2,017 research outputs found
Quantum tunneling dynamics of an interacting Bose-Einstein condensate through a Gaussian barrier
The transmission of an interacting Bose-Einstein condensate incident on a
repulsive Gaussian barrier is investigated through numerical simulation. The
dynamics associated with interatomic interactions are studied across a broad
parameter range not previously explored. Effective 1D Gross-Pitaevskii equation
(GPE) simulations are compared to classical Boltzmann-Vlasov equation (BVE)
simulations in order to isolate purely coherent matterwave effects. Quantum
tunneling is then defined as the portion of the GPE transmission not described
by the classical BVE. An exponential dependence of transmission on barrier
height is observed in the purely classical simulation, suggesting that
observing such exponential dependence is not a sufficient condition for quantum
tunneling. Furthermore, the transmission is found to be predominately described
by classical effects, although interatomic interactions are shown to modify the
magnitude of the quantum tunneling. Interactions are also seen to affect the
amount of classical transmission, producing transmission in regions where the
non-interacting equivalent has none. This theoretical investigation clarifies
the contribution quantum tunneling makes to overall transmission in
many-particle interacting systems, potentially informing future tunneling
experiments with ultracold atoms.Comment: Close to the published versio
Perancangan Buku Komik City Guide Pariwisata Kota Surabaya Berbasis Ilustrasi Digital Guna Menganalkan Wisata Surabaya
The purpose of the design a comic book City Surabaya tourism guide is to introduce and promote tourism. Further research is done using qualitative research methodsthat do interviews, observation, and literature to obtain data that is used in the creation of design concepts to support the comic book city Surabaya tourism guide. The data were analyzed by using multiple stage, apply the reduction of data, data presentation, and conclusion. After analyzing the data, the found discuss the design concepts or keywords "Modern". The complaint is the latest, cutting edge, attitude andway of thinking and acting in accordance with the demands of the times. The concept of "Modern" aims to show that Surabaya is a city that has developed technology.Acting, the concept of the menu-the menu is served to infuse the public perceptionthat the public Surabaya willing to learn and thrive in the new stuff. The result of designing a comic book City of Surabaya tourism guide is to introduce and promote tourism city of Surabaya Surabaya and so that people outside the city could've known tourism in Surabaya
Translation of findings from laboratory studies of food and alcohol intake into behavior change interventions : the experimental medicine approach.
Objectives: Laboratory studies have contributed important information about the determinants of food and alcohol intake, and they have prompted the development of behavior change interventions that have been evaluated in randomized controlled trials conducted in the field. In this article we apply a recent experimental medicine (EM) framework to this body of research.
Method: A conceptual review and focused discussion of the relevant literature is presented.
Results: We illustrate how it is possible to translate findings from studies of food and alcohol intake in the laboratory into interventions that are effective for changing behavior in the real world. We go on to demonstrate how systematic failures can occur at different stages within the EM framework, and how these failures ultimately result in interventions that are ineffective for changing behavior. We also consider methodological issues that may constrain the external validity of findings from laboratory studies including demand effects, participant characteristics, and the timing and dose of behavioral interventions. Throughout, we make recommendations to improve the translation of findings from laboratory studies into behavior change interventions that are effective in the field.
Conclusions: Consideration of the EM framework will help to ensure that promising candidate interventions for eating and drinking that are identified in laboratory studies can fulfill their translational promise
Believing in food addiction: helpful or counter-productive for eating behaviour?
Objective: Obesity is often attributed to an addiction to food, and many people believe themselves to be “food addicts.” However, little is known about how such beliefs may affect dietary control and weight management. The current research examined the impact of experimentally manipulating participants' personal food addiction beliefs on eating behavior. Methods In two studies, female participants (study 1: N = 64; study 2: N = 90) completed food‐related computerized tasks and were given bogus feedback on their performance which indicated that they had high, low, or average food addiction tendencies. Food intake was then assessed in an ad libitum taste test. Dietary concern and time taken to complete the taste test were recorded in study 2. Results: In study 1, participants in the high‐addiction condition consumed fewer calories than those in the low‐addiction condition, F (1,60) = 7.61, P = 0.008, η p2 = 0.11. Study 2 replicated and extended this finding, showing that the effect of the high‐addiction condition on food intake was mediated by increased dietary concern, which reduced the amount of time participants willingly spent exposed to the foods during the taste test, b = −0.06 (0.03), 95% confidence interval = −0.13 to −0.01. Conclusions: Believing oneself to be a food addict is associated with short‐term dietary restriction. The longer‐term effects on weight management now warrant attention
Suppression of Implanted MDA-MB 231 Human Breast Cancer Growth in Nude Mice by Dietary Walnut
Walnuts contain components that may slow cancer growth including omega 3 fatty acids, phytosterols, polyphenols, carotenoids, and melatonin. A pilot study was performed to determine whether consumption of walnuts could affect growth of MDA-MB 231 human breast cancers implanted into nude mice. Tumor cells were injected into nude mice that were consuming an AIN-76A diet slightly modified to contain 10% corn oil. After the tumors reached 3 to 5 mm diameter, the diet of one group of mice was changed to include ground walnuts, equivalent to 56 g (2 oz) per day in humans. The tumor growth rate from Day 10, when tumor sizes began to diverge, until the end of the study of the group that consumed walnuts (2.9 ± 1.1 mm3/day; mean ± standard error of the mean) was significantly less (P \u3e 0.05, t-test of the growth rates) than that of the group that did not consume walnuts (14.6 ± 1.3 mm 3 /day). The eicosapentaenoic and docosahexaenoic acid fractions of the livers of the group that consumed walnuts were significantly higher than that of the group that did not consume walnuts. Tumor cell proliferation was decreased, but apoptosis was not altered due to walnut consumption. Further work is merited to investigate applications to cancer in humans
Observation of a Modulational Instability in Bose-Einstein condensates
We observe the breakup dynamics of an elongated cloud of condensed Rb
atoms placed in an optical waveguide. The number of localized spatial
components observed in the breakup is compared with the number of solitons
predicted by a plane-wave stability analysis of the nonpolynomial nonlinear
Schr\"odinger equation, an effective one-dimensional approximation of the
Gross-Pitaevskii equation for cigar-shaped condensates. It is shown that the
numbers predicted from the fastest growing sidebands are consistent with the
experimental data, suggesting that modulational instability is the key
underlying physical mechanism driving the breakup.Comment: 6 pages, 5 figure
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