Creating and Probing Electron Whispering Gallery Modes in Graphene

Designing high-finesse resonant cavities for electronic waves faces challenges due to short electron coherence lengths in solids. Previous approaches, e.g. the seminal nanometer-sized quantum corrals, depend on careful positioning of adatoms at clean surfaces. Here we demonstrate an entirely different approach, inspired by the peculiar acoustic phenomena in whispering galleries. Taking advantage of graphene's unique properties, namely gate-tunable light-like carriers, we create Whispering Gallery Mode (WGM) resonators defined by circular pn-junctions, induced by a scanning tunneling probe. We can tune the resonator size and the carrier concentration under the probe in a back-gated graphene device over a wide range, independently and in situ. The confined modes, revealed through characteristic resonances in the tunneling spectrum, originate from Klein scattering at pn junction boundaries. The WGM-type confinement and resonances are a new addition to the quantum electron-optics toolbox, paving the way to real-world electronic lenses and resonators

Interannual variability in carbon dioxide fluxes and flux–climate relationships on grazed and ungrazed northern mixed-grass prairie

The annual carbon (C) budget of grasslands is highly dynamic, dependent on grazing history and on effects of interannual variability (IAV) in climate on carbon dioxide (CO2) fluxes. Variability in climatic drivers may directly affect fluxes, but also may indirectly affect fluxes by altering the response of the biota to the environment, an effect termed ‘functional change’

Interaction Driven Quantum Hall Wedding cake-like Structures in Graphene Quantum Dots

Quantum-relativistic matter is ubiquitous in nature; however it is notoriously difficult to probe. The ease with which external electric and magnetic fields can be introduced in graphene opens a door to creating a table-top prototype of strongly confined relativistic matter. Here, through a detailed spectroscopic mapping, we provide a spatial visualization of the interplay between spatial and magnetic confinement in a circular graphene resonator. We directly observe the development of a multi-tiered "wedding cake"-like structure of concentric regions of compressible/incompressible quantum Hall states, a signature of electron interactions in the system. Solid-state experiments can therefore yield insights into the behaviour of quantum-relativistic matter under extreme conditions

Applying a menthol pain reliever prior to strength training reduces chronic low back pain and increases functional capacity in overweight or obese older adult

The combined effect of a muscle strength training program with the previous application of a topical menthol gel on the intensity of chronic low back pain (CLP) and the functional capacity of overweight/obese older women was evaluated. A randomized controlled clinical trial with parallel group comparison was conducted. In Phase 1 (12-weeks), 31 women were randomly assigned: (i) a control group that did not change their habits (CG; n = 11); (ii) group of strength training prior to application of a gel with menthol (RTM; n = 10) and (iii) group that performed the same training prior to application of a placebo gel (RTP; n = 10). After 12 weeks of no training, phase 2 of the study (32-week duration) was run, where the RTM and RTP women were randomly reassigned. It was evaluated before and after each phase: body composition, functional capacity, pain perception and Oswestry disability index. The significance level established for the study was p ≤ .05. Both training groups significantly improved all variables after stages 1 and 2, with significant post-intervention differences but no significant intergroup differences, although RTM obtained better results. The percentage of improvement in pain perception and functional parameters were related to the intervention time without positive effects for CG. In conclusion, the use of menthol gel prior to a muscle strength program reduced pain and enhanced the functional improvements achieved as a result of moderate-high intensity training in older adult women with CLP and overweight or obesity

FROM SCHOOL TO HOME: UNDERSTANDING THE EXPERIENCES OF PARENTS AND LEARNERS IN MODULAR LEARNING

The emergence of the COVID-19 pandemic brought a major shift in the delivery of instruction. Parents and learners were caught unprepared for this situation. As such, this study aimed to describe the experiences of parents and learners in modular learning. Following a phenomenological approach, 10 parents and 30 learners from the Schools Division of the City of Batac underwent unstructured interviews via home visits, phone calls, and messenger calls. It adopted the Hycner transcription analysis methodology for the data analysis. Findings revealed that parents’ experiences could be described along four themes: multiple roles, learning management challenges, home learning strategies, and support systems. Meanwhile, learners’ experiences were revealed by these four themes: learning preferences, learning struggles, learning strategies, and learning support. Interestingly, these experiences magnify the need for attention to shared responsibility, understanding, cooperation, commitment, and compassion for modular learning to succeed in the context of a pandemic. Furthermore, the findings could serve as a basis for providing comprehensive and inclusive educational policies that facilitate the adjustments of learners and parents in a new learning setup. As such, schools can create and implement more adoptive, relevant, and inclusive institutional plans, projects, activities, and programs for the attainment of optimum learning gains. &nbsp

Glomerulonefritis proliferativa extracapilar pauciinmune, una manifestación paraneoplásica inusual asociada a linfoma B del manto

The relationship between neoplasia and secondary renal involvement is increasing. Membranous glomerulonephritis is the main cause of nephrotic syndrome, associated with solid tumors, and less frequently hematologic neoplasia. Hodgkin’s lymphoma is the hematologic neoplasia most closely associated with minimal change disease. However, there are case reports that describe a relationship with non-Hodgkin’s lymphomas and leukemias. The usual clinical manifestation is the nephrotic syndrome,which may precede for several months or coexist with the diagnosis of lymphoma. Its pathophysiology is not very clear. It is suggested that it is related to T lymphocyte dysfunction. In addition, there are reports of thrombotic microangiopathy, related to the use of biological therapy and antineoplastic agents.Rapidly progressive glomerulonephritis is a clinical syndrome associated with glomerular extracapillary proliferation, usually related to vasculitis associated with ANCA and vasculitis mediated by immunocomplexes. Neoplasias are also related to a large number of vasculopathies. Glomerulonephritis with extracapillary proliferation are much more common in malignant solid tumors. In addition, associations with myelodysplastic syndrome, chronic lymphocytic leukemia and Hodgking lymphoma have been reported. The association between Mantle Cell B lymphomas and glomerulonephritis with extracapillary proliferation is unusual. The following is a case of a patient diagnosed with Mantle Cell B lymphoma who has a rapidly progressive glomerulonephritis secondary to extracapillary, necrotizing and pauci-immune proliferative lesions.La relación entre neoplasia y compromiso renal secundario es creciente. La glomerulonefritis membranosa es la principal causa de síndrome nefrótico asociado a tumores sólidos y con menos frecuencia a neoplasia hematológica. El linfoma Hodgkin es la neoplasia hematológica que más se relaciona con enfermedad de cambios mínimos. Sin embargo, hay reportes de casos que describen una relación con linfomas no Hodgkin y leucemias. La manifestación clínica usual es el síndrome nefrótico; el cual puede preceder por varios meses o coexistir con el diagnóstico de linfoma. La fisiopatogénesis no está muy clara. Se sugiere que está relacionada con una disfunción del linfocito T. Adicionalmente, hay reportes de microangiopatía trombótica relacionada con el uso de terapia biológica y antineoplásicos.La glomerulonefritis rápidamente progresiva, es un síndrome clínico asociado a proliferación extracapilar glomerular; usualmente relacionado con vasculitis asociadas a ANCAS y vasculitis mediadas por inmunocomplejos. Las neoplasias también están relacionadas con un amplio número de vasculopatías. Las glomerulonefritis con proliferación extracapilar son mucho más frecuentes en tumores sólidos malignos.Además, se han descrito asociaciones con síndrome mielodisplásico, leucemia linfocítica crónica y linfoma Hodgkin. La asociación entre linfomas B del manto y glomerulonefritis con proliferación extracapilar, esinusual.A continuación, se describe un caso de un paciente con diagnóstico de linfoma B del manto que cursa con una glomerulonefritis rápidamente progresiva secundaria a lesiones proliferativas extracapilares, necrosantes y pauciinmunitaria

A complete view of galaxy evolution: panchromatic luminosity functions and the generation of metals

When and how did galaxies form and their metals accumulate? Over the last decade, this has moved from an archeological question to a live investigation: there is now a broad picture of the evolution of galaxies in dark matter halos: their masses, stars, metals and supermassive blackholes. Galaxies have been found and studied in which these formation processes are taking place most vigorously, all the way back in cosmic time to when the intergalactic medium (IGM) was still largely neutral. However, the details of how and why the interstellar medium (ISM) in distant galaxies cools, is processed, recycled and enriched in metals by stars, and fuels active galactic nuclei (AGNs) remain uncertain. In particular, the cooling of gas to fuel star formation, and the chemistry and physics of the most intensely active regions is hidden from view at optical wavelengths, but can be seen and diagnosed at mid- & far-infrared (IR) wavelengths. Rest-frame IR observations are important first to identify the most luminous, interesting and important galaxies, secondly to quantify accurately their total luminosity, and finally to use spectroscopy to trace the conditions in the molecular and atomic gas out of which stars form. In order to map out these processes over the full range of environments and large-scale structures found in the universe - from the densest clusters of galaxies to the emptiest voids - we require tools for deep, large area surveys, of millions of galaxies out to z~5, and for detailed follow-up spectroscopy. The necessary tools can be realized technically. Here, we outline the requirements for gathering the crucial information to build, validate and challenge models of galaxy evolution.Comment: A whitepaper submitted on 15th February 2009 in response to the call from the Astro2010 panel: astro2010.org; uploaded as an 8-page pdf fil

Evidence Against the Sciama Model of Radiative Decay of Massive Neutrinos

We report on spectral observations of the night sky in the band around 900 angstroms where the emission line in the Sciama model of radiatively decaying massive neutrinos would be present. The data were obtained with a high resolution, high sensitivity spectrometer flown on the Spanish MINISAT satellite. The observed emission is far less intense than that expected in the Sciama model.Comment: 9 pages, accepted to Ap