215 research outputs found
The Impact of Disruptive Innovation on Therapeutic Communication in the Healthcare Setting
While disruptive innovators (a newly introduced technique that transforms caregiver-patient communications) can maximize efficiency, can it be at the cost of the human component of patient care? Does increased reliance on disruptive innovation ultimately affect the quality of care as the perception of higher efficiency reduces the length and quality of nurse-patient contact? Is therapeutic communication (the foundation of caring for a patient through verbal and nonverbal interactions) becoming an abandon skill due to the rising use of disruptive innovators
“The Golden Door”: Does Business Hold the Key?
“The New Colossus,” Emma Lazarus’ poem, although a later addition to Liberty Island, has now become synonymous with the Statue of Liberty itself. Its words, however, are not without controversy. Was Lazarus arguing that the United States is morally obligated to open her door to the poor and the oppressed? If so, what role does/should business play in granting immigrants entry? The poem frames this discussion of a contemporary understanding of what it means to be human in a global society and, building on this concept, the paper evaluates current US employment-based immigration law and suggests a paradigm to assess future policy
Towards a Chemically Defined Medium for Sf-9 Cell Culture: Micronutrients Reduce Dependence on Yeast Extract
Spodoptera frugiperda clonal isolate 9 (Sf-9) insect cells in conjunction with recombinant baculovirus are an industrially relevant system for producing biologics. Sf-9 cells are capable of robust high-density growth in single cell suspension. However, unlike many other continuous cell lines, Sf-9 cell culture media remains undefined. Typically, the growth medium requires undefined hydrolysate supplementation (most often yeast extract) in order to support cell proliferation. The lack of chemical definition makes medium and process optimization difficult, leads to batch-to-batch variability, and potentially affects downstream processing. This work aims to combine available information on the composition of yeast extract and the composition of media for other cell lines to reduce the concentration of undefined components (yeast extract) in the medium and elucidate the effects of micronutrient compounds.
Utilizing an in-house medium based on the classic IPL-41 medium with yeast extract as the only undefined component, several steps were taken towards chemical definition. Through fortifying the trace metal and vitamin content in the medium and the addition of 11 micronutrients, the yeast extract content was successfully reduced 10-fold (from 4 g/L to 0.4 g/L). Without medium fortification and micronutrient addition, the cells were incapable of growth at low yeast extract concentration. Sf-9 cells adapted to this new medium were capable of long-term consistent growth. Micronutrients of key importance in this medium were identified as glycine betaine, ascorbic acid, and the polyamine putrescine. The presence of glycine betaine (1 mM), ascorbic acid (10 uM), and putrescine (10 uM) improved maximum cell density by 32%, 41%, and 28% respectively in the low yeast extract medium. The role of these micronutrients could be properly investigated only after medium enhancement and yeast extract reduction. Further, this medium was found to be cost-effective compared to commercially available alternatives and the potential for added cost-savings related to lipid supplementation was identified.
This enhanced low yeast extract medium could allow for micronutrient and other component investigation with less convolution and is particularly applicable to designed compound screening experiments (e.g. Plackett-Burman). Identification and supplementation of additional required components provided solely by the yeast extract could lead to a chemically defined medium
Characterization of Alternative FBR Development Strategies
Near-term decisions regarding the nature and place of the FBR development program must be made. This study is part of a larger program designed to provide the Department of Energy (DOE) with imformation that can be used to make strategic programmatic decisions. The focus of this report is the description of alternative approaches for developing the FBR and the quantification of the duration and cost of each alternative. The time frames of the alternative approaches are investigated in companion reports (White 1981 and Fraley 1981). The results of these analyses will be described in a summary report (Burnham et al. 1981)
Controlled expansion of shell-shaped Bose–Einstein condensates
Motivated by the recent experimental realization of ultracold quantum gases in shell topology, we propose a straightforward implementation of matter-wave lensing techniques for shell-shaped Bose–Einstein condensates. This approach allows to significantly extend the free evolution time of the condensate shell after release from the trap and enables the study of novel quantum many-body effects on curved geometries. With both analytical and numerical methods we derive optimal parameters for realistic schemes to conserve the shell shape of the condensate for times up to hundreds of milliseconds
La maladie des muqueuses en Afrique centrale. Observations cliniques et Ă©pizootiologiques
Après avoir décrit les techniques virologiques mises en oeuvre pour identifier les souches non cytopathogènes du virus de la maladie des muqueuses, les auteurs passent en revue les facteurs gouvernant l'épizootiologie de la maladie en Afrique centrale puis décrivent les particularités cliniques observées dans cette région et signalent les éléments du diagnostic. Une enquête sérologique indique que 75 p. 100 des bovins adultes possèdent des anticorps, rencontrés également chez des moutons, des antilopes et des gazelles. La répartition des anticorps par classes d'âge chez les bovins semble dénoter que la maladie des muqueuses évolue en Afrique centrale par poussées épizootique
Shell-shaped Bose-Einstein condensates realized with dual-species mixtures
Confining Bose-Einstein condensates (BECs) in shell-shaped trapping potentials enables the generation of hollow quasi-2D topologies with superfluid properties. Motivated by recent microgravity experiments, these shell-shaped BECs are nowadays actively studied both theoretically and experimentally, with radio-frequency (rf) dressing being the main trapping mechanism under study. Here we present an alternative approach that utilizes the repulsive interaction in a dual-species mixture to achieve shell-shaped BECs, which could be realized in the future BECCAL mission. In contrast to the rf case, which relies on a dynamical transition from a filled to a hollow condensate, the mixture approach is based on realizing the shell structure as the ground state of the system, where one species is located at the center of the trap surrounded by the other and kept in place by the repulsive inter-species interaction. We compare both approaches by analyzing the initial states, the free expansion dynamics, and the collective excitation spectrum with analytical and numerical methods. In all three categories the mixture performs similar to the rf approach. Moreover, the interaction-driven expansion of the mixture allows to increase the size of the shell during time-of-flight without distorting its shape and therefore magnifying the dynamics within the shell; a mechanism not realizable in the rf case. We conclude by performing a feasibility analysis for both approaches that takes residual gravitational effects and possible trap asymmetries into account, which currently are the main obstacles to experimentally realize shell-shaped BECs
Asymmetric Tunneling of Bose-Einstein Condensates
In his celebrated textbook, \textit{Quantum Mechanics: Nonrelativistic
Theory}, Landau argued that, for single particle systems in 1D, tunneling
probability remains the same for a particle incident from the left or the right
of a barrier. This left-right symmetry of tunneling probability holds
regardless of the shape of the potential barrier. However, there are a variety
of known cases that break this symmetry, e.g. when observing composite
particles. We computationally (and analytically, in the simplest case) show
this breaking of the left-right tunneling symmetry for Bose-Einstein
condensates (BEC) in 1D, modelled by the Gross-Pitaevskii equation (GPE). By
varying , the parameter of inter-particle interaction in the BEC, we
demonstrate that the transition from symmetric () to asymmetric tunneling
is a threshold phenomenon. Our computations employ experimentally feasible
parameters such that these results may be experimentally demonstrated in the
near future. We conclude by suggesting applications of the phenomena to design
atomtronic diodes, synthetic gauge fields, Maxwell's demons, and black-hole
analogues.Comment: 15 pages, 16 figure
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