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1.
Prev Vet Med ; 181: 105060, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32540717

RESUMO

Bovine Nodular Thelitis (BNT) is a granulomatous dermatitis of teat skin associated with acid-fast bacilli. A similar condition has been recorded in a dairy goat flock in France recently. The causative agent was shown to be related to the leprosy-causing bacilli Mycobacterium leprae and M. lepromatosis, then sequenced and named M. uberis. Following the initial report in goats, the aim of this study was to investigate new cases of Caprine Nodular Thelitis (CNT) in the same area to confirm the presence of M. uberis by molecular techniques and to get a better description of the clinical signs and of the affected flocks. Twenty-six animals (25 females and 1 male) from 11 flocks were included in the study. Lesions were located on the udder/teat skin (24/25), on the body skin (6/25) or on the scrotum skin (1/1). Udder skin lesions were circular, nodular and/or ulcerate covered with a crust and associated with supramammary lymph node enlargement. Body skin lesions were located at different parts of the body, showed large necrotizing ulcers with undetermined edges and were associated with regional lymph node enlargement. Histopathological results indicated granulomatous dermatitis and lymphadenitis of varying intensity with no acid-fast bacilli seen after Fite-Faraco staining. M. uberis DNA was amplified from 26 samples out of 47 (udder: 11/22; lymph node: 11/20; body: 4/5). The female goats were mostly older than 4 year of age and originated from breeding units characterized by large flock size and high proportion of goat in continuous lactation.


Assuntos
Doenças das Cabras/patologia , Mastite/veterinária , Infecções por Mycobacterium/veterinária , Mycobacterium/isolamento & purificação , Animais , Feminino , Doenças dos Genitais Masculinos/microbiologia , Doenças dos Genitais Masculinos/patologia , Doenças dos Genitais Masculinos/veterinária , Doenças das Cabras/microbiologia , Cabras , Masculino , Mastite/microbiologia , Mastite/patologia , Infecções por Mycobacterium/microbiologia , Infecções por Mycobacterium/patologia , Escroto/patologia
2.
Transbound Emerg Dis ; 64(6): 1771-1781, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27670151

RESUMO

Quick detection and recovery of country's freedom status remain a constant challenge in animal health surveillance. The efficacy and cost efficiency of different surveillance components in proving the absence of infection or (early) detection of bluetongue serotype 8 in cattle populations within different countries (the Netherlands, France, Belgium) using surveillance data from years 2006 and 2007 were investigated using an adapted scenario tree model approach. First, surveillance components (sentinel, yearly cross-sectional and passive clinical reporting) within each country were evaluated in terms of efficacy for substantiating freedom of infection. Yearly cross-sectional survey and passive clinical reporting performed well within each country with sensitivity of detection values ranging around 0.99. The sentinel component had a sensitivity of detection around 0.7. Secondly, how effective the components were for (early) detection of bluetongue serotype 8 and whether syndromic surveillance on reproductive performance, milk production and mortality data available from the Netherlands and Belgium could be of added value were evaluated. Epidemic curves were used to estimate the timeliness of detection. Sensitivity analysis revealed that expected within-herd prevalence and number of herds processed were the most influential parameters for proving freedom and early detection. Looking at the assumed direct costs, although total costs were low for sentinel and passive clinical surveillance components, passive clinical surveillance together with syndromic surveillance (based on reproductive performance data) turned out most cost-efficient for the detection of bluetongue serotype 8. To conclude, for emerging or re-emerging vectorborne disease that behaves such as bluetongue serotype 8, it is recommended to use passive clinical and syndromic surveillance as early detection systems for maximum cost efficiency and sensitivity. Once an infection is detected and eradicated, cross-sectional screening for substantiating freedom of infection and sentinel for monitoring the disease evolution are recommended.


Assuntos
Vírus Bluetongue/imunologia , Bluetongue/epidemiologia , Doenças dos Bovinos/epidemiologia , Leite/metabolismo , Reprodução , Animais , Bélgica/epidemiologia , Bluetongue/economia , Bluetongue/virologia , Vírus Bluetongue/fisiologia , Bovinos , Doenças dos Bovinos/virologia , Custos e Análise de Custo , Estudos Transversais , Diagnóstico Precoce , França/epidemiologia , Liberdade , Países Baixos/epidemiologia , Vigilância de Evento Sentinela/veterinária , Sorogrupo
3.
Rev Sci Instrum ; 86(12): 123702, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26724037

RESUMO

We present a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) one-dimensional sequences and two-dimensional arrays as an effective method for spectral characterization in the spatial frequency domain of a broad variety of metrology instrumentation, including interferometric microscopes, scatterometers, phase shifting Fizeau interferometers, scanning and transmission electron microscopes, and at this time, x-ray microscopes. The inherent power spectral density of BPR gratings and arrays, which has a deterministic white-noise-like character, allows a direct determination of the MTF with a uniform sensitivity over the entire spatial frequency range and field of view of an instrument. We demonstrate the MTF calibration and resolution characterization over the full field of a transmission soft x-ray microscope using a BPR multilayer (ML) test sample with 2.8 nm fundamental layer thickness. We show that beyond providing a direct measurement of the microscope's MTF, tests with the BPRML sample can be used to fine tune the instrument's focal distance. Our results confirm the universality of the method that makes it applicable to a large variety of metrology instrumentation with spatial wavelength bandwidths from a few nanometers to hundreds of millimeters.

4.
Opt Lett ; 39(19): 5645-8, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25360949

RESUMO

This Letter presents the design and experimental results for an on-chip photonic device for laser spectrum monitoring that combines a nanospectrometer and an array of Young's interferometers. The array of Young's interferometers and the spectrometer measure the width and wavelength of a spectrum in visible light, respectively. The accuracy of spectral width measurements is around 10% for FWHM higher than 2.5 pm. The spectrometer-on-chip is based on a digital planar hologram, and provides a resolution around 145 pm within the spectral range of 719-861 nm (142 nm bandwidth). The performance of the device is demonstrated for distinguishing between the single- and two-longitudinal mode operation of a fiber Bragg grating laser diode with 23 pm mode separation.

5.
Prev Vet Med ; 116(1-2): 168-82, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24880624

RESUMO

Farmers' vigilance is essential for the detection of epidemics, including potential emerging diseases, in marine shellfish. A field study was conducted to investigate oyster farmers' reporting practices and behaviour, and to identify factors influencing the reporting process of oyster mortality, with the ultimate aim of improving early detection of unexplained oyster mortality outbreaks. A retrospective case-control study of oyster farmers from Charente-Maritime (France) was designed, based on interviews with 27 non-reporting and 89 reporting farmers, further split into 40 formerly-reporting and 49 currently-reporting farmers. Information about farmer and farm characteristics, farming practices, farm health history and related financial compensation on the farm, knowledge of the mortality reporting system and reporting behaviour was collected. Sampling design was considered in the calculations and farmers' reporting behaviour was modelled using an ordinal logistic regression (continuation-ratio model). Notification procedures were fairly well known among farmers and the reporting system was well accepted overall. Nevertheless, a lack of awareness of the aims of the reporting system was revealed, which contributed to late reporting. Factors identified as driving a farmer's decision to report oyster mortality concerned their lack of awareness of mortality reporting (production type, farm size, location of the production cycle, accessibility of the leasing grounds) and willingness to report (possibility and extent of financial compensation, a feeling of not being involved, whether it was first year of reporting). Overall classification performance of the model built in this study was 64%. In particular, financial compensation for oyster production losses appeared to be a clear incentive for reporting, but was countered by a habituation effect combined with a lack of awareness of the aims of the reporting system: oyster farmers looking for benefits for themselves in reporting, rather than early detection of a disease outbreak. Both economic compensation and the farmers' non-economic values and perceptions should be considered to improve oyster farmers' reporting compliance and sustainability of the reporting system. Education and participatory approaches could help to change these attitudes and thus improve oyster farmers' compliance with reporting duties, resulting in improved early detection of epidemics and emerging or exotic oyster diseases.


Assuntos
Aquicultura/métodos , Atitude , Conscientização , Ostreidae/fisiologia , Percepção , Animais , Aquicultura/normas , Aquicultura/tendências , Estudos de Casos e Controles , França , Humanos , Estudos Retrospectivos , Inquéritos e Questionários
6.
Nanotechnology ; 24(10): 105303, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23416694

RESUMO

A strategy for fabricating nanoimprint templates with sub-10 nm line and 20 nm pitch gratings is demonstrated, by combining electron beam lithography and atomic layer deposition. This is achieved through pitch division using a spacer double-patterning technique. The nanostructures are then replicated using step-and-repeat ultra-violet assisted nanoimprint lithography.

7.
Opt Lett ; 37(4): 695-7, 2012 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-22344151

RESUMO

A novel type of multiband wavelength demultiplexer for on-chip spectroscopy applications is proposed, and first results of the device fabrication and characterization are reported. The devices are based on computer-designed digital planar holograms, which involve millions of lines specifically located and oriented in order to direct output light into designed focal channels according to the wavelength. Devices operate in four individual bandwidths within the visible range (477.2-478.0 nm, 528.8-529.9 nm, 586.4-587.7 nm, 628.9-630.4 nm) with 96 channels and spectral channel spacing down to 0.0375 nm/channel.

8.
Nanotechnology ; 23(1): 015305, 2012 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-22155980

RESUMO

A novel strategy for fabricating nanoimprint templates with sub-10 nm patterns is demonstrated by combining electron beam lithography and atomic layer deposition. Nanostructures are replicated by step-and-repeat nanoimprint lithography and successfully transferred into functional material with high fidelity. The process extends the capacity of step-and-repeat nanoimprint lithography as a single digit nanofabrication method. Using the ALD process for feature shrinkage, we identify a size dependent deposition rate.

9.
Nanotechnology ; 21(44): 445301, 2010 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-20921594

RESUMO

A step and repeat UV nanoimprint lithography process on pre-spin coated resist film is demonstrated for patterning a large area with features sizes down to sub-15 nm. The high fidelity between the template and imprinted structures is verified with a difference in their line edge roughness of less than 0.5 nm (3σ deviation value). The imprinted pattern's residual layer is well controlled to allow direct pattern transfer from the resist into functional materials with very high resolution. The process is suitable for fabricating numerous nanodevices.

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