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1.
J Agric Biol Environ Stat ; 26(4): 604-611, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34335011

RESUMEN

We discuss the methods and results of the RESSTE team in the competition on spatial statistics for large datasets. In the first sub-competition, we implemented block approaches both for the estimation of the covariance parameters and for prediction using ordinary kriging. In the second sub-competition, a two-stage procedure was adopted. In the first stage, the marginal distribution is estimated neglecting spatial dependence, either according to the flexible Tuckey g and h distribution or nonparametrically. In the second stage, estimation of the covariance parameters and prediction are performed using Kriging. Vecchias's approximation implemented in the GpGp package proved to be very efficient. We then make some propositions for future competitions. SUPPLEMENTARY INFORMATION: The online version supplementary material available at 10.1007/s13253-021-00462-2.

2.
PLoS One ; 15(9): e0238410, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32915815

RESUMEN

Discrepancies in population structures, decision making, health systems and numerous other factors result in various COVID-19-mortality dynamics at country scale, and make the forecast of deaths in a country under focus challenging. However, mortality dynamics of countries that are ahead of time implicitly include these factors and can be used as real-life competing predicting models. We precisely propose such a data-driven approach implemented in a publicly available web app timely providing mortality curves comparisons and real-time short-term forecasts for about 100 countries. Here, the approach is applied to compare the mortality trajectories of second-line and front-line European countries facing the COVID-19 epidemic wave. Using data up to mid-April, we show that the second-line countries generally followed relatively mild mortality curves rather than fast and severe ones. Thus, the continuation, after mid-April, of the COVID-19 wave across Europe was likely to be mitigated and not as strong as it was in most of the front-line countries first impacted by the wave (this prediction is corroborated by posterior data).


Asunto(s)
Infecciones por Coronavirus/mortalidad , Modelos Teóricos , Neumonía Viral/mortalidad , COVID-19 , Infecciones por Coronavirus/epidemiología , Humanos , Pandemias , Neumonía Viral/epidemiología
3.
Glob Chang Biol ; 23(12): 5092-5107, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28580624

RESUMEN

Damage due to wind-storms and droughts is increasing in many temperate forests, yet little is known about the long-term roles of these key climatic factors in forest dynamics and in the carbon budget. The objective of this study was to estimate individual and coupled effects of droughts and wind-storms on adult tree mortality across a 31-year period in 115 managed, mixed coniferous forest stands from the Western Alps and the Jura mountains. For each stand, yearly mortality was inferred from management records, yearly drought from interpolated fields of monthly temperature, precipitation and soil water holding capacity, and wind-storms from interpolated fields of daily maximum wind speed. We performed a thorough model selection based on a leave-one-out cross-validation of the time series. We compared different critical wind speeds (CWSs) for damage, wind-storm, and stand variables and statistical models. We found that a model including stand characteristics, drought, and storm strength using a CWS of 25 ms-1 performed the best across most stands. Using this best model, we found that drought increased damage risk only in the most southerly forests, and its effect is generally maintained for up to 2 years. Storm strength increased damage risk in all forests in a relatively uniform way. In some stands, we found positive interaction between drought and storm strength most likely because drought weakens trees, and they became more prone to stem breakage under wind-loading. In other stands, we found negative interaction between drought and storm strength, where excessive rain likely leads to soil water saturation making trees more susceptible to overturning in a wind-storm. Our results stress that temporal data are essential to make valid inferences about ecological impacts of disturbance events, and that making inferences about disturbance agents separately can be of limited validity. Under projected future climatic conditions, the direction and strength of these ecological interactions could also change.


Asunto(s)
Sequías , Árboles , Viento , Bosques , Francia , Lluvia , Suelo , Suiza , Temperatura , Agua
4.
Plant Methods ; 13: 38, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28529535

RESUMEN

BACKGROUND: Plant density and its non-uniformity drive the competition among plants as well as with weeds. They need thus to be estimated with small uncertainties accuracy. An optimal sampling method is proposed to estimate the plant density in wheat crops from plant counting and reach a given precision. RESULTS: Three experiments were conducted in 2014 resulting in 14 plots across varied sowing density, cultivars and environmental conditions. The coordinates of the plants along the row were measured over RGB high resolution images taken from the ground level. Results show that the spacing between consecutive plants along the row direction are independent and follow a gamma distribution under the varied conditions experienced. A gamma count model was then derived to define the optimal sample size required to estimate plant density for a given precision. Results suggest that measuring the length of segments containing 90 plants will achieve a precision better than 10%, independently from the plant density. This approach appears more efficient than the usual method based on fixed length segments where the number of plants are counted: the optimal length for a given precision on the density estimation will depend on the actual plant density. The gamma count model parameters may also be used to quantify the heterogeneity of plant spacing along the row by exploiting the variability between replicated samples. Results show that to achieve a 10% precision on the estimates of the 2 parameters of the gamma model, 200 elementary samples corresponding to the spacing between 2 consecutive plants should be measured. CONCLUSIONS: This method provides an optimal sampling strategy to estimate the plant density and quantify the plant spacing heterogeneity along the row.

5.
S Afr Med J ; 101(3): 189-94, 2011 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-21382251

RESUMEN

INTRODUCTION: Trauma is a well-known leading cause of unnatural death and disability in South Africa. Internationally the trend is moving toward systematised care. AIM: To revise the Trauma Centre Criteria of the Trauma Society of South Africa and align these with the terminology and modern scope of emergency care practice, using best-care principles as a prelude to the development of trauma systems in South Africa. METHODOLOGY: Revision of existing documents of the Trauma Society of South Africa, the Emergency Medicine Society of South Africa and the Critical Care Society of Southern Africa, where these are relevant to the care of trauma. The committee attempted to harmonise these criteria with the goals of the World Health Organization essential trauma care guidelines for trauma centres and trauma systems. Wide expert consultation was undertaken to refine the criteria before final compilation. RESULTS AND RECOMMENDATIONS: Four levels of trauma care facility are outlined, with the criteria focusing on the trauma-specific requirements of the facilities and their place in the greater trauma system. Accreditation of hospitals according to the criteria will allow for appropriate transfer and designation of patient destination for trauma patients and will improve the quality of care provided. The criteria address structural, process and human resource requirements and medical aspects for the accreditation of various level of trauma centre. CONCLUSION: There is a great opportunity to apply best practice criteria to improve the care of trauma in South Africa and improve patient outcome.


Asunto(s)
Centros Traumatológicos/normas , Hospitales Comunitarios , Humanos , Atención Primaria de Salud , Garantía de la Calidad de Atención de Salud , Sudáfrica , Centros Traumatológicos/clasificación , Servicios Urbanos de Salud
6.
Rev Med Suisse ; 4(167): 1754-6, 1758, 2008 Aug 20.
Artículo en Francés | MEDLINE | ID: mdl-18800753

RESUMEN

Surgery of trauma adds an insult which is proportional to the duration of the operative treatment. The aim of DCS is to prevent the onset of the fatal triad stopping the major bleeder. Treating the contamination, it also makes the Multiple Organ Deficiency Syndrome less likely. DCS requests specific surgical skills. The best results are obtained when an abbreviated surgery is performed in collaboration with the intensive care. The non trauma surgical specialties should be involved in the reconstruction surgery. Courses are dedicated to the decision making and to these specific DCS procedures. They should be more widely implemented in Europe. They could be an asset for centers dealing with major trauma.


Asunto(s)
Traumatismo Múltiple/cirugía , Humanos , Procedimientos Quirúrgicos Operativos/métodos
7.
J Biol Chem ; 279(20): 21206-16, 2004 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-15014077

RESUMEN

The fetoprotein transcription factor (FTF) gene was inactivated in the mouse, with a lacZ gene inserted inframe into exon 4. LacZ staining of FTF+/- embryos shows that the mFTF gene is activated at initial stages of zygotic transcription. FTF gene activity is ubiquitous at the morula and blastocyst stages and then follows expression patterns indicative of multiple FTF functions in fetal development. FTF-/- embryos die at E6.5-7.5, with features typical of visceral endoderm dysfunction. Adult FTF+/- mice are hypocholesterolemic, and express liver FTF at about 40% of the normal level. Overexpression of liver FTF in transgenic mice indicates in vivo that FTF is an activator of CYP7A1. However, CYP7A1 expression is increased in FTF+/- liver. Gene expression profiles indicate that higher CYP7A1 expression is caused by attenuated liver cell stress signaling. Diet experiments support a model where FTF is quenched both by activated c-Jun, and by SHP as a stronger feedback mechanism to repress CYP7A1. A DR4 element is conserved in the FTF gene promoter and activated by LXR-RXR and TR-RXR, qualifying the FTF gene as a direct metabolic sensor. Liver FTF increases in rats treated with thyroid hormone or a high cholesterol diet. The FTF DR4 element tightens functional links between FTF and LXRalpha in cholesterol homeostasis and can explain transient surges of FTF gene activities during development and FTF levels lower than predicted in FTF+/- liver. The FTF-lacZ mouse establishes a central role for FTF in developmental, nutritive, and metabolic functions from early embryogenesis through adulthood.


Asunto(s)
Proteínas de Unión al ADN/genética , Desarrollo Embrionario y Fetal/genética , Regulación del Desarrollo de la Expresión Génica/genética , Factores de Transcripción/genética , Envejecimiento/genética , Animales , Secuencia de Bases , Colesterol/metabolismo , Cartilla de ADN , Proteínas de Unión al ADN/deficiencia , Muerte Fetal/genética , Eliminación de Gen , Genes Esenciales , Homeostasis , Hígado/embriología , Hígado/fisiología , Ratones , Ratones Noqueados , Ratones Transgénicos , Reacción en Cadena de la Polimerasa , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF , Receptores del Factor de Necrosis Tumoral/genética , Células Madre/fisiología , Factores de Transcripción/deficiencia , beta-Galactosidasa/genética
8.
Can Vet J ; 43(5): 349-54, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12001500

RESUMEN

Vaccination of susceptible animals against foot-and-mouth disease (FMD) is a well established strategy for helping to combat the disease. Traditionally, FMD vaccine has been used to control a disease incursion in countries where the disease has been endemic rather than in countries considered free of the disease. In 2001, the use of vaccine was considered but not implemented in the United Kingdom (1), whereas vaccine was used to help to control FMD in The Netherlands (2,3). Canadian contingency plans provide for the use of vaccine; Canada is a member of the North American Foot-and-Mouth Disease Vaccine Bank, which could supply vaccine if needed. This article explains why Canada might use FMD vaccine to combat an outbreak and the factors that are relevant to the disposal of vaccinated animals and their products. It concludes that vaccination is an important mechanism in Canada's preparedness for an outbreak of FMD and that products from vaccinated animals are safe for human consumption.


Asunto(s)
Enfermedades de los Bovinos/prevención & control , Virus de la Fiebre Aftosa/inmunología , Fiebre Aftosa/prevención & control , Vacunación/veterinaria , Vacunas Virales , Animales , Canadá , Bovinos , Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/virología , Seguridad de Productos para el Consumidor , Brotes de Enfermedades/prevención & control , Brotes de Enfermedades/veterinaria , Fiebre Aftosa/inmunología , Fiebre Aftosa/virología , Virus de la Fiebre Aftosa/patogenicidad , Humanos , Legislación Veterinaria , Carne/normas , Zoonosis
9.
Can J Infect Dis ; 13(3): 185-90, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-18159390

RESUMEN

Food safety is growing in importance as a public health concern for health practitioners and the general public. The Canadian public is exposed more extensively than ever before to exotic foods and pathogens via international travel, changing lifestyles and domestic contact with fresh foodstuff that is imported from faraway lands. Global warming, changing microbial ecology and resistance, and reduced host immunity are also having their effect in increasing the risk. To manage the risk adequately, interventions must be implemented at every point of the food supply chain, from production and processing to distribution, preparation and consumption, at home and in retail food service establishments. The role of government is explained, and the roles of other stakeholders, including physicians, are reviewed briefly.

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