Expanding Space: the Root of all Evil?

While it remains the staple of virtually all cosmological teaching, the concept of expanding space in explaining the increasing separation of galaxies has recently come under fire as a dangerous idea whose application leads to the development of confusion and the establishment of misconceptions. In this paper, we develop a notion of expanding space that is completely valid as a framework for the description of the evolution of the universe and whose application allows an intuitive understanding of the influence of universal expansion. We also demonstrate how arguments against the concept in general have failed thus far, as they imbue expanding space with physical properties not consistent with the expectations of general relativity.Comment: 8 pages, accepted for publication in PAS

Toxicological Studies on Aquatic Contaminants Originating from Coal Production and Utilization: The Induction of Tolerance to Silver in Laboratory Populations of Fish and the Chronic Toxicity of Nickel to Fish Early Life Stages

Aquatic toxicity studies were performed on two important coal-derived contaminants, silver and nickel. Silver was investigated with regard to metal-induced tolerance in laboratory populations of the fathead minnow (Pimephales promelas). Fish were exposed to acute silver concentrations following acclimation to sublethal exposures of this metal. Based on median lethal times (LT50), animals which had received 14 days prior exposure to 1.5 and 15 μg Ag/L were three to four times more resistant to silver than were previously unexposed organisms. This metal-induced resistance was not a sustained response. After organisms which had been acclimated to 15 μg/L had been transferred to clean water for two weeks, LT50 values determined with these animals were statistically indistinguishable from those calculated with non-acclimated control fish. With respect to nickel, a 32-day continuous-flow test was performed with the fathead minnow. Nickel was administered in duplicate at six exposure concentrations ranging from 0.038 to 0.733 mg/Lin medium-hard water (100 mg CaC03/L). Animal test responses included mortality, teratogenesis, and growth. Based on frequencies of mortality after 32 days of continuous exposure, significant effects were recorded at a nickel concentration of 0.120 mg/L, and the no observed effect concentration (NOEC) was determined to be 0.057 mg Ni/L

Distribution patterns of HP1, a heterochromatin-associated nonhistone chromosomal protein of Drosophila

We have previously reported the identification of a nonhistone chromosomal protein (nhcp-19; now called HP1) preferentially associated with the heterochromatin of Drosophila melanogaster. A detailed study of the HP1 distribution pattern on polytene chromosomes by immunofluorescent staining, using monoclonal antibody C1A9, has been carried out. The results indicate that this protein is found within the centric beta-heterochromatin, in cytological regions 31, 41 and 80, and throughout polytene chromosome 4. Staining of telomeres is frequently observed, those of chromosome arms 2R and 3R and the X chromosome being the most conspicuous. Analysis of a fourth chromosome insertional translocation T(3;4)f/In(3L)P confirms an autonomous interaction with chromosome 4 material. Similarly, the beta-heterochromatin distal to light on chromosome arm 2L, moved to position 97D2 on chromosome arm 3R in the rearrangement ltx13, is prominently stained using the C1A9 antibody. Staining of intact salivary glands indicates that this rearranged segment of beta-heterochromatin is not associated with the polytene chromocenter, but provides an independent structural reference point. HP1 is not observed in the nuclei of the early syncytial embryo, but becomes concentrated in the nuclei at the syncytial blastoderm stage (ca. nuclear division cycle 10). This suggests that heterochromatin formation occurs at approximately the same stage at which nuclei first become transcriptionally competent. Thus, the C1A9 antibody may serve as a useful marker for both structural and functional studies of the Drosophila nucleus

Effect of visualising and re-expressing evidence of policy effectiveness on perceived effectiveness: a population-based survey experiment

Communicating evidence that a policy is effective can increase public support although the effects are small. In the context of policies to increase healthier eating in out-of-home restaurants, we investigate two ways of presenting evidence for a policy's effectiveness: (i) visualising and (ii) re-expressing evidence into a more interpretable form. We conducted an online experiment in which participants were randomly allocated to one of five groups. We used a 2 (text only vs visualisation) × 2 (no re-expression vs re-expression) design with one control group. Participants (n = 4500) representative of the English population were recruited. The primary outcome was perceived effectiveness and the secondary outcome was public support. Evidence of effectiveness increased perceptions of effectiveness (d = 0.14, p < 0.001). There was no evidence that visualising, or re-expressing, changed perceptions of effectiveness (respectively, d = 0.02, p = 0.605; d = −0.02, p = 0.507). Policy support increased with evidence but this was not statistically significant after Bonferroni adjustment (d = 0.08, p = 0.034, α = 0.006). In conclusion, communicating evidence of policy effectiveness increased perceptions that the policy was effective. Neither visualising nor re-expressing evidence increased perceived effectiveness of policies more than merely stating in text that the policy was effective

Microwave transmissivity of a metamaterial–dielectric stack

Copyright © 2009 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 95 (2009) and may be found at http://link.aip.org/link/?APPLAB/95/174101/1A metamaterial layer comprising of a conducting square mesh surrounding subwavelength holes has a largely pure imaginary effective refractive index. We explore the microwave transmissivity of a stack of such metamaterial layers separated by dielectric spacers. As expected, a family of high transmissivity bands is experimentally observed. It is found that the lowest frequency edge is independent of the number of unit cells making up the structure and is highly tunable by appropriate geometrical design of the metamaterial layers

Ontogeny of Human IgE-expressing B Cells and Plasma Cells

BACKGROUND: IgE‐expressing (IgE(+)) plasma cells (PCs) provide a continuous source of allergen‐specific IgE that is central to allergic responses. The extreme sparsity of IgE(+) cells in vivo has confined their study almost entirely to mouse models. OBJECTIVE: To characterize the development pathway of human IgE(+) PCs and to determine the ontogeny of human IgE(+) PCs. METHODS: To generate human IgE(+) cells, we cultured tonsil B cells with IL‐4 and anti‐CD40. Using FACS and RT‐PCR, we examined the phenotype of generated IgE(+) cells, the capacity of tonsil B‐cell subsets to generate IgE(+) PCs and the class switching pathways involved. RESULTS: We have identified three phenotypic stages of IgE(+) PC development pathway, namely (i) IgE(+)germinal centre (GC)‐like B cells, (ii) IgE(+) PC‐like ‘plasmablasts’ and (iii) IgE(+) PCs. The same phenotypic stages were also observed for IgG1(+) cells. Total tonsil B cells give rise to IgE(+) PCs by direct and sequential switching, whereas the isolated GC B‐cell fraction, the main source of IgE(+) PCs, generates IgE(+) PCs by sequential switching. PC differentiation of IgE(+) cells is accompanied by the down‐regulation of surface expression of the short form of membrane IgE (mIgE(S)), which is homologous to mouse mIgE, and the up‐regulation of the long form of mIgE (mIgE(L)), which is associated with an enhanced B‐cell survival and expressed in humans, but not in mice. CONCLUSION: Generation of IgE(+) PCs from tonsil GC B cells occurs mainly via sequential switching from IgG. The mIgE(L)/mIgE(S) ratio may be implicated in survival of IgE(+) B cells during PC differentiation and allergic disease

Animal Research beyond the Laboratory:Report from a Workshop on Places Other than Licensed Establishments (POLEs) in the UK

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Research involving animals that occurs outside the laboratory raises an array of unique challenges. With regard to UK legislation, however, it receives only limited attention in terms of official guidelines, support, and statistics, which are unsurprisingly orientated towards the laboratory environment in which the majority of animal research takes place. In September 2019, four social scientists from the Animal Research Nexus program gathered together a group of 13 experts to discuss nonlaboratory research under the Animals (Scientific Procedures) Act (A(SP)A) of 1986 (mirroring European Union (EU) Directive 2010/63/EU), which is the primary mechanism for regulating animal research in the UK. Such nonlaboratory research under the A(SP)A often occurs at Places Other than Licensed Establishments (POLEs). The primary objective of the workshop was to assemble a diverse group with experience across a variety of POLEs (e.g., wildlife field sites, farms, fisheries, veterinary clinics, zoos) to explore the practical, ethical, and regulatory challenges of conducting research at POLEs. While consensus was not sought, nor reached on every point of discussion, we collectively identified five key areas that we propose require further discussion and attention. These relate to: (1) support and training; (2) ethical review; (3) cultures of care, particularly in nonregulated research outside of the laboratory; (4) the setting of boundaries; and (5) statistics and transparency. The workshop generated robust discussion and thereby highlighted the value of focusing on the unique challenges posed by POLEs, and the need for further opportunities for exchanging experiences and sharing best practice relating to research projects outside of the laboratory in the UK and elsewhere

Mucus-responsive functionalized emulsions: design, synthesis and study of novel branched polymers as functional emulsifiers

Mucus lines the moist cavities throughout the body, acting as barrier by protecting the underlying cells against the external environment, but it also hinders the permeation of drugs and drug delivery systems. As the rate of diffusion is low, the development of a system which could increase retention time at the mucosal surface would prove beneficial. Here, we have designed a range of branched copolymers to act as functional mucus-responsive oil-in-water emulsifiers comprising the hydrophilic monomer oligo(ethylene glycol) methacrylate and a hydrophobic dodecyl initiator. The study aimed to investigate the importance of chain end functionality on successful emulsion formation, by systematically replacing a fraction of the hydrophobic chain ends with a secondary poly(ethylene glycol) based hydrophilic initiator in a mixed-initiation strategy; a decrease of up to 75 mole percent of hydrophobic chain ends within the branched polymer emulsifiers was shown to maintain comparative emulsion stability. These redundant chain ends allowed for functionality to be incorporated into the polymers via a xanthate based initiator containing a masked thiol group; thiol groups are known to have mucoadhesive character, due to their ability to form disulfide bonds with the cysteine rich areas of mucus. The mucoadhesive nature of emulsions stabilised by thiol-containing branched copolymers was compared to non-functional emulsions in the presence of a biosimilar mucosal substrate and enhanced adherence to the mucosal surface was observed. Importantly, droplet rupture and mucus triggered release of dye-containing oil was seen from previously highly-stable thiol-functional emulsions; this observation was not mirrored by non-functional emulsions where droplet integrity was maintained even in the presence of mucus

Delayed self-recognition in children with autism spectrum disorder.

This study aimed to investigate temporally extended self-awareness (awareness of one’s place in and continued existence through time) in autism spectrum disorder (ASD), using the delayed self-recognition (DSR) paradigm (Povinelli et al., Child Development 67:1540–1554, 1996). Relative to age and verbal ability matched comparison children, children with ASD showed unattenuated performance on the DSR task, despite showing significant impairments in theory-of-mind task performance, and a reduced propensity to use personal pronouns to refer to themselves. The results may indicate intact temporally extended self-awareness in ASD. However, it may be that the DSR task is not an unambiguous measure of temporally extended self-awareness and it can be passed through strategies which do not require the possession of a temporally extended self-concept

Spongivory in the Wakatobi Marine National Park, Southeast Sulawesi, Indonesia

Sponges are functionally important coral reef fauna and there is strong evidence from the Caribbean that predation has important impacts on sponge-Assemblage dynamics; whether the same is true for Indo-Pacific sponges remains unknown. As a first step toward understanding the potential effects of spongivores on sponge diversity and abundance, we identified sponge predators at nine sites in Wakatobi Marine National Park, Indonesia, and conducted a short-Term caging experiment to examine the effects of excluding predators on noncryptic reef sponges at this location. Nudibranchs were the most abundant invertebrate spongivores, although their low densities are likely to limit their influence on sponges. Fish were the most abundant vertebrate spongivores with 16 species from six families observed feeding on sponges. Based on their abundance and our feeding observations, the fish with the greatest potential to influence sponge assemblages in Wakatobi Marine National Park were Zanclus cornutus, Chaetodon kleinii, Pygoplites diacanthus, and Pomacanthus sexstriatus. We did not detect an effect of excluding spongivores on noncryptic reef sponge abundance in our caging experiment, which may be due to these species having evolved chemical defenses against predators. Important areas for further research include the chemical ecology of Indo-Pacific sponges and whether spongivory currently restricts some species to cryptic or nonreef habitats