Physical working capacity of male inhabitants from Upper Surinam

Aerobic power tests were carried out on twenty male Bushnegroes, as part of a medical survey in two villages on the Upper Marowijn river in the interior of Surinam (South America).The subjects were submitted to a discontinuous series of increasing submaximal loads by means of a bicycle ergometer. Heart rate and oxygen uptake were measured at each load. The maximum oxygen uptake was estimated according to Lange Andersen et al. (1971) and used as an index for the physical working capacity.The mean aerobic power of the Bushnegroes was 35 ml O₂/min/kg body weight or 2·2 I O₂/min per individual. These values are low in comparison with results obtained from professional forest workers in Surinam or in other countries.     

Calathea maasiorum (Marantaceae), a new species from French Guiana and Surinam

Calathea maasiorum from French Guiana and Surinam is described as new. It belongs toCalathea sectionBreviscapus Bentham. The foliage is patterned with a light green band along the midrib above. This new species has previously been confused withC. cyclophora Baker from Amazonian Colombia, Brazil, Venezuela, and Guyana but it is distinguished fromC. cyclophora by the absence of bracteoles, the elliptic to obovate leaf blade, and shorter (1–2 cm long) bracts.     

Developmental abnormalities of the permanent dentition in prehistoric Ohio Valley Amerindians

The frequencies of developmental abnormalities in size, shape, number of teeth, and enamel formation are presented for a sample of 389 prehistoric Ohio Valley Amerindians from the following cultural complexes: Glacial Kame, Adena, Ohio Hopewell, Cole, Fort Ancient, and Erie (Whittlesey Focus). In addition, the magnitude of fluctuating asymmetry is determined for each tooth and for individuals of these groups. Tests of association indicate complexes with Late Diffuse economic adaptations (Glacial Kame, Adena, Hopewell) exhibit significantly higher frequencies of numerical abnormalities of M₃ and M³ enamel pearls, while Late Focal complexes (Cole, Fort Ancient, Erie) exhibit a higher frequency of severe, general linear enamel hypoplasia. The magnitude of fluctuating asymmetry is, however, generally the same in the Late Diffuse and Late Focal groups. The occurrence of two rare abnormalities with large genetic components, essentially limited to one Hopewell and one Adena mound, raises the possibility that the individuals interred in these mounds are biologically related. Since it is widely held that mound burials represent a status class of the population, it is likely that the Late Diffuse sample is biased in favor of a number of highly select population segments each of which contains biologically related individuals. Accordingly, the lower frequency of severe, general linear enamel hypoplasia in Late Diffuse groups is hypothesized as the result of the more advantageous circumstances expected for high status individuals, and the higher frequencies of numerical abnormalities of M₃ and M³ enamel pearls are hypothesized primarily as the result of mitigated selection on masticatory complex integration, and/or a biased sample. Comparisons with the deciduous dentition show the permanent teeth exhibit higher frequencies of developmental abnormalities. This result is explicable in terms of the more favorable developmental environment of the primary teeth, or a stronger developmental canalization.     

Amazonian Amerindians exhibit high variability of KIR profiles

Natural killer cell immunoglobulin-like receptors (KIRs) mediate cell lysis through the recognition of human leukocyte antigen class I complexes in target cells, playing an important role in innate immune response. In this context, disease-based selective pressures could be relevant, leaving signatures detected by population studies. However, most population studies on KIR variability have focused on Europe and Asia, while Americas, Oceania, and Africa remain poorly studied. The aim of this study was to analyze the variability of KIR genes in Amerindian tribes from the Amazon region to infer about their evolutionary history. KIR profiles were estimated in 40 individuals from six Amazonian Amerindian tribes using single specific primer polymerase chain reaction. Twenty-five different profiles were identified, and surprisingly, the haplogroup A frequency was the lowest observed in human populations (16%). Results showed also that KIR variability was higher in this group in contrast to Venezuelan Amerindians. Principal components analysis evidenced that Amerindians formed a separated group from other worldwide populations and showed a higher intraethnic differentiation in comparison to other ethnic groups. Such pattern may reflect small effective size and intense genetic drift. However, because of the role of KIR in immune response, selective pressures cannot be entirely ruled out.     

Locomotor behavior,body size,and comparative ecology of seven Surinam monkeys

The locomotor behavior, of seven sympatric species of New World monkeys—Saguinus midas midas, Saimiri sciureus, Pithecia pithecia, Chiropotes satanas chiropotes, Cebus apella apella, Alouatta seniculus, and Ateles paniscus panisus—was studied at the Raleighvallen-Voltzberg Nature Reserve in Central Surinam. This paper examines the way in which locomotor behavior is related to body size and to ecological parameters such as forest stratification, forest type, and diet. Locomotor behavior is clearly related to the size of the species; with increasing size, the amount of climbing increases and the amount of leaping decreases. In general, larger monkeys use larger arboreal supports; however, Saguinus midas midas uses relatively larger, and Ateles paniscus paniscus relatively smaller supports than expected from body size alone. Leaping is associated with use of the forest understory and with use of liane forest. Other types of locomotion are associated with main canopy use in a variety of forest types. There are no consistent associations between diet and either locomotor behavior or forest utilization; rather, monkeys with similar diets show locomotor and habitat differentiation.     

Three new species of the genus Leucon Kröyer, 1846 (Crustacea: Cumacea) from the continental slope off Surinam

Three new, and apparently closely related, species of cumacean are described from the continental slope off Surinam: Leucon turgidulus sp.nov. from about 500 m depth, L. medius sp.nov. from about 1000m and about 1500m, and L.jonesi sp.nov from about 1500m and about 2000m. The species have not been found in extensive collections from other parts of the deep Atlantic. Leucon pallidus G.O. Sars, 1865 is the most closely comparable of the previously known members of the genus.     

Species Diversity of Edible Plants Grown in Homegardens of Chibchan Amerindians from Costa Rica

We studied edible crop species diversity at homegardens of two Chibchan Amerindian Reserves in Costa Rica: Talamanca and Coto Brus. We visited six settlements at Talamanca and five at Coto Brus. We recorded the number of edible crop species growing homegardens; we found 46 edible plant species at Talamanca and 27 at Coto Brus. The mean number of species per homegarden ranged between 3.80 and 6.80 at Coto Brus and 4.50 and 8.63 at Talamanca. We identified species that were common, i.e., found in most households and all settlements, and species that were rare. We estimated diversity indexes for each settlement and each Reserve. Also, we compared crop species composition between both Reserves and among settlements within each Reserve, using the Jaccard coefficient of community similarity. Settlements from the same Reserve were grouped together, with the exception of Villa Palacios from the Coto Brus Reserve.     

Blood pressure response to low level static contractions

The present study re-examines the 15% MVC concept, i.e. the existence of a circulatory steady-state in low intensity static contractions below 15% of maximal voluntary contraction (MVC). Mean arterial blood pressure was studied during static endurance contractions of the elbow flexor and extensor muscles at forces corresponding to 10% and 40% MVC. Mean value for endurance time at 10% MVC was significantly longer for flexion [111.3 (SD 56.1) min] than for extension [18.1 (SD 7.5) min; n = 7]. At 40% MVC the difference in mean endurance time disappeared [2.3 (SD 0.7) min for elbow flexion and 2.3 (SD 0.7) min for elbow extension]. Mean arterial blood pressure exhibited a continuous and progressive increase during the 10% MVC contractions indicating that the 15% MVC concept would not appear to be valid. The terminal blood pressure value recorded at the point of exhaustion in the 10% MVC elbow extension experiment was identical to the peak pressure attained in the 40% MVC contraction. For the elbow flexors the terminal pressor response was slightly but significantly lower at 10% MVC [122.3 (SD 10.1) mmHg, 16.3 (SD 1.4) kPa] in comparison with 40% MVC [130.4 (SD 7.4) mmHg, 17.4 (SD 1.0) kPa]. When the circulation to the muscles was arrested just prior to the cessation of the contraction, blood pressure only partly recovered and remained elevated for as long as the occlusion persisted, indicating the level of pressure-raising muscle chemoreflexes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Uniparental genetic markers in South Amerindians

A comprehensive review of uniparental systems in South Amerindians was undertaken. Variability in the Y-chromosome haplogroups were assessed in 68 populations and 1,814 individuals whereas that of Y-STR markers was assessed in 29 populations and 590 subjects. Variability in the mitochondrial DNA (mtDNA) haplogroup was examined in 108 populations and 6,697 persons, and sequencing studies used either the complete mtDNA genome or the highly variable segments 1 and 2. The diversity of the markers made it difficult to establish a general picture of Y-chromosome variability in the populations studied. However, haplogroup Q1a3a* was almost always the most prevalent whereas Q1a3* occurred equally in all regions, which suggested its prevalence among the early colonizers. The STR allele frequencies were used to derive a possible ancient Native American Q-clade chromosome haplotype and five of six STR loci showed significant geographic variation. Geographic and linguistic factors moderately influenced the mtDNA distributions (6% and 7%, respectively) and mtDNA haplogroups A and D correlated positively and negatively, respectively, with latitude. The data analyzed here provide rich material for understanding the biological history of South Amerindians and can serve as a basis for comparative studies involving other types of data, such as cultural data.     

Size and morphology of the permanent dentition in prehistoric Ohio Valley Amerindians.

Metric and morphological characterizations of the permanent teeth from a total of 155 prehistoric Amerindians are presented. The individuals represent samples from three Ohio Valley burial complexes (considered together as the Late Diffuse group): Glacial Kame, Adena and Ohio Hopewell. Metric data include common measures of central tendency and dispersion. From these measures estimates and analyses of the magnitude of sexual dimorphism and relative variability are presented as well as analyses of the patterns of these estimates. Forty morphological characters are also tabulated. The results indicate a number of provisional hypotheses: the generally larger tooth size of the Late Archaic Indian Knoll when compared to the Late Diffuse groups is consistent with the hypothesis of mitigated selective pressures in more technologically advanced groups; although tooth size is smaller in the Late Diffuse groups, dental morphology is as complex, or more so when compared to the Indian Knoll group. Since morphology and size do not covary exactly the biocultural forces resulting in smaller tooth size do not seem to act as strongly on dental morphology; odontological differences within the Late Diffuse arise primarily between the Glacial Kame-Adena and the Ohio Hopewell. These differences correspond to major biocultural changes in this area; although provisional hypotheses concerning odontological variability are erected, hypotheses concerning evolutionary trends must await the discovery of evolving lineages within these groups; similarities are noted among all compared groups including the pattern and magnitude of sexual dimorphism and relative variability. These parameters may be similar for all eastern Amerindians during this period; finally, the morphology of the deciduous dentition, which generally predicts that of the permanent teeth, is found to be less complex than the permanent teeth. This may be the result of a selective disadvantage for the individuals in the deciduous dentition sample which is reflected in the dentition.     

A descriptive and comparative study of the deciduous dentition of prehistoric Ohio Valley Amerindians

The deciduous dentition of 58 individuals from groups of prehistoric Ohio Valley Amerindians (2,000 B.C.-1,600 A.D.) was measured for antero-posterior and bucco-lingual dimensions and scored for morphological characteristics and macroscopic pathology. Only five dimensions of the posterior teeth and the frequency of severe linear enamel hypoplasia showed significant differences in the groups. In all cases focal agriculturalists exhibited smaller teeth and a higher frequency of severe linear enamel hypoplasia. These findings are explained as the result of changing diet and food preparation techniques, and/or sampling bias in the earlier burial cult groups where primarily higher status individuals may be the representatives. Comparison of metric and morphological characteristics of the deciduous dentition in the prehistoric Amerindians and roughly contemporaneous European groups indicates morphological characteristics are the better means of discrimination.     

Blood pressure and heart rate during rest-exercise and exercise-rest transitions

The transients of mean arterial blood pressure (BPa) and heart rate (fc) during rest-exercise and exercise-rest transitions have been studied in six healthy sport students. After 5 min of rest in an upright position on a cycle ergometer they exercised for 15 min and remained seated for a further 5 min. The subjects exercised at four different constant intensities (40 W, 80 W, 120 W, 160 W) in random order separated by at least 24 h. The BPa was determined by a noninvasive and continuous method. During the first minute of exercise, three phases of response could be distinguished, with the first two showing no clear relationship to intensity. Phase 1 consisted of simultaneous increases in both fc and BP during the first 6 s. In phase 2, BPa decreased while fc continued to increase. During phase 3, BPa and fc approximated constant values or a linear increase. Both parameters showed no comparable intensity-independent reactions during the off-transients. In conclusion, during the first 15 s of rest-exercise transitions there seems to be a fast and uniform cardiovascular drive which overrode other influences on fc.     

Genetic variation of cassava (Manihot esculenta Crantz) cultivated by Chibchan Amerindians of Costa Rica

This study focuses on the genetic diversity of the cassava (Manihot esculenta Crantz) grown by the Chibchan Amerindians of Costa Rica. The authors collected cassava in various locations within two Amerindian Reserves: Talamanca, inhabited by Cabecares and Bribris, and Coto Brus, inhabited by Guaymi. Through the use of isozyme electrophoretic techniques we found variation for six out of nine systems analyzed, namely DIA, EST, IDH, MDH, PGI, and SKD. No variation was found in ADH, PGD, and PGM systems. We analyzed the distribution of variation within and between the reserves, and found most of the variation occurred within reserves (Gst = 0.1084). Only low levels of genetic differentiation were found between reserves (Nei’s genetic distance = 0.0088). The high levels of genetic variation within reserves that we found concur with results of previous studies on cassava grown by South American Amerindians and farmers. The role of the breeding system of cassava and the agricultural practices of Amerindians in the maintenance of high levels of genetic diversity are discussed.     

The Life Cycle, Ecological, and Economic Determinants of Spousal Leisure Sharing: Panel Estimations from Tawahka Amerindians, Honduras

Researchers have used the amount of leisure as a yardstick to proxy for quality of life, but so far they have paid scant attention to the quality of leisure. Here I use spousal leisure sharing to proxy for quality of leisure and, by implication, for quality of life. I draw on life-cycle perspective, price theory, and on human ecology to frame hypotheses about the determinants of spousal leisure sharing. Drawing on longitudinal information collected over 2 years from 32 households in two villages of Tawahka Amerindians, a horticultural and foraging society in the tropical rain forest of eastern Honduras, I estimate the simultaneous effects of age and age squared, cash income, and climatic/seasonal variables on the amount of time spouses spend together in leisure. Analysis using different random and fixed-effect multivariate logit models suggests that (1) life-cycle determinants play a strong role in spousal leisure sharing and (2) neither climate/seasonal variables nor income correlate with spousal leisure sharing. As is true among couples in the United States, among Tawahka couples a change in the income of either spouse has a small effect on the amount of leisure shared by spouses. I find no evidence that economic development erodes spousal leisure sharing or that couples exhibit fissure in their pursuit of a common goal of leisure sharing.     

The technique of detecting systolic and diastolic pressure from the transducer output of a PC-based blood pressure monitoring system

A pressure to voltage transducer is used along with a cuff, in a PC-based blood pressure and pulse rate monitoring system for human body. During the blood pressure measurement cycle, the output voltage of the pressure to voltage transducer is recorded digitally using a data acquisition system. The recorded data are then analyzed using software routines to determine the blood pressure and pulse rate of the person under test. However, it is difficult to identify the points of systole and diastole correctly from the recorded data. This paper presents the technique that may be used to determine the systolic and diastolic pressure from the collected data.     

Blood pressure and thermal responses to whole body cold exposure in mildly hypertensive subjects

Six mildly hypertensive subjects were exposed three times to −15 °C (wind 3.5 m/s) for 15 min. After an initial exposure for familiarisation, second and third exposures were arranged in a random double blind, crossover fashion after a week's ingestion of hydrochlorothiazide or placebo. Cold decreased skin temperatures, but not rectal temperature. Blood pressure increased 30/20 mmHg and heart rate decreased 12 beats/min by cold. Blood pressure seems to react in 3 min to changes in ambient temperature. The skin temperatures of uncovered body parts were apparently responsible for that. Hydrochlorothiazide did not affect either cardiovascular or thermal responses in cold.     

Blood pressure changes validate phase related external suction, a controlled method for stimulation of human baroreceptors

Phase related external suction (PRES), a new controlled method for manipulating activity in human baroreceptors, applies precisely timed bursts of suction and pressure within the cardiac cycle through an external neck cuff. Seven healthy adult men participated in 32 pseudo-random trials of baroreceptor stimulation and inhibition. Blood pressure was assessed both intra-arterially and with a noninvasive device. In the present study, PRES baroreceptor stimulation elicited invasively measured blood pressure decreases of about 2.5 mmHg (0.33 kPa) and heart rate decreases of about 5 beats · min^–1, while baroreceptor inhibition increased invasively measured blood pressure by about 1.5 mmHg (0.20 kPa) and heart rate about 2.5 beats · min^–1. It was concluded that PRES is an effective method for baroreceptor manipulation with weaker size effect but better control of nonspecific factors in human subjects than other baroreceptor manipulation techniques. The noninvasive blood pressure measurement device was less sensitive to experimental variation than was the invasive device.     

High KIR diversity in Amerindians is maintained using few gene-content haplotypes

Interaction between killer cell immunoglobulin-like receptors (KIR) and cognate HLA class I ligands influences the innate and adaptive immune response to infection. The KIR family varies in gene content and allelic polymorphism, thereby, distinguishing individuals and populations. KIR gene content was determined for 230 individuals from three Amerindian tribes from Venezuela: the Yucpa, Bari and Warao. Gene-content haplotypes could be assigned to 212 individuals (92%) because only five different haplotypes were present—group A and four group B. Six different haplotype combinations accounted for >80% of individuals. Each tribe has distinctive genotype frequencies. Despite few haplotypes, all 14 KIR genes are at high frequency in the three tribes, with the exception of 2DS3. Each population has an even frequency of group A and B haplotypes. Allele-level analysis of 3DL1/S1 distinguished five group A haplotypes and six group B haplotypes. The high frequency and divergence of the KIR haplotypes in the Amerindian tribes provide greater KIR diversity than is present in many larger populations. An extreme case being the Yucpa, for whom two gene-content haplotypes account for >90% of the population. These comprise the group A haplotype and a group B haplotype containing all the KIR genes, except 2DS3, that typify the group B haplotypes. Here is clear evidence for balancing selection on the KIR system and the biological importance of both A and B haplotypes for the survival of human populations.Electronic Supplementary Material Supplementary material is available for this article at     

Genetic and sociocultural components of high blood pressure

The cardiovascular diseases exert widely differing contributions to the total burden of mortality and morbidity in extant human populations. To a large extent these differences are a reflection of the variable distribution of specific antecedent risk factors. For one such risk factor, blood pressure, there is considerable variability in its distribution between different ethnic groups, especially between traditional and nontraditional societies. Intensive epidemiological studies in Western societies, together with a number of cross-cultural comparisons, suggest that the major determinants of high blood pressure are likely to be a constellation of sociocultural factors, with genetic determination being limited to the interaction between genotype and environment. Studies of populations in sociocultural transition offer an unique opportunity to identify the relative influence of specific sociocultural factors on the rate of change of blood pressure. In addition, when the study of such populations is placed in a quasi-experimental context, genetic-environmental interactions may also be detected. This strategy is illustrated by a study of the changing blood pressure distribution in Tokelauan migrants. Such an approach requires the initial definition of a response variable which measures change in blood pressure as a consequence of migration. The response variable, which identifies the relative influence of concomitants such as weight, age, and obesity, can then be subjected to genetic analysis. In the Tokelau case, blood pressure response tends to be positive in migrants but negative in non-migrants. Further statistical analysis indicates that there is a small proportion of high responders in both populations and that these cluster in families in the migrant population. However, estimates of the transmission parameter suggest that sociocultural transmission, rather than Mendelian segregation, is responsible. To date there is little evidence that genetic-environmental interactions have had any impact on the development of hypertension in this migrant population.