Advances in Mexican bryology

After some 150 years of research there are more than 575 publications on Mexican bryophytes. Most of these appeared in the last two decades; it is suggested that research toward the preparation of the Manual of Mexican mosses increased the rate publication for that period of time

A guide to field stations in the tropics : I. Mexico

Herbaria: The National Council for the Flora of Mexico (Consejo Nacional de la Flora de México) recently published a revised edition of the catalogue of Mexican herbaria (Arreguín & Valenzuela 1986). This contains information on 58 institutional herbaria including name, accepted acronym -when available-, number of specimens, important col-lections, available services, staff research interests, geographical coverage, etc

Neotropical moss floras : species common to North and South America

North and South America share about 675 species that show two basic patterns, namely, those with a continuous range and those with a disjunct distribution. Both may have resulted from step-bystep migration, but the latter, including 118 species, may be due to break up of previous distributions by post-Tertiary tectonic and climatic changes or by long-distance dispersal

Vivir según la carne: La razón Poética a propósito de María Zambrano

En la tesis se aborda la crítica zambraniana a la racioanalida política-filosófica moderna y frente a ella se exponen las características de la razón poética que no renuncia ni al mundo, ni a la carne ni a sus paradoja

Study of the effect of mechanical stiffness substrata, assembled with polyelectrolyte multilayer thin films, on biofilm forming staphylococcus epidermidis' initial adhesion mechanism

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008.Includes bibliographical references (p. 35).Polyelectrolyte multilayer thin films are polymer films assembled through a layer-by-layer sequential addition of oppositely charged polymers. The layer-by-layer film assembly technique allows for properties such as film thickness, chemical functionality, and elastic moduli to be easily altered by changing the pH in solution, or the number of bilayers added. This thesis examined the use of polyelectrolyte multilayer films, assembled with poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA), to alter substrata mechanical stiffness, which was used to explore the response of biofilm forming staphylococci epidermidis. The formation of biofilms on medical device surfaces is currently responsible for a significant amount of infections acquired in hospitals. Currently mechanisms responsible for the initial adhesion of bacteria are not completely understood. Previous work completed in the Rubner and Van Vliet labs at MIT suggests a mechanoselective adhesion mechanism in prokaryotes. The existence of a positive correlation between mechanical stiffness and bacterial adhesion, independent of surface roughness or charge density, has already been shown in a non-biofilm forming strain of bacteria. This thesis focused on exploring the role mechanical stiffness substrata has on biofilm forming bacterial adhesion by conducting bacterial assay experiments on polyelectrolyte multilayer films. The results showed no positive correlation between mechanical stiffness and cell adhesion with biofilm forming staphylococcus epidermidis. Also, even under an applied shear force the amount of bacteria adhered on the surface was not affected. In all cases tested, the biofilm forming strain of bacteria was able to adhere and grow successfully.by Maricela Delgadillo.S.B

Insight to an Asbestos Laborer

Asbestos laborers are often overlooked and not cared for much in construction projects. While they are often forgotten in the construction industry, they play a big role in most remodels or demolition projects. Abatement workers are exposed to the dangers of asbestos on a daily basis. Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA) are the federal agencies that regulate asbestos. The EPA regulates the use, transportation and disposal of asbestos, while OSHA sets the standards for work involving asbestos minerals. OSHA has regulations that demolition and/or abatement contractors must comply with since asbestos is considered a hazardous material. The data collected for this paper focuses on what laborers, superintendents and others working in the industry think about this work. I wanted to see how dangerous they felt their work is and to identify if OSHA could do anything more to protect the workers. This data was collected from companies based in the Bay Area and laborers from Laborers Local 67 in Oakland, Californi