Entangled collective-spin states of atomic ensembles under non-uniform atom-light interaction

We consider the optical generation and verification of entanglement in atomic ensembles under non-uniform interaction between the ensemble and an optical mode. We show that for a wide range of parameters a system of non-uniformly coupled atomic spins can be described as an ensemble of uniformly coupled spins with a reduced effective atom-light coupling and a reduced effective atom number, with a reduction factor of order unity given by the ensemble-mode geometry. This description is valid even for complex entangled states with arbitrary phase-space distribution functions as long as the detection does not resolve single spins. Furthermore, we derive an analytic formula for the observable entanglement in the case, of relevance in practice, where the ensemble-mode coupling differs between state generation and measurement.Comment: 5 pages, 3 figure

How international students in chinese medical schools perceive distant learning during the COVID-19 pandemic

Purpose: The aim of this study is to assess the perception of international medical students of e-learning in China, since medical teaching during the COVID-19 pandemic had to adapt to challenges, and students had to cope with the new teaching modality, more so international students. Therefore, the opinion of students with their first contact to a fully virtual education will be helpful to modify e-teaching to better suit the students’ needs. Method: Four hundred seven medical students, in China, were recruited via social media and were asked to complete structured questionnaires, regarding technical and content aspects of their e-courses. Findings: Most issues reported were of technical nature, especially for students attending the school distantly and network instability/unavailability was frequently (52.48%). Moreover, the audio was less helpful than texts/images and the senior students were less satisfied with the technical (0.005) and content (p=0.001) aspects. They also were more critical of their teachers’ performance (p=0.042). Clinical cases and scenarios also received the lowest score. Implications for research and practice: Overall students did not feel confident with the e-learning, comfortable implementing it to patients and were reluctant to embrace it. Both technical difficulties and understanding issues impeded international students from embracing e-learning medical teaching, in China and efforts need to be made to acclimatise them to this new reality

Digital Injustice: A Case Study of Land Use Classification Using Multisource Data in Nairobi, Kenya

The utilisation of big data has emerged as a critical instrument for land use classification and decision-making processes due to its high spatiotemporal accuracy and ability to diminish manual data collection. However, the reliability and feasibility of big data are still controversial, the most important of which is whether it can represent the whole population with justice. The present study incorporates multiple data sources to facilitate land use classification while proving the existence of data bias caused digital injustice. Using Nairobi, Kenya, as a case study and employing a random forest classifier as a benchmark, this research combines satellite imagery, night-time light images, building footprint, Twitter posts, and street view images. The findings of the land use classification also disclose the presence of data bias resulting from the inadequate coverage of social media and street view data, potentially contributing to injustice in big data-informed decision-making. Strategies to mitigate such digital injustice situations are briefly discussed here, and more in-depth exploration remains for future work

Strictly nonclassical behavior of a mesoscopic system

We experimentally demonstrate the strictly nonclassical behavior in a many-atom system using a recently derived criterion [E. Kot et al., Phys. Rev. Lett. 108, 233601 (2012)] that explicitly does not make use of quantum mechanics. We thereby show that the magnetic moment distribution measured by McConnell et al. [R. McConnell et al., Nature 519, 439 (2015)] in a system with a total mass of $2.6\times 10^5$ atomic mass units is inconsistent with classical physics. Notably, the strictly nonclassical behavior affects an area in phase space $10^3$ times larger than the Planck quantum $\hbar$.Comment: 5 page

Inside Audit Firms

We develop and test hypotheses about compensation policy and auditor retention in accounting firms. Our analyses use de-identified employment and compensation data to investigate the entire pay distribution within accounting firms. Accounting firms all have low retention rates but exhibit differing pay structures. Big 4 firms give similar raises within each cohort, while non-Big 4 give substantial raises to a few top performers. Auditors often "move up" to Big 4 firms, but relatively few move the other way. Audit fees are consistently related to compensation structure. Overall, our results suggest that compensation policies in professional accounting firms affect auditor behavior

Carving Complex Many-Atom Entangled States by Single-Photon Detection

We propose a versatile and efficient method to generate a broad class of complex entangled states of many atoms via the detection of a single photon. For an atomic ensemble contained in a strongly coupled optical cavity illuminated by weak single- or multifrequency light, the atom-light interaction entangles the frequency spectrum of a transmitted photon with the collective spin of the atomic ensemble. Simple time-resolved detection of the transmitted photon then projects the atomic ensemble into a desired pure entangled state. This method can be implemented with existing technology, yields high success probability per trial, and can generate complex entangled states such as mesoscopic superposition states of coherent spin states with high fidelity.National Science Foundation (U.S.)United States. Defense Advanced Research Projects Agency. Quantum-Assisted Sensing and Readout (QuASAR) ProgramUnited States. Air Force Office of Scientific Research. Multidisciplinary University Research InitiativeUnited States. Army Research Office. Multidisciplinary University Research InitiativeNatural Sciences and Engineering Research Council of Canad

Nrdp1 Increases Ischemia Induced Primary Rat Cerebral Cortical Neurons and Pheochromocytoma Cells Apoptosis Via Downregulation of HIF-1α Protein

Neuregulin receptor degradation protein-1 (Nrdp1) is an E3 ubiquitin ligase that targets proteins for degradation and regulates cell growth, apoptosis and oxidative stress in various cell types. We have previously shown that Nrdp1 is implicated in ischemic cardiomyocyte death. In this study, we investigated the change of Nrdp1 expression in ischemic neurons and its role in ischemic neuronal injury. Primary rat cerebral cortical neurons and pheochromocytoma (PC12) cells were infected with adenoviral constructs expressing Nrdp1 gene or its siRNA before exposing to oxygen-glucose deprivation (OGD) treatment. Our data showed that Nrdp1 was upregulated in ischemic brain tissue 3 h after middle cerebral artery occlusion (MCAO) and in OGD-treated neurons. Of note, Nrdp1 overexpression by Ad-Nrdp1 enhanced OGD-induced neuron apoptosis, while knockdown of Nrdp1 with siRNA attenuated this effect, implicating a role of Nrdp1 in ischemic neuron injury. Moreover, Nrdp1 upregulation is accompanied by increased protein ubiquitylation and decreased protein levels of ubiquitin-specific protease 8 (USP8) in OGD-treated neurons, which led to a suppressed interaction between USP8 and HIF-1α and subsequently a reduction in HIF-1α protein accumulation in neurons under OGD conditions. In conclusion, our data support an important role of Nrdp1 upregulation in ischemic neuronal death, and suppressing the interaction between USP8 and HIF-1α and consequently the hypoxic adaptive response of neurons may account for this detrimental effect

Social Interaction Patterns of the Disabled People in Asymmetric Social Dilemmas

The social participation of the disabled people is unsatisfactory and low, one of the reasons often overlooked but of great importance may lie in the disparate patterns of social interaction between the disabled people and the abled people. The current study respectively recruited 41 and 80 disabled people in two experiments and adopted give-some games and public good dilemma to explore social interaction patterns between the disabled abled people. The results were as follows: (1) the disabled people preferred to interact with the disabled people and the abled people preferred to interact with the abled people. (2) The disabled abled people had higher cooperation, satisfaction and sense of justice when interacting with the disabled people than interacting with the abled people. (3) Advantage in the number of the disabled people could reverse their disadvantage in the identity. These results are of important practical value, which provides related theoretical support for the disabled people’s federation and communities when carrying out activities for the disabled people