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Drilling at Integrated Ocean Drilling Program Site U1381 on the Cocos Ridge offshore Costa Rica recovered 67 primary Miocene (ca. 8 Ma to ca. 16.5 Ma) marine fallout ash layers. Geochemical, volcanological, and geological criteria link these ashes to Plinian eruptions that carried ash to at least 50–450 km from the Galapagos hotspot. These ash layers are the first documentation of highly explosive Miocene Galapagos hotspot volcanism. This volcanism is bimodal with two-thirds of the tephra layers generated by basaltic magmas (glass compositions

During EOR recovery processes, asphaltenes macromolecules can flocculate and cause drastic changes in the petrophysical properties of the reservoir, therefore it is very important to determine the time at the flocculation begins and further the size of the aggregates, since ultimately this depends on whether these can be trapped in the porous media. This work aims to evaluate the change in the asphaltene hydrodynamic radius of at different concentrations of n-heptane and to detect the onset asphaltene floculation using a new technique known as 1H Diffusion ordered spectroscopy-NMR (DOSY-NMR). H-DOSY NMR is a method based on the pulsed field gradient spin-echo from nuclear magnetic resonance (PFGSE NMR) and it allows the identification of the molecular components of a mixture sample and at the same time obtain information of their size through the diffusion coefficient. For our specific case, the asphaltene hydrodynamic radius was 16.8 Å and the onset of asphaltene floculation can be observed when the concentration of solvent n-heptane was 30 wt %.

Background: Candida albicans is a commensal fungus of the mucosa in humans that may become an opportunistic pathogen causing recurrent infections in immunocompromised hosts. In individuals with HIV/AIDS, Histatin-5 levels are significantly reduced, causing oropharyngeal candidiasis to become a pathological process. Clinical and in vitro resistance to azoles is common whether by selection or acquisition of Candida-resistant strains. In 2008, the Clinical and Laboratory Standards Institute (CLSI) defined the cutoff point for active agents against the isolates of Candida species. The objective of this study was to determine the frequency of fungal isolates of C. albicans through VITEK II system and their susceptibility pattern in patients with HIV/AIDS and oropharyngeal candidiasis treated at the Hospital for Infectious Diseases in Mexico City. Methods: From June 2011-December 2012, there were 96 patients with HIV/AIDS and oropharyngeal candidiasis who were included in the study. Oral and esophageal specimens were directly examined to identify fungal structures. Cultures and sensitivity testing were done with the Vitek II method. Descriptive statistics and bivariate analysis were carried out. Results: Of 96 patients, 87 had C. albicans oral isolates identified and 73 esophageal isolates. Non-albicans Candida (NAC) was identified in three and ten patients (oral and esophageal) respectively, and Cryptococcus neoformans was isolated in both sites. Sensitivity of C. albicans to fluconazole was demonstrated in 87/90 strains. Conclusions: The fungal pathogen isolated was C. albicans followed by C. glabrata and C. parapsilopsis. C. albicans was identified through VITEK II in 90% of cases susceptible to fluconazole.

To determine Barrett's esophagus (BO) prevalence in patients diagnosed with colorectal carcinoma (CC) and feasibility-associated factors in a 10 week period from March 1st to June 15, 1999.Endoscopy Department, Oncology Hospital, Centro Médico Nacional Siglo XXI, IMSS.A prospective, transversal, observational and comparative assay of 48 patients with histologically confirmed diagnosis of colorectal carcinoma in whom high endoscopy with biopsy harvest was performed; otherwise, colonoscopy was performed in eight patients with confirmed BO.Thirty men and 18 women were studied with an average age of 53 years of age. In 100%, colon cancer was determined as adenocarcinoma and location were rectal in 43.7%. Prevalence of BO was 22.9% in addition to 0.74 to 2% in the general population. This implies an odds ratio calculated at 36.43 (p = 0.00000) and 3.09 p = 0.00007), respectively, for risk to present BO concomitant with CC. There was no statistical significance in relation to age, smoking habit, and/or alcoholism. Among eight patients with BO without CCR, only one had a tubulovellous polypus (12.5%) identified.Although the results were not to conclusive to affirm the association of BA with CCR, the high prevalence found justifies the performance of routine endoscopy in CCR carrier patients with reflux symptoms.