Oxygen isotope compositions of iron oxides from high-grade BIF-hosted iron ore deposits of the Central Hamersley Province, Western Australia: Constraints on the evolution of hydrothermal fluids

The Hamersley province of northwest Australia is one of the world's premier iron ore regions with high-grade martite-microplaty hematite iron ore deposits mostly hosted within banded iron formation (BIF) sequences of the Brockman Iron Formations of the Hamersley Group. These high-grade iron ores contain between 60 and 68 wt percent Fe, and formed by the multistage interaction of hydrothermal fluids with the host BIF formation. The oxygen isotope compositions of magnetite and hematite from BIF, hydrothermal alteration assemblages, and high-grade iron Ore were analyzed from the Mount Tom Price, Paraburdoo, and Charmar iron ore deposits. The delta(18)O values of magnetite and hematite from hydrothermal alteration assemblages and high-grade iron ore range from -9.0 to -2.9 per mil, a depletion of 5 to 15 per mil relative to the host BIF. The delta(18)O values are spatially controlled by faults within the deposits, a response to higher fluid flux and larger influence the isotopic compositions by the hydrothermal fluids. The oxygen isotope composition of hydrothermal fluids (delta(18)O(fluid)) indicates that the decrease in the (18)O content of iron oxides was due to the interaction of both basinal brines and meteoric fluids with the original BIF. Late-stage talc-bearing ore at the Mount Tom Price deposit formed in the presence of a pulse of delta(18)O-enriched basinal brine, indicating that hydrothermal fluids may have repeatedly interacted with the BIFs during the Paleoproterozoic.

Traitement nutritionnel du grand brûlé [Nutritional therapy in major burns]

Résumé Les brûlures graves (> 20 % surface corporelle [SC]) entraînent un stress oxydatif intense, des perturbations métaboliques et une réponse inflammatoire caractérisées par leur intensité et par leur durée, sans comparaison avec celles observées dans les autres pathologies. La modulation de ces réponses est devenue un objectif thérapeutique. Le brûlé nécessite des apports élevés en énergie (35-50 kcal/kg par jour), en glucides et en protéines (1,5-2,5 g/kg par jour) et faibles en lipides (idéalement moins de 20 % de l'apport calorique). La supplémentation en glutamine contribue à normaliser la réponse immunitaire et accélère la cicatrisation. La voie entérale (gastrique ou postpylorique) est la voie de choix et doit être utilisée dès le jour de l'accident. Les déficits aigus et précoces de micronutriments sont causés par des pertes exudatives par la peau lésée : la substitution est bénéfique sur le plan biologique et clinique. Les doses nécessaires sont de l'ordre de cinq à dix fois celles utilisées dans d'autres indications de nutrition parentérale pendant sept à 30 jours selon la SC brûlée. L'insuline qui favorise l'anabolisme et le propranolol qui réduit le catabolisme font partie de l'arsenal thérapeutique standard. Le suivi nutritionnel (poids et préalbumine hebdomadaire) est essentiel pour vérifier la réponse au support nutritionnel.

Contrasting spatio-temporal climatic niche dynamics during the eastern and western invasions of spotted knapweed in North America

Aim The spotted knapweed (Centaurea stoebe), a plant native to south-east and central Europe, is highly invasive in North America. We investigated the spatio-temporal climatic niche dynamics of the spotted knapweed in North America along two putative eastern and western invasion routes. We then considered the patterns observed in the light of historical, ecological and evolutionary factors. Location Europe and North America. Methods The niche characteristics of the east and west invasive populations of spotted knapweed in North America were determined from documented occurrences over 120 consecutive years (1890-2010). The 2.5 and 97.5 percentiles of values along temperature and precipitation gradients, as given by the two first axes of a principal component axis (PCA), were then calculated. We additionally measured the climatic dissimilarity between invaded and native niches using a multivariate environmental similarity surface (MESS) analysis. Results Along both invasion routes, the species established in regions with climatic conditions that were similar to those in the native range in Europe. An initial spread in ruderal habitats always preceded spread in (semi-)natural habitats. In the east, the niche gradually increased over time until it reached limits similar to the native niche. Conversely, in the west the niche abruptly expanded after an extended time lag into climates not occupied in the native range; only the native cold niche limit was conserved. Main conclusions Our study reveals that different niche dynamics have taken place during the eastern and western invasions. This pattern indicates different combinations of historical, ecological and evolutionary factors in the two ranges. We hypothesize that the lack of a well-developed transportation network in the west at the time of the introduction of spotted knapweed confined the species to a geographically and climatically isolated region. The invasion of dry rangelands may have been favoured during the agricultural transition in the 1930s by release from natural enemies, local adaptation and less competitive vegetation, but further experimental and molecular studies are needed to explain these contrasting niche patterns fully. Our study illustrates the need and benefit of applying large-scale, temporally explicit approaches to understanding biological invasions.

U-Pb zircon dating in the middle Penninic basement of the Western Alps (Valais, Switzerland)

New ages (U-Pb isotopic data) on zircon and monazite in the pre-Alpine basement of the Penninic realm (Valais, Switzerland) are presented. They are related to a Variscan metamorphic high-grade event (ca. 330 Ma) and to post-Variscan magmatic activities (ca. 270 Ma).

Is There a Crime Drop in Western Europe?

Combining data from police statistics and crime victim surveys, this article analyses the evolution of crime in Western Europe from 1988 to 2007. The results show that there is no general drop in crime. Property offences and homicide have been decreasing since the mid 1990s, while violent and drug offences have increased during the period under study. These trends highlight the limits of the explanations to the crime drop in the United States, which are based on the premise of a correlation in the evolution of all offences. The drop in property offences seems related to changes in the socioeconomic situation in Europe as well as to increases in security measures in households, and the reinforcement of private security. The increase in violent offences can be explained by the combination of several factors, including changes in youth's free time provoked by the development of the Internet, changing demographics, and the rise of episodic heavy alcohol consumption and street gangs.

Constraints on the late thermotectonic evolution of the Western Alps - Evidence for episodic rapid uplift

Forty-two new apatite and zircon fission track ages are presented for samples from the Western Alps in southern Switzerland, northern Italy, and southeastern France. Measured ages plotted against assumed closure temperatures yield cooling patterns for the final cooling, uplift, and exhumation of the Western Alps. Similar fission track zircon ages in the Penninic Gran Paradiso massif, Dent Blanche nappe, Sesia-Lanzo Zone, and Ivrea Zone indicate cooling of all four units to approximately 225-degrees-C by 33 Ma. Differences in apatite ages reveal differential cooling of the four blocks between 33 Ma and the present. In the Sesia-Lanzo Zone, similarity of apatite ages regardless of elevation, together with near-volcanic confined fission track length patterns suggest rapid cooling and uplift at approximately 25 Ma compared with slow cooling of other Western Alps units around 12 Ma. Uplift is thus not continuous but episodic, often over a short time interval beyond the resolution of other methods. Such episodes of uplift, as revealed here in the Sesia-Lanzo Zone, may be the rule rather than the exception.

Opportunistic testing for urogenital infection with Chlamydia trachomatis in south-western Switzerland, 2012 : a feasibility study

The feasibility of opportunistic screening of urogenital infections with Chlamydia trachomatis was assessed in a cross-sectional study in 2012, in two cantons of south-western Switzerland: Vaud and Valais. Sexually active persons younger than 30 years, not tested for C. trachomatis in the last three months, were invited for free C. trachomatis testing by PCR in urine or self-applied vaginal swabs. Of 2,461 consenting participants, 1,899 (77%) were women and all but six (0.3%) submitted a sample. Forty-seven per cent of female and 25% of male participants were younger than 20 years. Overall, 134 (5.5%) of 2,455 tested participants had a positive result and were followed up. Seven per cent of all candidates for screening were not invited, 10% of invited candidates were not eligible, 15% of the eligible candidates declined participation, 5% of tested participants testing positive were not treated, 29% of those treated were not retested after six months and 9% of those retested were positive for C. trachomatis. Opportunistic C. trachomatis testing proved technically feasible and acceptable, at least if free of charge. Men and peripheral rural regions were more difficult to reach. Efforts to increase testing and decrease dropout at all stages of the screening procedure are necessary.

Le grand nymphée de Leptis Magna : étude historiographique, urbanistique et architecturale

RESUME en français Centrée sur le grand nymphée de Leptis Magna la recherche met en évidence l'évolution et la signification de ce monument des eaux dans l'une des plus importantes cités africaines de l'époque romaine en mettant en lumière trois thèmes principaux. L'étude historiographique permet tout d'abord d'appréhender, à l'aide des témoignages littéraires des siècles derniers et d'une abondante documentation d'archive, l'histoire de l'édifice de son ensablement à sa remise au jour, puis de suivre les différentes étapes de son dégagement et de sa restauration, mettant ainsi en relief la perception des divers observateurs à l'encontre du monument. L'étude urbanistique permet ensuite de dégager la signification de l'édifice dans la cité par rapport aux autres monuments du secteur aux différentes périodes de son histoire, ainsi que de reconstituer l'approvisionnement en eau de Leptis Magna. Enfin, l'étude architecturale s'intéresse à l'analyse détaillée des structures, permettant la mise en évidence de la conception initiale, du fonctionnement et des transformations du nymphée. Cette dernière approche, qui s'accompagne d'un catalogue circonstancié des éléments du décor, fait intervenir des considérations sur les techniques de constructions, le traitement des blocs d'ornementation et, d'une manière plus générale, sur ('économie du chantier. Cette recherche permet non seulement de reconstituer l'aspect, le rôle et l'histoire du monument et de le replacer dans la série des nymphées romains, mais aussi de percevoir son impact sur les habitants du lieu aux différents moments de son histoire, cherchant ainsi à rejoindre par l'archéologie des considérations sociologiques. THE GREAT SEVERAN NYMPHAEUM OF LEPTIS MAGNA: HISTORIOGRAPHICAL, URBANISTIC AND ARCHITECTURAL STUDY RESUME en anglais Based on the great nymphaeum of Leptis Magna, the research considers the development and significance of this water monument in one of the most important African cities of the Roman period, through three principal aspects. The historiographical study aboards the subject through literary testimony from the last centuries and an abundance of documentary archives, the history of the edifice from its burial to its reconstruction, studying the different stages of its unearthing and its restoration, thus pinpointing perspectives from various observers of the monument. The urban study divulges the significance of the edifice in the city, in comparison with other monuments in the region over different periods of its history, as well as reconstituting Leptis Magna's water supply. Finally, the architectural study undertakes a detailed analysis of the structures, which highlights the conception and the transformations of the nymphaeum, as well as its hydraulic functions. This architectural approach, which is accompanied by a detailed catalogue of the decorative elements, juxtaposes the technical considerations of construction with the ornamental treatment of the marble blocks, accounting for the economical aspects of the site of the nymphaeum. This research proposes not only a consideration of the appearance, the role and the history of the monument and situates it within the series of Roman nymphaea, but also the perception of its impact on the local inhabitants at different moments in its history, looking for accomplish by archaeology some sociological considerations.

New palaeontological investigations in the Jurassic of western Thailand

The paleontological investigations of the Jurassic of Western Thailand, districts of Mae Sot (Tak-Mae Sot highway, Padaeng Tak and Ban Mae Kut Luang Zinc mines) and Umphang (Klo Tho), provide age constraints for the Late Indosinian orogeny, the Paleotethys closure and the timing of the marine Jurassic inundation of Sundaland. The basal conglomerate of the Jurassic is derived from the pelagic Triassic Mae Sariang substratum. Stratigraphy, microfacies and paleontology of the Jurassic marine strata focus especially on ammonites, bivalves, large benthic foraminifera and algae. Among ammonites, the Tethyan Catulloceras perisphinctoides Gemmellaro marks the Upper Toarcian (Aalensis Zone) along the Tak-Mae Sot highway and Riccardiceras longalvum (Vacek). Malladaites pertinax (Vacek), Abbasites sp. and Vacekia sp. indicate Middle Aalenian to lowermost Bajocian in the Padaeng Mine (SE of Mae Sot) and Klo-Tho (Umphang). Vacekia sp., Spinammatoceras schindewolfi Linares and Sandoval and Malladaites vaceki Linares and Sandoval indicate Middle Aalenian to lowermost Upper Aalenian at Ban Mae Kut Luang (NE of Mae Sot). Among foraminifers, the large benthic foraminifer Timidonella sarda Bassoullet, Chabrier and Fourcade in the Western Tethys is indicative for Aalenian-Bajocian times, as characterized in the section at the Tak-Padaeng Zinc mine and the Klo-Tho Formation near Umphang. The endemic foraminifer Gutnicella kaempferi characterizes the Pu Khloe Khi Formation near Umphang. Among bivalves, shallow marine, dominantly endemic fauna includes Parvamussium donaiense (Mansuy) and Bositra ornate (Quenstedt), from the Toarcian to the Early Bajocian. A consideration of the faunal affinity shows that the fauna is partly endemic with Northern Tethyan (Eurasian) affinity. Crown Copyright (C) 2010 Published by Elsevier B.V. on behalf of International Association for Gondwana Research. All rights reserved.