Shutters, Boxes, But No Paradoxes: Time Symmetry Puzzles in Quantum Theory

The ``N-Box Experiment'' is a much-discussed thought experiment in quantum mechanics. It is claimed by some authors that a single particle prepared in a superposition of N+1 box locations and which is subject to a final ``post-selection'' measurement corresponding to a different superposition can be said to have occupied ``with certainty'' N boxes during the intervening time. However, others have argued that under closer inspection, this surprising claim fails to hold. Aharonov and Vaidman have continued their advocacy of the claim in question by proposing a variation on the N-box experiment, in which the boxes are replaced by shutters and the pre- and post-selected particle is entangled with a photon. These authors argue that the resulting ``N-shutter experiment'' strengthens their original claim regarding the N-box experiment. It is argued in this paper that the apparently surprising features of this variation are no more robust than those of the N-box experiment and that it is not accurate to say that the particle is ``with certainty'' in all N shutters at any given time.Comment: Presentation improved; to appear in International Studies in Philosophy of Scienc

Correction: Emotional impact of screening: A systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>There is a widely held expectation that screening for disease has adverse emotional impacts. The aim of the current review is to estimate the short (< 4 weeks) and longer term (> 4 weeks) emotional impact of such screening.</p> <p>Methods</p> <p>Studies selected for inclusion were (a) randomised controlled trials in which (b) participants in one arm underwent screening and received test results, and those in a control arm did not, and (c) emotional outcomes were assessed in both arms. MEDLINE via PubMed (1950 to present), EMBASE (1980 to present), PsycINFO (1985 to present) using OVID SP, and CINAHL (1982 to present) via EBSCO were searched, using strategies developed with keywords and medical subject headings. Data were extracted on emotional outcomes, type of screening test and test results.</p> <p>Results</p> <p>Of the 12 studies that met the inclusion criteria, six involved screening for cancer, two for diabetes, and one each for abdominal aortic aneurysms, peptic ulcer, coronary heart disease and osteoporosis. Five studies reported data on anxiety, four on depression, two on general distress and eight on quality of life assessed between one week and 13 years after screening (median = 1.3 years).</p> <p>Meta-analyses revealed no significant impact of screening on longer term anxiety (pooled SMD 0.01, 95% CI -0.10, 0.11), depression (pooled SMD -0.04, 95% CI -.12, 0.20), or quality of life subscales (mental and self-assessed health pooled SMDs, respectively: 0.03; -0.01, (95% CI -.02, 0.04; 0.00, 95% CI -.04, 0.03).</p> <p>Conclusion</p> <p>Screening does not appear to have adverse emotional impacts in the longer term (> 4 weeks). Too few studies assessed outcomes before four weeks to comment on the shorter term emotional impact of screening.</p

Leading, learning, and teaching: an exploration of instructor leadership in a retention intervention program

There is a distressing dilemma in higher education concerning the increase in student attrition rates (Angelino, Williams, &amp; Natvig, 2007; Hagedorn, 2006; Kramer, 2007; Lau, 2003, Seidman, 2005; Tinto, 2006). The seminal query of this study asks what higher education institutions are doing to effectively retain these students and secure student success. At a public university in the southeastern part of the United States, appreciative advising is utilized as a teaching strategy in a retention intervention program to answer this question. Developed as a theoretical framework by academic advisors where focus is on a student's strengths instead of on weaknesses (Bloom &amp; Martin, 2002), appreciative advising was integrated into a curriculum designed to empower students to recover and retain academic good standing (Bloom, Hutson, &amp; He, 2008; Bloom, Hutson, He, &amp; Robinson, 2011; Hutson, 2006). This empowerment suggests a relationship between classroom instructor leadership and student self-leadership. The purpose of this study was to explore the perceptions of classroom instructors and how they describe their teaching experiences in this retention intervention program. The researcher desired to know how these classroom instructors perceived their role, experienced instructional leadership, and sought to facilitate self-leadership in their students. Specifically, how an appreciative mindset inspired transformational leadership, encouraged transformational teaching, and aspired to impact transformational learning. Utilizing a qualitative instrumental case study design and applying an interpretivist research paradigm, a total of eleven past and current instructors were interviewed employing online Email and Instant Messaging (IM)/Chat as a means of data collection (Briggs &amp; Coleman, 2007). Unfortunately, the data analyses revealed 9 of the 11 instructors were neither familiar with the core principles of appreciative advising nor understand its relevancy to the retention intervention program. However, the data analyses also indicated the majority of instructors did perceive their role as influencing positive change in the attitudes and behaviors of their students regardless of this deficiency in their knowledge base. This evidenced an intuitive and deductive acknowledgment of appreciative advising in the instructors' teaching experience that innately supported an appreciative mindset. It is through the participants' appreciative mindset that appreciative advising and instructor leadership are explored. Several themes emerged from the data relative to leading, learning, teaching, and the appreciative mindset. These themes reflect the instructors' perceptions of their teaching experiences and student learning: (a) a sense of responsibility central to their desire to impact student success; (b) leadership defined as guiding versus influencing: (c) engaging with students in reflection a primary teaching strategy; (d) belief that student self-awareness contributes to empowerment resulting in self-appreciation; (e) opinion that owning the circumstances of their academic probationary status allows students to practice self-leadership. However, one major theme emerged: leading, learning, and teaching are all relational. This study suggests the integration of appreciative advising with instructional leadership may contribute to enhanced learning experiences for students in pedagogical contexts and increase undergraduate student retention

Frailty: A global measure of the multisystem impact of COPD

Chronic obstructive pulmonary disease (COPD) is a multisystem disease that resembles the accumulation of multiple impairments seen in aging. A comprehensive geriatric assessment (CGA) captures multisystem deficits, from which a frailty index (FI) can be derived. We hypothesized that patients with COPD would be frailer than a comparator group free from respiratory disease. In this cross-sectional analysis, the CGA questionnaire was completed and used to derive an FI in 520 patients diagnosed with COPD and 150 comparators. All subjects were assessed for lung function, body composition, 6-minute walking distance (6MWD), and handgrip strength. Patients completed validated questionnaires on health-related quality of life and respiratory symptoms. Patients and comparators were similar in age, gender, and body mass index, but patients had a greater mean ± SD FI 0.16 ± 0.08 than comparators 0.05 ± 0.03. In patients, a stepwise linear regression 6MWD (β = −0.43), number of comorbidities (β = −0.38), handgrip (β = −0.11), and number of exacerbations (β = 0.11) were predictors of frailty (all p < 0.01). This large study suggests patients with COPD are frailer than comparators. The FI derived from the CGA captures the deterioration of multiple systems in COPD and provides an overview of impairments, which may identify individuals at increased risk of morbidity and mortality in COPD

Novel compound mutations in the mitochondrial translation elongation factor (TSFM) gene cause severe cardiomyopathy with myocardial fibro-adipose replacement

Primary mitochondrial dysfunction is an under-appreciated cause of cardiomyopathy, especially when cardiac symptoms are the unique or prevalent manifestation of disease. Here, we report an unusual presentation of mitochondrial cardiomyopathy, with dilated phenotype and pathologic evidence of biventricular fibro-adipose replacement, in a 33-year old woman who underwent cardiac transplant. Whole exome sequencing revealed two novel compound heterozygous variants in the TSFM gene, coding for the mitochondrial translation elongation factor EF-Ts. This protein participates in the elongation step of mitochondrial translation by binding and stabilizing the translation elongation factor Tu (EF-Tu). Bioinformatics analysis predicted a destabilization of the EF-Ts variants complex with EF-Tu, in agreement with the dramatic steady-state level reduction of both proteins in the clinically affected myocardium, which demonstrated a combined respiratory chain enzyme deficiency. In patient fibroblasts, the decrease of EF-Ts was paralleled by up-regulation of EF-Tu and induction of genes involved in mitochondrial biogenesis, along with increased expression of respiratory chain subunits and normal oxygen consumption rate. Our report extends the current picture of morphologic phenotypes associated with mitochondrial cardiomyopathies and confirms the heart as a main target of TSFM dysfunction. The compensatory response detected in patient fibroblasts might explain the tissue-specific expression of TSFM-associated disease

Using the theory of planned behaviour as a process evaluation tool in randomised trials of knowledge translation strategies : A case study from UK primary care

Peer reviewedPublisher PD

Clinical and Genetic Evaluation of People with or at Risk of Hereditary ATTR Amyloidosis: An Expert Opinion and Consensus on Best Practice in Ireland and the UK

Hereditary transthyretin-mediated amyloidosis (hATTR) is challenging to diagnose early owing to the heterogeneity of clinical presentation, which differs according to the TTR gene variant and its penetrance in each individual. The TTR variants seen most frequently in the UK and Ireland (T80A, V142I and V50M) differ to those commonly occurring in other geographic locations and warrant a specific consideration for diagnosis and genetic testing. In addition, recent availability of treatment for this condition has reinforced the need for a more consistent approach to the management of patients, including access to specialist services, genetic testing and counselling, and clinical investigation for families living in the UK and Ireland. A multidisciplinary panel of experts from the UK and Ireland was convened to identify the current challenges, provide recommendations, and develop a consensus for the diagnosis and screening of people with, or at risk of, hATTR. Over a series of meetings, experts shared their current practices and drafted, refined and approved a consensus statement. This consensus statement provides recommendations for three different groups: (1) people with symptoms raising a possibility of hATTR amyloidosis; (2) people with biopsy-confirmed hATTR amyloidosis; and (3) people without symptoms who may have hATTR amyloidosis (i.e. relatives of people with identified TTR variants). For each group, recommendations are made for the required steps for the diagnosis and follow-up of symptomatic patients, and for guidance on the specialist support for counselling and pre-symptomatic genetic testing of at-risk individuals. This guidance is intended to be practical and based on available evidence. The aim is for regional amyloid specialist centres to provide timely diagnosis, clinical screening, and treatment for individuals and their families with hATTR amyloidosis

dynamAedes: a unified modelling framework for invasive Aedes mosquitoes

Mosquito species belonging to the genus Aedes have attracted the interest of scientists and public health officers because of their capacity to transmit viruses that affect humans. Some of these species were brought outside their native range by means of trade and tourism and then colonised new regions thanks to a unique combination of eco-physiological traits. Considering mosquito physiological and behavioural traits to understand and predict their population dynamics is thus a crucial step in developing strategies to mitigate the local densities of invasive Aedes populations. Here, we synthesised the life cycle of four invasive Aedes species (Ae. aegypti, Ae. albopictus, Ae. japonicus and Ae. koreicus) in a single multi-scale stochastic modelling framework which we coded in the R package dynamAedes. We designed a stage-based and time-discrete stochastic model driven by temperature, photo-period and inter-specific larval competition that can be applied to three different spatial scales: punctual, local and regional. These spatial scales consider different degrees of spatial complexity and data availability by accounting for both active and passive dispersal of mosquito species as well as for the heterogeneity of the input temperature data. Our overarching aim was to provide a flexible, open-source and user-friendly tool rooted in the most updated knowledge on the species’ biology which could be applied to the management of invasive Aedes populations as well as to more theoretical ecological inquirie

Prenatal Treatment for Serious Neurological Sequelae of Congenital Toxoplasmosis: An Observational Prospective Cohort Study

Background: The effectiveness of prenatal treatment to prevent serious neurological sequelae (SNSD) of congenital toxoplasmosis is not known.Methods and Findings: Congenital toxoplasmosis was prospectively identified by universal prenatal or neonatal screening in 14 European centres and children were followed for a median of 4 years. We evaluated determinants of postnatal death or SNSD defined by one or more of functional neurological abnormalities, severe bilateral visual impairment, or pregnancy termination for confirmed congenital toxoplasmosis. Two-thirds of the cohort received prenatal treatment (189/293; 65%). 23/293 (8%) fetuses developed SNSD of which nine were pregnancy terminations. Prenatal treatment reduced the risk of SNSD. The odds ratio for prenatal treatment, adjusted for gestational age at maternal seroconversion, was 0.24 (95% Bayesian credible intervals 0.07-0.71). This effect was robust to most sensitivity analyses. The number of infected fetuses needed to be treated to prevent one case of SNSD was three (95% Bayesian credible intervals 2-15) after maternal seroconversion at 10 weeks, and 18 (9-75) at 30 weeks of gestation. Pyrimethamine-sulphonamide treatment did not reduce SNSD compared with spiramycin alone (adjusted odds ratio 0.78, 0.21-2.95). The proportion of live-born infants with intracranial lesions detected postnatally who developed SNSD was 31.0% (17.0%-38.1%).Conclusion: The finding that prenatal treatment reduced the risk of SNSD in infected fetuses should be interpreted with caution because of the low number of SNSD cases and uncertainty about the timing of maternal seroconversion. As these are observational data, policy decisions about screening require further evidence from a randomized trial of prenatal screening and from cost-effectiveness analyses that take into account the incidence and prevalence of maternal infection

Cancer risks following diagnostic and therapeutic radiation exposure in children

The growing use of interventional and fluoroscopic imaging in children represents a tremendous benefit for the diagnosis and treatment of benign conditions. Along with the increasing use and complexity of these procedures comes concern about the cancer risk associated with ionizing radiation exposure to children. Children are considerably more sensitive to the carcinogenic effects of ionizing radiation than adults, and children have a longer life expectancy in which to express risk. Numerous epidemiologic cohort studies of childhood exposure to radiation for treatment of benign diseases have demonstrated radiation-related risks of cancer of the thyroid, breast, brain and skin, as well as leukemia. Many fewer studies have evaluated cancer risk following diagnostic radiation exposure in children. Although radiation dose for a single procedure might be low, pediatric patients often receive repeated examinations over time to evaluate their conditions, which could result in relatively high cumulative doses. Several cohort studies of girls and young women subjected to multiple diagnostic radiation exposures have been informative about increased mortality from breast cancer with increasing radiation dose, and case-control studies of childhood leukemia and postnatal diagnostic radiation exposure have suggested increased risks with an increasing number of examinations. Only two long-term follow-up studies of cancer following cardiac catheterization in childhood have been conducted, and neither reported an overall increased risk of cancer. Most cancers can be induced by radiation, and a linear dose-response has been noted for most solid cancers. Risks of radiation-related cancer are greatest for those exposed early in life, and these risks appear to persist throughout life