Quantum walks: a comprehensive review

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing Journa

Women’s beliefs about medicines and adherence to pharmacotherapy in pregnancy: Opportunities for community pharmacists?

Background During pregnancy women might weigh benefits of treatment against potential risks to the unborn child. However, non-adherence to necessary treatment can adversely affect both mother and child. To optimize pregnant women’s beliefs and medication adherence, community pharmacists are ideally positioned to play an important role in primary care. Objective This narrative review aimed to summarize the evidence on 1) pregnant women’s beliefs, 2) medication adherence in pregnancy, and 3) community pharmacists’ counselling during pregnancy. Method Three search strategies were used in Medline and Embase to find original studies evaluating women’s beliefs, medication adherence and community pharmacists’ counselling during pregnancy. All original descriptive and analytic epidemiological studies performed in Europe, North America and Australia, written in English and published from 2000 onwards were included. Results We included 14 studies reporting on women’s beliefs, 11 studies on medication adherence and 9 on community pharmacists’ counselling during pregnancy. Women are more reluctant to use medicines during pregnancy and tend to overestimate the teratogenic risk of medicines. Risk perception varies with type of medicine, level of health literacy, education level and occupation. Furthermore, low medication adherence during pregnancy is common. Finally, limited evidence showed current community pharmacists’ counselling is insufficient. Barriers hindering pharmacists are insufficient knowledge and limited access to reliable information. Conclusion Concerns about medication use and non-adherence are widespread among pregnant women. Community pharmacists’ counselling during pregnancy is insufficient. Further education, training and research are required to support community pharmacists in fulfilling all the opportunities they have when counselling pregnant women

Development of a core descriptor set for Crohn's anal fistula

AIM: Crohn's anal fistula (CAF) is a complex condition, with no agreement on which patient characteristics should be routinely reported in studies. The aim of this study was to develop a core descriptor set of key patient characteristics for reporting in all CAF research. METHOD: Candidate descriptors were generated from published literature and stakeholder suggestions. Colorectal surgeons, gastroenterologists and specialist nurses in inflammatory bowel disease took part in three rounds of an international modified Delphi process using nine-point Likert scales to rank the importance of descriptors. Feedback was provided between rounds to allow refinement of the next ratings. Patterns in descriptor voting were assessed using principal component analysis (PCA). Resulting PCA groups were used to organize items in rounds two and three. Consensus descriptors were submitted to a patient panel for feedback. Items meeting predetermined thresholds were included in the final set and ratified at the consensus meeting. RESULTS: One hundred and thirty three respondents from 22 countries completed round one, of whom 67.0% completed round three. Ninety seven descriptors were rated across three rounds in 11 PCA-based groups. Forty descriptors were shortlisted. The consensus meeting ratified a core descriptor set of 37 descriptors within six domains: fistula anatomy, current disease activity and phenotype, risk factors, medical interventions for CAF, surgical interventions for CAF, and patient symptoms and impact on quality of life. CONCLUSION: The core descriptor set proposed for all future CAF research reflects characteristics important to gastroenterologists and surgeons. This might aid transparent reporting in future studies

Low incidence of colorectal cancer in Australian ulcerative colitis patients

Background: Ulcerative colitis (UC) causes significant morbidity and patients may ultimately require colectomy. UC is also associated with an increased risk of developing colorectal cancer (CRC), which may be as high as 18% after 30 years although some recent studies have reported lower rates. Aims: This study aimed to ascertain the cumulative incidences of colectomy and CRC in Australian UC patients. Methods: The study is based on a prevalence cohort (1977–1992) of Sydney IBD patients was fi rst described in 1995 and longitudinally followed. UC patients were included in this analysis if they were either diagnosed after 1977 or had yet to experience colectomy or CRC in 1977 Cumulative incidences for colectomy and CRC were calculated by competing risk survival analysis using the statistical software R. Phenotyping was performed using the Montreal Classification. The influence of extent of colitis, sex, age at diagnosis and year of diagnosis on cumulative incidences were also examined. Results: 504 patients (267 males, median age at diagnosis 34 years) were followed up for a median of 14 years (8006 patient years). The cumulative incidence of colectomy was 15% (95% CI 11%–19%) after 10 years, 26% (95% CI 21%–30%) after 20 years and 31% (95% CI 25–36%) by 30 years. Pancolitis was associated with an increased risk of colectomy (hazard ratio of 13.15; 95% CI 3.2–54.01, P < 0.001), but neither age at diagnosis nor year of diagnosis influenced colectomy risk. CRC occurred in 24 patients for a cumulative incidence of CRC of 1% (95% CI 0–2%) at 10 years, 3% (95% CI 1–5%) at 20 years and 7% (95% CI 4%–10%) at 30 years. Patients diagnosed before 1980 had a hazard ratio for CRC of 5.2 (95% CI 1.74–15.5, P = 0.003) compared to those diagnosed ≥1980. The extent of colitis (left-sided versus pancolitis) was not found to influence CRC risk possibly due the small number of cancers (P = 0.8).Conclusion: We have demonstrated a very low incidence of CRC in this Australian cohort of UC patients. The decreased risk of developing CRC in patients diagnosed after 1980 suggests a positive effect from modern management by dedicated gastroenterologists. The finding of lower cancer rates than in other cohorts should reassure patients and physicians alike. Only a quarter of patients required colectomy within 20 years and the risk was higher for patients with pancolitis.Christian Selinger, Jane Andrews, Andrew Titman, Rupert W Leon

Poor Inflammatory Bowel Disease (IBD)-specific pregnancy knowledge in patients with Inflammatory Bowel Disease: predictive factors and implications

Abstract - Luminal ClinicalMB Roberts, CP Selinger, RWL Leong, JM Andrew

Impact of Opioid Use on the Natural History of Inflammatory Bowel Disease: Prospective Longitudinal Follow-up Study

Background Opioid use is increasingly prevalent amongst patients with inflammatory bowel disease (IBD), but whether opioids have deleterious effects, or their use is merely linked with more severe disease, is unclear. We conducted a longitudinal follow-up study examining this issue. Methods Data on demographics, gastrointestinal and psychological symptoms, quality of life, and opioid use were recorded at baseline. Data on healthcare use and adverse disease outcomes were obtained from a review of electronic medical records at 12 months. Characteristics at baseline of those using opioids and those who were not were compared, in addition to occurrence of flare, prescription of glucocorticosteroids, treatment escalation, hospitalization, or intestinal resection during the 12 months of follow-up. Results Of 1029 eligible participants, 116 (11.3%) were taking opioids at baseline. Medium (odds ratio [OR], 4.67; 95% confidence interval [CI], 1.61-13.6) or high (OR, 8.03; 95% CI, 2.21-29.2) levels of somatoform symptom-reporting and use of antidepressants (OR, 2.54; 95% CI, 1.34-4.84) or glucocorticosteroids (OR, 6.63; 95% CI, 2.26-19.5; P < .01 for all analyses) were independently associated with opioid use. Following multivariate analysis, opioid users were significantly more likely to undergo intestinal resection (hazard ratio,  7.09; 95% CI, 1.63 to 30.9; P = .009), particularly when codeine or dihydrocodeine were excluded (hazard ratio, 42.9; 95% CI, 3.36 to 548; P = .004). Conclusions Opioid use in IBD is associated with psychological comorbidity and increased risk of intestinal resection, particularly in stronger formulations. Future studies should stratify the risk of individual opioids, so that robust prescribing algorithms can be developed and assess whether addressing psychological factors in routine IBD care could be an effective opioid avoidance strategy

Mortality in a large Australian metropolitan cohort of Crohn's disease patients

Background: Crohn’s disease (CD) causes significant morbidity and can cause fatal complications. Data from Europe and North America suggest that mortality (CD) is increased by up to 50% in CD. There is a paucity of data from Australia. Methods: This longitudinal study of CD patients diagnosed between 1971 and 1992 builds upon a cohort previously described in 1995 by extending follow-up to 2008. Survival status and cause of death (COD) data were extracted from the National Death Index (Australian Institute of Health and Welfare) with complete follow-up of available data. Relative survival analysis (SURV2, Finnish Cancer Registry) was used to compare the observed survival of patients with the expected survival of a comparable group based upon official life tables for the population of New South Wales, adjusting for year of birth, year of diagnosis and sex. The relation between COD and CD was judged independently by two Gastroenterologists. Results: Of 373 CD patients (153 M, 220 F) 82 (21.9%) had died at the end of the study period. Median follow up was 22.7 years [M] and 22.2 years [F] respectively. There was no difference in mortality compared to the general population. Relative survival was 1.03 [M] (95%CI 0.98–1.08) and 0.98 ([F] 95%CI 0.94–1.0) at 10 years, 0.98 ([M] 95%CI 0.89–1.06) and 0.98 ([F] 95%CI 0.93–1.04) at 20 years, 0.98 ([M] 95%CI 0.86–1.1) and 0.88 ([F] 95%CI 0.76–0.99) at 30 years. There was no difference in survival between patients diagnosed from 1971 to 1979 and those diagnosed from 1980 to 1992. Death from all malignant diseases occurred in 22.1% (lung 2.9%, pancreas 2.9%, bile duct 2.9%, colorectal 2.9%). A definite or possible relation between CD and COD was found in 27.9%.Conclusion Over a quarter of deaths are caused by CD itself, but overall survival is similar to that of the general population. This finding stands in contrast to current and older data from Europe and North America. This discrepancy could be due to differences in disease severity, health care system, social or environmental factors.S Bath, J Andrews, O Dent, RW Leon

Probiotic VSL#3 prevents antibiotic-associated diarrhoea in a double-blind, randomized, placebo-controlled clinical trial

SummaryBackgroundAntibiotic-associated diarrhoea (AAD) is a frequent complication of systemic antibiotic therapy and Clostridium difficile-associated diarrhoea (CDAD) is its most serious form due to associated morbidity and mortality.AimThis trial aimed to investigate whether the probiotic VSL#3 prevents AAD and CDAD in average-risk hospital patients.MethodsAdult hospital inpatients exposed to systemic antibiotics were recruited to this multicentre, randomized, double-blind, placebo-controlled trial. One sachet of VSL#3 or placebo was given twice daily for the length of the antibiotics course and for seven days thereafter. Primary outcomes were AAD and CDAD.FindingsPatients randomized to active (N = 117) and placebo (N = 112) groups were well-matched for baseline demographic patient data. No cases of CDAD were detected. The rate of AAD was significantly lower in the active group on per protocol analysis (0% active vs 11.4% placebo; P = 0.006). On intention-to-treat analysis the difference in AAD incidence (4.3% active vs 8.9% placebo; P = 0.19) was not significant.ConclusionsVSL#3 is associated with a significant reduction in the incidence of AAD in average-risk hospital inpatients exposed to systemic antibiotics. As the incidence of CDAD has fallen sharply, no cases of CDAD were found. Probiotic administration as prophylaxis for CDAD may not be indicated in average-risk hospital patients

Persistence of Symptoms of Anxiety and Depression in Inflammatory Bowel Disease: A Longitudinal Follow‐Up Study

Background Poor psychological health affects many patients with inflammatory bowel disease (IBD), but the persistence of these symptoms is unclear. Methods We performed a longitudinal follow-up study of patients whose anxiety and depression trajectories were established by symptom data collected at 3-monthly intervals over the course of 1 year. We collected further anxiety and depression symptom data at yearly intervals over 2 years to determine the persistence of these symptoms in patients with IBD. Disease outcomes (flare/need for glucocorticosteroids, escalation of medical therapy, hospitalisation, or intestinal resection) were recorded to determine the effect of mood trajectories on the natural history of IBD. Results Of 770 patients with established anxiety trajectories, 486 (63.1%) provided further anxiety symptom data at 12 months, and 358 (45.5%) at 24 months. Of the 777 patients with established depression trajectories, 491 (63.2%) provided further depression symptom data at 12 months, and 362 (45.6%) at 24 months. Participants with symptoms of anxiety at 24 months were more likely to have a fluctuating, or persistently abnormal or worsening, anxiety trajectory during the first year (p < 0.001 for trend). Participants with symptoms of depression at 24 months were more likely to have a fluctuating, or persistently abnormal or worsening, depression trajectory during the first year (p < 0.001 for trend). Adverse disease outcomes were no more likely according to anxiety or depression trajectories. Discussion Poor psychological health persists for a substantial number of patients with IBD. Further work is needed to establish the long-term effect of mood trajectories on disease outcomes