417 research outputs found
Indigenous child care - leading the way
We believe that the Australian early childhood sector is not performing well. The incidence of poor outcomes for children is increasing, and we believe that current service delivery is not capable of addressing this. We argue that, as a sector, there is an abundance of evidence of the kinds of programs and initiatives that could address our national concerns, and review some of that evidence. We also point out that there is considerable knowledge in Australia, based on Australian programmes and experience, that can be used to build a different early childhood sector with the potential to significantly impact on growing disadvantage. We conclude with the principles or themes around which such initiatives should be developed and a call to advocate for the development of such services. Appropriate services supporting all of our young children, their families and their communities, have the potential to make a huge impact on our society, and we can no longer hide from our responsibilities and avoid providing such services
Improved long-term survival with subdural drains following evacuation of chronic subdural haematoma
Background
Chronic subdural haematoma (CSDH) is a common condition that is effectively managed by burrhole drainage but requires repeat surgery in a significant minority of patients. The Cambridge Chronic Subdural Haematoma Trial (CCSHT) was a randomised controlled study that showed placement of subdural drains for 48 h following burrhole evacuation significantly reduces the incidence of reoperation and improves survival at 6 months. The present study examined the long-term survival of the patients in the trial.
Methods
In the original trial patients at a single neurosurgical centre from 2004–2007 were randomly assigned to receive a drain (n = 108) or no drain (n = 107) following burrhole drainage of CSDH. We ascertained whether the trial patients were alive in February 2016—a minimum of 8 years following enrollment—via the UK NHS tracing service. Survival was compared between the trial groups and against expected survival for the UK general population matched for age and sex.
Results
At 5 years following surgery the drain group continued to have significantly better survival than the no drain patients (p = 0.027), but this was no longer apparent at 10 years. Survival of patients in the drain group did not differ significantly from that of the general population whereas patients who did not receive a drain had significantly lower survival than expected (p = 0.0006).
Conclusion
Subdural drains following CSDH evacuation are associated with improved long-term survival, which appears similar to that expected for the general population of the same age and sex. All patients having burrhole CSDH evacuation should receive a drain as standard practice unless specifically contraindicated
Demonstration of Niobium Tin in 218 MHz Low-beta Quarter Wave Accelerator Cavity
A 218 MHz quarter wave niobium cavity has been fabricated for the purpose of
demonstrating Nb3Sn technology on a low-beta accelerator cavity. Niobiumtin has
been established as a promising next generation SRF material, but development
has focused primarily in high-beta elliptical cell cavities. This material has
a significantly higher TC than niobium, allowing for design of higher frequency
quarter wave cavities (that are subsequently smaller) as well as for
significantly lowered cooling requirements (possibly leading to cryocooler
based designs). The fabrication, initial cold testing, and Nb3Sn coating are
discussed as well as test plans and details of future applications.Comment: 21st Intl Conf Radio Frequency Superconductivity (SRF 2023
(In)finite extent of stationary perfect fluids in Newtonian theory
For stationary, barotropic fluids in Newtonian gravity we give simple
criteria on the equation of state and the "law of motion" which guarantee
finite or infinite extent of the fluid region (providing a priori estimates for
the corresponding stationary Newton-Euler system). Under more restrictive
conditions, we can also exclude the presence of "hollow" configurations. Our
main result, which does not assume axial symmetry, uses the virial theorem as
the key ingredient and generalises a known result in the static case. In the
axially symmetric case stronger results are obtained and examples are
discussed.Comment: Corrections according to the version accepted by Ann. Henri Poincar
Photoelectron spectroscopy of manganese-based Heusler alloys
Ultraviolet-photoemission spectroscopy has been employed to investigate the valence-band electronic structures of the magnetic alloys Co2MnSn, Cu2MnAl, and Pd2MnSn.The valence band of Co2MnSn extends to approximately 5 eV below the Fermi level with a high density of states immediately below the Fermi edge. Cu2MnAl and Pd2MnSn have valence-band widths of 6 and 7 eV, respectively, with the highest density of states lying some 3 eV below the Fermi level in each case. Photoemission measurements in the region of the Mn 3p threshold indicate that Mn 3d character extends across the full width of the valence band for all three alloys. For Pd2MnSn, additional photoemission measurements in the region of the Pd 4d Cooper minimum confirm this conclusion. Modulations in photocurrent resulting from Mn 3p-to-3d resonances across the valence band of Co2MnSn are most intense towards the bottom of the band. This is discussed in terms of possible variations in initial-state hybridization. The experimental photoemission spectra are compared with calculated spectra derived from theoretical band structures. Although there are some differences in shape, the bandwidths of the calculated spectra agree very well with the experimental results
Advanced surface treatments for medium-velocity superconducting RF cavities for high accelerating gradient continuous-wave operation
Nitrogen-doping and furnace-baking are advanced high-Q0 recipes developed for
1.3 GHz TESLA-type cavities. These treatments will significantly benefit the
high-Q0 linear accelerator community if they can be successfully adapted to
different cavity styles and frequencies. Strong frequency- and geometry-
dependence of these recipes makes the technology transfer amongst different
cavity styles and frequencies far from straightforward, and requires rigorous
study. Upcoming high-Q0 continuous-wave linear accelerator projects, such as
the proposed Michigan State University Facility for Rare Isotope Beam Energy
Upgrade, and the underway Fermilab's Proton Improvement Plan-II, could benefit
enormously from adapting these techniques to their beta_opt = 0.6 ~650 MHz
5-cell elliptical superconducting rf cavities, operating at an accelerating
gradient of around ~17 MV/m. This is the first investigation of the adaptation
of nitrogen doping and medium temperature furnace baking to prototype 644 MHz
beta_opt = 0.65 cavities, with the aim of demonstrating the high-Q0 potential
of these recipes in these novel cavities for future optimization as part of the
FRIB400 project R&D. We find that nitrogen-doping delivers superior Q0, despite
the sub-GHz operating frequency of these cavities, but is sensitive to the
post-doping electropolishing removal step and experiences elevated residual
resistance. Medium temperature furnace baking delivers reasonable performance
with decreased residual resistance compared to the nitrogen doped cavity, but
may require further recipe refinement. The gradient requirement for the FRIB400
upgrade project is comfortably achieved by both recipes.Comment: 16 pages, 5 figure
Yang's gravitational theory
Yang's pure space equations (C.N. Yang, Phys. Rev. Lett. v.33, p.445 (1974))
generalize Einstein's gravitational equations, while coming from gauge theory.
We study these equations from a number of vantage points: summarizing the work
done previously, comparing them with the Einstein equations and investigating
their properties. In particular, the initial value problem is discussed and a
number of results are presented for these equations with common energy-momentum
tensors.Comment: 28 pages, to appear in Gen. Rel. Gra
Clinical Experience and Results of Microsurgical Resection of Arterioveonous Malformation in the Presence of Space-Occupying Intracerebral Hematoma
BACKGROUND: Management of ruptured arteriovenous malformations (AVMs) with a mass-producing intracerebral hematoma (ICH) represents a surgical dilemma. OBJECTIVE: To evaluate the clinical outcome and obliteration rates of microsurgical resection of AVM when performed concomitantly with evacuation of an associated space-occupying ICH. METHODS: Data of patients with AVM were collected prospectively. Cases were identified in which an AVM was resected and an associated space-occupying ICH was evacuated at the same time, and divided into "group 1," in which the surgery was performed acutely within 48 h of presentation (secondary to elevated intracranial pressure); and "group 2," in which selected patients were operated upon in the presence of a liquefying ICH in the "subacute" stage. Clinical outcomes were assessed using the modified Rankin Scale, with a score of 0 to 2 considered a good outcome. Obliteration rates were assessed using postoperative angiography. RESULTS: From 2001 to 2015, 131 patients underwent microsurgical resection of an AVM, of which 65 cases were included. In "group 1" (n = 21; Spetzler-Ponce class A = 13, class B = 5, and class C = 3), 11 of 21 (52%) had a good outcome and in 18 of 19 (95%) of those who had a postoperative angiogram the AVMs were completely obliterated. In "group 2" (n = 44; Spetzler-Ponce class A = 33, class B = 9, and class C = 2), 31 of 44 (93%) had a good outcome and 42 of 44 (95%) were obliterated with a single procedure. For supratentorial AVMs, the ICH cavity was utilized to provide an operative trajectory to a deep AVM in 11 cases, and in 26 cases the ICH cavity was deep to the AVM and hence facilitated the deep dissection of the nidus. CONCLUSION: In selected patients the presence of a liquefying ICH cavity may facilitate the resection of AVMs when performed in the subacute stage resulting in a good neurological outcome and high obliteration rate
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