Constraints on the Neutron Star Equation of State from GW170817

The first detection of gravitational waves from a neutron star-neutron star merger, GW170817, has opened up a new avenue for constraining the ultradense-matter equation of state (EOS). The deviation of the observed waveform from a point-particle waveform is a sensitive probe of the EOS controlling the merging neutron stars' structure. In this topical review, I discuss the various constraints that have been made on the EOS in the year following the discovery of GW170817. In particular, I review the surprising relationship that has emerged between the effective tidal deformability of the binary system and the neutron star radius. I also report new results that make use of this relationship, finding that the radius inferred from GW170817 lies between 9.8 and 13.2 km at 90% confidence, with distinct likelihood peaks at 10.8 and 12.3 km. I compare these radii, as well as those inferred in the literature, to X-ray measurements of the neutron star radius. I also summarize the various maximum mass constraints, which point towards a maximum mass < 2.3 M_sun, depending on the fate of the remnant, and which can be used to additionally constrain the high-density EOS. I review the constraints on the EOS that have been performed directly, through Bayesian inference schemes. Finally, I comment on the importance of disentangling thermal effects in future EOS constraints from neutron star mergers.Comment: Invited contribution to the EPJA topical issue "The first neutron star merger observation - Implications for nuclear physics

The Poetry of Christina Rossetti and Dante Gabriel Rossetti: Same Femme, Different Fate

Siblings Dante Gabriel Rossetti and Christina Rossetti both lived during the Victorian era and wrote poetry which epitomizes the Pre-Raphaelite movement. Although they were related, these two poets were drastically different, and their differences are evident in their poetry. Dante Gabriel was infatuated with beautiful women and many of his poems express sexual desire, while Christina was intensely devoted to God and many of her poems provide moral instruction. However, these poets both make femme fatales the subjects of their poems “Body’s Beauty,” “The Card-Dealer,” “The World,” and “Babylon the Great.” This paper analyzes the different ways in which Dante Gabriel Rossetti uses the image of a dangerous, eroticized woman to symbolize the threat that the power of female beauty poses to a man\u27s life, while Christina Rossetti uses this image to symbolize the threat that worldly desires pose to a person\u27s eternal life

The Community of Nursing: Moral Friends, Moral Strangers, Moral Family

Unlike bioethicists who contend that there is a morality common to all, H. Tristan Engelhardt (1996) argues that, in a pluralistic secular society, any morality that does exist is loosely connected, lacks substantive moral content, is based on the principle of permission and, thus, is a morality between moral strangers. This, says Engelhardt, stands in contrast to a substance-full morality that exists between moral friends, a morality in which moral content is based on shared beliefs and values and exists in communities that tend to be closely knit and religiously based. Of what value does Engelhardt’s description of ethics as moral friends and moral strangers have for nursing? In this essay, I attempt to show how Engelhardt’s description serves to illustrate how the nursing community historically had been one of moral friends but has gradually become one of moral strangers and, hence, at risk of failing to protect patients in their vulnerability and of compromising the integrity of nursing. Building on Engelhardt’s concepts, I suggest we might consider modern nursing like a moral family to the extent that members might at times relate to one another as moral strangers but still possess a desire and a need to reconnect with the common thread that binds us as moral friends. Nursing is a practice discipline. Given the challenges of modern bioethics, an applied ethic is needed to give moral direction to clinicians as we strive to conduct ourselves ethically in the practice of our profession. To that end, nursing should reflect upon and seek to reconnect with the content-full morality that is historically and religiously based

Carolyn Gamtso and Patricia Halpin travel to Ireland

In August 2014, we travelled together to Limerick, Republic of Ireland to participate jointly in a panel discussion at the Information Literacy Section Satellite Meeting of the International Federation of Library Associations (IFLA) World Library and Information Congress. Hosted by the Limerick Institute of Technology, the conference’s theme was “Facing the Future: Librarians and Information Literacy in a Changing Landscape.” The topics discussed and debated (information literacy and social media; information literacy as a “meta-literacy”; information literacy and distance learning)relate directly to conversations our UNH Manchester colleagues are having about how best to teach our students the transferable critical thinking skills they will need both as members of the workforce and members of their communities. We were very excited to have our presentation proposal accepted at this competitive conference. Our presentation was an opportunity for us to share our teaching practices and our research with an international audience of librarians and educators. It was also a chance to meet and network with colleagues from around the world, colleagues who, like us, are dedicated to developing students’ information fluency in an environment of constant technological change. Our trip was generously funded by the UNH Center for International Education, the UNH Manchester Humanities Division, the UNH Manchester Science &Technology Division, and the UNH Manchester Deans & Chairs

Viral pathogens and acute lung injury: investigations inspired by the SARS epidemic and the 2009 H1N1 influenza pandemic.

Acute viral pneumonia is an important cause of acute lung injury (ALI), although not enough is known about the exact incidence of viral infection in ALI. Polymerase chain reaction-based assays, direct fluorescent antigen (DFA) assays, and viral cultures can detect viruses in samples from the human respiratory tract, but the presence of the virus does not prove it to be a pathogen, nor does it give information regarding the interaction of viruses with the host immune response and bacterial flora of the respiratory tract. The severe acute respiratory syndrome (SARS) epidemic and the 2009 H1N1 influenza pandemic provided a better understanding of how viral pathogens mediate lung injury. Although the viruses initially infect the respiratory epithelium, the relative role of epithelial damage and endothelial dysfunction has not been well defined. The inflammatory host immune response to H1N1 infection is a major contributor to lung injury. The SARS coronavirus causes lung injury and inflammation in part through actions on the nonclassical renin angiotensin pathway. The lessons learned from the pandemic outbreaks of SARS coronavirus and H1N1 capture key principles of virally mediated ALI. There are pathogen-specific pathways underlying virally mediated ALI that converge onto a common end pathway resulting in diffuse alveolar damage. In terms of therapy, lung protective ventilation is the cornerstone of supportive care. There is little evidence that corticosteroids are beneficial, and they might be harmful. Future therapeutic strategies may be targeted to specific pathogens, the pathogenetic pathways in the host immune response, or enhancing repair and regeneration of tissue damage

From Neutron Star Observables to the Equation of State. I. An Optimal Parametrization

The increasing number and precision of measurements of neutron star masses, radii, and, in the near future, moments of inertia offer the possibility of precisely determining the neutron star equation of state. One way to facilitate the mapping of observables to the equation of state is through a parametrization of the latter. We present here a generic method for optimizing the parametrization of any physically allowed EoS. We use mock equations of state that incorporate physically diverse and extreme behavior to test how well our parametrization reproduces the global properties of the stars, by minimizing the errors in the observables mass, radius, and the moment of inertia. We find that using piecewise polytropes and sampling the EoS with five fiducial densities between ~1-8 times the nuclear saturation density results in optimal errors for the smallest number of parameters. Specifically, it recreates the radii of the assumed EoS to within less than 0.5 km for the extreme mock equations of state and to within less than 0.12 km for 95% of a sample of 42 proposed, physically-motivated equations of state. Such a parametrization is also able to reproduce the maximum mass to within 0.04 M_sun and the moment of inertia of a 1.338 M_sun neutron star to within less than 10% for 95% of the proposed sample of equations of state.Comment: Minor changes made to match published ApJ versio

Confronting Models of Massive Star Evolution and Explosions with Remnant Mass Measurements

The mass distribution of compact objects provides a fossil record that can be studied to uncover information on the late stages of massive star evolution, the supernova explosion mechanism, and the dense matter equation of state. Observations of neutron star masses indicate a bimodal Gaussian distribution, while the observed black hole mass distribution decays exponentially for stellar-mass black holes. We use these observed distributions to directly confront the predictions of stellar evolution models and the neutrino-driven supernova simulations of Sukhbold et al. (2016). We find excellent agreement between the black hole and low-mass neutron star distributions created by these simulations and the observations. We show that a large fraction of the stellar envelope must be ejected, either during the formation of stellar-mass black holes or prior to the implosion through tidal stripping due to a binary companion, in order to reproduce the observed black hole mass distribution. We also determine the origins of the bimodal peaks of the neutron star mass distribution, finding that the low-mass peak (centered at ~1.4 M_sun) originates from progenitors with M_zams ~ 9-18 M_sun. The simulations fail to reproduce the observed peak of high-mass neutron stars (centered at ~1.8 M_sun) and we explore several possible explanations. We argue that the close agreement between the observed and predicted black hole and low-mass neutron star mass distributions provides new promising evidence that these stellar evolution and explosion models are accurately capturing the relevant stellar, nuclear, and explosion physics involved in the formation of compact objects.Comment: Typos in fit coefficients corrected, results unchanged. 13 pages, 10 figures. Submitted to Ap