Searching for MHz gravitational waves from harmonic sources

A MHz gravitational wave search for harmonic sources was conducted using a 704 h dataset obtained from the Holometer, a pair of 40 m power recycled Michelson interferometers. Our search was designed to look for cosmic string loops and eccentric black hole binaries in an entirely unexplored frequency range from 1 to 25 MHz. The measured cross-spectral density between both interferometers was used to perform four different searches. First, we search to identify any fundamental frequencies bins that have excess power above 5σ. Second, we reduce the per-bin threshold on any individual frequency bin by employing that a fundamental frequency and its harmonics all collectively lie above a threshold. We vary the number of harmonics searched over from n = 4 up to n = 23. Third, we perform an agnostic approach to identify harmonic candidates that may have a single contaminated frequency bin or follow a power-law dependence. Lastly, we expand on the agnostic approach for individual candidates and search for a potential underlying population of harmonic sources. Each method was tested on the interferometer dataset, as well as a dark noise, photon shot-noise-limited, and simulated Gaussian-noise datasets. We conclude that these four different search methods did not find any candidate frequencies that would be consistent with harmonic sources. This work presents a new way of searching for gravitational wave candidates, which allowed us to survey a previously unexplored frequency range

Searching for MHz gravitational waves from harmonic sources

A MHz gravitational wave search for harmonic sources was conducted using a 704 h dataset obtained from the Holometer, a pair of 40 m power recycled Michelson interferometers. Our search was designed to look for cosmic string loops and eccentric black hole binaries in an entirely unexplored frequency range from 1 to 25 MHz. The measured cross-spectral density between both interferometers was used to perform four different searches. First, we search to identify any fundamental frequencies bins that have excess power above 5σ. Second, we reduce the per-bin threshold on any individual frequency bin by employing that a fundamental frequency and its harmonics all collectively lie above a threshold. We vary the number of harmonics searched over from n = 4 up to n = 23. Third, we perform an agnostic approach to identify harmonic candidates that may have a single contaminated frequency bin or follow a power-law dependence. Lastly, we expand on the agnostic approach for individual candidates and search for a potential underlying population of harmonic sources. Each method was tested on the interferometer dataset, as well as a dark noise, photon shot-noise-limited, and simulated Gaussian-noise datasets. We conclude that these four different search methods did not find any candidate frequencies that would be consistent with harmonic sources. This work presents a new way of searching for gravitational wave candidates, which allowed us to survey a previously unexplored frequency range

The [Ne III]/[Ne II] line ratio in NGC 253

We present results of the mapping of the nucleus of the starburst galaxy NGC 253 and its immediate surroundings using the Infrared Spectrograph on board the Spitzer Space Telescope. The map is centered on the nucleus of the galaxy and spans the inner 800 × 688 pc^2. We perform a brief investigation of the implications of these measurement on the properties of the star formation in this region using theories developed to explain the deficiency of massive stars in starbursts

The timeline of epigenetic drug discovery:from reality to dreams

The flexibility of the epigenome has generated an enticing argument to explore its reversion through pharmacological treatments as a strategy to ameliorate disease phenotypes. All three families of epigenetic proteins-readers, writers, and erasers- A re druggable targets that can be addressed through small-molecule inhibitors. At present, a few drugs targeting epigenetic enzymes as well as analogues of epigenetic modifications have been introduced into the clinic use (e.g. to treat haematological malignancies), and a wide range of epigenetic-based drugs are undergoing clinical trials. Here, we describe the timeline of epigenetic drug discovery and development beginning with the early design based solely on phenotypic observations to the state-of-the-art rational epigenetic drug discovery using validated targets. Finally, we will highlight some of the major aspects that need further research and discuss the challenges that need to be overcome to implement epigenetic drug discovery into clinical management of human disorders. To turn into reality, researchers from various disciplines (chemists, biologists, clinicians) need to work together to optimise the drug engineering, read-out assays, and clinical trial design

Microbially-induced sedimentary structures (MISS) in the Puerto Rosales tidal flat, Bahía Blanca estuary

El estudio de matas microbianas en ambientes marinos costeros silicoclásticos actuales constituye una importante fuente de información para el análisis de análogos fósiles. En el estuario de Bahía Blanca se estudiaron planicies de marea cubiertas por matas desde un enfoque geobiológico, con el objetivo de identificar y describir estructuras inducidas por actividad microbiana (ESIAM), y distinguir rasgos presentes en los sistemas actuales que permitan reconocer estas comunidades de microorganismos en depósitos fósiles. Se realizaron muestreos biológicos y sedimentológicos, y se implementaron técnicas de microscopía óptica y electrónica para la determinación de microorganismos y la identificación de texturas características y minerales autigénicos. Las matas microbianas resultaron estar dominadas por cianobacterias y, en menor proporción, diatomeas; microorganismos que generan sustancias exopoliméricas que bioestabilizan la superficie sedimentaria. Se reconocieron texturas típicas de matas epibentónicas, tales como granos orientados y granos pequeños unidos por la mata, pirita framboidal y ceolitas. En la zona intermareal-supramareal se identificaron domos de gas, fábrica porosa esponjosa y superficies tipo colador. Además se observaron grietas de contracción, dobleces, fragmentos de mata, depresiones y remanentes erosivos, pliegues y arrugas, así como también ondulitas multidireccionales. Las estructuras halladas están relacionadas con condiciones de calma/latencia, exposición prolongada (desecación) y eventos de tormenta con alta energía erosiva sobre la planicie (olas y corrientes fuertes). En este sentido, las ESIAM resultan importantes indicadoras de condiciones ambientales particulares que presentan un elevado potencial de preservación. Su reconocimiento en el registro fósil, a través de rasgos macro y microscópicos, permiten refinar las interpretaciones paleoambientales en sucesiones marino-costeras.The study of microbial mats in modern siliciclastic coastal marine settings represents an important analogue for the analysis of fossil deposits in similar paleoenvironments. In the Bahía Blanca estuary, mat-covered tidal flats were studied from a geobiological perspective with the aims of identifying and describing microbially-induced sedimentary structures (MISS), and to distinguish features in modern systems that allow the recognition of such microbial communities in fossil deposits. Systematic biological and sedimentological samplings were carried out, and the identification of microorganisms and the recognition and characterization of typical textures and authigenic minerals were performed through light and electronic microscopy techniques. Microbial mats were dominated by cyanobateria, followed by diatoms; both groups of microorganisms are known to secrete extracellular polymeric substances (EPS) and biostabilize the sedimentary surface. Characteristic textures of epibenthic mats, such as oriented grains and mat-bound small grains, framboidal pyrite and zeolites were recognized. In the intertidal-supratidal zone, MISS termed gas domes, sponge pore fabric, and sieve-like surfaces were identified. Moreover, shrinkage cracks, flip-overs, mat chips, erosional remnants and pockets, folds, as well as multidirected ripple marks were observed. These structures are related to calm conditions/latencies, prolonged subaerial exposure (desiccation), and storm events with high hydrodynamic energy (erosive) acting over the tidal flat (e.g. waves and currents). In this sense, MISS constitute important indicators of specific environmental conditions and thus their recognition in the rock record allows a refined interpretation of the paleoenvironment in coastal marine successions.Fil: Bournod, Constanza Naimé. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: Cuadrado, Diana G.. Universidad Nacional del Sur. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: Carmona, Noelia Beatriz. Universidad Nacional de Rio Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiologia y Geologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ponce, Juan Jose. Universidad Nacional de Rio Negro. Sede Alto Valle. Instituto de Investigaciones En Paleobiologia y Geologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pan, Jeronimo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Marinas; Argentin

Flat-band localization and interaction-induced delocalization of photons

Advances in quantum engineering have enabled the design, measurement, and precise control of synthetic condensed matter systems. The platform of superconducting circuits offers two particular capabilities: flexible connectivity of circuit elements that enables a variety of lattice geometries, and circuit nonlinearity that provides access to strongly interacting physics. Separately, these features have allowed for the creation of curved-space lattices and the realization of strongly correlated phases and dynamics in one-dimensional chains and square lattices. Missing in this suite of simulations is the simultaneous integration of interacting particles into lattices with unique band dispersions, such as dispersionless flat bands. An ideal building block for flat-band physics is the Aharonov-Bohm cage: a single plaquette of a lattice whose band structure consists entirely of flat bands. Here, we experimentally construct an Aharonov-Bohm cage and observe the localization of a single photon, the hallmark of all-bands-flat physics. Upon placing an interaction-bound photon pair into the cage, we see a delocalized walk indicating an escape from Aharonov-Bohm caging. We further find that a variation of caging persists for two particles initialized on opposite sites of the cage. These results mark the first experimental observation of a quantum walk that becomes delocalized due to interactions and establish superconducting circuits for studies of flat-band-lattice dynamics with strong interactions.Comment: 8 + 9 pages, 4 + 12 figures, 0 + 2 tables; modified title, added a supplementary figure, and modified the definition used for tunneling tim

To expand coverage, or increase frequency: Quantifying the tradeoffs between equity and efficiency facing cervical cancer screening programs in low‐resource settings

Cervical cancer is a leading cause of cancer death worldwide, with 85% of the disease burden residing in less developed regions. To inform evidence‐based decision‐making as cervical cancer screening programs are planned, implemented, and scaled in low‐ and middle‐income countries, we used cost and test performance data from the START‐UP demonstration project in Uganda and a microsimulation model of HPV infection and cervical carcinogenesis to quantify the health benefits, distributional equity, cost‐effectiveness, and financial impact of either (1) improving access to cervical cancer screening or (2) increasing the number of lifetime screening opportunities for women who already have access. We found that when baseline screening coverage was low (i.e., 30%), expanding coverage of screening once in a lifetime to 50% can yield comparable reductions in cancer risk to screening two or three times in a lifetime at 30% coverage, lead to greater reductions in health disparities, and cost 150 international dollars (I$) per year of life saved (YLS). At higher baseline screening coverage levels (i.e., 70$590 per YLS) below Uganda's per capita GDP. Given very low baseline coverage at present, we conclude that a policy focus on increasing access for previously unscreened women appears to be more compatible with improving both equity and efficiency than a focus on increasing frequency for a small subset of women