Missing persons patterns from Mexico: evidence of a forensic emergency crisis.

The relatives of missing persons in Mexico have denounced the slowness with which a court prosecution file is created by the justice administration system. Theoretically, the search is immediate, but many cases must wait 72 h to build an investigation folder as a legal criterion. This standard has been copied from the UK and Australian police reports without adapting to the Mexican context.

Neanderthal introgression in SCN9A impacts mechanical pain sensitivity.

The Nav1.7 voltage-gated sodium channel plays a key role in nociception. Three functional variants in the SCN9A gene (encoding M932L, V991L, and D1908G in Nav1.

Teaching Forensic Entomology, Forensic Anthropology, and Haematology & Serology during the COVID-19 pandemic: Practical activities for distance learning.

As the COVID-19 pandemic upended college and university instruction throughout the world, instructors were hard-pressed to find suitable alternatives for practical activities typically carried out outside of classrooms-in laboratories, workshops, clinics, and in the field. In response to this unanticipated challenge, they relied on their ingenuity to achieve pre-pandemic goals under pandemic conditions that necessitated the shift to online teaching. The Forensic Science Undergraduate Program housed in the School of Medicine of the National Autonomous University of Mexico was not exempt from this educational upheaval but, due to its interdisciplinary nature, required creating and/or adopting a wide range of activities capable of training students to perform practical tasks associated with subject areas that span the natural and social sciences, the humanities, and the law.

The impact of socioeconomic and phenotypic traits on self-perception of ethnicity in Latin America.

Self-perception of ethnicity is a complex social trait shaped by both, biological and non-biological factors. We developed a comprehensive analysis of ethnic self-perception (ESP) on a large sample of Latin American mestizos from five countries, differing in age, socio-economic and education context, external phenotypic attributes and genetic background. We measured the correlation of ESP against genomic ancestry, and the influence of physical appearance, socio-economic context, and education on the distortion observed between both.

Analysis of C concentration in teeth to estimate the year of birth in the Mexican population.

The C analysis of permanent teeth employing nuclear techniques has a direct application in Forensic Sciences since teeth are the hardest part of the human body and can survive natural decay or extreme conditions. After the first Accelerator Mass Spectrometry Laboratory AMS-LEMA at UNAM, our research group is interested in reproducing C analysis on teeth as other countries to estimate age in the Mexican population samples. One of the main goals of this exploratory study is to know the best methodology considering relevant biological factors based on differences in tissues (enamel and dentin) that allows us to know the year of birth through the C concentration comparing the yield between C analyses from carbonate in enamel and collagen in dentin.

Physician Prehospital Care in Mexico City: Retrospective Analysis of Endotracheal Intubation in Patients with Severe Head Trauma.

Introduction: In Mexico, physicians have become part of public service prehospital care. Head injured patients are a sensitive group that can benefit from early advanced measures to protect the airway, with the objective to reduce hypoxia and maintain normocapnia.

Problem: The occurrence of endotracheal intubation to patients with severe head injuries by prehospital physicians working at Mexico City's Service of Emergency Medical Care (SAMU) is unknown.

Latin Americans show wide-spread Converso ancestry and imprint of local Native ancestry on physical appearance.

Historical records and genetic analyses indicate that Latin Americans trace their ancestry mainly to the intermixing (admixture) of Native Americans, Europeans and Sub-Saharan Africans. Using novel haplotype-based methods, here we infer sub-continental ancestry in over 6,500 Latin Americans and evaluate the impact of regional ancestry variation on physical appearance. We find that Native American ancestry components in Latin Americans correspond geographically to the present-day genetic structure of Native groups, and that sources of non-Native ancestry, and admixture timings, match documented migratory flows.

Mitochondrial DNA Analysis of Mazahua and Otomi Indigenous Populations from Estado de México Suggests a Distant Common Ancestry.

The indigenous Mazahua and Otomi have inhabited the same localities in Estado de México since pre-Columbian times. Their languages, Mazahua and Otomi, belong to the Oto-Manguean linguistic family, and although they share cultural traditions and a regional history that suggest close genetic relationships and common ancestry, the historical records concerning their origin are confusing. To understand the biological relationships between Mazahua and Otomi, we analyzed mitochondrial DNA (mtDNA) genetic variation.

Developmental pathways inferred from modularity, morphological integration and fluctuating asymmetry patterns in the human face.

Facial asymmetries are usually measured and interpreted as proxies to developmental noise. However, analyses focused on its developmental and genetic architecture are scarce. To advance on this topic, studies based on a comprehensive and simultaneous analysis of modularity, morphological integration and facial asymmetries including both phenotypic and genomic information are needed.

Correction: Socioeconomic Status Is Not Related with Facial Fluctuating Asymmetry: Evidence from Latin-American Populations.

[This corrects the article DOI: 10.1371/journal.pone.

Socioeconomic Status Is Not Related with Facial Fluctuating Asymmetry: Evidence from Latin-American Populations.

The expression of facial asymmetries has been recurrently related with poverty and/or disadvantaged socioeconomic status. Departing from the developmental instability theory, previous approaches attempted to test the statistical relationship between the stress experienced by individuals grown in poor conditions and an increase in facial and corporal asymmetry. Here we aim to further evaluate such hypothesis on a large sample of admixed Latin Americans individuals by exploring if low socioeconomic status individuals tend to exhibit greater facial fluctuating asymmetry values.

A genome-wide association scan implicates DCHS2, RUNX2, GLI3, PAX1 and EDAR in human facial variation.

We report a genome-wide association scan for facial features in ∼6,000 Latin Americans. We evaluated 14 traits on an ordinal scale and found significant association (P values<5 × 10(-8)) at single-nucleotide polymorphisms (SNPs) in four genomic regions for three nose-related traits: columella inclination (4q31), nose bridge breadth (6p21) and nose wing breadth (7p13 and 20p11). In a subsample of ∼3,000 individuals we obtained quantitative traits related to 9 of the ordinal phenotypes and, also, a measure of nasion position.

A genome-wide association scan in admixed Latin Americans identifies loci influencing facial and scalp hair features.

We report a genome-wide association scan in over 6,000 Latin Americans for features of scalp hair (shape, colour, greying, balding) and facial hair (beard thickness, monobrow, eyebrow thickness). We found 18 signals of association reaching genome-wide significance (P values 5 × 10(-8) to 3 × 10(-119)), including 10 novel associations. These include novel loci for scalp hair shape and balding, and the first reported loci for hair greying, monobrow, eyebrow and beard thickness.

Shifts in subsistence type and its impact on the human skull's morphological integration.

Objective: Here we evaluate morphological integration patterns and magnitudes in different skull regions to detect if shifts in morphological integration are correlated to the appearance of more processed (softer) diets.

Methods: To do so, three transitional populations were analyzed, including samples from groups that inhabited the same geographical region and for which the evidence shows that major changes occurred in their subsistence mode. Ninety three-dimensional landmarks were digitized on 357 skulls and used as the raw data to develop geometric morphometric analyses.

A genome-wide association study identifies multiple loci for variation in human ear morphology.

Here we report a genome-wide association study for non-pathological pinna morphology in over 5,000 Latin Americans. We find genome-wide significant association at seven genomic regions affecting: lobe size and attachment, folding of antihelix, helix rolling, ear protrusion and antitragus size (linear regression P values 2 × 10(-8) to 3 × 10(-14)). Four traits are associated with a functional variant in the Ectodysplasin A receptor (EDAR) gene, a key regulator of embryonic skin appendage development.

Facial asymmetry and genetic ancestry in Latin American admixed populations.

Fluctuating and directional asymmetry are aspects of morphological variation widely used to infer environmental and genetic factors affecting facial phenotypes. However, the genetic basis and environmental determinants of both asymmetry types is far from being completely known. The analysis of facial asymmetries in admixed individuals can be of help to characterize the impact of a genome's heterozygosity on the developmental basis of both fluctuating and directional asymmetries.

The relationship between facial shape asymmetry and attractiveness in Mexican students.

Objectives: It has been postulated that symmetric faces are considered more attractive than asymmetric ones because symmetry may signal high quality due to developmental stability. However, other studies showed that both symmetric and slightly asymmetric faces are considered attractive. Here we aim to explore this discrepancy, beginning with the analysis of the normal prevalence of facial symmetry in a population as a necessary first step prior to any attractiveness assessment.

Admixture in Latin America: geographic structure, phenotypic diversity and self-perception of ancestry based on 7,342 individuals.

The current genetic makeup of Latin America has been shaped by a history of extensive admixture between Africans, Europeans and Native Americans, a process taking place within the context of extensive geographic and social stratification. We estimated individual ancestry proportions in a sample of 7,342 subjects ascertained in five countries (Brazil, Chile, Colombia, México and Perú). These individuals were also characterized for a range of physical appearance traits and for self-perception of ancestry.

FGFR1 signaling is associated with the magnitude of morphological integration in human head shape.

Objectives: The head can be used as a model to study complex phenotypes controlled simultaneously by morphological integration (MI) due to common factors, and modular patterns caused by local factors affecting the development and functional demands of specific structures. The fibroblast growth factor and receptor system (FGF/FGFR) participates in cell communication and pattern formation in osseous tissues, among others, and there is compelling evidence from mouse model studies suggesting a role of the FGF/FGFR pathway as a covariance-generating signaling process in head development. Here we use human data to test if specific genetic variants of another gene of this pathway, the FGFR1 gene, can be associated with differences in the integration of the head.

Lack of support for the association between facial shape and aggression: a reappraisal based on a worldwide population genetics perspective.

Antisocial and criminal behaviors are multifactorial traits whose interpretation relies on multiple disciplines. Since these interpretations may have social, moral and legal implications, a constant review of the evidence is necessary before any scientific claim is considered as truth. A recent study proposed that men with wider faces relative to facial height (fWHR) are more likely to develop unethical behaviour mediated by a psychological sense of power.

Comparison of methods to determine sex by evaluating the greater sciatic notch: Visual, angular and geometric morphometrics.

Sex estimation is the first step for biological profile reconstruction of an unknown skeleton (archaeological or contemporary) and consequently for positive identification of skeletal remains recovered from forensic settings. Several tools have been developed using different osseous structures. With the intention to provide an objective method comparison, we reported the analysis of three different methods (visual, metric and geometric morphometrics) for sex assessment of the greater sciatic notch.