124 research outputs found

    Empirical Evaluation of the Parallel Distribution Sweeping Framework on Multicore Architectures

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    In this paper, we perform an empirical evaluation of the Parallel External Memory (PEM) model in the context of geometric problems. In particular, we implement the parallel distribution sweeping framework of Ajwani, Sitchinava and Zeh to solve batched 1-dimensional stabbing max problem. While modern processors consist of sophisticated memory systems (multiple levels of caches, set associativity, TLB, prefetching), we empirically show that algorithms designed in simple models, that focus on minimizing the I/O transfers between shared memory and single level cache, can lead to efficient software on current multicore architectures. Our implementation exhibits significantly fewer accesses to slow DRAM and, therefore, outperforms traditional approaches based on plane sweep and two-way divide and conquer.Comment: Longer version of ESA'13 pape

    Characterizing the performance of Flash memory storage devices and its impact on algorithm design

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    Initially used in digital audio players, digital cameras, mobile phones, and USB memory sticks, flash memory may become the dominant form of end-user storage in mobile computing, either completely replacing the magnetic hard disks or being an additional secondary storage. We study the design of algorithms and data structures that can exploit the flash memory devices better. For this, we characterize the performance of NAND flash based storage devices, including many solid state disks. We show that these devices have better random read performance than hard disks, but much worse random write performance. We also analyze the effect of misalignments, aging and past I/O patterns etc. on the performance obtained on these devices. We show that despite the similarities between flash memory and RAM (fast random reads) and between flash disk and hard disk (both are block based devices), the algorithms designed in the RAM model or the external memory model do not realize the full potential of the flash memory devices. We later give some broad guidelines for designing algorithms which can exploit the comparative advantages of both a flash memory device and a hard disk, when used together

    The occurrence of diversion colitis in patients with a sigmoid neovagina

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    Diversion colitis is an inflammatory process occurring in segments of the colorectum surgically diverted from the fecal stream. Clinical symptoms of this condition are rectal discomfort, pain, discharge, and bleeding. We diverted isolated segments of sigmoid to create neovaginas in patients with aplasia vaginae and in male to female transsexuals. In contrast to what is reported in most studies of diversion colitis, the neovagina consists of an isolated segment not connected to the anus in patients without any pre-existing bowel disease. To investigate the occurrence of diversion colitis in these sigmoid-neovaginas we studied biopsy specimens from 13 patients. Most of the patients complained of discharge and slight blood loss from their sigmoid-neovagina. Microscopic examination of the biopsy specimens showed lymphocytic infiltration in all cases. Four cases showed an acute inflammatory infiltrate in the lamina propria. Our results indicate that the changes observed on clinical and histopathologic examinations represent the entity of mild diversion colitis. We conclude that diversion colitis also occurs in a sigmoid neovagina

    Long-term effectiveness of the midwifery initiated oral health-dental service program on maternal oral health knowledge, preventative dental behaviours and the oral health status of children in Australia

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    Background The Midwifery Initiated Oral Health-Dental Service was developed to train midwives to promote maternal oral health, and a large trial showed it substantially improved the oral health, knowledge and behaviours of pregnant women. Aim Evaluate the long-term effectiveness of the program (post-trial) on maternal oral health knowledge, dental behaviours, and early childhood caries in offspring. Methods A prospective cohort study involving 204 women and children 3–4 years (followed after trial) was conducted in Sydney, Australia from 2017 to 2019. Results The program did not have a significant impact on the study measures. Mothers who received the program did have comparatively better knowledge around preventative behaviours to reduce early childhood caries and significantly more mothers were engaging in a key behaviour of using a cup to feed their child. Overall maternal oral health knowledge and level of education did have a protective effect on the dental decay of children. Higher knowledge and levels of education reduced the odds of having a dmft of one or more by over half (OR 0.473), and almost 80% (OR 0.212) respectively. Conclusions Although the MIOH-DS program was not effective, there is still value in exploring other complementary interventions to improve maternal oral health, especially for disadvantaged families. Future research should focus on co-designing an antenatal and postnatal oral health intervention and exploring its long-term impact on the oral health of children

    Gene expression profiles of human endometrial cancer samples using a cDNA-expression array technique: assessment of an analysis method

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    The recently developed cDNA expression array technique can be used to generate gene-expression fingerprints of tumour specimens. To gain insight into molecular mechanisms involved in the development and progression of cancer, this cDNA expression array technique could be a useful tool, however, no established methods for interpreting the results are yet available. We used the Atlas cancer cDNA expression array (Clontech, USA) for analysing total RNA isolated from four human endometrial carcinoma samples (two cell-lines and two tissue samples), one benign endometrial tissue sample and a human breast cancer cell-line, in order to develop a method for analysing the array data. The obtained gene-expression profiles were highly reproducible. XY-scatterplots and regression analysis of the logarithmic transformed data provided a practical method to analyse the data without the need of preceding normalization. Three genes (Decorin, TIMP3 and Cyclin D1) were identified to be differentially expressed between the benign endometrial tissue sample and the endometrial carcinoma samples (tissue and cell-lines). These three genes may potentially be involved in cancer progression. A higher degree of similarity in gene-expression profile was found between the endometrial samples (tissue and cell-lines) than between the endometrial samples and the breast cancer cell-line, which is indicative for an endometrial tissue-specific gene-expression profile. © 2000 Cancer Research Campaig

    Age standardisation – an indigenous standard?

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    The study of inequities in health is a critical component of monitoring government obligations to uphold the rights of Indigenous Peoples. In Aotearoa/New Zealand the indigenous Māori population has a substantially younger age structure than the non-indigenous population making it necessary to account for age differences when comparing population health outcomes. An age-standardised rate is a summary measure of a rate that a population would have if it had a standard age structure. Changing age standards have stimulated interest in the potential impact of population standards on disparities data and consequently on health policy

    Consequences of loss of progesterone receptor expression in development of invasive endometrial cancer

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    PURPOSE: In endometrial cancer, loss of progesterone receptors (PR) is associated with more advanced disease. This study aimed to investigate the mechanism of action of progesterone and the loss of its receptors (PRA and PRB) in development of endometrial cancer. EXPERIMENTAL DESIGN: A 9600-cDNA microarray analysis was performed to study regulation of gene expression in the human endometrial cancer subcell line Ishikawa PRAB-36 by the progestagen medroxy progesterone acetate (MPA). Five MPA-regulated genes were selected for additional investigation. Expression of these genes was studied by Northern blot and by immunohistochemistry in Ishikawa subcell lines expressing different PR isoforms. Additionally, endometrial cancer tissue samples were immunohistochemically stained to study the in vivo protein expression of the selected genes. RESULTS: In the PRAB-36 cell line, MPA was found to regulate the expression of a number of invasion- and metastasis-related genes. On additional investigation of five of these genes (CD44, CSPG/Versican, Tenascin-C, Fibronectin-1, and Integrin-beta 1), it was observed that expression and progesterone regulation of expression of these genes varied in subcell lines expressing different PR isoforms. Furthermore, in advanced endometrial cancer, it was shown that loss of expression of both PR and E-cadherin was associated with increased expression CD44 and CSPG/Versican. CONCLUSION: The present study shows that progestagens exert a modulatory effect on the expression of genes involved in tumor cell invasion. As a consequence, loss of PR expression in human endometrial cancer may lead to development of a more invasive phenotype of the respective tumor

    Statin use is associated with fewer periodontal lesions: A retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Inflammatory processes are considered to participate in the development of cardiovascular disease (CVD). Statins have been used successfully in the prevention and treatment of coronary heart disease. Chronic periodontitis has been suggested to contribute to CVD. The aim of this study was to examine the association of statin use and clinical markers of chronic periodontitis.</p> <p>Methods</p> <p>Periodontal probing pocket depth (PPD) values were collected from dental records of 100 consecutive adult patients referred to a university dental clinic for treatment of advanced chronic periodontitis. A novel index, Periodontal Inflammatory Burden Index (PIBI), was derived from the PPD values to estimate systemic effects of periodontitis.</p> <p>Results</p> <p>Periodontitis patients taking statins had a 37% lower number of pathological periodontal pockets than those without statin medication (P = 0.00043). PIBI, which combines and unifies the data on PPD, was 40% smaller in statin using patients than in patients without statin (P = 0.00069). PIBI of subjects on simvastatin and atorvastatin both differed significantly from patients without statin and were on the same level. The subjects' number of teeth had no effect on the results</p> <p>Conclusion</p> <p>Patients on statin medication exhibit fewer signs of periodontal inflammatory injury than subjects without the statin regimen. PIBI provides a tool for monitoring inflammatory load of chronic periodontitis. The apparent beneficial effects of statins may in part be mediated by their pleiotropic anti-inflammatory effect on periodontal tissue.</p
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