Research on the Efe and Lese populations of the Ituri forest,Zaire

Since 1980, as part of the Ituri Project, researchers have been studying numerous aspects of the biology, health, economy, and social relations of Efe (Pygmies) and Lese villagers living in the Ituri Forest region of north-eastern Zaire. The Efe are seminomadic people who hunt and gather forest resources for their own consumption and for exchange with sedentary subsistence farmers. The Lese are Sudanic-speaking subsistence farmers who practice shifting slash-and-burn horticulture and live in semipermanent villages. Relations between the Efe and Lese have been close for many generations and extend beyond economic exchange to include most aspects of ritual and social life. This paper serves as an introduction to five subsequent papers that report findings from research on these two forest-living populations. It provides background information concerning the ecology and history of human occupation of the Ituri region of central Africa; it describes the study area and the study populations; it discusses how the annual subsistence cycles of the Efe and Lese relate to rainfall and food availability; and it provides further information concerning Ituri Project research during the last 7 years.     

Fitness and Oxygen uptake of children in the Ituri forest. Natural selection or adaptation to the environment?

For the inhavitants of an isolated niche like the Ituri rain forest of N-E Zaire, the interplay of natural selection and conditioning by daily physical activity should influence the physical development of growing children, provided general health and nutrition stay within acceptable limits. The general health of 389 children between 5 and 15 years of age (207 Lese villagers and 182 Efe Pygmies) living in that area, appears to be fairly good, although the hematocrite is low (37 and 34% respectively). Tuberculine reaction is positive in over 50%, intestinal parasites generally present while more than 50% are free of dental caries. Efe children stand peristently some 10 cm smaller and weigh 5 to 6 kg less than Lese of the same age, who reach only the 3rd percentile of European children (Tanner-Whithouse 1963). In the motorfitness, Efe score better than Lese for balance and flexibility tests. Both appear superior to European children of the same age, they are equal or better for strength, even when adjusted for body size. Against this background, the Oxygen uptake (VO₂) at increasing work load on the step test of 58 Lese and 56 Efe indicates similar efficiency. The Efe reach a fixed VO₂ with higher Heart Rate (HR), which is consistent with their smaller size, hence smaller heart and stroke volume. The difference disappears when adjusted for body size. Children living in the Ituri forest tend to be fitter than Europeans notwithstanding their health condition. This belies any Energy Proteine Malnutrition (EPM) form earky childhood on, and supports the thesis that the small body size of the Efe follows genetic factors and does not result from poor health or chronic EPM in childhood.     

Historical trends in forager and farmer exchange in the Ituri rain forest of northeastern Zaïre

Using oral histories, archival materials, and observations of present behavior, a largely hypothetical historical reconstruction of the natural resource exploitation and subsistence practices of Lese farmers and Efe foragers in the Ituri Forest of northeastern Zaïre is presented. Distinct epochs associated with the advent of forest agriculture, Belgian colonization, and post-independence economic collapse have resulted in changes in local population density, the range of forest resources exploited, and the spatial distribution and intensity of resource use. Broadly speaking, there has been a historical trend toward sedentism, spatial clumping of settlements, localization of resource exploitation, reduced importance of forest carbohydrates in the diet, and an increased reliance on agricultural products. Over time the Efe and Lese exchange system has changed, in relation to the items traded and the relative dependence of each partner on the exchange relationship. Involvement in this alliance has had a considerable impact on Efe settlement pattern, diet, and probably fecundity. It ultimately placed the Lese in a position of power over the Efe, and provided the farmers with means to enter a transient monetary economy. By providing a retrospective on Efe and Lese subsistence, we hope to demonstrate that to decipher the relative benefits and constraints of this contemporary exchange relationship, we must understand their historical etiology.     

Anomalously low endemic goiter prevalence among Efe pygmies

The existence of endemic goiter, caused by iodine deficiency and the presence of a dietary goitrogen, has been noted in eastern Zaire by a number of authors (De Visscher et al.: Journal of Clinical Endocrinology and Metabolism 21:175-188, 1961; Delange et al.: Journal of Clinical Endocrinology and Metabolism 34:1059, 1972). In the Ituri Forest of Huate-Zaire, two distinct populations, the Efe (pygmy) and Lese (Bantu), live in association with each other and have similar diets. The goiter survey reported here documents differences in goiter prevalence and severity between the nomadic pygmy and village-living Bantu populations. While the Efe have an overall goiter prevalence of 9.4%, the Lese have a goiter prevalence of 42.9%. Furthermore, Efe women living in Lese villages and subsisting on a Lese diet have a prevalence of goiter similar to that of forest-living Efe women. Village-living individuals born of Efe mothers and Lese fathers have a prevalence of goiter greater than that of pure Efe but less than that of Lese. While our data cannot exclude dietary explanations for the difference in goiter prevalence between the Efe and Lese, they do support the hypothesis that the Efe possess an adaptation to an iodine-deficient environment that does not result in the development of goiters.     

Nutritional status of Efe pygmies and Lese horticulturists

We assessed the nutritional status of 90 pygmies (Efe) and 211 members of a neighboring horticultural Lese in the Ituri forest in northeast Zaire. Clinical signs of iron and iodine deficiency were highly prevalent, but the frequency of these and other clinical signs of nutritional deficiency did not differ between the two groups. Infectious diseases such as yaws, cellulitis, and filiariasis were common. Absolute heights and weights of both Efe males and females aged 2–18 years were less than the 5th percentile of the National Center for Health Statistics standards. Weights for height of both groups were within the normal range. Weights and heights, expressed as percentages of the 50th percentile for age and sex, were significantly lower (P < .001) in Efe males and females than among Lese males and females, but weights for height did not differ significantly. Z-Scores of height and weight were also significantly lower in Efe males and females than among their Lese counterparts. The differences in weight and height, expressed either as a percentage of the 50th percentile or as Z-scores, were most apparent in older adolescents and persisted among adults. The normal weight for height among both populations indicated that acute undernutrition did not exist at the time of the survey. Despite comparable levels of adult fatness, measured by triceps skinfold thickness, heights of Efe males and females were lower than those of the Lese. These observations support the hypothesis that genetic differences account for the short stature of the Ituri pygmy. However, because the environments shared by the two groups are not identical and because other practices differ, nutritional effects cannot be excluded.     

Digital ridge-counts of Efe pygmies

The mean total digital ridge-counts among a sample of Efe of the Ituri forest is 96.4 in males (n = 153) and 96.6 in females (n = 54). These are the lowest values yet recorded and probably represent the lower extreme in the spectrum of ridge-counts of non-pathological populations.     

The ecology of birth seasonality among agriculturalists in central Africa.

The Lese are subsistence farmers living in the Ituri Forest of north-east Za?re. They exhibit significant birth seasonality, with lowest frequencies of conception when food production is least, nutritional status is low and ovarian function, as measured by salivary steroid hormone levels, is reduced. Efe pygmy foragers, who live in the same geographical area but are less dependent on cultivated foods and have a more flexible life style, do not exhibit frequent fluctuations in nutritional status nor significant birth seasonality. These findings support a model of birth seasonality relating climatic variables to variation in fertility through a causal chain linking rainfall to food production to energy balance to ovarian function to fertility. The model, which emphasises an ecological approach to the study of human reproduction, should have broad applicability since seasonality of food production and energy balance is widespread geographically and across a wide variety of economies and cultures.     

Humans as primates: The social relationships of Efe pygmy men in comparative perspective

The Efe are short-statured specialized hunger-gatherers living in the moist tropical forest in northeast Zaire. They live in small mobile groups averaging 18 individuals and practice viripatrilocal residence — what primatologists refer to as male philopatry and female dispersal. This study uses methods commonly employed by primatologists to study the social relationships of Efe men. It compares their association and affiliation patterns with those of two nonhuman primate species that show male philopatry and female transfer. The analyses of 376 hr of focal behavior observations on 16 Efe men reveal that the majority of their associations were with other adult men. Men associated preferentially with kin over non-kin, and with close kin more than with distant kin. Men's close relationships, or companionships,sensu Smuts' (1985) friendships among anubis baboons, were predominantly with other adult men; however, each man who cohabited with a woman had his strongestcompanionship by far with that woman. These quantitative measures of affinity are consistent with the Efe's pattern of viripatrilocal residence, where-by males remain in their natal group with their close male kin and females join or are recruited from other patriclans. The social relationships of Efe men are similar in some respects to those of hamadryas and chimpanzees; however, Efe men's social networks are larger and more fluid. We speculate that the explanation proposed for male philopatry and female dispersal among nonhuman primates also applies to the Efe.     

Salivary progesterone and luteal function in two low-fertility populations of Northeast Zaire

30 Ituri women (Zaire) -- 14 Efe and 16 Balese -- were targeted as subjects in this study designed to verify that, under field conditions, the salivary steroid method can reliably discern follicular and luteal levels of progesterone in normal menstrual cycles and to examine the hypothesis that infertility among these women is due to tubal factors. Findings of normal ovulatory function in fertile women would support the hypothesis; findings of abnormal gonadal function might either indicate a chronic endocrine imbalance or the short-term effects of nutritional and other stressors. All potential subjects ranged in age between 20-35 years, were involved in stable conjugal unions, had no nursing children, and reported either no births or none within the last 6 years. 25 women completed the study. The Boston field control subjects consisted of 18 volunteers ranging in age between 18-43 years. All reported a history of regular menstrual cycles and were nither using oral steroid contraceptives nor engaged in a regular exercise program. The African women had significantly lower luteal progesterone levels than did the Boston controls. Additionally, a significantly higher proportion of the African women failed to demonstrate clear luteal activity, suggesting that a higher rate of anovulation contributed to the low average luteal progesterone levels. The composite-cross-sectional profile for the Ituri Forest women suggests that the average luteal phase for this group was shorter than for the Boston controls. Further investigations need to determine whether gonadal dysfunction such as observed in this study is a regular feature of the reproductive physiology of women in the Ituri Forest, or whether it emerges only in periods of food shortage and significant weight loss. Gonorrhea may be the major cause of infertility in the Ituri region, but it is likely that other factors directly affecting gonadal function contributed to the observed pattern of low fertility. Clearly, the study illustrates the potential usefulness of salivary steroid assays.     

Significance of the social relationships of Efe Pygmy men in the Ituri forest,Zaire

Efe Pygmies in northeast Zaire exhibit features of social organization (small group size, flexible but predominantly patrilocal residence, close relations with kin, and pair bonds) that are common to many hunting and gathering societies. This study uses methods commonly employed in studies of nonhuman primates to investigate the associations of Efe men with other individuals as a function of their age, sex, and kinship, and it tests the hypothesis that Efe are patrilocal because hunting efficiency is improved by hunting with male relatives. The analyses of 376 hours of focal behavior observations on 16 Efe men and observations of 71 cooperative group hunts show that the majority of associations between Efe men were with other adult men. Men associated preferentially with kin over nonkin, and they associated with close kin more than with distant kin. Men's close relationships (what we call “Companionships” sensu Smuts' “Friendships” in baboons) were predominantly with other adult men, but each man who cohabited with a woman had his strongest Companionship by far with that woman. Neither the efficiency of hunts nor the hunting success of individual men were found to be related to the degree of relatedness of hunters nor the proportion of relatives on the hunt. Alternative hypotheses concerning the functional significance of patrilocality and male kin groups are considered. We conclude that strong affiliative bonds between male kin and between males and females may arise as much from the need for strong allies in the face of competitive social situations as from economic or ecological necessity.     

The occurrence of an Eastern African haplochromine cichlid in the Ituri River (Aruwimi,Congo basin): adaptive divergence in an introduced species?

Recently, specimens belonging to the genus ‘Haplochromis’ have been found in the Ituri River (Congo basin). They clearly do not belong to any of the species known from the Congo basin, but strongly resemble ‘H’. aeneocolor from the Lake Edward/George system. We examined whether this population represents a new species or is conspecific with ‘H’. aeneocolor. A morphological comparative study was executed based on 11 counts and 23 measurements on 64 specimens. The results revealed the Ituri specimens to differ from the types of ‘H’. aeneocolor in snout length, premaxillary pedicel length and eye diameter. Since these few differences are correlated, and head morphology is known to be subject to adaptive responses in haplochromine cichlids, they were considered the result of morphological adaptation to a riverine habitat rather than an indication of heterospecificity. Probably, ‘H’. aeneocolor has accidentally been introduced into the Ituri region together with tilapias used in aquaculture, and has subsequently established a stable population in a riverine environment. As fish introductions can have a severe impact on aquatic ecosystems, improving our knowledge as well as a good management of aquacultural activities is essential.     

Gender Difference in Associations between Chronic Temporomandibular Disorders and General Quality of Life in Koreans: A Cross-Sectional Study

Background

Chronic temporomandibular disorder (TMD) is known to have strong correlations with psychological factors and to display gender disparity. However, while chronic TMD is known to affect quality of life, large-scale studies investigating the influence on quality of life by gender are scarce.

Methods

This cross-sectional study assessed the data of 17,198 participants aged ≥19 years who completed chronic TMD and EuroQol-5 Dimension sections in the 4^th Korean National Health and Nutrition Examination Survey (2007–2009). We adjusted for covariates (health behavior, sociodemographic factors) in regression analysis for complex sampling design to calculate regression coefficients and 95% CIs for gender difference in the association between chronic TMD and quality of life. We also evaluated which covariates of somatic health, mental health, health behavior, and sociodemographic factors weakened the relationship between TMD and EQ-5D.

Results

Prevalence of chronic TMD was 1.6% (men 1.3%, women 1.8%), and chronic TMD persisted to negatively impact quality of life even after adjusting for confounding variables. Low sociodemographic factors and health behavior had a negative effect on quality of life. Somatic health and mental health were most affected by chronic TMD. As for quality of life, women were affected to a greater extent than men by TMD. Women were more affected by osteoarthritis and general mental health (stress, depressive symptoms, and thoughts of suicide), and men by employment.

Conclusions

These results imply that chronic diseases and psychological factors are important in chronic TMD, and that there may be physiological and pathological gender differences in TMD.     

Quality of life and affective well-being in middle-aged and older people with chronic medical illnesses: a cross-sectional population based study

Background

There has been considerable research into the impact of chronic illness on health-related quality of life. However, few studies have assessed the impact of different chronic conditions on general quality of life (QOL). The objective of this paper was to compare general (rather than health-related) QOL and affective well-being in middle aged and older people across eight chronic illnesses.

Methods and Findings

This population-based, cross-sectional study involved 11,523 individuals aged 50 years and older, taking part in wave 1 of the English Longitudinal Study of Ageing. General QOL was assessed using the CASP-19, happiness was evaluated using two items drawn from the GHQ-12, and depression was measured with the CES-D. Analysis of covariance and logistic regression, adjusting for age, gender and wealth, were performed. General QOL was most impaired in people with stroke (mean 37.56, CI 36.73–38.39), and least in those reporting cancer (mean 41.78, CI 41.12–42.44, respectively), compared with no illness (mean 44.15, CI 43.92–44.39). Stroke (mean 3.65, CI 3.58–3.73) was also associated with the greatest reduction in positive well-being whereas diabetes (mean 3.81, CI 3.76–3.86) and cancer were least affected (3.85, CI 3.79–3.91), compared with no illness (mean 3.97, CI 3.95–4.00). Depression was significantly elevated in all conditions, but was most common in chronic lung disease (OR 3.04, CI 2.56–3.61), with more modest elevations in those with osteoarthritis (OR 2.08, CI 1.84–2.34) or cancer (OR 2.07, CI 1.69–2.54). Multiple co-morbidities were associated with greater decrements in QOL and affective well-being.

Conclusion

The presence of chronic illness is associated with impairments in broader aspects of QOL and affective well-being, but different conditions vary in their impact. Further longitudinal work is needed to establish the temporal links between chronic illness and impairments in QOL and affective well-being.     

Comparative life cycle assessment of re-use and replacement for video projectors

Purpose

The current focus of environmental legislation for energy-using products is an efficient energy consumption in the use stage. However, the production and waste treatment of electronic products are also related to environmental impacts in terms of declining metal resources and growing waste streams. This paper investigates the environmental impacts of life time extension versus energy efficiency for the product group video projector using life cycle assessment (LCA).

Methods

The product under study was an average video projector based on three LCD projectors. The studied systems included two possibilities after a regular first usage period: reconditioning for a second use or replacement by a primary successor with an energy efficiency increase of 5 and 10%. All impacts addressed were accounted using the ReCiPe 2008 method. The impact contribution of projector components was identified at midpoint and endpoint levels, while life cycle impacts were calculated with a focus on three impact categories. Furthermore, the amortization period of production emissions was quantified.

Results and discussion

LCA results showed that the use stage dominates life cycle impacts of the global warming potential and primary energy demand. For the metal depletion potential, the production stage accounts for most of the total life cycle load. The highest shares in production emissions were identified for electronic components, namely printed wired boards and integrated circuits. Reconditioning and reuse of a secondary projector resulted in minor environmental impacts compared to the replacement and use of a primary projector with an energy efficiency increase of 5%. The saving potential of the primary energy demand is higher only in the case of a 10% more efficient device as compared to the secondary projector.

Conclusions

The study concluded that production emissions and their amortization period are relevant factors offsetting any environmentally beneficial measures applied during the use phase. The study suggests that life time extension of video projectors can provide higher environmental improvement potentials, while energy efficiency increase during usage is less beneficial, given that major improvements in energy efficiency do not occur. Recommendations are valid for this particular case study. The study suggests that the current focus of mandatory product requirements for energy-using products on energy efficiency increase should be extended to measures of life time extension in order to serve the intent of an integrated product policy.

     

Influence of Observer Presence on Pacific Damsel Bug Behavior: Who is Watching Whom?

When direct observations are used to study animal behavior the presence of the observer may alter the animal and hence influence the data being collected, yet few studies have quantified this effect. We conducted direct observation studies in the glasshouse to assess the relative influence of observer presence on the behavior of Pacific damsel bugs, Nabis kinbergii, a potentially important predator of crop pests. Comparisons of predator activity, predator distribution, prey (Helicoverpa armigera) mortality and prey distribution between frequently observed and minimally observed treatments, during diurnal and nocturnal observation sessions showed that the frequency of observer presence had no apparent impact on Pacific damsel bug behavior. This is the first documented test of the impact of observer presence in an insect system. To place our results in context, we reviewed 15 papers on the influence of observer presence in a range of animals. We established that just over half of these papers found evidence for an effect. Nevertheless, direct observations should be useful in further studies of Pacific damsel bug behavior, and researchers using direct observations to study the behavior of other animals should be cognizant of observer effects during design and interpretation of their study.     

不同出生体重儿童的生命质量研究

目的:探讨不同出生体重对学龄期儿童生命质量及影响因素.方法:采用Achendach儿童行为量表、儿少主观生命质量问卷及自制儿童生命质量影响因素问卷,对台湾基隆市8-11岁儿童进行调查,依研究对象按照不同出生体重分组并进行分析.结果:在所调查的350名儿童中,出现行为问题的儿童有21.14%(74/350).使用Logistic回归检验发现行为问题与父亲与主要养育人的教育程度、受试儿童是否对家庭造成心理负担及经济负担四个方面有密切关系.对不同出生体重儿童主观生命质量满意度的分析结果提示:低出生体重儿与正常出生体重儿相比,在生命质量中的情感成份满意度较低(F=2.601;P=0.028);而巨大儿在认知成份满意度较正常出生体重儿差(F=3.189;P=0.012),且多元逐步回归发现:主要养育人的教育程度与母亲每周与孩子相处时间的长短是影响儿童主观生命质量满意度的因素.结论:低出生体重儿生命质量的情感成份满意度较低.而巨大儿生命质量的认知成份满意度较差,出生体重是影响儿童生命质量的因素.     

The influence of contaminants in the environmental impact of recovered paper: a life cycle assessment perspective

Purpose

This study aims to analyze and quantify the environmental impacts associated with the production of testliner paper using 100?% recovered paper as fiber raw material, by applying the life cycle assessment principles. A simulation of advanced sorting technology was done to prepare and use batches of raw materials with different levels of contaminants. Comparative studies of environmental impact assessment were focused on the quality of recovered paper, which is decisively influenced by the efficiency of the sorting process. The particularity of the study is that so far it is the only one that analyzes the environmental impact generated by recovered paper quality.

Methods

To analyze the environmental impacts in the scenarios, life cycle assessment methodology was considered. Potential environmental impacts were assessed by using the CML 2009, Dec.07 method developed by the Centre for Environmental Science from the University of Leiden.

Results and discussion

In this study, acidification potential, abiotic resources depletion potential, eutrophication potential, global warming potential, photochemical ozone creation potential, and human toxicity potential were the impact categories analyzed. Considering that the system boundaries refer only to the paper mill that was obtained, all unitary processes involved in the manufacturing of product system influence in varying proportions the impact categories chosen for evaluation. A higher concentration of contaminants leads to a higher amount of energy and water used, and thus, a significant amount of waste and emissions generated. Simulations performed have highlighted the importance of sorting technology that influences the quality of raw material that will be used.

Conclusions

Utilization of recovered paper batches with a low quality contributes to an increased environmental impact associated with the testliner paper manufacturing stage. A low quality of recovered paper will influence energy consumption in different modules of the system (recycled fiber pulp preparation, paper machine, and wastewater treatment), the volume of waste generated, and consequently the emissions released both in air and water.     

Concentration effect of hydrophilic ionic liquids on the enzymatic activity of Candida antarctica lipase B

A systematic study of the effects of hydrophilic ionic liquids concentration and nature (alkyl chain length and type of anion) on the activity of Candida antarctica lipase B is here reported. The increase in the concentration of the studied ionic liquids is shown to cause a decrease of the enzyme activity, but the effect is dependent on the ionic liquid used. This behavior is partially due to the ionic liquid impact on the thermodynamic water activity, but direct interactions between the hydrophilic ionic liquid and the enzyme are also disclosed. Cations with longer alkyl chains decrease the enzyme activity by obstruction of its non-polar active site, while direct interactions established between the enzyme and the anions, dominated by dispersion forces and hydrogen-bonding, contribute also for the loss of activity observed.