Entangled Rings

Consider a ring of N qubits in a translationally invariant quantum state. We ask to what extent each pair of nearest neighbors can be entangled. Under certain assumptions about the form of the state, we find a formula for the maximum possible nearest-neighbor entanglement. We then compare this maximum with the entanglement achieved by the ground state of an antiferromagnetic ring consisting of an even number of spin-1/2 particles. We find that, though the antiferromagnetic ground state does not maximize the nearest-neighbor entanglement relative to all other states, it does so relative to other states having zero z-component of spin.Comment: 19 pages, no figures; v2 includes new results; v3 corrects a numerical error for the case N=

Monitoring methane emissions from oil and gas operations

The atmospheric concentration of methane has more than doubled since the start of the Industrial Revolution. Methane is the second-most-abundant greenhouse gas created by human activities and a major driver of climate change. This APS-Optica report provides a technical assessment of the current state of monitoring U.S. methane emissions from oil and gas operations, which accounts for roughly 30% of U.S. anthropogenic methane emissions. The report identifies current technological and policy gaps and makes recommendations for the federal government in three key areas: methane emissions detection, reliable and systematized data and models to support mitigation measures, and effective regulation. &nbsp;</p

The role of Allee effect in modelling post resection recurrence of glioblastoma

Resection of the bulk of a tumour often cannot eliminate all cancer cells, due to their infiltration into the surrounding healthy tissue. This may lead to recurrence of the tumour at a later time. We use a reaction-diffusion equation based model of tumour growth to investigate how the invasion front is delayed by resection, and how this depends on the density and behaviour of the remaining cancer cells. We show that the delay time is highly sensitive to qualitative details of the proliferation dynamics of the cancer cell population. The typically assumed logistic type proliferation leads to unrealistic results, predicting immediate recurrence. We find that in glioblastoma cell cultures the cell proliferation rate is an increasing function of the density at small cell densities. Our analysis suggests that cooperative behaviour of cancer cells, analogous to the Allee effect in ecology, can play a critical role in determining the time until tumour recurrence

A deep learning approach to photo–identification demonstrates high performance on two dozen cetacean species

We thank the countless individuals who collected and/or processed the nearly 85,000 images used in this study and those who assisted, particularly those who sorted these images from the millions that did not end up in the catalogues. Additionally, we thank the other Kaggle competitors who helped develop the ideas, models and data used here, particularly those who released their datasets to the public. The graduate assistantship for Philip T. Patton was funded by the NOAA Fisheries QUEST Fellowship. This paper represents HIMB and SOEST contribution numbers 1932 and 11679, respectively. The technical support and advanced computing resources from University of Hawaii Information Technology Services—Cyberinfrastructure, funded in part by the National Science Foundation CC* awards # 2201428 and # 2232862 are gratefully acknowledged. Every photo–identification image was collected under permits according to relevant national guidelines, regulation and legislation.Peer reviewedPublisher PD

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

To Keep the Peace: The United Nations Condemnatory Resolution

The first purpose of the United Nations is “to maintain international peace and security.” Among the chief methods employed to attain this end has been the condemnatory resolution, in which international outrage is expressed at the policies or actions of a given state. Here William W. Orbach undertakes to explore the nature of the United Nations and its role in international politics through an examination of the history of such resolutions, the reasons for condemnations, and the process by which they are enacted or rejected. He concludes that the United Nations is not an independent actor on the international stage but a microcosm of that stage, as such in a unique position to further international peace. William W. Orbach is assistant professor of studies in religion at the Belknap Campus of the University of Louisville.https://uknowledge.uky.edu/upk_political_science_international_relations/1014/thumbnail.jp

Correlation of apparent diffusion coefficient with neuropsychological testing in temporal lobe epilepsy

BACKGROUND AND PURPOSE: Patients with nonlesional temporal lobe epilepsy have long been known to have abnormalities of memory. Recently, these patients have been shown to have increased diffusivity in the hippocampus. We hypothesized that in these patients, a negative correlation would exist between diffusivity measures of the mesial temporal lobe and performance on neuropsychological tests. METHODS: Twenty presurgical patients with temporal lobe epilepsy and 20 age- and sex-matched healthy controls underwent MR imaging of the brain. Apparent diffusion coefficient region of interest measures were taken in both hippocampi and parahippocampal gyri by 2 independent observers. Mean whole brain diffusivity was calculated. All patients completed neuropsychological testing. Electroencephalogram and pathology results were collected. Patients and controls were compared with respect to each apparent diffusion coefficient measure. In patients, apparent diffusion coefficients ipsilateral and contralateral to the seizure focus were compared. Associations were assessed between diffusivity measures and neuropsychological scores. RESULTS: Eleven patients had right-sided seizure foci and 9 had left-sided seizure foci. Patients demonstrated higher apparent diffusion coefficient values than controls over the whole brain, in the hippocampi, and in the parahippocampal gyri (P <.05). Patients demonstrated higher apparent diffusion coefficient within the ipsilateral hippocampus (1.19 +/- 0.22 x 10(-3) s/mm2) and parahippocampal gyrus (1.02 +/- 0.12 x 10(-3) s/mm2) compared with the contralateral side (1.02 +/- 0.16 x 10(-3) s/mm2 and 0.96 +/- 0.09 x 10(-3) s/mm2, respectively) (P <.05). Negative correlations were seen between hippocampal apparent diffusion coefficients and multiple memory tests (P <.05). CONCLUSION: Quantitative diffusion measurements in the hippocampus correlate with memory dysfunction in patients with temporal lobe epilepsy

The treatment approach to pediatric non-rhabdomyosarcoma soft tissue sarcomas: a critical review from the INternational Soft Tissue SaRcoma ConsorTium

The current article focuses on non-rhabdomyosarcoma soft tissue sarcoma (NRSTS), the heterogeneous group of mesenchymal tumours different from rhabdomyosarcoma that may affect children and adolescents, with clinical behaviour varying from relatively benign to highly malignant. This review represents the effort of the international scientific paediatric community within the context of the INternational Soft Tissue SaRcoma ConsorTium (INSTRuCT), a project founded by the leadership of three large cooperative groups - Children\u27s Oncology Group, Cooperative Weichteilsarkom Studiengruppe and European paediatric Soft tissue sarcoma Study Group - with the main goal to pool expertise and resources on a broader international level in order to improve knowledge of soft tissue sarcomas of children, adolescents and young adults. This article describes the current standard treatment approach in NRSTS, with a focus on the controversies and challenges in the management of these tumours. Developing research projects and clinical protocols for NRSTS has always been challenging, supporting the need to develop international integrated prospective dedicated programs, including paediatric NRSTS experts together with the adult sarcoma community. INSTRuCT provides a unique mechanism to increase international collaboration by agreeing on a common language, developing consensus standards to guide diagnosis and treatment, comparing clinical trial results across cooperative groups, and through a shared data dictionary providing answers to questions that can only be addressed by a larger data set