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Radium has four naturally occurring isotopes that have proven useful in constraining water mass source, age, and mixing rates in the coastal and open ocean. In this study, we used radium isotopes to determine the fate and flux of runoff-derived cesium from the Fukushima Dai-ichi Nuclear Power Plant (FNPP). During a June 2011 cruise, the highest cesium (Cs) concentrations were found along the eastern shelf of northern Japan, from Fukushima south, to the edge of the Kuroshio Current, and in an eddy ~ 130 km from the FNPP site. Locations with the highest cesium also had some of the highest radium activities, suggesting much of the direct ocean discharges of Cs remained in the coastal zone 2–3 months after the accident. We used a short-lived Ra isotope (223Ra, t1/2 = 11.4 d) to derive an average water mass age (Tr) in the coastal zone of 32 days. To ground-truth the Ra age model, we conducted a direct, station-by-station comparison of water mass ages with a numerical oceanographic model and found them to be in excellent agreement (model avg. Tr = 27 days). From these independent Tr values and the inventory of Cs within the water column at the time of our cruise, we were able to calculate an offshore 134Cs flux of 3.9–4.6 × 1013 Bq d−1. Radium-228 (t1/2 = 5.75 yr) was used to derive a vertical eddy diffusivity (Kz) of 0.7 m2 d−1 (0.1 cm2 s−1); from this Kz and 134Cs inventory, we estimated a 134Cs flux across the pycnocline of 1.8 × 104 Bq d−1 for the same time period. On average, our results show that horizontal mixing loss of Cs from the coastal zone was ~ 109 greater than vertical exchange below the surface mixed layer. Finally, a mixing/dilution model that utilized our Ra-based and oceanographic model water mass ages produced a direct ocean discharge of 134Cs from the FNPP of 11–16 PBq at the time of the peak release in early April 2011. Our results can be used to calculate discharge of other water-soluble radionuclides that were released to the ocean directly from the Fukushima NPP.

Molecular spectroscopy offers opportunities for the exploration of the fundamental laws of nature and the search for new particle physics beyond the standard model 1 – 4 . Radioactive molecules—in which one or more of the atoms possesses a radioactive nucleus—can contain heavy and deformed nuclei, offering high sensitivity for investigating parity- and time-reversal-violation effects 5 , 6 . Radium monofluoride, RaF, is of particular interest because it is predicted to have an electronic structure appropriate for laser cooling 6 , thus paving the way for its use in high-precision spectroscopic studies. Furthermore, the effects of symmetry-violating nuclear moments are strongly enhanced 5 , 7 – 9 in molecules containing octupole-deformed radium isotopes 10 , 11 . However, the study of RaF has been impeded by the lack of stable isotopes of radium. Here we present an experimental approach to studying short-lived radioactive molecules, which allows us to measure molecules with lifetimes of just tens of milliseconds. Energetically low-lying electronic states were measured for different isotopically pure RaF molecules using collinear resonance ionisation at the ISOLDE ion-beam facility at CERN. Our results provide evidence of the existence of a suitable laser-cooling scheme for these molecules and represent a key step towards high-precision studies in these systems. Our findings will enable further studies of short-lived radioactive molecules for fundamental physics research. Measurements of low-energy electronic states of radium monofluoride validate predictions of the use of this short-lived radioactive molecule in exploring fundamental physics and provide evidence of its suitability for laser cooling.

Molecules containing heavy radioactive nuclei are predicted to be extremely sensitive to violations of the fundamental symmetries of nature. The nuclear octupole deformation of certain radium isotopes massively boosts the sensitivity of radium monofluoride molecules to symmetry-violating nuclear properties. Moreover, these molecules are predicted to be laser coolable. Here we report measurements of the rovibronic structure of radium monofluoride molecules, which allow the determination of their laser cooling scheme. We demonstrate an improvement in resolution of more than two orders of magnitude compared to the state of the art. Our developments allowed measurements of minuscule amounts of hot molecules, with only a few hundred per second produced in a particular rotational state. The combined precision and sensitivity achieved in this work offer opportunities for studies of radioactive molecules of interest in fundamental physics, chemistry and astrophysics. Measurements of the rovibronic structure of radium monofluoride molecules allow the identification of a laser cooling scheme. This will enable precise tests of fundamental physics, such as searches for parity or time-reversal symmetry violation.

We have used a translational convergent functional genomics (CFG) approach to identify and prioritize genes involved in schizophrenia, by gene-level integration of genome-wide association study data with other genetic and gene expression studies in humans and animal models. Using this polyevidence scoring and pathway analyses, we identify top genes (DISC1, TCF4, MBP, MOBP, NCAM1, NRCAM, NDUFV2, RAB18, as well as ADCYAP1, BDNF, CNR1, COMT, DRD2, DTNBP1, GAD1, GRIA1, GRIN2B, HTR2A, NRG1, RELN, SNAP-25, TNIK), brain development, myelination, cell adhesion, glutamate receptor signaling, G-protein–coupled receptor signaling and cAMP-mediated signaling as key to pathophysiology and as targets for therapeutic intervention. Overall, the data are consistent with a model of disrupted connectivity in schizophrenia, resulting from the effects of neurodevelopmental environmental stress on a background of genetic vulnerability. In addition, we show how the top candidate genes identified by CFG can be used to generate a genetic risk prediction score (GRPS) to aid schizophrenia diagnostics, with predictive ability in independent cohorts. The GRPS also differentiates classic age of onset schizophrenia from early onset and late-onset disease. We also show, in three independent cohorts, two European American and one African American, increasing overlap, reproducibility and consistency of findings from single-nucleotide polymorphisms to genes, then genes prioritized by CFG, and ultimately at the level of biological pathways and mechanisms. Finally, we compared our top candidate genes for schizophrenia from this analysis with top candidate genes for bipolar disorder and anxiety disorders from previous CFG analyses conducted by us, as well as findings from the fields of autism and Alzheimer. Overall, our work maps the genomic and biological landscape for schizophrenia, providing leads towards a better understanding of illness, diagnostics and therapeutics. It also reveals the significant genetic overlap with other major psychiatric disorder domains, suggesting the need for improved nosology.

In recent times, the sensitivity of low-mass direct dark matter searches has been limited by unknown low energy backgrounds close to the energy threshold of the experiments known as the low energy excess (LEE). The CRESST experiment utilises advanced cryogenic detectors constructed with different types of crystals equipped with Transition Edge Sensors (TESs) to measure signals of nuclear recoils induced by the scattering of dark matter particles in the detector. In CRESST, this low energy background manifests itself as a steeply rising population of events below 200 eV. A novel detector design named doubleTES using two identical TESs on the target crystal was studied to investigate the hypothesis that the events are sensor-related. We present the first results from two such modules, demonstrating their ability to differentiate between events originating from the crystal’s bulk and those occurring in the sensor or in its close proximity.

Diamond operated as a cryogenic calorimeter is an excellent target for direct detection of low-mass dark matter candidates. Following the realization of the first low-threshold cryogenic detector that uses diamond as absorber for astroparticle physics applications, we now present the resulting exclusion limits on the elastic spin-independent interaction cross-section of dark matter with diamond. We measured two 0.175 g CVD (Chemical Vapor Deposition) diamond samples, each instrumented with a Transition Edge Sensor made of Tungsten (W-TES). Thanks to the energy threshold of just 16.8 eV of one of the two detectors, we set exclusion limits on the elastic spin-independent interaction of dark matter particles with carbon nuclei down to dark matter masses as low as 0.122 GeV/c 2 . This work shows the scientific potential of cryogenic detectors made from diamond and lays the foundation for the use of this material as target for direct detection dark matter experiments.

Highly accurate and precise electronic structure calculations of heavy radioactive atoms and their molecules are important for several research areas, including chemical, nuclear, and particle physics. Ab initio quantum chemistry can elucidate structural details in these systems that emerge from the interplay of relativistic and electron correlation effects, but the large number of electrons complicates the calculations, and the scarcity of experiments prevents insightful theory-experiment comparisons. Here we report the spectroscopy of the 14 lowest excited electronic states in the radioactive molecule radium monofluoride (RaF), which is proposed as a sensitive probe for searches of new physics. The observed excitation energies are compared with state-of-the-art relativistic Fock-space coupled cluster calculations, which achieve an agreement of ≥99.64% (within  ~12 meV) with experiment for all states. Guided by theory, a firm assignment of the angular momentum and term symbol is made for 10 states and a tentative assignment for 4 states. The role of high-order electron correlation and quantum electrodynamics effects in the excitation energies is studied and found to be important for all states. Heavy-atom molecules can possess complicated electronic structures due to pronounced electron correlation and relativistic effects. Here, the authors describe electronic states of RaF in detail by combining accurate spectroscopy and theory approaches.

Abstract The objective was to evaluate the sensitivity of Piptadenia gonoacantha seeds to desiccation and storage conditions. The seeds were subjected to artificial drying in a forced air convection oven (39.7 °C ± 0.78 and 28.1% ± 1.90 RH) for different periods. After each drying period, evaluation methods were performed to determine the seeds water content and germination (germination test). The seeds were divided into two lots in the storage experiment: with previous drying (at 6.0% water content) and without previous drying (control, at 11% water content), and were stored for 36 months in a plastic bag in three conditions: refrigerator at 5 °C, freezer at -20 °C and natural condition (29 °C). The seeds were removed every three months and subjected to water content measurement and germination tests. The reduction of the initial water content of the seeds from 14% to 6% upon artificial drying resulted in the loss of 1/3 of their viability, suggesting that the seeds are sensitive to desiccation. The best practice to store seeds of P. gonoacantha found in this study was without previous drying, into the freezer. The seeds lost only 14% of their germination after 36 months under these conditions. Resumo O objetivo foi avaliar a sensibilidade de sementes de Piptadenia gonoacantha às condições de dessecação e armazenamento. As sementes foram submetidas à secagem artificial em câmara com circulação forçada de ar (39,7°C ± 0,78 e 28,1% ± 1,90 UR) por diferentes períodos. Após cada período de secagem, as sementes foram avaliadas quanto ao teor de água e à germinação. As sementes foram divididas em dois lotes no experimento de armazenamento: com secagem prévia (a 6,0% de teor de água) e sem secagem prévia (controle, a 11% de teor de água), e foram armazenadas por 36 meses em saco plástico em três ambientes: geladeira à 5 °C, freezer a -20 °C e ambiente natural (29 °C). As sementes foram retiradas a cada três meses e submetidas a aferição do teor de água e teste de germinação. A redução do teor inicial de água das sementes de 14% para 6% com a secagem artificial resultou na perda de 1/3 de sua viabilidade, sugerindo que a espécie seja sensível à dessecação. A melhor forma de armazenar as sementes de P. gonoacantha foi sem secagem prévia em freezer. Nestas condições, as sementes perderam somente 14% da germinação após 36 meses.

Cryogenic scintillating calorimeters are ultra- sensitive particle detectors for rare event searches, particularly for the search for dark matter and the measurement of neutrino properties. These detectors are made from scintillating target crystals generating two signals for each particle interaction. The phonon (heat) signal precisely measures the deposited energy independent of the type of interacting particle. The scintillation light signal yields particle discrimination on an event-by-event basis. This paper presents a likelihood framework modeling backgrounds and a potential dark matter signal in the two-dimensional plane spanned by phonon and scintillation light energies. We apply the framework to data from CaWO 4 -based detectors operated in the CRESST dark matter search. For the first time, a single likelihood framework is used in CRESST to model the data and extract results on dark matter in one step by using a profile likelihood ratio test. Our framework simultaneously fits (neutron) calibration data and physics (background) data and allows combining data from multiple detectors. Although tailored to CaWO 4 -targets and the CRESST experiment, the framework can easily be expanded to other materials and experiments using scintillating cryogenic calorimeters for dark matter search and neutrino physics.