Search Results (18)

This study assessed the spatial distribution and composition of airborne particulate matter within a 10 km long urban green corridor in Zacatecas, Mexico, using magnetic biomonitoring with Tillandsia recurvata and SEM-EDS particle characterization. A total of 44 samples were collected from distinct urban park contexts (e.g., commercial zones, malls, bus stops), revealing mass-specific magnetic susceptibility χ values ranging from −6.71 to 61.1 × 10⁻⁸ m³ kg⁻¹. Three compositional groups were identified based on a PCA performed using elemental concentrations from SEM-EDS and magnetic data, which are associated with traffic emissions and industrial inputs. SEM-EDS images confirmed abundant magnetite-like particles (1–8 μm) with hazardous metals including Pb (up to 5.6 wt.%), Ba (up to 67.6 wt.%), and Cr (up to 31.5 wt.%). Wind direction data indicated predominant SSW–NNE transport, correlating with hotspots in central and northeastern park areas. Overall, vegetated zones exhibited markedly lower magnetic loads (mean χ = 8.84 × 10⁻⁸ m³ kg⁻¹) than traffic-exposed sites (mean χ = 17.27 × 10⁻⁸ m³ kg⁻¹), representing an approximate 50% reduction in magnetic particle accumulation, which highlights the effective role of continuous vegetation cover as a functional green barrier that attenuates the lateral transport and deposition of airborne particulate matter within the park. This research highlights the applicability of combined magnetic and microscopic techniques for evaluating the dynamics of airborne pollution in urban parks and supports their use for identifying both pollution hotspots and mitigation zones, reinforcing the role of urban green spaces as biofunctional filters in cities facing vehicular air pollution. Full article

The plateaus of north-central Mexico have an arid to semiarid climate and groundwater naturally contaminated with inorganic arsenic (iAs) and fluoride (F). Like other arid and semiarid areas, this region faces great challenges to maintain a safe supply of drinking and irrigation water. Studies conducted in the past few decades on various locations within this region have reported groundwater iAs, F, and nitrate-nitrogen (NO₃-N), and either their source, enrichment processes, health risks, and/or potential water treatments. The relevant findings are analyzed and condensed here to provide an overview of the groundwater situation of the region. Studies identify volcanic rocks (rhyolite) and their weathering products (clays) as the main sources of iAs and F and report that these solutes become enriched through evaporation and residence time. In contrast, NO₃-N is reported as anthropogenic, with the highest concentrations found in large urban centers and in agricultural and livestock farm areas. Health risks are high since the hot spots of contamination correspond to populated areas. Health problems associated with NO₃-N in drinking water may be underestimated. Removal technologies of the contaminants remain at the laboratory or pilot stage, except for the reverse osmosis filtration units fitted to selected wells within the state of Chihuahua. A recent approach to supplying drinking water free of iAs and F to two urban centers consisted of switching from groundwater to surface water. Incipient research currently focuses on the potential repercussions of irrigating crops with As-rich water. The groundwater predicaments concerning contamination, public health impact, and irrigation suitability depicted here can be applied to semiarid areas worldwide. Full article

Considering a circular economy perspective, this study evaluates the possible effect of targeted short-term supplementation with Withania somnifera L. (WS; Ashwagandha) on ram’s seminal quality, socio-sexual behaviors, and blood constituents. Black Belly rams (n = 20) received a basal diet comprising feed-leftovers from dairy cows in the north-arid Mexico (i.e., Comarca Lagunera CL). The experimental units, with proven libido and fertility, were homogeneous in terms of age (3.41 ± 0.21 yr.), live weight (LW; 53.8 ± 3.3 kg), body condition (BC; 2.96 ± 0.01 units), initial sperm concentration (2387 ± 804 × 10⁶), and viability (23.9 ± 15.6%). Rams were randomly assigned during the transition reproductive period (i.e., May to Jun; 25° NL) to three treatment groups: non-supplemented control group (CONT; n = 6), low WS-supplemented (LWS; i.e., 100 mg kg LW⁻¹ d⁻¹ × 40 d; n = 7), and high-WS-supplemented (HWS; i.e., 200 mg kg LW⁻¹ d⁻¹ × 40 d; n = 7). The basal leftover diet was offered twice daily (0700 and 1600 h); the experimental period (EP) lasted 47 d. No differences (p > 0.05) among treatments occurred regarding LW and BCS at the onset of the EP. Whereas the greater scrotal circumference (SCRC, cm) arose in the LWS and CONT rams, an increased ejaculated volume (VOLEJA, mL) occurred in the WS-rams. A total of 5/9 (i.e., 55%) appetitive and 3/3 (i.e., 100%) consummatory sexual behaviors favored (p < 0.05) the WS-rams, particularly the HWS rams, towards the final EP. The same was true (p < 0.05) regarding the hemogram variables white blood cell count (×10⁹ cells L⁻¹), hemoglobin concentration (g dL⁻¹), and medium corpuscular volume (fL). This study, based on a rethink–reuse–reduce enquiry approach, enabled connectedness between two noteworthy animal systems in the CL: dairy cows and meat sheep schemes. Certainly, the use of dairy cow feed-leftovers aligned with the short-term supplementation with WS promoted enhanced testicular function, augmented seminal volume, and an increased sexual behavior in Black Belly rams in northern Mexico. Finally, while our research outcomes should enhance not only the resilience and sustainability of sheep production and the well-being of sheep-producers and their families, it may also embrace clinical translational applications. Full article

Bean production is at risk due to climate change, declining water resources, and inadequate crop management. To address these challenges, dynamic models that predict crop growth and development can be used as fundamental tools to generate basic and applied knowledge such as production management and decision support. This study aimed to calibrate and evaluate the SIMPLE model under irrigation conditions for a semi-arid region in north-central Mexico and to simulate thermal time, biomass (Bio), and grain yield (GY) of common beans cv. ‘Pinto Saltillo’ using experimental data from four crop evapotranspiration treatments (ETct) (I₅₀, I₇₅, I₁₀₀, and I₁₂₅) applied during the 2020 and 2021 growing seasons. Both experiments were conducted in a randomized complete block design with three replicates. Model calibration was carried out by posing and solving an optimization problem with the differential-evolution algorithm with 2020 experimental data, while the evaluation was performed with 2021 experimental data. For Bio, calibration values had a root-mean-square error and Nash and Sutcliffe’s efficiency of <0.58 t ha⁻¹ and >0.93, respectively, while the corresponding evaluation values were <1.80 t ha⁻¹ and >0.89, respectively. The I₅₀ and I₁₀₀ ETct had better fit for calibration, while I₅₀ and I₇₅ had better fit in the evaluation. On average, the model fitted for the predicted GY values had estimation errors of 37% and 22% for the calibration and evaluation procedures, respectively. Therefore, an empirical model was proposed to estimate the harvest index (HI), which produced, on average, a relative error of 6.9% for the bean-GY estimation. The SIMPLE model was able to predict bean biomass under irrigated conditions for these semi-arid regions of Mexico. Also, the use of both crop Bio and transpiration simulated by the SIMPLE model to calculate the HI significantly improved GY prediction under ETct. However, the harvest index needs to be validated under other irrigation levels and field experiments in different locations to strengthen the proposed model and design different GY scenarios under water restrictions for irrigation due to climate change. Full article

Estimation of carbon (C) stocks revealed a very high carbon sequestration potential of mangroves, which play a major role in the global C cycle. The C stored in the biomass of live trees can be estimated from above- and below-ground measurements, i.e., tree diameter and height, leaf litter, root biomass, necromass, and soil. The allocation of biomass and C in the scrub mangrove forest is influenced by various factors, including low structural development. The objective of this study was to estimate the carbon stock (in relation to biomass) and storage in the soil of the San Ignacio and El Dátil lagoons in an arid region of the north Pacific. Above-ground biomass (AGB) was estimated based on mangrove structure and leaf litter; below-ground biomass (BGB) was measured by extracting root cores (45 cm depth) and soil (1.2 m depth). Biomass values were converted to carbon with allometric equations. We found an inverse relationship between BGB content (roots) and above-ground structural development, with a mean total biomass (AGB + BGB) of 101.7 MgC ha⁻¹. Below-ground carbon content (roots, necromass, and soil) was 2.8 times higher than above-ground carbon content (trees and litter). Control sites (devoid of vegetation) adjacent to the mangrove have recorded low carbon stocks of 7.3 MgC ha⁻¹, which supports the recommendations for conserving and restoring degraded areas. The present study contributes valuable information on carbon related to mangrove biomass and stored in the soil of arid mangrove areas of northwestern Mexico. Full article

Reference evapotranspiration (ET₀) is the first step in calculating crop irrigation demand, and numerous methods have been proposed to estimate this parameter. FAO-56 Penman–Monteith (PM) is the only standard method for defining and calculating ET₀. However, it requires radiation, air temperature, atmospheric humidity, and wind speed data, limiting its application in regions where these data are unavailable; therefore, new alternatives are required. This study compared the accuracy of ET₀ calculated with the Blaney–Criddle (BC) and Hargreaves–Samani (HS) methods versus PM using information from an automated weather station (AWS) and the NASA-POWER platform (NP) for different periods. The information collected corresponds to Module XII of the Lagunera Region Irrigation District 017, a semi-arid region in the North of Mexico. The HS method underestimated the reference evapotranspiration (ET₀) by 5.5% compared to the PM method considering the total ET₀ of the study period (26 February to 9 August 2021) and yielded the best fit in the different evaluation periods (daily, 5-day mean, and 5-day cumulative); the latter showed the best values of inferential parameters. The information about maximum and minimum temperatures from the NP platform was suitable for estimating ET₀ using the HS equation. This data source is a suitable alternative, particularly in semi-arid regions with limited climatological data from weather stations. Full article

Based on a circular economy approach, we evaluated the possible effect of targeted supplementation with leftover feed from dairy cows (i.e., intensive system) on the reproductive performance of crossbred/rangeland goats (i.e., extensive system) in arid Northern Mexico. During the deep-anestrous season (i.e., March–April, 25° North), multiparous goats (n = 38) with a similar body weight (BW) and body condition score (BCS) were randomly assigned to two groups: (1) supplemented group (SG; n = 19; BCS: 1.76 ± 0.07; BW: 43.7 ± 1.8 kg), receiving 400 g goat d⁻¹ of dairy-cow-feed leftovers prior to grazing; and (2) non-supplemented group (NS; n = 19; BCS: 1.76 ± 0.06; BW: 44.3 ± 2.5 kg). Both groups were directed to the rangeland for a period of ≈8 h. While the experimental period lasted 36 d, the experimental breeding considered 11 d (d0–d10). The anovulatory status of goats was ultrasonographically confirmed on days −20, −10, and −1 prior to male–female interaction. Previously, bucks were separated for 3 weeks from the experimental females and received exogenous testosterone every third day (i.e., 50 mg i.m.) prior to mating. With respect to the response variables, namely BW, BCS, blood glucose levels (BGLs), estrus induction (GIE, %), latency to estrus (LTE, h), estrus duration (ED, h), and luteal tissue volume (LTV, mm), no differences (p > 0.05) occurred between experimental groups. However, the response variables, namely goats ovulating (GO, %; 78.9 vs. 47.3), total number of corpuses luteum (TNCL, n; 27 vs. 13), ovulation rate (OR, n; 1.42 vs. 0.73), multiple ovulation (MO, %; 73.3 vs. 55.5), and pregnancy rate on d 36 (PRd36, %, 68.4 vs. 36.8), favored (p < 0.05) the SG over the NS goats. Our results demonstrate that connecting the circularity of two divergent ruminant production systems (i.e., cow-intensive and goat-extensive) by using dairy cows’ feed leftovers as a targeted supplementation strategy in anestrous goats under a marginal-rangeland production system enhanced out-of-season reproductive outcomes (i.e., ovulation rate and pregnancy rate), thus benefiting marginal goat producers and their families. Full article

The possible effect of heat stress (HS), measured with the temperature–humidity index (THI) across seasons of the year (SY) upon milk production (MP), feed-to-milk efficiency (FME), and cow comfort (CC) was assessed in Holstein–Friesian cows in northern-arid Mexico. Data from 2467 cows (2146 milking and 321 dry) were recorded across SY [spring (SP), summer (SM), autumn (AT), and winter (WN)] between 2016 and 2019 in an intensive dairy farm located in the Comarca Lagunera (25° NL) with large fluctuations regarding ambient temperature and solar radiation. The THI was stratified into four classes: non-HS, <68; light HS, 68–71; moderate HS, 72–76; and intense HS, ≥77. The considered response variables were Milk production: both on a farm basis (totMP) and on a cow basis (cowMP); Nutritional efficiency: dry matter intake (DMI, kg); Feed conversion efficiency (FCE, kg) and energy-corrected milk (ECM, kg); Percentage of milking cows: (MC%); and Cow comfort: lying time (LT, h). Analyses of variance for unbalanced data were performed through “R”. Both totMP and cowMP differed (p < 0.05) as HS increased; the largest values (i.e., 77,886 L and 35.9 L) occurred at lower THIs (i.e., <68 and 68–71) while the milk production fell (i.e., 66,584 L and 31.7 L) with the highest THIs (i.e., ≥77). Not only feed-to-milk efficiency (i.e., DMI, FCE, and ECM) but also the MC% exhibited a similar trend; a visible drop (p < 0.05) occurred from a THI of 68–71 onwards. Furthermore, the LT declined as the THI augmented, from 10.6 h at <68 to 8.5 h at ≥77. Moreover, differences (p < 0.05) also arose across seasons; TotMP, cowMP, DMI, FCE, and ECM revealed their largest (p < 0.05) values in WN and SP, halfway ones in AT, with the lowermost figures in SM. In the same way, cow comfort differed (p < 0.05) among seasons, with diverse lying times (h); WT, 10.5; AT, 10.20; SP, 9.3 h; and 8.8 in SM. Finally, the potential economic burden that HS caused at the producer (USD 233.2 million) and industry-market levels (USD 311.1 M), as well as its impact upon nutrient and alimentary security at the society level (i.e., 311 M milk liters and 195,415.82 Gcal), were also quantified. Full article

In contrast to birds, the relationship between migration and immunity has been scarcely studied in bats. We examined how the expression of the humoral portion of the constitutive immunity varied in a bat with partial, sex-biased migration: the lesser long-nosed bat (Leptonycteris yerbabuenae (Phyllostomidae)). The lesser long-nosed bat is a nectarivorous species distributed in the arid and semi-arid regions of North and Central America. We evaluated the bacteria-killing abilities (BKAs) of the plasma of male and female lesser long-nosed bats on the Pacific coast in different periods of the year. Because adult males are resident, they were used to explore the effect of reproductive activity on BKA, and we predicted higher values in mating males (i.e., individuals presenting scrotal testicles and a fresh dorsal patch). In contrast to males, most females migrate to cactus deserts in northern Mexico during pregnancy and lactation, and then return to the dry forests of west-central Mexico to mate. We predicted that the combined effect of breeding and migration would have an adverse effect on BKA; therefore, migratory pregnant and lactating females were expected to exhibit a lower BKA than mating females in west-central Mexico. We compared the BKAs of females captured in October and December in central Mexico, and we predicted that migratory females that had recently arrived in October should exhibit a lower BKA than females captured two months later. In addition, we compared the BKAs between lactating females and young in northern Mexico and predicted lower values in recently born individuals. We found that the BKAs of males were higher in reproductive individuals than in non-reproductive individuals. We found a significant difference in the BKAs between females at the two extremes of their migratory range: the values of pregnant females in Sonora and females in December were higher than those of females captured in October. Finally, we found no difference in BKAs between lactating females and young individuals. Our findings indicate that the basal levels of the innate humoral component are heightened in mating males, that this response is reduced in females that recently returned to their mating grounds, and that the constitutive immunity of young individuals matures early, probably in anticipation of the potential to encounter pathogens during their migration to west-central Mexico. Full article

Groundwater is one of the primary sources of water for both drinking and industrial use in northeastern Mexican territory, around 46% of the total, due to the lack of precipitation during the year and solar radiation index. The presence of arsenic in brackish soil and groundwater is a severe health issue, specifically in semi-arid and arid regions in the north of Mexico. Additionally, it represents the only source of drinking water in communities far from big cities, mainly due to the absence of hydric infrastructure. This work presents a new approach to treating polluted water with arsenic. The system based on activating jute fiber with nanoparticles of zero-valent iron immobilized over graphene oxide will allow nZVI particles to preserve their unique qualities for water sanitization. A dynamic flow test was designed to determine the effectivity of activated jute fibers as a water sanitation system. The results showed a reduction in the total arsenic content from 350 ppb to 34 ppb with a filtrate flow of 20 mL/min. The above represents 90% adsorption by the activated fiber. The analyzed sample corresponds to contaminated groundwater taken from Coahuila, Mexico. This sanitation system could be applied to low-income populations lacking robust infrastructure, such arsenic treatment plants. Full article

Assimilation to the internal CO₂ (ACi) response curve and gas exchange parameters were quantified for four North American willows ((Salix cordata (COR), S. discolor (DIS), S. eriocephala (ERI), and S. interior (INT)) grown in a 2 × 2 factorial of atmospheric CO₂ and soil moisture treatments to see how they would respond to climate change factors. After the first year of greenhouse growth under said treatments, we saw no difference in the aboveground stem biomass between CO₂ treatments. Thus, in the second year, a second experiment on a subset of well-watered, coppiced willows was conducted in a 2 × 2 factorial of atmospheric CO₂ and soil fertilization (FERT) treatments. In both experiments, the maximum rate of carboxylation (V_cmax) significantly declined for all four species in response to elevated CO₂ (eCO₂). In response to a drought treatment (DRT), V_cmax declined, except for INT, which increased V_cmax. In both experiments, INT had the greatest V_cmax, maximum rate of electron transport (J_max), and triose phosphate utilization, followed by COR and ERI, with DIS having the lowest values. FERT resulted in a strong increase in assimilation (A) and stomatal conductance (G_wv) by 92 and 119%, respectively. G_wv is the primary driver and A is a minor driver of water use efficiency (WUE) under DRT. FERT mitigated the V_cmax and A downregulation in eCO₂, but eCO₂ did not mitigate the DRT downregulation effect. Differences between INT and the other three willows in a number of adaptive traits and responses related to drought may reflect the evolutionary origins of INT and the taxonomic group Longifoliae in the arid southwest USA and Mexico. Full article

The quantity and quality of the supply of fresh water to households, commercial areas, small industries, green spaces irrigation and public and private institutions in large cities face challenges from the supply sources availability and suitable distribution network performance to the full satisfaction of the established drinking water guidelines. In Mexico, the main source of water comes from groundwater. Most of the Mexican aquifers are located in arid and semi-arid weather conditions. The groundwater’s physical–chemical properties are closely related to geology. This study was carried out at the north-central part of the country in which igneous and sedimentary rocks predominate, with high calcium carbonate (CaCO₃) concentrations. The accumulation of CaCO₃ in the pipelines is also known as scale deposit that decreases the fluid flow, causing a deficiency in the water supply. The main objectives of this study were determining the physical–chemical groundwater parameters and saturation indexes injected into the drinking water networks and characterizing the scale deposits by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicate that the scale deposits are mainly calcium carbonate and silica oxide crystals, caused by the water aggressiveness according to the saturation indexes and the lack of control over the saturation pH. Full article

Arid and semiarid regions are geographic units that cover approximately 43% of the earth’s surface worldwide, and conditions of extreme drought and reduced vegetation cover predominate in these regions. In Mexico, arid and semiarid ecosystems cover more than half of the territory, with desertification, mainly caused by anthropogenic activities and climatic events, as the main problem in these regions. The present research aimed to assess, identify, and classify arid and semiarid zones by employing a methodology based on multicriteria evaluation analysis (MCA) using the weighted linear combination (WLC) technique and geographic information systems (GIS) in the hydrological administrative regions (HARs) of the North Pacific, Northwest, and Baja California Peninsula, located in Northwest Mexico. Data related to aridity, desertification, degradation, and drought were investigated, and the main factors involved in the aridity process, such as surface temperature, soil humidity, precipitation, slopes, orientations, the normalized difference vegetation index (NDVI), and evapotranspiration, were obtained. For the standardization of factors, a fuzzy inference system was used. The weight of each factor was then determined with the analytical hierarchy process (AHP). To delimit arid regions, the classification of arid zones proposed by the United Nations Environment Program (UNEP) was used, and the result was an aridity suitability map. To validate the results, the sensitivity analysis method was applied. Quantitative and geospatial aridity indicators were obtained at the administrative hydrological level and by state. The main results indicated that semiarid and dry subhumid zones predominated, representing 40% and 43% of the surface of the study area, respectively, while arid regions represented 17%, and humid regions represented less than 1%. In addition, of the states for which 100% of the surface lay in the study area, it was observed that Baja California and Baja California Sur had the largest arid and semiarid zones, while subhumid regions predominated in Sonora and Sinaloa. Full article

The general bacterial microbiota of the soft tick Ornithodoros turicata found on Bolson tortoises (Gopherus flavomarginatus) were analyzed using next generation sequencing. The main aims of the study were to establish the relative abundance of bacterial taxa in the tick, and to document the presence of potentially pathogenic species for this tortoise, other animals, and humans. The study was carried-out in the Mapimi Biosphere Reserve in the northern-arid part of Mexico. Bolson tortoises (n = 45) were inspected for the presence of soft ticks, from which 11 tortoises (24.4%) had ticks in low loads (1–3 ticks per individual). Tick pools (five adult ticks each) were analyzed through 16S rRNA V3–V4 region amplification in a MiSeq Illumina, using EzBioCloud as a taxonomical reference. The operational taxonomic units (OTUs) revealed 28 phyla, 84 classes, 165 orders, 342 families, 1013 genera, and 1326 species. The high number of taxa registered for O. turicata may be the result of the variety of hosts that this tick parasitizes as they live inside G. flavomarginatus burrows. While the most abundant phyla were Proteobacteria, Actinobacteria, and Firmicutes, the most abundant species were two endosymbionts of ticks (Midichloria-like and Coxiella-like). Two bacteria documented as pathogenic to Gopherus spp. were registered (Mycoplasma spp. and Pasteurella testudinis). The bovine and ovine tick-borne pathogens A. marginale and A. ovis, respectively, were recorded, as well as the zoonotic bacteria A. phagocytophilum,Coxiella burnetii, and Neoehrlichia sp. Tortoises parasitized with O. turicata did not show evident signs of disease, which could indicate a possible ecological role as a reservoir that has yet to be demonstrated. In fact, the defense mechanisms of this tortoise against the microorganisms transmitted by ticks during their feeding process are still unknown. Future studies on soft ticks should expand our knowledge about what components of the microbiota are notable across multiple host–microbe dynamics. Likewise, studies are required to better understand the host competence of this tortoise, considered the largest terrestrial reptile in North America distributed throughout the Chihuahuan Desert since the late Pleistocene. Full article

Mexico holds the largest single bean production area in the world that is vulnerable to drought. Using field data and two future climate scenarios (RCP4.5 and RCP8.5) for the period 2020–2039, this study evaluated three common bean (Phaseolus vulgaris L.) cultivars planted under rainfed conditions at different densities in two locations in the north-central Mexican semi-arid temperate highlands. The sowing densities were 90,000, 145,000, and 260,000 plants ha⁻¹ established in single rows (SR), three rows (3R), and six rows (6R), respectively. The climate change scenarios were derived from an assembly model integrating 11 general circulation models (GCM) selected for Mexico with a 30” arc resolution. The baseline climate was for the period 1961–2010. The ALMANACMEX model (USDA-ARS-INIFAP, Temple, USA) was parameterized and evaluated and then re-run using the climate scenarios. Beans planted at 6R showed the highest increase in seed yield in both climate scenarios, although the response varied by cultivar and time periods. For the growth habit III cultivars, Flor de Mayo Bajio showed no difference in yield, while Pinto Saltillo, a drought-resistant cultivar, showed increases of 13% to 16% at 6R only until 2033. Growth habit I cultivar Azufrado 2 showed more than 60% increases at 6R in both climate scenarios for the full period 2020–2039. These results suggest that considering the projected climate conditions, high sowing densities may be a viable agronomic option for common bean production under rainfed conditions in semi-arid temperate regions, such as the highlands of Mexico, in the near future; however, the selection of the cultivar is a key element to consider in this regard. Full article