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The present study compared the age of first solid foods in a cohort of preterm infants with term infants and identified factors influencing timing of solid food introduction.
Structured interviews on infant feeding practices, growth and medical status at term equivalence and at 3, 6, 9 and 12 months corrected postnatal age. The age of solid food introduction was compared between term and preterm infants, and the influence of maternal, infant and milk feeding factors was assessed.
This prospective longitudinal study recruited primary carers of preterm and term infants from a regional metropolitan referral hospital in eastern Australia.
One hundred and fifty infants (preterm, n 85; term, n 65).
When corrected for prematurity, preterm infants received solid foods before the recommended age for the introduction of solid foods for term infants. Median introduction of solid foods for preterm infants was 14 weeks corrected age (range 12–17 weeks). This was significantly less than 19 weeks (range 17–21 weeks) for term infants (P < 0·001). Lower maternal education and male gender were associated with earlier introduction of solid foods among preterm infants.
Preterm infants are introduced to solid foods earlier than recommended for term infants, taking account of their corrected age. Further research is needed to assess any risk or benefit associated with this pattern and thus to develop clear evidence-based feeding guidelines for preterm infants.
With the advent of surveys such as the Catalina Real-Time Transient Survey, the Palomar Transient Factory, Pan-STARRS and Gaia, the search for variable objects and transient events is rapidly accelerating. There are, however important existing data-sets from instruments not originally designed to find such events. One example of such an instrument is the Solar Mass Ejection Imager (SMEI), an all-sky space-based differential photometer which is able to produce light curves of bright objects (m ≤ 8) with a 102-minute cadence. In this paper we discuss the use of such an instrument for investigations of novæ, and outline future plans to find other variable objects with this hitherto untapped resource.
A Rapid Thermal Annealing (RTA) system was used to anneal sputtered and MOVPE-grown Aluminum Nitride (AlN) thin films at temperatures up to 1000°C in ambient and controlled environments. According to Energy Dispersive X-Ray Analysis (EDAX), the films annealed in an ambient environment rapidly oxidize after five minutes at 1000°C. Below 1000°C the films oxidized linearly as a function of annealing temperature which is consistent with what has been reported in literature . Laser Doppler Vibrometry (LDV) was used to measure the piezoelectric coefficient, d33, of these films. Films annealed in an ambient environment had a weak piezoelectric response indicating that oxidation on the surface of the film reduces the value of d33. A high temperature furnace has been built that is capable of taking in-situ measurements of the piezoelectric response of AlN films. In-situ d33 measurements are recorded up to 300°C for both sputtered and MOVPE-grown AlN thin films. The measured piezoelectric response appears to increase with temperature up to 300°C possibly due to stress in the film.
XSHAPE has been developed to aid the better understanding of the 3D morphologies and kinematics of PNe and novae, by producing models which closely predict the observed 2D images and long-slit spectra of these objects. Early successes include plausible simulations for the elliptical PN Sa 2-21 and the nova HR Del.
Supersonic and even hypersonic outflows have been found in a wide variety of PNe using the Manchester Echelle spectrometer (MES; Meaburn et al. 1984). Dramatic examples of these extreme motions found over many years are highlighted here for comparison with their most recent discovery in the bipolar PN, MyCn 18.
Form deprivation has been shown to result in myopia
in a number of species such that the eye enlarges if one
eye is permanently closed at the time of eye opening. In
the quokka wallaby, the eye grows slowly throughout life.
After form deprivation, the eye enlarges by 1–1.5
years of age to the size of that in a 4–6-year-old
animal and the number of multinucleated retinal pigment
epithelial (RPE) cells in the enlarged retina remains much
lower than would be expected in eyes of comparable size.
Here we have repeated the experiment but examined animals
at 4 years of age. The sutured eye grew significantly larger
than did its partner. Numbers of RPE cells were comparable
between sutured and partner eyes but were lower than in
normal animals of similar age. Reductions in RPE cell density
were greater in nasal than in dorsal or ventral retina
and were not seen in temporal retina. The distribution
of multinucleated cells was quite different in the sutured
and open eyes. As in normal eyes, partner eyes had most
multinucleated cells in ventral retina, while in the sutured
eyes such cells were located mainly in the far periphery.
In conclusion, the RPE is significantly changed by the
eye enlargement process. However, it is not known whether
this change results from an active part played by the RPE
in the retinal expansion process or whether the changes
are simply a result of a passive increase in area of the
The frequency-doubling efficiency and resultant
focal spot quality of a large aperture (140 × 89
mm) subpicosecond, chirped pulse amplified (CPA) 1054-nm
beam for laser–matter interaction studies has been
investigated using the Vulcan Nd:glass laser system (Danson
et al. 1998). The effect of B-integral on the
CPA beam quality was studied and is shown not to be the
dominant cause of the observed frequency-doubled beam break-up.
Conversion efficiency tests were carried out on small aperture
KDP (type 1) crystals at a range of incident intensities
up to 3 × 1011 W/cm2 giving
the optimum crystal thickness for pulses in the 0.3–3
ps region. A large-aperture frequency-doubled beam was
commissioned and delivered pulses of over 10 TW onto target
for an electron acceleration experiment.
Various possible mechanisms for the recently discovered enhanced Seebeck coefficient S in PbTe/Te superlattices relative to the corresponding PbTe bulk are investigated. Among the various mechanisms which can account for the enhanced S, the energy dependent τ model (τ ∼ ɛr) seems the most plausible. Here the effective scattering parameter r is preferably increased due to the extra scattering by the periodic Te layers introduced in the superlattice. Other transport properties including the longitudinal magnetoresistance are also discussed.
The retinal pigment epithelium (RPE) of the quokka wallaby, Setonix brachyurus, grows and changes throughout life. To investigate factors that determine changes in the quokka RPE, we have examined topography of this tissue in experimentally enlarged eyes. Unilateral eyelid suture was conducted at the time of normal eye opening, postnatal day (P) 110, and animals were examined at 1 or 1½ years of age. The numbers and densities of RPE cells and the extent of multinucleation were compared with those in normal animals. Eyelid suture resulted in a 9.8% and 17.4% increase in retinal area at 1 and 1½ years, respectively; a significant degree of myopia was associated with this enlargement. Cell density topography in experimental eyes was not the same as in controls. Cells from central retina were disproportionately larger in the experimental than control eyes. However, the RPE cell topography in sutured eyes was not the same as that of aged retinae of a similar size. Notably, in sutured eyes there was no development of the high or highest cell densities seen in equatorial and temporal central RPE in aged retinae, respectively. Furthermore, the degree of cell enlargement in peripheral regions was slight compared with that observed in similar-sized, aged retinae. There was no increase in RPE cell number; rather, average cell area increased accompanied by no change or a slight decrease in RPE thickness. Consequently, overall volume of cells did not change significantly. The large number of multinucleate cells normally seen in aged animals was not observed in experimentally enlarged eyes, implying that an increase in cell volume may be the trigger for multinucleation.
Between the 17th and the 21st of July, 1995 a group of about fifty mathematicians gathered in Cardiff for the Symposium on Sieve Methods, Exponential Sums and their Applications in Number Theory. They exchanged lectures and informal discussions and posed problems in the broad subject area defined by the title of the Symposium. This volume of papers gives an account of work described at the Symposium. Certain articles include a description of work done after the Symposium closed, some of this being prompted by questions posed during the Symposium.
Many of the contributions involve connections between the additive and multiplicative sides of analytic number theory, an interplay which the Symposium had been planned both to reflect and to promote. The reader will find represented here most of the branches of this subject which, as this volume demonstrates, has its roots in antiquity with the Sieve of Eratosthenes, yet is currently vibrant and receiving fresh stimulus from such diverse topics as trace formulae and elliptic curves.
Many of the participants at the Symposium were supported by the Engineering and Physical Sciences Research Council of the U.K. Others were able to bring their own support with them. The administrative costs were underwritten by the London Mathematical Society. The organisers, who are also the editors of this volume, are grateful to all the sources of support which made the Symposium possible.
The papers in this volume have been refereed to the standards required by leading journals; we take this opportunity to thank the referees for their work.
This volume comprises the proceedings of the 1995 Cardiff symposium on sieve methods, exponential sums, and their applications in number theory. Included are contributions from many leading international figures in this area which encompasses the main branches of analytic number theory. In particular, many of the papers reflect the interaction between the different fields of sieve theory, Dirichlet series (including the Riemann Zeta-function), and exponential sums, whilst displaying the subtle interplay between the additive and multiplicative aspects of the subjects. The fundamental problems discussed include recent work on Waring's problem, primes in arithmetical progressions, Goldbach numbers in short intervals, the ABC conjecture, and the moments of the Riemann Zeta-function.