Search Results (216)

This study develops a statistical and technological framework to analyze extreme rainfall in Colima, Mexico, by integrating historical precipitation records, probabilistic modeling, and spatial visualization. Using data from CONAGUA meteorological stations, we identify high-intensity rainfall events and model their recurrence using the Generalized Extreme Value (GEV) distribution to estimate key return periods. The results support flood-risk assessment and territorial planning in Colima. Spatial interpolation was performed in Python (version 3.13), and QGIS (version 3.38) produces exceedance maps that illustrate geographic variations in rainfall intensity across the state. These exceedance maps reveal a consistent spatial pattern, with the northern and western areas of Colima experiencing the highest frequencies of extreme events. Based on these results, the integration of real-time sensor technologies and satellite observations may improve flood monitoring and risk management frameworks. Full article

Antimicrobial resistance (AMR) continues to represent a significant global public health concern. Gram-negative bacilli (GNB) are the primary causative agents of severe nosocomial infections and possess a notable capacity to develop resistance mechanisms that restrict therapeutic options. The objective of this study was to characterize the antimicrobial susceptibility profiles of GNB isolated at a secondary-level hospital in Guadalajara, Mexico, with the aim of identifying predominant resistance patterns and the most effective therapeutic alternatives. A descriptive, retrospective, cross-sectional study was conducted using clinical isolates of Acinetobacter spp., Pseudomonas spp., Escherichia coli, Klebsiella spp., Morganella morganii, Proteus spp., and Enterobacter spp. collected during 2024. The identification and susceptibility testing were carried out using the VITEK^® 2 automated system, and the results were interpreted in accordance with CLSI guidelines. High resistance rates were observed in Acinetobacter spp. and Pseudomonas spp., particularly to carbapenems (>50% and >40%, respectively). Escherichia coli and Klebsiella spp. demonstrated resistance to third-generation cephalosporins and trimethoprim/sulfamethoxazole, exhibiting high susceptibility to amikacin and carbapenems (>90%). New-generation β-lactam/β-lactamase inhibitor combinations, such as ceftazidime/avibactam and ceftolozane/tazobactam, have demonstrated high efficacy against resistant strains. Overall, GNB isolates in this secondary-level hospital demonstrated elevated resistance levels, particularly to β-lactams and carbapenems, which pose a significant therapeutic challenge. Nevertheless, amikacin, carbapenems, and new-generation β-lactams persist as valuable therapeutic options. In order to contain the spread of multidrug-resistant organisms, it is imperative to strengthen local surveillance, optimize antibiotic stewardship, and reinforce infection control measures. Full article

Background/Objectives: Insulin resistance is a major public health issue in Mexico, closely linked to obesity, prediabetes, and type 2 diabetes. The euglycemic–hyperinsulinemic clamp is the diagnostic gold standard but is impractical for routine use. The triglyceride–glucose (TyG) index has been proposed as a simple alternative validated in diverse populations. We aimed to assess the utility of TyG relative to HOMA-IR and QUICKI as an early diagnostic tool in young Mexican adults. Methods: We performed an analytical cross-sectional study in young adults. Clinical, anthropometric, and fasting biochemical variables were collected to compute TyG. We compared TyG with HOMA-IR and QUICKI and evaluated diagnostic performance using receiver operating characteristic analysis to estimate area under the curve (AUC) and identify the optimal cut-off. Results: We analyzed 115 participants; 66.9% were insulin resistant by HOMA-IR, 79.1% by QUICKI, and 42.6% by TyG. TyG showed significant associations with anthropometric and biochemical measures. Diagnostic performance was good (AUC 0.707 vs. HOMA-IR; 0.960 vs. QUICKI). The optimal cut-off was 4.38, yielding sensitivity of 70.1% and specificity of 68.4% for diagnosing insulin resistance compared with HOMA-IR. Conclusions: The TyG index appears to be a useful, accessible, and cost-effective biomarker for early detection of insulin resistance in young Mexican adults. Its implementation could facilitate earlier diagnosis and prevention of cardiometabolic complications. Longitudinal, multicenter studies are warranted to establish population-specific reference values and to confirm its predictive value for adverse outcomes. Full article

Commercial forest plantations (CFPs) provide timber and ecosystem services, particularly carbon (C) sequestration, but the performance of native tropical hardwoods in pure versus mixed systems is still poorly understood. We evaluated growth, productivity, biomass, and C storage in 17-year-old plantations of Tabebuia rosea, T. donnell-smithii, and Swietenia humilis in western Mexico. Four plantation systems were assessed: pure T. rosea (PPT1), pure T. donnell-smithii (PPT2), mixed T. rosea + T. donnell-smithii (MPT1T2), and mixed T. donnell-smithii + S. humilis (MPT2S). Tree structure (DBH, height, basal area, volume), litter layer, and soils (0–15 cm) were measured. Thirty trees per species were destructively sampled to develop species-specific biometric models. Model performance was evaluated with adjusted R², RMSE, and residual analysis. PPT1 was the most productive system (39.8 m³ ha⁻¹; 55 Mg C ha⁻¹), while PPT2 had the lowest values (20.5 m³ ha⁻¹; 45.1 Mg C ha⁻¹). MPT1T2 increased basal area (+29.8% vs. PPT1) and litter layer C (3.3 Mg C ha⁻¹; +190% vs. PPT2) but did not surpass PPT1 in standing volume. Soil C was highest in PPT1 (36.5 Mg C ha⁻¹). Biometric models achieved high accuracy (R² = 0.91–0.99), confirming DBH as a reliable predictor of biomass and C. We conclude that pure T. rosea maximizes short-term productivity and soil C, whereas mixed systems diversify C allocation by enhancing litter layer pools. These findings highlight the complementary roles of pure and mixed CFPs and provide reliable models for C accounting in tropical hardwood plantations. Full article

Teak (Tectona grandis L.f.) is a leading tropical plantation species valued for high-quality timber and carbon (C) storage. This study assessed stand growth across ages and sites, quantified biomass and C by tree component and stand, and developed DBH-based allometric equations for biomass and C estimation. Six stand ages (5, 6, 9, 11, 14, and 17 years) were assessed in three municipalities of Nayarit, Mexico. Dendrometric inventories in permanent plots and destructive sampling of 35 trees provided calibration data for leaves, branches, stem, and roots. C concentration was determined with an elemental analyzer, and nonlinear regression models were adjusted and validated. Stand biomass and C increased with age, peaking at ages 11–14 (>130 Mg ha⁻¹; >60 Mg C ha⁻¹), with lower values at age 17. San Blas and Rosamorada accumulated significantly more than Tuxpan, reflecting site quality. C concentration was stable across sites and ages, with stem and roots consistently ranging between 48% and 50%, and leaves and branches averaging 45%–46%. Allometric equations were most accurate for stem and total biomass/C (R² = 0.73–0.79), while foliage showed higher variability. On average, 60%–70% of biomass was allocated to the stem and 15%–20% to roots. Indicators were stable, with an aboveground-to-belowground ratio (A:B) ≈ 4.9 and a biomass expansion factor (BEF) ≈ 1.5. The current annual increment (CAI) presented two main peaks: ~20 Mg ha⁻¹ yr⁻¹ at ages 5–6 and ~11 Mg ha⁻¹ yr⁻¹ at ages 9–11, followed by a decline after age 14. Teak in western Mexico reaches peak productivity at ages 6–11, with belowground biomass essential for accurate C accounting. Full article

The distribution and quality of the Lower Cretaceous reservoir sandstone units of the Mesozoic–Cenozoic Scotian Basin, offshore eastern Canada, is well known in producing fields but difficult to extrapolate to less-explored areas of the deep-basin floor. Prediction of reservoir risk is complicated by salt tectonism and the strong influence of diagenesis on reservoir quality. This study investigates the burial diagenetic dissolution of detrital K-feldspar in the subarkosic sandstones and the preservation of the resulting secondary porosity. K-feldspar abundance declines with increasing depth, creating secondary porosity, which in open systems is preserved but in closed systems is clogged by carbonates and clays. The distribution of detrital K-feldspar has been simulated using forward stratigraphic modeling and is compared to thermal modeling, fault mapping, and sand distribution to determine the risk due to the reservoir quality, illustrated as common risk segment maps. Sand deposits have the lowest risk of poor reservoir quality along the shelf edge and upper slope of the central and western basin, where growth faulting created an open diagenetic system. This novel combination of petrographic study and forward modeling has applications to other regions where diagenesis has a strong influence on the reservoir quality, such as the Gulf of Mexico. Full article

There has been an increasing interest in studying species of the thecate dinophysoid dinoflagellates, especially the genera Dinophysis and Phalacroma, all around the world. Abundant net phytoplankton material collected from coasts of the western coast of Baja California, the central Mexican Pacific (including the Gulf of California), and the Gulf of Mexico was analyzed, and the diversity and morphology of planktonic species of dinophysoids were studied in certain detail by LM and SEM. Particular morphological characteristics, which can be critical, such as the structure of the cingulum and cingular lists, union of sulcal lists, and theca ornamentation, were observed using SEM. Seventy-five (75) taxa (73 species and two varieties) were found and identified, which belong to the following 10 genera: Amphisolenia, Citharistes, Dinofurcula, Dinophysis, Histioneis, Metaphalacroma, Ornithocercus, Oxyphysis, Phalacroma, and Pseudophalacroma. We also included the following four new records: three for the Mexican Pacific (Amphisolenia brevicauda, A. deltiana, and Phalacroma stenopterygium) and one for the Gulf of Mexico (Phalacroma ornamentatum). Descriptions, illustrations, measurements, and distribution data are provided for each species. Taxonomical remarks concerning synonymies of species of the genus Phalacroma were added. Phalacroma whittingiae (Balech) Esqueda-Lara et Hernández-Becerril nov. comb. is a new taxonomic proposal. Full article

Background: Mutations in the TP53 gene can alter its tumor suppressor functions, thereby promoting oncogenic activity. The TP53 IVS3 16 bp genetic variant overlaps with nucleotide sequences that can alter regulatory structures, potentially affecting its function. The aim of the present study was to evaluate the association between TP53 IVS3 16 bp genetic variant and the risk of breast cancer (BC) in women from western Mexico. Methods: The study included 220 women diagnosed with BC and 198 cancer-free controls. Clinical and demographic data were collected through structured questionnaires and verified with medical records. Genotyping of the TP53 IVS3 16 bp genetic variant was performed using polymerase chain reaction (PCR) and visualized on 6% polyacrylamide gels. Results: Compared to controls, women with BC more frequently reported a family history of the disease and menopausal status (p < 0.05). Genotypic analysis revealed that carriers of the D/I genotype and the combined D/I + I/I genotypes were associated with a reduced risk of BC in codominant (OR = 0.53; 95% CI 0.32–0.88) and dominant (OR = 0.57; 95% CI 0.35–0.93) models. Conclusions: The D/I and D/I + I/I genotypes in codominant and dominant models showed a lower risk against BC. More studies are needed to confirm these findings. Full article

Coccidioidomycosis (CM) is an endemic disease in the western United States, northern Mexico, and Central and South America. The severity of coccidioidal infection is highly variable, with potential factors including comorbidities and the patient’s innate and adaptive immune response. Based on data from a predominantly healthy and mainly Caucasian male survey conducted nearly a century ago, approximately 60% of infections are asymptomatic, with an estimated 40% of people experiencing some respiratory symptoms; with 10% of those diagnosed with CM. Disseminated disease occurs in approximately 1% of cases and can involve the meninges and, potentially, any place in the body. It is not yet fully understood why some people experience severe disease while many people do not; it is understood that the immune response has a major role. Immunomodulators, including dupilumab and interferon-gamma (IFN-γ), have shown promise in treating patients with disseminated infection. This article summarizes the latest genetic and immunologic evidence demonstrating immune dysfunction. Immunomodulators and potential therapeutic strategies based on the above are reviewed. Full article

Type 2 diabetes mellitus (T2DM) affects 90% of diabetes cases and worsens cardiovascular health by causing oxidative stress, which leads to oxidized LDL (oxLDL) and foam cell formation, contributing to atherosclerosis. This study examined the relationship between CD36 gene variants, soluble CD36 (sCD36), oxLDL, and MDA-LDL in T2DM and ST-segment elevation myocardial infarction (STE-T2DM) patients in western Mexico. The analysis included 400 T2DM patients, 400 STE-T2DM patients, and 400 healthy controls. Results showed that STE-T2DM patients were older, mainly male, and had higher rates of smoking, sedentarism, and hypertension. Both diabetic groups exhibited elevated triacylglycerols and low HDL, with significantly higher C-reactive protein in STE-T2DM (p < 0.0001). No significant differences in CD36 gene variant frequencies were found, but sCD36 levels were elevated in STE-T2DM, with associations to specific genotypes. oxLDL was higher in STE-T2DM compared to controls (p = 0.0268). Binary logistic regression analysis identified male sex, younger age, sedentarism, and rs3173798 T/T genotype as independent risk factors for myocardial infarction (AUC: 0.9267, p < 0.0001). Elevated sCD36 levels may reflect atherosclerosis progression in diabetes, indicating the need for further studies to clarify CD36’s role in cardiometabolic dysfunction. These findings highlight CD36’s involvement in oxidative stress responses through its interaction with oxLDL and MDA-LDL, suggesting its potential role as a molecular target in antioxidant defense mechanisms. Full article

Background/Objectives: Epstein–Barr virus (EBV) detection patterns in lymphoproliferative disorders (LPDs) show significant geographical variation worldwide. Regional epidemiological data are essential for understanding viral distribution patterns and developing appropriate clinical surveillance strategies. This study aimed to determine EBV detection frequency in LPDs using available molecular and immunohistochemical methods in Western Mexico. Methods: We conducted a cross-sectional study of 200 formalin-fixed paraffin-embedded tissue samples from patients diagnosed with LPDs (2015–2019) at Hospital Civil de Guadalajara. EBV detection combined with real-time PCR targeting the BNTp143 gene and immunohistochemistry for LMP-1 protein. Cases were classified following current WHO criteria. Statistical analysis included multivariate logistic regression, diagnostic concordance assessment, and age-stratified analysis. Results: EBV detection frequency reached 35.5% overall, with marked differences between neoplastic (53.9%) and reactive LPDs (24.2%) (OR: 3.515; 95% CI: 1.859–6.645, p < 0.001). Hodgkin lymphoma showed the highest detection rate (80.6%), significantly exceeding non-Hodgkin lymphoma (39.3%) (OR: 6.43; 95% CI: 2.08–19.41, p = 0.001). Age-stratified analysis revealed predominant adult involvement (49.1% vs. 22.0% in young adults, p = 0.025). We identified three epidemiological categories based on detection probability patterns. Conclusions: This study represents the first comprehensive molecular and immunohistochemical characterization of Epstein–Barr virus in lymphoproliferative disorders from Western Mexico, establishing distinct epidemiological patterns that align with Latin American regional characteristics. The validated methodology provides a reproducible framework for multi-center studies, while the epidemiological data serve as an essential baseline for future longitudinal research and resource optimization in similar healthcare settings. Full article

Objective: To evaluate the predictive risk factors associated with the prevalence of metabolic syndrome (MetS) in adolescents from the western region of Mexico. Materials and Methods: An analytical cross-sectional study was conducted with a sample of 516 adolescents. Anthropometric data, blood pressure, and biochemical determinations were obtained. The diagnosis of MetS was based on the criteria proposed by de Ferranti in 2004. The triglyceride–glucose index (TyG index) was calculated, where a value >4.68 indicates insulin resistance (IR). Risk factors associated with MetS were evaluated using a logistic regression model. The statistical analysis was performed with the level of statistical significance established was p < 0.05. Results: The MetS prevalence was 17.2% among adolescents. One out of every two adolescents with obesity presented with MetS. Abdominal obesity and dyslipidemia are the most common components. Predictors of MetS included male sex, early adolescence, waist-to-height ratio (WHtR) > 0.5, increased body fat percentage, and TyG Index > 4.68 (IR). In the sex-specific analysis, a WHtR > 0.5 and IR were associated with MetS in female adolescents. In male adolescents, IR and body fat percentage were associated with MetS. The WHtR was associated with IR, and hypertriglyceridemia was associated with elevated alanine aminotransferase. Conclusions: In this study, two out of ten adolescents presented with MetS. In boys, a high prevalence of abdominal obesity, hypoalphalipoproteinemia, insulin resistance and MetS was observed. The risk of developing MetS is greater in preadolescent boys with abdominal obesity, high levels of body fat, and a TyG index > 4.68. Full article

Background/Objectives: Cognitive impairment in older adults has emerged as a growing public health concern, particularly in relation to COVID-19 infection and its associated neuropsychiatric symptoms. The identification of modifiable risk factors may contribute to the development of targeted preventive strategies. This study aimed to assess predictors of cognitive impairment in older adults with and without recent SARS-CoV-2 infection. Methods: A prospective cohort study was conducted from June 2023 to March 2024 at a tertiary hospital in western Mexico. Adults aged 65 years or older with confirmed SARS-CoV-2 infection within the previous six months, along with uninfected controls, were enrolled. Cognitive function (Mini-Mental State Examination), depression (PHQ-9), anxiety (Geriatric Anxiety Inventory), insomnia (Insomnia Severity Index), functional status (Katz Index and Lawton–Brody Scale), and laboratory markers were evaluated at baseline, three months, and six months. The primary outcome was cognitive impairment at six months. Independent predictors were identified using a multivariable generalized linear mixed-effects model. Results: Among the 111 participants, 20 (18.8%) developed cognitive impairment within six months. Low serum magnesium (adjusted risk ratio [aRR] 2.73; 95% CI 1.04–7.17; p = 0.041) and depression (aRR 5.57; 95% CI 1.88–16.48; p = 0.002) were independently associated with a higher risk. A significant synergistic among COVID-19, depression, and hypomagnesemia was observed (RR 44.30; 95% CI 9.52–206.21; p < 0.001), corresponding to the group with simultaneous presence of all three factors compared to the group with none. Conclusions: Depression and hypomagnesemia appear to be independent predictors of cognitive impairment in older adults with recent COVID-19 infection. These findings suggest potential targets for prevention and support the implementation of routine neuropsychiatric and biochemical assessments in this population. Full article

Human exploitation has been a major driver of marine turtle population declines, particularly affecting naturally scarce species such as the pantropical hawksbill turtle. Although hawksbill sea turtles have been documented in the Gulf of California since the early 20th century, data on their historical demography during periods of high exploitation in this region are nonexistent. We investigated the size structure of hawksbill turtles from the Western Central Gulf of California by examining a unique sample of decorative taxidermies, corresponding to 31 specimens captured during fishing operations near Santa Rosalía, Baja California Sur, Mexico, between 1980 and 1990. An analysis of the curved carapace measures revealed a length range (nuchal notch to posterior of supracaudals) of 29.5–59.5 cm (mean = 38.75 ± 6.67 cm) and a width range of 25.0–51.5 cm (mean = 33.63 ± 5.66 cm), with 87% of specimens having lengths between 30 and 45 cm. Based on the carapace length measurements, we estimated the ages to be between 7 and 20 years, indicating that the population included juveniles. Our findings provide baseline data for an understudied period and region, suggesting that this area previously served as an important juvenile habitat. These results contribute essential historical demographic information for conservation planning. Full article

Anthropogenic disturbance alters macro- and microclimatic conditions, often increasing ambient temperatures. These changes can strongly affect insects, particularly those experiencing high thermal stress (i.e., large differences between body and environmental temperature), as prolonged exposure to elevated temperatures can reduce their energetic reserves due to increased metabolic demands and physiological stress. We evaluated thermal stress in 16 insect dragonfly species during two sampling periods (2019 and 2022) in preserved and disturbed sites within a tropical dry forest in western Mexico. Also, we compared energetic condition (lipid and protein content) and thoracic mass for the seven most abundant species between both habitat types. In preserved sites, insects showed higher thermal stress at lower maximum temperatures, which decreased as temperatures increased. Dragonflies in disturbed sites maintained consistent levels of thermal stress across the temperature gradient. Thermal stress was linked to lower lipid and protein content, and individuals from disturbed sites had reduced energy reserves. We also found a weak but consistent positive relationship between mean ambient temperature and protein content. In preserved sites, thoracic mass increased with thermal stress, but only at high mean temperatures. These findings suggest that although species can persist in disturbed environments, their energetic condition may be compromised, potentially affecting their performance and fitness. Preserving suitable habitats is essential for preserving both biodiversity and ecological function. Full article