Search Results (101)

The Sonora Estuarine Biocultural Corridor (CBES) is made up of six coastal wetlands with mangrove forest, internationally certified as Ramsar Sites. Four are part of indigenous territories whose inhabitants have serious development lags and low water security. Five are within one or more of six irrigation districts of national relevance. The objective is to learn about the socio-environmental problems of the CBES, focused on the issue of water, as well as community proposals for solutions. Intercultural, mixed methodology approach. Prospecting visits were carried out in the six estuaries of the CBES, and 84 semi-structured interviews were conducted with experts from all social sectors who know the problems of the CBES in three (out of six) estuaries associated with indigenous territories. The main problem is centered on the issue of water: they receive contaminated water from agroindustry, aquaculture, and the municipal service; the fresh water of the rivers is almost nil, rainfall has decreased while the heat increases, and marine and terrestrial biodiversity decreases. This affects the food and economic security of the local population and generates conflicts between the different productive activities. A multisectoral organization that integrates the six estuaries would improve community wellbeing and, in turn, climate resilience. Full article

The objective of this study was to determine the epidemiological, clinical, and laboratory characteristics of newborns with sepsis in northwestern Mexico, identify the microorganisms causing early- and late-onset sepsis, and assess antimicrobial resistance. Additionally, it sought to associate neonatal characteristics with antimicrobial resistance or mortality. A retrospective study was conducted from August 2021 to April 2023, during which 8382 neonatal clinical records were analyzed to collect epidemiological, clinical, and laboratory characteristics, as well as microorganisms isolated from neonates and their antimicrobial resistance profiles. Of these, 314 neonates with sepsis were included. The incidence of neonatal sepsis was 4% (314/8382), and the mortality was 12.7% (40/314); late-onset sepsis (65.3%) was more frequent than early-onset sepsis (34.7%). Staphylococcus epidermidis was the most frequently isolated bacterium in neonates with sepsis (both early- and late-onset). Gram-positive bacteria, such as Staphylococcus hominis and Enterococcus faecium, were associated with early-onset sepsis, whereas fungi, particularly Candida albicans, were associated with late-onset sepsis. Of the microorganisms, 52.6% were multidrug resistant (MDR), 10.8% were extensively drug resistant (XDR), and 5.5% were pan-drug resistant (PDR). Low birth weight, prematurity, cesarean section, mechanical ventilation, tachycardia, and low hemoglobin and platelet levels, among others, were associated with XDR or MDR microorganisms. In contrast, low birth weight, mechanical ventilation, stroke, unexpected delivery, respiratory distress, tachycardia, convulsive crisis, high procalcitonin, urea, and AST/TGO levels, among others, were associated with mortality. The incidence, types of sepsis, antimicrobial resistance, and associations identified in this study will aid in diagnosing neonatal sepsis earlier and may reduce mortality in our region. Full article

Changes in the structure and composition of mangroves may be influenced by anthropogenic and natural causes. Mangrove coverage in Marismas Nacionales Nayarit –a Biosphere Reserve in northwestern Mexico—has declined in the last decades, mostly related to human activities (e.g., opening of the Cuautla inlet) and climate variability (e.g., El Niño Southern Oscillation and hurricanes), leading to diverse ecological and socioeconomic consequences. This contribution reports the impact of Cissus verticillata—a climbing plant species—in the structure of mangroves distributed in this Natural Protected Area during 2019 and 2022. Forest structure analysis was compared in four plots of 20 m × 20 m each, all of them influenced by San Pedro Mezquital river. Two plots (Unión de Corrientes) showed the presence of Cissus verticillata, while two nearby plots (Boca de Camichín) recorded no presence of this species. A poor mangrove structure, no natural seedling recruitment and high mortality was observed in those sites with the presence of C. verticillata. These results highlight the vulnerability of mangroves to C. verticillata in Marismas Nacionales Nayarit Biosphere Reserve, which in addition to other human and climate stressors may compromise its ecological integrity in the future. Full article

Background: Dental fluorosis (DF) is an irreversible alteration of tooth enamel formation caused by excessive fluoride (F) consumption during tooth growth, leading to skeletal fluorosis development due to the high F content of tap water, which should be detected. Objective: To detect the signs of skeletal fluorosis by comparison of the bone mineral density (BMD) of the lumbar spine, femoral neck, and total femur, and the fluor (F) intake from water between adults without and with DF from northwestern Mexico. Methods: Participants were 36 adults without DF (G1) and 42 with DF (G2). Dean criteria, DEXA, and SPADNS methods were used to evaluate DF, BMD, and F content in water, respectively. Results. G1 participants consumed 0.789 ± 1.55 mg F/d from water with 0.385 ± 0.32 mg F/L, while G2 participants drank 2.42 ± 2.65 mg F/d from water with 1.46 ± 0.59 mg F/L. The binary variable DF and BMD values were not associated (p > 0.05); however, according to severity degree, questionable DF was associated with total femur BMD (p = 0.025). BMD in the evaluated regions was no different between both groups and could be related to actual moderate levels of F in the tap water and to the partial or total consumption of bottled water. Conclusions. There was no association between DF and the measured BMD to infer skeletal fluorosis. Bone region BMD was no different between both evaluated groups and could be related to adequate F intake, with moderate F levels in tap water, and the consumption of negligible F content bottled water. Full article

The herpetofaunal diversity of northwestern Mexico, encompassing the Californian, Baja California, and Sonoran Desert biogeographic provinces, is characterized by relatively low species richness but a high degree of endemism. This region, particularly the islands of the Gulf of California, is recognized as a biodiversity hotspot. However, amphibian and reptile species in this area, especially those on the Gulf islands, are facing significant threats to their survival, including non-native species, habitat loss, and climate change. These factors pose considerable challenges to their conservation. In this study, we compiled updated lists of amphibian and reptile species across these three provinces, assessed their conservation status, identified the threats they face, and compared them with those in neighboring biogeographic provinces. Our analysis recorded a total of 228 species, comprising 29 amphibians and 199 reptiles, with a notable proportion of endemics, particularly in Baja California. Amphibians, due to the region’s arid conditions, are underrepresented and generally face a lower level of conservation concern. In contrast, reptiles, especially those on the islands, are at higher risk, primarily due to habitat loss, invasive species, and climate change. Of the 228 species, one amphibian and 21 reptiles are classified in a category of conservation concern (Vulnerable, Endangered, Critically Endangered) by the International Union for Conservation of Nature (IUCN) Red List. In addition, 47 species (one amphibian and 46 reptiles) are listed as threatened (A) or at risk of extinction (P) by the Secretaría del Medio Ambiente y Recursos Naturales (SEMARNAT). These findings emphasize the urgent need for conservation strategies, particularly for island reptile species, that involve collaboration among scientists, local communities, and federal and state authorities to address these threats and safeguard the region’s herpetofauna. Similarity analysis revealed significant ecological connectivity among the amphibian and reptile communities across the three provinces. The similarity in species between the Californian, Baja California, and Sonoran Desert provinces highlights the role of historical climatic events, geographic barriers, and ecological factors in shaping species distributions of amphibians and reptiles in northwestern Mexico. Full article

Chagas disease is a neglected disease caused by the parasite Trypanosoma cruzi, a public health problem in both endemic and non-endemic countries. In Mexico, the southern region is considered endemic, and cases are frequently reported; however, in the northwestern region, only a few cases are confirmed annually. This study describes, for the first time, the Discrete Typing Unit (DTU) of Trypanosoma cruzi in a volunteer blood donor rejected for being reactive in the northwestern region of Mexico. Seroreactivity was confirmed using “in-house” ELISAs which employed three different antigens: total extract from Trypanosoma cruzi isolated from a vector (Triatoma rubida) from Sonora (strain T1), strain H1 and CL-Brener. The molecular characterization of Trypanosoma cruzi was conducted by amplifying satellite DNA by qPCR and posterior sequencing of the mini-exon gene, using Next Generation Sequencing (NGS) to enhance the accuracy of genetic characterization. The results show that the reactive status of this blood donor was confirmed using our in-house ELISAs, and the presence of Trypanosoma cruzi by detecting TcI DTU confirmed the infection status. Full article

High evaporation rates due to solar intensity and low precipitation could represent a challenging culture environment in northwestern Mexico, generating osmotic stress in shrimp due to high salinity. Bacterial infections by pathogenic Vibrio strains are highly virulent in shrimp culture. This study evaluated betaine aldehyde dehydrogenase (BADH) activity and glycine betaine (GB) levels in Litopenaeus vannamei under high salinity levels plus experimental infection with virulent Vibrio parahaemolyticus. At 35 ppt (control group) and 40 ppt after infection, GB levels increased two-fold in the gills except at 45 ppt and were significantly higher at 50 ppt. The highest GB levels were in the hepatopancreas of the uninfected group at 45 ppt. In the gills, BADH activity decreased after 2 h of exposure at 40 and 45 ppt; at 50 ppt, there was a significant increase in the uninfected groups. However, upon infection, activity increased at all salinities except 50 ppt. In the hepatopancreas of the uninfected groups, the highest activity was at 40 ppt and this was lowest at 50 ppt after 8 h. In the muscles, BADH was detectable at all salinities; infection caused an increase in its activity at 45 and 50 ppt. Despite sudden exposure to high salinity plus experimental infection, our results show that Litopenaeus vannamei does not inhibit BADH activity, allowing GB synthesis, which may play a role in shrimp survival under these conditions. Full article

Coastal lagoons play an essential role in the energy balance and heat exchange to the atmosphere. Furthermore, at mesoscale Monsoon systems and at local scales, sea breeze influences surface processes; however, there is a lack of information on such processes in arid and semiarid regions. We aimed to characterize the atmospheric conditions during sea and land breeze in different seasons and analyze at different temporal scales the variation of atmospheric stability, turbulent fluxes, lifting condensation level, and atmospheric boundary layer height. The study site is a subtropical semiarid coastal lagoon, Estero El Soldado, located in Northwestern Mexico (27°57.248′ N, 110°58.350′ W). Measurements were performed from January 2019 to September 2020 with an Eddy Covariance system (EC) and micrometeorological instruments over the water surface. Results show that there is a strong seasonality that enhances sea–land breeze dominance; sea breeze was 83% more frequent during the Monsoon, and the land breeze was 55% more frequent in the Post-Monsoon. Specific humidity (23.32 ± 3.84 g kg⁻¹, q), potential temperature (307 ± 2.98 K, θ_p), latent heat (135 W m⁻², LE), and turbulent kinetic energy (0.81 m² s⁻², TKE) were significantly higher during the Monsoon season at sea breeze events. Atmospheric boundary layer (ABL) and lifting condensation level (LCL) were higher in the Pre-Monsoon season (3250 ± 71 m and 1142 ± 565 m, respectively). During the Monsoon, surface conditions lead to lower LCL (~800 m) due to the amount of water vapor (q = 23.3 g kg⁻¹). Full article

The conventional Trombe wall (TW) with concrete construction has been shown to enhance the indoor environment of buildings in cold and Mediterranean climates. Thus, a TW is an option for reducing energy consumption related to thermal comfort for buildings in the northwestern region of Mexico, characterized by arid and semi-arid conditions with low winter temperatures. The thermal behavior of the TW and a conventional facade (CF) of concrete were compared when installed in the southern wall of reduced-scale test boxes in Ensenada, B.C. Unlike other research works available in the literature, which typically monitored a data point measure of the wall and room temperatures, the present study measured the temperature of key components: the absorber wall, the air at the bottom and top vents, the glass cover, and the air at the cross-section plane of the TW test box. The results showed that the TW increases the air temperature through its channel up to ${14}^{ \circ }$C and yields a maximum thermal efficiency of 84% during a sunny winter week. Further, the indoor air temperature at the midpoint of the TW test module is up to $6^{ \circ }$C greater than the obtained on the CF-test module; therefore, the TW improved the thermal comfort conditions during winter. Full article

This study addresses the environmental challenges posed by consumerism, evaluating the impact of Degradation-Resistant Organic Compounds (DROCs), such as fats and oils, on surface environments, the subsurface, groundwater, and aquifers. Climate variability has intensified the dispersion of these compounds, particularly in open landfills and poorly managed sites, making it urgent to identify affected areas to plan remediation efforts and mitigate their effects on ecosystems and human health. The objective was to analyze the dispersion of DROCs in an abandoned landfill in northwestern Mexico and develop strategies to characterize the decomposition stages of these compounds. In 2021 and 2022, a two-dimensional geoelectric tomography (GT) was conducted using a SARIS-Scintrex resistivimeter, recording variations in the apparent resistivity of subsoil. Using resistivity measures, the progressive and regressive numerical interpolation of Newton for finite differences, combined with the Lévy-type diffusion operator, classified the invasion areas into three principal ranges: high (recent invasions), intermediate (transition phase), and low (mature invasions).. These ranges indicated how pollutants migrate from the surface to the saturated zones of the aquifer. To validate the presence of fats and oils, a 24-m-deep well was drilled, revealing a positive correlation (R² = 0.863) between the areas covered by the tomograms and the detected contaminants. The results emphasize the need for improved waste management and the careful selection of disposal sites to reduce environmental degradation. The methodology proved effective and rapid, facilitating remediation planning and highlighting the importance of sustainable practices in final disposal to mitigate the impacts of DROCs, reduce greenhouse gas emissions, and protect public and environmental health. Full article

The Las Cruces intrusive suite is located at the southern extent of the Baja California Peninsula in northwestern Mexico. The suite constitutes the northern part of the Los Cabos Batholitic Complex. It is correlated with extensive Cretaceous magmatic activity extending across California and the Baja Peninsula, known as the Peninsular Ranges Batholith. Despite its significance for understanding the regional tectonic and magmatic evolution, detailed information to fully support this correlation remains limited. This work provides new cartographic and structural data of the units comprising the intrusive suite and the temporal relationships between lithological units, supported by U-Pb zircon geochronology. The suite consists of granite in its central part, tonalite displaying magmatic foliation at its NW and SE margins, and two gabbro apophyses along the western edge. The host rocks consist of intercalations of hornblende and biotite schists, forming screens and roof pendants. Late magmatic felsic dikes, derived from the granite, intrude into the suite units. Five new U-Pb zircon age determinations indicate that the suite has a normal crystallization history with ages from 103.5 ± 1.2 to 97.6 ± 0.8 Ma for the tonalite and from 93.6 ± 0.7 to 95.0 ± 0.9 Ma for the granite. The gabbro is the oldest intrusive unit, with previous U-Pb zircon ages reported near 109 ± 2.3 and 102.3 ± 2.9 Ma. Structural analysis indicates that the gabbro and tonalite were emplaced during an E–W synmagmatic compressional event, evidenced by N–S oriented magmatic foliation, aligning subparallel to the granite and metasedimentary screens contacts. Later, the granite was emplaced during a compressional stress relaxation phase, causing the tonalite dissection and forming the current suite margins. The calculated U-Pb ages for the Las Cruces intrusive suite and reported geochemical and geophysical data from the northern Baja California Peninsula support its correlation with the Peninsular Ranges batholith. Full article

A cold-chain meat packaging project was developed for a meat product company in northwestern Mexico that moves high volumes of fresh meat into national and international markets. The objective of the present research is to evaluate the supply process for three types of thermo-shrinkable polyethylene bags to provide a technological solution for high-volume meat packaging based on a graphical user interface. A system dynamics (SD) methodology is developed in seven stages to generate a technological solution: (1) system mapping; (2) causal diagram construction; (3) stock, flow modeling, and equations; (4) model simulation; (5) model validation; (6) scenarios and multicriteria analysis; and (7) graphical user interface development. The main result for the company was a technological solution that could communicate with decision-makers and the proposed graphical user interface. Future optimistic and pessimistic scenarios were self-evaluated based on the current situation related to three thermo-shrinkable bags used for selling high volumes of fresh meat. In these solutions, previously simulated costs and savings can be implemented in a real situation. Quantitative graphical user interface data can be observed to adequately manage box and bag inventories and minimize costs. Using SD enables the development of technological solutions in complex environments with robust simulations and models that offer data to people interested in the system under study. Full article

Northwestern Mexico has a desert climate with high solar resources. Clear skies and low humidity during most of the year favor their use. In winter, the arrival of cold air masses from the polar latitudes cause instability and abrupt changes in atmospheric variables, increasing the error of short-term forecasts. This work focuses on the evaluation of the Weather Research and Forecasting (WRF) model for predicting the global horizontal irradiance (GHI), considering different parameterizations of shortwave and longwave solar radiation during the influence of five cold fronts that affected the desert region of northwestern Mexico. The simulation was carried out under four main shortwave configurations and the results were evaluated with surface measurements and compared with climate information from NASA-POWER. The GHI predicted with the Dudhia parameterization showed an overestimation of the WRF model during most of the analyzed events; the most accurate predictions obtained correlation values between 0.85 and 0.91 and a mean absolute error between 15 and 45 W m⁻². In periods where intermittent clouds prevailed, the mean error increased by almost 20%. An evaluation of the different proposed configurations shows advantages with the shortwave Dudhia and longwave RRTM parameterizations, providing a useful meteorological tool for predicting short-range variations in the GHI to improve the operability of solar power generation systems. Full article

Understanding how ocean currents influence larval dispersal and measuring its magnitude is critical for conservation and sustainable exploitation, especially in the Tropical Eastern Pacific (TEP), where the larval transport of rocky reef fish remains untested. For this reason, a lagrangian simulation model was implemented to estimate larval transport pathways in Northwestern Mexico and TEP. Particle trajectories were simulated with data from the Hybrid Ocean Coordinate Model, focusing on three simulation scenarios: (1) using the occurrence records of Lutjanus peru and L. argentiventris as release sites; (2) considering a continuous distribution along the study area, and (3) taking the reproduction seasonality into account in both species. It was found that the continuous distribution scenario largely explained the genetic structure previously found in both species (genetic brakes between central and southern Mexico and Central America), confirming that the ocean currents play a significant role as predictors of genetic differentiation and gene flow in Northwestern Mexico and the TEP. Due to the oceanography of the area, the southern localities supply larvae from the northern localities; therefore, disturbances in any southern localities could affect the surrounding areas and have impacts that spread beyond their political boundaries. Full article

Liver cancer is the fourth leading cause of cancer-related death worldwide. In Mexico, there is a high burden of liver cancer mortality in rural states, affecting both women and men equally. Thus, we aimed to describe the demographic and clinical characteristics of hepatocellular cancer (HCC) by sex in Mexico. Demographic and clinical information was extracted retrospectively from the medical records of patients with HCC initially treated (2015–2022) at institutions participating in a national survey across the country. The male-to-female ratio was calculated at the national and regional levels, and the results were stratified by sex. Among 697 HCC patients, the age at diagnosis was 65.4 ± 11.9 years and 20% were diagnosed at ≥75 years. The male-to-female ratio was 1.4:1, ranging from 1:1 in the northwestern and southwestern regions, to 2.1:1 in the western region. The proportion of cirrhosis was similar between the sexes; however, the etiology of cirrhosis differed: cryptogenic cirrhosis was higher in women and alcohol consumption was higher in men. Men had a higher proportion of advanced HCC, poor/undifferentiated tumors, and ≥4 nodules than women. HCC in the Mexican population affects both men and women at a 1.4:1 male-to-female ratio. This unique proportion by sex could be explained by the differences in the prevalence of risk factors across our heterogeneous country. Full article