7,820 research outputs found

    Linear resolutions of powers and products

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    The goal of this paper is to present examples of families of homogeneous ideals in the polynomial ring over a field that satisfy the following condition: every product of ideals of the family has a linear free resolution. As we will see, this condition is strongly correlated to good primary decompositions of the products and good homological and arithmetical properties of the associated multi-Rees algebras. The following families will be discussed in detail: polymatroidal ideals, ideals generated by linear forms and Borel fixed ideals of maximal minors. The main tools are Gr\"obner bases and Sagbi deformation

    Acute knockdown of Kv4.1 regulates repetitive firing rates and clock gene expression in the suprachiasmatic nucleus and daily rhythms in locomotor behavior

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    AbstractRapidly activating and inactivating A-type K+currents (IA) encoded by Kv4.2 and Kv4.3 pore-forming (α) subunits of the Kv4 subfamily are key regulators of neuronal excitability. Previous studies have suggested a role for Kv4.1 α-subunits in regulating the firing properties of mouse suprachiasmatic nucleus (SCN) neurons. To test this, we utilized an RNA-interference strategy to knockdown Kv4.1, acutely and selectively, in the SCN. Current-clamp recordings revealed that thein vivoknockdown of Kv4.1 significantly (p&lt; 0.0001) increased mean ± SEM repetitive firing rates in SCN neurons during the day (6.4 ± 0.5 Hz) and at night (4.3 ± 0.6 Hz), compared with nontargeted shRNA-expressing SCN neurons (day: 3.1 ± 0.5 Hz; night: 1.6 ± 0.3 Hz). IAwas also significantly (p&lt; 0.05) reduced in Kv4.1-targeted shRNA-expressing SCN neurons (day: 80.3 ± 11.8 pA/pF; night: 55.3 ± 7.7 pA/pF), compared with nontargeted shRNA-expressing (day: 121.7 ± 10.2 pA/pF; night: 120.6 ± 16.5 pA/pF) SCN neurons. The magnitude of the effect of Kv4.1-targeted shRNA expression on firing rates and IAwas larger at night. In addition, Kv4.1-targeted shRNA expression significantly (p&lt; 0.001) increased mean ± SEM nighttime input resistance (Rin; 2256 ± 166 MΩ), compared to nontargeted shRNA-expressing SCN neurons (1143 ± 93 MΩ). Additional experiments revealed that acute knockdown of Kv4.1 significantly (p&lt; 0.01) shortened, by ∼0.5 h, the circadian period of spontaneous electrical activity, clock gene expression and locomotor activity demonstrating a physiological role for Kv4.1-encoded IAchannels in regulating circadian rhythms in neuronal excitability and behavior.</jats:p

    Surveillance system and method having an adaptive sequential probability fault detection test

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    System and method providing surveillance of an asset such as a process and/or apparatus by providing training and surveillance procedures that numerically fit a probability density function to an observed residual error signal distribution that is correlative to normal asset operation and then utilizes the fitted probability density function in a dynamic statistical hypothesis test for providing improved asset surveillance

    Animals, Archetypes, and Popular Culture: Tales from the Tabloid Press

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    This paper characterizes the portrayal of animals and human-animal relations in one genre of American popular culture—the “supermarket” tabloid press. A total of 789 animal-related stories and photographs in 82 issues of four tabloid magazines were analyzed according to theme. The items fell into nine categories in which animals were portrayed as objects of affection, saviors, threats, victims, things to be used, sex objects, imaginary and mythological beings, surrogate humans, and objects of wonder. It is argued that these themes represent archetypes reflecting the roles that animals have had in human cultural and psychological life since the historical origins of our species

    The Ethical Judgment of Animal Research

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    One hundred sixty subjects acted as members of a hypothetical Institutional Animal Care and Use Committee and evaluated five proposals in which animals were to be used for research or educational purposes. They were asked to approve or reject the proposals and to indicate what factors were important in reaching their ethical decisions. Gender and differences in personal moral philosophy were related to approval decisions. The reasons given for the decisions fell into three main categories: metacognitive statements, factors related to the animal, and factors related to the design of the experiment

    Complexity, Age, and Building Preference

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    The authors explore the role of complexity in the relation between building age and preference. Age was assessed as a categorical (via stimulus selection) and a continuous (via ratings of 64 color slides of urban buildings) variable. In either case, the authors replicated earlier research in showing that modern buildings were preferred over older buildings when building maintenance was not controlled, but when it was controlled, the relation reversed, and the older buildings were better liked. However, when a composite-rating measure of complexity was introduced, a somewhat different pattern emerged. Complexity interacted with rated age. The nature of the interaction was that throughout most of the range of complexity scores, age was negatively related to preference, but at the higher end of the complexity range, there was no relation between age and preference. Other findings: Buildings with visible entrances were preferred to those without, and distant views were preferred over near views

    Ethical Ideology, Animal Rights Activism, and Attitudes Toward the Treatment of Animals

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    In two studies, we used the Ethics Position Questionnaire (EPQ) to investigate the relationship between individual differences in moral philosophy, involvement in the animal rights movement, and attitudes toward the treatment of animals. In the first, 600 animal rights activists attending a national demonstration and 266 nonactivist college students were given the EPQ. Analysis of the returns from 157 activists and 198 students indicated that the activists were more likely than the students to hold an absolutist moral orientation (high idealism, low relativism). In the second study, 169 students were given the EPQ with a scale designed to measure attitudes toward the treatment of animals. Multiple regression showed that gender and the EPQ dimension of idealism were related to attitudes toward animal use

    Animals, Archetypes, and Popular Culture: Tales from the Tabloid Press

    Get PDF
    This paper characterizes the portrayal of animals and human-animal relations in one genre of American popular culture—the “supermarket” tabloid press. A total of 789 animal-related stories and photographs in 82 issues of four tabloid magazines were analyzed according to theme. The items fell into nine categories in which animals were portrayed as objects of affection, saviors, threats, victims, things to be used, sex objects, imaginary and mythological beings, surrogate humans, and objects of wonder. It is argued that these themes represent archetypes reflecting the roles that animals have had in human cultural and psychological life since the historical origins of our species
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