Cyclododecane exposure in the field of conservation and restoration of art objects

PURPOSE: Recent work practices in the conservation and restoration involve the use of cyclododecane (CDD, CAS 294-62-2) to protect fragile artifacts during their handling or transportation. Little is known about its toxicity, and no previous exposure has been reported. A short field investigation was conducted to characterize the exposure conditions to both CDD vapors and aerosols.METHODS: Measurements were conducted in the laboratory of conservation and restoration of the archeological service in Bern (Switzerland). Three indoor and four outdoor typical work situations, either during brush or spray gun applications, were investigated. Measurements were performed on charcoal adsorbent tube and analyzed by a gas chromatograph equipped with a flame ionization detector.RESULTS: Measurements have been conducted during both brush and spray gun applications. Indoor exposures were of 0.75-15.5 mg/m(3), while outdoors exposures were 19.5-53.9 mg/m(3). Exposures appear to be extremely localized due to both physicochemical properties and application methods of the CDD. Vapor exposure increases dramatically with the confinement of the workplace.CONCLUSION: Preventive measures should be undertaken to limit as much as possible these exposures. Field work in confined areas (ditches, underground) is of particular concern. CDD-coated artifacts or materials should be stored in ventilated areas to avoid delayed exposures. [Authors]

Comparative testing of a miniature diffusion size classifier to assess airborne ultrafine particles under field conditions

Miniature diffusion size classifiers (miniDiSC) are novel handheld devices to measure ultrafine particles (UFP). UFP have been linked to the development of cardiovascular and pulmonary diseases; thus, detection and quantification of these particles are important for evaluating their potential health hazards. As part of the UFP exposure assessments of highwaymaintenance workers in western Switzerland, we compared a miniDiSC with a portable condensation particle counter (P-TRAK). In addition, we performed stationary measurements with a miniDiSC and a scanning mobility particle sizer (SMPS) at a site immediately adjacent to a highway. Measurements with miniDiSC and P-TRAK correlated well (correlation of r = 0.84) but average particle numbers of the miniDiSC were 30%âeuro"60% higher. This difference was significantly increased for mean particle diameters below 40 nm. The correlation between theminiDiSC and the SMPSduring stationary measurements was very high (r = 0.98) although particle numbers from the miniDiSC were 30% lower. Differences between the three devices were attributed to the different cutoff diameters for detection. Correction for this size dependent effect led to very similar results across all counters.We did not observe any significant influence of other particle characteristics. Our results suggest that the miniDiSC provides accurate particle number concentrations and geometric mean diameters at traffic-influenced sites, making it a useful tool for personal exposure assessment in such settings.

Cosmopolitan Capital and the Internationalization of the Field of Business Elites: Evidence from the Swiss Case

The aim of this contribution is to explore how the recent internationalization and the increasing importance of 'cosmopolitan capital' has impacted on the structure and character of the field of the Swiss business elite. For this purpose we will develop the notion of cosmopolitan capital and comparatively investigate the field of the Swiss business elite in 1980, 2000 and 2010 with multiple correspondence analysis. We can show that in this period international managers with transnational careers and networks not only grow in number, but come to conquer the apex of the biggest and highest capitalized Swiss firms. At the same time, national forms of capital decline in importance and Swiss managers themselves are differentiated increasingly into national and international fractions.

Female-biased dispersal in the monogamous mammal Crocidura russula: evidence from field data and microsatellite patterns.

We investigated dispersal patterns in the monogamous Crocidura russula, based both on direct field observations (mark-recapture data) and on genetic analyses (microsatellite loci). Natal dispersal was found to be low. Most juveniles settled within their natal territory or one immediately adjacent. Migration rate was estimated to two individuals per year and per population. The correlation between genetic and geographical distances over a 16 km transect implies that migration occurs over short ranges. Natal dispersal was restricted to first-litter juveniles weaned in early May; this result suggests a direct dependence of dispersal on reproductive opportunities. Natal dispersal was highly female biased, a pattern unusual among mammals. Its association with monogamy provides support for the resource-competition model of dispersal. Our results demonstrate that a state-biased dispersal can be directly inferred from microsatellite genotype distributions, which opens new perspectives for empirical studies in this area.

Dense deformation field estimation for atlas-based segmentation of pathological MR brain images.

Atlas registration is a recognized paradigm for the automatic segmentation of normal MR brain images. Unfortunately, atlas-based segmentation has been of limited use in presence of large space-occupying lesions. In fact, brain deformations induced by such lesions are added to normal anatomical variability and they may dramatically shift and deform anatomically or functionally important brain structures. In this work, we chose to focus on the problem of inter-subject registration of MR images with large tumors, inducing a significant shift of surrounding anatomical structures. First, a brief survey of the existing methods that have been proposed to deal with this problem is presented. This introduces the discussion about the requirements and desirable properties that we consider necessary to be fulfilled by a registration method in this context: To have a dense and smooth deformation field and a model of lesion growth, to model different deformability for some structures, to introduce more prior knowledge, and to use voxel-based features with a similarity measure robust to intensity differences. In a second part of this work, we propose a new approach that overcomes some of the main limitations of the existing techniques while complying with most of the desired requirements above. Our algorithm combines the mathematical framework for computing a variational flow proposed by Hermosillo et al. [G. Hermosillo, C. Chefd'Hotel, O. Faugeras, A variational approach to multi-modal image matching, Tech. Rep., INRIA (February 2001).] with the radial lesion growth pattern presented by Bach et al. [M. Bach Cuadra, C. Pollo, A. Bardera, O. Cuisenaire, J.-G. Villemure, J.-Ph. Thiran, Atlas-based segmentation of pathological MR brain images using a model of lesion growth, IEEE Trans. Med. Imag. 23 (10) (2004) 1301-1314.]. Results on patients with a meningioma are visually assessed and compared to those obtained with the most similar method from the state-of-the-art.

The activity of Crocidura russula (Insectivora, Soricidae) in the field and in captivity

Studied was the activity of the shrew Crocidura russula in the field (by radioactive tracking) and in laboratory (by continuous recording of nest temperature and by video). Under natural conditions, the total daily activity remained nearly constant throughout the year accounting for about 33 % of the total time. Activity was polyphasic and showed a daily rhythm; on an average, one activity phases occured every two hours and lasted 36 min. The activity periods of captive shrews were generally shorter, but always more frequent, and the total daily activity of captive shrews was much lower in winter. Two experiments carried out in the filed on shrews artificially fed, demonstrated that under natural conditions, foraging takes a major part of the winter activity. The activity patterns of Crocidura russula are compared with those of another European shrew, Sorex araneus.

Are invasive marsh frogs (Pelophylax ridibundus) replacing the native P. lessonae /P. esculentus hybridogenetic complex in Western Europe? Genetic evidence from a field study.

The water-frog L-E system, widespread in Western Europe, comprises the pool frog Pelophylax lessonae and the hybridogenetic edible frog P. esculentus, which originated from hybridization between pool frogs and marsh frogs (P. ridibundus). In P. esculentus, the lessonae (L) genome is eliminated during meiosis and has to be gained anew each generation from a P. lessonae partner, while the ridibundus (R') genome is transmitted clonally. It therefore accumulates deleterious mutations, so that R'R' offspring from P. esculentus x P. esculentus crosses are normally unviable. This system is now threatened by invasive P. ridibundus (RR) imported from Eastern Europe and the Balkans. We investigated the genetic interactions between invasive marsh frogs and native water frogs in a Swiss wetland area, and used genetic data collected in the field to validate several components of a recently postulated mechanism of species replacement. We identified neo-ridibundus individuals derived from crosses between invasive ridibundus and native esculentus, as well as newly arisen hybridogenetic esculentus lineages stemming from crosses between invasive ridibundus (RR) and native lessonae (LL). As their ridibundus genomes are likely to carry less deleterious mutations, such lineages are expected to produce viable ridibundus offspring, contributing to species replacement. However, such crosses with invasive ridibundus only occurred at a limited scale; moreover, RR x LL crosses did not induce any introgression from the ridibundus to the lessonae genome. We did not find any ridibundus stemming from crosses between ancient esculentus lineages. Despite several decades of presence on the site, introduced ridibundus individuals only represent 15% of sampled frogs, and their spatial distribution seems shaped by specific ecological requirements rather than history of colonization. We therefore expect the three taxa to coexist stably in this area.

The central Sesia-Lanzo zone (Western Italian Alps) - New field observations and lithostratigraphic subdivisions

An extensive study of the central part of the Sesia Lanzo Zone has been undertaken to identify pre-Alpine protoliths and to reconstruct the lithologic and tectonic setting of this part of the Western Alps. Three main complexes have been defined: 1) the Polymetamorphic Basement Complex, corresponding to the lower unit of the Sesia Lanzo Zone after COMPAGNONI et al. (1977), is further subdivided into the three following units: a) an Internal Unit characterized by eo-Alpine high pressure (HP) assemblages (DAL PIAZ et al., 1972) (Eclogitic Micaschists); b) an Intermediate Unit where HP parageneses are partially re-equilibrated under greenschist conditions and c) an External Unit where the main foliation is defined by a greenschist paragenesis (Gneiss Minuti auct.). 2) the Monometamorphic Cover Complex, subdivided into the followings: a) the Bonze Unit, composed of sheared metagabbros, eclogitized metabasalts with MORB geochemical affinity and related metasediments (micaschists, quartzites and Mn-cherts) and b) the Scalaro Unit, containing predominantly metasediments of supposed Permo-Triassic age (yellow dolomitic marbles, calcschists and conglomeratic limestones, micaschists and quartzites with thin levels of basic rocks with within plate basalts [WPB] geochimical affinity). Multiple lithostratigraphic sequences for the Monometamorphic Cover Complex are proposed. The contact between the Bonze and Scalaro Units is defined by repetitions of dolomitic marbles and metabasalts; the ages of the metasediments have been assigned solely by analogy with other sediments of the Western Alps, due to the absence of fossils. The Monometamorphic Cover Complex can be considered as the autochthonous cover of the Sesia Lanzo Zone because of the primary contacts with the basement and because of the presence of preAlpine HT basement blocks in the cover sequences. 3) The pre-Alpine high temperature (HT) Basement Complex (or `'Seconda Zona Diorito-Kinzigitica''), comprises HT Hercynian rocks like kinzigites, amphibolites, granulites and calcite marbles; this Complex is always located between the Internal and the External Units and can be followed continuously for several kilometers south of the Gressoney Valley to the Orco Valley. A schematic evolution for the Sesia Lanzo Zone is proposed; based on available data together with new geochronological data, this study shows that the internal and external parts of the polymetamorphic basement of the Sesia Zone experienced different cooling histories .