Nonlinear chemoconvection in the Methylene-blue-glucose system

Interfacial hydrodynamic instabilities arise in a range of chemical systems. One mechanism for instability is the occurrence of unstable density gradients due to the accumulation of reaction products. In this paper we conduct two-dimensional nonlinear numerical simulations for a member of this class of system: the methylene-blue¿glucose reaction. The result of these reactions is the oxidation of glucose to a relatively, but marginally, dense product, gluconic acid, that accumulates at oxygen permeable interfaces, such as the surface open to the atmosphere. The reaction is catalyzed by methylene-blue. We show that simulations help to disassemble the mechanisms responsible for the onset of instability and evolution of patterns, and we demonstrate that some of the results are remarkably consistent with experiments. We probe the impact of the upper oxygen boundary condition, for fixed flux, fixed concentration, or mixed boundary conditions, and find significant qualitative differences in solution behavior; structures either attract or repel one another depending on the boundary condition imposed. We suggest that measurement of the form of the boundary condition is possible via observation of oxygen penetration, and improved product yields may be obtained via proper control of boundary conditions in an engineering setting. We also investigate the dependence on parameters such as the Rayleigh number and depth. Finally, we find that pseudo-steady linear and weakly nonlinear techniques described elsewhere are useful tools for predicting the behavior of instabilities beyond their formal range of validity, as good agreement is obtained with the simulations.

Blue luminescence at room temperature in defective MgO films

Luminescence spectroscopy has been used to characterize MgO films prepared by rf-sputtering. A clear correlation is found between the appearance of an emission peak centered at approximately 460 nm and the detection of ferromagnetic ordering in the samples. We suggest that cationic vacancies are responsible for the blue-light emission by introducing p states into the electronic band-gap. In accordance with this, our results strongly indicate that cationic vacancies are at the heart of the appearance of long-range magnetic ordering in MgO films.

Clinical implications in the shift of syndecan-1 expression from the cell membrane to the cytoplasm in bladder cancer

Background To determine the diagnostic and prognostic capability of urinary and tumoral syndecan-1 (SDC-1) levels in patients with cancer of the urinary bladder. Methods SDC-1 levels were quantitated by enzyme-linked immunosorbent assay (ELISA) in 308 subjects (102 cancer subjects and 206 non-cancer subjects) to assess its diagnostic capabilities in voided urine. The performance of SDC-1 was evaluated using the area under the curve of a receiver operating characteristic curve. In addition, immunohistochemical (IHC) staining assessed SDC-1 protein expression in 193 bladder specimens (185 cancer subjects and 8 non-cancer subjects). Outcomes were correlated to SDC-1 levels. Results Mean urinary levels of SDC-1 did not differ between the cancer subjects and the non-cancer subjects, however, the mean urinary levels of SDC-1 were reduced in high-grade compared to low-grade disease (p < 0.0001), and in muscle invasive bladder cancer (MIBC) compared to non-muscle invasive bladder cancer (NMIBC) (p = 0.005). Correspondingly, preliminary data note a shift from a membranous cellular localization of SDC-1 in normal tissue, low-grade tumors and NMIBC, to a distinctly cytoplasmic localization in high-grade tumors and MIBC was observed in tissue specimens. Conclusion Alone urinary SDC-1 may not be a diagnostic biomarker for bladder cancer, but its urinary levels and cellular localization were associated with the differentiation status of patients with bladder tumors. Further studies are warranted to define the potential role for SDC-1 in bladder cancer progression.

Clinical implications in the shift of syndecan-1 expression from the cell membrane to the cytoplasm in bladder cancer

Background To determine the diagnostic and prognostic capability of urinary and tumoral syndecan-1 (SDC-1) levels in patients with cancer of the urinary bladder. Methods SDC-1 levels were quantitated by enzyme-linked immunosorbent assay (ELISA) in 308 subjects (102 cancer subjects and 206 non-cancer subjects) to assess its diagnostic capabilities in voided urine. The performance of SDC-1 was evaluated using the area under the curve of a receiver operating characteristic curve. In addition, immunohistochemical (IHC) staining assessed SDC-1 protein expression in 193 bladder specimens (185 cancer subjects and 8 non-cancer subjects). Outcomes were correlated to SDC-1 levels. Results Mean urinary levels of SDC-1 did not differ between the cancer subjects and the non-cancer subjects, however, the mean urinary levels of SDC-1 were reduced in high-grade compared to low-grade disease (p < 0.0001), and in muscle invasive bladder cancer (MIBC) compared to non-muscle invasive bladder cancer (NMIBC) (p = 0.005). Correspondingly, preliminary data note a shift from a membranous cellular localization of SDC-1 in normal tissue, low-grade tumors and NMIBC, to a distinctly cytoplasmic localization in high-grade tumors and MIBC was observed in tissue specimens. Conclusion Alone urinary SDC-1 may not be a diagnostic biomarker for bladder cancer, but its urinary levels and cellular localization were associated with the differentiation status of patients with bladder tumors. Further studies are warranted to define the potential role for SDC-1 in bladder cancer progression.

Anàlisi “shift share” de l’evolució del cens de porcí a Espanya (1962-2005)

El desenvolupament de la ramaderia intensiva s’ha produït mitjançant aglomeracions espacials de les explotacions ramaderes. El sector porcí és un dels principals exponents d’aquesta aglomeració i concentració espacial. Per això s'ha realitzat el present PFC amb l'objectiu d'estudiar el procés de concentració de la producció porcina a les diferents Comunitats Autònomes entre els anys 1962 i 2005, investigant els efectes diferencials i d’assignació de l’anàlisi “shift share”. Es conclou que en els anys estudiats hi ha hagut dos pols d'aglomeració de la cabana porcina, Catalunya+Osca i la Regió de Múrcia, que han estat cabdals en l'abastiment dels mercats.

Fast Blue and Diamidino Yellow as retrograde tracers in peripheral nerves: efficacy of combined nerve injection and capsule application to transected nerves in the adult rat

Capsule application of Diamidino Yellow (DY) to the cut end of the sciatic nerve immediately followed by capsule application of Fast Blue (FB) resulted in approximate to 95% double-labelled dorsal root ganglion neurones (DRGn) and motoneurones (Mn). Nerve injection of DY followed either immediately or 2 months later by capsule application of FB resulted in approximate to 90% double-labelled DRGn and Mn, indicating that DY and FB label similar populations of DRGn and Mn, and that insignificant DY fading occurred during this period. Inversing the order of application, however, i.e. nerve injection of FB followed immediately by capsule application of DY, resulted in double labelling in only approximate to 10% of the DRGn and Mn. These percentages increased to 70% of the DRGn and 60% of the Mn when the FB injection was followed 1 or 2 months after by the DY application, indicating that DY uptake is blocked by recent administration of FB. The results indicate that DY and FB might be useful for sequential labelling before and after nerve injury as a tool to investigate the accuracy of sensory and motor regeneration.

Forecasting a language shift based on cellular automata

Language extinction as a consequence of language shifts is a widespread social phenomenon that affects several million people all over the world today. An important task for social sciences research should therefore be to gain an understanding of language shifts, especially as a way of forecasting the extinction or survival of threatened languages, i.e., determining whether or not the subordinate language will survive in communities with a dominant and a subordinate language. In general, modeling is usually a very difficult task in the social sciences, particularly when it comes to forecasting the values of variables. However, the cellular automata theory can help us overcome this traditional difficulty. The purpose of this article is to investigate language shifts in the speech behavior of individuals using the methodology of the cellular automata theory. The findings on the dynamics of social impacts in the field of social psychology and the empirical data from language surveys on the use of Catalan in Valencia allowed us to define a cellular automaton and carry out a set of simulations using that automaton. The simulation results highlighted the key factors in the progression or reversal of a language shift and the use of these factors allowed us to forecast the future of a threatened language in a bilingual community.

Efficacy of the fluorescent dyes Fast Blue, Fluoro-Gold, and Diamidino Yellow for retrograde tracing to dorsal root ganglia after subcutaneous injection

The present study was designed to investigate the efficacy of the fluorescent dyes Fast Blue (FB), Fluoro-Gold (FG), and Diamidino Yellow (DY) for retrograde tracing of lumbar dorsal root ganglia after their subcutaneous injection into different hindlimb digits. Injection of equal volumes (0.5 mu l) of 5% FB or 2% FG resulted in similar mean numbers of sensory neurones labelled by each tracer. Injection of equal volumes (0.5 mu l) of FB or FG in a single digit followed 10 days later by a second injection of the same volume of 5% DY into the same digit resulted in similar mean numbers of labelled sensory neurones for each of the three tracers. Furthermore, on average, 75% of all the FB-labelled cells and 74% of all FC-labelled cells also contained DY. Repeating the same experiment with an increased volume of DY (1.5 mu l) resulted in an increase in the mean number of double-labelled profiles to 82 and 84% for FB and FG, respectively. The results show that FB, FG and DY label similar numbers of cutaneous afferents and that a high level of double labelling may be obtained after sequential injections in digits. These properties make them suitable candidates in investigations where a combination of tracers with similar labelling efficacies is needed.

A mechanistic approach to methylene blue sorption on two vegetable wastes: Cork bark and grape stalks

Two vegetable wastes, cork bark and grape stalks, were investigated for the removal of methylene blue from aqueous solution. The effects of contact time, dye concentration, pH, and temperature on sorption were studied relative to adsorption on a commercially-activated carbon. The highest adsorption yield was obtained within the pH range 5 to 10 for grape stalks and 7 to 10 for cork bark. The sorption kinetics of dye onto activated carbon and grape stalks was very fast. Kinetics data were fitted to the pseudo-first and second order kinetic equations, and the values of the pseudo-second-order initial rate constants were found to be 1.69 mg g-1 min-1 for activated carbon, 2.24 mg g-1 min-1 for grape stalks, and 0.90 mg g-1 min-1 for cork bark. Langmuir maximum sorption capacities for activated carbon, grape stalks, and cork bark for methylene blue estimated by the Orthogonal Distance Regression method (ODR) were 157.5 mg g-1, 105.6 mg g-1, and 30.52 mg g-1, respectively. FTIR spectra indicated that carboxylic groups and lignin play a significant role in the sorption of methylene blue. Electrostatic forces, n-p interactions, cation-p, and p-p stacking interactions contribute to methylene blue sorption onto grape stalks and cork bark. Grape stalks can be considered an efficient biosorbent and as a viable alternative to activated carbon and ion-exchange resins for the removal of methylene blue