1,451 research outputs found

    Modelling Ultrasonic Inspection of Rough Defects

    Get PDF
    Ultrasonic signals are affected by the nature of the defects under investigation. One defect property known to alter signal amplitudes and pulse shapes is surface roughness. No exact theory is available to describe the interaction of ultrasonic waves with rough defects but approximate theories are of great value, over various regimes of validity [1,2]. We have combined one such approximation. Kirchhoff theory [1,2], with many aspects of a real inspection system, to provide a model for simulating the ultrasonic inspection of randomly rough defects. The model is currently acoustic, such that mode conversion effects cannot be predicted. This paper presents some details of the model, together with sample results. These include a comparison with experimental measurements from rough surfaces, showing favourable agreement

    Karyomegalic interstitial nephritis with a novel FAN1 gene mutation and concurrent ALECT2 amyloidosis

    Get PDF
    Background: Karyomegalic interstitial nephritis (KIN) is a rare hereditary cause of chronic kidney disease. It typically causes progressive renal impairment with haemoproteinuria requiring renal replacement therapy before 50 years of age. It has been associated with mutations in the Fanconi anaemia-associated nuclease 1 (FAN1) gene and has an autosomal recessive pattern of inheritance. Leukocyte chemotactic factor 2 amyloidosis (ALECT2) is the third most common cause of amyloid nephropathy presenting with chronic kidney disease and variable proteinuria. We report a novel mutation in the FAN1 gene causing KIN and to our knowledge, the first case of concurrent KIN and ALECT. / Case presentation: We describe the case of 44 year old Pakistani woman, presenting with stage four non-proteinuric chronic kidney disease, and a brother on dialysis. Renal biopsy demonstrated KIN and concurrent ALECT2. Genetic sequencing identified a novel FAN1 mutation as the cause of her KIN and she is being managed conservatively for chronic kidney disease. Her brother also had KIN with no evidence of amyloidosis and is being worked up for kidney transplantation. / Conclusion: This case highlights two rare causes of chronic kidney disease considered underdiagnosed in the wider population due to their lack of proteinuria, and may contribute to the cohort of patients reaching end stage renal disease without a renal biopsy. We report a novel mutation of the FAN1 gene causing KIN, and report the first case of concurrent KIN and ALECT2. This case highlights the importance of renal biopsy in chronic kidney disease of unclear aetiology which has resulted in a diagnosis with implications for kidney transplantation and family planning

    Reply to Piper et al.: Drosophila dietary restriction—Does it hold water?

    Get PDF
    No abstract

    Propagation of chaos for rank-based interacting diffusions and long time behaviour of a scalar quasilinear parabolic equation

    Get PDF
    We study a quasilinear parabolic Cauchy problem with a cumulative distribution function on the real line as an initial condition. We call 'probabilistic solution' a weak solution which remains a cumulative distribution function at all times. We prove the uniqueness of such a solution and we deduce the existence from a propagation of chaos result on a system of scalar diffusion processes, the interactions of which only depend on their ranking. We then investigate the long time behaviour of the solution. Using a probabilistic argument and under weak assumptions, we show that the flow of the Wasserstein distance between two solutions is contractive. Under more stringent conditions ensuring the regularity of the probabilistic solutions, we finally derive an explicit formula for the time derivative of the flow and we deduce the convergence of solutions to equilibrium.Comment: Stochastic partial differential equations: analysis and computations (2013) http://dx.doi.org/10.1007/s40072-013-0014-

    Development and evaluation of a diagnostic cytokine-release assay for Mycobacterium suricattae infection in meerkats (Suricata suricatta)

    Get PDF
    CITATION: Clarke, C., et al. 2017. Development and evaluation of a diagnostic cytokine-release assay for mycobacterium suricattae infection in meerkats (Suricata suricatta). BMC Veterinary Research, 13:2, doi:10.1186/s12917-016-0927-x.The original publication is available at http://bmcvetres.biomedcentral.comBackground: Sensitive diagnostic tools are necessary for the detection of Mycobacterium suricattae infection in meerkats (Suricata suricatta) in order to more clearly understand the epidemiology of tuberculosis and the ecological consequences of the disease in this species. We therefore aimed to develop a cytokine release assay to measure antigen-specific cell-mediated immune responses of meerkats. Results: Enzyme-linked immunosorbent assays (ELISAs) were evaluated for the detection of interferon-gamma (IFN-γ) and IFN-γ inducible protein 10 (IP-10) in meerkat plasma. An IP-10 ELISA was selected to measure the release of this cytokine in whole blood in response to Bovigam® PC-HP Stimulating Antigen, a commercial peptide pool of M. bovis antigens. Using this protocol, captive meerkats with no known M. suricattae exposure (n = 10) were tested and results were used to define a diagnostic cut off value (mean plus 2 standard deviations). This IP-10 release assay (IPRA) was then evaluated in free-living meerkats with known M. suricattae exposure, categorized as having either a low, moderate or high risk of infection with this pathogen. In each category, respectively, 24.7%, 27.3% and 82.4% of animals tested IPRA-positive. The odds of an animal testing positive was 14.0 times greater for animals with a high risk of M. suricattae infection compared to animals with a low risk. Conclusion: These results support the use of this assay as a measure of M. suricattae exposure in meerkat populations. Ongoing longitudinal studies aim to evaluate the value of the IPRA as a diagnostic test of M. suricattae infection in individual animals.http://bmcvetres.biomedcentral.com/articles/10.1186/s12917-016-0927-xPublisher's versio

    Diagnosis, pathogenesis and outcome in leucocyte chemotactic factor 2 (ALECT2) amyloidosis

    Get PDF
    Introduction: Renal biopsy series from North America suggest that leucocyte chemotactic factor 2 (ALECT2) amyloid is the third most common type of renal amyloid. We report the first case series from a European Centre of prevalence, clinical presentation and diagnostic findings in ALECT2 amyloidosis and report long-term patient and renal outcomes for the first time. Methods: We studied the clinical features, diagnostic investigations and the outcome of all patients with ALECT2 amyloidosis followed systematically at the UK National Amyloidosis Centre (NAC) between 1994 and 2015. Results: Twenty-four patients, all non-Caucasian, were diagnosed with ALECT2 amyloidosis representing 1.3% of all patients referred to the NAC with biopsy-proved renal amyloid. Diagnosis was made at median age of 62 years, usually from renal histology; immunohistochemical staining was definitive for ALECT2 fibril type. Median estimated glomerular filtration rate (GFR) at diagnosis was 33 mL/min/1.73 m2 and median proteinuria was 0.5 g/24 h. Hepatic amyloid was evident on serum amyloid P component (SAP) scintigraphy in 11/24 cases but was not associated with significant derangement of liver function. No patient had evidence of cardiac amyloidosis or amyloid neuropathy. Median follow-up was 4.8 (range 0.5–15.2) years, during which four patients died and four progressed to end-stage renal disease. The mean rate of GFR loss was 4.2 (range 0.5–9.6) mL/min/year and median estimated renal survival from diagnosis was 8.2 years. Serial SAP scans revealed little or no change in total body amyloid burden. Conclusions: ALECT2 amyloidosis is a relatively benign type of renal amyloid, associated with a slow GFR decline, which is reliably diagnosed on renal histology. Neither the molecular basis nor the factors underlying the apparent restriction of ALECT2 amyloidosis to non-Caucasian populations have been determined

    Insecticide resistance and the future of malaria control in Zambia.

    Get PDF
    BACKGROUND: In line with the Global trend to improve malaria control efforts a major campaign of insecticide treated net distribution was initiated in 1999 and indoor residual spraying with DDT or pyrethroids was reintroduced in 2000 in Zambia. In 2006, these efforts were strengthened by the President's Malaria Initiative. This manuscript reports on the monitoring and evaluation of these activities and the potential impact of emerging insecticide resistance on disease transmission. METHODS: Mosquitoes were captured daily through a series of 108 window exit traps located at 18 sentinel sites. Specimens were identified to species and analyzed for sporozoites. Adult Anopheles mosquitoes were collected resting indoors and larva collected in breeding sites were reared to F1 and F0 generations in the lab and tested for insecticide resistance following the standard WHO susceptibility assay protocol. Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 14 years. RESULTS: A total of 619 Anopheles gambiae s.l. and 228 Anopheles funestus s.l. were captured from window exit traps throughout the period, of which 203 were An. gambiae malaria vectors and 14 An. funestus s.s.. In 2010 resistance to DDT and the pyrethroids deltamethrin, lambda-cyhalothrin and permethrin was detected in both An. gambiae s.s. and An. funestus s.s.. No sporozoites were detected in either species. Prevalence of P. falciparum in the sentinel sites remained below 10% throughout the study period. CONCLUSION: Both An. gambiae s.s. and An. funestus s.s. were controlled effectively with the ITN and IRS programme in Zambia, maintaining a reduced disease transmission and burden. However, the discovery of DDT and pyrethroid resistance in the country threatens the sustainability of the vector control programme

    Green turtles (Chelonia mydas) foraging at Arvoredo Island in Southern Brazil: Genetic characterization and mixed stock analysis through mtDNA control region haplotypes

    Get PDF
    We analyzed mtDNA control region sequences of green turtles (Chelonia mydas) from Arvoredo Island, a foraging ground in southern Brazil, and identified eight haplotypes. Of these, CM-A8 (64%) and CM-A5 (22%) were dominant, the remainder presenting low frequencies (< 5%). Haplotype (h) and nucleotide (π) diversities were 0.5570 ± 0.0697 and 0.0021 ± 0.0016, respectively. Exact tests of differentiation and AMOVA ΦST pairwise values between the study area and eight other Atlantic foraging grounds revealed significant differences in most areas, except Ubatuba and Rocas/Noronha, in Brazil (p > 0.05). Mixed Stock Analysis, incorporating eleven Atlantic and one Mediterranean rookery as possible sources of individuals, indicated Ascension and Aves islands as the main contributing stocks to the Arvoredo aggregation (68.01% and 22.96%, respectively). These results demonstrate the extensive relationships between Arvoredo Island and other Atlantic foraging and breeding areas. Such an understanding provides a framework for establishing adequate management and conservation strategies for this endangered species

    The Precursors and Products of Justice Climates: Group Leader Antecedents and Employee Attitudinal Consequences

    Get PDF
    Drawing on the organizational justice, organizational climate, leadership and personality, and social comparison theory literatures, we develop hypotheses about the effects of leader personality on the development of three types of justice climates (e.g., procedural, interpersonal, and informational), and the moderating effects of these climates on individual level justice- attitude relationships. Largely consistent with the theoretically-derived hypotheses, the results showed that leader (a) agreeableness was positively related to procedural, interpersonal and informational justice climates, (b) conscientiousness was positively related to a procedural justice climate, and (c) neuroticism was negatively related to all three types of justice climates. Further, consistent with social comparison theory, multilevel data analyses revealed that the relationship between individual justice perceptions and job attitudes (e.g., job satisfaction, commitment) was moderated by justice climate such that the relationships were stronger when justice climate was high
    • …
    corecore