Towards quantum superpositions of a mirror

We propose a scheme for creating quantum superposition states involving of order $10^{14}$ atoms via the interaction of a single photon with a tiny mirror. This mirror, mounted on a high-quality mechanical oscillator, is part of a high-finesse optical cavity which forms one arm of a Michelson interferometer. By observing the interference of the photon only, one can study the creation and decoherence of superpositions involving the mirror. All experimental requirements appear to be within reach of current technology.Comment: 5 pages, 2 figures, submitted to Phys. Rev. Let

Predictors of preeclampsia in women in the metformin in gestational diabetes (MiG) study

Background: Gestational Diabetes Mellitus (GDM), maternal obesity and pregnancy weight gain are associated with an increased risk of developing Preeclampsia (PE). The aim of this study was to examine the predictors of PE in women commencing pharmacotherapy for GDM in the Metformin in Gestational diabetes trial.Methods: Descriptive and logistic regression analyses examined the relationship between maternal enrolment characteristics and later development of PE.Results: 46 (6.3%) of 703 women developed PE. At enrolment ((30 (SD3.2) weeks gestation), women who later developed PE had higher HbA1c (6.14% (95% CI 5.84, 6.45) vs. 5.73% (95% CI 5.67, 5.78), P = 0.003), fasting triglycerides (2.93 mmol/L (95% CI 2.57, 3.29) vs. 2.55mmol/L (95% CI 2.47, 2.62), P = 0.03) and blood pressure. Their infants were born 9 days earlier (P < 0.001) but were otherwise not different. In univariate analysis, the strongest positive predictors for PE were Polynesian ethnicity (OR 2.75 (95% CI 1.48, 5.09), P= 0.001), personal or family history of PE (OR 2.65 (95% CI 1.36, 5.16), P=0.004), maternal HbA1c (OR 1.96 (95% CI 1.35, 2.89), P< 0.001), triglycerides (OR 1.45 (95% CI 1.07,1.97), P=0.002), and weight gain from early pregnancy (OR 1.09 (95% CI 1.03,1.17), P=0.01). HDL-C was a negative predictor of PE (OR 0.29 (95% CI 0.09, 0.94), P= 0.04).Following adjustment for Polynesian ethnicity and personal or family history of PE, and when further adjusted for HbA1c or early pregnancy BMI, these variables remained significant.Conclusion: Treatment allocation and BMI were not associated with risk of PE. Personal or family history of PE, Polynesian ethnicity, degree of hyperglycemia, maternal triglycerides and weight gain prior to treatment signal increased risk of subsequent PE in women needing pharmacotherapy for GDM

A method for exposing rodents to resuspended particles using whole-body plethysmography

BACKGROUND: Epidemiological studies have reported increased risks of cardiopulmonary-related hospitalization and death in association with exposure to elevated levels of particulate matter (PM) across a wide range of urban areas. In response to these findings, researchers have conducted animal inhalation exposures aimed at reproducing the observed toxicologic effects. However, it is technically difficult to quantitate the actual amount of PM delivered to the lung in such studies, and dose is frequently estimated using default respiration parameters. Consequently, the interpretation of PM-induced effects in rodents exposed via whole-body inhalation is often compromised by the inability to determine deposited dose. To address this problem, we have developed an exposure system that merges the generation of dry, aerosolized particles with whole-body plethysmography (WBP), thus permitting inhalation exposures in the unrestrained rat while simultaneously obtaining data on pulmonary function. RESULTS: This system was validated using an oil combustion-derived particle (HP12) at three nominal concentrations (3, 12, and 13 mg/m(3)) for four consecutive exposure days (6 hr/day); a single 6-hour exposure to 13 mg/m(3 )of HP12 was also conducted. These results demonstrated that the system was both reliable and consistent over these exposure protocols, achieving average concentrations that were within 10% of the targeted concentration. In-line filters located on the exhaust outlets of individual WBP chambers showed relative agreement in HP12 mass for each day and were not statistically different when compared to one another (p = 0.16). Temperatures and relative humidities were also similar between chambers during PM and air exposures. Finally, detailed composition analyses of both HP12 filter and bulk samples showed that grinding and aerosolization did not change particle chemistry. CONCLUSION: The results of this study demonstrate that it is possible to expose rodents to resuspended, dry PM via whole-body inhalation while these animals are maintained in WBP chambers. This new methodology should significantly improve the ability to assess dosimetry under minimally stressful exposure conditions