Devaluation of a constitutional guarantee : the history of section 51(xxiiiA) of the Commonwealth Constitution

This article describes constitutional and socio-historical background to the referendum that led to the inserrion of s 51(xxiijA) into the Commonwealth Constitution. It traces judicial interpretations of the clause 'but not so as to authorise any fonn of civil conscription' through the major cases, including British Medical Association v Commonwealth, General Practitioners Society v Commonwealth, and Alexandra Private Geriatric Hospital Pty Ud v Commonwealth. The issue of the powers of the Commonwealth to regulate private medical practice without infringing the constitutional guarantee against civil conscription is analysed in the context of the development of National Health Care Schemes for financing medical benefits (Health Insurance Commission v Peverill). Constitutional aspects of the 1995 legislation enabling the introduction into Australia of purchaser-provider agreements ('managed care ') are also examined. Finally, the article questions the constitutionality of the Australian Competition and Consumer Commission s powers to regulate the essential elements of the patient-doctor relationship.

Correlation between shoulder flow zone quality and material flow quantity during friction stir welding of thick aluminum section using scroll shoulder tool

The so-called scroll shoulder tool is widely used particularly for thick section friction stir welding (FSW). However, the correlation between its shoulder flow zone weld quality and material flow quantity remains unclear. This information is important for tool design. In the present study, a scroll shoulder tool was used to FSW 20mm thick 6061 aluminum (Al) plates at a range of welding parameters. The pick-up material (PUM) by the scroll was quantified, and the effect of welding parameters and PUM on the shoulder flow zone formation and weld quality was studied. It was found that there is a positive linear relationship between the PUM and weld quality. In order to obtain a defect-free FSW weld produced by the scroll shoulder tool, scroll groove needs to be fully filled by PUM.

Material flow forming the shoulder flow zone using scroll shoulder tool during friction stir welding of thick section aluminum alloys

Scroll shoulder tools are widely used and they do not need to be tilted during friction stir welding (FSW). However, the detailed material flow, which is important for proper scroll shoulder tool design and subsequently for forming the defect-free shoulder flow zone, has not been fully explained. In the present study, features of material flow in shoulder flow zone, during FSW of thick 6061 aluminium (Al) plates using a scroll shoulder tool were investigated. It was observed that there is a simple layer-to-layer banded structure which appears in the bottom portion of shoulder flow zone, but disappears in the top portion of this weld zone. When the scroll shoulder tool is plunged into the workpiece to a determined depth, the workpiece material is extruded by the tool pin, and pushed up into the scroll groove beneath the shoulder forming the pick-up material. During the forward movement of the tool, the central portion of pick-up material was driven downward by the root portion of pin and then it detaches from the tip portion of pin in a layer-to-layer manner to form the weld.

Special section : trusted computing

Security and privacy have been the major concern when people build computer networks and systems. Any computer network or system must be trustworthy to avoid the risk of losing control and retain confidence that it will not fail [1] Jun Ho Huh, John Lyle, Cornelius Namiluko and Andrew Martin, Managing application whitelists in trusted distributed systems. Future Generation Computer Systems,  27 2 (2011), pp. 211–226. [1]. Trust is the key factor to enable dynamic interaction and cooperation of various users, systems and services [2]. Trusted Computing aims at making computer networks, systems, and services available, predictable, traceable, controllable, assessable, sustainable, dependable, and security/privacy protectable. This special section focuses on the issues related to trusted computing, such as trusted computing models and specifications, trusted reliable and dependable systems, trustworthy services and applications, and trust standards and protocols.

Introduction to section 4

The nature and extent of the implementation of digital technology in mathematics curricula along with issues of access and equity were the issues considered by one working group of this ICMI study. A summary of the discussion conducted by the working group and the findings reported in the following chapters on this theme are presented. It is clear that widespread and sustained use of digital technology is not common and that where digital technology is used there are complex and confounding equity issues.

Effects of continuity of care by a primary midwife (caseload midwifery) on caesarean section rates in women of low obstetric risk : the COSMOS randomised controlled trial

Objective  To determine whether primary midwife care (caseload midwifery) decreases the caesarean section rate compared with standard maternity care.

Design  Randomised controlled trial.

Setting  Tertiary-care women’s hospital in Melbourne, Australia.

Population  A total of 2314 low-risk pregnant women.

Methods  Women randomised to caseload received antenatal, intrapartum and postpartum care from a primary midwife with some care by ‘back-up’ midwives. Women randomised to standard care received either midwifery or obstetric-trainee care with varying levels of continuity, or community-based general practitioner care.

Main outcome measures  Primary outcome: caesarean birth. Secondary outcomes included instrumental vaginal births, analgesia, perineal trauma, induction of labour, infant admission to special/neonatal intensive care, gestational age, Apgar scores and birthweight.

Results  In total 2314 women were randomised–1156 to caseload and 1158 to standard care. Women allocated to caseload were less likely to have a caesarean section (19.4% versus 24.9%; risk ratio [RR] 0.78; 95% CI 0.67–0.91; P = 0.001); more likely to have a spontaneous vaginal birth (63.0% versus 55.7%; RR 1.13; 95% CI 1.06–1.21; P < 0.001); less likely to have epidural analgesia (30.5% versus 34.6%; RR 0.88; 95% CI 0.79–0.996; P = 0.04) and less likely to have an episiotomy (23.1% versus 29.4%; RR 0.79; 95% CI 0.67–0.92; P = 0.003). Infants of women allocated to caseload were less likely to be admitted to special or neonatal intensive care (4.0% versus 6.4%; RR 0.63; 95% CI 0.44–0.90; P = 0.01). No infant outcomes favoured standard care.

Conclusion  In settings with a relatively high baseline caesarean section rate, caseload midwifery for women at low obstetric risk in early pregnancy shows promise for reducing caesarean births.