The characterization of gas migration through low-permeability clay formations has been a focus of R&D programs for radioactive waste disposal, which is also of great importance for shale gas ...exploration, cap-rock behavior of hydrocarbon reservoirs, and
CO
2
sequestration. Laboratory tests have been performed on Opalinus Clay, a Mesozoic claystone that is being investigated in Switzerland as a potential host rock for the storage of nuclear waste. The laboratory program included specific water and air injections tests, as well as oedometer and isotropic compression tests. Undisturbed core samples have been retrieved from a shallow borehole in the Mont Terri Underground Research Laboratory (URL) and from a deep borehole in northern Switzerland. For the shallow cores from Mont Terri URL, largely linear-elastic deformations associated with the gas injection test could be inferred and the change in void ratio was accounted for by the pore compressibility. The corresponding change in permeability was obtained from the results of the water tests, indicating a log-linear relation between permeability and porosity. The derived porosity change and the corresponding change in permeability were implemented in the standard TOUGH2 code, which reproduced the measured gas test results using fitted water retention data derived from laboratory measurements. Similar air injection tests performed on Opalinus Clay cores from the borehole at greater depth showed overall similar behavior, but at lower porosities, lower permeability values, and lower compressibility. These cases indicated nonlinear behavior which was implemented using an effective stress-dependent porosity change and the associated change in permeability. In addition, the anisotropy associated with the bedding planes of the clay formation was considered by assuming different properties for “soft” and “hard” layers to account for storage capacity for the injected gas prior to gas breakthrough. The computed change in the overall porosity could be compared to the measured axial deformation during the gas injection test and was used for calibration of the parameters describing the relationship between the effective stress and porosity, as well as the corresponding change in permeability and capillary pressure.
A key challenge of functional genomics today is to generate well-annotated data sets that can be interpreted across different platforms and technologies. Large-scale functional genomics data often ...fail to connect to standard experimental approaches of gene characterization in individual laboratories. Furthermore, a lack of universal annotation standards for phenotypic data sets makes it difficult to compare different screening approaches. Here we address this problem in a screen designed to identify all genes required for the first two rounds of cell division in the Caenorhabditis elegans embryo. We used RNA-mediated interference to target 98% of all genes predicted in the C. elegans genome in combination with differential interference contrast time-lapse microscopy. Through systematic annotation of the resulting movies, we developed a phenotypic profiling system, which shows high correlation with cellular processes and biochemical pathways, thus enabling us to predict new functions for previously uncharacterized genes.
A poorly understood feature of the tauopathies is their very different clinical presentations. The frontotemporal lobar degeneration (FTLD) spectrum is dominated by motor and emotional/psychiatric ...abnormalities, whereas cognitive and memory deficits are prominent in the early stages of Alzheimer’s disease (AD). We report two novel mouse models overexpressing different human tau protein constructs. One is a full-length tau carrying a double mutation P301S/G335D; line 66 (L66) and the second is a truncated 3-repeat tau fragment which constitutes the bulk of the PHF core in AD corresponding to residues 296–390 fused with a signal sequence targeting it to the endoplasmic reticulum membrane (line 1; L1). L66 has abundant tau pathology widely distributed throughout the brain, with particularly high counts of affected neurons in hippocampus and entorhinal cortex. The pathology is neuroanatomically static and declines with age. Behaviourally, the model is devoid of a higher cognitive phenotype but presents with sensorimotor impairments and motor learning phenotypes. L1 displays a much weaker histopathological phenotype, but shows evidence of neuroanatomical spread and amplification with age that resembles the Braak staging of AD. Behaviourally, the model has minimal motor deficits but shows severe cognitive impairments affecting particularly the rodent equivalent of episodic memory which progresses with advancing age. In both models, tau aggregation can be dissociated from abnormal phosphorylation. The two models make possible the demonstration of two distinct but nevertheless convergent pathways of tau molecular pathogenesis. L1 appears to be useful for modelling the cognitive impairment of AD, whereas L66 appears to be more useful for modelling the motor features of the FTLD spectrum. Differences in clinical presentation of AD-like and FTLD syndromes are therefore likely to be inherent to the respective underlying tauopathy, and are not dependent on presence or absence of concomitant APP pathology.
The Opalinus Clay in Northern Switzerland has been identified as a potential host rock formation for the disposal of radioactive waste. Comprehensive understanding of gas transport processes through ...this low-permeability formation forms a key issue in the assessment of repository performance. Field investigations and laboratory experiments suggest an intrinsic permeability of the Opalinus Clay in the order of 10-20 to 10-21 m2 and a moderate anisotropy ratio < 10. Porosity depends on clay content and burial depth; values of ~0.12 are reported for the region of interest. Porosimetry indicates that about 10-30% of voids can be classed as macropores, corresponding to an equivalent pore radius > 25 nm. The determined entry pressures are in the range of 0.4-10 MPa and exhibit a marked dependence on intrinsic permeability. Both in situ gas tests and gas permeameter tests on drillcores demonstrate that gas transport through the rock is accompanied by porewater displacement, suggesting that classical flow concepts of immiscible displacement in porous media can be applied when the gas entry pressure (i.e. capillary threshold pressure) is less than the minimum principal stress acting within the rock. Essentially, the pore space accessible to gas flow is restricted to the network of connected macropores, which implies a very low degree of desaturation of the rock during the gas imbibition process. At elevated gas pressures (i.e. when gas pressure approaches the level of total stress that acts on the rock body), evidence was seen for dilatancy controlled gas transport mechanisms. Further field experiments were aimed at creating extended tensile fractures with high fracture transmissivity (hydro- or gasfracs). The test results lead to the conclusion that gas fracturing can be largely ruled out as a risk for post-closure repository performance.
Les argiles d'Opalinus, au nord de la Suisse, sont envisagées pour l'implantation d'un site de stockage pour déchets radioactifs en formation géologique profonde. La compréhension approfondie des processus de transport des gaz au travers de cette roche peu perméable est un élément clé dans l'évaluation de l'aptitude du site au stockage. Selon les données fournies par les campagnes de reconnaissance géologique et les expériences en laboratoire, la perméabilité intrinsèque d'argiles d'Opalinus serait de l'ordre de 10-20 à 10-21 m2, pour un rapport d'anisotropie modéré (< 10). La porosité dépend de la composition de l'argile et de la profondeur d'enfouissement ; pour la zone envisagée, on a mesuré des valeurs de l'ordre de ~0,12. Selon les données porosimétriques, on peut classer 10-30% des vides dans la catégorie des macropores, avec un diamètre équivalent > 25 nm. Les pressions d'entrée déterminées sont de l'ordre de 0.4-10 MPa et dépendent largement de la perméabilité intrinsèque. Les tests, tant in situ qu'en laboratoire (essais par perméamètre au gaz sur les carottes de forage), montrent un fort couplage entre la migration de gaz à travers la roche et les déplacements de l'eau interstitielle. Il semblerait donc possible d'appliquer les modèles de déplacement immiscible de fluides dans les milieux poreux, et ceci lorsque la pression d'entrée du gaz (c'est-à-dire le seuil de pression capillaire) est inférieure au niveau minimal de contrainte au sein de la roche. Il faut noter que la circulation de gaz est limitée au réseau des macropores connectés entre eux, d'où un très faible degré de désaturation de la roche au cours du processus d'imbibition du gaz. Lorsque que la pression du gaz est élevée (c'est-à-dire lorsqu'elle approche le niveau de la contrainte maximale exercée sur la roche), on a pu observer des mécanismes de transport induits par effet de dilatation. Par le biais d'autres expériences de terrain, on a tenté de produire des fractures de rupture de grande extension et à haute transmissivité (hydrofracs, gasfracs). Les résultats de ces tests permettent de conclure que la fracturation due aux gaz peut, dans une large mesure, être exclue des risques inhérents au comportement d'un dépôt après fermeture.
In saturated bentonite, free water is hosted in the meso- and macropores. Microscopic characterization of free water and the associated pore structure is very difficult because of the swelling- and ...shrinking-behaviour of montmorillonite. In this article, we present state of the art cryo-preparation techniques including high pressure freezing and low temperature freeze substitution, which enable the stabilization of bentonite microstructures. Microscopic analyses of cryo-stabilized bentonite samples are then performed with conventional SEM, with cryo-SEM and with FIB-nanotomography. From the resulting 2D- and 3D-images, so-called “continuous pore size distributions” are calculated and the 3D-connectivities of the mesopores are documented. Furthermore, from the comparison with pore size analyses that are based on conventional preparation techniques (oven drying and freeze drying), it is shown that high pressure freezing leads to more reliable results. Overall, it is demonstrated that reliable quantitative 3D-characterization can be achieved from the bentonite pore structure when high resolution 3D-imaging by FIB-nanotomography is combined with modern cryo-preparation techniques (i.e. high pressure freezing).
Vitamin D deficiency is associated with higher morbidity. However, there is few data regarding the effect of vitamin D deficiency on health care costs. This study examined the cross-sectional and ...longitudinal associations between the serum 25-hydroxy vitamin D concentration (25OHD) and direct health care costs and hospitalization in two independent samples of the general population in North-Eastern Germany.
We studied 7217 healthy individuals from the ‘Study of Health in Pomerania’ (SHIP n = 3203) and the ‘Study of Health in Pomerania-Trend’ (SHIP-Trend n = 4014) who had valid 25OHD measurements and provided data on annual total costs, outpatient costs, hospital stays, and inpatient costs. The associations between 25OHD concentrations (modelled continuously using factional polynomials) and health care costs were examined using a generalized linear model with gamma distribution and a log link. Poisson regression models were used to estimate relative risks of hospitalization.
In cross-sectional analysis of SHIP-Trend, non-linear associations between the 25OHD concentration and inpatient costs and hospitalization were detected: participants with 25OHD concentrations of 5, 10 and 15 ng/ml had 226.1%, 51.5% and 14.1%, respectively, higher inpatient costs than those with 25OHD concentrations of 20 ng/ml (overall p-value = 0.001) in multivariable models.
We found a relation between lower 25OHD concentrations and increased inpatient health care costs and hospitalization. Our results thus indicate an influence of vitamin D deficiency on health care costs in the general population.
Key Points
Explicit particle tracking in fractures and background matrix
Direct comparison of advection and diffusion in fractured sedimentary aquifers
Explicit particle‐tracking simulations in both ...fractures and surrounding sediments are conceptually complex and difficult to implement. This is mainly due to the difference in the nature of the velocity fields in fractures and the matrix. The major problems are (1) to avoid particles in the matrix jumping over fractures and (2) to control particle behavior at the interfaces between fractures and the matrix. We developed a particle‐tracking method that models advection and diffusion explicitly in both fractures and the matrix. Analogously to most flow simulations, we conceptualize transport by two separate domains, the fracture and the matrix domains, which exchange particles between them. No a priori assumptions on transport mechanisms in the matrix have to be made. Each individual particle step stops at an interface between two matrix cells, between two fracture cells, or between the matrix and a fracture. Mass exchange at the interface from fractures to the matrix is controlled by the fracture aperture, the matrix flux perpendicular to the fracture plane, the flux within the fracture, and a diffusive component. The method is developed for fractured sedimentary rocks where the advective fluxes in the matrix can be as large as the fracture fluxes. However, it could also be applied to fractured crystalline rocks where the matrix contribution is smaller. Finally, some simple applications to a fractured shale formation in northern Switzerland are included to illustrate the usefulness of this method to investigate transport in fractured sedimentary formations.
Abstract
Objective
While symptoms following youth concussion typically resolve within one month of injury, some patients report persistent post-concussive symptoms (PPCS). The current project aims to ...characterize a sample of sports neuropsychology patients, examine clinical outcomes, and determine relevant factors.
Methods
Sports neuropsychology evaluated 38 consecutively referred patients at a rural academic medical center. The sample was 50% female, mostly White (91.9%), and ranged from 7–22 years of age (M = 16.45, SD = 2.92). Most had pre-existing conditions (medical/psychiatric; 78.9%), and 63% had at least one previous concussion. Months-from-injury varied (median = 4; range = 1–29). FSIQ was average (M = 107, SD = 15.45). We analyzed relationships between factors and outcomes using correlations (Spearman’s rho or Pearson’s r) and stepwise linear regression to determine prediction.
Results
Only nine patients’ persistent complaints were due to concussion, while medical or psychiatric etiologies explained PPCS in the majority of the sample (76.3%). Outcomes were uncorrelated with gender, age, race, IQ, or months-since-injury. Pre-existing depression (rs(37) = −0.40, p = 0.01) and migraines (rs(37) = −0.35, p = 0.02) both showed significant moderate correlations with outcome. Stepwise regression indicated that only pre-existing depression (β = −0.360, p = 0.01) significantly predicted the non-concussion clinical outcome.
Conclusions
In our sample, the etiology of PPCS was something other than concussion in over 76% of youth seen by sports neuropsychology. Pre-existing depression and migraines were significantly correlated with this outcome, and depression was a significant predictor. These results add to the literature on PPCS in children. Neuropsychologist involvement earlier in concussion care may help prevent PPCS by rapidly connecting patients to the proper interventions, thereby reducing families’ economic burden and improving patients’ quality of life.
Highlights • Health care workers were interviewed to gain insight into various aspects of care quality. • Differences between patients affected or not affected by multidrug-resistant organisms were ...compared. • Implications for 4 different facility types were investigated. • Appropriate management of affected patients must consider facility characteristics.
Jews in Nevada Marschall, John
2011, 2008, 2011-03-28
eBook
Jews have always been one of Nevada's most active and influential ethnic minorities. They were among the state's earliest Euro-American settlers, and from the beginning they have been involved in ...every area of the state's life as businessmen, agrarians, scholars, educators, artists, politicians, and civic, professional, and religious leaders. Jews in Nevada is an engaging, multilayered chronicle of their lives and contributions to the state. Here are absorbing accounts of individuals and families who helped to settle and develop the state, as well as thoughtful analyses of larger issues, such as the reasons Jews came to Nevada in the first place, how they created homes and interacted with non-Jews, and how they preserved their religious and cultural traditions as a small minority in a sparsely populated region.
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