11,705 research outputs found

    Anomalous diffusion in polymers: long-time behaviour

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    We study the Dirichlet boundary value problem for viscoelastic diffusion in polymers. We show that its weak solutions generate a dissipative semiflow. We construct the minimal trajectory attractor and the global attractor for this problem.Comment: 13 page

    Searching for Masculine Capital: Experiences Leading to High Drive for Muscularity in Men

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    Studies on the drive for muscularity (DFM) have primarily been quantitative, focused on identifying correlates. Currently little is known about men’s experiences leading them to desire high levels of muscle and engage in behaviours to increase their masculine capital. Our purpose was to explore the stories of men with high DFM revealing the socio-cultural and personal factors leading to DFM and their search for masculine capital. In-depth life-history interviews and multiple in-the-field conversations were undertaken with twenty men (Mean age=28.45, SD=6.96, years) scoring ≥ 3 on the Drive for Muscularity Scale (Mean=4.30, SD=0.70). Men’s stories focused on a set of dysfunctional childhood and adolescent socio-cultural interactions, including forms of symbolic violence, between them and significant others. In these interactions men were exposed to dominant social narratives of masculinity, and through comparisons and reinforcement they identified discrepancies between themselves and these narratives. In late adolescence and early adulthood men came to believe that they lacked masculine capital. Men struggled to increase their masculine capital through engagement with other traditional masculine activities (e.g., sport) and driven by activating events, they compensated through DFM desires and behaviours. This study advances knowledge by revealing the socio-cultural and personal processes participants believed led to their high DFM. Findings disclose that men’s search for masculine capital may have led them to develop and maintain high levels of DFM

    Magnetic phase transitions in Gd64Sc36 studied using non-contact ultrasonics

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    The speed and attenuation of ultrasound propagation can be used to determine material properties and identify phase transitions. Standard ultrasonic contact techniques are not always convenient due to the necessity of using couplant; however, recently reliable non-contact ultrasonic techniques involving electromagnetic generation and detection of ultrasound with electromagnetic acoustic transducers (EMATs) have been developed for use on electrically conducting and/or magnetic materials. We present a detailed study of magnetic phase transitions in a single crystal sample of Gd64Sc36 magnetic alloy using contact and non-contact ultrasonic techniques for two orientations of external magnetic field. Phase diagrams are constructed based on measurements of elastic constant C33, the attenuation and the efficiency of generation when using an EMAT. The EMATs are shown to provide additional information related to the magnetic phase transitions in the studied sample, and results identify a conical helix phase in Gd64Sc36 in the magnetic field orientation

    Muscle dysmorphia: Current insights

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    Since 1997, there has been increasing research focused on Muscle Dysmorphia, a condition underpinned by people’s beliefs they have insufficient muscularity, in both the Western and non-western medical and scientific communities. Much of this empirical interest has surveyed nonclinical samples, and there is limited understanding of people with the condition beyond knowledge about their characteristics. Much existing knowledge about people with the condition is unsurprising and inherent in the definition of the disorder, such as dissatisfaction with muscularity and adherence to muscle-building activities. Only recently have investigators started to explore questions beyond these limited tautological findings that may give rise to substantial knowledge advances, such as the examination of masculine and feminine norms. There is limited understanding of additional topics such as etiology, prevalence, nosology, prognosis, and treatment. Further, the evidence is largely based on a small number of unstandardized case reports and descriptive studies (involving small samples), largely confined to Western (North American, British, and Australian) males. Although much research has been undertaken since the term Muscle Dysmorphia entered the psychiatric lexicon in 1997, there remains tremendous scope for knowledge advancement. A primary task in the short term is for investigators to examine the extent that the condition exists among well-defined populations to help determine the justification for research funding relative to other public health issues. A greater variety of research questions and designs may contribute to a broader and more robust knowledge base than currently exists. Future work will help clinicians assist a group of people whose quality of life and health is placed at risk by their muscular preoccupation

    Predicting Muscularity-Related Behavior, Emotions, and Cognitions in Men: The Role of Psychological Need Thwarting, Drive for Muscularity, and Mesomorphic Internalization

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    We examine the relationships that internalization, need thwarting (NT), and drive for muscularity (DFM), along with their interactions, had with weightlifting, muscle dissatisfaction (MD), and muscle-related-worry (MRW). A sample of 552 men (MAGE = 20.5 years, SD = 3.1) completed the Psychological Need Thwarting Scale, the Internalization subscale of the male version of the Sociocultural Attitudes Towards Appearance Questionnaire, the Drive for Muscularity Scale-Attitudes subscale, the Male Body Attitudes Scale-Muscularity subscale, the Body Change Inventory-Worry subscale, and an inventory assessing weightlifting behavior. DFM significantly predicted weightlifting, MRW, and MD. Internalization significantly predicted weightlifting and MRW. NT significantly predicted weightlifting and MD, and its relationship with MRW approached significance. The interaction terms did not predict weightlifting or MRW. The NT/DFM and NT/Internalization interaction terms predicted MD. These results highlight the role of NT in predicting appearance variables in men

    Effect of Fat and CHO Meals on Intermittent Exercise in Soccer Players

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    Pre-exercise meals containing carbohydrates (CHO) are recommended to athletes, although there is evidence to suggest that a high fat meal prior to exercise increases utilisation of fats yet may not adversely affect performance. This study investigated the effect of a high fat and high CHO pre-exercise meal prior to high intensity intermittent exercise. Ten male recreational soccer players performed a soccer specific protocol followed by a 1 km time trial 3 ½ h after ingesting one of 2 test meals, high fat meal (HFM) or a high CHO meal (HCM). Blood glucose, fatty acids (FA), glycerol, β-hydroxybutyrate, lactate and insulin were assessed prior to the meal, pre-exercise, halftime, and post-exercise, whilst rates of CHO and fat oxidation were determined at 4 time points during the exercise as well as heart rate (HR) and rating of perceived exertion (RPE). Significant increases in FA, glycerol, β-hydroxybutyrate and fat oxidation after the HFM were observed, while CHO oxidation was significantly higher following the HCM (P < 0.05). No performance effect was found for the 1 km time trial (HFM: 228.6+14.4 s; HCM: 229.4+26.5 s) (mean+SD). These findings suggest that the type of meal ingested prior to soccer simulated exercise has an impact on metabolism, but not on the subsequent performance as determined in the present study

    Quantum state transformations and the Schubert calculus

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    Recent developments in mathematics have provided powerful tools for comparing the eigenvalues of matrices related to each other via a moment map. In this paper we survey some of the more concrete aspects of the approach with a particular focus on applications to quantum information theory. After discussing the connection between Horn's Problem and Nielsen's Theorem, we move on to characterizing the eigenvalues of the partial trace of a matrix.Comment: 40 pages. Accepted for publication in Annals of Physic

    RocA truncation underpins hyper-encapsulation, carriage longevity and transmissibility of serotype M18 group A streptococci

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    Group A streptococcal isolates of serotype M18 are historically associated with epidemic waves of pharyngitis and the non-suppurative immune sequela rheumatic fever. The serotype is defined by a unique, highly encapsulated phenotype, yet the molecular basis for this unusual colony morphology is unknown. Here we identify a truncation in the regulatory protein RocA, unique to and conserved within our serotype M18 GAS collection, and demonstrate that it underlies the characteristic M18 capsule phenotype. Reciprocal allelic exchange mutagenesis of rocA between M18 GAS and M89 GAS demonstrated that truncation of RocA was both necessary and sufficient for hyper-encapsulation via up-regulation of both precursors required for hyaluronic acid synthesis. Although RocA was shown to positively enhance covR transcription, quantitative proteomics revealed RocA to be a metabolic regulator with activity beyond the CovR/S regulon. M18 GAS demonstrated a uniquely protuberant chain formation following culture on agar that was dependent on excess capsule and the RocA mutation. Correction of the M18 rocA mutation reduced GAS survival in human blood, and in vivo naso-pharyngeal carriage longevity in a murine model, with an associated drop in bacterial airborne transmission during infection. In summary, a naturally occurring truncation in a regulator explains the encapsulation phenotype, carriage longevity and transmissibility of M18 GAS, highlighting the close interrelation of metabolism, capsule and virulence

    Experiments in randomly agitated granular assemblies close to the jamming transition

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    We present here the preliminary results obtained for two experiments on randomly agitated granular assemblies using a novel way of shaking. First we discuss the transport properties of a 2D model system undergoing classical shaking that show the importance of large scale dynamics for this type of agitation and offer a local view of the microscopic motions of a grain. We then develop a new way of vibrating the system allowing for random accelerations smaller than gravity. Using this method we study the evolution of the free surface as well as results from a light scattering method for a 3D model system. The final aim of these experiments is to investigate the ideas of effective temperature on the one hand as a function of inherent states and on the other hand using fluctuation dissipation relations.Comment: Contribution to the volume "Unifying Concepts in Granular Media and Glasses", edt.s A. Coniglio, A. Fierro, H.J. Herrmann and M. Nicodem
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