283 research outputs found
Gaussian stationary processes over graphs, general frame and maximum likelihood identification
In this paper, using spectral theory of Hilbertian operators, we study ARMA
Gaussian processes indexed by graphs. We extend Whittle maximum likelihood
estimation of the parameters for the corresponding spectral density and show
their asymptotic optimality
E. coli K 99+ infection in calves : protective eff ect of smectite
Chez les veaux nouveau-nés, l’infection colibacillaire est responsable de gastro-entérite. Douze heures après l’inoculation d’une souche d’E. coli entéro- toxinogène apparaît la diarrhée puis la déshydratation. L’observation ultra- structurale en microscopic électronique à balayage confirme l’effet pathogène du colibacille qui se manifeste par un allongement des villosités intestinales et une altération des entérocytes. Si les veaux reçoivent en même temps que l’inoculum de la smectite à la dose de 500 m g/kg/4 jours, les signes diarrhéiques sont réduits et sans déshydratation. Ces résultats sont confirmés par les mesures de concentrations plasma- tiques des ions Na+, K+, et de l’acide lactique. Par ailleurs, d’un point de vue ultrastructural, les villosités intestinales gardent un aspect normal. En conclusion, la smectite, argile colloïdale, par ses propriétés d’adsorp- tion du colibacille et ses effets sur le mucus protège la muqueuse iléale des effets pathogènes des colibacilles entérotoxinogènes.Nouvelles de nos Organisation
A New syndrome of the charolais neonatal calf : paralysis in gastroenteritis
Un nouveau syndrome diarrhéique associé à des symptômes nerveux généraux et locomoteurs a été identifié en Charoláis chez des veaux de moins de deux semaines d’âge. Il présente des analogies avec une maladie congénitale liée à un trouble du métabolisme des aminoacides ramifiés mais le rôle plus probable de colibacilles produisant des cytotoxines neu rotoxiques est à confirmer.A new diarrheic syndrome associated with general and locomotor nervous symptoms has been identified in the charoláis area in calves under 2 weeks of age. This condition presents some similarities to a congenital disease related to impaired branched-aminoacid metabolism, but the more probable involvment of neurotoxic cytotoxin-producing E. Coli bacteria remains to be confirmed
A Kriging procedure for processes indexed by graphs
International audienceWe provide a new kriging procedure of processes on graphs. Based on the construction of Gaussian random processes indexed by graphs, we extend to this framework the usual linear prediction method for spatial random fields, known as kriging. We provide the expression of the estimator of such a random field at unobserved locations as well as a control for the prediction error
Recherche par une technique d'hémagglutination passive des traces sérologiques des principaux virus respiratoires des bovins et de Chlamydia psittaci dans un échantillon de la population des bovidés du Togo
D'après les résultats obtenus par la technique d'hémagglutination passive, le principal virus respiratoire des bovins du Togo est celui de la rhinotrachéite infectieuse bovine. Les autres virus et Chlamydia psittaci semblent avoir moins d'importanc
The role of pasteurella spp and of Mycoplasma bovis in respiratory diseases in young cattle
Lors des essais terrains d’un traitement antibiotique chez des veaux d’éle vage atteints de maladies respiratoires, la flore trachéobronchique a été inven toriée à différentes périodes : à l’arrivée, avant traitement et après guérison. Le rôle de l’association synergique Mycoplasma bovis - Pasteurella haemoly- tica Al apparaît clairement. Les conditions d’élevage et la participation de certains virus (RSV) sont encore des éléments importants de la pathogénèse et du pronostic des bronchopneumonies infectieuses enzootiques.When we tried an antibiotic treatment on clinical trials on weaner calves with respiratory diseases, tracheobronchial flora was examined at different moments : on the day of the arrival, before treatment and after recovery. The role of the synergistic association of Mycoplasma bovis / Pasteurella haemo- lytica A1 in the development of troubles appears to be confirmed. Bad breeding conditions and the participation of a virus (RSV) are important components of pathogenesis and prognosis of bovine Endemic Infectious Broncho pneumonia
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A feasibility randomised controlled trial of a motivational interviewing-based intervention for weight loss maintenance in adults
Background
Obesity has significant health and NHS cost implications. Relatively small reductions in weight have clinically important benefits, but long-term weight loss maintenance (WLM) is challenging. Behaviour change interventions have been identified as key for WLM. Motivation is crucial to supporting behaviour change, and motivational interviewing (MI) has been identified as a successful approach to changing health behaviours. The study was designed as an adequately powered, pragmatic randomised controlled trial (RCT); however, owing to recruitment issues, the study became a feasibility trial.
Objectives
To assess recruitment, retention, feasibility, acceptability, compliance and delivery of a 12-month intervention to support WLM. Secondary objectives were to assess the impact of the intervention on body mass index (BMI) and other secondary outcomes.
Design
Three-arm individually randomised controlled trial comprising an intensive arm, a less intensive arm and a control arm.
Setting
Community setting in South Wales and the East Midlands.
Participants
Individuals aged 18�70 years with a current or previous BMI of ??30 kg/m2 who could provide evidence of at least 5% weight loss during the previous 12 months.
Intervention
Participants received individually tailored MI, which included planning and self-monitoring. The intensive arm received six face-to-face sessions followed by nine telephone sessions. The less intensive arm received two face-to-face sessions followed by two telephone sessions. The control arm received a leaflet advising them on healthy lifestyle.
Main outcome measures
Feasibility outcomes included numbers recruited, retention and adherence. The primary effectiveness outcome was BMI at 12 months post randomisation. Secondary outcomes included waist circumference, waist-to-hip ratio, physical activity, proportion maintaining weight loss, diet, quality of life, health service resource usage, binge eating and well-being. A process evaluation assessed intervention delivery, adherence, and participants� and practitioners� views. Economic analysis aimed to assess cost-effectiveness in terms of quality-adjusted life-years (QALYs).
Results
A total of 170 participants were randomised. Retention was good (84%) and adherence was excellent (intensive, 83%; less intensive, 91%). The between-group difference in mean BMI indicated the intensive arm had BMIs 1.0?kg/m2 lower than the controls [95% confidence interval (CI) �2.2 kg/m2 to 0.2?kg/m2]. Similarly, a potential difference was found in weight (average difference of 2.8?kg, 95% CI �6.1 kg to 0.5?kg). The intensive arm had odds of maintaining on average 43% [odds ratio(OR) 1.4, 95% CI 0.6 to 3.5] higher than controls. None of these findings were statistically significant. Further analyses controlling for level of adherence indicated that average BMI was 1.2?kg/m2 lower in the intensive arm than the control arm (95% CI �2.5?kg/m2 to 0.0?kg/m2). The intensive intervention led to a statistically significant difference in weight (mean �3.7?kg, 95% CI �7.1?kg to �0.3?kg). The other secondary outcomes showed limited evidence of differences between groups. The intervention was delivered as planned, and both practitioners and participants were positive about the intervention and its impact. Although not powered to assess cost-effectiveness, results of this feasibility study suggest that neither intervention as currently delivered is likely to be cost-effective in routine practice.
Conclusion
This is the first trial of an intervention for WLM in the UK, the intervention is feasible and acceptable, and retention and adherence were high. The main effectiveness outcome showed a promising mean difference in the intensive arm. Owing to the small sample size, we are limited in the conclusions we can draw. However, findings suggest that the intensive intervention may facilitate long-term weight maintenance and, therefore, further testing in an effectiveness trial may be indicated. Research examining WLM is in its infancy, further research is needed to develop our understanding of WLM and to expand theory to inform the development of interventions to be tested in rigorously designed RCTs with cost-effectiveness assessed
SPIRIT and CONSORT extensions for early phase dose-finding clinical trials:the DEFINE (DosE FIndiNg Extensions) study protocol
Introduction Early phase dose-finding (EPDF) studies are critical for the development of new treatments, directly influencing whether compounds or interventions can be investigated in further trials to confirm their safety and efficacy. There exists guidance for clinical trial protocols and reporting of completed trials in the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2013 and CONsolidated Standards Of Reporting Randomised Trials (CONSORT) 2010 statements. However, neither the original statements nor their extensions adequately cover the specific features of EPDF trials. The DEFINE (DosE-FIndiNg Extensions) study aims to enhance transparency, completeness, reproducibility and interpretation of EPDF trial protocols (SPIRIT-DEFINE) and their reports once completed (CONSORT-DEFINE), across all disease areas, building on the original SPIRIT 2013 and CONSORT 2010 statements.
Methods and analysis A methodological review of published EPDF trials will be conducted to identify features and deficiencies in reporting and inform the initial generation of the candidate items. The early draft checklists will be enriched through a review of published and grey literature, real-world examples analysis, citation and reference searches and consultation with international experts, including regulators and journal editors. Development of CONSORT-DEFINE commenced in March 2021, followed by SPIRIT-DEFINE from January 2022. A modified Delphi process, involving worldwide, multidisciplinary and cross-sector key stakeholders, will be run to refine the checklists. An international consensus meeting in autumn 2022 will finalise the list of items to be included in both guidance extensions.
Ethics and dissemination This project was approved by ICR’s Committee for Clinical Research. The Health Research Authority confirmed Research Ethics Approval is not required. The dissemination strategy aims to maximise guideline awareness and uptake, including but not limited to dissemination in stakeholder meetings, conferences, peer-reviewed publications and on the EQUATOR Network and DEFINE study websites
Time-dependent visibility modelling of a relativistic jet in the X-ray binary MAXI J1803-298
Tracking the motions of transient jets launched by low-mass X-ray binaries
(LMXBs) is critical for determining the moment of jet ejection, and identifying
any corresponding signatures in the accretion flow. However, these jets are
often highly variable and can travel across the resolution element of an image
within a single observation, violating a fundamental assumption of aperture
synthesis. We present a novel approach in which we directly fit a single
time-dependent model to the full set of interferometer visibilities, where we
explicitly parameterise the motion and flux density variability of the emission
components, to minimise the number of free parameters in the fit, while
leveraging information from the full observation. This technique allows us to
detect and characterize faint, fast-moving sources, for which the standard time
binning technique is inadequate. We validate our technique with synthetic
observations, before applying it to three Very Long Baseline Array (VLBA)
observations of the black hole candidate LMXB MAXI J1803-298 during its 2021
outburst. We measured the proper motion of a discrete jet component to be
mas/hr, and thus we infer an ejection date of MJD
, which occurs just after the peak of a radio flare
observed by the Australia Telescope Compact Array (ATCA) and the Atacama Large
Millimeter/Sub-Millimeter Array (ALMA), while MAXI J1803-298 was in the
intermediate state. Further development of these new VLBI analysis techniques
will lead to more precise measurements of jet ejection dates, which, combined
with dense, simultaneous multi-wavelength monitoring, will allow for clearer
identification of jet ejection signatures in the accretion flow.Comment: 15 pages, 9 figures, 4 tables; Accepted for publication in MNRA
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