Virial mass in DGP brane cosmology

We study the virial mass discrepancy in the context of a DPG brane-world scenario and show that such a framework can offer viable explanations to account for the mass discrepancy problem. This is done by defining a geometrical mass $\mathcal{N}$ that we prove to be proportional to the virial mass. Estimating $\mathcal{N}$ using observational data, we show that it behaves linearly with $r$ and has a value of the order of $M_{200}$, pointing to a possible resolution of the virial mass discrepancy. We also obtain the radial velocity dispersion of galaxy clusters and show that it is compatible with the radial velocity dispersion profile of such clusters. This velocity dispersion profile can be used to differentiate various models predicting the virial mass.Comment: 12 pages, 1 figure, to appear in CQ

The US in Uterus: A Collaborative Autoethnography of Psychologists Advocating for Reproductive Justice

In light of the recent Supreme Court decision to overturn Roe v. Wade, millions of people with uteruses have been forced to navigate precarious access to reproductive care. Although health service psychologists have an ethical responsibility to engage in reproductive justice advocacy, training programs often do not adequately address sexual and reproductive health. Therefore, we sought to better understand how health service psychologists’ personal and professional experiences influence each other and explore the ways in which we as reproductive beings and advocates sustain ourselves amidst tremendous sociopolitical uncertainty. In order to do so, we employed a feminist collaborative autoethnography approach grounded in critical theory. Attending to intersectional identities that help shape diverse expectations and experiences, two early career psychologists and four trainees uncovered 12 domains: barriers in academia; reproductive (dis)empowerment; relational connection; power(lessness) associated with social locations; internalization of sex-negative messages; the influence of sociopolitical climate; burdens related to reproductive rights; evaluations of reproductive justice efforts; component of professional identity; expectations from family and community; overwhelming and exhausting advocacy; and fears of inadequacy. We conclude with limitations and implications for the continued promotion of advocacy through practice and training within and beyond the field of psychology

Spectral Evidence for Emergent Order in Ba1−x_{1-x}Nax_xFe2_2As2_2

We report an angle-resolved photoemission spectroscopy study of the iron-based superconductor family, Ba$_{1-x}$Na$_x$Fe$_2$As$_2$. This system harbors the recently discovered double-Q magnetic order appearing in a reentrant C$_4$ phase deep within the underdoped regime of the phase diagram that is otherwise dominated by the coupled nematic phase and collinear antiferromagnetic order. From a detailed temperature-dependence study, we identify the electronic response to the nematic phase in an orbital-dependent band shift that strictly follows the rotational symmetry of the lattice and disappears when the system restores C$_4$ symmetry in the low temperature phase. In addition, we report the observation of a distinct electronic reconstruction that cannot be explained by the known electronic orders in the system

Microscopic Theory of Heterogeneity and Non-Exponential Relaxations in Supercooled Liquids

Recent experiments and computer simulations show that supercooled liquids around the glass transition temperature are "dynamically heterogeneous" [1]. Such heterogeneity is expected from the random first order transition theory of the glass transition. Using a microscopic approach based on this theory, we derive a relation between the departure from Debye relaxation as characterized by the $\beta$ value of a stretched exponential response function $\phi(t) =e^{-(t/ \tau_{KWW})^{\beta}}$, and the fragility of the liquid. The $\beta$ value is also predicted to depend on temperature and to vanish as the ideal glass transition is approached at the Kauzmann temperature.Comment: 4 pages including 3 eps figure

Anomalous relaxation and self-organization in non-equilibrium processes

We study thermal relaxation in ordered arrays of coupled nonlinear elements with external driving. We find, that our model exhibits dynamic self-organization manifested in a universal stretched-exponential form of relaxation. We identify two types of self-organization, cooperative and anti-cooperative, which lead to fast and slow relaxation, respectively. We give a qualitative explanation for the behavior of the stretched exponent in different parameter ranges. We emphasize that this is a system exhibiting stretched-exponential relaxation without explicit disorder or frustration.Comment: submitted to PR

Onset of rigidty in glasses: from random to self-organized networks

We review in this paper the signatures of a new elastic phase that is found in glasses with selected compositions. It is shown that in contrast with random networks, where rigidity percolates at a single threshold, networks that are able to self-organize to avoid stress will remain in an almost stress- free state during a compositional interval, an intermediate phase, that is bounded by a flexible phase and a stressed rigid phase. We report the experimental signatures and describe the theoretical efforts that have been accomplished to characterize the intermediate phase. We illustrate one of the methods used in more detail with the example of Group III chalcogenides and finally suggest further possible experimental signatures of self-organization.Comment: 27 pages, 6 figures, Proceedings of the Conference on Non-Crystalline Materials 10, to appear in Journal of Non-Crystalline Solid

The role of ethylene and 1-MCP in early-season sweet cherry ‘Burlat’ storage life

Sweet cherries (Prunus avium L.) are highly appreciated because of their bioactive compound content and attractive organoleptic characteristics; however, they are very perishable. The aim of this work was to investigate whether ethylene and its antagonist 1-MCP affect the postharvest quality of an early-season sweet cherry cultivar, allowing storage life extension. ‘Burlat’ sweet cherries were subjected to three treatments at 1 °C for one month: i) control (air); ii) continuous ethylene supplementation (10 μL L−1); and iii) 1-Methylcyclopropene (1-MCP; 1 μL L−1 for 24 h) followed by air. The incidence of postharvest physiological disorders, the evolution of physical and functional quality traits, and fruit senescence were evaluated at 0, 7, 14, 21, and 30 days. Results showed that sweet cherries were sensitive to both ethylene and 1-MCP treatments. Continuous ethylene exposure reduced abscisic acid accumulation, resulting in higher weight and firmness loss. Moreover, ethylene application decreased titratable acidity through storage, indicating an effect on sweet cherry senescence. No significant differences among treatments were found for soluble solids content and individual sugars. Conversely, 1-MCP preserved firmness during the first 7 days of storage, while reduced the incidence of physiological disorders at the end of storage life. Furthermore, 1-MCP delayed the accumulation of cyanidin-3-O-glucoside for 7 days compared to control and ethylene treated cherries. Taken together these results highlight the potential use of 1-MCP to extend the postharevst life of early season sweet cherry fruit

Lattice dynamics and correlated atomic motion from the atomic pair distribution function

The mean-square relative displacements (MSRD) of atomic pair motions in crystals are studied as a function of pair distance and temperature using the atomic pair distribution function (PDF). The effects of the lattice vibrations on the PDF peak widths are modelled using both a multi-parameter Born von-Karman (BvK) force model and a single-parameter Debye model. These results are compared to experimentally determined PDFs. We find that the near-neighbor atomic motions are strongly correlated, and that the extent of this correlation depends both on the interatomic interactions and crystal structure. These results suggest that proper account of the lattice vibrational effects on the PDF peak width is important in extracting information on static disorder in a disordered system such as an alloy. Good agreement is obtained between the BvK model calculations of PDF peak widths and the experimentally determined peak widths. The Debye model successfully explains the average, though not detailed, natures of the MSRD of atomic pair motion with just one parameter. Also the temperature dependence of the Debye model largely agrees with the BvK model predictions. Therefore, the Debye model provides a simple description of the effects of lattice vibrations on the PDF peak widths.Comment: 9 pages, 11 figure

Spinning Loop Black Holes

In this paper we construct four Kerr-like spacetimes starting from the loop black hole Schwarzschild solutions (LBH) and applying the Newman-Janis transformation. In previous papers the Schwarzschild LBH was obtained replacing the Ashtekar connection with holonomies on a particular graph in a minisuperspace approximation which describes the black hole interior. Starting from this solution, we use a Newman-Janis transformation and we specialize to two different and natural complexifications inspired from the complexifications of the Schwarzschild and Reissner-Nordstrom metrics. We show explicitly that the space-times obtained in this way are singularity free and thus there are no naked singularities. We show that the transformation move, if any, the causality violating regions of the Kerr metric far from r=0. We study the space-time structure with particular attention to the horizons shape. We conclude the paper with a discussion on a regular Reissner-Nordstrom black hole derived from the Schwarzschild LBH and then applying again the Newmann-Janis transformation.Comment: 18 pages, 18 figure

Toward a wiki guide for obstetrics and gynecology trainees in Ireland.

BACKGROUND: The present paper describes the implementation of a novel, web-based, comprehensive national information hub for trainees in obstetrics and gynecology in Ireland. This was a unique development in the context of an entire medical specialty and was aligned with the communication strategy of the governing professional body. To date, trainee doctors working in Ireland undergo an incoherent and inconsistent new-staff induction and handover. In the healthcare setting, staff integration can have a major impact on the quality of patient care. METHODS: A free wiki software platform (PBworks) was used for the website, and freely available software (Google Analytics) was used to determine user interaction and level of engagement. RESULTS: In the first year, 442 user visits were recorded. The average duration of site visits was 4minutes 39seconds, which compared favorably with the 4-minute duration for visits to Wikipedia. CONCLUSION: The project was successful as a proof concept and in practice. Other medical faculties have expressed an interest in adopting the concept and developing it for their trainees. The concept is widely applicable to other countries, with the negligible cost relevant to resource-poor areas