Cameroonian Sample Research Articles

A - 71 Cross-Cultural Comparison of Cognitive Performance between Americans and Cameroonians while Controlling for Age and Education

Abstract Objective The development of cognitive abilities varies based on social and cultural factors. Given the expansion of neuropsychological measures internationally, an accurate understanding of performance across different countries is necessary to understand the appropriateness of different cognitive tests. To expand the existing knowledge base, this study explores the differences in cognitive test performance between Cameroonian and American adults. Methods The Cameroonian sample, 250 adults ages 22–72 (mean age = 42.91 [SD = 13.76], 52% male, mean education = 13.54 [SD = 4.58]) resided in Yaoundé, Cameroon. Participants were tested at a district center. Deidentified data from a community mental health center’s archival database comprised the American sample. A one-factor between MANCOVA examined differences in performance on selected measures between Americans and Cameroonians after controlling for age and education. Results Age and education statistically significantly affected scores on all selected subtests except for WMS-IV Logical Memory I. Additional analyses revealed that performance still differed between conditions while controlling for age (F (6, 749) = 33.87, p < 0.001; Wilk’s ∧ = 0.787, partial ŋ2 = 0.21), and education (F (6, 749) = 18.95, p < 0.001; Wilk’s ∧ = 0.868, partial ŋ2 = 0.13) for WAIS-IV Digit span, WAIS-IV Symbol search, WAIS-IV Coding, Stroop color word, and WMS Logical Memory I & II subtests. Conclusion Age and education are important predictors of performance on cognitive tests. The importance of appropriately norming new assessments and re-norming older assessments is underscored when those variables are controlled for and differences in performance are maintained between the two conditions. Current findings indicate that cultural differences and their effect on cognitive development explain performance beyond age and education level.

“Fort Aux Fesses”, “Fort Aux Poches”, “Fort Au Cœur”: Buzz or Reality? Initial Validation of Love Scale French Version and Effect of Women’s Mate Profile on Their Love and Happiness

This research structured in two studies had as main objective to study the effect of women’s mate profile on their love and happiness. It was conducted with a French-speaking Cameroonian sample. In the absence of a French-language love scale available in literature, one had to be validated. The first study was therefore intended to validate in a Cameroonian context, the French version of love scale. The results showed the French version has psychometric qualities which testify to its adjustment in Cameroonian context with a four-dimensional factor structure and 19 items. That tool made it possible to undertake the second study, which aimed to test the priming effect of the feeling of having a partner with a profile “fort aux fesses” vs. “fort aux poches” vs. “fort au cœur” on women love and happiness. According with hypothesis results showed that none of these profiles makes women more in love and/or happier at the expense of other profiles. The idea of a standard woman’ mate profile which would provide a certain degree of love and happiness seems irrelevant as evolutionary psychology argues. The debate which has inflamed social networks in Cameroon, tending to maintain that a “fort aux fesses” partner makes women more in love and/or happier at the expense of other partner profiles would be a “buzz”. This research enriches the literature on the evolutionary psychological perspective contribution in the study of romantic relationship.

Sexual Dimorphism in Facial Contrast: A Case from Central Africa.

Apart from morphological differences, male and female faces also vary in color, especially in overall lightness and facial contrast, i.e., the contrast between the luminance and color of facial features (eyes, lips, or brows) and luminance and color of the surrounding skin. In many populations, it has been demonstrated that women tend to be lighter than men. Other differences were found in facial contrast: women have a higher contrast between the lightness of their eyes and lips and the surrounding skin. Manipulation of this contrast in an artificial genderless face can result in a masculine or feminine appearance. So far, however, this phenomenon has been studied mostly in Euro-American and East Asian samples, with little evidence from populations with darker facial tone. We explored natural sexual dimorphism in both facial contrast and lightness in an African, namely Cameroonian, sample, and compared it with results for a European, in particular Czech, population. Our findings showed that sexual differences in luminance contrast of eyes and brows were in both studied populations similar but in the Cameroonian sample, significant difference in lips contrast was absent. These results indicate that sex differences in facial contrast are a side effect of the sex differences in skin color and can be used as a proxy for skin color perception.

Cephalometric Characteristics of Cameroonian Adults: Dimensional Analysis of 80 Cases

Introduction and Objectives: The reference values used in Cephalometry to determine the orthodontic treatment to be realized are mostly of Caucasian origin. In Cameroon, the need for care is growing; but little information is available in Cephalometry. Should we treat with imported cephalometric standards? To answer this question, we conducted this study in order to determine the craniofacial morphological characteristics of a sample of Cameroonian subjects in the Yaounde Central hospital having high health standard in Cameroon. Methodology: We carried out an analytical study at the Yaounde Central Hospital from January to March 2016, on scout view scanographic images of patients, aged 20 to 50 years. 15 cephalometric variables were measured and their mean values and standard deviation calculated. To determine the reference values, we used indicator means with their 95% confidence interval as the best estimator of our population measures. Results: We included 80 subjects with an average age was 32.3years. Cameroonian subjects have sex differences only for SNB and SND measures that were higher in men. Compared with Caucasian values according to Steiner, the Cameroonian population had a protrusive dento-alveolar structure with higher average values except for inter-incisal angles 119.3o and SND 78.8o which showed a lower value against 1310 and 790 for Steiner. Conclusion: Differences between Cameroonian men and women were in SNB and SND measurements that were higher in men. The averages of the Cameroonian sample are significantly different from the Caucasian averages in most measurements. Considering these differences, this work enabled us to propose a charter of cephalometric values, thus providing clear indications as to the type of Cameroonian.

A comparative study of some kaolinites surface properties

The surface properties of five kaolinites of various origins were analyzed using potentiometric titration, electrokinetic measurements and low-pressure gas adsorption associated to derivative isotherm summation (DIS) modeling. The data show that sample structure is important in determining the surface properties. The combined analytical results clearly shows the existence of a permanent negative layer charge for all the samples. The general features that could be observed for the five kaolinites are: the titration curves are shifted to lower pH with increasing ionic strength due to the layer charge; the amount of consumed proton is influenced by the permanent layer charge; although low, the permanent charge determines the electrokinetic behavior. The shape anisotropy and the charge distribution on the basal and edge surfaces are crucial parameters to understand the behavior of kaolinite particles in aqueous media. The Cameroonian sample of the set exhibits a significant permanent charge together with large specific surface area associated to fine particle size and considerable shape anisotropy.

African and European perception of African female attractiveness

Abstract Majority of research on attractiveness is restricted to faces of European origin. The perception of attractiveness may, however, vary across communities due to variations in both facial morphology and local standards of beauty. We investigated the relative contribution of four facial markers of attractiveness based on 101 female facial portraits (standardized, non-manipulated) from Cameroon and Namibia, which were assessed by local male raters and by raters from a distant European population, the Czech Republic. Images from Cameroon include only women of Bantu origin, while Namibians are represented by women of both Bantu (Owambo/Herero) and Nama origin. While controlling for age and BMI, we explored the relationship between female attractiveness and a set of facial traits: fluctuating asymmetry, averageness, shape sexual dimorphism, and skin color (rated and measured in CIELab color space). In the Cameroonian sample, local male raters favored lighter-skinned female faces with morphology closer to average. The attractiveness of Nama women as rated by Nama men positively correlated with lighter complexion, but this did not extend to rating by Cameroonian men. The attractiveness of Namibian Owambo/Herero women was positively associated with facial femininity and lighter complexion when judged by both Cameroonian and Nama male raters. In all samples, the attractiveness as rated by Czech men was predicted by age and BMI, but not by skin color. We found no significant association between attractiveness and fluctuating asymmetry in any of the tested samples. When controlling for age, the effect of skin color on attractiveness turned to be non-significant in the Owambo/Herrero and Nama sample, but remained significant in the Cameroonian sample. Variations in skin color thus represent an important factor of African female attractiveness within the African context, but they do not seem to affect judgements made by European raters. Sensitivity to some facial markers of female attractiveness thus seems to be restricted to regional populations and/or constrained by shared ethnicity.

Evidence of unique genetic diversity in Aspergillus fumigatus isolates from Cameroon.

Aspergillus fumigatus is a saprophytic fungus that can cause lethal invasive aspergillosis in immunocompromised patients. Recent studies have shown that Eurasian and North American populations of A.fumigatus often consist of genetically diverse strains. However, very little is known about African populations of A.fumigatus. Here, we characterise the genetic diversity and triazole susceptibility of A.fumigatus in Cameroon, West Africa. A total of 495 soil samples were obtained from nine collection sites in three Cameroonian regions. Nine microsatellite markers were used to genotype all 51 identified A.fumigatus isolates. In vitro susceptibility to itraconazole and voriconazole was tested using micro broth dilution. The 51 Cameroonian A.fumigatus isolates belonged to 45 genotypes. Consistent with recombination, 32 of 36 possible pairwise loci combinations are phylogenetically incompatible. Interestingly, evidence for geographic sub-structuring was found within Cameroon and the sub-population with the most evidence of recombination was also the least susceptible sub-population to the triazole antifungals tested. Furthermore, the Cameroonian sample was significantly differentiated from those in Eurasia and North America. Overall, our results indicate the genetic uniqueness of Cameroonian A.fumigatus populations and that additional novel genetic diversity likely exist in other parts of Africa.

Relationship Between Subjectively Evaluated Health and Fear of Death Among Elderly in Three Cultural Contexts.

It is often argued that declining health in elderly people makes death more salient and threatening. However, we argue that health, optimism, and social support interact to predict fear of death in samples from Cameroon, the Czech Republic, and Germany. Low health was associated with enhanced fear of death for participants who received only little social support. As the measure of optimism did not comply with psychometric requirements in the Cameroonian sample, the three-way interaction was tested only in the Czech and German samples. It was found that the two-way interaction was further qualified by optimism in that low health was associated with enhanced fear of death for participants with little social support unless they reported pronounced optimism. Thus, internal and external resources, respectively, can serve to buffer the effect of declining health on the fear of death in the elderly.

Imitative Learning of Nso and German Infants at 6 and 9 Months of Age

The present study focused on the assessment of imitation performance in a large sample of 6- and 9-month-old infants from two different cultural contexts: German middle-class infants from urban areas and Nso infants from a rural area in northwestern Cameroon were tested by using age-adapted deferred imitation tasks that were varied regarding their cultural familiarity (two types of instruments each being highly familiar for one of the two cultural contexts). Within both cultural groups and without being influenced by the cultural familiarity of the instruments, infants performed more target actions in the test compared with the baseline phase, even though this difference did not yield significance in the group of 6-month-old Cameroonian Nso infants. Moreover, a higher mean number of imitated actions has been observed for 9-month-olds compared with 6-month-olds demonstrating an age-related improvement of infants’ learning ability. Furthermore, at 9 months of age, German infants showed a higher level of baseline activity compared with the infants in the Cameroonian sample, which is assumed to be based on differences regarding the degree of object experiences. Results provide evidence that early in infancy, imitation is a universal learning tool in different cultural environments.

A Picture Story Exercise Set in a German and a Cameroonian Sample

Building on a recent study by Schultheiss, Liening, and Schad (2008 ), we examined the internal consistency, retest reliability, sample-level profile stability, and ipsative stability of a Picture Story Exercise (PSE) measure for implicit achievement, affiliation, and power motive. While Schultheiss et al. (2008 ) examined these indices by administering eight picture cues to students with 2 weeks between assessment occasions, in the present study adult samples from Germany (n = 129) and Cameroon (n = 122) provided data on five picture cues at two assessment times 18 months apart. Despite these differences, reliability indices are comparable to those presented by Schultheiss and colleagues: Internal consistency is low, but retest reliability and ipsative stability are in the expected range. The reliability of the PSE is also discussed and compared to the reliability of self-report and other non-self-report measures.

Genetic Structure of the Tiger Mosquito, Aedes albopictus, in Cameroon (Central Africa)

Background Aedes albopictus (Skuse, 1884) (Diptera: Culicidae), a mosquito native to Asia, has recently invaded all five continents. In Central Africa it was first reported in the early 2000s, and has since been implicated in the emergence of arboviruses such as dengue and chikungunya in this region. Recent genetic studies of invasive species have shown that multiple introductions are a key factor for successful expansion in new areas. As a result, phenotypic characters such as vector competence and insecticide susceptibility may vary within invasive pest species, potentially affecting vector efficiency and pest management. Here we assessed the genetic variability and population genetics of Ae. albopictus isolates in Cameroon (Central Africa), thereby deducing their likely geographic origin.Methods and ResultsMosquitoes were sampled in 2007 in 12 localities in southern Cameroon and analyzed for polymorphism at six microsatellite loci and in two mitochondrial DNA regions (ND5 and COI). All the microsatellite markers were successfully amplified and were polymorphic, showing moderate genetic structureamong geographic populations (FST = 0.068, P<0.0001). Analysis of mtDNA sequences revealed four haplotypes each for the COI and ND5 genes, with a dominant haplotype shared by all Cameroonian samples. The weak genetic variation estimated from the mtDNA genes is consistent with the recent arrival of Ae. albopictus in Cameroon. Phylogeographic analysis based on COI polymorphism indicated that Ae. albopictus populations from Cameroon are related to tropical rather than temperate or subtropical outgroups.ConclusionThe moderate genetic diversity observed among Cameroonian Ae. albopictus isolates is in keeping with recent introduction and spread in this country. The genetic structure of natural populations points to multiple introductions from tropical regions.

Central corneal thickness in black Cameroonian ocular hypertensive and glaucomatous subjects

PurposeTo evaluate central corneal thickness (CCT) in a black Cameroonian population of ocular hypertensive and glaucomatous subjects.Material and methodsThis was a prospective study undertaken with an ultrasonic pachymeter from January 2009 to December 2009 in an eye clinic (INNEL Medical center) in Yaoundé, Cameroon.ResultsOne hundred subjects (200 eyes) were enrolled in the study. Sixty subjects were glaucomatous (primary open angle glaucoma, POAG group), and 40 ocular hypertensive (OHT group). The mean age of the sample was 52.60 ± 12.23 years. For the whole sample, CCT was 534.71 ± 37.95 μm in the right eye and 533.61 ± 37.67 μm in the left eye, with no statistically significant difference between the 2 eyes (P = 0.446). CCT in the POAG group was 526.30 ± 37.34 μm in the right eye and 524.90 ± 35.92 μm in the left eye. CCT in the OHT group was 547.32 ± 35.71 μm in the right eye and 546.67 ± 36.85 μm in the left eye. There was a statistically significant difference between CCT of the 2 groups (right eye: P = 0.013; left eye: P = 0.007).ConclusionMean CCT of ocular hypertensive subjects was thicker than CCT of glaucomatous ones in our Cameroonian sample. However, in both ocular hypertensive or glaucomatous patients, CCT of black Cameroonians is thinner than that reported in other studies in Caucasian populations.

Identification of HIV-1 infected infants and young children using real-time RT PCR and dried blood spots from Uganda and Cameroon

Serodiagnosis of HIV infection in infants born to HIV-infected mothers is problematic due to the prolonged presence of maternal antibodies in infants. Nucleic acid-based amplification assays have been used to overcome this problem. Here a simplified, one-tube, real-time, duplex reverse transcription PCR (RT PCR) assay is shown to detect HIV-1 total nucleic acid (TNA) isolated from dried blood spots. The detection of TNA, as opposed to DNA alone, increases the HIV target molecules and thus makes the assay more robust. This method was used to detect HIV from the DBS collected from HIV-1 exposed infants and young children in Uganda ( n = 128) and Cameroon ( n = 315). The gold-standards used were a plasma viral assay in Uganda and Amplicor DNA assay in Cameroon. The concordance of this real-time assay and the gold standards was 99.2% (127/128) and 99.4% (313/315) with the Ugandan and Cameroonian samples, respectively. This simple and cost-effective assay is potentially useful for the diagnosis of pediatric HIV infection and for evaluating programs to reduce mother-to-child transmission of HIV-1.

Isolates in a corridor of migrations: a high-resolution analysis of Y-chromosome variation in Jordan

A high-resolution, Y-chromosome analysis using 46 binary markers has been carried out in two Jordan populations, one from the metropolitan area of Amman and the other from the Dead Sea, an area geographically isolated. Comparisons with neighboring populations showed that whereas the sample from Amman did not significantly differ from their Levantine neighbors, the Dead Sea sample clearly behaved as a genetic outlier in the region. Its high R1*-M173 frequency (40%) has until now only been found in northern Cameroonian samples. This contrasts with the comparatively low presence of J representatives (9%), which is the modal clade in Middle Eastern populations, including Amman. The Dead Sea sample also showed a high presence of E3b3a-M34 lineages (31%), which is only comparable to that found in Ethiopians. Although ancient and recent ties with sub-Saharan and eastern Africans cannot be discarded, it seems that isolation, strong drift, and/or founder effects are responsible for the anomalous Y-chromosome pool of this population. These results demonstrate that, at a fine scale, the smooth, continental clines detected for several Y-chromosome markers are often disrupted by genetically divergent populations.

Evaluation of different V3 peptides in an enzyme immunoassay for specific HIV type 1 group O antibody detection.

Strategies to discriminate group O from group M infections need to be improved. We have developed and evaluated an HIV-1 group O V3 peptide-based enzyme immunoassay (PEIA) for specific HIV-1 group O antibody detection among HIV-1-infected patients. Synthetic peptides, derived from the amino acid sequences of the V3 loop of 15 different group O strains and 7 group O consensus sequences, were evaluated in a PEIA against a panel of genetically confirmed group O (n = 33), group M (n = 90), and HIV-1 antibody-negative sera (n = 17). The best-performing PEIA(s) were then used to screen 134 sera of European and 336 sera of Cameroonian origin for the presence of anti-HIV-1 group O antibodies. The reactivity of reference ("gold standard") sera to individual peptides in the PEIA resulted in the selection of five different peptides with sensitivities (sens), specificities (spec), and test efficiencies (TEs) in the range of 90 to 100%. Improvement of the PEIA was obtained with simultaneous reactivity of at least two different peptides in separate wells of an ELISA plate, together with stringent criteria for positivity. We were able to select seven peptide combinations each with a sens, spec, and TE of 96.9, 100, and 99.2%, respectively. None of the 134 European and 4 (1.2%) of the 336 Cameroonian samples sera were group O positive in the optimized HIV-1 group O PEIA; this was confirmed by the repeated presence of reactives, in agreement with the present knowledge of group O infection distribution. Finally, we were able to develop a strategy with a higher TE (99.2%) than the previously used ANT-70 (98.5%) and ANT-70/MVP5180 (95.7%). Our results show that optimal specificity rather than optimal sensitivity makes the V3 PEIA a sufficiently accurate epidemiological tool to be useful in estimating specifically group O infection among HIV-1-infected patients.