Search results for "difference"
showing 10 items of 1534 documents
Continuous optimal control sensitivity analysis with AD
2000
In order to apply a parametric method to a minimum time control problem in celestial mechanics, a sensitivity analysis is performed. The analysis is continuous in the sense that it is done in the infinite dimensional control setting. The resulting sufficient second order condition is evaluated by means of automatic differentiation, while the associated sensitivity derivative is computed by continuous reverse differentiation. The numerical results are given for several examples of orbit transfer, also illustrating the advantages of automatic differentiation over finite differences for the computation of gradients on the discretized problem.
Timing and patterns of ENSO impacts in Africa over the last 30 years: insights from Normalized Difference Vegetation Index data.
2012
International audience; In this study we reassess and provide a more complete picture of the timing and patterns of ENSO impacts for the whole of Africa over the three last decades. We analyse the vegetation photosynthetic activity estimated by the NOAA-AVHRR Normalized Difference Vegetation Index (NDVI) rather than rainfall itself, because NDVI allows us to document the impacts at fine space and time scales. The use of the monthly time-step adds important new insights to the findings of previous works based largely on annual or seasonal time-scales and on a regional spatial-scale: several dipolar and propagative patterns are highlighted. In addition, we show that the less-studied winter ra…
Sex-specific transgenerational effects of early developmental conditions in a passerine.
2007
Most studies dealing with the trade-off between offspring number and quality have overlooked the long-term consequences for the progeny. High investment in offspring number usually results in an increased competition among nest mates. The deterioration of the early developmental conditions, due to this increased competition, can impair individual quality over the long term, and subsequently affect survival and lifetime fecundity. Moreover, the consequences of the allocation rule to offspring number vs. quality can extend across generations and give raise to grandparental effects. These transgenerational trade-offs have been explored rarely. In the present study, we manipulated the breeding …
Gender differences for escorting children among dual earners families in the Paris Region
2012
International audience
Contribution of the Temporal Dominance of Sensations (TDS) method to the sensory description of subtle differences in partially dealcoholized red win…
2007
ln this study, effect of partial alcohol reductio.n on the sensory modification of red wines was investigated. Preliminary triangle tests indicated the existencèof very slight differences between the dealcoholized wines of the study. Therefore, adapted descriptive methodologies had ta be used. ln addition to a comparative sensory profile, the Temporal Dominance of Sensations (TDS) method was chosen. Both types of profiles will be linked ta consumer preferences. A Merlat and a Syrah wine were partially dealcoholized using reverse osmosis technique to span a range of four different alcohol contents (14 % to 10 %) by grape variety. ln a first step, the four wines of each variety were compared …
Difference testing: Methods and appropriate use
2010
National audience; Difference tests are some of the most common methods employed in sensory evaluation of food and beverages. The objective of difference tests is basically to determine whether a difference exists between two products. There are many different types of test, such as the duo-trio test, the triangle test, the same-different test and the A-not A test. These tests, with their strengths and weaknesses, will be presented briefly during the talk. Whatever the test employed, some basic principles must be respected, e.g. sample coding with three digit numbers, and sample presentation in a balanced order. In some instances the tests must be restricted to one sensory modality. In such…
Participation and performance trends in multistage ultramarathons--the 'Marathon des Sables' 2003-2012
2012
International audience; BackgroundThe purpose of this study was to investigate participation and performance changes in the multistage ultramarathon 'Marathon des Sables' from 2003 to 2012.MethodsParticipation and performance trends in the four- or six-stage running event covering approximately 250 km were analyzed with special emphasis on the nationality and age of the athletes. The relations between gender, age, and nationality of finishers and performance were investigated using regression analyses and analysis of variance.ResultsBetween 2003 and 2012, a number of 7,275 athletes with 938 women (12.9%) and 6,337 men (87.1%) finished the Marathon des Sables. The finisher rate in both women…
Plasma omega 3 polyunsaturated fatty acids and macular pigment optical density in subjects at high risk for age-related macular degeneration: the Lim…
2016
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.; Purpose: In numerous epidemiological studies, omega 3 polyunsaturated fatty acids (PUFAs) have been associated with a decreased risk of age-related macular degeneration (AMD). Beyond their structural, functional and neuroprotective roles, omega 3 PUFAs may favor the retinal accumulation of lutein and zeaxanthin and thus increase macular pigment optical density (MPOD). We examined the associations of MPOD with plasma omega 3 PUFAs in subjects with at least one parent affected by neovascular AMD. Methods: The Limpia study is a double-blind, placebo controlled, prospective randomize…
Determination of taste-active compounds of a bitter camembert cheese by omission tests
2001
The taste-active compounds of a Camembert cheese selected for its intense bitterness defect were investigated. The water-soluble fraction (WSE) was extracted with pure water and fractionated by successive tangential ultrafiltrations and nanofiltration. The physicochemical assessment of these fractions led to the construction of a model WSE which was compared by sensory evaluation to the crude water-soluble extract, using a panel of 16 trained tasters. As no significant difference was perceived, this model WSE was then used directly or mixed with other cheese components for omission tests. Among the main taste characteristics of the WSE (salty, sour, umami and bitter), bitterness was found t…
Taste receptors to L-glutamate
2007
National audience