Prokaryotic transport in electrohydrodynamic structures.

When a high-voltage direct-current is applied to two beakers filled with water, a horizontal electrohydrodynamic (EHD) bridge forms between the two beakers. In this work we study the transport and behavior of bacterial cells added to an EHD bridge set-up. Organisms were added to one or to both beakers, and the transport of the cells through the bridge was monitored using optical and microbiological techniques. It is shown that Escherichia coli top10 (Invitrogen, Carlsbad, CA, USA) and bioluminescent E. coli YMC10 with a plasmid (pJE202) containing Vibrio fischeri genes can survive the exposure to an EHD liquid bridge set-up and the cells are drawn toward the anode due to their negative surface charge. Dielectrophoresis and hydrostatic forces are likely to be the cause for their transport in the opposite direction which was observed as well, but to a much lesser extent. Most E. coli YMC10 bacteria which passed the EHD bridge exhibited increased luminescent activity after 24 h. This can be explained by two likely mechanisms: nutrient limitation in the heavier inoculated vials and a 'survival of the strongest' mechanism.

The effect of local defects on water adsorption in silicalite-1 zeolite: a joint experimental and molecular simulation study.

We report a joint experimental and molecular simulation study of water condensation in silicalite-1 zeolite. A sample was synthesized using the fluoride route and was found to contain essentially no defects. A second sample synthesized using the hydroxide route was found to contain a small amount of silanol groups. The thermodynamics of water condensation was studied in these two samples, as well as in a commercial sample, in order to understand the effect of local defects on water adsorption. The molecular simulation study enabled us to qualitatively reproduce the experimentally observed condensation thermodynamics features. A shift and a rounding of the condensation transition was observed with an increasing hydrophilicity of the local defect, but the condensation transition was still observed above the water saturation vapor pressure P0. Both experiments and simulations agree on the fact that a small water uptake can be observed at very low pressure, but that the bulk liquid does not form from the gas phase below P0. The picture that emerges from the observed water condensation mechanism is the existence of a heterogeneous internal surface that is overall hydrophobic, despite the existence of hydrophilic "patches". This heterogeneous surface configuration is thermodynamically stable in a wide range of reduced pressures (from P/P0 = 0.2 to a few thousands), until the condensation transition takes place.

Soret coefficient for liquid argon-krypton mixtures via equilibrium and nonequilibrium molecular dynamics: a comparison with experiments.

The Soret and the other transport coefficients, characterizing the heat and mass transport in binary mixtures, have been obtained by equilibrium and nonequilibrium molecular dynamics (EMD and NEMD, respectively). Two state points of the argon-krypton mixture are considered, for which experimental values of the Soret coefficient are available. To attempt a comparison between simulations and experiments the common enthalpy-diffusion-free expression for the heat flux has been chosen. The comparison of the simulations with the experiments shows a remarkable agreement, for all the several utilized EMD and NEMD techniques (dynamical and stationary). The techniques, used over 0.3 micros of total simulation time span, are slow convergent but have comparable performances.

The course in the history of psychology: present status and future concerns.

The present study provides a turn-of-the-century status report on the teaching of the history of psychology in colleges and universities in the United States. The data indicate that the course is offered regularly in most departments of psychology and is frequently required of majors; these findings are consistent with earlier research. Most instructors teach the course largely out of personal interest and self-taught expertise with their primary teaching and research commitments to other areas of psychology. Few instructors engage in publication of research and scholarship in the history of psychology, although there are 2 journals in the field that provide an outlet for scholarship. The few positions that allow for primary commitment to teaching and research in the history of psychology is a possible cause of concern for the future of the course and for its place in the education of psychologists in the 21st century.

Placement of cations in NaX faujasite-type zeolite using (N,V,T) Monte Carlo simulations.

The cation distribution in dehydrated NaX was predicted using appropriate interatomic potentials and (N,V,T) simulations, considering the cations as 'guest' particles and the framework as a 'host'; the simulations not only yield the expected different types of sites, but also highlight the cooperative placement of supercage cations which results essentially from electrostatic interactions between the cations.

Teaching the introductory course in psychology circa 1900.

Teachers of introductory courses in psychology and those who wrote the textbooks for the courses at the start of the 20th century represented the new psychology that replaced the old psychology of mental philosophy. Teachers and texts presented psychology as a natural science of the mind and mental processes, described its methods, and suggested its potential applications to practical concerns. Textbooks and teachers varied in their approaches to psychology, their priorities among its methods, and their emphases on applying psychology. The introductory course in psychology accurately reflected the state of the discipline at the turn of the century.

Contributions of American mental philosophers to psychology in the United States.

Professors of mental philosophy who taught and wrote textbooks in colleges and universities in the United States before the Civil War contributed significantly to the development of the new psychology that replaced mental philosophy in the last quarter of the 19th century. Their contributions have been neglected in textbooks on the history of psychology, even those devoted to the history of psychology in the United States. These mental philosophers eased the transition to, and influenced the nature of, the new psychology in the United States by establishing a place in the curriculum for mental philosophy that the new psychology came to occupy; by identifying the topics for laboratory methods to address; by pursuing an empirical, inductive, scientific approach to the study of the mind; and by their tradition of functional analysis that came to characterize psychology in the United States.

Psychology and "the Babe".

Psychologists and baseball players were among those Americans who formed professional associations in the last quarter of the nineteenth century. Psychologists used laboratory tasks to quantify mental and behavioral processes while sportswriters and baseball organizers measured individual and team performance. The most popular baseball player of the 1920s, George Herman "Babe" Ruth, possessed superior batting skills that were evident in the statistical indices of baseball performance. In 1921, he was brought to the psychological laboratory at Columbia University to perform standard laboratory tasks in an effort to discover the basis for his success in hitting home runs and to suggest the potential of tests for identifying future baseball stars. Baseball's addiction to quantitative indices of performance was thus brought together with a new science devoted to quantitative assessment and a desire to make such assessments useful. The attempt to analyze the basis of Ruth's batting skills is part of the history of applied psychology, sport psychology, and popular interest in the science of psychology.

14q32 translocations are associated with mixed-lineage expression in childhood acute leukemia.

The frequency and characteristics of childhood acute leukemia with a 14q32 translocation [other than the t(8;14)(q24;q32)] were determined in 335 cases of newly diagnosed acute lymphoblastic leukemia (ALL) and 105 cases of acute nonlymphoblastic leukemia (ANLL). Ten children, representing 2.3% of the entire cohort, had this abnormality (1.5% of ALL patients and 4.8% of ANLL patients). By French-American-British (FAB) criteria, 4 cases were classified as L1, 1 as L2, 2 as M1, 1 as M2, and 2 as M5. Remarkably, mixed-lineage expression was found in 6 of these 10 cases, but in only 21 of the other 430 cases without a 14q32 translocation (P less than .001). Leukemic cells from 5 of these 6 cases (4 ANLL, and 1 ALL) coexpressed CD13, a myeloid-associated antigen, and CD2, a T-cell-associated antigen; blasts from the sixth case (ALL) coexpressed CD13 and CD19, a B-lineage-associated antigen. Thus, in addition to the well-described 11q23 translocations and t(9;22), 14q32 translocations also appear to be associated with mixed lineage antigen expression. Break-points of the reciprocal chromosomes from chromosome 14 were identified in five of these cases: 1q23, 6q23-q25, 7p15, 8q11, and 12q13. Of the four mixed-lineage cases that were tested, none showed rearrangement of the immunoglobulin heavy chain (IgH) gene. This suggests that the 14q32 breakpoint does not involve the IgH gene and that an unidentified important gene may reside on 14q32.