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A technique is developed for determining the sound field scattered by a compact body when it is close enough to an acoustic source to be in its near field. Our approach is based on the fact that large regions of many near fields may be well approximated at each point in space by a subsonic plane wave (also called an inhomogeneous plane wave, or an evanescent wave). Such a wave is defined by the property that in one direction it propagates with subsonic phase speed, while in a perpendicular direction it has exponential amplitude variation. Hence by defining a canonical problem, compact scattering of a subsonic plane wave, and solving it, we are able to give a unified analytical treatment of many near-field scattering problems. Our approach draws on the formulae of Rayleigh scattering (as applied to an incident field with complex wavenumber) and the asymptotic theory of the wave equation. For an arbitrary three-dimensional multipole, we determine in full detail how its subsonic wave structure depends on the spherical harmonic parameters (m,n) , and show that our approach has a very large region of validity. [ABSTRACT FROM AUTHOR]

A difficulty in the theory of a thin elastic interface is that series expansions in its thickness become disordered in the high-contrast limit, i.e. when the interface is much softer or much stiffer than the media on either side. We provide a mathematical analysis of such series for an annular coating around a cylindrical fibre embedded in an elastic matrix subject to biaxial forcing. We determine the order of magnitude of successive terms in the series, and hence the terms that need to be retained in order to ensure that every neglected term is smaller in order of magnitude than at least one retained term. In this way, we obtain uniform approximations for quantities such as the jump in the displacement and stress across the coating, and explain some peculiarities that have been observed in numerical work. A key finding is that it is essential to distinguish three types of boundary-value problem, corresponding to 'distant forcing', 'localized forcing' and 'the homogeneous problem', since they give different patterns of disorder in the corresponding series expansions. This provides a meaningful correspondence between physical principles and our mathematical results. [ABSTRACT FROM AUTHOR]

A mathematical analysis of wave propagation along an elastic cylindrical tube is presented, with the aim of determining the range of Poisson's ratio for which backward wave propagation (i.e. at negative group velocity) can occur near the ring frequency. This range includes zero Poisson's ratio and a surrounding interval of positive and negative values, whose width depends on the thickness of the tube. The whole range of Poisson's ratio is considered, so that the work applies to modern materials, e.g. composites. All results are presented in simple analytic form by means of a dominant balance in parameter space. The identification of this balance, which is unique, is a main new result in the paper, which makes possible a new type of shell theory based on 'Poisson scaling'. The mathematical approach is deductive from the equations of motion, rather than being based on kinematic hypotheses. A key finding, accessible via the Poisson scaling, is that the regime of negative group velocities extends to high wavenumbers, while being confined to a narrow band of frequencies. Thus responses localized in space are possible for near-monochromatic forcing, an important fact for nonlinear theories of tube dynamics near the ring frequency. This article is part of the theme issue 'Wave generation and transmission in multi-scale complex media and structured metamaterials (part 1)'. [ABSTRACT FROM AUTHOR]

A technique involving the higher Wronskians of a differential equation is presented for analysing the dispersion relation in a class of wave propagation problems. The technique shows that the complicated transcendental-function expressions which occur in series expansions of the dispersion function can, remarkably, be simplified to low-order polynomials exactly, with explicit coefficients which we determine. Hence simple but high-order expansions exist which apply beyond the frequency and wavenumber range of widely used approximations based on kinematic hypotheses. The new expansions are hypothesis-free, in that they are derived rigorously from the governing equations, without approximation. Full details are presented for axisymmetric elastic waves propagating along a tube, for which stretching and bending waves are coupled. New approximate dispersion relations are obtained, and their high accuracy confirmed by comparison with the results of numerical computations. The weak coupling limit is given particular attention, and shown to have a wide range of validity, extending well into the range of strong coupling. [ABSTRACT FROM AUTHOR]

This paper derives an explicit formula for a type of fractional power series, known as a Puiseux series, arising in a wide class of applied problems in the physical sciences and engineering. Detailed consideration is given to the gaps which occur in these series (lacunae); they are shown to be determined by a number-theoretic argument involving the greatest common divisor of a set of exponents appearing in the Newton polytope of the problem, and by two number-theoretic objects, called here Sylvester sets, which are complements of Frobenius sets. A key tool is Faà di Bruno's formula for high derivatives, as implemented by Bell polynomials. Full account is taken of repeated roots, of arbitrary multiplicity, in the leading-order polynomial which determines a fractional-power expansion, namely the facet polynomial. For high multiplicity, the fractional powers are shown to have large denominators and contain irregularly spaced gaps. The orientation and methods of the paper are those of applications, but in a concluding section we draw attention to a more abstract approach, which is beyond the scope of the paper. [ABSTRACT FROM AUTHOR]

This paper presents a technique, based on a deferred approach to a limit, for analysing the dispersion relation for propagation of long waves in a curved waveguide. The technique involves the concept of an analytically satisfactory pair of Bessel functions, which is different from the concept of a numerically satisfactory pair, and simplifies the dispersion relations for curved waveguide problems. Details are presented for long elastic waves in a curved layer, for which symmetric and antisymmetric waves are strongly coupled. The technique gives high-order corrections to a widely used approximate dispersion relation based a kinematic hypothesis, and determines rigorously which of its coefficients are exact. [ABSTRACT FROM AUTHOR]

This paper presents a class of approximations to a type of wave field for which the dispersion relation is transcendental. The approximations have two defining characteristics: (i) they give the field shape exactly when the frequency and wavenumber lie on a grid of points in the (frequency, wavenumber) plane and (ii) the approximate dispersion relations are polynomials that pass exactly through points on this grid. Thus, the method is interpolatory in nature, but the interpolation takes place in (frequency, wavenumber) space, rather than in physical space. Full details are presented for a non-trivial example, that of antisymmetric elastic waves in a layer. The method is related to partial fraction expansions and barycentric representations of functions. An asymptotic analysis is presented, involving Stirling's approximation to the psi function, and a logarithmic correction to the polynomial dispersion relation. [ABSTRACT FROM AUTHOR]

Background: Autoantibodies may be present in a variety of underlying cancers several years before tumours can be detected and testing for their presence may allow earlier diagnosis. We report the clinical validation of an autoantibody panel in newly diagnosed patients with lung cancer (LC).Patients and methods: Three cohorts of patients with newly diagnosed LC were identified: group 1 (n = 145), group 2 (n = 241) and group 3 (n = 269). Patients were individually matched by gender, age and smoking history to a control individual with no history of malignant disease. Serum samples were obtained after diagnosis but before any anticancer treatment. Autoantibody levels were measured against a panel of six tumour-related antigens (p53, NY-ESO-1, CAGE, GBU4-5, Annexin 1 and SOX2). Assay sensitivity was tested in relation to demographic variables and cancer type/stage.Results: The autoantibody panel demonstrated a sensitivity/specificity of 36%/91%, 39%/89% and 37%/90% in groups 1, 2 and 3, respectively, with good reproducibility. There was no significant difference between different LC stages, indicating that the antigens included covered the different types of LC well.Conclusion: This assay confirms the value of an autoantibody panel as a diagnostic tool and offers a potential system for monitoring patients at high risk of LC. [ABSTRACT FROM AUTHOR]

Background: Publications on autoantibodies to tumour-associated antigens (TAAs) have failed to show either calibration or reproducibility data. The validation of a panel of six TAAs to which autoantibodies have been described is reported here. [ABSTRACT FROM PUBLISHER]

Background: People with lung cancer usually present at a late stage in the course of their disease when their chances of long-term survival are low. At present there is little to offer for early diagnosis, even in those at high risk of developing the disease. Autoantibodies have been shown to be present in the circulation of people with various forms of solid tumour before cancer-associated antigens can be detected, and these molecules can be measured up to 5 years before symptomatic disease. Objective: To assess the potential of a panel of tumour- associated autoantibody profiles as an aid to other lung cancer screening modalities. Methods: Plasma from normal controls (n = 50), patients with non-small cell lung cancer )n = 82) and patients with small cell lung cancer (n = 22) were investigated for the presence of autoantibodies to p53, c-myc, HER2, NY-ESO-1, CAGE, MUC1 and GBU4-5 by enzyme-linked immunosorbent assay. Results: Raised levels of autoantibodies were seen to at least 1/7 antigens in 76% of all the patients with lung cancer plasma tested, and 89% of node-negative patients, with a specificity of 92%. There was no significant difference between the detection rates in the lung cancer subgroups, although more patients with squamous cell carcinomas (92%) could be identified. Conclusion: Measurement of an autoantibody response to one or more tumour-associated antigens in an optimised panel assay may provide a sensitive and specific blood test to aid the early detection of lung cancer. [ABSTRACT FROM AUTHOR]

Provides information on a study which investigated the long-term survival and growth of Norway lobsters, Nephrops norvegicus, in relation to light-induced retina breakdown. Materials and methods used in the study; Information on the eye damage in lobsters released in 1978 and 1983; Sex ratios and length composition of the lobsters; Reproductive condition of female lobsters.

The V4-34 (VH4-21) gene has been found to encode certain IgM autoantibodies, and is mandatory for pathological IgM anti-erythrocyte antibodies of I/i specificity. The gene is also commonly used by normal IgM-positive B lymphocytes, but its involvement in B cells which have undergone class switching to IgG or IgA is less clear. In order to track V4-34 gene usage and class switching events during a normal immune response, we have probed RNA in a limited area of human tonsil. Results indicate that the V4-34 gene undergoes class switching to IgG or IgA. with the progeny either remaining unmutated or containing large numbers of somatic mutations. Mutational patterns indicate possible 'hot spots', und some mutations appear deleterious. At the level of individual B cells, we have tracked a clonal isotype switch event from IgM to IgA. with each retaining close to germ-line configuration. In addition. we have followed a clonal switch from a mutated IgM to IgG. with no further accumulation of somatic mutations. These data indicate that the V4-34 gene is involved in a maturing immune response, and that the routes to production of IgG or IgA antibodies are various. [ABSTRACT FROM AUTHOR]

This study investigated the ability of foetal thymic epithelium prepared by 24 culture (24 -TE) or treatment with deoxyguanosine (dGuo-TE), to induce tolerance in nude mice. Thymic chimeras were constructed in which the thymic epithelium differed from the host at both major histocompatibility complex (MHC) antigens and multiple minor histocompatibility antigens (mHa), or at mHa only. Peripheral CTL from nude mice receiving dGuo-TE disparate for mi-Ia, or both MHC antigens and mHa, were uniformly tolerant of thymic mHa. CTL from nude mice grafted with 24 -TE or dGuo-TE were tolerant of host MHC antigens, but the two treatments differed in the efficiency with which they induced tolerance to thymic MHC antigens. CTL responses specific for thymic MHC antigens could be generated in vitro from dGuo-TE grafted mice but not from those receiving 24 -TE. The addition of concanavalin A (Con A) supernatant had no effect on the CTL tolerance observed in 24 -TE grafted mice, suggesting that the lack of CTL responses was not due to tolerance in MHC class 11 restricted 'helper' cells. However, CTL responses against the thymic MI-IC antigens of dGuo-TE grafted mice displayed high sensitivity to blocking by anti-CD8 antibodies, indicating that these CTL were of low affinity. These results suggest that 24 -TE induces tolerance in most thymic MHC-specific CTL precursors, whereas dGuo-TE induces tolerance only in CTL with high affinity for thymic MHC antigens. Therefore, 24 -TE and dGuo-TE arc both capable of inducing Cit tolerance, consistent with the previously reported acceptance of thymic donor-type skin grafts by nude recipients of dGuo- TE treatment. We conclude that MHC class I molecules on thymic epithelium play a role in negative selection of the developing T-cell repertoire. [ABSTRACT FROM AUTHOR]

Aim: The aim of this work was to evaluate colorectal cancer (CRC) outcomes after 'low' (sub‐threshold) faecal immunochemical test (FIT) results in symptomatic patients tested in primary care. Method: This work comprised a retrospective audit of 35 289 patients with FIT results who had consulted their general practitioner with lower gastrointestinal symptoms and had subsequent CRC diagnoses. The Rapid Colorectal Cancer Diagnosis pathway was introduced in November 2017 to allow incorporation of FIT into clinical practice. The local '4F' protocol combined FIT results with blood tests and digital rectal examination (DRE): FIT, full blood count, ferritin and finger [DRE]. The outcome used was detection rates of CRC, missed CRC and time to diagnosis in local 4F protocols for patients with a subthreshold faecal haemoglobin (fHb) result compared with thresholds of 10 and 20 μg Hb/g faeces. Results: A single threshold of 10 μg Hb/g faeces identifies a population in whom the risk of CRC is 0.2%, but this would have missed 63 (10.5%) of 599 CRCs in this population. The Nottingham 4F protocol would have missed fewer CRCs [42 of 599 (7%)] despite using a threshold of 20 μg Hb/g faeces for patients with normal blood tests. Subthreshold FIT results in patients subsequently diagnosed with a palpable rectal tumour yielded the longest delays in diagnosis. Conclusion: A combination of FIT with blood results and DRE (the 4F protocol) reduced the risk of missed or delayed diagnosis. Further studies on the impact of such protocols on the diagnostic accuracy of FIT are expected. The value of adding blood tests to FIT may be restricted to specific parts of the fHb results spectrum. [ABSTRACT FROM AUTHOR]

Objective To understand the usage and acceptability of a faecal collection device amongst participants in the National Health Service Bowel Cancer Screening Programme, with the aim of influencing future uptake. Setting Participants completing faecal occult blood test retests as part of the routine Bowel Cancer Screening Programme in Eastern England. Methods A faecal collection device and questionnaire were sent to all potential retest participants during a one-month period to collect information on prior stool collection methods and ease of use and usefulness of the enclosed faecal collection device. Results Out of 1087 participants invited, 679 (62.5%) returned their questionnaire. Of these, 429 (63.2%) trialled the faecal collection device at least once, 163 (38.4%) found the device made collecting their sample easier than previously, 189 (44.6%) found it made collection more difficult and 72 (17.0%) said it made no difference. Similar numbers reported finding that the faecal collection device made collecting the sample more pleasant (130, 31.5%), less pleasant (103, 25.0%) and no different (179, 43.4%) compared with previous collection without a faecal collection device. Conclusion Although a small proportion of participants found the faecal collection device helpful, a considerable majority did not or did not use it at all. Offering faecal collection devices is unlikely to produce a substantial increase in bowel cancer screening uptake. [ABSTRACT FROM AUTHOR]

Background: Guidelines for urgent investigation of colorectal cancer (CRC) are based on age and symptom-based criteria. This study aims to compare the diagnostic value of clinical features and faecal immunochemical test (FIT) results to identify those at a higher risk of CRC, thereby facilitating effective triage of patients. Methods: We undertook a review of all patients referred for investigation of CRC at our centre between September 2016 and June 2018. Patients were identified using a prospectively recorded local database. We performed a logistic regression analysis of factors associated with a diagnosis of CRC. Results: One-thousand-and-seven-hundred-eighty-four patients with FIT results were included in the study. Change in bowel habit (CIBH) was the most common referring clinical feature (38.3%). Patients diagnosed with CRC were significantly older than those without malignancy (74.0 years vs 68.9 years, p = 0.0007). Male patients were more likely to be diagnosed with CRC than females (6.5% vs 2.5%, Chi-squared 16.93, p < 0.0001). CRC was diagnosed in 3.5% (24/684) with CIBH compared to 8.1% (6/74) with both CIBH and iron deficiency anaemia. No individual or combination of referring clinical features was associated with an increased diagnosis of CRC (Chi-squared, 8.03, p = 0.155). Three patients with negative FIT results (< 4 µg Hb/g faeces) were diagnosed with CRC (3/1027, 0.3%). The highest proportion of cancers detected was in the ≥ 100 µg Hb/g faeces group (55/181, 30.4%). Conclusion: In a multivariate model, FIT outperforms age, sex and all symptoms prompting referral. FIT has greater stratification value than any referral symptoms. FIT does have value in patients with iron deficiency anaemia. [ABSTRACT FROM AUTHOR]

Numerous reports document the existence of autoantibodies to MUC1 in the circulation of individuals with breast and other solid malignancies, with the majority of researchers utilizing MUC1 peptides in their detection. This report documents the purification, using peptide and whole molecule, and characterization of such autoantibodies from an individual with an unusual, highly MUC1-positive, myosarcoma. Purification of autoantibodies from serum was performed using affinity chromatography against either MUC1 peptide or whole molecule MUC1 [derived both from the patient (Pt-MUC1) and from a pool of sera from patients with advanced breast cancer (ABC-MUC1)]. Enzyme-linked immunosorbent assays (ELISAs) were used to compare specificity of purified autoantibodies. Peptide epitopes were determined by Ptifcan system against 7-mer peptides covering the 20 amino acid repeat of the MUC1 extracellular domain. Substantially higher amounts of autoantibodies were isolated when purifying against Pt-MUC1 rather than either ABC-MUC1 or peptide. Whole molecule purified autoantibodies demonstrated an increased specificity for tumour-derived MUC1. Pt-MUC1 autoantibodies were of both the immunoglobulin (Ig)G and IgM class, whilst autoantibodies purified against ABC-MUC1 and MUC1 peptide were IgG only. A greater range of peptide epitopes was defined by those autoantibodies purified against whole molecule. This report presents data indicating the presence of autoantibodies to MUC1 in an individual diagnosed with a MUC1 over-expressing myosarcoma. Confirmation of these autoantibodies as being specific for tumour-associated MUC1 is given. Further, it suggests that, although autoantibodies are present that recognize core protein determinants, the initial, and dominant, immunizing epitope is not purely pretentious in nature. [ABSTRACT FROM AUTHOR]

We have previously described complement-independent killing of human B lymphocytes by two IgM MoAbs derived from the VH4-34 (VH4.21) gene. Analysis of 17 independently derived VH4-34- encoded MoAbs shows that B cell toxicity is not limited to the two described MoAbs, but is a general property shared by a subset of MoAbs derived from the VH4-34 gene. As observed by two independent microscopy techniques, giant membrane pores were formed on target B cells within 10-15 min of exposure to cytotoxic VH4-34-derived MoAbs. Toxicity by individual MoAb correlated directly to its B cell binding intensity measured by FACS, i.e. stronger the binding greater the killing. Sequence analysis showed that VH region in germ-line or in near germ-line configuration was necessary but not sufficient for B cell binding. In addition, a particular sequence motif enriched in basic amino acids in the CDR3 may be required to supplement the reactivity mediated by the VH region of the MoAb molecule. VH4- 34-encoded antibodies that fulfil the above sequence requirements have cold agglutinin activity towards the i antigen of cord erythrocytes. In vivo, such anti-i/anti-B cell antibodies are rarely detected in healthy adults, but serum levels are dramatically elevated in selective pathological conditions, such as systemic lupus erythematosus and infectious mononucleosis. This strict regulation may be related to the novel and rapid mechanism of human B cell toxicity demonstrated by antibodies encoded by a single human VH gene. [ABSTRACT FROM AUTHOR]