2,198 research outputs found
Introduction to high-energy gamma-ray astronomy
The present issue is the first of of a two-volume review devoted to gamma-ray
astronomy above 100 MeV which has witnessed considerable progress over the last
20 years. The motivations for research in this area are explained, the
follow-on articles of these two thematic issues are introduced and a brief
history of the field is given.Comment: 15 pages, 6 figures. Introduction to a two-volume topical issue on
Gamma-ray Astronomy above 100 MeV coordinated by the author
Shell and glass beads from the tombs of Kindoki, Mbanza Nsundi, Lower Congo
The ancient Kingdom of Kongo originated in Central Africa in the 14th century. In the 15th century, the Portuguese organized tight contacts with the Bakongo. From then on European goods gained new significance in the local culture and even found their way into funerary rites. Among the most important grave goods in the Kingdom of Kongo were shell and glass beads. They occur in many tombs and symbolize wealth, status, or femininity. At the burial site of Kindoki, linked with the former capital of Kongo’s Nsundi province, a great number of shell and glass beads were found together with symbols of power in tombs attributed primarily to the first half of the 19th century. Determining the origin of these beads and their use in the Kongo Kingdom leads to interesting insights into the social and economic organization of the old Bakongo society, their beliefs, and the symbolic meaning of the beads
Decidability of Difference Logic over the Reals with Uninterpreted Unary Predicates
First-order logic fragments mixing quantifiers, arithmetic, and uninterpreted
predicates are often undecidable, as is, for instance, Presburger arithmetic
extended with a single uninterpreted unary predicate. In the SMT world,
difference logic is a quite popular fragment of linear arithmetic which is less
expressive than Presburger arithmetic. Difference logic on integers with
uninterpreted unary predicates is known to be decidable, even in the presence
of quantifiers. We here show that (quantified) difference logic on real numbers
with a single uninterpreted unary predicate is undecidable, quite surprisingly.
Moreover, we prove that difference logic on integers, together with order on
reals, combined with uninterpreted unary predicates, remains decidable.Comment: This is the preprint for the submission published in CADE-29. It also
includes an additional detailed proof in the appendix. The Version of Record
of this contribution will be published in CADE-2
Rapport sur la chaîne du livre : mission d\u27audit de modernisation
Le rapport a pour objet d\u27étudier les modalités selon lesquelles est organisée l\u27aide publique à la chaîne du livre au sein du ministère de la Culture, puis d\u27en évaluer l\u27impact et l\u27efficacité, pour rechercher une optimisation des moyens financiers nécessaires à l\u27exercice des missions de l\u27État comme de l\u27organisation y concourant, grâce à des réformes de structures envisagées à moyen terme
Adequacy of child anthropometric indicators for measuring nutritional stress at population level: a study from Niakhar, Senegal
Abstract Objective To compare the responsiveness of different anthropometric indicators for measuring nutritional stress among children in developing countries. Design Growth was studied within 6-month intervals in a rural Senegalese community during one dry and two rainy (hungry) seasons. Responsiveness was defined as the change divided by the standard deviation of each anthropometric indicator. Contrast was defined as the difference in responsiveness between dry and rainy seasons. Setting The study was conducted in Niakhar, a rural area of Senegal under demographic surveillance, with contrasted food and morbidity situations between rainy and dry seasons. Subjects Some 5000 children under 5 years of age were monitored at 6-month intervals in 1983-1984. The present analysis was carried out on a sub-sample of children aged 6-23 months with complete measures, totalling 2803 children-intervals. Results In both univariate and multivariate analysis, mid-upper arm circumference was found to be more responsive to nutritional stress than the commonly used weight-for-height Z-score (contrast = −0·64 for mid-upper arm circumference v. −0·53 for weight-for-height Z-score). Other discriminant indicators were: muscle circumference, weight-for-height, BMI and triceps skinfold. Height, head circumference and subscapular skinfold had no discriminating power for measuring the net effect of nutritional stress during the rainy season. Conclusions The use of mid-upper arm circumference for assessing nutritional stress in community surveys should be considered and preferred to other nutritional indicators. Strict standardization procedures for measuring mid-upper arm circumference are required for optimal us
From selection to cultivation with the support of all stakeholders: first registration in France of two bread wheat varieties after VCU in organic farming system
As bread wheat is the most important cash crops for French organic farmers, the question of the kind of varieties farmers should be using is therefore very important. Most of varieties available were bred for intensive “conventional” farming systems (with high inputs of mineral fertilizers and pesticides), also screening current varieties for organic conditions becomes a necessity to identifiy suitable varieties for organic farming conditions in a short term experiment. After 20 years of selection and screening combined in two different crop management systems, low inputs and organic, two lines, Hendrix and Skerzzo, have been registered in the official catalogue with the special mention « organic farming ». For the second year of seed production, 150 hectares were sown in autumn 2013 to be sell to organic farmers in 2014. This successful process was possible with the support of all the agricultural organic sector associated in the initiative
Connaissance et perceptions du Bas-Canada en France de 1830 à 1842
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal
Risques de décès associés à différents états nutritionnels chez l'enfant d'âge préscolaire
Cette étude à pour but de déterminer le risque de décès associé à différents états nutritionnels chez l'enfant d'âge préscolaire (0-5 ans), au Sénégal, plus précisemment dans la région de Niakhar. Les principales données de l'étude, ainsi que les détails de la méthodologie du travail sur le terrain, sont ainsi rendus disponibles pour l'usage des chercheurs et des responsables de santé publique. (VRL
Geometric Modelling and Deformation for Shape Optimization of Ship Hulls and Appendages
International audienceThe precise control of geometric models plays an important role in many domains such as computer-aided geometric design and numerical simulation. For shape optimization in computational fluid dynamics (CFD), the choice of control parameters and the way to deform a shape are critical.In this article, we describe a skeleton-based representation of shapes adapted for CFD simulation and automatic shape optimization. Instead of using the control points of a classic B-spline representation, we control the geometry in terms of architectural parameters. We assure valid shapeswith a strong shape consistency control. Deformations of the geometry are performed by solving optimization problems on the skeleton. Finally, a surface reconstruction method is proposed to evaluate the shape's performances with CFD solvers. We illustrate the approach on two problems: thefoil of an AC45 racing sail boat and the bulbous bow of a fishing trawler. For each case, we obtained a set of shape deformations and then we evaluated and analyzed the performances of the different shapes with CFD computations
- …