The PROSPECT and STEREO collaborations present a combined measurement of the pure ^{235}U antineutrino spectrum, without site specific corrections or detector-dependent effects. The spectral measurements of the two highest precision experiments at research reactors are found to be compatible with χ^{2}/ndf=24.1/21, allowing a joint unfolding of the prompt energy measurements into antineutrino energy.
View Article and Find Full Text PDFA joint determination of the reactor antineutrino spectra resulting from the fission of ^{235}U and ^{239}Pu has been carried out by the Daya Bay and PROSPECT Collaborations. This Letter reports the level of consistency of ^{235}U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent.
View Article and Find Full Text PDFReactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties becoming lower than those from theory, carefully considering all sources of is important when making theoretical predictions. One source of that is often neglected arises from the irradiation of the nonfuel materials in reactors.
View Article and Find Full Text PDFNucl Instrum Methods Phys Res A
January 2020
Neutral particle detection in high-background environments is greatly aided by the ability to easily load Li into liquid scintillators. We describe a readily available and inexpensive liquid scintillation cocktail stably loaded with a Li mass fraction up to 1 %. Compositions that give thermodynamically stable microemulsions (reverse-micellar systems) were explored, using a Compton spectrum quenching technique to distinguish these from unstable emulsions.
View Article and Find Full Text PDFThis Letter reports the first measurement of the ^{235}U ν[over ¯]_{e} energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9 m from the 85 MW_{th} highly enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678±304(stat) ν[over ¯]_{e}-induced inverse beta decays, the largest sample from HEU fission to date, 99% of which are attributed to ^{235}U.
View Article and Find Full Text PDFThis Letter reports the first scientific results from the observation of antineutrinos emitted by fission products of ^{235}U at the High Flux Isotope Reactor. PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, consists of a segmented 4 ton ^{6}Li-doped liquid scintillator detector covering a baseline range of 7-9 m from the reactor and operating under less than 1 m water equivalent overburden. Data collected during 33 live days of reactor operation at a nominal power of 85 MW yield a detection of 25 461±283 (stat) inverse beta decays.
View Article and Find Full Text PDFA precise value of the neutron lifetime is important in several areas of physics, including determinations of the quark-mixing matrix element │ │, related tests of the Standard Model, and predictions of light element abundances in Big Bang Nucleosynthesis models. We report the progress on a new measurement of the neutron lifetime utilizing the cold neutron beam technique. Several experimental improvements in both neutron and proton counting that have been developed over the last decade are presented.
View Article and Find Full Text PDFNeutron spin rotation is expected from quark-quark weak interactions in the standard model, which induce weak interactions among nucleons that violate parity. We present the results from an experiment searching for the effect of parity violation via the spin rotation of polarized neutrons in a liquid He medium. The value for the neutron spin rotation angle per unit length in He, rad/m, is consistent with zero.
View Article and Find Full Text PDFContext: Insulin resistance in polycystic ovary syndrome (PCOS) may increase the risk of reactive hypoglycaemia (RH) and decrease glucagon-like peptide-1 (GLP-1) secretion. The possible effects of treatment with oral contraceptives (OCP) and/or metformin on GLP-1 secretion and risk of RH in PCOS is undetermined.
Setting: Outpatient clinic.
J Radioanal Nucl Chem
January 2017
Liquid scintillation cocktails loaded with neutron capture agents such as Li are used in both neutron and neutrino detectors. For detectors designed to operate over extended timespans, long-term stability can be a concern. We demonstrate the identification of thermodynamically unstable emulsions as distinct from stable microemulsions, driving phase separation with centrifugation.
View Article and Find Full Text PDFThe standard model predicts that, in addition to a proton, an electron, and an antineutrino, a continuous spectrum of photons is emitted in the β decay of the free neutron. We report on the RDK II experiment which measured the photon spectrum using two different detector arrays. An annular array of bismuth germanium oxide scintillators detected photons from 14 to 782 keV.
View Article and Find Full Text PDFStudy Question: What is the prevalence of reactive hypoglycemia (RH) in polycystic ovary syndrome (PCOS) versus age- and body mass index (BMI)-matched healthy controls.
Summary Answer: The prevalence of RH was increased in PCOS versus controls.
What Is Known Already: Previous studies suggested an increased prevalence of RH in PCOS.
We present the development of the miniTimeCube (mTC), a novel compact neutrino detector. The mTC is a multipurpose detector, aiming to detect not only neutrinos but also fast/thermal neutrons. Potential applications include the counterproliferation of nuclear materials and the investigation of antineutrino short-baseline effects.
View Article and Find Full Text PDFObjective: Polycystic ovary syndrome (PCOS) is associated with risk factors for cardiovascular disease (CVD) which may be modified by the use of metformin and oral contraceptives (OC). Thrombin generation (TG) measures are risk markers of CVD and address the composite of multiple factors that influence blood coagulation. This prospective, randomized, intervention study evaluated the potential influence of PCOS on TG measures and the effect of OC and/or metformin on TG measures in women with PCOS.
View Article and Find Full Text PDFWe present the design, description, calibration procedure, and an analysis of systematic effects for an apparatus designed to measure the rotation of the plane of polarization of a transversely polarized slow neutron beam as it passes through unpolarized matter. This device is the neutron optical equivalent of a crossed polarizer/analyzer pair familiar from light optics. This apparatus has been used to search for parity violation in the interaction of polarized slow neutrons in matter.
View Article and Find Full Text PDFObjectives: To investigate obstetric outcomes in Danish women with different phenotypes of polycystic ovary syndrome (PCOS) and isolated hyperandrogenism (HA) and describe the risk of adverse obstetric outcomes in women with PCOS and HA compared to controls.
Design: Cohort study.
Setting: Odense University Hospital, Denmark.
Context: Central obesity in polycystic ovary syndrome (PCOS) is associated with increased inflammatory markers and increased risk for type 2 diabetes.
Objective: To evaluate if improved body composition during treatment with metformin (M) vs. oral contraceptive pills (OCP) was associated with changes in circulating adiponectin, interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1.
Study Question: Is there an association between prolactin and markers of metabolic risk in polycystic ovary syndrome (PCOS)?
Summary Answer: Low serum prolactin was a metabolic risk marker in PCOS.
What Is Known Already: Prolactin is routinely measured to exclude endocrine diseases in PCOS. Recent studies have suggested that prolactin can be used as a marker for metabolic and cardiovascular risk.
Context: Central obesity in polycystic ovary syndrome (PCOS) is associated with increased inflammatory markers and increased risk for type 2 diabetes.
Objective: The objective of the study was to evaluate whether treatment with metformin (M) or M combined with oral contraceptive pills (OCPs) resulted in a more advantageous body composition than treatment with OCP alone.
Setting: The study was conducted at an outpatient clinic.
Objective: To study the association between birth weight and polycystic ovary syndrome (PCOS) in adult life in Danish women born 1973-1991.
Design: Register study.
Setting: Data were extracted from the Danish Medical Birth Register and the Danish National Patient Register (NPR).
Clinical manifestations and metabolic risk factors may differ according to age in patients with polycystic ovary syndrome (PCOS). Therefore, a retrospective trans-sectional study in academic tertiary-care medical center was designed. A cohort of 446 premenopausal, Caucasian women (age range 15-49 years) with PCOS were divided into 4 subgroups according to age: group 1 (15-19 years, n=42), group 2 (20-29 years, n=180), group 3 (30-39 years, n=187), group 4 (40-49 years, n=37) and underwent clinical evaluation (Ferriman-Gallwey score, BMI, waist, blood pressure), hormone analyses (sex hormones, fasting lipids, insulin, glucose), transvaginal ultrasound, oral glucose tolerance tests (OGTT) (n=234), and ACTH tests (n=201).
View Article and Find Full Text PDFObjective: To study hemoglobin A1c (HbA1c) as a tool for diagnosing diabetes and to study HbA1c as a cardiovascular risk marker in patients with polycystic ovary syndrome (PCOS).
Design: Retrospective observational study.
Setting: Academic tertiary-care medical center.
We report the results of an improved determination of the triple correlation DP·(p(e)×p(v)) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the standard model. Our result is D=[-0.96±1.
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