To compare the rate of refractive growth (RRG3) of the crystalline lens (“lens”) versus the eye excluding the lens (“globe”) for the fellow, noncataractous eyes of participants in the Infant Aphakia ...Treatment Study.
Retrospective cohort study.
A total of 114 children who had unilateral cataract surgery as infants were recruited. Biometric and refraction data were obtained from the normal eyes at surgery and at 1, 5, and 10 years. Subjects were included if complete data (axial length AL, corneal power, and refraction) were available at surgery and at 10 years of age.
At surgery and at 1, 5, and 10 years, AL, corneal power, and cycloplegic refraction were measured in the normal eyes. For each eye, the RRG3 was defined by linear regression of refraction at the intraocular lens (IOL) plane against log10 (age + 0.6 years). The RRG3 for the globe was based on IOL power for emmetropia; the RRG3 for the lens was based on IOL power calculated to give the observed refractions. Intraocular lens powers were calculated with the Holladay 1 formula. The means were compared with a paired 2-tailed t test, and linear regression was used to look for a correlation between RRG3 of the lens globe.
The RRG3 of the lens and globe.
Complete data were available for 107 normal eyes. The mean RRG3 of the lenses was −12.0 ± 2.5 diopters (D) and the mean RRG3 of the globes was −14.1 ± 2.7 D (P < 0.001). The RRG3 of the lens correlated with the RRG3 of the globe (R2 = 0.25, P < 0.001).
The RRG3 was 2 D more negative in globes compared with lenses in normal eyes. Globes with a greater rate of growth tended to have lenses with a greater rate of growth.
To compare the imaging results obtained with two different in vitro prototype dental optical coherence tomography (OCT) systems.
Two prototypes were evaluated: an 850 nm wavelength, 700 microW OCT ...system with a relatively low numerical aperture (0.03) and a 1310 nm wavelength, 140 microW system with a higher numerical aperture (0.20).
Using the 850 nm system a characteristic scattering signal was observed that correlated with the depth of a periodontal probe. There was, however, insufficient light penetration to create images with adequate resolution. Improved image quality was achieved with the 1310 nm OCT system; these images had sufficient resolution to allow identification of anatomical structures important for the diagnostic assessment of oral structures.
These results illustrate the improvement in imaging dental structures that can be obtained with a prototype 1310 nm OCT system. The feasibility of OCT as a dental imaging technique is verified.
We provide the first combined cosmological analysis of South Pole Telescope (SPT) and Planck cluster catalogs. The aim is to provide an independent calibration for Planck scaling relations, ...exploiting the cosmological constraining power of the SPT-SZ cluster catalog and its dedicated weak lensing (WL) and X-ray follow-up observations. We build a new version of the Planck cluster likelihood. In the \(\nu \Lambda\)CDM scenario, focusing on the mass slope and mass bias of Planck scaling relations, we find \(\alpha_{\text{SZ}} = 1.49_{-0.10}^{+0.07}\) and \((1-b)_{\text{SZ}} = 0.69_{-0.14}^{+0.07}\) respectively. The results for the mass slope show a \(\sim 4 \, \sigma\) departure from the self-similar evolution, \(\alpha_{\text{SZ}} \sim 1.8\). This shift is mainly driven by the matter density value preferred by SPT data, \(\Omega_m = 0.30 \pm 0.03\), lower than the one obtained by Planck data alone, \(\Omega_m = 0.37_{-0.06}^{+0.02}\). The mass bias constraints are consistent both with outcomes of hydrodynamical simulations and external WL calibrations, \((1-b) \sim 0.8\), and with results required by the Planck cosmic microwave background cosmology, \((1-b) \sim 0.6\). From this analysis, we obtain a new catalog of Planck cluster masses \(M_{500}\). We estimate the ratio between the published Planck \(M_{\text{SZ}}\) masses and our derived masses \(M_{500}\), as a "measured mass bias", \((1-b)_M\). We analyse the mass, redshift and detection noise dependence of \((1-b)_M\), finding an increasing trend towards high redshift and low mass. These results mimic the effect of departure from self-similarity in cluster evolution, showing different dependencies for the low-mass high-mass, low-z high-z regimes.
Subsequent to its capture by Neptune, Triton could have experienced an episode of tidal heating sufficient to melt its icy mantle and possibly its rocky core as well. This heating would have driven ...hydrothermal circulation at the core-rock/mantle-ocean boundary. We consider the chemical consequences of this hydrothermal reprocessing on Triton's volatile budget by assuming an initial cometary composition for the icy mantle and evaluating the effects of changes in temperature and oxidation state. We assume that the latter would have been controlled by mineral assemblages in the rock. Such reprocessing could explain the lack of carbon monoxide in the atmosphere of Triton and its depletion relative to N2 and (apparently) CO2 in the satellite's surface ices. Our calculations also show that whatever the original source of nitrogen in Triton, N2 and/or NH3 are likely abundant products of hydrothermal reprocessing. Depending on the temperature and prevailing oxidation state, acetic acid, ethanol, urea, methanol, and ethanamine are possible important components, in addition to ammonia, of the resulting mantle material. Triton may thus preserve the organic chemistry that might have led to the origin of life in early terrestrial hydrothermal systems.
We search for the signature of cosmological shocks in stacked gas pressure profiles of galaxy clusters using data from the South Pole Telescope (SPT). Specifically, we stack the latest Compton-y maps ...from the 2500 deg^2 SPT-SZ survey on the locations of clusters identified in that same dataset. The sample contains 516 clusters with mean mass = 1e14.9 msol and redshift = 0.55. We analyze in parallel a set of zoom-in hydrodynamical simulations from The Three Hundred project. The SPT-SZ data show two features: (i) a pressure deficit at R/R200m = \(1.08 \pm 0.09\), measured at \(3.1\sigma\) significance and not observed in the simulations, and; (ii) a sharp decrease in pressure at R/R200m = \(4.58 \pm 1.24\) at \(2.0\sigma\) significance. The pressure deficit is qualitatively consistent with a shock-induced thermal non-equilibrium between electrons and ions, and the second feature is consistent with accretion shocks seen in previous studies. We split the cluster sample by redshift and mass, and find both features exist in all cases. There are also no significant differences in features along and across the cluster major axis, whose orientation roughly points towards filamentary structure. As a consistency test, we also analyze clusters from the Planck and Atacama Cosmology Telescope Polarimeter surveys and find quantitatively similar features in the pressure profiles. Finally, we compare the accretion shock radius (Rsh_acc) with existing measurements of the splashback radius (Rsp) for SPT-SZ and constrain the lower limit of the ratio, Rsh_acc/Rsp > \(2.16 \pm 0.59\).
Cesarean delivery on demand: What will it cost? Bost, Brent W.
American journal of obstetrics and gynecology,
June 2003, 2003-Jun, 2003-06-00, 20030601, Letnik:
188, Številka:
6
Journal Article
Recenzirano
Objective: The purpose of this study was to estimate the cost differences between elective cesarean delivery and the alternative of attempted vaginal delivery and to assess the economic impact of ...cesarean delivery on demand. Study Design: Cost data were obtained over a 12-month period from a not-for-profit community hospital to calculate a per-patient cost for clinical alternatives. Results: The average cost of an attempted vaginal delivery without oxytocin (Pitocin) or epidural anesthesia was 15.1% lower in nulliparous women and 20% lower in multiparous women than with elective cesarean delivery. However, in nulliparous women, the addition of Pitocin nullified any cost differences; if epidural anesthesia was also used, total costs exceeded the cost of elective cesarean delivery by almost 10%. The cost of a failed attempt at vaginal delivery was much higher than elective cesarean delivery for both groups. The average cost for all women who attempted vaginal delivery was only 0.2% less than the per-patient cost of elective cesarean delivery. Conclusion: The adoption of a policy of cesarean delivery on demand should have little impact on the overall cost of obstetric care. (Am J Obstet Gynecol 2003;188:1418-23.)
We show the improvement to cosmological constraints from galaxy cluster surveys with the addition of CMB-cluster lensing data. We explore the cosmological implications of adding mass information from ...the 3.1\(\sigma\) detection of gravitational lensing of the cosmic microwave background (CMB) by galaxy clusters to the Sunyaev-Zel'dovich (SZ) selected galaxy cluster sample from the 2500 deg\(^2\) SPT-SZ survey and targeted optical and X-ray followup data. In the \(\Lambda\)CDM model, the combination of the cluster sample with the Planck power spectrum measurements prefers \(\sigma_8 \left(\Omega_m/0.3 \right)^{0.5} = 0.831 \pm 0.020\). Adding the cluster data reduces the uncertainty on this quantity by a factor of 1.4, which is unchanged whether or not the 3.1\(\sigma\) CMB-cluster lensing measurement is included. We then forecast the impact of CMB-cluster lensing measurements with future cluster catalogs. Adding CMB-cluster lensing measurements to the SZ cluster catalog of the on-going SPT-3G survey is expected to improve the expected constraint on the dark energy equation of state \(w\) by a factor of 1.3 to \(\sigma(w) = 0.19\). We find the largest improvements from CMB-cluster lensing measurements to be for \(\sigma_8\), where adding CMB-cluster lensing data to the cluster number counts reduces the expected uncertainty on \(\sigma_8\) by factors of 2.4 and 3.6 for SPT-3G and CMB-S4 respectively.
Objective: This study was undertaken to determine whether women with high-risk pregnancies and an amniotic fluid index of ≤5 cm require labor induction to prevent adverse perinatal outcomes.
Study ...Design: All women at high risk at ≥34 weeks’ gestation with an amniotic fluid index of ≤5 cm were admitted to the hospital for labor induction. Each woman was compared with the next patient at high risk seen with an amniotic fluid index of >5 cm and the same pregnancy complication. Case patients were also matched with control subjects for maternal race, age, parity, and gestational age.
Results: Prospectively, 79 women at high risk with an amniotic fluid index of ≤5 cm were compared with 79 control subjects. There were no statistically significant differences between the 2 groups in the risks of thick meconium (
P = .29), variable decelerations (moderate
P = .27, severe
P = .37), amnioinfusion (
P = .37), cesarean delivery for fetal distress (
P = .4), and umbilical artery pH <7.10 (
P = .29).
Conclusion: High-risk pregnancies with an amniotic fluid index of ≤5 cm appear to carry intrapartum complication rates similar to those of similar high-risk pregnancies with an amniotic fluid index of >5. (Am J Obstet Gynecol 1999;180:1354-9.)
Optical coherence tomography is a new method for noninvasively imaging internal tooth and soft tissue microstructure. The intensity of backscattered light is measured as a function of depth in the ...tissue. Low coherence interferometry is used to selectively remove the component of backscattered signal that has undergone multiple scattering events, resulting in very high resolution images (< 15 microns). Lateral scanning of the probe beam across the biological tissue is then used to generate a 2-D intensity plot, similar to ultrasound images. This imaging method provides information that is currently unobtainable by any other means, making possible such diverse applications as diagnosis of periodontal disease, caries detection, and evaluation of restoration integrity. This chapter presents an overview of this exciting new imaging technique and its current application to dental diagnosis.
PDF