Improved Bounds for rr-Identifying Codes of the Hex Grid

For any positive integer $r$, an $r$-identifying code on a graph $G$ is a set $C\subset V(G)$ such that for every vertex in $V(G)$, the intersection of the radius-$r$ closed neighborhood with $C$ is nonempty and pairwise distinct. For a finite graph, the density of a code is $|C|/|V(G)|$, which naturally extends to a definition of density in certain infinite graphs which are locally finite. We find a code of density less than $5/(6r)$, which is sparser than the prior best construction which has density approximately $8/(9r)$.Comment: 12p

Spent Culture Medium from Virulent Borrelia burgdorferi Increases Permeability of Individually Perfused Microvessels of Rat Mesentery

Background Lyme disease is a common vector-borne disease caused by the spirochete Borrelia burgdorferi(Bb), which manifests as systemic and targeted tissue inflammation. Both in vitro and in vivostudies have shown that Bb-induced inflammation is primarily host-mediated, via cytokine or chemokine production that promotes leukocyte adhesion/migration. Whether Bb produces mediators that can directly alter the vascular permeability in vivo has not been investigated. The objective of the present study was to investigate if Bb produces a mediator(s) that can directly activate endothelial cells resulting in increases in permeability in intact microvessels in the absence of blood cells. Methodology/Principal Findings The effects of cell-free, spent culture medium from virulent (B31-A3) and avirulent (B31-A) B. burgdorferi on microvessel permeability and endothelial calcium concentration, [Ca2+]i, were examined in individually perfused rat mesenteric venules. Microvessel permeability was determined by measuring hydraulic conductivity (Lp). Endothelial [Ca2+]i, a necessary signal initiating hyperpermeability, was measured in Fura-2 loaded microvessels. B31-A3 spent medium caused a rapid and transient increase in Lp and endothelial [Ca2+]i. Within 2–5 min, the mean peak Lp increased to 5.6±0.9 times the control, and endothelial [Ca2+]i increased from 113±11 nM to a mean peak value of 324±35 nM. In contrast, neither endothelial [Ca2+]i nor Lp was altered by B31-A spent medium. Conclusions/Significance A mediator(s) produced by virulent Bb under culture conditions directly activates endothelial cells, resulting in increases in microvessel permeability. Most importantly, the production of this mediator is associated with Bb virulence and is likely produced by one or more of the 8 plasmid(s) missing from strain B31-A

Dignity and Narrative Medicine

Critiques of the dehumanising aspects of contemporary medical practice have generated increasing interest in the ways in which health care can foster a holistic sense of wellbeing. We examine the relationship between two areas of this humanistic endeavour: narrative and dignity. This paper makes two simple arguments that are intuitive but have not yet been explored in detail: that narrative competence of carers is required for maintaining or recreating dignity, and that dignity promotion in health care practice is primarily narrative in form. The multiple meanings that dignity has in a person’s life are what give the concept power and can only be captured by narrative. This has implications for health care practice where narrative work will be increasingly required to support patient dignity in under-resourced and over-subscribed health care system

The use of protocol in breaking bad news: evidence and ethos

This article discusses health professionals use of protocol in the breaking of bad news, focusing particularly on the well-known SPIKES framework. The evidence of impact on the patient experience is examined and recommendations are made for further outcome-based research. Existing evidence suggests that the model as commonly interpreted may not fully meet the needs of patients or reflect the clinical experience of breaking bad news for some professionals and further guidance may be needed to support them in their practice. The ethos of the step-wise protocol is debated, questioning whether it helps or hinders individualised care and the formation of a genuine relationship between patient and professional. Finally, recommendations for practice are offered

Four Butterflies: End of Life Stories of Transition and Transformation

In this article, the author discusses her experiences as an Artist In Residence in the Department of Palliative Care and Rehabilitation Medicine at the University of Texas M. D. Anderson Cancer Center. Emphasis is placed on the ways in which end of life images and narratives often unfold in the fragile yet powerful space where conceptions of aesthetics and spirituality intersect with critical issues in the medical humanities. Drawing on four vivid case studies, the author examines the ways in which end of life narratives shed valuable light on conceptions of the subtlety of human embodiment; issues of violation, sorrow, and forgiveness; the mystical dimensions of traditional cultural beliefs; and the capacity for perceiving the natural world as a living symbol of grace. In so doing, she explores how the themes of transition and transformation become invested with meaningful existential and symbolic dimensions in artworks that give voice and presence to some of the most vulnerable, and often invisible, members of our societyﾗpeople at the end of life

Initial Characterization of the FlgE Hook High Molecular Weight Complex of Borrelia burgdorferi

The spirochete periplasmic flagellum has many unique attributes. One unusual characteristic is the flagellar hook. This structure serves as a universal joint coupling rotation of the membrane-bound motor to the flagellar filament. The hook is comprised of about 120 FlgE monomers, and in most bacteria these structures readily dissociate to monomers (∼ 50 kDa) when treated with heat and detergent. However, in spirochetes the FlgE monomers form a large mass of over 250 kDa [referred to as a high molecular weight complex (HMWC)] that is stable to these and other denaturing conditions. In this communication, we examined specific aspects with respect to the formation and structure of this complex. We found that the Lyme disease spirochete Borrelia burgdorferi synthesized the HMWC throughout the in vitro growth cycle, and also in vivo when implanted in dialysis membrane chambers in rats. The HMWC was stable to formic acid, which supports the concept that the stability of the HMWC is dependent on covalent cross-linking of individual FlgE subunits. Mass spectrometry analysis of the HMWC from both wild type periplasmic flagella and polyhooks from a newly constructed ΔfliK mutant indicated that other proteins besides FlgE were not covalently joined to the complex, and that FlgE was the sole component of the complex. In addition, mass spectrometry analysis also indicated that the HMWC was composed of a polymer of the FlgE protein with both the N- and C-terminal regions remaining intact. These initial studies set the stage for a detailed characterization of the HMWC. Covalent cross-linking of FlgE with the accompanying formation of the HMWC we propose strengthens the hook structure for optimal spirochete motility

Epistemic injustices in clinical communication: The example of narrative elicitation in person-centred care.

The increasing popularity of the term ‘person‐centred’ in the healthcare literature and a wide range of ideals and practices it implies point to the need for a more inclusive and holistic healthcare provision. A framework developed in a Swedish context suggested narrative elicitation as a key practice in transition to person‐centred care. Initiating clinical communication by inviting people to tell their stories makes persistent yet often subtle problems in clinical communication visible. By drawing upon an observational study on narrative elicitation and vignette‐based focus group interviews with nurses, our aim is to trace ‘credibility deficits’ (Fricker 2007. Epistemic Injustice. Power and the Ethics of Knowing. Oxford: Oxford University Press) and ‘credibility excesses’ (Medina 2011, Social Epistemology, 25, 1, 15–35, 2013, The Epistemology of Resistance: Gender and Racial Oppression, Epistemic Injustice, and the Social Imagination. Oxford: Oxford University Press) in narrative elicitation. We argue that narrative elicitation may be one way to tackle epistemic injustices by giving voice to previously silenced groups, yet it is not enough to erase the effects of ‘credibility deficits’ in clinical communication. Rather than judging individual professionals’ success or failure in eliciting narratives, we underline some extrinsic problems of narrative elicitation, namely structural and positional inequalities reflecting on narrative elicitation and the credibility of patients. ‘Credibility excesses’ can be useful and indicative to better understand where they are missing