Calorimetry of dehydrogenation and dangling-bond recombination in several hydrogenated amorphous silicon materials

Differential scanning calorimetry (DSC) was used to study the dehydrogenation processes that take place in three hydrogenated amorphous silicon materials: nanoparticles, polymorphous silicon, and conventional device-quality amorphous silicon. Comparison of DSC thermograms with evolved gas analysis (EGA) has led to the identification of four dehydrogenation processes arising from polymeric chains (A), SiH groups at the surfaces of internal voids (A'), SiH groups at interfaces (B), and in the bulk (C). All of them are slightly exothermic with enthalpies below 50 meV/H atoms , indicating that, after dissociation of any SiH group, most dangling bonds recombine. The kinetics of the three low-temperature processes [with DSC peak temperatures at around 320 (A),360 (A'), and 430°C (B)] exhibit a kinetic-compensation effect characterized by a linea relationship between the activation entropy and enthalpy, which constitutes their signature. Their Si-H bond-dissociation energies have been determined to be E (Si-H)0=3.14 (A), 3.19 (A'), and 3.28 eV (B). In these cases it was possible to extract the formation energy E(DB) of the dangling bonds that recombine after Si-H bond breaking [0.97 (A), 1.05 (A'), and 1.12 (B)]. It is concluded that E(DB) increases with the degree of confinement and that E(DB)>1.10 eV for the isolated dangling bond in the bulk. After Si-H dissociation and for the low-temperature processes, hydrogen is transported in molecular form and a low relaxation of the silicon network is promoted. This is in contrast to the high-temperature process for which the diffusion of H in atomic form induces a substantial lattice relaxation that, for the conventional amorphous sample, releases energy of around 600 meV per H atom. It is argued that the density of sites in the Si network for H trapping diminishes during atomic diffusion

Three-dimensional sequence stratigraphy and subtle stratigraphic traps associated with systems tracts: West Cameron region, offshore Louisiana, Gulf of Mexico

Three-dimensional sequence stratigraphy is a potent exploration and development tool for the discovery of subtle stratigraphic traps. Reservoir morphology, heterogeneity and subtle stratigraphic trapping mechanisms can be better understood through systematic horizontal identification of sedimentary facies of systems tracts provided by three-dimensional attribute maps used as an important complement to the sequential analysis on the two-dimensional seismic lines and the well log data. On new prospects as well as on already-producing fields, the additional input of sequential analysis on three-dimensional data enables the identification, location and precise delimitation of new potentially productive zones. The first part of this paper presents four typical horizontal seismic facies assigned to the successive systems tracts of a third- or fourth-order sequence deposited in inner to outer neritic conditions on a elastic shelf. The construction of this synthetic representative sequence is based on the observed reproducibility of the horizontal seismic facies response to cyclic eustatic events on more than 35 sequences registered in the Gulf coast Plio-Pleistocene and Late Miocene, offshore Louisiana in the West Cameron region of the Gulf of Mexico. The second part shows how three-dimensional sequence stratigraphy can contribute in localizing and understanding sedimentary facies associated with productive zones. A case study in the early Middle Miocene Cibicides opima sands shows multiple stacked gas accumulations in the top slope fan, prograding wedge and basal transgressive systems tract of the third-order sequence between SB15.5 and SB 13.8 Ma.

Transcutaneous carbon dioxide tension in newborn infants: reliability and safety of continuous 24-hour measurement at 42 degrees C.

In 58 newborn infants a new iridium oxide sensor was evaluated for transcutaneous carbon dioxide (tcPCO2) monitoring at 42 degrees C with a prolonged fixation time of 24 hours. The correlation of tcPCO2 (y; mm Hg) v PaCO2 (x; mm Hg) for 586 paired values was: y = 4.6 + 1.45x; r = .89; syx = 6.1 mm Hg. The correlation was not influenced by the duration of fixation. The transcutaneous sensor detected hypocapnia (PaCO2 less than 35 mm Hg) in 74% and hypercapnia (PCO2 greater than 45 mm Hg) in 74% of all cases. After 24 hours, calibration shifts were less than 4 mm Hg in 90% of the measuring periods. In 86% of the infants, no skin changes were observed; in 12% of infants, there were transitional skin erythemas and in 2% a blister which disappeared without scarring. In newborn infants with normal BPs, continuous tcPCO2 monitoring at 42 degrees C can be extended for as many as 24 hours without loss of reliability or increased risk for skin burns.

Assessment of terrestrial small mammals and a record of the critically endangered shrew Crocidura wimmeri in Banco National Park (Cote d'Ivoire)

This study investigated the small mammal community of the periurban Banco National Park (34 km(2)), Abidjan, Cote d'Ivoire, using identical numbers of Sherman and Longworth traps. We aimed to determine the diversity and distribution of rodents and shrews in three different habitats: primary forest, secondary forest and swamp. Using 5014 trap-nights, 91 individuals were captured that comprised seven rodent and four shrew species. The trapping success was significantly different for each species, i.e., the Longworth traps captured more soricids (31/36 shrews), whereas the Sherman traps captured more murids (37/55 mice). The most frequent species was Praomys cf. rostratus, followed by Crocidura buettikoferi, Hybomys trivirgatus and Crocidura jouvenetae. Indices of species richness (S) and diversity (H') were greatest in primary forest, followed by secondary forest and swamp. - Several expected species, such as Crocidura obscurior, were not found, whereas we captured four specimens of the critically endangered (IUCN 2012) Wimmer's shrew Crocidura wimmeri, a species that has vanished from its type locality, Adiopodoume. Therefore, Banco National Park represents an important sanctuary, not only for plants, birds and primates, but also for other small forest vertebrates.

Evaluation of Muscardinus avellanarius population density by nest box and by trap checking

Population densities of marked common dormice Muscardinus avellanarius are generally based on nest box checks. As dormice also use natural cavities and leaf nests, we tried to answer the question "what proportion of the population cannot be monitored by nest boy checks", using parallel trapping sessions. We selected a forest of 1.7ha where a 5-year nest box survey revealed an annual mean of 3.4 ± 1.4 dormice per check. The trap design (permanent grid of 77 hanging platforms) was developed in June. During July and August the traps were set every second week (4 sessions of two nights = 8 nights) resulting in a total of 75 captures with mean of 9.4 dormice per night and the presence of 16 different individuals. The grid of 60 nest boxes was checked weekly (8 times) which allowed the recapture of 19 dormice with a mean of 2.4 dormice, per control day and the presence of 6 different individuals. Population density estimated by calendar of capture and the minimal number of dormice alive methods gave for nest-box checks a value of 2.4 animals/ha and the trap checks 6.6 animals/ha with the conclusion that 63% of the population were not being monitored by nest box checks.

Social organization and mating system of free-ranging, greater white-toothed shrews, Crocidura russula

Indirect evidence from trapping suggests that Crocidura russula is less solitary and territorial than other shrews. To study the social organization and mating system, free-ranging adult and juvenile C. russula were tracked simultaneously throughout the year using a radioactive tracking technique. Coincident rest, coincident activity and home range overlap were measured. During winter, all individuals used the same communal nest and spent on average 84% of their total rest in coincident rest. This led to a large home range overlap (52% on average). Coincident activity was low (2% on average). At the onset of the reproductive season the females became, territorial and shared their nest with only one male. During pair formation, coincident activity and home range overlap were significantly greater between than within sexes. The social organization of C. russula appeared to be strongly influenced by season and differed in this respect from the other species in the genus Sorex which are territorial throughout the year.

A Novel Autonomous Observation Platform for Multi-Disciplinary Investigations at the Cape Verde Ocean Observatory (CVOO)

In order to investigate the spatial and temporal variability (daily, seasonal and inter-annual) of CO2 and O2 air-sea fluxes and their underlying processes, a dense network of observations is required. For this purpose, the Cape Verde Ocean Observatory (CVOO) provides a unique infrastructure. Information thus obtained also links biological productivity and atmospheric composition. To expand these capabilities, a novel “virtual mooring” approach for high resolution measurements, based on a modified NEMO profiling float, is pursued. This Profiling Float was equipped with O2 and pCO2 sensors for the first time, in order to collect daily depth profiles (0-200 m) in the vicinity of the ocean site. Data access and remote control is provided through Iridium satellite telemetry. Recalibrations and redeployments are carried out every 1-3 month. First, we present the new developed instrument and the innovative in situ and real-time approach behind. Second, we show the inter-disciplinary scientific objectives which will benefit from this approach as a result of the intensive partnership between IFM-GEOMAR and INDP during the last years.

The role of soil in vegetated gravelly river braid plains: more than just a passive response?

This paper reviews the role of alluvial soils in vegetated gravelly river braid plains. When considering decadal time scales of river evolution, we argue that it becomes vital to consider soil development as an emergent property of the developing ecosystem. Soil processes have been relatively overlooked in accounts of the interactions between braided river processes and vegetation, although soils have been observed on vegetated fluvial landforms. We hypothesise that soil development plays a major role in the transition (speed and pathway) from a fresh sediment deposit to a vegetated soil-covered landform. Disturbance (erosion and/or deposition), vertical sediment structure (process history), vegetation succession, biological activity and water table fluctuation are seen as the main controls on early alluvial soil evolution. Erosion and deposition processes may not only act as soil disturbing agents, but also as suppliers of ecosystem resources, because of their role in delivering and changing access (e.g. through avulsion) to fluxes of water, fine sediments and organic matter. In turn, the associated initial ecosystem may influence further fluvial landform development, such as through the trapping of fine-grained sediments (e.g. sand) by the engineering action of vegetation and the deposit stabilisation by the developing above and belowground biomass. This may create a strong feedback between geomorphological processes, vegetation succession and soil evolution which we summarise in a conceptual model. We illustrate this model by an example from the Allondon River (CH) and identify the research questions that follow.

The magmatic to hydrothermal evolution of the intrusive Mont Saint-Hilaire Complex: Insights into the late-stage evolution of peralkaline rocks

The Cretaceous Mont Saint-Hilaire complex (Quebec, Canada) comprises three major rock units that were emplaced in the following sequence: (I) gabbros; (II) diorites; (III) diverse partly agpaitic foid syenites. The major element compositions of the rock-forming minerals, age-corrected Nd and oxygen isotope data for mineral separates and trace element data of Fe-Mg silicates from the various lithologies imply a common source for all units. The distribution of the rare earth elements in clinopyroxene from the gabbros indicates an ocean island basalt type composition for the parental magma. Gabbros record temperatures of 1200 to 800 degrees C, variable silica activities between 0 center dot 7 and 0 center dot 3, and f(O2) values between -0 center dot 5 and +0 center dot 7 (log delta FMQ, where FMQ is fayalite-magnetite-quartz). The diorites crystallized under uniform a(SiO2) (a(SiO2) = 0 center dot 4-0 center dot 5) and more reduced f(O2) conditions (log delta FMQ similar to-1) between similar to 1100 and similar to 800 degrees C. Phase equilibria in various foid syenites indicate that silica activities decrease from 0 center dot 6-0 center dot 3 at similar to 1000 degrees C to < 0 center dot 3 at similar to 550 degrees C. Release of an aqueous fluid during the transition to the hydrothermal stage caused a(SiO2) to drop to very low values, which results from reduced SiO(2) solubilities in aqueous fluids compared with silicate melts. During the hydrothermal stage, high water activities stabilized zeolite-group minerals. Fluid inclusions record a complex post-magmatic history, which includes trapping of an aqueous fluid that unmixed from the restitic foid syenitic magma. Cogenetic aqueous and carbonic fluid inclusions reflect heterogeneous trapping of coexisting immiscible external fluids in the latest evolutionary stage. The O and C isotope characteristics of fluid-inclusion hosted CO(2) and late-stage carbonates imply that the surrounding limestones were the source of the external fluids. The mineral-rich syenitic rocks at Mont Saint-Hilaire evolved as follows: first, alkalis, high field strength and large ion lithophile elements were pre-enriched in the (late) magmatic and subsequent hydrothermal stages; second, percolation of external fluids in equilibrium with the carbonate host-rocks and mixing processes with internal fluids as well as fluid-rock interaction governed dissolution of pre-existing minerals, element transport and precipitation of mineral assemblages determined by locally variable parameters. It is this hydrothermal interplay between internal and external fluids that is responsible for the mineral wealth found at Mont Saint-Hilaire.

3D seismic facies characterization and geological patterns recognition (Australian North West Shelf)

EXECUTIVE SUMMARY This PhD research, funded by the Swiss Sciences Foundation, is principally devoted to enhance the recognition, the visualisation and the characterization of geobodies through innovative 3D seismic approaches. A series of case studies from the Australian North West Shelf ensures the development of reproducible integrated 3D workflows and gives new insight into local and regional stratigraphic as well as structural issues. This project was initiated in year 2000 at the Geology and Palaeontology Institute of the University of Lausanne (Switzerland). Several collaborations ensured the improvement of technical approaches as well as the assessment of geological models. - Investigations into the Timor Sea structural style were carried out at the Tectonics Special Research Centre of the University of Western Australia and in collaboration with Woodside Energy in Perth. - Seismic analysis and attributes classification approach were initiated with Schlumberger Oilfield Australia in Perth; assessments and enhancements of the integrated seismic approaches benefited from collaborations with scientists from Schlumberger Stavanger Research (Norway). Adapting and refining from "linear" exploration techniques, a conceptual "helical" 3D seismic approach has been developed. In order to investigate specific geological issues this approach, integrating seismic attributes and visualisation tools, has been refined and adjusted leading to the development of two specific workflows: - A stratigraphic workflow focused on the recognition of geobodies and the characterization of depositional systems. Additionally, it can support the modelling of the subsidence and incidentally the constraint of the hydrocarbon maturity of a given area. - A structural workflow used to quickly and accurately define major and secondary fault systems. The integration of the 3D structural interpretation results ensures the analysis of the fault networks kinematics which can affect hydrocarbon trapping mechanisms. The application of these integrated workflows brings new insight into two complex settings on the Australian North West Shelf and ensures the definition of astonishing stratigraphic and structural outcomes. The stratigraphic workflow ensures the 3D characterization of the Late Palaeozoic glacial depositional system on the Mermaid Nose (Dampier Subbasin, Northern Carnarvon Basin) that presents similarities with the glacial facies along the Neotethys margin up to Oman (chapter 3.1). A subsidence model reveals the Phanerozoic geodynamic evolution of this area (chapter 3.2) and emphasizes two distinct mode of regional extension for the Palaeozoic (Neotethys opening) and Mesozoic (abyssal plains opening). The structural workflow is used for the definition of the structural evolution of the Laminaria High area (Bonaparte Basin). Following a regional structural characterization of the Timor Sea (chapter 4.1), a thorough analysis of the Mesozoic fault architecture reveals a local rotation of the stress field and the development of reverse structures (flower structures) in extensional setting, that form potential hydrocarbon traps (chapter 4.2). The definition of the complex Neogene structural architecture associated with the fault kinematic analysis and a plate flexure model (chapter 4.3) suggest that the Miocene to Pleistocene reactivation phases recorded at the Laminaria High most probably result from the oblique normal reactivation of the underlying Mesozoic fault planes. This episode is associated with the deformation of the subducting Australian plate. Based on these results three papers were published in international journals and two additional publications will be submitted. Additionally this research led to several communications in international conferences. Although the different workflows presented in this research have been primarily developed and used for the analysis of specific stratigraphic and structural geobodies on the Australian North West Shelf, similar integrated 3D seismic approaches will have applications to hydrocarbon exploration and production phases; for instance increasing the recognition of potential source rocks, secondary migration pathways, additional traps or reservoir breaching mechanisms. The new elements brought by this research further highlight that 3D seismic data contains a tremendous amount of hidden geological information waiting to be revealed and that will undoubtedly bring new insight into depositional systems, structural evolution and geohistory of the areas reputed being explored and constrained and other yet to be constrained. The further development of 3D texture attributes highlighting specific features of the seismic signal, the integration of quantitative analysis for stratigraphic and structural processes, the automation of the interpretation workflow as well as the formal definition of "seismo-morphologic" characteristics of a wide range of geobodies from various environments would represent challenging examples of continuation of this present research. The 21st century will most probably represent a transition period between fossil and other alternative energies. The next generation of seismic interpreters prospecting for hydrocarbon will undoubtedly face new challenges mostly due to the shortage of obvious and easy targets. They will probably have to keep on integrating techniques and geological processes in order to further capitalise the seismic data for new potentials definition. Imagination and creativity will most certainly be among the most important quality required from such geoscientists.

Novas Pragas Agrícolas na Ilha de São Nicolau - Cabo Verde - Tuta absoluta (Meyrick) (Lep - Gelechiidae) e Bactrocera invadens (Drew, Tsuruta & White) (Dipt - Tephritidae)

Em algumas das ilhas do Arquipélago de Cabo Verde entraram, nos últimos dois anos, espécies invasoras que constituem pragas de culturas agrícolas e que têm apresentado elevada repercussão económica. Entre elas contam-se a traça do tomateiro, Tuta absoluta (Meyrick) (Lepidoptera: Gelechidae) e Bactrocera invadens (Drew, Tsuruta & White) (Diptera: Tephritidae). Com o objectivo de avaliar a presença destas pragas na ilha de São Nicolau, foram instaladas armadilhas com atractivos em quatro zonas com bananeiras (Ribeira Prata, Fajã, Maiama e Campo de Preguiça) para a monitorização da mosca da fruta. Foram também instaladas ensaios em seis parcelas de tomateiro para a comparação de estratégias de protecção contra T. absoluta, armadilha com feromona sexual para captura em massa em conjunto com Bacillus thuringiensis e tratamento com deltametrina. Das quatro zonas monitorizadas, B. invadens só foi encontrada no Vale da Fajã. No que diz respeito a T. absoluta, fez-se a comparação entre a população presente em três estratos do tomateiro e não se encontraram diferenças significativas. As estratégias de protecção contra T. absoluta também não diferiram significativamente no que se refere ao número de minas nas folhas e frutos furados. Nesidiocoris tenuis foi identificado como inimigo natural de T. absoluta presente na ilha.

A new species of Zamischus (Hymenoptera, Cynipoidea, Figitidae) from Brazil

A new species of Zamischus (Hymenoptera, Cynipoidea, Figitidae) from Brazil. A new species of Zamischus from Brazil is described and diagnosed. The species is closely related to Z. brasiliensis but differs in the morphology of antennae and scutellum. Z. aquilesi sp. nov. was collected via Malaise trapping in a tobacco field in Santa Cruz do Sul, Rio Grande do Sul.

Fruit flies (Diptera, Tephritidae) and their parasitoids on cultivated and wild hosts in the Cerrado-Pantanal ecotone in Mato Grosso do Sul, Brazil

Fruit flies (Diptera, Tephritidae) and their parasitoids on cultivated and wild hosts in the Cerrado-Pantanal ecotone in Mato Grosso do Sul, Brazil. Information on frugivorous flies in cultivated or wild host plants and their parasitoids in the Cerrado-Pantanal ecotone in Aquidauana, Mato Grosso do Sul is presented and discussed. Fruit fly samples were collected weekly in specific fruit trees, and McPhail® traps were installed in the same trees for a period of two years. The fruit flies infested ripe and unripe fruits of Averrhoa carambola L., Schoepfia sp., Psidium guajava L. and Pouteria torta (Mart.) Radlk and mature fruits of Anacardium occidentale L. and Inga laurina (Sw.) Willd. Nineteen fruit fly species were obtained with the combination of sampling methods (collecting fruits and trapping), nine of them obtained with both methods, five found only in fruits and five only in traps. This is the first record of Anastrepha striata Schiner in a species of Sapotaceae, as well as for A. castanea Norrbom and A. daciformes Bezzi in Schoepfia sp. (Olacaceae), and for A. distincta Greene in fruits of P. guajava in the state of Mato Grosso do Sul. Fruit collections simultaneously associated with capture of fruit flies by McPhail traps in the same host plants are essential to understand the diversity of fruit flies and their relationship with hosts and parasitoids. Species of Braconidae and Pteromalidae were recovered, where Doryctobracon areolatus (Szépligeti) was the most abundant parasitoid in larvae of tephritids infesting both cultivated and wild host fruits.

Indications, management, and complications of temporary inferior vena cava filters

PURPOSE: We describe the results of a preliminary prospective study using different recently developed temporary and retrievable inferior vena cava (IVC) filters. METHODS: Fifty temporary IVC filters (Gunther, Gunther Tulip, Antheor) were inserted in 47 patients when the required period of protection against pulmonary embolism (PE) was estimated to be less than 2 weeks. The indications were documented deep vein thrombosis (DVT) and temporary contraindications for anticoagulation, a high risk for PE, and PE despite DVT prophylaxis. RESULTS: Filters were removed 1-12 days after placement and nine (18%) had captured thrombi. Complications were one PE during and after removal of a filter, two minor filter migrations, and one IVC thrombosis. CONCLUSION: Temporary filters are effective in trapping clots and protecting against PE, and the complication rate does not exceed that of permanent filters. They are an alternative when protection from PE is required temporarily, and should be considered in patients with a normal life expectancy.

Resultados preliminares obtenidos a partir de una trampa Malaise situada en una zona mediterránea pirenaica

En este estudio se da cuenta de los distintos órdenes de artrópodos capturados mediante una trampa Malaise en Santa Coloma (Andorra) después de un año de muestreo. Han sido colectados 141.522 ejemplares pertenecientes a 20 órdenes distintos. El 99,5% corresponden a insectos, entre los cuales los dípteros (con el 74,1%), juntamente con los himenópteros (15,2%) y los homópteros (5,8%) constituyen más del 95% de las capturas realizadas. Se discute la fenología anual de los distintos grupos en el área de estudio y su relación con las circunstancias meteorológicas del año 1993. En general, las mayores abundancias de los principales grupos se registran entre la segunda mitad de la primavera y la primera mitad del verano debido a las condiciones xerotérmicas de dicha localidad.