2,920 research outputs found
Sequences of purchases in credit card data reveal life styles in urban populations
Zipf-like distributions characterize a wide set of phenomena in physics,
biology, economics and social sciences. In human activities, Zipf-laws describe
for example the frequency of words appearance in a text or the purchases types
in shopping patterns. In the latter, the uneven distribution of transaction
types is bound with the temporal sequences of purchases of individual choices.
In this work, we define a framework using a text compression technique on the
sequences of credit card purchases to detect ubiquitous patterns of collective
behavior. Clustering the consumers by their similarity in purchases sequences,
we detect five consumer groups. Remarkably, post checking, individuals in each
group are also similar in their age, total expenditure, gender, and the
diversity of their social and mobility networks extracted by their mobile phone
records. By properly deconstructing transaction data with Zipf-like
distributions, this method uncovers sets of significant sequences that reveal
insights on collective human behavior.Comment: 30 pages, 26 figure
Does the CAPON Gene Confer Susceptibility to Schizophrenia?
Eastwood discusses a new study in PLoS Medicine that suggests that overexpression of the CAPON gene, leading to disruption of NMDA receptor function, may be important in the etiology of severe mental illnesses
Kinesin-II is required for axonal transport of choline acetyltransferase in Drosophila
KLP64D and KLP68D are members of the kinesin-II family of proteins in Drosophila. Immunostaining for KLP68D and ribonucleic acid in situ hybridization for KLP64D demonstrated their preferential expression in cholinergic neurons. KLP68D was also found to accumulate in cholinergic neurons in axonal obstructions caused by the loss of kinesin light chain. Mutations in the KLP64D gene cause uncoordinated sluggish movement and death, and reduce transport of choline acetyltransferase from cell bodies to the synapse. The inviability of KLP64D mutations can be rescued by expression of mammalian KIF3A. Together, these data suggest that kinesin-II is required for the axonal transport of a soluble enzyme, choline acetyltransferase. in a specific subset of neurons in Drosophila. Furthermore, the data lead to the conclusion that the cargo transport requirements of different classes of neurons may lead to upregulation of specific pathways of axonal transport
2023 China Business Report: On Business Performance and Operations of Companies in China in the New Business Environment
The China and Europe International Business School (CEIBS) Research Team with three professors and two research assistants conducted an online survey from November 18th to November 27th 2022, receiving 1,474 unique responses in total. 1,181 (80.2%) survey participants work for Chinese-owned firms or firms with 50% or more Chinese ownership, and 291 (19.8%) participants work for foreign-owned firms in China or firms with more than 50% foreign ownership.The professional distributions show that the survey sample is not a typical sample of enterprises operating in China, but rather reflects the situation of the enterprises of the senior executives who have study experiences in CEIBS, especially that of enterprises of more than half of the EMBA alumni and students. According to the class profile of CEIBS EMBA programme, the average age of participants is 41, average years of working experience is 17, and their average years of managing experience is 12. More than 95% of the participants are senior managers. CEIBS has more than 20,000 alumni, including EMBA alumni who participated the most in this survey among all alumni or students. Based on the above information, we conclude that the survey result has reference value in the sense that it largely reflects how “head companies” (the leading companies and most active ones in their respective industries) in China assessed and judged the impacts of business environment and innovation on business operations. This is also confirmed by the survey results of the reported market positioning of their products and services
From grassroots to celebrities in healthcare– professionality as a new persona in China’s celebrity culture
The global pandemic motivated the emergence of grassroots celebrities in healthcare who led online opinion through their professional insights and sharing of health and medical-related knowledge in China. A certain number of practitioners introduced their professional guidance to general netizens through pay-for-answer subscription with the help of Chinese social media. This article interrogates grassroots celebrities via Zhihu, China’s largest community for questions and answers (CQA). It extends Western-focused scholarship on microcelebrities
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Characteristics of the Quiet-Time Hot Spot GravityWaves Observed by GOCE Over the Southern Andes on 5 July 2010
We analyze quiet-time data from the Gravity Field and Ocean Circulation Explorer satellite as it overpassed the Southern Andes at z≃275 km on 5 July 2010 at 23 UT. We extract the 20 largest traveling atmospheric disturbances from the density perturbations and cross-track winds using Fourier analysis. Using gravity wave (GW) dissipative theory that includes realistic molecular viscosity, we search parameter space to determine which hot spot traveling atmospheric disturbances are GWs. This results in the identification of 17 GWs having horizontal wavelengths λH = 170–1,850 km, intrinsic periods τIr = 11–54 min, intrinsic horizontal phase speeds cIH = 245–630 m/s, and density perturbations (Formula presented.) 0.03–7%. We unambiguously determine the propagation direction for 11 of these GWs and find that most had large meridional components to their propagation directions. Using reverse ray tracing, we find that 10 of these GWs must have been created in the mesosphere or thermosphere. We show that mountain waves (MWs) were observed in the stratosphere earlier that day and that these MWs saturated at z∼ 70–75 km from convective instability. We suggest that these 10 Gravity Field and Ocean Circulation Explorer hot spot GWs are likely tertiary (or higher-order) GWs created from the dissipation of secondary GWs excited by the local body forces created from MW breaking. We suggest that the other GW is likely a secondary or tertiary (or higher-order) GW. This study strongly suggests that the hot spot GWs over the Southern Andes in the quiet-time middle winter thermosphere cannot be successfully modeled by conventional global circulation models where GWs are parameterized and launched in the troposphere or stratosphere. ©2019. The Authors
First-Principles Approach for Coupled Quantum Dynamics of Electrons and Protons in Heterogeneous Systems
The coupled quantum dynamics of electrons and protons is ubiquitous in many
dynamical processes involving light-matter interaction, such as solar energy
conversion in chemical systems and photosynthesis. A first-principles
description of such nuclear-electronic quantum dynamics requires not only the
time-dependent treatment of nonequilibrium electron dynamics but also that of
quantum protons. Quantum mechanical correlation between electrons and protons
adds further complexity to such coupled dynamics. Here we extend real-time
nuclear-electronic orbital time-dependent density functional theory
(RT-NEO-TDDFT) to periodic systems and perform first-principles simulations of
coupled quantum dynamics of electrons and protons in complex heterogeneous
systems. The process studied is electronically excited state intramolecular
proton transfer of o-hydroxybenzaldehyde in water and at a silicon (111)
semiconductor-molecule interface. These simulations illustrate how environments
such as hydrogen-bonding water molecules and an extended material surface
impact the dynamical process on the atomistic level. Depending on how the
molecule is chemisorbed on the surface, excited state electron transfer from
the molecule to the semiconductor surface can inhibit ultrafast proton transfer
within the molecule. This work elucidates how heterogeneous environments
influence the balance between the quantum mechanical proton transfer and
excited electron dynamics. The periodic RT-NEO-TDDFT approach is applicable to
a wide range of other photoinduced heterogeneous processes
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