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Waters, Ruiz, and Roisman (2017) recently published evidence based on the Minnesota Longitudinal Study of Risk and Adaptation (MLSRA) that sensitive caregiving during childhood is associated with higher levels of secure base script knowledge during the Adult Attachment Interview (AAIsbs). At present, however, little is known about the role of variation in atypical caregiving, including abuse and/or neglect, in explaining individual differences in AAIsbs. This study revisited data from the MLSRA (N = 157) to examine the association between experiencing abuse and/or neglect in the first 17.5 years of life and secure base script knowledge measured at ages 19 and 26 years. Several aspects of abuse and/or neglect experiences were assessed, including perpetrator identity, timing, and type. Regressions revealed that childhood abuse and/or neglect was robustly associated with lower AAIsbs scores in young adulthood, above and beyond previously documented associations with maternal sensitivity and demographic covariates. Follow-up analyses provided evidence that the predictive significance of abuse for secure base script knowledge was specific to perpetration by parental figures, rather than non-caregivers. Exploratory analyses indicated that abuse and/or neglect: (a) in middle childhood and adolescence (but not infancy and early childhood) and (b) physical abuse (but not sexual abuse or neglect) were uniquely associated with lower AAIsbs scores.
Using semi-empirical isochrones, we find the age of the Taurus star-forming region to be 3-4 Myr. Comparing the disc fraction in Taurus to young massive clusters suggests discs survive longer in this low density environment. We also present a method of photometrically de-reddening young stars using iZJH data.
Inelastic x-ray scattering measurements of the phonon density of states (DOS) of PuO2(+2%Ga) were made and compared to recent predictions from the literature made using three leading theoretical approaches; Density Functional Theory (DFT), DFT plus the Hubbard U (DFT+U), and Dynamical Mean-Field Theory (DMFT). The DFT prediction, which does not account for strong electronic correlations, underestimates the measured energies of most features. The DFT+U and DMFT predictions, which include approximations to strong correlation effects, more accurately reflect the low energy features but exaggerate splitting in the highest energy optic oxygen modes. The exaggeration of the splitting is worse for DFT+U than for DMFT. The transverse acoustic mode shows the least sensitivity to calculation type, and is well reproduced by all three theories. The longitudinal acoustic mode, which is thought to control the thermal conductivity, is more sensitive to calculation type, suggesting an important role for electronic correlations in making application-critical predictions.
The goal of this effort was to reduce central venous catheter (CVC)-associated bloodstream infections (BSIs) in pediatric intensive care unit (ICU) patients by means of a multicenter evidence-based intervention.
An observational study was conducted in 26 freestanding children's hospitals with pediatric or cardiac ICUs that joined a Child Health Corporation of America collaborative. CVC-associated BSI protocols were implemented using a collaborative process that included catheter insertion and maintenance bundles, daily review of CVC necessity, and daily goals. The primary goal was either a 50% reduction in the CVC-associated BSI rate or a rate of 1.5 CVC-associated BSIs per 1,000 CVC-days in each ICU at the end of a 9-month improvement period. A 12-month sustain period followed the initial improvement period, with the primary goal of maintaining the improvements achieved.
The collaborative median CVC-associated BSI rate decreased from 6.3 CVC-associated BSIs per 1,000 CVC-days at the start of the collaborative to 4.3 CVC-associated BSIs per 1,000 CVC-days at the end of the collaborative. Sixty-five percent of all participants documented a decrease in their CVC-associated BSI rate. Sixty-nine CVC-associated BSIs were prevented across all teams, with an estimated cost avoidance of $2.9 million. Hospitals were able to sustain their improvements during a 12-month sustain period and prevent another 198 infections.
We conclude that our collaborative quality improvement project demonstrated that significant reduction in CVC-associated BSI rates and related costs can be realized by means of evidence-based prevention interventions, enhanced communication among caregivers, standardization of CVC insertion and maintenance processes, enhanced measurement, and empowerment of team members to enforce adherence to best practices.
We present three new methods for determining the age of groups of pre-main-sequence stars. The first, creating empirical isochrones allows us to create a robust age ordering, but not to derive actual ages. The second, using the width of the gap in colour-magnitude space between the pre-main-sequence and main-sequence (the radiative convective gap) has promise as a distance and extinction independent measure of age, but is as yet uncalibrated. Finally we discuss τ2 fitting of the main sequence as the stars approach the terminus of the main sequence. This method suggests that there is a factor two difference between these “nuclear” ages, and more conventional pre-main-sequence contraction ages.
Rotation periods and projected equatorial velocities of pre-main-sequence (PMS) stars in star forming regions can be combined to give projected stellar radii. Assuming random axial orientation, a Monte-Carlo model is used to illustrate that distributions of projected stellar radii are very sensitive to ages and age dispersions between 1 and 10Myr which, unlike age estimates from conventional Hertzsprung-Russell diagrams, are relatively immune to uncertainties due to extinction, variability, distance etc. Application of the technique to the Orion Nebula cluster reveals radius spreads of a factor of 2–3 (FWHM) at a given effective temperature. Modelling this dispersion as an age spread suggests that PMS stars in the ONC have an age range larger than the mean cluster age, that could be reasonably described by the age distribution deduced from the Hertzsprung-Russell diagram. These radius/age spreads are certainly large enough to invalidate the assumption of coevality when considering the evolution of PMS properties (rotation, disks etc.) from one young cluster to another.
Electrical resistivity measurements performed under applied hydrostatic pressure and in magnetic fields have been used to probe the hidden order (HO) and superconducting (SC) states of URu2Si2, which have ambient-pressure transition temperatures TO = 17.5 K and Tc = 1.5 K, respectively. TO increases with applied pressure and a distinct kink in its pressure dependence is observed at 15 kbar; this feature is associated with the onset of antiferromagnetism. The pressure dependence of the SC upper critical field has been measured with the external field aligned parallel to both crystalline axes. The SC phase is smoothly suppressed to a critical pressure of about 15 kbar and no qualitative change in the critical field curves is observed. The co-evolution of the HO and SC phases is discussed within the context of a model in which the two phases compete for Fermi surface fraction.
The gallium-stabilized Pu-2.0 at. % Ga alloy undergoes a partial or incomplete low-temperature martensitic transformation from the metastable δ phase to the gallium-containing, monoclinic α′ phase near -100 °C. This transformation has been shown to occur isothermally and it displays anomalous double-C kinetics in a time-temperature-transformation (TTT) diagram, where two nose temperatures anchoring an upper- and lower-C describe minima in the time for the initiation of transformation. The underlying mechanisms responsible for the double-C behavior are currently unresolved, although recent experiments suggest that a conditioning treatment—wherein, following an anneal at 375 °C, the sample is held at a sub-anneal temperature for a period of time—significantly influences the upper-C of the TTT diagram. As such, elucidating the effects of the conditioning treatment upon the δ⟶α′ transformation can provide valuable insights into the fundamental mechanisms governing the double-C kinetics of the transition. Following a high-temperature anneal, a differential scanning calorimeter (DSC) was used to establish an optimal conditioning curve that depicts the amount of α′ formed during the transformation as a function of conditioning temperature for a specified time. With the optimal conditioning curve as a baseline, the DSC was used to explore the circumstances under which the effects of the conditioning treatment were destroyed, resulting in little or no transformation.
Under ambient conditions, a Pu-2.0 at.% Ga alloy is retained in the metastable δ phase. Upon cooling to approximately -120 °C, the face-centered-cubic δ phase partially transforms to the metastable monoclinic α′ phase via a martensitic transformation. The kinetics of the δ⟶α′ transformation are reported to have double-C curve kinetics in a time-temperature-transformation (TTT) diagram, but the mechanisms responsible for this unusual behavior are not understood. Our work focuses on determining the underlying cause of the two noses. Optical microscopy has been used to investigate the role of “conditioning”—an isothermal hold at sub-anneal temperatures—on the δ⟶α′ transformation and to illuminate any disparities in transformation products. Conditioning was found to affect substantially the amount of transformation that occurs at particular points corresponding to both the upper- and lower-C of the TTT diagram.
We present IZJHKL′ photometry of the core of the cluster NGC 6611 in the Eagle Nebula. This photometry is used to constrain the Initial Mass Function (IMF) and the circumstellar disk frequency of the young stellar objects. Optical spectroscopy of 258 objects is used to confirm membership and constrain contamination as well as individual reddening estimates. Our overall aim is to assess the influence of the ionizing radiation from the massive stars on the formation and evolution of young low-mass stars and their disks. The disk frequency determined from the JHKL′ colour-colour diagram suggests that the ionizing radiation from the massive stars has little effect on disk evolution (Oliveira et al. 2005). The cluster IMF seems indistinguishable from those of quieter environments; however towards lower masses the tell-tale signs of an environmental influence are expected to become more noticeable, a question we are currently addressing with our recently acquired ultra-deep (ACS and NICMOS) HST images.
Recent experiments on single crystals of the compounds CeRh1−xCoxIn5 and PrOs4Sb12 are briefly reviewed. The temperature-composition (T-x) phase diagram of the heavy fermion pseudoternary system CeRh1−xCoxIn5, delineating the regions in which superconductivity, antiferromagnetism, and the coexistence of these two phenomena occur, has been established. Entropy vs x isotherms and residual resistivity vs x plots exhibit peaks near the critical concentration xcr ≈ 0.8 at which the Néel temperature appears to vanish (quantum critical point). The filled skutterudite compound PrOs4Sb12 exhibits unconventional superconductivity below Tc = 1.85 K that involves heavy fermion quasiparticles with an effective mass m* ≈ 50 me, where me is the mass of the free electron. The unconventional superconducting state appears to consist of several distinct superconducting phases and to break time reversal symmetry. A high field ordered phase occurs below ∼ 1 K and between ∼ 4.5 T and ∼ 15 T that appears to be associated with quadrupolar order. The heavy fermion state and superconductivity in PrOs4Sb12 may originate from the interaction between Pr3+ electric quadrupole moments and the charges of the conduction electrons. When Ru is substituted for Os in PrOs4Sb12, a minimum in Tc occurs at Pr(Os0.4Ru0.6)4Sb12, suggesting a competition between two types of superconductivity.
I examine the possibility that large, cool prominences can be formed in close binary systems, when coronal structures grow beyond the point where centrifugal force balances gravitational attraction. X-ray light curves of the eclipsing binary XY UMa indicate that an extended corona is probably present and this is likely to reach heights > 1.5 R⊙, where centrifugal compression may render plasma in the coronal loop apexes unstable to thermal perturbations. Cool condensations could form, explaining features such as the dips in the X-ray light curves of V471 Tau, and the circumstellar material deduced to be present in several close binary systems.
Guinea pigs were treated with a single dose of Cisplatin (5 mg IP). After 2–4 days the cochleas were prepared for morphological analysis by scanning electron microscopy and chemical analysis by X-ray dispersive microanalysis. Following Cisplatin, the bundles of stereocilia on the hair cells were found to be rough, disarrayed, fused, and finally absorbed. Significant increases were found in the levels of calcium, sulphur, and phosporus in the abnormal hair cells. It is suggested that the high calcium levels might be due to the inhibition of enzymes which normally keep cytoplasmic calcium low, and that some of the changes in the stereocilia might be secondary to this.
Human cochleae were fixed in glutaraldehyde, without the use of osmium. Crosslinks were seen between the stereocilia, similar to those we have previously reported for the guinea pig: first, stereocilia of the same row on each hair cell were joined by horizontally-running links; secondly, the shorter stereocilia had pointed tips, each giving rise to a single, vertically-pointing link, which ran upwards to join the adjacent taller stereocilium of the next row. We suggest that distortion of this link is involved in sensory transduction. The links were sparser than had been seen in the guinea pig which may be a reflection of the vulnerability of the links to nonoptimal fixation, and the greater difficulty in producing good fixation in human specimens.