2,286 research outputs found

    Revolutionaries and spies: Spy-good and spy-bad graphs

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    We study a game on a graph GG played by rr {\it revolutionaries} and ss {\it spies}. Initially, revolutionaries and then spies occupy vertices. In each subsequent round, each revolutionary may move to a neighboring vertex or not move, and then each spy has the same option. The revolutionaries win if mm of them meet at some vertex having no spy (at the end of a round); the spies win if they can avoid this forever. Let σ(G,m,r)\sigma(G,m,r) denote the minimum number of spies needed to win. To avoid degenerate cases, assume |V(G)|\ge r-m+1\ge\floor{r/m}\ge 1. The easy bounds are then \floor{r/m}\le \sigma(G,m,r)\le r-m+1. We prove that the lower bound is sharp when GG has a rooted spanning tree TT such that every edge of GG not in TT joins two vertices having the same parent in TT. As a consequence, \sigma(G,m,r)\le\gamma(G)\floor{r/m}, where γ(G)\gamma(G) is the domination number; this bound is nearly sharp when γ(G)m\gamma(G)\le m. For the random graph with constant edge-probability pp, we obtain constants cc and cc' (depending on mm and pp) such that σ(G,m,r)\sigma(G,m,r) is near the trivial upper bound when r<clnnr<c\ln n and at most cc' times the trivial lower bound when r>clnnr>c'\ln n. For the hypercube QdQ_d with drd\ge r, we have σ(G,m,r)=rm+1\sigma(G,m,r)=r-m+1 when m=2m=2, and for m3m\ge 3 at least r39mr-39m spies are needed. For complete kk-partite graphs with partite sets of size at least 2r2r, the leading term in σ(G,m,r)\sigma(G,m,r) is approximately kk1rm\frac{k}{k-1}\frac{r}{m} when kmk\ge m. For k=2k=2, we have \sigma(G,2,r)=\bigl\lceil{\frac{\floor{7r/2}-3}5}\bigr\rceil and \sigma(G,3,r)=\floor{r/2}, and in general 3r2m3σ(G,m,r)(1+1/3)rm\frac{3r}{2m}-3\le \sigma(G,m,r)\le\frac{(1+1/\sqrt3)r}{m}.Comment: 34 pages, 2 figures. The most important changes in this revision are improvements of the results on hypercubes and random graphs. The proof of the previous hypercube result has been deleted, but the statement remains because it is stronger for m<52. In the random graph section we added a spy-strategy resul

    Dealing with Religious, Cultural, and Spiritual Pluralism in Adult and Higher Education Practice in an Age of Terrorism: Challenges and Controversies

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    This symposium addresses the challenges, controversies, and perceived responsibilities in dealing with religious, cultural, and spiritual pluralism in adult education practice from the perspective of a multiple presenters of different positionalities and spiritual traditions

    The Intersecting Roles of Religion, Culture, and Spirituality in Emancipatory Adult Education

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    This paper discusses why considering the intersection of religion, spirituality, and culture is important in emancipatory education efforts and provides discussion of approaches for doing so in practice

    Rapid reduction versus abrupt quitting for smokers who want to stop soon: a randomised controlled non-inferiority trial

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    Background: The standard way to stop smoking is to stop abruptly on a quit day with no prior reduction in consumption of cigarettes. Many smokers feel that reduction is natural and if reduction programmes were offered, many more might take up treatment. Few trials of reduction versus abrupt cessation have been completed. Most are small, do not use pharmacotherapy, and do not meet the standards necessary to obtain a marketing authorisation for a pharmacotherapy.\ud Design/Methods: We will conduct a non-inferiority andomised trial of rapid reduction versus standard abrupt cessation among smokers who want to stop smoking. In the reduction arm,participants will be advised to reduce smoking consumption by half in the first week and to 25% of baseline in the second, leading up to a quit day at which participants will stop smoking completely.This will be assisted by nicotine patches and an acute form of nicotine replacement therapy. In the abrupt arm participants will use nicotine patches only, whilst smoking as normal, for two weeks prior to a quit day, at which they will also stop smoking completely. Smokers in either arm will have standard withdrawal orientated behavioural support programme with a combination of nicotine patches and acute nicotine replacement therapy post-cessation.\ud Outcomes/Follow-up: The primary outcome of interest will be prolonged abstinence from smoking, with secondary trial outcomes of point prevalence, urges to smoke and withdrawal\ud symptoms. Follow up will take place at 4 weeks, 8 weeks and 6 months post-quit day

    PDT in the Thoracic Cavity: Spectroscopic Methods and Fluence Modeling for Treatment Planning

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    PDT for the thoracic cavity provides a promising cancer treatment modality, but improvements in treatment planning, particularly in PDT dosimetry, can be made to improve uniformity of light delivery. When a cavity of arbitrary geometry is illuminated, the fluence increases due to multiple-scattered photons, referred to as the Integrating Sphere Effect (ISE). Current pleural PDT treatment protocol at the University of Pennsylvania monitors light fluence (hereafter simply fluence, measured in W/cm2) via seven isotropic detectors sutured at different locations in thoracic cavity of a patient. This protocol monitors light at discrete locations, but does not provide a measurement of fluence for the thoracic cavity as a whole. Current calculation of light fluence includes direct light only and thus does not account for the unique optical properties of each tissue type present, which in turn affects the accuracy of the calculated light distribution in the surrounding tissue and, in turn, the overall cell death and treatment efficacy. Treatment planning for pleural PDT can be improved, in part, by considering the contribution of scattered light, which is affected by the two factors of geometry and in vivo optical properties. We expanded the work by Willem Star in regards to the ISE in a spherical cavity. A series of Monte Carlo (MC) simulations were run for semi-infinite planar, spherical, and ellipsoidal geometries for a range of optical properties. The results of these simulations are compared to theory and numerical solutions for fluence in the cavity and at the cavity-medium boundary. The development via MC simulations offers a general method of calculating the required light fluence specialized to each patient, based on the treatment surface area. The scattered fluence calculation is dependent on in vivo optical properties (μa and μs\u27) of the tissues treated. Diffuse reflectance and fluorescence spectroscopy methods are used to determine the optical properties and oxygenation (reflectance measurements) and drug concentration (fluorescence measurements) of different tissues in vivo, before and after treatment, in patients enrolled the Phase I HPPH study ongoing at the University of Pennsylvania. This work aims to provide the building blocks essential to pleural PDT treatment planning by more accurately calculating the required fluence using a model that accounts for the effects of treatment geometry and optical properties measured in vivo

    Is small size at birth associated with early childhood morbidity in white British and Pakistani origin UK children aged 0-3? Findings from the born in Bradford cohort study

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    Abstract Background Low birthweight is associated with increased infant morbidity, poorer developmental outcomes and risk of adult disease and its prevention remains a public health priority. South Asian children are more likely to be born small and there is some debate around whether this is a normal phenomenon within this population or whether they have a greater risk of morbidity. We examined the association between small size at birth and morbidity in White British and Pakistani origin children aged 0–3 participating in the Born in Bradford cohort study. Methods We included 4119 White British and 4731 Pakistani origin children and examined health service use (General Practitioner (GP) consultations, the most common prescribing categories (analgesics, antibiotics, bronchodilators), emergency and elective hospital episodes) as markers of morbidity, in children born small defined as: (i) low birthweight (< 2500 g) (ii) small for gestational age (SGA) using customised birth charts. We used negative binomial regression models to predict the adjusted incidence of morbidity markers. Results 8.7% of Pakistani and 5% of White British children were born with a low birthweight (< 2500 g). Using customised charts, these proportions were 15.3 and 6.2% respectively. Children born small in both groups irrespective of the criteria used, generally had a higher rate of episodes for morbidity markers compared to normal weight children. Incidence of GP consultations (IRR 1.48 (95% CI 1.27, 1.73) to 1.55 (95% CI 1.36, 1.76) depending on birthweight category), analgesic (IRR 1.76 (95% CI 1.37, 2.25) to 2.31 (95% CI 2.19, 2.45) and antibiotic prescriptions (IRR 1.13 (95% CI 0.08, 1.46) to 1.38 (95% CI 1.30, 1.48) and emergency hospital episodes (IRR 1.20 (95% CI 1.06, 1.36) to 1.46 (95% CI 0.92, 2.32), was higher in Pakistani origin children with either a low or normal birthweight. Conclusion Being born small is associated with greater morbidity estimated by use of health services, in both White British and Pakistani origin children underlining the importance of public health policy to reduce low birthweight. Pakistani origin children access health services more frequently than White British children irrespective of birthweight and this has implications for health service planning in areas with South Asian populations

    A new version of the HBSC Family Affluence Scale - FAS III: Scottish qualitative findings from the International FAS Development Study

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    A critical review of the Family Affluence Scale (FAS) concluded that FAS II was no longer discriminatory within very rich or very poor countries, where a very high or a very low proportion of children were categorised as high FAS or low FAS respectively (Currie et al. 2008). The review concluded that a new version of FAS - FAS III - should be developed to take into account current trends in family consumption patterns across the European region, the US and Canada. In 2012, the FAS Development and Validation Study was conducted in eight countries - Denmark, Greenland, Italy, Norway, Poland, Romania, Slovakia and Scotland. This paper describes the Scottish qualitative findings from this study. The Scottish qualitative fieldwork comprising cognitive interviews and focus groups sampled from 11, 13 and 15 year-old participants from 18 of the most- and least- economically deprived schools. These qualitative results were used to inform the final FAS III recommendations.Publisher PDFPeer reviewe
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