Nest sanitation behavior does not increase the likelihood of parasitic egg rejection in herring gulls

Birds’ behavioral response to brood parasitism can be influenced not only by evolution but also by context and individual experience. This could include nest sanitation, in which birds remove debris from their nests. Ultimately, nest sanitation behavior might be an evolutionary precursor to the rejection of parasitic eggs. Proximately, the context or experience of performing nest sanitation behavior might increase the detection or prime the removal of parasitic eggs, but evidence to date is limited. We tested incubation-stage nests of herring gulls Larus argentatus to ask whether nest sanitation increased parasitic egg rejection. In an initial set of 160 single-object experiments, small, red, blocky objects were usually rejected (18 of 20 nests), whereas life-sized, 3D-printed herring gull eggs were not rejected whether red (0 of 20) or the olive-tan base color of herring gull eggs (0 of 20). Next, we simultaneously presented a red, 3D-printed gull egg and a small, red block. These nests exhibited frequent nest sanitation (small, red block removed at 40 of 48 nests), but egg rejection remained uncommon (5 of those 40) and not significantly different from control nests (5 of 49) which received the parasitic egg but not the priming object. Thus, performance of nest sanitation did not shape individuals’ responses to parasitism. Interestingly, parents were more likely to reject the parasitic egg when they were present as we approached the nest to add the experimental objects. Depending on the underlying mechanism, this could also be a case of experience creating variation in responses to parasitism

Non-existence of normal tokamak equilibria with negative central current

Recent tokamak experiments employing off-axis, non-inductive current drive have found that a large central current hole can be produced. The current density is measured to be approximately zero in this region, though in principle there was sufficient current drive power for the central current density to have gone significantly negative. Recent papers have used a large aspect-ratio expansion to show that normal MHD equilibria (with axisymmetric nested flux surfaces, non-singular fields, and monotonic peaked pressure profiles) can not exist with negative central current. We extend that proof here to arbitrary aspect ratio, using a variant of the virial theorem to derive a relatively simple integral constraint on the equilibrium. However, this constraint does not, by itself, exclude equilibria with non-nested flux surfaces, or equilibria with singular fields and/or hollow pressure profiles that may be spontaneously generated.Comment: 5 pages, 3 figures. Submitted to Physics of Plasmas, Feb. 14, 2003. Revised Feb. 24, 2003. Vers. 2: revised May 29 to clarify points raised by referee, add references to recent work. July 18, accepted for publicatio

Pathogenic Activation of Mesenchymal Stem Cells is induced by the Disease Microenvironment in Systemic Sclerosis

Objective: In systemic sclerosis (SS c), a persistent tissue repair process leads to progressive fibrosis of the skin and internal organs. The role of mesenchymal stem cells (MSC s), which characteristically initiate and regulate tissue repair, has not been fully evaluated. We undertook this study to investigate whether dividing metakaryotic MSC s are present in SS c skin and to examine whether exposure to the disease microenvironment activates MSC s and leads to transdifferentiation. Methods: Skin biopsy material from patients with recent‐onset diffuse SS c was examined by collagenase spread of 1‐mm–thick surface‐parallel sections, in order to identify dividing metakaryotic stem cells in each tissue plane. Adipose‐derived MSC s from healthy controls were treated with dermal blister fluid (BF ) from patients with diffuse SS c and profiled by next‐generation sequencing, or they were evaluated for phenotypic changes relevant to SS c. Differential responses of dermal fibroblasts were studied in parallel. Results: MSC ‐like cells undergoing active metakaryotic division were identified in SS c sections (but not control sections) most prominently in the deep dermis and adjacent to damaged microvessels, in both clinically involved and uninvolved skin. Furthermore, exposure to SS c BF caused selective MSC activation, inducing a myofibroblast signature, while reducing signatures of vascular repair and adipogenesis and enhancing migration and contractility. Microenvironmental factors implicated in inducing transdifferentiation included the profibrotic transforming growth factor β, the presence of lactate, and mechanosensing, while the microenvironment Th2 cytokine, interleukin‐31, enhanced osteogenic commitment (calcinosis). Conclusion: Dividing MSC ‐like cells are present in the SS c disease microenvironment where multiple factors, likely acting in concert, promote transdifferentiation and lead to a complex and resistant disease state

A Role of Myocardin Related Transcription Factor-A (MRTF-A) in Scleroderma Related Fibrosis.

In scleroderma (systemic sclerosis, SSc), persistent activation of myofibroblast leads to severe skin and organ fibrosis resistant to therapy. Increased mechanical stiffness in the involved fibrotic tissues is a hallmark clinical feature and a cause of disabling symptoms. Myocardin Related Transcription Factor-A (MRTF-A) is a transcriptional co-activator that is sequestered in the cytoplasm and translocates to the nucleus under mechanical stress or growth factor stimulation. Our objective was to determine if MRTF-A is activated in the disease microenvironment to produce more extracellular matrix in progressive SSc. Immunohistochemistry studies demonstrate that nuclear translocation of MRTF-A in scleroderma tissues occurs in keratinocytes, endothelial cells, infiltrating inflammatory cells, and dermal fibroblasts, consistent with enhanced signaling in multiple cell lineages exposed to the stiff extracellular matrix. Inhibition of MRTF-A nuclear translocation or knockdown of MRTF-A synthesis abolishes the SSc myofibroblast enhanced basal contractility and synthesis of type I collagen and inhibits the matricellular profibrotic protein, connective tissue growth factor (CCN2/CTGF). In MRTF-A null mice, basal skin and lung stiffness was abnormally reduced and associated with altered fibrillar collagen. MRTF-A has a role in SSc fibrosis acting as a central regulator linking mechanical cues to adverse remodeling of the extracellular matrix

Microscopic dynamics of thin hard rods

Based on the collision rules for hard needles we derive a hydrodynamic equation that determines the coupled translational and rotational dynamics of a tagged thin rod in an ensemble of identical rods. Specifically, based on a Pseudo-Liouville operator for binary collisions between rods, the Mori-Zwanzig projection formalism is used to derive a continued fraction representation for the correlation function of the tagged particle's density, specifying its position and orientation. Truncation of the continued fraction gives rise to a generalised Enskog equation, which can be compared to the phenomenological Perrin equation for anisotropic diffusion. Only for sufficiently large density do we observe anisotropic diffusion, as indicated by an anisotropic mean square displacement, growing linearly with time. For lower densities, the Perrin equation is shown to be an insufficient hydrodynamic description for hard needles interacting via binary collisions. We compare our results to simulations and find excellent quantitative agreement for low densities and qualtitative agreement for higher densities.Comment: 21 pages, 6 figures, v2: clarifications and improved readabilit

Casimir Energy of a Spherical Shell

The Casimir energy for a conducting spherical shell of radius $a$ is computed using a direct mode summation approach. An essential ingredient is the implementation of a recently proposed method based on Cauchy's theorem for an evaluation of the eigenfrequencies of the system. It is shown, however, that this earlier calculation uses an improper set of modes to describe the waves exterior to the sphere. Upon making the necessary corrections and taking care to ensure that no mathematically ill-defined expressions occur, the technique is shown to leave numerical results unaltered while avoiding a longstanding criticism raised against earlier calculations of the Casimir energy.Comment: LaTeX, 14 pages, 1 figur

Electromagnetic modes of Maxwell fisheye lens

We provide an analysis of the radial structure of TE and TM modes of the Maxwell fisheye lens, by means of Maxwell equations as applied to the fisheye case. Choosing a lens of size R = 1 cm, we plot some of the modes in the infrared range.Comment: 2+6 pages in Latex, 3 figures to be found in the published referenc

Developing and testing a strategy to enhance a palliative approach and care continuity for people who have dementia: Study overview and protocol

Background: Typically, dementia involves progressive cognitive and functional deterioration, leading to death. A palliative approach recognizes the inevitable health decline, focusing on quality of life. The approach is holistic, proactive, supports the client and the family, and can be provided by the client’s usual care team. In the last months of life, distressing symptoms, support needs, and care transitions may escalate. This project trialed a strategy intended to support a consistent, high quality, palliative approach for people with dementia drawing close to death. The strategy was to implement two communities of practice, drawn primarily from service provider organizations across care sectors, supporting them to address practice change. Communities comprised practitioners and other health professionals with a passionate commitment to dementia palliative care and the capacity to drive practice enhancement within partnering organizations. Project aims were to document: (i) changes driven by the communities of practice; (ii) changes in staff/practitioner characteristics during the study (knowledge of a palliative approach and dementia; confidence delivering palliative care; views on death and dying, palliative care, and a palliative approach for dementia); (iii) outcomes from perspectives of family carers, care providers, and community of practice members; (iv) the extent to which changes enhanced practice and care continuity; and (v) barriers to and facilitators of successful community of practice implementation. Methods/design: This action research project was implemented over 14 months in 2010/11 in metropolitan Perth, Western Australia and regional Launceston, Tasmania. Each state based community of practice worked with the researchers to scope existing practice and its outcomes. The research team compiled a report of existing practice recommendations and resources. Findings of these two steps informed community of practice action plans and development of additional resources. Change implementation was recorded and explored in interviews, comparisons being made with practice recommendations. Changes in staff/practitioner characteristics were evaluated using survey data. Findings from semi structured interviews and survey administration established outcomes from perspectives of family carers, care providers, and community of practice members. Consideration of processes and outcomes, across the two state based settings, informed identification of barriers and facilitators. Community of practice reflections also informed study recommendations

On the Possibility of Measuring the Abraham Force using Whispering Gallery Modes

Critical experimental tests of the time-dependent Abraham force in phenomenological electrodynamics are scarce. In this paper we analyze the possibility of making use of intensity-modulated whispering gallery modes in a microresonator for this purpose. Systems of this kind appear attractive, as the strong concentration of electromagnetic fields near the rim of the resonator serves to enhance the Abraham torque exerted by the field. We analyze mainly spherical resonators, although as an introductory step we consider also the cylinder geometry. The order of magnitude of the Abraham torques are estimated by inserting reasonable values for the various input parameters. As expected, the predicted torques turn out to be very small, although probably not beyond any reach experimentally. Our main idea is essentially a generalization of the method used by G. B. Walker et al. [Can. J. Phys. 53, 2577] for low-frequency fields, to the optical case.Comment: 6 pages, no figures. Minor typos corrected, acknowledgment added. To appear in Phys. Rev.

Differences in level of confidence in diabetes care between different groups of trainees: the TOPDOC diabetes study

Background There is an increasing prevalence of diabetes. Doctors in training, irrespective of specialty, will have patients with diabetes under their care. The aim of this further evaluation of the TOPDOC Diabetes Study data was to identify if there was any variation in confidence in managing diabetes depending on the geographical location of trainees and career aspirations. Methods An online national survey using a pre-validated questionnaire was administered to trainee doctors. A 4-point confidence rating scale was used to rate confidence in managing aspects of diabetes care and a 6-point scale used to quantify how often trainees would contribute to the management of patients with diabetes. Responses were grouped depending on which UK country trainees were based and their intended career choice. Results Trainees in Northern Ireland reported being less confident in IGT diagnosis, use of IV insulin and peri-operative management and were less likely to adjust oral treatment, contact specialist, educate lifestyle, and optimise treatment. Trainees in Scotland were less likely to contact a specialist, but more likely to educate on lifestyle, change insulin, and offer follow-up advice. In Northern Ireland, Undergraduate (UG) and Postgraduate (PG) training in diagnosis was felt less adequate, PG training in emergencies less adequate, and reporting of need for further training higher. Trainees in Wales felt UG training to be inadequate. In Scotland more trainees felt UG training in diagnosis and optimising treatment was inadequate. Physicians were more likely to report confidence in managing patients with diabetes and to engage in different aspects of diabetes care. Aspiring physicians were less likely to feel the need for more training in diabetes care; however a clear majority still felt they needed more training in all aspects of care. Conclusions Doctors in training have poor confidence levels dealing with diabetes related care issues. Although there is variability between different groups of trainees according to geographical location and career aspirations, this is a UK wide issue. There should be a UK wide standardised approach to improving training for junior doctors in diabetes care with local training guided by specific needs.</p