3,153 research outputs found

    The Effect of Mutators on Adaptability in Time-Varying Fitness Landscapes

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    This Letter studies the quasispecies dynamics of a population capable of genetic repair evolving on a time-dependent fitness landscape. We develop a model that considers an asexual population of single-stranded, conservatively replicating genomes, whose only source of genetic variation is due to copying errors during replication. We consider a time-dependent, single-fitness-peak landscape where the master sequence changes by a single point mutation every time τ \tau . We are able to analytically solve for the evolutionary dynamics of the population in the point-mutation limit. In particular, our model provides an analytical expression for the fraction of mutators in the dynamic fitness landscape that agrees well with results from stochastic simulations.Comment: 4 pages, 3 figure

    Results from RHIC with Implications for LHC

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    Results from the PHENIX experiment at RHIC in p-p and Au+Au collisions are reviewed from the perspective of measurements in p-p collisions at the CERN-ISR which serve as a basis for many of the techniques used. Issues such as J/Psi suppression and hydrodynamical flow in A+A collisions require data from LHC-Ions for an improved understanding. Suppression of high pT particles in Au+Au collisions, first observed at RHIC, also has unresolved mysteries such as the equality of the suppression of inclusive pi0 (from light quarks and gluons) and direct-single electrons (from the decay of heavy quarks) in the transverse momentum range 4< pT < 9 GeV/c. This disfavors a radiative explanation of suppression and leads to a fundamental question of whether the Higgs boson gives mass to fermions. Observation of an exponential distribution of direct photons in central Au+Au collisions for 1< pT <2 GeV/c where hard-processes are negligible and with no similar exponential distribution in p-p collisions indicates thermal photon emission from the medium at RHIC, making PHENIX at the moment ``the hottest experiment in Physics''.Comment: Invited lectures at the International School of Subnuclear Physics, 47th Course, "The most unexpected at LHC and the status of High Energy Frontier'', Erice, Sicily, Italy, August 29-September 7. 2009. 32 pages, 22 figure

    Effectiveness of continence promotion for older women via community organisations: A cluster randomised trial

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    This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/3.0/Objectives: The primary objective of this cluster randomised controlled trial was to compare the effectiveness of the three experimental continence promotion interventions against a control intervention on urinary symptom improvement in older women with untreated incontinence recruited from community organisations. A second objective was to determine whether changes in incontinence-related knowledge and new uptake of risk-modifying behaviours explain these improvements. Setting: 71 community organisations across the UK. Participants: 259 women aged 60 years and older with untreated incontinence entered the trial; 88% completed the 3-month follow-up. Interventions: The three active interventions consisted of a single 60 min group workshop on (1) continence education (20 clusters, 64 women); (2) evidence-based self-management (17 clusters, 70 women); or (3) combined continence education and self-management (17 clusters, 61 women). The control intervention was a single 60 min educational group workshop on memory loss, polypharmacy and osteoporosis (17 clusters, 64 women). Primary and secondary outcome measures: The primary outcome was self-reported improvement in incontinence 3 months postintervention at the level of the individual. The secondary outcome was change in the International Consultation on Incontinence Questionnaire (ICIQ) from baseline to 3-month follow-up. Changes in incontinence-related knowledge and behaviours were also assessed. Results: The highest rate of urinary symptom improvement occurred in the combined intervention group (66% vs 11% of the control group, prevalence difference 55%, 95% CI 43% to 67%, intracluster correlation 0). 30% versus 6% of participants reported significant improvement respectively (prevalence difference 23%, 95% CI 10% to 36%, intracluster correlation 0). The number-needed-to-treat was 2 to achieve any improvement in incontinence symptoms, and 5 to attain significant improvement. Compared to controls, participants in the combined intervention reported an adjusted mean 2.05 point (95% CI 0.87 to 3.24) greater improvement on the ICIQ from baseline to 3-month follow-up. Changes in knowledge and self-reported risk-reduction behaviours paralleled rates of improvement in all intervention arms. Conclusions: Continence education combined with evidence-based self-management improves symptoms of incontinence among untreated older women. Community organisations represent an untapped vector for delivering effective continence promotion interventions.Canadian Institutes of Health Research – Institute on Aging and the Economic and Social Research Council (UK

    Direct Route to Phenol from Benzene

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    Phenol production, expected to exceed 13MM metric tons in 2017, is a significant global industry with many flaws in its current manufacturing method. The Hock process essentially converts high value propylene to low value acetone. The proposed process design, detailed in this report, provides an alternative reaction pathway that utilizes a direct synthesis from benzene, as developed at the Council of Scientific and Industrial Research (CSIR) in New Delhi, India. The endorsed proposal is in accordance with US Patent 8,772,552 B2, that describes the production of phenol via vapor phase oxidation of benzene over a copper chromium oxide catalyst. Environmental protection and worker safety are paramount concerns due to the hazardous nature of phenol and benzene. The inclusion of a ventilation system with flare hoods keeps the concentration of hazardous materials within OSHA guidelines. The design uses air to oxidize benzene within four separate packed-bed reactors with inter-stage coolers. Downstream separation removes non-condensable species, recycles up to 98% of the unreacted benzene, and purifies phenol to design specifications. The plant’s capacity is 500MM lb/operating-year of phenol and will be located on the U.S. Gulf Coast as part of an industrial complex. The final product is 99.83% phenol by mass, and contains an aldehyde byproduct as the principal impurity. The design requires an initial investment of 83.6MM,yieldsafifteen−yearnetpresentvalue(NPV)of83.6MM, yields a fifteen-year net present value (NPV) of 90M, and has an estimated investor’s rate of return (IRR) of 29.2%. The proposed project is forecasted to break-even in Q1 of 2025 immediately following the second year of maximum production capacity. The design is recommended based on project specifications and marketing team projections, though investors should exercise caution with regards to the effect of realistic market data on proposal sensitivities

    Review of Engaging Education: Developing Emotional Literacy, Equity and Co-education. Brian Matthews. (Book Review)

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    The book is only about a fraction of its title Engaging Education. His section on ‘engaging the emotions’ sums this up: whereas the book is largely about engaging the emotions positively, the definition of ‘Engaging’ is more far reaching: “that pupils should be involved in their learning; be active and absorbed and not just passive recipients of a set curriculum. Additionally, they should feel engaged in the processes of education and have some input into creating their own agendas for learning” (p.2). Exploring the full impact of this statement across the curriculum really needs a different book

    Offenders' Crime Narratives across Different Types of Crimes

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    The current study explores the roles offenders see themselves playing during an offence and their relationship to different crime types. One hundred and twenty incarcerated offenders indicated the narrative roles they acted out whilst committing a specific crime they remembered well. The data were subjected to Smallest Space Analysis (SSA) and four themes were identified: Hero, Professional, Revenger and Victim in line with the recent theoretical framework posited for Narrative Offence Roles (Youngs & Canter, 2012). Further analysis showed that different subsets of crimes were more like to be associated with different narrative offence roles. Hero and Professional were found to be associated with property offences (theft, burglary and shoplifting), drug offences and robbery and Revenger and Victim were found to be associated with violence, sexual offences and murder. The theoretical implications for understanding crime on the basis of offenders' narrative roles as well as practical implications are discussed

    PHENIX Highlights

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    Recent highlights of measurements by the PHENIX experiment at RHIC are presented.Comment: 8 pages, 9 figures. Talk at Quark Matter 200

    Nearly optimal solutions for the Chow Parameters Problem and low-weight approximation of halfspaces

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    The \emph{Chow parameters} of a Boolean function f:{−1,1}n→{−1,1}f: \{-1,1\}^n \to \{-1,1\} are its n+1n+1 degree-0 and degree-1 Fourier coefficients. It has been known since 1961 (Chow, Tannenbaum) that the (exact values of the) Chow parameters of any linear threshold function ff uniquely specify ff within the space of all Boolean functions, but until recently (O'Donnell and Servedio) nothing was known about efficient algorithms for \emph{reconstructing} ff (exactly or approximately) from exact or approximate values of its Chow parameters. We refer to this reconstruction problem as the \emph{Chow Parameters Problem.} Our main result is a new algorithm for the Chow Parameters Problem which, given (sufficiently accurate approximations to) the Chow parameters of any linear threshold function ff, runs in time \tilde{O}(n^2)\cdot (1/\eps)^{O(\log^2(1/\eps))} and with high probability outputs a representation of an LTF fâ€Čf' that is \eps-close to ff. The only previous algorithm (O'Donnell and Servedio) had running time \poly(n) \cdot 2^{2^{\tilde{O}(1/\eps^2)}}. As a byproduct of our approach, we show that for any linear threshold function ff over {−1,1}n\{-1,1\}^n, there is a linear threshold function fâ€Čf' which is \eps-close to ff and has all weights that are integers at most \sqrt{n} \cdot (1/\eps)^{O(\log^2(1/\eps))}. This significantly improves the best previous result of Diakonikolas and Servedio which gave a \poly(n) \cdot 2^{\tilde{O}(1/\eps^{2/3})} weight bound, and is close to the known lower bound of max⁥{n,\max\{\sqrt{n}, (1/\eps)^{\Omega(\log \log (1/\eps))}\} (Goldberg, Servedio). Our techniques also yield improved algorithms for related problems in learning theory
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