The Physics of Miniature Worlds

This excerpt from a book length work on the history of the methodology of experimental physical models (physically similar systems) interwoven in Ludwig Wittgenstein's life begins in 1913-1914. It also discusses works by physicists around the same time that were thematically related to the philosophical topics he was working on: Ludwig Boltzmann, Wilhelm Ostwald, Edgar Buckingham, James Thomson, D'Arcy Wentworth Thompson, Henry Crew (and his new translation of Galileo's Two New Sciences during this period), Heike Kamerlingh Onnes, Van Der Waals, and Rayleigh (following up on the work of Gabriel Stokes), and Richard C Tolman. The landmark work at Britain's National Physical Laboratory in 1914 on Similar Motions by Stanton and Pannell, following up on Osborne Reynolds' work in Manchester, is also described and discussed. Connections between physics and the history of flight are mentioned, too: Penuad's successes, Boltzmann's relationship with engineer Otto Lilienthal, and the significance that Hermann von Helmholtz's landmark paper in meteorology which addressed the problem of steering aircraft, took on during this period

Inhibition of sulfur mustard-induced cytotoxicity and inflammation by the macrolide antibiotic roxithromycin in human respiratory epithelial cells

<p>Abstract</p> <p>Background</p> <p>Sulfur mustard (SM) is a potent chemical vesicant warfare agent that remains a significant military and civilian threat. Inhalation of SM gas causes airway inflammation and injury. In recent years, there has been increasing evidence of the effectiveness of macrolide antibiotics in treating chronic airway inflammatory diseases. In this study, the anti-cytotoxic and anti-inflammatory effects of a representative macrolide antibiotic, roxithromycin, were tested <it>in vitro </it>using SM-exposed normal human small airway epithelial (SAE) cells and bronchial/tracheal epithelial (BTE) cells. Cell viability, expression of proinflammatory cytokines including interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor (TNF), and expression of inducible nitric oxide synthase (iNOS) were examined, since these proinflammatory cytokines/mediators are import indicators of tissue inflammatory responses. We suggest that the influence of roxithromycin on SM-induced inflammatory reaction could play an important therapeutic role in the cytotoxicity exerted by this toxicant.</p> <p>Results</p> <p>MTS assay and Calcein AM/ethidium homodimer (EthD-1) fluorescence staining showed that roxithromycin decreased SM cytotoxicity in both SAE and BTE cells. Also, roxithromycin inhibited the SM-stimulated overproduction of the proinflammatory cytokines IL-1β, IL-6, IL-8 and TNF at both the protein level and the mRNA level, as measured by either enzyme-linked immunosorbent assay (ELISA) or real-time RT-PCR. In addition, roxithromycin inhibited the SM-induced overexpression of iNOS, as revealed by immunocytochemical analysis using quantum dots as the fluorophore.</p> <p>Conclusion</p> <p>The present study demonstrates that roxithromycin has inhibitory effects on the cytotoxicity and inflammation provoked by SM in human respiratory epithelial cells. The decreased cytotoxicity in roxithromycin-treated cells likely depends on the ability of the macrolide to down-regulate the production of proinflammatory cytokines and/or mediators. The results obtained in this study suggest that macrolide antibiotics may serve as potential vesicant respiratory therapeutics through mechanisms independent of their antibacterial activity.</p

Productivity of Osprey, Pandion haliaetus, Nesting on Natural and Artificial Structures in the Kawartha Lakes, Ontario, 1991-2001

Ospreys (Pandion haliaetus) declined throughout the Great Lakes basin during the 1950s to 1970s due to usage of organochlorine pesticides. Following the banning of DDT in 1972, artificial elevated nest structures were erected in the Kawartha Lakes region of south-central Ontario to aid in their recovery. As the population grew, large stumps of flooded trees, &lt; 1 m above the surface of the water became important nesting sites, despite their propensity to flood in turbulent weather conditions. We compared the productivity of Ospreys among nest substrates and longevity of the nests in this area from 1991 to 2001. Of 260 individual nesting attempts made over the 11 years, 57% used man-made structures, primarily either quadrupod nesting platforms or utility poles. Of nests on natural substrates, stump nests accounted for 37% of total nesting attempts; elevated tree nests were relatively uncommon (6%). Productivity of stump nests was significantly greater than that of artificial or tree nests (1.48 versus 1.16 and 0.73 chicks produced per occupied nest, respectively). Nevertheless, survivorship of stump nests was less than that of platform nests after 3 years of age, as high water levels, storms or winter ice activity destroyed some of these low nests between breeding seasons. Ospreys were able to attain greater productivity in these stump nests than on man-made nesting substrates

Why rational argument fails the genetic modification (GM) debate

AbstractGenetic modification (GM) of crops provides a methodology for the agricultural improvements needed to deliver global food security. However, public opposition to GM-food is great. The debate has tended to risk communication, but here we show through study of a large nationally representative sample of British adults that public acceptance of GM-food has social, cultural and affective contexts. Regression models showed that metaphysical beliefs about the sanctity of food and an emotional dislike of GM-food were primary negative determinants, while belief in the value of science and favourable evaluation of the benefits-to-risks of GM-food were secondary positive determinants. Although institutional trust, general knowledge of the GM-food debate and belief in the eco-friendliness of GM-food were all associated with acceptance, their influence was minor. While a belief in the sanctity of food had a direct inverse effect on GM acceptance, belief in the value of science was largely mediated through favourable perception of benefits-to-risks. Furthermore, segmentation analysis demonstrated that anxiety about GM-food had social and cultural antecedents, with white men being least anxious and older vegetarian women being most anxious. Rational argument alone about the risks and benefits of GM-food is unlikely to change public perceptions of GM-technology

Fluid/solid transition in a hard-core system

We prove that a system of particles in the plane, interacting only with a certain hard-core constraint, undergoes a fluid/solid phase transition

Cardiac rehabilitation services for people in rural and remote areas: an integrative literature review

Introduction: Morbidity and mortality from heart disease continues to be high in Australia with cardiac rehabilitation (CR) recognised as best practice for people with heart disease. CR is known to reduce mortality, reoccurrence of heart disease, hospital readmissions and costs, and to improve quality of life. Australian Aboriginal and Torres Strait Islanders (Australian First Peoples or Indigenous peoples) have a greater need for CR due to their higher burden of disease. However, CR referral, access and attendance remain low for all people who live in rural and remote areas. The aim of this integrative review was to identify barriers, enablers and pathways to CR for adults living independently in rural and remote areas of high-income countries, including Australia. Methods: Studies were identified through five online data bases, plus reference lists of the selected studies. The studies focused on barriers and enablers of CR for adults in rural and remote areas of Australia and other high-income countries, in English peer reviewed journals (2007-2016). A mix of qualitative, quantitative and mixed method studies were reviewed through a modified Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA), followed by a critical review and thematic analysis. Results: Sixteen studies were selected: seven qualitative, four quantitative and five mixed method. Five themes that influence CR attendance were identified: referral, health services pathways and planning; cultural and geographic factors necessitating alternative and flexible programs; professional roles and influence; knowing, valuing, and psychosocial factors; and financial costs - personal and health services. Factors identified that impact on referral and access to CR were hospital inpatient education programs on heart disease and risk factors; discharge processes including CR eligibility criteria and referral to ensure continuum and transition of care; need for improved accessibility of services, both geographically and through alternative programs, including home based with IT and/or telephone support Also, the need to ensure that health professionals understand, value and support CR; the impact of mental health, coping with change and competing priorities; costs including travel, medications and health professional consultations; as well as low levels of involvement of Australian First Peoples in their own care and poor cultural understanding by non-Australian First Peoples staff all negatively impact on CR access and attendance. Conclusion: This study found weak systems with low referral rates and poor access to CR in rural and remote areas. Underlying factors include lack of health professional and public support, often based on poor perception of benefits of CR, compounded by scarce and inflexible services. Low levels of involvement of Australian First Peoples, as well as a lack of cultural understanding by non-Australian First Peoples staff, is evident Overall, the findings demonstrate the need for improved models of referral and access, greater flexibility of programs and professional roles, with management support Further, increased education and involvement of Australian First Peoples, including Indigenous health workers taking a lead in their own people's care, supported by improved education and greater cultural awareness of non Australian First Peoples staff, is required

Quantum dots – a versatile tool in plant science?

An optically stable, novel class of fluorophores (quantum dots) for in situ hybridisation analysis was tested to investigate their signal stability and intensity in plant chromosome analyses. Detection of hybridisation sites in situ was based on fluorescence from streptavidin-linked inorganic crystals of cadmium selenide. Comparison of quantum dots (QDs) with conventional detection systems (Alexa 488) in immunolabeling experiments demonstrated greater sensitivity than the conventional system. In contrast, detection of QDs in in situ hybridisation of several plant chromosomes, using several high-copy sequences, was less sensitve than Alexa 488. Thus, semiconductor nanocrystal fluorophores are more suitable for immunostaining but not for in situ hybridisation of plant chromosomes

Improving access to cardiac rehabilitation in rural and remote areas: a protocol for a community-based qualitative case study

Background/Aims Heart disease is the largest single cause of death and contributes to poor quality of life and high healthcare costs in Australia. There are higher rates of heart disease in rural and remote areas, with the highest rates in Aboriginal and Torres Strait Islander people. Cardiac rehabilitation is known to improve health outcomes for people with heart disease but referral rates remain low (30.2% overall and 46% following acute coronary syndrome) in Australia. Further, access to cardiac rehabilitation in rural and remote areas is affected by there being few centre-based services, and poor use of home-based services. The aim of this protocol is to investigate: (i) understanding of cardiac rehabilitation by health staff, community leaders and community participants discharged from hospital following treatment for heart disease; (ii) access and support for cardiac rehabilitation in rural and remote areas via health service availability in each community. Methods A qualitative case study methodology, using an interpretive descriptive framework, will be used together with content analysis that will encompass identification of themes through a deductive/inductive process. Conclusions To improve access to services and health outcomes in rural and remote areas, a strong evidence base is essential. To achieve this, as well as having appropriate methodology, it is necessary to build relationships and trust with local communities and healthcare providers. This research protocol describes a qualitative community-based case study, together with processes to build sound relationships required for effective data collection through semi-structured interviews or focus groups. Each step of the pre-research planning data collection and analysis is described in detail for the guidance of future researchers

A critical role for suppressor of cytokine signalling 3 in promoting M1 macrophage activation and function in vitro and in vivo

Funded by Medical Research Council. Grant Number: 74804 NHS Grampian Endowments Research Trust. Grant Number: 12/16 Kidney Research UK. Grant Number: RP1/2012 Cunningham Trust. Grant Number: ACC/KWF/CT08/03Peer reviewedPublisher PD

Isolation of an Asymmetric RNA Uncoating Intermediate for a Single-Stranded RNA Plant Virus

AbstractWe have determined the three-dimensional structures of both native and expanded forms of turnip crinkle virus (TCV), using cryo-electron microscopy, which allows direct visualization of the encapsidated single-stranded RNA and coat protein (CP) N-terminal regions not seen in the high-resolution X-ray structure of the virion. The expanded form, which is a putative disassembly intermediate during infection, arises from a separation of the capsid-forming domains of the CP subunits. Capsid expansion leads to the formation of pores that could allow exit of the viral RNA. A subset of the CP N-terminal regions becomes proteolytically accessible in the expanded form, although the RNA remains inaccessible to nuclease. Sedimentation velocity assays suggest that the expanded state is metastable and that expansion is not fully reversible. Proteolytically cleaved CP subunits dissociate from the capsid, presumably leading to increased electrostatic repulsion within the viral RNA. Consistent with this idea, electron microscopy images show that proteolysis introduces asymmetry into the TCV capsid and allows initial extrusion of the genome from a defined site. The apparent formation of polysomes in wheat germ extracts suggests that subsequent uncoating is linked to translation. The implication is that the viral RNA and its capsid play multiple roles during primary infections, consistent with ribosome-mediated genome uncoating to avoid host antiviral activity