331 research outputs found

    Electronic decoupling of an epitaxial graphene monolayer by gold intercalation

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    The application of graphene in electronic devices requires large scale epitaxial growth. The presence of the substrate, however, usually reduces the charge carrier mobility considerably. We show that it is possible to decouple the partially sp3-hybridized first graphitic layer formed on the Si-terminated face of silicon carbide from the substrate by gold intercalation, leading to a completely sp2-hybridized graphene layer with improved electronic properties.Comment: 7 pages, 4 figures, 1 tabl

    The Fine Line Between Normal and Starburst Galaxies

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    Recent literature suggests that there are two modes through which galaxies grow their stellar mass - a normal mode characterized by quasi-steady star formation, and a highly efficient starburst mode possibly triggered by stochastic events such as galaxy mergers. While these differences are established for extreme cases, the population of galaxies in-between these two regimes is poorly studied and it is not clear where the transition between these two modes of star formation occurs. We utilize ALMA observations of the CO J=3-2 line luminosity in a sample of 20 infrared luminous galaxies that lie in the intermediate range between normal and starburst galaxies at z ~ 0.25-0.6 in the COSMOS field to examine the gas content and star formation efficiency of these galaxies. We compare these quantities to the galaxies' deviation from the well-studied "main sequence" correlation between star formation rate and stellar mass (MS) and find that at log(SFR/SFRMSSFR/SFR_{MS}) < 0.6, a galaxy's distance to the main sequence is mostly driven by increased gas content, and not a more efficient star formation process.Comment: 21 pages, 10 figure

    Diversity in Honors: Understanding Systemic Biases through Student Narratives

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    Centered on superiority over a certain group or individual, discrimination becomes predominant in prestigious institutions that pride themselves on exclusivity. Collegiate honors programs tend to deepen this practice by creating highly elite spaces accessible only to a select few. This rigidity can lead to an underrepresentation of historically marginalized groups, students who often lack the necessary resources for achieving academic excellence. This case study examines the ways honors programs inadvertently perpetuate discrimination among different social identities. Using inductive interviewing of honors students (n = 12) to gauge individual perceptions of program diversity, researchers rely on content analysis to generate four themes (relationship, discrimination, exclusion, conformity). By cross-analyzing participant responses with social identities, key programmatic components that may have led to covert systemic bias are uncovered. Results further indicate a possible link between a student’s racial identity and their sense of belonging within the program, with people of color reporting more instances of “othering” and discrimination. This study reveals a pressing need for increasing access to honors for minority students and improving the level of integration and retention among students currently enrolled

    How many species of fungi are there at the tip of Africa?

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    Several recent studies have reviewed the extent of fungal biodiversity, and have used these data as basis for revised estimates of species numbers based on known numbers of plants and insects. None of these studies, however, have focused on fungal biodiversity in South Africa. Coinciding with the 100th anniversary of the National Collection of Fungi (PREM) in South Africa in 2005, it is thus timely to reflect on the taxonomic research that has been conducted in South Africa over the past Century. Information is presented on the extent of fungal collections preserved at PREM, and the associated research publications that have largely resulted from this resource. These data are placed in context of the known plant and insect biodiversity, and used as basis to estimate the potential number of fungi that could be expected in South Africa. The conservative estimate is of approximately 200 000 species without taking into account those associated with a substantial insect biodiversity

    The Student Movement Volume 107 Issue 14: Week of Prayer, Wind Symphony, and Working at WAUS: Another Week at AU

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    HUMANS Andrews University Social Justice Club: Sara Santana, Interviewed by: Timmy Duado Honors Thesis Project: Alexander Hess, Interviewed by: Anna Pak Meet Reagan McCain of WAUS, Interviewed by: Nora Martin ARTS & ENTERTAINMENT Currently: MrBeast, Solana Campbell IN a World of Fascination: The Thematic Musicality of the AU Wind Symphony Concert, Bella Hamann Where Do I Find God - Part III, Anonymous NEWS Getting Unrealistic with Pastor Snell, Interviewed by: Gloria Oh New Recession Cracks Egg Economics Open, Andrew Francis What\u27s Happening in Peru?, Julia Randall IDEAS Facing the End of the World: What Apocalypse Stories Teach Us About Humanity, Isabella Koh I Knew You Were Trouble: On Ticketmaster\u27s Judiciary Hearing, Nora Martin Ron\u27s Gone Wrong: The Implications of the Stop W.O.K.E. Act, Bella Hamann PULSE Rutgers University Poet and Professor to Speak for Environmental Fridays, Desmond H. Murray Sex Education in the Adventist System, Zothile Sibanda Week of Prayer: Get Unrealistic, Amelia Stefanescu LAST WORD Knock Knock, Gio Leehttps://digitalcommons.andrews.edu/sm-107/1013/thumbnail.jp

    Interlaboratory comparison study of the Colony Forming Efficiency assay for assessing cytotoxicity of nanomaterials

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    Nanotechnology has gained importance in the past years as it provides opportunities for industrial growth and innovation. However, the increasing use of manufactured nanomaterials (NMs) in a number of commercial applications and consumer products raises also safety concerns and questions regarding potential unintended risks to humans and the environment. Since several years the European Commission’s Joint Research Centre (JRC) is putting effort in the development, optimisation and harmonisation of in vitro test methods suitable for screening and hazard assessment of NMs. Work is done in collaboration with international partners, in particular the Organisation for Economic Co-operation and Development (OECD). This report presents the results from an interlaboratory comparison study of the in vitro Colony Forming Efficiency (CFE) cytotoxicity assay performed in the frame of OECD's Working Party of Manufactured Nanomaterials (WPMN). Twelve laboratories from European Commission, France, Italy, Japan, Poland, Republic of Korea, South Africa and Switzerland participated in the study coordinated by JRC. The results show that the CFE assay is a suitable and robust in vitro method to assess cytotoxicity of NMs. The assay protocol is well defined and is easily and reliably transferable to other laboratories. The results obtained show good intra and interlaboratory reproducibility of the assay for both the positive control and the tested nanomaterials. In conclusion the CFE assay can be recommended as a building block of an in vitro testing battery for NMs toxicity assessment. It could be used as a first choice method to define dose-effect relationships for other in vitro assays.JRC.I.4-Nanobioscience

    Comparison of 2016–17 and Previous Epizootics of Highly Pathogenic Avian Influenza H5 Guangdong Lineage in Europe

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    We analyzed the highly pathogenic avian influenza (HPAI) H5 epizootic of 2016–17 in Europe by epidemiologic and genetic characteristics and compared it with 2 previous epizootics caused by the same H5 Guangdong lineage. The 2016–17 epizootic was the largest in Europe by number of countries and farms affected and greatest diversity of wild birds infected. We observed significant differences among the 3 epizootics regarding region affected, epidemic curve, seasonality, and outbreak duration, making it difficult to predict future HPAI epizootics. However, we know that in 2005–06 and 2016–17 the initial peak of wild bird detections preceded the peak of poultry outbreaks within Europe. Phylogenetic analysis of 2016–17 viruses indicates 2 main pathways into Europe. Our findings highlight the need for global surveillance of viral changes to inform disease preparedness, detection, and control

    BurstCube: A CubeSat for gravitational wave counterparts

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    BurstCube aims to expand sky coverage in order to detect, localize, and rapidly disseminate information about gamma-ray bursts (GRBs). BurstCube is a\u276U\u27 CubeSat with an instrument comprised of 4 Cesium Iodide (CsI) scintillators coupled to arrays of Silicon photo-multipliers (SiPMs) and will be sensitive to gamma-rays between 50 keV and 1 MeV. BurstCube will assist current observatories, such as Swift and Fermi, in the detection of GRBs as well as provide astronomical context to gravitational wave (GW) events detected by LIGO, Virgo, and KAGRA. BurstCube is currently in its development phase with a launch readiness date in early 2022

    COVID-19: Third dose booster vaccine effectiveness against breakthrough coronavirus infection, hospitalisations and death in patients with cancer: A population-based study

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    Purpose: People living with cancer and haematological malignancies are at increased risk of hospitalisation and death following infection with acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Coronavirus third dose vaccine boosters are proposed to boost waning immune responses in immunocompromised individuals and increase coronavirus protection; however, their effectiveness has not yet been systematically evaluated. Methods: This study is a population-scale real-world evaluation of the United Kingdom’s third dose vaccine booster programme for cancer patients from 8th December 2020 to 7th December 2021. The cancer cohort comprises individuals from Public Health England’s national cancer dataset, excluding individuals less than 18 years. A test-negative case-control design was used to assess third dose booster vaccine effectiveness. Multivariable logistic regression models were fitted to compare risk in the cancer cohort relative to the general population. Results: The cancer cohort comprised of 2,258,553 tests from 361,098 individuals. Third dose boosters were evaluated by reference to 87,039,743 polymerase chain reaction (PCR) coronavirus tests. Vaccine effectiveness against breakthrough infections, symptomatic infections, coronavirus hospitalisation and death in cancer patients were 59.1%, 62.8%, 80.5% and 94.5% respectively. Lower vaccine effectiveness was associated with a cancer diagnosis within 12 months, lymphoma, recent systemic anti-cancer therapy (SACT) or radiotherapy. Lymphoma patients had low levels of protection from symptomatic disease. In spite of third dose boosters, following multivariable adjustment, individuals with cancer remain at increased risk of coronavirus hospitalisation and death compared to the population control (OR 3.38, 3.01 respectively. p<0.001 for both). Conclusions: Third dose boosters are effective for most individuals with cancer, increasing protection from coronavirus. However, their effectiveness is heterogenous, and lower than the general population. Many patients with cancer will remain at increased risk of coronavirus infections, even after 3 doses. In the case of patients with lymphoma, there is a particularly strong disparity of vaccine effectiveness against breakthrough infection and severe disease. Breakthrough infections will disrupt cancer care and treatment with potentially adverse consequences on survival outcomes. The data support the role of vaccine boosters in preventing severe disease, and further pharmacological intervention to prevent transmission and aid viral clearance to limit disruption of cancer care as the delivery of care continues to evolve during the coronavirus pandemic
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