Three-point density correlation functions in the fractional quantum Hall regime

In this paper we consider the three-particle density correlation function for a fractional quantum Hall liquid. The study of this object is motivated by recent experimental studies of fractional quantum Hall systems using inelastic light scattering and phonon absorption techniques. Symmetry properties of the correlation function are noted. An exact sum-rule is derived which this quantity must obey. This sum-rule is used to assess the convolution approximation that has been used to estimate the matrix elements for such experiments. PACS Numbers: 73.40.Hm, 73.20.Mf, 72.10.DiComment: 12 pages + 1 (PS) figur

Global Transcriptomic Profiling of Bovine Endometrial Immune Response In Vitro. II. Effect of Bovine Viral Diarrhea Virus on the Endometrial Response to Lipopolysaccharide

Infection with noncytopathic bovine viral diarrhea virus (ncpBVDV) is associated with uterine disease and infertility. This study investigated the influence of ncpBVDV on immune functions of the bovine endometrium by testing the response to bacterial lipopolysaccharide (LPS). Primary cultures of mixed epithelial and stromal cells were divided into four treatment groups (control [CONT], BVDV, CONT+LPS, and BVDV+LPS) and infected with ncpBVDV for 4 days followed by treatment with LPS for 6 h. Whole-transcriptomic gene expression was measured followed by Ingenuity Pathway Analysis. Differential expression of 184 genes was found between CONT and BVDV treatments, showing interplay between induction and inhibition of responses. Up-regulation of TLR3, complement, and chemotactic and TRIM factors by ncpBVDV all suggested an ongoing immune response to viral infection. Down-regulation of inflammatory cytokines, chemokines, CXCR4, and serine proteinase inhibitors suggested mechanisms by which ncpBVDV may simultaneously counter the host response. Comparison between BVDV+LPS and CONT+LPS treatments showed 218 differentially expressed genes. Canonical pathway analysis identified the key importance of interferon signaling. Top down-regulated genes were RSAD2, ISG15, BST2, MX2, OAS1, USP18, IFIT3, IFI27, SAMD9, IFIT1, and DDX58, whereas TRIM56, C3, and OLFML1 were most up-regulated. Many of these genes are also regulated by IFNT during maternal recognition of pregnancy. Many innate immune genes that typically respond to LPS were inhibited by ncpBVDV, including those involved in pathogen recognition, inflammation, interferon response, chemokines, tissue remodeling, cell migration, and cell death/survival. Infection with ncpBVDV can thus compromise immune function and pregnancy recognition, thereby potentially predisposing infected cows to postpartum bacterial endometritis and reduced fertility

Corrosive wear behaviour of various stainless steel alloys and a Stellite 6 weld cladding

This study has comprised an investigation the corrosive wear behaviour of UNS S31600, a low hardness (280Hv) UNS S42000, a high hardness (480Hv) UNS S42000 and a single layer Stellite 6 (UNS R30006) weld cladding on a low alloy carbon steel (UNS G43400). Erosion-corrosion testing was conducted using a submerged jet of 3.5% NaCl aqueous solution with spherical silica sand particles. The sand concentration was 2.4g/l, the velocity of the jet was 18m/s and the testing temperature range was 16°C-27°C. Both normal incidence (90°) and low angle (20°) tests were performed. Mass losses, wear scar depths and a volumetric analysis technique were used to assess the damage in the direct impinged zone (DIZ) and the outer area (OA) of the specimens. For all materials, it was found that mass loss was higher at 20° tests than that of 90°. However, when comparing wear scar depths the opposite trend was found. The results are discussed in terms of comparative material behaviour, the influence of material hardness and the corrosive wear mechanisms in different regions formed during slurry jet impingement

Diversifying selection and host adaptation in two endosymbiont genomes

Background: The endosymbiont Wolbachia pipientis infects a broad range of arthropod and filarial nematode hosts. These diverse associations form an attractive model for understanding host: symbiont coevolution. Wolbachia's ubiquity and ability to dramatically alter host reproductive biology also form the foundation of research strategies aimed at controlling insect pests and vector-borne disease. The Wolbachia strains that infect nematodes are phylogenetically distinct, strictly vertically transmitted, and required by their hosts for growth and reproduction. Insects in contrast form more fluid associations with Wolbachia. In these taxa, host populations are most often polymorphic for infection, horizontal transmission occurs between distantly related hosts, and direct fitness effects on hosts are mild. Despite extensive interest in the Wolbachia system for many years, relatively little is known about the molecular mechanisms that mediate its varied interactions with different hosts. We have compared the genomes of the Wolbachia that infect Drosophila melanogaster, wMel and the nematode Brugia malayi, wBm to that of an outgroup Anaplasma marginale to identify genes that have experienced diversifying selection in the Wolbachia lineages. The goal of the study was to identify likely molecular mechanisms of the symbiosis and to understand the nature of the diverse association across different hosts. Results: The prevalence of selection was far greater in wMel than wBm. Genes contributing to DNA metabolism, cofactor biosynthesis, and secretion were positively selected in both lineages. In wMel there was a greater emphasis on DNA repair, cell division, protein stability, and cell envelope synthesis. Conclusion: Secretion pathways and outer surface protein encoding genes are highly affected by selection in keeping with host: parasite theory. If evidence of selection on various cofactor molecules reflects possible provisioning, then both insect as well as nematode Wolbachia may be providing substances to hosts. Selection on cell envelope synthesis, DNA replication and repair machinery, heat shock, and two component switching suggest strategies insect Wolbachia may employ to cope with diverse host and intra-host environments

Transverse sectioning in the evaluation of skin biopsy specimens from alopecic dogs.

Transverse sectioning of skin biopsy specimens has revolutionised assessment of human alopecia by demonstration of every hair in each specimen, allowing quantitative evaluation of follicular activity. Since only vertical sectioning is performed routinely in veterinary laboratories, we aimed to determine whether transverse sectioning was a valuable technique in assessment of canine alopecia. Paired vertical and transverse sections of biopsy specimens from 31 alopecic dogs were examined independently in triplicate in random order and blinded to previous diagnosis using a standard check-list proforma. Assessments of key features (follicular activity [anagen/telogen], infundibular hyperkeratosis, sebaceous gland abnormalities, pigment clumping, dermal inflammation) by each sectioning method were compared. In the 31 cases, (atrophic [n = 13], dysplastic [n = 12], inflammatory diseases [n = 6]), follicular inactivity scores (median, [lower-upper quartile]) in transverse sections significantly exceeded those in vertical sections (transverse 4 [3-5], vertical 3 [2-4]). Agreement between the two sectioning planes was moderate for infundibular hyperkeratosis (kappa = 0.5210) and dermal inflammation (0.4351), fair for sebaceous gland abnormalities (0.3966) and pigment clumping (0.2197), but slight for follicular activity (0.1041). Vertical sectioning demonstrated diagnostically important epidermal pathology (n = 2) and dermal thinning (n = 3) whereas transverse sectioning enhanced assessment of hair growth phase (n = 11), follicular structure and architecture (n = 11), and focal luminal or mural folliculitides (n = 3). Transverse sectioning confers significant benefits and complements traditional vertical sectioning in the histological assessment of canine hair follicle diseases, particularly when subtle abnormalities comprise distorted compound follicle architecture, hair cycle arrest or when relatively few adnexal structures are affected. [Abstract copyright: © 2020 The Authors. Journal of Small Animal Practice published by John Wiley & Sons Ltd on behalf of British Small Animal Veterinary Association.

Comparison of bulk milk antibody and youngstock serology screens for determining herd status for Bovine Viral Diarrhoea Virus

BACKGROUND: This paper examines the use of Bulk Milk antibody (BM Ab), Youngstock (YS) serology (Check Tests) and Bulk Milk PCR (BM PCR) for determining the presence or absence of animals persistently infected (PI) with Bovine Viral Diarrhoea Virus (BVDV) within a herd. Data is presented from 26 herds where average herd sizes were 343 and 98 animals for dairy and beef units respectively. Seventeen herds had sufficient data to analyse using Receiver Operating Characteristic (ROC) and probability curves enabling calculation of the sensitivity and specificity of BM Ab and YS Check tests for determining the presence of PI animals within herds in this dataset. RESULTS: Using BM Ab to screen a herd for the presence of PI animals, achieved a herd level sensitivity and specificity of 80.00 % (44.39–97.48 %) and 85.71 % (42.13–99.64 %) respectively (95 % confidence intervals quoted). Sensitivity and specificity of YS Check Tests at a cut off of 3/10 Ab positive YS were 81.82 % (48.22–97.72 %) and 66.67 % (22.28–95.67 %) respectively (95 % confidence interval). These results were achieved by comparing the screening tests to whole herd PI searches that took place 1–19 months after the initial screen with a mean interval of 8 months. Removal of this delay by taking BM samples on the day of a whole herd test and simulating a YS Check Test from the herd test data produced improvements in the reliability of the Check Tests. BM Ab sensitivity and specificity remained unchanged. However, the Check Test sensitivity and specificity improved to 90.9 % (58.72–99.77 %) and 100 % (54.07–100 %) respectively (95 % confidence interval) at a cut of off 2.5/10 Ab positive animals. Our limited BM PCR results identified 5/23 dairy farms with a positive BM PCR result; two contained milking PIs, two had non-milking PIs and another had no PIs identified. CONCLUSIONS: Delaying a PI search following an initial herd screen decreased the diagnostic accuracy and relevance of our results. With careful interpretation, longitudinal surveillance using a combination of the techniques discussed can successfully determine farm status and therefore allow changes in BVDV status to be detected early, thus enabling prompt action in the event of a BVDV incursion

Enhanced neutralising antibody response to bovine viral diarrhoea virus (BVDV) induced by DNA vaccination in calves

DNA vaccination is effective in inducing potent immunity in mice; however it appears to be less so in large animals. Increasing the dose of DNA plasmid to activate innate immunity has been shown to improve DNA vaccine adaptive immunity. Retinoic acid-inducible gene I (RIG-I) is a critical cytoplasmic double-stranded RNA pattern receptor required for innate immune activation in response to viral infection. RIG-I recognise viral RNA and trigger antiviral response, resulting in type I interferon (IFN) and inflammatory cytokine production. In an attempt to enhance the antibody response induced by BVDV DNA in cattle, we expressed BVDV truncated E2 (E2t) and NS3 codon optimised antigens from antibiotic free-plasmid vectors expressing a RIG-I agonist and designated either NTC E2t(co) and NTC NS3(co). To evaluate vaccine efficacy, groups of five BVDV-free calves were intramuscularly injected three times with NTC E2t(co) and NTC NS3(co) vaccine plasmids individually or in combination. Animals vaccinated with our (previously published) conventional DNA vaccines pSecTag/E2 and pTriExNS3 and plasmids expressing RIG-I agonist only presented both the positive and mock-vaccine groups. Our results showed that vaccines coexpressing E2t with a RIG-I agonist induced significantly higher E2 antigen specific antibody response (p < 0.05). Additionally, E2t augmented the immune response to NS3 when the two vaccines were delivered in combination. Despite the lack of complete protection, on challenge day 4/5 calves vaccinated with NTC E2t(co) alone or NTC E2t(co) plus NTC NS3(co) had neutralising antibody titres exceeding 1/240 compared to 1/5 in the mock vaccine control group. Based on our results we conclude that co-expression of a RIG-I agonist with viral antigen could enhance DNA vaccine potency in cattle

Magnetoroton scattering by phonons in the fractional quantum Hall regime

Motivated by recent phonon spectroscopy experiments in the fractional quantum Hall regime we consider processes in which thermally excited magnetoroton excitations are scattered by low energy phonons. We show that such scattering processes can never give rise to dissociation of magnetorotons into unbound charged quasiparticles as had been proposed previously. In addition we show that scattering of magnetorotons to longer wavelengths by phonon absorption is possible because of the shape of the magnetoroton dispersion curve and it is shown that there is a characteristic cross-over temperature above which the rate of energy transfer to the electron gas changes from an exponential (activated) to a power law dependence on the effective phonon temperature.Comment: LaTex document, 3 eps figures. submitted to Phys Rev

Canonical Generations and the British Left: The Narrative Construction of the Miners’ Strike 1984–85

‘Generations’ have been invoked to describe a variety of social and cultural relationships, and to understand the development of self-conscious group identity. Equally, the term can be an applied label and politically useful construct; generations can be retrospectively produced. Drawing on the concept of ‘canonical generations’ – those whose experiences come to epitomise an event of historic and symbolic importance – this article examines the narrative creation and functions of ‘generations’ as collective memory shapes and re-shapes the desire for social change. Building a case study of the canonical role of the miners’ strike of 1984–85 in the narrative history of the British left, it examines the selective appropriation and transmission of the past in the development of political consciousness. It foregrounds the autobiographical narratives of activists who, in examining and legitimising their own actions and prospects, (re)produce a ‘generation’ in order to create a relatable and useful historical understanding

Mars oxygen production system design

The design and construction phase is summarized of the Mars oxygen demonstration project. The basic hardware required to produce oxygen from simulated Mars atmosphere was assembled and tested. Some design problems still remain with the sample collection and storage system. In addition, design and development of computer compatible data acquisition and control instrumentation is ongoing