San Luis Potosi Research Articles

Delineation of Groundwater Potential Zones (GWPZs) in a Semi-Arid Basin through Remote Sensing, GIS, and AHP Approaches

Groundwater occurrence in semi-arid regions is variable in space and time due to climate patterns, terrain features, and aquifer properties. Thus, accurate delineation of Groundwater Potential Zones (GWPZs) is essential for sustainable water resources management in these environments. The present research aims to delineate and assess GWPZs in a semi-arid basin of San Luis Potosi (SLP), Mexico, through the integration of Remote Sensing (RS), Geographic Information System (GIS), and Analytic Hierarchy Process (AHP). Seven thematic layers (geology, lineament density, land use and land cover, topographic wetness index (TWI), rainfall, drainage density, and slope) were generated in raster format. After the AHP procedure and rank assignment, the thematic layers were integrated using the raster calculator to obtain the GWPZs map. The results indicated that 68.21% of the area is classified as low groundwater potential, whereas 26.30% is classified as moderate. Validation was done by assessing the water residence time data from 15 wells distributed in the study area. Furthermore, the Receiver Operating Characteristics (ROC) curve was obtained, indicating a satisfactory accuracy prediction (AUC = 0.677). This study provides valuable information for decision-makers regarding the conservation and sustainable management of groundwater resources.

A Feasibility Study on the Use of an Atmospheric Water Generator (AWG) for the Harvesting of Fresh Water in a Semi-Arid Region Affected by Mining Pollution

Worldwide, the shortage of fresh water has increased exponentially due to population growth and contamination of available water, especially in water tables that provide water for general consumption. One of the main pollutants of water is arsenic (As), present in the environment and in most mining/metallurgical processes, which is a major health risk, especially as a carcinogen. In the region of Matehuala, San Luis Potosi (SLP), Mexico, a highly productive mining area, arsenic concentrations of 138.1 mg/kg have been found in soils—6.2 times higher than what is allowed in domestic soils, while in water it is reported up to 158 mg/L, exceeding permissible limits for human consumption. In addition to As pollution, the region suffers from water shortage both in the city and in rural communities. Therefore, it is necessary to explore new technologies to provide the population with fresh water. This paper presents a feasibility study on the use of an atmospheric water generator (AWG) to capture fresh water in the region of Matehuala, SLP. The region was found to have the necessary environmental conditions to use AWGs, with an annual average relative humidity (RH) of approximately 60%. Using a mathematical model of a dehumidifier, water harvesting can be evaluated under the region’s prevailing climatic conditions. The month with lowest harvest was found to be January, with 0.89 to 3.6 L/day, while the month with largest harvest was August at 3.9 to 18 L/day and water production costs of 0.0093 and $ 0.038 USD/L, respectively. The study concludes that the use of AWGs would help alleviate water shortages, thus benefiting marginalized people or communities, preserving ecosystems and the environment.

Natural controls validation for handling elevated fluoride concentrations in extraction activated Tóthian groundwater flow systems: San Luis Potosí, Mexico

Fluoride concentration in groundwater supply above the guideline value of 1.5 mg/L is a health hazard for the population living in two thirds of the Mexican territory. Enhanced groundwater extraction in the city of San Luis Potosi (SLP), Mexico, led to a substantial territorial increase in water with high fluoride (F−) which originates from thermal water–rock interaction with regional rhyolites. Previous knowledge of the Tothian groundwater flow systems around SLP City and their F− concentrations from 1987 data provided an insight into natural F− controls for the construction and operation of boreholes. During the period 1987–2007, the number of new boreholes increased as well as the relocation of boreholes whose production diminished. Overall estimated extraction augmented from 2.6 to 4.1 m3/s. Results obtained for 2007 suggest that F− controls defined for 1987 data (e.g., variable portions of F−-rich deep thermal water in borehole yields) are also valid in newly constructed boreholes. Water authority actions related to groundwater extraction lack consideration of proposed F− controls, so constructed boreholes progressively tapping the high F− groundwater flow system resulted in a 85% increase in the F− affected territory (> 2 mg/L) between 1987 and 2007. Reduction in F− extraction following the proposed natural control mechanisms (e.g., fluorite precipitation) was also confirmed. Applying geochemical and mineralogical analysis, rhyolites surrounding the SLP graben basin and contributing to its volcano-clastic sedimentary filling were identified as the primary F− source for elevated concentrations in groundwater of the area under investigation.

Environmental exposure to arsenic and chromium in children is associated with kidney injury molecule-1

Environmental hazards from natural or anthropological sources are widespread, especially in the north-central region of Mexico. Children represent a susceptible population due to their unique routes of exposure and special vulnerabilities. In this study we evaluated the association of exposure to environmental kidney toxicants with kidney injury biomarkers in children living in San Luis Potosi (SLP), Mexico. A cross-sectional study was conducted with 83 children (5–12 years of age) residents of Villa de Reyes, SLP. Exposure to arsenic, cadmium, chromium, fluoride and lead was assessed in urine, blood and drinking water samples. Almost all tap and well water samples had levels of arsenic (81.5%) and fluoride (100%) above the permissible levels recommended by the World Health Organization. Mean urine arsenic (45.6ppb) and chromium (61.7ppb) were higher than the biological exposure index, a reference value in occupational settings. Using multivariate adjusted models, we found a dose-dependent association between kidney injury molecule-1 (KIM-1) across chromium exposure tertiles [(T1: reference, T2: 467pg/mL; T3: 615pg/mL) (p-trend=0.001)]. Chromium upper tertile was also associated with higher urinary miR-200c (500 copies/μl) and miR-423 (189 copies/μL). Arsenic upper tertile was also associated with higher urinary KIM-1 (372pg/mL). Other kidney injury/functional biomarkers such as serum creatinine, glomerular filtration rate, albuminuria, neutrophil gelatinase-associated lipocalin and miR-21 did not show any association with arsenic, chromium or any of the other toxicants evaluated. We conclude that KIM-1 might serve as a sensitive biomarker to screen children for kidney damage induced by environmental toxic agents.

Diabetes and Other Risk Factors for Multi-drug Resistant Tuberculosis in a Mexican Population with Pulmonary Tuberculosis: Case Control Study

Multidrug resistant tuberculosis (MDR-TB) poses problems in treatment, costs and treatment outcomes. It is not known if classically described risk factors for MDR-TB in other countries are the same in Mexico and the frequency of the association between diabetes mellitus (DM) and MDR-TB in our country is not clear. We undertook this study to analyze risk factors associated with the development of MDR-TB, with emphasis on DM. A case-control study in the state of San Luis Potosi (SLP), Mexico was carried out. All pulmonary MDR-TB patients diagnosed in the state of SLP between 1998 and 2013 (36 cases) evaluated at a state pharmacoresistant tuberculosis (TB) clinic and committee; 139 controls were randomly selected from all pulmonary non-multidrug-resistant tuberculosis (non-MDR-TB) cases identified between 2003 and 2008. Cases and controls were diagnosed and treated under programmatic conditions. Age, gender, malnutrition, being a health-care worker, HIV/AIDS status, and drug abuse were not significantly different between MDR-TB and non-MDR-TB patients. Significant differences between MDR-TB and non-MDR-TB patients were DM (47.2 vs. 28.1%; p = 0.028); previous anti-TB treatments (3 vs. 0, respectively; p <0.001), and duration of first anti-TB treatment (8 vs. 6 months, respectively; p <0.001). MDR-TB and DM are associated in 47.2% of MDR TB cases (17/36) in this study. Other recognized factors were not found to be significantly different in MDR-TB compared to non-MDR-TB in this study. Cost-feasible strategies must be implemented in the treatment of DM-TB in order to prevent the selection of MDR-TB.

Transgresores de la legalidad: los militares y su lucha legítima por el poder en San Luis Potosí, 1869-1870

&lt;p&gt;En este artículo, se analizan las razones que motivaron a un grupo de militares encabezados por el general Francisco Antonio Aguirre a inconformarse ante el desarrollo de las elecciones para gobernador en el año de 1869 ya que los miembros de la legislatura local, no declararon gobernador constitucional electo. Ante este escenario indefinido, los militares transgredieron el orden al iniciar un pronunciamiento para externar su inconformidad. El gobierno general intervino en la vida política interna de los potosinos al ordenar a una facción del ejército regular de la federación que sofocara a los pronunciados. El movimiento político tomó otra dimensión y los sublevados redactaron un Plan político en contra del presidente Benito Juárez y sus ministros. El movimiento se mantuvo vigente al iniciar 1870 así el gobierno general envió a San Luis Potosí al general Mariano Escobedo con el propósito de restablecer a las autoridades legítimas. Luego de conseguir su objetivo, Escobedo se postuló como gobernador y ganó las elecciones en ese año. Las fuentes documentales primarias que utilicé se localizan en archivos locales y del extranjero.&lt;/p&gt;

Salt Leaching in Sulphatic Soils of Palomas, San Luis Potosí, Mexico

The aim of this study was to evaluate the initial salinity and the type and amount of salt evacuated from soils of palomas, san luispotosi in a leaching process. These soils present primary and secondary salinization problems, induced by irrigation which affects their productive capacity. The study was conducted in a greenhouse and in the soils laboratory of the graduate college, from april to august 2010. Leaching of salts was done in soil columns that were applied with three soil-water extraction ratios, namely, 1 ≈0.2-0.6, 1:5 and 1:10, and the normal rates of leaching ��

Subsidence associated with land use changes in urban aquifers with intensive extraction

Land use change is a major factor in alterations in natural processes and cycles. Remote sensing has become an excellent tool to evaluate technological changes in land cover and land use changes over large areas, such as those occurring in the Valley of San Luis Potosi (VSLP). Here, such changes have impacted a system which is 95% dependent on the aquifer. The methodology for the present study is based on the use of satellite images for the years 1976, 1986, 1995 and 2000. To asses land use change, a supervised classification process was used with a decision tree technique and ENVI 4.3 software. The evolution of groundwater levels for the years 1977, 1986, 1995, 1998 and 2007 was also analyzed, as well as problems of subsidence and fissuring in the urban area of the valley in 2006. With the support of remote sensing, it was possible to analyze the dynamic changes in land use over large areas and highlight their impact on the environment.

Occurrence of AH1N1 viral infection and clinical features in symptomatic patients who received medical care during the 2009 influenza pandemic in Central Mexico

BackgroundIn 2009 a new influenza serotype (AH1N1) was identified in Mexico that spread rapidly generating worldwide alarm. San Luis Potosi (SLP) was the third state with more cases reported in that year. The clinical identification of this flu posed a challenge to medical staff. This study aimed at estimating the AH1N1 infection, hospitalization and mortality rates, and at identifying related clinical features in persons who received medical care during the influenza pandemic.MethodsRetrospective study with persons with flu-like illness who received public or private medical care in SLP from 15.03.09 to 30.10.09. Physicians purposely recorded many clinical variables. Samples from pharyngeal exudate or bronchoalveolar lavage were taken to diagnose AH1N1 using real-time PCR. Clinical predictors were identified using multivariate logistic regression with infection as a dependent variable. Odds ratios (OR) with 95% confidence intervals (CI) were computed. Analyses were stratified by age group based on the distribution of positive cases.ResultsFrom the 6922 persons with flu symptoms 6158 had available laboratory results from which 44.9% turned out to be positive for AH1N1. From those, 5.8% were hospitalized and 0.7% died. Most positive cases were aged 5–14 years and, in this subgroup, older age was positively associated with A H1N1 infection (95% CI 1.05-1.1); conversely, in patients aged 15 years or more, older age was negatively associated with the infection (95% CI 0.97-0.98). Fever was related in those aged 15 years or more (95% CI 1.4-3.5), and headache (95% CI 1.2-2.2) only in the 0–14 years group. Clear rhinorrhea and cough were positively related in both groups (p < 0.05). Arthralgia, dyspnea and vaccination history were related to lesser risk in persons aged 15 years or more, just as dyspnea, purulent rhinorrhea and leukocytosis were in the 0–14 years group.ConclusionThis study identified various signs and symptoms for the clinical diagnosis of AH1N1 influenza and revealed that some of them can be age-specific.

Importance of the vertical component of groundwater flow: a hydrogeochemical approach in the valley of San Luis Potosi, Mexico

Fractured volcanics exert a control on groundwater flow in the San Luis Potosi (SLP) valley. The chemical composition and temperature of water pumped from boreholes partially penetrating the fractured volcanics indicate that the produced water originates from an upward vertical flow. Most of the thermal groundwater has been detected in areas related to regional faults and lineaments. Intensive and uncontrolled pumping from the upper 1 4 of the aquifer (total depth > 1500 m) causes the rise of water from a deep regional flow system that mixes with the shallower waters. The deep waters contain high fluoride concentrations that contaminate the mixture and cause substantial health related effects. The recharge controls on the regional flow system require further research; however, hydrogeochemical evidence supports the view that the origin of this recharge is limited to the western bounding Sierra Madre Occidental. Higher levels of dissolved Na +, Li +, F − (and SO 4 −2) derived from Tertiary volcanics have been introduced into the exploited region; the concentrations indicate lengthy and deep circulation flow. Li + concentration was used as an indicator of groundwater residence time, and therefore of the length of the groundwater flow path. Hydrogeochemical interpretation indicates the presence of three flow systems: a shallow local one controlled by a clay layer that subcrops most of the valley floor, an intermediate system in which water infiltrates just beyond the boundary of the clay layer, and a deep regional system which originates outside the surface catchment. The local and intermediate systems circulate through materials with comparatively low hydraulic conductivity. Low Cl − concentrations suggest rapid flow in the regional system. Concentrations of Li + and F − can be used to calculate percentages of waters in mixtures of regional and intermediate flows. Concentrations of Na +, Ca 2+ and SO 4 −2 appear to be controlled by water-rock reactions. Uncontrolled pumping increases will tend to enhance fluoride concentration and its undesirable effects. Lack of management of aquifers in basins similar to the SLP valley can result in groundwater contamination, not only from surface anthropogenic sources, but also from natural water-rock interactions.

DESCRIPCION DE UNA NUEVA SUBESPECIE DE TUZA, CRATOGEOMYS GOLDMANÍ (RODENTIA: GEOMYIDAE), DE SAN LUIS POTOSI, MEXICO

Se aruilizan ejerTipliftis de tuzas de diferentes subespecies de Cratogeomys goldrnam' del estado de San luis Potosí y aledaños, onnontrando que las que tiabitan en los alrededores de El Cedral, San luis Potosí, presentan caracteres craneales y de coloración peculiares, que nos inducen a nombrar diciia población conu; una subespecie no descrita. la principal característica de esta población es tener nianciias blancas con for.'na irregular, pero presentándose éstas casi siempre en el mismo sitio del cuerpo; f;sta característica es evidente en el 97% de los ejemplares de la región de El Cedral siendo El Cedral el centro de un gradiente de esta peculiar coloración.

Endemic Fluorosis in San-Luis-Potosi, Mexico .1. Identification of Risk-Factors Associated with Human Exposure to Fluoride

In order to identify risk factors associated with human exposure to fluoride in San Luis Potosi (SLP), Mexico, a biochemical and epidemiological study was carried out in 1992. Results from the analysis of fluoride sources showed that 61% of tap water samples had fluoride levels above the optimal level of 0.7-1.2 ppm. The levels were higher after boiling. In bottled water, fluoride levels ranged from 0.33 to 6.97 ppm. These sources are important since in SLP 82% of the children drink tap water, 31% also drink bottled water, 92% prepare their food with tap water, 44% boiled all the drinking water, and 91% used infant formula reconstituted with boiled water. The prevalence and severity of dental fluorosis in children (11-13 years old) increased as the concentration of water fluoride increased. At levels of fluoride in water lower than 0.7 ppm a prevalence of 69% was found for total dental fluorosis, whereas at levels of fluoride in water higher than 2.0 ppm a prevalence of 98% was found. In the same children, fluoride levels in urine were quantified. The levels increased as the concentration of water fluoride increased. Regressional analysis showed an increment of 0.54 ppm (P < 0.0001) of fluoride in urine for each ppm of fluoride in water. Fluoride urinary levels were higher in samples collected during the afternoon (1800) when compared with sample collected during the morning (1100). Taking together all these results, three risk factors for human exposure to fluoride in SLP can be identified: ambient temperature, boiled water, and food preparation with boiled water. These factors explain the prevalence of dental fluorosis in SLP.

Thermal history of the upper mantle beneath a young back-arc extensional zone: ultramafic xenoliths from San Luis Potos�, Central Mexico

At the San Luis Potosi (SLP) volcanic field (Central Mexico), Quaternary basanites and tuff breccias have sampled a suite of ultramafic xenoliths, predominately spinel lherzolites, spinel-olivine websterites, spinel pyroxenites, and hornblende-rich pyroxenites. Spinel lherzolites from the La Ventura maars have protogranular to equigranular textures, those from the Santo Domingo maars are strongly sheared. Both spinel-lherzolite types show similar whole-rock major and trace-element abundances. They are fertile to slightly depleted with mineralogical and geochemical heterogeneities induced by partial melting processes. Pyroxenites with either magmatic or metamorphic textures are high-pressure cumulates. Hornblende-rich pyroxenites are genetically linked to the host basanites. Most of the protogranular spinel lherzolites contain veinlets of glass along grain boundaries. These glasses are chemically homogeneous and have trachybasaltic to trachyandesitic compositions. Mg- and Fe2+-partitioning between olivine and glass suggests chemical equilibrium between the melts represented by the glasses and the spinel-lherzolite mineral assemblage at about 1,000°C and 10 to 15 kbar. The melts are interpreted to be of upper mantle origin. They may have been formed by in-situ partial melting in the presence of volatiles or represent percolating melts chemically buffered by the spinel-lherzolite mineral assemblage at uppermost mantle conditions. Mineral chemistry in all rock types of the whole xenolith suite reveals distinct disequilibrium features reflecting partial re-equilibration stages towards lower temperatures estimated to be from 1,050°C to 850°C at 9 to 15 kbar. The presence of similar zoning and exsolution features mainly documented in pyroxenes along with similar maximum and minimum temperatures requires all sampled xenoliths to have undergone the same temperature regime within the upper mantle. The sheared spinel lherzolites from the Sto. Domingo field are interpreted as formerly protogranular material which was sheared during uplift and cooling. The estimated mantle temperatures are higher than those predicted by low heat-flow measurements at the SLP fild, indicating that surface heat flow has not equilibrated to elevated temperatures at depth. This strongly supports a young perturbation event beneath the SLP area and connects the onset of uplift and cooling of the SLP-mantle segment with the back-arc extensional regime of the Quaternary volcanic cycle of the Transmexican Volcanic Belt.

Description du mâle de Mexistenasellus parzefalli (Crustacea Isopoda Asellota cavernicole du Mexique) et observations sur cette espèce

Description of the male of the Mexican cavernicolous Stenasellid Mexistenasellus parzefalli Magniez, 1972, from Huizache Cave, San-Luis Potosi State, Mexico. In the female with a brood pouch, the coxopodit of the maxilliped contains two provisional, oostegit-like plates, whereas the ovigerous female of european Stenasellids have only the inner one. This temporary sexual female character is known in other Isopods, such as the cavernicolous Caecosphaeroma burgundum Dollfus.

Moss Records from Eastern Mexico. II

Anomodon thraustus, an Asiatic species, and Drummondia prorepens are reported as additions to the bryoflora of Mexico. Range extensions in Mexico are reported for Forsstroemia ohioensis and Pilotrichum amazonum. A report of some new records of mosses for Mexico, based on collections made during the summer of 1961, was given previously (Reese & Pursell 1963). The species listed in the present report were identified from specimens also collected at that time. ANOMODON THRAUSTUS C. Miill. The present specimen could not be identified with any of the species of Anomodon listed by Crum (1951). However, Dr. Z. Iwatsuki tentatively identified it as belonging to A. thraustus, an Asiatic species whose range includes Pakistan, India, China, Korea, and Japan. Dr. Iwatsuki recently sent us speciments of A. thraustus from Japan and Korea, and the Mexican material agrees.with them. Iwatsuki (1963), in a revision of the eastern Asiatic species of Anomodon, considers A. thraustus to be closely allied to A. minor (Hedw.) Fiirnr. It is, however, distinguishable by a number of characteristics: The secondary stems of A. thraustus are more densely branched than those of A. minor. When moist, the leaves of A. thraustus are squarrose to recurved, as opposed to the two-ranked or complanate appearance in A. minor. The upper or lingulate portion of 1 This work was supported by Grant G-13306 from the National Science Foundation. 2 Department of Botany, Pennsylvania State University, University Park, Pennsylvania 16802. 3 Department of Biology, University of Southwestern Louisiana, Lafayette, Louisiana 70506. This content downloaded from 207.46.13.159 on Sun, 23 Oct 2016 04:37:42 UTC All use subject to http://about.jstor.org/terms 1966] PURSELL & REESE: MEXICAN MOSS RECORDS 503 the leaves of A. thraustus is narrower and more fragile than that of A. minor. And, whereas the costa of A. minor is distinct throughout its length, the distal portion of the costa of A. thraustus is usually obscured by overlying chlorophyllose cells similar to those of the lamina. MEXICO. TAMAULIPAS: Oak forest, 30 mi W of Antiguo Morelos along the road to Huizache, 4,000 ft, Pursell & Reese 5413 (PAC). DRUMMONDIA PROREPENS (Hedw.) Britt. The occurrence of this species in the mountains of eastern Mexico is not too surprising in view of the several other species that are characteristic of eastern North America that also appear there. This species also occurs in Japan. The presence of this species and Anomodon thraustus in Mexico is of especial interest in view of a recent paper in which Sharp and Iwatsuki (1965) compared the moss floras of Mexico and Japan and found that there are approximately 93 species, distributed among 65 genera, common to the two countries. MEXICO. TAMAULIPAS: Oak forest, 16 mi SW of Cd. Victoria along the road to Tula, 3,500 ft, Pursell & Reese 5553 (PAC). FORSSTROEMIA OHIOENSIS (Sull.) Lindb. This species was first reported from Mexico by Robinson (1964) from specimens collected near Jacala, Hidalgo. The present collections extend the known range of the species in Mexico approximately 259 miles northward. Forsstroemia ohioensis is also known from Missouri, Ohio, Virginia, and Paraguay. Duplicates of our collection 5561 are being distributed through the A.B.S. Moss Exchange. MEXICO. TAMAULIPAS: Scrub woods below the E rim of Mesa La Chorrito, 60 mi NW of Victoria, 1,100 ft, Reese & Pursell 5561, 5574 (LAF, PAC). PILOTRICHUM AMAZONUM Mitt. Crum (1951) reported this species from Niltepec, Oaxaca, based on a specimen collected by Sharp. The present collection extends the known range of the species in Mexico some 500 miles northward. The specimen is rather depauperate and was identified by Dr. H. Robinson. MEXICO. SAN LUIS POTOSi: Wooded slope beside the waterfall, El Salto, 7 mi N of the Antiguo Morelos-Huizache Road, 700-1,000 ft, Pursell & Reese, 5281 (PAC).