279 research outputs found
Obstetric and psychosocial risk factors for Australian-born and non-Australian born women and associated pregnancy and birth outcomes : a population based cohort study
Background: One in four Australians is born overseas and 47 % are either born overseas or have a parent who was. Obstetric and psychosocial risk factors for these women may differ. Method: Data from one Sydney hospital (2012–2013) of all births recorded in the ObstetriX™ database were analysed (n = 3,092). Demographics, obstetric and psychosocial risk profile, obstetric interventions and complications and selected maternal and neonatal outcomes were examined for women born in Australia and overseas. Results: Women born in Australia were younger, more likely to be primiparous (28.6 v 27.5 %), be obese (32.0 % v
21.4 %), smoke (19.7 % v 3.0 %), have an epidural (26.2 % v 20.2 %) and were less likely to have gestational diabetes mellitus (GDM) (6.8 % v 13.7 % when compared to non-Australian born women. The highest rates of GDM, Gestational
Hypertension (GH) and maternal anaemia were seen in women born in China, the Philippines and Pakistan respectively. Differences were also seen in psychosocial screening between Australian and non-Australian women with Australian-born women more likely to smoke and report a mental health disorder. There was an association between having an Edinburgh Postnatal Depression Scale (EPDS) ≥ 13 and other psychosocial issues, such as thoughts of self-harm,
domestic violence, childhood abuse etc. These women were also less likely to breastfeed. Women with an EPDS ≥ 13 at booking compared to women with EPDS ≤12 had a higher chance of being diagnosed with GDM (AOR 1.85 95 % CI 1.14–3.0).
Conclusions: There are significant differences in obstetric and psychosocial risk profiles and maternal and neonatal outcomes between Australian-born and non-Australian born women. In particular there appears to be an association
between an EPDS of ≥13 and developing GDM, which warrants further investigation
Eigenphase preserving two-channel SUSY transformations
We propose a new kind of supersymmetric (SUSY) transformation in the case of
the two-channel scattering problem with equal thresholds, for partial waves of
the same parity. This two-fold transformation is based on two imaginary
factorization energies with opposite signs and with mutually conjugated
factorization solutions. We call it an eigenphase preserving SUSY
transformation as it relates two Hamiltonians, the scattering matrices of which
have identical eigenphase shifts. In contrast to known phase-equivalent
transformations, the mixing parameter is modified by the eigenphase preserving
transformation.Comment: 16 pages, 1 figur
Supersymmetric transformations for coupled channels with threshold differences
The asymptotic behaviour of the superpotential of general SUSY
transformations for a coupled-channel Hamiltonian with different thresholds is
analyzed. It is shown that asymptotically the superpotential can tend to a
diagonal matrix with an arbitrary number of positive and negative entries
depending on the choice of the factorization solution. The transformation of
the Jost matrix is generalized to "non-conservative" SUSY transformations
introduced in Sparenberg et al (2006 J. Phys. A: Math. Gen. 39 L639). Applied
to the zero initial potential the method permits to construct superpartners
with a nontrivially coupled Jost-matrix. Illustrations are given for two- and
three-channel cases.Comment: 17 pages, 3 explicit examples and figures adde
Aging and memory phenomena in magnetic and transport properties of vortex matter: a brief review
There is mounting experimental evidence that strong off-equilibrium
phenomena, such as ``memory'' or ``aging'' effects, play a crucial role in the
physics of vortices in type II superconductors. We give a short review, based
on a recently introduced schematic vortex model, of current progresses in
understanding out of equilibrium vortex behaviours. We develop a unified
description of ``memory'' phenomena in magnetic and transport properties, such
as magnetisation loops and their ``anomalous'' 2nd peak, logarithmic creep,
``anomalous'' finite creep rate in the limit of vanishing temperature,
``memory'' and ``irreversibility'' in I-V characteristics, time dependent
critical currents, ``rejuvenation'' and ``aging'' of the system response.Comment: updated versio
Effects of crack tip geometry on dislocation emission and cleavage: A possible path to enhanced ductility
We present a systematic study of the effect of crack blunting on subsequent
crack propagation and dislocation emission. We show that the stress intensity
factor required to propagate the crack is increased as the crack is blunted by
up to thirteen atomic layers, but only by a relatively modest amount for a
crack with a sharp 60 corner. The effect of the blunting is far less
than would be expected from a smoothly blunted crack; the sharp corners
preserve the stress concentration, reducing the effect of the blunting.
However, for some material parameters blunting changes the preferred
deformation mode from brittle cleavage to dislocation emission. In such
materials, the absorption of preexisting dislocations by the crack tip can
cause the crack tip to be locally arrested, causing a significant increase in
the microscopic toughness of the crack tip. Continuum plasticity models have
shown that even a moderate increase in the microscopic toughness can lead to an
increase in the macroscopic fracture toughness of the material by several
orders of magnitude. We thus propose an atomic-scale mechanism at the crack
tip, that ultimately may lead to a high fracture toughness in some materials
where a sharp crack would seem to be able to propagate in a brittle manner.
Results for blunt cracks loaded in mode II are also presented.Comment: 12 pages, REVTeX using epsfig.sty. 13 PostScript figures. Final
version to appear in Phys. Rev. B. Main changes: Discussion slightly
shortened, one figure remove
Linear, Deterministic, and Order-Invariant Initialization Methods for the K-Means Clustering Algorithm
Over the past five decades, k-means has become the clustering algorithm of
choice in many application domains primarily due to its simplicity, time/space
efficiency, and invariance to the ordering of the data points. Unfortunately,
the algorithm's sensitivity to the initial selection of the cluster centers
remains to be its most serious drawback. Numerous initialization methods have
been proposed to address this drawback. Many of these methods, however, have
time complexity superlinear in the number of data points, which makes them
impractical for large data sets. On the other hand, linear methods are often
random and/or sensitive to the ordering of the data points. These methods are
generally unreliable in that the quality of their results is unpredictable.
Therefore, it is common practice to perform multiple runs of such methods and
take the output of the run that produces the best results. Such a practice,
however, greatly increases the computational requirements of the otherwise
highly efficient k-means algorithm. In this chapter, we investigate the
empirical performance of six linear, deterministic (non-random), and
order-invariant k-means initialization methods on a large and diverse
collection of data sets from the UCI Machine Learning Repository. The results
demonstrate that two relatively unknown hierarchical initialization methods due
to Su and Dy outperform the remaining four methods with respect to two
objective effectiveness criteria. In addition, a recent method due to Erisoglu
et al. performs surprisingly poorly.Comment: 21 pages, 2 figures, 5 tables, Partitional Clustering Algorithms
(Springer, 2014). arXiv admin note: substantial text overlap with
arXiv:1304.7465, arXiv:1209.196
Parental experience of an early developmental surveillance programme for autism within Australian general practice: A qualitative study
Objectives Implementing support and services early in the life course has been shown to promote positive developmental outcomes for children at high likelihood of developmental conditions including autism. This study examined parents'/caregivers' experiences and perceptions about a digital developmental surveillance pathway for autism, the autism surveillance pathway (ASP), and usual care, the surveillance as usual (SaU) pathway, in the primary healthcare general practice setting. Design This qualitative study involves using a convenience selection process of the full sample of parents/caregivers that participated in the main programme, 'General Practice Surveillance for Autism', a cluster-randomised controlled trial study. All interviews were audio-recorded, transcribed and coded using NVivo V.12 software. An inductive thematic interpretive approach was adopted and data were analysed thematically. Participants Twelve parents/caregivers of children with or without a developmental condition/autism (who participated in the main programme) in South Western Sydney and Melbourne were interviewed. Settings All interviews were completed over the phone. Results There were seven major themes and 20 subthemes that included positive experiences, such as pre-existing patient-doctor relationships and their perceptions on the importance of knowing and accessing early support/services. Barriers or challenges experienced while using the SaU pathway included long waiting periods, poor communication and lack of action plans, complexity associated with navigating the healthcare system and lack of understanding by general practitioners (GPs). Common suggestions for improvement included greater awareness/education for parents/carers and the availability of accessible resources on child development for parents/caregivers. Conclusion The findings support the use of digital screening tools for developmental surveillance, including for autism, using opportunistic contacts in the general practice setting. Trial registration number ANZCTR (ACTRN12619001200178)
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