Comparison of the design and methodology of Phase 3 clinical trials of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) and dolutegravir-based dual therapy (DTG) in HIV: a systematic review of the literature

Introduction: Current recommended antiretroviral regimens include a combination of two (dual; DT) or three (triple; TT) antiretroviral drugs. This study aims to determine whether the quality of evidence from clinical trials of dolutegravir (dolutegravir/lamivudine [DTG/3TC] or dolutegravir/rilpivirine [DTG/RPV]) is methodologically comparable to that of clinical trials conducted with bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). Areas covered: A systematic review of the medical literature was carried out in PubMed without date or language restrictions, following the PRISMA guidelines. All aspects of the methodological design of phase 3 randomized clinical trials (RCTs) of DT and TT, evaluated by the European Medicines Agency (registration trials), were reviewed. The quality of clinical trials was assessed using the Jadad scale. Expert opinion: The search identified 5, 3 and 2 phase 3 RCTs with BIC/FTC/TAF, DTG/3TC and DTG/RPV, respectively, that met the inclusion criteria. The designs would not be comparable due to differences in pre-randomization losses, blinding, patient recruitment, as well as differences in methodological quality, with the average score of the RCTs conducted with BIC/FTC/TAF, DTG/3TC and DTG/RPV being 4.2 (high quality), 3.0 (medium quality) and 3.0 (medium quality), respectively. Due to methodological differences between the BIC/FTC/TAF, DTG/3TC and DTG/RPV RCTs, the results of these are not comparable

Capacidad de dos especies vegetativas en la acumulación de metales pesados

Habitat fragmentation allows for vegetative species to be used as indicators of environmental pollution by heavy metals. Considering the distribution of Prosopis laevigata (mesquite) and Schinus molle (pepper tree) heavy metal concentrations were determined as potential indicators of environmental impact assessment for agricultural and livestock, rural settlement, commercial and service, urban settlement and mining land uses. A total of 30 sampling points were established during summer, autumn, winter and spring, based on the presence of the two species. Applying the technique of ICP-MS, concentrations of Al, As, Co, Cu, Cd, Pb, Ti, V and Zn were determined. With a statistic model the interactions between species, type of land use and season with respect to the concentration of these minerals in the leaf material were determined. Results indicated that the presence of heavy metals is determined by the effect of the species, land use and season, and the possible association between these. The specie of mesquite was the most efficient for bioaccumulation of Pb, Co and Al. In the same way, the pepper tree was more efficient with respect to Ti. On one hand, trees located in the mining land use showed the highest concentrations of Cu, Zn, Cd, Pb, Co and As. On the other hand, the spring season presented the highest concentration of Cu, Zn, Co, Ti and V. With that, it could be demonstrated that As, Co, Cd, Pb, Ti and Zn concentrations were above the normal limit. Therefore, the dynamics and functionality, environmental factors and physiological differences to develop physicalchemical processes in the absorption and transport of these elements towards the leaves are a determining factor of vegetative species placed under conditions of fragmentation, are good elements for surveying on pollution and environmental impact.La fragmentación del hábitat permite aprovechar especies vegetativas como indicadoras de contaminación ambiental por metales pesados. Considerando la distribución de Prosopis laevigata (mezquite) y Schinus molle (pirul) se determinaron las concentraciones de metales pesados en material foliar para evaluar el impacto ambiental de los usos de suelo agropecuario, residencial rural, comercial y servicio, residencial urbano y minero. Fueron establecidos 30 puntos de muestro durante las estaciones de verano, otoño, invierno y primavera, basados en la presencia de las dos especies. Aplicando la Técnica ICP-MS fueron determinadas las concentraciones de Al, As, Co, Cu, Cd, Pb, Ti, V y Zn. Con un ANOVA se probaron las interacciones entre especie, tipo de uso de suelo y estación con respecto a la concentración de estos minerales en material foliar. Los resultados indicaron que la presencia de metales pesados está condicionada por el efecto de la especie, uso de suelo y la estación, así como la posible asociación entre estos. El mezquite resultó ser más eficiente en la bioacumulación de Pb, Co y Al. En el caso del pirul solo fue más eficiente con respecto al Ti. Los árboles ubicados en el uso de suelo minero obtuvieron las mayores concentraciones de Cu, Zn, Cd, Pb, Co y As. Por otra parte, la estación de primavera incidió en la mayor concentración de Cu, Co, Ti y V. Con esto se pudo demostrar que As, Co, Cd, Pb Ti y Zn presentaron concentraciones arriba del límite normal en material foliar. Por lo tanto, la dinámica y funcionalidad, factores ambientales y diferencias fisiológicas para desarrollar procesos físico-químicos en la absorción y transporte de estos elementos hacia las hojas son un factor determinante de las especies vegetativas situadas bajo condición de fragmentación, lo que contribuye ser un buen elemento de estudio de la contaminación y evaluación del impacto ambiental.Fil: Alcalá Jáuregui, Jorge. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Rodríguez Ortíz, Juan C.. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Hernández Montoya, Alejandra. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Filippini, María Flavia. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Martínez Carretero, Eduardo. Instituto Argentino de Investigaciones de las Zonas Áridas Fil: Diaz Flores, Paola Elizabeth. Universidad Autónoma de San Luis Potosí. Facultad de Agronomí

Bark of P. laevigata (Fabaceae) and S. molle (Anacardiaceae) as bioindicator of heavy metal contamination

La corteza arbórea constituye un elemento viable para diagnosticar la contaminación por metales pesados. Fue evaluada la presencia de once metales pesados en corteza de P. laevigata &quot;mezquite&quot; y S. molle &quot;pirul&quot; como indicador de impacto ambiental en San Luis Potosí, México. Basado en la presencia de estas dos especies sobre un sistema fragmentado por usos de suelo agropecuario, asentamiento rural, comercial y servicio, asentamiento urbano y minero, se tomó muestras de corteza durante las estaciones de verano, otoño, invierno y primavera. Se aplicó la técnica ICP-MS y se determinó las concentraciones de Al, As, Co, Cu, Cd, Cr, Ni, Pb, Ti, V y Zn, diseñando un modelo General Lineal para su análisis. Los resultados indicaron concentraciones promedio de Ni&gt;Al&gt;Z &gt;Pb&gt;Cu&gt;As&gt;Ti&gt;V&gt;Cd&gt;Cr&gt;Co. La presencia de metales pesados fue condicionada por el efecto de la especie, uso de suelo y la temporada, así como la relación entre estos factores. Las cortezas de S. molle resultaron tener mayores concentraciones de Al, As, Co, Cd, Cr, Ni, Pb y Ti. En otoño se presentaron las mayores concentraciones de Al, Cu, Cr, Co y Ni. El uso de suelo para asentamiento urbano presentó las mayores concentraciones de Al, Co, Cr, Ni, Ti y V y el uso de suelo minero las de Cu, Cd, Zn y Pb. Se demuestra el potencial bioindicador de la corteza de ambas especies. Se sugiere continuar realizando estudios que permitan ampliar el conocimiento de las condiciones ambientales de la zona.The tree bark is a valuable component to diagnose heavy metal air pollution. In bark of P. laevigata and S. molle presence of eleven heavy metals was evaluated, as indicator of environmental impact in San Luis Potosí, México. Based on the presence of both species on a soil system fragmented agricultural uses, rural settlements, trade and services, urban settlements and mineral uses, bark samples were taken during summer, autumn, winter and spring seasons. In each species thirty exemplars were sampled. Concentrations of Al, As, Co, Cu, Cd, Cr, Ni, Pb, Ti, V and Zn were determined by applying the ICP-MS technique, and for data analysis the General lineal model was applied. Results indicated that the average concentrations vary according to Ni&gt; Al&gt; Zn&gt; Pb &gt; Cu&gt; As&gt; Ti&gt; V&gt; Cd&gt; Cr&gt; Co. The presence of heavy metals was determined by the species effect, land use and season, and the relationship between these factors. The pepper tree bark was found to have higher concentrations of Al, As, Co, Cd, Cr, Ni, Pb and Ti. The highest concentrations of Al, Cu, Cr, Co and Ni were in the fall season. The urban settlement showed higher concentrations of Al, Co, Cr, Ni, Ti and V; meanwhile in the mining soil use Cu, Cd, Zn and Pb were relevant. The potential bio-indicator value of bark of both species was evidenced. Consequently, it is convenient to continue with these studies to increase knowledge of the environmental conditions of the San Luis Potosí.Fil: Alcalá Jáuregui, Jorge. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Rodríguez Ortíz, Juan C.. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Hernández Montoya, Alejandra. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Díaz Flores, Paola Elisabeth. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Filippini, María Flavia. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Martínez Carretero, Eduardo. Instituto Argentino de Investigaciones de las Zonas Áridas <IADIZA

Tectono-Sedimentary Cenozoic Evolution of the El Habt and Ouezzane Tectonic Units (External Rif, Morocco)

An interdisciplinary study based on lithostratigraphic, biostratigraphic, petrographic and mineralogical analyses has been performed in order to establish the Cenozoic tectono-sedimentary evolution of the El Habt and Ouezzane Tectonic Units (External Intrarif Subzone, External Rif, Morocco). The reconstructed record allowed identification of the depositional architecture and related sedimentary processes of the considered units. The Cenozoic successions were biochronologically defined allowing, at the same time, identification of unconformities and associated stratigraphic gaps. The presence of five unconformities allowed for the definition of the main stratigraphic units arranged in a regressive trend: (1) lower Paleocene interval (Danian p.p.) assigned to a deep basin; (2) Eocene interval (lower Ypresian-lower Bartonian p.p.) from a deep basin to an external carbonate-siliceous platform; (3) lower Rupelian-upper Chattian p.p. interval deposited on unstable slope with turbidite channels passing upward to an external siliciclastic platform; (4) Burdigalian p.p. interval from a slope; (5) Langhian-Serravallian p.p. interval from slope to external platform realms. The petrography of the arenites and calcarenites allowed for the identification of the supplies derived from erosion of a recycled orogen (transitional and quartzose subtypes). The clay-mineralogy analysis indicates an unroofing (first erosion of Cretaceous terrains followed by upper Jurassic rocks) always accomplished by erosion of Cenozoic terrains. Several tectofacies checked in some stratigraphic intervals seem to indicate the beginning of deformation of the basement generating gentle folds and first activation of blind thrusts, mainly during the Paleogene. A preorogenic tectonic framework is considered as responseto the generalized tectonic inversion (from extension to compression) as frequently registered in the central-western peri-Mediterranean areas. The large volumes of reworked terrigeneous supply during the latest Oligocene-Miocene p.p. indicates the beginningsof the synorogenic sedimentation (foredeep stage of the basins) controlled by active tectonics.Research Project CGL2016-75679-P (Spanish Ministry of Education and Science); Research Groups, Projects of the Generalitat Valenciana, Alicante University (CTMA-IGA); Grants from the University of Urbino Carlo Bo (M. Tramontana)

Heavy metals as an indicator of ecological impact of a fragmented land uses, San Luis Potosi, Mexico

La necesidad de estudiar la presencia de metales pesados en el suelo radica en su impacto como indicador de contaminación ambiental. Se determinó la presencia de Cu, Zn, Pb y Cd en suelos donde se distribuyen especies vegetales en un corredor ecológico. Entre los municipios de Soledad de Graciano Sánchez y San Luis Potosí (México) fueron establecidos 30 puntos distribuidos en cinco prácticas dominantes de usos de suelo: agropecuario, residencial rural, comercio y servicios, residencial urbano y minero. Los muestreos se realizaron en cuatro épocas durante 2009 y 2010 (verano, otoño, invierno y primavera). Se encontró un efecto significativo del uso del suelo en cuanto a los niveles de Cu (p = 0,000), Pb (p = 0,043) y Cd (p = 0,010). En el caso del Zn, el uso del suelo (p = 0,000) y la estación (p = 0,059) fueron significativos. El uso del suelo minero mostró las mayores concentraciones de metales y el agrícola las menores. Los niveles de los cuatro metales se encuentran en el rango marcado como alto por la EPA y por otras fuentes técnicas. En el caso de Pb y Cd no rebasan los estándares NOM-147- SEMARNAT-SSA1. Estos resultados reflejan el potencial indicativo del uso del suelo en la evaluación de la calidad ambiental, sin embargo, se requiere continuar con un monitoreo de metales pesados en la zona.The need to study the presence of heavy metals in the soil lies on their impact as a indicator of environmental pollution. Therefore, it was determined the presence of Cu, Zn, Pb and Cd in soils where plant species were distributed in an ecological corridor. Among the municipalities of Soledad Graciano Sanchez and San Luis Potosi (Mexico), 30 points were established, distributed in five land uses: agricultural , rural residential, trade and services, urban residential and mining. Sampling was conducted from 2009 to 2010 (summer, fall, winter and spring). A significant effect of land use was found in terms of Cu (p = 0.000), Pb (p = 0.043) and Cd (p = 0.010). In the case of Zn both the land use (p = 0.000) and season (p = 0.059) had significant effects. It is emphasized that mining land use presented the highest concentrations of the studied metals and agricultural land use the lowest. The levels of four metals are in the range marked like high by the EPA and other technical sources. The levels of Pb and Cd do not exceed the NOM-147-SEMARNAT-SSA1. These results reflect the indicative potential of the soil and its consideration for future to evaluate the habitat of plant species. These results reflect the potential indicative land use in the assessment of environmental quality, however, requires continued monitoring of heavy metals in the area.Fil: Alcalá Jáuregui, Jorge. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Ávila Castorena, Cecilia. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Rodríguez Ortíz, Juan C.. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Hernández Montoya, Alejandra. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Beltrán Morales, F. Alfredo. Universidad Autónoma de Baja California Sur (México)Fil: Rodríguez Fuentes, Humberto. Universidad Autónoma de Nuevo León (México). Facultad de Agronomía.Fil: Loya Ramírez, J. Guadalupe. Universidad Autónoma de Baja California Sur (México

Vegetative as bioindicators of heavy metals in a semiarid system

Evaluar la contaminación por metales pesados en los ecosistemas permite conocer la capacidad bioindicativa de especies vegetativas. El objetivo fue determinar la concentración de metales pesados en Prosopis laevigata, Acacia spp. y Schinus molle bajo el efecto de usos suelo y temporalidad. El área se sitúa en la colindancia de los Municipios de Soledad de Graciano Sánchez y San Luis Potosí fragmentada por usos de suelo: agropecuario, comercio y servicios, residencial urbano y minero. Fueron tomadas muestras de hojas de las tres especies en las estaciones de verano, otoño, invierno y primavera y se evaluó la concentración de metales pesados a través de la técnica de ICP-MS. Los análisis estadísticos indicaron niveles de Aluminio (Al) &gt; Cinc (Zn) &gt; Plomo (Pb) &gt; Cobre (Cu) &gt; Titanio (Ti) &gt; Vanadio (V) &gt; Arsénico (As) &gt; Cromo (Cr) &gt; Cadmio (Cd) &gt; Cobalto (Co). Los elementos Al, As, Cd, Cr, Pb y Ti presentaron niveles por encima del umbral normal en vegetación. El uso de suelo tuvo efecto significativo con Al, Ti, Cd, As y Pb; los árboles ubicados en los usos de suelo minero, comercio y servicios tuvieron la mayor concentración. La especie tuvo efecto significativo con Al y Pb siendo Acacia spp. el que presentó la mayor capacidad de acumulación. La temporada del año impactó significativamente en la acumulación de As, Cd, Co, Cu, Cr y Ti en las tres especies. La dinámica antropogénica de los diferentes usos de suelo genera partículas y residuos con metales pesados impactando en la disponibilidad y acumulación en las especies evaluadas. Se contribuye a evaluar el impacto ambiental en el sistema fragmentado recomendando dar continuidad a este tipo de estudios.The evaluation of pollution by heavy metals on ecosystems can determine the bioindicative capacity of plant species. The presence of heavy metals was determined in Prosopis laevigata, Acacia spp. and Schinus molle under the effect of different of land uses and seasons. The area is located near of the municipalities of Soledad de Graciano Sánchez and San Luis Potosi which has fragmented land use such as: agriculture, commercial and services, urban residential and mining. Samples were taken from leaves of the three species during summer, autumn, winter and spring to assess the concentrations of heavy metals through the technique of ICP-MS. Statistical analyzes showed levels of Aluminum (Al) &gt; Zinc (Zn) &gt; Lead (Pb) &gt; Copper (Cu) &gt; Titanium (Ti) &gt; Vanadium (V) &gt; Arsenic (As) &gt; Chromium (Cr) &gt; Cadmium (Cd) &gt; Cobalt (Co). The elements Al, As, Cd, Cr, Pb and Ti had levels above the normal threshold in vegetation. Land use had a significant effect with Al, Ti, Cd, As and Pb having the trees being located in the land with mining and commercial and services use the greater concentrations. The species had a significant effect on Al and Pb with Acacia spp., having the largest storage capacity. The season of the year significantly impacted the accumulation of As, Cd, Co, Cu, Cr and Ti in the three species. The anthropogenic dynamics of different land uses generated waste particles and residues of heavy metals, impacting the availability and accumulation in the species evaluated. This study contribute to evaluate the environmental impact in the system with a fragmented land use and the continuation of this type of studies is recommended.Fil: Alcalá Jáuregui, Jorge. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Rodríguez Ortíz, Juan C.. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Villaseñor Zuñiga, María Elena. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Hernández Montoya, Alejandra. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: García Arreola, María Elena. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Beltrán Morales, F. Alfredo. Universidad Autónoma de Baja California Sur (México)Fil: Rodríguez Fuentes, Humberto. Universidad Autónoma de Nuevo León (México). Facultad de Agronomía

Metallic elements in foliar material and fruits of three tree species as bioindicators

This study aimed to determine the presence of metal elements in fruits and leaves of three tree species as bioindicators in San Luis Potosi, Mexico. Ninety fruit and 90 leaf samples (30 per tree species) were collected at five sites (agricultural, suburban, commercial and services, urban, and mining), using the site and the presence of P. laevigata, S. molle, and A. farnesiana as references. Total concentrations of 13 metal elements were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The species were significantly affected by Co, As, and Pb (ANOVA, p≤0.05). Considering the land use and the species, the contents determined in the leaves and fruits of the three species had sufficient and phytotoxic contents of Al, Cd, Co, Ni, Mn, Ti, and Cr, and excessive ranges with the possible phytotoxic effect of As, Cu, Pb, Zn, V, and Fe. The A. farnesiana had the highest concentrations of 12 heavy metals analyzed (HM). The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%, with V, As, and Cr being prominent. The functionality of these tree species as phytoremediators and bioindicators is reviewed to evaluate environmental impacts on land use. Highlights Tree species represent a potential bioindicator for studying environmental pollutants due to their ability to accumulate heavy metals. The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06% The contents determined in the leaves and fruits of the three species trees had sufficient and phytotoxic HM contents. The tree species have phytoremediators capacity to evaluate environmental impacts and environmental contamination of land use.This study aimed to determine the presence of metal elements in fruits and leaves of three tree species as bioindicators in San Luis Potosi, Mexico. Ninety fruit and 90 leaf samples (30 per tree species) were collected at five sites (agricultural, suburban, commercial and services, urban, and mining), using the site and the presence of P. laevigata, S. molle, and A. farnesiana as references. Total concentrations of 13 metal elements were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The species were significantly affected by Co, As, and Pb (ANOVA, p≤0.05). Considering the land use and the species, the contents determined in the leaves and fruits of the three species had sufficient and phytotoxic contents of Al, Cd, Co, Ni, Mn, Ti, and Cr, and excessive ranges with the possible phytotoxic effect of As, Cu, Pb, Zn, V, and Fe. The A. farnesiana had the highest concentrations of 12 heavy metals analyzed (HM). The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%, with V, As, and Cr being prominent. The functionality of these tree species as phytoremediators and bioindicators is reviewed to evaluate environmental impacts on land use. Highlights Tree species represent a potential bioindicator for studying environmental pollutants due to their ability to accumulate heavy metals. The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06% The contents determined in the leaves and fruits of the three species trees had sufficient and phytotoxic HM contents. The tree species have phytoremediators capacity to evaluate environmental impacts and environmental contamination of land use

The Spitzer c2d survey of Large, Nearby, Interstellar Clouds. V. Chamaeleon II Observed with IRAC

We present IRAC (3.6, 4.5, 5.8, and 8.0 micron) observations of the Chamaeleon II molecular cloud. The observed area covers about 1 square degree defined by $A_V >2$. Analysis of the data in the 2005 c2d catalogs reveals a small number of sources (40) with properties similar to those of young stellaror substellar objects (YSOs). The surface density of these YSO candidates is low, and contamination by background galaxies appears to be substantial, especially for sources classified as Class I or flat SED. We discuss this problem in some detail and conclude that very few of the candidate YSOs in early evolutionary stages are actually in the Cha II cloud. Using a refined set of criteria, we define a smaller, but more reliable, set of 24 YSO candidates.Comment: 19 pages, 10 figures, in press Ap

Metales pesados en polvo atmosférico depositado en hojas de Acacia farnesiana (Fabaceae) y Prosopis laevigata (Fabaceae)

Atmospheric dust establishes an element of study to know the distribution of pollutant particles such as heavy metals and their effects on ecological systems. The objective was to determine the elemental composition of particles deposited in two species of trees as an indicator of environmental impact in San Luis Potosí, México. The distribution of Acacia farnesiana and Prosopis laevigata trees was taken into account in five soil uses to collect leaf material and extract atmospheric dust during the spring and summer seasons, determining the concentration of heavy metals using the ICP-MS technique. The results indicated the presence of Al&gt; Cu&gt; Zn&gt; Pb&gt; V&gt; As&gt; Ni&gt; Cd&gt; Ti&gt; Cr&gt; Co. Correlations with values of r2&gt; 0.90 were presented between V-Ti, Ni-V, Ni-Ti, Al-Ti and Cr-V. The species factor conditioned the concentrations of Al, Ti, V, Cr, Ni and Zn mainly in the particles deposited in Prosopis leaves. Particles of nine elements were conditioned by the activities of the five land uses, where the use of mineral soil affected by the presence of Al, Cd, Co, Pb, Cu and Zn. Concentrations of Cd were 6.2 times higher in the use of mining soil than in the agricultural sector; 5.9 and 5.4 times the concentrations of Co and Pb in the use of mining soil with respect to the trade and service respectively. The season had only significant effects on Cr and Pb particles. This study indicates the existence of pollutants that can affect ecological systems so it falls within the context of continued evaluation of environmental impacts.El polvo atmosférico se establece como elemento de estudio para conocer la distribución de partículas contaminantes, como son los metales pesados y sus efectos sobre los sistemas ecológicos. El objetivo fue determinar la composición elemental de las partículas depositadas en dos especies de árboles como un indicador de impacto ambiental en San Luis Potosí, México. La distribución de los árboles de Acacia farnesiana y Prosopis laevigata se tomó en cuenta en cinco usos del suelo para recolectar material foliar y extraer el polvo atmosférico durante la primavera y el verano, determinando la concentración de metales pesados utilizando la técnica ICP-MS. Los resultados indicaron la presencia de Al&gt; Cu&gt; Zn&gt; Pb&gt; V&gt; As&gt; Ni&gt; Cd&gt; Ti&gt; Cr&gt; Co. Se presentaron correlaciones con valores de r2&gt; 0,90 entre V-Ti, Ni-V, Ni-Ti, Al-Ti y Cr-V. El factor especie condicionó las concentraciones de Al, Ti, V, Cr, Ni y Zn principalmente en las partículas depositadas en las hojas de Prosopis. Las partículas de nueve elementos fueron condicionadas por las actividades de los cinco usos de la tierra, donde el uso del suelo mineral se vio afectado por la presencia de Al, Cd, Co, Pb, Cu y Zn. Las concentraciones de Cd fueron 6,2 veces más altas en el uso de suelo minero que en el sector agrícola; 5,9 y 5,4 veces las concentraciones de Co y Pb en el uso del suelo minero con respecto al comercio y al servicio, respectivamente. La temporada solo tuvo efectos significativos sobre las partículas de Cr y Pb. Este estudio indica la existencia de contaminantes que pueden afectar los sistemas ecológicos, por lo que entran en el contexto de la evaluación de los impactos ambientales.Fil: Jorge Alcalá Jáuregui. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Juan C. Rodríguez Ortiz. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Alejandra Hernández Montoya. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: María Flavia Filippini. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Eduardo Martinez Carretero. Instituto Argentino de Investigaciones de las Zonas Áridas Fil: Paola Elizabeth Díaz Flores. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Ángel Natanael Rojas Velázquez. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Humberto Rodríguez-Fuentes. Universidad Autónoma de Nuevo León (México). Facultad de Agronomía.Fil: Félix Alfredo Beltrán Morales. Universidad Autónoma de Baja California Sur (México