Modeling managed aquifer recharge processes in a highly heterogeneous, semi-confined aquifer system

Widespread groundwater overdraft in alluvial aquifer systems like the Central Valley (CV) in California, USA, has increased interest in managed aquifer recharge (MAR). Like most clastic sedimentary basins, recharge to the productive semi-confined CV aquifer system remains a challenge due to the presence of nearly ubiquitous, multiple confining units (silt and clay) that limit recharge pathways. Previous studies suggest the presence of interconnected networks of coarse-texture sand and gravel deposits that bypass regional confining units over a small fraction of the CV near the American and Cosumnes rivers. Here, variably saturated infiltration and recharge processes were simulated across a domain that includes high-resolution representation of the heterogeneous alluvial geologic architecture in this area. Results show that recharge potential is highly dependent on subsurface geologic architecture, with a nearly 2 order-of-magnitude range of recharge across the domain. Where interconnected coarse-texture recharge pathways occur, results show that these features can (1) accommodate rapid, high-volume MAR and (2) propagate widespread and rapid pressure responses over multi-kilometer distances in the semi-confined aquifer system. For all MAR simulations, results show that the majority of MAR is accommodated by filling unsaturated-zone (UZ) pore volume. Results also show that coarse-texture UZ facies (where present) accommodate the majority of MAR volume during early time, but fine-texture facies ultimately accommodate the majority of the total MAR volume, even for coarse-dominated sites. These findings highlight the large variability of MAR potential across the landscape and demonstrate the importance of fine-texture facies for accommodating MAR in alluvial aquifer systems

The Hypothesis of Locality and its Limitations

The hypothesis of locality, its origin and consequences are discussed. This supposition is necessary for establishing the local spacetime frame of accelerated observers; in this connection, the measurement of length in a rotating system is considered in detail. Various limitations of the hypothesis of locality are examined.Comment: LaTeX file, no figures, 14 pages, to appear in: "Relativity in Rotating Frames", edited by G. Rizzi and M.L. Ruggiero (Kluwer Academic Publishers, Dordrecht, 2003

Moisture transport by Atlantic tropical cyclones onto the North American continent

Tropical Cyclones (TCs) are an important source of freshwater for the North American continent. Many studies have tried to estimate this contribution by identifying TC-induced precipitation events, but few have explicitly diagnosed the moisture fluxes across continental boundaries. We design a set of attribution schemes to isolate the column-integrated moisture fluxes that are directly associated with TCs and to quantify the flux onto the North American Continent due to TCs. Averaged over the 2004–2012 hurricane seasons and integrated over the western, southern and eastern coasts of North America, the seven schemes attribute 7 to 18 % (mean 14 %) of total net onshore flux to Atlantic TCs. A reduced contribution of 10 % (range 9 to 11 %) was found for the 1980–2003 period, though only two schemes could be applied to this earlier period. Over the whole 1980–2012 period, a further 8 % (range 6 to 9 % from two schemes) was attributed to East Pacific TCs, resulting in a total TC contribution of 19 % (range 17 to 22 %) to the ocean-to-land moisture transport onto the North American continent between May and November. Analysis of the attribution uncertainties suggests that incorporating details of individual TC size and shape adds limited value to a fixed radius approach and TC positional errors in the ERA-Interim reanalysis do not affect the results significantly, but biases in peak wind speeds and TC sizes may lead to underestimates of moisture transport. The interannual variability does not appear to be strongly related to the El Nino-Southern Oscillation phenomenon

The factors driving evolved herbicide resistance at a national scale

Repeated use of xenobiotic chemicals has selected for the rapid evolution of resistance threatening health and food security at a global scale. Strategies for preventing the evolution of resistance include cycling and mixtures of chemicals and diversification of management. We currently lack large-scale studies that evaluate the efficacy of these different strategies for minimizing the evolution of resistance. Here we use a national scale dataset of occurrence of the weed Alopecurus myosuroides (Blackgrass) in the UK to address this. Weed densities are correlated with assays of evolved resistance, supporting the hypothesis that resistance is driving weed abundance at a national scale. Resistance was correlated with the frequency of historical herbicide applications suggesting that evolution of resistance is primarily driven by intensity of exposure to herbicides, but was unrelated directly to other cultural techniques. We find that populations resistant to one herbicide are likely to show resistance to multiple herbicide classes. Finally, we show that the economic costs of evolved resistance are considerable: loss of control through resistance can double the economic costs of weeds. This research highlights the importance of managing threats to food production and healthcare systems using an evolutionarily informed approach in a proactive not reactive manner

Fluctuations in granular gases

A driven granular material, e.g. a vibrated box full of sand, is a stationary system which may be very far from equilibrium. The standard equilibrium statistical mechanics is therefore inadequate to describe fluctuations in such a system. Here we present numerical and analytical results concerning energy and injected power fluctuations. In the first part we explain how the study of the probability density function (pdf) of the fluctuations of total energy is related to the characterization of velocity correlations. Two different regimes are addressed: the gas driven at the boundaries and the homogeneously driven gas. In a granular gas, due to non-Gaussianity of the velocity pdf or lack of homogeneity in hydrodynamics profiles, even in the absence of velocity correlations, the fluctuations of total energy are non-trivial and may lead to erroneous conclusions about the role of correlations. In the second part of the chapter we take into consideration the fluctuations of injected power in driven granular gas models. Recently, real and numerical experiments have been interpreted as evidence that the fluctuations of power injection seem to satisfy the Gallavotti-Cohen Fluctuation Relation. We will discuss an alternative interpretation of such results which invalidates the Gallavotti-Cohen symmetry. Moreover, starting from the Liouville equation and using techniques from large deviation theory, the general validity of a Fluctuation Relation for power injection in driven granular gases is questioned. Finally a functional is defined using the Lebowitz-Spohn approach for Markov processes applied to the linear inelastic Boltzmann equation relevant to describe the motion of a tracer particle. Such a functional results to be different from injected power and to satisfy a Fluctuation Relation.Comment: 40 pages, 18 figure

ANKRD26 and Its Interacting Partners TRIO, GPS2, HMMR and DIPA Regulate Adipogenesis in 3T3-L1 Cells

Partial inactivation of the Ankyrin repeat domain 26 (Ankrd26) gene causes obesity and diabetes in mice and increases spontaneous and induced adipogenesis in mouse embryonic fibroblasts. However, it is not yet known how the Ankrd26 protein carries out its biological functions. We identified by yeast two-hybrid and immunoprecipitation assays the triple functional domain protein (TRIO), the G protein pathway suppressor 2 (GPS2), the delta-interacting protein A (DIPA) and the hyaluronan-mediated motility receptor (HMMR) as ANKRD26 interacting partners. Adipogenesis of 3T3-L1 cells was increased by selective down-regulation of Ankrd26, Trio, Gps2, Hmmr and Dipa. Furthermore, GPS2 and DIPA, which are normally located in the nucleus, were translocated to the cytoplasm, when the C-terminus of ANKRD26 was introduced into these cells. These findings provide biochemical evidence that ANKRD26, TRIO, GPS2 and HMMR are novel and important regulators of adipogenisis and identify new targets for the modulation of adipogenesis

The Glu27 genotypes of the Beta2-adrenergic receptor are predictors for severe coronary artery disease

BACKGROUND: The role of the Beta2-adrenoceptor (beta2-AR) Gln27Glu polymorphism in the manifestation of cardiovascular diseases is still unclear. METHODS: In the present study, we evaluated the potential relevance of the c.79 C>G (p.Gln27Glu) polymorphism of this receptor gene for coronary artery disease (CAD) and its associated risk factors in Saudi Arabs. Genotyping was performed by PCR using the confronting two-pair primer (PCR-CTPP) method. RESULTS: In the general population group (BD) (n = 895), 68.5% were homozygous wild-type C/C, 28.3% were heterozygous C/G and 3.2% were homozygous mutant G/G. Among the CAD patients (n = 773), 50.6% were homozygous wild-type C/C, 43.6% were heterozygous C/G and 5.8% were homozygous mutant G/G, while in the angiographed control group (CON) (n = 528), 71.8% were C/C, 24.4% C/G and 3.8% G/G genotypes. These results indicate that both the C/G (p = < .001) and G/G (p = .005) genotypes are significantly associated with CAD, when compared to the CON group. In addition, C/G (p = < .001) and G/G (p = < .001) were significantly associated with CAD, when compared to the BD group. Furthermore, stepwise logistic regression showed that the genotype [C/G (p < .001) and G/G (p < .001)] increase the risk of CAD. CONCLUSION: These results shows that the Gln27Glu genotypes (homo- or heterozygous) of the beta2-AR may be independent predictors of severe CAD

Illness perceptions and explanatory models of viral hepatitis B & C among immigrants and refugees: a narrative systematic review.

© 2015 Owiti et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Hepatitis B and C (HBV, HCV) infections are associated with high morbidity and mortality. Many countries with traditionally low prevalence (such as UK) are now planning interventions (screening, vaccination, and treatment) of high-risk immigrants from countries with high prevalence. This review aimed to synthesise the evidence on immigrants' knowledge of HBV and HCV that might influence the uptake of clinical interventions. The review was also used to inform the design and successful delivery of a randomised controlled trial of targeted screening and treatment. METHODS: Five databases (PubMed, CINHAL, SOCIOFILE, PsycINFO & Web of Science) were systematically searched, supplemented by reference tracking, searches of selected journals, and of relevant websites. We aimed to identify qualitative and quantitative studies that investigated knowledge of HBV and HCV among immigrants from high endemic areas to low endemic areas. Evidence, extracted according to a conceptual framework of Kleinman's explanatory model, was subjected to narrative synthesis. We adapted the PEN-3 model to categorise and analyse themes, and recommend strategies for interventions to influence help-seeking behaviour. RESULTS: We identified 51 publications including quantitative (n = 39), qualitative (n = 11), and mixed methods (n = 1) designs. Most of the quantitative studies included small samples and had heterogeneous methods and outcomes. The studies mainly concentrated on hepatitis B and ethnic groups of South East Asian immigrants residing in USA, Canada, and Australia. Many immigrants lacked adequate knowledge of aetiology, symptoms, transmission risk factors, prevention strategies, and treatment, of hepatitis HBV and HCV. Ethnicity, gender, better education, higher income, and English proficiency influenced variations in levels and forms of knowledge. CONCLUSION: Immigrants are vulnerable to HBV and HCV, and risk life-threatening complications from these infections because of poor knowledge and help-seeking behaviour. Primary studies in this area are extremely diverse and of variable quality precluding meta-analysis. Further research is needed outside North America and Australia

Improved charge extraction in inverted perovskite solar cells with dual-site-binding ligands

Inverted (pin) perovskite solar cells (PSCs) afford improved operating stability in comparison to their nip counterparts but have lagged in power conversion efficiency (PCE). The energetic losses responsible for this PCE deficit in pin PSCs occur primarily at the interfaces between the perovskite and the charge-transport layers. Additive and surface treatments that use passivating ligands usually bind to a single active binding site: This dense packing of electrically resistive passivants perpendicular to the surface may limit the fill factor in pin PSCs. We identified ligands that bind two neighboring lead(II) ion (Pb2+) defect sites in a planar ligand orientation on the perovskite. We fabricated pin PSCs and report a certified quasi–steady state PCE of 26.15 and 24.74% for 0.05– and 1.04–square centimeter illuminated areas, respectively. The devices retain 95% of their initial PCE after 1200 hours of continuous 1 sun maximum power point operation at 65°C