1,695 research outputs found

    A latent green fluorescent styrylcoumarin probe for the selective growth and detection of Gram negative bacteria

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    A novel, green fluorescent β-alanylstyrylcoumarin derivative was synthesized and evaluated for its performance as a fluorogenic enzyme substrate on a range of clinically relevant microorganisms. The substrate was selectively hydrolysed by β-alanyl aminopeptidase producing P. aeruginosa resulting in an on-to-off fluorescent signal. Growth inhibitory effect of the substrate was observed on Gram positive bacteria and yeasts. Meanwhile, Gram negative species, despite their extremely protective cell envelope, showed ready uptake and accumulation of the substrate within their healthy growing colonies displaying intense green fluorescence.NHMR

    An Analytical Study of Coupled Two-State Stochastic Resonators

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    The two-state model of stochastic resonance is extended to a chain of coupled two-state elements governed by the dynamics of Glauber's stochastic Ising model. Appropriate assumptions on the model parameters turn the chain into a prototype system of coupled stochastic resonators. In a weak-signal limit analytical expressions are derived for the spectral power amplification and the signal-to-noise ratio of a two-state element embedded into the chain. The effect of the coupling between the elements on both quantities is analysed and array-enhanced stochastic resonance is established for pure as well as noisy periodic signals. The coupling-induced improvement of the SNR compared to an uncoupled element is shown to be limited by a factor four which is only reached for vanishing input noise.Comment: 29 pages, 5 figure

    Assessing the accuracy of perceptions of intelligence based on heritable facial features

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    Perceptions of intelligence based on facial features can have a profound impact on many social situations, but findings have been mixed as to whether these judgements are accurate. Even if such perceptions were accurate, the underlying mechanism is unclear. Several possibilities have been proposed, including evolutionary explanations where certain morphological facial features are associated with fitness-related traits (including cognitive development), or that intelligence judgements are over-generalisation of cues of transitory states that can influence cognition (e.g., tiredness). Here, we attempt to identify the morphological signals that individuals use to make intelligence judgements from facial photographs. In a genetically informative sample of 1660 twins and their siblings, we measured IQ and also perceptions of intelligence based on facial photographs. We found that intelligence judgements were associated with both stable morphological facial traits (face height, interpupillary distance, and nose size) and more transitory facial cues (eyelid openness, and mouth curvature). There was a significant association between perceived intelligence and measured IQ, but of the specific facial attributes only interpupillary distance (i.e., wide-set eyes) significantly mediated this relationship. We also found evidence that perceived intelligence and measured IQ share a familial component, though we could not distinguish between genetic and shared environmental sources

    An examination of autism spectrum traits in adolescents with anorexia nervosa and their parents

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    There may be a link between anorexia nervosa and autism spectrum disorders. The aims of this study were to examine whether adolescents with anorexia nervosa have autism spectrum and/or obsessive-compulsive traits, how many would meet diagnostic criteria for autism spectrum disorder, and whether these traits are shared by parents

    Self-interest And Public Interest: The Motivations Of Political Actors

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    Self-Interest and Public Interest in Western Politics showed that the public, politicians, and bureaucrats are often public spirited. But this does not invalidate public-choice theory. Public-choice theory is an ideal type, not a claim that self-interest explains all political behavior. Instead, public-choice theory is useful in creating rules and institutions that guard against the worst case, which would be universal self-interestedness in politics. In contrast, the public-interest hypothesis is neither a comprehensive explanation of political behavior nor a sound basis for institutional design

    An examination of the clinical outcomes of adolescents and young adults with broad autism spectrum traits and autism spectrum disorder and anorexia nervosa: A multi centre study

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    Objectives: To compare the clinical outcomes of adolescents and young adults with anorexia nervosa (AN) comorbid with broad autism spectrum disorder (ASD) or ASD traits. Method: The developmental and well‐being assessment and social aptitude scale were used to categorize adolescents and young adults with AN (N = 149) into those with ASD traits (N = 23), and those who also fulfilled diagnostic criteria for a possible/probable ASD (N = 6). We compared both eating disorders specific measures and broader outcome measures at intake and 12 months follow‐up. Results: Those with ASD traits had significantly more inpatient/day‐patient service use (p = .015), as well as medication use (p < .001) at baseline. Both groups had high social difficulties and poorer global functioning (strengths and difficulties questionnaire) at baseline, which improved over time but remained higher at 12 months in the ASD traits group (p = .002). However, the improvement in eating disorder symptoms at 12 months was similar between groups with or without ASD traits. Treatment completion rates between AN only and ASD traits were similar (80.1 vs. 86.5%). Discussion: Adolescents with AN and ASD traits show similar reductions in their eating disorder symptoms. Nevertheless, their social difficulties remain high suggesting that these are life‐long difficulties rather than starvation effects

    Cliophysics: Socio-political Reliability Theory, Polity Duration and African Political (In)stabilities

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    Quantification of historical sociological processes have recently gained attention among theoreticians in the effort of providing a solid theoretical understanding of the behaviors and regularities present in sociopolitical dynamics. Here we present a reliability theory of polity processes with emphases on individual political dynamics of African countries. We found that the structural properties of polity failure rates successfully capture the risk of political vulnerability and instabilities in which 87.50%, 75%, 71.43%, and 0% of the countries with monotonically increasing, unimodal, U-shaped and monotonically decreasing polity failure rates, respectively, have high level of state fragility indices. The quasi-U-shape relationship between average polity duration and regime types corroborates historical precedents and explains the stability of the autocracies and democracies.Comment: 4 pages, 3 figures, 1 tabl

    μ-CS: An extension of the TM4 platform to manage Affymetrix binary data

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    <p>Abstract</p> <p>Background</p> <p>A main goal in understanding cell mechanisms is to explain the relationship among genes and related molecular processes through the combined use of technological platforms and bioinformatics analysis. High throughput platforms, such as microarrays, enable the investigation of the whole genome in a single experiment. There exist different kind of microarray platforms, that produce different types of binary data (images and raw data). Moreover, also considering a single vendor, different chips are available. The analysis of microarray data requires an initial preprocessing phase (i.e. normalization and summarization) of raw data that makes them suitable for use on existing platforms, such as the TIGR M4 Suite. Nevertheless, the annotations of data with additional information such as gene function, is needed to perform more powerful analysis. Raw data preprocessing and annotation is often performed in a manual and error prone way. Moreover, many available preprocessing tools do not support annotation. Thus novel, platform independent, and possibly open source tools enabling the semi-automatic preprocessing and annotation of microarray data are needed.</p> <p>Results</p> <p>The paper presents <it>μ</it>-CS (Microarray Cel file Summarizer), a cross-platform tool for the automatic normalization, summarization and annotation of Affymetrix binary data. <it>μ</it>-CS is based on a client-server architecture. The <it>μ</it>-CS client is provided both as a plug-in of the TIGR M4 platform and as a Java standalone tool and enables users to read, preprocess and analyse binary microarray data, avoiding the manual invocation of external tools (e.g. the Affymetrix Power Tools), the manual loading of preprocessing libraries, and the management of intermediate files. The <it>μ</it>-CS server automatically updates the references to the summarization and annotation libraries that are provided to the <it>μ</it>-CS client before the preprocessing. The <it>μ</it>-CS server is based on the web services technology and can be easily extended to support more microarray vendors (e.g. Illumina).</p> <p>Conclusions</p> <p>Thus <it>μ</it>-CS users can directly manage binary data without worrying about locating and invoking the proper preprocessing tools and chip-specific libraries. Moreover, users of the <it>μ</it>-CS plugin for TM4 can manage Affymetrix binary files without using external tools, such as APT (Affymetrix Power Tools) and related libraries. Consequently, <it>μ</it>-CS offers four main advantages: (i) it avoids to waste time for searching the correct libraries, (ii) it reduces possible errors in the preprocessing and further analysis phases, e.g. due to the incorrect choice of parameters or the use of old libraries, (iii) it implements the annotation of preprocessed data, and finally, (iv) it may enhance the quality of further analysis since it provides the most updated annotation libraries. The <it>μ</it>-CS client is freely available as a plugin of the TM4 platform as well as a standalone application at the project web site (<url>http://bioingegneria.unicz.it/M-CS</url>).</p

    Thermal Resonance in Signal Transmission

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    We use temperature tuning to control signal propagation in simple one-dimensional arrays of masses connected by hard anharmonic springs and with no local potentials. In our numerical model a sustained signal is applied at one site of a chain immersed in a thermal environment and the signal-to-noise ratio is measured at each oscillator. We show that raising the temperature can lead to enhanced signal propagation along the chain, resulting in thermal resonance effects akin to the resonance observed in arrays of bistable systems.Comment: To appear in Phys. Rev.

    Development of a High Efficiency Ceiling Fan

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    The potential of ceiling fans to improve comfort during the cooling season is well documented (Rohles et al.. 1983; Fairey et al.. 1986). There are at least two cases: In the first where air conditioning is unavailable, adding ceiling fans may significantly improve building comfort and health although actually increasing energy use. However, the more common circumstance is where ceiling fans are used with the objective of providing a higher cooling system thermostat set point with acceptable comfort. Fans can also potentially avoid the use of air conditioning during "swing" seasons. Although studies commonly suggest a 2-6OF increase in the thermostat set point, data from 386 surveyed Central Florida households suggests that although fans are used an average of 13.4 hours per day, no statistically valid difference can be observed in thermostat settings between households using fans and those without them (James et al., 1996). Part of this may be due to the lack of sufficiently wide air distribution coverage within rooms (Rohles et al, 1983; Sonne and Parker, 1998). Studies touting potential cooling savings of up to 40% have usually been sponsored by fan manufacturers (eg. A.D. Little, 1981). These often make unrealistic assumptions such as presuming that occupants are within four feet of a fan with only one fan in use and a 6°F elevation of the thermostat setting. An environmental chamber study by Consumer Reports showed that the long-reported de-stratification benefits when heating are largely unsubstantiated (Consumer Reports. 1993). Thus. benefits from ceiling fans are only to reduce cooling needs and this is completely contingent on sufficient changes in interior comfort to warrant raising of the cooling thermostat. Two other factors must be taken into account in assessing the benefits of fans: their actual energy use and the added internal heat gains produced by the fans during operation. The measured electrical demand of ceiling fans varies between 5 and 115 Watts depending on model and speed selection. A power demand of 40 W at medium speed is probably typical (Chandra, 1985). Thus, a fan used for six months of the year would use 175 kwh. With 4.3 ceiling fans in an average Florida home, this amounts to about 800 kwh of fan energy consumption --about 5% of total electricity use. Also, all of the energy use of fans is eventually converted to heat within the home which must eventually be removed by ventilation air or the cooling system
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