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Intragroup variation in human cranial samples is much less well understood than intergroup variation. The aims of this study were to develop a flexible and assumption-free approach for detailed explorations and comparisons of intragroup metric variation in any number of samples and to create user-friendly software for these purposes. We revisited the classic study design based on a comparison between the samples from Berg, Zalavar and Oslo from the W.W. Howells craniometric data set. Fourteen mid-facial dimensions were chosen for the analysis. "WorldPCA" software was employed for most of the analyses. This software implements a number of analytical functions aimed at exploring the results of principal component analysis. Our results confirm that the male sample from Berg displays a higher degree of variation. The cluster analyses have shown that intragroup variation in the three samples is mainly of a continuous nature. Arguably, the tendency to separate into distinct clusters is more pronounced in the samples from Oslo and Berg than from Zalavar. Some male individuals from Zalavar display distinct craniofacial features similar to those found in a South Siberian sample. Potential applications of these techniques and software are not restricted to cranial measurements but can be used for exploring any type of continuously varying data. No assumptions about the nature of the data should be made, and any number of samples can be compared simultaneously. La variation intragroupe dans les échantillons crâniens humains est beaucoup moins bien comprise que la variation intergroupe. Cette étude avait pour objectif de développer une approche flexible et sans hypothèse pour l’exploration détaillée et la comparaison de la variation métrique intragroupe dans n’importe quel nombre d’échantillons et de créer un logiciel convivial à ces fins. Nous avons revisité le plan d’étude classique basé sur la comparaison entre les échantillons de Berg, Zalavar et Oslo de l’ensemble de données craniométriques de W.W. Howells. Quatorze dimensions du milieu du visage ont été choisies pour l’analyse. Le logiciel "WorldPCA" a été utilisé pour la plupart des analyses. Le logiciel met en œuvre un certain nombre de fonctions analytiques visant à explorer les résultats de l’analyse en composantes principales. Nos résultats ont confirmé que l’échantillon masculin de Berg présente un niveau de variation accru. Les analyses de grappes ont montré que la variation intragroupe dans les trois échantillons est principalement de nature continue. Nous pouvons dire que la tendance à se séparer en groupes distincts est plus prononcée dans les échantillons d’Oslo et de Berg que de Zalavar. Certains individus masculins de Zalavar présentent des caractéristiques craniofaciales distinctes, similaires à celles trouvées dans un échantillon du sud de la Sibérie. Les applications potentielles de ces techniques et logiciels ne se limitent pas aux mesures crâniennes mais peuvent être utilisées pour explorer tout type de données à variation continue. Aucune hypothèse sur la nature des données ne doit être faite, et n’importe quel nombre d’échantillons peut être comparé simultanément.

Objectives Noise emissions from wind turbines are one of multiple wind turbine features capable of generating annoyance that ranges in magnitude from not at all annoyed to extremely annoyed. No analysis to date can simultaneously reflect the change in all magnitudes of annoyance toward multiple wind turbine features. The primary objective in this study was to use principal component analysis (PCA) to provide a single construct for overall annoyance to wind turbines based on reactions to noise, blinking lights, shadow flicker, visual impacts, and vibrations evaluated as a function of proximity to wind turbines. Methods The analysis was based on data originally collected as part of Health Canada’s cross-sectional Community Noise & Health Study (CNHS). One adult participant (18–79 years), randomly selected from dwellings in Ontario (ON) (n = 1011) and Prince Edward Island (PEI) (n = 227), completed an in-person questionnaire. Content relevant to the current analysis included the annoyance responses to wind turbines. Results The first construct tested in the PCA explained 58–69% of the variability in total annoyance. Reduced distance to turbines was associated with elevated aggregate annoyance scores among ON and PEI participants. In the ON sample, aggregate annoyance was effectively absent in areas beyond 5 km (mean 0.12; 95% CI 0.00, 1.19), increasing significantly between (2 and 5] km (mean 2.13; 95% CI 0.92, 3.33), remaining elevated, but with no further increase until (0.550–1] km (mean 3.37; 95% CI 3.02, 3.72). At ≤ 0.550 km, the average overall annoyance was 3.36 (95% CI 2.03, 4.69). In PEI, aggregate annoyance was essentially absent beyond 1 km; i.e., (1–2] km (mean 0.21; 95% CI 0.00, 0.88); (2–5] km (mean 0.00; 95% CI 0.00, 1.37); > 5 km (mean 0.00; 95% CI 0.00, 1.58). Annoyance significantly increased in areas between (0.550 and 1] km (mean 1.59; 95% CI 1.02, 2.15) and was highest within 550 m (mean 4.25; 95% CI 3.34, 5.16). Conclusion The advantages and disadvantages to an aggregated annoyance analysis, including how it should not yet be considered a substitute for relationships based on changes in high annoyance, are discussed. Electronic supplementary material The online version of this article (10.17269/s41997-018-0040-y) contains supplementary material, which is available to authorized users.

Quantifying and mapping ecosystem services (ES), their indicators and their relationships is of crucial importance for environmental management. In this article, we analyze the spatial distribution of multiple-ES indicators at three locations on the pioneer fronts of the Brazilian Amazon. We identify trade-offs and synergies between six ES indicators for soil, vegetation and biodiversity characterization. We also propose spatial representations of multiple-ES indicators (vegetation carbon stocks, rates of water infiltration into soil, soil chemical quality, soil carbon stocks, biodiversity and richness in Sphingidae). Finally, we discuss three different methods to map them depending on the goals of the maps, arguing that maps lean on objective-oriented approaches. The study is based on remote sensing and sampling data from 135 sampling points. We created multiple-ES indicators maps based on Principal Component Analysis (PCA), a score of ES richness, and discrimination of land cover units. PCA is an appropriate tool for showing high correlations between indicators, nevertheless has notable limitations for visual communication. The scoring method may help mapping ES hotspots, however it fails to consider relationships among them. The land-cover-based method has the advantage of being simple and easy to interpret, still it may not consider important indicators not related to land-cover changes. We discuss the interests and limitations of these different ways to map multiple-ES indicators, regarding the final goals of the maps.

Body condition is an indirect estimation of the level of body reserves, and its variation reflects cumulative variation in energy balance. It interacts with reproductive and health performance, which are important to consider in dairy production but not easy to monitor. The commonly used body condition score (BCS) is time consuming, subjective, and not very sensitive. The aim was therefore to develop and validate a method assessing BCS with 3-dimensional (3D) surfaces of the cow's rear. A camera captured 3D shapes 2 m from the floor in a weigh station at the milking parlor exit. The BCS was scored by 3 experts on the same day as 3D imaging. Four anatomical landmarks had to be identified manually on each 3D surface to define a space centered on the cow's rear. A set of 57 3D surfaces from 56 Holstein dairy cows was selected to cover a large BCS range (from 0.5 to 4.75 on a 0 to 5 scale) to calibrate 3D surfaces on BCS. After performing a principal component analysis on this data set, multiple linear regression was fitted on the coordinates of these surfaces in the principal components' space to assess BCS. The validation was performed on 2 external data sets: one with cows used for calibration, but at a different lactation stage, and one with cows not used for calibration. Additionally, 6 cows were scanned once and their surfaces processed 8 times each for repeatability and then these cows were scanned 8 times each the same day for reproducibility. The selected model showed perfect calibration and a good but weaker validation (root mean square error = 0.31 for the data set with cows used for calibration; 0.32 for the data set with cows not used for calibration). Assessing BCS with 3D surfaces was 3 times more repeatable (standard error = 0.075 versus 0.210 for BCS) and 2.8 times more reproducible than manually scored BCS (standard error = 0.103 versus 0.280 for BCS). The prediction error was similar for both validation data sets, indicating that the method is not less efficient for cows not used for calibration. The major part of reproducibility error incorporates repeatability error. An automation of the anatomical landmarks identification is required, first to allow broadband measures of body condition and second to improve repeatability and consequently reproducibility. Assessing BCS using 3D imaging coupled with principal component analysis appears to be a very promising means of improving precision and feasibility of this trait measurement.

Trout farming is the main fish production system in France. This article describes a system to classify trout farms based on environmental impacts calculated by life cycle assessment and technical and economic indicators. Since the number of surveyed farms was too small for a robust assessment, we combined principal component analysis (PCA) with a non-parametric bootstrap technique. French trout farms were surveyed to collect technical and economic indicators. The representativeness of the survey was verified by comparing it to a national inventory. Life cycle assessment was used to estimate environmental impacts of farms and the contribution of each production stage to impacts. PCA was used to evaluate both technical-economic and environmental indicators of the trout farms, which were separated into three groups based on the size of fish produced (pan-size, large and mixed-size, and very large). Non-parametric bootstrap was used to compare the groups and to test the significance of PCA results. Results validated the fish-farm classification system based on the size of fish produced and indicated that farm operations and fish feeding contributed the most to environmental impacts. The PCA method distinguished three groups via their technical indicators, with non-significant differences among the groups in environmental impacts. However, environmental indicators showed strong links with technical and economic indicators. In conclusion, bootstrapped PCA offers the ability to assess groups of trout production system when the sample size is too small and provides more conservative results by considering uncertainty. Future studies should focus on providing reliable data to reduce uncertainty.[br/]

Objective An aggregate annoyance construct has been developed to account for annoyance that ranges from not at all annoyed to extremely annoyed, toward multiple wind turbine features. The practical value associated with aggregate annoyance would be strengthened if it was related to health. The objective of the current paper was to assess the association between aggregate annoyance and multiple measures of health. Methods The analysis was based on data originally collected as part of Health Canada’s Community Noise and Health Study (CNHS). One adult participant per dwelling (18–79 years), randomly selected from Ontario (ON) (n = 1011) and Prince Edward Island (PEI) (n = 227), completed an in-person questionnaire. Results The average aggregate annoyance score for participants who indicated they had a health condition (e.g., chronic pain, Pittsburgh Sleep Quality Index (PSQI) > 5, tinnitus, migraines/headaches, dizziness, highly sensitive to noise, and reported a high sleep disturbance) ranged from 2.53 to 3.72; the mean score for those who did not report these same conditions ranged between 0.96 and 1.41. Household complaints about wind turbine noise had the highest average aggregate annoyance (8.02), compared to an average of 1.39 among those who did not complain. Conclusion A mean aggregate annoyance score that could reliably distinguish participants who self-report health effects (or noise complaints) from those who do not could be one of several factors considered by jurisdictions responsible for decisions regarding wind turbine developments. However, the threshold value for acceptable changes and/or levels in aggregate annoyance has not yet been established and could be the focus of future research efforts.

« Les forêts précèdent les peuples, les déserts les suivent »François René de Chateaubriand Pluie et forêt ! ces éléments sont sans conteste liés puisque plus il pleut et plus la végétation naturelle est dense. Et les zones de forêts sont souvent associées aux montagnes ; les unes et les autres sont souvent liées, et ont pu paraître répulsives ou effrayantes même à diverses époques (Corbin, 2001). Aujourd'hui où l'on cherche des endroits « sauvages », ce qu'il reste de milieux « moins anthrop...

NERICA rices are interspecific inbred progeny derived from crosses between Oryza sativa × O. glaberrima. In this study, we evaluated 70 BC2 interspecific lines, developed by crossing a tropical japonica variety (WAB 56-104) as the recurrent parent to an O. glaberrima variety (CG 14) as the donor parent, followed by the use of anther culture to derive doubled haploids (DH) (26 lines) or eight generations of inbreeding to fix the lines (44 lines). Seven of these BC2 derived inbred lines have been released as NERICA 1-NERICA 7. This study examined the relative contribution of each parent and the extent of genetic differences among these 70 sister lines using 130 well-distributed microsatellite markers which cover 1725 cM of the rice genome. The average proportion of O. sativa recurrent parent genome was 87.4% (1,508 cM), while the observed average proportion of O. glaberrima donor genome was 6.3% (108 cM). Non-parental alleles were detected in 83% of the lines and contributed an average of 38 cM per line (~2.2% of genomic DNA). Lines that had undergone eight generations of inbreeding in the field contained significantly more non-parental alleles (av. 2.7%) compared to the DH lines (av. 1.3%) that were developed from BC2 anthers. Using both cluster and principal component analyses, two major groups were detected in these materials. The NERICA varieties (NERICA 1 to 7) clustered in one group while the remaining 63 lines clustered in another group, suggesting that the second group may offer significant opportunities for further selection and variety development.

El presente trabajo analiza la diversidad de parásitos monogenoideos como un carácter independiente, esperando que por su alta especificidad, éstos parásitos puedan caracterizar las poblaciones de sus hospederos, la piraña blanca, Serrasalmus rhombeus. El estudio se llevó acabo en cuatro sub-cuencas de la Cuenca Amazónica Boliviana (Iténez, Beni, Madre de Dios e Ichilo); se obtuvieron 1135 parásitos, los cuales fueron agrupados en seis géneros y once especies: Anacanthorus jegui, A. amazonicus, A. rondonensis, A. gravihamulatus, A. sciponophallus, Anacanthorus sp.1, Anacanthorus sp.2, Anacanthorus sp.3; Notothecium deleastum, N. deleastoideum, Notozothecium teinodendrum; Mymarothecium galeolum; Anphithecium diclonophallum y Enallothecium aegidatum. La elevada diversidad de parásitos encontrada puede deberse a que existe o existió un complejo de especies o poblaciones diferenciadas de Serrasalmus rhombeus The present work analyse monogenoids parasite diversity as one independent character, hoping they can characterize the white piranha (Serrasalmus rhombeus) populations by its high specificity. Study was carried out in four sub-basins (Iténez, Beni, Madre de Dios e Ichilo) from the Bolivian Amazon Basin. A total of 1135 parasites were obtained, belonging to six genera and 11 species: Anacanthorus jegui, A. amazonicus, A. rondonensis, A. gravihamulatus, A. sciponophallus, Anacanthorus sp.1, Anacanthorus sp.2, Anacanthorus sp.3; Notothecium deleastum, N. deleastoideum, Notozothecium teinodendrum; Mymarothecium galeolum; Anphithecium diclonophallum y Enallothecium aegidatum. The high parasite diversity could be related to one complex of populations or species of Serrasalmus rhombeus existent or extintic.

L'étude s'intéresse au problème de la migration de la population des municipalités de l'Outaouais selon les différentes catégories d'âge. Une analyse en composantes principales après transformation KHI, appliquée à une matrice évaluant les écarts entre la population réelle en 1981 et la population estimée à partir d'une hypothèse de population fermée, a permis d'identifier les principaux comportements migratoires associés aux différentes catégories d'âge. Les résultats montrent l'importance du rôle joué par certaines catégories, notamment celles à l'intérieur desquelles des changements dans la composition du ménage ont une plus grande probabilité d'occurrence. Enfin, l'analyse des notes factorielles souligne le caractère particulier des municipalités de la Communauté régionale de l'Outaouais par rapport à celles se situant dans les municipalités régionales de comté de l'Outaouais., This study concerns the migration flows by age groups of the Outaouais population for the period 1971-1981. The method used is a principal components analysis applied on net migration data, for the 103 municipalities of the region, using a KHI transformation. The results identify clearly the main migration behaviors which have affected the spatial redistribution of the population between 1971 and 1981 in the Outaouais region. They also show the key role played by some age categories, especially those who have a greater probability of household composition change. Finally, it is shown that the demographic evolution of the municipalities forming the Communauté regionale de l'Outaouais is quite different from that of other municipalities and may lead to some more severe disparities.

L'évaluation de la qualité de l'eau de rivières pose un certain nombre de problèmes non encore résolus. Parmi ceux-là, nous en avons retenu un qui porte sur la méthodologie généralement adoptée pour réaliser cette évaluation et qui est à la base de nombreux autres problèmes. Actuellement en France, ainsi que dans de nombreux autres pays européens, la qualité de l'eau est évaluée à partir de grilles de valeurs limites de paramètres physico-chimiques ou biologiques. L'usage de telles grilles sous-entend que les paramètres qui la composent sont indépendants les uns des autres alors qu'il n'en est rien. En effet, il est indispensable de considérer les milieux aquatiques comme étant des systèmes chimiques, physiques et biologiques plus ou moins éloignés de leurs états d'équilibre et pour lesquels les paramètres qui les décrivent, considérés à un instant donné, sont liés les uns des autres par des relations qui évoluent avec leurs états.En plus du problème précédent, il faut rappeler que toute évaluation de l'état d'une masse d'eau (au sens de la Directive Cadre européenne sur l'Eau (DCE)) nécessite que soit précisé au préalable un état de référence. La diversité, hors anthropisation, des milieux aquatiques pose alors le problème du choix de telles références.Ce travail qui a pour cadre un cours d'eau du centre de la France (la Vienne) s'inscrit donc en partie dans cette double problématique.S'appuyant sur un suivi analytique mensuel en huit points, réalisé au cours d'une période de 27 mois entre 1999 et 2002, nous avons tenté de montrer que la méthode bien connue de l'analyse en composante principale (ACP) avec étude des corrélations, pouvait, moyennant quelques préalables, être un outil permettant de préciser avec une bonne objectivité l'état, ainsi que l'évolution spatio-temporelle de ces eaux.Nous avons également tenté de montrer que l'un de ces préalables était la prise en compte dans l'ACP de variables caractéristiques de la matière organique dissoute (MOD). Les paramètres classiques actuellement utilisés, en particulier par le système français d'évaluation de la qualité de l'eau (SEQ-Eau), qui sont essentiellement minéraux, ne suffisent pas à eux seuls pour expliquer et mettre en évidence les effets liés aux apports anthropiques.Dans cette étude, nous nous sommes donc attachés de différentes manière à montrer sur ce milieu, que les représentations ACP prenaient en compte les principales observations connues comme liées aux rejets polluants., Satisfactory systems for evaluating river water quality have not yet been established. In France, as in many other European countries, water quality is evaluated using physico-chemical or biological parameter grids. This method implicitly assumes that these parameters are independent from each other and that a universal state of reference exists. In fact, when taking into account the great diversity of rivers it is clear that any evaluation of water quality requires that reference conditions be specified for each water system. Although it is one of the objectives of the new European Water Framework Directive, this problem has not yet been resolved. In addition, it is important to note that the state of water is characterised by dependent analytical parameters, and that the relationships linking these parameters evolve with the state of the water; this variable dependence must be taken into account. Lastly, it is important to note that organic matter is generally underestimated by current water quality evaluation systems.In the present study an attempt was made to evaluate the water quality of the Vienne River situated in western France. This study provided us with the opportunity to verify the accuracy of the current system. A monthly analytical monitoring program at eight study sites was carried out during the period 1999-2001. It allowed us to demonstrate that the well-known method of the principal component analysis (PCA), together with correlation analysis, was an appropriate tool for this purpose. More specifically, we showed that when using parameters characteristic of organic matter, this tool is well adapted for monitoring spatial and temporal changes in water quality. As this method is graphical, it made the choice of a reference point possible.This study showed that traditional parameters currently used, which are primarily inorganic, were not sufficient to identify anthropogenic contributions. For this reason we used unconventional organic variables, formerly used to study the structure of the dissolved organic matter (DOM) in surface waters, such as:- the distribution of the various organic fractions, such as humic (or hydrophobic) substances and non humic (or hydrophilic) substances, after filtration through macroporous XAD8 and XAD4 resins, under well-defined conditions;- the distribution of the apparent molecular weights, by ultrafiltration through membranes with molecular weight cut-offs of 30, 10 and 3 kDaltons;- fluorescence spectrometry;- the ratio UV-absorbance at 254 nm/dissolved organic carbon (SUVA).It was noted in this study that these organic variables, coupled with those classically analysed (Chemical Oxygen Demand, COD; Biological Oxygen Demand, BOD5), were often mainly responsible for the variations in the water quality. Principal Component Analysis was used to extract the main factors associated with water quality variability. The graphical representation obtained underlined that the greatest variability of the points characteristic of the stations could be observed on the first principal component. This component was linked to the organic variables. The second principal component was linked to inorganic variables indicative of the geological substrate. In addition, it was shown that the temporal dispersion of stations in the PCA graphical representation can be used to evaluate (either from the variance of the PCA factors, or from the box plots of these same factors) the disturbances related to the contributions of anthropogenic origin. The proportion of variability in water quality due to hydrological conditions could be also highlighted by PCA.

L'impact des pollutions ponctuelles sur les phytocénoses aquatiques est étudié autour des rejets de 12 agglomérations dont 9 sont équipées d'une station d'épuration. Un échantillonnage systématique avec segmentation du cours d'eau autour de chaque rejet est réalisé. Sur chaque secteur, des relevés de végétation sont pratiqués au niveau de faciès d'écoulements homogènes dont on caractérise le milieu physique parallèlement à une analyse physicochimique de l'eau.L'ensemble des rejets provoque globalement une élévation de la conductivité, des teneurs en ammonium, nitrates et orthophosphates.Cela ce traduit par la régression de la phytocénose à Callitriche hamulata et Myriophyllum alterniflorum, par le développement de Ranunculus peltatus, Callitriche platycarpa et d'espèces cryptogames telles que Leptodyctium riparium, ou Melosira sp.Une Analyse en Composantes Principales menée sur l'ensemble des données permet d'opposer des phytocénoses propres aux secteurs amonts (Scapania undulata, Chiloscyphus polyanthus) à d'autres situées au niveau de rejets (Callitriche platycarpa, Leptodictyum riparium, Melosira sp.,).Une Analyse Canonique de Correspondances valide le déterminisme de la qualité physicochimique de l'eau sur la végétation. La conductivité, les teneurs en ammonium, nitrates et orthophosphates deviennent prépondérants par rapport aux facteurs du milieu physique classiquement discriminants dans l'installation des phytocénoses dans les rivières limousines., The impact of located pollution on aquatic phytocénoses is studied around 12 cities discharge. Nine of them are fitted out purification plant.The sampling method is based on consecutive segments from upstream to downstream. On each sector, vegetation records are realized in homogeneous water runoff facies, which are characterized by physical factors as well as water value measures.The whole discharge leads globally to an increase of conductivity, ammonium amount, nitrates and orthophosphates. The consequence of that is a decrease of Callitriche hamulata and Myriophyllum alterniflorum phytocénoses, a development of Ranunculus peltatus, Callitriche platycarpa and cryptogams species like Leptodictyum riparium or Melosira sp.A Component Principal Analysis applied on data, distinguishes phytocénoses belonging to upstream sectors (Scapania undulata, Chiloscyphus polyanthus) from the ones of discharges (Callitriche platycarpa, Leptodictyum riparium, Melosira sp.).A Canonical Correspondence Analysis validates the impact of physico-chemical water quality on vegetation. Conductivity, ammonium amount, nitrates and orthophosphates become more preponderant in comparison with physical environments usually discriminant for phytocénoses installation in Limousin rivers.

A study was undertaken to investigate the effect of soil physical and chemical properties on nematodes associated with sugarcane. Principal component analysis (PCA) showed little or no change in the nematode community between nematicide treated and untreated plots or between sugarcane varieties. Analysis of the topsoil revealed very small differences in chemical elements between varieties. Soil of plots with the variety N16 had higher levels of Mg and Ca and lower levels of Fe. The study of soil characteristics of the topsoil and of the deeper layer revealed a heterogeneous situation alluding to the distinction of two zones over the area. However, the overall distribution of the entire nematode community, described by the factorial values of the PCA, was not related to the location of these two soil delimited zones. The coinertia analysis was then performed to identify the relationship between individual soil factors and individual species. These relationships were shown to be significant and concerned mainly the Mn level in the soil, the size of the plant–parasitic community and the abundance of Helicotylenchus dihystera and Xiphinema elongatum . All three decreased as the Mn content increased. To a lesser extent, pH and Na were positively associated with the numbers of free-living nematodes.

Numerical analyses of remotely sensed data may valuably contribute to an understanding of the vegetation/land surface interface by pointing out at which scales a given variable displays a high level of spatial variability. Thus, there is a need of methods aimed at classifying many one-dimensional signals, such as airborne laser profiles, on the basis of their spatial structure. The present paper proposes a theoretical framework ensuring a consistent combination of a multi-scale pattern characterization, based on the Haar wavelet variance (also called in ecology Two Terms Local Variance, TTLV), with two multivariate techniques such as principal components analysis (PCA) and hierarchical cluster analysis. We illustrate our approach by comparing and classifying 257 laser profiles, with a length of 64 measurements (448 m), that were collected by the BRGM in French Guiana over three main landscape units with distinct geomorphological and ecological characteristics. We calculate for each profile a scalogram that summarized the multi-scale pattern and analyze the structural variability of profiles via a typology and a classification of one-dimensional patterns. More than 80% of the variability between spatial patterns of laser profiles has been summarized by two PCA axes, while four classes of spatial patterns were identified by cluster analysis. Each landscape unit was associated with one or two dominant classes of spatial patterns. These results confirmed the ability of the method to extract landscape scaling properties from complex and large sets of remotely sensed data.

Grâce aux données génétiques publiées sur les Berberophones du nord de l'Afrique nous tenterons d'exposer dans cet article le parallélisme des dérives génétiques et linguistiques dans ces populations isolées par leur histoire et leurs implantations geographiques. Une analyse en composantes principales sur seize échantillons offre une cartographie satisfaisante de ce parallélisme. Using the genetic data already published on Berber-speaking groups of northern Africa, we intend in this paper to demonstrate the parallel nature of the genetic and linguistic drifts in these populations, isolated by their history and geographical locations. A principal component analysis of sixteen geographical samples provides a satisfactory cartography of such a parallel evolution.

Differences in rates of infestation of root-knot nematode (Meloidogyne spp.) populations by the endospore-forming bacterium Pasteuria penetrans were not entirely due to inter/intra-specific variability of the organisms. Soil conditions, especially texture and chemical characteristics, are also involved. Focusing studies on vegetable crops, interactions between the occurrence of Meloidogyne spp. juveniles encumbered with spores of P. penetrans and some physico-chemical soil characteristics were analysed both between regions (West Africa, e.g. Burkina Faso and Senegal; South America, e.g. Ecuador; the Caribbean, e.g. Trinidad and Tobago; and Mediterranean Europe, e.g. Crete) and within Ecuador, Burkina Faso and Senegal. In Ecuador (clay or silty-clay soils), the mean proportion of infested juveniles was high (41.9%). In the sandiest soils, as in Senegal, there were very few infested juveniles (4.7%). In Crete, Burkina Faso, and Trinidad and Tobago, where the soils are siltier, the mean proportions of infested juveniles range between 14 and 24.4%. Multivariate analysis performed on the data from Senegal and Burkina Faso revealed that a significant increase of the mean clay content (1.4 and 10.5%, respectively) improved the mean proportions of infested juveniles (from 1.6 to 42.2% and from 10.7 to 79.4%, respectively). Influences of the soil texture and structure on the availability of the spores of P. penetrans to infest the juveniles of Meloidogyne spp. are discussed.

The aim of this work was to analyse the phenological variation of a residual invasive semi-evergreen shrub in Sahelian fallows in Niger. This species, Guiera senegalensis (Combretaceae), has benefited from the elimination of other species thanks to its high resistance to the increasing cutting pressure for cultivation. We sought to identify traits of its life cycle that could contribute to its persistence and widespread dominance under such a disturbance regime. Leafing, flowering and fruiting were monitored on seven fallows differing in topographic location, age, shrub density and degradation state, during two rainy seasons and one dry season. Phenological spectra showed similar timing of the three phenophases of the seven populations. Differences were observed mainly in magnitude of the phases. However, there were both a high intra-fallow variability (64.6% of the whole variability) and a statistically significant inter-fallow variability, despite only 35.4% of the total variability being due to differences between fallows. A statistical classification of the fallows was proposed based on shrub phenological course over the two cycles monitored. This classification corresponds to a gradient of life-cycle achievement primarily linked to the topographic situation of the stations, and then to a combination of other factors. The flexibility of the phenology at the individual, population and metapopulation scales, inherent to its specific semi-evergreenness property, appeared as an essential phenological attribute contributing to successful widespread persistence of G. senegalensis in the study area.

A 4-year trial was conducted in the Sudanian area of Senegal to study how the manipulation of the plant composition of a natural fallow might increase soil fertility. The influence of fencing combined with stump removal or planting of Andropogon gayanus on the nematode communities was studied. Apart from fencing, all intervention favoured the multiplication of the plant parasitic nematodes for the duration of the trial. Fencing significantly reduced nematode abundance and modified the balance between the species in the community. The population of Scutellonema cavenessi, a serious pest of food crops in the region, was dramatically reduced to the benefit of the weaker pathogen, Helicotylenchus dihystera. Planting Andropogon increased the H. dihystera population slightly. Disappearance of ligneous plant material by stump removal was associated with the greatest increase in the proportion of S. cavenessi. The results suggested that the soil disturbance when planting, removing stumps, or even grazing could affect the nematode community in the topsoil layer, resulting in a decrease in H. dihystera. This species did not recover during a 4-year fallow, even if a suitable situation was promoted through fencing or the planting of Andropogon, a host plant of H. dihystera.

In West Africa different insecticides had been applied in selected river areas for the reduction of the blackfly populations vectors of Onchocerca volvulus, a parasite causing blindness. To evaluate the possible long term effects of the larvicides on the non target fauna an aquatic monitoring programme has been up from the initial phase of the project. Addressing the attention to the invertebrates data collected in four countries during a maximum period ranging from 1977 to 1996, this paper shows and discusses the data analysis strategy for the measure and interpretation of the biological variation. In particular the application of quantitative ecological analysis methods: Principal Component Analysis, rank abundance models and the community diversity indexes, is critically discussed and comments are given to the ecological interpretation of the results. ©1998 Elsevier Science Ltd. All rights reserved

International audience; 1. Spatial patterns of freshwater fish species at regional and local scales were investigated to explore the possible role of interspecific interactions in influencing distribution and abundance within communities occupying coastal streams of North-Western France. 2. Nine sites from nine streams situated in the same biogeographical region were sampled annually over the 6-year period from 1990 to 1995. 3. Similar habitats (sites) with richer regional colonization pools exhibited proportionally richer local communities in terms of number of species, total density and total biomass of individuals. Furthermore, no negative relationships were found between density and biomass of each of the most common species and local species richness. 4. Results of dynamic regression models (applied to the above-mentioned species) suggest an absence of strong competition between all pairs of species. 5. The evidence on lack of density compensation for species-poor communities and absence of perceptible interspecific competition between species suggest that the communities studied are non-interactive. 6. Two main explanations can be advanced. First, the local abundance of species in the communities studied could be determined through differential responses to unpredictable environmental changes, rather than through biological interactions. Second, as a result of historical events, the communities studied are reduced in congeneric species which can limit, in turn, the influence of interspecific competition in structuring these communities. 7. These results underline the strong influence of regional processes in shaping local riverine fish communities and minimize the possible influence of species interactions in governing these communities.

Iu Summary-Spatial distribution of the endogeic earthworm Polypheretima elorigata, soil texture, carbon and nitrogen contents were investigated in a 10-y-old pasture established on a vertisol, by measuring each variable at 57 points randomly located in a 25 x 60 m plot. Soil variables were measured at three depths: 0-10, 10-20 and 20-3Ocm. Principal component analysis (PCA) of the data set showed the absence of relationships between density of P. elongata and environmental variables. The first principal component expressed a marked gradient of soil texture and soil organic matter (SOM). Sampling point coordinates on the first principal component axis were used as a composite variable assumed to account for the major source of soil heterogeneity at this site. The spatial pattern of this variable and three age classes of P. eloiigata were investigated using geostatistics. There was no evidence of any relationship between soil heterogeneity and earthworm distribution. Population of P. elorzgata exhibited a marked patchy distribution with opposite patterns between adults and other age classes (juveniles and cocoons). These results suggest that at the study site processes responsible for the spatial distribution of P. elongata population are of demographic rather than environmental origin. 0 1997 Elsevier Science Ltd

The principal aims of a core collection are: 1) to include the maximum of diversity of the base collection in a sample of minimum size; and 2) to avoid redundancies. We present here a new method (the Principal Component Scoring) which fulfills these aims. The use of P.C.S. has consequences for sampling stratification and choice of sample size. P.C.S. requires quantitative data, but with small changes can be used for qualitative data.

The aim of this thesis is to model the dynamics of international term structure of interest rates taking into consideration several dependence channels.Thanks to a new international Treasury yield curve database, we observe that the explained variability decision criterion, suggested by the literature, is not able to select the best combination of factors characterizing the joint dynamics of yield curves. We propose a new methodology based on the maximisation of the likelihood function of a Gaussian state-space model with common and local factors. The associated identification problem is solved in an innovative way. By estimating several sets of countries, we select two global (and three local) factors which are also useful to forecast macroeconomic variables in each considered economy.In addition, our method allows us to detect hidden factors in the international bond returns. They are not visible through a classical principal component analysis of expected bond returns but they are helpful to forecast inflation and industrial production. Keywords: International treasury yield curves, common and local factors, state-space models, EM algorithm, International bond risk premia, principal components.

Markers are commonly used in nutritional studies to evaluate the transit and degradation rate of food. Poly(ethylene glycol) is a water-soluble marker that is poorly quantified by the turbimetric technique in some digestive samples. In the present work, an alternative for quantifying poly(ethylene glycol) was tested. In the mid-infrared region, poly(ethylene glycol) has a characteristic absorption band around 1080 cm -1 which increases with the poly(ethylene glycol) content. A prediction equation for the poly(ethylene glycol) was assessed by applying a principal component regression to infrared spectral data recorded between 900 and 1200 cm -1 . The correlation coefficient and the standard error obtained were 0.99 and 0.29 g L -1 , respectively. Samples resulting from an in vitro digestion of bread were submitted to this equation. The results showed that infrared spectroscopy could be a relevant technique for the measurement of poly(ethylene glycol). In addition, the soluble carbohydrates could be evaluated by mid-infrared spectroscopy.

La communication établie une typologie de pays en fonction (i) de leurs comportements quant aux émissions de GES et (ii) des facteurs donnant lieu à ces comportements. L’Analyse en Composantes Principales comme mécanisme de réduction de l’information et l’Analyse Cluster comme mécanisme de classification ont été les principales techniques statistiques utilisées dans ce travail. This paper shows a country’s typology based on: (i) the GHG emission behaviours of the countries, and (ii) the main driving forces determining them. Main Component Analysis and Cluster Analysis have been used as a tool for simplifying original data and for statistical classification.

In a study about La Rochelle and its suburbs, the methods of data analysis have allowed to bring into light certain features of its structure. When analysing the main features, one can see on a graph that 55 communes have disappeared from the area. Using a method of classification, 9 groups can be identified and mapped. Subsequently one can notice that the rural-urban fringe forms à belt between the built-up and rural areas., RÉSUMÉ Dans une étude de l'agglomération rochelaise, les méthodes de l'analyse des données ont permis de mettre à jour certains traits de structure. Une analyse en composantes principales a fait voir sur un graphique la disposition des 55 communes de l'agglomération. Une méthode de classification a séparé en 9 groupes ces communes, ce qui a permis une représentation cartographique. Ainsi, le péri-urbain rochelais apparaît comme une couronne s 'intercalant entre centre-ville et banlieue proche, d'un côté, et milieu rural, de l'autre., Anglade Francis. Le périurbain à La Rochelle. Utilisation des méthodes d'analyse des données. In: Norois, n°154, Avril-Juin 1992. pp. 229-240.

International audience; The occurrence of disease amongst the occupants of "mouldy" environments has been widely described in the literature. However, the detection of such moulds in closed environments remains difficult, particularly in the event of recent (before the first deterioration) or masked contamination (behind a material). In this context, the present study aimed to determine a specific chemical fingerprint for fungal development detectable in closed environments (dwellings, office, museum...). To achieve this, chemical emissions from sterile and artificially contaminated by moulds materials were analyzed and compared using a descriptive statistical method. Principal Component Analysis is thus chosen to analyze the results. PCA generated optimum and similar graphical representations of the scatterplot representing the data matrix. This statistical approach made it possible to identify an emission fingerprint without applying any preconception as to the type of emitted compound. Statistical analysis of the data then enabled confirmation of the impact of moulds on total VOC emissions. This emission of specific compounds resulted in obtaining a signature for the presence of fungal development in an environment, defined by specific ions. This analysis, and use of these ions applied to dwellings, made it possible to distinguish those with proven fungal development from those with no sign of mould or with a context favorable to fungal development, thus demonstrating that a chemical fingerprint specific to fungal development could be detected in indoor environments.

Los ambientes acuáticos de la Amazonía Boliviana tienen una amplia diversidad de fauna íctica, y sólo recientemente se está empezando a obtener una imagen completa. A pesar del importante incremento en el conocimiento de esta ictiofauna de la cuenca amazónica, existen aún grandes vacíos de información sobre la distribución, biología, ecología y parasitología de los peces (Samiento & Barrera, 2003). El estudio se llevó a cabo en seis ríos de la cuenca amazónica (San Martín, Madre de Dios 1 - 2 y 3, Beni e Ichilo), el Madre de Dios 2 no tuvo presencia de parásitos. Se tomaron 31 branquias en 12 #Serrasalmus rhombeus# (piraña blanca), de las cuales se extrajeron un total de 858 parásitos. (Résumé d'auteur)

A partir de variables elaboradas para dar cuenta del medio ambiente urbano, es decir de los modos de produccion y de consumo de los bienes comunes en Quito, se realizaron analisis estadisticos - Analisis en Componentes Principales (ACP) y nubes dinamicas principalmente - que permitieron destacar perfiles ambientales que expresan una verdadera estructura ambiental de la ciudad. Tal estructura se construye primeramente con base en una diferenciacion del modo de produccion y de consumo del suelo entre la zona central y el area periferica. Los mayores desafios de la cuestion ambiental en Quito remiten, por una parte, al manejo de la centralidad urbana y, por otra, al desarrollo urbano de los espacios residenciales recientes. Se trata en especial de crear nuevos modos de producir y de consumir los bienes comunes, particularmente el suelo y la movilidad. (Résumé d'auteur)

Signs of climate change in West Africa over the last few decades are among the significant observed in the tropics, in particular the decrease in mean annual precipitation. Although such change has brought about new eco-climatic constraints on vegetation forms, it has not proven easy to determine interannual and intra-seasonal variations on a regional scale for major vegetation forms, whether natural or highly artificial as a result of human activities. The present study analyzes vegetation activity via a Normalized Difference Vegetation Index (NDVI) defined from ten-day SPOT-VGT data (one-km resolution, covering the period from 2002 to 2012) in the African Monsoon Multidisciplinary Analysis (AMMA) Program observation zone, located in the Upper Oueme River Basin in Benin. The statistical analysis is mainly based on a multifactor approach allowing approximately 54% of interannual NDVI variations to be accounted for. Results show that spatio-temporal NDVI variability in the River Basin is highly dependent on land use, be it forest, wooded savanna, farmland or areas undergoing conversion.

In NIR spectroscopy, multidimensional analyses such as Principal Component Analysis (PCA) may be applied to examine the similarity between spectra of natural products. However, such an approach is often limited by the effect of spectral interference due to water or particle size distribution of the samples. In the present work, the advantage of the elimination of such spectral interference before performing PCA was investigated. Unwanted component spectra were eliminated by a least-squares procedure. They were first orthogonalized and normalized by the Gram-Schmidt orthogonalization method. The subtraction coefficients were then assessed, similarly to principal component (PC) scores, by projection of the NIR spectra on the orthogonalized component spectra, and PCA was performed on the corrected spectra. This method was applied on an illustrative collection of wheat semolina conditioned in three levels of water content. Water was the component to be eliminated and had been previously modeled by two spectral patterns. These spectral patterns were used as the unwanted component spectra. PCA was applied independently before and after spectral correction of the collection of spectra and graphs obtained by the two procedures were compared. The squared correlation coefficient of the 3 first PC scores with water content was 0.979 before correction, with the 3 groups of water content appearing clearly on PCA graphs. After correction, the corresponding squared correlation coefficient for the 7 first PC scores was 0.016. PCA graphs obtained with corrected spectra also showed that the water effect was completely eliminated. At this moment, samples were separated according to their technological nature. The procedure developed may be useful in pattern recognition study and for automatic clustering of NIR spectra. It may also be applied in fields other than NIR spectroscopy.

Resume La decroissance des valeurs propres successives dans un certain nombre d'analyses en composantes principales portant sur 20 variables et 44 individus, est comparee a la decroissance des segments dans le modele du ‘bâton brise’, ou une quantite fixe (la longueur du bâton) est divisee simultanement en S par S-1 points au hasard. On constate que les deux premieres valeurs propres sont situees au dessus du modele, et indiquent sans doute l'existence de facteurs agissant sur les variables. La variance residuelle semble se partager entre les axes restant suivant un modele proche du bâton brise; cependant l'ajustement n'est pas parfait, car la variance non due aux facteurs se repartit sur l'ensemble des axes y compris les deux premiers, et il est impossible de discerner dans ces derniers variance factorielle et variance aleatoire. Le modele semble cependant suffisant pour permettre de determiner empiriquement le nombre d'axes significatifs.

Comparaison des peuplements de poissons d'une aire protégée en zone de mangrove (le bolon de Bamboung, Sine Saloum, Sénégal) avec les peuplements de deux sites proches non protégés de l'exploitation halieutique Sommaire Introduction .

Les petits barrages représentent une part importante des ressources en eau pérennes du nord de la Côte d'Ivoire. Ils correspondent à ce titre à un outil important pour l'aménagement du territoire ivoirien. Sur le plan halieutique, ces retenues constituent une source non négligeable de production de poissons (entre 7,0 et 22,4 t km-2 an-1, DA COSTA et al., 1998). Au regard des normes indiquées par la FAO pour les petits barrages, entre 10 et 75 t km-2 an-1 (PALM, 1989), cette production de pêche pourrait être accrue. Cependant, toute mesure d'aménagements halieutiques dans ce sens nécessite une connaissance préalable de la diversité fonctionnelle de ces plans d'eau, en termes de régime hydrologique et limnologique, de diversité biologique et trophique. La présente étude a pour objectif de caractériser les peuplements de poissons et les réseaux trophiques des petits barrages. Une typologie des retenues basée sur les structures trophiques identifiées, la diversité trophique et la régularité du partage des individus entre les espèces des peuplements de poissons observés (sensu FRONTIER et PICHOD-VIALE, 1998) est proposée.

Bambara groundnut (#Vigna subterranea$ (L.) Verdc.) is an important crop in many countries of tropical Africa. Compared with other leguminous crops, little is known about the organization of its genetic diversity. Our goal was to investigate its population structure and the partitioning of genetic diversity between domesticated and wild accessions. Seventy-nine accessions of domesticated and 21 wild Bambara groundnut populations were evaluated for genetic diversity at 41 isozyme loci, representing 23 enzyme systems. Domesticated accessions were characterized by very low genetic diversity (Ht = 0.052) with only 7 polymorphic loci. Wild populations were characterized by higher genetic diversity (Ht = 0.087), with 14 polymorphic. This suggests a marked bottleneck between wild and domesticated forms. Intrapopulation diversity was comparatively high (Hs = 0.033 for domesticated and Hs = 0.025 for wild populations) despite the near absence of heterozygous individuals, which suggests a predominantly selfing mode of pollination in both wild and domesticated Bambara groundnut. High genetic identity between wild and domesticated forms suggests that wild Bambara groundnut is the true progenitor of domesticated Bambara groundnut. Both morphological and isozyme data show a gradient between true wild and domesticated Bambara groundnut through weedy populations. The improved understanding of the organization of genetic diversity of Bambara groundnut provided by our data will allow a better conservation of its genetic resources. (Résumé d'auteur)

In this paper, we apply a variant of Principal Component Analysis (PCA) to data coming from classical dance movement observation. The movement capture is achieved by means of sensors conveniently fastened to the dancer's body, which provide a series of regular space positions during the choreographic figure performance. Since data are time dependant, we intend that their temporal order is taken into account by the analysis technique we apply. Consequently, we refer to 'Relational PCA', that is a generalisation of usual PCA, and is based upon an additional relational parameter called the 'Graph Laplacian'. The Graph Laplacian accounts for a time neighbourhood within the set of observations. The span of the neighbourhood can be set by the analyst in order to control which pairs of observations will effectively contribute to sensors covariance. As an application, we propose the analysis of three typical classical dance movements, e.g. : 'Bending, Fall', 'Turn Jumped' and 'Walk'. With the first movement we show an instance of the analysis technique ; with the second, we discuss movement reconstruction through selected principal components, and with the last one, we give a criterion and way for choosing an optimal span for the Graph Laplacian.