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Spycher N.,Lawrence Berkeley National Laboratory | Peiffer L.,Lawrence Berkeley National Laboratory | Peiffer L.,University Nacionalautonoma Of Mexico | Sonnenthal E.L.,Lawrence Berkeley National Laboratory | And 3 more authors.
Geothermics | Year: 2014

The previously developed and well-demonstrated mineral saturation geothermometry method is revisited with the objective to ease its application, and to improve the prediction of geothermal reservoir temperatures using full and integrated chemical analyses of geothermal fluids. Reservoir temperatures are estimated by assessing numerically the clustering of mineral saturation indices computed as a function of temperature. The reconstruction of the deep geothermal fluid compositions, and geothermometry computations, are implemented into one stand-alone program, allowing unknown or poorly constrained input parameters to be estimated by numerical optimization using existing parameter estimation software. The geothermometry system is tested with geothermal waters from previous studies, and with fluids at various degrees of fluid-rock chemical equilibrium obtained from laboratory experiments and reactive transport simulations. Such an integrated geothermometry approach presents advantages over classical geothermometers for fluids that have not fully equilibrated with reservoir minerals and/or that have been subject to processes such as dilution and gas loss. © 2013 Elsevier Ltd.


Wanner C.,Lawrence Berkeley National Laboratory | Peiffer L.,Lawrence Berkeley National Laboratory | Peiffer L.,University Nacionalautonoma Of Mexico | Sonnenthal E.,Lawrence Berkeley National Laboratory | And 3 more authors.
Geothermics | Year: 2014

A 2D reactive transport model of the Dixie Valley geothermal area in Nevada, USA was developed to assess fluid flow pathways and fluid rock interaction processes. The model includes two major normal faults and the incorporation of a dual continuum domain to simulate the presence of a small-scale thermal spring being fed by a highly permeable but narrow fracture zone. Simulations were performed incorporating fluid flow, heat conduction and advection, and kinetic mineral-water reactions. Various solute geothermometry methods were applied to simulated spring compositions, to compare estimated reservoir temperatures with "true" modeled reservoir temperatures, for a fluid ascending the simulated fracture and cooling on its way to the surface. Under the modeled conditions (cooling but no mixing or boiling), the classical Na-K(-Ca) geothermometers performed best because these are least affected by mineral precipitation upon cooling. Geothermometry based on computed mineral saturation indices and the quartz geothermometer were more sensitive to re-equilibration upon cooling, but showed good results for fluid velocities above ca. 0.1m/d and a reactive fracture surface area 1-2 orders of magnitude lower than the corresponding geometric surface area. This suggests that such upflow rates and relatively low reactive fracture surface areas are likely present in many geothermal fields. The simulations also suggest that the presence of small-scale fracture systems having an elevated permeability of 10-12 to 10-10m2 can significantly alter the shallow fluid flow regime of geothermal systems. For the Dixie Valley case, the model implies that such elevated permeabilities lead to a shallow (less than 1km) convection cell where superficial water infiltrates along the range front normal fault and connects the small-scale geothermal spring through basin filling sediments. Furthermore, we conclude that a fracture permeability on the order of 10-12m2 may lead to near surface temperature >100°C whereas a permeability of 10-10m2 is not realistic because this permeability led to extreme upflow velocities and to a short-circuit of the regional fault zone. © 2013 Elsevier Ltd.


Lopez-Rincon G.,Research Center istencia En Tecnologia seno Del Estado Of Jalisco Ac | Lopez-Rincon G.,University Nacionalautonoma Of Mexico | Gutierrez-Pabello J.T.,University Nacionalautonoma Of Mexico | Diaz-Otero F.,Instituto Nacional de Investigaciones Nucleares | And 3 more authors.
Comparative Immunology, Microbiology and Infectious Diseases | Year: 2013

Prolactin receptor (PRLr) is a member of the cytokine receptor superfamily 1 showing tissue specific structural diversity. Expression of PRLr isoforms in lymphoid tissues has been associated with immunomodulatory function of prolactin. Bovine tuberculosis (bTB) is characterized by chronic inflammation caused by the persistent infection of lymphoid tissues with Mycobacterium bovis. To test the hypothesis of the influence of PRLr in the pathogenesis of bTB, the aim of this study was to identify PRLr isoforms expressed during bTB in different tissues and to analyze their association with the pathogenesis of bTB. We examined lymphoid and non-lymphoid tissues ex vivo from experimentally and naturally infected cattle, as well as from bTB-free cattle, by Western blot (WB) and immunohistochemistry (IH). In vitro, monocytes from exposed, infected, and healthy cattle were stimulated with M. bovis antigens and then analyzed by WB. To detect transcriptional levels of PRLr in macrophages (MØ) exposed to M. bovis, real time PCR was performed. WB revealed diversity of PRLr isoforms in tissues from infected cattle but not in tissues from bTB-free cattle. PRLr isoforms 100. kDa 75, 50 and 40 were found expressed in tissues of animals infected with M. bovis, while only the short isoform of 40. kDa correlated with the immunopathology and ability to infect MØ. We confirmed the synthesis of PRLr mRNA in MØ after M. bovis exposure and propose that molecular pathogen patterns of M. bovis might modulate inflammation during bTB through expression of the PRLr isoform in MØ. © 2013 Elsevier Ltd.


Suarez G.,University Nacionalautonoma Of Mexico | Jaramillo S.H.,University Nacionalautonoma Of Mexico | Bandy W.L.,University Nacionalautonoma Of Mexico
Pure and Applied Geophysics | Year: 2013

So far, the direction and rate of relative motion between the Rivera and the North American plates (RIV-NAM) has been determined by the combination of two Euler poles: Rivera (RIV), with respect to Pacific (PAC), and PAC with respect to North America. Here, we estimate the relative motion of this plate pair (RIV-NAM) assuming that the horizontal projection of the direction of slip of the earthquakes occurring on the RIV-NAM boundaries reflect their relative plate motion. A catalog of earthquakes for which focal mechanisms are reported since 1976 is used in the analysis. Earthquakes were considered in the three segments of the RIV-NAM plate boundary: the subduction zone of the Rivera plate beneath the Jalisco block, the Tres Marias Escarpment and the events associated with the Tamayo Fracture Zone. The best fitting Euler pole is determined using a grid search of 64 potential poles. The slip direction predicted for each grid point is compared to the slip direction of the focal mechanisms of the earthquakes on the plate boundary. The best fitting Euler pole, determined in a root mean square sense (RMS), is located at 21.8°N, 107.6°W. A rate of rotation of 5.3°/year is estimated assuming the seismic earthquake cycle of the 1932 and 1995 great earthquakes represents a lower bound of the rate of plate motion in the subduction zone. The best fitting Euler pole shows that the subduction of the Rivera plate takes place in a direction perpendicular to the trench with a relative velocity of 4.3 cm/year, offshore Manzanillo. The rate of relative motion RIV-NAM decreases from SE to NW. North of approximately 21°N, the subduction of the Rivera plate becomes oblique to the trench and the relative velocity between the two plates decreases to an average of 1.9 cm/year. This slow rate of convergence may explain the rapid decrease of seismicity in the trench and the apparent absence of large earthquakes in this region. In the Tres Marias Escarpment, our best-fitting pole suggests that subduction stops, giving way to high-angle reverse faulting perpendicular to the Tres Marias Escarpment, in agreement with the reverse faulting earthquakes occurring here. To the north of 22.5°N, the slip predicted by the best-fitting pole suggests right-lateral faulting in a direction parallel to the Tamayo Fracture Zone, at a very low velocity (0.5-1.0 cm/year). The best fitting Euler pole determined here lies very close to the RIV-NAM plate boundary in the vicinity of the Tamayo Fracture Zone. This location of our best fitting Euler pole explains the low relative plate velocity, the relatively low level of seismic activity and the presence of a broad zone of deformation that accommodates the RIV-NAM motion. © 2013 Springer Basel.


Hinojosa G.,University of Nevada, Reno | Hinojosa G.,University Nacionalautonoma Of Mexico | Covington A.M.,University of Nevada, Reno | Alna'Washi G.A.,University of Nevada, Reno | And 12 more authors.
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

Photoionization of Kr+ ions was studied in the energy range from 23.3 to 39.0 eV at a photon energy resolution of 7.5 meV. Absolute measurements were performed by merging beams of Kr+ ions and of monochromatized synchrotron undulator radiation. Photoionization (PI) of this Br-like ion is characterized by multiple Rydberg series of autoionizing resonances superimposed on a direct PI continuum. Resonance features observed in the experimental spectra are spectroscopically assigned and their energies and quantum defects tabulated. The high-resolution cross-section measurements are benchmarked against state-of-the-art theoretical cross-section calculations from the Dirac-Coulomb R-matrix method. © 2012 American Physical Society.


Alvarez-Elias A.C.,Hospital Infantil Of Mexico Federico Gomez | Garcia-Roca P.,Hospital Infantil Of Mexico Federico Gomez | Velasquez-Jones L.,Hospital Infantil Of Mexico Federico Gomez | Valverde S.,Hospital Infantil Of Mexico Federico Gomez | And 3 more authors.
Transplantation Proceedings | Year: 2016

Background CYP3A5 gene polymorphism rs776746 has been associated with lower tacrolimus dose requirements and bioavailability in both adults and children. This variant causes a loss of CYP3A5 activity owing to a splice site variant leading to a truncated inactive enzyme. The aim of this study was to determine if the rs776746 gene polymorphism is related to the time to reach tacrolimus therapeutic levels in renal transplant children. Methods A prospective study was performed in renal transplant children receiving tacrolimus as part of their immunosuppressive regime. CYP3A5 genotype was determined by direct sequencing. Tacrolimus trough levels and serum creatinine at 1 week and 1 month after renal transplantation was obtained from clinical chart. Results A total of 42 patients were included; 19 (45.2%) were female, 23 (54.8%) received living-donor transplants, and 21 patients expressed CYP3A5∗1/∗1 or CYP3A5∗1/∗3. Tacrolimus dose was higher in expressers at week 1 (0.13 vs 0.10 mg/kg/d; P =.011), and week 4 after transplantation (0.17 vs 0.09 mg/kg/d; P <.0001). At 4 weeks after renal transplantation, only 9 patients from the expressers group (42.8%) had levels ≥7 ng/mL, in contrast to 18 in the nonexpressers group (85.7%; Fisher exact P =.008). Conclusions Tacrolimus dose was significant higher in functional CYP3A5 expressers. Only 42.8% of such expressers had tacrolimus trough levels ≥7 ng/mL at 1 month after transplantation despite dose adjustments. Long-term follow up is needed to address the consequences of early post-transplantation bioavailability differences due to CYP3A5 genotype. © 2016 Elsevier Inc.


Barcenas-Arguello M.-L.,Colegio de Mexico | Barcenas-Arguello M.-L.,University Nacionalautonoma Of Mexico | Gutierrez-Castorena M.C.D.C.,Colegio de Mexico | Terrazas T.,National Autonomous University of Mexico
Micron | Year: 2015

Mineral inclusions in plant cells are genetically regulated, have an ecological function and are used as taxonomic characters. In Cactaceae, crystals in epidermal and cortical tissues have been reported; however, few studies have conducted chemical and morphological analyses on these crystals, and even fewer have reported non-mineral calcium to determine its systematic value. Cephalocereus apicicephalium, C. totolapensis and C. nizandensis are Cactaceae species endemic to the Isthmus of Tehuantepec, Mexico with abundant epidermal prismatic crystals. In the present study, we characterize the mineral cell inclusions, including their chemical composition and their morphology, for three species of Cephalocereus. Crystals of healthy branches of the three species were isolated and studied. The crystals were identified by X-ray diffraction (XRD), their morphology was described using a petrographic and scanning electron microscope (SEM), and their elemental composition was measured with Energy Dispersive X-ray (EDXAR). The three species synthesized weddellite with different degrees of hydration depending on the species. The optical properties of calcium oxalate crystals were different from the core, which was calcium carbonate. We observed a large diversity of predominantly spherical forms with SEM. EDXAR analysis detected different concentrations of Ca and significant amounts of elements, such as Si, Mg, Na, K, Cl, and Fe, which may be related to the edaphic environment of these cacti. The occurrence of weddellite is novel for the genus according to previous reports. The morphological diversity of the crystals may be related to their elemental composition and may be a source of phylogenetic characters. © 2015 Elsevier Ltd.


PubMed | University Nacionalautonoma Of Mexico and Hospital Infantil Of Mexico Federico Gomez
Type: Journal Article | Journal: Transplantation proceedings | Year: 2016

CYP3A5 gene polymorphism rs776746 has been associated with lower tacrolimus dose requirements and bioavailability in both adults and children. This variant causes a loss of CYP3A5 activity owing to a splice site variant leading to a truncated inactive enzyme. The aim of this study was to determine if the rs776746 gene polymorphism is related to the time to reach tacrolimus therapeutic levels in renal transplant children.A prospective study was performed in renal transplant children receiving tacrolimus as part of their immunosuppressive regime. CYP3A5 genotype was determined by direct sequencing. Tacrolimus trough levels and serum creatinine at 1 week and 1 month after renal transplantation was obtained from clinical chart.A total of 42 patients were included; 19 (45.2%) were female, 23 (54.8%) received living-donor transplants, and 21 patients expressed CYP3A5*1/*1 or CYP3A5*1/*3. Tacrolimus dose was higher in expressers at week 1 (0.13 vs 0.10mg/kg/d; P= .011), and week 4 after transplantation (0.17 vs 0.09mg/kg/d; P<.0001). At 4 weeks after renal transplantation, only 9 patients from the expressers group (42.8%) had levels7ng/mL, in contrast to 18 in the nonexpressers group (85.7%; Fisher exact P= .008).Tacrolimus dose was significant higher in functional CYP3A5 expressers. Only 42.8% of such expressers had tacrolimus trough levels7ng/mL at 1 month after transplantation despite dose adjustments. Long-term follow up is needed to address the consequences of early post-transplantation bioavailability differences due to CYP3A5 genotype.


PubMed | University Nacionalautonoma Of Mexico
Type: Journal Article | Journal: American journal of botany | Year: 2011

A comparative study between an unburned evergreen sclerophyllousvegetation located in south-central Mexico under a wet-summer climate,with mediterranean regions was conducted in order to re-analyzevegetation and plant characters claimed to converge under mediterraneanclimates. The comparison considered floristic composition,plant-community structure, and plant characters as adaptations tomediterranean climates and analyzed them by means of a correspondenceanalysis, considering a tropical spiny shrubland as the external group.We made a species register of the number of species that resproutedafter a fire occurred in 1995 and a distribution map of the evergreensclerophyllous vegetation in Mexico (mexical) under nonmediterraneanclimates.The Tehuacn mexical does not differ from the evergreensclerophyllous areas of Chile, California, Australia, and theMediterranean Basin, according to a correspondence analysis, whichordinated the Tehuacn mexical closer to the mediterranean areasthan to the external group.All the vegetation and floristic characteristics of the mexical, aswell as its distribution along the rain-shadowed mountain parts ofMexico, support its origin in the Madrean-Tethyan hypothesis of Axelrod.Therefore, these results allow to expand the convergence paradigm of thechaparral under an integrative view, in which a general trend to ariditymight explain floristic and adaptive patterns detected in theseenvironments.


PubMed | University Nacionalautonoma Of Mexico
Type: Journal Article | Journal: Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology | Year: 2012

-Dystroglycan (-DG) is a transmembrane glycoprotein that links the intracellular cytoskeleton to the extracellular matrix and is crucial for the molecular pathway of lateral force transmission in muscle. We aimed to investigate the effect of decreasing sarcolemmal cholesterol on the distribution of -DG, its interaction with dystrophin and the impact on the contraction efficiency of muscle.Isolated rat extensor digitorum longus muscles were incubated with methyl -cyclodextrin (MCD) to deplete cholesterol and with MCD-cholesterol to restore cholesterol. Electric stimulation protocols were used to determine muscle force and fatigue. Detergent-resistant membranes (lipid rafts) were separated from isolated skeletal muscle sarcolemma. The distribution and interactions of -DG, caveolin-3 and dystrophin were determined by an immunoreactivity analysis.Cholesterol depletion in muscle results in a weakened force of contraction, which recovers after cholesterol restoration. The rate of fatigue is unaffected, but fatigue recovery is dependent upon cholesterol restoration. MCD modifies the structures of lipid rafts obtained from MCD-treated muscles by, displacing the membrane proteins -DG and caveolin-3 f from the lipid raft, thus reducing the interaction of -DG with dystrophin.Cholesterol depletion weakens the muscle contractile force by disturbing the sarcolemmal distribution of -dystroglycan and its interaction with dystrophin, two key proteins in the alignment of lateral force transmission pathway.

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