Finite-element modelling of mechanobiological factors influencing sesamoid tissue morphology in the patellar tendon of an ostrich

The appearance and shape of sesamoid bones within a tendon or ligament wrapping around a joint are understood to be influenced by both genetic and epigenetic factors. Ostriches (Struthio camelus) possess two sesamoid patellae (kneecaps), one of which (the distal patella) is unique to their lineage, making them a good model for investigating sesamoid tissue development and evolution. Here we used finite-element modelling to test the hypothesis that specific mechanical cues in the ostrich patellar tendon favour the formation of multiple patellae. Using three-dimensional models that allow application of loading conditions in which all muscles, or only distal or only proximal muscles to be activated, we found that there were multiple regions within the tendon where transformation from soft tissue to fibrocartilage was favourable and therefore a potential for multiple patellae based solely upon mechanical stimuli. While more studies are needed to better understand universal mechanobiological principles as well as full developmental processes, our findings suggest that a tissue differentiation algorithm using shear strain and compressive strain as inputs may be a roughly effective predictor of the tissue differentiation required for sesamoid development

Perturbed Self-Similar Massless Scalar Field in the Spacetimes with Circular Symmetry in 2+1 Gravity

We present in this work the study of the linear perturbations of the 2+1-dimensional circularly symmetric solution, obtained in a previous work, with kinematic self-similarity of the second kind. We have obtained an exact solution for the perturbation equations and the possible perturbation modes. We have shown that the background solution is a stable solution.Comment: no figure

Gravitational Collapse of Self-Similar and Shear-free Fluid with Heat Flow

A class of solutions to Einstein field equations is studied, which represents gravitational collapse of thick spherical shells made of self-similar and shear-free fluid with heat flow. It is shown that such shells satisfy all the energy conditions, and the corresponding collapse always forms naked singularities.Comment: 34 pages, 9 figures, late

Synergism between Medihoney and Rifampicin against Methicillin-Resistant Staphylococcus aureus (MRSA)

Skin and chronic wound infections caused by highly antibiotic resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are an increasing and urgent health problem worldwide, particularly with sharp increases in obesity and diabetes. New Zealand manuka honey has potent broad-spectrum antimicrobial activity, has been shown to inhibit the growth of MRSA strains, and bacteria resistant to this honey have not been obtainable in the laboratory. Combinational treatment of chronic wounds with manuka honey and common antibiotics may offer a wide range of advantages including synergistic enhancement of the antibacterial activity, reduction of the effective dose of the antibiotic, and reduction of the risk of antibiotic resistance. The aim of this study was to investigate the effect of Medihoney in combination with the widely used antibiotic rifampicin on S. aureus. Using checkerboard microdilution assays, time-kill curve experiments and agar diffusion assays, we show a synergism between Medihoney and rifampicin against MRSA and clinical isolates of S. aureus. Furthermore, the Medihoney/rifampicin combination stopped the appearance of rifampicin-resistant S. aureus in vitro. Methylglyoxal (MGO), believed to be the major antibacterial compound in manuka honey, did not act synergistically with rifampicin and is therefore not the sole factor responsible for the synergistic effect of manuka honey with rifampicin. Our findings support the idea that a combination of honey and antibiotics may be an effective new antimicrobial therapy for chronic wound infections. © 2013 Müller et al

How the Charge Can Affect the Formation of Gravastars

In recent work we physically interpreted a special gravastar solution characterized by a zero Schwarzschild mass. In fact, in that case, none gravastar was formed and the shell expanded, leaving behind a de Sitter or a Minkowski spacetime, or collapsed without forming an event horizon, originating what we called a massive non-gravitational object. This object has two components of non zero mass but the exterior spacetime is Minkowski or de Sitter. One of the component is a massive thin shell and the other one is de Sitter spacetime inside. The total mass of this object is zero Schwarzschild mass, which characterizes an exterior vacuum spacetime. Here, we extend this study to the case where we have a charged shell. Now, the exterior is a Reissner-Nordstr\"om spacetime and, depending on the parameter $\omega=1-\gamma$ of the equation of state of the shell, and the charge, a gravastar structure can be formed. We have found that the presence of the charge contributes to the stability of the gravastar, if the charge is greater than a critical value. Otherwise, a massive non-gravitational object is formed for small charges.Comment: 17 pages and 7 figures, several typos corrected, accepted for publication in JCA

Visual function due to regeneration of optic nerve or optic tract through peripheral nerve homografts

Segments of sciatic nerve from one leg were used to induce regeneration of transected optic nerve (ON) or tract in Syrian hamsters. In the first group, the nerve graft was sutured to the stump of the transected ON of the right eye in young adult animals, and the other end was placed below the surface of the ipsilateral superior colliculus (SC); the opposite eye was removed. In one animal, orienting movements in the wrong direction were elicited and recorded on videotape, beginning when the animal was more than 1.5 yr old, over 1 yr after surgery. In the second group, a similar procedure was used but with the nerve going to the contralateral SC. In 3 of 4 long-term survivors, visually elicited turning was obtained and recorded, most reliably in the final 4 mo of their 2-yr life. Regenerating retinofugal axons were traced and their terminations in SC reconstructed using a CT-B procedure and immunohistochemistry (secondary AB conjugated to Alexa-488) and fluorescence microscopy. The visually unresponsive animal had no regeneration, and the most responsive animal had the greatest amount of regeneration. In a 3rd procedure, the right brachium of SC was transected, and 2 or 3 segments of sciatic nerve were implanted as bridges to elicit optic tract regeneration. The first 3 of these animals were operated at age 13-19 days; considerable regeneration was verified anatomically in each case, after behavioral demonstration of visual orienting. Supported by NIH grant EY00126.published_or_final_versio

Knowledge and information needs of informal caregivers in palliative care : a qualitative systematic review

Objectives: To review current understanding of the knowledge and information needs of informal caregivers in palliative settings. Data sources: Seven electronic databases were searched for the period January 1994–November 2006: Medline, CINAHL, PsychINFO, Embase, Ovid, Zetoc and Pubmed using a meta-search engine (Metalib®). Key journals and reference lists of selected papers were hand searched. Review methods: Included studies were peer-reviewed journal articles presenting original research. Given a variety of approaches to palliative care research, a validated systematic review methodology for assessing disparate evidence was used in order to assign scores to different aspects of each study (introduction and aims, method and data, sampling, data analysis, ethics and bias, findings/results, transferability/generalizability, implications and usefulness). Analysis was assisted by abstraction of key details of study into a table. Results: Thirty-four studies were included from eight different countries. The evidence was strongest in relation to pain management, where inadequacies in caregiver knowledge and the importance of education were emphasized. The significance of effective communication and information sharing between patient, caregiver and service provider was also emphasized. The evidence for other caregiver knowledge and information needs, for example in relation to welfare and social support was weaker. There was limited literature on non-cancer conditions and the care-giving information needs of black and minority ethnic populations. Overall, the evidence base was predominantly descriptive and dominated by small-scale studies, limiting generalizability. Conclusions: As palliative care shifts into patients’ homes, a more rigorously researched evidence base devoted to understanding caregivers knowledge and information needs is required. Research design needs to move beyond the current focus on dyads to incorporate the complex, three-way interactions between patients, service providers and caregivers in end-of-life care setting

GPs’ strategies in exploring the preschool child’s wellbeing in the paediatric consultation

Background: Although General Practitioners (GPs) are uniquely placed to identify children with emotional, social, and behavioural problems, they succeed in identifying only a small number of them. The aim of this article is to explore the strategies, methods, and tools employed by GPs in the assessment of the preschool child’s emotional, mental, social, and behavioural health. We look at how GPs address parental care of the child in general and in situations where GPs have a particular awareness of the child. Method: Twenty-eight Danish GPs were purposively selected to take part in a qualitative study which combined focus-group discussions, observation of child consultations, and individual interviews with GPs. Results: Analysis of the data suggests that GPs have developed a set of methods, and strategies to assess the preschool child and parental care of the child. They look beyond paying narrow attention to the physical health of the child and they have expanded their practice to include the relations and interactions in the consultation room. The physical examination of the child continues to play a central role in doctor-child communication. Conclusion: The participating GPs’ strategies helped them to assess the wellbeing of the preschool child but they often find it difficult to share their impressions with parents

Public perception of cross-infection control in dentistry

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Since the advent of HIV/AIDS at the beginning of the 1980s, concern has generated considerable impetus for change in cross-infection control procedures in dentistry. This process has been hastened partly by media coverage which, in tending to favour sensation over rational discourse, has played a not inconsiderable role in shaping public uderstanding and expectations. This study aimed to investigate public perceptions of cross-infection control in dentistry in Australia using a postal follow-up to the 1995 National Dental Telephone rate was 85.2 per cent. Concerns about the procedures used by their dentist to sterilize instruments were reported by 13.3 per cent of respondents overall, and this was greater among non-health-card-holders, individuals who mainly spoke a language other than English in the home, and those who reported a non-routine dental visiting pattern. Avoidance or delaying of dental visits due to the perceived cross-infection risk was reported by an overall 3.6 per cent of people, and this was higher among females and those who expressed concern about cross-infection control. The profession has a responsibility to ensure that information on the measures which have been taken to reduce the risk of cross-infection in dentisry is disseminated as widely and as clearly as possible so that undue public concern and avoidance of dental care are minimized.W. Murray Thomson, Judith F. Stewart, Knute D. Carter and A. John Spence