(Table 1) Results of pore water analyses, including boron content and boron isotope ratios

Drilling a transect of holes across the Costa Rica forearc during ODP Leg 170 demonstrated the margin wedge to be of continental, non accretionary origin, which is intersected by permeable thrust faults. Pore waters from four drillholes, two of which penetrated the décollement zone and reached the underthrust lower plate sedimentary sequence of the Cocos Plate, were examined for boron contents and boron isotopic signatures. The combined results show dilution of the uppermost sedimentary cover of the forearc, with boron contents lower than half of the present-day seawater values. Pore fluid "refreshening" suggests that gas hydrate water has been mixed with the sediment interstitial water, without profoundly affecting the d11B values. Fault-related flux of a deeply generated fluid is inferred from high B concentration in the interval beneath the décollement, being released from the underthrust sequence with incipient burial. First-order fluid budget calculations over a cross-section across the Costa Rica forearc indicate that no significant fluid transfer from the lower to the upper plate is inferred from boron fluid profiles, at least within the frontal 40 km studied. Expulsed lower plate pore water, which is estimated to be 0.26-0.44 km3 per km trench, is conducted efficiently along and just beneath the décollement zone, indicating effective shear-enhanced compaction. In the upper plate forearc wedge, dewatering occurs as diffuse transport as well as channelled flow. A volume of approximately 2 km3 per km trench is expulsed due to compaction and, to a lesser extent, lateral shortening. Pore water chemistry is influenced by gas hydrate instability, so that it remains unknown whether deep processes like mineral dehydration or hydrocarbon formation may play a considerable role towards the hinterland.

Ecological classification of Herschel Island based on supervised classification of multispectral satellite imagery

Permafrost landscapes experience different disturbances and store large amounts of organic matter, which may become a source of greenhouse gases upon permafrost degradation. We analysed the influence of terrain and geomorphic disturbances (e.g. soil creep, active-layer detachment, gullying, thaw slumping, accumulation of fluvial deposits) on soil organic carbon (SOC) and total nitrogen (TN) storage using 11 permafrost cores from Herschel Island, western Canadian Arctic. Our results indicate a strong correlation between SOC storage and the topographic wetness index. Undisturbed sites stored the majority of SOC and TN in the upper 70 cm of soil. Sites characterised by mass wasting showed significant SOC depletion and soil compaction, whereas sites characterised by the accumulation of peat and fluvial deposits store SOC and TN along the whole core. We upscaled SOC and TN to estimate total stocks using the ecological units determined from vegetation composition, slope angle and the geomorphic disturbance regime. The ecological units were delineated with a supervised classification based on RapidEye multispectral satellite imagery and slope angle. Mean SOC and TN storage for the uppermost 1?m of soil on Herschel Island are 34.8 kg C/m**2 and 3.4 kg N/m**2, respectively.

Shear Strength of Granular Materials, 1967

A theory was developed to allow the separate determination of the effects of the interparticle friction and interlocking of particles on the shearing resistance and deformational behavior of granular materials. The derived parameter, angle of solid friction, is independent of the type of shear test, stress history, porosity and the level of confining pressure, and depends solely upon the nature of the particle surface. The theory was tested against published data concerning the performance of plane strain, triaxial compression and extension tests on cohesionless soils. The theory also was applied to isotropically consolidated undrained triaxial tests on three crushed limestones prepared by the authors using vibratory compaction. The authors concluded that, (1) the theory allowed the determination of solid friction between particles which was found to depend solely on the nature of the particle surface, (2) the separation of frictional and volume change components of shear strength of granular materials qualitatively corroborated the postulated mechanism of deformation (sliding and rolling of groups of particles over other similar groups with resulting dilatancy of specimen), (3) the influence of void ratio, gradation confining pressure, stress history and type of shear test on shear strength is reflected in values of the omega parameter, and (4) calculation of the coefficient of solid friction allows the establishment of the lower limit of the shear strength of a granular material.

Validation of Gyratory Mix Design in Iowa, TR-667, 2016

The design number of gyrations (Ndesign) introduced by the Strategic Highway Research Program (SHRP) and used in the Superior Performing Asphalt Pavement (Superpave) mix design method has been commonly used in flexible pavement design throughout the US since 1996. Ndesign, also known as the compaction effort, is used to simulate field compaction during construction and has been reported to produce air voids that are unable to reach ultimate pavement density within the initial 2 to 3 years post-construction, potentially having an adverse impact on long-term performance. Other state transportation agencies have conducted studies validating the Ndesign for their specific regions, which resulted in modifications of the gyration effort for the various traffic levels. Validating this relationship for Iowa asphalt mix designs will lead to better correlations between mix design target voids, field voids, and performance. A comprehensive analysis of current Ndesign levels investigated the current levels with existing mixes and pavements and developed initial asphalt mix design recommendations that identify an optimum Ndesign through the use of performance data tests.

Développement à visée clinique d’une prothèse vasculaire décellularisée de faible diamètre produite par génie tissulaire

Il existe un besoin clinique pour les prothèses vasculaires de faible diamètre (< 6 mm), notamment pour effectuer des pontages vasculaires. Les prothèses synthétiques de faible diamètre, n’ayant pas d’endothélium, sont sujettes à la thrombose. Ainsi les chirurgiens préfèrent utiliser les vaisseaux autologues des patients. Pour cela, la veine saphène est de loin la plus utilisée. Cependant, de nombreux patients n’ont pas de vaisseaux adéquats, soit parce qu’ils ont déjà été utilisés, soit parce qu’ils sont malades. Pour pallier ce manque, le LOEX a développé un substitut vasculaire reconstruit en laboratoire par la méthode d’auto-assemblage du génie tissulaire. Ces substituts, faits à partir de cellules humaines, ont une longue période de production et ne peuvent être faits à l’avance ni préservés. L’objectif principal de cette thèse est le développement d’une prothèse vasculaire de faible diamètre facilitant le transfert du laboratoire vers la clinique. S’inspirant de travaux antérieurs, les travaux focalisent sur des prothèses obtenues à partir de fibroblastes dermiques humains puis décellularisés. Comme la réponse immunitaire se fait principalement contre les cellules et non pas contre la matrice extracellulaire, la décellularisation permet de gagner une compatibilité immunitaire inter-individu, voire inter-espèce. Ainsi, des prothèses ont été implantées dans six rats pendant six mois sans immunosuppression avec un taux de succès de 83%. Les explants présentaient une infiltration cellulaire suggérant la formation d’une nouvelle media recouverte d’un endothélium. Par ailleurs, nous avons démontré qu’il était également possible de produire des prothèses de grandeur et diamètre adéquats pour une utilisation clinique. Ces prothèses ont été préservées durant trois mois sans altérer leurs propriétés mécaniques. Nous avons également endothélialisé des vaisseaux qui ont ensuite été conditionnés en bioréacteur durant une semaine. Le processus entraînait une compaction de la matrice extracellulaire et un gain dans la résistance à la traction du matériau. En conclusion, les prothèses vasculaires décellularisées offrent deux avantages majeurs facilitant ainsi les essais précliniques et accélérant leur transfert du laboratoire vers les patients.

Spatial and temporal interaction between sediment and microphytobenthos in a temperate estuarine macro-intertidal bay

Intertidal flats of the estuarine macro-intertidal Baie des Veys (France) were investigated to identify spatial features of sediment and microphytobenthos (MPB) in April 2003. Gradients occurred within the domain, and patches were identified close to vegetated areas or within the oyster-farming areas where calm physical conditions and biodeposition altered the sediment and MPB landscapes. Spatial patterns of chl a content were explained primarily by the influence of sediment features, while bed elevation and compaction brought only minor insights into MPB distribution regulation. The smaller size of MPB patches compared to silt patches revealed the interplay between physical structure defining the sediment landscape, the biotic patches that they contain, and that median grain-size is the most important parameter in explaining the spatial pattern of MPB. Small-scale temporal dynamics of sediment chl a content and grain-size distribution were surveyed in parallel during 2 periods of 14 d to detect tidal and seasonal variations. Our results showed a weak relationship between mud fraction and MPB biomass in March, and this relationship fully disappeared in July. Tidal exposure was the most important parameter in explaining the summer temporal dynamics of MPB. This study reveals the general importance of bed elevation and tidal exposure in muddy habitats and that silt content was a prime governing physical factor in winter. Biostabilisation processes seemed to behave only as secondary factors that could only amplify the initial silt accumulation in summer rather than primary factors explaining spatial or long-term trends of sediment changes.

Desempenho de sulcadores no desenvolvimento e produtividade da soja em solo submetido a diferentes níveis de compactação

On the national scene, soybean crop occupies a prominent position in cultivated area and volume production, being cultivated largely in the no tillage system. This system, due to the intense traffic of machines and implements on its surface has caused soil compaction problems, which has caused the yield loss of crops. In order to minimize this effect the seeder-drill uses the systems to opening the furrow by shank or the double disc type. The use of the shank has become commonplace for allowing the disruption of the compacted surface layer, however requires greater energy demand and may cause excessive tillage in areas where there is not observed high levels of compaction. Thus, this study aimed to evaluate the effects of furrowers mechanisms and levels of soil compacting on traction requirement by a seeder-drill and on the growing and productivity of soybean in an Oxisol texture clay, in a two growing seasons. The experimental design consisted of randomized blocks with split plots with the main plots composed of four levels of soil compaction (N0 – no tillage without additional compaction, N1, N2 and N3 – no tillage subjected to compaction through two, four and six passes with tractor, respectively) corresponding to densities of soil 1.16, 1.20, 1.22 and 1.26 g cm-3, and subplots by two furrowers mechanisms (shank and double disc) with four replicates. To evaluate the average, maximum and specific traction force requested by the seeder-drill, was used a load cell, with capacity of 50 kN and sensitivity of 2 mV V-1, coupled between the tractor and seeder-drill, whose data are stored in a datalogger system model CR800 of Campbell Scientific. In addition, were evaluated the bulk density, soil mechanical resistance to penetration, sowing depth, depth and groove width, soil area mobilized, emergence speed index, emergence operation, final plant stand, stem diameter, plant height, average number of seeds per pod, weight of 1,000 seeds, number of pods per plant and crop productivity. Data were subjected to analysis of variance, the mean of furrowers were compared by Tukey test (p≤0.05), while for the factor soil compaction, polynomial regression analysis was adopted, selected models by the criterion of greater R2 and significance (p≤0.05) of equation parameters. Regardless of the crop season, penetration resistance increase as soil compaction levels up to around 0.20 m deep, and bulk density influenced the sowing quality parameters, however, did not affect the crop yield. In the first season, there was a higher productivity with the use of the shank type. In the second crop season, the shank demanded greater energetic requirement with the increase of bulk density and opposite situation with the double disc. The locking of sowing lines allow better performance of the shank to break the compacted layer.

Qualidade física e matéria orgânica do solo em sistema de integração lavoura - pecuária submetido a doses de nitrogênio

The animal trampling favors the soil compaction process in sheep raising and crop production integrated systems. This compression has negative effects, hindering the development of roots, the availability of nutrients, water and aeration, causing production losses, making it essential for the assessment of soil physical attributes for monitoring soil quality. Soil organic matter can be used to assess the quality of the soil, due to its relationship with the chemical, physical and biological soil properties. Conservation management system with tillage, along with systems integration between crops and livestock are being used to maintain and even increase the levels of soil organic matter. For that, a field experiment was carried out over a Oxisol clayey Alic in Guarapuava, PR, from de 2006 one. experiment sheep raising and crop production integrated systems The climate classified as Cfb .. The study was to evaluate the soil physical properties and quantify the stock of soil organic carbon and its compartmentalization in system integration crop - livestock with sheep under four nitrogen rates (0, 75, 150 and 225 kg ha-1) in the winter pasture, formed by the consortium oat (Avena strigosa) and ryegrass (Lolium multiflorum) and the effect of grazing (with and without). The soil samples blades density evaluations, total porosity, macro and micro, aggregation and carbon stocks were held in two phases: Phase livestock (after removal of the animals of the area) and phase crop (after maize cultivation). The collection of soil samples were carried out in layers of 0-0.5, 0.05-0.10, 0.10-0.20 and m. Data were subjected to analysis of variance and the hypotheses tested by the F test (p <0.05). For the quantitative effect data regression and the qualitative effect used the test medium. In non-significant regressions used the average and standard deviation treatments. The animal trampling caused an increase in bulk density in the 0.10-0.20 m layer. The dose of 225 kg N ha-1 in winter pasture increased total soil porosity at 8% compared to dose 0 kg N ha-1 in the crop stage. The grazing had no effect on soil macroporosity. GMD of aggregates in the phase after grazing the surface layer was damaged by grazing. Nitrogen rates used in the winter pasture and grazing not influence the total organic carbon stocks. The TOC is not influenced by nitrogen fertilization on grassland. The grazing increases the stock of POC in the 0.10-0.20 m layer livestock phase and cause the stock of POC in the 0-0.5 m layer in the crop stage. The MAC is not influenced by N rates applied in the pasture or by grazing.

Measuring nitrous oxide emissions from conventional and controlled release fertilisers in south-east Queensland pineapple production

Nitrous oxide (N2O) is a potent greenhouse gas with a global warming potential 298 times higher than carbon dioxide. Soils are a natural source of N2O, contributing 65% of global emissions. This paper is the first in Australia to measure and compare N2O emissions from pre-plant controlled release (CR) and conventional granular (CV) fertilisers in pineapple production using static PVC chambers to capture N2O emissions. Farm 1 cumulative emissions from the CR fertiliser were 3.22 kg ha-1 compared to 6.09 kg ha-1 produced by the CV. At farm 2 the CV blend emitted 2.36 kg ha-1 in comparison to the CR blend of 2.92 kg ha-1. Daily N2O flux rates showed a relationship of direct response to rainfall and soil moisture availability. High emissions were observed for wheel tracks where increased N2O emissions may be linked to soil compaction and waterlogging that creates anaerobic conditions after rain events. Emission measurements over three months highlighted the inconsistencies found in other studies relative to reducing emissions through controlled release nitrogen. More investigations are required to verify the benefits associated with controlled release fertiliser use in pineapples, placement and seasonal timing to address N2O emissions in pineapples.

Novel insights into mitotic chromosome condensation

The fidelity of mitosis is essential for life, and successful completion of this process relies on drastic changes in chromosome organization at the onset of nuclear division. The mechanisms that govern chromosome compaction at every cell division cycle are still far from full comprehension, yet recent studies provide novel insights into this problem, challenging classical views on mitotic chromosome assembly. Here, we briefly introduce various models for chromosome assembly and known factors involved in the condensation process (e.g. condensin complexes and topoisomerase II). We will then focus on a few selected studies that have recently brought novel insights into the mysterious way chromosomes are condensed during nuclear division.

Efeitos da adição da cal hidratada na estabilização de um solo sedimentar para pavimentação urbana na região de Curitiba

Urban paving is of paramount importance for a city, both socioeconomic and in quality of life. The urban flooring not different so-called road surface are constituted by a set of horizontal layers, overlaid on the ground, which have the main function of supporting the actions induced by the vehicle redistributing the stresses transmitted to the ground. Soils are important materials for the execution of paving, mainly because they are part of the basic structure of the floor and mostly be available in abundance, with a very low cost, however, their properties usually do not meet the requirements necessary to perform the floor. The soil stabilization for the implementation of urban pavement bases and sub-bases is an increasingly important aspect in the current situation, because always there is the concern with the environment, and there is now the clear awareness that every effort should be made to minimize the effects caused by the exploitation of deposits and deposition of material. In this sense this work presents the effects of adding different proportions of lime to stabilize a sedimentary soil sample from the urban area of the city of Curitiba. It selected a sample quantity of soil in the region to study the stabilization insertion of hydrated lime type (CHIII) powder. The two variables in the study are related to the content of lime mixed with the soil at 0% percentages of 3%, 6%, 8% and 16%, and cure times at which these mixtures were subjected to (0, 7, 14, 28 and 56 days). The tested mixtures were prepared from dosages defined by two methods: one checking the chemical behavior of the samples by means of changes in pH values, and the second analyzing the mechanical behavior through the RCS values. It has been found that the chemical stability analyzed by addition of lime, provided an average increase of RCS in most soil samples studied, because of some physical and chemical characteristics thereof. For mixtures with 6%, 8% and 16% of lime after 28 days of curing, the average RCS was 0,57 MPa, 1,06 MPa and 2,37 MPa, respectively, for the normal proctor, and as for intermediate proctor, in the same curing time and on the same percentages RCS results were 0,54 MPa, 1,04 MPa and 2,71 MPa, respectively. In global terms, the soil-lime mixtures studied showed acceptable behavior by law to use as layers of sub-base. However, only the mixture with 16% of lime, at 28 days, is recommended for use on floors bases. Even so, the mixtures studied constitute a good alternative economic and socio-environmental.

Small strain elastic behaviour of unsaturated soil investigated by bender/extender element testing

The aim of this project was to investigate very small strain elastic behaviour of soils under unsaturated conditions, using bender/extender element (BEE) testing. The behaviour of soils at very small strains has been widely studied under saturated conditions, whereas much less work has been performed on very small strain behaviour under unsaturated conditions. A suction-controlled double wall triaxial apparatus for unsaturated soil testing was modified to incorporate three pairs of BEEs transmitting both shear and compression waves with vertical and horizontal directions of wave transmission and wave polarisation. Various different techniques for measuring wave travel time were investigated in both the time domain and the frequency domain and it was concluded that, at least for the current experimental testing programme, peak-to-first-peak in the time domain was the most reliable technique for determining wave travel time. An experimental test programme was performed on samples of compacted speswhite kaolin clay. Two different forms of compaction were employed (i.e. isotropic and anisotropic). Compacted kaolin soil samples were subjected to constant suction loading and unloading stages at three different values of suction, covering both unsaturated conditions (s= 50kPa and s= 300kPa) and saturated conditions (s=0). Loading and unloading stages were performed at three different values of stress ratio (η=0, η=1 and η=-1 ). In some tests a wetting-drying cycle was performed before or within the loading stage, with the wetting-drying cycles including both wetting-induced swelling and wetting-induced collapse compression. BEE tests were performed at regular intervals throughout all test stages, to measure shear wave velocity Vs and compression wave velocity Vp and hence to determine values of shear modulus G and constrained modulus M. The experimental test programme was designed to investigate how very small strain shear modulus G and constrained modulus M varied with unsaturated state variables, including how anisotropy of these parameters developed either with stress state (stress-induced anisotropy) or with previous straining (strain-induced anisotropy). A new expression has been proposed for the very small strain shear modulus G of an isotropic soil under saturated and unsaturated conditions. This expression relates the variation of G to only mean Bishop’s stress p* and specific volume v, and it converges to a well-established expression for saturated soils as degree of saturation approaches 1. The proposed expression for G is able to predict the variation of G under saturated and unsaturated conditions at least as well as existing expressions from the literature and it is considerably simpler (employing fewer state variables and fewer soil constants). In addition, unlike existing expressions from the literature, the values of soil constants in the proposed new expression can be determined from a saturated test. It appeared that, in the current project at least, any strain-induced anisotropy of very small strain elastic behaviour was relatively modest, with the possible exception of loading in triaxial extension. It was therefore difficult to draw any firm conclusion about evolution of strain-induced anisotropy and whether it depended upon the same aspects of soil fabric as evolution of anisotropy of large strain plastic behaviour. Stress-induced anisotropy of very small strain elastic behaviour was apparent in the experimental test programme. An attempt was made to extend the proposed expression for G to include the effect of stress-induced anisotropy. Interpretation of the experimental results indicated that the value of shear modulus was affected by the values of all three principal Bishop’s stresses (in the direction of wave transmission, the direction of wave polarisation and the third mutually perpendicular direction). However, prediction of stress-induced anisotropy was only partially successful, and it was concluded that the effect of Lode angle was also significant.

Sequence stratigraphy and sea-level history of Kangan formation in south pars field

Dehram group includes Faraghan, Dalan and Kangan formations. Kangan formation ages lower terias. That is one of the important reservoir rocks of southern Iran and Persian Gulf. In this research Kangan formation is studied in two A and B wells. Based on 75 studies on thin section, four carbonate litho acies association A, B, C, D with 12 subfacies are identified. A lithofacies association includes 4 subfacies: A1, A2, A3 and A4. B lithofacies association consists of 3 subfacies: B1, B2 and B3. C lithofacies association consists of 3 subfacies: C1, C2, C3 and D lithofacies association includes 2 subfacies: D1 and D2. On the base of studies lithofacies association of Kangan formations are formed in 3 environments of: Tidal Flat, Lagoon and Barrier Shore Complex in a Carbonated Platform Ramp type. Diagenetic processes have effected this formation. The most important Diagenetic processes are: Cementation, Anhydritization, Micrization, Neomorphism, Bioturbation, Dissolution, Compaction, Dolomitization and Porosity. Sequence staratigraphy studies were performed base on the vertical and horizontal relationship of lithofacies association and well logging in gamma ray and sonic type that causes the identification of two sedimentary sequences: First sedimentary sequence includes: Transgressive System Tract (TST) and High Stand System Tract (HST). The lower boundary of this sequence is in Sequence Boundary 1 (SB1) which shows unconformities of Dalan and Kangan that are Permian-terias unconformities. The upper boundary is in Sequence Boundary 2 (SB2) type that is identified by carbonate facies associated by anhydrite nodular. Second sedimentary sequence includes: TST and HST. Lower and upper boundaries of these sequences are both in SB2 type. The lower and upper boundary is made of carbonate facies with anhydrite nodular.

Exact solutions for cluster-growth kinetics with evolving size and shape profiles

In this paper we construct a model for the simultaneous compaction by which clusters are restructured, and growth of clusters by pairwise coagulation. The model has the form of a multicomponent aggregation problem in which the components are cluster mass and cluster diameter. Following suitable approximations, exact explicit solutions are derived which may be useful for the verification of simulations of such systems. Numerical simulations are presented to illustrate typical behaviour and to show the accuracy of approximations made in deriving the model. The solutions are then simplified using asymptotic techniques to show the relevant timescales of the kinetic processes and elucidate the shape of the cluster distribution functions at large times.

Resistência do solo à penetração e ao cisalhamento em diversos usos do solo em áreas de preservação permanente

The soil resistance to penetration and shear can be used as indicators of soil compaction and to indicate the susceptibility of a soil to erosion. The objective of this study was to quantify and compare the impact provided by different land uses in a haplic cambissol in areas of permanent preservation, from the soil resistance to penetration and shear. The experimental area was located in an area of permanent preservation, the sub-basin of the Ribeira Iguape River - SP, with different land uses: banana cultivation - CBAN, degraded pasture - PDEG, silvopastoral system - MPIS and native forest - MNAT. The test for resistance to penetration was accomplished with a digital penetrometer compaction of manual effort, to a depth of 40 cm. The soil shear strength was determined by Vane Test at a depth between 0 and 5 cm. The degraded pasture was similar to native forest, with less resistance to penetration. The banana cultivation and silvopastoral system were the land uses with the highest resistance to penetration, bringing serious risk of erosion in areas of permanent preservation. The soil under native forest had lower shear strength. The cultivation of bananas, degraded pasture and silvopastoral system were the land uses with higher shear strength of soil, indicating that the use of these soils in areas of permanent preservation is promoting the same compression.