Testing and improving the IntCal20 calibration curve with independent records

Connecting calendar ages to radiocarbon (14C) ages, i.e. constructing a calibration curve, requires 14C samples that represent, or are closely connected to, atmospheric 14C values and that can also be independently dated. In addition to these data, there is information that can serve as independent tests of the calibration curve. For example, information from ice core radionuclide data cannot be directly incorporated into the calibration curve construction as it delivers less direct information on the 14C age–calendar age relationship but it can provide tests of the quality of the calibration curve. Furthermore, ice core ages on 14C-dated volcanic eruptions provide key information on the agreement of ice core and radiocarbon time scales. Due to their scarcity such data would have little impact if directly incorporated into the calibration curve. However, these serve as important “anchor points” in time for independently testing the calibration curve and/or ice-core time scales. Here we will show that such information largely supports the new IntCal20 calibration record. Furthermore, we discuss how floating tree-ring sequences on ice-core time scales agree with the new calibration curve. For the period around 40,000 years ago we discuss unresolved differences between ice core 10Be and 14C records that are possibly related to our limited understanding of carbon cycle influences on the atmospheric 14C concentration during the last glacial period. Finally, we review the results on the time scale comparison between the Greenland ice-core time scale (GICC05) and IntCal20 that effectively allow a direct comparison of 14C-dated records with the Greenland ice core data

Evidence for Shape Co-existence at medium spin in 76Rb

Four previously known rotational bands in 76Rb have been extended to moderate spins using the Gammasphere and Microball gamma ray and charged particle detector arrays and the 40Ca(40Ca,3pn) reaction at a beam energy of 165 MeV. The properties of two of the negative-parity bands can only readily be interpreted in terms of the highly successful Cranked Nilsson-Strutinsky model calculations if they have the same configuration in terms of the number of g9/2 particles, but they result from different nuclear shapes (one near-oblate and the other near-prolate). These data appear to constitute a unique example of shape co-existing structures at medium spins.Comment: Accepted for publication in Physics Letters

Short time evolved wave functions for solving quantum many-body problems

The exact ground state of a strongly interacting quantum many-body system can be obtained by evolving a trial state with finite overlap with the ground state to infinite imaginary time. In this work, we use a newly discovered fourth order positive factorization scheme which requires knowing both the potential and its gradients. We show that the resultaing fourth order wave function alone, without further iterations, gives an excellent description of strongly interacting quantum systems such as liquid 4He, comparable to the best variational results in the literature.Comment: 5 pages, 3 figures, 1 tabl

Drug interaction potential of high-dose rifampicin in patients with pulmonary tuberculosis

Accumulating evidence supports the use of higher doses of rifampicin for tuberculosis (TB) treatment. Rifampicin is a potent inducer of metabolic enzymes and drug transporters, resulting in clinically relevant drug interactions. To assess the drug interaction potential of higher doses of rifampicin, we compared the effect of high-dose rifampicin (40 mg/kg daily, RIF40) and standard-dose rifampicin (10 mg/kg daily, RIF10) on the activities of major cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp). In this open-label, single-arm, two-period, fixed-order phenotyping cocktail study, adult participants with pulmonary TB received RIF10 (days 1-15), followed by RIF40 (days 16-30). A single dose of selective substrates (probe drugs) was administered orally on days 15 and 30: caffeine (CYP1A2), tolbutamide (CYP2C9), omeprazole (CYP2C19), dextromethorphan (CYP2D6), midazolam (CYP3A), and digoxin (P-gp). Intensive pharmacokinetic blood sampling was performed over 24 hours after probe drug intake. In all, 25 participants completed the study. Geometric mean ratios (90% confidence interval) of the total exposure (area under the concentration versus time curve, RIF40 versus RIF10) for each of the probe drugs were as follows: caffeine, 105% (96%-115%); tolbutamide, 80% (74%-86%); omeprazole, 55% (47%-65%); dextromethorphan, 77% (68%-86%); midazolam, 62% (49%-78%), and 117% (105%-130%) for digoxin. In summary, high-dose rifampicin resulted in no additional effect on CYP1A2, mild additional induction of CYP2C9, CYP2C19, CYP2D6, and CYP3A, and marginal inhibition of P-gp. Existing recommendations on managing drug interactions with rifampicin can remain unchanged for the majority of co-administered drugs when using high-dose rifampicin. Clinical Trials registration number NCT04525235.</p

Radiative Decay of a Long-Lived Particle and Big-Bang Nucleosynthesis

The effects of radiatively decaying, long-lived particles on big-bang nucleosynthesis (BBN) are discussed. If high-energy photons are emitted after BBN, they may change the abundances of the light elements through photodissociation processes, which may result in a significant discrepancy between the BBN theory and observation. We calculate the abundances of the light elements, including the effects of photodissociation induced by a radiatively decaying particle, but neglecting the hadronic branching ratio. Using these calculated abundances, we derive a constraint on such particles by comparing our theoretical results with observations. Taking into account the recent controversies regarding the observations of the light-element abundances, we derive constraints for various combinations of the measurements. We also discuss several models which predict such radiatively decaying particles, and we derive constraints on such models.Comment: Published version in Phys. Rev. D. Typos in figure captions correcte

Structural and dynamical properties of superfluid helium: a density functional approach

We present a novel density functional for liquid 4He, properly accounting for the static response function and the phonon-roton dispersion in the uniform liquid. The functional is used to study both structural and dynamical properties of superfluid helium in various geometries. The equilibrium properties of the free surface, droplets and films at zero temperature are calculated. Our predictions agree closely to the results of ab initio Monte Carlo calculations, when available. The introduction of a phenomenological velocity dependent interaction, which accounts for backflow effects, is discussed. The spectrum of the elementary excitations of the free surface and films is studied.Comment: 37 pages, REVTeX 3.0, figures on request at [email protected]

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Pituitary Adenylate Cyclase Activating Peptide (1-38) and its analog (Acetyl-[Ala15, Ala20] PACAP 38-polyamide) reverse methacholine airway hyperresponsiveness in rats

O objetivo deste estudo foi investigar funcionalmente e estruturalmente efeito broncodilatador do peptídeo ativador da adenilato ciclase pituitária (PACAP1-38) e da acetil-[Ala15, Ala20]PACAP 38-poliamida, potente análogo do PACAP-38, nos ratos desafiados pelo metacolina (MeCh). Ratos Wistar machos foram aleatoriamente divididos em cinco grupos. Grupos 1 e 2, inalando aerossóis de solução salina ou doses crescentes de MeCh (0,5, 1, 2,12, 4,25, 8,5, 17, 34 e 68 mg/L). Os outros grupos recebendo terbutalina (Terb) (250 µg/rato) (10-6M), PACAP-38 (50 µg/rato) (0.1 mM) ou análogo do PACAP-38 (50 µg/rato) associados a MeCh na dose de 4,25 mg/L. A resistência pulmonar total (RL) foi registrada antes e 2 min após a administração de Mech pelo equipamento pneumomultiteste. A administração MeCh induziu aumento significativo e dose dependente (pThe aim of this study was to investigate both functionally and structurally bronchodilator effects of Pituitary adenylate cyclase activating peptide (PACAP38) and acetyl-[Ala15, Ala20] PACAP38-polyamide, a potent PACAP38 analog, in rats challenged by methacholine (MeCh). Male Wistar rats were divided randomly into five groups. Groups 1 and 2 inhaled respectively aerosols of saline or increasing doses of MeCh (0.5, 1, 2.12, 4.25, 8.5, 17, 34 and 68mg/L). The other groups received terbutaline (Terb) (250 µg/rat) (10-6 M), PACAP38 (50 µg/rat) (0.1 mM) or PACAP38 analog (50 µg/rat) associated to MeCh from the dose of 4.25 mg/L. Total lung resistances (RL) were recorded before and 2 min after MeCh administration by pneumomultitest equipment. MeCh administration induced a significant and a dose-dependent increase (

General Overview of Black Hole Accretion Theory

I provide a broad overview of the basic theoretical paradigms of black hole accretion flows. Models that make contact with observations continue to be mostly based on the four decade old alpha stress prescription of Shakura & Sunyaev (1973), and I discuss the properties of both radiatively efficient and inefficient models, including their local properties, their expected stability to secular perturbations, and how they might be tied together in global flow geometries. The alpha stress is a prescription for turbulence, for which the only existing plausible candidate is that which develops from the magnetorotational instability (MRI). I therefore also review what is currently known about the local properties of such turbulence, and the physical issues that have been elucidated and that remain uncertain that are relevant for the various alpha-based black hole accretion flow models.Comment: To be published in Space Science Reviews and as hard cover in the Space Sciences Series of ISSI: The Physics of Accretion on to Black Holes (Springer Publisher