Effective Three-Body Interactions in Jaynes-Cummings-Hubbard Systems.

A generalisation of the Jaynes-Cummings-Hubbard model for coupled-cavity arrays is introduced, where the embedded two-level system in each cavity is replaced by a Ξ-type three-level system. We demonstrate that the resulting effective polariton-polariton interactions at each site are both two-body and three-body. By tuning the ratio of the two transition dipole matrix elements, we show that the strength and sign of the two-body interaction can be controlled whilst maintaining a three-body repulsion. We then proceed to demonstrate how different two-body and three-body interactions alter the mean field superfluid-Mott insulator phase diagram, with the possible emergence of a pair superfluid phase in the two-body attractive regime.

Association of unit-wide oxygen saturation target on incidence of pulmonary hypertension in very low birthweight premature infants.

OBJECTIVE: Assess the effect of increasing pulse oximetry targets on incidence of pulmonary hypertension in very low birthweight premature infants. STUDY DESIGN: Retrospective cohort study comparing pulmonary hypertension incidence among three cohorts of premature infants exposed to varying oxygen saturation targets (Cohort 1: n=459, 1 May 2009 to 30 April 2011, 85-94%; Cohort 2: n=474, 1 May 2011 to 31 May 2013, 88-94%; Cohort 3: n=387, 1 June 2013 to 31 May 2015, 90-95%). Subjects had birth weight <1500 g and gestational age 23-32 weeks. Chi-square, Kruskall-Wallis and Anderson-Darling tests were used, as well as multivariable logistic regression. RESULTS: Incidence of pulmonary hypertension declined with higher oxygen saturation targets (19.0% Cohort 1, 7.9% Cohort 2, 9.6% Cohort 3, P<0.001). Other parameters were largely not different between cohorts though rates of chorioamnionitis and prenatal steroids increased and oxygen use, inhaled nitric oxide use, necrotizing enterocolitis and patent ductus arteriosus ligation decreased over time. CONCLUSION: Higher oxygen saturation targets for very low-birthweight premature infants were associated with reduced rates of pulmonary hypertension in this retrospective cohort study.

Microchimerism of presumed fetal origin in thyroid specimens from women: a case-control study.

BACKGROUND: Some so-called autoimmune diseases in women might be alloimmune and represent a chronic graft-versus-host response attributable to transplacentally acquired fetal cells. Thyroid disease is more common in women than men, and post partum exacerbation of thyroiditis is common. Our aim was to investigate whether there is an association between fetal cell microchimerism and thyroid disease in women. METHODS: Surgical specimens were obtained from 29 women who underwent thyroidectomy for various thyroid disorders. Control specimens were taken from clinically and histologically normal thyroids obtained at necropsy from eight women who died from unrelated conditions. Medical records and pregnancy histories were reviewed. Fluorescence in-situ hybridisation analysis was done with probes specific for X and Y chromosomes. Slides were examined with a fluorescence microscope to detect the presence of male cells-with one X and one Y signal in the nucleus-among maternal cells containing two X signals. FINDINGS: Male cells were seen in thyroid sections from 16 patients but not in those from controls (p=0.01). Male cells (1-165 per slide) were seen individually or in clusters in all thyroid diseases and were not restricted to inflammatory thyroid diseases. In one patient with a progressively enlarging goitre, we noted fully differentiated male thyroid follicles closely attached to and indistinguishable from the rest of the thyroid. INTERPRETATION: Our findings suggest a relation between fetal cell microchimerism and thyroid disease. Furthermore, fetal stem cells might be capable of differentiation into mature thyroid follicles in their mothers with favourable environmental and developmental factors.

Infant sleep position and SIDS: a hospital-based interventional study.

CONTEXT: Avoidance of the prone sleeping position is considered an important factor contributing to the decline in the incidence of sudden infant death syndrome (SIDS). OBJECTIVES: To determine infant sleep positioning practices and SIDS awareness before and after a hospital-based Back to Sleep campaign. DESIGN: A questionnaire-based, descriptive, and cross-sectional before-after trial. SETTING: The pediatric outpatient department of an inner-city hospital in Brooklyn, New York. SUBJECTS: Two consecutive samples of 250 mothers of healthy infants younger than 6 months old born in and attending the outpatient clinics of the hospital before and after the intervention. INTERVENTION AND MAIN OUTCOME MEASURES: Specific policies promoting Back to Sleep were established in our newborn nursery and outpatient department. Reduction in prone infant sleep positioning was the primary outcome measure. Increased parental SIDS awareness was a secondary outcome. RESULTS: The proportion of infants sleeping prone was reduced significantly (from 27% to 18%) after the intervention (P < .005). Among the mothers who chose the prone sleeping position for their infants, 49.6% worried about choking. Older mothers (> 22 years) responded to the intervention by a 45.6% reduction in prone placement (P < .005) as opposed to a 11.4% reduction among younger mothers (< 22 years) (P = ns). Other factors contributing to reduced prone positioning included marriage (adjusted odds ratio [OR] 0.57; 95% confidence interval [CI] 0.93, 0.34) and breast feeding (adjusted OR 0.66; 95% CI 1.1, 0.4). SIDS awareness was 79.6% and 82.4% in the preintervention and postintervention groups, respectively (P = ns). CONCLUSIONS: The Back to Sleep campaign was effective in our hospital setting. Our data indicate the need for special targeting of young, unmarried, and non-breast-feeding mothers. Fear of choking remains an important deterrent to proper infant sleep positioning.