Interaction of nutritional and socioeconomic status as determinants of cognitive development in disadvantaged urban Guatemalan children

The relationship between nutritional status, measured by height for age, and cognition, measured by WISC full-scale IQ, was studied in a longitudinal sample of 459 urban Guatemalan children, aged 4-9 years, from a disadvantage community of the fringe of Guatemala City, examined annually over a 3 year period. Socioeconomic status (SES) was controlled by developing a composite index for each home. The mean IQ differed significantly from the lowest to the highest quartiles of stature, the difference between the two extreme quartiles being approximately 0.3 SD of IQ. There was a significant interaction between SES and stature in their effects on IQ. Whereas nutritional status and SES affected IQ in an additive fashion in the upper three SES quartiles, there was no difference in IQ attributible to stature among children from the most disadvantaged homes. This analysis indicates that the mild-to-moderate protein-energy malnutrition (defined by height for age) that is prevalent among children from disadvantaged environments in developing countries is significantly related to cognitive development. However, in the poorest homes, SES is seen as a more important determinant of cognitive development than stature.     

Diet and dental caries among later stone age inhabitants of the Cape Province, South Africa.

Stable carbon isotope measurements and incidences of dental caries are presented for three groups of prehistoric human skeletons from different regions of the Cape Province, South Africa. The isotopic analyses of bone collagen demonstrate the importance of marine foods in the diet and vary through time, across space, and according to sex. The incidence of dental caries ranges from 0% among heavily marine-dependent individuals from the south-western Cape coast, to 17.7% among skeletons from an archaeological site on the south coast. The extremely high incidence of caries in a hunter-gatherer population may be related to lack of fluoride in the water.     

Body composition and nutritional status of urban Guatemalan children of high and low socioeconomic class

The effects of socioeconomic differences on the nutritional status of two groups of urban living children are considered via an anthropometric assessment of body composition. The sample consists of 981 Guatemala City children, 7.00 to 13.99 years old, of high and low socioeconomic status (SES). High SES children have larger median values for triceps skinfold, subscapular skinfold, arm circumference, and estimated mid-arm muscle and fat areas than low SES children. Compared with children of a US reference sample, the high SES children generally have larger values for all variables and the low SES children have smaller values. However, the differences between the low SES children and the children of the other two samples are greater for arm fat area than for arm muscle area. The analysis suggests that low SES Guatemalan children suffer to a greater extent from chronic energy, rather than protein, undernutrition. A similar pattern of energy malnutrition has been observed for rural Guatemalan children. These combined data suggest that estimates of fat reserves of the arm provide a useful indication of nutritional status for Third-World children. Results from rural Costa Rican and Honduran studies have been taken to mean that muscle reserves are better than fat reserves as indicators of nutritional status in developing countries. But, those studies did not estimate cross-sectional muscle and fat areas and only considered the extremes of the population distribution for muscle and fat.     

Comparative analysis of genetic diversity in pea assessed by RFLP- and PCR-based methods

DNA-based molecular-marker techniques have been proven powerful in genetic diversity estimations. Among them, RFLP was the first and is still the most commonly used in the estimation of genetic diversity of eukaryotic species. The recently developed PCR-based multiple-loci marker techniques, which include RAPD, AFLP, Microsatellite-AFLP and inter-SSR PCR, are playing increasingly important roles in this type of research. Despite the wide application of these techniques, no direct comparison of these methods in the estimation of genetic diversity has been carried out. Here we report a direct comparison of DNA-based RFLP with various PCR-based techniques regarding their informativeness and applicability for genetic diversity analysis. Among ten pea genotypes studied, all the PCR-based methods were much more informative than cDNA-RFLP. Genetic diversity trees were derived from each marker technique, and compared using Mantel's test. By this criterion, all trees derived from the various molecular marker techniques, except for the tree derived from inter-SSR PCR, were significantly correlated, suggesting that these PCR-based techniques could replace RFLP in the estimation of genetic diversity. On the basis of this result, AFLP analysis was applied to assess the genetic diversity of a sample of accessions representing the various species and subspecies within the genus Pisum.     

Longitudinal study of anthropometric,skinfold, work,and motor characteristics of boys and girls,three to six years of age

Groups of preschool children were followed longitudinally: boys, n = 36, from 3.48 up to 6.02 years and girls, n = 22, from 3.53 up to 6.03 years. Anthropometric dimensions, skinfold thicknesses, reaction of the cardiovascular system to a work load (modified step test), motor performance, and hand grip strength were measured. Boys had greater values for height, weight, length, and circumferential measures, with the exception of the thigh. Boys had also smaller skinfolds and better performances in 20 meter dash, broad jump, cricket ball throw, and grip strength compared to girls. All anthropometric dimensions increased with age, but these increase did not have the same character. Children became more linear in spite of relatively greater increase in total body weight. Chest and abdomen circumferences increased more in boys during the last year of the study. Skinfold thicknesses decreased significantly in boys, and stayed the same in girls. Motor performance and muscle strength also increased during the experimental period. Pulse rate at rest, during modified step test and recovery period decreased with age, and the economy of cardiac work improved significantly as indicated by step test index and/or cardiac efficiency index. The changes derived from longitudinal observations corresponded to previous results of cross-sectional data.     

Assessment of species composition change in savanna vegetation by means of woody plants' size class distributions and local information

A new method is presented for assessment of compositional changes in disturbed savanna systems and for identification of species susceptible to local extinction. Such information is urgently needed as a basis for management plans that aim at ensuring conservation and sustainable use of savanna vegetation. Size class distributions (SCDs) of trees and shrubs from a fire-disturbed savanna in Senegal are analysed and compared to observations provided by local people on declining species. Many species, particularly large trees, have few young individuals and therefore flat SCDs that deviate from the reverse-J shape SCD characterizing species with abundant and constant rejuvenation. Based on comparisons of SCDs with local information and historical records, it is concluded that most of the flat distributions analysed are effects of declining population sizes caused by human impact, particularly fire. Results from the analyses certify that a change in species composition from a vegetation characterized by large trees to one dominated by shrubs takes place. Whereas most of the declining species are locally appreciated, this is not the case for the few species with good rejuvenation. Therefore, if the observed trend continues, it will have severe implications for the local communities.     

Effect of water table depth and tillage methods on plant-water status and yield of rice

Summary Effects of water table depths on plant-water status, and on growth and yields of two rice varieties (TOS 78 and TOS 848) were studied in a lysimetric investigation. A field study was also conducted on a hydromorphic soil to investigate the effects of fluctuating water table on rice. The leaf-water potential of TOS 78 monitored at 1300 hours at 50% flowering stage was –17.5 and –23.0 bars for 0 and 60 cm water table depths, respectively. When grown under soil moisture stress, TOS 848 maintained higher leaf-water potential (–17.5 barvs –22.5 bar) and yielded more than TOS 78. Under hydromorphic soil conditions, no-tillage treatments yielded the same as conventionally tilled plots.     

Multimodal alarm behavior in urban and rural gray squirrels studied by means of observation and a mechanical robot

Urbanization of animal habitats has the potential to affect the natural communication systems of any species able to survive in the changed environment. Urban animals such as squirrels use multiple signal channels to communicate, but it is un-known how urbanization has affected these behaviors. Multimodal communication, involving more than one sensory modality, can be studied by use of biomimetic mechanical animal models that are designed to simulate the multimodal signals and be pre-sented to animal subjects in the field. In this way the responses to the various signal components can be compared and contrasted to determine whether the multimodal signal is made up of redundant or nonredundant components. In this study, we presented wild gray squirrels in relatively urban and relatively rural habitats in Western Massachusetts with a biomimetic squirrel model that produced tail flags and alarm barks in a variety of combinations. We found that the squirrels responded to each unimodal component on its own, the bark and tail flag, but they responded most to the complete multimodal signal, containing both the acoustic and the moving visual components, providing evidence that in this context the signal components are redundant and that their combination elicits multimodal enhancement. We expanded on the results of Parian et al. (2009) by providing data on sig-naling behavior in the presence and absence of conspecifics, suggesting that alarm signaling is more likely if conspecifies are present. We found that the squirrels were more active in the urban habitats and that they responded more to tail flagging in the urban habitats as compared to the rural ones, suggesting the interesting possibility of a multimodal shift from reliance on audio to visual signals in noisier more crowded urban habitats.     

Biosynthesis of acyclic and cyclic carotenoids in higher plants and the control by phytochrome

Radish plants ( Raphanus sativus L. cv. Saxa treib) were grown in the presence of three different herbicides interfering with the biosynthesis of cyclic carotenoids. The herbicides caused an accumulation of acyclic biosynthetic intermediates. Plants were then irradiated using four different light programs in order to gain more insight into the first steps of carotenoid biosynthesis and their control by light and phytochrome. Plants grown in the dark in the presence of SAN 6706 or aminotriazole accumulated the acyclic intermediate phytoene, and those treated with J 852, the intermediates phytoene, phytofluene and zeta-carotene. In herbicide-treated plants short time irradiation with red light enhanced the formation of phytoene, phytofluene, zeta-carotene or lycopene, consistent with an effect of phytochrome on the early steps of carotenoid biosynthesis. Biosynthesis of cyclic carotenoids was also enhanced by red light in the untreated controls. In amitrole-treated plants formation of β-carotene, but not that of xanthophylls was stimulated by red light. In many cases neither the red light-induced biosynthesis of cyclic carotenoids nor the formation of acyclic intermediates could be prevented by a subsequent irradiation with far-red light. Similar enhancement as with red light was also obtained after treatment with far-red light only. Presented data may be taken as evidence that the biosynthesis and dehydrogenation of phytoene and the cyclization of lycopene are activated by a low threshold of active phytochrome. This may be further supported by the observation that far-red light itself stimulated carotenoid biosynthesis.     

Age- and gender-related oxidative status determined in healthy subjects by means of OXY-SCORE,a potential new comprehensive index

Oxidative stress has been related to various diseases, gender and ageing, and has been measured by various markers. The authors developed a procedure to compute a global oxidative stress index (OXY-SCORE), reflecting both oxidative and antioxidant markers in healthy subjects. Its performance was tested in relation to age and gender and in coronary artery disease (CAD) patients. Eighty-two healthy subjects and 20 CAD patients were enrolled. Plasma free and total malondialdehyde (F- and T-MDA), glutathione disulphide/reduced form ratio (GSSG/GSH) and urine isoprostanes (iPF_2α-III) levels were combined as oxidative damage markers (damage score). GSH, α- and γ-tocopherol (TH) levels, and individual antioxidant capacity were combined as antioxidant defence indexes (protection score). The OXY-SCORE was computed by subtracting the protection score from the damage score. Among single parameters, T-MDA and iPF_2α-III significantly correlated with age; only GSH and both tocopherols correlated with male gender in healthy subjects. The OXY-SCORE was positively associated with age (p=0.004) and male gender (p=0.03). As expected, the OXY-SCORE was higher in CAD with a very significant p-value (<0.0001), after adjusting for age, gender and smoking. Combining different markers can potentially provide a powerful index in the evaluation of oxidative stress related to age, gender and CAD status.     

Adequacy of food rations in soldiers during exercise in hot, day-time conditions assessed by doubly labelled water and energy balance methods

The energy requirements of people doing physical work in hot climates are not clearly understood. In particular, we know little about the combined effects of heat stress and muscular work on energy requirements. During military exercises in the African bush soldiers are supplied with standard rations, the adequacy of which is unknown. We have now assessed the adequacy of these food and water rations in 12 male Zimbabwean soldiers during 12 days of strenuous, heat-stress exercise in the field. We used two methods to measure energy expenditure: the double-labelled water method (DLW) and the energy balance method (i.e. comparing dietary energy with changes, if any, in body energy stores). Two groups were studied: one group (eight subjects) carried out field exercises; the control group consisted of four soldiers doing normal work. Mean daily energy expenditure as assessed by the DLW method was [mean (SE)] 23 (1.5) MJ · day⁻¹ for the field group and 14 (0.5) MJ · day⁻¹ for the control group (P<0.001). By the energy balance method, daily energy expenditure was calculated to be 26 (0.7) MJ · day⁻¹ and 15.5 (0.4) MJ · day⁻¹ for the field group and control group, respectively. Body mass loss was 3 (0.1) kg [4.6 (0.3)% of body mass] for the field group, but the control group gained 1.1 (0.1) kg. Mean daily fluid intake was 11 (0.5) 1 · day⁻¹, suggesting that the standard ration supplied was inadequate. Body mass loss was caused by both the energy deficit and total body water loss. These results suggest strenuous work in hot, dry field conditions imposes extra energy requirements. Accepted: 21 January 1997     

Influence of age and dental status on chewing behaviour studied by EMG recordings during consumption of various food samples

Objective: To evaluate the effects of age and dental status on chewing performance in humans. Design: Electromyography recordings (EMG) were made during chewing of six foods (rice, beef, cheese, crispy bread, apple, and peanuts) to compare the masticatory patterns of four subject groups with different ages and dental status. Subjects: Nineteen elders (mean age 67.2 years) classified into three categories according to their number of opposing post‐canine teeth pairs (i.e. functional units) and a control group of 10 young adults (mean age 26.5 years) with a high number of functional units. Main outcome measures: Number of chewing cycles, chewing time, total muscle activity and muscle activity per chew, burst and inter‐burst durations, maximum and mean voltages from EMG recordings. Results: Time‐related EMG parameters increased from young subjects to elderly subjects with high, middle and low dental status. Parameters related to EMG voltages per chew decreased in the same order among the different groups of subjects. These tendencies were observed for all the studied products. Subjects with weak muscle contraction may compensate for their poor chewing performance by lengthening both chewing cycle and sequence duration. Additional alterations in the chewing patterns were observed when age effect was associated with a dental status degradation in terms of number of functional units. Conclusion: Impairment in mastication for the elderly is due to both ageing and decreasing number of functional pairs of post‐canine teeth.     

Trypanosoma lewisi: comparative activity of a feral isolate in two strains of rats assessed by measurement of cell population, reproductive development and respiratory activity.

Lee C. M., Harris L. M. and Aboko-Cole G. F. 1978. Trypanosoma lewisi: comparative activity of a feral isolate in two strains of rats assessed by measurement of cell population, reproductive development and respiratory activity. International Journal for Parasitclogy8: 187–192. Comparative respiratory behaviour, population growth and host antibody formation were examined for a feral isolate of Trypanosoma lewisi grown in albino and black rats. Oxygen uptake was measured for endogenous, glucose or normal homologous rat serum substrates. Trypanosomes from albino rats respired 72% faster endogenously, 70% faster with glucose, and 60% faster with rat serum than parasites from black rats. Greater oxygen consumption of T. lewisi from albino rat hosts correlated well with the fact that the trypanosome developed greater parasitemias in albino than in black rats. Parasitemias were patent longer in albino rats and peak populations were found 2 days later in these hosts than in black rats. On the average, higher coefficients of variability in cell length continued five days longer in albino rats than in black animals. Delay in reproductive development was indicated by continued low variability in trypanosome cell sizes in albino and black rats.     

Effects of equatorial ligand bulk on the orientation of axial ligands in methyl organocobalt B12 models assessed by X-ray and NMR methods

We prepared two new analogues of ([CH₃Co((DO)(DOH)pn)L]⁺) [(DO)(DOH)pn = N²,N^2′-propane-1,3-diylbis(2,3-butanedione-2-imine-3-oxime)] B₁₂ models but with an O-BF₂-O unit replacing the O-H?O unit as follows: [CH₃Co((DO)(DOBF₂)pn)L]PF₆ with L = pyridine (py) and 1,5,6-trimethylbenzimidazole (Me₃Bzm). Our goal was to compare the properties of these new O-BF₂-O complexes with the well-established O-H?O analogues. The Co-CH₃¹H NMR shifts indicate that the BF₂ group makes the Co(III) less electron rich. The X-ray crystal structures determined for the new compounds were compared to the one known structure with L = imidazole (Im). With increasing size of L, in the series Im < py < Me₃Bzm, the plane of L orients so as to avoid the bulky BF₂ group. This orientation effect becomes apparent in the L ¹H NMR shifts, which are not sensitive to Co(III) electronic properties. Thus, in the O-BF₂-O versus the O-H?O analogue, the Me₃Bzm H4 signal shifts 0.41 ppm upfield from the anisotropic effect of the equatorial ligand double bonds. We advance the concept (applicable to a broad series of complexes) that steric interactions between L and the equatorial ligands are alleviated by a combination of Co-N_ax bond elongation and opening of the N_eq-Co-N_ax angles.     

Aneuploidy assessed by DNA index influences the effect of iron status on plasma and/or supernatant cytokine levels and progression of cells through the cell cycle in a mouse model

Aneuploidy, a condition associated with altered chromosome number, hence DNA index, is frequently seen in many diseases including cancers and affects immunity. Iron, an essential nutrient for humans, modulates the immune function and the proliferation of normal and cancer cells. To determine whether impaired immunity seen in iron-deficient subjects may be related to aneuploidy, we measured spleen cell DNA index, percent of cells in different phases of the cell cycle, plasma and/or supernatant IL-2, IL-10, IL-12, and interferon-gamma in control, pair-fed, iron-deficient, and iron-replete mice (N = 20–22/group). The test and control diets differed only in iron content (0.09 mmol/kg versus 0.9 mmol/kg) and were fed for 68 days. Mean levels of hemoglobin and liver iron stores of iron-deficient and iron-replete mice were 40–60% lower than those of control and pair-fed mice (P < 0.05). Mean plasma levels of IL-10, interferon-gamma and percent of cells in S + G2/M phases were lower in mice with than in those without aneuploidy (P < 0.05). Lowest plasma IL-12 and interferon-gamma concentrations were observed in iron-deficient mice with aneuploidy. Mean percents of cultures with aneuploidy and DNA indexes were higher in iron-deficient and iron-replete than in control and pair-fed mice likely due to delayed cell division (P < 0.05). Aneuploidy decreased the concentration of IL-2 and interferon-gamma in baseline cultures while it increased that of interferon-gamma in anti-CD3 treated cultures. Aneuploidic indexes negatively correlated with cytokine levels, percents of cells in S + G2/M phases and indicators of iron status (P < 0.05). Although chromosome cytogenetics was not performed, for the first time, we report that increased aneuploidy rate may modulate the immune function during iron-deficiency.     

Long flights in Cydia pomonella L. (Lepidoptera: Tortricidae) measured by a flight mill: influence of sex, mated status and age

Abstract. The flight capacity of Cydia pomonella L. (Lepidoptera: Tortricidae) was measured in the laboratory by using computer-linked flight mills. Codling moths showed a large variation in flight capacity between individuals. We defined arbitrarily a longest single flight (LSF) of more than 5 km as an index for long-flyers. About 16.7% of virgin and 10.0% of mated males and 20.0% of virgin and 7.4% of mated females undertook such flights. Based on the LSF and the total distance flown (TDF^we concluded that males and females have little or no difference in flight capacity and that both the within-and between-habitat flights are similar in number and magnitude for both sexes. In the field, females are therefore potentially able to undertake flights of up to 11 km, as reported for males by other authors. This ability was highest at ages of 2–7 days after emergence, i.e. the first third of their lifetime, for virgin and mated male moths and for virgin female moths. Mated females showed peak flight capacity between 1 and 3 days after eclosion, which corresponded with the major egg-laying period. Few long flights were undertaken before oviposition. These findings do not agree with the oogenesis flight syndrome described by other authors, and this theory is believed not to apply to C.pomonella. Our laboratory results are discussed in relation to field experiments in general and hypotheses are developed about the significance of long-flyers for this species.     

The influence of ethylene perception on sex expression in melon (<Emphasis Type="Italic">Cucumis melo </Emphasis>L.) as assessed by expression of the mutant ethylene receptor, <Emphasis Type="Italic">At-etr1-1</Emphasis>, under the control of constitutive and floral targeted promoters

Sexual diversity expressed by Curcurbitaceae species is a primary example of developmental plasticity in plants. Ethylene, which promotes femaleness (carpel development), plays a key role in sex determination. We sought to determine the critical location for ethylene perception in developing floral primodia. The dominant negative Arabidopsis ethylene response mutant gene, etr1-1, was introduced into melon (Cucumis melo L.) plants under control of the constitutive cauliflower mosaic virus (CaMV) 35S promoter, or floral-targeted Apetela3 (AP3) and Crab’s Claw (CRC) promoters, which in Arabidopsis, promote expression in petal and stamen, and carpel and nectary primordia, respectively. Based on effects of exogenous ethylene, it was predicted that inhibition of ethylene perception by carpel primordia would inhibit carpel development. Constitutive expression of etr1-1 caused several phenotypes associated with ethylene insensitivity, verifying that etr1-1 inhibits ethylene perception in the heterologous melon system. Carpel-bearing bud production was essentially abolished in 35S::etr1-1 melons, providing direct demonstration of the requirement for ethylene perception for carpel development. CRC::etr1-1 plants, however, showed enhanced femaleness as manifested by earlier and increased number of carpel-bearing buds, and production of female (rather than bisexual) buds. Despite increased carpel-bearing bud formation, a greater proportion of the CRC::etr1-1 carpel-bearing buds aborted before anthesis. AP3::etr1-1 plants showed increased maleness by nearly exclusive staminate flower production, and poorly developed carpels in the rare bisexual flowers. These results indicate that ethylene perception by the stamen (or petal) primordia plays a critical role in promoting carpel development at the time of sex determination, while ethylene perception by the carpel is important for maturation of carpel-bearing flowers to anthesis.