353 research outputs found
Passing crisis and emergency risk communications: the effects of communication channel, information type, and repetition.
Three experiments explore several factors which influence information transmission when warning messages are passed from person to person. In Experiment 1, messages were passed down chains of participants using five different modes of communication. Written communication channels resulted in more accurate message transmission than verbal. In addition, some elements of the message endured further down the chain than others. Experiment 2 largely replicated these effects and also demonstrated that simple repetition of a message eliminated differences between written and spoken communication. In a final field experiment, chains of participants passed information however they wanted to, with the proviso that half of the chains could not use telephones. Here, the lack of ability to use a telephone did not affect accuracy, but did slow down the speed of transmission from the recipient of the message to the last person in the chain. Implications of the findings for crisis and emergency risk communication are discussed
Scalable quantum tomography in a photonic chip
© 2017 IEEE. We formulate a method of quantum tomography that scales linearly with the number of photons and involves only one optical transformation. We demonstrate it experimentally for two-photon entangled states using a special photonic chip
Multi-dimensional synthetic space and state measurement with spectral photonic lattices
© OSA 2018. We propose and experimentally realize spectral photonic lattices with pumpinduced frequency couplings, which can emulate multi-dimensional dynamics with synthetic gauge fields and enable single-shot measurement of the signal phase and coherence
Performance-based social comparisons in humans and long-tailed macaques
Social comparisons are a fundamental feature of human thinking and affect self-evaluations and task performance. Little is known about the evolutionary origins of social comparison processes, however. Previous studies that investigated performance-based social comparisons in nonhuman primates yielded mixed results. We report three experiments that aimed (a) to explore how the task type may contribute to performance in monkeys, and (b) how a competitive set-up affects monkeys compared to humans. In a co-action touchscreen task, monkeys were neither influenced by nor interested in the performance of the partner. This may indicate that the experimental set-up was not sufficiently relevant to trigger social comparisons. In a novel co-action foraging task, monkeys increased their feeding speed in competitive and co-active conditions, but not in relation to the degree of competition. In an analogue of the foraging task, human participants were affected by partner performance and experimental context, indicating that the task is suitable to elicit social comparisons in humans. Our studies indicate that specifics of task and experimental setting are relevant to draw the monkeysâ attention to a co-actor and that, in line with previous research, a competitive element was crucial. We highlight the need to explore what constitutes ârelevantâ social comparison situations for monkeys as well as nonhuman animals in general, and point out factors that we think are crucial in this respect (e.g. task type, physical closeness, and the speciesâ ecology). We discuss that early forms of social comparisons evolved in purely competitive environments with increasing social tolerance and cooperative motivations allowing for more fine-grained processing of social information. Competition driven effects on task performance might constitute the foundation for the more elaborate social comparison processes found in humans, which may involve context-dependent information processing and metacognitive monitoring
Synthetic photonic lattice for single-shot reconstruction of frequency combs
We formulate theoretically and demonstrate experimentally an all-optical
method for reconstruction of the amplitude, phase and coherence of frequency
combs from a single-shot measurement of the spectral intensity. Our approach
exploits synthetic frequency lattices with pump-induced spectral short- and
long-range couplings between different signal components across a broad
bandwidth of of hundreds GHz in a single nonlinear fiber. When combined with
ultra-fast signal conversion techniques, this approach has the potential to
provide real-time measurement of pulse-to-pulse variations in the spectral
phase and coherence properties of exotic light sources.Comment: 15 pages, 4 figure
Tunable entangled photon states from a nonlinear directional coupler
Integrated optical platforms enable the realization of complex quantum photonic circuits for a variety of applications including quantum simulations, computations, and communications. The development of on-chip integrated photon sources, providing photon quantum states with on-demand tunability, is currently an important
research area. A flexible approach for on-chip generation of entangled photons is based on spontaneous nonlinear
frequency conversion, with possibilities to integrate several photon-pair sources [1] and realize subsequent post
processing using thermo-optically or electro-optically controlled interference [2, 3]. However, deterministic postprocessing can only provide a limited set of output states, whereas quantum gates with probabilistic operation are
needed to generate arbitrary two-photon states [4]
A Framework for Assessing the Solutions in Chromatographic Process Design and Operation for Large Scale Manufacture
Chromatographic separation of biopharmaceuticals is complex and tools for the prediction of performance and the trade-offs necessary for efficient operation are limited and time-consuming. This complexity is due to the large number of possible column aspect ratios that satisfy process and economic needs. This paper demonstrates a framework for the design and analysis of chromatographic steps. The functionalities are illustrated by application to a Protein A separation where the effects of column diameter, bed length and linear flow rate on cost of goods (COG/g) and productivity (g/h) are investigated so as to identify the optimal operating strategy. Results are presented as a series of âwindows of operationâ to address key design and operating decisions. The tool allows the designer to customise limiting constraints based on product and process specific knowledge. Results indicate the significant impact on COG/g of column over-sizing and how this can be balanced by increased levels of productivity
A Framework for Assessing the Solutions in Chromatographic Process Design and Operation for Large Scale Manufacture
Chromatographic separation of biopharmaceuticals is complex and tools for the prediction of performance and the trade-offs necessary for efficient operation are limited and time-consuming. This complexity is due to the large number of possible column aspect ratios that satisfy process and economic needs. This paper demonstrates a framework for the design and analysis of chromatographic steps. The functionalities are illustrated by application to a Protein A separation where the effects of column diameter, bed length and linear flow rate on cost of goods (COG/g) and productivity (g/h) are investigated so as to identify the optimal operating strategy. Results are presented as a series of âwindows of operationâ to address key design and operating decisions. The tool allows the designer to customise limiting constraints based on product and process specific knowledge. Results indicate the significant impact on COG/g of column over-sizing and how this can be balanced by increased levels of productivity
A scale-down mimic for mapping the process performance of centrifugation, depth and sterile filtration
In the production of biopharmaceuticals disk-stack centrifugation is widely used as a harvest step for the removal of cells and cellular debris. Depth filters followed by sterile filters are often then employed to remove residual solids remaining in the centrate. Process development of centrifugation is usually conducted at pilot-scale so as to mimic the commercial scale equipment but this method requires large quantities of cell culture and significant levels of effort for successful characterization. A scale-down approach based upon the use of a shear device and a bench-top centrifuge has been extended in this work towards a preparative methodology that successfully predicts the performance of the continuous centrifuge and polishing filters. The use of this methodology allows the effects of cell culture conditions and large-scale centrifugal process parameters on subsequent filtration performance to be assessed at an early stage of process development where material availability is limited
Phase-field modeling of microstructural pattern formation during directional solidification of peritectic alloys without morphological instability
During the directional solidification of peritectic alloys, two stable solid
phases (parent and peritectic) grow competitively into a metastable liquid
phase of larger impurity content than either solid phase. When the parent or
both solid phases are morphologically unstable, i.e., for a small temperature
gradient/growth rate ratio (), one solid phase usually outgrows and
covers the other phase, leading to a cellular-dendritic array structure closely
analogous to the one formed during monophase solidification of a dilute binary
alloy. In contrast, when is large enough for both phases to be
morphologically stable, the formation of the microstructurebecomes controlled
by a subtle interplay between the nucleation and growth of the two solid
phases. The structures that have been observed in this regime (in small samples
where convection effect are suppressed) include alternate layers (bands) of the
parent and peritectic phases perpendicular to the growth direction, which are
formed by alternate nucleation and lateral spreading of one phase onto the
other as proposed in a recent model [R. Trivedi, Metall. Mater. Trans. A 26, 1
(1995)], as well as partially filled bands (islands), where the peritectic
phase does not fully cover the parent phase which grows continuously. We
develop a phase-field model of peritectic solidification that incorporates
nucleation processes in order to explore the formation of these structures.
Simulations of this model shed light on the morphology transition from islands
to bands, the dynamics of spreading of the peritectic phase on the parent phase
following nucleation, which turns out to be characterized by a remarkably
constant acceleration, and the types of growth morphology that one might expect
to observe in large samples under purely diffusive growth conditions.Comment: Final version, minor revisions, 16 pages, 14 EPS figures, RevTe
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