A hard metallic material: Osmium Diboride

We calculate the structural and electronic properties of OsB2 using density functional theory with or without taking into account spin-orbit (SO) interaction. Our results show that the bulk modulus with and without SO interaction are 364 and 365 Gpa respectively, both are in good agreement with experiment (365-395 Gpa). The evidence of covalent bonding of Os-B, which plays an important role to form a hard material, is indicated both in charge density, atoms in molecules analysis, and density of states analysis. The good metallicity and hardness of OsB2 might suggest its potential application as hard conductors.Comment: Figures improve

Comparison of standardised versus non-standardised methods for testing the in vitro potency of oxytetracycline against mannheimia haemolytica and pasteurella multocida

The in vitro pharmacodynamics of oxytetracycline was established for six isolates of each of the calf pneumonia pathogens Mannheimia haemolytica and Pasteurella multocida. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and bacterial time-kill curves were determined in two matrices, Mueller Hinton broth (MHB) and calf serum. Geometric mean MIC ratios, serum:MHB, were 25.2:1 (M. haemolytica) and 27.4:1 (P. multocida). The degree of binding of oxytetracycline to serum protein was 52.4%. Differences between serum and broth MICs could not be accounted for by oxytetracycline binding to serum protein. In vitro time-kill data suggested a co-dependent killing action of oxytetracycline. The in vitro data indicate inhibition of the killing action of oxytetracycline by serum factor(s). The nature of the inhibition requires further study. The outcome of treatment with oxytetracycline of respiratory tract infections in calves caused by M. haemolytica and P. multocida may not be related solely to a direct killing action

Biodigital publics: personal genomes as digital media artifacts

The recent proliferation of personal genomics and direct-to-consumer (DTC) genomics has attracted much attention and publicity. Concern around these developments has mainly focused on issues of biomedical regulation and hinged on questions of how people understand genomic information as biomedical and what meaning they make of it. However, this publicity amplifies genome sequences which are also made as internet texts and, as such, they generate new reading publics. The practices around the generation, circulation and reading of genome scans do not just raise questions about biomedical regulation, they also provide the focus for an exploration of how contemporary public participation in genomics works. These issues around the public features of DTC genomic testing can be pursued through a close examination of the modes of one of the best known providers—23andMe. In fact, genome sequences circulate as digital artefacts and, hence, people are addressed by them. They are read as texts, annotated and written about in browsers, blogs and wikis. This activity also yields content for media coverage which addresses an indefinite public in line with Michael Warner’s conceptualisation of publics. Digital genomic texts promise empowerment, personalisation and community, but this promise may obscure the compliance and proscription associated with these forms. The kinds of interaction here can be compared to those analysed by Andrew Barry. Direct-to-consumer genetics companies are part of a network providing an infrastructure for genomic reading publics and this network can be mapped and examined to demonstrate the ways in which this formation both exacerbates inequalities and offers possibilities for participation in biodigital culture

Imbibition in Disordered Media

The physics of liquids in porous media gives rise to many interesting phenomena, including imbibition where a viscous fluid displaces a less viscous one. Here we discuss the theoretical and experimental progress made in recent years in this field. The emphasis is on an interfacial description, akin to the focus of a statistical physics approach. Coarse-grained equations of motion have been recently presented in the literature. These contain terms that take into account the pertinent features of imbibition: non-locality and the quenched noise that arises from the random environment, fluctuations of the fluid flow and capillary forces. The theoretical progress has highlighted the presence of intrinsic length-scales that invalidate scale invariance often assumed to be present in kinetic roughening processes such as that of a two-phase boundary in liquid penetration. Another important fact is that the macroscopic fluid flow, the kinetic roughening properties, and the effective noise in the problem are all coupled. Many possible deviations from simple scaling behaviour exist, and we outline the experimental evidence. Finally, prospects for further work, both theoretical and experimental, are discussed.Comment: Review article, to appear in Advances in Physics, 53 pages LaTe

‘Look into the Book of Life’: Muslim musicians, Sufism, and postmodern spirituality in Britain

Spirituality has been theorised as a characteristic of late-modern society, a consequence of individualisation and of a relativized marketplace of religion. Drawing on findings from ethnographic fieldwork conducted with Muslim musicians in the UK, the author claims that spirituality can indeed be considered a postmodern discourse of belief – with trans-religious applicability – but that at the same time it can be articulated from within a clear understanding of group/religious membership. The concepts of ‘spiritual capital’ and ‘expressive communalism’ are used to explain the ways through which a postmodern discourse of spirituality is utilised by Muslim musicians from within contemporary networks of Sufism in the West. The author suggests that the cosmopolitan and inclusive nature of these types of Sufism in Britain – particularly amongst third and fourth generation Muslims – represents a frontier of religious change in the UK and a challenge to traditional forms of religious authority, discourse and membership

Religious Tastes and Styles as Markers of Class Belonging: A Bourdieuian Perspective on Pentecostalism in South America

Studies on the relationship between social class and religion tend to highlight the demographic dimension of class, but neglect its symbolic dimension. By addressing the symbolic dimensions through a Bourdieuian approach, this article contends that religious tastes and styles can be employed as class markers within the sphere of religion. A case study on Argentinean Pentecostalism and in-depth analysis of a lower and middle class church illustrate how symbolic class differences are cultivated in the form of distinctive religious styles. While the lower class church displays a style marked by emotional expressiveness and the search for life improvement through spiritual practices, the middle class church performs a sober and calm style of Pentecostalism. The study highlights the role of styles in the reproduction of class boundaries, while shedding a critical light on the importance of tastes

Age-dependent resistance to Porcine reproductive and respiratory syndrome virus replication in swine

<p>Abstract</p> <p>Background</p> <p>Porcine reproductive and respiratory syndrome virus (PRRSV) causes a prolonged, economically devastating infection in pigs, and immune resistance to infection appears variable. Since the porcine adaptive immune system is not fully competent at birth, we hypothesized that age influences the dynamics of PRRSV infection. Thus, young piglets, growing 16-20-week-old finisher pigs, and mature third parity sows were infected with virulent or attenuated PRRSV, and the dynamics of viral infection, disease, and immune response were monitored over time.</p> <p>Results</p> <p>Virulent PRRSV infection and disease were markedly more severe and prolonged in young piglets than in finishers or sows. Attenuated PRRSV in piglets also produced a prolonged viremia that was delayed and reduced in magnitude, and in finishers and sows, about half the animals showed no viremia. Despite marked differences in infection, antibody responses were observed in all animals irrespective of age, with older pigs tending to seroconvert sooner and achieve higher antibody levels than 3-week-old animals. Interferon γ (IFN γ) secreting peripheral blood mononuclear cells were more abundant in sows but not specifically increased by PRRSV infection in any age group, and interleukin-10 (IL-10) levels in blood were not correlated with PRRSV infection status.</p> <p>Conclusion</p> <p>These findings show that animal age, perhaps due to increased innate immune resistance, strongly influences the outcome of acute PRRSV infection, whereas an antibody response is triggered at a low threshold of infection that is independent of age. Prolonged infection was not due to IL-10-mediated immunosuppression, and PRRSV did not elicit a specific IFN γ response, especially in non-adult animals. Equivalent antibody responses were elicited in response to virulent and attenuated viruses, indicating that the antigenic mass necessary for an immune response is produced at a low level of infection, and is not predicted by viremic status. Thus, viral replication was occurring in lung or lymphoid tissues even though viremia was not always observed.</p

Rate-dependent Ca2+ signalling underlying the force-frequency response in rat ventricular myocytes: A coupled electromechanical modeling study

Rate-dependent effects on the Ca2+ sub-system in a rat ventricular myocyte are investigated. Here, we employ a deterministic mathematical model describing various Ca2+ signalling pathways under voltage clamp (VC) conditions, to better understand the important role of calmodulin (CaM) in modulating the key control variables Ca2+/calmodulin-dependent protein kinase-II (CaMKII), calcineurin (CaN), and cyclic adenosine monophosphate (cAMP) as they affect various intracellular targets. In particular, we study the frequency dependence of the peak force generated by the myofilaments, the force-frequency response (FFR). Our cell model incorporates frequency-dependent CaM-mediated spatially heterogenous interaction of CaMKII and CaN with their principal targets (dihydropyridine (DHPR) and ryanodine (RyR) receptors and the SERCA pump). It also accounts for the rate-dependent effects of phospholamban (PLB) on the SERCA pump; the rate-dependent role of cAMP in up-regulation of the L-type Ca2+ channel (ICa;L); and the enhancement in SERCA pump activity via phosphorylation of PLB.Our model reproduces positive peak FFR observed in rat ventricular myocytes during voltage-clamp studies both in the presence/absence of cAMP mediated -adrenergic stimulation. This study provides quantitative insight into the rate-dependence of Ca2+-induced Ca2+-release (CICR) by investigating the frequency-dependence of the trigger current (ICa;L) and RyR-release. It also highlights the relative role of the sodium-calcium exchanger (NCX) and the SERCA pump at higher frequencies, as well as the rate-dependence of sarcoplasmic reticulum (SR) Ca2+ content. A rigorous Ca2+ balance imposed on our investigation of these Ca2+ signalling pathways clarifies their individual roles. Here, we present a coupled electromechanical study emphasizing the rate-dependence of isometric force developed and also investigate the temperature-dependence of FFR. Our model provides mechanistic biophysically based explanations for the rate-dependence of CICR, generating useful and testable hypotheses. Although rat ventricular myocytes exhibit a positive peak FFR in the presence/absence of beta-adrenergic stimulation, they show a characteristic increase in the positive slope in FFR due to the presence of Norepinephrine or Isoproterenol. Our study identifies cAMP-mediated stimulation, and rate-dependent CaMKII-mediated up-regulation of ICa;L as the key mechanisms underlying the aforementioned positive FFR

Spirals of Spirituality: A Qualitative Study Exploring Dynamic Patterns of Spirituality in Turkish Organizations

This paper explores organizational spirituality, uncovers it as spiralling dynamics of both positive and negative potentialities, and proposes how leaders can shape these dynamics to improve the human conditions at the workplace. Based on case study of five Turkish organizations and drawing on the emerging discourse on spirituality in organizations literature, this study provides a deeper understanding of how dynamic patterns of spirituality operate in organizations. Insights from participant observation, organizational data, and semi-structured interviews yield three key themes of organizational spirituality: reflexivity, connectivity, and responsibility. Each of these themes has been found to be connected to upward spirals (inspiration, engagement, and calling) and downward spirals (incivility, silence, and fatigue). The study provides a detailed and holistic account of the individual and organizational processes through which spirituality is enacted both positively and negatively, exploring its dynamic and dualistic nature, as embodied in the fabric of everyday life and culture

Low Concentrations of Hexavalent Chromium in Drinking Water Induce Alzheimer’s Disease Neuropathology: Using a Toxic Aging Coin Approach to Assess Hexavalent Chromium Neurotoxicity

Introduction: We are currently facing an aging crisis, as 20% of the U.S. population will be geriatric (65+) by 2030. This growing geriatric population will result in increasing prevalence of age-related diseases, coinciding with increasingly prevalent environmental pollution. Environmental pollution is a ubiquitous health threat that affects people at all ages and contributes to aging pathology. However, geriatric individuals are likely more susceptible to the negative health effects from environmental pollution. The distinct effects of environmental pollutants across age groups are currently understudied. We use a Toxic Aging Coin approach to investigate: 1) how age impacts toxicity (heads), and 2) how chemicals accelerate aging (tails). Alzheimer’s disease (AD) is the most prevalent age-related neurodegenerative disease, projected to affect 153 million people by 2050. AD pathology is characterized by amyloid-β plaques and abnormally phosphorylated tau protein which leads to neurofibrillary tangles. Both amyloid-β plaques and tau protein tangles can induce oxidative stress and neurodegeneration in multiple brain regions. This AD pathology spreads through distinct brain regions in a pattern ­­­known as Braak staging, beginning with the entorhinal and transentorhinal regions before spreading to the hippocampus and eventually to neocortical areas. Behaviorally, AD often presents as memory loss, confusion, disorientation, and loss of muscle coordination. Many environmental pollutants, such as metals (e.g., lead, cadmium, and arsenic) are linked to AD etiology, but hexavalent chromium [Cr(VI)] has received limited attention in the context of AD. Cr(VI) has been linked to other neurological disorders in humans, such as polyneuropathy, motor neuron disease, and Autism Spectrum Disorder. In rodents, Cr(VI) impairs social memory and muscle coordination, which is symptomatic of AD. Blood levels of Cr were found significantly elevated in blood of AD patients and is linked to acute schizophrenia. Here, we use the heads side of our Toxic Aging Coin to assess Cr(VI) neurotoxicity across different age groups. Methods: We exposed Sprague-Dawley rats (both sexes) at three ages (3-, 7-, and 18-months-old) to low concentrations of Cr(VI) in drinking water (0.05 and 0.1 mg/L) for 90 days. Importantly, 0.05 mg/L and 0.1 mg/L Cr(VI) correspond to the WHO and U.S. EPA permissible drinking water limits for Cr(VI), respectively. We assessed spatial memory by measuring spontaneous non-alternations in the Y-Maze assay after 4- and 10-weeks exposure. After 90 days, we harvested the brains and used silver stain to examine neurodegeneration in AD-associated brain regions (e.g., dorsal hippocampus, entorhinal cortex). Silver staining marks degenerating neurons jet black and provides a qualitative assessment of the degree of neurodegeneration. Results: We observed middle-aged (7-month old) males exhibited a concentration-associated increase in non-alternations, suggesting impaired spatial memory. Whereas middle-aged females exposed to Cr(VI) exhibited a concentration-associated decrease in non-alternations, suggesting an improvement in spatial memory; however, extensive hippocampal damage may lead to a side preference that resembles improved memory. Upon examining rat brains for neurodegeneration using silver stain, the hippocampus was more affected than the entorhinal cortex, and 3-m.o. rats were the least affected. 7-month-old rats exhibited increased neurodegeneration in the CA1, CA3 and dentate gyrus of the dorsal hippocampus, with females exhibiting more severe neurodegeneration. 7-month-old females showed the most severe neurodegeneration compared to age- and sex-matched controls, suggesting this pathology may have induced a side-preference behavior in the Y-Maze assay. 18-month-old rats exhibited increased neurodegeneration in hippocampus compared to age-matched controls. Conclusions: The extensive level of damage to the hippocampus, especially in 7-month-old females and geriatric rats, suggests that Cr(VI) exposure induced damage in a similar manner to Braak stages III and IV of AD pathology. Pathology and the noted sex differences suggest Cr(VI) exposure may increase the risk of AD. The observed sex differences also indicate that females are more susceptible to Cr(VI)-induced neurodegeneration. Future directions will examine other pathologies associated with AD (e.g., protein aggregation, white matter damage) and cell specific targets of Cr(VI) neurotoxicity (e.g. astrocytes, microglia)