De la Mioglobina al SARS-CoV-2: ¡50 años del Protein Data Bank!

<p><span>La Mioglobina fue la primer proteína visualizada en tres dimensiones (3D) a través de la cristalografía de rayos-X, sentando las bases para una nueva era de comprensión biológica. A partir de este hecho, se comenzaron a determinar estructuralmente una serie de macromoléculas de considerable interés biológico. Sin embargo, este impresionante avance en las ciencias de la vida, contrastaba radicalmente con la ausencia de un repositorio global para archivar y compartir los datos cristalográficos colectados de los experimentos de difracción. Con el propósito de llenar este vacío, en 1971 se estableció el Protein Data Bank (PDB) en el Brookhaven National Laboratory, como el único almacén central de estructuras 3D de macromoléculas biológicas. Establecido con apenas siete estructuras, el PDB ha evolucionado a un gigantesco repositorio de acceso abierto, almacenando datos estructurales de más de 170,000 biomoléculas, principalmente de proteínas y ácidos nucleicos. Además de ser un banco de datos biológicos, el PDB sirve como un portal educativo a través del PDB-101, ofreciendo un conjunto de recursos extraordinarios para admirar el mundo biológico. En esta revisión, festejamos los 50 años de oro del PDB con una mirada a su historia y un recorrido por algunas herramientas educativas que el archivo pone a disposición de estudiantes, investigadores, profesores y público no especializado. Ilustramos el valor de estos recursos con la estructura 3D de la maquinaria biológica recientemente depositada en el archivo, del ubicuo y nuevo coronavirus causante del síndrome respiratorio agudo severo (SARS-CoV-2) o COVID-19.</span></p>

Implementation of ACTS into sPHENIX Track Reconstruction

AbstractsPHENIX is a high energy nuclear physics experiment under construction at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory (BNL). The primary physics goals of sPHENIX are to study the quark-gluon-plasma, as well as the partonic structure of protons and nuclei, by measuring jets, their substructure, and heavy flavor hadrons in $$p$$ p $$+$$ + $$p$$ p , p + Au, and Au + Au collisions. sPHENIX will collect approximately 300 PB of data over three run periods, to be analyzed using available computing resources at BNL; thus, performing track reconstruction in a timely manner is a challenge due to the high occupancy of heavy ion collision events. The sPHENIX experiment has recently implemented the A Common Tracking Software (ACTS) track reconstruction toolkit with the goal of reconstructing tracks with high efficiency and within a computational budget of 5 s per minimum bias event. This paper reports the performance status of ACTS as the default track fitting tool within sPHENIX, including discussion of the first implementation of a time projection chamber geometry within ACTS.

On the interpretation of annual oscillations in 32Si and 36Cl decay rate measurements

The 32Si decay rate measurement data of Alburger et al. obtained in 1982–1986 at Brookhaven National Laboratory have been presented repeatedly as evidence for solar neutrino-induced beta decay. The count rates show an annual sinusoidal oscillation of about 0.1% amplitude and maximum at February–March. Several authors have claimed that the annual oscillations could not be explained by environmental influences on the set-up, and they questioned the invariability of the decay constant. They hypothesised a correlation with changes in the solar neutrino flux due to annual variations in the Earth-Sun distance, in spite of an obvious mismatch in amplitude and phase. In this work, environmental conditions at the time of the experiment are presented. The 32Si decay rate measurements appear to be inversely correlated with the dew point in a nearby weather station. Susceptibility of the detection set-up to local temperature and humidity conditions is a likely cause of the observed instabilities in the measured decay rates. Similar conclusions apply to 36Cl decay rates measured at Ohio State University in 2005–2012.

Supersymmetric interpretation of the muon g – 2 anomaly

The Fermilab Muon g− 2 collaboration recently announced the first result of measurement of the muon anomalous magnetic moment (g− 2), which confirmed the previous result at the Brookhaven National Laboratory and thus the discrepancy with its Standard Model prediction. We revisit low-scale supersymmetric models that are naturally capable to solve the muon g− 2 anomaly, focusing on two distinct scenarios: chargino-contribution dominated and pure-bino-contribution dominated scenarios. It is shown that the slepton pair-production searches have excluded broad parameter spaces for both two scenarios, but they are not closed yet. For the chargino-dominated scenario, the models with $$ {m}_{{\tilde{\mu}}_{\mathrm{L}}}\gtrsim {m}_{{\tilde{\chi}}_1^{\pm }} $$ m μ ˜ L ≳ m χ ˜ 1 ± are still widely allowed. For the bino-dominated scenario, we find that, although slightly non-trivial, the region with low tan β with heavy higgsinos is preferred. In the case of universal slepton masses, the low mass regions with $$ {m}_{\tilde{\mu}} $$ m μ ˜ ≲ 230 GeV can explain the g− 2 anomaly while satisfying the LHC constraints. Furthermore, we checked that the stau-bino coannihilation works properly to realize the bino thermal relic dark matter. We also investigate heavy staus case for the bino-dominated scenario, where the parameter region that can explain the muon g− 2 anomaly is stretched to $$ {m}_{\tilde{\mu}} $$ m μ ˜ ≲ 1.3 TeV.

Texas A&M US Nuclear DATA Program

Nuclear data evaluation is an independent century-long expert activity accompanying the development of the nuclear physics science. Its goal is to produce periodic surveys of the world literature in order to recommend and maintain the set of the best nuclear data parameters of common use in all basic and applied sciences. After WWII the effort extended and while it became more international it continued to be supported mainly by the US for the benefit of the whole world. The Evaluated Nuclear Structure Data File (ENSDF) is the most comprehensive nuclear structure database worldwide maintained by the United States National Nuclear Data Center(NNDC)at Brookhaven National Laboratory(BNL)and echoed by the IAEA Vienna Nuclear Data Services. Part of the US Nuclear Data Program since 2005 the Cyclotron Institute is one of the important contributors to ENSDF. Since 2018 we became an international evaluation center working in a consortium of peers hosted traditionally by prestigious national institutes as well as universities. In this paper the main stages of the evaluation work are presented in order to facilitate a basic understanding of the process as a guide for our potential users. Our goals are to maintain a good productivity vs. quality performance assuring the currency of the data and participating in the effort of modernizing the structure of ENSDF databases in order to make them compatible with the data-centric paradigms of the future.

Measurement of Longitudinal Single-Spin Asymmetry for W± Production in Polarized Proton+Proton Collisions at STAR

The contribution from the sea quark polarization to the nucleon spin is an important piece for the complete understanding of the nucleon spin structure. The production of W ± bosons in longitudinally polarized p+p collisions at the RHIC collider at Brookhaven National Laboratory provides a unique probe of the sea quark polarization, through the parity-violating single-spin asymmetry, AL . At the STAR experiment, the W bosons that decay through the W → ev channel at mid-rapidity (|η <1.3) can be effectively determined with the Electromagnetic Calorimeters and Time Projection Chamber. The STAR measurements of AL for W boson from datasets taken in 2011 and 2012 at s =510 GeV have been included in the global analysis of polarized parton distribution functions, and provided significant constraints on the helicity distribution functions of u ¯ and d ¯ quarks. The final AL results from 2013 STAR data sample are reported, which is about three times larger than the total integrated luminosity of previous years. The combined results of AL for 2011-2013 data are also given. A flavor asymmetry of light sea quark helicity distribution, Δ u ¯ ( x ) − Δ d ¯ ( x ) > 0 , is confirmed from a re-weighting of global analysis NNPDFpol1.1 after including the new AL results. In addition, results on the double-spin asymmetries ALL for W ±, and AL for Z/γ* production are also reported.

Chiral Magnetic Effects in Nuclear Collisions

The interplay of quantum anomalies with strong magnetic fields and vorticity in chiral systems could lead to novel transport phenomena, such as the chiral magnetic effect (CME), the chiral magnetic wave (CMW), and the chiral vortical effect (CVE). In high-energy nuclear collisions, these chiral effects may survive the expansion of a quark–gluon plasma fireball and be detected in experiments. The experimental searches for the CME, the CMW, and the CVE have aroused extensive interest over the past couple of decades. The main goal of this article is to review the latest experimental progress in the search for these novel chiral transport phenomena at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN. Future programs to help reduce uncertainties and facilitate the interpretation of the data are also discussed.

Approaches for Surveying Cosmic Radiation Damage in Large Populations of Arabidopsis thaliana Seeds – Antarctic Balloons and Particle Beams

The Cosmic Ray Exposure Sequencing Science (CRESS) payload system was a proof of concept experiment to assess the genomic impact of space radiation on seeds. CRESS was designed as a secondary payload for the December 2016 high-altitude, long-duration south polar balloon flight carrying the Boron and Carbon Cosmic Rays in the Upper Stratosphere (BACCUS) experiment. Investigation of the biological effects of Galactic Cosmic Radiation (GCR), particularly those of ions with High-Z and Energy (HZE), was of interest due to the genomic damage this type of radiation inflicts. The biological effects of radiation above Antarctica (ANT) were studied using Arabidopsis thaliana seeds and compared to a simulation of GCR at Brookhaven National Laboratory (BNL) and to laboratory control seeds. The CRESS payload was broadly designed to 1U CubeSat specifications (10 cm × 10 cm × 10 cm, ≤1.33 kg), maintained 1 atm internal pressure, and carried an internal cargo of 580,000 seeds and twelve CR-39 Solid-State Nuclear Track Detectors (SSNTDs). Exposed BNL and ANT M0 seeds showed significantly reduced germination rates and elevated somatic mutation rates when compared to non-irradiated controls, with the BNL mutation rate also being higher than that of ANT. Genomic DNA from plants presenting distinct aberrant phenotypes was evaluated with whole-genome sequencing using PacBio SMRT technology, which revealed an array of structural genome variants in the M0 and M1 plants. This study was the first whole-genome characterization of space-irradiated seeds and demonstrated both the efficiency and efficacy of Antarctic long-duration balloons for the study of space radiation effects on eukaryote genomes.