counterparts to hla-a, -b, and -c, and kir that recognize the a3/11, bw4, c1, and c2 epitopes, either individually or in combination. because rhesus macaque has counterparts of hla-a and -b, but not hla-c, we expected that rhesus kir would better recognize hla-a and -b, than hl ...	2011	21614583
human pirnas are under selection in africans and repress transposable elements.	piwi-interacting rnas (pirnas) are a recently discovered class of 24-30 nucleotide noncoding rnas whose best understood function is to repress transposable elements (tes) in animal germlines. in humans, te-derived sequences comprise ∼45% of the genome and there are several active te families, including line-1 and alu elements, which are a significant source of de novo mutations and intra-population variability. in the "ping-pong model", pirnas are thought to alternatively cleave sense and anti-s ...	2011	21613236
characterization of a canine homolog of hepatitis c virus.	an estimated 3% of the world's population is chronically infected with hepatitis c virus (hcv). although hcv was discovered more than 20 y ago, its origin remains obscure largely because no closely related animal virus homolog has been identified; furthermore, efforts to understand hcv pathogenesis have been hampered by the absence of animal models other than chimpanzees for human disease. here we report the identification in domestic dogs of a nonprimate hepacivirus. comparative phylogenetic an ...	2011	21610165
how tufted capuchin monkeys (cebus apella spp) and common chimpanzees (pan troglodytes) align objects to surfaces: insights into spatial reasoning and implications for tool use.	this report addresses phylogenetic variation in a spatial skill that underlies tool use: aligning objects to a feature of a surface. fragaszy and cummins-sebree's [behavioral and cognitive neuroscience reviews 4:282-306, 2005] model of relational spatial reasoning and skill development and perception-action theories guided the design of the study. we examined how capuchins and chimpanzees place stick objects of varying shapes into matching grooves on a flat surface. although most individuals ali ...	2011	21608008
physical intuitions about support relations in monkeys (macaca fuscata) and apes (pan troglodytes).	nonhuman primates, like humans, have demonstrated various physical intuitions. cacchione and krist (2004) examined chimpanzees' intuitions about support relations with the violation-of-expectation task. they reported that the chimpanzees possessed intuitions about support, but their intuitions differed from those of humans in part; they were sensitive to "contact/no-contact" and "amount of contact" but not "type of contact" rule. to further explore intuitions about support in nonhuman primates, ...	2011	21604855
chimpanzee (pan troglodytes) relational matching: playing by their own (analogical) rules.	chimpanzees (pan troglodytes) have been known to exhibit rudimentary abilities in analogical reasoning (flemming, beran, thompson, kleider, & washburn, 2008; gillian, premack, & woodruff, 1981; haun & call, 2009; thompson & oden, 2000; thompson, oden, & boysen, 1997). with a wide array of individual differences, little can be concluded about the species' capacity for analogies, much less their strategies employed for solving such problems. in this study, we examined analogical strategies in 3 ch ...	2011	21604854
the human brain: rewired and running hot.	the past two decades have witnessed tremendous advances in noninvasive and postmortem neuroscientific techniques, advances that have made it possible, for the first time, to compare in detail the organization of the human brain to that of other primates. studies comparing humans to chimpanzees and other great apes reveal that human brain evolution was not merely a matter of enlargement, but involved changes at all levels of organization that have been examined. these include the cellular and lam ...	2011	21599696
male chimpanzees' grooming rates vary by female age, parity, and fertility status.	copulation preferences in our closest living relative, the chimpanzee, suggest that males prefer older females who have had previous offspring. however, this finding is counter to some behavioral models, which predict that chimpanzee males, as promiscuous breeders with minimal costs to mating, should show little or no preference when choosing mating partners (e.g. should mate indiscriminately). to determine if the preferences indicated by copulations appear in other contexts as well as how they ...	2011	21590699
a microarray system for y chromosomal and mitochondrial single nucleotide polymorphism analysis in chimpanzee populations.	chimpanzee populations are diminishing as a consequence of human activities, and as a result this species is now endangered. in the context of conservation programmes, genetic data can add vital information, for instance on the genetic diversity and structure of threatened populations. single nucleotide polymorphisms (snp) are biallelic markers that are widely used in human molecular studies and can be implemented in efficient microarray systems. this technology offers the potential of robust, m ...	2008	21585830
analogical reasoning and the differential outcome effect: transitory bridging of the conceptual gap for rhesus monkeys (macaca mulatta).	monkeys, unlike chimpanzees and humans, have a marked difficulty acquiring relational matching-to-sample (rmts) tasks that likely reflect the cognitive foundation upon which analogical reasoning rests. in the present study, rhesus monkeys (macaca mulatta) completed a categorical (identity and nonidentity) rmts task with differential reward (pellet ratio) and/or punishment (timeout ratio) outcomes for correct and incorrect choices. monkeys in either differential reward-only or punishment-only con ...	2011	21574737
the magic cup: great apes and domestic dogs (canis familiaris) individuate objects according to their properties.	despite current interest in dog (canis familiaris) cognition, very little is known about how dogs represent objects and how they compare with other species, such as the great apes. therefore, we investigated how dogs and great apes (chimpanzees [pan troglodytes], bonobos [pan paniscus], orangutans [pongo pygmaeus], gorillas [gorilla gorilla]) individuate objects in a classical violation of expectation paradigm. we used a container (magic cup) with a double bottom that allowed us to change the ty ...	2011	21574687
an inversion effect modified by expertise in capuchin monkeys.	the face inversion effect may be defined as the general impairment in recognition that occurs when faces are rotated 180°. this phenomenon seems particularly strong for faces as opposed to other objects and is often used as a marker of a specialized face-processing mechanism. four brown capuchin monkeys (cebus apella) were tested on their ability to discriminate several classes of facial and non-facial stimuli presented in both their upright and inverted orientations in an oddity task. results r ...	2011	21573949
mutation rate distribution inferred from coincident snps and coincident substitutions.	mutation rate variation has the potential to bias evolutionary inference, particularly when rates become much higher than the mean. we first confirm prior work that inferred the existence of cryptic, site-specific rate variation on the basis of coincident polymorphisms-sites that are segregating in both humans and chimpanzees. then we extend this observation to a longer evolutionary timescale by identifying sites of coincident substitutions using four species. from these data, we develop analyti ...	2011	21572094
animal models of human respiratory syncytial virus disease.	infection with the human pneumovirus pathogen, respiratory syncytial virus (hrsv), causes a wide spectrum of respiratory disease, notably among infants and the elderly. laboratory animal studies permit detailed experimental modeling of hrsv disease and are therefore indispensable in the search for novel therapies and preventative strategies. current animal models include several target species for hrsv, including chimpanzees, cattle, sheep, cotton rats and mice, as well as alternative animal pne ...	2011	21571908
two-step multiplex polymerase chain reaction improves the speed and accuracy of genotyping using dna from noninvasive and museum samples.	many studies in molecular ecology rely upon the genotyping of large numbers of low-quantity dna extracts derived from noninvasive or museum specimens. to overcome low amplification success rates and avoid genotyping errors such as allelic dropout and false alleles, multiple polymerase chain reaction (pcr) replicates for each sample are typically used. recently, two-step multiplex procedures have been introduced which drastically increase the success rate and efficiency of genotyping. however, co ...	2009	21564562
a retrospective analysis of factors correlated to chimpanzee (pan troglodytes schweinfurthii) respiratory health at gombe national park, tanzania.	infectious disease and other health hazards have been hypothesized to pose serious threats to the persistence of wild ape populations. respiratory disease outbreaks have been shown to be of particular concern for several wild chimpanzee study sites, leading managers, and researchers to hypothesize that diseases originating from and/or spread by humans pose a substantial risk to the long-term survival of chimpanzee populations. the total chimpanzee population in gombe national park, tanzania, has ...	2011	21562902
serial gesturing by wild chimpanzees: its nature and function for communication.	chimpanzees at budongo, uganda, regularly gesture in series, including 'bouts' of gesturing that include response waiting and 'sequences' of rapid-fire gesturing without pauses. we examined the distribution and correlates of 723 sequences and 504 bouts for clues to the function of multigesture series. gesturing by older chimpanzees was more likely to be successful, but the success rate of any particular gesture did not vary with signaller age. rather, older individuals were more likely to choose ...	2011	21562816
primate population dynamics over 32.9 years at ngogo, kibale national park, uganda.	we present census data for eight primate species spanning 32.9 years along the same transect at ngogo, kibale national park, uganda, demonstrating major changes in the composition of the primate community. correlated with an estimated decline of ∼89% in the red colobus population was an increase in encounter rates with chimpanzee parties. our data, along with the unusually high rates of predation by chimpanzees on red colobus at ngogo and the fact that the chimpanzee community at ngogo is the la ...	2011	21557287
siglec12: a human-specific segregating (pseudo) gene encodes a signaling molecule expressed in prostate carcinomas.	the primate siglec12 gene encodes one of the cd33-related siglec family of signaling molecules in immune cells. we had previously reported that this gene harbors a human-specific missense mutation of the codon for an arg residue required for sialic acid recognition. here we show that this r122c mutation of the siglec-xii protein is fixed in the human population, i.e., it occurred prior to the origin of modern humans. additional mutations have since completely inactivated the siglec12 gene in som ...	2011	21555517
completion of hepatitis c virus replication cycle in heterokaryons excludes dominant restrictions in human non-liver and mouse liver cell lines.	hepatitis c virus (hcv) is hepatotropic and only infects humans and chimpanzees. consequently, an immunocompetent small animal model is lacking. the restricted tropism of hcv likely reflects specific host factor requirements. we investigated if dominant restriction factors expressed in non-liver or non-human cell lines inhibit hcv propagation thus rendering these cells non-permissive. to this end we explored if hcv completes its replication cycle in heterokaryons between human liver cell lines a ...	2011	21552323
retraction. variation in chimpanzee 'culture' is predicted by local ecology, not geography.		2012	21543393
the perception of self-agency in chimpanzees (pan troglodytes).	the ability to distinguish actions and effects caused by oneself from events occurring in the external environment is a fundamental aspect of human cognition. underlying such distinctions, self-monitoring processes are often assumed, in which predicted events accompanied by one's own volitional action are compared with actual events observed in the external environment. although many studies have examined the absence or presence of a certain type of self-recognition (i.e. mirror self-recognition ...	2011	21543355
brief communication: dental development timing in captive pan paniscus with comparisons to pan troglodytes.	dental eruption provides markers of growth and is one component of a chimpanzee's physical development. dental markers help characterize transitions between life stages, e.g., infant to juvenile. most of what we know about the timing of development in chimpanzees derives from pan troglodytes. much less is known about the sister species, pan paniscus, with few in captivity and a restricted wild range in central africa. here we report on the dental eruption timing for female captive p. paniscus (n ...	2011	21541924
natural variation at position 45 in the d1 domain of lineage iii killer cell immunoglobulin-like receptors (kir) has major effects on the avidity and specificity for mhc class i.	alternative lysine and methionine residues at position 44 in the d1 domain determine the specificities of human lineage iii killer cell immunoglobulin-like receptors (kir) for the c1 and c2 epitopes of hla-c. kir having glutamate 44 are also present in orangutans (popy2dlb) and chimpanzees (pt-2dl9) but notably absent from humans. popy2dlb exhibits broad specificity for both the c1 and c2 epitopes, whereas pt-2dl9 has narrow specificity for c2. mutation of phenylalanine 45 in popy2dlb to the cys ...	2011	21541786
functional analysis and treatment of human-directed undesirable behavior exhibited by a captive chimpanzee.	a functional analysis identified the reinforcer maintaining feces throwing and spitting exhibited by a captive adult chimpanzee (pan troglodytes). the implementation of a function-based treatment combining extinction with differential reinforcement of an alternate behavior decreased levels of inappropriate behavior. these findings further demonstrate the utility of function-based approaches to assess and treat behavior problems exhibited by captive animals.	2011	21541106
modeling the effects of weaning age on length of female reproductive period: implications for the evolution of human life history.	human life history is unique among primates. despite our extended lifespan, the length of the female reproductive period is shorter in humans than in our closest living relatives, chimpanzees. here, we investigate whether this difference could be explained by another unique aspect of human life history-a young weaning age.	2011	21538649
validation of a cortisol enzyme immunoassay and characterization of salivary cortisol circadian rhythm in chimpanzees (pan troglodytes).	monitoring concentrations of stress hormones is an important tool for behavioral research and conservation for animals both in the wild and captivity. glucocorticoids can be measured in mammals as an indicator of stress by analyzing blood, feces, urine, hair, feathers, or saliva. the advantages of using saliva for measuring cortisol concentrations are three-fold: it is minimally invasive, multiple samples can be collected from the same individual in a short timeframe, and cortisol has a relative ...	2011	21538448
in vivo adaptation of hepatitis c virus for efficient virus production and evasion of apoptosis.	hepatitis c virus (hcv) employs various strategies to establish persistent infection that can cause chronic liver disease. our previous study showed that both the original patient serum from which the hcv jfh-1 strain was isolated and the cell culture-generated jfh-1 virus (jfh-1cc) established infection in chimpanzees, and that infected jfh-1 strains accumulated mutations after passage through chimpanzees. the aim of this study was to compare the in vitro characteristics of jfh-1 strains emerge ...	2011	21538444
the evolution of face processing in primates.	the ability to recognize faces is an important socio-cognitive skill that is associated with a number of cognitive specializations in humans. while numerous studies have examined the presence of these specializations in non-human primates, species where face recognition would confer distinct advantages in social situations, results have been mixed. the majority of studies in chimpanzees support homologous face-processing mechanisms with humans, but results from monkey studies appear largely depe ...	2011	21536559
the many faces of research on face perception.	face perception is fundamental to human social interaction. many different types of important information are visible in faces and the processes and mechanisms involved in extracting this information are complex and can be highly specialized. the importance of faces has long been recognized by a wide range of scientists. importantly, the range of perspectives and techniques that this breadth has brought to face perception research has, in recent years, led to many important advances in our under ...	2011	21536550
association of brain-type natriuretic protein and cardiac troponin i with incipient cardiovascular disease in chimpanzees (pan troglodytes).	cardiovascular disease (cvd) is the primary cause of morbidity and mortality in chimpanzees, but its etiology and clinical presentations remain poorly understood. the disease in chimpanzees differs sufficiently from that in humans that simple extrapolation from human findings are inadequate to guide clinical diagnoses. nevertheless, the burden of disease posed by cvd made it important to attempt to identify specific chimpanzees at risk of developing cvd to allow clinical intervention prior to cl ...	2011	21535928
the gestural repertoire of the wild chimpanzee.	great ape gestural communication is known to be intentional, elaborate and flexible; yet there is controversy over the best interpretation of the system and how gestures are acquired, perhaps because most studies have been made in restricted, captive settings. here, we report the first systematic analysis of gesture in a population of wild chimpanzees. over 266 days of observation, we recorded 4,397 cases of intentional gesture use in the sonso community, budongo, uganda. we describe 66 distinct ...	2011	21533821
chimpanzee vocal signaling points to a multimodal origin of human language.	the evolutionary origin of human language and its neurobiological foundations has long been the object of intense scientific debate. although a number of theories have been proposed, one particularly contentious model suggests that human language evolved from a manual gestural communication system in a common ape-human ancestor. consistent with a gestural origins theory are data indicating that chimpanzees intentionally and referentially communicate via manual gestures, and the production of man ...	2011	21533079
molecular characterization of the interaction between sialylated neisseria gonorrhoeae and factor h.	human factor h (hufh), a key inhibitor of the alternative pathway of complement, binds to neisseria gonorrhoeae and constitutes an important mechanism of human-specific complement evasion. the c-terminal domain 20 of hufh contains the binding site for sialylated gonococci. we exploited differences in amino acid sequences between human and non-binding chimpanzee fh domain 20 to create cross-species mutations to define amino acids important for binding to sialylated gonococci. we used fh/fc fusion ...	2011	21531728
nonhuman primates do declare! a comparison of declarative symbol and gesture use in two children, two bonobos, and a chimpanzee.	while numerous publications have shown that apes can learn some aspects of human language, one frequently cited difference between humans and apes is the relative infrequency of declaratives (comments and statements) as opposed to imperatives (requests) in ape symbol use. this paper describes the use of declaratives in three language-competent apes and two children. the apes produced a lower proportion of spontaneous declaratives than did the children. however, both groups used declaratives to n ...	2011	21516208
i'll be a monkey's uncle: a moral challenge to human genetic enhancement research.	the potential for genetic engineering of enhancements to complex human traits has been the subject of vigorous debate for a number of years. most of the discussion has centered on the possible moral consequences of pursuing enhancements, especially those that might affect complex behaviours and components of personality. little has been written on the actual process of implementing this technology. this paper presents a 'thought experiment' about the likely form of final preclinical testing for ...	2011	21515875
initial description of a quantitative, cross-species (chimpanzee-human) social responsiveness measure.	comparative studies of social responsiveness, an ability that is impaired in autism spectrum disorders, can inform our understanding of both autism and the cognitive architecture of social behavior. because there is no existing quantitative measure of social responsiveness in chimpanzees, we generated a quantitative, cross-species (human-chimpanzee) social responsiveness measure.	2011	21515200
chimpanzees: a model "model system" for social responsiveness.		2011	21515192
an experimental mouse model for hepatitis c virus.	chronic hepatitis c virus (hcv) infection affects approximately 170 million people and is a major global health problem because infected individuals can develop liver cirrhosis and hepatocellular carcinoma. despite significant improvements in antiviral drugs, only around 50% of treated patients with genotype 1 and 4 demonstrate hcv clearance. unfortunately, an anti-hcv vaccine is still not available. to progress treatment of hcv, it is necessary to understand the mechanism(s) by which hcv infect ...	2011	21512264
mechanism of birth in chimpanzees: humans are not unique among primates.	researchers have argued that the process of human birth is unique among primates and mammals in that the infant emerges with its face oriented in the opposite direction from its mother (occiput anterior) and head rotation occurs in the birth canal. however, this notion of human uniqueness has not been substantiated, because there are few comparative studies of birth in non-human primates. this paper reports the mechanism of birth in chimpanzees (pan troglodytes) based on the first clear, close-u ...	2011	21508028
case study: training a chimpanzee (pan troglodytes) to use a nebulizer to aid the treatment of airsacculitis.	bacterial airsacculitis has been reported in a variety of nonhuman primates, and is widely treated using a combination of surgery and oral antibiotics. this case study details an alternative method of administering antibiotics (via the use of a nebulizer) when the chimpanzee subject developed resistance to all available oral preparations. training the chimpanzee to use the nebulizer was performed using positive reinforcement techniques (prt). it took a total of 89 sessions (<7 hr 25 min) to trai ...	2013	21506143
comparative analysis of the nucleus basalis of meynert among primates.	long projection axons from the ch4 cell group of the nucleus basalis of meynert (nbm) provide cholinergic innervation to the neurons of the cerebral cortex. this cortical cholinergic innervation has been implicated in behavioral and cognitive functions, including learning and memory. recent evidence revealed differences among primate species in the pattern of cholinergic innervation specific to the prefrontal cortex. while macaques displayed denser cholinergic innervation in layers i and ii rela ...	2011	21504783
great apes use landmark cues over spatial relations to find hidden food.	we investigated whether chimpanzees, bonobos, and orangutans encoded the location of a reward hidden underneath one of three identical cups in relation to (1) the other cups in the array-i.e., the relative position of the baited cup within the array; or (2) the landmarks surrounding the cups-e.g., the edge of the table. apes witnessed the hiding of a food reward under one of three cups forming a straight line on a platform. after 30 s, they were allowed to search for the reward. in three differe ...	2011	21503688
studies on viral disinfection: an evaluation of moist heat disinfection for hbv by using a0 concept defined in iso 15883-washer-disinfectors.	international organization for standardization (iso) 15883 for washer-disinfectors has introduced the a(0) concept to allow comparison of the lethality of moist heat processes. the a(0) value is the equivalent disinfection time in seconds at 80 °c calculated on the basis of microbial killing kinetics when the disinfection temperature is over 65 °c. hepatitis b virus (hbv), transmissible only to humans and chimpanzees, is an important heat-resistant, blood-borne pathogen. therefore, it is mandato ...	2010	21502033
the sequence, structure and evolutionary features of hotair in mammals.	abstract:	2011	21496275
ingroup-outgroup bias in contagious yawning by chimpanzees supports link to empathy.	humans favor others seen as similar to themselves (ingroup) over people seen as different (outgroup), even without explicitly stated bias. ingroup-outgroup bias extends to involuntary responses, such as empathy for pain. however, empathy biases have not been tested in our close primate relatives. contagious yawning has been theoretically and empirically linked to empathy. if empathy underlies contagious yawning, we predict that subjects should show an ingroup-outgroup bias by yawning more in res ...	2011	21494669
correlations between genetic and behavioural dissimilarities in wild chimpanzees (pan troglodytes) do not undermine the case for culture.		2011	21490014
chimpanzees (pan troglodytes) show the isolation effect during serial list recognition memory tests.	the isolation effect (or von restorff effect) occurs when one item in a to-be-remembered list is distinctive from all remaining items, and memory for that item is enhanced. four chimpanzees were presented with a serial list of four photographs. in the homogeneous condition, all list items were from the same semantic category (e.g., four fruits). in the isolate condition, three items were from the same category, but the fourth item (the isolate) was from a different category (e.g., three fruits a ...	2011	21487695
protein kinase ck2 regulates the formation and clearance of aggresomes in response to stress.	misfolded protein aggregates elicit a stress response, and their clearance is crucial for cell survival. these aggregates are transported by cytoplasmic deacetylase hdac6 and dynein motors to the aggresome via the microtubule network, and are removed by autophagic degradation. hdac6 activity is necessary for both the transport and clearance of protein aggregates. however, the cellular factors that regulate hdac6 activity remain unknown. here we show that protein kinase ck2 is a crucial modulator ...	2011	21486957
insectivory of savanna chimpanzees (pan troglodytes verus) at fongoli, senegal.	little is known about the behavior of chimpanzees living in savanna-woodlands, although they are of particular interest to anthropologists for the insight they can provide regarding the ecological pressures affecting early hominins living in similar habitats. fongoli, senegal, is the first site where savanna chimpanzees have been habituated for observational data collection and is the hottest and driest site where such observation of chimpanzees occurs today. previously, indirect evidence sugges ...	2011	21484757
major chimpanzee-specific structural changes in sperm development-associated genes.	a comprehensive analysis of transcriptional structures of chimpanzee sperm development-associated genes is of significant interest for deeply understanding sperm development and male reproductive process. in this study, we sequenced 7,680 clones from a chimpanzee testis full-length cdna library and obtained 1,933 nonredundant high-quality full-length cdna sequences. comparative analysis between human and chimpanzee showed that 78 sperm development-associated genes, most of which were yet unchara ...	2011	21484476
stream/bounce perception and the effect of depth cues in chimpanzees (pan troglodytes).	the stream/bounce display represents an ambiguous motion event in which two identical visual objects move toward one another and the objects overlap completely before they pass each another. in our perception, they can be interpreted as either streaming past one another or bouncing off each other. previous studies have shown that the streaming percept of the display is generic for humans, suggesting the inertial nature of the motion integration process. in this study, chimpanzees took part in be ...	2011	21479722
stone tool use by adult wild bearded capuchin monkeys (cebus libidinosus). frequency, efficiency and tool selectivity.	chimpanzees have been the traditional referential models for investigating human evolution and stone tool use by hominins. we enlarge this comparative scenario by describing normative use of hammer stones and anvils in two wild groups of bearded capuchin monkeys (cebus libidinosus) over one year. we found that most of the individuals habitually use stones and anvils to crack nuts and other encased food items. further, we found that in adults (1) males use stone tools more frequently than females ...	2011	21470663
expression of siglec-11 by human and chimpanzee ovarian stromal cells, with uniquely human ligands: implications for human ovarian physiology and pathology.	siglecs (sialic acid-binding immunoglobulin superfamily lectins) are cell surface signaling receptors of the i-type lectin group that recognize sialic acid-bearing glycans. cd33-related-siglecs are a subset with expression primarily in cells of hematopoietic origin and functional relevance to immune reactions. earlier we reported a human-specific gene conversion event that markedly changed the coding region for the extracellular domain of siglec-11, associated with human-specific expression in m ...	2011	21467073
differences between chimpanzees and bonobos in neural systems supporting social cognition.	our two closest living primate relatives, chimpanzees (pan troglodytes) and bonobos (pan paniscus), exhibit significant behavioral differences despite belonging to the same genus and sharing a very recent common ancestor. differences have been reported in multiple aspects of social behavior, including aggression, sex, play and cooperation. however, the neurobiological basis of these differences has only been minimally investigated and remains uncertain. here, we present the first ever comparison ...	2012	21467047
similarity in recombination rate estimates highly correlates with genetic differentiation in humans.	recombination varies greatly among species, as illustrated by the poor conservation of the recombination landscape between humans and chimpanzees. thus, shorter evolutionary time frames are needed to understand the evolution of recombination. here, we analyze its recent evolution in humans. we calculated the recombination rates between adjacent pairs of 636,933 common single-nucleotide polymorphism loci in 28 worldwide human populations and analyzed them in relation to genetic distances between ...	2011	21464928
preclinical pharmacokinetics and pharmacodynamics of apixaban, a potent and selective factor xa inhibitor.	apixaban is a potent, highly selective, reversible, oral, direct factor xa (fxa) inhibitor in development for thrombosis prevention and treatment. the preclinical pharmacokinetic (pk) attributes of apixaban feature small volume of distribution (vd), low systemic clearance (cl), and good oral bioavailability. apixaban is well absorbed in rat, dog, and chimpanzee, with absolute oral bioavailability of approximately 50% or greater. the steady-state vd of apixaban is approximately 0.5, 0.2, and 0.17 ...	2011	21461793
deep trophoblast invasion and spiral artery remodelling in the placental bed of the chimpanzee.	deep trophoblast invasion is usually considered to be a unique feature of human placentation as compared to other primates. because of the occasional occurrence of preeclampsia in great apes, which in the human is associated with impaired deep invasion, this uniqueness may be questioned. the availability of two well-documented pregnant chimpanzee uteri in the hubrecht collection (museum für naturkunde, berlin) allowed us to evaluate the extent of trophoblast invasion in this species. by adjustin ...	2011	21459441
characterization of enterobius vermicularis in a human population, employing a molecular-based method from adhesive tape samples.	human infection with the parasitic nematode enterobius vermicularis occurs worldwide, particularly in children. although its prevalence may exceed 35% in some parts of the world, molecular studies of e. vermicularis in humans are limited. the aim of the present study was to investigate the genetic variation within e. vermicularis in a human population. for this purpose, 77 adhesive tape samples taken from greek children infested with e. vermicularis were tested. new primers were designed to ampl ...	2011	21458560
historical sampling reveals dramatic demographic changes in western gorilla populations.	today many large mammals live in small, fragmented populations, but it is often unclear whether this subdivision is the result of long-term or recent events. demographic modeling using genetic data can estimate changes in long-term population sizes while temporal sampling provides a way to compare genetic variation present today with that sampled in the past. in order to better understand the dynamics associated with the divergences of great ape populations, these analytical approaches were appl ...	2011	21457536
what history tells us xxiii. the genetic distance between humans and chimpanzees: what did mary-claire king and allan wilson really say in 1975?		2011	21451244
planum temporale grey matter asymmetries in chimpanzees (pan troglodytes), vervet (chlorocebus aethiops sabaeus), rhesus (macaca mulatta) and bonnet (macaca radiata) monkeys.	brain asymmetries, particularly asymmetries within regions associated with language, have been suggested as a key difference between humans and our nearest ancestors. these regions include the planum temporale (pt) - the bank of tissue that lies posterior to heschl's gyrus and encompasses wernicke's area, an important brain region involved in language and speech in the human brain. in the human brain, both the surface area and the grey matter volume of the pt are larger in the left compared to r ...	2011	21447349
genes expressed in specific areas of the human fetal cerebral cortex display distinct patterns of evolution.	the developmental mechanisms through which the cerebral cortex increased in size and complexity during primate evolution are essentially unknown. to uncover genetic networks active in the developing cerebral cortex, we combined three-dimensional reconstruction of human fetal brains at midgestation and whole genome expression profiling. this novel approach enabled transcriptional characterization of neurons from accurately defined cortical regions containing presumptive broca and wernicke languag ...	2011	21445258
rapid metabolic evolution in human prefrontal cortex.	human evolution is characterized by the rapid expansion of brain size and drastic increase in cognitive capabilities. it has long been suggested that these changes were accompanied by modifications of brain metabolism. indeed, human-specific changes on gene expression or amino acid sequence were reported for a number of metabolic genes, but actual metabolite measurements in humans and apes have remained scarce. here, we investigate concentrations of more than 100 metabolites in the prefrontal an ...	2011	21444806
diagnosis and prevalence of uterine leiomyomata in female chimpanzees (pan troglodytes).	uterine leiomyomata are common, affecting 70-80% of women between 30 and 50 years of age. leiomyomata have been reported for a variety of primate species, although prevalence rates and treatments have not been widely reported. the prevalence, diagnosis, and treatment of uterine leiomyomata in the alamogordo primate facility and the keeling center for comparative medicine and research were examined. uterine leiomyomata were diagnosed in 28.4% of chimpanzees with an average age at diagnosis of 30. ...	2011	21442632
diagnosis and treatment of degenerative joint disease in a captive male chimpanzee (pan troglodytes).	degenerative joint disease (djd), also known as osteoarthritis, has been well documented in aging populations of captive and free-ranging macaques; however, successful treatments for djd in nonhuman primates have not been published. published data on chimpanzees show little to no djd present in the wild, and there are no published reports of djd in captive chimpanzees. we report here the first documented case of djd of both the right and left femorotibial joints in a captive male chimpanzee. pro ...	2011	21439223
determination of hemoglobin a1c and fasting blood glucose reference intervals in captive chimpanzees (pan troglodytes).	type 2 diabetes mellitus (t2dm), reaching epidemic proportions in humans, has emerged as a disease in aging captive populations of adult chimpanzees; however, little information is available regarding t2dm in chimpanzees. our goals were to: (1) distinguish between normal, healthy chimpanzees and those with early (prediabetes) or advanced diabetes; (2) establish and compare the fasting (16 h) blood glucose reference range for chimpanzees at our facility with published reference ranges; and (3) es ...	2011	21439208
the use of the friedman test for pregnancy with chimpanzees.		1939	21433870
the time of ovulation in chimpanzees.		1938	21433772
concerning reproduction in the chimpanzee.		1937	21433749
death among geladas (theropithecus gelada): a broader perspective on mummified infants and primate thanatology.	despite intensive study in humans, responses to dying and death have been a neglected area of research in other social mammals, including nonhuman primates. two recent reports [anderson jr, gillies a, lock lc. 2010. pan thanatology. current biology 20:r349-r351; biro d, humle t, koops k, souse c, hayashi m, matsuzawa t. 2010. chimpanzee mothers at bossou, guinea carry the mummified remains of their dead infants. current biology 20:r351-r352] offered exciting new insights into behavior toward dyi ...	2011	21432869
redescription and resurrection of bertiella satyri (cestoda, anoplocephalidae) parasitizing the orangutan (pongo abelii) in indonesia.	the tapeworm species bertiella satyri from a semi-wild sumatran orangutan (pongo abelii: ponginae) is redescribed and the sequence of its 18s rdna is presented. the tapeworms parasitizing the genera pan, pongo, homo and hylobates from muséum national d'histoire naturelle, paris and from muséum d´histoire naturelle, genève are also presented. the validity of b. satyri is confirmed. b. satyri (bsa) differs from the most similar species bertiella studeri (bstu) in the following characteristics: (1) ...	2011	21424808
non-invasive genetic monitoring of wild central chimpanzees.	an assessment of population size and structure is an important first step in devising conservation and management plans for endangered species. many threatened animals are elusive, rare and live in habitats that prohibit directly counting individuals. for example, a well-founded estimate of the number of great apes currently living in the wild is lacking. developing methods to obtain accurate population estimates for these species is a priority for their conservation management. genotyping non-i ...	2011	21423611
hand biomechanics during simulated stone tool use.	human radial digits have derived features compared with apes, with long robust thumbs, relatively larger joint surfaces, and hypertrophic thenar muscles. here we test the hypothesis that these features evolved in the context of making and using stone tools, specifically for producing large gripping forces and for countering large joint contact stresses. we used portable force plates simulating early stone tools to: 1) document and compare the magnitude of external/internal forces and joint stres ...	2011	21420144
difficulties with the neurological assessment of humans following a chimpanzee attack.	chimpanzee attacks can be vicious, mutilating, and disabling if not fatal. stereotypically, the hands and face are targeted, and in male victims, genitalia are mutilated. the authors present a case highlighting the difficulties with early neurological assessment following such an attack. this 55-year-old woman was attacked by a 14-year-old chimpanzee. she suffered mutilation of both hands, severe midface bony, soft-tissue, and eye injuries, and scalp degloving. an emergency tracheotomy was perfo ...	2011	21417702
pathogenetic elements of hepatitis e and animal models of hev infection.	the pathogenesis of hev infection responsible for liver pathology and clinical disease is not well understood. the main target for the virus is the hepatocyte, where it replicates and is released to bile and gastrointestinal tract. viremia is regularly seen during the virus replication. the exact mechanism of hepatocytic death is uncertain. in experimentally infected non-human primates, the peak of liver lesions, measured by alanine aminotransferase activity elevation, is concordant with the vir ...	2011	21414365
elemental variation in the termite fishing of wild chimpanzees (pan troglodytes).	chimpanzee tool behaviours vary dramatically in their complexity and extent of geographical distribution. the use of tool sets with specific design features to gather termites extends across a large portion of central africa. detailed examination of the composition and uniformity of such complex tool tasks has the potential to advance our understanding of the cognitive capabilities of tool users and processes underlying the maintenance of technological skills. in this study, we examined variatio ...	2011	21411449
comparative evolutionary analyses of beta globin gene in eutherian, dinosaurian and neopterygii taxa.	comparative genomics and evolutionary analyses of conserved genes have enabled us to understand the complexity of genomes of closely related species. for example: ß-globin gene present in human hemoglobin is one such gene that has experienced many genetic changes in many related taxa and produced more than 600 variants. one of the variant, hbs causes sickle-cell anemia in humans but offers protection against severe malaria due to plasmodium falciparum. in the present study, we characterized and ...	2011	21406734
position and sequence conservation in amniota of polymorphic enhancer hs1.2 within the palindrome of igh 3'regulatory region.	the immunoglobulin heavy chain (igh) 3' regulatory region (3'rr), located at the 3' of the constant alpha gene, plays a crucial role in immunoglobulin production. in humans, there are 2 copies of the 3'rr, each composed of 4 main elements: 3 enhancers and a 20 bp tandem repeat. the single mouse 3'rr differs from the two human ones for the presence of 4 more regulative elements with the double copy of one enhancer at the border of a palindromic region.	2011	21406099
[leprosy in a chimpanzee].	leprosy is suspected to develop after a long period of latency following infection with mycobacterium leprae (m. leprae) during infancy, but definitive proof has been lacking. we found a rare case of leprosy in a chimpanzee (pan troglodytes) born in west africa (sierra leone) and brought to japan around 2 years of age. at 31, the ape started exhibiting pathognomic signs of leprosy. pathological diagnosis, skin smear, serum anti-phenolic glycolipid-i (pgl-i) antibody, and by pcr analysis demonstr ...	2011	21404593