Search Results (130)

The relationship between prostate-specific antigen (PSA) and testosterone during sexual maturation in male dromedary camels remains poorly understood, despite its clinical importance in prostate health monitoring and reproductive management. In 50 intact male dromedaries divided into five age groups, we looked at the longitudinal changes of these biomarkers. Testosterone showed a substantial correlation with age (r = 0.89), although PSA only showed a modest connection (r = 0.41). Phase-specific correlations between PSA and testosterone were non-significant, ranging from slightly negative (r = −0.39) during the transitional phase to modestly positive (r = 0.40) after puberty. In conclusion, these findings demonstrate a distinct divergence between PSA and testosterone trajectories during camel maturation, which may reflect developmental and functional changes associated with prostatic cellular differentiation and functional maturation during puberty, with the possibility of specific regulatory mechanisms that may not be entirely androgen-dependent. Establishing these age-specific profiles provides an essential biomarker framework to enhance reproductive health assessment and veterinary management strategies in dromedary camels. Full article

This qualitative study examines how menstruation structures the lives and futures of married adolescent girls in the Centre for Girls’ Education’s Married Adolescent Safe Spaces (MAS) program in rural northern Nigeria. It addresses a key gap by focusing on married adolescents and treating menstruation as a social process linked to early marriage, schooling, mobility, and sexual and reproductive health, rather than only a hygiene issue. Guided by an intersectional social ecological and menstrual health-and-rights framework, the study draws on three years of ethnographic fieldwork. Methods include participant observation in MAS clubs, in-depth interviews, informal group discussions, and Hausa field notes from multiple rural communities, analyzed through iterative thematic coding and collaborative memoing. Findings show that menstruation operates as a “catalyst of constraint.” Menarche signals sexual maturity, intensifying moral surveillance, prompting threats or realities of school withdrawal, and accelerating pressure toward marriage. Girls describe menstruation as a “joy killer” and becoming “a shadow of myself,” as stains, pain, and shaming by teachers and peers lead to absenteeism and, at times, permanent dropout. Silence and stigma mean that asking questions can be read as promiscuity, pushing girls away from parents, religious leaders, and male teachers and toward sisters, peers, and mentors for incomplete guidance. Structural deprivation further individualizes the burden of menstrual management. Poverty, lack of affordable pads and underwear, and inadequate WASH facilities compel girls to “make do” with cloths and other unsafe materials, restrict movement during bleeding, and engage in small income-generating activities or kin negotiations to obtain basic supplies. MAS safe spaces partially disrupt these patterns by offering rare venues to discuss menstruation openly, learn cycle tracking and hygiene, and build peer solidarity and self-advocacy. However, the analysis underscores that program benefits remain constrained when poverty, weak school infrastructure, and restrictive gender norms remain intact. The study highlights how equitable sexual and reproductive health interventions must integrate menstrual health centrally, combining safe-space programming with subsidized products, improved WASH infrastructure, protective school policies, and norm change efforts. Full article

This study evaluated variations in phenotypic and physiological traits of Snowy White chickens reared under high-altitude conditions in Lhasa, China, at 3650 m and low-altitude conditions in Ya’an, China, at 600 m. Chickens reared at high altitude showed delayed sexual maturity and peak laying, as well as lower laying rate and hatchability. In contrast, egg weight at first laying was higher in chickens reared at high altitude. Organ index analysis showed that high-altitude chickens had a higher heart index but lower liver, stomach, and spleen indices than low-altitude chickens (p < 0.05). High-altitude chickens also had greater chest depth and chest circumference but shorter shank length and smaller shank circumference (p < 0.05). Multivariate analyses further indicated liver and spleen indices as major contributors to the separation between altitude groups. These results show that high-altitude rearing is associated with altered reproductive performance, organ development, and body conformation in Snowy White chickens. These findings may inform the evaluation, breeding, and management of layer chickens in plateau production systems. Full article

Background: The reproductive toxicity of first-line antituberculosis drugs remains poorly understood, particularly when used in combination. Rifampicin, isoniazid, pyrazinamide, and ethambutol are essential in tuberculosis therapy, but their potential influence on female fertility is uncertain. This pilot study evaluated their effects, given alone or in dual, triple, and quadruple combinations, on oxidative stress, endocrine markers, and reproductive outcomes in healthy female rats. Materials and Methods: Ninety-six albino Wistar-type female rats were divided into sixteen groups of six animals each and treated with single, dual, triple, or quadruple regimens of first-line antituberculosis drugs for 28 days. After treatment, two sexually mature males were introduced per group, and therapy continued for seven additional days. Serum malondialdehyde (MDA), total glutathione (tGSH), prolactin, and anti-Mullerian hormone (AMH) levels were measured, and fertility outcomes were evaluated. Results: In single-drug groups, MDA increased and tGSH decreased, but detectable infertility was not recorded. Prolactin remained stable except in the pyrazinamide group, where it declined. Dual-drug regimens increased oxidative imbalance; fertility failure occurred only in pyrazinamide-lacking groups and was accompanied by higher prolactin and lower AMH. Triple and quadruple combinations produced prominent oxidative imbalance. In triple-drug regimens, infertility was lower in pyrazinamide-containing groups than in the pyrazinamide-free group, but this pattern was not maintained in the quadruple regimen. Fertility impairment was not consistently aligned with the degree of oxidative stress and may involve prolactin and AMH alterations. Conclusions: These findings suggest that reproductive impairment under these experimental conditions may involve endocrine alterations and cannot be explained solely by serum oxidative imbalance. Pyrazinamide-associated fertility preservation appeared context-dependent and requires further confirmation in larger mechanistic studies with broader reproductive and endocrine assessment. Full article

Animal growth involves changes in size with age and is associated with environmental factors. The aim was to conduct a study of a representative group of the Santandereana Creole goat breed to evaluate morphometric allometry according to sex. A sample of 23 males and 76 females, ranged 8–72 and 8–84 months of age respectively, was studied. Morphometric allometry was evaluated using 30 linear characters. A Mann–Whitney test assessed right- and left-side differences in horns (length and perimeter) and ears (length and width). A one-way PERMANOVA, using Gower distances, assessed sex differences. Principal component analysis (PCA) using a var-covar matrix identified the most discriminating traits. A one-way ANCOVA, using loadings at PC1, was performed to compare allometric trends between sexes. Differences between sexes were observed in linear traits (p = 0.0101) and indices (p = 0.0364). No differences were observed between the right and left sides in horns and ears. Differences were observed in size, with body weight, body length, thoracic perimeter, and horn length (right/left) being the most discriminating values reflecting sexual dimorphism of size. The indexes corroborated the larger size of males, especially in relation to skull width, rump length, chest depth, and body weight. Detected differences may reflect variations in the development of skeletal maturity. The indexes confirm that the Santandereana Creole goat is an animal with a tendency for meat production, with larger males and brachycephalic features due to the shape of the head. Discriminatory measures can be considered as parameters of interest for preserving the breed and establishing genetic improvement programs. Full article

Epimedium is a traditional Chinese tonic used to tonify the kidneys, enhance sexual function, and strengthen muscles and bones. However, the potential effects of Epimedium on the semen quality of Bama boars remain incompletely elucidated. The objective of this study was to evaluate the effects of dietary Epimedium ultrafine powder (EP) supplementation on the semen quality of Bama boars and to explore the underlying mechanisms. The objective of this study was to evaluate the effects of dietary EP supplementation on the semen quality of Bama boars and to explore the underlying mechanisms. Eighteen healthy, sexually mature adult male Bama boars were randomly divided into three groups (n = 6) and fed either a basal diet (CON) or the basal diet supplemented with 0.3% (EP3) or 0.5% (EP5) Epimedium ultrafine powder for five weeks. This study employed enzyme-linked immunosorbent assay (ELISA), 16S RNA gene sequencing, non-targeted metabolomics (CON and EP5), and Spearman correlation analysis, among other methods. The results indicated that dietary Epimedium (0.3% and 0.5%) increased the levels of serum TP, FSH, and SOD and decreased the abnormal sperm rate and the levels of serum TBA, TNF-α, and IL-6. Among them, adding 0.5% Epimedium in the diet increased sperm motility and the levels of serum T, LH, and IgG. 16S rRNA gene sequencing analysis revealed that both 0.3% and 0.5% Epimedium supplementation reduced the abundance of Streptococcus. Specifically, the 0.3% dose decreased Prevotella abundance, while the 0.5% dose reduced Escherichia-Shigella abundance. PICRUSt2 analysis revealed that the pathways of phenylalanine, butanoate, biotin, and arachidonic acid metabolism were significantly enriched in the Epimedium group. A non-targeted metabolomics analysis identified that indole-3-acrylic acid, DL-tryptophan, 2-hydroxyphenylalanine, and propionylcarnitine showed significant upregulation after Epimedium supplementation. Spearman correlation analysis indicated that Streptococcus was negatively correlated with sperm motility and serum-related parameters (TP, T, LH, IgM, and IgG). Streptococcus and Escherichia-Shigella were negatively correlated with indole-3-acrylic acid, DL-tryptophan, and biotin. In conclusion, Epimedium has a positive impact on the seminal quality, reproductive hormones, and immune–antioxidant levels of Bama boars by regulating the composition and metabolites of the intestinal microbiota. Full article

Male infertility is an increasing global health concern associated with declining population growth. Mancozeb (MZ) exposure may induce reproductive toxicity through endocrine disruption and oxidative stress, impairing spermatogenesis. This study evaluated the effects of White Bualuang extract (WBE) on sexual behavior, testicular histomorphometry, and spermatogenic parameters in rats exposed to MZ. Thirty mature male rats were randomly assigned to the following five groups (n = 6): Control, MZ 500 mg/kg, MZ + 0.55 mg/kg WBE, MZ + 1.10 mg/kg WBE, and MZ + 2.20 mg/kg WBE, for 30 days. Sexual behaviors, relative testis weight, antioxidant properties, and histomorphometry parameters were determined. MZ-exposed rats had significantly decreased courtship behavior, seminiferous tubule diameter, and a tendency toward decreased spermatogenic cell numbers, along with enlarged interstitial spaces. However, pretreatment with WBE, especially at a dose of 0.55 mg/kg, showed improvements in courtship behavior and several histomorphometry parameters and was associated with increased Sertoli cell efficiency and spermatogenic organization compared with the MZ group. WBE showed potential to reduce lipid peroxidation (LPO) and advanced oxidation protein products (AOPP) in MZ-exposed rats, particularly, the 0.55 mg/kg dose improved courtship behavior and reproductive parameters, supporting further investigation of WBE as an antioxidant and potential functional supplement. Full article

The Kazakh horse represents a significant genetic resource within China’s equine population, characterized by notable resilience and an ability to thrive on coarse forage. Nevertheless, a decline in its numbers has been observed recently, making the improvement of its reproductive performance crucial for the preservation of this breed and the advancement of the related industry. In this study, testicular tissues from 1-year-old (pre-pubertal) and 2-year-old (post-pubertal) Kazakh horses were analyzed. miRNA sequencing was conducted on tissues from these age groups, followed by bioinformatics analyses to elucidate the functions of differentially expressed miRNAs (DEmiRNAs). The reliability of the sequencing data was subsequently verified using RT-qPCR. Analysis revealed 165 differentially expressed miRNAs (DEmiRNAs) in the testicular tissues between the two age groups. Of these, 118 DEmiRNAs (e.g., eca-miR-206 and eca-miR-2483) were significantly up-regulated (p < 0.05), and 47 DEmiRNAs (e.g., eca-miR-196a and eca-miR-211) were significantly down-regulated (p < 0.05). These DEmiRNAs were mainly implicated in biological processes including lipid metabolism and signal transduction. Their predicted target genes are potentially involved in key reproductive processes, notably testicular development and spermatogenesis. This study identifies candidate miRNAs and potential regulatory pathways associated with sexual maturation in Kazakh horses, providing a preliminary molecular basis for future functional validation and improvement of equine reproductive performance. Full article

Increasing environmental contamination with microplastics (MPs) raises significant concerns regarding their potential impact on reproductive health. This study evaluated the effects of prolonged oral exposure to fluorescent polystyrene microplastics (FPS-MPs) of different sizes on the male reproductive system in Wistar rats. Juvenile male rats at 21 days of age were exposed to FPS-MPs of 1 µm and 5 µm for 52 days, covering the period of sexual maturation and a complete spermatogenesis cycle. Body weight, reproductive organ indices, serum levels of testosterone (T), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), as well as sperm motility and morphology, were assessed. Reproductive potential and accumulation of microplastics in reproductive tissues were also evaluated. No significant differences were observed in body weight or most reproductive organ indices, except for a slight reduction in the left epididymis index in the group exposed to 5 µm particles. FPS-MPs induced size-dependent changes in the hormonal profile, including decreases in T and E2 and compensatory increases in FSH and LH, as well as impairments in sperm quality, which were more pronounced in rats exposed to smaller particles. In conclusion, fertility potential remained preserved, while FPS-MPs accumulated in the testes and epididymides, demonstrating subclinical, size-dependent effects on the male reproductive system. Full article

Chirostoma humboldtianum is an endemic atherinopsid from Mexico that has been of high socio-cultural and economic importance since pre-Hispanic times. It was the first ictic species from Mexico described for science, and it is considered the basal species that gave rise to a nominal group known as white fish or silversides. The aim of this research was to analyze semen quality in relation to breeding fish size and its effect on sperm cryopreservation during an annual cycle. Sexually mature males were collected from January to December 2023, in San Felix dam, Tiacaque, Mexico State, Mexico. The water temperature was measured, and the photoperiod was obtained from the Instituto Nacional de Geografía y Estadística (INEGI). Males were classified into two groups of total length (TL) after analyzing the variation in TL through a size histogram: (G1) 9–13 cm and (G2) longer than 13 cm. Semen volume (µL), sperm concentration (cells µL⁻¹), and motility percentage (%) were determined in all individuals of each group. Likewise, eight straws were cryopreserved per month per group, each one with 10 µL of semen from a mixture of three randomly selected individuals and cryopreserved at −196 °C for 72 h. The post-thawing motility percentage was subsequently verified. Males produce semen continuously all year round, with two periods of higher volume, March and June–August, defining two reproductive periods. The beginning of the first one coincides with the increase in water temperature, from 13 ± 2 to 18 °C. Males with a length more than 13 cm had a higher semen production compared to smaller males (17.33 ± 7.34 and 12.52 ± 4.41 µL, respectively, p < 0.05). The largest semen volumes were registered in March and from June to August in both groups. However, G2 males presented with a larger semen volume. Both groups had a marked decrease in a similar manner in April–May and September to January (p < 0.05). Sperm concentration was similar throughout the year in both groups (p > 0.05) (G1 = 1.35 ± 0.36 × 10⁶ µL⁻¹) (G2 = 1.31 ± 0.35 × 10⁶ µL⁻¹). In addition, fresh sperm motility was high in both groups (G1 = 96 ± 3%, G2 = 97 ± 4%) (p > 0.05). The highest sperm concentrations were observed in March to July, through to October for both groups (p > 0.05), while post-thaw sperm motility decreased by about 50% (G1 = 45 ± 4%) (G2 = 46 ± 6%) during the annual cycle (p > 0.05). The largest post-thaw motility was observed in March and from July to September in G1 and in March and from June to October in G2. Analysis of semen quality throughout the annual cycle reveals aspects of the reproductive biology of C. humboldtianum, including two reproductive peaks and continuous semen production. Full article

N6-methyladenosine (m⁶A) is a reversible RNA modification that dynamically regulates gene expression by modulating RNA stability, splicing, nuclear export, translation, and maturation—thereby orchestrating organismal development. In birds, including geese, the liver is a multi-functional organ central to metabolic regulation. Studies on the dynamic patterns of RNA m⁶A modifications during healthy liver growth and development remain limited. Here, we performed integrative methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) on liver tissues from geese at three biologically defined stages: post-hatch day 0 (0 week, P), fast growth (10 weeks, F), and sexual maturation (30 weeks, S). The level of m⁶A modification in total RNA extracted from liver tissues was higher in P than in F samples. Compared with other groups, the S group recorded the lowest m⁶A modification. In addition, 1641, 668, and 558 m⁶A peaks were differentially modified in the P, F, and S groups, respectively. The m⁶A peaks in the liver of the three groups were mainly enriched in the coding sequence and 3′ untranslated region. Moreover, integrated multi-omics analysis (MeRIP-seq and RNA-seq), combined with protein–protein interaction networks analysis, identified CDK1 as a core cell cycle regulator and IGF2BP3—a well-established m⁶A reader—as a consistently differentially expressed gene across all developmental stages. The m⁶A-regulated cell cycle, p53 signaling pathway, and pyrimidine metabolism pathway were identified in liver tissue as novel potential targets for controlling geese growth and metabolism. Together, these findings shed light on the dynamic regulation of RNA methylation during distinct growth phases in geese and advance our understanding of epigenetic mechanisms underlying poultry liver development. Full article

The paper focuses on materials characterization and in vivo biocompatibility tests of Ti–6Al–7Nb–0.3REE wt.% alloys (REEs—Y, Ce, La) for use as a promising material to produce personalized medical implants and shed light on possible toxicity effects of REE alloy microdoping. All alloys were produced by the electric arc melting method and characterized by scanning electron microscopy (SEM), optical microscopy (OM), energy-dispersive X-ray spectroscopy analysis (EDX), X-ray diffraction (XRD), true density analysis, micro- and nanoindentation methods, and reducing/oxidation melting techniques. True density of alloys increased in the following order: Ti−6Al−7Nb−0.3Y (4.4563 ± 0.1075 g/cm³) < Ti−6Al−7Nb−0.3Ce (4.7255 ± 0.2853 g/cm³) < Ti−6Al−7Nb−0.3La (4.8019 ± 0.0111 g/cm³). XRD analysis indicated that Ti–6Al–7Nb–0.3Y alloy consisted of single α–Ti phase in comparison with Ti–6Al–7Nb–0.3La (α–Ti to β–Ti = 82 to 18) and Ti–6Al–7Nb–0.3Ce (α–Ti to β–Ti = 90.5 to 9.5). The single-phase Ti–6Al–7Nb–0.3Y alloy had the finest α–Ti phase crystallites (22.32 nm); the larger α–Ti crystallites in the dual-phase Ti–6Al–7Nb–0.3Ce and Ti–6Al–7Nb–0.3La (30.77 nm and 29.83 nm, respectively) suggested the presence of the β–Ti phase (23.34 nm and 25.61 nm, respectively). REE microdoping of alloys changed the lattice volume (∆V): α–Ti phase—0.269% for Ti–6Al–7Nb–0.3Y, 1.799% for Ti–6Al–7Nb–0.3Ce, 0.595% for Ti–6Al–7Nb–0.3La; and β–Ti phase—0.334% for Ti–6Al–7Nb–0.3Ce, 0.670% for Ti–6Al–7Nb–0.3La. Nanohardness (H) and elastic modulus (E) increased in the following order: Ti−6Al−7Nb−0.3La (4.01 GPa and 135 GPa, respectively) < Ti−6Al−7Nb−0.3Y (4.39 GPa and 137 GPa, respectively) < Ti−6Al−7Nb−0.3Ce (4.67 GPa and 146 GPa, respectively). In vivo tests were conducted using 46 sexually mature male Wistar rats by means of skin implantation of samples with d = 11 mm and h = 1 mm. Our research shows that Ti–6Al–7Nb–0.3La alloy (Group 2) and Ti–6Al–7Nb–0.3Ce alloy (Group 3) induced sustained hepatotoxic and nephrotoxic effects. Ti–6Al–7Nb–0.3Y alloy induced a slight local inflammatory response; however, serum biochemical analysis suggested this effect was compensated. Full article

The induction of triploidy, a strategy to mitigate unwanted pre-harvest sexual maturation and a genetic containment measure for escaped farmed Atlantic salmon (Salmo salar), may give rise to challenges because of the distinct environmental and dietary requirements of sterile triploid fish. Smoltification is a critical phase in the life cycle of Atlantic salmon, so knowledge about parr–smolt transformation in triploids is important for the salmon farming industry. This study covered an investigation of hepatic expression of growth hormone receptor (GHrec) and insulin-like growth factor-I (IGF-I) genes, both of which are intimately involved in the regulation of osmoregulation and growth. Additionally, hepatic presence and location of IGF-I mRNA were examined using RNAscope^®, an advanced in situ hybridization technique. Triplicate groups of juvenile diploid and triploid salmon were reared at low temperature (10 °C) and fed either a standard diet or one enriched with hydrolyzed fish proteins from the start of feeding onwards. Liver samples were collected from three fish per tank each month from October to December (2454–3044 degree-days post-start feeding), the period encompassing smoltification, and hepatic expression of IGF-I and GHrec genes was quantified by real-time PCR. The results indicated that neither ploidy nor diet significantly influenced IGF-I or GHrec gene expression, suggesting that, under our conditions, triploidy and diet did not adversely affect this molecular pathway linked to growth and osmoregulation. IGF-I gene expression exhibited significant temporal variation, correlating with the progression of smoltification, while GHrec gene expression showed a similar, albeit non-significant, trend. Triploids exhibited IGF-I and GHrec gene expression patterns comparable to diploids, and both the temporal changes and lack of difference between triploids and diploids were mirrored in the quantification of IGF-I mRNA within the liver cells. The potential applicability to a commercial aquaculture setting requires further investigation. Full article

The aim of this study was to investigate the effects of dietary supplementation with 0.11% N-carbamylglutamate (NCG) during early pregnancy (0–90 days) on reproductive performance and fetal development, and to elucidate the underlying placental regulatory mechanisms in primiparous Hu sheep. Twenty-two 10-month-old sexually mature primiparous Hu sheep meeting the mating criteria were randomly assigned to two groups. The control group was fed a basal diet, while the NCG group received the basal diet supplemented with 0.11% NCG, with both feeding regimens maintained for 90 days. By measuring uterine and fetal growth indices, maternal plasma biochemical parameters, and amino acid levels, as well as assessing cotyledon indices and observing cotyledon morphology and histological structure, basic data related to placental function and fetal growth in pregnant ewes was collected. Combined with transcriptomic sequencing of maternal placental tissue, the mechanism by which NCG influences placental function and fetal growth and development in pregnant ewes was further investigated. The supplementation of NCG could increase the number of fetuses, total weight of fetuses, the number of corpus luteum and the ratio of fetuses to corpus luteum, but the difference was not significant (p > 0.05). The levels of plasma NO, inducible Nitric Oxide Synthase (iNOS) and several amino acids were significantly increased (p < 0.05). In ewes’ uteri, the average uterine weight, number of uterine glands, total cotyledon weight, and average weight per cotyledon were significantly increased (p < 0.05), whereas uterine mucosal thickness was markedly decreased. The Quantitative Real-time PCR (q-PCR) results for differentially expressed genes were consistent with those of transcriptomic analysis, showing significant changes in the expression levels of certain differentially expressed genes in maternal placental tissues. These changes regulated pathways such as vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), phosphatidylinositol 3-kinase–protein kinase B (PI3K–AKT) signaling pathways and Mitogen-Activated Protein Kinase (MAPK) pathway, which are involved in angiogenesis, energy supply and metabolism, and somatic growth and development. Dietary supplementation with NCG during early pregnancy can significantly improve the reproductive performance of primiparous Hu sheep, optimize the intrauterine environment and nutrient supply, and thereby facilitate pregnancy maintenance and fetal development. The underlying mechanism may involve promoting endogenous arginine synthesis in ewes, increasing plasma levels of NO, arginine, and certain amino acids, which collectively validate the positive effects of NCG on the reproductive performance and growth of Hu sheep during early pregnancy at the molecular level. Full article

The aim of this study was to map global research on community-based strategies to reduce risky alcohol consumption and promote health, aiming to clarify growth, leading contributors, thematic structure, and integration with public-health frameworks. Using a PubMed corpus, we analyzed production, authorship, and collaboration indicators, built a thematic map (centrality/density) to identify core topics, and applied Multiple Correspondence Analysis to assess conceptual proximity between alcohol-specific and broader prevention domains. The dataset comprised 2607 documents across 916 sources, with output led by the USA, with substantial contributions from Australia, Canada, the UK, and rising activity in sub-Saharan Africa. The thematic map showed a mature core centered on adolescents and pregnancy, cross-cutting foundations in health education and sexual behavior with substance-related disorders, measurement-oriented niches at the periphery, and emerging work linking family planning. The Multiple Correspondence Analysis positioned alcohol-prevention terms close to health promotion, primary prevention, and epidemiology, with maternal–child health bridging community programs and clinical prevention. Overall, community-based alcohol prevention is expanding, globally distributed, and embedded in mainstream public-health practice. Limitations include the absence of citation data in PubMed, and future work should integrate citation-enabled databases and compare patterns across income groups. Full article