8 research outputs found
One-loop thermal radiation exchange in gravitational wave power spectrum
The radiation-dominated universe is a key ingredient of the standard Big Bang
cosmology. Radiation comprises numerous quantum elementary particles, and the
macroscopic behavior of radiation is described by taking the quantum thermal
average of its constituents. While the interactions between individual
particles and gravitational waves are often neglected in this context, it
raises the question of whether these elementary particles interact with
gravitational waves in the framework of quantum field theory. To address this
question, this paper aims at exploring the quantum mechanical aspects of
gravitational waves in a universe dominated by a massless scalar field, whose
averaged energy-momentum tensor plays the role of background radiation. We
establish the equivalence between the classical Einstein equation and the
mean-field approximation of the Heisenberg equation in a local thermal state.
Beyond the mean-field approximation, we analyze the quantum corrections to
gravitational waves, particularly focusing on the thermal radiation loop
corrections. Interestingly, we find the 1-loop correction surpasses the
tree-level spectrum of primordial gravitational waves, which is
where is the ratio of the inflationary Hubble
parameter to the Planck mass. Then, to see if this result persists even if we
take into account all the higher order loop corrections, the loop expansion is
reorganized in the series expansion in . We find all the loop diagrams
that may give contributions. We leave explicit computations of
these diagrams for future studies. Thus, although we cannot claim that the
whole loop corrections exceed the tree-level spectrum at the moment, our
findings highlight the significance of considering quantum effects when
studying the interaction between radiation and gravitational waves in the
cosmological context.Comment: 22 page
Factors Associated with Infant Feeding Methods after the Nuclear Power Plant Accident in Fukushima: Data from the Pregnancy and Birth Survey for the Fiscal Year 2011 Fukushima Health Management Survey
Utility of Maternal 6-Thioguanine Nucleotide Levels in Predicting Neonatal Pancytopenia
Abstract
An infant with pancytopenia was born to a mother who used the common immunosuppressant azathioprine (AZA). Maternal and neonatal blood levels of 6-thioguanine nucleotides (6TGN; metabolite of AZA) were 1890 and 1480 pmol/8 × 108 red blood cells, respectively. Maternal 6TGN levels could be useful in predicting neonatal pancytopenia
Histopathologic characteristics of early stage esophageal carcinoma: A comparative study with gastric carcinoma
Pregnancy and birth survey after the great East Japan earthquake and fukushima daiichi nuclear power plant accident in fukushima prefecture
Background: On 11 March 2011, the Great East Japan Earthquake followed by a powerful tsunami hit the Pacific Coast of Northeast Japan and damaged Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Plant, causing a radiation hazard in Fukushima Prefecture. The objective of this report is to describe some results of a questionnaire-based pregnancy and birth survey conducted by the Radiation Medical Science Center for the Fukushima Health Management Survey. Materials and Methods: Questionnaires were sent to women who received maternal and child health handbooks from municipal officers in Fukushima Prefecture between 1 August 2010 and 31 July 2011, with the aim of reaching those who were pregnant at the time of the disaster. Mailing began 18 January 2012. Data were analyzed separately for six geographic areas in Fukushima Prefecture. Results: The total number of women meeting survey criteria was 15,972. The number of responses received to date is 9,298 (58.2%). Data from 8602 respondents were analyzed after excluding 634 invalid responses and 5 induced and 57 spontaneous abortions (less than 22 gestational weeks). The incidences of stillbirth (over 22 completed gestational weeks), preterm birth, low birth weight and congenital anomalies were 0.25%, 4.4%, 8.7% and 2.72%, respectively. These incidences are similar to recent averages elsewhere in Japan. Conclusion: Considering the pregnancy and birth survey data in aggregate, our disaster seemed to provoke no significant adverse outcomes over the whole of Fukushima prefecture. But post-disaster prenatal care and support intended for patients' safety and security should be coupled with ongoing surveillance and rigorous data analysis