Explore the vast range of titles available.

Exposure to radioactivity inside homes potentially poses severe health risks which can be exacerbated by the interaction between radioactive particles and fine indoor particles; in particular, the presence of α particles are a key risk factor. Hence, in this study, particle radioactivity was concurrently measured in the family rooms and basements of 26 homes to assess its concentrations and identify its sources, both indoors and outdoors, across two seasons. The levels of radon, air ions, and particle radioactivity, which included short- and long-lived α-activity (SLA and LLA, respectively), varied greatly but were substantially higher in the basements. Also, particle radioactivity—as well as PM 2 5 and sulfur concentrations—were lower during the heating season. SLA was associated with radon, which was consistently of indoor origin, whereas LLA was more strongly related to the sulfur measured in indoor PM 2 5 , which is a proxy of outdoor infiltration. A regression model adjusted for sulfur and SLA also indicated a predominance of outdoor sources, likely due to the short residence time of indoor particles. Our results suggest that radiation in homes originates from both the decay of indoor radon and the infiltration of outdoor radioactivity.

Recent studies conducted in the USA have shown that adverse health effects of fine particulate matter (PM2.5) persist at levels below the national air quality standards. More recently, particle radioactivity has also been associated with adverse health effects. However, the importance of particle radioactivity at low PM2.5 levels has not been thoroughly explored. The present paper investigates the temporal trends and the relationship of particle gross β-activity (PM-β) and PM2.5 mass in the 48 states of the contiguous USA during the period of 2001–2017. With the implementation of stringent air pollution control policies, national ambient PM2.5 concentrations decreased by 38.5% during this period. However, a smaller decrease of 9.4% was observed for PM-β, while the mean PM-β/PM2.5 ratio increased by 49.1%. PM-β is mostly associated with radon emissions and its progeny, which do not change much with time. The largest PM2.5 and PM-β reductions were observed in the Southeast, while the smallest were found in the West. When the aggregated PM-β to PM2.5 ratio is stratified by PM2.5 levels, the ratio was found to be highest when PM2.5 is <3 μg/m3, with a median PM-β to PM2.5 ratio of 0.77 (0.64–0.88; 25th–75th percentiles). Overall, when not stratified by PM2.5 levels, the greatest state-wide overall PM-β /PM2.5 ratios were found in Wyoming (0.69) and South Dakota (0.51), areas with higher radon, while the lowest (0.17) were in Delaware followed by New Jersey (0.18). These results indicate that the ratio of ambient particle radioactivity to particle mass concentration typically is higher at low PM2.5 levels, and consequently, the toxicity per unit mass is expected to be higher.

Preformed cluster model is applied to examine the ground state decay of various even isotopes of Z  = 113 (Nh) parent nucleus with A  = 278–292. Within the Skyrme energy density formalism, SVand SAMi Skyrme forces are used to identify the probable clusters from the considered emitters by investigating the fragment (cluster) mass yield (or cluster formation probability P 0 ). The calculations suggest that, for 278–292 113 parent nuclei, the maxima at cluster region arises due to the shell closure effects around neutron magic number N  = 50. However, with the increase in mass of the emitter, the magicity of daughter also start to appear around N  = 126.

The radioactive component of particulate matter (PM), particle radioactivity (PR), can continue to emit radiation after inhalation. While PR has been associated with other adverse pregnancy outcomes, no studies have examined the association with fetal growth. Our retrospective cohort included singleton pregnancies that underwent obstetric ultrasounds at an academic medical center in Massachusetts from 2011 through 2016. PR was represented by particle gross β-activity estimated from an ensemble model and was assigned based on residential zip code. We considered the cumulative (conception until date of fetal growth measurement) and first 16 weeks of gestation PR exposure windows. Standardized z-scores were constructed for biparietal diameter (BPD), head circumference, femur length (FL), abdominal circumference (AC), and birth weight. We used linear mixed regression models adjusted for PM ≤2.5 μm exposure, maternal sociodemographic factors, meteorological variables, and long-term trends. Among 9404 pregnancies, an interquartile range increase in cumulative PR exposure was associated with reduced BPD (−0.06 [95% CI: −0.12, −0.01] z-score) and FL (−0.06 [95% CI: −0.12, −0.01] z-score) in scans conducted before 24 weeks’ gestation, with increased AC (0.05 [95% CI: 0.01, 0.09]) in scans conducted on or after 24 weeks’ gestation, and with lower birth weight (-0.05 [95% CI: −0.11, −0.001] z-score). The first 16 weeks of gestation was not a critical exposure window. Prenatal PR was associated with fetal growth, with associations generally negative before 24 weeks’ gestation and positive later in pregnancy. Our findings bring awareness to a novel environmental exposure.

Background Exposure to ionizing radiation has been associated with insulin resistance and type 2 diabetes. In light of recent work showing an association between ambient particulate matter (PM) gross β-activity and gestational diabetes mellitus (GDM) among pregnant women, we examined pregnancy glucose levels in relation to PM gross β-activity to better understand this pathway. Methods Our study included 103 participants receiving prenatal care at Beth Israel Deaconess Medical Center in Boston, MA. PM gross β-activity was obtained from US Environmental Protection Agency’s RadNet program monitors, and blood glucose levels were obtained from the non-fasting glucose challenge test performed clinically as the first step of the 2-step GDM screening test. For each exposure window we examined (i.e., moving average same-day, one-week, first-trimester, and second-trimester PM gross β-activity), we fitted generalized additive models and adjusted for clinical characteristics, socio-demographic factors, temporal variables, and PM with an aerodynamic diameter ≤ 2.5 μm (PM 2.5 ). Subgroup analyses by maternal age and by body mass index were also conducted. Results An interquartile range increase in average PM gross β-activity during the second trimester of pregnancy was associated with an increase of 17.5 (95% CI: 0.8, 34.3) mg/dL in glucose concentration. Associations were stronger among younger and overweight/obese participants. Our findings also suggest that the highest compared to the lowest quartile of one-week exposure was associated with 17.0 (95% CI: − 4.0, 38.0) mg/dL higher glucose levels. No associations of glucose were observed with PM gross β-activity during same-day and first-trimester exposure windows. PM 2.5 was not associated with glucose levels during any exposure window in our data. Conclusions Exposure to higher levels of ambient PM gross β-activity was associated with higher blood glucose levels in pregnant patients, with implications for how this novel environmental factor could impact pregnancy health.

Inhalation of particulate matter (PM) radioactivity is an important pathway of ionizing radiation exposure. We investigated the associations between short-term exposures to PM gamma radioactivity with oxidative stress in COPD patients. Urinary concentrations of 8-hydroxy-2’-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) of 81 COPD patients from Eastern Massachusetts were measured 1–4 times during 2012–2014. Daily ambient and indoor PM gamma activities (gamma-3 through gamma-9) were calculated based on EPA RadNet data and indoor–outdoor infiltration ratios. Linear mixed-effects models were used to examine the associations between biomarkers with PM gamma activities for moving averages from urine collection day to 7 days before. Our results indicate that ambient and indoor PM gamma activities were positively associated with 8-OHdG, with stronger effects for exposure windows closer to urine collection day. For per interquartile range increase in indoor PM gamma activities averaged over urine collection day and 1 day before, 8-OHdG increased from 3.41% (95% CI: −0.88, 7.88) to 8.87% (95% CI: 2.98, 15.1), adjusted for indoor black carbon. For MDA, the timing of greatest effects across the exposure week varied but was nearly all positive. These findings provide insight into the toxigenic properties associated with PM radioactivity and suggest that these exposures promote systemic oxidative stress.

The anomalous magnetic moment of the electron a e measured in a Penning trap occupies a unique position among high precision measurements of physical constants in the sense that it can be compared directly with the theoretical calculation based on the renormalized quantum electrodynamics (QED) to high orders of perturbation expansion in the fine structure constant α , with an effective parameter α / π . Both numerical and analytic evaluations of a e up to ( α / π ) 4 are firmly established. The coefficient of ( α / π ) 5 has been obtained recently by an extensive numerical integration. The contributions of hadronic and weak interactions have also been estimated. The sum of all these terms leads to a e ( theory ) = 1 159 652 181.606 ( 11 ) ( 12 ) ( 229 ) × 10 − 12 , where the first two uncertainties are from the tenth-order QED term and the hadronic term, respectively. The third and largest uncertainty comes from the current best value of the fine-structure constant derived from the cesium recoil measurement: α − 1 ( Cs ) = 137.035 999 046 ( 27 ) . The discrepancy between a e ( theory ) and a e ( ( experiment ) ) is 2.4 σ . Assuming that the standard model is valid so that a e (theory) = a e (experiment) holds, we obtain α − 1 ( a e ) = 137.035 999 1496 ( 13 ) ( 14 ) ( 330 ) , which is nearly as accurate as α − 1 ( Cs ) . The uncertainties are from the tenth-order QED term, hadronic term, and the best measurement of a e , in this order.

A bstract We study A 4 × A 4 × A 4 modular symmetric flavor models to realize quark mass hierarchies and mixing angles without fine-tuning. Mass matrices are written in terms of modular forms. At modular fixed points τ = i∞ and ω , A 4 is broken to Z 3 residual symmetry. When the modulus τ is deviated from the fixed points, modular forms show hierarchies depending on their residual charges. Thus, we obtain hierarchical structures in mass matrices. Since we begin with A 4 × A 4 × A 4 , the residual symmetry is Z 3 × Z 3 × Z 3 which can generate sufficient hierarchies to realize quark mass ratios and absolute values of the CKM matrix |V CKM | without fine-tuning. Furthermore, CP violation is studied. We present necessary conditions for CP violation caused by the value of τ . We also show possibilities to realize observed values of the Jarlskog invariant J CP , quark mass ratios and CKM matrix |V CKM | simultaneously, if (10) adjustments in coefficients of Yukawa couplings are allowed or moduli values are non-universal.

We discuss a possible link between the deformation parameter \\[\\Theta ^{\\mu \\nu }\\] arising in the framework of noncommutative geometry and the parameter \\[\\beta \\] of the generalized uncertainty principle (GUP). We compute the shift of the Hawking temperature induced by the \\[\\Theta ^{\\mu \\nu }\\]-deformed Schwarzschild geometry, and then we relate it to one obtained by GUP. Results suggest a granular structure of specetime at the Planck scales. The current bounds on \\[\\beta \\] allow to constraint the noncommutative parameter \\[\\Theta ^{\\mu \\nu }\\].

Alpha particles with energies on the order of megaelectronvolts will be the main source of plasma heating in future magnetic confinement fusion reactors. Instead of heating fuel ions, most of the energy of alpha particles is transferred to electrons in the plasma. Furthermore, alpha particles can also excite Alfvénic instabilities, which were previously considered to be detrimental to the performance of the fusion device. Here we report improved thermal ion confinement in the presence of megaelectronvolts ions and strong fast ion-driven Alfvénic instabilities in recent experiments on the Joint European Torus. Detailed transport analysis of these experiments reveals turbulence suppression through a complex multi-scale mechanism that generates large-scale zonal flows. This holds promise for more economical operation of fusion reactors with dominant alpha particle heating and ultimately cheaper fusion electricity. Experiments at the Joint European Torus tokamak show improved thermal ion confinement in the presence of highly energetic ions and Alfvénic instabilities in the plasma.