PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Statistics, Nonparametric”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources

Clinical, haematological and biochemical findings in foals with neonatal Equine herpesvirus-1 infection compared with septic and premature foals.

A retrospective multicentre study comparing historical, clinical, haematological, acid-base and biochemical findings of foals with Equine herpesvirus-1 (EHV-1) infection, septicaemia or prematurity was performed to determine if early diagnosis of EHV-1 foals was possible. Fifty-three foals were studied and were assigned to one of 2 groups: herpes positive (n = 14) or herpes negative (n = 39). The latter group included 20 septic, 11 premature, and 8 premature and septic foals. The presence of herpes antigen was confirmed by immunoperoxidase histochemical staining of tissues from necropsied foals. A nonparametric statistical analysis followed by a backwards elimination logistic regression was performed to establish a model at a P value of <0.05. All herpes positive foals died, while 47% (9/19) of the septic foals survived. Based upon our analysis, herpes positive foals were more likely to have total white blood cell counts less than 3 x 10(9)/l and to be icteric as compared to the septic and premature foals. Despite profound hepatic necrosis in the herpes positive foals, liver enzymes were not elevated and were not significantly different from the controls.

Acid-Base Equilibrium↗

Absence of association between total heterotrophic and total coliform bacteria from a public water supply.

Heterotrophic plate counts (HPC) and total coliforms (TC) are two major microbial indicators that are used to monitor the potability of water. Although the presence of heterotrophs has been hypothesized to predict the presence of TC, there have been few documented reports. Intensive sampling of raw, treated effluent and distribution water from a public water supply serving 400,000 people provided an opportunity to study the relationship between these two indicator groups of bacteria. A total of 26,158 samples were analyzed, including 12,970 from 1986 and 13,188 from 1985. There were 13,429 samples from the distribution system, 5,524 from treatment effluents, and 7,205 from raw water. The associations between HPC and TC were made on both a hits-and-misses and numerical comparison (CFU per milliliter) basis. The periodicity of the two indicators was also analyzed to determine whether the presence of one group could predict the presence of the other. Atypical bacteria were also related to the presence of these two indicator bacteria. Venn diagrams and nonparametric statistics revealed the following correlation coefficients for HPC and TC for 1985 and 1986 combined: raw water r = 0.45, treated effluent r = 0.06, and distribution system r = 0.10. Atypical bacteria showed a similar relationship with HPC. There was no predictive periodicity for HPC and TC within +/- 10 days of isolation of each other. Therefore, in a 2-year survey of a public water supply, the presence of HPC had a low correlation coefficient with TC, as determined by hits-and-misses and numerical comparisons. The enumeration of one group was found to be independent of the other.

Enterobacteriaceae↗

National field evaluation of a defined substrate method for the simultaneous detection of total coliforms and Escherichia coli from drinking water: comparison with presence-absence techniques.

A defined substrate method was applied to drinking water to simultaneously enumerate total coliforms and total Escherichia coli directly from samples. After incubation at 35 degrees C for 24 h, the development of yellow in an initially colorless solution was specific for total coliforms; fluorescence at 366 nm in the same tube(s) or vessel demonstrated the presence of E. coli. No confirmatory or completed steps were necessary. Known as autoanalysis colilert (AC), this method was constituted as a presence-absence test and compared with the methods described in Standard Methods (SM) in the P-A format. Seven water utilities representing a wide geological and hydrological spectrum participated in the evaluation. A total of 702 split drinking water samples were analyzed. Of these, 358 were negative in both tests (SM- and AC-); 302 were positive (SM+ and AC+); and 42 were mixed (SM+ and AC-, 20; AC+ and SM-, 22). The overall agreement rate was 94%. Comparison of the SM and AC results by nonparametric statistics demonstrated no differences. Heterotrophic plate count bacteria exerted no discernible effect on the AC test. By subculture, each time the AC test was yellow, a total coliform was present; when the test was fluorescent, E. coli was isolated.

Colony Count, Microbial↗

Microeukaryote community patterns along an O2/H2S gradient in a supersulfidic anoxic fjord (Framvaren, Norway).

To resolve the fine-scale architecture of anoxic protistan communities, we conducted a cultivation-independent 18S rRNA survey in the superanoxic Framvaren Fjord in Norway. We generated three clone libraries along the steep O(2)/H(2)S gradient, using the multiple-primer approach. Of 1,100 clones analyzed, 753 proved to be high-quality protistan target sequences. These sequences were grouped into 92 phylotypes, which displayed high protistan diversity in the fjord (17 major eukaryotic phyla). Only a few were closely related to known taxa. Several sequences were dissimilar to all previously described sequences and occupied a basal position in the inferred phylogenies, suggesting that the sequences recovered were derived from novel, deeply divergent eukaryotes. We detected sequence clades with evolutionary importance (for example, clades in the euglenozoa) and clades that seem to be specifically adapted to anoxic environments, challenging the hypothesis that the global dispersal of protists is uniform. Moreover, with the detection of clones affiliated with jakobid flagellates, we present evidence that primitive descendants of early eukaryotes are present in this anoxic environment. To estimate sample coverage and phylotype richness, we used parametric and nonparametric statistical methods. The results show that although our data set is one of the largest published inventories, our sample missed a substantial proportion of the protistan diversity. Nevertheless, statistical and phylogenetic analyses of the three libraries revealed the fine-scale architecture of anoxic protistan communities, which may exhibit adaptation to different environmental conditions along the O(2)/H(2)S gradient.

Anaerobiosis↗

Age related alterations in the complexity of respiratory patterns.

The objective of this study is to investigate the relative contributions of maturation to the dynamic behavior of respiration during ontogeny in the neonate. The phrenic neurogram, an output of the respiratory network, was recorded during eupnea at three postnatal ages (3-7, 12-19, and 26-31 days) in decerebrate piglets. The inter-breath interval (IBI) time series were reconstructed from phrenic neurograms for each piglet and analyzed using the approximate entropy (ApEn) method. The mean values of the approximate entropy were high during the first seven days of the postnatal age [1.02 +/- 0.02 (standard error)] and decreased for the 12-19 days (0.67 +/- 0.008) and increased during subsequent maturation [the 26-31 days age group (0.92 +/- 0.015)]. The mean approximate entropy values for the 3-7 days age group was significantly different from those of the 12-19 days age groups (p < 0.05) using the nonparametric statistical test. The complexity values for the 3-7 days age group were slightly higher than those of the 26-31 days age group, but these differences were not statistically significant (p > 0.05). Therefore, these findings suggest that a decrease in the complexity values is unique to the 12-19 days age groups. This could be due to a reduction in the number of dendritic terminals per cell for the 12-19 days age groups. The results of these preliminary experiments also indicate that the behavior of the respiratory pattern generator in the neonate fluctuates during the early maturation period.

Aging↗

Right ventricular MR abnormalities in myotonic dystrophy and relationship with intracardiac electrophysiologic test findings: initial results.

PURPOSE: To prospectively determine whether a relationship exists between magnetic resonance (MR) imaging abnormalities of the right ventricle (RV) and intracardiac electrophysiologic (EP) test results in patients with myotonic dystrophy. MATERIALS AND METHODS: Conventional T1-weighted single-shot black-blood fast spin-echo and gradient-echo MR imaging of the heart was prospectively performed in 32 patients with myotonic dystrophy who required EP testing. Patients were divided into two groups according to EP test results: (a) inducible (n = 15), indicating inducible ventricular tachyarrhythmias, and (b) noninducible (n = 17). Morphologic and functional MR data were analyzed by two independent investigators. Nonparametric statistical methods and kappa statistics were used. RESULTS: No morphologic or functional abnormalities of the RV wall were observed in noninducible patients. Increased signal intensity of the RV wall, indicative of fatty replacement, was identified in 13 inducible patients. Myocardial thinning of the RV was observed in six inducible patients. An overlap of morphologically abnormal areas and areas of hypo- or dyskinesis were present in 11 inducible patients. RV outflow tract diameter was larger and RV ejection fraction was smaller in inducible patients than in noninducible patients, although differences were not significant. Interobserver agreement for MR findings was good (increased signal intensity: kappa = 0.87, P >.30 [pairwise Wilcoxon signed rank test]; myocardial thinning: kappa = 0.87, P >.30; hypo- or dyskinesis: kappa = 1.00, P >.99). There was a strong relationship between MR abnormalities and inducibility during EP testing (increased signal intensity, P <.001; myocardial thinning, P <.01; hypo- or dyskinesis, P <.01). CONCLUSION: The relationship between MR morphologic and functional RV abnormalities and EP testing suggests potential for the use of MR imaging as a noninvasive method to estimate the individual risk of arrhythmia in patients with myotonic dystrophy.

Adult↗

Björk-Shiley convexoconcave valves: susceptibility artifacts at brain MR imaging and mechanical valve fractures.

PURPOSE: To assess the relationship between heart valve history and susceptibility artifacts at magnetic resonance (MR) imaging of the brain in patients with Björk-Shiley convexoconcave (BSCC) valves. MATERIALS AND METHODS: MR images of the brain were obtained in 58 patients with prosthetic heart valves: 20 patients had BSCC valve replacements, and 38 had other types of heart valves. Two experienced neuroradiologists determined the presence or absence of susceptibility artifacts in a consensus reading. Artifacts were defined as characteristic black spots that were visible on T2*-weighted gradient-echo MR images. The statuses of the 20 explanted BSCC valves-specifically, whether they were intact or had an outlet strut fracture (OSF) or a single-leg fracture (SLF)-had been determined earlier. Number of artifacts seen at brain MR imaging was correlated with explanted valve status, and differences were analyzed with nonparametric statistical tests. RESULTS: Significantly more patients with BSCC valves (17 [85%] of 20 patients) than patients with other types of prosthetic valves (18 [47%] of 38 patients) had susceptibility artifacts at MR imaging (P =.005). BSCC valve OSFs were associated with a significantly higher number of artifacts than were intact BSCC valves (P =.01). No significant relationship between SLF and number of artifacts was observed. CONCLUSION: Susceptibility artifacts at brain MR imaging are not restricted to patients with BSCC valves. These artifacts can be seen on images obtained in patients with various other types of fractured and intact prosthetic heart valves.

Adult↗

Comparison of Z-axis automatic tube current modulation technique with fixed tube current CT scanning of abdomen and pelvis.

PURPOSE: To compare image quality, diagnostic acceptability, and radiation exposure associated with 16-section multi-detector row computed tomographic (CT) examinations of abdomen and pelvis performed with z-axis modulation technique of automatic tube current modulation and with manual selection of fixed tube current. MATERIALS AND METHODS: Sixty-two consecutive subjects (mean age, 60 years; age range, 19-84 years; male-to-female ratio, 35:27) underwent follow-up CT of abdomen and pelvis with use of a 16-section multi-detector row scanner and z-axis modulation technique (10.5-12.0-HU noise index, 10-380 mA). Scanning parameters included 140 kVp, 0.5-1.0-second gantry rotation time, 0.938:1 beam pitch, and 5-mm reconstructed section thickness. For each subject, images obtained with z-axis modulation were compared with previous images obtained with fixed tube current (200-300 mA) and with other parameters identical. Images were compared for noise and diagnostic acceptability by two subspecialty radiologists using a five-point scale (1, unacceptable; 3, acceptable; 5, excellent) at five levels: upper liver at diaphragm, porta hepatis, right kidney hilum, iliac crest, and upper margin of acetabulum. Tube current and gantry rotation time used for acquisitions at these levels were recorded. Data were analyzed with parametric and nonparametric statistical tests. RESULTS: Although no significant differences were found (P =.34), images acquired with z-axis modulation at the levels of the upper liver (diaphragm) and acetabulum had a higher noise and lower diagnostic quality, compared with images acquired with fixed tube current. Compared with fixed tube current, z-axis modulation resulted in tube current-time product reduction in 54 (87%) of 62 examinations (mean reduction, 71.2 mAs) and increase in eight (13%) (mean increase, 17.0 mAs). CONCLUSION: Compared with manually selected fixed tube current, z-axis automatic tube current modulation resulted in reduced tube current-time product and similar image noise and diagnostic acceptability at CT of abdomen and pelvis.

Abdominal Neoplasms↗

MR evaluation of the glomerular homing of magnetically labeled mesenchymal stem cells in a rat model of nephropathy.

PURPOSE: To assess renal glomerular homing of intravenously injected superparamagnetic iron oxide (SPIO)-labeled mesenchymal stem cells (MSCs) at in vivo and ex vivo magnetic resonance (MR) imaging in an experimental rat model of mesangiolysis. MATERIALS AND METHODS: Animal procedures were performed in accordance with protocols approved by Institutional Animal Care and Use Committee. Fourteen rats were divided into two groups: one pathologic (n = 10), with persistent mesangiolysis following simultaneous injection of OX-7 monoclonal antibody and puromycin aminonucleoside in which 10(7) SPIO- and DiI-labeled MSCs were injected, and one control (n = 4). In vivo and ex vivo MR imaging examinations were performed with 4.7- and 9.4-T spectrometers, respectively, and T2*-weighted sequences. In vivo signal intensity variations were measured in the liver and kidney before and 6 days after MSC injection. Intrarenal signal intensity variations were correlated with histopathologic data by means of colocalization of DiI fluorescence, alpha-actin, and Prussian blue stain-positive cells. Histologic differences between the glomerular homing of MSCs in different kidney portions were correlated to the areas of MR signal intensity decrease with nonparametric statistical tests. RESULTS: On in vivo images, signal intensity measurements of pathologic kidneys following MSC injection did not show any signal intensity decrease (P = .7), whereas a 34% +/- 14 (mean +/- standard deviation) signal intensity decrease was observed in the liver (P < .01), where a substantial number of labeled cells were trapped. On ex vivo images, pathologic kidneys showed focal cortical (glomerular) areas of signal intensity loss, which was absent in controls. The areas of low signal intensity correlated well with alpha-actin and Prussian blue stain- and DiI-positive areas (P < .01), which indicates that MSCs specifically home to injured tissue. No MSCs were detected in the kidneys of control animals. CONCLUSION: Intravenously injected MSCs specifically home to focal areas of glomerular damage and can be detected at ex vivo MR imaging.

Animals↗

Upper abdominal lymph nodes: criteria for normal size determined with CT.

Reports of the upper limits of normal for lymph node size at abdominal computed tomography have varied from 6 to 20 mm. Establishment of an upper limit for node size by specific location, analogous to that which has been reported for mediastinal lymph nodes, was sought. Short-axis diameters of the lymph nodes were measured in 130 patients who were not likely to have enlarged abdominal lymph nodes. Seven locations were defined, and the largest nodal measurement for each was recorded. Histographic analysis and nonparametric statistical methods were used to determine threshold values for the maximum node size in each region. The upper limits of normal by location were as follows: retrocrural space, 6 mm; paracardiac, 8 mm; gastrohepatic ligament, 8 mm; upper paraaortic region, 9 mm; portacaval space, 10 mm; porta hepatis, 7 mm; and lower paraaortic region, 11 mm. Lower paraaortic lymph nodes larger than 11 mm by short-axis measurement are abnormal. In other locations, nodes smaller than 1 cm may be abnormal if the determined thresholds are exceeded.

Adolescent↗

Aberrant baroreceptor mechanotransduction in adult Dahl rats on low-salt diet.

Single fiber, regularly discharging baroreceptors (n = 118) from adult Dahl salt-sensitive (DS) and salt-resistant (DR) rats on a low-salt diet were studied using an in vitro aortic arch-aortic nerve preparation. Pressure thresholds (Pth) and suprathreshold pressure sensitivities (Sth) were determined from responses to slow ramps of pressure. Pressure-diameter relationships measured in each rat were used to transform Pth and Sth values to their mechanical equivalents in terms of aortic wall strain. DS and DR ages were not different (approximately 50 wk). Despite the low-salt diet, DS tail systolic blood pressures were significantly higher than DR by approximately 25 mmHg. Pth averaged 84 mmHg in DR and 97 mmHg in DS. Sth values were similar in DR and DS (average 1.44 and 1.39 spikes.s-1.mmHg-1 in DR and DS, respectively). Increased variance of baroreceptor properties of DS over DR was a prominent finding and necessitated use of nonparametric statistics. The cumulative distribution of Pth values of DS was significantly different from DR, but Sth values were similar. Thus baroreceptor pressure set points are altered in adult DS, but pressure sensitivity per se is not. The differences in pressure parameters were not eliminated by conversion to their mechanical equivalents. Correlation analysis found only weak relationships between Pth and blood pressure for DS and DR (r less than 0.40). Thus in contrast to previous studies in the spontaneously hypertensive rat model, baroreceptors in adult DS on low salt are characterized by elevated variability and a weaker than expected correlation to the prevailing blood pressure in the animal.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

Long-term dysfunctions of neural stereoscopic mechanisms after unilateral extraocular muscle proprioceptive deafferentation.

1. Neural correlates of the permanent deficits in depth perception that occur when extraocular muscle proprioceptive (EMP) afferents are interrupted unilaterally in kittens were investigated by performing extracellular recordings in the primary visual cortex (area 17) in adulthood. Unilateral section of the ophthalmic branch of the trigeminal nerve (V1 nerve) were performed in 11 cats when they were between 5 and 12 weeks of age (uni-V1 group). Electrophysiological results were compared with those obtained in 17 normal adult cats (control group). 2. Binocular interactions were assessed by testing the sensitivity of cortical neurons to dichoptic presentations of moving sine-wave gratings whose interocular positional phase relationship was randomly varied. The amplitude modulation between the minimum and the maximum binocular responses defined the dynamic range. The degree of binocular suppression or facilitation was assessed by comparing these binocular response limits with the optimal monocular responses evoked through either eye at the best spatial frequency. The variability of both monocular and binocular responses was estimated by using the variation coefficient. 3. In uni-V1 cats, both the dynamic range and the degree of binocular suppression were significantly less pronounced than in controls, whereas binocular facilitation was not affected. The variability of the binocular responses was significantly increased, unlike monocular responses, whose variability was similar to control values. 4. From Fourier analysis of the poststimulus time histograms, two clear-cut categories of cells emerged that were differentially affected in the uni-V1 group. The "modulated" cells showed significantly less binocular suppression than in controls, and the "unmodulated" cells had binocular responses that were significantly more variable than in controls. Results from "simple" cells were similar to those of modulated cells, and results from "complex" cells were similar to those of unmodulated cells. However, in the unmodulated population, which was composed of both simple and complex cells, it was shown that the increase of variability was due to that of complex cells. 5. A nonparametric statistical test was applied on the interocular phase shift tuning curves to determine the minimum stimulus change necessary to elicit a significant change in the neural response. Two categories of cells were determined: the "discriminative" cells (80% in controls but 45% in uni-V1 cats) combined pronounced binocular suppression and dynamic range with relatively low variability. The reverse was true in the case of "nondiscriminative" cells (20% in controls and 55% in uni-V1 cats). 6. In uni-V1 cats, about half of the cells were monocularly activated.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗

Utility of the blood for gene expression profiling and biomarker discovery in chronic fatigue syndrome.

Chronic fatigue syndrome (CFS) is a debilitating illness lacking consistent anatomic lesions and eluding conventional laboratory diagnosis. Demonstration of the utility of the blood for gene expression profiling and biomarker discovery would have implications into the pathophysiology of CFS. The objective of this study was to determine if gene expression profiles of peripheral blood mononuclear cells (PMBCs) could distinguish between subjects with CFS and healthy controls. Total RNA from PBMCs of five CFS cases and seventeen controls was labeled and hybridized to 1764 genes on filter arrays. Gene intensity values were analyzed by various classification algorithms and nonparametric statistical methods. The classification algorithms grouped the majority of the CFS cases together, and distinguished them from the healthy controls. Eight genes were differentially expressed in both an age-matched case-control analysis and when comparing all CFS cases to all controls. Several of the differentially expressed genes are associated with immunologic functions (e.g., CMRF35 antigen, IL-8, HD protein) and implicate immune dysfunction in the pathophysiology of CFS. These results successfully demonstrate the utility of the blood for gene expression profiling to distinguish subjects with CFS from healthy controls and for identifying genes that could serve as CFS biomarkers.

Adult↗

Psychopathological assessment and diagnosis. A study of specificity of single symptoms.

The importance of single symptoms in the diagnostic process has not been adequately studied, mainly because of the complexity of the information involved. The aim of the present study is to investigate the interconnection between psychopathological assessment and diagnostic classification, with the aid of a nonparametric, inductive pattern recognition method. Using the concept of inductive logic and a theory of inductive knowledge acquisition, a model has been developed to describe psychopathological assessment and diagnostic classification. Based on a comprehensive psychopathological assessment in 837 patients with 14 different diagnoses, classification values were calculated for specific symptoms in different diagnostic groups. Furthermore, nonparametric statistical procedures have advantages over discriminant analytic approaches: more information is utilized in differentiating the groups and differentiations can be made between more groups, whereby the rate of correctly classified cases is comparable with discriminant analytic approaches. The pattern recognition method appears to illustrate the multidimensional, medical decision-making in a comprehensible way.

Adult↗

A folate-dependent metabolite in amniotic fluid from pregnancies with normal or trisomy 21 chromosomes.

INTRODUCTION: Previous studies have given conflicting results as to whether or not folate metabolism is altered in Down syndrome. Folate is necessary to facilitate metabolism of one-carbon units. Folate accepts one-carbon units from one-carbon unit donors, including formiminoglutamate (FIGLU). Folate deficiency leads to accumulation of FIGLU and impairment of one-carbon unit metabolism. FIGLU is a functional measure of folate deficiency. MATERIALS AND METHODS: Archived anonymized amniotic fluid specimens were obtained from normal pregnancies and those with Down syndrome. Gas liquid chromatography/mass spectrometry was used to quantitate FIGLU, which is elevated in folate deficiency. A tetra-deuterated FIGLU was used as a standard, and single-ion monitoring was performed. Nonparametric statistical analysis was performed with the Mann-Whitney U test. RESULTS: FIGLU was significantly lower in pregnancies with Down syndrome. The median FIGLU level was 0.9 micromol/l in amniotic fluid from fetuses with Down syndrome. The median FIGLU level was 1.3 in amniotic fluid from control fetuses. This difference was statistically significant (p = 0.009). No statistically significant differences were found with histidine or glutamate. DISCUSSION: There was no evidence of folate deficiency. FIGLU was decreased, not increased. Decreased FIGLU might result from accelerated activity of one or more genes on chromosome 21, by a gene dosage effect. Genes which might explain the reduced FIGLU include one which degrades FIGLU (glutamate formiminotransferase-cyclodeaminase), one which participates in purine synthesis, and one which degrades homocysteine (cystathionine-beta-synthase).

Amniocentesis↗

Problems and pitfalls in treatment trials of multiple sclerosis.

In MS only the results of a properly randomized, double-blind, placebo-controlled trial can provide adequate evidence of efficacy. When therapy cannot be blinded one can conclude only that a therapeutic regimen which includes the test agent or procedure differs from one without it, but not that the difference is necessarily due to the agent. Measure of treatment effect in MS requires a standardized schema of assessing neurologic dysfunction due to the disease as the criterion for change (better, same, worse). Quantitation of impairment as measured by such scales can be compared between regimens only by means of nonparametric statistical tests, since no scale in use is a true numerical (equal-interval, additive, multiplicative) scale. The specific scale employed is not irrelevant; in the ACTH study of acute bouts the agent was concluded only to 'hasten improvement' with one scale, but to be an effective treatment with another.

Adolescent↗

The affected-pedigree-member method: power to detect linkage.

The affected-pedigree-member (APM) method of linkage analysis is a nonparametric statistic for testing for nonindependent segregation of a marker to affected members of a pedigree. We present here results of a simulation study evaluating the power of the APM method to detect linkage. We have systematically explored, by computer simulation, the effect of a variety of factors on the power to detect linkage using the single-locus APM statistic. These factors include mode of inheritance, marker polymorphism, the distance between marker and disease, phenocopy rate, heterogeneity, and misspecified marker allele frequencies. We also evaluated the relative power obtained under fixed-structure sampling and sequential sampling. For a dominant disease, sequential sampling led to increased power as compared to fixed-structure sampling, while for a recessive disease, there was no clear advantage in sampling beyond nuclear families.

Alleles↗

Dermatoglyphic patterns and pattern intensities of Callicebus (primates: Cebidae): description and comparison of three species.

The palmar and plantar dermatoglyphic pattern types are described for three species of Callicebus (18 Callicebus moloch, 18 Callicebus torquatus and 7 Callicebus personatus). Mean pattern intensities (API) were calculated for each of seven areas of the palm and nine areas of the sole, and a summed mean total pattern intensity (TPI) for each volar surface. Nonparametric statistical testing showed no significant bilateral asymmetry or sexual dimorphism in pattern intensities. Pattern profiles describing the relative relationships of API values across the left palm and sole are presented. The profiles typical of the genus closely resemble those of Aotus and Saimiri. Significant interspecific differences, particularly in the plantar API values, were detected. The results are discussed with reference to the present taxonomic classification of the species of Callicebus and their postulated evolutionary history.

Animals↗