965 research outputs found

    Can a falling tree make a noise in two forests at the same time?

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    It is a commonplace to claim that quantum mechanics supports the old idea that a tree falling in a forest makes no sound unless there is a listener present. In fact, this conclusion is far from obvious. Furthermore, if a tunnelling particle is observed in the barrier region, it collapses to a state in which it is no longer tunnelling. Does this imply that while tunnelling, the particle can not have any physical effects? I argue that this is not the case, and moreover, speculate that it may be possible for a particle to have effects on two spacelike separate apparatuses simultaneously. I discuss the measurable consequences of such a feat, and speculate about possible statistical tests which could distinguish this view of quantum mechanics from a ``corpuscular'' one. Brief remarks are made about an experiment underway at Toronto to investigate these issues.Comment: 9 pp, Latex, 3 figs, to appear in Proc. Obsc. Unr. Conf.; Fig 2 postscript repaired on 26.10.9

    The writing on the wall: the concealed communities of the East Yorkshire horselads

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    This paper examines the graffiti found within late nineteenth and early-twentieth century farm buildings in the Wolds of East Yorkshire. It suggests that the graffiti were created by a group of young men at the bottom of the social hierarchy - the horselads – and was one of the ways in which they constructed a distinctive sense of communal identity, at a particular stage in their lives. Whilst it tells us much about changing agricultural regimes and social structures, it also informs us about experiences and attitudes often hidden from official histories and biographies. In this way, the graffiti are argued to inform our understanding, not only of a concealed community, but also about their hidden histor

    The Influence of Temperature on Coumarin 153 Fluorescence Kinetics

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    The influence of temperature varied in the range 183 K–323 K on the fluorescence quantum yield, fluorescence lifetime, absorption and emission transition moments and non-radiative deactivation rate was determined for the well known and largely used dye Coumarin 153, dissolved in 1-chloropropane. The Kennard-Stepanov relation connecting the absorption and emission spectra was used to check for the presence of more than one absorbing/emitting species and to investigate whether intramolecular vibrational redistribution completes in the C153 excited S1 state before the emission takes place. The emission spectrum corresponding to S1→S0 transition, was fitted at each temperature to the model function including the information on the dye vibrational modes coupling. In this way the displacement in equilibrium distance for the most active vibrational mode was determined for C153 in S1 and in S0. Using the temperature dependence of the fluorescence decay time and quantum yield, the non-radiative deactivation rate was determined. Its temperature dependence was compared to that calculated using the theoretical model with the most active vibrational mode displacement values taken from steady-state spectra analysis. The somewhat surprising dependence of the fluorescence decay time and quantum yield on temperature was related to non-trivial coupling between low-frequency vibrational modes of C153 in the excited and ground states

    Postcopulatory sexual selection

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    The female reproductive tract is where competition between the sperm of different males takes place, aided and abetted by the female herself. Intense postcopulatory sexual selection fosters inter-sexual conflict and drives rapid evolutionary change to generate a startling diversity of morphological, behavioural and physiological adaptations. We identify three main issues that should be resolved to advance our understanding of postcopulatory sexual selection. We need to determine the genetic basis of different male fertility traits and female traits that mediate sperm selection; identify the genes or genomic regions that control these traits; and establish the coevolutionary trajectory of sexes

    Upfront autologous haematopoietic stem-cell transplantation versus carfilzomib–cyclophosphamide–dexamethasone consolidation with carfilzomib maintenance in patients with newly diagnosed multiple myeloma in England and Wales (CARDAMON): a randomised, phase 2, non-inferiority trial

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    Background: Standard-of-care treatment for patients with newly diagnosed multiple myeloma is bortezomib-based induction followed by high-dose melphalan and autologous haematopoietic stem-cell transplantation (HSCT) and lenalidomide maintenance. We aimed to evaluate whether an immunomodulatory-free carfilzomib-based induction, consolidation, and maintenance protocol without autologous HSCT was non-inferior to the same induction regimen followed by autologous HSCT and maintenance. Methods: CARDAMON is a randomised, open-label, phase 2 trial in 19 hospitals in England and Wales, UK. Newly diagnosed, transplantation-eligible patients with multiple myeloma aged 18 years or older with an Eastern Cooperative Oncology Group (ECOG) performance status of 0–2 received four 28-day cycles of carfilzomib (56 mg/m2 intravenously on days 1, 2, 8, 9, 15, and 16), cyclophosphamide (500 mg orally on days 1, 8, and 15), and dexamethasone (40 mg orally on days 1, 8, 15, and 22; KCd), followed by peripheral blood stem cell mobilisation. Patients with at least a partial response were randomly assigned (1:1) to either high-dose melphalan and autologous HSCT or four cycles of KCd. All randomised patients received 18 cycles of carfilzomib maintenance (56 mg/m2 intravenously on days 1, 8, and 15). The primary outcomes were the proportion of patients with at least a very good partial response after induction and difference in progression-free survival rate at 2 years from randomisation (non-inferiority margin 10%), both assessed by intention to treat. Safety was assessed in all patients who started treatment. The trial is registered with ClinicalTrials.gov (NCT02315716); recruitment is complete and all patients are in follow-up. Findings: Between June 16, 2015, and July 8, 2019, 281 patients were enrolled, with 218 proceeding to randomisation (109 assigned to the KCd consolidation group [99 of whom completed consolidation] and 109 to the HSCT group [104 of whom underwent transplantation]). A further seven patients withdrew before initiation of carfilzomib maintenance (two in the KCd consolidation group vs five in the HSCT group). Median age was 59 years (IQR 52 to 64); 166 (59%) of 281 patients were male and 115 (41%) were female. 152 (71%) of 214 patients with known ethnicity were White, 37 (17%) were Black, 18 (8%) were Asian, 5 (2%) identified as Mixed, and 2 (1%) identified as other. Median follow-up from randomisation was 40·2 months (IQR 32·7 to 51·8). After induction, 162 (57·7%; 95% CI 51·6 to 63·5) of 281 patients had at least a very good partial response. The 2-year progression-free survival was 75% (95% CI 65 to 82) in the HSCT group versus 68% (95% CI 58 to 76) in the KCd group (difference –7·2%, 70% CI –11·1 to –2·8), exceeding the non-inferiority margin. The most common grade 3–4 events during KCd induction and consolidation were lymphocytopenia (72 [26%] of 278 patients who started induction; 15 [14%] of 109 patients who started consolidation) and infection (50 [18%] of 278 for induction; 15 [14%] of 109 for consolidation), and during carfilzomib maintenance were hypertension (20 [21%] of 97 patients in the KCd consolidation group vs 23 [23%] of 99 patients in the HSCT group) and infection (16 [16%] of 97 patients vs 25 [25%] of 99). Treatment-related serious adverse events at any point during the trial were reported in 109 (39%) of 278 patients who started induction, with infections (80 [29%]) being the most common. Treatment-emergent deaths were reported in five (2%) of 278 patients during induction (three from infection, one from cardiac event, and one from renal failure) and one of 99 patients during maintenance after autologous HSCT (oesophageal carcinoma). Interpretation: KCd did not meet the criteria for non-inferiority compared with autologous HSCT, but the marginal difference in progression-free survival suggests that further studies are warranted to explore deferred autologous HSCT in some subgroups, such as individuals who are MRD negative after induction. Funding: Cancer Research UK and Amgen

    Tobacco prevention policies in west-African countries and their effects on smoking prevalence

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    Background: The WHO Framework Convention on Tobacco Control was shown to effectively lower smoking prevalence in in high income countries, however knowledge for low and middle income settings is sparse. The objective of this study was to describe WHO MPOWER policy measures in thirteen West-African countries and to investigate their correlation with smoking prevalence. Methods: Age-standardized smoking prevalence data and policy measures were collected from various WHO reports. For analysis MPOWER measures from 2008 and 2010, were combined with prevalence data from 2009 and 2011. Multiple linear regression models were set up. Results: In West-Africa mean smoking prevalence was approximately 20 % among males and approximately 3 % among females. Policy measures were mostly at a middle or low level. Regression analysis showed that tobacco cessation programs, health warnings on cigarettes, and higher price of cigarettes were negatively correlated with smoking prevalence. Significant effects were observed for only one policy measure (tobacco cessation programs) and only within the male population where smoking prevalence is generally higher. Conclusions: Tobacco control policies are enforced at relatively low levels in West-African countries. However, improving tobacco control policy implementation according to the WHO Framework Convention on Tobacco Control should assist in the reduction of smoking prevalence in African countries, thereby counteracting pro-smoking initiatives set forth by the tobacco industry

    Accuracy of syndrome definitions based on diagnoses in physician claims

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    <p>Abstract</p> <p>Background</p> <p>Community clinics offer potential for timelier outbreak detection and monitoring than emergency departments. However, the accuracy of syndrome definitions used in surveillance has never been evaluated in community settings. This study's objective was to assess the accuracy of syndrome definitions based on diagnostic codes in physician claims for identifying 5 syndromes (fever, gastrointestinal, neurological, rash, and respiratory including influenza-like illness) in community clinics.</p> <p>Methods</p> <p>We selected a random sample of 3,600 community-based primary care physicians who practiced in the fee-for-service system in the province of Quebec, Canada in 2005-2007. We randomly selected 10 visits per physician from their claims, stratifying on syndrome type and presence, diagnosis, and month. Double-blinded chart reviews were conducted by telephone with consenting physicians to obtain information on patient diagnoses for each sampled visit. The sensitivity, specificity, and positive predictive value (PPV) of physician claims were estimated by comparison to chart review.</p> <p>Results</p> <p>1,098 (30.5%) physicians completed the chart review. A chart entry on the date of the corresponding claim was found for 10,529 (95.9%) visits. The sensitivity of syndrome definitions based on diagnostic codes in physician claims was low, ranging from 0.11 (fever) to 0.44 (respiratory), the specificity was high, and the PPV was moderate to high, ranging from 0.59 (fever) to 0.85 (respiratory). We found that rarely used diagnostic codes had a higher probability of being false-positives, and that more commonly used diagnostic codes had a higher PPV.</p> <p>Conclusions</p> <p>Future research should identify physician, patient, and encounter characteristics associated with the accuracy of diagnostic codes in physician claims. This would enable public health to improve syndromic surveillance, either by focusing on physician claims whose diagnostic code is more likely to be accurate, or by using all physician claims and weighing each according to the likelihood that its diagnostic code is accurate.</p

    Determinants of elevated healthcare utilization in patients with COPD

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    <p>Abstract</p> <p>Background</p> <p>Chronic obstructive pulmonary disease (COPD) imparts a substantial economic burden on western health systems. Our objective was to analyze the determinants of elevated healthcare utilization among patients with COPD in a single-payer health system.</p> <p>Methods</p> <p>Three-hundred eighty-nine adults with COPD were matched 1:3 to controls by age, gender and area of residency. Total healthcare cost 5 years prior recruitment and presence of comorbidities were obtained from a computerized database. Health related quality of life (HRQoL) indices were obtained using validated questionnaires among a subsample of 177 patients.</p> <p>Results</p> <p>Healthcare utilization was 3.4-fold higher among COPD patients compared with controls (p < 0.001). The "most-costly" upper 25% of COPD patients (n = 98) consumed 63% of all costs. Multivariate analysis revealed that independent determinants of being in the "most costly" group were (OR; 95% CI): age-adjusted Charlson Comorbidity Index (1.09; 1.01 - 1.2), history of: myocardial infarct (2.87; 1.5 - 5.5), congestive heart failure (3.52; 1.9 - 6.4), mild liver disease (3.83; 1.3 - 11.2) and diabetes (2.02; 1.1 - 3.6). Bivariate analysis revealed that cost increased as HRQoL declined and severity of airflow obstruction increased but these were not independent determinants in a multivariate analysis.</p> <p>Conclusion</p> <p>Comorbidity burden determines elevated utilization for COPD patients. Decision makers should prioritize scarce health care resources to a better care management of the "most costly" patients.</p

    Shared Skeletal Support in a Coral-Hydroid Symbiosis

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    Hydroids form symbiotic relationships with a range of invertebrate hosts. Where they live with colonial invertebrates such as corals or bryozoans the hydroids may benefit from the physical support and protection of their host's hard exoskeleton, but how they interact with them is unknown. Electron microscopy was used to investigate the physical interactions between the colonial hydroid Zanclea margaritae and its reef-building coral host Acropora muricata. The hydroid tissues extend below the coral tissue surface sitting in direct contact with the host's skeleton. Although this arrangement provides the hydroid with protective support, it also presents problems of potential interference with the coral's growth processes and exposes the hydroid to overgrowth and smothering. Desmocytes located within the epidermal layer of the hydroid's perisarc-free hydrorhizae fasten it to the coral skeleton. The large apical surface area of the desmocyte and high bifurcation of the distal end within the mesoglea, as well as the clustering of desmocytes suggests that a very strong attachment between the hydroid and the coral skeleton. This is the first study to provide a detailed description of how symbiotic hydroids attach to their host's skeleton, utilising it for physical support. Results suggest that the loss of perisarc, a characteristic commonly associated with symbiosis, allows the hydroid to utilise desmocytes for attachment. The use of these anchoring structures provides a dynamic method of attachment, facilitating detachment from the coral skeleton during extension, thereby avoiding overgrowth and smothering enabling the hydroid to remain within the host colony for prolonged periods of time
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