4,336 research outputs found

    The gluon splitting function at moderately small x

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    It is widely believed that at small x, the BFKL resummed gluon splitting function should grow as a power of 1/x. But in several recent calculations it has been found to decrease for moderately small-x before eventually rising. We show that this `dip' structure is a rigorous feature of the P_gg splitting function for sufficiently small alpha_s, the minimum occurring formally at ln 1/x of order 1/sqrt(alpha_s). We calculate the properties of the dip, including corrections of relative order sqrt(alpha_s), and discuss how this expansion in powers of sqrt(alpha_s), which is poorly convergent, can be qualitatively matched to the fully resummed result of a recent calculation, for realistic values of alpha_s. Finally, we note that the dip position, as a function of alpha_s, provides a lower bound in x below which the NNLO fixed-order expansion of the splitting function breaksdown and the resummation of small-x terms is mandatory.Comment: 10 pages, LaTeX, 3 figure

    Mortality among children and young people who survive cancer in Northern Ireland

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    ABSTRACT: Whilst survival rates for childhood cancers are excellent, it is known that these patients have an increased risk of death from disease recurrence and other causes. We investigate patterns, trends and survival of cancers in children and young adults in N. Ireland. MATERIALS AND METHODS: 21 years (1993-2013) of cancer incidence data including non-malignant brain tumours from the N. Ireland Cancer Registry for persons aged 0-24 years was analysed using Joinpoint regresssion for trend and the Kaplan Meier method for survival analysis up to end 2013 with excess mortality calculated at one and five years after first cancer diagnosis using standardised mortality ratios. RESULTS: 2633 children and young people were diagnosed with cancer, 1386 (52.6%) male and 1247 female with 1139 (43.3%) aged 0-14. While trends increased over time they did not reach statistical significance except in the 15-24 age group for males and females combined. The most common cancers for age 0-14 were brain, eye and central nervous system and leukaemia with skin (including non-melanoma skin) the most common in the 15-24 age group. 59 patients (2.2%) had a record of a second cancer. Survival was high at 90.7% after 1 year, better among females and similar for older and younger groups. Although mortality in children is low overall, there was an excess mortality 24.7% (22-27.5) p<0.001 at one year and 7.3% (5.5-9.2) p<0.001 for those who survived 5 years. Excluding the primary cancer there was an excess mortality for one year survivors, with deaths twice that of the background level (SMR= 2.2 (1.3-3.0)p=0.005 and although one and a half times background levels at 5 years, the excess mortality was not significant 1.5 (0.6-2.3 p=0.269). CONCLUSION: Whilst survival from childhood cancers is excellent, this work in common with larger studies, highlights the need for ongoing monitoring of cancer survivors. Preventable skin cancer was identified as a problem in young adults

    Management and disclosure of quality issues in forensic science: A survey of current practice in Australia and New Zealand

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    The investigation of quality issues detected within the forensic process is a critical feature in robust quality management systems to provide assurance of the validity of reported results and inform strategies for continuous improvement and innovation. A survey was conducted to gain insight into the current state of practice in the management and handling of quality issues amongst the government service provider agencies of Australia and New Zealand. The results demonstrate the value of standardised quality system structures for the recording and management of quality issues, but also areas where inconsistent reporting increases the risk of overlooking important data to inform continuous improvement. With new international changes requiring mandatory reporting of quality issues, this highlights compliance challenges that agencies will face. This study reinforces the need for further research into the standardisation of systems underpinning the management of quality issues in forensic science to support transparent and reliable justice outcomes

    Breast cancer mortality in neighbouring European countries with different levels of screening but similar access to treatment: trend analysis of WHO mortality database

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    Objective To compare trends in breast cancer mortality within three pairs of neighbouring European countries in relation to implementation of screening
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