Quantum walks can find a marked element on any graph

We solve an open problem by constructing quantum walks that not only detect but also find marked vertices in a graph. In the case when the marked set $M$ consists of a single vertex, the number of steps of the quantum walk is quadratically smaller than the classical hitting time $HT(P,M)$ of any reversible random walk $P$ on the graph. In the case of multiple marked elements, the number of steps is given in terms of a related quantity $HT^+(\mathit{P,M})$ which we call extended hitting time. Our approach is new, simpler and more general than previous ones. We introduce a notion of interpolation between the random walk $P$ and the absorbing walk $P'$, whose marked states are absorbing. Then our quantum walk is simply the quantum analogue of this interpolation. Contrary to previous approaches, our results remain valid when the random walk $P$ is not state-transitive. We also provide algorithms in the cases when only approximations or bounds on parameters $p_M$ (the probability of picking a marked vertex from the stationary distribution) and $HT^+(\mathit{P,M})$ are known.Comment: 50 page

The effectiveness of case management for comorbid diabetes type 2 patients; the CasCo study. Design of a randomized controlled trial

BACKGROUND: More than half of the patients with type 2 diabetes (T2DM) patients are diagnosed with one or more comorbid disorders. They can participate in several single-disease oriented disease management programs, which may lead to fragmented care because these programs are not well prepared for coordinating care between programs. Comorbid patients are therefore at risk for suboptimal treatment, unsafe care, inefficient use of health care services and unnecessary costs. Case management is a possible model to counteract fragmented care for comorbid patients. It includes evidence-based optimal care, but is tailored to the individual patients' preferences.The objective of this study is to examine the effectiveness of a case management program, in addition to a diabetes management program, on the quality of care for comorbid T2DM patients. METHODS/DESIGN: The study is a randomized controlled trial among patients with T2DM and at least one comorbid chronic disease (N=230), who already participate in a diabetes management program. Randomization will take place at the level of the patients in general practices. Trained practice nurses (case managers) will apply a case management program in addition to the diabetes management program. The case management intervention is based on the Guided Care model and includes six elements; assessing health care needs, planning care, create access to other care providers and community resources, monitoring, coordinating care and recording of all relevant information. Patients in the control group will continue their participation in the diabetes management program and receive care-as-usual from their general practitioner and other care providers. DISCUSSION: We expect that the case management program, which includes better structured care based on scientific evidence and adjusted to the patients' needs and priorities, will improve the quality of care coordination from both the patients' and caregivers' perspective and will result in less consumption of health care services. TRIAL REGISTRATION: Netherlands Trial Register (NTR): NTR1847. (aut. ref.

Chemotherapy-induced nausea and vomiting in daily clinical practice: a community hospital-based study

Background Chemotherapy-induced nausea and vomiting (CINV) are major adverse effects of cancer chemotherapy. This study investigated: (1) the impact of CINV on patients' health-related quality of life (HRQL) in daily clinical practice; (2) the association between patient characteristics and type of antiemetics and CINV; and (3) the role of CINV in physicians' decisions to modify antiemetic treatment. Patients and methods This prospective, multicenter study was conducted in nine general hospitals in the Netherlands. During three consecutive chemotherapy cycles, patients used a diary to record episodes of nausea, vomiting and antiemetic use. For each cycle, these ratings were made 1 day prior to and 7 days after having received chemotherapy. The influence of CINV on patients' HRQL was evaluated with the Functional Living Index-Emesis (FLIE) questionnaire at day 6 of each treatment cycle. (Changes in) antiemetic use were recorded by the treating nurse. Patient inclusion took place between May 2005 and May 2007. Results Two hundred seventy-seven patients were enrolled in the study. Acute and delayed nausea during the first treatment cycle was reported by 39% and 68% of the patients, respectively. The comparable figures for acute and delayed vomiting were 12% and 23%. During the first and subsequent treatment cycle, approximately one-third of the patients indicated that CINV had a substantial impact on their daily lives. Female patients and younger patients reported significantly more CINV than male and older patients. At all treatment cycles, patients receiving treatment with moderately emetogenic chemotherapy, containing anthracycline, reported more acute nausea than patients receiving highly emetogenic chemotherapy. Acute vomiting was associated significantly with change in (i.e., additional) antiemetic treatment. Delayed CINV did not influence antiemetic treatment. Conclusion CINV continues to be a problem that adversely affects the daily lives of patients. CINV is worse in women and in younger patients. In daily clinical practice, acute CINV, but not delayed CINV, results in changes in antiemetic treatment. In view of the effects of not only acute, but also delayed CINV on daily life, more attention should be paid to adjustment of antiemetic treatment to cover CINV complaints, later during the chemotherapy cycle

Usability of a barcode scanning system as a means of data entry on a PDA for self-report health outcome questionnaires: a pilot study in individuals over 60 years of age

BACKGROUND: Throughout the medical and paramedical professions, self-report health status questionnaires are used to gather patient-reported outcome measures. The objective of this pilot study was to evaluate in individuals over 60 years of age the usability of a PDA-based barcode scanning system with a text-to-speech synthesizer to collect data electronically from self-report health outcome questionnaires. METHODS: Usability of the system was tested on a sample of 24 community-living older adults (7 men, 17 women) ranging in age from 63 to 93 years. After receiving a brief demonstration on the use of the barcode scanner, participants were randomly assigned to complete two sets of 16 questions using the bar code wand scanner for one set and a pen for the other. Usability was assessed using directed interviews with a usability questionnaire and performance-based metrics (task times, errors, sources of errors). RESULTS: Overall, participants found barcode scanning easy to learn, easy to use, and pleasant. Participants were marginally faster in completing the 16 survey questions when using pen entry (20/24 participants). The mean response time with the barcode scanner was 31 seconds longer than traditional pen entry for a subset of 16 questions (p = 0.001). The responsiveness of the scanning system, expressed as first scan success rate, was less than perfect, with approximately one-third of first scans requiring a rescan to successfully capture the data entry. The responsiveness of the system can be explained by a combination of factors such as the location of the scanning errors, the type of barcode used as an answer field in the paper version, and the optical characteristics of the barcode scanner. CONCLUSION: The results presented in this study offer insights regarding the feasibility, usability and effectiveness of using a barcode scanner with older adults as an electronic data entry method on a PDA. While participants in this study found their experience with the barcode scanning system enjoyable and learned to become proficient in its use, the responsiveness of the system constitutes a barrier to wide-scale use of such a system. Optimizing the graphical presentation of the information on paper should significantly increase the system's responsiveness

Hemiarthroplasty versus angle-stable locking compression plate osteosynthesis in the treatment of three- and four-part fractures of the proximal humerus in the elderly: design of a randomized controlled trial

ABSTRACT: BACKGROUND: The optimal surgical management of dislocated three- and four-part fractures of the proximal humerus in elderly patients remains unclear. Most used techniques are hemiarthroplasty and angle-stable locking compression plate osteosynthesis. In the current literature there is no evidence available presenting superior results between hemiarthroplasty and angle-stable locking compression plate osteosynthesis in terms of speed of recovery, pain, patient satisfaction, functional outcome, quality of life or complications. METHODS/DESIGN: A randomized controlled multicenter trial will be conducted. Patients older than 60 years of age with a dislocated three- or four-part fracture of the proximal humerus as diagnosed by X-rays and CT-scans will be included. Exclusion criteria are a fracture older than 14 days, multiple comorbidity, multitrauma, a pathological fracture, previous surgery on the injured shoulder, severely deranged function caused by a previous disease, "head-split" proximal humerus fracture and unwillingness or inability to follow instructions. Participants will be randomized between surgical treatment with hemiarthroplasty and angle-stable locking compression plate osteosynthesis. Measurements will take place preoperatively and 3 months, 6 months, 9 months, 12 months and 24 months postoperatively. Primary outcome measure is speed of recovery of functional capacity of the affected upper limb using the Disabilities of Arm, Shoulder and Hand score (DASH). Secondary outcome measures are pain, patient satisfaction, shoulder function, quality of life, radiological evaluation and complications. Data will be analyzed on an intention-to-treat basis, using univariate and multivariate analyses. DISCUSSION: Both hemiarthroplasty and angle-stable locking compression plate osteosynthesis are used in the current treatment of dislocated three-and four-part fractures of the proximal humerus. There is a lack of level-1 studies comparing these two most-used surgical treatment options. This randomized controlled multicenter trial has been designed to determine which surgical treatment option provides the fastest recovery of functional capacity of the affected upper limb, and will provide better outcomes in pain, satisfaction, shoulder function, quality of life, radiological evaluation and complications. TRIAL REGISTRATION NUMBER: The trial is registered in the Netherlands Trial Registry (NTR2461)

Does training increase the use of more emotionally laden words by nurses when talking with cancer patients? A randomised study

The emotional content of health care professionals–cancer patient communication is often considered as poor and has to be improved by an enhancement of health care professionals empathy. One hundred and fifteen oncology nurses participating in a communication skills training workshop were assessed at three different periods. Nurses randomly allocated to a control group arm (waiting list) were assessed a first time and then 3 and 6 months later. Nurses allocated to the training group were assessed before training workshop, just after and 3 months later. Each nurse completed a 20-min clinical and simulated interview. Each interview was analysed by three content analysis systems: two computer-supported content analysis of emotional words, the Harvard Third Psychosocial Dictionary and the Martindale Regressive Imagery Dictionary and an observer rating system of utterances emotional depth level, the Cancer Research Campaign Workshop Evaluation Manual. The results show that in clinical interviews there is an increased use of emotional words by health care professionals right after having been trained (P=0.056): training group subjects use 4.3 (std: 3.7) emotional words per 1000 used before training workshop, and 7.0 (std: 5.8) right after training workshop and 5.9 (std: 4.3) 3 months later compared to control group subjects which use 4.5 (std: 4.8) emotional words at the first assessment point, 4.3 (std: 4.1) at the second and 4.4 (std: 3.3) at the third. The same trend is noticeable for emotional words used by health care professionals in simulated interviews (P=0.000). The emotional words registry used by health care professionals however remains stable over time in clinical interviews (P=0.141) and is enlarged in simulated interviews (P=0.041). This increased use of emotional words by trained health care professionals facilitates cancer patient emotion words expressions compared to untrained health care professionals especially 3 months after training (P=0.005). This study shows that health care professionals empathy may be improved by communication skills training workshop and that this improvement facilitates cancer patients emotions expression

Quality of life and cost-effectiveness of interferon-alpha in malignant melanoma: results from randomised trial

A definitive conclusion regarding the value of low-dose extended duration adjuvant interferon-alpha therapy in the treatment of malignant melanoma is only possible once data on health-related quality of life (HRQoL) and costs have been considered. This trial randomised 674 patients to interferon alpha-2a (3 megaunits three times per week for 2 years or until recurrence) or placebo. Health-related quality of life (QoL) was to be assessed up to 60 months using the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30. Data for the economic analysis, including cost information and the EQ-5D were also collected. Patients in the observation (OBS) group had significantly better mean follow-up quality of on five dimensions of the EORTC QLQ-C30 functional scales: role functioning (P=0.033), emotional functioning (P=0.003), cognitive functioning (P=0.001), social functioning (P=0.003) and global health status (P=0.001). Patients in the OBS group had significantly better mean follow-up symptom scores on seven dimensions of the EORTC QLQ-C30 V1 symptom scales. Economic data showed that costs were £3066 higher in the interferon group and produces an incremental cost per quality-adjusted life year of £41 432 at 5 years. The results show that interferon has significant effects on QoL and symptomatology and is unlikely to be cost-effective in this patient group in the UK

Measurements on the reality of the wavefunction

Quantum mechanics is an outstandingly successful description of nature, underpinning fields from biology through chemistry to physics. At its heart is the quantum wavefunction, the central tool for describing quantum systems. Yet it is still unclear what the wavefunction actually is: does it merely represent our limited knowledge of a system, or is it an element of reality? Recent no-go theorems argued that if there was any underlying reality to start with, the wavefunction must be real. However, that conclusion relied on debatable assumptions, without which a partial knowledge interpretation can be maintained to some extent. A different approach is to impose bounds on the degree to which knowledge interpretations can explain quantum phenomena, such as why we cannot perfectly distinguish non-orthogonal quantum states. Here we experimentally test this approach with single photons. We find that no knowledge interpretation can fully explain the indistinguishability of non-orthogonal quantum states in three and four dimensions. Assuming that some underlying reality exists, our results strengthen the view that the entire wavefunction should be real. The only alternative is to adopt more unorthodox concepts such as backwards-in-time causation, or to completely abandon any notion of objective reality.Comment: 7 pages, 4 figure

Impact of screening for breast cancer in high-risk women on health-related quality of life

The effectiveness of intensive surveillance in women at high risk for breast cancer due to a familial or genetic predisposition is uncertain and is currently being evaluated in a Dutch magnetic resonance imaging (MRI) screening (MRISC) study, in which annual imaging consists of mammography and MRI. Unfavourable side effects on health-related quality of life may arise from this screening process. We examined the short-term effects of screening for breast cancer in high-risk women on generic health-related quality of life and distress. A total of 519 participants in the MRISC study were asked to complete generic health-status questionnaires (SF-36, EQ-5D) as well as additional questionnaires for distress and items relating to breast cancer screening, at three different time points around screening. The study population showed significantly better generic health-related quality of life scores compared to age-/sex-adjusted reference scores from the general population. Neither generic health-related quality of life scores nor distress scores among the study sample (n = 334) showed significant changes over time. The impact of the screening process on generic health status did not differ between risk categories. Relatively more women reported mammography as quite to very painful (30.1%) compared to MRI. Anxiety was experienced by 37% of the women undergoing MRI. We conclude that screening for breast cancer in high-risk women does not have an unfavourable impact on short-term generic health-related quality of life and general distress. In this study, high-risk women who opted for regular breast cancer screening had a better health status than women from the general population