Effect of high shear stress on microbial viability

Escherichia coli and Saccharomyces cerevisiae suspensions were submitted to controlled shear stress. Above a threshold value shear stress induced a decrease in micro-organism viability. The threshold of shear stress efficiency depended on the micro-organisms, being between 1292Pa and 2770 Pa for S cerevisiae, and about 1250 Pa for E coli. Above 1810 Pa, Ecoli cells were disrupted whereas the S cerevisiae cells remained intact. The higher the cellular concentration, the greater the rate of decrease in viability. Viability loss was influenced by the number of passages through the experimental shear stress device and by exposure time

Living and Learning With New Media: Summary of Findings From the Digital Youth Project

Summarizes findings from a three-year study of how new media have been integrated into youth behaviors and have changed the dynamics of media literacy, learning, and authoritative knowledge. Outlines implications for educators, parents, and policy makers

A new method for the determination of Leuconostoc mesenteroides cell number

Dilution needed for plate counts (CFU/ml) is known to disrupt streptococci chains, and therefore the validity of this method is controversial. A novel apparatus was designed to disrupt Leuconostoc mesenteroides chains in pairs, by forcing them to pass through a narrow capillary tube. When Leuconostoc mesenteroides occurs in pairs it appears that the real cell concentration can be simply deduced by doubling the CFU/ml

Systematic error and comparison of four methods for assessing the viability ofSaccharomyces cerevisiae suspensions

Four methods for the determination of cell viability were compared: the plate count technique, the flow cytometer, and two microscopic numerations- one after methylene blue staining and the other one with epifluorescence. The experimental error of these techniques was for the first time estimated: 8% for both numerations under microscope and 13% for the plate count technique. The staining mechanisms were explained by comparing the numerations under microscope and the flow cytometer analysis

Efecto de auxinas en el enraizamiento de estaquillas de Buxus sempervirens L. en distintas épocas del año

Tesis para optar al grado de Magister Scientiae en Cultivos Intensivos, de la Universidad Nacional del Litoral, en 2013El Boj (Buxus sempervirens) es una importante planta de uso ornamental. El enraizamiento de las estacas es lento y desparejo. Este trabajo tuvo como objetivo evaluar el efecto de auxinas en el enraizamiento de estaquillas en distintas épocas del año. El diseño utilizado en las distintas épocas fue completamente aleatorizado con 8 tratamientos. Las concentraciones utilizadas de ácido indol-butírico (IBA) y ácido naftalen-acético (ANA) fueron: cero (control), 1500 mg L-1, 2500 mg L-1, 3500 mg L-1 y 4000 mg L-1 (ésta última sólo en el caso de ANA). A los 30, 60 y 90 días se realizaron las evaluaciones de 1) número de raíces por estaquilla; 2) longitud total de raíces (cm); 3) número de estaquillas con raíz (porcentaje de enraizamiento). Al finalizar el ensayo se realizó el recuento de estaquillas muertas. Los datos fueron sometidos a un análisis conjunto de experimentos, se realizó un análisis de varianza con prueba de Tukey (p≤ 0.05) y regresión. Para las condiciones en que este ensayo fue realizado se concluye que no existen barreras estructurales que impidan el enraizamiento y que la época más propicia para multiplicar Buxus sempervirens por medio de estaquillas es la primavera. El uso del ANA presentó mejores tasas de enraizamiento que el uso del IBA en las concentraciones utilizadas siendo la concentración de 3500 mg L-1 de ANA la que presentó mayores porcentajes de estaquillas enraizadas, con mayor número de raíces por estaquilla y mayor longitud total de las mismas, acelerando la producción de plantines en vivero.The Boxwood (Buxus sempervirens) is an important ornamental plant . Rooting of cuttings is slow and uneven. This work aimed to evaluate the effect of auxin on the rooting of cuttings in different seasons. The design used at different times was completely randomized with 8 treatments. The used concentrations of indole butyric acid (IBA) and naphthalene acetic acid (NAA) were: zero (control), 1500 mg L-1, 2500 mg L-1, 3500 mg L-1 and 4000 mg L-1 (latter only in the case of ANA). At 30, 60 and 90 day assessments of 1) number of roots per cuttings were made, 2) Total root length (cm), number of rooted cuttings (rooting percentage). At the end of the trial the count of dead cuttinds was performed. The data was subjected to an analysis set of experiments, analysis of variance with Tukey test (p≤ 0.05) and regression. For the conditions under which this test was performed is concluded that there are no structural barriers to rooting and the most propitious time to multiply Buxus sempervirens by cuttings is spring. Use of ANA showed better rooting rates using the IBA concentrations used in the concentration of 3500 mg. L-1 of ANA which showed higher percentages of rooted cuttings, with the highest number of roots per cuttings and greater total length them, accelerating the production of seedlings in nursery.EEA CorrientesFil: Lange, Patricia Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Corrientes. Agencia de Extensión Rural Corrientes; Argentin

Israel: A jewish state or a state for all its citizens? Eine diskursanalytische Untersuchung der arabisch-palästinensischen Minderheit und ihrer Beziehung zum israelischen Staat

Die Studie befasst sich mit dem politischen Diskurs über die aktuellen sozialen und politischen Probleme im Zusammenleben zwischen palästinensisch-arabischen und jüdischen Israelis. Ziel ist es herauszufinden, wie die Politik des Staates Israel gegenüber der arabischen Minderheit im eigenen Staat in den Medien dargestellt und bewertet wird. Zu diesem Zweck wird mittels einer Diskursanalyse die Berichterstattung der englischsprachigen israelischen Tages-zeitungen Jerusalem Post und Haaretz über das 2011 verabschiedete Admissions Committee Law untersucht. Das Gesetz gibt Gemeinden mit weniger als 400 Haushalten in den Regionen Galiläa und Negev das Recht, Auswahlkommissionen zu bilden und potentielle Einwohner auf ihre Eignung für das Leben in der Gemeinde zu prüfen. Im medienvermittelten Diskurs spielt die ethnische und kulturelle Zugehörigkeit jüdischer und arabischer Israelis eine wichtige Rolle, wobei eine Grenzziehung auf Basis des kulturellen Bewusstseins erfolgt. Die Analyse zeigt somit, dass sich der zentrale Konflikt, der das Zusammenleben der jüdisch-israelischen Mehrheit und der arabischen Minderheit bestimmt, um die Frage nach dem Charakter des Staates Israel dreht. Soll Israel a jewish state oder a state for all its citizens sein? Diese Grundüberlegung bestimmt das Handeln des Staates auf der einen Seite und die Forderungen der arabischen Minderheit nach Gleichberechtigung auf der anderen Seite

Functional Health Literacy in an Urban Primary Care Clinic

The purpose of this study was to determine the level of functional health literacy in a sample of patients treated in 1of our 5 primary care clinics. A total of 92 randomly selected adults (mean age = 59 years) completed the TOFHLA while waiting for a scheduled appointment. Twenty eight percent of the sample had less than adequate levels of functional health literacy. Income, car ownership and education were significant and independent predictors of literacy level in this sample. Low levels of functional health literacy limit a patient\u27s ability to read, understand and act on health information. It is essential that nurse practitioners and clinical nurse specialists use relevant cues to assess for illiteracy and modify their methods of providing health information when appropriate

Pea-derived vaccines demonstrate high immunogenicity and protection in rabbits against rabbit haemorrhagic disease virus

Vaccines against rabbit haemorrhagic disease virus (RHDV) are commercially produced in experimentally infected rabbits. A genetically engineered and manufactured version of the major structural protein of RHDV (VP60) is considered to be an alternative approach for vaccine production. Plants have the potential to become an excellent recombinant production system, but the low expression level and insufficient immunogenic potency of plant-derived VP60 still hamper its practical use. In this study, we analysed the expression of a novel multimeric VP60-based antigen in four different plant species, including Nicotiana tabacum L., Solanum tuberosum L., Brassica napus L. and Pisum sativum L. Significant differences were detected in the expression patterns of the novel fusion antigen cholera toxin B subunit (CTB)::VP60 (ctbvp60(SEKDEL)) at the mRNA and protein levels. Pentameric CTB::VP60 molecules were only detected in N. tabacum and P. sativum, and displayed equal levels of CTB, at approximately 0.01% of total soluble protein (TSP), and traces of detectable VP60. However, strong enhancement of the CTB protein content via self-fertilization was only observed in P. sativum, where it reached up to 0.7% of TSP. In rabbits, a strong decrease in the protective vaccine dose required from 48-400 microg potato-derived VP60 [Castanon, S., Marin, M.S., Martin-Alonso, J.M., Boga, J.A., Casais, R., Humara, J.M., Ordas, R.J. and Parra, F. (1999) Immunization with potato plants expressing VP60 protein protects against rabbit hemorrhagic disease virus. J. Virol. 73, 4452-4455; Castanon, S., Martin-Alonso, J.M., Marin, M.S., Boga, J.A., Alonso, P., Parra, F. and Ordas, R.J. (2002) The effect of the promoter on expression of VP60 gene from rabbit hemorrhagic disease virus in potato plants. Plant Sci. 162, 87-95] to 0.56-0.28 microg antigenic VP60 (measured with VP60 enzyme-linked immunosorbent assay) of crude CTB::VP60 pea extracts was demonstrated. Rabbits immunized with pea-derived CTB::VP60 showed anti-VP60-specific antibodies, similar to RikaVacc((R))-immunized rabbits, and survived RHDV challenge

Living and Learning with New Media

This report summarizes the results of an ambitious three-year ethnographic study, funded by the John D. and Catherine T. MacArthur Foundation, into how young people are living and learning with new media in varied settings—at home, in after school programs, and in online spaces. It offers a condensed version of a longer treatment provided in the book Hanging Out, Messing Around, and Geeking Out (MIT Press, 2009). The authors present empirical data on new media in the lives of American youth in order to reflect upon the relationship between new media and learning. In one of the largest qualitative and ethnographic studies of American youth culture, the authors view the relationship of youth and new media not simply in terms of technology trends but situated within the broader structural conditions of childhood and the negotiations with adults that frame the experience of youth in the United States. The book that this report summarizes was written as a collaborative effort by members of the Digital Youth Project, a three-year research effort funded by the John D. and Catherine T. MacArthur Foundation and conducted at the University of California, Berkeley, and the University of Southern California. John D. and Catherine T. MacArthur Reports on Digital Media and Learnin