2,013 research outputs found

    The Cognitive Principle of Relevance and its Application to Anti Iraq War Posters

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    Relevance theory is a psychological model for understanding the cognitive interpretation of language, was developed by Dan Sperber and Deirdre Wilson in 1986 and republished in 1995. They argue that the thing that causes an input to stand out from others is its relevance to the receiver and that every utterance creates in the addressee an expectation of relevance. The underlying assumption of relevance theory is that in any given context, the addressee has to assume that what people say is relevant.     In this paper the problem of the cognitive principle of relevance theory presented by Sperber and Wilson is approached in its application to the posters painted by people who are opposing an American led war against Iraq. The analysis will be conducted to find out how these posters achieve a successful communication and how is that the audience recognizes that the designer of each poster has something to say that matters, something that is relevant and how the addressee understands the content of these posters and how he/she uses their cognition to interpret the posters’ contents and finds them relevant as they are apposing the war against Iraq.

    An Efficient Representation of Euclidean Gravity I

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    We explore how the topology of spacetime fabric is encoded into the local structure of Riemannian metrics using the gauge theory formulation of Euclidean gravity. In part I, we provide a rigorous mathematical foundation to prove that a general Einstein manifold arises as the sum of SU(2)_L Yang-Mills instantons and SU(2)_R anti-instantons where SU(2)_L and SU(2)_R are normal subgroups of the four-dimensional Lorentz group Spin(4) = SU(2)_L x SU(2)_R. Our proof relies only on the general properties in four dimensions: The Lorentz group Spin(4) is isomorphic to SU(2)_L x SU(2)_R and the six-dimensional vector space of two-forms splits canonically into the sum of three-dimensional vector spaces of self-dual and anti-self-dual two-forms. Consolidating these two, it turns out that the splitting of Spin(4) is deeply correlated with the decomposition of two-forms on four-manifold which occupies a central position in the theory of four-manifolds.Comment: 31 pages, 1 figur

    A Genome-Wide Analysis of Promoter-Mediated Phenotypic Noise in Escherichia coli

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    Gene expression is subject to random perturbations that lead to fluctuations in the rate of protein production. As a consequence, for any given protein, genetically identical organisms living in a constant environment will contain different amounts of that particular protein, resulting in different phenotypes. This phenomenon is known as “phenotypic noise.” In bacterial systems, previous studies have shown that, for specific genes, both transcriptional and translational processes affect phenotypic noise. Here, we focus on how the promoter regions of genes affect noise and ask whether levels of promoter-mediated noise are correlated with genes' functional attributes, using data for over 60% of all promoters in Escherichia coli. We find that essential genes and genes with a high degree of evolutionary conservation have promoters that confer low levels of noise. We also find that the level of noise cannot be attributed to the evolutionary time that different genes have spent in the genome of E. coli. In contrast to previous results in eukaryotes, we find no association between promoter-mediated noise and gene expression plasticity. These results are consistent with the hypothesis that, in bacteria, natural selection can act to reduce gene expression noise and that some of this noise is controlled through the sequence of the promoter region alon

    Dynamics of heteropolymers in dilute solution: effective equation of motion and relaxation spectrum

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    The dynamics of a heteropolymer chain in solution is studied in the limit of long chain length. Using functional integral representation we derive an effective equation of motion, in which the heterogeneity of the chain manifests itself as a time-dependent excluded volume effect. At the mean field level, the heteropolymer chain is therefore dynamically equivalent to a homopolymer chain with both time-independent and time-dependent excluded volume effects. The perturbed relaxation spectrum is also calculated. We find that heterogeneity also renormalizes the relaxation spectrum. However, we find, to the lowest order in heterogeneity, that the relaxation spectrum does not exhibit any dynamic freezing, at the point when static (equilibrium) ``freezing'' transition occurs in heteropolymer. Namely, the breaking of fluctuation-dissipation theorem (FDT) proposed for spin glass dynamics does not have dynamic effect in heteropolymer, as far as relaxation spectrum is concerned. The implication of this result is discussed

    Breastfeeding in Bolivia – information and attitudes

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    BACKGROUND: The main objective of the present study was to investigate the relationship between the attitudes of the mother and her family towards breastfeeding and the actual feeding pattern in a Bolivian population. A second objective was to study the relationship between breastfeeding information, specified according to source and timing, and feeding pattern. METHODS: Cross-sectional interviews with 420–502 Bolivian mothers with an infant less than or equal to 1 year of age. Duration of exclusive breastfeeding, use of prelacteal food and/or colostrum were the main outcome measures. RESULTS: The attitudes of the mother, her partner (the infant's father) and the infant's grandmother towards breastfeeding did not influence the infant feeding pattern. Women who had received breastfeeding information from health care personnel before birth or on the maternity ward breastfed exclusively for a longer duration (adjusted p = 0.0233) and avoided prelacteal food to a greater extent (adjusted odds ratio (AOR) = 0.42; 95% confidence interval for adjusted odds ratio (95% CI AOR) = 0.23–0.72). Information from a doctor before birth or on the maternity ward was associated with less use of prelacteal food (AOR = 0.53; 95% CI AOR = 0.31–0.93), an increased use of colostrum (AOR = 3.30; 95% CI AOR = 1.16–9.37), but was not linked to the duration of exclusive breastfeeding (p = 0.1767). CONCLUSION: The current study indicates that breastfeeding information delivered by health care personnel in a non-trial setting may affect the infant feeding pattern including the use of prelacteal foods and colostrum. There was no evidence that the attitudes of the mother, or the infant's father or grandmother influenced actual feeding behavior. The lack of a "negative or neutral attitude" towards breastfeeding in the participants of the current study does, however, diminish the chances to link attitude to feeding behavior

    Different Prey Resources Suggest Little Competition Between Non-Native Frogs and Insectivorous Birds Despite Isotopic Niche Overlap

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    Non-native amphibians often compete with native amphibians in their introduced range, but their competitive effects on other vertebrates are less well known. The Puerto Rican coqui frog (Eleutherodactylus coqui) has colonized the island of Hawaii, and has been hypothesized to compete with insectivorous birds and bats. To address if the coqui could compete with these vertebrates, we used stable isotope analyses to compare the trophic position and isotopic niche overlap between the coqui, three insectivorous bird species, and the Hawaiian hoary bat. Coquis shared similar trophic position to Hawaii amakihi, Japanese white-eye, and red-billed leiothrix. Coquis were about 3 ‰ less enriched in δ15N than the Hawaiian hoary bat, suggesting the bats feed at a higher trophic level than coquis. Analyses of potential diet sources between coquis and each of the three bird species indicate that there was more dietary overlap between bird species than any of the birds and the coqui. Results suggest that Acari, Amphipoda, and Blattodea made up \u3e90% of coqui diet, while Araneae made up only 2% of coqui diet, but approximately 25% of amakihi and white-eye diet. The three bird species shared similar proportions of Lepidoptera larvae, which were ~25% of their diet. Results suggest that coquis share few food resources with insectivorous birds, but occupy a similar trophic position, which could indicate weak competition. However, resource competition may not be the only way coquis impact insectivorous birds, and future research should examine whether coqui invasions are associated with changes in bird abundance

    Efficient Conversion of Astrocytes to Functional Midbrain Dopaminergic Neurons Using a Single Polycistronic Vector

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    Direct cellular reprogramming is a powerful new tool for regenerative medicine. In efforts to understand and treat Parkinson's Disease (PD), which is marked by the degeneration of dopaminergic neurons in the midbrain, direct reprogramming provides a valuable new source of these cells. Astrocytes, the most plentiful cells in the central nervous system, are an ideal starting population for the direct generation of dopaminergic neurons. In addition to their potential utility in cell replacement therapies for PD or in modeling the disease in vitro, astrocyte-derived dopaminergic neurons offer the prospect of direct in vivo reprogramming within the brain. As a first step toward this goal, we report the reprogramming of astrocytes to dopaminergic neurons using three transcription factors – ASCL1, LMX1B, and NURR1 – delivered in a single polycistronic lentiviral vector. The process is efficient, with 18.2±1.5% of cells expressing markers of dopaminergic neurons after two weeks. The neurons exhibit expression profiles and electrophysiological characteristics consistent with midbrain dopaminergic neurons, notably including spontaneous pacemaking activity, stimulated release of dopamine, and calcium oscillations. The present study is the first demonstration that a single vector can mediate reprogramming to dopaminergic neurons, and indicates that astrocytes are an ideal starting population for the direct generation of dopaminergic neurons

    Ifugao males, learning and teaching for the improvement of maternal and child health status in the Philippines: an evaluation of a program

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    <p>Abstract</p> <p>Background</p> <p>Improving Maternal and Child Health (MCH) is a prioritized global agenda in achieving the United Nations Millennium Development Goal 5. In this challenge, involving males has been an important agenda, and a program with such intent was conducted in <it>Alfonso Lista, Ifugao</it>, of the Philippines. The objectives of this study were: (1) to evaluate the effectiveness in knowledge, attitude, and practice before and after a MCH session; (2) to evaluate the session's effectiveness in relation to socio-demographic characteristics; and (3) to examine if males who have learned about MCH topics can teach another group of males.</p> <p>Methods</p> <p>A male community representative who received a lecture from the health office staff was assigned to teach a group of community males [Group 1, N = 140] in 5 sessions, using educational materials. 10 male volunteers from Group 1 then taught a different group of males [Group 2, N = 105] in their own <it>barangays </it>(villages). To evaluate its effectiveness, a self-administered questionnaire survey pertaining knowledge, attitude and practice regarding MCH was conducted at three different time points: before the session (Time 1, T1), after the session (Time 2, T2), and 3 months following the session (Time 3, T3). A repeated measures analysis of variance was conducted to test for changes over time and its interaction effect between specific socio-demographic variables.</p> <p>Results</p> <p>In Group 1, there was a significant positive increase in knowledge score over time at T1-T2 and T1-T3 (<it>p </it>< 0.001). For attitude, the score increased only at T1-T2 (<it>p </it>= 0.027). The effectiveness in knowledge and attitude did not vary by socio-demographic characteristics. As for practice, majority of the participants reported that they had talked about MCH topics in their community and assisted a pregnant woman in some ways. A comparison between Group 1 and Group 2 revealed that Group 2 had similar effectiveness as Group 1 in knowledge improvement immediately after the session (<it>p </it>< 0.001), but no such improvement in the attitude score.</p> <p>Conclusion</p> <p>Although the change in attitude needs further assessment, this strategy of continuous learning and teaching of MCH topics within community males is shown to improve knowledge and has a potential to uplift the MCH status, including the reduction of maternal deaths, in <it>Alfonso Lista, Ifugao, Philippines</it>.</p
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