1,709 research outputs found

    Baryon Exotics in the Quark Model, the Skyrme Model and QCD

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    We identify the quantum numbers of baryon exotics in the Quark Model, the Skyrme Model and QCD, and show that they agree for arbitrary colors and flavors. We define exoticness, E, which can be used to classify the states. The exotic baryons include the recently discovered qqqq qbar pentaquarks (E=1), as well as exotic baryons with additional q qbar pairs (E >=1). The mass formula for non-exotic and exotic baryons is given as an expansion in 1/N, and allows one to relate the moment of inertia of the Skyrme soliton to the mass of a constituent quark

    A star-forming galaxy at z= 5.78 in the Chandra Deep Field South

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    We report the discovery of a luminous z = 5.78 star-forming galaxy in the Chandra Deep Field South. This galaxy was selected as an ‘i-drop’ from the GOODS public survey imaging with the Hubble Space Telescope/Advanced Camera for Surveys (object 3 in the work of Stanway, Bunker & McMahon 2003). The large colour of (iâ€Č−zâ€Č)AB = 1.6 indicated a spectral break consistent with the Lyman α forest absorption shortward of Lyman α at z≈ 6. The galaxy is very compact (marginally resolved with ACS with a half-light radius of 0.08 arcsec, so rhl 5. Our spectroscopic redshift for this object confirms the validity of the iâ€Č-drop technique of Stanway et al. to select star-forming galaxies atz≈ 6

    Ageing and chronic illness in language and sexuality

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    An ageing demographic in Western societies as well as globally has made public health issues, such as dementias, subject to hyperbolic metaphor such as “tsunami” and “time bomb.” This chapter reviews the state of knowledge regarding language, sexualities, ageing, and chronic illness. In particular, we focus on discursive research from across the social sciences that furthers understandings of older people’s lives and experiences. We highlight research that has focused on ageism and chronic conditions impacting older people (specifically, dementia and type 2 diabetes), including empirical research on these conditions, and on manifestations of heterosexism and heteronormativity in these contexts. Using illustrative examples that emphasize the intersection of discourse and issues that relate to ageing, we foreground this area as an important element of language and sexuality scholarship. Last, we indicate future directions for the development of research focusing on these topics

    The diversity of microbial aldo/keto reductases from Escherichia coli K12

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    The genome of Escherichia coli K12 contains 9 open reading frames encoding aldo/keto reductases (AKRs) that are differentially regulated and sequence diverse. A significant amount of data is available for the E. coli AKRs through the availability of gene knockouts and gene expression studies, which adds to the biochemical and kinetic data. This together with the availability of crystal structures for nearly half of the E. coli AKRs and homologues of several others provides an opportunity to look at the diversity of these representative bacterial AKRs. Based around the common AKR fold of (ÎČ/α)8 barrel with two additional α-helices, the E. coli AKRs have a loop structure that is more diverse than their mammalian counterparts, creating a variety of active site architectures. Nearly half of the AKRs are expected to be monomeric, but there are examples of dimeric, trimeric and octameric enzymes, as well as diversity in specificity for NAD as well as NADP as a cofactor. However in functional assignments and characterisation of enzyme activities there is a paucity of data when compared to the mammalian AKR enzymes

    Observation of coherent delocalized phonon-like modes in DNA under physiological conditions

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    Underdamped terahertz-frequency delocalized phonon-like modes have long been suggested to play a role in the biological function of DNA. Such phonon modes involve the collective motion of many atoms and are prerequisite to understanding the molecular nature of macroscopic conformational changes and related biochemical phenomena. Initial predictions were based on simple theoretical models of DNA. However, such models do not take into account strong interactions with the surrounding water, which is likely to cause phonon modes to be heavily damped and localized. Here we apply state-of-the-art femtosecond optical Kerr effect spectroscopy, which is currently the only technique capable of taking low-frequency (GHz to THz) vibrational spectra in solution. We are able to demonstrate that phonon modes involving the hydrogen bond network between the strands exist in DNA at physiologically relevant conditions. In addition, the dynamics of the solvating water molecules is slowed down by about a factor of 20 compared with the bulk

    Implications for Training on Smartphone Medication Reminder App Use by Adults With Chronic Conditions: Pilot Study Applying the Technology Acceptance Model

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    Background: The majority of middle-aged to older patients with chronic conditions report forgetting to take medications as prescribed. The promotion of patients’ smartphone medication reminder app (SMRA) use shows promise as a feasible and cost-effective way to support their medication adherence. Providing training on SMRA use, guided by the technology acceptance model (TAM), could be a promising intervention to promote patients’ app use. Objective: The aim of this pilot study was to (1) assess the feasibility of an SMRA training session designed to increase patients’ intention to use the app through targeting perceived usefulness of app, perceived ease of app use, and positive subjective norm regarding app use and (2) understand the ways to improve the design and implementation of the training session in a hospital setting. Methods: A two-group design was employed. A total of 11 patients older than 40 years (median=58, SD=9.55) and taking 3 or more prescribed medications took part in the study on one of two different dates as participants in either the training group (n=5) or nontraining group (n=6). The training group received an approximately 2-hour intervention training session designed to target TAM variables regarding one popular SMRA, the Medisafe app. The nontraining group received an approximately 2-hour control training session where the participants individually explored Medisafe app features. Each training session was concluded with a one-time survey and a one-time focus group. Results: Mann-Whitney U tests revealed that the level of perceived ease of use (P=.13) and the level of intention to use an SMRA (P=.33) were higher in the training group (median=7.00, median=6.67, respectively) than in the nontraining group (median=6.25, median=5.83). However, the level of perceived usefulness (U=4.50, Z=−1.99, P=.05) and the level of positive subjective norm (P=.25) were lower in the training group (median=6.50, median=4.29) than in the nontraining group (median=6.92, median=4.50). Focus groups revealed the following participants’ perceptions of SMRA use in the real-world setting that the intervention training session would need to emphasize in targeting perceived usefulness and positive subjective norm: (1) the participants would find an SMRA to be useful if they thought the app could help address specific struggles in medication adherence in their lives and (2) the participants think that their family members (or health care providers) might view positively the participants’ SMRA use in primary care settings (or during routine medical checkups). Conclusions: Intervention training session, guided by TAM, appeared feasible in targeting patients’ perceived ease of use and, thereby, increasing intention to use an SMRA. Emphasizing the real-world utility of SMRA, the training session could better target patients’ perceived usefulness and positive subjective norm that are also important in increasing their intention to use the app. [JMIR Formativ Res 2017;1(1):e5

    Type IIn Supernova Detections in z ~ 2 Lyman Break Galaxies: Probing the IMF Directly

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    Type IIn supernovae (SNe IIn) exhibit luminous ultraviolet continua during outburst and luminous, long-lived narrow ultraviolet and optical emission lines attributed to circumstellar interaction. These properties have enabled successful detections at z ~ 2 in archival imaging and continued investigations from late-time spectroscopy. Because SNe IIn are believed to have massive (≳50M_☉) progenitors, searches in the well-studied Lyman break galaxy (LBG) host population offer the prospect of testing the form of the high-redshift stellar initial mass function (IMF) in a high density star formation environment directly. I briefly discuss our z ~ 2 photometric detection method targeting LBGs in the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) and present data from the first 6 confirmed z ~ 2 SNe IIn pulled from 30 photometric SN candidates. A comparison of the color and magnitude distributions of the SN host galaxies to that of the full LBG sample finds that z ~ 2 SNe preferentially occur in bluer, fainter galaxies. I conclude with a discussion of an approach that uses the CFHTLS pilot sample to provide a first estimate of the form of the high-redshift IMF. Upcoming deep synoptic imaging surveys will greatly improve z ~ 2 SNe IIn statistics from ~10^5 expected detections and future large aperture space- and ground-based telescopes will have the sensitivities to extend this work to z ≳ 6

    Asymptotics of the mean-field Heisenberg model

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    We consider the mean-field classical Heisenberg model and obtain detailed information about the total spin of the system by studying the model on a complete graph and sending the number of vertices to infinity. In particular, we obtain Cramer- and Sanov-type large deviations principles for the total spin and the empirical spin distribution and demonstrate a second-order phase transition in the Gibbs measures. We also study the asymptotics of the total spin throughout the phase transition using Stein's method, proving central limit theorems in the sub- and supercritical phases and a nonnormal limit theorem at the critical temperature.Comment: 44 page
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