Probabilistic coverage of the frontal aslant tract in young adults: Insights into individual variability, lateralization, and language functions.

The frontal aslant tract (FAT) is a crucial neural pathway of language and speech, but little is known about its connectivity and segmentation differences across populations. In this study, we investigate the probabilistic coverage of the FAT in a large sample of 1065 young adults. Our primary goal was to reveal individual variability and lateralization of FAT and its structure-function correlations in language processing. The study utilized diffusion MRI data from 1065 subjects obtained from the Human Connectome Project. Automated tractography using DSI Studio software was employed to map white matter bundles, and the results were examined to study the population variation of the FAT. Additionally, anatomical dissections were performed to validate the fiber tracking results. The tract-to-region connectome, based on Human Connectome Project-MMP parcellations, was utilized to provide population probability of the tract-to-region connections. Our results showed that the left anterior FAT exhibited the most substantial individual differences, particularly in the superior and middle frontal gyrus, with greater variability in the superior than the inferior region. Furthermore, we found left lateralization in FAT, with a greater difference in coverage in the inferior and posterior portions. Additionally, our analysis revealed a significant positive correlation between the left FAT inferior coverage area and the performance on the oral reading recognition (p = .016) and picture vocabulary (p = .0026) tests. In comparison, fractional anisotropy of the right FAT exhibited marginal significance in its correlation (p = .056) with Picture Vocabulary Test. Our findings, combined with the connectivity patterns of the FAT, allowed us to segment its structure into anterior and posterior segments. We found significant variability in FAT coverage among individuals, with left lateralization observed in both macroscopic shape measures and microscopic diffusion metrics. Our findings also suggested a potential link between the size of the left FAT's inferior coverage area and language function tests. These results enhance our understanding of the FAT's role in brain connectivity and its potential implications for language and executive functions.

Healthcare utilization is increased in children living in urban areas, with ethnicity-related disparities: A big data analysis study.

This study aimed to investigate differences in pediatric healthcare utilization in Israel over 10 years by examining differences across populations defined by living environment and ethnicity. Data was obtained from the Clalit Health Care data warehouse, covering over 250,000 children residing in Haifa and Western Galilee districts. The population groups were categorized based on ethnicity (Jewish vs Arab) and residential settings (urban vs rural). Healthcare utilization was consistently higher among Jewish than Arab children, irrespective of the specific dimension analyzed. Additionally, urban-dwelling children exhibited higher usage rates than those residing in rural areas in all investigated dimensions. However, Jewish children showed significantly about 18% lower hospitalization rates than Arab children across all years (P < 0.001). No significant differences in hospitalizations were observed between urban and rural children (RR 0.999, CI (0.987-1.011)). Notably, the study revealed reduced antibiotic consumption and hospitalizations over the years for all populations. Additionally, we found that Arab children and those living in rural areas had reduced access to healthcare, as evidenced by 10-40% fewer physician visits, laboratory tests, and imaging (P < 0.001).    Conclusion: This study highlights the substantial population-based disparities in healthcare utilization among children in Israel despite the equalizing effect of the national health insurance law. Rural and low socioeconomic populations seem to have reduced healthcare access, showing decreased healthcare utilization. Consequently, it is imperative to address these disparities and implement targeted interventions to enhance healthcare access for Arab children and rural communities. The decline in antibiotic usage and hospitalizations suggests positive trends in pediatric health care, necessitating ongoing efforts to ensure equitable access and quality of care for all populations. What is Known: • Healthcare systems worldwide vary in coverage and accessibility, including Israel, which stands out for its diverse population. • Existing research primarily focuses on healthcare utilization among adults, leaving a need for comprehensive data on children's healthcare patterns globally. What is New: • Investigating over 250,000 children, this study reveals higher healthcare utilization among Jewish and urban children across all dimensions. • Despite Israel's national health insurance law, the study underscores the significant population-based disparities in healthcare utilization.

Intra-species quantification reveals differences in activity and sleep levels in the yellow fever mosquito, Aedes aegypti.

Aedes aegypti is an important mosquito vector of human disease with a wide distribution across the globe. Climatic conditions and ecological pressure drive differences in the biology of several populations of this mosquito species, including blood-feeding behaviour and vector competence. However, no study has compared activity and/or sleep among different populations/lineages of Ae. aegypti. Having recently established sleep-like states in three mosquito species with observable differences in timing and amount of sleep among species, we investigated differences in activity and sleep levels among 17 Ae. aegypti lines drawn from both its native range in Africa and its invasive range across the global tropics. Activity monitoring indicates that all the lines show consistent diurnal activity, but significant differences in activity level, sleep amount, number of sleep bouts and bout duration were observed among the lines. The variation in day activity was associated with differences in host preference and ancestry for the lineages collected in Africa. This study provides evidence that the diurnal sleep and activity profiles for Ae. aegypti are consistent, but there are significant population differences for Ae. aegypti sleep and activity levels and interactions with host species may significantly impact mosquito activity.

Accommodating population differences when validating risk prediction models.

Validation of risk prediction models in independent data provides a more rigorous assessment of model performance than internal assessment, for example, done by cross-validation in the data used for model development. However, several differences between the populations that gave rise to the training and the validation data can lead to seemingly poor performance of a risk model. In this paper we formalize the notions of "similarity" or "relatedness" of the training and validation data, and define reproducibility and transportability. We address the impact of different distributions of model predictors and differences in verifying the disease status or outcome on measures of calibration, accuracy and discrimination of a model. When individual level information from both the training and validation data sets is available, we propose and study weighted versions of the validation metrics that adjust for differences in the risk factor distributions and in outcome verification between the training and validation data to provide a more comprehensive assessment of model performance. We provide conditions on the risk model and the populations that gave rise to the training and validation data that ensure a model's reproducibility or transportability, and show how to check these conditions using weighted and unweighted performance measures. We illustrate the method by developing and validating a model that predicts the risk of developing prostate cancer using data from two large prostate cancer screening trials.

Rest-activity profiles among U.S. adults in a nationally representative sample: a functional principal component analysis.

BACKGROUND: The 24-h rest and activity behaviors (i.e., physical activity, sedentary behaviors and sleep) are fundamental human behaviors essential to health and well-being. Functional principal component analysis (fPCA) is a flexible approach for characterizing rest-activity rhythms and does not rely on a priori assumptions about the activity shape. The objective of our study is to apply fPCA to a nationally representative sample of American adults to characterize variations in the 24-h rest-activity pattern, determine how the pattern differs according to demographic, socioeconomic and work characteristics, and examine its associations with general health status. METHODS: The current analysis used data from adults 25 or older in the National Health and Nutrition Examination Survey (NHANES, 2011-2014). Using 7-day 24-h actigraphy recordings, we applied fPCA to derive profiles for overall, weekday and weekend rest-activity patterns. We examined the association between each rest-activity profile in relation to age, gender, race/ethnicity, education, income and working status using multiple linear regression. We also used multiple logistic regression to determine the relationship between each rest-activity profile and the likelihood of reporting poor or fair health. RESULTS: We identified four distinct profiles (i.e., high amplitude, early rise, prolonged activity window, biphasic pattern) that together accounted for 86.8% of total variation in the study sample. We identified numerous associations between each rest-activity profile and multiple sociodemographic characteristics. We also found evidence suggesting the associations differed between weekdays and weekends. Finally, we reported that the rest-activity profiles were associated with self-rated health. CONCLUSIONS: Our study provided evidence suggesting that rest-activity patterns in human populations are shaped by multiple demographic, socioeconomic and work factors, and are correlated with health status.

Interleukin-8 genetic diversity, haplotype structure and production differ in two ethnically distinct South African populations.

A single nucleotide polymorphism (SNP), 251 bases upstream from the IL-8 transcription start (-251A>T, rs4073), has been extensively investigated in cancers and inflammatory and infectious diseases in predominantly European and Asian populations. We sequenced the IL-8 gene of 109 black and 32 white South African (SA) individuals and conducted detailed characterization of gene variation and haplotype structure. IL-8 production in phytohaemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMCs) of a subset (black: N = 22; white: N = 32) of these individuals was measured using ELISA. Select variants were genotyped for additional black individuals (N = 141), and data from the 1000 Genomes Project were used for haplotype analysis and comparative purposes. In white individuals, the -251A>T SNP formed part of a prevalent six-variant haplotype [haplotype frequency (HF): 61%], Hap-1C, involving the following variants: -251A>T; +394T>G (rs2227307); +780C>T (rs2227306); +1240->A (rs2227541); +1635C>T (rs2227543) and +2770A>T (rs2227543). Hap-1C (-251T+394T+780C+1240+A+1635C+2770A) was composed of two three-variant sub-haplotypes [Hap-1Ca: -251T+394T+1240+A; Hap-1Cb: +780C+1635C+2770A) sharing similarities with haplotypes identified in the black population. Hap-1C was found to be present in European, East and South Asian populations. Four haplotypes were identified in the black population with the two prevalent haplotypes each comprised of two variants: Hap-1B [-251A>T and +1240->A; -251T+1240+A; HF: 14%] and Hap-2B [-743T>C (rs2227532) and +2452A>C (rs2227545); -743C+2452C; HF: 13%]. Populations did not differ in unstimulated PBMC IL-8 production. Upon PHA stimulation, PBMCs from white individuals produced more IL-8 (P = 0.04), suggesting the -251T allele is responsible for higher production, however further analysis revealed that Hap-1C (and constituent sub-haplotypes), did not associate with IL-8 production. Populations did however differ in monocyte number with the white population having significantly more monocytes compared to the black population (P = 0.025), and furthermore monocyte number strongly correlated with IL-8 production in both population groups (black: p = 0.0002, r = 0.71; white: P = 0.0005, r = 0.59). Hap-1B, Hap-2B, and a SNP located one base pair upstream of the IL-8 ATG start codon, +100C>T SNP (rs2227538), all associated with higher IL-8 production in the black population - individuals harbouring at least one of these haplotypes/variant associated with higher IL-8 production (P = 0.003) compared to individuals without. The black population was enriched for individuals harbouring Hap-1B and/or Hap-2B compared to the 1000 Genomes project sub-Saharan African population (P = 0.006), suggesting that SA black individuals may be high IL-8 producers. Given the paucity of IL-8-related studies that have been conducted in populations from sub-Saharan Africa, this study has significantly increased our understanding of this important chemokine in the South African population.

Ecological niche differences between two polyploid cytotypes of Saxifraga rosacea.

PREMISE: Different cytotypes of a species may differ in their morphology, phenology, physiology, and their tolerance of extreme environments. We studied the ecological niches of two subspecies of Saxifraga rosacea with different ploidy levels: the hexaploid Central European endemic subspecies sponhemica and the more widely distributed octoploid subspecies rosacea. METHODS: For both cytotypes, we recorded local environmental conditions and mean plant trait values in populations across their areas of distribution, analyzed their distributions by niche modeling, studied their performance at two transplant sites with contrasting conditions, and experimentally tested their cold resistance. RESULTS: Mean annual temperature was higher in hexaploid than in octoploid populations and experiments indicated that frost tolerance of the hexaploid is lower than that of the octoploid. Reproduction of octoploids from Central Europe was higher than that of hexaploids at a transplant site in subarctic Iceland, whereas the opposite was true in temperate Luxembourg, indicating adaptation of the octoploids to colder conditions. Temperature variables were also most important in niche models predicting the distribution of the two cytotypes. Genetic differences in survival among populations were larger for the octoploids than for the hexaploids in both field gardens, suggesting that greater genetic variability may contribute to the octoploid's larger distributional range. CONCLUSIONS: Our results support the hypotheses that different cytotypes may have different niches leading to spatial segregation, and that higher ploidy levels can result in a broader ecological niche and greater tolerance of more extreme conditions.

Genetic studies on systemic lupus erythematosus in East Asia point to population differences in disease susceptibility.

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with extreme clinical heterogeneity and significant differences between populations. East Asian populations are known to have higher prevalence and more severe clinical manifestations for SLE than Europeans. The difference could be the result of genetic and environmental factors, and the interactions between them. Thus, identifying genetic associations from diverse populations provides an opportunity to better understand the genetic architecture of this heterogeneous disease. It is also necessary to elucidate population differences and to apply the findings in future stratified treatment of the disease, with ethnicity likely a major factor to consider. Indeed, it has shown that there are significant differences between East Asians and European populations in several genetic loci for SLE. Genetic studies on SLE are very active in East Asian countries and there have been close collaborations among scientists in this region. Here, we document some work done in this region on SLE genetic research and discuss the aspect of population differences.

Evolutionary Origins of the Differences in Osteoporosis Risk in US Populations.

Over the past 50 years, it has been increasingly evident that there are population differences in bone mass and the risk of osteoporosis. In the United States, many studies have reported a lower prevalence of osteoporosis in African Americans compared with people of European descent. If we trace the trajectory of changes in lifeways from the earliest migrations of early Homo out of Africa over the past two million years or so, to include lower vitamin D levels in higher latitudes; more meat in the diet; increasing sedentism; and a longer lifespan/longer postmenopausal period, it is not surprising that osteoporosis occurs more frequently in populations of European descent. While many scholars have explored the apparent "paradox" of higher bone mass, lower vitamin D levels, and higher parathyroid hormone levels among African Americans, this brief review of evolutionary shifts that affected our species may change the approach to understanding the current population differences in the United States.

Vocal Repertoire and Intraspecific Variation within Two Loud Calls of the Small-Eared Greater Galago (Otolemur garnettii) in Tanzania and Kenya.

Vocal repertoires and call structure can provide insights into the behaviour and evolution of species, as well as aid in taxonomic classification. Nocturnal primates have large vocal repertoires. This suggests that acoustic communication plays an important role in their life histories. Little is known about the behavioural context or the intraspecific variation of their vocalisations. We used autonomous recording units and manual recorders to investigate the vocal behaviour and structure of loud calls of the small-eared greater galago (Otolemur garnettii)in Kenya and Tanzania. We describe the vocal repertoire, temporal calling patterns and structure of 2 loud calls of 2 subspecies: O. g. panganiensis and O. g. kikuyuensis. We found considerable intraspecific structural differences in both loud calls. These are congruent with the current subspecies classification. Differences in vocalisations among populations are not consistent with the "acoustic adaptation hypothesis," rather they are likely a result of geographic variation due to isolation caused by vegetational barriers in southern Kenya.

Differences between populations in host manipulation by the tapeworm Schistocephalus solidus - is there local adaptation?

Host manipulation whereby a parasite increases its transmission to a subsequent host by altering the behaviour of its current host is very far spread. It also occurs in host-parasite systems that are widely distributed. This offers the potential for local adaptation. The tapeworm Schistocephalus solidus modifies its first intermediate copepod host's predation susceptibility to suit its own needs by reducing its activity before it becomes infective and increasing it thereafter. To investigate potential differences in host manipulation between different populations and test for potential local adaptation with regard to host manipulation, I experimentally infected hosts from two distinct populations with parasites from either population in a fully crossed design. Host manipulation differed between populations mostly once the parasite had reached infectivity. These differences in infective parasites were mostly due to differences between different parasite populations. In not yet infective parasites, however, host population also had a significant effect on host manipulation. There was no evidence of local adaptation; parasites were able to manipulate foreign and local hosts equally well. Likewise, hosts were equally poor at resisting host manipulation by local and foreign parasites.

Divergences in learning and memory among wild zebrafish: Do sex and body size play a role?

Given its diverse ecological distribution, zebrafish has great potential for investigations on the effect of habitat characteristics on cognition. Studies were conducted on four wild-caught zebrafish populations to understand the role of native habitat, sex, and body size in determining learning through a novel task associated with a food reward. The habitat variables, namely, the relative abundances of zebrafish and predatory fish and the substrate and vegetation diversity, were quantified during fish sampling. Fish were subjected to a novel task to find a food reward in a maze over successive training trials followed by a test for memory. Performances of subjects were based on time taken to find the food reward and number of mistakes made during trials, and tests for memory. The experiments revealed significant differences in learning rates and memory across populations. Males made significantly fewer mistakes than females only within two populations. No relationship between performance and body size was observed. The differences in learning and memory among wild zebrafish could be due to differences in predation, complexity, and stability of the native habitats. These findings suggest the possible role of multiple interacting factors in determining learning and memory among populations and point to a need for incorporating effects of several factors in future studies.

Lynn's r/k selection theory of criminality revisited: Consideration of individual differences and developmental life history contributions to the patterning of population differences in antagonistic social strategies.

We revisit an old theory proposed by Lynn, connecting race differences in criminality and psychopathy with r/k selection. The origin of this group-difference is attributed to cold-selection in the Pleistocene. We contend that newer models of Life History Theory provide a better rubric within which to evaluate Lynn's arguments as a) they better account for the adaptive logic of the coherence pattern among the traits characteristic of so-called 'psychopathic personality', b) provide a normatively free language with which group differences in behavior can be described, and c) make predictions at the level of both the individual and intra-individual (developmental) levels, which permit the role of environmental contributions to these dispositions to be better comprehended. Thus newer approaches to understanding life history are necessarily more empirically nuanced. We also consider the merits of future, more systematic studies along the lines of Lynn's contribution.

Age estimation of immature human skeletal remains from the metaphyseal and epiphyseal widths of the long bones in the post-natal period.

OBJECTIVES: This study provides regression and classical calibration models for the estimation of age from the dimensions of the metaphyses and epiphyses of the six long bones. METHODS: A sample of 148 known sex and age individuals (56 females and 92 males), aged between birth and 12 years of age, selected from Portuguese and English skeletal collections. Age estimation models were obtained separately for each sex and for the sexes combined, for the entire sample and for the sample divided into two subsamples at the age of 2 years. RESULTS: The best performing epiphysis is the proximal epiphysis of the tibia. For the metaphyses, the distal metaphysis of the tibia and the proximal metaphysis of the femur are best for individuals below and above 2 years of age, respectively. Growth of the metaphyses is similar to that of the diaphysis. Results suggest that age can be as accurately estimated from the width of the metaphyses and epiphyses as from the length of the diaphyses, or as from the length of the deciduous and permanent teeth. CONCLUSIONS: These models may be useful for fragmentary material in both archaeological and forensic contexts. However, due to the background of the samples, the models would be most applicable to individuals exposed to adverse environmental conditions during growth and development. Metaphyseal and epiphyseal widths may be less affected by ecological conditions than diaphyseal length.

Ontogeny of prosocial behavior across diverse societies.

Humans are an exceptionally cooperative species, but there is substantial variation in the extent of cooperation across societies. Understanding the sources of this variability may provide insights about the forces that sustain cooperation. We examined the ontogeny of prosocial behavior by studying 326 children 3-14 y of age and 120 adults from six societies (age distributions varied across societies). These six societies span a wide range of extant human variation in culture, geography, and subsistence strategies, including foragers, herders, horticulturalists, and urban dwellers across the Americas, Oceania, and Africa. When delivering benefits to others was personally costly, rates of prosocial behavior dropped across all six societies as children approached middle childhood and then rates of prosociality diverged as children tracked toward the behavior of adults in their own societies. When prosocial acts did not require personal sacrifice, prosocial responses increased steadily as children matured with little variation in behavior across societies. Our results are consistent with theories emphasizing the importance of acquired cultural norms in shaping costly forms of cooperation and creating cross-cultural diversity.

Consanguinity in Saudi Arabia: a unique opportunity for pediatric kidney research.

Identification of disease-related genes is a critical step in understanding the molecular basis of disease and developing targeted therapies. The genetic study of diseases occurring in the offspring of consanguineous unions is a powerful way to discover new disease genes. Pediatric nephrology provides an excellent example because ∼70% of cases of kidney disease in childhood are congenital with a likely genetic basis. This percentage is likely to be even higher in countries with a high consanguinity rate, such as the Kingdom of Saudi Arabia. However, there are a number of challenges, such as cultural, legal, and religious restrictions, that should be appreciated before carrying out genetic research in a tradition-bound country. In this article, we discuss the background, opportunities, and challenges involved with this unique opportunity to conduct studies of such genetic disorders. Keys to success include collaboration and an understanding of local traditions and laws.

Nut-cracking success and efficiency in two wild capuchin monkey populations.

Capuchins can employ several strategies to deal with environmental challenges, such as using stone tools to access encapsulated resources. Nut-cracking is customary in several capuchin populations and can be affected by ecological and cultural factors; however, data on success and efficiency are only known for two wild populations. In this work, using camera traps, we assessed palm nut-cracking success and efficiency in two newly studied wild bearded capuchin populations (Sapajus libidinosus) and compared them with other sites. We tested the hypothesis that the overall success and efficiency of nut-cracking would be similar between sites when processing similar resources, finding partial support for it. Although using hammerstones of different sizes, capuchins had a similar success frequency. However, efficiency (number of strikes to crack a nut) was different, with one population being more efficient. We also tested whether success and efficiency varied between sexes in adults. We predict adult males would be more successful and efficient when cracking hard nuts. We found no differences between the sexes in one site but found sex differences in the other, although also for the low-resistant nut, which was unexpected. Our data add to the knowledge of capuchin nut-cracking behaviour flexibility, variance and potential cultural traits.

Determining impairment in the Swedish, Polish and German ECAS: the importance of adjusting for age and education.

Objective: Age and years of education are strong predictors of cognitive performance in several versions of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS) and cutoffs for the Swedish and Polish versions are not established yet. Here we evaluated the performance of healthy subjects on the national versions of the Swedish and Polish ECAS and compared cognitive performance on three European translations of the ECAS. Methods: The ECAS performances of healthy subjects from Sweden (n = 111), Poland (n = 124) and Germany (n = 86) were compared. Based on the test results on the national versions of ECAS, age- and education-adjusted cutoffs were compared for the German, Swedish and Polish versions, respectively. Results: Age and years of education correlated with performance in the ECAS. Swedish subjects under the age of 60 years and Swedish subjects with low education level scored significantly higher in memory than the respective German and Polish subgroups. German and Polish subjects over 60 years of age performed significantly better in language than the respective Swedish subgroup. The Polish cohort in total had lower executive scores compared to the Swedish cohort, and lower than the German subjects in the higher education subgroup. Conclusions: The results highlight the importance of establishing age- and education-adjusted ECAS cutoffs not only in general, but also for seemingly similar populations of different origins. The results should be taken into account when comparing cognition data across patient populations including in drug trials where an ECAS test result is being used as an inclusion criterium or outcome measure.

Population differences in completeness and reliability of Dutch COVID-19 registry data: The influence of testing policy, test readiness, and registration policy from an epidemiological perspective.

During the COVID-19 pandemic, the bidirectional relationship between policy and data reliability has been a challenge for researchers of the local municipal health services. Policy decisions on population specific test locations and selective registration of negative test results led to population differences in data quality. This hampered the calculation of reliable population specific infection rates needed to develop proper data driven public health policy.

Predicting Eye and Hair Color in a Turkish Population Using the HIrisPlex System.

Forensic DNA Phenotyping (FDP) can reveal the appearance of an unknown individual by predicting the ancestry, phenotype (i.e., hair, eye, skin color), and age from DNA obtained at the crime scene. The HIrisPlex system has been developed to simultaneously predict eye and hair color. However, the prediction accuracy of the system needs to be assessed for the tested population before implementing FDP in casework. In this study, we evaluated the performance of the HIrisPlex system on 149 individuals from the Turkish population. We applied the single-based extension (SNaPshot chemistry) method and used the HIrisPlex online tool to test the prediction of the eye and hair colors. The accuracy of the HIrisPlex system was assessed through the calculation of the area under the receiver characteristic operating curves (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The results showed that the proposed method successfully predicted the eye and hair color, especially for blue (100%) and brown (95.60%) eye and black (95.23) and brown (98.94) hair colors. As observed in previous studies, the system failed to predict intermediate eye color, representing 25% in our cohort. The majority of incorrect predictions were observed for blond hair color (40.7%). Previous HIrisPlex studies have also noted difficulties with these phenotypes. Our study shows that the HIrisPlex system can be applied to forensic casework in Turkey with careful interpretation of the data, particularly intermediate eye color and blond hair color.