Search Results (66)

Plant-derived bioactive metabolites have emerged as promising modulators of oxidative stress and inflammation, two interconnected processes involved in the pathogenesis of numerous chronic diseases. Arid ecosystems, particularly the Sonoran Desert, constitute an underexplored source of structurally diverse phytochemicals with significant pharmacological potential. This review provides a comprehensive overview of major classes of plant-derived bioactives, including polyphenols, flavonoids, terpenoids, and alkaloids, with emphasis on their molecular mechanisms of antioxidant and anti-inflammatory action. These compounds exert cytoprotective effects through direct reactive oxygen species (ROS) scavenging and indirect regulation of endogenous defense systems, primarily via activation of the Nrf2/Keap1 pathway and suppression of NF-κB signaling. Additional pathways, including MAPK, PI3K/Akt, AMPK, and mitochondrial regulatory networks, are discussed as critical mediators of redox balance and inflammatory control. Particular attention is given to Sonoran Desert plant species such as Bucida buceras, Phoradendron californicum, Larrea tridentata, Opuntia spp., and Agave deserti, all of which demonstrate promising biological activities associated with enhanced adaptation to environmental stress. Experimental approaches used to evaluate phytochemical bioactivity, including chemical assays, cellular models, omics technologies, and translational strategies, are also examined. Furthermore, this review discusses current limitations related to bioavailability, phytochemical variability, and clinical validation, highlighting emerging nanodelivery systems and precision medicine approaches as potential solutions. Collectively, the evidence supports the therapeutic relevance of Sonoran Desert plant bioactives as multi-target agents for modulating oxidative stress, inflammation, and chronic disease progression Full article

The mule deer population in Mexico declined severely during the early 20th century but recovered due to public policies centered on sport hunting. Sonora is considered the main reference for mule deer management in Mexico; however, the conservation status of the species in the state remains unclear. This study aimed to estimate the relative abundance and population structure of mule deer in Sonora. An aerial survey was conducted from 4 to 24 November 2019 using linear transects distributed across 62 sampling quadrants (30 × 30 km each). Over 82 flight hours, a total of 1376 deer were observed, with a male:female:fawn ratio of 24:100:12. The number of sightings and deer observed per quadrant followed a normal distribution, with averages of five sightings and twenty-two deer per sampling unit. The quadrants with the lowest abundance corresponded to areas containing towns and agricultural fields, whereas the areas with the highest deer numbers coincided with those containing a high concentration of Wildlife Conservation Management Units, where habitat improvement actions were implemented. The results falls within the limits of a stable population of desert mule deer; however, the low proportion of fawns suggests that limiting factors may be exerting pressure on the population. These findings highlight the importance of continued habitat management and monitoring to promote population stability and support recruitment in Sonoran mule deer populations. Full article

The Phoenix Metropolitan Area (PMA) is situated in the Sonoran Desert of Central Arizona, USA. The PMA is a focus of ongoing climate change and urban heat island research. This paper addresses differences in the receipt of shortwave irradiance (global radiation) between the city and its surroundings. Several weather networks (e.g., AZ Met, an Arizona agricultural network) and air quality monitoring sites allow for the determination of shortwave irradiance between urban and rural locales, as well as a preliminary relation to seasonal patterns of suspended particulates. Particulate matter 10 μm and smaller (PM10) ranges from ca. 10 µg/m³ to 30 µg/m³ from winter to summer in rural areas, whereas in the metropolitan area, PM10 often exceeds 40 µg/m³ year-round. On average, urban transmissivity (T) of shortwave irradiance is lower than rural values by 1% in summer to over 5% in winter, like other urban studies evaluating effects on irradiance. Percentage differences between a site on a local mountain and the valley floor (about 400 m difference) range from 1% in summer to 5% in winter, in sync with seasonal mixing height changes and vertical mixing of particulates. Full article

Our aim was to compare certain physiological traits and pregnancy rates in dairy heifers classified by coat color during summer and winter months in a Sonoran Desert region. Sixty Holstein heifers were randomly selected (age and weight of 13.1 ± 0.82 months and 382 ± 5.3 kg) and divided by season (i.e., winter and summer) and hair coat color (i.e., black and white). There were 28 summer heifers (13 black/15 white) and 32 in winter (18 black/14 white). Respiratory frequency (RF) was determined visually, and body surface temperatures (BSTs) of several anatomic regions were collected using thermography at 06:00 and 15:00 h every 3rd day. Furthermore, three blood samples were collected from each heifer in each season to determine hematological profiles and serum analytes (i.e., electrolytes, metabolites, hormones). Reproductive variables were pregnancy rate and services per pregnancy. Ambient temperatures ranged from 25 to 49 °C in summer and 3 to 28 °C in winter. In summer and winter, RF and most BST were higher (p < 0.05) in black heifers in the morning, while only head, right flank, and loin were higher (p < 0.05) in the afternoon. Cortisol and progesterone concentrations were higher (p < 0.01) in summer, while thyroid hormones were higher (p < 0.05) in winter. Glucose, triglycerides, cholesterol, urea, and sodium were higher (p < 0.05) in winter. Reproductive traits were unaffected by season or coat color. Although there were some differences in physiological variables and some biochemical parameters by season and coat color, these alterations were not enough to modify reproductive responses of Holstein heifers. Full article

Microbiome studies report a decrease in diversity associated with active infections. Under the endozoan hypothesis, Coccidioides can inhabit a host without causing disease. In this study, we describe and compare the lung mycobiome of Coccidioides-positive and -negative samples obtained from wildlife. If Coccidioides is not causing infection, we predict there will be no differences in the mycobiome between positive and negative samples. Lung samples were obtained from mammals previously trapped in Tucson, Arizona, USA (n = 26), and Mesa, Arizona, USA (n = 14). Samples were screened for Coccidioides with CocciDx, and mycobiome was characterized through Illumina-based amplicon sequencing of the internal transcribed spacer 2 (ITS2). We compared alpha and beta diversity of the mycobiome to assess the effects of Coccidioides’ presence and host taxonomy. A greater number of reads were captured from Tucson samples (114,706.4 ± 57,945.8) than from Mesa (384.9 ± 953.5); however, Mesa (16.8 ± 8.8) and Tucson (12 ± 7.8) had a similar number of fungal genera per sample. CocciDx detected Coccidioides in more samples than the ITS2 amplicon sequencing. All samples from Mesa and five from Tucson tested positive for Coccidioides. Therefore, Mesa samples were excluded from statistical analysis. No difference in alpha and beta diversity was associated with Coccidioides presence, which is consistent with the endozoan hypothesis. Host taxonomy had a significant effect on beta diversity. This effect is likely driven by host behavioral and physiological differences. Full article

The introduction of exotic forage species to new environments for livestock purposes is a common practice to increase productivity. Unfortunately, the population dynamics of introduced species as well as that of native species that persist in grasslands has been poorly studied. In Sonora, the introduction of exotic buffelgrass pasture has caused substantial modifications in the structure of desert scrublands. In this study, an evaluation of the population dynamics of buffelgrass pasture in two grasslands with different times (10 and 50 years) was carried out using classification by size category according to the total number of stems per plant. For each size category of stems, the probabilities of permanence, transition, and regression, and for estimating seed establishment and fecundity were evaluated. The results obtained indicate that in both grasslands, the population growth values (λ) were slightly greater than 1 (λ > 1), which indicates that the populations are stable. The results of this study suggest that the permanence of individual buffelgrass plants in established grasslands is the determining factor in λ. Likewise, our results suggest that in both grasslands, pasture management plays an important role in the permanence or deterioration of buffelgrass pastures. Full article

Surface urban heat island (SUHI) effects are intensifying in arid desert cities due to rapid urban expansion, limited vegetation, and increasing impervious and barren land surfaces. This leads to serious ecological and socio-environmental challenges in cities. This study investigates the relationship between landscape composition and land surface temperature (LST) in Phoenix and Tucson, two rapidly growing cities located in the Sonoran Desert of the southwestern United States. Landsat-9 OLI-2/TIRS-2 satellite imagery was used to derive the LST value and calculate spectral indices. A multi-resolution grid-based approach was applied to assess spatial correlations between land cover and mean LST across varying spatial scales. The strongest positive correlations were observed with barren land, followed by impervious surfaces, while green space showed a negative correlation. Furthermore, the Urban Thermal Field Variation Index (UTFVI) and the Ecological Evaluation Index (EEI) assessments indicated that over one-third of both cities are exposed to strong SUHI effects and poor ecological quality. The findings highlight the critical need for ecologically sensitive urban planning, emphasizing the importance of the morphological structure of cities, the necessity of planning holistic blue–green infrastructure systems, and the importance of reducing impervious surfaces to decrease LST, mitigate SUHI and SUHI impacts, and increase urban resilience in desert environments. These results provide evidence-based guidance for landscape planning and climate adaptation in hyper-arid urban environments. Full article

Bobcats (Lynx rufus) are an iconic North American predator; however, there is limited knowledge regarding their associated parasites. In this case study, we used a metagenomic approach to identify associated viruses and helminth species from a deceased bobcat. We determined the full mitochondrial genome of the bobcat and three helminths, i.e., tapeworm (Taenia sp.), stomach worm (Physaloptera sp.), and lung worm (Metathelazia sp.). Furthermore, we identified four circovirids; two (identified in a tapeworm and fecal swab) are members of the genus Circovirus and share 96.7% genome-wide identity between isolates and 87.4–88.6% identity with members of the species Circovirus miztontli. These appear to infect vertebrate species common to the Sonoran Desert, which could be a rodent preyed upon by the bobcat, and/or bobcat itself. The other two circovirids are novel members of the genus Cyclovirus (both identified in a tapeworm), one sharing 99.8% with those in the species Cyclovirus misi from a rodent and the other <67.3% with all other Cycloviruses. Our data support that these two Cycloviruses are likely tapeworm-infecting; however, more studies are needed to confirm the host. These findings enhance our understanding of viruses and helminths in bobcats, emphasizing the need for further research to unravel the ecology of parasites in these elusive predators. 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

The North American Monsoon (NAM) in southern Arizona continues to be a topic of interest to many ecologists studying the triggers and characteristics of plant growth and reproduction in relation to the onset of the monsoon. The purpose of this article is to report interannual variation in the timing of NAM onset found while researching the phenology of Saguaro cactus (Carnegiea gigantea). Using a daily rainfall dataset from 33 stations located in Pima and Pinal Counties, Arizona, from 1990–2022, we analyzed monsoon onset, monsoon precipitation, annual precipitation, and the proportion of annual station precipitation received during the monsoon season. Onset was measured by the first day from 1 June to 30 September with precipitation ≥ 10 mm counted from the day of the vernal equinox of the year. Generalized Additive Models (GAMs) identified sinusoidal waves with a period of 8.6 years and amplitudes of 14–29 days, providing frequency and amplitude estimates for Sinusoidal Regression Models (SRMs). Sinusoidal wave patterns found in the monsoon onset dataset are suggested in monsoon, annual, and proportion of monsoon in station-averaged annual precipitation although in and approximately mirror-image. These unexpected findings may have important implications for forecasters as well as ecologists interested in plant phenology. Full article

Fungal spore calendars for Mexico are non-existent. This research represents the first fungal spore concentration data in the atmosphere of Hermosillo, Mexico, a city in the Sonoran Desert with high rates of allergies and public health problems. We used standardized sampling techniques frequently used by aerobiologists, including a Burkard spore trap to monitor airborne fungal spores daily for 2016–2019 and 2022–2023. Results are expressed as daily fungal spore concentrations in air (spores/m³ air). The most common fungal outdoor spores corresponded to Cladosporium (44%), Ascospora (17%), Smut (14%), Alternaria (12%), and Diatrypaceae (7%) of the total 6-year data. High minimum temperatures produce an increase in the most important spores in the air (Cladosporium and Alternaria), whereas precipitation increases Ascospore concentrations. The most important peak of fungal spore concentration in the air is recorded during summer–fall in all cases. Airborne fungal spores at Hermosillo had a greater impact on human health. These data will be of great help for the prevention, diagnostics, and treatment of seasonal allergies in the population and for the agricultural sector that has problems with some pathogens of their crops caused by fungus. Full article

Extreme climatic conditions cause a decrease in ecosystem services, the disruption of the ecological balance, and damage to human populations, especially in areas with socially vulnerable groups. Nature-based solutions applying blue-green infrastructure (BGI) against these negative impacts of climate change have an important role in planning sustainable cities. This study aims to identify priority areas and develop scenarios and strategies for spatial planning to understand the tradeoffs in approaches and to maximize the benefits of ecosystem services provided by BGI in cities with arid and semi-arid climates, using Phoenix, Arizona, a swiftly urbanizing city in the Sonoran Desert, as the study area. Using GIS-based multi-criteria decision-making techniques and the Green Infrastructure Spatial Planning model integrated with the city’s existing water structures, this study is conducted at the US census scale. The hotspots for BGI are mapped from the combined GIS-based multi-criteria evaluation and expert stakeholder-driven weighting. In the hotspots where priority areas for BGI in Phoenix are identified, the city center area with a high density of impervious surfaces is identified as the highest priority area. It is revealed that social vulnerability and environmental risks (flooding, heat) have a positive correlation in Phoenix, and stormwater management and the urban heat island are the criteria that should be considered first in BGI planning. Full article

Brachynemurus bowlesi, sp. n. is a newly discovered myrmeleontid from the Sonoran Province, the northernmost subtropical region of Mexico. The new species fits within the Brachynemurus versutus subgroup, which now includes five species, all of them occurring in Mexico and the central and western United States. The new species may be identified by characteristics of the internal male genitalia, especially by a roof-like mediuncus, as well as the basal part of the 10th gonostyli, with paired processes in an acute angle and a shield-like expansion more evident in the dorsocaudal view. The formerly proposed synonymy of Brachynemurus mexicanus Banks, under B. versutus (Walker), is herein reinstated and supported. Full article

Arizona is home to many mosquito species, some of which are known vectors of infectious diseases that harm both humans and animals. Here, we provide an overview of the 56 mosquito species that have been identified in the State to date, but also discuss their known feeding preference and the diseases they can (potentially) transmit to humans and animals. This list is unlikely to be complete for several reasons: (i) Arizona’s mosquitoes are not systematically surveyed in many areas, (ii) surveillance efforts often target specific species of interest, and (iii) doubts have been raised by one or more scientists about the accuracy of some collection records, which has been noted in this article. There needs to be an integrated and multifaceted surveillance approach that involves entomologists and epidemiologists, but also social scientists, wildlife ecologists, ornithologists, representatives from the agricultural department, and irrigation and drainage districts. This will allow public health officials to (i) monitor changes in current mosquito species diversity and abundance, (ii) monitor the introduction of new or invasive species, (iii) identify locations or specific populations that are more at risk for mosquito-borne diseases, and (iv) effectively guide vector control. Full article

Natural resource managers may utilize remotely sensed data to monitor vegetation within their decision-making frameworks for improving habitats. Under binational agreements between the United States and Mexico, seven reaches were targeted for riparian habitat enhancement. Monitoring was carried out using Landsat 8 16-day intervals of the two-band enhanced vegetation index 2 (EVI2) for greenness and actual evapotranspiration (ETa). In-channel water was delivered in 2021 and 2022 at four places in Reach 4. Three reaches (Reaches 4, 5 and 7) showed no discernable difference in EVI2 from reaches that did not receive in-channel water (Reaches 1, 2, 3 and 6). EVI2 in 2021 was higher than 2020 in all reaches except Reach 3, and EVI2 in 2022 was lower than 2021 in all reaches except Reach 7. ET(EVI2) was higher in 2020 than in 2021 and 2022 in all seven reaches; it was highest in Reach 4 (containing restoration sites) in all years. Excluding restoration sites, compared with 2020, unrestored reaches showed that EVI2 minimally increased in 2021 and 2022, while ET(EVI2) minimally decreased despite added water in 2021–2022. Difference maps comparing 2020 (no-flow year) to 2021 and 2022 (in-channel flows) reveal areas in Reaches 5 and 7 where the in-channel flows increased greenness and ET(EVI2). Full article