The interaction of steady free-surface flows of viscoplastic material with a surface-piercing obstruction of square cross-section on an inclined plane is investigated theoretically. The flow thickness increases upstream of the obstruction and decreases in its lee. The flow depends on two dimensionless parameters: an aspect ratio that relates the flow thickness, the obstruction width and the plane inclination; and a Bingham number that quantifies the magnitude of the yield stress relative to the gravitationally induced stresses. Flows with a non-vanishing yield stress always form a static ‘dead’ zone in a neighbourhood of the upstream and downstream stagnation points. For relatively wide obstructions, a deep ‘ponded’ region develops upstream with a small dead zone, while the deflected flow reconnects over relatively long distances downstream. The depth of the upstream pond increases with both the dimensionless yield stress and width of the obstruction, while the unyielded dead zone varies primarily with the yield stress. Both are predicted asymptotically by balancing the volume flux of fluid into and out of the ponded region. When the obstruction is narrow, the perturbation to the depth of the oncoming flow is reduced. It exhibits fore–aft antisymmetry, while the dead zone is symmetric to leading order. Increasing the yield stress leads to larger dead zones that eventually encompass all of the upstream- and downstream-facing boundaries of the obstruction and fully divert the flow. Results for obstructions with circular and rhomboidal cross-sections are also presented and illustrate the effects of boundary shape on the properties of the steady flow.

The interaction of gravitationally driven, free-surface flows of viscous fluid with topographic features is investigated theoretically. The motion is studied in the regime where the depth of the flow is much smaller than the streamwise extent of the topography. A lubrication model of the motion is developed, integrated numerically and analysed asymptotically. For small mounds, it is shown that the flow surmounts the obstacles, but for larger mounds the flow is deflected around it and can form dry zones in its wake into which fluid does not flow, as well as forming deeper ponded regions upstream. Which of these phenomena prevails is shown to depend upon the amplitude of the mound height and the thickness of the oncoming flow relative to the streamwise length scale over which the topography varies. By using numerical and asymptotic results, we demonstrate that relatively wide mounds lead to the development of deep ponds of material upstream, which may lead to flow overtopping if the mound is not sufficiently high. These insights can be used to inform the design of barriers that defend built infrastructures from lava flows, and it is shown how this model can also provide an upper bound on the force exerted by the flow on them.

The Taipan galaxy survey (hereafter simply ‘Taipan’) is a multi-object spectroscopic survey starting in 2017 that will cover 2π steradians over the southern sky (δ ≲ 10°, |b| ≳ 10°), and obtain optical spectra for about two million galaxies out to z < 0.4. Taipan will use the newly refurbished 1.2-m UK Schmidt Telescope at Siding Spring Observatory with the new TAIPAN instrument, which includes an innovative ‘Starbugs’ positioning system capable of rapidly and simultaneously deploying up to 150 spectroscopic fibres (and up to 300 with a proposed upgrade) over the 6° diameter focal plane, and a purpose-built spectrograph operating in the range from 370 to 870 nm with resolving power R ≳ 2000. The main scientific goals of Taipan are (i) to measure the distance scale of the Universe (primarily governed by the local expansion rate, H 0) to 1% precision, and the growth rate of structure to 5%; (ii) to make the most extensive map yet constructed of the total mass distribution and motions in the local Universe, using peculiar velocities based on improved Fundamental Plane distances, which will enable sensitive tests of gravitational physics; and (iii) to deliver a legacy sample of low-redshift galaxies as a unique laboratory for studying galaxy evolution as a function of dark matter halo and stellar mass and environment. The final survey, which will be completed within 5 yrs, will consist of a complete magnitude-limited sample (i ⩽ 17) of about 1.2 × 106 galaxies supplemented by an extension to higher redshifts and fainter magnitudes (i ⩽ 18.1) of a luminous red galaxy sample of about 0.8 × 106 galaxies. Observations and data processing will be carried out remotely and in a fully automated way, using a purpose-built automated ‘virtual observer’ software and an automated data reduction pipeline. The Taipan survey is deliberately designed to maximise its legacy value by complementing and enhancing current and planned surveys of the southern sky at wavelengths from the optical to the radio; it will become the primary redshift and optical spectroscopic reference catalogue for the local extragalactic Universe in the southern sky for the coming decade.

Aberrant microbiota composition and function have been linked to several pathologies, including type 2 diabetes. In animal models, prebiotics induce favourable changes in the intestinal microbiota, intestinal permeability (IP) and endotoxaemia, which are linked to concurrent improvement in glucose tolerance. This is the first study to investigate the link between IP, glucose tolerance and intestinal bacteria in human type 2 diabetes. In all, twenty-nine men with well-controlled type 2 diabetes were randomised to a prebiotic (galacto-oligosaccharide mixture) or placebo (maltodextrin) supplement (5·5 g/d for 12 weeks). Intestinal microbial community structure, IP, endotoxaemia, inflammatory markers and glucose tolerance were assessed at baseline and post intervention. IP was estimated by the urinary recovery of oral 51Cr-EDTA and glucose tolerance by insulin-modified intravenous glucose tolerance test. Intestinal microbial community analysis was performed by high-throughput next-generation sequencing of 16S rRNA amplicons and quantitative PCR. Prebiotic fibre supplementation had no significant effects on clinical outcomes or bacterial abundances compared with placebo; however, changes in the bacterial family Veillonellaceae correlated inversely with changes in glucose response and IL-6 levels (r −0·90, P=0·042 for both) following prebiotic intake. The absence of significant changes to the microbial community structure at a prebiotic dosage/length of supplementation shown to be effective in healthy individuals is an important finding. We propose that concurrent metformin treatment and the high heterogeneity of human type 2 diabetes may have played a significant role. The current study does not provide evidence for the role of prebiotics in the treatment of type 2 diabetes.

The International Accounting Standards Board is undertaking a project to develop an Accounting Standard for Insurance. The basis for these proposals is that assets and liabilities should be shown at fair values (market values for quoted instruments). This is an updated version of a paper, prepared by a Working Party established by the General Insurance Research Organisation (GIRO) of the General Insurance Board of the actuarial profession of the United Kingdom, which was first presented to the GIRO Conference in October 2002. This paper summarises and comments upon the principal features of the proposals as they have emerged up to February 2003. The paper considers the implications for general insurance companies of these proposals. In particular, it examines the concept of market value margins, and the practical issues that insurance companies are likely to encounter in implementing them. The emphasis of the paper is on reporting for general insurance business, although many of the principles apply equally to life assurance.

Four recently weaned pigs were dosed orally with oxytetracycline. This caused a rapid increase in the incidence of tetracycline resistance (TcR) among Escherichia coli isolates from the faecal flora. The isolates were differentiated further on the basis of O-serogroup, biotype and resistance pattern. There was no evidence that the administration of the antibiotic selected for a few TcR clones, but rather a relatively large number of TcR strains were identified during the dosing period. Using selective isolation media a proportion of these strains were demonstrated in the minority faecal Esch. coli flora before dosing, while the remainder were recognized for the first time after dosing commenced.

The incidence of TcR among Esch. coli isolates also increased after weaning in other pigs which were not dosed with oxytetracycline or any other antibacterial agent. In a proportion of these animals this increase was associated with the dominance of a TcR enteropathogenic serotype (0149:K 91, K 88a, c) in the faecal Esch. coli flora which was probably ingested in small numbers before weaning. The source of other TcR strains was probably the environment in which each pig was placed after weaning.

A survey was undertaken of the occurrence, serotype, antimicrobial sensitivity and plasmid content of members of the tribe Proteeae in the environment of two calf-rearing units in the county of Avon in South West England. Examples of the following species were found: Proteus mirabilis, Prot. vulgaris, Prot. vulgaris Biogroup 2, Morganella morganii, Providencia stuartii, Prov. alcalifaciens and Prov. rettgeri. A wide range of sero types was found, many having been previously reported from nosocomial isolates. A total of 15% of isolates carried plasmids; six pairs of isolates were identified which had identical sero typesbut different patterns of plasmid carriage. The antimicrobial sensitivity of the isolates was generally similar to isolates of Proteeae from humans. Although no truly aminoglycosideresistantisolates were found, some isolates of Prov. stuartii and Prov. rettgeri had MIC's higher than the other isolates to gentamicin and netilmicin, suggesting the presence of lowlevels of the enzyme AAC 2′. The study demonstrates that there is a considerable diversityof species and types of Proteeae associated with calves and their environment. It seems likely that a potential cause of colonization of the human gut by Proteeae is the consumption of meat.

Visual markers detectable by histochemical staining have been developed for analysing the time course and tissue specificity of maize infections by Fusarium moniliforme. Three F. moniliforme strains, RRC 374, MRC 826 and RRC PAT, were transformed with a plasmid, pHPG, containing the gusA reporter gene which codes for β-glucuronidase (GUS) and the hph gene for hygromycin resistance as the selectable marker. Introduction of plasmid DNA into germinating conidia yielded 1·2×10−7 transformants per conidium; expression of both gusA and hph was however, transient. Stable transformants were obtained using protoplasts as the recipient, but transformation frequency was reduced. Southern blot and PCR analyses confirmed incorporation of pHPG into the genome of all three F. moniliforme strains with gusA properly inserted in MRC 826 and RRC PAT, but apparently disrupted in RRC 374. The growth pattern for transformed F. moniliforme isolates and the parental wild types followed a sigmoid curve on minimal and enriched media. Hygromycin totally inhibited growth for wild type isolates, but not of transformants. Transformed isolates maintained the ability to infect the maize plant. Thus, this study is the first report of F. moniliforme transformed with a visibly detectable reporter gene to use for analysing this endophyte-host interaction of world-wide importance to animal and human health.

Endoscopy of the upper airways in neonates and infants has traditionally been accomplished using rigid laryngoscopes and bronchoscopes. The laryngeal mask may be used both to control the airway for anaesthetic ventilation and to guide a fibre-optic endoscope to the laryngeal inlet and beyond.

We report our experience with five neonatal and paediatric cases where fibre-optic laryngoscopy and bronchoscopy were performed through the laryngeal mask airway. All were cases in which standard rigid endoscopy had proved difficult with only a poor and restricted view of the laryngeal inlet being obtained due to the age of the infants, or abnormal anatomy of the upper airways.

No problems have been encountered with maintenance of the airway or with the endoscopic view obtained. In fact in neonatal patients, this technique has been found to be preferable with regard to safety and ease of use when compared to the ventilating bronchoscope. With the size 1 laryngeal mask airway it is not possible to simultaneously ventilate and endoscope the patient. Cases included, a vascular ring, Goldenhar's syndrome, laryngomalacia, supraglottis and vocal fold paresis.

This technique provides a secure method of maintaining anaesthetic ventilation during airway endoscopy, and also a means of easily locating the glottis.

In the quest for hearing preservation in patients with acoustic schwannomas it is essential that surgeons do not lose sight of the concept of ‘useful’ hearing. There is an important difference between hearing preservation which pleases the surgeon and that which will be appreciated by the patient.

Tumour size, pure tone audiogram average differences between ears and speech discrimination scores have been recorded in a series of 114 patients with unilateral acoustic schwannomas. Criteria for useful hearing are presented in terms of pure tone audiogram average difference and speech discrimination scores.

There were 11 patients (10 per cent) with a speech discrimination score of 50 per cent or more, a pure tone audiogram average difference of 30 dB or better and a tumour size of no more than 2 cm. Only one patient (0.9 per cent) had a speech discrimination score of 50 per cent or more, a pure tone audiogram average difference of 20 dB or better and a tumour size of no more than 1 cm.

It is concluded that hearing preservation techniques may be applicable to between 1 and 10 per cent of patients with unilateral acoustic schwannomas.

Part I is about valuing fairness, II chiefly about not valuing it. Equally, I is about knowing fairness or taking yourself to know what it is, while II is chiefly about not knowing what it is: absolutely not knowing what it is, or not knowing what it is except when it is thought of in a narrow way. I want to know what all those states involve, e.g. whether knowing what fairness is involves valuing it, and most of all (in Part II) whether those two aforesaid ways of not knowing what fairness is involve some knowably undesirable kind of ignorance; in that sense, incur a cognitive penal sanction. But I begin elsewhere.

Many years ago we often witnessed a testy insistence, on the part of some purist, that some very familiar philosophical ‘ism’ be defined before being discussed; when most people either thought that had been done already or were happy to wait for the discussion itself to identify the ‘ism’. The old new style, that featured those unexpected demands for definition, ended by trying people's patience in its turn. Today there is a widespread assumption that we know, well enough, what is meant in philosophy by Scepticism. Perhaps the majority view is something like this:

The philosophical term Scepticism admittedly covers a number of different stances. The one that a given philosopher wants to discuss may or may not be the most like that of the original ancient Skeptics. Still the context normally makes it clear enough what is meant, and there is more point in discussing whatever thing is meant than in quarrelling about the name. As for the way, or ways, in which the word scepticism with a small s is used when people are not referring to any traditional philosophical position—we can safely disregard colloquial usage in this context. As a rule the main point is to see how, if at all, the Scepticism in question is best combated or refuted.

A Levinson theorem is proved for a Dirac system with one singular endpoint. The number ofbound state is expressed in terms of the change in asymptotic phase of an appropriate solution and in terms of factors whose values depend on the presence of half-bound states. The behaviour of the asymptotic phase is used to determine the asymptotic behaviour of the Titchmarsh-Weyl m-function.